CENTRAL AMYGDALOID-LESIONS ATTENUATE CARDIOVASCULAR-RESPONSES TO ACUTE STRESS IN RATS WITH BORDERLINE HYPERTENSION

The present study tested the hypothesis that lesions of the central nu cleus of the amygdala (CeA) would reduce the cardiovascular responses to acute stress in a rodent model that is genetically predisposed towa rd hypertension. Male borderline hypertensive rats (BHR) were given bi lateral electrolytic lesions directed to destroy the CeA or were subje cted to a sham procedure. Direct measurements of blood pressure and he art rate were recorded during rest during 10 min of acute stress, and for 10 min following stress. Analysis of the data revealed that BHR wi th CeA lesions had a significant attenuation of the stress-induced pre sser response compared to sham-operated subjects. Behavioral measures taken in an open field chamber before and after lesions revealed no di fferences in numbers of squares crossed or rearings. These results sug gest that the CeA is an important neural structure in mediating cardio vascular responses to acute stress in a model susceptible to environme ntally induced hypertension.