Platelet-derived growth factor (PDGF) plays an important role not only in mesenchyme-derived tissues, but also in the mammalian central nervous system. The Patch mutant (Ph/+) lacks one copy of the PDGFR-alpha gene. However, it is not clear whether there are differences in expression of PDGF receptor alpha-subunit (PDGFR-alpha) in brain tissue of the Patch heterozygous (Ph/+) mutants compared to wild-type C57Bl (+/+) mice. 2. The level of PDGRF-alpha mRNA expression is slightly lower in Patch mutant than in normal littermate. 3. Protein and total RNA isolated from mouse brain tissue and primary type 1 astrocyte cultures were studied with Western and Northern blotting techniques. There was no measurable difference ir PDGFR-alpha protein expression between the Patch and wild-type mouse nervous system. Adjustment of transcriptional efficiency and messenger stability may contribute to this phenomenon, whose biological significance remains unclear. 4. Further, the expression of PDGRF-alpha protein and message in mouse brain tissues is developmentally regulated. Its level remains high during the embryonic period and declines below measurable levels in adult.