Bioimpedance modeling to monitor astrocytic response to chronically implanted electrodes
Bioimpedance modeling to monitor astrocytic response to chronically implanted electrodes
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DOI：
10.1088/1741-2560/6/5/055005
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发表时间：
2009-10-01
影响因子：
4
通讯作者：
Bellamkonda, R. V.
中科院分区：
文献类型：
--
作者：
McConnell, G. C.;Butera, R. J.;Bellamkonda, R. V.
神经假体装置的广泛采用目前受到阻碍，因为我们无法可靠地记录来自长期植入电极的神经信号。对植入电极的局部组织反应影响记录失败的程度还不清楚。为了研究这种现象，阻抗谱已显示出作为一种非侵入性工具来估计微电极的局部组织响应的前景。在这里，我们使用完善的科尔模型对慢性植入大鼠的阻抗谱进行建模，并对建模参数与星形胶质细胞瘢痕的组织学标志物（包括胶质细胞酸性蛋白（GFAP）和4 '，6-二脒基-2-苯基吲哚（DAPI））进行相关性分析。模型参数和GFAP之间的相关性是显着的三个参数的研究：Py值，R-0和垂直酒吧Z垂直酒吧（1）（kHz），并在所有情况下被限制到第一个100 μ m的接口。在前100 μ m中，Py值是唯一与DAPI相关的参数。我们的实验结果，沿着计算机模拟，表明星形胶质细胞是一个主要的细胞球员影响电阻抗谱。结果还表明，从反应性星形胶质细胞对阻抗谱的最大贡献发生在第一个100 μ m的接口，电极是最有可能记录电信号。这些结果形成了未来方法的基础，其中阻抗谱可用于评估神经植入物，评估策略，以尽量减少疤痕，并可能开发闭环假体装置。
The widespread adoption of neural prosthetic devices is currently hindered by our inability to reliably record neural signals from chronically implanted electrodes. The extent to which the local tissue response to implanted electrodes influences recording failure is not well understood. To investigate this phenomenon, impedance spectroscopy has shown promise for use as a non-invasive tool to estimate the local tissue response to microelectrodes. Here, we model impedance spectra from chronically implanted rats using the well-established Cole model, and perform a correlation analysis of modeled parameters with histological markers of astroglial scar, including glial fibrillary acid protein (GFAP) and 4',6-diamidino-2-phenylindole (DAPI). Correlations between modeled parameters and GFAP were significant for three parameters studied: Py value, R-o and vertical bar Z vertical bar(1) (kHz), and in all cases were confined to the first 100 mu m from the interface. Py value was the only parameter also correlated with DAPI in the first 100 mu m. Our experimental results, along with computer simulations, suggest that astrocytes are a predominant cellular player affecting electrical impedance spectra. The results also suggest that the largest contribution from reactive astrocytes on impedance spectra occurs in the first 100 mu m from the interface, where electrodes are most likely to record electrical signals. These results form the basis for future approaches where impedance spectroscopy can be used to evaluate neural implants, evaluate strategies to minimize scar and potentially develop closed-loop prosthetic devices.