[How the studies of the reproduction process contributed to the appearance of neuroendocrinology].

Geoffrey W. Harris, inspired by Francis H. Marshall, began the experimental studies in order to demonstrate a vascular connection between the hypothalamus and the adenohypophysis, with neuropeptides as messengers. This confirmed his theory that the mechanism consists in that the nerve fibers in the hypothalamus release hormonal substances in the capillaries of the primary plex in the medium eminence, and that these substances are carried by the vessels of the portal circulation to stimulate or inhibit the pars distalis cells of the hypophysis. This theory placed the hypothalamus as the fundamental structure to understand the link between the brain and the hypophysis. Later, it was known the structure of neurohormones, particularly the responsible for producing gonadotrophins. By this way, it was possible to go into the processes involved in reproduction. This was the origin of neuroendocrinology, gestated by investigations made in the reproduction of animals, including man. The purification, sequentiation and synthesis of the hormone that controls the FSH and LH production have allowed to study the physiology and disorders of the neuroendocrine circuit.