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Monitoring Food Intake, Water Intake and Ingestive Behavior In Group-Housed Rodents
An informative webinar for researchers interested in the latest technology and best practices for studying food and water intake as well as feeding kinetics of group-housed rodents in their home cage.
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1. Introduction to the HM-2 monitoring system
2. Setting up experiments
• Overview of general procedures for setting up an experiment
• Food and water intake, and activity monitoring
• Alcohol preference test
• Leptin test or dosing experiments (compounds)
3. Advantages of the HM-2 system versus manual monitoring
What are we going to cover today?
Monitoring Food Intake, Water Intake and Ingestive Behavior In Group-Housed Rodents
Copyright 2016 R. Vestergaard, MBRose ApS and InsideScientific. All Rights Reserved.
René Vestergaard Sales & Marketing Manager,MBRose ApS
HM-2 IDEA
• Group housed animals
• Client server solution
• Embedded computer
• Easy cleaning and maintenance
The HM-2 StationConsists of:
• Base station
• Detectors for station status
• Standard cages can be fit
• PIR sensor for activity monitoring
• Two configurable channels with load cells and detectors – Setup Feed/water or water/water or feed/feed
The Channels
• Two channels give access to the feed and/or water
• Electronic identification by injected microchips
• Photocell detects animal, identification made, load cell instability create meal events
• Spillage automatically deducted
WS-1 Weigh Station
• Combines scale and electronic identification
• Registering the animals into the system
• Body weighing
• Dose calculation from body-weight
On Group housing
• Animal Welfare bodies admit group housing policies
• Refinement
• No adaptation to new conditions – The HM-2 system is the home
• High throughput
DIRECTIVE 2010/63/EU of 22 September 2010 on the protection of animals
used for scientific purposes – section 3.3. Housing and enrichment, (a) Housing.
Experiment planning
Animal registration
Running sessions
Animal body-weighing & dosingExtract results
Data coming from all runningHM-2 stations
New experiments
Client Server Solution
HM-2 SoftwareCockpit view
• Monitoring & control
• 3 sections will be highlighted
• Cage overview
• Live cage
• Accumulated data per animal
HM-2 Results
• Easy access to raw data
• 5 steps from raw data to graph.
• Come back at any time and generate a different report from the raw data.
Measuring behavior is our expertise
Your supplier of standardized platforms for feed,
liquid intake and activity monitoring offering instant
response systems that provides unprecedented
results and opportunities.
LEARN MORE AT WWW.MBROSE.DK.
Thank you to our webinar sponsor
Monitoring Food Intake, Water Intake and Ingestive Behavior In Group-Housed Rodents
Copyright 2016 M. Kjølby, MBRose ApS and InsideScientific. All Rights Reserved.
Mads Kjolby, MD, PhD Assistant Professor,Aarhus University
Surgery/RFID
Day -2
Habituation in cages
Day 0 Day 4
Begin experiment
RFID subQRFID/microchip surgery:
1) Place subQ close to head (enters channels first)
2) Close with glue or sutures.
3) In fat mice - longer healing time is needed!
Setting Up Experiments Using HM-2
Surgery/RFID
Day -2
Habituation in cages
Day 0 Day 4
Begin experiment
Habituation:
1) House 4-8 mice/cage (db/db max 4) – the higher # higher risk of tail bites
2) Choose the right size of feeding/drinking channel
3) Choose channel content (food, water?)
Setting Up Experiments Using HM-2
Day 4
Begin experimentSurgery/RFID
Day -2
Habituation in cages
Day 0
Experiments:
We are going to go through 3 experiment types today;
1) Food and water intake over longer periods of time: accumulated food intake, meal size and frequency, who eats first? Etc…
2) Dosing experiments – leptin test.
3) Two bottles and ad lib food: Alcohol preference test.
Setting Up Experiments Using HM-2
Food and water intake monitoring over longer periods of time.
• 2 genotypes of animals, same gender (no new groups if males). Day/night cycle 12/12 hrs (light 6 am to 6 pm).
• High fat diet (Sticks together and become rancid) – Only add food for 2-3 days, check daily for access.
• Software setup: 2 groups, may be within or between cages. Assign a mouse (RFID) to a cage, define group thereafter (genotype I or II), so you can (for example) have different groups/treatments in the same cage.
