Short-Term Neurochemical Effects of Transcutaneous Vagus Nerve Stimulation using 7T Magnetic Resonance Spectroscopy

Motivation: Transcutaneous auricular vagus nerve stimulation (taVNS) has shown therapeutic efficacy in treating conditions such as epilepsy and depression. Recently, its potential to improve cognitive performance in healthy adults has been explored. Goal(s): However, little is known about the neurochemical processes underlying performance enhancing outcomes. This study assessed immediate and residual effects of taVNS on neurochemical activity in brain regions associated with attention, vigilance, and stress. Approach: Magnetic resonance spectroscopy was used to non-invasively quantify neurochemical responses immediately after and 60 minutes post-stimulation compared with baseline. Results: Increased myo-inositol was observed in the posterior cingulate immediately after taVNS but not sustained for 60 minutes. Impact: Using magnetic resonance spectroscopy allowed for the evaluation of the short-term neurochemical response across multiple brain regions from transcutaneous auricular vagus nerve stimulation, which helps elucidate the mechanisms of the potential therapeutic and performance-improvement effects achieved from stimulation