Three types of proton-gated currents were recorded in DRG neurons. Example traces of a slow-inactivating current followed by a small sustained component (A), and a fast-inactivating current (B), a sustained current with a small transient phase (C). All three types of proton-induced currents could be partly inhibited by 10 nM PcTx1, a specific antagonist of homomeric ASIC1a channels. These currents could be completely or partly blocked by 100 µM amiloride (Amil), a broad-spectrum ASIC channel blocker. The TRPV1 blocker AMG 9810 (1 µM) has little effect on the transient peak phases of three types of acid currents. The bar graph in (D) shows relative amplitude of peak currents induced by pH 5.5 after application of amiloride, PcTx1 and AMG 9810. Proton-induced currents were evoked by extracellular application of a pH 5.5 solution for 5 s. *P<0.05,**P<0.01, ***P<0.001, one way analysis of variance followed by post hoc Bonferroni’s test, compared with control. Each column represents the mean ± SEM of 8–11 neurons.