一次力竭运动过程中大鼠丘脑腹外侧核神经元电活动及NR2B、GABAAα-1蛋白表达变化的研究

The research on the neuronal firing activity and the expression of NR2B and GABAAα-1 in the ventrolateral nucleus of the thalamus during a fatiguing exercise

目的:探讨运动疲劳发生、发展过程中大鼠丘脑腹外侧核在"基底神经节-丘脑-皮层"通路的神经中继调控作用。方法:实验选用8周龄雄性Wistar大鼠,SPF级,采用在体局部场电位记录技术(local field potentials,LFPs),对一次性力竭运动过程中大鼠丘脑腹外侧核(ventrolateral nuleus,VL)神经元电活动变化进行同步动态观察;采用免疫荧光双标技术对力竭运动前后及恢复90min时刻大鼠丘脑腹外侧核的NR2B和GABAAα-1的蛋白表达水平进行检测。结果:在一次性力竭运动过程中大鼠丘脑腹外侧核的神经元电活动变化呈现明显的阶段性特征:自主运动期神经元电活动α波活动显著增高(P<0.05),功率谱重心频率显著升高(P<0.05),兴奋性升高;疲劳初期和力竭期神经元电活动δ、θ波活动显著增高(P<0.05),功率谱重心频率显著降低(P<0.05),兴奋性下降;与安静状态相比,大鼠丘脑腹外侧核在力竭即刻和恢复90min时GABAAα-1受体阳性细胞数量显著增多(P<0.05,P<0.01)。结论:丘脑腹外侧核作为"基底神经节-丘脑-皮层"神经通路的中继核团,在力竭运动过程中神经元兴奋性发生改变,GABAAα-1受体蛋白表达的改变是导致该核团神经元兴奋性变化的机制之一。

Objective: To explore the neural relay regulation effect of the ventrolateral nucleus of the thalamus in the "basal ganglia-thalamic-cortex" pathway during occurrence and development of sport fatigue.Method:In the experiment,8-week-old male Wistar rats(SPF) were used. The local field potential electrical recording technology was used to synchronously observe the changes in the electrical activity of the ventrolateral nucleus of the thalamus in the rat during a one-time exhaustive exercise. The immunofluorescence double-labeling technique was used to detect the expression of NR2 B and GABAAα-1 in the ventrolateral nucleus before and after exhaustive exercise, and at 90 minutes after recovery.Result: The neural activity of the ventrolateral nucleus showed obvious stage characteristics in the different stages of exhaustive exercise. Under automatic exercise stage,the percentage of α wave was increased significantly(P<0.05),the gravity frequency increased significantly(P<0.05). Under early fatigue and exhaustion stage,the percentage of δ, θ wave was increased significantly(P<0.05), the gravity frequency decreased significantly(P<0.05). Compared with the control group,the concentration of GABAAα-1 receptor of the ventrolateral nucleus at the exhaustive moment and 90 minutes after recovery was increased significantly(P<0.05).Conclusion:The ventrolateral nucleus of the thalamus acts as a relay nucleus of the "basal ganglia-thalamuscortex" pathway. The excitability of neurons changes during exhaustive exercise. The change in the expression of GABAAα-1 receptor protein is possibly responsible for the changes in the excitability of neurons of this nucleus.