神经病理性痛大鼠背根神经节细胞电生理学特征的改变

CHANGES OF ELECTROPHYSIOLOGICAL PROPERTIES IN DORSAL ROOT GANGLION NEURONS LSOLATED FROM NEUROPATHIC PAIN RATS

目的 :研究神经病理性痛大鼠背根神经节 (dorsalrootganglion ,DRG)细胞电生理特征的改变。方法 :以单侧L5和L6 脊神经结扎制备大鼠神经病理性痛模型 ,运用全细胞电流钳技术进行电生理记录。结果 :引起损伤侧DGR中、小直径神经元兴奋的基强度降低 ,动作电位爆发阈值下降 ,小直径神经元的动作电位时程变宽 ,自发放电的细胞比率明显升高。结论 :神经损伤诱导初级感觉神经元的兴奋性增强 ,这可能是引起动物神经病理性痛敏的原因之一。

Objective: Pain and hyperalgesia can occur when nerves were injured. The present study aims to examine the electrophysiological changes of dorsal root ganglion (DRG) neurons in rats with neuropathic pain. Methods: The neuropathic pain model in rat was prepared by tight ligation of right side L 5 and L 6 spinal nerve. Whole cell current clamp technique was used for electrophysiological recording. Results: The rheobase and the threshold of action potential were reduced in both small and medium DRG neurons after nerve ligation, while the duration of action potential at half amplitude (APD 0.5 ) was broadened in small injured neurons. Nerve injury also induced spontaneous activities in small neurons. No significant changes were observed in other electrophysiological properties. Conclusion: These results suggested that nerve ligation could induce hyperexcitability of nociceptors, which might be an important mechanism underlying chronic neuropathic pain.