Junying Du1, Junfan Fang1, Zitong Xu1, Xuaner Xiang1, Sisi Wang1, Haiju Sun1, Xiaomei Shao1, Yongliang Jiang1, Boyi Liu1, Jianqiao Fang2. 1. Department of Neurobiology and Acupuncture Research, the Third Clinical Medical College, Zhejiang Chinese Medical University, Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Hangzhou 310053, China. 2. Department of Neurobiology and Acupuncture Research, the Third Clinical Medical College, Zhejiang Chinese Medical University, Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Hangzhou 310053, China. Electronic address: fjq@zcmu.edu.cn.
Abstract
BACKGROUND: The neuropeptide S/Neuropeptide S receptor (NPS/NPSR) system is involved in the regulation of anxiety in rodents. Chronic inflammation can induce anxiety. Our lab has observed that electroacupuncture (EA) has a beneficial effect on chronic inflammatory pain and pain-related anxiety; however, the mechanism should be further clarified. In the present study, we used an inflammatory pain model to investigate the role of the NPS/NPSR system in the anterior cingulate cortex (ACC) in the analgesic and antianxiety effects of EA. RESULTS: In an inflammatory pain model, the paw withdrawal thresholds (PWTs) were decreased, pain-related anxiety-like behaviors were induced, and the ipsilateral protein expression of NPS and NPSR was decreased in the ACC. EA stimulation increased the PWTs, reduced pain-related anxiety-like behavior, and enhanced the ipsilateral protein expression of NPS and NPSR in the ACC. NPS microinjection increased the PWTs and decreased pain-related anxiety-like behaviors. Furthermore, an NPSR inhibitor combined with EA reversed the effect of EA on the PWTs and pain-related anxiety-like behaviors. CONCLUSIONS: Our results suggest that EA suppresses pain and pain-related anxiety-like behavior of chronic inflammation in rats by increasing the expression of the NPS/NPSR system in the ACC.
BACKGROUND: The neuropeptide S/Neuropeptide S receptor (NPS/NPSR) system is involved in the regulation of anxiety in rodents. Chronic inflammation can induce anxiety. Our lab has observed that electroacupuncture (EA) has a beneficial effect on chronic inflammatory pain and pain-related anxiety; however, the mechanism should be further clarified. In the present study, we used an inflammatory pain model to investigate the role of the NPS/NPSR system in the anterior cingulate cortex (ACC) in the analgesic and antianxiety effects of EA. RESULTS: In an inflammatory pain model, the paw withdrawal thresholds (PWTs) were decreased, pain-related anxiety-like behaviors were induced, and the ipsilateral protein expression of NPS and NPSR was decreased in the ACC. EA stimulation increased the PWTs, reduced pain-related anxiety-like behavior, and enhanced the ipsilateral protein expression of NPS and NPSR in the ACC. NPS microinjection increased the PWTs and decreased pain-related anxiety-like behaviors. Furthermore, an NPSR inhibitor combined with EA reversed the effect of EA on the PWTs and pain-related anxiety-like behaviors. CONCLUSIONS: Our results suggest that EA suppresses pain and pain-related anxiety-like behavior of chronic inflammation in rats by increasing the expression of the NPS/NPSR system in the ACC.