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of TH in selected regions of the rat brain have suggested that L-T4can be uptaken by the brain (Pinna et al., 1999). Additionally,previous studies demonstrated that mouse organic anion trans-porting polypeptide 14 (mOatp14) involves in the uptake of T4across the bloodebrain barrier (Tohyama et al., 2004), and T4 is

the Rotterdam Scan Study, no signicant correlation is foundbetween free T4 levels and global cognition in euthyroid patientswith AD (de Jong et al., 2006).

While examining the association between TH and AD andinvestigating themechanism bywhich THmight inuencememoryperformance are important for applying TH to prevent AD, to date,there are few relative prospective studies. Therefore, in the presentstudy, we used AD mouse model induced by aggregated Ab toexplore the possibility that TH might be applied for therapy of AD.

* Corresponding author. Tel.: 86 23 6825 0267.

Contents lists availab

Neuropharm

ev

Neuropharmacology 58 (2010) 722e729E-mail address: Fuailing1008@yahoo.com.cn (A.L. Fu).senile plaques, and the amount of Ab to form the plaques iscorrelative with the degree of neuronal damage and cognitivedecits (Blennow et al., 2006; Mattson, 2004). Although AD hasbecome the most common cause of dementia diagnosed after theage of 60 today, there is still now not fully elucidated and no ef-cient method for its treatment.

Thyroid hormones (TH), including T3 and T4, are essential fordevelopment of mammalian brain and maintenance of optimalcognitive ability in different periods (Bgin et al., 2008; Zhang et al.,2009). In the study of TH in the brain, extraction and quantication

be a role for TH to increase the ability of learning andmemory of AD.Although laboratory studies and clinical reports support a close

link between TH and Alzheimer's pathophysiology (Ceresini et al.,2009; Rivas and Naranjo, 2007; van den Beld et al., 2005; Yoshi-masu et al., 1991), studies examining the relationship between THand AD have yielded contradictory results. Low TH level is associ-ated with AD in some studies (Breteler et al., 1991; Ganguli et al.,1996), but not in others (Yoshimasu et al., 1991). Conversely, somestudies show that hyper- rather than hypo-thyroidism is proposedas risk factors for AD (van Osch et al., 2004; Kalmijn et al., 2000). InFree radicalNeuronal apoptosis

1. Introduction

Alzheimer's disease (AD) is a neuacterized by progressive loss of mcognitive functions. The neuropathoinclude neurobrillary tangles and seof which is believed to be responsibpatients. Amyloid b-peptide (Ab) is0028-3908/$ e see front matter 2009 Elsevier Ltd.doi:10.1016/j.neuropharm.2009.12.020nerative disorder char-and deterioration of

l features of AD brainsaques, the neurotoxicityhe neuronal loss in ADajor component of the

found to be stereospecic, saturable, and energy dependent trans-port into amouse neuroblastoma cell line (Lakshmanan et al.,1990).Furthermore, animal behavioral experiments suggested thatthyroxine treatment reverses hypo-thyroidism-induced impair-ment of hippocampus-dependent cognition in thyroidectomizedadult rats, (Alzoubi et al., 2009). In clinical practices, TH treatmentcan signicantly improve cognition and emotion in patients (Baueret al., 2008; Bunevicius, 2009). These results imply that there mayCognitionCholinergic functionAlzheimer's disease 2009 Elsevier Ltd. All rights reserved.Thyroid hormone prevents cognitive deof Alzheimer's disease

Ai Ling Fu*, Cheng Yu Zhou, Xiang ChenSchool of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China

a r t i c l e i n f o

Article history:Received 31 May 2009Received in revised form21 December 2009Accepted 21 December 2009

Keywords:Thyroxine

a b s t r a c t

This study aimed to examAlzheimer's disease (AD). Mproduce AD animal modemodel mice prevented thenisms of L-T4 treating AD mof AD model mice against dThe results of the present

journal homepage: www.elsAll rights reserved.it in a mouse model

the feasibility of using thyroid hormone (TH) as a therapeutic agent forwere injected intra-hippocampally aggregated amyloid b-peptide (Ab) to

ntraperitoneal administration of L-thyroxine (L-T4) into Ab-induced ADognitive impairment and improved their memory function. The mecha-t be associated with regulating cholinergic function, protecting the brainsage from free radicals, and rescuing hippocampal neurons from apoptosis.y indicate that the use of TH has some therapeutic potential in AD.

le at ScienceDirect

acology

ier .com/locate/neuropharm

We found that TH prevented cognitive decit and improved theneurological function in AD model mice by regulating cholinergicfunction, inhibiting the damage of free radicals, and increasing thenumber of neurons in the brains of AD mice.

