Behavioral responsiveness of ovariectomized rats to ovarian hormones following hypothalamic lesions

Abstract

Bilateral electrolytic lesions were made in either the anterior hypothalamic area of ventromedial nucleus of the hypothalamus of ovariectomized rats. Sham-lesioned and unoperated rats served as controls. The subjects were tested for feminine sexual behavior after priming with varying dosages of estrogen alone and in combination with progesterone. Lesions in either site disrupted lordotic behavior during pre-progesterone tests, but sham-operated subjects also showed some degree of impairment. Soliciting was prominently displayed by control groups only during post-progesterone tests. Results from these tests showed that the lesions disrupted both lordotic and soliciting behavior. The results suggest an excitatory influence of medial hypothalamic nuclei in mediating feminine sexual behavior.