Neuropeptide modulation of social and exploratory behaviors in laboratory rodents

Neuropeptide influences on exploratory and social behaviors were investigated, using a video-monitored computer-assisted automated animal behavior analysis system. Cholecystokinin decreased exploratory tendencies in the dose range 0.1-5.0 microgram/kg IP and 0.5-5.0 microgram/IVT, indicating a peripheral mechanism in the CCK reduction of spontaneous behaviors. Neither arginine vasopressin nor alpha-melanocyte stimulating hormone changed parameters of exploratory and social behaviors, strengthening the possibility that their roles in increasing acquisition and retention of operant tasks are specific to neural mechanisms involved in memory and learning. Analysis of spontaneous exploratory and social behavior patterns appears to be a sensitive and effective tool for detecting changes in arousal and attention to environmental stimuli which may underlie more specific behavioral effects of brain neuropeptides.