小鼠耳蜗螺旋神经节细胞电生理学特性的研究

Electrophisiologic study of murine spiral ganglion neurons

目的:应用膜片钳技术记录小鼠耳蜗螺旋神经节细胞的全细胞电流,了解电压依赖性离子通道的基本电生理学特性,并比较耳蜗顶、底转螺旋神经节细胞电生理学特性的差异。方法:应用全细胞构型电压钳制技术,采用不同的电极内液及阻断剂,在不同的刺激参数下记录耳蜗顶、底转螺旋神经节细胞的电压依赖性离子通道电流,并进行分析比较。结果:实验记录到了内向的钠电流、延迟整流钾电流、超极化激活内向阳离子通道电流及瞬时外向钾电流,并发现耳蜗顶、底转螺旋神经节细胞的延迟整流钾电流及瞬时外向钾电流的电生理学特性具有显著性差异(P<0.05)。结论:实验记录到的各种离子电流数据表明耳蜗螺旋神经节细胞具有完成动作电位的形成、传导并对其功能进行调节的离子通道基础;耳蜗顶、底转螺旋神经节细胞电生理学特性的差异有助于听觉的形成过程。

Objective： To explore the nature of voltage dependent ion channels and basic electrophysiological characteristics of cochlear spiral ganglion neurons of apical and basal turn by patch clamp techniques of whole cell configure on murine spiral ganglion neurons. Method： Different voltage dependent ionic currents were recorded with patch clamp techniques of whole cell configure on the condition of different internal electrode solution, blockers and stimulus protocol. Result： Inward sodium channel current（INa）, hyperpolarization-activated inward cationic cur rent（Ih） , outward delay rectification potassium current （IK） and outward transient potassium current （IA）were recorded , significant difference of electrophysiological characteristics of IA and IK was found between apical and basal turns（P〈0.05）. Conclusion： Various ionic currents are recorded, which shows that spiral ganglion neurons have the base of ionic channels to complete formation, conduction and modulation of action potential for auditory information transduction, the difference of electrophysiological characteristics between apical and basal turns contributes to the course of hearing formation.