Progenitor cells of the adult mouse subventricular zone proliferate, migrate and differentiate into oligodendrocytes after demyelination

Identifying a source of cells with the capacity to generate oligodendrocyte s in the adult CNS would help in the development of strategies to promote r emyelination. In the present study, we examined the ability of the precurso r cells of the adult mouse subventricular zone (SVZ) to differentiate into remyelinating oligodendrocytes. After lysolecithin-induced demyelination of the corpus callosum, progenitors of the rostral SVZ (SVZa) and the rostral migratory pathway (RMS), expressing the embryonic polysialylated form of t he neural cell adhesion molecule (PSA-NCAM), increased progressively with a maximal expansion occurring after 2 weeks. This observation correlated wit h an increase in the proliferation activity of the neural progenitors locat ed in the SVZa and RMS. Moreover, polysialic acid (PSA)-NCAM-immunoreactive cells arizing from the SVZa were detected in the lesioned corpus callosum and within the lesion. Tracing of the constitutively cycling cells of the a dult SVZ and RMS with H-3-thymidine labelling showed their migration toward the lesion and their differentiation into oligodendrocytes and astrocytes but not neurons. These data indicate that, in addition to the resident popu lation of quiescent oligodendrocyte progenitors of the adult CNS, neural pr ecursors from the adult SVZ constitute a source of oligodendrocytes for mye lin repair.