An M-like potassium current in the guinea pig cochlea
An M-like potassium current in the guinea pig cochlea
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DOI：
10.1159/000085439
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Järlebark, L
中科院分区：
文献类型：
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作者：
Liang, GH;Moore, EJ;Järlebark, L
钾离子电流在稳定静息膜电位中起作用。这些电流之前已经在包括感觉受体在内的几种细胞类型中被发现。考虑到维持膜兴奋性对内耳的机电转导很重要，我们在豚鼠听觉器官分离的外毛细胞中研究了M电流的存在。使用脉冲协议设计强调M电流与全细胞膜片钳技术，电压和时间依赖性，非失活，低阈值电流（M电流的标志）被记录。氯化镉显著降低了这些电流。RT-PCR分析结果显示，编码M通道亚基KCNQ2和KCNQ3的基因在豚鼠耳蜗中表达。我们的数据表明，豚鼠外毛细胞表达一个m样钾电流，在声音刺激后，可能在将膜电位恢复到静息水平，从而调节外毛细胞突触机制方面发挥重要作用。版权所有(C) 2005 S. Karger AG，巴塞尔。
Potassium M currents play a role in stabilizing the resting membrane potential. These currents have previously been identified in several cell types, including sensory receptors. Given that maintaining membrane excitability is important for mechano-electrical transduction in the inner ear, the presence of M currents was investigated in outer hair cells isolated from the guinea pig hearing organ. Using a pulse protocol designed to emphasize M currents with the whole-cell patch-clamp technique, voltage- and time-dependent, non-inactivating, low-threshold currents (the hallmarks of M currents) were recorded. These currents were significantly reduced by cadmium chloride. Results from RT-PCR analysis indicated that genes encoding M channel subunits KCNQ2 and KCNQ3 are expressed in the guinea pig cochlea. Our data suggest that guinea pig outer hair cells express an M-like potassium current that, following sound stimulation, may play an important role in returning the membrane potential to resting level and thus regulating outer hair cell synaptic mechanisms. Copyright (C) 2005 S. Karger AG, Basel.