Effects of Glial Cells on Electrode Impedance Recorded from Neural Prosthetic Devices In Vitro

Springer Science and Business Media LLC - Tập 38 - Trang 1031-1047 - 2010
John P. Frampton1,2, Matthew R. Hynd3, Michael L. Shuler4, William Shain1,3
1Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, USA
2Biggs Laboratory, Albany, USA
3Wadsworth Center, New York State Department of Health, Albany, USA
4Department of Biomedical Sciences, Cornell University, Ithaca, USA

Tóm tắt

Neural prosthetic devices hold the potential to be used in the treatment of a variety of neurological disorders. However, their long-term clinical success is currently limited by the ability to achieve stable interfaces between devices and the CNS. Immunohistochemical analysis has shown that cellular responses occur in tissue surrounding implanted devices. These cellular responses have been correlated with the impedance measured from device electrodes, leading to the hypothesis that a possible mechanism resulting in inconsistent device performance is the formation of an electrically insulating glial sheath at the implantation site. However, little is known about what cellular and tissue changes affect impedance values and thus contribute to the decreases in electrode performance. We have designed an in vitro system in which cell conditions can be varied within an artificial tissue matrix surrounding a neural prosthetic device. In this study, high-density cultures of glial cells were analyzed by immunohistochemical methods and impedance spectroscopy. Astrocytes and microglia were cultured at various ratios within the matrix surrounding the probes, and were observed over a period of 2 weeks. Cell seeding conditions and confocal images were compared to impedance data to enable the effects of glial cell type on electrode impedance to be determined.

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