Rapid Changes of Potassium Concentration at the Outer Surface of Exposed Single Neurons during Membrane Current Flow
Rapid Changes of Potassium Concentration at the Outer Surface of Exposed Single Neurons during Membrane Current Flow
复制标题
膜电流流动期间暴露的单个神经元外表面钾浓度的快速变化
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
H. Lux
中科院分区：
文献类型：
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作者：
Erwin Neher;H. Lux
K+-敏感的液体离子交换微电极被证明是能够测量发生在毫秒时间尺度上的浓度变化。然而，一些季铵离子，如四乙基铵和乙酰胆碱，当浓度低至10-4至10-3 M时，能够阻断电极功能。通过这些电极可以测量由蜗牛的暴露的单个神经元的尖峰活动或电压钳脉冲引起的细胞外钾浓度的变化。定量分析表明，在钳位脉冲后短时间内在细胞附近发现的过量钾的总量与膜电流携带的钾的量相对较好地一致。
K+-sensitive liquid ion-exchanger microelectrodes are shown to be capable of measuring concentration changes which occur on a millisecond time scale. However, some quaternary ammonium ions, such as tetraethylammonium and acetylcholine, are able to block electrode function when present in concentrations as low as 10-4 to 10-3 M. Changes in extracellular potassium concentration caused by spike activity or voltage clamp pulses of exposed single neurons of the snail Helix pomatia may be measured by these electrodes. Quantitative analysis shows that the total amount of excess potassium found in the vicinity of the cell a short time after a clamp pulse, is in relatively good agreement with the amount of potassium carried by the membrane current.