Figure 1.

Relationship between hippocampal neurites and NG2 cells in vitro. A–C, P1 hippocampal neurons grown on NG2 cells (A), mature oligodendrocytes (B), and MAG-CHO cells (C) for 16 h and double immunolabeled for βIII-tubulin (green) and NG2 (A), O1 (B), or MAG (C) in red. Scale bar: in C (A–C), 24 μm. D, Quantification of the contact between neurites and cellular substrate. Black bars, Percentage of neurite tips associated with each type of non-neuronal cellular substrate. Gray bars, Percentage of surface area occupied by each type of non-neuronal cellular substrate. A significantly greater percentage of neurites are associated with NG2 cells compared with mature oligodendrocytes or MAG-CHO cells (*p < 0.001, one-way ANOVA with Tukey's post analysis). E, F, P1 hippocampal neurons grown on a mixed culture of NG2 cells (red) and mature oligodendrocytes labeled for O1 (purple). Neurites labeled for βIII-tubulin (green) appear to be turning away from the O1+ cell toward the NG2+ cells. F represents quantification of the contact between neurite tips and NG2 cells or oligodendrocytes. Data in D and F are shown as means ± SEs. Scale bar: E, 24 μm.