Statistical Analysis of Multiple Ion Channel Data

Abstract

Biological cell membranes contain molecular structures known as ion channels. The electrical activity of these channels regulates a number of cellular functions, such as heartbeat and neural transmission. Often the experimenter can only observe the combined current conducted through a cell patch containing an unknown number of ion channels, each channel of equal conductance. The observed current record is a step function with unit up or down steps occurring at random times. Based on such data, we obtain a goodness-of-fit test for the hypothesis that the channels in a portion of cellular membrane are operating independently, and that $K$ types ($K$ small) of channels exist in the membrane. If the hypothesis is accepted, estimates for the mean behaviour of each type of channel in the experiment are obtained. These techniques are applied to simulated and biological data.