Opposite effects of angiotensin II and IV in the lateral nucleus of the amygdala

In this study the effects of angiotensin II and norleucine(1)-angiotensin I V have been studied in a horizontal in vitro slice preparation of female ra t brains. Extracellular field potentials of the lateral nucleus of the baso lateral amygdala were recorded. The results show that angiotensin II signif icantly increased the amplitude of field potentials induced by the electric al stimulation of the lateral nucleus, whereas norleucine(1)-angiotensin IV caused a significant decrease in the amplitude of field potentials. The an giotensin-induced effects could be blocked by specific angiotensin receptor antagonists. These opposite effects of angiotensin II and IV on electrophy siological parameters are in agreement with behavioral studies that have de monstrated that angiotensin It and IV produce opposite effects on the reten tion of an inhibitory shock-avoidance response and correlate with their dif ferent effects on the blood vessels. (C) 1998 Elsevier Science Inc.