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目的:利用大鼠背根节慢性压迫模型确定,来自于外周的触、压刺激可以被有自发放电活动的背根节神经元(DRG)所放大,并与伤害性感受神经元之间形成交叉兴奋,从而造成触诱发痛信号的传入。方法:在体单纤维细胞外记录及在体细胞内记录技术。结果:大鼠背根节慢性压迫损伤后,具有不同感受野性质的外周神经传入信号可以通过DRG胞体向中枢传递。在具有阈下膜电位振荡(SMPO)的DRG神经元,刺激坐骨神经后,外周传入信号可被放大。慢波振荡放电(SWO)是在损伤DRG神经元上观察到的一类较为特殊的阵发放电形式,细胞内记录显示,其发生基于周期存在的去极-复极化膜电位变化。在每一阵发时相内,放电频率有一低-高-低的规律变化。在SWO放电神经元,坐骨神经刺激施加于膜电位的去极化时相时,会诱发该放电的提前出现,且在A及C类神经元均可看到。在坐骨神经给予仅兴奋A类纤维的刺激,若该纤维上存在SWO放电的模式,则可在邻近的C类纤维记录到传入放电活动,即产生了神经节内A-C交叉兴奋现象。结论:外周传入信号在经过大鼠损伤的背根神经节神经元上传时,信号可被放大。且在A类神经元发生慢波振荡放电时,在神经节内产生A-C交叉兴奋现象。该交叉兴奋现象的出现,与阻断神经元钠通道的失活,增强持续性钠电流的开放密切相关。
OBJECTIVE: Using rat model of chronic dorsal root ganglia compression, contact and pressure stimulation from the periphery can be amplified by DRG with spontaneous discharge activity and cross with nociceptive neurons Excited, resulting in the introduction of Touching pain signals. Methods: Extracellular recording of monofibrils and recording in somatic cells. RESULTS: After chronic compression injury of dorsal root ganglion, peripheral nerve afferent signals with different receptive field properties could be transmitted to the central nervous system through the DRG cell body. In DRG neurons with subthreshold membrane potential oscillations (SMPO), the peripheral afferent signals can be amplified after stimulation of the sciatic nerve. Slow wave oscillatory discharge (SWO) is a special form of PD seen on DRG neurons. Intracellular recordings show that the occurrence of SWO is based on periodic changes in the depolarization-repolarization membrane potential. In each burst of time, the discharge frequency has a low - high - low regular changes. In SWO discharge neurons, the sciatic nerve stimulates the depolarization phase applied to the membrane potential, leading to an early appearance of this discharge and is visible in both A and C neurons. In the sciatic nerve, stimulation of only excited type A fibers was observed. If SWO discharge mode was present on the fibers, the afferent discharge activity could be recorded in adjacent fibers of class C, resulting in the phenomenon of A-C cross-excitement in ganglia. CONCLUSIONS: Peripheral afferent signals can be amplified when they are uploaded through the dorsal root ganglion neurons injured by the rat. A class C neurons in the slow wave oscillation discharge occurs in the ganglion A-C cross-excited phenomenon. The emergence of this cross-excitement phenomenon is closely related to blocking the inactivation of neuronal sodium channels and enhancing the openness of persistent sodium currents.