Hindawi Publishing CorporationEvidence-Based Complementary and Alternative MedicineVolume 2013 Article ID 789674 7 pageshttpdxdoiorg1011552013789674

Research ArticleEffects of Electroacupuncture at Auricular ConchaRegion on the Depressive Status of Unpredictable Chronic MildStress Rat Models

Ru-Peng Liu1 Ji-Liang Fang12 Pei-Jing Rong1 Yufeng Zhao3 Hong Meng1 Hui Ben1

Liang Li1 Zhan-Xia Huang4 Xia Li4 Ying-Ge Ma3 and Bing Zhu1

1 Institute of Acupuncture and Moxibustion China Academy of Chinese Medical Sciences Beijing 100700 China2 Guanganmen Hospital China Academy of Chinese Medical Sciences Beijing 100053 China3 Clinical Evaluation Center Institute of Basic Research in Clinical Medicine China Academy of Chinese Medical SciencesBeijing 100700 China

4 Beijing University of Chinese Medicine Beijing 100029 China

Correspondence should be addressed to Pei-Jing Rong rongpjmailcintcmaccn

Received 24 August 2012 Revised 21 November 2012 Accepted 14 December 2012

Academic Editor Wolfgang Schwarz

Copyright copy 2013 Ru-Peng Liu et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

To explore new noninvasive treatment options for depression this study investigated the effects of electroacupuncture (EA) at theauricular concha region (ACR) of depression rat models Depression in rats was induced by unpredictable chronic mild stress(UCMS) combined with isolation for 21 days Eighty male Wistar rats were randomly assigned into four groups normal UCMSalone UCMSwith EA-ACR treatment andUCMSwith EA-ear-tip treatment Rats under inhaled anesthesia were treated once dailyfor 14 daysThe results showed that blood pressure and heart rate were significantly reduced in the EA-ACR group than in theUCMSalone group or the EA-ear-tip group The open-field test scores significantly decreased in the UCMS alone and EA-ear-tip groupsbut not in the EA-ACR group Both EA treatments downregulated levels of plasma cortisol andACTH inUCMS rats back to normallevels The present study suggested that EA-ACR can elicit similar cardioinhibitory effects as vagus nerve stimulation (VNS) andEA-ACR significantly antagonized UCMS-induced depressive status in UCMS ratsThe antidepressant effect of EA-ACR is possiblymediated via the normalization of the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity

1 Introduction

Vagus nerve stimulation (VNS) was approved by the US Food and Drug Administration in 2005 and has beenfrequently used as a treatment option for treatment-resistantdepression (TRD) [1ndash4] Its mechanisms of antidepressantaction are not fully elucidated however its neuromechanismsare based on the direct stimulation of the cervical trunkof the left vagus nerve The afferent fibers of vagus nerveproject to solitary nucleus (SN) Fibers of SN project tothe neuroendocrine systems in the limbic system structuresand the autonomic nervous system These areas are stronglyinterconnected by monoamine-related pathways includingthe ventral tegmental area brainstem the hypothalamusthalamus amygdala anterior insula nucleus accumbens and

the lateral prefrontal cortex [5] Furthermore the ventraltegmental area has a dense dopaminergic input to theprefrontal cortex fibers from the SN project to the locusceruleus and dorsal raphe nucleus which aremajor brainstemnuclei related to noradrenergic (NE) and serotonergic (5-HT) innervations of the entire brain cortex respectivelyIt is well known that the serotonergic dopaminergic andnoradrenergic systems are commonly involved in the patho-physiology of depression and in the neuromechanisms ofaction of antidepressants [6]

Nonetheless typical implantation of VNS device requiresan invasive surgical procedure whichmay be accompanied bysome side effects such as infection of wound hoarse voicedyspnea difficulty swallowing neck pain paresthesia eme-sis laryngospasms dyspepsia cardiac asystole bradycardia

2 Evidence-Based Complementary and Alternative Medicine

and even heart failure Worse still technical complications ofdevice malfunction may aggravate patient conditions [7 8]

Enlightened by themechanismofVNS researchers in ourteam found that auricular concha region (ACR) is denselyinnervated by free nerve endings of the vagus nerve Ourprevious animal studies found that electroacupuncture (EA)at ACR (EA-ACR) had significant effects in the managementof primary hypertension [9 10] diabetes mellitus [11 12] andpartial epilepsy [13 14] EA-ACR is a noninvasive procedurewhich requires a portable EA device and no side effects Witha similar mechanism to VNS EA vagus nerve stimulationmay provide beneficial effects in the treatment of depres-sion

EA-ACR is one of the acupuncture therapeutic methodswhich can be considered as auriculotherapy Theories ofauriculotherapy dates back to 2000 years ago as first men-tioned in the book of Yellow Emperorrsquos Canon of Medicine(Huang Di Nei Jing) [15] Modern auriculotherapy with 42points was firstly introduced by Dr P Nogier (France) in1956 The international standard map of auricularpoints waspublished in China and later was recommended by WHOin 1993 Acupuncture part of the oriental medicine hasbeen used in eastern Asian countries for the management ofvarious emotional psychological and psychiatric disordersincluding anxiety stress insomnia and depression In recentyears acupuncture has become one of themost popular com-plementary therapies in the West and the therapeutic effec-tiveness of acupuncture on depression has been confirmedby modern research studies Allen et al [16] found that bodyacupuncture and auriculotherapy could significantly reducethe severity of depression Similar results were demonstratedin the studies of Luo et al [17] and Zhang et al [18] in whichresearchers found that electroacupuncture was as efficaciousas fluxetine in the management of major depression Ingeneral increasing evidences support that acupuncture is aneffective treatment for patients with depressive disorders [19ndash23]

In the current study we aimed to verify the vagus nerveresponses during EA at ACR Furthermore antidepressioneffects of EA-ACRwere investigated by observation of behav-iors and measurement of blood biochemicals in the ratmodels of unpredictable chronic mild stress (UCMS)

The results will provide a fundamental evidence for theanti-depression effects of EA-ACR and will facilitate EA-ACR to become a new noninvasive and low-cost therapy fordepression

2 Methods and Materials

21 Animals Male Wistar rats in 150ndash170 g were obtainedfrom the Laboratory Animal Resources Center NationalInstitute for the Control of Pharmaceutical and BiologicalProducts Beijing (Certificate no SCXK (jing) 2009-0017)These animals were individually caged on a 12 h lightdarkcycle (lights on at 800 am lights off at 800 pm) undercontrolled temperature (22 plusmn 1∘C) and humidity (50 plusmn5) conditions Standard rat chow and water were givenad libitum Animals were allowed to acclimatize for seven

days before the study All experiment procedures complywith the guidelines of the ldquoPrinciples of Laboratory AnimalCarerdquo (NIH publication number 80-23 revised 1996) and thelegislation of the Peoplersquos Republic of China for the use andcare of laboratory animals The experimental protocols wereapproved by the Animal Experimentation Ethics Committeeof the Institute of Acupuncture and Moxibustion ChinaAcademy of Chinese Medical Sciences Efforts were made tominimize the number of animal use and the suffering of theexperimental animals

22 Open Field Test for Behavioral Scoring The open fieldapparatus was constructed of black plywood and measured80 times 80 cm with 40 cm walls White lines were drawn on thefloor The lines divided the floor into twenty-five 16 times 16 cmsquares A central square (16 cm times 16 cm) was drawn in themiddle of the open field Rats were put on the central squareat the same time the video camera was turned on for videorecording from the top of the open field apparatus Behaviorsof rats were recorded for 3 minutes with the grid numberbeing counted as the horizontal score and the time of bothfrontal claws uplifting from the ground as the vertical scoreThe total locomotor activity of each animal was then scoredas the sum of the number of line crosses and rears [24 25]

23 Unpredictable ChronicMild Stress (UCMS)Model EightyRats were evenly randomized into 4 groups Forty-two ratswere recruited with the total score of 30ndash120 in the openfield test [25] A successful UCMSmodel rat was created withthe score of the open field test equal or minus 60 Qualifiedrats were distributed into four groups the normal control(119899 = 10) UCMS alone (119899 = 8) UCMS with EA-ACRtreatment (EA-ACR) (119899 = 12) and UCMS with EA-ear-tipas the treatment control (EA-ear-tip) (119899 = 12) Every five ratsin the normal group were housed in one cage However ratsin the UCMS alone EA-ACR and EA-ear-tip groups werecaged individually Depression model was established by 21days of UCMS combined with isolation UCMS procedureswere based on published studies [25 26] including sevenkinds of stressors food deprivation water deprivation cagetilt 45∘ (Ugo Basile srl hotcold plate Model 35100ndash001Italy) swimming in 4∘C ice water clipping tail 3min 50Velectric shock (Electronic stimulator NIHON KOHDENJapan) and overnight illumination The stressors were givenrandomly 3 times daily for 21 continuous daysThe rats in thenormal control group were housed undisturbedly except fornecessary procedures such as routine cage cleaning

24 Experimental Procedures (Figure 1) The open field teston all rats was conducted on the day before the studythe 22th day (after UCMS) the 36th day (after treatment)and the 50th day in the study course After the modelsof UCMS were established in 21 days the EA treatmentof 14 days was applied to the bilateral auricular concharegion (Figure 1) of rats in the EA-ACR group once dailyfor 20min For the EA-ear-tip group the EA applied to thebilateral ear tips (Figure 1) followed the same procedure andEA parameters as the EA-ACR All rats in the EA groups

Evidence-Based Complementary and Alternative Medicine 3

accepted the inhaled anesthesia during the treatment EAwas set at the frequency of 2Hz the intensity of 1mAby using the electroacupuncture stimulator (HANS-100ANanjing Gensun Medical Technology Co Ltd China) Theinhaled anesthesia was conducted on the ISOFLURANEVAPORIZER (Matrx VIP 3000 Midmark corporation USA)with isoflurane (Hebei Nine Sent Pharmaceutical Co LtdHeibei China) Blood pressure including systolic diastolicand mean pressures and heart rate of rats were monitorednoninvasively by using the apparatus (BP-98A Beijing SoftLong Biological Technology Co Ltd China) during one EAtreatmentanesthesia The data were recorded in numericalvalues at the starting point of anesthesia (0min pre-EA) the1st min of anesthesia (EA begins) the 6th min of anesthesia(EA 5min) the 11th min of anesthesia (EA 10min) the 16thmin of anesthesia (EA 15min) and the 21stmin of anesthesia(EA 20min) on the same day for three UCMS groups At the51st day of the study the rats were sacrificed and their neckvenous blood was sampled for the tests of plasma cortisol(ELISA RampD USA) andACTH (Acthlisa RampD USA) levels

25 Statistical Analysis The statistical analysis was per-formed by using one-way analysis of variance (ANOVA)followed by a Turkey test with software SPSS 130 119875 lt 005which was considered statistically significant and the datawere expressed as means plusmn standard deviation

3 Results

31 Effects of EA-ACR Treatment on Heart Rate and BloodPressure in UCMS Rats (Figures 2 and 3) No statisticaldifference was found in heart rate and blood pressure amongrats of the three UCMS groups at the beginning of the studyBoth of the heart rate and blood pressure in three UCMSgroups showed a descending trend during the anesthesiaperiod However the two EA treatment groups reduced heartrate and blood pressure significantly compared to the UCMSalone group The mean heart rate from the 6th to 11th mindecreased significantly in the EA-ACRgroup compared to theEA-ear-tip group furthermore the mean blood pressure wasdownregulated significantly in the EA-ACR group comparedto the EA-ear-tip group in the treatment periodThe EA-ACRtreatment resulted in a significant decrease in the heart ratebetween the starting point of anesthesia and the 11th min ofanesthesia (119875 lt 005) and in the mean pressure between thestarting point of anesthesia and the 16th min of anesthesia(119875 lt 005)

32 The Different Influences of EA-Treatments on the OpenField Test Score of UCMS Rats (Figure 4) The total scoreof rats exposed to the open field test showed a significantdecrease on the 22th day compared to the beginning in boththe UCMS alone group and the EA-ear-tip group (119875 lt 001and 119875 lt 001 resp) However the score did not showremarkable differences between the two time spots in thenormal group or in the EA-ACR group respectively But theEA-ACR group reached the score of 60 in the open field test

and was thus qualified as the UCMS model In the EA-ear-tip group the score decreased significantly on the 36th daycompared to the 22nd day

33 Effects of EA Treatment on Plasma Cortisol and ACTHLevels in UCMS Rats (Figures 5 and 6) As compared withthe normal group plasma cortisol levels in the three UCMSgroups showed significant increases (119875 lt 001 for all com-parisons) On the other hand the mean plasma cortisol levelof the EA-ACR group and the EA-ear-tip group decreasedsignificantly compared to the UCMS alone group (119875 lt 005and 119875 lt 005 resp)

The 21-day UCMS exposure significantly increased theconcentration of ACTH in rat blood (119875 lt 001) when theUCMS group was compared with the normal control on the51st day of the study However EA treatments significantlydecreased the concentration of ACTH compared to theUCMSalone group (119875 lt 001 and119875 lt 001 resp) while noneof the EA treatment groups showed a significant difference inthe concentration of ACTH as the normal control group did

4 Discussion

In general EA treatments down-regulated the heart rate andblood pressure as well as the concentration of plasma cortisoland ACTH However the heart rate and blood pressure wereinfluenced more intensively by the EA-ACR than the EA-ear-tip and the open field test score was kept at a higher level byEA-ACR only

