Threshold diversity effects on the electric currents of voltage-gated ion channels

Abstract

The effect of threshold diversity on the electrical response of domains of voltage-gated ion channels is studied. The noise terms included are dynamic (the thermal and input signal noises) and static (the domain diversity described by statistical distributions for the individual threshold potentials for ionic conduction). The results show how the different noise sources affect the electrical currents of ion channels and biosensors reconstituted into membranes. In particular, the correlation between the input and output signals attains a maximum at a given value of the input signal noise and the diversity allows an extended dynamic response of the channels. Ionic currents and potential gradients across ion channels are also involved in the cell cycle and embryogenesis. We suggest that domains of ion channels with locally different charge distributions (and then different threshold potentials) localized asymmetrically over the cell membrane can produce local electrical signals (potentials and fluxes) that may be relevant to understand the spatial patterns involved in cell growing and differentiation.