Voltage Fluctuations and Collective Effects in Ion-Channel Protein Ensembles.

We study experimentally the noise in ensembles of voltage-gated ion channels. The coupling between the microscopic state of the channels and the macroscopic voltage fluctuations leads to collective effects which (i) induce damped oscillations in the voltage noise and (ii) reduce the voltage noise in absolute terms, with a stronger reduction for larger numbers of participating channels. These results are confirmed by numerical simulations and explained in the context of a simple model that presents the ensemble of channels as a damped harmonic oscillator. [S0031-9007(96)01604-3]