(A) Only one-third of the cells in the optic nerve astroglial cell cultures expressed GFAP, AQP4 and GLAST by immunocytochemistry. Double-labeling with NG2 and GFAP revealed that ~70% of the cells are NG2+. Scale bars=100 μm. (B) RNA microarray analysis demonstrates markedly increased Cspg4 (NG2) mRNA expression in ON astroglial cells with extremely low Sox10, Mag or Mog expression. The y-axis represents the level of gene expression as determined by MAS 5.0. Error bars represent the mean±SEM. (C) mRNA levels of the four representative ON astroglial cell-specific genes as determined by quantitative real-time RT-PCR. (D & E) Graphic representative of the data presented in (C) for independently-generated astroglial cell cultures (D) and whole brain tissue (E). Error bars represent the mean ±SEM. *, p < 0.05; **, p < 0.01; ***, p < 0.001.