Automated home cage observations as a tool to measure the effects of wheel running on cage floor locomotion

De Visser L, Van den Bos R and Spruijt B.M.

The paper introduces PhenoLab as a tool to measure the effects of wheel running on the time distribution and daily organization of cage floor locomotor activity in mice.  
To study these effects, female C57BL/6 mice were assigned to either a running wheel group or a control group with no running wheel. Observations of home cage behavior and running wheel activity were continuously recorded during both the dark (i.e. active) period and light period for 6 consecutive days. The following parameters with regard to locomotor activity were computed with PhenoLab: sheltertime, cage floor movement, running wheel activity, total movement, distance moved, and velocity.
Results showed that access to a running wheel increases the total movement (i.e. time spent in running wheel and on cage floor) and decreases cage floor movement and sheltertime, but only during the dark period. Running wheel availability also affected the organization of locomotor activity, with a peak halfway the dark period.
The results were discussed in light of the use of running wheels as a tool to measure general activity and as an object for environmental enrichment. Furthermore, the possibilities of using automated home cage observations (i.e. PhenoTyper) for behavioural phenotyping are discussed.