SINGLE-CHANNEL CURRENTS RECORDED FROM MEMBRANE OF DENERVATED FROG MUSCLE-FIBERS
SINGLE-CHANNEL CURRENTS RECORDED FROM MEMBRANE OF DENERVATED FROG MUSCLE-FIBERS
复制标题
DOI：
10.1038/260799a0
复制
发表时间：
1976-01-01
期刊：
影响因子：
64.8
通讯作者：
SAKMANN, B
中科院分区：
文献类型：
--
作者：
NEHER, E;SAKMANN, B
在骨骼肌纤维的神经肌肉接头处与乙酰胆碱（ACh）受体相关的离子通道可能是生物膜中描述得最好的通道。然而，个别渠道的属性仍然是未知的，因为以前的研究关注的是平均人口属性。宏观电导波动发生在乙酰胆碱的存在下进行了分析，以提供单通道电导和平均开放时间的估计1 -3。然而，获得的值取决于对基本电导贡献形状的假设，例如，基本贡献是一个方形脉冲状事件2。显然，改进电导测量技术以解决预期在单通道打开或关闭时发生的电导的离散变化将是非常有意义的。由于过多的外来背景噪音，迄今未能做到这一点。我们报告了一个更灵敏的电导测量方法，它在适当的条件下，揭示了离散的电导变化，显示了许多功能，已被假定为单离子通道。
THE ionic channel associated with the acetylcholine (ACh) receptor at the neuromuscular junction of skeletal muscle fibres is probably the best described channel in biological membranes. Nevertheless, the properties of individual channels are still unknown, as previous studies were concerned with average population properties. Macroscopic conductance fluctuations occurring in the presence of ACh were analysed to provide estimates for single channel conductance and mean open times1–3. The values obtained, however, depended on assumptions about the shape of the elementary conductance contribution—for example, that the elementary contribution is a square pulse-like event2. Clearly, it would be of great interest to refine techniques of conductance measurement in order to resolve discrete changes in conductance which are expected to occur when single channels open or close. This has not been possible so far because of excessive extraneous background noise. We report on a more sensitive method of conductance measurement, which, in appropriate conditions, reveals discrete changes in conductance that show many of the features that have been postulated for single ionic channels.