Younbyoung Chae
Florian Beissner2
Hee-Young Kim
Richard E. Harris- 1Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul, Republic of Korea
- 2Insula Institute for Integrative Therapy Research, Hanover, Germany
- 3Department of Physiology, Yonsei University College of Medicine, Seoul, Republic of Korea
- 4Department of Anesthesiology, Chronic Pain and Fatigue Research Center, University of Michigan, Ann Arbor, MI, United States
- 5Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States
- 6Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, Charlestown, MA, United States
Editorial on the Research Topic
Neural substrates of acupuncture: From peripheral to central nervous system mechanisms, volume II
During the past several decades, acupuncture therapy has been extensively studied and shown to be clinically effective for a variety of illnesses, particularly pain disorders (Lee et al., 2020). The efficacy and mechanism of action of acupuncture are two key issues. In fact, a large number of clinical trials have been conducted to investigate the efficacy of acupuncture treatment (Vickers et al., 2018). To clarify the underlying mechanisms of acupuncture, numerous mechanistic investigations have been performed using both human and non-human (i.e., rodent) pre-clinical models (Han, 2004; Moffet, 2006; Napadow et al., 2008; Chae et al., 2013). While our understanding of acupuncture mechanisms has certainly improved, multiple questions, such as problem of acupoint specificity, has not yet been fully understood (Xing et al., 2013; Langevin and Wayne, 2018).
The World Health Organization has proposed a standardized nomenclature and locations for acupoints, but variation is still seen among practitioners (Molsberger et al., 2012; Godson and Wardle, 2019). Although numerous studies have investigated the anatomical features and electrical properties of acupoints (Langevin et al., 2002; Ahn et al., 2008, 2010; Soh, 2009; Lee et al., 2019), they remain to be fully elucidated (Colbert et al., 2011), and more research is needed. This research will include novel explorations as well as the synthesis of existing information on acupoints and biomarkers in databases and the published literature.
The current issue includes six articles on the state of research on neural substrates of acupuncture. Three original studies investigated the neural circuitry underlying electro-acupuncture for cardiovascular diseases, functional connectivity alterations associated with moxibustion for primary dysmenorrhea, and neurobiological markers for electroacupuncture in an animal irritable bowel syndrome model. In addition, three review articles are also included and explore the neural pathways and biophysical features of acupoints, along with neurobiological markers of sham acupuncture—a form of control intervention commonly used in clinical trials.
By balancing the somato-sympathetic and the somato-parasympathetic reflexes, electro-acupuncture at ST25 reduced visceral hypersensitivity in an animal model of irritable bowel syndrome (Zhang et al.). Electroacupuncture applied to PC5-PC6 acupoints (innervated by median afferents) was found to control a cardiopulmonary reflex through the hypothalamic paraventricular nucleus (Tjen-A-Looi et al.). In another human brain imaging study, moxibustion at CV4, CV8, and SP6 modulated pain in dysmenorrhea by altering the connectivity between the inferior frontal gyrus and default mode network involved in the pain reappraisal and processing (Yang et al.). Based on these results, we speculate that specific acupoints can modulate neural pathways to exert various effects on visceral function.
Regarding acupoint characteristics, Cui et al., investigated the functions of cutaneous C nociceptors to understand acupoint sensitization and plasticity. Additionally, Lee et al., posited that myofascial trigger points are closely related to so-called “Ashi” points, and proposed a relationship among classical acupuncture points, extra-acupuncture points, and Ashi points. Furthermore, based on the outcomes of 51 sham acupuncture experiments, Kim et al., reported that sham acupuncture, as commonly used in acupuncture RCT's, had similar effects on biomarkers to acupuncture.
We hope that readers will enjoy this issue of Frontiers in Neuroscience, which expands on the neurological mechanisms of acupuncture and fundamental issues regarding acupuncture points and placebo controls for clinical trials. We believe that these findings may help establish the link between clinical acupuncture therapy and basic and translational research.
Author contributions
All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.
Funding
This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (No. 2021R1F1A1046705). Support was also provided by the National Center for Complementary and Integrative Health (NCCIH), NIH (R61/R33-AT009306, P01-AT009965, and R01-AT011429 to VN).
