Precocious ovarian stimulation following interruption of stria terminalis

¹ Department of Anatomy, Baylor University College of Medicine, Houston, Texas

To study the effects of interruption of stria terminalis on ovarian activity in immature rats, bilateral electrolytic lesions were placed in 69 female Holtzmann rats at 18–20 days of age; 41 nonoperated littermates served as controls. All animals were killed at 33 days of age and the endocrine organs and uteri were weighed. Brains were serially sectioned and examined histologically for lesion localization. Seventeen rats with bilateral interruption of stria terminalis had a mean uterine weight of 146.1 ± 13.60 mg compared with 85.3 ± 4.38 mg for the controls (P < .01). Although the vaginas of all control rats remained closed, five rats with bilateral transection of stria terminalis had open vaginas prior to autopsy. Similar stimulatory effects were not observed with bilateral lesions of thalamus, caudate-putamen, fimbria of the fornix or internal capsule. The results support the inclusion of the amygdaloid complex in neural mechanisms that inhibit gonadotrophin secretion in the immature female rat and suggest that the influence of the amygdala is mediated primarily through the stria terminalis.