9320250 Wirsig-Wiechmann Coordination of sensory, motor and neuroendocrine systems is essential for survival of many species. Indeed two nasal chemosensory systems, the olfactory and vomeronasal systems, are known to play a significant role in reproductive activities of many vertebrates species. The nervus terminalis is another neural system in the nasal cavity. Unlike the olfactory and vomeronasal systems, however, little is known about the function of this cranial nerve. Dr. Wirsig-Wiechmann has shown that this neural complex which extends into the brain contains gonadotropin-releasing hormone, a hormone mediating many aspects of reproduction. Using a comparative approach combined with a variety of state-of-the-art anatomical techniques, she will determine the neuroanatomical organization of the nervus terminalis and the corresponding distribution of receptors for this hormone. To examine its function, Dr. Wirsig-Wiechmann will examine sensory and behavioral conditions that activate gene expression in nervus terminalis neurons. The results of these studies will better define the interrelationship between sensory, neurohormonal and behavioral systems. It may lead to a more thorough understanding of how the animals environment affects its reproductive capabilities that are important for survival. ***