Lesions of central amygdala abolish angiotensin II improvement of recall in passive avoidance situation.

Abstract

Our earlier experiments have shown that facilitating action of angiotensin II (AII) on recall of passive avoidance is mediated by dopaminergic systems. In an attempt to evaluate the possible site of action of AII on memory processes, bilateral lesions of the structures belonging to the limbic system, receiving efferentation from A 10 dopaminergic neurons were made before behavioral testing of the influence of intracerebroventricular (icv) AII injection on recall in a passive avoidance situation. Bilateral lesions of the nucleus centralis corporis amygdaloidei totally abolished the facilitating effect of AII on recall, while the lesions of the nucleus septi lateralis were ineffective. These results may suggest that improvement of recall in passive avoidance situation after icv injection of AII is mediated by A 10 dopaminergic neurons projecting to the central amygdala.