Hardy IBN-9815481 Social stress is a common and enduring feature of life with important behavioral and physiological effects. A multidisciplinary research collaboration between the Laboratory of Behavioral Neurobiology at the University of Hawaii and the Laboratory of Neuroendocrinology at the Rockefeller University is aimed at description and analysis of these effects. Previous work with laboratory rodents indicates that single, two-week stress periods can produce a variety of potentially damaging changes, including: increased defensive behavior and decreased social and sexual behavior; higher levels of stress hormones and impairment of brain mechanisms that normally limit stress hormone action; impairment of brain and peripheral mechanisms of male sex hormone production; and widespread changes in brain neurochemical systems. Work in an initial granting period has begun to outline the time course of these changes and to describe their permanence or reversibility; crucial factors in understanding the dynamics of the stress cascade. The proposed program will undertake a fine-grained analysis of the development of stress effects by using behavioral, brain system, and hormone measures taken at closely spaced intervals. This will enable comparison of the relative time course of these changes, enabling the creation of more precise hypotheses concerning the relationships among these phenomena. A second focus will involve the role of male sex hormones in the development of dominance-subordination relationships and in modulating the stress responses of subordinate males. The final focus of the proposed work is on analysis of the role of previous (early or recent) stressful experience in modulating or exacerbating the response to subordination. These studies, using an ecologically appropriate model, will provide detailed information in several areas that are crucial in understanding the mammalian stress response and its widespread behavioral and physiologica l consequences.
