Abstracts - Dipartimento di Elettronica Applicata
Abstracts - Dipartimento di Elettronica Applicata
Abstracts - Dipartimento di Elettronica Applicata
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Meta 2010 & FEM 2010 – Rome, 13-15 December 2010<br />
Finite Element model of charge transport across ionic<br />
channels<br />
S. Coco and A. Laudani<br />
(1) University of Catania, DIEES<br />
Catania, Italy – e-mail: alaudani@<strong>di</strong>ees.unict.it, coco@<strong>di</strong>ees.unict.it<br />
The exchange of signals between living cells takes place mainly through the cellular<br />
membrane, which represents a selective permeable barrier between the cell and<br />
extracellular environment. Among interesting substances, ions are of paramount<br />
importance, since activation of several critical signaling pathways and a number of<br />
cellular functions depend on ionic concentrations (especially Ca++ and K+). The flow<br />
of ions across cell membranes takes place through membrane channels, which are<br />
typical hydrophobic regions having a size of the order of few Å, where the membrane<br />
lipid bilayer exhibits ’openings’ [1]. The simulation of the mechanism of ion flow<br />
across ionic channels is a very complicated task, mainly for the lack of accurate<br />
descriptions of channel structure, the <strong>di</strong>fficulty of modeling the behaviour of the<br />
proteic chains constituting the channel walls, the very high number of atoms, the very<br />
short time scale of the involved dynamical phenomena, etc. Several attempts have<br />
been made to build coherent representations of ion flow across ionic channels, in<br />
accordance with experimental measurements. In literature the most investigated<br />
approaches are Molecular Dynamic (MD), Brownian Dynamic (BD), Langevin-<br />
Lorentz-Poisson (LLP) particle model, and Poisson-Nernst-Planck (PNP) [2-4].<br />
In this paper a 3-D Finite Element (FE) model of charge transport across ionic<br />
channel membrane is presented. The use of irregular FE mesh allows us to model the<br />
3-D channel geometry with a lower number of degree of freedom with respect to FD.<br />
The problem is solved by a FE <strong>di</strong>scretization and by an appositely developed iterative<br />
scheme. The model allows us to obtain an accurate description of ion flow across the<br />
cell membrane. The results are globally summarized by the computed I/V<br />
characteristic relationship, in which the ionic current flowing through the channel is<br />
shown as a function of the membrane voltage.<br />
References<br />
[1] B. Hille, Ionic Channels of Excitable Membranes, Sunderland, MA: Sinauer, 1992.<br />
[2] Salvatore Coco, Daniela S. M. Gazzo, Antonino Laudani, Giuseppe Pollicino, “3-D Finite Element<br />
Poisson-Nernst-Planck model for the analysis of ion transport across ionic channels”, IEEE trans.<br />
on Magnetics, 43, 1461-1464, 2007.<br />
[3] M. E. Oliveri, S. Coco, D. S. M. Gazzo, A. Laudani and G. Pollicino, “3-D FE particle based<br />
model of ion transport across ionic channels”, Scientific Computing in Electrical Engineering,<br />
Mathematics in Industry, Springer-Verlag, 9, 2006<br />
[4] S. Aboud, D. Marreiro, M.Saraniti, and R. Eisenberg, “A poisson p3m force field scheme for<br />
particle-based simulations of ionic liquids,” Journal of Computational Electronics, vol. 3, pp. 117–<br />
133, 2004.<br />
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