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A Procedure for Implanting Organized Arrays of Microwires for Single-unit Recordings in Awake, Behaving Animals
Published on: February 14, 2014
Quantitative analysis of the tissue response to chronically implanted microwire electrodes in rat cortex
Brent D Winslow1, Patrick A Tresco
1The Keck Center for Tissue Engineering, Department of Bioengineering, College of Engineering, University of Utah, 20 S 2030 E Building, 570 BPRB, Salt Lake City, UT 84112, USA.
Biomaterials
|December 8, 2009
Summary
Brain tissue reaction to recording electrodes shows persistent inflammation and blood-brain barrier changes, but not progressive gliosis or neuronal loss over three months.
Area of Science:
- Neuroscience
- Biomaterials Science
- Tissue Engineering
Background:
- Brain tissue reaction to implanted electrodes impacts device biocompatibility.
- Hypotheses include progressive astrocyte changes and neuronal loss over time.
Purpose of the Study:
- Analyze the spatial distribution of biomarkers related to the foreign body response to insulated microwires in rat cerebral cortex.
- Examine the temporal progression of tissue reactivity and neuronal health around implanted electrodes.
Main Methods:
- Quantitative analysis of biomarker distribution at 2, 4, and 12 weeks post-implantation.
- Utilized insulated microwires implanted in rat cerebral cortex.
- Compared tissue response to previously reported data for silicon microelectrode arrays.
Main Results:
- Observed a stereotypical tissue response with lower cortical reactivity compared to silicon arrays.
- Found no evidence of increasing reactive gliosis or progressive neuronal loss over 12 weeks.
- Detected persistent inflammation and enhanced blood-brain barrier (BBB) permeability at the electrode-tissue interface up to 3 months.
- Noted increased animal-to-animal variability in tissue response at 3 months.
Conclusions:
- The foreign body response to insulated microwires is characterized by persistent inflammation and BBB changes, not progressive gliosis or neuronal loss.
- Microwire implants demonstrate a generally lower degree of cortical tissue reactivity.
- Long-term implantation reveals significant variability in the brain tissue interface response.
