Flexible microelectrode array for interfacing with the surface of neural ganglia

Area of Science:

• Neuroscience
• Biomedical Engineering
• Materials Science

Background:

• Dorsal root ganglia (DRG) are crucial for sensory information processing.
• Existing electrode technologies face limitations in interfacing with the DRG surface.
• Novel approaches are needed to leverage the DRG's potential for neural interfaces.

Purpose of the Study:

• To develop and evaluate a flexible, non-penetrating polyimide electrode array for interfacing with the DRG surface.
• To assess the capability of the Ganglionic Surface Electrode Array (GSEA) for recording neural activity.
• To explore the potential of GSEA for neural mapping and sensory input analysis.

Main Methods:

• Designed and fabricated a 64-channel iridium electrode array with small pitch (down to 25 µm).
• Utilized invertebrate buccal ganglia (Aplysia californica) for technique development.
• Tested the GSEA in vivo on feline lumbosacral DRG, recording responses to various sensory stimuli.

Main Results:

• Successfully recorded single- and multi-unit activity from feline DRG in response to cutaneous, joint, and bladder pressure stimuli.
• Demonstrated spatial oversampling to estimate neural source locations (25-107 µm depth).
• Showcased potential for creating a spatial sensory map of the DRG.

Conclusions:

• The GSEA effectively records diverse neural information from ganglia.
• This technology holds significant promise for neural mapping and developing advanced neural interfaces.
• Further development of GSEA could enhance understanding and utilization of sensory neural pathways.