41 Cardioinhibitory Effects of EA-ACR Are Similar to theVagus Nerve Stimulation In the present study EA-ACRelicited a significant decrease in heart rate andmean pressureunder the anesthesia however the EA-ear-tip treatmentdid not induce similar changes during the treatment Theseresults suggested that EA stimulation at the auricular concharegion induced similar effects as that of the direct vagus nerveelectric stimulation had on the heart [7 27 28] VNS whichstimulates the cervical trunk of the vagus nerve directly isa procedure that was approved by FDA to treat primaryhypertension years ago [7 27] Our previous research showedthat acupuncture at auricular concha area could effectivelydecrease essential hypertension in ratmodels [9] In additionwe found that electric stimulation on nucleus dorsalis nervevagi could induce immediate decrease in heart rate andcorresponding changes of electrocardiogram [29]

Anatomical knowledge of the vagus nerve informs thatthe auricular fibers of vagus nerve densely distribute in theconcha and external auditory meatus of the ear howeverthere are a few vagus nerve fibers around the ear tip [30]Theauricular branch of the vagus nerve ascends to the superiorvagal ganglion (nucleus dorsalis nerve vagi) where thecholinergic preganglionic parasympathetic neurons give riseto the branchial efferent motor fibers innervating the heartand stimulating pathway induces cardioinhibitory effects[28] Afferent signals elicited by EA-ACR may be integratedat the medulla oblongata which then generates regulatorysignals to activate the cardiac vagus nerve Cardiac vagus

4 Evidence-Based Complementary and Alternative Medicine

1

2

Figure 1 Electrical stimulation spot Black spot 1 on the ear-tip area(nonauricular concha control) Black spot 2 on the auricular concharegion (ACR) Positive iron pole (diameter 03mm) on the frontalside of ear and the negative iron pole (diameter 03mm) on the backside

nerve activation slows the heart rate and decreases the bloodpressure immediately

42 EA-ACR Treatment Improved the Depressive Status ofUCMSRats in theOpen Field Test Theunpredictable chronicmild stress (UCMS) has already contributed to the eluci-dation of the pathophysiological mechanisms of depressionsuch as decreased neurogenesis and HPA axis alterations[26 31] In the current study this model was used to explorethe relations between depressive-like behavior in rats and EA-ACR treatment The open field test provides simultaneousmeasurement of UCMS A higher score in the test indicatesincreased locomotion and exploration andor a lower levelof anxiety [25 26 31] In our study the scores of open fieldtest were significantly decreased in the UCMS alone andEA-ear-tip groups on day 22 compared to the beginningdate but no significant decrease was found in the EA-ACR group However all the rats in the EA-ACR groupwere qualified for modeling with a standard recruiting scoreof 60 It was apparent that EA-ACR kept the score on ahigher level in the treatment course while the score of theEA-ear-tip group showed a significant decrease during thetreatmentThis phenomenon indicated that EA-ACR inducedthe antidepressive effects The UCMS model and the openfield test were also successfully introduced into previous EAstudies on depression For example EA at Baihui (GV20) andYingtang (EX-HN3) on the top and front head scalp for 21days can significantly improve the symptom of the depressiverats the crossing and rearing movement times and thenumber of p-CREB-positive neuron in the hippoeampus asthe fluoxetine compared with the UCMS alone group [25]

43 EATreatmentNormalized theHyperactivity of Hypothala-mic-Pituitary-Adrenal (HPA) Axis In the present study21 daysrsquo UCMS exposure significantly increased the con-centrations of plasma cortisol and ACTH in rats It is

400

380

360

340

320

3000 1 6 11 16 21

Mea

n h

eart

rat

e (b

eat

min

)

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowast

lowast lowast lowast

lowastlowast

lowastlowastlowastlowast

Figure 2 The time course of heart rate for three UCMS groupsduring one EA treatmentanesthesia Comparison between the EA-treated UCMS group and the UCMS alone group lowast119875 lt 005lowastlowast

119875 lt 001 Comparison between the EA-ACR group and the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparison between thestarting point of anesthesia and the 11th min in the EA-ACR group119875 lt 001

consistent with the previous research studies on bothhuman beings and animal models with depressive status[32 33] Furthermore 14 days of EA treatments (both EA-ACR and EA-ear-tip) right after UCMS down-regulatedthe plasma cortisol and ACTH in UCMS rats to normallevels Researchers found that EA at acupointsNeiguan(PC6)Sanyinjiao(SP6) and Taichong(LV3) can lower plasma cor-tisol and ACTH levels and improve symptoms in depress-ion [33]

Several hypotheses have been proposed for the patholog-ical mechanism of depression Besides disturbed monoamin-ergic neurotransmission hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis is closely related to majordepression [34ndash36] The HPA axis is the primary neuroen-docrine system responsible for coordinating the mammalianstress response and has thus been a major focus of neu-robiological research of depression Major components ofthe HPA axis include corticotropin-releasing factor (CRF)adrenocorticotropin hormone (ACTH) and glucocorticoidsCortisol is the major glucocorticoid in humans and ani-mals During stress response neurons in the paraventricularnucleus (PVN) of the hypothalamus release CRF into thehypothalamo-pituitary portal system CRF then stimulatesthe release of adrenocorticotropin (ACTH) from the anteriorpituitary into systemic circulation which in turn stimulatesthe adrenal cortex to secrete cortisol Cortisol is responsiblefor many of the physiological changes associated with thestress response and it also provides negative feedback to thehypothalamus and pituitary to decrease the synthesis andrelease of CRF and ACTH

Evidence-Based Complementary and Alternative Medicine 5

90

80

70

60

50

Mea

n b

lood

pre

ssu

re (

mm

Hg)

0 1 6 11 16 21

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowastlowastlowast

lowastlowast lowastlowast lowastlowast

Figure 3 The time course of the mean blood pressure for the threeUCMS groups during one EA treatmentanesthesia Comparisonbetween the EA-treated UCMS group and the UCMS alone grouplowast

119875 lt 005 lowastlowast119875 lt 001 Comparison between the EA-ACR groupand the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparisonbetween the starting point of anesthesia and the 16thmin in the EA-ACR group 119875 lt 005

120

100

80

60

40

20

Normal UCMS alone EA-ACR EA-ear-tip

Day 0Day 22

Day 36Day 50

Tota

l sco

re o

f op

en-fi

eld

test

(sco

re)

0

lowastlowast

Figure 4 The influence of EA-ACR on the open field test score ofrats The 22nd day compared with the day before the test (day 0) inthe same group 119875 lt 005 119875 lt 001 the 36th day compared withthe 22nd day in the EA-ear-tip group lowastlowast119875 lt 001

Patients with depression show hyperactivity of the HPAaxis that may result from the impaired negative feedbackregulation of glucocorticoid release [34] Moreover researchstudy also found that normalization of these HPA axisabnormalities is associated with successful antidepressanttreatment and patients whose HPA abnormalities do notnormalize are significantly more likely to relapse [37] Ina VNS treatment study OrsquoKeane et al [38] found that theCRFACTH (adrenocorticotropic hormone) responses in thedepressed group before VNS implantation were significantlyhigher than in the healthy group and were reduced to normalvalues after 3months of VNS treatment in addition they alsofound significant improvement in depression symptoms

lowastlowastlowastlowast lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

70

60

50

40

30

20

10

0

Pla

sma

cort

isol

(n

gm

L)

Figure 5 The effect of EA-ACR treatment on plasma cortisolin normal and UCMS rats Comparison of plasma cortisol levelbetween UCMS and normal groups lowastlowast119875 lt 001 Comparisonbetween the EA-treated UCMS group and the UCMS alone group119875 lt 005

lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

180

160

140

120

100

80

60

40

20

0

AC

TH

(pg

mL

)

Figure 6The effect of EA-ACR treatment on ACTH in normal andUCMS rats Comparison of the ACTH level between normal andUCMS groups lowastlowast119875 lt 001 Comparison between the EA-treatedUCMS group and the UCMS alone group 119875 lt 001

The result of the present studymdashEA-ACR significantlyantagonized UCMS-induced depressive status of ratsmdashisconsistent with the findings of the mentioned researchstudies As demonstrated through changes in plasma cortisoland ACTH levels the antidepressant effect of EA-ACR maybe mediated via normalization of the HPA axis hyperactivityOtherwise EA-ear-tip also was found to be the apparentdown-regulation effect on the plasma cortisol and ACTH Itis found that a few vagus nerve fibers are around the ear tip[30] and HPAmay be modulated by other nervous pathwaysbeside the vagus nerve for example greater auricular nerveand lesser occipital nerve are densely innervated in the areaof ear tip and the EA signals can be transmitted by them tothe cervical spinal cord and brain then modulate the HPAFurther investigation has been warranted for this hypothesis

5 Limitation

This pilot EA-ACR study on depression has a small sam-ple size Meanwhile EA-ACR does not only stimulate the

6 Evidence-Based Complementary and Alternative Medicine

vagus nerve but also affects other sensory nerves suchas nervous auricularis magnus lesser occipital nerve facialnerve and glossopharyngeal nerve fibers Although EA-ACRelicited similar effects to VNS the interaction among thenerves in the area should be explored in the future Furtherinvestigation on EA-ACR for the disturbed monoaminergicneurotransmission of depression has been warranted

6 Conclusions

EA-ACR can elicit similar cardioinhibitory effects to vagusnerve stimulation (VNS) and EA-ACR significantly antago-nized UCMS-induced depressive status of rats The antide-pressant effect of EA-ACR is possibly mediated via normal-ization of the HPA axis hyperactivity

Authorrsquos Contribution

Ru-Peng Liu and Ji-Liang Fang contributed equally to thispaper

Acknowledgments

This scientific work was supported by the National Nat-ural Science Foundation of China Research Grants (no30973798) the Twelfth Five-Year Plan of theNational Scienceand Technology Support Program of China (2012BAF14B10)and the Beijing Natural Science Foundation (no 711117)

References

[1] H A Sackeim A J Rush M S George et al ldquoVagus nervestimulation (VNSŮ) for treatment-resistant depression effi-cacy side effects and predictors of outcomerdquoNeuropsychophar-macology vol 25 no 5 pp 713ndash728 2001

[2] A J Rush L B Marangell H A Sackeim et al ldquoVagus nervestimulation for treatment-resistant depression a randomizedcontrolled acute phase trialrdquo Biological Psychiatry vol 58 no 5pp 347ndash354 2005

[3] A J Rush H A Sackeim L B Marangell et al ldquoEffects of12 months of vagus nerve stimulation in treatment-resistantdepression a naturalistic studyrdquo Biological Psychiatry vol 58no 5 pp 355ndash363 2005

[4] A A Nierenberg J E Alpert E E Gardner-Schuster S Seayand DMischoulon ldquoVagus nerve stimulation 2-year outcomesfor bipolar versus unipolar treatment-resistant depressionrdquoBiological Psychiatry vol 64 no 6 pp 455ndash460 2008

[5] M S GeorgeHA SackeimA J Rush et al ldquoVagus nerve stim-ulation a new tool for brain research and therapyrdquo BiologicalPsychiatry vol 47 no 4 pp 287ndash295 2000

[6] M J Millan ldquoThe role of monoamines in the actions ofestablished and rdquonovelrdquo antidepressant agents a critical reviewrdquoEuropean Journal of Pharmacology vol 500 no 1ndash3 pp 371ndash384 2004

[7] W Sperling U Reulbach S Bleich F Padberg J KornhuberandMMueck-Weymann ldquoCardiac effects of vagus nerve stim-ulation in patients withmajor depressionrdquo Pharmacopsychiatryvol 43 no 1 pp 7ndash11 2010

[8] S Spuck V Tronnier I Orosz et al ldquoOperative and technicalcomplications of vagus nerve stimulator implantationrdquo Neuro-surgery vol 67 no 2 pp 489ndash494 2010

[9] X Y Gao Y H Li P J Rong and B Zhu ldquoEffect of acupunc-ture of auricular concha area on blood pressure in primaryhypertension and normal rats and analysis on its mechanismrdquoAcupuncture Research vol 31 pp 90ndash95 2006

[10] X Y Gao Y H Li K Liu et al ldquoAcupuncture-like stimulationat auricular point Heart evokes cardiovascular inhibition viaactivating the cardiac-related neurons in the nucleus tractussolitariusrdquo Brain Research vol 1397 pp 19ndash27 2011

[11] Z G Mei B Zhu Y H Li P J Rong H Ben and L LildquoResponses of glucose-sensitive neurons and insulin-sensitiveneurons in nucleus tractus solitarius to electroacupuncture atauricular concha in ratsrdquo Chinese Acupuncture amp Moxibustionvol 27 no 12 pp 917ndash922 2007

[12] F Huang P J RongH CWangHMeng and B Zhu ldquoClinicalobservation on the intervention of auricular vagus nerve stimu-lation treating 35 cases of impaired glucose tolerance patientsrdquoChina Journal of Traditional Chinese Medicine and Pharmacyvol 25 no 12 pp 2185ndash2186 2010

[13] W He C L Zhao Y H Li et al ldquoEffect of electroacupunctureat auricular concha on behaviors and electroencephalogram inepileptic ratsrdquoChinese Journal of Pathophysiology vol 27 no 10pp 1913ndash1916 2011

[14] W He Y H Li P J Rong L Li H Ben and B Zhu ldquoEffectof electroacupuncture of different regions of the auricle onepileptic seizures in epilepsy ratsrdquo Acupuncture Research vol38 no 6 pp 417ndash422 2011

[15] Tang Wang Bing Inner Canon of Huang Di Chinese AncientBooks Publishing House Yin the Qing Dynasty JingkouWencheng Tang inscription of Song Beijing China 2003

