Silicon microelectrode array technology holds considerable promise in advancing the goal of developing stable, electrode-brain interfaces. Chronic unit recordings from multiple neurons in the brain would significantly enhance our understanding of normal physiology and provide a valuable control signal for use in neuro-prosthetic devices. However, the current generation of silicon microelectrodes does not allow stable long-term recordings. The precise mechanisms that cause failure of silicon microelectrode mediated recordings are not known. We hypothesize that the million-fold stiffness mismatch between silicon and neural tissues generates shearing forces at the interface resulting in an astro-glial scar formation that progressively excludes neurons from the vicinity of the recording electrodes. To test our hypothesis, we propose novel and innovative methods to a) determine the strain-sensitivity of primary astrocytes in terms of their adopting a scarring phenotype; b) determine if strain-induced scar formation around Si-microelectrodes degrades their recording capabilities in organotypic hippocampal slice cultures; and c) design coatings for Si-microelectrodes that allow the sustained local release of anti-inflammatory agents to decrease scarring and increase recording stability. The above aims represent a highly inter-disciplinary investigation of an important problem in the design and development of stable neuro-prosthetic devices. Successful completion of our research goals is likely to impact the mechanical and biochemical aspects of the design of the next generation of silicon microelectrode arrays, and subsequently significantly impact the quality of life of persons with disabilities.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
3R01NS045072-06S1
Application #
7670771
Study Section
Special Emphasis Panel (ZRG1-GRM (01))
Program Officer
Pancrazio, Joseph J
Project Start
2002-12-15
Project End
2009-05-31
Budget Start
2007-06-01
Budget End
2009-05-31
Support Year
6
Fiscal Year
2008
Total Cost
$52,850
Indirect Cost
Name
Georgia Institute of Technology
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
097394084
City
Atlanta
State
GA
Country
United States
Zip Code
30332
McConnell, George C; Rees, Howard D; Levey, Allan I et al. (2009) Implanted neural electrodes cause chronic, local inflammation that is correlated with local neurodegeneration. J Neural Eng 6:056003
McConnell, G C; Butera, R J; Bellamkonda, R V (2009) Bioimpedance modeling to monitor astrocytic response to chronically implanted electrodes. J Neural Eng 6:055005
Zhong, Yinghui; Bellamkonda, Ravi V (2008) Biomaterials for the central nervous system. J R Soc Interface 5:957-75
Zhong, Yinghui; Bellamkonda, Ravi V (2007) Dexamethasone-coated neural probes elicit attenuated inflammatory response and neuronal loss compared to uncoated neural probes. Brain Res 1148:15-27
McConnell, George C; Schneider, Thomas M; Owens, D Jason et al. (2007) Extraction force and cortical tissue reaction of silicon microelectrode arrays implanted in the rat brain. IEEE Trans Biomed Eng 54:1097-107
He, Wei; McConnell, George C; Bellamkonda, Ravi V (2006) Nanoscale laminin coating modulates cortical scarring response around implanted silicon microelectrode arrays. J Neural Eng 3:316-26
Lee, Hyunjung; Bellamkonda, Ravi V; Sun, Wei et al. (2005) Biomechanical analysis of silicon microelectrode-induced strain in the brain. J Neural Eng 2:81-9
Zhong, Yinghui; Bellamkonda, Ravi V (2005) Controlled release of anti-inflammatory agent alpha-MSH from neural implants. J Control Release 106:309-18