IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
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Recording Techniques for Behavior and Activity
Howard M. Cooper
Laboratory Brain and Vision, Department of Chronobiolog, INSERM U371,
Lyon France
General introduction – why study behavior?
Envionmental and pathological factors affect a wide range of behavioral and physiological
processes in animals. Exogenous (light, temperature, drugs) endogenous (hormones) factors
have powerful influences on behavior and can either facilitate or repress behavioral processes.
Many of these effects are expressed over different time courses, with durations ranging from
minutes to days or much longer periods. These effects can be monitored in awake freely moving
animals using a variety of techniques to measure locomotor activity, body temperature,
behavioral strategies, feeding and drinking behaviors, EEG, electrocardiogram, etc.
The purpose of this workshop is to provide an overview of the different techniques that
can be used to study animal behavior. In recent years, advances in electronics, computer
science, and detector technologies have led to miniaturisation of components and rendered many
of these techniques accessible and relatively simple to use. Behavioral monitoring can be used to
autonomously gather a large quantity of data from many different animals simultaneously. This
data can reveal acute or long term changes in behavior over space and time resulting from
changes in environment, physiological state, hormones, drug administratiion, learning processes.
A wide variety of questions can be addressed by analysing different aspects of behavior:
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What types and aspects of behavior are altered in a given experimental situtation?
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Are the temporal patterns of behavioral expression altered?
Are behavioral effects dose or time dependent?
Does the observed behavioral effect depend on the environmental context?
Which aspects of behavior are altered ?
Are there inter-individual differences in the responses (related to age, sex or
reproductive state)?
In this workshop we will describe four different methods that can be used to study behavior:
1) Techniques for recording and analysis of daily patterns of locomotor activity
2) Video camera recording of motor activity
3) Data Logging Techniques
4) Telemetry recording techniques
1) Techniques for recording daily patterns of locomotor activity
Material used for demonstration: Circadian Activity Monitoring System (CAMS,
INSERM). ClockLab circadian analysis program (Actimetrics)
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
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A number of systems are available which record locomotor displacement over time. A
typical system for recording daily patterns of activity consists of the following: (see Figure 1
below)
1. Captors for detecting the animal's movements, feeding drink or other behaviors
2. An interface for linking the captor to the computer and communicating data
3. Computer/data acquisition program to acquire and store the data
4. Optionally, output controls of light, temperature or other devices.
SCHEMATIC DIAGRAM OF SYSTEM COMPONENTS
running
wheel
Infrared
captor
interface
transponder
switches,
lick meter
system computer data analysis program
Output controls: light,
temperature, doors
light, temperature
detectors
CAPTORS
Figure 1
All the recording systems use a central computer to gather data from many different types
of captors located in the animal's cages. Some systems are capable of monitoring activity in over
400 animals simultaneously and have been used in large-scale drug testing or screening of
mutant animals. These systems allow very long term monitoring of behavioral changes over
weeks and months. Data is typically averaged over 1 to 5 minute intervals to provide the general
temporal pattern of activity and it's evolution over time. This allows for mass data acquisition with
a trade-off for loss of fine detail of behaviors (absence of measure of rapid modifications, lack of
detailed parameters in time and space). For example, these systems are a major tool for the
study of variations in circadian locomotor activity in relation to the circadian clock located in the
suprachiasmatic nucleus. The type of activity recorded depends on the characteristics of the
captor employed.
Captor Devices – Several types of captors are commonly used to detect activity. The most
commonly used device for detecting locomotor activity is the running wheel, which is equipped
with a simple mechanical or magnetic switch. In rats, mice, hamsters and other rodents, wheel
running activity is a robust measure of circadian clock output, and nocturnal rodents show clear
activity periods with distinct onsets and offsets (See example in figure 2) However, the running
wheel is not adapted to large animals, or to jumping or arboreal animals such as primates and
thus other devices are needed.
