(a) The mean current amplitudes of pH currents at pH 5, 6, 6.5, and 6.8 are not significantly different between groups injected with pH 4.0 (Injection 1, n = 22; Injection 2, n = 24) and controls injected with pH 7.2 (Injection 1, n = 19; Injection 2, n = 25), or uninjected controls (n = 28). (b) Data from (2A) was normalized to the peak transient currents evoked by pH 5 to analyze pH dose responses. pH dose responses and were not different between groups injection with pH 4.0 (Injection 1, n = 21; Injection 2, n = 24) and those injected with pH 7.2 (Injection 1, n = 19; Injection 2, n = 24) or uninjected controls (n = 27).