ACETYLCHOLINE, AGING, AND ALZHEIMERS-DISEASE

A substantial body of literature has suggested that the memory and lea rning deficits associated with Alzheimer's disease and aging are attri butable to degeneration of the cholinergic magnocellular neurons of th e nucleus basalis of Meynert (nbM). Subsequently, lesion-induced damag e to the cholinergic projections from the nbM to the neocortex has bee n utilized extensively as an animal model of dementia. In addition, th e effect of the normal aging process on deterioration of these neurons and on cognitive function has also been examined. Such studies have r evealed, for example, that many of the learning and memory impairments traditionally attributed to the cholinergic corticopetal system are n ot due to degeneration of the cholinergic neurons of the nbM, but inst ead may be due to damage of more rostral elements of the cholinergic b asal forebrain system. This review will examine the contribution of be havioural animal and human studies to our understanding of the role of the basal forebrain cholinergic neurons in age-related cognitive impa irments. (C) 1997 Elsevier Science Inc.