Selective targeting of GnRH-II neurons to block ovulation

Background: In rhesus macaques, luteinizing hormone (LH) secretion appears to be regulated by two distinct gonadotropin-releasing hormone (GnRH) neuronal populations, which can be distinguished by their unique anatomical locations and because they express different molecular forms of GnRH (GnRH-I and GnRH-II). Study Design: The effect of estradiol on GnRH gene expression was examined. Results: Estradiol inhibited GnRH-I neurons but stimulated GnRH-II neurons, suggesting that GnRH-II neurons play the dominant role in mediating estradiol-positive feedback and triggering the midcycle preovulatory LH surge. Conclusions: Selective silencing of GnRH-II neurons in women could serve as a novel contraceptive, by blocking ovulation while leaving the rest of the reproductive axis relatively unperturbed.