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher's note
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References
Ahn, A. C., Colbert, A. P., Anderson, B. J., Martinsen, O. G., Hammerschlag, R., Cina, S., et al. (2008). Electrical properties of acupuncture points and meridians: a systematic review. Bioelectromagnetics 29, 245–256. doi: 10.1002/bem.20403
Ahn, A. C., Park, M., Shaw, J. R., Mcmanus, C. A., Kaptchuk, T. J., and Langevin, H. M. (2010). Electrical impedance of acupuncture meridians: the relevance of subcutaneous collagenous bands. PLoS ONE 5, e11907. doi: 10.1371/journal.pone.0011907
Chae, Y., Chang, D. S., Lee, S. H., Jung, W. M., Lee, I. S., Jackson, S., et al. (2013). Inserting needles into the body: a meta-analysis of brain activity associated with acupuncture needle stimulation. J. Pain 14, 215–222. doi: 10.1016/j.jpain.2012.11.011
Colbert, A. P., Spaulding, K., Larsen, A., Ahn, A. C., and Cutro, J. A. (2011). Electrodermal activity at acupoints: literature review and recommendations for reporting clinical trials. J. Acupunct. Meridian Stud. 4, 5–13. doi: 10.1016/S2005-2901(11)60002-2
Godson, D. R., and Wardle, J. L. (2019). Accuracy and precision in acupuncture point location: a critical systematic review. J. Acupunct. Meridian Stud. 12, 52–66. doi: 10.1016/j.jams.2018.10.009
Han, J. S. (2004). Acupuncture and endorphins. Neurosci. Lett. 361, 258–261. doi: 10.1016/j.neulet.2003.12.019
Langevin, H. M., Churchill, D. L., Wu, J., Badger, G. J., Yandow, J. A., Fox, J. R., et al. (2002). Evidence of connective tissue involvement in acupuncture. FASEB J. 16, 872–874. doi: 10.1096/fj.01-0925fje
Langevin, H. M., and Wayne, P. M. (2018). What is the point? The problem with acupuncture research that no one wants to talk about. J. Altern. Complement. Med. 24, 200–207. doi: 10.1089/acm.2017.0366
Lee, I. S., Lee, H., Chen, Y. H., and Chae, Y. (2020). Bibliometric analysis of research assessing the use of acupuncture for pain treatment over the past 20 years. J. Pain Res. 13, 367–376. doi: 10.2147/JPR.S235047
Lee, M., Longenecker, R., Lo, S., and Chiang, P. (2019). Distinct neuroanatomical structures of acupoints kidney 1 to kidney 8: a cadaveric study. Med. Acupunct. 31, 19–28. doi: 10.1089/acu.2018.1325
Moffet, H. H. (2006). How might acupuncture work? A systematic review of physiologic rationales from clinical trials. BMC Complement. Altern. Med. 6, 25. doi: 10.1186/1472-6882-6-25
Molsberger, A. F., Manickavasagan, J., Abholz, H. H., Maixner, W. B., and Endres, H. G. (2012). Acupuncture points are large fields: the fuzziness of acupuncture point localization by doctors in practice. Eur. J. Pain 16, 1264–1270. doi: 10.1002/j.1532-2149.2012.00145.x
Napadow, V., Ahn, A., Longhurst, J., Lao, L., Stener-Victorin, E., Harris, R., et al. (2008). The status and future of acupuncture mechanism research. J. Altern. Complement. Med. 14, 861–869. doi: 10.1089/acm.2008.SAR-3
Soh, K. S. (2009). Bonghan circulatory system as an extension of acupuncture meridians. J. Acupunct. Meridian Stud. 2, 93–106. doi: 10.1016/S2005-2901(09)60041-8
Vickers, A. J., Vertosick, E. A., Lewith, G., Macpherson, H., Foster, N. E., Sherman, K. J., et al. (2018). Acupuncture for chronic pain: update of an individual patient data meta-analysis. J. Pain 19, 455–474. doi: 10.1016/j.jpain.2017.11.005
Keywords: acupuncture, biomarker, neuroscience, somatosensation, acupoints
Citation: Chae Y, Beissner F, Kim H-Y, Harris RE and Napadow V (2023) Editorial: Neural substrates of acupuncture: From peripheral to central nervous system mechanisms, volume II. Front. Neurosci. 16:1119829. doi: 10.3389/fnins.2022.1119829
Received: 09 December 2022; Accepted: 28 December 2022;
Published: 19 January 2023.
Edited and reviewed by: Ye-Seul Lee, Jaseng Medical Foundation, Republic of Korea
Copyright © 2023 Chae, Beissner, Kim, Harris and Napadow. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Younbyoung Chae, 
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