Function of Mammalian Nicotinic Acetylcholine Receptors: Agonist Concentration Dependence of Single Channel Current Kinetics

This chapter summarizes the studies of the activation of acetylcholine receptors (AchRs) of BC3H-1 mammalian clonal muscle cells. Receptor activation is described in the context of a linear four-state scheme, and transition rates are estimated for each reaction step in this scheme. Attention is turned to a description of activation by acetylcholine (Ach) and to the dependence of single channel current kinetics on Ach concentration. The analysis presented in the chapter recasts the original dwell-time histograms using a logarithmic time axis as described by Sigworth and Sine. The linear-to-logarithmic transformation compresses a single dwell-time distribution, allowing it to be displayed on a single panel. Histograms from several experiments, then, may be compared more readily, such as closed time histograms at different agonist concentrations.