Low- and high-frequency transcutaneous electrical acupoint stimulation induces different effects on cerebral μ-opioid receptor availability in rhesus monkeys.
Although systematic studies have demonstrated that acupuncture or electroacupuncture (EA) analgesia is based on their accelerating endogenous opioid release to activate opioid receptors and that EA of different frequencies is mediated by different opioid receptors in specific areas of the central nervous system, there is little direct, real-time evidence to confirm this in vivo. The present study was designed to investigate the effects of transcutaneous electrical acupoint stimulation (TEAS), an analogue of EA, at low and high frequencies on μ-opioid receptor (MOR) availability in the brain of rhesus monkeys. Monkeys underwent 95-min positron emission tomography (PET) with (11) C-carfentanil three times randomly while receiving 0, 2, or 100 Hz TEAS, respectively. Each TEAS was administered in the middle 30 min during the 95-min PET scan, and each session of PET and TEAS was separated by at least 2 weeks. The results revealed that 2 Hz but not 100 Hz TEAS evoked a significant increase in MOR binding potential in the anterior cingulate cortex, the caudate nucleus, the putamen, the temporal lobe, the somatosensory cortex, and the amygdala compared with 0 Hz TEAS. The effect remained after the end of TEAS in the anterior cingulate cortex and the temporal lobe. The selective increase in MOR availability in multiple brain regions related to pain and sensory processes may play a role in mediating low-frequency TEAS efficacy.
Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, and Key Laboratory for Neuroscience of the Ministry of Education and the Ministry of Public Health, Beijing, China; Department of Hepatopancreatobiliary and Splenic Medicine, Affiliated Hospital of Logistics University of Chinese People's Armed Police Forces, Tianjin, China.
Xiao-Hui
XH
Xiang
Ying-Mao
YM
Chen
Jin-Ming
JM
Zhang
Jia-He
JH
Tian
Ji-Sheng
JS
Han
Cai-Lian
CL
Cui
D015669:Acupuncture Points; D000344:Afferent Pathways / Q000502:physiology; D000701:Analgesics, Opioid / Q000493:pharmacokinetics; D000818:Animals; D055592:Biophysical Phenomena / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D005283:Fentanyl / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D008253:Macaca mulatta; D008297:Male; D049268:Positron-Emission Tomography; D011485:Protein Binding / Q000187:drug effects; D011859:Radiography; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D013997:Time Factors; D015898:Tomography Scanners, X-Ray Computed; D004561:Transcutaneous Electric Nerve Stimulation
D000701:Analgesics, Opioid; D017450:Receptors, Opioid, mu; C017114:carfentanil; D005283:Fentanyl
positron emission tomography (PET); transcutaneous electrical acupoint stimulation (TEAS); μ-opioid receptor (MOR)