9309451 Renner Serotonin, or 5-hydroxytryptamine (5HT) is a central neurotransmitter. This neurotransmitter has been implicated in the control of an extremely diverse group of physiological and behavior functions including aggression, sleep, renal regulation, pain perception, hormone secretion, thermoregulation, motor activity, food intake, cardiovascular function and reproduction. For example, serotonin is shown to influence female estrous behavior possibly through its interaction with the gonadal steroids. Indeed, Dr. Renner has demonstrated that sequential administration of estrogen and progesterone reduce serotonin turnover in several brain regions known to be important for the expression of reproductive behavior. He will now extend these findings by determining the physiological relevance of ovarian effects on serotonergic functioning. Dr. Renner will use a novel technique, in vivo microdialysis, to pinpoint the alterations in serotonin neurotransmission that may contribute to the regulation of reproductive behavior. Using this technique, he will examine the relationship between estrogen and progesterone, serotonin release, and reproductive behavior in several different brain regions in freely moving animals. This work will help define the functional linkage between sites within the neural network controlling reproductive behavior. Dr. Renner will also monitor the neurochemical and behavioral effects of various pharmacological interventions in animals primed with different regimes of ovarian hormones. These results are likely to help unlock some of the secrets underlying the integration of the neurochemical events by which gonadal steroid hormones induce a behavioral response. ***
