Activation of VSP (Dr-VSP) inhibits KCNQ2/3 current. (A) Currents recorded in cells transfected with KCNQ2/3 alone. (B) Currents in cells transfected with KCNQ2/3 and Dr-VSP. Note the reduction of current at −20 mV after depolarization to +100 mV. (C) Responses in the same cell as in B to a family of stimuli with increasing duration at +100 mV. Magnified time scale as compared with B also shows reduction of current at +100 mV. (D) Summary of normalized outward current at −20 mV (after/before step to +100 mV) for different durations at +100 mV (note log scale of x axis) for 5–12 cells.