Fig. 3.

Enhanced voltage-gated potassium currents during DTDP-induced apoptosis. A, Whole-cell potassium currents obtained in two separate cortical neurons ∼3 hr after a 10 min exposure to either vehicle (0.1% DMSO) or 100 μm DTDP. Cells were maintained in MEM at 37°C for the interval between drug exposure and the recordings. Potassium currents were evoked by a series of voltage steps to +35 mV from a holding potential of −70 mV. Note that currents are substantially larger in the DTDP-treated cell, when compared with the vehicle-treated neuron. TEA (10 mm)blocked ∼50% of the currents in both cases. B, Acute application of 100 μm DTDP or 4 mmdithiothreitol (DTT; a disulfide reducing agent) did not produce appreciable changes in the amplitude of potassium currents.