Mean cerebral blood flow (CBF) values showing the effects of scalp acupuncture (electroacupuncture; EA) and somatic acupuncture at different timepoints: (A and E), 5 minutes before EA; (B and F), 10 minutes of EA; (C and G), 20 minutes of EA; and (D and H), 5 minutes after EA. During the entire observation period, mean CBF values increased significantly after GB 15 (Toulinqi) stimulation (A–D), while ST 36 (Zusanli) stimulation produced no obvious increase of CBF values during the observation period (E–H).