Residual currents in 1 µM RY785 resemble endogenous CHO currents. (A) Top: Voltage command. Bottom: Representative currents from Kv2.1-CHO cells or CHO cells without heterologous Kv2.1, in vehicle (black) and RY785 (red). Black arrow indicates time point used for current amplitude quantification in B. (B) Current amplitudes at +90 mV. Currents from 98 to 100 ms after stepping to +90 mV from a holding potential of −100 mV (symbols). Exemplars from A are shown as stars. Three cells had voltage clamp errors exceeding 10 mV at +90 mV (triangles). For these three cells, currents were analyzed from +20 to +30 mV, where voltage clamp errors were <10 mV, and extrapolated to +90 mV using the Boltzmann fit to the Kv2.1 G–V (Fig. 3 E). n = 8 Kv2.1-CHO cells and n = 4 CHO cells. Bars are arithmetic means ± SEM.