If a single ion channel record is observed in which two ion channels are never simultaneously open, then it is often of interest to know whether the observations indeed arose from the activity of only one ion channel. This question can be answered if it is possible to calculate the distribution of the duration of runs of single openings in a membrane patch that contains two active channels. If the observed run of single openings is much longer than that expected for a patch with two channels it is likely that only one channel was active. An approximate method is presented for calculating the distribution of the duration of runs of single openings in a patch with two active channels; this method has the advantage that it can be calculated from observable quantities, and requires no knowledge of the details of the ion-channel mechanism or its rate constants. The accuracy of this approximation is tested by exact calculations of the properties of runs of single openings, and of single bursts, for two specific mechanisms and a large range of rate constants. The approximation is good in all cases in which openings occur singly, or in closely spaced bursts. If, as is common in practice, openings occur in clusters that are separated by long shut periods, then overlap of clusters from two different channels may be detected, if no double opening is produced, as a period in the middle of a cluster in which the probability of being open doubles. The results derived here can be applied to such a period to test whether it results from the simultaneous activity of two channels, rather than from a change in the properties of a single channel.

中文翻译：

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包含两个通道的膜片中离子通道开口和爆发的随机特性：当观察到仅包含单个开口的记录时，有关通道数量的证据。

如果观察到一个单个离子通道记录，其中两个离子通道从未同时打开，那么通常很想知道观察结果是否确实来自仅一个离子通道的活动。如果可以计算包含两个活动通道的膜片中单个开口的运行持续时间的分布，则可以回答此问题。如果观察到的单个开口的行程比带有两个通道的贴片的预期行程长得多，则很可能只有一个通道处于活动状态。提出了一种近似方法，用于计算具有两个活动通道的贴片中单个开口的运行持续时间的分布。这种方法的优点是可以根据可观察到的数量进行计算，并且不需要了解离子通道机理的细节或其速率常数。通过对两种特定机制和大范围的速率常数的单孔和单脉冲的运行特性的精确计算，可以测试这种近似的准确性。在开口单独出现或紧密间隔开的所有情况下，近似值都很好。如果在实践中很常见，如果在由长关闭周期分隔开的簇中出现开口，那么如果没有产生双重打开，则可以检测到来自两个不同通道的簇重叠，作为簇中间的一个周期，开放的可能性加倍。此处得出的结果可以应用于这样的时间段，以测试它是否是由两个通道的同时活动引起的，