• E.g. You can house a litter of heterozygote breedings in ONE cage, but assign them to DIFFERENT groups.
The mice exhibit diurnal eating behaviour. They consume most of their food during dark phase (82% here), and less during light phase (18%). This rhythm is disturbed in db/db mice.
In dbdb you see more equal consumption of food in both light and dark phase.
Water intake follows food intake –more during dark phase. (3-4 g food and 3-4 g water).
Food and Water Intake Monitoring Over Longer Periods of Time
Food and Water Intake Monitoring Over Longer Periods of Time
The mice exhibit diurnal eating behaviour. They consume most of their food during dark phase (82% here), and less during light phase (18%). This rhythm is disturbed in db/db mice.
In dbdb you see more equal consumption of food in both light and dark phase.
Water intake follows food intake –more during dark phase. (3-4 g food and 3-4 g water).
0
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I (g
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Body weight Ambulatory activity
A B C
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Body fat% (MRI)
2 genotypes are monitored over 12 days. The total (accumulated) food intake is lower in genotype X compared
to WT. The FI difference can be observed over time. This could with some effort be done simply by weighing
the food/cage every 12 hrs. But here we can get resolution down in 1 min interval of food intake on individual
mice. This n=1 is 1 mouse, and not 1 cage, which is what is usually done if measuring /cage FI.
Food and Water Intake Monitoring Over Longer Periods of Time
0
10
20
30
40
To
tal F
I (g
)
WT
X
p=0,0183
*
Start Day 12 Day 1620
25
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We
igh
t (
g)
WT
X
WT X
0
5000
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15000
20000
25000
Min
ute
s
Active
Resting
100 200 300 400
-2
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Time (h)
FI D
iffe
rence (g)
Accumulated food intake Total food intake Food intake difference
Body weight Ambulatory activity
A B C
ED
0 100 200 3000
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Time (hours)
FI A
ccu
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Feed
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# o
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Mean FI intervalNumber of meals Meal size
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Fa
t%
WT
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Body fat% (MRI)It is also possible to get information on the meals/water: number of meals, meal size, meal
duration, and interval between meals. Genotype X eats less (previous slide) in total, but eats
more meals of a smaller size.
Food and Water Intake Monitoring Over Longer Periods of Time
Kinetics – first meal latency
1 mark is an average of 10 days observation just after dark phase begins of 1 mouse.
There is a hierarchy in the cage, and it is stable over time, and consistent between cages.
Kinetics
• You can observe hierarchy in the cage. Stable phenotype across cages, mice and time.
Can this be used?
• If treatment with compounds that alters satiety or causes nausea, you should observe changes in meal latency, size, time and frequency.
0
10
20
30
40
To
tal F
I (g
)
WT
X
p=0,0183
*
Start Day 12 Day 1620
25
30
We
igh
t (
g)
WT
X
WT X
0
5000
10000
15000
20000
25000
Min
ute
s
Active
Resting
100 200 300 400
-2
0
2
4
6
Time (h)
FI D
iffe
rence (g)
Accumulated food intake Total food intake Food intake difference
Body weight Ambulatory activity
A B C
ED
0 100 200 3000
10
20
30
40
Time (hours)
FI A
ccu
mu
late
d (
g)
WT
X
Feed
Wat
er0
200
400
600
# o
f e
ve
nts
WT
X
Feed
Wat
er0.00
0.05
0.10
0.15
0.20
Av
era
ge
me
al s
ize
(g
)
WT
X
Feed
0
20
40
60
80
Me
an
in
terv
al (s
)
WT
X
F
HG I
Mean FI intervalNumber of meals Meal size
Sta
rtEnd
0
5
10
15
20
25
Fa
t%
WT
X
Body fat% (MRI)
Body weight can be monitored by weighing the animals with the weight that comes with system. The data is
logged with the data including time stamp. Weighing is done manually. MRI scans are not possible when the
RFID chip is inserted. Ambulatory activity can be monitored in a binary fashion. You cannot get information on
how far the animals walk or similar. Only information on lying still/moving.
This information is per cage, not individual animals.
