RUI: Dissecting Neuroendocrine GnRH Pulsatility in the Rat Hypothalamus

University Of Wisconsin-Whitewater, Whitewater WI

Investigators

Abstract

This project investigates the role of cell-cell communication in coordinating the secretion of the main hormone that controls all aspects of reproductive function, Gonadotropin Releasing Hormone (GnRH). GnRH controls the production and release of the sex hormones (Testosterone in males, Estrogen and Progesterone in females) and the production of gametes (sperm in males, eggs in females) in all vertebrate species studied to date. The main hypothesis is that one or more molecules are involved in coordinating the brain cells that release GnRH. The investigation of molecules that likely control GnRH release using both cell and tissue culture of rat brains, and microscopy and electron microscopy to look at anatomical relationships between the GnRH neurons. The culture system places brain tissue into a chamber and pumps artificial cerebral spinal fluid past the tissue constantly for hours. The fluid is collected after it baths the tissue, divided up in 10 minute samples and measured using an extremely sensitive assay that measures the GnRH released in our culture system. GnRH release profiles are then plotted over time. Preliminary results that suggest the first metabolite of the 10 amino acid signal molecule GnRH (GnRH1-5 made up of the first 5 amino acids of GnRH) is capable of stimulating GnRH release in culture and in whole animals. Determination of the mechanism that controls release of GnRH represents a fundamental science question impacting population control (both contraception and fertility) for all vertebrate species. Even more fundamental is the question of cell-cell communication between the GnRH neurons involved in generating the signal needed for reproductive function. This work will directly involve 15 undergraduate researchers, and indirectly affect many others through involvement in other aspects of this project, participation in our REU summer research program, and peer mentorship by students directly impacted in this proposal