Androgens in health and disease: an overview.

In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: Editorial Androgens in health and disease: An overview This special issue of Hormones and Behavior, " Androgens in health and disease: new insights into roles and mechanisms of action, " is prompted by a number of relatively recent findings that androgens affect brain morphology and function in ways not previously or widely appreciated. Moreover, recent results also make it clear that andro-gens utilize a variety of signaling molecules to exert their effects on the brain, which may or may not depend on the classic nuclear androgen receptor (AR). The papers in this issue underscore these two points. This overview is not intended as a comprehensive review of androgen action on the nervous system, since the papers in this issue serve that purpose, but rather to frame the basic issues and themes that tie these papers together. The sum effect of the stories told in this issue encourages us to broaden and refocus our view of androgen action on brain and behavior—to recognize that androgens affect many aspects of brain structure and function throughout the lifespan, from shaping its sexual phenotype to influencing its propensity for disease and repair, and that at least some of these actions are exerted via nonclassical modes of action that in many cases were first identified in non-neural tissue or cells. Setting the stage: lessons from the periphery Sexual differentiation depends on testicular androgens Perhaps the first lesson that studies in the periphery taught us is that the same factors driving sexual differentiation of the periphery in mammals also drive sexual differentiation of the brain and behavior. What are these factors? Androgens produced and secreted by the testes. While the story is admittedly a bit more complicated than this, several decades of research support this basic tenet that testicular androgens critically mediate sexual differentiation of both the periphery and the brain and thus, behavior. Among the earlier work that was influential in giving rise to this basic tenet was that of Alfred Jost followed by the work of Phoenix, Goy, Gerall and Young. In the 1940s and 50 s, Jost (1953, 1972) carried out elegant experiments to identify the factors involved in sexual differentiation of the …