Figure 5.

All brain NG2⁺ OPCs express I_Na and proliferate. a–j, Images of dye fills of whole-cell patch-clamped GFP⁺ cells in CC, Ctx, and aPC (red) and labeling for NG2 (green) and EdU [or Hoechst 33258 (Hst) in g, i] (blue) (left), together with current responses to depolarizing voltage steps in 20 mV increments from −70 mV (right). Cells fell into one of three main groups: a–f, NG2⁺ I_Na⁺ mitotic (EdU⁺) OPCs; g, h, NG2^low I_Na^low early differentiating OLs; and i, j, electrically passive OLs (NG2^neg, I_Na^neg). k–n, The average electrophysiological data for NG2⁺ OPCs (mean ± SEM) at P9 (CC, n = 20; Ctx, n = 15; aPC, n = 14 cells) and P33 (CC, n = 22; Ctx, n = 17; aPC, n = 41 cells) are shown, including the following: k, peak inward current on depolarization from −70 to +10 mV; l, membrane resistance at −70 mV; m, membrane capacitance; and n, peak outward current (on depolarization from −70 to +10 mV). Scale bars, 20 μm.