Monitoring Food Intake, Water Intake and Ingestive Behavior In Group-Housed Rodent

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?


Copyright 2016 R. Vestergaard, MBRose ApS and InsideScientific. All Rights Reserved.

René Vestergaard Sales & Marketing Manager,MBRose ApS

Introduction To The HM-2 System

HM-2 IDEA

• Group housed animals

• Client server solution

• Embedded computer

• Easy cleaning and maintenance

The HM-2 system

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.

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Copyright 2016 M. Kjølby, MBRose ApS and InsideScientific. All Rights Reserved.

Mads Kjolby, MD, PhD Assistant Professor,Aarhus University

Setting Up Experiments Using HM-2

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!


Surgery/RFID

Day -2


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?)


Day 4

Begin experimentSurgery/RFID

Day -2


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.


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


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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Accumulated food intake Total food intake Food intake difference

Body weight Ambulatory activity

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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.


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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.


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.

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A B C

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FI A

ccu

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g)

WT

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Feed

Wat

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# o

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WT

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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.


• 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).



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



• N=7

• Intake for full 12-h dark period relative to baseline values



• N=7

• Results shown with 15 min and 1 hr resolution

Analyzing reduction in food intake compared to expected food intake.



• N=7

• Results shown with 15 min and 1 hr resolution




• N=7

• Individual response to treatment


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

[email protected]

René Vestergaard

MBRose ApS

[email protected]

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Monitoring Food Intake, Water Intake and Ingestive Behavior In Group-Housed Rodent