**2.4 Novel targets of androgens and why they may be meaningful**

Individual differences in responses to androgens may be attributed in part to current and past exposure to androgens and/or their manipulation, and subsequent actions at ERβ and BDNF. To address this challenging question of individual differences in responses to androgens, a unique strain and species comparison approach has been utilized. Rat and mouse models with different androgen load, androgen replacement, and 5α-reductase inhibition have been utilized. Social/reproductive, cognitive, and affective behavior, androgen levels, and indices of growth (BDNF, prostate weight) has been measured to model age- and androgen manipulation-related changes in physical and psychological function. One-rate limiting step to elucidating better treatment options for androgen-related pathologies is to have animal models that mimic the human condition and can be used to systematically address question about persistent effects of androgens in the brain and peripheral targets. These studies address questions of clinical importance with substantial depth and breadth for human health, given the pervasive nature of androgens' lifelong effects throughout the body.
