Figure 8.
Evidence for a persistent sodium current in ET cells. A, Voltage-clamp ramps were performed from –80 to –40 mV at a speed of 30 mV/sec in control and during application of TTX (1 μm). The sodium current generated using this protocol was calculated by subtracting the current–voltage curves in both conditions. B, As shown by the average from four cells, sodium current is activated at holding potentials more positive than –60 mV. All recordings in this figure were performed from spontaneously bursting ET cells in the presence of synaptic blockers.