The plan here is to develop an in vivo model to study the regulation of synthesis and secretion of hormones by the hypothalamus, the interacting region of the brain that regulates many of the growth and reproductive functions of the pituitary gland. The regulation of the hormone (LHRH) controlling the release of pituitary luteinizing hormone (regulates many aspects of gonad function and the reproductive cycle) is the particular focus of this research effort. The model will allow examination of the neural connections and transmission of neurally derived hormones throughout the circulation from the hypothalamus to the pituitary gland. The experiments involve electron microscopy with computer-assisted image enhancement and immunological staining techniques to identify the secretory neurons in the hypothalamus. Companion experiments will employ specific pharmacological agents and electrical stimulations to modify synthesis and secretion. A most critical set of experiments deal with the regulation of the hormones involved in the ovulatory surge in female rats. Another set of studies focuses on the LHRH secreting neurons in normal and castrated male and female rats to evaluate acute and chronic alterations in LHRH synthesis and secretion in androgen and estrogen deprived animals. The results of this research should lead to new understandings of how the brain controls reproductive functions. The techniques to be used are novel and will be useful to others studying any aspect of the neural control of pituitary gland function.
