HYPOTHALAMIC OVARIAN-STEROID HORMONE-SENSITIVE NEURONS INVOLVED IN FEMALE SEXUAL-BEHAVIOR

Estradiol and progesterone regulate. sexual behaviors in guinea pigs a nd rats, at least in part, through interaction with intracellular ster oid hormone receptors. In the present review of work from the laborato ry of the authors, we summarize recent work which has focused on one o f the sites of hormone action in female guinea pigs-the ventrolateral hypothalamus, We summarize results of earlier experiments in which the regulation of steroid hormone receptors in this area was assessed aft er hormonal treatments with predictable effects on female sexual behav ior. We then review the results of recent tract-tracing experiments in which we have examined the projections from the steroid receptor-immu noreactive neurons in this region, as well as the afferent projections from other neuroanatomical areas, including neurons which themselves contain estrogen receptors. We also present studies on the afferent in put into these neurons by noradrenergic neurons and discuss the possib ility that noradrenergic input influences steroid hormone sensitivity in these neurons. Finally, we discuss the results of experiments in wh ich Fos-immunocytochemistry was used in rats to identify the neurons r esponding to a particular tactile stimulus associated with female repr oduction, i.e., vaginal-cervical stimulation. These experiments furthe r define a complex neuroanatomical system, in which many of the elemen ts are estradiol or progesterone-responsive, that is involved in the h ormonal regulation of sexual behavior in guinea pigs and rats.