Auricular transcutaneous vagus nerve stimulation modulates the heart-evoked potential

Tasha Poppa; Lars Benschop; Paula Horczak; Marie-Anne Vanderhasselt; Evelien Carrette; Antoine Bechara; Chris Baeken; Kristl Vonck

doi:10.1016/j.brs.2021.12.004

Auricular transcutaneous vagus nerve stimulation modulates the heart-evoked potential

Brain Stimul. 2022 Jan-Feb;15(1):260-269. doi: 10.1016/j.brs.2021.12.004. Epub 2021 Dec 18.

Authors

Tasha Poppa¹, Lars Benschop², Paula Horczak², Marie-Anne Vanderhasselt², Evelien Carrette³, Antoine Bechara⁴, Chris Baeken⁵, Kristl Vonck³

Affiliations

¹ Ghent Experimental Psychiatry Lab, Psychiatry and Medical Psychology, Department of Head and Skin, Ghent University Hospital, Belgium; Department of Psychology, University of Southern California, Los Angeles, CA, USA. Electronic address: natalie.poppa@ugent.be.
² Ghent Experimental Psychiatry Lab, Psychiatry and Medical Psychology, Department of Head and Skin, Ghent University Hospital, Belgium.
³ 4Brain, Neurology, Department of Head and Skin, Ghent University Hospital, Belgium.
⁴ Department of Psychology, University of Southern California, Los Angeles, CA, USA.
⁵ Ghent Experimental Psychiatry Lab, Psychiatry and Medical Psychology, Department of Head and Skin, Ghent University Hospital, Belgium; Department of Psychiatry, Brussels University Hospital, Belgium; Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands.

PMID: 34933143
DOI: 10.1016/j.brs.2021.12.004

Abstract

Background: There is active interest in biomarker discovery for transcutaneous auricular vagus nerve stimulation (taVNS). However, greater understanding of the neurobiological mechanisms is needed to identify candidate markers. Accumulating evidence suggests that taVNS influences activity in solitary and parabrachial nuclei, the primary brainstem relays for the transmission of visceral sensory afferents to the insula. The insula mediates interoception, which concerns the representation and regulation of homeostatic bodily states. Consequently, interoceptive pathways may be relevant to taVNS mechanisms of action.

Hypotheses: We hypothesized that taVNS would modulate an EEG-derived marker of interoceptive processing known as the heart-evoked potential (HEP). We also hypothesized that taVNS-induced HEP effects would be localizable to the insula.

Methods: Using a within-subject, sham-controlled design, we recorded EEG and ECG concurrent to taVNS in 43 healthy adults. Using ECG and EEG data, we extracted HEPs. Estimation of the cortical sources of the taVNS-dependent HEP responses observed at the scalp were computed using the Boundary Element Method and weighted Minimum Norm Estimation. Statistics were calculated using cluster-based permutation methods.

Results: taVNS altered HEP amplitudes at frontocentral and centroparietal electrode sites at various latencies. The taVNS-dependent HEP effect was localized to the insula, operculum, somatosensory cortex, and orbital and ventromedial prefrontal regions.

Conclusion: The results support the hypothesis that taVNS can access the insula as well as functionally and anatomically connected brain regions. HEPs may serve as an objective, non-invasive outcome parameter for the cortical effects of taVNS.

Keywords: Auricular; Central autonomic network; Electroencephalography; Heart-evoked potential; Insula; Interoception; Source-localization; Transcutaneous; Vagus nerve stimulation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Evoked Potentials
Heart Rate
Humans
Transcutaneous Electric Nerve Stimulation* / methods
Vagus Nerve / physiology
Vagus Nerve Stimulation* / methods