过刊浏览

偏侧咀嚼模型大鼠三叉神经运动核的功能可塑性

王云¹, 余兰芳^1,2, 汪萌芽^2,*

¹皖南医学院口腔医学院，芜湖 241002；²皖南医学院细胞电生理研究室，芜湖 241002

摘要

为了观察偏侧咀嚼模型大鼠的三叉神经运动核(trigeminal motor nucleus, Mo5)及咬肌H反射的变化，以探讨长期偏侧咀嚼可能涉及的运动中枢功能可塑性机制，本研究取成年Wistar大鼠54只随机分为偏侧咀嚼1月(n = 10)、3月(n = 10)和16月(n = 7)模型组及相应对照组。模型组采用左侧(建模侧)临床牙冠间断磨除法建立偏侧咀嚼大鼠模型。在麻醉状态下进行双侧Mo5生物电活动细胞外记录，同时进行双侧咬肌H反射试验并记录各侧咬肌肌电(electromyography, EMG)。实验结果显示：1、3、16月的模型组大鼠建模侧Mo5神经元自发放电频率均低于非建模侧和相应对照组左侧；给予左侧咬肌神经电刺激在1、3月模型组大鼠建模侧Mo5诱导反应的潜伏期均长于相应对照组左侧；给予左侧咬肌神经电刺激诱导咬肌H反射时，3、16月模型组大鼠建模侧H波幅值低于相应对照组左侧。本研究结果提示，偏侧咀嚼降低了废用侧Mo5神经元的兴奋性，可能是偏侧咀嚼涉及的运动中枢功能可塑性机制之一。

关键词： 三叉神经运动核; H反射 ; 细胞外记录 ; 偏侧咀嚼 ; 神经可塑性

分类号：R332;R363.2;R329.2

Functional plasticity of trigeminal motor nucleus in unilateral mastication model rats

WANG Yun¹, YU Lan-Fang^1,2, WANG Meng-Ya^2,*

¹School of Stomatology, Wannan Medical College, Wuhu 241002, China；²Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu 241002, China

Abstract

To observe the plasticity changes of trigeminal motor nucleus (Mo5) and masseter H-reflex in unilateral mastication model rats and explore the possible mechanism of functional plasticity in motor center involved in unilateral mastication, 54 adult male Wistar rats were randomly divided into 1-month (n = 10), 3-month (n = 10), and 16-month (n = 7) model groups and their corresponding control groups, respectively. Unilateral mastication model rats were prepared by intermittent removal of clinical crowns of left teeth (model side). Rats were anesthetized (20% urethane, i.p.), and bilateral Mo5 were chosen to conduct extracellular recordings, while bilateral electromyography (EMG) of masseter muscle and its H-reflex were simultaneously recorded by a polygraph. It was observed that the firing rate of Mo5 neurons in model sides was significantly lower than that of right sides in 3 model groups, and that of left sides in their control groups. The response latency of Mo5, which was evoked by electrical stimulation of masseter nerve in model sides of 1-month and 3-month model groups, was significantly longer than that of left sides in their control groups. Moreover, the amplitude of H-wave in model sides of 3-month and 16-month model groups was lower than that of left sides in their control groups when H-reflex was evoked by electrical stimulation of left masseter nerve. These results suggest that unilateral mastication in model rats decreases the Mo5 neuron excitability, and this may be one of the functional plasticity mechanisms in motor center involved in unilateral mastication.

Key words: trigeminal motor nucleus; H-reflex ; extracellular recording ; unilateral mastication ; neural plasticity

收稿日期：2017-04-19　　录用日期：2017-12-08

通讯作者：汪萌芽　　E-mail: wangmy@wnmc.edu.cn

DOI: 10.13294/j.aps.2017.0089

引用本文：

王云, 余兰芳, 汪萌芽. 偏侧咀嚼模型大鼠三叉神经运动核的功能可塑性[J]. 生理学报 2018; 70 (1): 9-16.

WANG Yun, YU Lan-Fang, WANG Meng-Ya. Functional plasticity of trigeminal motor nucleus in unilateral mastication model rats. Acta Physiol Sin 2018; 70 (1): 9-16 (in Chinese with English abstract).