The inflammatory pain test was performed on days −1, 0, 1, 3, 5, and 7 after CFA injection or EA according to previous work.3 (link) In brief, 25 µL of CFA (1 mg/mL; Sigma-Aldrich, St. Louis, MO) was subcutaneously injected into the right hind paw at day 0 (CFA group). Twenty-five microliters of phosphate-buffered saline (pH 7.4) were injected as control (Sham group).
Mice in CFA+EA group received EA stimulation under anesthetization with 1% sevoflurane; Sham group and CFA group were similarly anesthetized at the same time. For the EA stimulation, 2 needles, 0.3 × 13 mm (Yunlong, China), were inserted at a depth of 1.5 mm in the right hind leg at acupoints corresponding to Zusanli (ST36) and Sanyinjiao (SP6), as described previously.22 (link) The needles were connected to HANS LH202H Han's acupoint nerve stimulator (Beijing Hua Wei Industrial Development Co, Beijing, China). Electroacupuncture stimulation (2-15 Hz alternating wave, 1.0 mA) was initiated after CFA injection and lasted for 30 minutes. This process was repeated every 2 days (Fig.1 ). Sham eletroacupuncture (SEA) was acupuncture needle insertion into acupoints without electrical stimulation or manual needle manipulation.45
Mice in CFA+EA group received EA stimulation under anesthetization with 1% sevoflurane; Sham group and CFA group were similarly anesthetized at the same time. For the EA stimulation, 2 needles, 0.3 × 13 mm (Yunlong, China), were inserted at a depth of 1.5 mm in the right hind leg at acupoints corresponding to Zusanli (ST36) and Sanyinjiao (SP6), as described previously.22 (link) The needles were connected to HANS LH202H Han's acupoint nerve stimulator (Beijing Hua Wei Industrial Development Co, Beijing, China). Electroacupuncture stimulation (2-15 Hz alternating wave, 1.0 mA) was initiated after CFA injection and lasted for 30 minutes. This process was repeated every 2 days (Fig.