2. Materials and methods

2.1. Materials

L-T4 and Ab (1e42) were purchased from Sigma. L-T4 was dissolved in sodiumhydroxide, and hydrochloric acid was added to regulate the pH of the solution to 7.4.Ab (1e42) was dissolved in 0.01 M PBS (pH 7.4) at a concentration of 10 mM, sealedand incubated for 3 d at 37 C to form the aggregated Ab. All other reagents were ofchemical grade.

A.L. Fu et al. / Neuropharmaco2.2. Animals and housing conditions

Healthy mice, Kunming species, male, weighing 25e30 g at the beginning of theexperiments, provided by the Animal Breeding Center Afliated to ChongqingMedical University, China, were used throughout the study. Animals were housedunder conditions of natural illumination with food and water available ad libitum.Animal experiments were performed in accordance with the Chinese Guides for theCare and Use of Laboratory Animals.

2.3. AD model mouse and L-T4 treatment

The model of AD mice induced by Ab was made according to the previousreports (Stephan et al., 2001; Yan et al., 2001). Animals were anesthetized withsodium pentobarbital (40 mg/kg), and the injection of aggregated Ab was madebilaterally into the CA1 region of hippocampus (from Bregma 2.3 mm caudally,2.1 mm laterally and from skull surface 1.8 mm ventrally) (Paxinos and Franklin,2001) in sterotaxic apparatus using a 26-gauge needle connected to a 5 mL Hamiltonmicrosyringe by polyethylene tubing. For each side of the hippocampus, a volume of1.0 mL was administered over a period of 2 min (0.5 mL/min) followed by an addi-tional 2 min waiting time before the injection needle was removed. The controlanimals were infused with PBS accordingly. After administration, the animal wasreturned to its home cage. The mice were determined as the AD model by behaviortests and immunostaining 7 d after injection of the aggregated Ab.

For the AD model, mice were intraperitoneally injected with 2.5 mg/kg of L-T4once a day for 4 consecutive days as described previously (Meaney et al., 1987; Smithet al., 2002). The control animals were injected with PBS in parallel. The detail isdescribed in Fig. 1.

2.4. Water maze test

The Morris water maze apparatus (Chengdu Technology & Market Co. LTD,China) was used to test the spatial learning and memory as previously described(Tsai et al., 2007). The water in the maze was opaque so that the platform, oncesubmerged, was not visible. For navigation test, there were four trials per sessionand two sessions per day, with one session given in themorning and the other in theafternoon. For a complete test, a total of six sessions over 3 d were given. In each ofthe four trials, the animals were placed randomly at four different starting positionsat the junction between two adjacent quadrants (the east, north, west or south polesof themaze). The animals were allowed 120 s to nd the platform. If an animal couldnot nd the platform in 120 s, it was guided to it. After mounting the platform, theanimals were allowed to stay there for 30 s. The time that an individual mouse spentto reach the platform was recorded as the escape latency.

Probe test was performed 24 h after the navigation test completed. The platformwas removed from the pool, and the mice began from a unique starting locationdirectly opposite the platform. During the probe trial, mice remained in the pool forthe entire 90 s. All trials were recorded with a digital camera using the computer

A injection TH treatment Probe test

(Day) 0 8 12 14 15

Navigation test Fig. 1. Experimental design for TH treatment in aggregated Ab-induced AD mousemodel.software of Water Maze. During the navigation test, the escape latencies to platformof all trials were recorded. The spatial learning ability was evaluated by averageescape latency to platform in every session. Additionally, time spent in the targetquadrant was recorded during the probe trial. The ratio of time spent in the targetquadrant in 90 s was used to evaluate the spatial memory ability.

