Effects of gonadotropin-releasing hormones, corticotropin-releasing hormone, and vasopressin on female sexual behavior.

The effects of intracerebroventricular (icv) infusion of four neuropeptides on female sexual behavior were examined in the female musk shrew (Suncus murinus). In the first experiment, (icv) infusion of 100 ng of the mammalian form of gonadotropin-releasing hormone (mGnRH) facilitated rapid display of receptivity. Gonadotropin-releasing hormone-infused females had shorter latencies to rump present and tail wag, compared with controls. In a second experiment, icv administration of the other form of GnRH present in musk shrew brain, the chicken GnRH-II form, produced no changes in female behavior relative to the control condition. In Experiment 3, icv delivery of corticotropin-releasing hormone (CRH) facilitated female sexual behavior, relative to vasopressin and controls. The females treated with CRH had shorter latencies to display rump present, tail wag, and for the receipt of the first missed intromission compared with females in the other treatment groups. Vasopressin increased female scent marking relative to that of CRH-treated females. These data indicate that neurohormones of the hypothalamic-pituitary-gonadal and the hypothalamic-pituitary-adrenal axes can facilitate reproductive behavior in S. murinus.