Multidimensional Pain Modulation by Acupuncture Analgesia: The Reward Effect of Acupuncture on Pain Relief

Abstract

Pain is an intrinsically unpleasant experience with features that protect an organism by promoting motivation and learning. Pain relief, a negative reinforcement of pain, is considered a reward and activates the brain’s reward system. The reward circuit in the brain involves reward and pain. Acupuncture has a multidimensional and comprehensive regulating effect on chronic pain. However, the reward effect of acupuncture in relieving chronic pain and the mechanism of the brain reward circuit involved in acupuncture analgesia are not thoroughly studied. In this article, we have reviewed the definition of pain abnormalities and negative emotions in patients with chronic pain, the conceptual characteristics of analgesic reward, and the new progress in studying brain reward circuits and functions. Moreover, we have expounded on the critical clinical and scientific significance of studying the reward effect of acupuncture analgesia and related brain reward circuits, the pain mechanism obtained from human neuroimaging studies, and the survey results on the effects of acupuncture on reward/motivation circuits. Some viewpoints and suggestions on the reward effect of acupuncture analgesia and related reward circuits have been put forward to clarify the multidimensional characteristics and benign regulation of acupuncture analgesia. Studies on the reward effect of acupuncture in relieving chronic pain and the regulating effect of the brain reward loop on acupuncture analgesia help to deepen the clinical understanding of acupuncture analgesia, innovate the research concept of acupuncture analgesia, and provide help for further studies on the central mechanism of acupuncture in improving chronic pain in the future.

Glutamatergic neurons in the infralimbic cortex for motivational response of pain relief induced by electroacupuncture

“…This conclusion is consistent with the concept of negative reinforcement elicited by relief of an aversive state [47]. Also, the results of our behavioral experiments extend the conclusions of previous studies on the benign regulation of EA [48,49]. The variability in the response to EA might be explained partially by state-dependent effects of EA [49].…”

“…Also, the results of our behavioral experiments extend the conclusions of previous studies on the benign regulation of EA [48,49]. The variability in the response to EA might be explained partially by state-dependent effects of EA [49].…”

Clinical Efficacy and Central Mechanisms of Electroacupuncture Treatment for Low Back Pain in Primary Osteoporosis: Study Protocol for a Randomized Controlled Trial

“…Because of its wide application, quick effect and few adverse reactions, acupuncture has become a recognized green analgesia method at home and abroad [10]. Acupuncture not only relieves pain, but also improves the quality of life of patients with pain, and can avoid addiction, immunosuppression, gastrointestinal injury and other adverse reactions caused by analgesics to a certain extent [11]. Acupuncture has been a means of relieving opioid withdrawal symptoms for more than 50 years.…”

Efficacy of acupuncture for whiplash injury: a systematic review and meta-analysis

“…Acupuncture is used for the treatment of various musculoskeletal disorders, such as WAD, 9–11 as it can target the neurological mechanisms to relieve physical pain via the release of opioids and 5-hydroxytryptamine in the brain reward/motivation circuit. 12 However, its effectiveness is yet to be recognised despite its usefulness in clinical practice. 13 The Canadian and Australian WAD clinical practice guidelines (CPGs) do not recommend acupuncture for treating WAD 14 ; moreover, one of the guidelines does not conclude that acupuncture is effective.…”