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Tools for Surface Treatment of Silicon Planar Intracortical Microelectrodes
Published on: June 8, 2022
Neuronal cell loss accompanies the brain tissue response to chronically implanted silicon microelectrode arrays
Roy Biran1, David C Martin, Patrick A Tresco
1The Keck Center for Tissue Engineering, Department of Bioengineering, University of Utah, 20S 2030E Bldg. 570 Rm. 108, Salt Lake City, UT 84112, USA.
Experimental Neurology
|July 28, 2005
Summary
Chronic inflammation around brain implants causes neuronal loss, leading to recording failures in neuroprosthetics. This study identifies a new mechanism for device malfunction due to the foreign body response to silicon microelectrodes.
Area of Science:
- Neuroscience
- Biomaterials Science
- Medical Devices
Background:
- Implantable silicon microelectrode arrays offer high-resolution neuronal activity sampling for neuroprosthetics.
- Long-term performance degradation is a significant limitation, with brain tissue response implicated but mechanisms unclear.
Purpose of the Study:
- To investigate the mechanisms underlying chronic recording failure in implantable silicon microelectrode arrays.
- To elucidate the brain tissue response to implanted microelectrodes and its impact on neuronal function.
Main Methods:
- Implantation of silicon microelectrode arrays in adult rat cortex.
- Histological analysis using ED1 immunoreactivity to assess inflammatory response.
- Evaluation of nerve fiber density and neuronal cell bodies.
- Analysis of explanted electrodes and in vitro cell culture to study inflammatory markers.
Main Results:
- Persistent ED1 immunoreactivity observed around implanted arrays, indicating an ongoing inflammatory response.
- Significant reduction in nerve fiber density and neuronal cell bodies near the electrodes.
- ED1/MAC-1 positive cells on explanted electrodes released inflammatory cytokines (MCP-1, TNF-alpha).
- Control experiments ruled out mechanical trauma as the sole cause, implicating the foreign body response.
Conclusions:
- Chronic inflammation at the microelectrode-brain tissue interface, characterized by neuronal loss, is a potential mechanism for recording failure.
- The foreign body response to silicon microelectrodes contributes to device malfunction.
- Findings suggest strategies to mitigate inflammation for improved long-term neuroprosthetic performance.
