Role of amygdala norepinephrine in mediating stress hormone regulation of memory storage

There is extensive evidence indicating that the noradrenergic system of the amygdala, particularly the basolateral nucleus of the amygdala (BLA), is i nvolved in memory consolidation. This article reviews the central hypothesi s that stress hormones released during emotionally arousing experiences act ivate noradrenergic mechanisms in the BLA, resulting in enhanced memory for those events. Findings from experiments using rats have shown that the mem ory-modulatory effects of the adrenocortical stress hormones epinephrine an d glucocorticoids involve activation of beta-adrenoceptors in the BLA. In a ddition, both behavioral and microdialysis studies have shown that the nora drenergic system of the BLA also mediates the influences of other neuromodu latory systems such as opioid peptidergic and GABAergic systems on memory s torage. Other findings indicate that this stress hormone-induced activation of noradrenergic mechanisms in the BLA regulates memory storage in other b rain regions.