Immunohistological responses in mice implanted with Parylene HT - ITO ECoG devices

Area of Science:

• Neuroscience
• Biocompatibility Testing
• Implantable Medical Devices

Background:

• Transparent epidural devices enabling simultaneous electrophysiology and neuroimaging are emerging tools in neuroscience.
• Assessing the biocompatibility and immune response of novel implantable devices is crucial for their widespread adoption.
• Parylene HT/indium-tin oxide (ITO) based electrocorticography (ECoG) devices offer potential for advanced neural monitoring.

Purpose of the Study:

• To conduct an immunohistochemical evaluation of Parylene HT/ITO ECoG devices.
• To provide long-term biocompatibility data for these devices at various chronic implantation durations.
• To assess the evoked astroglial response, neuronal density, and cortical thickness following device implantation.

Main Methods:

• Epidural implantation of Parylene HT/ITO ECoG devices in 5 mice.
• Immunohistochemical analysis to evaluate astroglial response, neuronal density, and cortical thickness.
• Comparison of implanted brain tissue with contralateral unimplanted controls at multiple time points.

Main Results:

• Increased astroglial response observed in superficial cortical layers of implanted mice, diminishing over time.
• Reduced neuronal density noted only at the final time point on the implanted side.
• Decreased cortical thickness observed at earlier time points, but not at the final assessment.

Conclusions:

• Parylene HT/ITO ECoG devices demonstrate feasibility for chronic implantation.
• The study provides essential long-term biocompatibility data for these transparent neural devices.
• Findings support the continued development and application of these devices in neuroscience research.