Gonadotropin-releasing hormone (GnRH) targets the pituitary and regulates the release of luteinizing hormone and follicle stimulating hormone, which is essential for proper reproductive function. Preliminary studies indicate a subset of GnRH neurons provides direct contact with cerebrospinal fluid (CSF). Recent evidence in ewes strongly suggests GnRH secreted into CSF is required for facilitation of mating behavior and may be necessary for the synchronization of events around the time of ovulation. Therefore, in this project, the GnRH neurons providing input to CSF will be examined during the periovulatory period using neuroanatomical and immunocytochemical techniques to identify the source of GnRH release into CSF, and to determine whether mating increases the activation of these neurons. Since there is very close synchronization of secretion between GnRH secreted into CSF and pituitary portal circulation, it will be determined whether the same or different GnRH neurons contact both CSF and pituitary circulation. These experiments will provide fundamental knowledge necessary for future studies focusing on the mechanism(s) of action of GnRH secreted into CSF for normal reproduction. Increased understanding of the functions and mechanisms of action of this CSF route of GnRH secretion would have broad-ranging implications for such areas as endangered species breeding programs, livestock production, and treatment of infertility and sexual dysfunction in women. This work will have broader impacts in a number of areas including enhancing the infrastructure for research and training women and underrepresented minorities in the sciences. Lastly, the findings of this research will be disseminated through public outreach programs and interactions with staff at zoological gardens committed to endangered species conservation.