Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2015; 21(48): 13480-13489
Published online Dec 28, 2015. doi: 10.3748/wjg.v21.i48.13480
Neural mechanism of gastric motility regulation by electroacupuncture at RN12 and BL21: A paraventricular hypothalamic nucleus-dorsal vagal complex-vagus nerve-gastric channel pathway
Hao Wang, Wen-Jian Liu, Guo-Ming Shen, Meng-Ting Zhang, Shun Huang, Ying He
Hao Wang, Guo-Ming Shen, Institute of Integrated Chinese and Western Medicine, Anhui University of Traditional Chinese Medicine, Hefei 230038, Anhui Province, China
Wen-Jian Liu, Department of Thoracic Surgery, The First Affiliated Hospital of Anhui University of Traditional Chinese Medicine, Hefei 230061, Anhui Province, China
Meng-Ting Zhang, Shun Huang, Ying He, Clinical College of Integrated Chinese and Western Medicine, Anhui University of Traditional Chinese Medicine, Hefei 230038, Anhui Province, China
Author contributions: Wang H and Liu WJ contributed equally to this work; they drafted the article and made critical revisions related to the intellectual content of the manuscript, performed the research, and analyzed the data; Shen GM designed the study and critically reviewed the manuscript; Zhang MT, Huang S and He Y assisted with the experiments; all authors approved the final version of the article to be published.
Supported by The National Nature Science Foundation Council of China, No. 81473784; the Natural Science Foundation of Anhui Province, No. 1408085MH166; and the Natural Science Foundation of Anhui University of Traditional Chinese Medicine, No. 2013qn002.
Institutional review board statement: The study was reviewed and approved by the Anhui University of Traditional Chinese Medicine Institutional Review Board (No. 201409106).
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of the Anhui University of Traditional Chinese Medicine (IACUC No. 24564562W).
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at shengm_66@163.com. Participants gave informed consent for data sharing.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Guo-Ming Shen, Professor, Institute of Integrated Chinese and Western Medicine, Anhui University of Traditional Chinese Medicine, No. 70, Meishan Road, Hefei 230038, Anhui Province, China. shengm_66@163.com
Telephone: +86-551-65169317 Fax: +86-551-65169317
Received: June 8, 2015
Peer-review started: June 11, 2015
First decision: July 10, 2015
Revised: August 6, 2015
Accepted: October 12, 2015
Article in press: October 16, 2015
Published online: December 28, 2015
Processing time: 198 Days and 17.8 Hours
Abstract

AIM: To study the neural mechanism by which electroacupuncture (EA) at RN12 (Zhongwan) and BL21 (Weishu) regulates gastric motility.

METHODS: One hundred and forty-four adult Sprague Dawley rats were studied in four separate experiments. Intragastric pressure was measured using custom-made rubber balloons, and extracellular neuron firing activity, which is sensitive to gastric distention in the dorsal vagal complex (DVC), was recorded by an electrophysiological technique. The expression levels of c-fos, motilin (MTL) and gastrin (GAS) in the paraventricular hypothalamic nucleus (PVN) were assayed by immunohistochemistry, and the expression levels of motilin receptor (MTL-R) and gastrin receptor (GAS-R) in both the PVN and the gastric antrum were assayed by western blotting.

RESULTS: EA at RN12 + BL21 (gastric Shu and Mu points), BL21 (gastric Back-Shu point), RN12 (gastric Front-Mu point), resulted in increased neuron-activating frequency in the DVC (2.08 ± 0.050, 1.17 ± 0.023, 1.55 ± 0.079 vs 0.75 ± 0.046, P < 0.001) compared with a model group. The expression of c-fos (36.24 ± 1.67, 29.41 ± 2.55, 31.79 ± 3.00 vs 5.73 ± 2.18, P < 0.001), MTL (22.48 ± 2.66, 20.76 ± 2.41, 19.17 ± 1.71 vs 11.68 ± 2.52, P < 0.001), GAS (24.99 ± 2.95, 21.69 ± 3.24, 23.03 ± 3.09 vs 12.53 ± 2.15, P < 0.001), MTL-R (1.39 ± 0.05, 1.22 ± 0.05, 1.17 ± 0.12 vs 0.84 ± 0.06, P < 0.001), and GAS-R (1.07 ± 0.07, 0.91 ± 0.06, 0.78 ± 0.05 vs 0.45 ± 0.04, P < 0.001) increased in the PVN after EA compared with the model group. The expression of MTL-R (1.46 ± 0.14, 1.26 ± 0.11, 0.99 ± 0.07 vs 0.65 ± 0.03, P < 0.001), and GAS-R (1.63 ± 0.11, 1.26 ± 0.16, 1.13 ± 0.02 vs 0.80 ± 0.11, P < 0.001) increased in the gastric antrum after EA compared with the model group. Damaging the PVN resulted in reduced intragastric pressure (13.67 ± 3.72 vs 4.27 ± 1.48, P < 0.001). These data demonstrate that the signals induced by EA stimulation of acupoints RN12 and BL21 are detectable in the DVC and the PVN, and increase the levels of gastrointestinal hormones and their receptors in the PVN and gastric antrum to regulate gastric motility.

CONCLUSION: EA at RN12 and BL21 regulates gastric motility, which may be achieved through the PVN-DVC-vagus-gastric neural pathway.

Keywords: Dorsal vagal complex; Gastrin receptor; Motilin receptor; Neuronal firing activity; Paraventricular hypothalamic nucleus; RN12; BL21

Core tip: This study supports the “targeted convergence” hypothesis: Shu-acu point and Mu-acu point signals gather not only in spinal cord but also evince a ‘targeted convergence’ in brain stem and hypothalamus. We determined that the signals induced by electroacupuncture (EA) stimulation of gastric Shu and Mu points gather in the dorsal vagal complex (DVC) and paraventricular hypothalamic nucleus (PVN), increasing levels of gastrointestinal hormones and their receptors in the PVN and gastric antrum to regulate gastric motility. We hypothesize that EA at gastric Shu and Mu points regulates gastric motility, which may be achieved through the PVN-DVC-vagus-gastric pathway.