[Immuno-cytologic study of LH-RH cells and fibers in the human fetus].

The application of immunofluorescence and immunoenzymology techniques with an anti LH RH I.S. permitted to reveal neurons and fibers in the human fetal hypothalamus from the 13th week up to birth. The morphology and dispersion areas of the neurons in the mediobassal, premammillary and anterior hypothalamus (lamina terminalis and its surroundings and the septum) as well as the direction and the destination of the immuno-reactive fibers of the hypothalamo infundibular tract have been described. These fibers are in contact with the capillaries of the Mantelplexus before and after the apparition of the intra-eminential loops at the 16th week. The general topography of the LH RH peptidergic system in the human fetus can be compared with the topography of other adult primates. The role of this system in the maturation and the control of gonadotropic cells is evoked.