The purpose of this study was to investigate the ontogeny of oxytocin- and vasopressin-specific neurons in the supraoptic and paraventricular nuclei of the human fetal hypothalamus. Eight human fetuses, 17- to 22-week gestation, were used in this study. Tissues of fetal hypothalami were fixed with 10% neutral buffered formalin, embedded in paraplast, and cut serially in coronal planes. Representative sections were stained with cresyl violet for the contour of both nuclei and monoclonal antibodies to oxytocin and vasopressin were used for immunohistochemistry. In the hypothalamus, oxytocin- and vasopressin-specific neurons were first observed in a 18-week fetus. In the fetus oxytocin-specific neurons were observed in both supraoptic and paraventricular nucleus and vasopressin-specific neurons were observed only in the supraoptic nucleus. Both neurons were observed in both nuclei of the fetuses and after 19-week of gestation. In both nuclei, oxytocin-specific neurons predominate in number in each stages. The shape of two cell types was mostly oval, and no significant differences of the size between two in each stages.
Antibodies, Monoclonal* ; Fetus* ; Formaldehyde ; Humans* ; Hypothalamus ; Immunohistochemistry ; Neurons* ; Oxytocin ; Paraventricular Hypothalamic Nucleus ; Pregnancy ; Supraoptic Nucleus ; Vasopressins ; Viola