Effect of Midbrain Lesions on Ovulation and Adrenal Response to Stress in Female Rats.

Abstract

Four days after lesion placement in the posterior portion of the midbrain and the level of the rostral pons of female rats, increased corticosterone levels as high as 3 times (92 [mu]g) normal levels (33 [mu]g) were recovered from total 30 min. adrenal venous effluents following surgical stress. Lesions in the posterior diencephalon and the rostral midbrain resulted in 50% reduced corticosterone levels (19 [mu]g). Decrease in adrenal ascorbic acid or its inhibition following same stress was not correlated with corticosterone response. The lesioned midbrain area (mammillary peduncle) blocking ovulation could not be consistently correlated with either increased or decreased corticosterone release levels or with adrenal ascorbic acid responses.