MEMORY FOR EMOTIONAL EVENTS - DIFFERENTIAL-EFFECTS OF CENTRALLY VERSUS PERIPHERALLY ACTING BETA-BLOCKING-AGENTS

Substantial evidence from animal research indicates that enhanced memo ry associated with emotional experiences involves activation of the be ta-adrenergic system. This hypothesis is further supported by the find ing in human subjects that blockade of beta-adrenergic receptors with propranolol selectively reduced memory for emotional events. In the pr esent study, we compared the effects of propranolol, a lipid soluble d rug which crosses the blood-brain barrier easily, with those of nadolo l, a water soluble drug which crosses the blood-brain barrier to a con siderably lesser extent, to determine whether the effect involved peri pheral or central beta-adrenergic receptors. tors. The effects of thes e drugs, taken before subjects watched a slide show that was either em otionally arousing or relatively neutral in content, were tested 1 wee k later with a surprise memory test. Consistent with previous results, propranolol impaired memory (recall and recognition) in the subjects who saw the emotional version of the slide show. In contrast, nadolol did not impair memory of the emotional slide show. These results indic ate that the blockade of central beta-adrenergic receptors is responsi ble for the reduction in storage of emotional events. The results supp ort the view that memory of a mild emotional event involves activation of central, but not necessarily peripheral beta-adrenergic receptors.