Developmental expression of platelet-derived growth factor alpha-receptor in neurons and glial cells of the mouse CNS.

The synthesis of platelet-derived growth factor-alpha receptor (PDGF-alphaR) is commonly attributed to oligodendrocyte progenitors during late embryonic and postnatal development. However, we recently demonstrated that mature neurons could also synthesize PDGF-alphaR, emphasizing a larger role for this receptor than previously described. In the present study, to analyze the pattern of PDGF-alphaR expression during postnatal development of the mouse CNS, we used in situ hybridization and immunohistochemistry on brain and spinal cord tissue sections. We found that, in addition to immature cells of the oligodendrocyte lineage, neurons of various CNS regions express PDGF-alphaR transcripts and protein as early as postnatal day 1 (P1). Whereas neuronal expression was maintained at all ages, the oligodendroglial expression strongly decreased after P21. In the adult, PDGF-alphaR was detected in very few oligodendrocyte progenitors scattered in the cerebral cortex or in white matter tracts, thus suggesting the presence of PDGF-alphaR on O-2Aadult progenitors. In the mature CNS, PDGF-alphaR transcripts and protein were mainly localized in neurons of numerous structures, such as the olfactory bulb, cerebral cortex, hippocampus, and brainstem nuclei and in motor neurons of the ventral horn of the spinal cord. The differential expression of PDGF-alphaR in oligodendroglia and neurons argues in favor of several roles of PDGF during development.