SINGLE NA+ CHANNEL CURRENTS OBSERVED IN CULTURED RAT MUSCLE-CELLS
SINGLE NA+ CHANNEL CURRENTS OBSERVED IN CULTURED RAT MUSCLE-CELLS
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DOI：
10.1038/287447a0
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发表时间：
1980-01-01
期刊：
影响因子：
64.8
通讯作者：
NEHER, E
中科院分区：
文献类型：
--
作者：
SIGWORTH, FJ;NEHER, E
膜Na+通道的电压和时间依赖性电导负责神经肌肉细胞中动作电位的传播。在含有104-107个Na+通道的神经元制备的电压-阶跃箝位实验中，膜电导随时间平滑变化，但波动分析和其他证据表明，潜在的单通道电导变化是随机的，在闭合和打开状态之间快速转换，正如在其他通道类型中看到的那样。本文报道了在生理条件下使用细胞外膜片钳技术在培养的大鼠肌肉细胞上首次观察到通过单个Na+通道的电流。这些观察结果支持先前关于通道门控的推断，并显示单通道电导为。apprx。18ps [piosiemens]。
The voltage- and time-dependent conductance of membrane Na+ channels is responsible for the propagation of action potentials in nerve muscle cells. In voltage-step-clamp experiments on neurone preparations containing 104-107 Na+ channels, the membrane conductance shows smooth variations in time but analysis of fluctuations and other evidence suggests that the underlying single-channel conductance changes are stochastic, rapid transitions between closed and open states as seen in other channel types. Reported here are the 1st observations of currents through individual Na+ channels under physiological conditions using an improved version of the extracellular patch-clamp technique on cultured rat muscle cells. These observations support earlier inferences about channel gating and show a single-channel conductance of .apprx. 18 pS [pioosiemens].