In vivo analysis of glial cell phenotypes during a viral demyelinating disease in mice

The antigenic phenotype and mitogenic potential of the glial cell types involved in CNS remyelination of small rodents has not yet been studied in detail. In contrast, recent Catherine Godfraind's present address is Service dAnatomie Pathologique, Cliniques Universitaires St we, Avenue Hippocrate 10, B1200 Bruxelles, Belgium. Victor Friedrich's present address is Brookdale Center for Molecular Biology, Box 1128 A, Mount Sinai Medical Center, One Gustav L. Levy Place, New York, NY 10029. studies have elucidated the nature of the cell lineage involved in myelination during development (reviewed in Raft and Miller, 1984; and Raft, 1989) . A bipotential progenitor cell has been demonstrated to give rise to oligodendrocytes and to type 2 astrocytes which are both involved in the construction of myelinated tracts (ffrench-Constant and Raft, 1986) . Therefore this progenitor is called the O-2A progenitor and the cells derived from these cells constitute, with their progenitor, that O-2A lineage (Raft et al., 1983b ). An antibody crucial to the identification of this lineage in optic nerve has been the A2B5 antibody which reacts with a subset of gangliosides on the cell surface (Eisenbarth et al., 1979) and was used both in vitro and in vivo to stain O-2A progenitors (Raffet al., 1983b (Raffet al., , 1984b David et al., 1984; Miller et al., 1985; Behar et al., 1988) . In vivo studies with this antibody in other parts of the nervous system have been difficult because these specific gangliosides are also expressed in neuronal components (Eisenbarth et al., 1979) .