[16] J J B Allen R N Schnyer and S K Hitt ldquoThe efficacy ofacupuncture in the treatment of major depression in womenrdquoPsychological Science vol 9 no 5 pp 397ndash401 1998

[17] H C Luo H Ureil Y C Shen et al ldquoComparative study ofelectroacupuncture and fiuoxetine for treatment of depressionrdquoChinese Journal of Psychiatry vol 36 pp 215ndash219 2003

[18] W J Zhang X B Yang and B L Zhong ldquoCombinationof acupuncture and fluoxetine for depression a randomizeddouble-blind sham-controlled trialrdquo Journal of Alternative andComplementary Medicine vol 15 no 8 pp 837ndash844 2009

[19] H Wang H Qi B S Wang et al ldquoIs acupuncture beneficial indepression a meta-analysis of 8 randomized controlled trialsrdquoJournal of Affective Disorders vol 111 no 2-3 pp 125ndash134 2008

[20] Y L Sun S B Chen Y Gao and J Xiong ldquoAcupuncture versuswestern medicine for depression in China a systematic reviewrdquoChinese Journal of Evidence-Based Medicine vol 8 no 5 pp340ndash345 2008

[21] J N Ren ldquoAuricular acupuncture to treat depression 50 casesrdquoHenan Traditional Chinese Medicine vol 25 no 2 pp 75ndash782005

[22] Y M Liu and H P Su ldquoObservation of clinical efficacyon acupuncture with auricular acupressure to treatment ofdepressionrdquo Liaoning Journal of Traditional Chinese Medicinevol 35 no 1 pp 122ndash125 2008

[23] J M Li ldquoObservation of clinical curative effect on the treatmentof 35 cases of depression with acupuncture and auriculartherapyrdquo Journal of Yunnan University of Traditional ChineseMedicine vol 33 no 1 pp 5ndash6 2010

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

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PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

2 Evidence-Based Complementary and Alternative Medicine

and even heart failure Worse still technical complications ofdevice malfunction may aggravate patient conditions [7 8]

Enlightened by themechanismofVNS researchers in ourteam found that auricular concha region (ACR) is denselyinnervated by free nerve endings of the vagus nerve Ourprevious animal studies found that electroacupuncture (EA)at ACR (EA-ACR) had significant effects in the managementof primary hypertension [9 10] diabetes mellitus [11 12] andpartial epilepsy [13 14] EA-ACR is a noninvasive procedurewhich requires a portable EA device and no side effects Witha similar mechanism to VNS EA vagus nerve stimulationmay provide beneficial effects in the treatment of depres-sion

EA-ACR is one of the acupuncture therapeutic methodswhich can be considered as auriculotherapy Theories ofauriculotherapy dates back to 2000 years ago as first men-tioned in the book of Yellow Emperorrsquos Canon of Medicine(Huang Di Nei Jing) [15] Modern auriculotherapy with 42points was firstly introduced by Dr P Nogier (France) in1956 The international standard map of auricularpoints waspublished in China and later was recommended by WHOin 1993 Acupuncture part of the oriental medicine hasbeen used in eastern Asian countries for the management ofvarious emotional psychological and psychiatric disordersincluding anxiety stress insomnia and depression In recentyears acupuncture has become one of themost popular com-plementary therapies in the West and the therapeutic effec-tiveness of acupuncture on depression has been confirmedby modern research studies Allen et al [16] found that bodyacupuncture and auriculotherapy could significantly reducethe severity of depression Similar results were demonstratedin the studies of Luo et al [17] and Zhang et al [18] in whichresearchers found that electroacupuncture was as efficaciousas fluxetine in the management of major depression Ingeneral increasing evidences support that acupuncture is aneffective treatment for patients with depressive disorders [19ndash23]

In the current study we aimed to verify the vagus nerveresponses during EA at ACR Furthermore antidepressioneffects of EA-ACRwere investigated by observation of behav-iors and measurement of blood biochemicals in the ratmodels of unpredictable chronic mild stress (UCMS)

The results will provide a fundamental evidence for theanti-depression effects of EA-ACR and will facilitate EA-ACR to become a new noninvasive and low-cost therapy fordepression

2 Methods and Materials

21 Animals Male Wistar rats in 150ndash170 g were obtainedfrom the Laboratory Animal Resources Center NationalInstitute for the Control of Pharmaceutical and BiologicalProducts Beijing (Certificate no SCXK (jing) 2009-0017)These animals were individually caged on a 12 h lightdarkcycle (lights on at 800 am lights off at 800 pm) undercontrolled temperature (22 plusmn 1∘C) and humidity (50 plusmn5) conditions Standard rat chow and water were givenad libitum Animals were allowed to acclimatize for seven

days before the study All experiment procedures complywith the guidelines of the ldquoPrinciples of Laboratory AnimalCarerdquo (NIH publication number 80-23 revised 1996) and thelegislation of the Peoplersquos Republic of China for the use andcare of laboratory animals The experimental protocols wereapproved by the Animal Experimentation Ethics Committeeof the Institute of Acupuncture and Moxibustion ChinaAcademy of Chinese Medical Sciences Efforts were made tominimize the number of animal use and the suffering of theexperimental animals

22 Open Field Test for Behavioral Scoring The open fieldapparatus was constructed of black plywood and measured80 times 80 cm with 40 cm walls White lines were drawn on thefloor The lines divided the floor into twenty-five 16 times 16 cmsquares A central square (16 cm times 16 cm) was drawn in themiddle of the open field Rats were put on the central squareat the same time the video camera was turned on for videorecording from the top of the open field apparatus Behaviorsof rats were recorded for 3 minutes with the grid numberbeing counted as the horizontal score and the time of bothfrontal claws uplifting from the ground as the vertical scoreThe total locomotor activity of each animal was then scoredas the sum of the number of line crosses and rears [24 25]

23 Unpredictable ChronicMild Stress (UCMS)Model EightyRats were evenly randomized into 4 groups Forty-two ratswere recruited with the total score of 30ndash120 in the openfield test [25] A successful UCMSmodel rat was created withthe score of the open field test equal or minus 60 Qualifiedrats were distributed into four groups the normal control(119899 = 10) UCMS alone (119899 = 8) UCMS with EA-ACRtreatment (EA-ACR) (119899 = 12) and UCMS with EA-ear-tipas the treatment control (EA-ear-tip) (119899 = 12) Every five ratsin the normal group were housed in one cage However ratsin the UCMS alone EA-ACR and EA-ear-tip groups werecaged individually Depression model was established by 21days of UCMS combined with isolation UCMS procedureswere based on published studies [25 26] including sevenkinds of stressors food deprivation water deprivation cagetilt 45∘ (Ugo Basile srl hotcold plate Model 35100ndash001Italy) swimming in 4∘C ice water clipping tail 3min 50Velectric shock (Electronic stimulator NIHON KOHDENJapan) and overnight illumination The stressors were givenrandomly 3 times daily for 21 continuous daysThe rats in thenormal control group were housed undisturbedly except fornecessary procedures such as routine cage cleaning

24 Experimental Procedures (Figure 1) The open field teston all rats was conducted on the day before the studythe 22th day (after UCMS) the 36th day (after treatment)and the 50th day in the study course After the modelsof UCMS were established in 21 days the EA treatmentof 14 days was applied to the bilateral auricular concharegion (Figure 1) of rats in the EA-ACR group once dailyfor 20min For the EA-ear-tip group the EA applied to thebilateral ear tips (Figure 1) followed the same procedure andEA parameters as the EA-ACR All rats in the EA groups

Evidence-Based Complementary and Alternative Medicine 3

accepted the inhaled anesthesia during the treatment EAwas set at the frequency of 2Hz the intensity of 1mAby using the electroacupuncture stimulator (HANS-100ANanjing Gensun Medical Technology Co Ltd China) Theinhaled anesthesia was conducted on the ISOFLURANEVAPORIZER (Matrx VIP 3000 Midmark corporation USA)with isoflurane (Hebei Nine Sent Pharmaceutical Co LtdHeibei China) Blood pressure including systolic diastolicand mean pressures and heart rate of rats were monitorednoninvasively by using the apparatus (BP-98A Beijing SoftLong Biological Technology Co Ltd China) during one EAtreatmentanesthesia The data were recorded in numericalvalues at the starting point of anesthesia (0min pre-EA) the1st min of anesthesia (EA begins) the 6th min of anesthesia(EA 5min) the 11th min of anesthesia (EA 10min) the 16thmin of anesthesia (EA 15min) and the 21stmin of anesthesia(EA 20min) on the same day for three UCMS groups At the51st day of the study the rats were sacrificed and their neckvenous blood was sampled for the tests of plasma cortisol(ELISA RampD USA) andACTH (Acthlisa RampD USA) levels

25 Statistical Analysis The statistical analysis was per-formed by using one-way analysis of variance (ANOVA)followed by a Turkey test with software SPSS 130 119875 lt 005which was considered statistically significant and the datawere expressed as means plusmn standard deviation

3 Results

31 Effects of EA-ACR Treatment on Heart Rate and BloodPressure in UCMS Rats (Figures 2 and 3) No statisticaldifference was found in heart rate and blood pressure amongrats of the three UCMS groups at the beginning of the studyBoth of the heart rate and blood pressure in three UCMSgroups showed a descending trend during the anesthesiaperiod However the two EA treatment groups reduced heartrate and blood pressure significantly compared to the UCMSalone group The mean heart rate from the 6th to 11th mindecreased significantly in the EA-ACRgroup compared to theEA-ear-tip group furthermore the mean blood pressure wasdownregulated significantly in the EA-ACR group comparedto the EA-ear-tip group in the treatment periodThe EA-ACRtreatment resulted in a significant decrease in the heart ratebetween the starting point of anesthesia and the 11th min ofanesthesia (119875 lt 005) and in the mean pressure between thestarting point of anesthesia and the 16th min of anesthesia(119875 lt 005)

32 The Different Influences of EA-Treatments on the OpenField Test Score of UCMS Rats (Figure 4) The total scoreof rats exposed to the open field test showed a significantdecrease on the 22th day compared to the beginning in boththe UCMS alone group and the EA-ear-tip group (119875 lt 001and 119875 lt 001 resp) However the score did not showremarkable differences between the two time spots in thenormal group or in the EA-ACR group respectively But theEA-ACR group reached the score of 60 in the open field test

and was thus qualified as the UCMS model In the EA-ear-tip group the score decreased significantly on the 36th daycompared to the 22nd day

33 Effects of EA Treatment on Plasma Cortisol and ACTHLevels in UCMS Rats (Figures 5 and 6) As compared withthe normal group plasma cortisol levels in the three UCMSgroups showed significant increases (119875 lt 001 for all com-parisons) On the other hand the mean plasma cortisol levelof the EA-ACR group and the EA-ear-tip group decreasedsignificantly compared to the UCMS alone group (119875 lt 005and 119875 lt 005 resp)

The 21-day UCMS exposure significantly increased theconcentration of ACTH in rat blood (119875 lt 001) when theUCMS group was compared with the normal control on the51st day of the study However EA treatments significantlydecreased the concentration of ACTH compared to theUCMSalone group (119875 lt 001 and119875 lt 001 resp) while noneof the EA treatment groups showed a significant difference inthe concentration of ACTH as the normal control group did

4 Discussion

In general EA treatments down-regulated the heart rate andblood pressure as well as the concentration of plasma cortisoland ACTH However the heart rate and blood pressure wereinfluenced more intensively by the EA-ACR than the EA-ear-tip and the open field test score was kept at a higher level byEA-ACR only

41 Cardioinhibitory Effects of EA-ACR Are Similar to theVagus Nerve Stimulation In the present study EA-ACRelicited a significant decrease in heart rate andmean pressureunder the anesthesia however the EA-ear-tip treatmentdid not induce similar changes during the treatment Theseresults suggested that EA stimulation at the auricular concharegion induced similar effects as that of the direct vagus nerveelectric stimulation had on the heart [7 27 28] VNS whichstimulates the cervical trunk of the vagus nerve directly isa procedure that was approved by FDA to treat primaryhypertension years ago [7 27] Our previous research showedthat acupuncture at auricular concha area could effectivelydecrease essential hypertension in ratmodels [9] In additionwe found that electric stimulation on nucleus dorsalis nervevagi could induce immediate decrease in heart rate andcorresponding changes of electrocardiogram [29]

Anatomical knowledge of the vagus nerve informs thatthe auricular fibers of vagus nerve densely distribute in theconcha and external auditory meatus of the ear howeverthere are a few vagus nerve fibers around the ear tip [30]Theauricular branch of the vagus nerve ascends to the superiorvagal ganglion (nucleus dorsalis nerve vagi) where thecholinergic preganglionic parasympathetic neurons give riseto the branchial efferent motor fibers innervating the heartand stimulating pathway induces cardioinhibitory effects[28] Afferent signals elicited by EA-ACR may be integratedat the medulla oblongata which then generates regulatorysignals to activate the cardiac vagus nerve Cardiac vagus

4 Evidence-Based Complementary and Alternative Medicine

1

2

Figure 1 Electrical stimulation spot Black spot 1 on the ear-tip area(nonauricular concha control) Black spot 2 on the auricular concharegion (ACR) Positive iron pole (diameter 03mm) on the frontalside of ear and the negative iron pole (diameter 03mm) on the backside

nerve activation slows the heart rate and decreases the bloodpressure immediately

