Failure of Ovarian Hormones to Cause Mating Reactions in Spayed Guinea Pigs with Hypothalamic Lesions. ∗

Abstract

Summary

Following appropriately placed lesions at the level of the posterior border of the optic chiasma, ovariectomized guinea pigs failed to respond to previously effective dosages of estrogen and progesterone. The results reported here indicate that the failure of these animals to show estrous behavior is not due to a lack of ovarian hormones. It is possible that the lack of response to the hormones is a result of the destruction of a portion of the central nervous system which is indispensable to the integration of a complex behavior pattern. If further control experiments prove this to be the case, then the possibility must be considered that the integrating mechanism involved is located in the midventral portion of the anterior hypothalamus instead of the region of the mammillary bodies or the mesencephalic tegmentum.