Neuroendocrinology of Reproduction

Gonadotropin-releasing hormone (GnRH)-secreting neurons represent the final common pathway for central neuroendocrine control of reproduction. Pulsatile GnRH secretion from the hypothalamus governs luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release from pituitary gonadotropes, which subsequently directs ovarian function. Higher-level afferent inputs (e.g. neurons releasing kisspeptin, neurokinin B, and dynorphin) substantially impact GnRH neuron function and largely mediate sex steroid negative feedback and the reproductive effects of altered nutrition, physiological stress, and lactation. These complex hypothalamic–pituitary–ovarian interactions achieve ovarian follicular development; episodic presentation of ova for possible fertilization (ovulation); and physiological preparation for possible pregnancy (e.g. endometrial decidualization).