Distribution of estrogen-concentrating, neurophysin-containing magnocellular neurons in the rat hypothalamus as demonstrated by a technique combining steroid autoradiography and immunohistology in the same tissue.

The distribution of estrogen-concentrating cells in the rat brain has been previously described in detail as has the distribution of cells containing oxytocin, vasopressin, and their associated neurophysins. This report describes the simultaneous localization of [3H]estradiol by steroid autoradiography and neurophysin by immunohistology in cells in the rat hypothalamus. In the rat, neurophysin-containing cells were found in three major nuclei - the supraoptic nucleus, the paraventricular nucleus (PVN) and the anterior commissural nucleus - as well as in a number of accessory nuclei and as individual cells in the anterior hypothalamic area. Of these, only the PVN has appreciable numbers of cells which both concentrate estradiol and contain neurophysin. Within the PVN these cells are found predominantly in the posterior subnucleus.