@article{oai:nagasaki-u.repo.nii.ac.jp:00019368,
 author = {Zeredo, Jorge L and Hirano, Takafumi and Kimoto, Mari and Moritaka, Kentaro and Nasution, Fajar H and Toda, Kazuo},
 issue = {3},
 journal = {American Journal of Chinese Medicine},
 month = {},
 note = {The present study was conducted to clarify the role of the anterior cingulate cortex
(ACCX) in acupuncture analgesia. Experiments were performed on 35 female Wistar albino rats weighing about 300 g. Single unit recordings were made from ACCX
neurons with a tungsten microelectrode. Descending ACCX neurons were identified by
antidromic activation from electrical shocks applied to the ventral part of the ipsilateral PAG through a concentric needle electrode. Cathodal electroacupuncture stimulation of Ho-Ku (0.1 ms in duration, 45 Hz) for 15 min was done by inserting stainless steel needles bilaterally. An anodal silver-plate electrode (30 mm x 30 mm) was placed on the center of the abdomen. Naloxone (1.0 mg/kg, i.v.) was used to test whether changes of ACCX activities were induced by the endogenous opioid system or not. Data were collected from a total of 73 ACCX neurons. Forty-seven neurons had descending projection to the PAG, and 26 had no projections to the PAG. A majority of descending ACCX neurons were inhibited by electroacupuncture stimulation. By contrast, non-projection ACCX neurons were mainly unaffected by electroacupuncture. Naloxone did not reverse acupuncture effects on the changes of ACCX neuronal activities. Acupuncture stimulation had predominantly inhibitory effects on the activities of descending ACCX neurons. Since the functional connection between ACCX and 3/21 PAG is inhibitory, electroacupuncture caused disinhibition of PAG neurons, whose activity is closely related to descending antinociception to the spinal cord. This
disinhibitory effect elicited by acupuncture stimulation is thought to play a significant role in acupuncture analgesia., American Journal of Chinese Medicine, 36(3), pp.569-577; 2008},
 pages = {569--577},
 title = {Disinhibitory involvement of the anterior cingulate cortex in the descending antinociceptive effect induced by electroacupuncture simulation in rats},
 volume = {36},
 year = {2008}
}