Platelet‐derived growth factor receptor is expressed by cells in the early oligodendrocyte lineage

Abstract

We report the loaclization of PDGFRα mRNA (PDGFRα) in phenotypically defined cells during the first postanatal week of rat forebrain development. Using a method of combined immunocytochemistry and in situ hybridization we have demonstrated the cellular colocalization of PDGFRα mRNA with GD₃ ganglioside or 04 sulfatide, phenotypic markers of oligodendrocytes, in the gray and white matter of the dorsal cerebral cortex at all ages studies. Population analysis of the PDGFRα+/G₃+ and PDGFRα+/analysis of the PDGFRα+/G_D3+and PDGFRα+/04+ cells revealed that three populations express PDGFRα: G_D3+, G_D3+/04+, and 04+, corresponding to two lineage stages, progenitor and preoligodendrocyte, in oligodendrocyte development. Immature oligodendrocytes, identifice by galactocerebroside immunoreactivity, did not express detectable levels of PDGFR α mRNA. Post‐mitotic neurons, identifice by immunoperodxidase localization of the 68 kD neurofilament, and astrocytes identified by S‐100 or GFAP immunoreactivity were also negative for PDGFRα mRNA occured in oligodendrocyte cell populations which are post‐migratory and proliferative, but which do not express myelin proteins characteristic of post‐mitotic oligodendrocytes.