title: Electropermeabilization of adherent cells with cochlear implant electrical stimulation in vitro.
abstract: Cochlear implant stimulation creates a reduction in electrode impedance that returns to pre-stimulation levels following cessation of stimulation and is presumed to be associated with the fibrous tissue covering over the electrode array. This study assessed the possibility that transitory impedance reduction originates from a change in the membrane permeability of cells on the electrode (electropermeabilization). These changes can be recorded using the dye propidium iodide, which fluoresces upon entry into the leaky cell. The in vitro model used showed impedance reduction and dye uptake into adherent cells overlying planar gold electrodes stimulated with as little as 5 min of clinically relevant cochlear implant stimulation. The delayed additions of propidium iodide showed a similar dye uptake to those groups with concurrent dye addition, suggesting the electropermeabilization was not reversible. Further understanding of the mechanisms behind these impedance and cell permeability changes with cochlear implant electrical stimulation may provide opportunities for creating long-lasting reductions in electrode impedance.
authors.affiliation: The HEARing CRC, Melbourne, Vic., Australia.
authors.forename: Carrie
authors.initials: C
authors.lastname: Newbold
authors.forename: Andrew
authors.initials: A
authors.lastname: Farrington
authors.forename: Lawson
authors.initials: L
authors.lastname: Peters
authors.forename: Robert
authors.initials: R
authors.lastname: Cowan
authors.forename: Karina
authors.initials: K
authors.lastname: Needham
mesh_terms: D000818:Animals; D002462:Cell Membrane; D003054:Cochlear Implants; D004285:Dogs; D017097:Electric Impedance; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D018274:Electroporation; D004847:Epithelial Cells; D005355:Fibrosis; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D061985:Madin Darby Canine Kidney Cells; D011419:Propidium
chemical_list: D007202:Indicators and Reagents; D011419:Propidium