The long-term objective of this research is to increase our understanding of processes underlying memory storage. The goal for the current three-year period is to determine the involvement of adrenal catecholamines and peripheral catecholamine receptors in memory storage processes. During the current year, we found that adrenal medullectomy abolishes the amnestic effects of amygdala stimulation. In searching for a pathway by which the amygdala might "communicate" with the periphery, we have found that knife cuts through the stria terminalis, a major amydgalda efferent pathway, also abolish the amnestic effects of amygdala stimulation. In other experiments we have found that the peripherally acting drug 4-OH amphetamine, which enhances retention of an inhibitory avoidance task, also has effects on brain catecholamines. Finally, we demonstrated that the drug improves retention of active avoidance learning. This year we plan to see if 4-OH amphetamine also modulates memory for non-aversively motivated tasks. In addition, research will be conducted to further study the effects of the drug on brain and peripheral catecholamines. We will also examine whether alterations in corticosteroids contribute to the effects of adrenal demedullation on memory. Finally, we will investigate the role of enkephalinergic efferents from the amygdala via the stria terminalis in mediating the amnestic effects of amygdala stimulation.