A flexible, thin-film microchannel electrode array device for selective subdiaphragmatic vagus nerve recording

Area of Science:

• Neuroscience
• Biomedical Engineering
• Gastroenterology

Background:

• The vagus nerve (VN) is crucial for gastrointestinal (GI) regulation via the parasympathetic nervous system and enteric nervous system (ENS).
• Limited understanding of VN-GI neurophysiology hinders treatments for related autonomic dysfunctions.
• Advanced microfabrication technologies are needed to develop devices for studying VN neurophysiology.

Purpose of the Study:

• To develop and evaluate a novel, thin-film microchannel electrode array for interfacing with subdiaphragmatic VN branches.
• To investigate the neurophysiological signals transmitted by specific VN fibers relevant to GI autonomic control.
• To overcome limitations of existing bulky nerve interface devices.

Main Methods:

• Fabrication of a flexible, thin-film microchannel electrode array (11.5 µm thickness).
• In vivo recording of evoked compound action potentials (ECAPs) from a transected rat VN branch.
• Signal analysis to identify the origin of recorded neurophysiological signals.

Main Results:

• Successfully demonstrated the recording of ECAPs from a multi-fiber nerve ending using the thin-film device.
• Confirmed that recorded signals originate from C-fibers, which are critical for GI autonomic neurophysiology.
• The flexible device showed potential for minimally invasive neural interfacing.

Conclusions:

• The developed thin-film microchannel electrode array is a promising tool for studying VN neurophysiology.
• This technology enables detailed investigation of C-fiber activity in the VN-GI axis.
• The findings contribute to advancing treatments for VN-related autonomic dysfunctions.