2.5. Biochemistry assay

Biochemical parameters were measured after learning and memory tests. Theassaymethods were described by previous report (Fu et al., 2006). Briey, micewereeuthanized by decapitation, and the cortex and hippocampus were dissected andkept at70 C ready for use. Ten percent (1:10, w/v) homogenate in cold saline wereprepared (5000 rpm, 5 s for twice with 30 s interval) in ice bath. Superoxide dis-mutase (SOD) activity was assayed by the xanthine oxidase method (Sousa et al.,2008). Glutathione (GSH) was determined by the spectrophotometric method basedon the use of Ellman's reagent (Beutler, 1979). Choline acetyltransferase (ChAT)activity was determined spectrophotometrically according to Wolfgram (1972), andacetylcholine (ACh) level was examined by using the method of Hestrin (Vincentet al., 1958). Catalase (CAT) activity was measured by the spectrophotometricalmethod (Johansson and Borg, 1988), and glutathione peroxidase (GSH-Px) activitywas assayed according to the method of Beutler (1979). The content of ATP wasmeasured by bioLuminescence method (Fukuda et al., 1983). Protein concentrationwas determined according to Lowry et al. (1951). All biochemical parameters werenormalized to total homogenate protein.

2.6. Immunouorescence staining

Immunouorescence staining was performed after animal behavioral tests. Themicewere anesthetized and xed by intracardical perfusion of 4% paraformaldehydein PBS (0.01 M, pH 7.4). After the brains were cryoprotected in sucrose at 4 C, thecoronal sections were cut on a cryostat microtome. The slices of the hippocampus(30 mm; Bregma 1.6 to 2.8) were incubated in 10% normal goat serum diluted inPBS at 4 C overnight. For the Ab recognition, we used amousemonoclonal antibody(Santa Cruz; 1:1000) and for neuron specic enolase (NSE) a rabbit polyclonal anti-NSE (Santa Cruz; 1:1000). FITC-labeled goat anti-mouse IgG (Ab) and FITC-labeledgoat anti-rabbit IgG (NSE; Beijing Boaoshen Biotechnology Company, China) wereused as secondary antibodies. The PBS was used to wash the slices before eachaddition. The slices were air dried and placed on coverslips using a uorescentmounting medium. All Immunostaining sections were analyzed with a uorescencemicroscope (Olympus Optical Co., Ltd., Japan). The average number of positive cellsfrom the sections of CA1 region of hippocampus (Bregma 1.6 to 2.8), locatedaccording to the atlas of Paxinos and Franklin (2001), was a calculated average ofthree sequential brain slices throughout the area of interest and measured both inthe left and right hemisphere. The counting of positive cells was performed by anindividual blind to the treatment conditions, using the same magnication andidentical color scale setting as a correction for background staining.

2.7. TUNEL staining

The mice were euthanized after behavioral tests. The brains were rapidlydissected, frozen and sectioned (30 mm) on a cryostat microtome, then the sectionswere processed for TUNEL staining (TUNEL uorescence FITC Kit, Nanjing KaijiBiotech. Co. Ltd., China). The sections (30 mm thickness) were observed undera uorescence microscope and the TUNEL-positive cells in the CA1 region ofhippocampus (Bregma 1.6 to 2.8) were counted.

2.8. Statistical analysis

Data were showed as mean S.E.M. The data were analyzed with computerprogram by one-way analysis of variance (ANOVA), followed by Dunnett's MultipleRange Test, with SPSS 10.0 software. Differences with p < 0.05 were consideredstatistically signicant.

3. Results

3.1. Preparation of AD model mice

In this study, we set up the AD mouse model induced byaggregated Ab according to previous reported, and examined themodel by immunouorescence staining and animal behavior tests.The results of immunostaining with anti-Ab showed that Abaggregation was deposited in the cerebral cortex and hippocampus(Fig. 2A). In the animal behavior tests, the Ab-treated mice showeda longer swimming time in water maze performance as compared

logy 58 (2010) 722e729 723with PBS-treated mice (Fig. 2B). These results indicated that AD

acoA.L. Fu et al. / Neuropharm724model mice had been successfully reproduced by intra-hippo-campal injection of aggregated Ab.

3.2. L-T4 improved learning and memory ability in AD model mice

To evaluate whether L-T4 could prevent the neurological defectsof the Ab-induced AD mice, the water maze task was used. Innavigation test, the escape latency of L-T4-treated AD mice wassignicantly less than that of the PBS-treated AD mice from theforth session (Fig. 3A), and there was no difference in swimmingspeed between the two groups (Fig. 3B), which indicated that thecognitive ability of mice was improved rather than motor functionafter L-T4 treatment. In probe test, the time spent in target quad-rant of L-T4-treated AD mice was markedly longer than that of ADmice [F(9,11) 14.45, p < 0.01] (Fig. 3C). These data indicated thatadministration of L-T4 signicantly restored learning and memoryfunction of mice with induced AD features.

