STRESS-INDUCED ACTIVATION OF PREFRONTAL CORTEX DOPAMINE TURNOVER - BLOCKADE BY LESIONS OF THE AMYGDALA

Stress consistently has been found to activate peripheral and central catecholamine systems. Dopamine (DA) turnover in the prefrontal cortex is especially sensitive to stress produced by relatively mild footsho ck, conditioned fear, or exposure to a novel cage. Because lesions of the central nucleus of the amygdala block the effects of both stress a nd fear in many experimental paradigms, the present study evaluated wh ether such lesions would block stress-induced increases in prefrontal dopamine turnover using either mild footshock or novelty as stressors. In Experiment 1 electrolytic lesions of the central nucleus of the am ygdala attenuated the increase in the dopamine metabolite homovanillic acid (HVA) in the prefrontal cortex evaluated in post-mortem tissue n ormally produced by footshock. In Experiment 2 similar lesions attenua ted the increase in dopamine turnover in the prefrontal cortex using a different stressor, novelty, and a different measure of dopamine turn over, DOPAC/DA ratios. These data provide further evidence for the cri tical role of the amygdala in stress.