Figure 5

TRPV1 agonist (capsaicin) injection at ST36 replicated the analgesic effect of acupuncture. The behavioral test design was similar to that of MA, with the exception that capsaicin was injected at a concentration of 0.5% and a volume of 10 μL into ST36 or sham point. (A) In within-group tests, capsaicin injections into ST36 showed significant effect on D3 post (P < 0.01) and on D4 (P < 0.05). (B) In between-group tests, capsaicin injections at ST36 yielded significant differences compared with injections at the sham point (P < 0.01) and vehicle injections at ST36 (P < 0.05) on D3 post. (C) There were no significant differences in between-group tests on D4. Within-group and between-group tests were designed similar to the MA behavioral test (*P < 0.05, **P < 0.01; Mann–Whitney rank sum test, n = 11–13). Data are means ± S.E.M.