42 EA-ACR Treatment Improved the Depressive Status ofUCMSRats in theOpen Field Test Theunpredictable chronicmild stress (UCMS) has already contributed to the eluci-dation of the pathophysiological mechanisms of depressionsuch as decreased neurogenesis and HPA axis alterations[26 31] In the current study this model was used to explorethe relations between depressive-like behavior in rats and EA-ACR treatment The open field test provides simultaneousmeasurement of UCMS A higher score in the test indicatesincreased locomotion and exploration andor a lower levelof anxiety [25 26 31] In our study the scores of open fieldtest were significantly decreased in the UCMS alone andEA-ear-tip groups on day 22 compared to the beginningdate but no significant decrease was found in the EA-ACR group However all the rats in the EA-ACR groupwere qualified for modeling with a standard recruiting scoreof 60 It was apparent that EA-ACR kept the score on ahigher level in the treatment course while the score of theEA-ear-tip group showed a significant decrease during thetreatmentThis phenomenon indicated that EA-ACR inducedthe antidepressive effects The UCMS model and the openfield test were also successfully introduced into previous EAstudies on depression For example EA at Baihui (GV20) andYingtang (EX-HN3) on the top and front head scalp for 21days can significantly improve the symptom of the depressiverats the crossing and rearing movement times and thenumber of p-CREB-positive neuron in the hippoeampus asthe fluoxetine compared with the UCMS alone group [25]

43 EATreatmentNormalized theHyperactivity of Hypothala-mic-Pituitary-Adrenal (HPA) Axis In the present study21 daysrsquo UCMS exposure significantly increased the con-centrations of plasma cortisol and ACTH in rats It is

400

380

360

340

320

3000 1 6 11 16 21

Mea

n h

eart

rat

e (b

eat

min

)

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowast

lowast lowast lowast

lowastlowast

lowastlowastlowastlowast

Figure 2 The time course of heart rate for three UCMS groupsduring one EA treatmentanesthesia Comparison between the EA-treated UCMS group and the UCMS alone group lowast119875 lt 005lowastlowast

119875 lt 001 Comparison between the EA-ACR group and the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparison between thestarting point of anesthesia and the 11th min in the EA-ACR group119875 lt 001

consistent with the previous research studies on bothhuman beings and animal models with depressive status[32 33] Furthermore 14 days of EA treatments (both EA-ACR and EA-ear-tip) right after UCMS down-regulatedthe plasma cortisol and ACTH in UCMS rats to normallevels Researchers found that EA at acupointsNeiguan(PC6)Sanyinjiao(SP6) and Taichong(LV3) can lower plasma cor-tisol and ACTH levels and improve symptoms in depress-ion [33]

Several hypotheses have been proposed for the patholog-ical mechanism of depression Besides disturbed monoamin-ergic neurotransmission hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis is closely related to majordepression [34ndash36] The HPA axis is the primary neuroen-docrine system responsible for coordinating the mammalianstress response and has thus been a major focus of neu-robiological research of depression Major components ofthe HPA axis include corticotropin-releasing factor (CRF)adrenocorticotropin hormone (ACTH) and glucocorticoidsCortisol is the major glucocorticoid in humans and ani-mals During stress response neurons in the paraventricularnucleus (PVN) of the hypothalamus release CRF into thehypothalamo-pituitary portal system CRF then stimulatesthe release of adrenocorticotropin (ACTH) from the anteriorpituitary into systemic circulation which in turn stimulatesthe adrenal cortex to secrete cortisol Cortisol is responsiblefor many of the physiological changes associated with thestress response and it also provides negative feedback to thehypothalamus and pituitary to decrease the synthesis andrelease of CRF and ACTH

Evidence-Based Complementary and Alternative Medicine 5

90

80

70

60

50

Mea

n b

lood

pre

ssu

re (

mm

Hg)

0 1 6 11 16 21

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowastlowastlowast

lowastlowast lowastlowast lowastlowast

Figure 3 The time course of the mean blood pressure for the threeUCMS groups during one EA treatmentanesthesia Comparisonbetween the EA-treated UCMS group and the UCMS alone grouplowast

119875 lt 005 lowastlowast119875 lt 001 Comparison between the EA-ACR groupand the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparisonbetween the starting point of anesthesia and the 16thmin in the EA-ACR group 119875 lt 005

120

100

80

60

40

20

Normal UCMS alone EA-ACR EA-ear-tip

Day 0Day 22

Day 36Day 50

Tota

l sco

re o

f op

en-fi

eld

test

(sco

re)

0

lowastlowast

Figure 4 The influence of EA-ACR on the open field test score ofrats The 22nd day compared with the day before the test (day 0) inthe same group 119875 lt 005 119875 lt 001 the 36th day compared withthe 22nd day in the EA-ear-tip group lowastlowast119875 lt 001

Patients with depression show hyperactivity of the HPAaxis that may result from the impaired negative feedbackregulation of glucocorticoid release [34] Moreover researchstudy also found that normalization of these HPA axisabnormalities is associated with successful antidepressanttreatment and patients whose HPA abnormalities do notnormalize are significantly more likely to relapse [37] Ina VNS treatment study OrsquoKeane et al [38] found that theCRFACTH (adrenocorticotropic hormone) responses in thedepressed group before VNS implantation were significantlyhigher than in the healthy group and were reduced to normalvalues after 3months of VNS treatment in addition they alsofound significant improvement in depression symptoms

lowastlowastlowastlowast lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

70

60

50

40

30

20

10

0

Pla

sma

cort

isol

(n

gm

L)

Figure 5 The effect of EA-ACR treatment on plasma cortisolin normal and UCMS rats Comparison of plasma cortisol levelbetween UCMS and normal groups lowastlowast119875 lt 001 Comparisonbetween the EA-treated UCMS group and the UCMS alone group119875 lt 005

lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

180

160

140

120

100

80

60

40

20

0

AC

TH

(pg

mL

)

Figure 6The effect of EA-ACR treatment on ACTH in normal andUCMS rats Comparison of the ACTH level between normal andUCMS groups lowastlowast119875 lt 001 Comparison between the EA-treatedUCMS group and the UCMS alone group 119875 lt 001

The result of the present studymdashEA-ACR significantlyantagonized UCMS-induced depressive status of ratsmdashisconsistent with the findings of the mentioned researchstudies As demonstrated through changes in plasma cortisoland ACTH levels the antidepressant effect of EA-ACR maybe mediated via normalization of the HPA axis hyperactivityOtherwise EA-ear-tip also was found to be the apparentdown-regulation effect on the plasma cortisol and ACTH Itis found that a few vagus nerve fibers are around the ear tip[30] and HPAmay be modulated by other nervous pathwaysbeside the vagus nerve for example greater auricular nerveand lesser occipital nerve are densely innervated in the areaof ear tip and the EA signals can be transmitted by them tothe cervical spinal cord and brain then modulate the HPAFurther investigation has been warranted for this hypothesis

5 Limitation

This pilot EA-ACR study on depression has a small sam-ple size Meanwhile EA-ACR does not only stimulate the

6 Evidence-Based Complementary and Alternative Medicine

vagus nerve but also affects other sensory nerves suchas nervous auricularis magnus lesser occipital nerve facialnerve and glossopharyngeal nerve fibers Although EA-ACRelicited similar effects to VNS the interaction among thenerves in the area should be explored in the future Furtherinvestigation on EA-ACR for the disturbed monoaminergicneurotransmission of depression has been warranted

6 Conclusions

EA-ACR can elicit similar cardioinhibitory effects to vagusnerve stimulation (VNS) and EA-ACR significantly antago-nized UCMS-induced depressive status of rats The antide-pressant effect of EA-ACR is possibly mediated via normal-ization of the HPA axis hyperactivity

Authorrsquos Contribution

Ru-Peng Liu and Ji-Liang Fang contributed equally to thispaper

Acknowledgments

This scientific work was supported by the National Nat-ural Science Foundation of China Research Grants (no30973798) the Twelfth Five-Year Plan of theNational Scienceand Technology Support Program of China (2012BAF14B10)and the Beijing Natural Science Foundation (no 711117)

References

[1] H A Sackeim A J Rush M S George et al ldquoVagus nervestimulation (VNSŮ) for treatment-resistant depression effi-cacy side effects and predictors of outcomerdquoNeuropsychophar-macology vol 25 no 5 pp 713ndash728 2001

[2] A J Rush L B Marangell H A Sackeim et al ldquoVagus nervestimulation for treatment-resistant depression a randomizedcontrolled acute phase trialrdquo Biological Psychiatry vol 58 no 5pp 347ndash354 2005

[3] A J Rush H A Sackeim L B Marangell et al ldquoEffects of12 months of vagus nerve stimulation in treatment-resistantdepression a naturalistic studyrdquo Biological Psychiatry vol 58no 5 pp 355ndash363 2005

[4] A A Nierenberg J E Alpert E E Gardner-Schuster S Seayand DMischoulon ldquoVagus nerve stimulation 2-year outcomesfor bipolar versus unipolar treatment-resistant depressionrdquoBiological Psychiatry vol 64 no 6 pp 455ndash460 2008

[5] M S GeorgeHA SackeimA J Rush et al ldquoVagus nerve stim-ulation a new tool for brain research and therapyrdquo BiologicalPsychiatry vol 47 no 4 pp 287ndash295 2000

[6] M J Millan ldquoThe role of monoamines in the actions ofestablished and rdquonovelrdquo antidepressant agents a critical reviewrdquoEuropean Journal of Pharmacology vol 500 no 1ndash3 pp 371ndash384 2004

[7] W Sperling U Reulbach S Bleich F Padberg J KornhuberandMMueck-Weymann ldquoCardiac effects of vagus nerve stim-ulation in patients withmajor depressionrdquo Pharmacopsychiatryvol 43 no 1 pp 7ndash11 2010

[8] S Spuck V Tronnier I Orosz et al ldquoOperative and technicalcomplications of vagus nerve stimulator implantationrdquo Neuro-surgery vol 67 no 2 pp 489ndash494 2010

[9] X Y Gao Y H Li P J Rong and B Zhu ldquoEffect of acupunc-ture of auricular concha area on blood pressure in primaryhypertension and normal rats and analysis on its mechanismrdquoAcupuncture Research vol 31 pp 90ndash95 2006

[10] X Y Gao Y H Li K Liu et al ldquoAcupuncture-like stimulationat auricular point Heart evokes cardiovascular inhibition viaactivating the cardiac-related neurons in the nucleus tractussolitariusrdquo Brain Research vol 1397 pp 19ndash27 2011

[11] Z G Mei B Zhu Y H Li P J Rong H Ben and L LildquoResponses of glucose-sensitive neurons and insulin-sensitiveneurons in nucleus tractus solitarius to electroacupuncture atauricular concha in ratsrdquo Chinese Acupuncture amp Moxibustionvol 27 no 12 pp 917ndash922 2007

[12] F Huang P J RongH CWangHMeng and B Zhu ldquoClinicalobservation on the intervention of auricular vagus nerve stimu-lation treating 35 cases of impaired glucose tolerance patientsrdquoChina Journal of Traditional Chinese Medicine and Pharmacyvol 25 no 12 pp 2185ndash2186 2010

[13] W He C L Zhao Y H Li et al ldquoEffect of electroacupunctureat auricular concha on behaviors and electroencephalogram inepileptic ratsrdquoChinese Journal of Pathophysiology vol 27 no 10pp 1913ndash1916 2011

[14] W He Y H Li P J Rong L Li H Ben and B Zhu ldquoEffectof electroacupuncture of different regions of the auricle onepileptic seizures in epilepsy ratsrdquo Acupuncture Research vol38 no 6 pp 417ndash422 2011

[15] Tang Wang Bing Inner Canon of Huang Di Chinese AncientBooks Publishing House Yin the Qing Dynasty JingkouWencheng Tang inscription of Song Beijing China 2003

[16] J J B Allen R N Schnyer and S K Hitt ldquoThe efficacy ofacupuncture in the treatment of major depression in womenrdquoPsychological Science vol 9 no 5 pp 397ndash401 1998

[17] H C Luo H Ureil Y C Shen et al ldquoComparative study ofelectroacupuncture and fiuoxetine for treatment of depressionrdquoChinese Journal of Psychiatry vol 36 pp 215ndash219 2003

[18] W J Zhang X B Yang and B L Zhong ldquoCombinationof acupuncture and fluoxetine for depression a randomizeddouble-blind sham-controlled trialrdquo Journal of Alternative andComplementary Medicine vol 15 no 8 pp 837ndash844 2009

[19] H Wang H Qi B S Wang et al ldquoIs acupuncture beneficial indepression a meta-analysis of 8 randomized controlled trialsrdquoJournal of Affective Disorders vol 111 no 2-3 pp 125ndash134 2008

[20] Y L Sun S B Chen Y Gao and J Xiong ldquoAcupuncture versuswestern medicine for depression in China a systematic reviewrdquoChinese Journal of Evidence-Based Medicine vol 8 no 5 pp340ndash345 2008

[21] J N Ren ldquoAuricular acupuncture to treat depression 50 casesrdquoHenan Traditional Chinese Medicine vol 25 no 2 pp 75ndash782005

[22] Y M Liu and H P Su ldquoObservation of clinical efficacyon acupuncture with auricular acupressure to treatment ofdepressionrdquo Liaoning Journal of Traditional Chinese Medicinevol 35 no 1 pp 122ndash125 2008

[23] J M Li ldquoObservation of clinical curative effect on the treatmentof 35 cases of depression with acupuncture and auriculartherapyrdquo Journal of Yunnan University of Traditional ChineseMedicine vol 33 no 1 pp 5ndash6 2010

