Effect of amygaloid lesions on gonadal maturation in male and female ferrets

Two experiments were performed to determine whether the amygdala is involved in theregulation of gonadal maturation in the ferret. In an experiment with prepuberal males it was found that testicular and epididymal wieghts, seminiferous tubule diameters, Leydid cell number, and ratings of spermatogenic development were the samein animals autopsied 4 wk after either the placement of a platinum-elctrode lesion in the amygdala or a sham operation. Testosterone concentrations both in testis and in blood tended to be lower, and body growth was significantly retarded in males with amygdaloid lesions. In a second experiment with prepuberal females it was found that the first estrus occurred significantly earlier in ferrets that had received amygdaloidlesions than in sham-operated controls. Neither body growth nor fertility of femaleswas affected. These findings suggest that the amygdala exerts an inhibitory influence on the hypothalamic mechanism which controls the secretion of gonadotropins required for initial estrus in female ferrets, but not for the initail masturation of the testes in males.