Intraneural ultramicroelectrode arrays for function-specific interfacing to the vagus nerve

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• The vagus nerve (VN) is a critical communication pathway between organs and the brain, vital for autonomic functions.
• Selective interfacing with the VN offers potential for disease diagnosis, treatment, and understanding neural circuits.
• Current intraneural electrode arrays lack the spatial resolution for highly selective VN recordings.

Purpose of the Study:

• To fabricate and characterize a 16-channel intraneural electrode array with ultramicro-dimensioned electrodes for selective vagus nerve recording.
• To demonstrate the array's capability for functionally selective recording of neural activity.
• To achieve spatially selective recording of micro-compound action potentials (μCAPs) within the VN.

Main Methods:

• Fabrication of amorphous silicon carbide ultramicroelectrode arrays (a-SiC UMEAs) with 16 channels.
• Intraneural implantation of the a-SiC UMEAs into the cervical vagus nerve (cVN).
• Recording of neural activity in response to physiological changes (oxygenation, blood pressure) and electrical stimulation of VN branches.

Main Results:

• The a-SiC UMEAs demonstrated selective detection of cVN neural activity correlated with systemic oxygenation and blood pressure.
• Spatially selective recording of μCAPs was achieved through electrical stimulation of subdiaphragmatic VN branches.
• Distinct neural activity was resolved on electrodes spaced less than 100 μm apart, indicating high spatial selectivity.

Conclusions:

• The developed 16-channel a-SiC UMEA enables high-resolution, functionally selective recording within the cervical vagus nerve.
• This technology represents a significant advancement in intraneural multielectrode array capabilities for the VN.
• The demonstrated spatial selectivity opens new avenues for precise neural interfacing for diagnostic and therapeutic applications.