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Evidence-Based Complementary and Alternative Medicine 3

accepted the inhaled anesthesia during the treatment EAwas set at the frequency of 2Hz the intensity of 1mAby using the electroacupuncture stimulator (HANS-100ANanjing Gensun Medical Technology Co Ltd China) Theinhaled anesthesia was conducted on the ISOFLURANEVAPORIZER (Matrx VIP 3000 Midmark corporation USA)with isoflurane (Hebei Nine Sent Pharmaceutical Co LtdHeibei China) Blood pressure including systolic diastolicand mean pressures and heart rate of rats were monitorednoninvasively by using the apparatus (BP-98A Beijing SoftLong Biological Technology Co Ltd China) during one EAtreatmentanesthesia The data were recorded in numericalvalues at the starting point of anesthesia (0min pre-EA) the1st min of anesthesia (EA begins) the 6th min of anesthesia(EA 5min) the 11th min of anesthesia (EA 10min) the 16thmin of anesthesia (EA 15min) and the 21stmin of anesthesia(EA 20min) on the same day for three UCMS groups At the51st day of the study the rats were sacrificed and their neckvenous blood was sampled for the tests of plasma cortisol(ELISA RampD USA) andACTH (Acthlisa RampD USA) levels

25 Statistical Analysis The statistical analysis was per-formed by using one-way analysis of variance (ANOVA)followed by a Turkey test with software SPSS 130 119875 lt 005which was considered statistically significant and the datawere expressed as means plusmn standard deviation

3 Results

31 Effects of EA-ACR Treatment on Heart Rate and BloodPressure in UCMS Rats (Figures 2 and 3) No statisticaldifference was found in heart rate and blood pressure amongrats of the three UCMS groups at the beginning of the studyBoth of the heart rate and blood pressure in three UCMSgroups showed a descending trend during the anesthesiaperiod However the two EA treatment groups reduced heartrate and blood pressure significantly compared to the UCMSalone group The mean heart rate from the 6th to 11th mindecreased significantly in the EA-ACRgroup compared to theEA-ear-tip group furthermore the mean blood pressure wasdownregulated significantly in the EA-ACR group comparedto the EA-ear-tip group in the treatment periodThe EA-ACRtreatment resulted in a significant decrease in the heart ratebetween the starting point of anesthesia and the 11th min ofanesthesia (119875 lt 005) and in the mean pressure between thestarting point of anesthesia and the 16th min of anesthesia(119875 lt 005)

32 The Different Influences of EA-Treatments on the OpenField Test Score of UCMS Rats (Figure 4) The total scoreof rats exposed to the open field test showed a significantdecrease on the 22th day compared to the beginning in boththe UCMS alone group and the EA-ear-tip group (119875 lt 001and 119875 lt 001 resp) However the score did not showremarkable differences between the two time spots in thenormal group or in the EA-ACR group respectively But theEA-ACR group reached the score of 60 in the open field test

and was thus qualified as the UCMS model In the EA-ear-tip group the score decreased significantly on the 36th daycompared to the 22nd day

33 Effects of EA Treatment on Plasma Cortisol and ACTHLevels in UCMS Rats (Figures 5 and 6) As compared withthe normal group plasma cortisol levels in the three UCMSgroups showed significant increases (119875 lt 001 for all com-parisons) On the other hand the mean plasma cortisol levelof the EA-ACR group and the EA-ear-tip group decreasedsignificantly compared to the UCMS alone group (119875 lt 005and 119875 lt 005 resp)

The 21-day UCMS exposure significantly increased theconcentration of ACTH in rat blood (119875 lt 001) when theUCMS group was compared with the normal control on the51st day of the study However EA treatments significantlydecreased the concentration of ACTH compared to theUCMSalone group (119875 lt 001 and119875 lt 001 resp) while noneof the EA treatment groups showed a significant difference inthe concentration of ACTH as the normal control group did

4 Discussion

In general EA treatments down-regulated the heart rate andblood pressure as well as the concentration of plasma cortisoland ACTH However the heart rate and blood pressure wereinfluenced more intensively by the EA-ACR than the EA-ear-tip and the open field test score was kept at a higher level byEA-ACR only

41 Cardioinhibitory Effects of EA-ACR Are Similar to theVagus Nerve Stimulation In the present study EA-ACRelicited a significant decrease in heart rate andmean pressureunder the anesthesia however the EA-ear-tip treatmentdid not induce similar changes during the treatment Theseresults suggested that EA stimulation at the auricular concharegion induced similar effects as that of the direct vagus nerveelectric stimulation had on the heart [7 27 28] VNS whichstimulates the cervical trunk of the vagus nerve directly isa procedure that was approved by FDA to treat primaryhypertension years ago [7 27] Our previous research showedthat acupuncture at auricular concha area could effectivelydecrease essential hypertension in ratmodels [9] In additionwe found that electric stimulation on nucleus dorsalis nervevagi could induce immediate decrease in heart rate andcorresponding changes of electrocardiogram [29]

Anatomical knowledge of the vagus nerve informs thatthe auricular fibers of vagus nerve densely distribute in theconcha and external auditory meatus of the ear howeverthere are a few vagus nerve fibers around the ear tip [30]Theauricular branch of the vagus nerve ascends to the superiorvagal ganglion (nucleus dorsalis nerve vagi) where thecholinergic preganglionic parasympathetic neurons give riseto the branchial efferent motor fibers innervating the heartand stimulating pathway induces cardioinhibitory effects[28] Afferent signals elicited by EA-ACR may be integratedat the medulla oblongata which then generates regulatorysignals to activate the cardiac vagus nerve Cardiac vagus

4 Evidence-Based Complementary and Alternative Medicine

1

2

Figure 1 Electrical stimulation spot Black spot 1 on the ear-tip area(nonauricular concha control) Black spot 2 on the auricular concharegion (ACR) Positive iron pole (diameter 03mm) on the frontalside of ear and the negative iron pole (diameter 03mm) on the backside

nerve activation slows the heart rate and decreases the bloodpressure immediately

42 EA-ACR Treatment Improved the Depressive Status ofUCMSRats in theOpen Field Test Theunpredictable chronicmild stress (UCMS) has already contributed to the eluci-dation of the pathophysiological mechanisms of depressionsuch as decreased neurogenesis and HPA axis alterations[26 31] In the current study this model was used to explorethe relations between depressive-like behavior in rats and EA-ACR treatment The open field test provides simultaneousmeasurement of UCMS A higher score in the test indicatesincreased locomotion and exploration andor a lower levelof anxiety [25 26 31] In our study the scores of open fieldtest were significantly decreased in the UCMS alone andEA-ear-tip groups on day 22 compared to the beginningdate but no significant decrease was found in the EA-ACR group However all the rats in the EA-ACR groupwere qualified for modeling with a standard recruiting scoreof 60 It was apparent that EA-ACR kept the score on ahigher level in the treatment course while the score of theEA-ear-tip group showed a significant decrease during thetreatmentThis phenomenon indicated that EA-ACR inducedthe antidepressive effects The UCMS model and the openfield test were also successfully introduced into previous EAstudies on depression For example EA at Baihui (GV20) andYingtang (EX-HN3) on the top and front head scalp for 21days can significantly improve the symptom of the depressiverats the crossing and rearing movement times and thenumber of p-CREB-positive neuron in the hippoeampus asthe fluoxetine compared with the UCMS alone group [25]

43 EATreatmentNormalized theHyperactivity of Hypothala-mic-Pituitary-Adrenal (HPA) Axis In the present study21 daysrsquo UCMS exposure significantly increased the con-centrations of plasma cortisol and ACTH in rats It is

400

380

360

340

320

3000 1 6 11 16 21

Mea

n h

eart

rat

e (b

eat

min

)

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowast

lowast lowast lowast

lowastlowast

lowastlowastlowastlowast

Figure 2 The time course of heart rate for three UCMS groupsduring one EA treatmentanesthesia Comparison between the EA-treated UCMS group and the UCMS alone group lowast119875 lt 005lowastlowast

119875 lt 001 Comparison between the EA-ACR group and the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparison between thestarting point of anesthesia and the 11th min in the EA-ACR group119875 lt 001

consistent with the previous research studies on bothhuman beings and animal models with depressive status[32 33] Furthermore 14 days of EA treatments (both EA-ACR and EA-ear-tip) right after UCMS down-regulatedthe plasma cortisol and ACTH in UCMS rats to normallevels Researchers found that EA at acupointsNeiguan(PC6)Sanyinjiao(SP6) and Taichong(LV3) can lower plasma cor-tisol and ACTH levels and improve symptoms in depress-ion [33]

Several hypotheses have been proposed for the patholog-ical mechanism of depression Besides disturbed monoamin-ergic neurotransmission hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis is closely related to majordepression [34ndash36] The HPA axis is the primary neuroen-docrine system responsible for coordinating the mammalianstress response and has thus been a major focus of neu-robiological research of depression Major components ofthe HPA axis include corticotropin-releasing factor (CRF)adrenocorticotropin hormone (ACTH) and glucocorticoidsCortisol is the major glucocorticoid in humans and ani-mals During stress response neurons in the paraventricularnucleus (PVN) of the hypothalamus release CRF into thehypothalamo-pituitary portal system CRF then stimulatesthe release of adrenocorticotropin (ACTH) from the anteriorpituitary into systemic circulation which in turn stimulatesthe adrenal cortex to secrete cortisol Cortisol is responsiblefor many of the physiological changes associated with thestress response and it also provides negative feedback to thehypothalamus and pituitary to decrease the synthesis andrelease of CRF and ACTH

Evidence-Based Complementary and Alternative Medicine 5

90

80

70

60

50

Mea

n b

lood

pre

ssu

re (

mm

Hg)

0 1 6 11 16 21

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowastlowastlowast

lowastlowast lowastlowast lowastlowast

Figure 3 The time course of the mean blood pressure for the threeUCMS groups during one EA treatmentanesthesia Comparisonbetween the EA-treated UCMS group and the UCMS alone grouplowast

119875 lt 005 lowastlowast119875 lt 001 Comparison between the EA-ACR groupand the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparisonbetween the starting point of anesthesia and the 16thmin in the EA-ACR group 119875 lt 005

120

100

80

60

40

20

Normal UCMS alone EA-ACR EA-ear-tip

Day 0Day 22

Day 36Day 50

Tota

l sco

re o

f op

en-fi

eld

test

(sco

re)

0

lowastlowast

Figure 4 The influence of EA-ACR on the open field test score ofrats The 22nd day compared with the day before the test (day 0) inthe same group 119875 lt 005 119875 lt 001 the 36th day compared withthe 22nd day in the EA-ear-tip group lowastlowast119875 lt 001

Patients with depression show hyperactivity of the HPAaxis that may result from the impaired negative feedbackregulation of glucocorticoid release [34] Moreover researchstudy also found that normalization of these HPA axisabnormalities is associated with successful antidepressanttreatment and patients whose HPA abnormalities do notnormalize are significantly more likely to relapse [37] Ina VNS treatment study OrsquoKeane et al [38] found that theCRFACTH (adrenocorticotropic hormone) responses in thedepressed group before VNS implantation were significantlyhigher than in the healthy group and were reduced to normalvalues after 3months of VNS treatment in addition they alsofound significant improvement in depression symptoms

lowastlowastlowastlowast lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

70

60

50

40

30

20

10

0

Pla

sma

cort

isol

(n

gm

L)

Figure 5 The effect of EA-ACR treatment on plasma cortisolin normal and UCMS rats Comparison of plasma cortisol levelbetween UCMS and normal groups lowastlowast119875 lt 001 Comparisonbetween the EA-treated UCMS group and the UCMS alone group119875 lt 005

lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

180

160

140

120

100

80

60

40

20

0

AC

TH

(pg

mL

)

Figure 6The effect of EA-ACR treatment on ACTH in normal andUCMS rats Comparison of the ACTH level between normal andUCMS groups lowastlowast119875 lt 001 Comparison between the EA-treatedUCMS group and the UCMS alone group 119875 lt 001

The result of the present studymdashEA-ACR significantlyantagonized UCMS-induced depressive status of ratsmdashisconsistent with the findings of the mentioned researchstudies As demonstrated through changes in plasma cortisoland ACTH levels the antidepressant effect of EA-ACR maybe mediated via normalization of the HPA axis hyperactivityOtherwise EA-ear-tip also was found to be the apparentdown-regulation effect on the plasma cortisol and ACTH Itis found that a few vagus nerve fibers are around the ear tip[30] and HPAmay be modulated by other nervous pathwaysbeside the vagus nerve for example greater auricular nerveand lesser occipital nerve are densely innervated in the areaof ear tip and the EA signals can be transmitted by them tothe cervical spinal cord and brain then modulate the HPAFurther investigation has been warranted for this hypothesis

5 Limitation

This pilot EA-ACR study on depression has a small sam-ple size Meanwhile EA-ACR does not only stimulate the

6 Evidence-Based Complementary and Alternative Medicine

vagus nerve but also affects other sensory nerves suchas nervous auricularis magnus lesser occipital nerve facialnerve and glossopharyngeal nerve fibers Although EA-ACRelicited similar effects to VNS the interaction among thenerves in the area should be explored in the future Furtherinvestigation on EA-ACR for the disturbed monoaminergicneurotransmission of depression has been warranted

6 Conclusions

EA-ACR can elicit similar cardioinhibitory effects to vagusnerve stimulation (VNS) and EA-ACR significantly antago-nized UCMS-induced depressive status of rats The antide-pressant effect of EA-ACR is possibly mediated via normal-ization of the HPA axis hyperactivity

