Effect of Electroacupuncture on Pain Perception and Pain-Related Affection: Dissociation or Interaction Based on the Anterior Cingulate Cortex and S1.

Yan Shi,Boyi Liu,Yingling Xu,Yilin Zhu,Shujing Yao,Xiaomei Shao,Zui Shen,Lijiao She,Yongliang Jiang,Zemin Wu,Junying Du,Yuanyuan Wu,Yi Liang,Jianqiao Fang,Jing Sun,Jing-Wen Yang

doi:10.1155/2020/8865096

Abstract

Electroacupuncture (EA) can effectively modulate pain perception and pain-related negative affect; however, we do not know whether the effect of EA on sensation and affect is parallel, or dissociated, interactional. In this study, we observed the effects of the anterior cingulate cortex (ACC) lesion and the primary somatosensory cortex (S1) activation on pain perception, pain-related affection, and neural oscillation in S1. ACC lesions did not affect pain perception but relieved pain-paired aversion. S1 activation increased pain perception and anxious behavior. EA can mitigate pain perception regardless of whether there is an ACC lesion. Chronic pain may increase the delta and theta band oscillatory activity in the S1 brain region and decrease the oscillatory activity in the alpha, beta, and gamma bands. EA intervention may inhibit the oscillatory activity of the alpha and beta bands. These results suggest that EA may mitigate chronic pain by relieving pain perception and reducing pain-related affection through different mechanisms. This evidence builds upon findings from previous studies of chronic pain and EA treatment.

Highlights

For a long time, it was generally believed that pain perception was well understood, while the pain related affection was yet unclear
In the present study, we examined chronic inflammatory pain perception, pain-paired aversion, and pain-related anxiety in rats with and without an anterior cingulate cortex (ACC) lesion and S1 activated and synchronous neural oscillations in S1, to explore whether pain perception and negative affection influence each other based on ACC and/or S1, and if the effect of EA on chronic pain is a result of the effect of EA on negative affect
This part was to explore whether pain perception and negative affect influence each other based on ACC

Summary

Introduction

It was generally believed that pain perception was well understood, while the pain related affection was yet unclear. Many studies have indicated that chronic pain aggravates pain perception and induces negative affective states (e.g., aversiveness, anxiety, depression, and anhedonia), sleep disorders, abnormal decision-making, and even suicide [3,4,5,6,7]. 20-30% of chronic pain patients have a negative affect [8, 9]. Experimental studies have indicated that emotional interventions, such as meditation, alleviate pain perception and negative affection and have a beneficial protective effect on the brain’s gray matter and pain regulation pathways [10, 11]. Mitigating chronic pain by modulating negative affect is a new research direction, and the mechanism of the interaction between chronic pain and negative affect remains unclear

Methods

Results

Discussion

Conclusion