This is an application for a Research Scientist Award (RSA) to support Dr. Michela Gallagher's research activities. Her research program is organized around two main lines of investigation. The first entails studies of neural systems involved in learning, an area of research that has been supported by NIMH since 1978. The research plan presented in this application builds on recent studies indicating a role for the amygdala in the regulation of attentional processes during associative learning. The second area focuses on the effects of aging on hippocampal/cortical systems, research presently supported by a National Institute on Aging program project grant. This research uses diverse methodologies (from behavioral analysis to molecular biological studies) in an examination of aging processes in the mammalian forebrain. The applicant's laboratory provides the Core Facilities for this multi- institutional effort. The studies in Dr. Gallagher's individual project within this program examines neurochemical systems in hippocampal pathways. Within the framework of her current activities, Dr. Gallagher has established a number of collaborations with other scientists. This network currently supports a strong interdisciplinary program of research drawing on advanced techniques in both neuroscience and the study of behavior. These collaborations also provide a favorable setting for extending the range of Dr. Gallagher's scientific training and expertise. Specific areas for future development in her work will include 1) the use of molecular neurobiological methods suitable for the study of neural systems (in situ hybridization methods) to complement other approaches already in place in the research program; 2) the use of computational modeling to examine the effects of aging on overall performance of neural systems, and 3) the extension of new models for amygdala function from rodents to the study of non-human primates. Collaborations are identified to support these objectives.