Authorrsquos Contribution

Ru-Peng Liu and Ji-Liang Fang contributed equally to thispaper

Acknowledgments

This scientific work was supported by the National Nat-ural Science Foundation of China Research Grants (no30973798) the Twelfth Five-Year Plan of theNational Scienceand Technology Support Program of China (2012BAF14B10)and the Beijing Natural Science Foundation (no 711117)

References

[1] H A Sackeim A J Rush M S George et al ldquoVagus nervestimulation (VNSŮ) for treatment-resistant depression effi-cacy side effects and predictors of outcomerdquoNeuropsychophar-macology vol 25 no 5 pp 713ndash728 2001

[2] A J Rush L B Marangell H A Sackeim et al ldquoVagus nervestimulation for treatment-resistant depression a randomizedcontrolled acute phase trialrdquo Biological Psychiatry vol 58 no 5pp 347ndash354 2005

[3] A J Rush H A Sackeim L B Marangell et al ldquoEffects of12 months of vagus nerve stimulation in treatment-resistantdepression a naturalistic studyrdquo Biological Psychiatry vol 58no 5 pp 355ndash363 2005

[4] A A Nierenberg J E Alpert E E Gardner-Schuster S Seayand DMischoulon ldquoVagus nerve stimulation 2-year outcomesfor bipolar versus unipolar treatment-resistant depressionrdquoBiological Psychiatry vol 64 no 6 pp 455ndash460 2008

[5] M S GeorgeHA SackeimA J Rush et al ldquoVagus nerve stim-ulation a new tool for brain research and therapyrdquo BiologicalPsychiatry vol 47 no 4 pp 287ndash295 2000

[6] M J Millan ldquoThe role of monoamines in the actions ofestablished and rdquonovelrdquo antidepressant agents a critical reviewrdquoEuropean Journal of Pharmacology vol 500 no 1ndash3 pp 371ndash384 2004

[7] W Sperling U Reulbach S Bleich F Padberg J KornhuberandMMueck-Weymann ldquoCardiac effects of vagus nerve stim-ulation in patients withmajor depressionrdquo Pharmacopsychiatryvol 43 no 1 pp 7ndash11 2010

[8] S Spuck V Tronnier I Orosz et al ldquoOperative and technicalcomplications of vagus nerve stimulator implantationrdquo Neuro-surgery vol 67 no 2 pp 489ndash494 2010

[9] X Y Gao Y H Li P J Rong and B Zhu ldquoEffect of acupunc-ture of auricular concha area on blood pressure in primaryhypertension and normal rats and analysis on its mechanismrdquoAcupuncture Research vol 31 pp 90ndash95 2006

[10] X Y Gao Y H Li K Liu et al ldquoAcupuncture-like stimulationat auricular point Heart evokes cardiovascular inhibition viaactivating the cardiac-related neurons in the nucleus tractussolitariusrdquo Brain Research vol 1397 pp 19ndash27 2011

[11] Z G Mei B Zhu Y H Li P J Rong H Ben and L LildquoResponses of glucose-sensitive neurons and insulin-sensitiveneurons in nucleus tractus solitarius to electroacupuncture atauricular concha in ratsrdquo Chinese Acupuncture amp Moxibustionvol 27 no 12 pp 917ndash922 2007

[12] F Huang P J RongH CWangHMeng and B Zhu ldquoClinicalobservation on the intervention of auricular vagus nerve stimu-lation treating 35 cases of impaired glucose tolerance patientsrdquoChina Journal of Traditional Chinese Medicine and Pharmacyvol 25 no 12 pp 2185ndash2186 2010

[13] W He C L Zhao Y H Li et al ldquoEffect of electroacupunctureat auricular concha on behaviors and electroencephalogram inepileptic ratsrdquoChinese Journal of Pathophysiology vol 27 no 10pp 1913ndash1916 2011

[14] W He Y H Li P J Rong L Li H Ben and B Zhu ldquoEffectof electroacupuncture of different regions of the auricle onepileptic seizures in epilepsy ratsrdquo Acupuncture Research vol38 no 6 pp 417ndash422 2011

[15] Tang Wang Bing Inner Canon of Huang Di Chinese AncientBooks Publishing House Yin the Qing Dynasty JingkouWencheng Tang inscription of Song Beijing China 2003

[16] J J B Allen R N Schnyer and S K Hitt ldquoThe efficacy ofacupuncture in the treatment of major depression in womenrdquoPsychological Science vol 9 no 5 pp 397ndash401 1998

[17] H C Luo H Ureil Y C Shen et al ldquoComparative study ofelectroacupuncture and fiuoxetine for treatment of depressionrdquoChinese Journal of Psychiatry vol 36 pp 215ndash219 2003

[18] W J Zhang X B Yang and B L Zhong ldquoCombinationof acupuncture and fluoxetine for depression a randomizeddouble-blind sham-controlled trialrdquo Journal of Alternative andComplementary Medicine vol 15 no 8 pp 837ndash844 2009

[19] H Wang H Qi B S Wang et al ldquoIs acupuncture beneficial indepression a meta-analysis of 8 randomized controlled trialsrdquoJournal of Affective Disorders vol 111 no 2-3 pp 125ndash134 2008

[20] Y L Sun S B Chen Y Gao and J Xiong ldquoAcupuncture versuswestern medicine for depression in China a systematic reviewrdquoChinese Journal of Evidence-Based Medicine vol 8 no 5 pp340ndash345 2008

[21] J N Ren ldquoAuricular acupuncture to treat depression 50 casesrdquoHenan Traditional Chinese Medicine vol 25 no 2 pp 75ndash782005

[22] Y M Liu and H P Su ldquoObservation of clinical efficacyon acupuncture with auricular acupressure to treatment ofdepressionrdquo Liaoning Journal of Traditional Chinese Medicinevol 35 no 1 pp 122ndash125 2008

[23] J M Li ldquoObservation of clinical curative effect on the treatmentof 35 cases of depression with acupuncture and auriculartherapyrdquo Journal of Yunnan University of Traditional ChineseMedicine vol 33 no 1 pp 5ndash6 2010

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

4 Evidence-Based Complementary and Alternative Medicine

1

2

Figure 1 Electrical stimulation spot Black spot 1 on the ear-tip area(nonauricular concha control) Black spot 2 on the auricular concharegion (ACR) Positive iron pole (diameter 03mm) on the frontalside of ear and the negative iron pole (diameter 03mm) on the backside

nerve activation slows the heart rate and decreases the bloodpressure immediately

42 EA-ACR Treatment Improved the Depressive Status ofUCMSRats in theOpen Field Test Theunpredictable chronicmild stress (UCMS) has already contributed to the eluci-dation of the pathophysiological mechanisms of depressionsuch as decreased neurogenesis and HPA axis alterations[26 31] In the current study this model was used to explorethe relations between depressive-like behavior in rats and EA-ACR treatment The open field test provides simultaneousmeasurement of UCMS A higher score in the test indicatesincreased locomotion and exploration andor a lower levelof anxiety [25 26 31] In our study the scores of open fieldtest were significantly decreased in the UCMS alone andEA-ear-tip groups on day 22 compared to the beginningdate but no significant decrease was found in the EA-ACR group However all the rats in the EA-ACR groupwere qualified for modeling with a standard recruiting scoreof 60 It was apparent that EA-ACR kept the score on ahigher level in the treatment course while the score of theEA-ear-tip group showed a significant decrease during thetreatmentThis phenomenon indicated that EA-ACR inducedthe antidepressive effects The UCMS model and the openfield test were also successfully introduced into previous EAstudies on depression For example EA at Baihui (GV20) andYingtang (EX-HN3) on the top and front head scalp for 21days can significantly improve the symptom of the depressiverats the crossing and rearing movement times and thenumber of p-CREB-positive neuron in the hippoeampus asthe fluoxetine compared with the UCMS alone group [25]

43 EATreatmentNormalized theHyperactivity of Hypothala-mic-Pituitary-Adrenal (HPA) Axis In the present study21 daysrsquo UCMS exposure significantly increased the con-centrations of plasma cortisol and ACTH in rats It is

400

380

360

340

320

3000 1 6 11 16 21

Mea

n h

eart

rat

e (b

eat

min

)

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowast

lowast lowast lowast

lowastlowast

lowastlowastlowastlowast

Figure 2 The time course of heart rate for three UCMS groupsduring one EA treatmentanesthesia Comparison between the EA-treated UCMS group and the UCMS alone group lowast119875 lt 005lowastlowast

119875 lt 001 Comparison between the EA-ACR group and the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparison between thestarting point of anesthesia and the 11th min in the EA-ACR group119875 lt 001

consistent with the previous research studies on bothhuman beings and animal models with depressive status[32 33] Furthermore 14 days of EA treatments (both EA-ACR and EA-ear-tip) right after UCMS down-regulatedthe plasma cortisol and ACTH in UCMS rats to normallevels Researchers found that EA at acupointsNeiguan(PC6)Sanyinjiao(SP6) and Taichong(LV3) can lower plasma cor-tisol and ACTH levels and improve symptoms in depress-ion [33]

Several hypotheses have been proposed for the patholog-ical mechanism of depression Besides disturbed monoamin-ergic neurotransmission hyperactivity of hypothalamic-pituitary-adrenal (HPA) axis is closely related to majordepression [34ndash36] The HPA axis is the primary neuroen-docrine system responsible for coordinating the mammalianstress response and has thus been a major focus of neu-robiological research of depression Major components ofthe HPA axis include corticotropin-releasing factor (CRF)adrenocorticotropin hormone (ACTH) and glucocorticoidsCortisol is the major glucocorticoid in humans and ani-mals During stress response neurons in the paraventricularnucleus (PVN) of the hypothalamus release CRF into thehypothalamo-pituitary portal system CRF then stimulatesthe release of adrenocorticotropin (ACTH) from the anteriorpituitary into systemic circulation which in turn stimulatesthe adrenal cortex to secrete cortisol Cortisol is responsiblefor many of the physiological changes associated with thestress response and it also provides negative feedback to thehypothalamus and pituitary to decrease the synthesis andrelease of CRF and ACTH

Evidence-Based Complementary and Alternative Medicine 5

90

80

70

60

50

Mea

n b

lood

pre

ssu

re (

mm

Hg)

0 1 6 11 16 21

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowastlowastlowast

lowastlowast lowastlowast lowastlowast

Figure 3 The time course of the mean blood pressure for the threeUCMS groups during one EA treatmentanesthesia Comparisonbetween the EA-treated UCMS group and the UCMS alone grouplowast

119875 lt 005 lowastlowast119875 lt 001 Comparison between the EA-ACR groupand the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparisonbetween the starting point of anesthesia and the 16thmin in the EA-ACR group 119875 lt 005

120

100

80

60

40

20

Normal UCMS alone EA-ACR EA-ear-tip

Day 0Day 22

Day 36Day 50

Tota

l sco

re o

f op

en-fi

eld

test

(sco

re)

0

lowastlowast

Figure 4 The influence of EA-ACR on the open field test score ofrats The 22nd day compared with the day before the test (day 0) inthe same group 119875 lt 005 119875 lt 001 the 36th day compared withthe 22nd day in the EA-ear-tip group lowastlowast119875 lt 001

Patients with depression show hyperactivity of the HPAaxis that may result from the impaired negative feedbackregulation of glucocorticoid release [34] Moreover researchstudy also found that normalization of these HPA axisabnormalities is associated with successful antidepressanttreatment and patients whose HPA abnormalities do notnormalize are significantly more likely to relapse [37] Ina VNS treatment study OrsquoKeane et al [38] found that theCRFACTH (adrenocorticotropic hormone) responses in thedepressed group before VNS implantation were significantlyhigher than in the healthy group and were reduced to normalvalues after 3months of VNS treatment in addition they alsofound significant improvement in depression symptoms

lowastlowastlowastlowast lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

70

60

50

40

30

20

10

0

Pla

sma

cort

isol

(n

gm

L)

Figure 5 The effect of EA-ACR treatment on plasma cortisolin normal and UCMS rats Comparison of plasma cortisol levelbetween UCMS and normal groups lowastlowast119875 lt 001 Comparisonbetween the EA-treated UCMS group and the UCMS alone group119875 lt 005

lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

180

160

140

120

100

80

60

40

20

0

AC

TH

(pg

mL

)

Figure 6The effect of EA-ACR treatment on ACTH in normal andUCMS rats Comparison of the ACTH level between normal andUCMS groups lowastlowast119875 lt 001 Comparison between the EA-treatedUCMS group and the UCMS alone group 119875 lt 001

The result of the present studymdashEA-ACR significantlyantagonized UCMS-induced depressive status of ratsmdashisconsistent with the findings of the mentioned researchstudies As demonstrated through changes in plasma cortisoland ACTH levels the antidepressant effect of EA-ACR maybe mediated via normalization of the HPA axis hyperactivityOtherwise EA-ear-tip also was found to be the apparentdown-regulation effect on the plasma cortisol and ACTH Itis found that a few vagus nerve fibers are around the ear tip[30] and HPAmay be modulated by other nervous pathwaysbeside the vagus nerve for example greater auricular nerveand lesser occipital nerve are densely innervated in the areaof ear tip and the EA signals can be transmitted by them tothe cervical spinal cord and brain then modulate the HPAFurther investigation has been warranted for this hypothesis

5 Limitation

This pilot EA-ACR study on depression has a small sam-ple size Meanwhile EA-ACR does not only stimulate the

6 Evidence-Based Complementary and Alternative Medicine

vagus nerve but also affects other sensory nerves suchas nervous auricularis magnus lesser occipital nerve facialnerve and glossopharyngeal nerve fibers Although EA-ACRelicited similar effects to VNS the interaction among thenerves in the area should be explored in the future Furtherinvestigation on EA-ACR for the disturbed monoaminergicneurotransmission of depression has been warranted

