The temporal sequence of five experimental groups in the dual acid injection model. (A) Experimental design to probe the role of ASIC3 and TRPV1 in acid-induced hyperalgesia in the dual acid-injection scheme spaced 5 days apart. (B,C) Experimental design to test the role of ASIC3 and TRPV1 in acid-induced hyperalgesic priming when the second acid injection was given at day 1 (B) or day 2 (C). (D) Experimental design to test the analgesic effect of NaV1.8 blocker on the acid-induced chronic widespread pain. (E) Experimental designs to test the role of PKCϵ on acid-induced hyperalgesic priming.