Guan Xiao-Ya, Zhang Xiao-Yi, Li Zhen-Hua, Qin Xia, DU Zhen-Ying, Zhao Xin, Li Jian-Guo, Zhang Ce, Zhang Yu
Key Laboratory of Cell Physiology, Ministry of Education, Department of Physiology, Shanxi Medical University, Taiyuan 030001, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2019 Nov;35(6):481-485. doi: 10.12047/j.cjap.5840.2019.105.
Increasing activities in anterior cingulate cortex (ACC) can enhance the aversion reactions associated with noxious stimuli. It has been known that opioid receptors activation can trigger endogenous analgesic effect. This study tried to explore whether opioid receptors activation in the ACC region could reduce the aversion associated with noxious stimuli.
The experimental rats were randomly divided into seven groups, Complete Freund's adjuvant (CFA) + normal saline (NS) group, normal saline (NS) + normal saline (NS) group, normal saline (NS) +DAMGO ((DAla, NMe-Phe, Gly-ol)enkephinlin, μ-opioid receptor agonist) group, complete Freund's adjuvant (CFA)+ 0.01/0.04/0.2/1 μg/μl DAMGO group(n=6). The experimental period was three days. The basal value was measured on the first day. The second day, 1 μl was administered through the ACC area, and then 0.08 ml of complete Freund's adjuvant (CFA) was injected into the left hind paw of the rat. CPA response, paw withdrawal reflex latency (PWL) and electrical activity in the ACC brain region of rats were observed on the third day.
①PWL was significantly decreased in rats after CFA was injected into left hind paw compared with post-injection(P＜0.05).② In the pain side of the apparatus, it took rats less residence time than that in the non-pain side. ③ 0.04/0.2/1 μg/μl DAMGO was given before CFA-injection, C-CPA reactions could be revised significantly. ④ Given 0.04/0.2/1 μg/μl DAMGO in the ACC region could decrease the increasing discharge frequency induced by CFA in ACC neurons.
The activation of the mu-opioid receptor in the ACC region alleviates the aversion induced by noxious stimulation.
前扣带回皮质（ACC）活动增强可增强与有害刺激相关的厌恶反应。已知阿片受体激活可触发内源性镇痛作用。本研究试图探讨ACC区域阿片受体激活是否能降低与有害刺激相关的厌恶感。
将实验大鼠随机分为七组，即完全弗氏佐剂（CFA）+生理盐水（NS）组、生理盐水（NS）+生理盐水（NS）组、生理盐水（NS）+DAMGO（（D-丙氨酸，N-甲基苯丙氨酸，甘氨醇）脑啡肽，μ-阿片受体激动剂）组、完全弗氏佐剂（CFA）+0.01/0.04/0.2/1μg/μl DAMGO组（n=6）。实验期为三天。第一天测量基础值。第二天，通过ACC区域给予1μl药物，然后将0.08ml完全弗氏佐剂（CFA）注射到大鼠左后爪。第三天观察大鼠的条件性位置偏爱（CPA）反应、爪撤离反射潜伏期（PWL）和ACC脑区的电活动。
①与注射后相比，将CFA注射到大鼠左后爪后，PWL显著降低（P＜0.05）。②在装置的疼痛侧，大鼠停留时间比非疼痛侧少。③在注射CFA前给予0.04/0.2/1μg/μl DAMGO，可显著改善条件性位置偏爱反应。④在ACC区域给予0.04/0.2/1μg/μl DAMGO可降低CFA诱导的ACC神经元放电频率增加。
ACC区域μ-阿片受体的激活减轻了有害刺激诱导的厌恶感。
