Figure 2.

Longer term expansion of rat cortical NPCs at 3% versus 20% O₂ demonstrates increased generation of oligodendrocytes at 3% O₂. (A): Rat cortical NPCs were expanded at either 3% or 20% O₂, with greater NPC numbers observed by passage 3 at 3% O₂ (p = .05; n = 3–4 per group). (B, C): NPCs plated for differentiation for 48 hours after 28 days in culture tended to generate oligodendrocyte lineage cells, rather than neurons or astrocytes, although significantly more O4-positive oligodendrocytes were generated at 3% O₂. (D, E): These oligodendrocyte lineage cells matured more rapidly when expanded and differentiated at 3% versus 20% O₂, as indicated through ng2, pdgf-rα, and mbp staining. (F): Quantification of day 28 NPC fate after 48 hours of differentiation; p values are .04 (olig2), .03 (pdgf-rα), .04 (ng2), <.0001 (O4), <.0001 (mbp), .45 (β-III tubulin), and .003 (gfap); n = 4–8 per group. Scale bars = 100 μm (B) and 50 μm (C–E). Abbreviations: Gfap, glial fibrillary acidic protein; Mbp, myelin basic protein; NPC, neural precursor cell; Pdgf-rα, platelet-derived growth factor receptor-α.