It is the goal of the proposed symposium to integrate current findings regarding the anatomy and function of the basal forebrain and thus to increase our understanding of this complex region of the central nervous system. Recent years have witnessed and impressive growth in research concerned with neuronal systems of the basal forebrain. This growth finds its impetus in contemporary observations that basal forebrain nuclei are involved in higher order functions necessary for the animal to interact appropriately with its environment. These functions include reward, perception, learning and memory, and a variety of motoric behaviors. Thus in this symposium, considerable attention will be given to the functional attributes of the basal forebrain. Anatomical evaluations reveal a complex interplay of neuronal systems and neurotransmitters in this brain region. There is a wealth of literature describing the acetylcholine-containing efferent projections, however, relatively little is known about inputs to the basal forebrain. This symposium, therefore, also will stress afferent influences on known outputs of the basal forebrain, with focus being placed on neuronal integration. Ultimately, preclinical evaluations of the basal forebrain should shed light on the human condition, specifically those situations which are a manifestation of basal forebrain dysfunction. Thus, the symposium will close with a summary on neurological disorders which express dementia. Considerable attention will be given to those disorders which have not yet been the subject of other reviews, for example, Parkinsonian dementia. The program has been designed so that discussion which crosses several lines of diverse technical expertise will develop among the neuroscientists. It is hoped that this will foster an integrative interpretation of recent laboratory and clinical observations. Only with such multidisciplinary interactions can one attempt to elucidate the whole picture of basal forebrain function and dysfunction.