title: Focusing in multiwell potentials: applications to ion channels.
abstract: We investigate nonequilibrium stationary distributions induced by stochastic dichotomous noise in double-well and multiwell models of ion channel gating kinetics. The channel kinetics is analyzed using both overdamped Langevin equations and master equations. With the Langevin equation approach we show a nontrivial focusing effect due to the external stochastic noise, namely, the concentration of the probability distribution in one of the two wells of a double-well system or in one or more of the wells of the multiwell model. In the multiwell system, focusing in the outer wells is shown to be achievable under physiological conditions, while focusing in the central wells has proved possible so far only at very low temperatures. We also discuss the strength of the focusing effect and obtain the conditions necessary for maximal focusing to appear. These conditions cannot be predicted by a simple master equation approach.
authors.affiliation: Dipartimento di Matematica e Fisica, Università Cattolica, via Musei 41, 25121 Brescia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Ponzoni
authors.forename: G L
authors.initials: GL
authors.lastname: Celardo
authors.forename: F
authors.initials: F
authors.lastname: Borgonovi
authors.forename: L
authors.initials: L
authors.lastname: Kaplan
authors.forename: A
authors.initials: A
authors.lastname: Kargol
mesh_terms: D003198:Computer Simulation; D015640:Ion Channel Gating / Q000502:physiology*; D007473:Ion Channels / Q000737:chemistry* / Q000502:physiology*; D007700:Kinetics; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D015233:Models, Statistical; D013269:Stochastic Processes
chemical_list: D007473:Ion Channels