OXYTOCIN AND RODENT SOCIOSEXUAL RESPONSES - FROM BEHAVIOR TO GENE-EXPRESSION

In most mammals, gonadal steroid hormones are required for the express ion of species-typical reproductive behavior. Over the past few years it has become evident that neuropeptides, such as oxytocin (OT) and va sopression (AVP), also play a key role in the regulation of both socia l and sexual behavior. Through studies of gonadal steroid/neuropeptide interactions, we have been able to discover species differences in be havioral and physiological responses to OT that may be associated with species-specific distributions of OT receptors or differential levels of OT gene expression in the central nervous system (CNS). However, t he characterization of OT's behavioral effects has been conducted prim arily in rats and the neural mechanisms underlying these behaviors are not clearly understood. The present paper will describe and discuss t he biological significance of OT-mediated behavioral responses in both female and male prairie voles and rats, speculate on the neural mecha nisms (OT receptor regulation) and reproductive physiology involved in species-specific sociosexual behavior, and present new methodologies for studying signal transduction mechanisms involved in OT gene expres sion in the CNS.