Neuronal influences on glial progenitor cell development.

The role of cell-cell interactions in the development of bipotential glial progenitor cells in cultures of rat cerebellum and optic nerve was studied. In the cerebellar cultures, progenitor cells divide slowly and most of their progeny develop into additional progenitor cells. Progenitor cells isolated from postconfluent cultures of cerebellum, however, develop rapidly into oligodendrocytes when grown in a serum-free medium. Factors secreted or shed into the medium by young cerebellar interneurons stimulate optic nerve progenitor cells to divide and promote the survival of progenitor cells. These factors appear to alter the function of the internal clock that regulates the timing of oligodendrocyte differentiation. These results suggest that the neuronal microenvironment can influence the lineage decisions of multipotential glial progenitor cells.