pH-dependent and voltage-independent inhibition of ASIC3 currents by tetracaine. A, B, C. Representative current traces showing inhibition of ASIC3 currents by 3 mM tetracaine at pH4.5, pH6.0, and pH7.0, respectively. D. Summary data showing inhibition of the ASIC3 current by 3 mM tetracaine at different pH levels as indicated (t test, n = 4; *p < 0.05). E. Representative current traces showing ASIC3 current activated at different holding potentials ranging from −60 to +60 mV in the absence and presence of 3 mM tetracaine. F. Current–voltage relationship (I-V curve) in the absence and presence of 3 mM tetracaine; n = 4.