三叉神经根慢性压迫损伤对大鼠三叉神经尾侧亚核内WDR神经元电活动的影响

目的:观察三叉神经根慢性压迫损伤对大鼠三叉神经脊束核尾侧亚核(caudal subnucleus of the spinaltrigeminal nucleus,Vc)内广动力范围(wide dynamic range neurons,WDR)神经元自发放电和诱发放电活动的影响。方法:通过慢性压迫损伤三叉神经根的方法建立三叉神经痛(TN)动物模型,采用在体细胞外记录技术观察空白对照组和TN模型组大鼠Vc内WDR神经元的自发放电和诱发的放电活动。结果:对照组和TN模型组大鼠Vc内WDR神经元自发放电频率分别为0.84±0.15 Hz和3.18±0.59 Hz;口面部感受野分别给予刷、压、夹机械刺激后,对照组大鼠Vc内WDR神经元的诱发放电频率分别为3.27±1.28 Hz、5.62±0.74 Hz和6.76±1.22 Hz,而TN组大鼠诱发放电频率则分别为7.85±1.57 Hz、10.04±0.72 Hz和12.04±1.77 Hz。结论:TN模型组大鼠Vc内WDR神经元的自发放电频率和诱发放电频率均显著高于对照组大鼠,提示三叉神经根慢性压迫损伤可诱导Vc内WDR神经元兴奋性增强。

Effects on electrophysiological activity of WDR neurons in the Vc following chronic compression injury of trigeminal nerve root in rats

Objective: To observe the spontaneous discharges and evoked discharges of wide dynamic range(WDR) neurons in the caudal subnucleus of the spinal trigeminal nucleus(Vc) following chronic compression injury of trigeminal nerve root in rats.Methods: The trigeminal neuralgia(TN) animal model was established by chronic compression injury of the trigeminal nerve root at first,then the spontaneous discharges and evoked discharges of the WDR neurons in Vc of control group and TN group were observed,using extracellular recording technique.Results: The frequency of Vc WDR neurons spontaneous discharges in the control group and TN group rats was 0.84±0.15 Hz and 3.18±0.59 Hz,respectively;The frequency of evoked discharges in Vc WDR neurons in control group was respectively 3.27±1.28 Hz,5.62±0.74 Hz and 6.76±1.22 Hz,while the frequency of that in TN group was respectively 7.85±1.57 Hz,10.04±0.72 Hz and 12.04±1.77 Hz,which were induced by mechanical stimulation of brush,press and pinch on the orofacial receptive field,respectively.Conclusion: The frequency of spontaneous discharges and evoked discharges in TN group rats were significantly higher than the control group,which indicate that chronic compression injury of the trigeminal nerve root may upregulate the electrophysiological activity of WDR neurons in the Vc of rats.