Identification and differentiation of GFP-OPCs. The GFP-OPCs induced from spinal cord-derived NPCs were cultured in different media for 5 days. (A~C): In the basal-OPC-medium containing PDGF and bFGF, the cells display bipolar or tri-polar morphology, the typical morphology of OPC (A), more than 95% of cells express both A2B5 (B) and PDGFR (C). Inserts show higher power photographs of OPCs. (D~I) In the medium containing T3 and without PDGF and bFGF, the cells display a multipolar morphology (D, G), more than 95% of the cells express RIP (E, F), and almost no cells express GFAP (H, I).(J~O) In the medium containing 10%FBS without PDGF and bFGF, the cells display the typical process-bearing morphology of astrocytes (J, M), few cells express RIP (K, L) and nearly all cells express GFAP (N, O). Cells in B, C, E, F, H, I, K, L, N and O were counterstained with Hoechst33342 (blue), a nuclear dye. Scale bars: 25 μm.