Proposal # 9423164 Susan E. Fahrbach, PI Gene E. Robinson, co-PI Behavioral development occurs in many species, including humans. As individuals age and pass through different stages of their life, their genetically determined behavioral responses to specific environmental stimuli change in predictable ways. Often these changes involve increasingly complex behavioral responses that involve learning. The goal of Drs. Fahrbach and Robinson is to understand how changes in brain structure relate to the development of behavior, particularly behavior that is characterized by a high degree of plasticity. Dr. Fahrbach and Dr. Robinson will test two hypotheses that explain the role of neuroanatomical plasticity and behavioral plasticity. The first hypothesis predicts that changes in brain structure occur in anticipation of changes in behavior, perhaps as a result of a specific neuroendocrine signal. According to this hypothesis, the neuroanatomical changes are necessary to support the transition to a more complex behavior. The second hypothesis predicts that changes in brain structure occur as a consequence of changes in behavior. According to this hypothesis, the neuroanatomical changes are necessary to support the continued performance of a more complex behavior. Drs. Fahrbach and Robinson will explore these hypotheses by studying brain structures insects after endocrine and experiential factors are experimentally manipulated. Studies of brain region volumes, synapse formation and molecular events leading to neural plasticity will be undertaken. The principal significance of this research will be to contribute to our understanding of the neuroanatomical basis for hormone-mediated behavioral plasticity in adult animals and humans.