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
INFRARED CAPTOR
WHEEL
L
D
L
D
LD
entrained
D
3
Days
Days
LD
DD
free run
S
Y
A
D
DD
0
Hours
48
48
0
Hours
48
Figure 2. Typical examples of daily recordings of locomotor activity in rodents. Each
horizontal line represents a successive day of recording. Vertical bars on each line represent
periods when the animal is active. The panel on the left shows wheel running activity in a
mouse. During exposure to a light/dark (LD) cycle, nocturnal activity is entrained to the dark
phase. In constant darkness (DD) the mouse. expresses it's endogenous circadian rhythm
and "free runs" with a period shorter than 24 hours. The panel on the right shows the same
type of recordings using an IR-captor in the rat. Here, the free running perios is longer than 24
hours. Data using the IR captor is more noisy, since all the animal's movements are detetcted.
Overall locomotor activity in a cage can be detected using infrared (IR) captors. These
are of two types: Passive IR captors detect the body heat (IR radiation) emitted by the animal,
which is focused by a lens onto the detector surface. When the distribution of the IR values
change due to displacement of the animal, the detector sends out a signal to the computer (see a
typical recording in figure 2). Active infrared captors use an IR light beam which, when
interrupted, sends out a signal. These are often used near a feeding or drinking well, or in the
passage of a tunnel.
Switches, lick meters, feeding meters. Any type of device, which provides a switch closure or
TTL logic signal, can be used to detect activity. Some of these captors include lick meters,
feeding meters, switches on doors, or other devices to detect specific behaviors.
Transponders. Transponders are electronic battery-less devices that are implanted into an
animal. The tags are energized by an electromagnetic field and send back information to a
receiver on locomotor activity and/or temperature. Some specialized transponders can also be
used to record heart rate. Transponders only work within close proximity to the receiver (10 cm)
and thus are only suited to small animals such as rodents. However, they have many advantages
in that the tags have an indefinite life span and can identify single individuals within a group by a
specific code. A device called the INTELLLICAGE (New Behavior) takes advantage of this feature
to track different activities of locomotion, temperature, feeding and drinking activities of individual
mice in a group situation.
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
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Programs for the analysis of circadian activity patterns
Using the above data collection systems, large quantities of information can be acquired,
which must then be analyzed. A program such as ClockLab (Actimetrics) has been specifically
designed to analyse these activity patterns.
A) Onset/offset of activity, duration
B) Phase shift of activity onset
C) Cumulatative mean activity profile
D) Periodogram
Figure 3. Several parameters can be derived from the recorded activtity patterns as
illustrated above. (A) Times of onsets and offsets of activity can be calculated and the
average duration determined. (B) Illustrates the shift in activity onset following a light
pulse. (C) The mean activity profile can be used to determine levels of activity during
different phases over the 24 hr cycle. (D) Several methids can be used to derive cyclic
activity patterns (periodogram analysis).
A number of parameters can be derived from the data which are significant to describe
long-term changes in behavior over time or short-term changes in response to a specific
treatment. Activity is commonly represented in an "actogram" in which successive days are
plotted against a time scale of 24 or 48 hrs (see figure 2, 3A-B). Commonly defined parameters,
which can be defined or calculated, are as follows:
Activity Onset – time of day at which the level of is greater than defined criteria in terms of
duration and amount (example figure 3A, red line).
Activity Offset – time of day at which activity is less than a defined criteria in terms of
duration and amount (example figure 3A, blue line).
Total Duration of Activity – Length of time activity between activity onset and activity offset
(figure 3A, distance between red and blue lines).
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
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Total Amount of Activity – Total counts of activity over the 24 day or within a given period of
the day. For example the number of wheel revolutions can be used to calculate the total
distance run per 24 hrs (energy expenditure). This can be calculated form the activity
profile, figure 3C)
Ratio of Day-time / Night-time Activity – Ratio of activity counts during the day to counts
during the night, for example to determine the degree of diurnality and nocturnality (can
be calculated from the mean activity profile, figure 3C).
Phase Shift – a change in the onset or offset of activity (change in Phase) in response to a
specific stimulus, hormone or drug administration. Figure 3B shows a phase delay in
activity onset after a light pulse (shift to the right of the blue line).
