Injection of an A
R agonist into the Weizhong acupuncture point (located within the popliteal fossa) has short-lasting antinociceptive effects. (A-A’) Cross section of the mouse hind limb cut through knee and popliteal fossa, shows proximity of Weizhong (BL40) and Zusanli (ST36) acupuncture points to each other and to peripheral nerves. Bones, nerves (n), blood vessels (b), muscle (m) and acupoints labeled. Tissue stained with PGP9.5 antibody (1:500) to visualize nerves. (B) Noxious thermal and (C) mechanical sensitivity in hindpaw following injection of CPA (5 nmol) into the popliteal fossa. (D) Noxious thermal and (E) mechanical sensitivity following injection of vehicle into the popliteal fossa (0.9% saline with 1% DMSO). (B-E) Ipsi = ipsilateral hindpaw. Contra = contralateral hindpaw. Contralateral popliteal fossa was not injected. Wild-type (n = 10) and A
R−/− (n = 10) male mice in each cohort. Data are plotted as means ± s.e.m. Paired t-tests were used to compare responses at each time point to baseline (BL). *P < 0.05, **P < 0.005, ***P < 0.0005.