The role of the anterior region of the medial basal hypothalamus in the control of ovulation and sexual behavior in sheep.

Cycling ewes with lesions placed in the anterior region of medial basal hypothalamus (MBH) showed no estrous behavior, but they all had ovulations and cyclical corpora lutea at physiological terms. Participation of the anterior region of MBH in control of sexual behavior was also supported by the experiments on castrated sheep implanted with 17-beta-estradiol into the area determined previously by lesions. Some of the lesioned ewes, which were observed throughout the subsequent anestrous period, showed continued cyclical ovulations with development of cyclical corpora lutea. This phenomenon seems to suggest that in the anterior region of MBH a center of inhibitory action over the liberation of gonadotrophin releasing factors exists.