受损背根节神经元持续性钠流的检测

目的:检测损伤大鼠背根节(DRG)神经元持续性钠流(persistent sodium current, Inap)并研究其与阈下膜电位振荡的关系. 方法: 术后3～6 d慢性痛大鼠模型背根节急性分离,消化离散成单细胞,对中小型DRG神经元运用全细胞膜片钳技术记录. 结果: 电压钳下,钳制电位在-80 mV,给予斜波去极化到-30 mV时,细胞产生一持续时间150～200 ms,幅值89～200 pA的持续性内向钠流,且对100 nmol/L TTX敏感.电流钳下,产生阈下膜电位振荡的细胞,给予100 nmol/L TTX后,振荡消失.结论:在受损DRG神经元上检测到的持续性钠流可能是产生阈下膜电位振荡的基础之一.

Detection of persistent sodium current in injured DRG neurons

AIM: To detect persistent sodium current and to study its relationship with subthreshold membrane potential oscillation in injured DRG neurons. METHODS: Whole-cell patch-clamp experiments were performed with medium and small DRG neurons freshly isolated from rats. RESULTS: In the voltage-clamp, DRG neurons with depolarizated membrane potential from -80 mV to -30 mV in ramp, produced a persistent sodium current for 150-200 ms. The current with amplitude of 89-200 pA was sensitive to 100 nmol/L TTX. In the current-clamp, when 100 nmol/L TTX was added to the cells with subthreshold membranepotential oscillation (SMPO), the oscillation disappeared. CONCLUSION: The INap detected in the injured DRG neurons may be in some way responsible for the production of SMPO.