The interaction of social experience and hormone changes in generating social status

Georgia State University Research Foundation, Inc., Atlanta GA

Investigators

Abstract

Participating in social interactions causes great changes in an individual's behavior and physiology. Some of these changes are very persistent and affect the way an individual behaves or responds physically in subsequent social encounters. These effects are most dramatic in cases where an individual acts aggressively or is the target of aggression from a social rival. In many animal species, such interactions lead to persistent changes in status within a social hierarchy, such as being dominant or subordinate. This project examines the brain changes that result from such aggressive social interactions and the subsequent change into a dominant or subordinate individual. The project focuses on a set of neurochemical agents called "neurotrophins" that are produced and released by neurons and that are known to be important in neural development and modification of brain areas important for learning. The project tests the hypothesis that social interactions cause these neurotrophins to be increased in key brain areas responsible for processing sensory signals, memory formation, and the regulation of emotional and physiological state, and that this increase triggers persistent changes in key brain areas and the social, emotional, and physiological processes they control. Furthermore, it tests the hypothesis that individuals that win aggressive interactions and become social dominants and individuals that lose such interactions and become social dominants show similar neurotrophin changes in sensory and general memory areas, but very different changes in the limbic system brain regions responsible for aggression, reproduction, emotional processing, and hormone regulation leading to very different brain organizations in individuals that experience different outcomes of their social interaction. The results of this project will provide new information about the factors leading to individual differences in aggression and other responses to social challenges and to a better understanding of brain's regulation of social behavior. The project will offer unique opportunities for student training and will expect that these student present their findings at national meetings and as co-authors on peer-reviewed publications.