PhenoTyper: 3 days Spontaneous behavior (Sheltering)
LSID: http://syli.cz/urn:lsid:public.sylics.com:automatedtest:9EGB-7D43-2586Materials and Methods
Mice were singly housed on sawdust in standard Makrolon type II cages enriched with cardboard nesting material for at least one week prior to experiments, with water and food ad libitum (7:00/19:00 lights on/off; providing an abrupt phase transition).
Activity in the home cage was automatically recorded by video tracking in specially designed cages (PhenoTyper model 3000, Noldus Information Technology, www.noldus.com/phenotyper). Each cage contains a top unit with built-in hardware for video-tracking, that is, an infrared-sensitive video camera. The latter provide constant and even illumination of the cage. An infrared filter placed in front of the camera prevents interference with room illumination. This method allows continuous behavioural recordings in both dark and light periods. EthoVision was used as video tracking and trial control software. PhenoTyper cages were connected in a specially designed computer network. The cages (L =30 × W =30 × H =35 cm) were made of transparent Perspex walls with an opaque Perspex floor covered with bedding based on cellulose. A feeding station and a water bottle were attached on to two adjacent walls outside of the cage. A shelter (height: 10 cm, diameter: 9 cm; non-transparent material) was fixed in one of the corners. The X-Y coordinates of the centre of gravity of mice were acquired and smoothed using EthoVision software and processed to generate behavioural parameters using AHCODA analysis software (Synaptologics BV, Amsterdam, The Netherlands, http://www.sylics.com/bioinformatics/ahcodatm-data-analysis/).
Associated Mammalian Phenotype Ontologies (MGI)
- MP:0001392 abnormal locomotor behaviour
- MP:0014039 abnormal sheltering behaviour
Spontaneous behavior
With respect to spontaneous behaviors in the first three days in the PhenoTyper, 6 groups of behavioral parameters are defined as described below. The first two groups describe specific behavioral elements related to kinematics of mice (description of movement characteristics, group1) and sheltering behavior (group 2). These behavioral parameters were analyzed with respect to temporal aspects, in particular over 4 different time scales, i.e., habituation effects across multiple days (group 3), effects of DarkLight phase across 24h (group 4), differences in the pattern of behavior in the few hours before and after phase shifts (group5), and differences in activity bout properties on the sub-minute time scale (group 6).
Group 2: Sheltering behavior
Mice frequently visit the shelter for a few seconds (i.e., passing through) during bouts of activity. In contrast, long shelter visits during which mice appeared to be resting or sleeping, are in the range of hours. Although long shelter visits were infrequent, they appeared as a separate class of events when the frequency distribution of shelter visit durations of the three days in the cage was plotted. Long shelter visits were readily identified by Gaussian mixture model fitting of shelter visit data of individual mice. The 90th percentile of the first fitted Gaussian was used as upper threshold to consistently distinguish short shelter visits.
See for instance the "histogram of shelter visit durations" for C57BL/6J mice at the bottom of this page:
http://mousedata.sylics.com/?page=strainhtp&loaded=true&s=11&htpid=114&e=10&batch=1&t=&texp=&list=batches&tdose=
Parameter information
| Parameter name | Units | Explanation |
| Short shelter visit duration - dark | s | Cummulative duration of short shelter visits during the dark phase |
| Mean short shelter visit duration - dark | s | Mean duration per short shelter visit during the dark phase |
| Short shelter visit number - dark | frequency | Cummulative number of short shelter visits during the dark phase |
| *Long shelter visit duration - dark | s | Cummulative duration of long shelter visits during the dark phase |
| Long shelter visit number - dark | frequency | Cummulative number of long shelter visits during the dark phase |
| Mean long shelter visit duration | s | Mean duration per long shelter visit during the first 3 days |
| *Short shelter visit threshold | log2(s) | Cut-off value to separate short and intermediate shelter visits |
| *Long shelter visit fraction of total visits | fraction | The fraction of shelter visits with duration longer than long shelter visit threshold |
| *Long shelter visit threshold | log2(s) | Cut-off value to separate intermediate and long shelter visits |
| Short shelter visit duration - light | s | Cummulative duration of short shelter visits during the light phase |
| Mean short shelter visit duration - light | s | Mean duration per short shelter visit during the light phase |
| Short shelter visit number - light | frequency | Cummulative number of short shelter visits during the light phase |
| Long shelter visit duration - light | s | Cummulative duration of long shelter visits during the light phase |
| Long shelter visit number - light | frequency | Cummulative number of long shelter visits during the light phase |