Effect of dexamethasone on affective behavior and adrenal reactivity following septal lesions in the rat

Dexamethasone blockade of ACTH secretion from the pituitary gland did not alter the characteristic appearance or duration of the septal syndrome in male Wistar rats observed at 2, 9, and 16 days postoperatively. Despite the lack of a behavioral effect dexamethasone blocked the normal plasma corticosterone response to the stimulus of behavior rating in all groups studied. In the absence of dexamethasone, Ss with a septal lesion had a 65% greater corticosterone level 15 min. following the behavior rating than nonlesion Ss 2 days after surgery and an average increase of 35% over the 3 postoperative observation times of 2, 9, and 16 days. Results provide evidence that, in addition to the adrenal, the pituitary-adrenal axis is not essential for disturbance of affective behavior following septal ablation. (34 ref.)