Primary monolayer culture of rat ependymal cells: an ultrastructural study.

Dissociated cerebella of newborn rats were cultured in vitro as a monolayer for a long period, and ependymal cell differentiation was investigated by scanning and transmission electron microscopy. Cells with actively beating cilia were recognized on the 3rd day, and gradually increased in number thereafter. At nine months of culturing, a number of areas appeared, some of which consisted of several hundreds of ciliated cells. Cultured ependymal cells showed a striking resemblance in their fine structure to the intact ependyma. They were always found to grow upon the feltwork of astrocytic processes which served as a subependymal structure, as observed in the intact ependyma. It is possible that astrocytes may play some role in ependymal differentiation. Cultured ependymal cells are helpful in understanding the control mechanism for the metachronal cilial movement.