Amygdalectomy Inhibits adrenocortical responses to somatosensory and olfactory stimulation

Adrenocortical responses, as measured by plasma corticosterone, to ether stress, photic, acoustic, sciatic and olfactory stimulation, were studied in amygdalectomized and in intact rats. While amygdalectomy had no effect on the adrenocortical responses following ether stress or photic and acoustic stimulation, the responses following sciatic and olfactory stimulation were markedly reduced. These results, taken together with our previous studies, suggest that the amygdala participates in the transmission of adrenocortical responses to olfactory stimulation and has also a modulatory facilitatory effect on the adrenocortical response to somatosensory stimulation. Amygdalectomy also reduced the effect of dexamethasone on basal plasma corticosterone secretion, indicating that the amygdala may participate in the feedback regulation of pituitary-adrenal function.