3.3. L-T4 increased the ChAT activity and ACh levelof AD model mice

To identify the effects of L-T4 on cholinergic function, weanalyzed the activity of ChAT (ACh biosynthetic enzyme anda marker for cholinergic neurons) and the level of ACh. The resultswere shown in Fig. 4. Aggregated Ab impaired the cholinergicneurons, and L-T4 treatment signicantly increased the activity ofChAT [F(4,5) 18.09, p < 0.01] and the level of ACh [F(4,5) 10.99,p < 0.01] as compared with the Ab-treated mice.

Fig. 2. Preparation of AD model mice by using aggregated Ab. (A) Representativephotographs of Ab immunostaining in CA1 region of hippocampus of AD mouse brain7 d after the Ab injection. Bar, 100 mm. (B) Morris water maze test was used to examinethe impairment of learning and memory ability 7 d after Ab administration. The spatiallearning ability was evaluated by escape latencies in six consecutive sessions of the test(n 10 for each group). **p < 0.01 compared to control group.3.4. L-T4 inhibited the damage of free radicals

To assess the effects of L-T4 on free radicals, we examined theactivity of the important enzymes against oxidative stress, SOD,CAT, GSH-Px, and the level of GSH (the rst line of defense againstoxidative stress in the form of reactive oxygen species) in the cortexand hippocampus of AD model mice. The results showed that thelevel of GSH and the activity of SOD, CAT and GSH-Px was lower inthe ADmice as compared with the control, whereas L-T4 treatmentincreased the GSH level [F(5,4) 8.78, p < 0.05] and the activity ofSOD [F(5,4) 6.39; p < 0.05], CAT [F(5,4) 6.81, p < 0.05], GSH-Px[F(5,4) 5.31, p< 0.05] in the brains of Ab-treatedmice (Fig. 5). Theresults suggested that L-T4 could diminish the damage of freeradical in neurons induced by Ab through increasing the activity ofantioxidant enzymes.

3.5. L-T4 elevated ATP content in the cortex and hippocampusof AD model mice

Total ATP content in the cortex and hippocampus of AD modelmice was signicantly decreased as compared with that of thecontrol mice (Fig. 6), while this reduction was reversed after L-T4treatment [F(5,4) 13.7, p < 0.01]. This suggested that L-T4 couldimprove cerebral energy production in AD model mice caused byaggregated Ab.

3.6. The anti-apoptotic effects of L-T4

TUNEL staining was used for testing neuronal apoptosis in theCA1 region of the hippocampus, and NSE staining for determinationneuronal population. The results showed that there were signi-cant TUNEL-positive cells in the AD model group (Fig. 7), and NSE-positive cells were markedly lower than that of control group(Fig. 8). However, the number of apoptotic cells and NSE-positivecells were close to that of the control group after L-T4 treatment.The results indicated that L-T4 could effectively inhibit neuronapoptosis and protect neurons against the damage caused by Ab.

4. Discussion

The present study demonstrated that L-T4 treatment signi-cantly enhanced the ability of aggregated Ab-induced AD modelmice to learn in a spatial learning and memory task. The mecha-nisms of L-T4 treating AD might be associated with regulatingcholinergic function, protecting the neurons against the damagefrom free radicals, and preventing neuronal apoptosis in AD modelmice.

4.1. L-T4 improved the neurological behavior of an induced ADmouse model

The aggregated Ab-induced AD mouse model is a frequentlyused animal model for AD type amnesia and for identifyingpotential drugs which have an ability to treat AD (Maurice et al.,1996; Phinney et al., 2003). In this study, we used this animalmodel to explore the possibility that L-T4 might be applied fortherapy of AD. There is a close correlation between aggregated Aband the neurodegenerative process of AD. Ab is a 39e43 aminoacid peptide that is formed by proteolytic processing of a muchlarger transmembrane protein, the amyloid precursor protein, byb- and g-secretase (Marks and Berg, 2008). Extracellular Abpeptides are highly cytotoxic to neuronal cells by activatinga variety of cell signaling pathways. Incubation of Ab peptides inwater for several days produces a conformational transformation

logy 58 (2010) 722e729from random coil to b-sheet coinciding with an increase in peptide

