Sex differences in brain and behavior are a result of the perinatal hormonal environment. Exposure to testicular androgens during critical developmental periods can permanently alter the anatomy, biochemistry and physiology of the brain. A major question is how do the gonadal steroids regulate the differentiation of the brain at the cellular level. Dr. Tobet has identified two sex-specific monoclonal antibodies which are influenced by perinatal androgen treatment. He will use these monoclonal antibodies as markers to follow selective molecular changes in development which are hormonally dependent. Dr. Tobet will pay special attention to the time course of antigen expression since it is believed that temporal synchronization between brief increases in gonadal steroid signals and transient neural changes induce sexual differentiation of the brain. This work will provide a greater understanding of the early manifestations of steroid actions which lead to normal brain development. Moreover, the results could help unravel the abnormal events that underlie major birth defects involving the sexual differentiation process. Finally, the importance of these hormonal events is underscored by evidence of sex differences and androgen influences in the susceptibility to certain syndromes, learning disorders and neurological disorders.
