Springer Online Journal Archives 1860-2000
Abstract In an effort to understand the gating properties of ionic channels in biological membranes, an efficient method was developed to estimate the kinetic constants from opening-closing events of the channels. Our method is suitable to single channel patch-clamp recordings that contain several ionic channels functioning simultaneously. It is different from the maximum likelihood method previous developed by Horn and Lange, in that our method is a continuum approach and makes uses of analytic expressions of the probability density functions of the event times. Combinatorial analysis was necessary to correctly include more typical multi-channel recordings. This yields computationally quicker results than the method of Horn and Lange, which uses a discretized time series. Model-dependent portions of the code are minimal and easily modified. To illustrate the goodness of our method, we have generated the open-close processes of the patch-clamp records on a digital computer using the exponential random number generators. For multi-channel patches, we have introduced a few plausible approximations to make our algorithm more efficient. The soundness of the our approximations were tested with such measures as the fraction of the open state at time t, p open(t), and frequencies of the number of openings per run. A copy of the computer code implementing this algorithm can be obtained from the authors.
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