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A.L. Fu et al. / Neuropharmneurotoxic potency. A single acute administration of aggregatedAb fragment in hippocampus or intracerebroventricle signicantlyinduces neuronal loss and amyloid deposits in brain and causesmarked amnesic effects in mice, evidenced as deciencies inlearning and memory (Yatin et al., 1999; Yamaguchi and Kawa-shima, 2001; Tsai et al., 2007). Ab-mediated neurotoxicity has beensuggested through various pathways (Hardy and Selkoe, 2002),such as free radical damage, oxidative stress and mitochondrialdysfunction of neurons, and ultimately, apoptotic cell death wasinduced.

In this study, Ab was incubated in 37 C for 3 days to formaggregated Ab, then the aggregated Ab was injected into thehippocampus of mouse brains. Another 7 d were allowed for the

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logy 58 (2010) 722e729 725injection to develop AD-like features according to previous reports.As indicated by immunouorescence staining with anti-Ab, whichidentied the locations of the Ab aggregation indeed formed in thehippocampus and cerebral cortex. Furthermore, behavior testsusing the Morris water maze task showed that mice receivingAb injection were impaired in their learning and memory abilities.However, after L-T4 administration, the neurological defects ofthe Ab-induced AD mice were prevented. The escape latency ofL-T4-treated AD mice was signicant shorter than that of AD micein navigation test. In probe test, the time spent in target quadrant ofL-T4-treated AD mice was markedly longer than that of AD mice.These data implied that L-T4 might be used to prevent AD from theimpairment of learning and memory function.

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the spatial learning disability of mice induced by Ab in navigation test (n 12 for PBS; #p < 0.05, ##p < 0.01 compared to Ab group. (B) The comparative of swimming speedS control; ##p < 0.01 compared to Ab group. (D) The representative swimming route of

4.2. L-T4 enhanced cholinergic function in AD model mice

The cholinergic system in the central nerve system (CNS) is alsoknown to participate in various cognitive and memory functions.Specic lesions of these cholinergic neurons have been shown tointerfere with the abilities of learning andmemory. It has beenwellknown that Ab can affect cholinergic neurons in vivo and in vitro(Kar et al., 2004; Watanabe et al., 2009). Several Ab fragments,including Ab (1e42), can inhibit ACh release from rat hippocampalslices. Moreover, intraventricular or hippocampal injection of Abinto the rat brain decreases ChAT activity and ACh release in the

maintenance of cholinergic function, especially in basal forebrainand hippocampus (Gould and Butcher, 1989; Rami et al., 1986;Smith et al., 2002). It has been well documented that the devel-opment of the cholinergic system has been markedly retarded andthe ability of cognitive has been prevented following perinatalthyroid deciency (Ahmed et al., 2008; Smith et al., 2002). In ourstudy, the ChAT activity and ACh level signicantly increased in thecortex and hippocampus of L-T4-treated AD model mice. Our datasupported the view that TH enhanced cholinergic function, andthat the augmentative effects on cognitive performance may bemediated through this increased cholinergic activity.

into the neuronal membrane bilayer and generates oxygen-dependent free radicals that then cause protein oxidation. Loss of

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A.L. Fu et al. / Neuropharmacology 58 (2010) 722e729726cortex and hippocampus and impairs memory (Fu et al., 2006;Maurice et al., 1996; Stephan et al., 2001; Tsai et al., 2007). In thepresent study, the cholinergic function, characterized by ChATactivity and ACh level, is impaired after injection Ab, which isconsistent with previous studies.

There exists a very close association between TH and cholinergicfunction. TH appears to support both the development and

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membrane integrity leads to cellular dysfunction. Neuronal death isthe consequence of these cellular dysfunctions (Yatin et al., 1999).

TH is also related with antioxidant defense systems. Hypo-thyroidism in both 1.5-month and 12-month old rat is accompaniedby the oxidative stress in the brain (Ali and Davydov, 2007), and

to have the ability of bilateral regulation and can keep a balance ofoxidanteantioxidant status.

4.4. L-T4 restored ATP content in AD model mice

Several lines of evidence have suggested that mitochondrialdysfunction impacts on the pathogenesis of AD (Mancuso et al.,2009). Neuronal Ab accumulation may be an important factor inmitochondrial dysfunction. Loss of mitochondrial function leads todepletion of ATP reserve, and then neuronal functions are impairedin AD model mice.

