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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:16 |
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Conference: Bucharest University Faculty of Physics 2006 Meeting
Section: Electricity and Biophysics
Title:
Electro-orientation of rod like cells
Authors:
M. Radu
Affiliation:
Department of Health and Environmental Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, PO Box MG6,Magurele, 077125, Romania,
E-mail
mradu@ifin.nipne.ro
Keywords:
rod-like cells,membrane permittivity, external conductivity
Abstract:
The orientation of rod-like cells in alternating electric field was theoretically studied. The interfacial polarization induced by a homogenous alternating electric field determines the orientation of elongated cells either parallel or perpendicular to the field lines in function of the field frequency. The theoretical model presented in this paper takes into account the geometrical and electrical parameters of the cell (size, membrane and cytosol conductivity and permittivity). The torque rotating the polarized cell was calculated and the reorientation frequency vs. electric conductivity of the external medium (the electro-orientation spectrum) was derived. Focusing the model on photoreceptor outer segment behaviour in alternating electric field, the disc stack electric properties were considered. The orientation spectrum seems to be very sensitive to membrane permittivity and cytosol conductivity. The last parameter limits the range of external conductivity in which the reorientation can be observed. Also, the spectrum is drastically changed by the width of interdiscal space. Enhancing the membrane permeability (feature of damaged cells) induces a decrease of the internal conductivity. This determines a sharp change in the orientation behaviour of cells in low conductive media. We consider that these results can be used in future studies for developing non-invasive methods to analyze the rod-like cells viability.
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