Expression and regulation of a glutamate receptor subunit by bFGF in oligodendrocyte progenitors

Oligodendrocyte progenitor cells (O-2A) express both kainate-preferring and AMPA-preferring glutamate receptors (Gallo et al., Soc. Neurosci. Abstr., 18:653, 1992b; Gallo et al., 1994). The expression and regulation of the GluR-4c, AMPA-preferring subunit by growth factors was studied by Northern blot analysis of total RNA from purified rat cortical O-2A progenitors. Differently from cortical neurons, O-2A progenitors only expressed two high molecular weight GluR-4c transcripts (6.2 and 4.2 kb), as observed also in cultured astrocytes. Basic fibroblast growth factor (bFGF) increased GluR-4c transcript levels in O-2A progenitors and its effects were not mimicked by platelet derived growth factor (PDGF) or fetal calf serum. Therefore, bFGF may regulate O-2A progenitor responsiveness to glutamate during development through the expression of glutamate receptor subunits.