Yet another approach to the dwell-time omission problem of single-channel analysis

Abstract

Distortion of the open-time or closed-time distributions of single channel currents, due to limited time resolution of the recording system, has been addressed by many authors. The calculation of the modified distributions generally involves the numerical inversion of a Laplace transform and is difficult to apply in fitting multistate kinetic schemes to data. Our approach is to introduce "virtual states" into the kinetic scheme, as suggested by Blatz and Magleby (1986. Biophys. J. 49:967-980) to account for missed events. To simplify the assignment of rate constants in multistate schemes we make use of Kienker's (1989. Proc. R. Soc. Lond. 236:296-309) theory to first transform schemes to uncoupled form. Our approach provides a good approximation to the exact solution, while allowing the observable dwell-time distributions, and also the second-order probability density functions, to be computed by standard matrix techniques.