TH is considered a major regulator of mitochondrial activity. It'sreported that TH induces mitochondrial biogenesis and enhancesATP generation within cells (Sterling et al., 1977; Menzies et al.,2009). Consistent with these reports, the ATP content in the cortexand hippocampus was restored in the AD model mice after L-T4treatment.

4.5. L-T4 inhibited neuronal apoptosis in AD model mice

Apoptosis in vitro models and animal models of AD has beenlargely documented, and evidence for DNA fragmentation in tissuesections of brains from AD patients, using TUNEL, has been demon-strated by several groups (Shimohama, 2000). Stimuli for apoptosis in

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A.L. Fu et al. / Neuropharmacology 58 (2010) 722e729 727hyperthyroidism results in a marked increase in intracellular anti-oxidant enzymes i.e., catalase and GPx activities as compared to thecontrol (Komosinka-Vassev et al., 2000). In the present study, theADmodel mice administered 2.5 mg/kg TH can diminish the radicaldamage in neurons induced by Ab through increasing the level ofGSH and the activity of antioxidant enzymes SOD, CAT and GSH-Px.The possible mechanism of action of TH on antioxidant enzymes isthat THmight act on the transcriptional and translational processesof antioxidant enzymes biosynthesis (Oommen et al., 2006).However, some studies have reported that enhanced oxidativestress also existed in hyperthyroidism. Administration of L-T4 ofdose 100 mg/kg of body mass to rabbits for 21 days which induceshyperthyroidism causes damage of the oxidanteantioxidantsystem (Kowalczyk et al., 2003). These results imply that TH seemsFig. 7. L-T4 rescued the hippocampal neuron from apoptosis. (A) Representative photomicroQuantitative analyses of TUNEL-positive cells. The number of brains used for uorescence imcompared to PBS control; ##p < 0.01 compared to Ab group.AD include increased oxidative stress, dysregulation of ion homeo-stasis, growth factor deprivation, accumulation of Ab, metabolicimpairment, reduced clearance of toxin, mitochondrial dysfunctionand DNA damage (Calissano et al., 2009; Wei et al., 2008).

TH is an important factor for stimulating neuronal proliferationand survival (Darras et al., 2009). Rats with perinatal hypo-thy-roidism shows a signicant increase number of apoptotic neuronsin the hippocampus, which is closely related to the learning andmemory decits (Huang et al., 2008). In our study, the neuronapoptosis was prevented and the number of hippocampal neuronswas increased after L-T4 treatment.

Our data here suggest the feasibility of using L-T4 as a thera-peutic strategy for the treatment of AD. In human aging, TH isrequired for retaining optimal cognition, and dementia appears to

graphs of TUNEL staining. The arrow points to the TUNEL-positive cells. Bar, 100 mm. (B)

aging were n 6 for PBS group, n 9 for Ab group, n 6 for Ab L-T4 group. **p< 0.01

acoA.L. Fu et al. / Neuropharm728be one of the dominant characteristic in the elderly hypothyroidpatients (Loosen, 1992). Moreover, the incidence of hypo-thyroid-ism increases with age, and CNS-specic hypo-thyroidism has beenreported in some patients with AD (Sampaolo et al., 2005). L-T4treatment increases the free T4 in blood and brain (Kassem et al.,2006), and then improves the cognitive functions in animals.Therefore, administration low dose L-T4 would be a perspectiveway for AD treatment.

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Thyroid hormone prevents cognitive deficit in a mouse model of Alzheimer's diseaseIntroductionMaterials and methodsMaterialsAnimals and housing conditionsAD model mouse and L-T4 treatmentWater maze testBiochemistry assayImmunofluorescence stainingTUNEL stainingStatistical analysis

ResultsPreparation of AD model miceL-T4 improved learning and memory ability in AD model miceL-T4 increased the ChAT activity and ACh level of AD model miceL-T4 inhibited the damage of free radicalsL-T4 elevated ATP content in the cortex and hippocampus of AD model miceThe anti-apoptotic effects of L-T4

DiscussionL-T4 improved the neurological behavior of an induced AD mouse modelL-T4 enhanced cholinergic function in AD model miceL-T4 prevented the brain against the damage of free radicalsL-T4 restored ATP content in AD model miceL-T4 inhibited neuronal apoptosis in AD model mice

References