The Influence of Stomach Back-Shu and Front-Mu Points on Insular Functional Connectivity in Functional Dyspepsia Rat Models.

Yuan Chen,Robert Yu-Sheng Tan,Yu Shi,Hua-Bin Zheng,Pu-Yue Zhang,Tao Long,Ying Zhao,Mi Liu

doi:10.1155/2021/2771094

Abstract

Functional Dyspepsia (FD) is a common functional gastrointestinal disease, which can reduce the quality of life in patients. Prior research has indicated that insula is closely related to FD and that acupuncture can regulate the functional connectivity (FC) of FD. Therefore, we hypothesized that acupuncture on FD was effected through the insular pathway. To test our hypothesis, we performed electroacupuncture (EA) on FD rat models and then examined the FC between insula and other brain regions through resting-state functional magnetic resonance imaging (rs-fMRI). Seven-day-old male infant Sprague-Dawley (SD) rats were randomly divided into control group, FD model group, and FD acupuncture group, with twelve rats per group (n = 36). Upon establishing successful models, the FD acupuncture group was subjected to EA intervention using Stomach back-shu (BL-21) and front-mu (RN-12) points for ten consecutive days for durations of 20 minutes each day. After intervention, each group was subject to rs-fMRI. The digital image data obtained were analyzed using FC analysis methods. Subsequently, gastric ligation was performed to measure gastric emptying rates. Before EA intervention, the FD model group exhibited decreased functional connections between the insula and a number of brain regions. After EA intervention, FD acupuncture group exhibited increasing FC between insula and regions when compared to the FD model group, such as the primary somatosensory cortex (S1), hippocampal CA3 (CA3), polymorphic layer of dentate gyrus (PoDG), caudate putamen (CPu), and oral pontine reticular nuclei (PnO) (P < 0.05); decreasing FC was also exhibited between insula and regions such as the bilateral primary and secondary motor cortexes (M1/2), paraventricular hypothalamic nucleus (PVA), and limbic cortex (LC). These findings indicate that the effective treatment of FD using EA may be through regulating the abnormal FC between insula and several brain regions, in particular CA3, PoDG, and PVA.

Highlights

Functional Dyspepsia (FD) is a functional gastrointestinal disorder defined by the Rome IV consensus as the presence of symptoms thought to originate from the upper gastrointestinal region without organic causes; it can be divided into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) [1]
Current conventional allopathic treatment options exist for FD, such as H. pylori eradication, proton pump inhibitors (PPIs), and histamine-type-2-receptor antagonists (H2RAs); their efficacies are modest at best [3, 4], and they result in negative side effects or negative long-term effects to the patient [5, 6]
Our current resting-state functional magnetic resonance imaging (rs-functional magnetic resonance imaging (fMRI)) study involving seed-based functional connectivity analysis on EA treatment of FD rat models establishing the insula as region of interest (ROI) has revealed the following: (a) the combination of RN-12 and BL-21 acupoints can be used to improve gastric motility, which confirms the results of previous studies [19,20,21], and, more importantly, (b) specific patterns of increasing and decreasing functional connectivity exist with regard to the insula in FD rat models and occur in EA intervention of FD

Summary

Introduction

Functional Dyspepsia (FD) is a functional gastrointestinal disorder defined by the Rome IV consensus as the presence of symptoms thought to originate from the upper gastrointestinal region without organic causes; it can be divided into postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) [1]. As an alternative form of treatment for FD that does not result in the same long-term side effects and resistance as drugs [7], acupuncture and/or electroacupuncture (EA) has been used in China for thousands of years to help relieve its various symptoms [8]. Research in this area has focused on the mechanisms behind both the pathogenesis of the condition [9] and the therapeutic effects of acupuncture on human and animal subjects [10,11,12]. Modeling of FD using animals has become an emerging area of research due to ethical or economic considerations arising from use of human FD patients

Objectives

Methods

Results

Discussion

Conclusion