Food and Water Intake Monitoring Over Longer Periods of Time
• Summary - Comparing manual versus HM-2 based food intake
– Normal manual food intake monitoring will give you a cage based food intake pr e.g. 12 hrs (single or group housed), problems with food lost into the cage (powder). No kinetics, meal number, meal size, very low resolution, and you get an average of a cage.
– HM-2 yields high resolution of food intake, and kinetics, on individual mice in correct social context. More data, less stress on the mouse, less daily work with cages. MRI scans are not possible with RFID, and activity is cage based (not individual).
Food and Water Intake Monitoring Over Longer Periods of Time
Monitoring Food Intake, Water Intake and Ingestive Behavior In Group-Housed Rodents
Copyright 2016 N. Wellner, MBRose ApS and InsideScientific. All Rights Reserved.
Niels Wellner, PhD Post-doctoral Fellow,Aarhus University
Leptin (dosing) experiment Protocol
• WT and genotype X animals are tagged and housed in HM-2 system
• 2-3 days of food (and water) intake with stable circadianrhythm of intake (80/20, night/day) are collected.
• Injection of leptin i.p. after weight using dosing scheme in software (5ug/g). Inj. 30 min before dark phase.
• Reduction in food intake analyzed compared to expected food intake.
Leptin (dosing) experiment Considerations
• Acute experiment – possibility to do “running start”
• Randomization and interpretation: Consider hierarchy in cage
• Sham injections prior to experiment to create minimal stress
Collect 2-3 days of food and water intake with stable circadian rhythm of intake…80/20, night/day
• Leptin test for acute FI inhibition.
• 5µg/g IP leptin injected at onset of darkness.
• N=7
• Intake for full 12-h dark period relative to baseline values
Collect 2-3 days of food and water intake with stable circadian rhythm of intake…80/20, night/day
• Leptin test for acute FI inhibition.
• 5µg/g IP leptin injected at onset of darkness.
• N=7
• Intake for full 12-h dark period relative to baseline values
• Leptin test for acute FI inhibition.
• 5µg/g IP leptin injected at onset of darkness.
• N=7
• Results shown with 15 min and 1 hr resolution
Analyzing reduction in food intake compared to expected food intake.
• Leptin test for acute FI inhibition.
• 5µg/g IP leptin injected at onset of darkness.
• N=7
• Results shown with 15 min and 1 hr resolution
Analyzing reduction in food intake compared to expected food intake.
• Leptin test for acute FI inhibition.
• 5µg/g IP leptin injected at onset of darkness.
• N=7
• Individual response to treatment
Analyzing reduction in food intake compared to expected food intake.
Alcohol Preference Test (2 Bottle)Protocol
• Setup both channels in HM-2 system for bottles. Ad lib food in cage lid.
• Run 3+ days with water in bottles to ensure 50/50 usage of both drinking stations
• Switch bottle to ethanol (here, 10%) and water
• Bottle switch (right/left) every 3 days, and repeat 4 times.
Alcohol Preference Test (2 Bottle)Considerations
• Important that you make one acidified batch of water for the whole experiment
• Extensively clean every bottle station before the experiment
• Log and plan disturbances in the room – HM-2 system notes or logbook
No place or taste preference for either bottle3-4 days habituation. Data from 1 cage; n=4 mice
HM-2 Cage 1: 2-bottle test HM-2 Cage 3: 2-bottle test
Run 3+ days with two water bottles to ensure 50/50 usage of both bottles.
Preference for taste – infected bottle? Data from 1 cage; n=4 mice
Switch bottles to ethanol (10%) and water.
• Alcohol intake in two mouse genotypes
• Compiled from total experiment
• N=8
Water/Ethanol bottle switch every 3 days. Same mice; n=8. Different or similar alcohol preference?
Bottle switch (right/left) every 3 days, and repeat 4 times.
Summary
• 3 types of experiments reviewed
• Pitfalls in surgery and in experiments
• The strength of the system compared to manual measurements, in terms of accuracy, reproducibility, high resolution, and kinetics.
Thank You:If you have questions for the presenters please contact them by email.
For additional information on the solutions presented in this webinar please visit:
http://mbrose.dk/
Niels Wellner, PhD
Aarhus [email protected]
Mads Kjolby, MD, PhD
Aarhus University
René Vestergaard
MBRose ApS