Mean Activity Profile – Average amount of activity over one or several days plotted against
a 24 hr time scale (figure 3C).
Periodiogram – Calculation of periodic components of the activity pattern over time (figure
3D). Uses chi-square or fast Fourier transform functions to derive ultradian or circadian
periodicities.
Advantages:
Can track large numbers of animals for long-term periods. Robust simple
systems. Good for studying changes in daily circadian activity patterns
and overall locomotor activity (energy expenditure). Moderate costs.
Disadvantages.
Data obtained only for locomotor behavior (no physiological data)
although some systems also record temperature.
Companies
MiniMitter, Stanford Chronokit, Actimetrics, New Behavior, Circadian
Activity monitoring system (CAMS)
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2) Video recording of motor activity
Material used for demonstration: ANYMAZE: video tracking system generously donated
by Any-Maze to IBRO Neuroscience school for demonstration purposes.
Many video tracking systems using simple digital or video cameras have been developed
in recent years. These systems are very useful for analyzing detailed and rapid changes in
locomotor activity patterns. They are also used in behavioral tests of maze learning, avoidance
behavior, stress and exploratory behaviors. The system uses a camera, a video capture card and
a computer program to analyse and store the data. Most systems can also analyse behavior
recorded by a VCR or digital recorder made offline. All are based on the principle of image
analysis to detect the contrasting outline of the animal against the background of the cage. The
video tracking system continually monitors the X-Y coordinates of the animal within the cage area
and "tracks" all motor displacements with high accuracy and speed (see example in figure 4). In
contrast to other detectors (wheel, IR captor, transponder) the video tracking system can be used
to calculate many different detailed parameters of the behavior such as distance and speed
travelled, number of turns, time spent in predefined areas, number of crossings from one area to
another, locomotor and behavioral strategies. Some systems use one camera to track a single
animal. Other systems can use a single or multiple cameras camera to track up to 16 individuals
simultaneously. These video-tracking systems can be used to track flies, fish, rodents and
primates. Some very complex systems can analyse the animal's outline to detect posture,
standing, grooming, feeding drinking, and other behaviors.
WinTrack is a sophisticated analysis program that is available for free and can be offline
used to analyze X-Y activity recordings obtained with several different capture systems.
Figure 4. Example of a video tracking image
obtained with a computerized video capture
system. In this case the trajectories of several
mice are followed simultaneously. The track of
each mouse is shown in a different color.
Many different parameters can be analyzed
from the recorded data (speed, doistance
travelled, time immobile, number of turns, time
in different zones etc. )
Advantages:
High temporal and spatial resolution, tracks 1–16 animals, definition of
specific areas of interest (feeding, drinking areas). Recording of multiple
parameters of locomotor displacement, learning situations. ,
Disadvantages.
Moderate to expensive, data only on locomotor behavior (no
physiological data), only follows one animal per cage.
Companies
Viewpoint, Noldus, Smart, Actimetrics, Anymaze, VideoMot, WinTrack
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
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3) Data Logging Techniques
Material used for demonstration: ActiTrac (IM Systems) wrist worn activity logger,
Onset light/temperature data logger (Onset Computer Comp.).
iButton (Maxim) implantable temperature logger.
Data loggers are a recent addition to autonomous recording techniques. Loggers are
remote self-contained storage devices, which are equipped with different types of sensors. A
simple type of logger is the ibutton (figure 5, Maxim), a small device that records temperature for
up to one month. This device can be easily implanted in an animal or worn externally. The start
time and sample interval can be predefined, for example: start recording in 10 days at intervals of
5 minutes. Accuracy varies from 0.5° to 0.03°C. This device is very inexpensive (less than $10),
robust and lasts for up to 10 years. More complicated loggers used internally in animals can
record several parameters (temperature, depth, position, light). Other loggers are commonly used
in medical applications for remote data acquisition to record EEG, ECG, temperature, activity etc.
Devices like the ActiWatch (Figure 6, Minimitter) and ActiTrac (IM Systems) are simple
wrist worn loggers which can monitor activity, position, temperature and light received by the
subject (Figure 7).
