豚鼠耳蜗离体外毛细胞的膜电位和离子电流

MEMBRANE POTENTIAL AND ION CURRENTS IN ISOLATED OUTER HAIR CELLS OF GUINEA PIG COCHLEA

利用膜片钳技术对分离的豚鼠耳蜗外毛细胞(OHC)进行了研究,结果表明:(1)新分离的正常OHC呈柱状,胞膜先滑,胞核位于底部,静纤毛由顶端表皮板伸出,4小时内形态无明显变化.(2)全细胞电压钳记录结合通道阻断剂实验表明,OHC膜电流主要由电压依赖性钾离子流组成.(3)利用全细胞记录方式得到的OHC静息电位值为-26±9mV((?)±SD,n=10).

Outer hair cells (OHCs) were isolated from guinea pig cochlea and investigated with the patch clamp techniques. These cells could maintain their morphology in vitro with no obvious change at room temperature for about 4 hours. Using simultaneous whole cell voltage clamp, it was demonstrated that the main transmembrane currents were voltage - dependent K+ current. The resting membrane potential of isolated OHCs ranged from - 10mV to - 36mV with a mean value of -26mV (n=10). The application of the patch clamp techniques to the study of hair cells has contributed to understanding not only of normal hair cell transduction and synapitc mechanisms. but also of the mechanisms of action ototoxic drugs at the molecular level.