RESUMO
Gonadotropin-Releasing Hormone (GnRH) immunoreactive neurons in dissociated cell culture from newborn rat hypothalamus were investigated on days 1,3,5,and 7 in vitro by means of the im-munocytochemical method. The results showed that GnRH was expressed in the first day of culture. GnRH neurons accounted for 12.1-14. 8% of the total neurons in culture,and they were mainly bipolar in type. There were growth cones on the end of GnRH processes. Various patterns of intercellular contacts between GnRH neurons and between GnRH and other neurons were also observed. These findings indicate that the cultured GnRH neurons exhibit the morphological and functional characteristics of the GnRH neurons in vivo,and serve as morphological evidence for pulsatile secretion of GnRH and its regulation.