Contrasting effects of mitogenic growth factors on oligodendrocyte precursor cell migration.

We have examined the effects of the mitogenic growth factors platelet derived growth factor (PDGF), basic fibroblast growth factor (bFGF) and glial growth factor-2 (GGF-2) on oligodendrocyte precursor migration. In an agarose drop migration assay PDGF and bFGF stimulated migration while GGF-2 had no effect. The migration-enhancing effect of bFGF cannot be blocked by neutralising antibodies against PDGF, confirming that this effect is direct and not mediated via upregulation of PDGF receptors. Based on our results, we propose a model in which the differing effects of PDGF and GGF-2 ensure appropriate numbers of oligodendrocyte precursor cells in the vicinity of axons to be myelinated during development.