Longitudinal neural and vascular structural dynamics produced by chronic microelectrode implantation
Cristin G Welle1, Yu-Rong Gao2, Meijun Ye3
1Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Radiological Devices, Food and Drug Administration, Silver Spring, MD, USA; Departments of Neurosurgery and Physiology & Biophysics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.
Biomaterials
|February 12, 2020
Summary
Brain computer interface (BCI) microelectrodes degrade over time. This study reveals neuronal atrophy and links hypoxia to signal loss, offering insights for improved BCI longevity.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Medical Imaging
Background:
- Brain computer interface (BCI) technology enables individuals with paralysis to control external devices using neural signals.
- Implanted microelectrode arrays are crucial for BCI function but suffer from signal degradation over time.
- The long-term biological response to implanted electrodes, particularly concerning neural and vascular tissue, remains poorly understood.
Purpose of the Study:
- To investigate the dynamic changes in neuronal and vascular structures surrounding microelectrode implants over a 3-month period.
- To identify potential biological mechanisms contributing to the decline in neural signal quality recorded by BCI devices.
Main Methods:
- Utilized in-vivo dual-modality imaging to simultaneously visualize neuronal and vasculature in the same animal model.
- Monitored structural changes for 3 months post-electrode implantation.
- Correlated observed tissue changes with potential physiological events like hypoxia.
Main Results:
- Observed significant neuronal atrophy in close proximity to the implanted electrode.
- Found relative stability in the vasculature surrounding the electrode.
- Identified evidence linking infrequent, sudden hypoxic events to neuronal process atrophy.
Conclusions:
- Long-term implantation of microelectrodes leads to neuronal atrophy, potentially explaining BCI signal degradation.
- Vascular integrity appears relatively maintained, suggesting neuronal health is a key factor in signal loss.
- Hypoxic events may play a critical role in the progressive damage of neural tissue near implants, impacting BCI performance.
