Electroacupuncture Alleviating the Affective Pain via δ-opioid Receptor in Anterior Cingulate Cortical Neurons in Rats
作者单位：Departmen of Physiology Shanxi Medical University Departmen of Pathology Shanxi Medical University
会议名称：《中国神经科学学会第十二届全国学术会议》
会议日期：2017年
学科分类：1005[医学-中医学] 100512[医学-针灸推拿学] 10[医学]
基 金：supported by the National Natural Science Foundation of China(No.81371254)
关 键 词：conditioned place avoidance(CPA) affective pain rostral anterior cingulate cortex(r ACC) δ-opioid receptor electroacupuncture(EA)
摘 要：Objective The sensory and emotional responses of pain are produced by different central mechanisms and are mediated by different neurotransmission pathways. The studies of Human and animal behavior, electrophysiology, brain imaging and other related technologies have provided evidence that the anterior cingulate cortex（ACC）, which locates in the frontal lobe of the brain, involves in chronic inflammation-induced disgust formation, and plays an important role in the behavioral responses of adverse emotions, especially in the rostral ACC（r ACC）. Previous studies have shown that electroacupuncture（EA） can relieve the affective pain through activation of μ-opioid receptor in r ACC brain area in rats, but it is not clear whether the pain can be relieved by activating δ-opioid receptor in r ACC. Methods A rat model of complete Freund’s adjuvant（CFA） induced conditional position avoidance（C-CPA） was used in this experiment. Different concentrations（1/2.5/5/10 μg/μl） of naltrindole, a δ-opioid receptor antagonist, were respectively microinjected into r ACC brain area in rats before EA（10 Hz,3 m A,0.1 ms） or sham EA stimulation in Huantiao acupoint（GB30）. Then we measured C-CPA responses and heat pain behavior（paw withdrawal latency, PWL）, and the expression of δ-opioid receptor and the phosphorylation of NR1/NR2 A/NR2 B subunit in r ACC subsequently were detected. Results（1） Subcutaneous injection of CFA significantly reduced the time of PWL.（2） In the painful environment, CFA rats stayed less time than in the non-painful environment.（3） EA stimulation relieved C-CPA responses in rats.（4） Naltrindole administrated at the dose of 5 or 10μg/μl in r ACC markedly reversed the role of EA relieving C-CPA responses, but the dose of 1/2.5 μg/μl had no obvious effect.（5） The phosphorylation of NR1/NR2 A/NR2 B subunit in r ACC was consistant with the change trends of CPA responses.（6） After EA stimulation, the expression of δ-opioid receptor in r ACC was significantly up-regulated in