Fig. 4.

Electrophysiological profiles of neurons derived from drNPCs. a, b Infrared DIC images of the drNPCs, with patch pipette attached. c–h Whole cell recordings from cells shown in a and b. c–f Current clamp recordings of action potentials evoked with 50 ms (c, d) and 250 ms (e, f) current pulses of varying intensities. The current pulses are shown in lower traces of c–f. Note the differences between the sizes and shapes of abortive (c, e) and more advanced action potentials (d, f). g, h Voltage clamp recordings from these cells show smaller Na currents (downward deflections, shown with arrows) in the cell with an abortive action potential (g) compared to the cell with a more advanced action potential (h). The voltage steps from − 80 mV holding level, with 10 mV increments, are shown in lower traces. i–k Statistical comparison of action potential parameters and Na and K currents in cells with abortive and more advanced action potentials