1 cm
Data loggers are also very useful for field studies or monitoring of laboratory conditions to
record environmental parameters such as temperature, humidity, light and rainfall. A simple
inexpensive device is made by Onset, although more complex systems are available. These can
often be fitted with other types of captors.
Figure 5. The ibutton, a small
battery powered temperature logger
that can be implanted in animals.
Figure 6. The ActiWatch is a wrist worn data
logger used to record light and sleep/wake activity
patterns in human subjects and patients.
Figure 7. Data recorded from a human subject over several days with the ActiTrac.
This type of logger can show period of insomnia during the night and napping periods
during the day.
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
Advantages:
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Remote data acquisition, high accuracy for temperature, recording of
environmental parameters, inexpensive, simple to use. Simple system to
use in human subjects.
Disadvantages.
In animals, mainly for temperature, data only available when implant is
removed from the animal.
Companies
Maxim, Onset Computer, Mini-Mitter, IM Systems
4) Telemetry Recording Techniques
Telemetry recording techniques include some of the most sophisticated methods for
monitoring animal behavior and for providing information on physiological parameters
inaccessible with other techniques. For laboratory studies radio telemetry can continuously
monitor several physiological parameters such as body temperature, EEG, ECG, EMG and blood
pressure. Some systems can record neuronal activity in the brain using implanted electrodes or
arrays of electrodes. A simple transmitter can weigh less than 1-2 grams and extreme
miniaturisation has building of transmitters small enough to record electromyograms in flying
moths. Improved telemetry and sensor technologies are a rapidly expanding field in biology, in
medical applications and in remote patient surveillance.
Advantages:
Remote on-line data acquisition, high speed and resolution, multiple
physiological parameters acquired simultaneously
Disadvantages.
Expensive, requires surgery, recording depends on battery life. Requires
technological expertise.
Companies
Mini-Mitter, DataSciences, D.I.S.S.
Future Developments of Behavioral Recording Techniques:
Laboratories and companies are currently interested in the following aspects for future
developments of data acquisition systems: n
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Mass screening of phenotype in animals
Miniaturisation of equipment, low power consumption, implantable systems
Portability, remote monitoring, transmission of data by radio or infrared
Communication between different data acquisition systems
Development of new sensors
Application to clinical situations for patient monitoring
IBRO_Nairobi_2005: Lecture and Workshop on Behavioral recording Techniques – HM Cooper
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SUMMARY TABLE: Behavioral and physiological parameters measured
Method
Locomotor
Temperature
EEG
Heart Rate Biopotentials
activity
Wheel
♦
IR captor
♦
Video Analysis
♦
Transponder
♦
♦
Data logger
♦
♦
Telemetry
♦
♦
♦
♦
♦
♦
INDEX TO WEBSITES OF MANUFACTURING COMPANIES, DISTRIBUTORS:
Circadian Activity Recording / Analysis Programs
Minimitter :
www.minimitter.com
Stanford Systems Chronokit
http://www.query.com/chronokit/
Actimetrics :
www.actimetrics.com
New Behavior
www.newbehavior.com
Circadian Activity Monitoring System (CAMS) : www.lyon.inserm.fr/371/index.html
Video Tracking Systems
Anymaze :
www.anymaze.com
ViewPoint :
www.viewpoint.fr
Noldus :
www.noldus.com
SMART :
www.sd-inst.com/prod_smart.htm
TSE – VideoMOT2
www.tse-systems.com/bh1a.htm
WinTrack :
www.dpwolfer.ch/wintrack/
Transponders
Minimitter
www/minimitter.com
New Behavior
www.newbehavior.com
Data loggers
Maxim – ibutton :
www.ibutton.com
Onset Computer :
www.onsetcomp.com
IM systems
www.imsystems.net
Telemetry Equipment
Minimitter :
www. Minimitter.com
DataSciences :
www.datasci.com/
Data Integrated Systems, DISS :
www.dissdata.com
Biotelemetry Manufacturers Directory : www.biotelem.org/manufact.htm