Using Behavioral Patterns Across Species in Mood Disorder Research

Measuring motor activity has been one of the most commonly used tools to assess behavior in rodents. The macroscopic measure of behavior called motor activity is actually composed of assemblies of microscopic responses however. These microscopic responses can be measured simultaneously producing multivariate profiles that reveal differential and specific patterns of effects of pharmacological, genetic, or environmental manipulations. Thus, while stimulants increase the amount of motor activity irrespective of their varying neurotransmitter effects, they produce very different behavioral patterns of exploration. Given the utility of this approach for understanding the effects of manipulations in rodents, we have recently begun measuring behavioral patterns of exploration in humans using the same microscopic measures. Unlike rating scales, this technique has yielded information on quantitative differences of exploration in multiple psychiatric populations, including bipolar disorder, methamphetamine dependence, and schizophrenia. While the exploratory patterns of the three groups differ from controls, they also differ from each other, providing us with quantitative differences which we have used to produce more patient population-specific animal models. Thus utilizing quantitative measurement of exploration in humans may provide us with (1) more specific animal models for disease states, (2) valuable insight into neural abnormalities in patient populations, and (3) quantitative assessment on the effects of treatments.