A method of analyzing nonstationary ionic channel current fluctuations in the presence of an additive measurement noise

A method for estimating the parameters of nonstationary ionic channel current fluctuations (NST-ICFs) in the presence of additive measurement noise is proposed. The case in which the sample records of corrupted NST-ICTs are available for estimation, and the experiment can be repeated many times to calculate the statistics of noisy NST-ICFs, is considered. The conventional second-order regression model expressed in terms of the mean and variance of noisy NST-ICFs is derived theoretically, assuming that NST-ICFs are binomially distributed. The parameters of NST-ICFs that are of interest can be estimated without interference from the additive measurement noise by identifying the regression coefficients. The accuracy of the parameter estimates is theoretically evaluated using the error-covariance matrix of the regression coefficients. The validity and effectiveness of the proposed method are demonstrated in a Monte Carlo simulation of Na ⁺ channels kinetics.