Identification of an adult-specific glial progenitor cell

Abstract

We have found that glial progenitor cells isolated from the optic nerves of adult rats are fundamentally different from their counterparts in perinatal animals. In our studies on bipotential oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells, we have seen that O-2^Aadutt progenitor cells can be distinguished from O-2^Aperinatal progenitors by their morphology and antigenic pheno type, their much longer cell cycle time (65 h versus 18 h), slower rate of migration rate (4μmh-¹versus 21μm h–¹), and their time course of differentiation into oligodendrocytes or type-2 astrocytes in vitro (⩽3 days versus >5 days). At least some of the differences between 0–2A^adult and 0–2^Aperinatal progenitor cells appear to be clearly related to the differing cellular requirements of the adult and perinatal central nervous system (CNS). The properties of the 0–2A^adult progenitor cells may make these cells ideally suited for the needs of the adult CNS, where rapid exponential increases in the number of oligodendrocytes and 0–2A progenitor cells would be inappropriate. However, the properties of the 0–2A^adult progenitor cells are such that they may not be able to replace oligodendrocytes in sufficient numbers to repair extensive or recurrent damage in the adult brain, such as in patients suffering from the human demyelinating disease multiple sclerosis. Moreover, available information about other tissues suggests that the transition from perinatal to adult progenitor cell types may rep resent a developmental mechanism of general import ance.