Vagus nerve stimulation increases stomach-brain coupling via a vagal afferent pathway

Author: Sophie J Müller1, Vanessa Teckentrup2, Ignacio Rebollo3, Manfred Hallschmid4, Nils B Kroemer5
Affiliation:
1 University of Tübingen, Tübingen Center for Mental Health, Department of Psychiatry and Psychotherapy, 72076, Tübingen, Germany.
2 University of Tübingen, Tübingen Center for Mental Health, Department of Psychiatry and Psychotherapy, 72076, Tübingen, Germany; Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland.
3 German Institute of Human Nutrition (DIfE), Department of Decision Neuroscience and Nutrition (DNN), Potsdam-Rehbruecke, 14558, Nuthetal, Germany.
4 University of Tübingen, Tübingen Center for Mental Health, Department of Medical Psychology and Behavioral Neurobiology, 72076, Tübingen, Germany; German Center for Diabetes Research (DZD), 85764, München-Neuherberg, Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University Tübingen, 72076, Tübingen, Germany.
5 University of Tübingen, Tübingen Center for Mental Health, Department of Psychiatry and Psychotherapy, 72076, Tübingen, Germany; University of Bonn, Department of Psychiatry and Psychotherapy, Bonn, Germany. Electronic address: nkroemer@uni-bonn.de.
Conference/Journal: Brain Stimul
Date published: 2022 Sep 3
Other: Special Notes: doi: 10.1016/j.brs.2022.08.019. , Word Count: 217


Background:
Maintaining energy homeostasis is vital and supported by vagal signaling between digestive organs and the brain. Previous research has established a gastric network in the brain that is phase synchronized with the rhythm of the stomach, but tools to perturb its function were lacking.

Objective:
To evaluate whether stomach-brain coupling can be acutely increased by non-invasively stimulating vagal afferent projections to the brain.

Methods:
Using a single-blind randomized crossover design, we investigated the effect of acute right-sided transcutaneous auricular vagus nerve stimulation (taVNS) versus sham stimulation on stomach-brain coupling.

Results:
In line with preclinical research, taVNS increased stomach-brain coupling in the nucleus of the solitary tract (NTS) and the midbrain while boosting coupling across the brain. Crucially, in the cortex, taVNS-induced changes in coupling occurred primarily in transmodal regions and were associated with changes in hunger ratings as indicators of the subjective metabolic state.

Conclusions:
taVNS increases stomach-brain coupling via an NTS-midbrain pathway that signals gut-induced reward, indicating that communication between the brain and the body is effectively modulated by vago-vagal signaling. Such insights may help us better understand the role of vagal afferents in orchestrating the recruitment of the gastric network which could pave the way for novel neuromodulatory treatments.

Keywords: Brain stimulation; Electrogastrogram; Functional connectivity; Gastric network; Interoceptive signals; tVNS.

PMID: 36067977 DOI: 10.1016/j.brs.2022.08.019

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