Measuring Behavior 2005: Visser et al.

Multi-level analysis of mouse behaviour in a home cage environment using PhenoLab

L. de Visser, R. van den Bos and B.M. Spruijt

Deptartment of Animals, Science and Society, Utrecht University, Utrecht, The Netherlands

To contribute to the refinement of behavioral phenotyping methods for inbred and mutant mice, we developed a reliable tool for observing and analyzing behavior in a home cage-like environment (PhenoLab^®, Noldus Information Technology, Wageningen, The Netherlands). Testing animals in their home cage environment holds several advantages; it allows for continuous observations over consecutive days and the evaluation of both challenge-induced and baseline behaviors. Home cage testing also minimizes human intervention (such as handling) and reduces interactions with other environmental factors not related to the behavioral test (such as animal transport). By carefully designing the home cage environment, different behavioral domains can be studied simultaneously, for example, by providing the animals with different stimuli and tasks (light, sound, novel objects, cognition tasks).

Here, data will be presented of studies in inbred strains of mice (C57BL/6, DBA/2, C3H and 129S2/Sv) on locomotor activity and anxiety-related behavior in the PhenoLab system. First, strain differences in locomotor activity were dependent on the time of testing (novel vs. baseline conditions) due to differences in rate of adaptation to the environment. Second, Principal component analysis (PCA) revealed two major components within the domain of locomotor activity, which could be interpreted as ‘general activity’ (or: how active is the animal?) and ‘way of moving’ (or: when active, how is the animal moving through the cage?). Anxiety-related behavior was further studied by introducing an aversive light stimulus in the cage after an adaptation period of 4 days. The light stimulus illuminated the area around the feeding station, creating an approach-avoidance conflict for the animals.

The results of these experiments are discussed in the light of the possibilities and limitations of PhenoLab as a tool for the behavioral phenotyping of genetically modified mice.

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.