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猫双侧扣带回前部内脏伤害感受神经元自发电活动特性的差异

吴敏范, 姚阳, 李玉芳, 杨宇, 滕国玺

沈阳医学院生理学教研室，沈阳 110034；沈阳药科大学药学院药理学教研室，沈阳 110016；中国医科大学脑研究所神经生理学研究室，沈阳 110001

摘要

本研究旨在阐明双侧大脑皮层扣带回前部(anterior cingulate gyrus, ACG)在内脏痛觉感受中的作用。实验用强电流刺激一侧内脏大神经(greater splanchnic nerve, GSN)作为内脏伤害性刺激，用在体微电极细胞内电位记录技术记录、分析ACG 内神经元对刺激的反应和自发生物电活动。根据对GSN 刺激是否发生反应，将ACG 内神经元分为产生诱发反应的GSN 刺激相关神经元(GSN-stimulus-relative neurons, GSRNs)与不产生诱发反应的非相关神经元。根据诱发反应的潜伏期等性质，GSRNs 进一步分为内脏伤害感受神经元(visceral nociceptive neurons, VNNs)与非伤害感受神经元(non-visceral nociceptiveneurons, NVNNs)；而VNNs 又分为特异性(specific visceronociceptive neurons, SVNNs)与非特异性内脏伤害感受神经元(non-specific visceronociceptive neurons, NSVNNs)。结果显示，对侧ACG 内GSRNs 比例为38.18%，显著高于同侧ACG内GSRNs 比例(29.49%, P<0.01)，表明GSN 传入纤维虽然投射到双侧ACG，但主要投射到对侧ACG。和同侧ACG 相比，对侧ACG 的SVNNs 比例较低，而NSVNNs 比例则较高(P<0.01)。同侧ACG 内GSRNs、VNNs、NVNNs 和SVNNs 的静息电位(resting potential, RP)绝对值均显著低于对侧ACG 的对应神经元(P<0.01)，而双侧ACG 内NSVNNs 的RP 绝对值没有明显差异。双侧ACG 内VNNs、NVNNs 的自发生物电活动形式、自发放电频率和幅值之间无明显差别；VNNs 中具有自发生物电活动的神经元比例显著高于NVNNs 中的比例。以上结果提示双侧ACG 皮层虽然都能感受GSN 的伤害性刺激信号，但双侧ACG 皮层的反应模式、反应程度不完全相同，从而为双侧脑功能的不对称性提供了新的科学实验依据。

关键词： 扣带回前部; 内脏痛; 伤害感受神经元; 细胞内电位; 自发生物电活动

分类号：Q424

[Difference in properties of spontaneous electric activities of visceral nociceptive neurons in bilateral anterior cingulate gyrus of cats.] [Ariticle in Chinese]

WU Min-Fan, YAO Yang, LI Yu-Fang, YANG Yu, TENG Guo-Xi

Department of Physiology, Shenyang Medical College, Shenyang 110034, China； Department of Pharmacology, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China； Laboratory of Neurophysiology, Brain Research Institute, China Medical University, Shenyang 110001, China

Abstract

The aim of the present study is to explore the role of anterior cingulate gyrus (ACG) in bilateral cerebral cortex in visceralnociceptive sensation. Electrical stimulation of greater splanchnic nerve (GSN) was used as visceral nociceptive stimulus, and intracellularrecording techniques in vivo was used to record and analyze the responses to stimuli and spontaneous electric activities of theneurons in the bilateral ACG. According to the responses to electrical stimulation of GSN, the neurons in the bilateral ACG were dividedinto GSN-stimulus-relative neurons (GSRNs) and GSN-stimulus-irrelative ones. According to the characteristics of the evoked responsesto electrical stimulation of the GSN, GSRNs could be further classified into visceral nociceptive neurons (VNNs) and nonvisceralnociceptive neurons (NVNNs). VNNs included specific visceral nociceptive neurons (SVNNs) and non-specific visceralnociceptive neurons (NSVNNs). The results showed that the percentage of GSRNs in the contralateral ACG (38.18%) was signifi- cantly higher than that in the ipsilateral ACG (29.49%, P<0.01), suggesting although GSN afferent fibers project to bilateral ACG, theymainly project to the contralateral ACG. Compared with ipsilateral ACG, contralateral ACG possessed lower proportion of SVNNsand higher proportion of NSVNNs (P<0.01). The absolute values of resting potentials (RP) of GSRNs, VNNs, NVNNs and SVNNs inipsilateral ACG were less than those of corresponding neurons in contralateral ACG. However, there were no significant differences inthe absolute values of RP of NSVNNs between ipsilateral and contralateral ACG. There were no significant differences in modes,frequencies and amplitudes of spontaneous electric activities of VNNs and NVNNs between ipsilateral and contralateral ACG.Additionally, the percentage of neurons having spontaneous electric activities from VNNs was significantly higher than that fromNVNNs, which indicated that the excitability of VNNs was higher than that of the NVNNs in bilateral ACG. These results suggest thatthe patterns and degrees of the responses to nociceptive GSN-stimulation of the ipsilateral and contralateral ACG are different, thusproviding new experimental data for the asymmetry of functions of the bilateral brain.

Key words: anterior cingulate gyrus; visceral pain; nociceptive neuron; intracellular potential; spontaneous biological electric activity

收稿日期：2010-08-12　　录用日期：2010-09-08

通讯作者：吴敏范　　E-mail: minfanwu0594@sina.com.cn

引用本文：

吴敏范, 姚阳, 李玉芳, 杨宇, 滕国玺. 猫双侧扣带回前部内脏伤害感受神经元自发电活动特性的差异[J]. 生理学报 2010; 62 (5): 450-454.

WU Min-Fan, YAO Yang, LI Yu-Fang, YANG Yu, TENG Guo-Xi. [Difference in properties of spontaneous electric activities of visceral nociceptive neurons in bilateral anterior cingulate gyrus of cats.] [Ariticle in Chinese] . Acta Physiol Sin 2010; 62 (5): 450-454 (in Chinese with English abstract).