腰5脊神经结扎大鼠腰4背根神经节神经元超极化激活电流的变化

CHANGE OF Ih IN LUMBAR 4 INTACT DRG NEURONS AFTER L5 SPINAL NERVE LIGATION IN RATS

目的:研究腰5脊神经结扎(L5spinal nerve ligation,SNL)神经病理痛大鼠腰4背根神经节(dorsal root ganglion,DRG)神经元超极化激活电流(Ih)及其通道超极化激活环核苷酸门控阳离子通道(HCN)发生的可塑性变化。方法:以单侧L5SNL制备神经病理痛大鼠模型,运用全细胞膜片钳技术记录和分析背根神经节神经元Ih的表达和激活特性。结果:L5SNL之后,腰4 DRG神经元Ih的电流密度降低,单位电导下降,而翻转电位及电压依赖特性未发生显著性改变。结论:腰4DRG神经元Ih的这些变化可能贡献于L5SNL大鼠的神经病理痛。

Objective： To investigate the changes of Ih and its channel, hyperpolarization-activated cyclic nucleotide gated cation channel （ HCN）, in the intact lumbar 4 DRG neurons following lumbar 5 （ L5 ） spinal nerve ligation （SNL）. Methods： Rat neuropathic pain model was produced by tight ligation of L5 spinal nerve and Ih was recorded with whole-cell patch clamp technique. Results： The current density and the maximal conductance of Ih in the SNL group were decreased significantly compared with those in the sham-operation control, while the reversal potential and the channel biophysics properties of HCN channel did not show any significant change. Conclusion： These electrophysiological changes of Ih and HCN channel properties in the L4 intact DRG neurons might contribute to peripheral sensitization in L5 SNL neuropathic pain.