Gating currents measured without using p/−8 leak and capacitance current subtraction. (A) Unsubtracted currents recorded under control ionic conditions using pulse protocol illustrated in top panel. (B) Unsubtracted currents for the same oocyte in the presence of 30 µM Cd²⁺. (C) Q_OFF-V relationships for gating currents recorded in the absence and presence of 30 µM Cd²⁺. Data were fitted to a Boltzmann function (smooth curves). In control conditions, V_1/2 = −22.1 mV and z = 2.29. In the presence of Cd²⁺, V_1/2 = +7.8 mV and z = 1.52. (D) Superimposed traces of unsubtracted Ig_OFF for control (black traces) and 30 µM Cd²⁺ (red traces) at −110 mV after activating pulses were applied to the indicated V_t. (E) Superimposed traces for p/−8 subtracted (blue) and unsubtracted currents (red) in the presence of 30 µM Cd²⁺ for a V_t of +60 mV. Note that I_Cd-out is approximately the same, indicating that it is not an artifact of the on-line leak subtraction protocol.