Intracranial Sites Regulating the Biphasic Action of Progesterone in Estrogen-Primed Golden Hamsters

摘要: Diencephalic and mesencephalic neural sites regulating the biphasic effect of progesterone (P) were investigated using hormone implantation technique in ovariectomized female golden hamsters primed with estrogen. Double barreled cannulae implanted unilaterally bilaterally medial preoptic area, anterior hypothalamus, ventromedial hypothalamus (VMH), central gray, or interpeduncular nucleus. Testing was conducted a sequential paradigm; facilitation tests commenced after 44 h estrogen priming. P-filled placed VMH region facilitated lordosis behavior 42% 60% females, respectively. In only P implants adjacent to area effectively promoted receptivity. Lordosis also observed 20-36% females area. gray nucleus regions had no significant facilitating on sexual behavior. Tests for inhibition occurred 24 testing consisted pretest, followed by systemic administration behavioral test 4-5 later. During pretest inhibition, that receptive attacked males more rapidly than previously nonreceptive animals showed decrements scores delivery. This completely inhibited receptivity among several group. Additional experiments, however, investigating suggested occurrence copulation may have been involved mediating subsequent increase aggressive suppression responsiveness test. Nevertheless, final experiment when sequentially VMH, and, importantly, later reduction even eliminated exerted inhibitory These findings demonstrate action hamster is regulated nerve cells located diencephalon, especially region.