HORMONAL AND NEUROTRANSMITTER REGULATION OF GNRH GENE-EXPRESSION AND RELATED REPRODUCTIVE BEHAVIORS

Gonadotropin-releasing hormone (GnRH), having a highly conserved struc ture across mammalian species, plays a pivotal role in the control of the neuroendocrine events and the inherent sexual behaviors essential for reproductive function. Recent advances in molecular genetic techno logy have contributed greatly to the investigation of several aspects of GnRH physiology, particularly steroid hormone and neurotransmitter regulation of GnRH gene expression. Behavioral studies have focused on the actions of GnRH in steroid-sensitive brain regions to understand better its role in the facilitation of mating behavior. To date, howev er, there are no published reports which directly correlate GnRH gene expression and reproductive behavior. The intent of this article is to review the current understanding of the way in which changes in GnRH gene expression, and modifications of GnRH neuronal activity, may ulti mately influence reproductive behavior.