6 Conclusions

EA-ACR can elicit similar cardioinhibitory effects to vagusnerve stimulation (VNS) and EA-ACR significantly antago-nized UCMS-induced depressive status of rats The antide-pressant effect of EA-ACR is possibly mediated via normal-ization of the HPA axis hyperactivity

Authorrsquos Contribution

Ru-Peng Liu and Ji-Liang Fang contributed equally to thispaper

Acknowledgments

This scientific work was supported by the National Nat-ural Science Foundation of China Research Grants (no30973798) the Twelfth Five-Year Plan of theNational Scienceand Technology Support Program of China (2012BAF14B10)and the Beijing Natural Science Foundation (no 711117)

References

[1] H A Sackeim A J Rush M S George et al ldquoVagus nervestimulation (VNSŮ) for treatment-resistant depression effi-cacy side effects and predictors of outcomerdquoNeuropsychophar-macology vol 25 no 5 pp 713ndash728 2001

[2] A J Rush L B Marangell H A Sackeim et al ldquoVagus nervestimulation for treatment-resistant depression a randomizedcontrolled acute phase trialrdquo Biological Psychiatry vol 58 no 5pp 347ndash354 2005

[3] A J Rush H A Sackeim L B Marangell et al ldquoEffects of12 months of vagus nerve stimulation in treatment-resistantdepression a naturalistic studyrdquo Biological Psychiatry vol 58no 5 pp 355ndash363 2005

[4] A A Nierenberg J E Alpert E E Gardner-Schuster S Seayand DMischoulon ldquoVagus nerve stimulation 2-year outcomesfor bipolar versus unipolar treatment-resistant depressionrdquoBiological Psychiatry vol 64 no 6 pp 455ndash460 2008

[5] M S GeorgeHA SackeimA J Rush et al ldquoVagus nerve stim-ulation a new tool for brain research and therapyrdquo BiologicalPsychiatry vol 47 no 4 pp 287ndash295 2000

[6] M J Millan ldquoThe role of monoamines in the actions ofestablished and rdquonovelrdquo antidepressant agents a critical reviewrdquoEuropean Journal of Pharmacology vol 500 no 1ndash3 pp 371ndash384 2004

[7] W Sperling U Reulbach S Bleich F Padberg J KornhuberandMMueck-Weymann ldquoCardiac effects of vagus nerve stim-ulation in patients withmajor depressionrdquo Pharmacopsychiatryvol 43 no 1 pp 7ndash11 2010

[8] S Spuck V Tronnier I Orosz et al ldquoOperative and technicalcomplications of vagus nerve stimulator implantationrdquo Neuro-surgery vol 67 no 2 pp 489ndash494 2010

[9] X Y Gao Y H Li P J Rong and B Zhu ldquoEffect of acupunc-ture of auricular concha area on blood pressure in primaryhypertension and normal rats and analysis on its mechanismrdquoAcupuncture Research vol 31 pp 90ndash95 2006

[10] X Y Gao Y H Li K Liu et al ldquoAcupuncture-like stimulationat auricular point Heart evokes cardiovascular inhibition viaactivating the cardiac-related neurons in the nucleus tractussolitariusrdquo Brain Research vol 1397 pp 19ndash27 2011

[11] Z G Mei B Zhu Y H Li P J Rong H Ben and L LildquoResponses of glucose-sensitive neurons and insulin-sensitiveneurons in nucleus tractus solitarius to electroacupuncture atauricular concha in ratsrdquo Chinese Acupuncture amp Moxibustionvol 27 no 12 pp 917ndash922 2007

[12] F Huang P J RongH CWangHMeng and B Zhu ldquoClinicalobservation on the intervention of auricular vagus nerve stimu-lation treating 35 cases of impaired glucose tolerance patientsrdquoChina Journal of Traditional Chinese Medicine and Pharmacyvol 25 no 12 pp 2185ndash2186 2010

[13] W He C L Zhao Y H Li et al ldquoEffect of electroacupunctureat auricular concha on behaviors and electroencephalogram inepileptic ratsrdquoChinese Journal of Pathophysiology vol 27 no 10pp 1913ndash1916 2011

[14] W He Y H Li P J Rong L Li H Ben and B Zhu ldquoEffectof electroacupuncture of different regions of the auricle onepileptic seizures in epilepsy ratsrdquo Acupuncture Research vol38 no 6 pp 417ndash422 2011

[15] Tang Wang Bing Inner Canon of Huang Di Chinese AncientBooks Publishing House Yin the Qing Dynasty JingkouWencheng Tang inscription of Song Beijing China 2003

[16] J J B Allen R N Schnyer and S K Hitt ldquoThe efficacy ofacupuncture in the treatment of major depression in womenrdquoPsychological Science vol 9 no 5 pp 397ndash401 1998

[17] H C Luo H Ureil Y C Shen et al ldquoComparative study ofelectroacupuncture and fiuoxetine for treatment of depressionrdquoChinese Journal of Psychiatry vol 36 pp 215ndash219 2003

[18] W J Zhang X B Yang and B L Zhong ldquoCombinationof acupuncture and fluoxetine for depression a randomizeddouble-blind sham-controlled trialrdquo Journal of Alternative andComplementary Medicine vol 15 no 8 pp 837ndash844 2009

[19] H Wang H Qi B S Wang et al ldquoIs acupuncture beneficial indepression a meta-analysis of 8 randomized controlled trialsrdquoJournal of Affective Disorders vol 111 no 2-3 pp 125ndash134 2008

[20] Y L Sun S B Chen Y Gao and J Xiong ldquoAcupuncture versuswestern medicine for depression in China a systematic reviewrdquoChinese Journal of Evidence-Based Medicine vol 8 no 5 pp340ndash345 2008

[21] J N Ren ldquoAuricular acupuncture to treat depression 50 casesrdquoHenan Traditional Chinese Medicine vol 25 no 2 pp 75ndash782005

[22] Y M Liu and H P Su ldquoObservation of clinical efficacyon acupuncture with auricular acupressure to treatment ofdepressionrdquo Liaoning Journal of Traditional Chinese Medicinevol 35 no 1 pp 122ndash125 2008

[23] J M Li ldquoObservation of clinical curative effect on the treatmentof 35 cases of depression with acupuncture and auriculartherapyrdquo Journal of Yunnan University of Traditional ChineseMedicine vol 33 no 1 pp 5ndash6 2010

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Evidence-Based Complementary and Alternative Medicine 5

90

80

70

60

50

Mea

n b

lood

pre

ssu

re (

mm

Hg)

0 1 6 11 16 21

Time course (min)

EA-ACR (n = 12)EA-ear-tip (n = 12)UCMS alone (n = 8)

lowastlowastlowast

lowastlowast lowastlowast lowastlowast

Figure 3 The time course of the mean blood pressure for the threeUCMS groups during one EA treatmentanesthesia Comparisonbetween the EA-treated UCMS group and the UCMS alone grouplowast

119875 lt 005 lowastlowast119875 lt 001 Comparison between the EA-ACR groupand the EA-ear-tip group 998779119875 lt 005 998779998779119875 lt 001 Comparisonbetween the starting point of anesthesia and the 16thmin in the EA-ACR group 119875 lt 005

120

100

80

60

40

20

Normal UCMS alone EA-ACR EA-ear-tip

Day 0Day 22

Day 36Day 50

Tota

l sco

re o

f op

en-fi

eld

test

(sco

re)

0

lowastlowast

Figure 4 The influence of EA-ACR on the open field test score ofrats The 22nd day compared with the day before the test (day 0) inthe same group 119875 lt 005 119875 lt 001 the 36th day compared withthe 22nd day in the EA-ear-tip group lowastlowast119875 lt 001

Patients with depression show hyperactivity of the HPAaxis that may result from the impaired negative feedbackregulation of glucocorticoid release [34] Moreover researchstudy also found that normalization of these HPA axisabnormalities is associated with successful antidepressanttreatment and patients whose HPA abnormalities do notnormalize are significantly more likely to relapse [37] Ina VNS treatment study OrsquoKeane et al [38] found that theCRFACTH (adrenocorticotropic hormone) responses in thedepressed group before VNS implantation were significantlyhigher than in the healthy group and were reduced to normalvalues after 3months of VNS treatment in addition they alsofound significant improvement in depression symptoms

lowastlowastlowastlowast lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

70

60

50

40

30

20

10

0

Pla

sma

cort

isol

(n

gm

L)

Figure 5 The effect of EA-ACR treatment on plasma cortisolin normal and UCMS rats Comparison of plasma cortisol levelbetween UCMS and normal groups lowastlowast119875 lt 001 Comparisonbetween the EA-treated UCMS group and the UCMS alone group119875 lt 005

lowastlowast

Normal UCMS alone EA-ACR EA-ear-tip

180

160

140

120

100

80

60

40

20

0

AC

TH

(pg

mL

)

Figure 6The effect of EA-ACR treatment on ACTH in normal andUCMS rats Comparison of the ACTH level between normal andUCMS groups lowastlowast119875 lt 001 Comparison between the EA-treatedUCMS group and the UCMS alone group 119875 lt 001

The result of the present studymdashEA-ACR significantlyantagonized UCMS-induced depressive status of ratsmdashisconsistent with the findings of the mentioned researchstudies As demonstrated through changes in plasma cortisoland ACTH levels the antidepressant effect of EA-ACR maybe mediated via normalization of the HPA axis hyperactivityOtherwise EA-ear-tip also was found to be the apparentdown-regulation effect on the plasma cortisol and ACTH Itis found that a few vagus nerve fibers are around the ear tip[30] and HPAmay be modulated by other nervous pathwaysbeside the vagus nerve for example greater auricular nerveand lesser occipital nerve are densely innervated in the areaof ear tip and the EA signals can be transmitted by them tothe cervical spinal cord and brain then modulate the HPAFurther investigation has been warranted for this hypothesis

5 Limitation

This pilot EA-ACR study on depression has a small sam-ple size Meanwhile EA-ACR does not only stimulate the

6 Evidence-Based Complementary and Alternative Medicine

vagus nerve but also affects other sensory nerves suchas nervous auricularis magnus lesser occipital nerve facialnerve and glossopharyngeal nerve fibers Although EA-ACRelicited similar effects to VNS the interaction among thenerves in the area should be explored in the future Furtherinvestigation on EA-ACR for the disturbed monoaminergicneurotransmission of depression has been warranted

6 Conclusions

EA-ACR can elicit similar cardioinhibitory effects to vagusnerve stimulation (VNS) and EA-ACR significantly antago-nized UCMS-induced depressive status of rats The antide-pressant effect of EA-ACR is possibly mediated via normal-ization of the HPA axis hyperactivity

Authorrsquos Contribution

Ru-Peng Liu and Ji-Liang Fang contributed equally to thispaper

Acknowledgments

This scientific work was supported by the National Nat-ural Science Foundation of China Research Grants (no30973798) the Twelfth Five-Year Plan of theNational Scienceand Technology Support Program of China (2012BAF14B10)and the Beijing Natural Science Foundation (no 711117)

References

[1] H A Sackeim A J Rush M S George et al ldquoVagus nervestimulation (VNSŮ) for treatment-resistant depression effi-cacy side effects and predictors of outcomerdquoNeuropsychophar-macology vol 25 no 5 pp 713ndash728 2001

[2] A J Rush L B Marangell H A Sackeim et al ldquoVagus nervestimulation for treatment-resistant depression a randomizedcontrolled acute phase trialrdquo Biological Psychiatry vol 58 no 5pp 347ndash354 2005

[3] A J Rush H A Sackeim L B Marangell et al ldquoEffects of12 months of vagus nerve stimulation in treatment-resistantdepression a naturalistic studyrdquo Biological Psychiatry vol 58no 5 pp 355ndash363 2005

[4] A A Nierenberg J E Alpert E E Gardner-Schuster S Seayand DMischoulon ldquoVagus nerve stimulation 2-year outcomesfor bipolar versus unipolar treatment-resistant depressionrdquoBiological Psychiatry vol 64 no 6 pp 455ndash460 2008

[5] M S GeorgeHA SackeimA J Rush et al ldquoVagus nerve stim-ulation a new tool for brain research and therapyrdquo BiologicalPsychiatry vol 47 no 4 pp 287ndash295 2000

[6] M J Millan ldquoThe role of monoamines in the actions ofestablished and rdquonovelrdquo antidepressant agents a critical reviewrdquoEuropean Journal of Pharmacology vol 500 no 1ndash3 pp 371ndash384 2004

[7] W Sperling U Reulbach S Bleich F Padberg J KornhuberandMMueck-Weymann ldquoCardiac effects of vagus nerve stim-ulation in patients withmajor depressionrdquo Pharmacopsychiatryvol 43 no 1 pp 7ndash11 2010

[8] S Spuck V Tronnier I Orosz et al ldquoOperative and technicalcomplications of vagus nerve stimulator implantationrdquo Neuro-surgery vol 67 no 2 pp 489ndash494 2010

[9] X Y Gao Y H Li P J Rong and B Zhu ldquoEffect of acupunc-ture of auricular concha area on blood pressure in primaryhypertension and normal rats and analysis on its mechanismrdquoAcupuncture Research vol 31 pp 90ndash95 2006

[10] X Y Gao Y H Li K Liu et al ldquoAcupuncture-like stimulationat auricular point Heart evokes cardiovascular inhibition viaactivating the cardiac-related neurons in the nucleus tractussolitariusrdquo Brain Research vol 1397 pp 19ndash27 2011

