FETAL EPENDYMA IN SHEEP AND GOAT - A SCANNING ELECTRON-MICROSCOPY STUDY

Morphology of the surface of apical membranes of ependymal cells has b een studied in the whole ventricular system of the brain in goat and s heep fetuses using a scanning electron microscope. The surface structu re of the ependymal lining surface in fetuses of small ruminants is ve ry similar to that in adult animals. Supraependymal cells were found o nly in the lower part of the third cerebral ventricle in goat fetuses, but not in sheep fetuses. In small ruminants the ependymal surface is already regionally differentiated within the end of the first half of prenatal development. Fetal ependyma of greats and sheep, unlike the adult ependyma, is characterized by a high secretory activity, which i s independent of sex or age of fetuses.