RESUMEN
Platelet-derived growth factor (PDGF) was initially described for its mitogenic activity on smooth muscle cells, fibroblast, and glial cells. The biological activities of PDGF include stimulation of mitogenesis, differentiation, wound healing, inflammation, and tumor formation. The localization of platelet-derived growth factor-alpha Receptor (PDGF-alpha R) in central nervous system was commonly restricted to oligodendrocyte progenitors during late embryonic and postnatal development. However, several studies recently demonstrated that postnatal neurons could also synthesize PDGF-alpha R in rodents. In the present study, to analyze the distributional pattern of PDGF-alpha R during postnatal development of the canine CNS, we used immunohistochemical method on sections of canine brain tissue. We found that neurons of various CNS regions, including cerebral cortex, striatum, diencephalon, nuclei of brain stem, cerebellum, spinal cord, exhibited the immunoreactivity to PDGF-alpha R as early as postnatal day 0. Generally PDGF-alpha R immunoreactivity was well localized in the dendrites and axons of neuron during the postnatal day 14 and postnatal day 28, and then showed diminished pattern. But neuronal immunoreactivity to PDGF-alpha R were maintained postnatal 6 month. These results suggest that the localization of PDGF-alpha R in postnatal developing neurons supports the several roles of PDGF for neurons including maturation and survival.