Longitudinal assessment of deliberate mouse behavior in the home cage and attached environments: Relevance to anxiety and mood disorders

Understanding behavioral regulation can further progress by developing new approaches that allow refinement of behavioral phenotypes. The current availability of several thousand different mutant mice and of human candidate genes for emotional (affective) disorders challenges behavioral neuroscientists to extend their views and methodologies to dissect complex behaviors into behavioral phenotypes and subsequently to define gene-behavioral phenotype relationships. Here, we put forward multiday automated behavioral and physiological observations in carefully designed environments to assess evolutionary conserved behavioral strategies in mice. This offers the opportunity to design experimental setups that allow the animals themselves to regulate their own behavior, using representations of continuous kinematic variables, studying the dynamics of behavior (change across time or change across activity); i.e., growth or decay processes of behavior and concomitant physiological adjustments such as heart rate. The measures characterizing these processes should have discriminative power (across strains or treatments) and be replicable (across laboratories). Furthermore, cross species genetic studies for these neurobehavioral and physiological traits may provide a novel way toward identifying neurobiological mechanisms underlying core features of complex psychiatric disorders.