[11] Z G Mei B Zhu Y H Li P J Rong H Ben and L LildquoResponses of glucose-sensitive neurons and insulin-sensitiveneurons in nucleus tractus solitarius to electroacupuncture atauricular concha in ratsrdquo Chinese Acupuncture amp Moxibustionvol 27 no 12 pp 917ndash922 2007

[12] F Huang P J RongH CWangHMeng and B Zhu ldquoClinicalobservation on the intervention of auricular vagus nerve stimu-lation treating 35 cases of impaired glucose tolerance patientsrdquoChina Journal of Traditional Chinese Medicine and Pharmacyvol 25 no 12 pp 2185ndash2186 2010

[13] W He C L Zhao Y H Li et al ldquoEffect of electroacupunctureat auricular concha on behaviors and electroencephalogram inepileptic ratsrdquoChinese Journal of Pathophysiology vol 27 no 10pp 1913ndash1916 2011

[14] W He Y H Li P J Rong L Li H Ben and B Zhu ldquoEffectof electroacupuncture of different regions of the auricle onepileptic seizures in epilepsy ratsrdquo Acupuncture Research vol38 no 6 pp 417ndash422 2011

[15] Tang Wang Bing Inner Canon of Huang Di Chinese AncientBooks Publishing House Yin the Qing Dynasty JingkouWencheng Tang inscription of Song Beijing China 2003

[16] J J B Allen R N Schnyer and S K Hitt ldquoThe efficacy ofacupuncture in the treatment of major depression in womenrdquoPsychological Science vol 9 no 5 pp 397ndash401 1998

[17] H C Luo H Ureil Y C Shen et al ldquoComparative study ofelectroacupuncture and fiuoxetine for treatment of depressionrdquoChinese Journal of Psychiatry vol 36 pp 215ndash219 2003

[18] W J Zhang X B Yang and B L Zhong ldquoCombinationof acupuncture and fluoxetine for depression a randomizeddouble-blind sham-controlled trialrdquo Journal of Alternative andComplementary Medicine vol 15 no 8 pp 837ndash844 2009

[19] H Wang H Qi B S Wang et al ldquoIs acupuncture beneficial indepression a meta-analysis of 8 randomized controlled trialsrdquoJournal of Affective Disorders vol 111 no 2-3 pp 125ndash134 2008

[20] Y L Sun S B Chen Y Gao and J Xiong ldquoAcupuncture versuswestern medicine for depression in China a systematic reviewrdquoChinese Journal of Evidence-Based Medicine vol 8 no 5 pp340ndash345 2008

[21] J N Ren ldquoAuricular acupuncture to treat depression 50 casesrdquoHenan Traditional Chinese Medicine vol 25 no 2 pp 75ndash782005

[22] Y M Liu and H P Su ldquoObservation of clinical efficacyon acupuncture with auricular acupressure to treatment ofdepressionrdquo Liaoning Journal of Traditional Chinese Medicinevol 35 no 1 pp 122ndash125 2008

[23] J M Li ldquoObservation of clinical curative effect on the treatmentof 35 cases of depression with acupuncture and auriculartherapyrdquo Journal of Yunnan University of Traditional ChineseMedicine vol 33 no 1 pp 5ndash6 2010

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

6 Evidence-Based Complementary and Alternative Medicine

vagus nerve but also affects other sensory nerves suchas nervous auricularis magnus lesser occipital nerve facialnerve and glossopharyngeal nerve fibers Although EA-ACRelicited similar effects to VNS the interaction among thenerves in the area should be explored in the future Furtherinvestigation on EA-ACR for the disturbed monoaminergicneurotransmission of depression has been warranted

6 Conclusions

EA-ACR can elicit similar cardioinhibitory effects to vagusnerve stimulation (VNS) and EA-ACR significantly antago-nized UCMS-induced depressive status of rats The antide-pressant effect of EA-ACR is possibly mediated via normal-ization of the HPA axis hyperactivity

Authorrsquos Contribution

Ru-Peng Liu and Ji-Liang Fang contributed equally to thispaper

Acknowledgments

This scientific work was supported by the National Nat-ural Science Foundation of China Research Grants (no30973798) the Twelfth Five-Year Plan of theNational Scienceand Technology Support Program of China (2012BAF14B10)and the Beijing Natural Science Foundation (no 711117)

References

[1] H A Sackeim A J Rush M S George et al ldquoVagus nervestimulation (VNSŮ) for treatment-resistant depression effi-cacy side effects and predictors of outcomerdquoNeuropsychophar-macology vol 25 no 5 pp 713ndash728 2001

[2] A J Rush L B Marangell H A Sackeim et al ldquoVagus nervestimulation for treatment-resistant depression a randomizedcontrolled acute phase trialrdquo Biological Psychiatry vol 58 no 5pp 347ndash354 2005

[3] A J Rush H A Sackeim L B Marangell et al ldquoEffects of12 months of vagus nerve stimulation in treatment-resistantdepression a naturalistic studyrdquo Biological Psychiatry vol 58no 5 pp 355ndash363 2005

[4] A A Nierenberg J E Alpert E E Gardner-Schuster S Seayand DMischoulon ldquoVagus nerve stimulation 2-year outcomesfor bipolar versus unipolar treatment-resistant depressionrdquoBiological Psychiatry vol 64 no 6 pp 455ndash460 2008

[5] M S GeorgeHA SackeimA J Rush et al ldquoVagus nerve stim-ulation a new tool for brain research and therapyrdquo BiologicalPsychiatry vol 47 no 4 pp 287ndash295 2000

[6] M J Millan ldquoThe role of monoamines in the actions ofestablished and rdquonovelrdquo antidepressant agents a critical reviewrdquoEuropean Journal of Pharmacology vol 500 no 1ndash3 pp 371ndash384 2004

[7] W Sperling U Reulbach S Bleich F Padberg J KornhuberandMMueck-Weymann ldquoCardiac effects of vagus nerve stim-ulation in patients withmajor depressionrdquo Pharmacopsychiatryvol 43 no 1 pp 7ndash11 2010

[8] S Spuck V Tronnier I Orosz et al ldquoOperative and technicalcomplications of vagus nerve stimulator implantationrdquo Neuro-surgery vol 67 no 2 pp 489ndash494 2010

[9] X Y Gao Y H Li P J Rong and B Zhu ldquoEffect of acupunc-ture of auricular concha area on blood pressure in primaryhypertension and normal rats and analysis on its mechanismrdquoAcupuncture Research vol 31 pp 90ndash95 2006

[10] X Y Gao Y H Li K Liu et al ldquoAcupuncture-like stimulationat auricular point Heart evokes cardiovascular inhibition viaactivating the cardiac-related neurons in the nucleus tractussolitariusrdquo Brain Research vol 1397 pp 19ndash27 2011

[11] Z G Mei B Zhu Y H Li P J Rong H Ben and L LildquoResponses of glucose-sensitive neurons and insulin-sensitiveneurons in nucleus tractus solitarius to electroacupuncture atauricular concha in ratsrdquo Chinese Acupuncture amp Moxibustionvol 27 no 12 pp 917ndash922 2007

[12] F Huang P J RongH CWangHMeng and B Zhu ldquoClinicalobservation on the intervention of auricular vagus nerve stimu-lation treating 35 cases of impaired glucose tolerance patientsrdquoChina Journal of Traditional Chinese Medicine and Pharmacyvol 25 no 12 pp 2185ndash2186 2010

[13] W He C L Zhao Y H Li et al ldquoEffect of electroacupunctureat auricular concha on behaviors and electroencephalogram inepileptic ratsrdquoChinese Journal of Pathophysiology vol 27 no 10pp 1913ndash1916 2011

[14] W He Y H Li P J Rong L Li H Ben and B Zhu ldquoEffectof electroacupuncture of different regions of the auricle onepileptic seizures in epilepsy ratsrdquo Acupuncture Research vol38 no 6 pp 417ndash422 2011

[15] Tang Wang Bing Inner Canon of Huang Di Chinese AncientBooks Publishing House Yin the Qing Dynasty JingkouWencheng Tang inscription of Song Beijing China 2003

[16] J J B Allen R N Schnyer and S K Hitt ldquoThe efficacy ofacupuncture in the treatment of major depression in womenrdquoPsychological Science vol 9 no 5 pp 397ndash401 1998

[17] H C Luo H Ureil Y C Shen et al ldquoComparative study ofelectroacupuncture and fiuoxetine for treatment of depressionrdquoChinese Journal of Psychiatry vol 36 pp 215ndash219 2003

[18] W J Zhang X B Yang and B L Zhong ldquoCombinationof acupuncture and fluoxetine for depression a randomizeddouble-blind sham-controlled trialrdquo Journal of Alternative andComplementary Medicine vol 15 no 8 pp 837ndash844 2009

[19] H Wang H Qi B S Wang et al ldquoIs acupuncture beneficial indepression a meta-analysis of 8 randomized controlled trialsrdquoJournal of Affective Disorders vol 111 no 2-3 pp 125ndash134 2008

[20] Y L Sun S B Chen Y Gao and J Xiong ldquoAcupuncture versuswestern medicine for depression in China a systematic reviewrdquoChinese Journal of Evidence-Based Medicine vol 8 no 5 pp340ndash345 2008

[21] J N Ren ldquoAuricular acupuncture to treat depression 50 casesrdquoHenan Traditional Chinese Medicine vol 25 no 2 pp 75ndash782005

[22] Y M Liu and H P Su ldquoObservation of clinical efficacyon acupuncture with auricular acupressure to treatment ofdepressionrdquo Liaoning Journal of Traditional Chinese Medicinevol 35 no 1 pp 122ndash125 2008

[23] J M Li ldquoObservation of clinical curative effect on the treatmentof 35 cases of depression with acupuncture and auriculartherapyrdquo Journal of Yunnan University of Traditional ChineseMedicine vol 33 no 1 pp 5ndash6 2010

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Evidence-Based Complementary and Alternative Medicine 7

[24] R J Katz K A Roth and B J Carroll ldquoAcute and chronic stresseffects on open field activity in the rat implications for a modelof depressionrdquoNeuroscience amp Biobehavioral Reviews vol 5 pp247ndash251 1981

[25] D M Duan Y Tu and L P Chen ldquoEffects of electroacupunc-ture at different acupoint groups on behavior activity and p-CREB expression in hippocampus in the rat of depressionrdquoChinese Acupuncture ampMoxibustion vol 28 no 5 pp 369ndash3732008

[26] P Willner ldquoValidity reliability and utility of the chronic mildstress model of depression a 10-year review and evaluationrdquoPsychopharmacology vol 134 no 4 pp 319ndash329 1997

[27] D A Groves andV J Brown ldquoVagal nerve stimulation a reviewof its applications and potential mechanisms that mediate itsclinical effectsrdquoNeuroscience and Biobehavioral Reviews vol 29no 3 pp 493ndash500 2005

[28] T Kawada S Shimizu M Li et al ldquoContrasting effects ofmoderate vagal stimulation on heart rate and carotid sinusbaroreflex-mediated sympathetic arterial pressure regulation inratsrdquo Life Sciences vol 89 no 13 pp 498ndash503 2011

[29] H J Sun H B Ai and X Y Cui ldquoEffects of electricalstimulation to the dorsal motor vagal nudens ucleus on HE-ECG signalsrdquo Journal of Shanxi University vol 27 pp 289ndash2912004

[30] S StandringGrayrsquos Anatomy Churchill Livingstone New YorkNY USA 40th edition 2008

[31] Y S Mineur C Belzung and W E Crusio ldquoEffects of unpre-dictable chronic mild stress on anxiety and depression-likebehavior in micerdquo Behavioural Brain Research vol 175 no 1pp 43ndash50 2006

[32] M P Boyle J A Brewer M Funatsu et al ldquoAcquired deficitof f orebrain glucocort icoid recept or produces depression-likechanges in adrenal axis regulation and behaviorrdquo Proceedings ofthe National Academy of Sciences of the United States of Americavol 102 no 2 pp 473ndash478 2005

[33] H Xu Z R Sun L P Li et al ldquoEffect s of acupunctureon the hypothalamus- pituitary-adrenal axis in the patients ofdepressionrdquo Chinese Acupuncture and Moxibustion vol 24 no2 pp 78ndash80 2004

[34] C B Nemeroff H S Mayberg S E Krahl et al ldquoVNS therapyin treatment-resistant depression clinical evidence and putativeneurobiological mechanismsrdquo Neuropsychopharmacology vol31 no 7 pp 1345ndash1355 2006

[35] J P Herman H Figueiredo N K Mueller et al ldquoCentralmechanisms of stress integration hierarchical circuitry con-trolling hypothalamo-pituitary-adrenocortical responsivenessrdquoFrontiers in Neuroendocrinology vol 24 no 3 pp 151ndash180 2003

[36] N Barden ldquoImplication of the hypothalamic-pituitary-adrenalaxis in the physiopathology of depressionrdquo Journal of Psychiatryand Neuroscience vol 29 no 3 pp 185ndash193 2004

[37] S M OrsquoToole L K Sekula and R T Rubin ldquoPituitary-adrenalcortical axismeasures as predictors of sustainedremission inmajor depressionrdquo Biological Psychiatry vol 42 pp 85ndash89 1997

[38] V OrsquoKeane T G Dinan L Scott and C Corcoran ldquoChangesin hypothalamic-pituitary-adrenal axis measures after vagusnerve stimulation therapy in chronic depressionrdquo BiologicalPsychiatry vol 58 no 12 pp 963ndash968 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom