Proliferating bipotential glial progenitor cells in adult rat optic nerve

We have shown previously that the rat optic nerve contains three types of macroglial cells - Oligodendrocytes and two types of astrocytes - Which develop as two distinct lineages. Type-1 astrocytes develop from one type of precursor cell beginning at embryonic day 16 (E16)¹, while oligodendrocytes and then type-2 astrocytes develop from a common, bipotential progenitor cell beginning at birth (E21) and postnatal days 7-10 (P7-10), respectively ². Here we report that proliferating bipotential oligoden-drocyte- type-2 astrocyte (0-2A) progenitor cells are present in the adult rat optic nerve, raising the possibility that these cells are produced continually from self-renewing stem cells throughout life.