目的 在体研究不同极性电流对耳蜗毛细胞感受器电位和频率响应的影响.方法 在成功建立豚鼠耳蜗毛细胞电反应记录方法后,将不同的极性电流通过微电极施加于被记录毛细胞,观察毛细胞频率响应和感受器电位的变化.结果 超极化电流对内毛细胞(IHCs)、外毛细胞(OHCs)感受器电位的交流(AC)反应有明显增加作用, 而去极化电流则使之减小.但极性电流对内、外毛细胞的去极化和超极化反应的影响是不对称的.用±1.0 nA极性电流对支持细胞AC和耳蜗中阶的反应均无影响.结论 认为毛细胞感受器电位的变化是由于极性电流改变了毛细胞侧膜电阻,毛细胞在耳蜗中作为一低通滤波器起作用.%Objective To study changes in hair cell receptor potentials and frequency response by polarizing currents in the guinea pig. Methods In vivo recordings of receptor potentials and frequency response were made intracellularly in cells of the Organ of Corti with or without constant polarizing current injection into the cells through the recording electrode. Results All cell responses were enhanced by hyperpolarization and decreased by depolarization. IHCs and OHCs showed somewhat different response patterns. Hyperpolarizing currents had a stronger effect on changing AC responses in IHCs than depolarizing currents. The opposite asymmetry characterized OHC receptor potential changes. In addition, the largest changes were seen at low frequencies and current-induced changes showed a trend toward a constant high-frequency asymptote between 1 ~ 2 kHz. Conclusion It is believed that the response changes induced by polarizing currents are due to changes in electric resistance of the basolateral cell membrane. The cochlear hair cells apparently work as a low-band filter
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