TY - JOUR
T1 - Extraction force and cortical tissue reaction of silicon microelectrode arrays implanted in the rat brain
AU - McConnell, George C.
AU - Schneider, Thomas M.
AU - Owens, D. Jason
AU - Bellamkonda, Ravi V.
PY - 2007/6
Y1 - 2007/6
N2 - Micromotion of implanted silicon multielectrode arrays (Si MEAs) is thought to influence the inflammatory response they elicit. The degree of strain that micromotion imparts on surrounding tissue is related to the extent of mechanical integration of the implanted electrodes with the brain. In this study, we quantified the force of extraction of implanted four shank Michigan electrodes in adult rat brains and investigated potential cellular and extracellular matrix contributors to tissue-electrode adhesion using immunohistochemical markers for microglia, astrocytes and extracellular matrix deposition in the immediate vicinity of the electrodes. Our results suggest that the peak extraction force of the implanted electrodes increases significantly from the day of implantation (day 0) to the day of extraction (day 7 and day 28 postimplantation) (1.68 ± 0.54 g, 3.99 ± 1.31 g, and 4.86 ± 1.49 g, respectively; mean ± SD; n=4). For an additional group of four shank electrode implants with a closer intershank spacing we observed a significant increase in peak extraction force on day 28 post implantation compared to day 0 and day 7 postimplantation (5.56 ± 0.76 g, 0.37 ± 0.12 g and 1.87 ± 0.88 g, respectively; n=4). Significantly, only glial fibrillary acidic protein (GFAP) expression was correlated with peak extraction force in both electrode designs of all the markers of astroglial scar studied. For studies that try to model micromotion-induced strain, our data implies that adhesion between tissue and electrode increases after implantation and sheds light on the nature of implanted electrode-elicited brain tissue reaction.
AB - Micromotion of implanted silicon multielectrode arrays (Si MEAs) is thought to influence the inflammatory response they elicit. The degree of strain that micromotion imparts on surrounding tissue is related to the extent of mechanical integration of the implanted electrodes with the brain. In this study, we quantified the force of extraction of implanted four shank Michigan electrodes in adult rat brains and investigated potential cellular and extracellular matrix contributors to tissue-electrode adhesion using immunohistochemical markers for microglia, astrocytes and extracellular matrix deposition in the immediate vicinity of the electrodes. Our results suggest that the peak extraction force of the implanted electrodes increases significantly from the day of implantation (day 0) to the day of extraction (day 7 and day 28 postimplantation) (1.68 ± 0.54 g, 3.99 ± 1.31 g, and 4.86 ± 1.49 g, respectively; mean ± SD; n=4). For an additional group of four shank electrode implants with a closer intershank spacing we observed a significant increase in peak extraction force on day 28 post implantation compared to day 0 and day 7 postimplantation (5.56 ± 0.76 g, 0.37 ± 0.12 g and 1.87 ± 0.88 g, respectively; n=4). Significantly, only glial fibrillary acidic protein (GFAP) expression was correlated with peak extraction force in both electrode designs of all the markers of astroglial scar studied. For studies that try to model micromotion-induced strain, our data implies that adhesion between tissue and electrode increases after implantation and sheds light on the nature of implanted electrode-elicited brain tissue reaction.
KW - Astroglial scar
KW - Chronic recordings
KW - Force measurement
KW - Immunohistochemistry
KW - Microelectrodes
KW - Micromotion
KW - Neuroprostheses
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U2 - 10.1109/TBME.2007.895373
DO - 10.1109/TBME.2007.895373
M3 - Article
C2 - 17554828
AN - SCOPUS:34249327727
SN - 0018-9294
VL - 54
SP - 1097
EP - 1107
JO - IEEE Transactions on Biomedical Engineering
JF - IEEE Transactions on Biomedical Engineering
IS - 6
ER -