Long-term recording performance and biocompatibility of chronically implanted cylindrically-shaped, polymer-based...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Devices

Background:

• Current stereo-electroencephalography (SEEG) depth electrodes have limitations in channel count and spatial resolution.
• These limitations hinder high-density local field potential and multi-unit recordings for precise epileptic focus localization.

Purpose of the Study:

• To evaluate the long-term electrophysiological recording performance and histocompatibility of a novel 32-microelectrode neural interface.
• To assess the suitability of this neural probe for SEEG recordings in epilepsy patients.

Main Methods:

• Chronically implanted polyimide (PI) cylindrical depth probes (32 microelectrodes) into rat brains for 13 weeks.
• Regularly recorded cortical and thalamic activity (local field potentials, single-unit, multi-unit activity).
• Utilized neuron-selective and astroglia-selective immunostaining to examine tissue reaction.

Main Results:

• Achieved stable single-unit and multi-unit activity recordings for several weeks.
• Observed a weak to moderate tissue reaction around the probe track, indicating good biocompatibility.
• Demonstrated potential for increased spatial resolution and detailed neural activity monitoring.

Conclusions:

• The novel 32-microelectrode neural probe exhibits promising long-term electrophysiological performance and biocompatibility.
• This neural interface is suitable for SEEG recordings in humans for up to 2 weeks, enhancing epileptic focus localization.
• The probe offers improved spatial resolution and the ability to monitor local field potentials and neuronal spiking activity.