Fig. 4.

Current–voltage relationship and voltage-jump relaxation kinetics for the H⁺-induced current.A, B, Voltage-clamp recordings from an rSERT-injected oocyte perfused with NMDG Ringer’s solution, pH 5.0, in the presence (A) or absence (B) of 10 μm desipramine. The membrane potential was held at −40 mV and then shifted for 600 msec to a series of test potentials ranging from −140 mV to +40 mV in 20 mV increments. C, Pure H⁺ leakage current obtained by subtracting Afrom B. Dashed line is at zero subtracted current. D, Steady-state currents obtained fromC were plotted as a function of membrane potential. Currents were averaged from the first 50 msec at the test potential.