The primary mechanism by which steroids exert their widespread effects is by altering the rate of synthesis of proteins within target cells. Testosterone, the major androgenic steroid, is secreted by the testes into the blood stream and readily enters cells by diffusion. Specific protein receptors are located in hormone responsive cells, such as hypothalamic neurons in the brain. Once the testosterone enters a target neuron, the receptors bind the hormone. The steroid receptor complexes then act on its genes to alter the expression of proteins. Dr. McGinnis will identify the proteins that are increased or decreased by testosterone within specific brain regions. In addition, she will determine how the altered neuronal properties produce behavioral and physiological changes. The results of these studies will be useful in devising molecular approaches to understanding androgen.regulated functions. Moreover, the findings may have clinical ramifications since they may prove useful in providing insight into the treatments of hormone dependent tumors, neurologic diseases influenced by androgens as well as male sterility.
