Channel Noise

Patch-clamp is the best method for analyzing single-channel current activities today. The method is not good, however, at measuring the total number of channels expressed on the cell membrane that are responsible for the current of concern. In contrast, noise analysis has some advantage over the single-channel recording as a method to estimate the total number of ion channels. Also, noise analysis can obtain some channel information regarding size and kinetics even when individual channel events are so small to be detected directly as single-channel events. In this chapter the logic of noise analysis for stationary currents and nonstationary currents follows a description of several classic experiments conducted during the 1970s–1980s. Several technical issues frequently encountered during experiments are also addressed.