Development of the subcommissural organ in the albino mouse (a Golgi study).

The Subcommissural organ (SCO) of the albino mouse has been examined using the Golgi method and stained paraffin sections from embryonic age E 11 up to adulthood. The SCO cells can first be distinguished from adjacent structures at E 14, but are not fully differentiated until the age of 6 postnatal weeks. The first signs of cytological maturation occur during early postnatal life with a progressive invagination of the nuclear membrane and a transformation of the peripheral processes, which involute or are lost in adulthood. The hypendyma appears at the age of three weeks. A third type of cell is described which is interpreted as a transitional element between ependymal and hypendymal SCO cells. In general, the mouse SCO is characterized by an early appearance in prenatal life and a late acquisition of the final differentiated state.