Tonic and phasic transcutaneous auricular vagus nerve stimulation both evoke rapid and transient pupil dilation DOI Creative Commons
Lina Skora, Anna Marzecová, Gerhard Jocham

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 22, 2023

Abstract Background Transcutaneous auricular vagus nerve stimulation (tVNS or taVNS) is a non-invasive method of electrical the afferent pathway nerve, suggested to drive changes in putative physiological markers noradrenergic activity, including pupil dilation. Objective However, it unknown whether different taVNS modes can map onto phasic and tonic activity. The effects on dilation humans are inconsistent, largely due differences protocols. Here, we attempted address these issues. Methods We investigated under (1 s) (30 taVNS, pre-registered, single-blind, sham-controlled, within-subject cross-over design, absence behavioural task. Results Phasic induced rapid increase size over baseline, significantly greater than sham stimulation, which rapidly declined after offset. Tonic similarly (and larger sham) returning baseline within 5 s, despite ongoing stimulation. Thus, both active closely resembled effect. There were no size, sustained size. Conclusions These results suggest that phasic- tonic-like standard parameters may modulate primarily mode as indexed by evoked dilation, above somatosensory effects. This result sheds light temporal profile with implications for their applicability further research.

Language: Английский

Tonic and phasic transcutaneous auricular vagus nerve stimulation (taVNS) both evoke rapid and transient pupil dilation DOI Creative Commons
Lina Skora, Anna Marzecová, Gerhard Jocham

et al.

Brain stimulation, Journal Year: 2024, Volume and Issue: 17(2), P. 233 - 244

Published: Feb. 28, 2024

BackgroundTranscutaneous auricular vagus nerve stimulation (tVNS or taVNS) is a non-invasive method of electrical the afferent pathway nerve, suggested to drive changes in putative physiological markers noradrenergic activity, including pupil dilation.ObjectiveHowever, it unknown whether different taVNS modes can map onto phasic and tonic activity. The effects on dilation humans are inconsistent, largely due differences protocols. Here, we attempted address these issues.MethodsWe investigated under (1 s) (30 taVNS, pre-registered, single-blind, sham-controlled, within-subject cross-over design, absence behavioural task.ResultsPhasic induced rapid increase size over baseline, significantly greater than sham stimulation, which rapidly declined after offset. Tonic similarly (and larger sham) returning baseline within 5 s, despite ongoing stimulation. Thus, both active closely resembled effect. There were no size, sustained size.ConclusionsThese results suggest that phasic- tonic-like standard parameters may modulate primarily mode as indexed by evoked dilation, above somatosensory effects. This result sheds light temporal profile with implications for their applicability further research.

Language: Английский

Citations

20
Does transcutaneous auricular vagus nerve stimulation alter pupil dilation? A living Bayesian meta-analysis DOI Creative Commons

Ipek Pervaz,

Lilly Thurn,

Cecilia Vezzani

et al.

Brain stimulation, Journal Year: 2025, Volume and Issue: 18(2), P. 148 - 157

Published: Jan. 29, 2025

Language: Английский

Citations

2
Three Hundred Hertz Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) Impacts Pupil Size Non‐Linearly as a Function of Intensity DOI Creative Commons
Ian Phillips, Michael Johns, Nick B. Pandža

et al.

Psychophysiology, Journal Year: 2025, Volume and Issue: 62(2)

Published: Feb. 1, 2025

ABSTRACT Transcutaneous auricular vagus nerve stimulation (taVNS) is a neuromodulatory technique that may have numerous potential health and human performance benefits. However, optimal parameters for maximizing taVNS efficacy are unknown. Progress impeded by disagreement on the identification of biomarker reliably indexes activation systems targeted taVNS, including locus coeruleus‐norepinephrine (LC‐NE) system. Pupil size varies with LC‐NE activity one has shown inconsistent sensitivity to in prior studies. The present study examined relationship between pupil using promising behavioral effects studies but received comparatively little attention. Participants trains 50 μs pulses delivered continuously below perceptual threshold at 300 Hz left external acoustic meatus (EAM) while was recorded during pupillary light reflex task. Analysis generalized additive mixed modeling (GAMM) revealed non‐linear intensity diameter. Active increased participants who 2 approximately 4.8 mA, not higher‐intensity (up 8.1 mA). In addition, persisted subsequent blocks, mitigating decreases over course These findings suggest activates system when applied EAM, its be counteracted higher intensities.

Language: Английский

Citations

2
Transcutaneous vagus nerve stimulation: a new strategy for Alzheimer’s disease intervention through the brain-gut-microbiota axis? DOI Creative Commons
Long Yan, Hong Li,

Yulin Qian

et al.

Frontiers in Aging Neuroscience, Journal Year: 2024, Volume and Issue: 16

Published: Feb. 27, 2024

Transcutaneous vagus nerve stimulation (tVNS) is an emerging non-invasive technique designed to stimulate branches of the distributed over body surface. Studies suggest a correlation between brain-gut-microbiota (BGM) axis and pathogenesis Alzheimer’s disease (AD). The BGM represents complex bidirectional communication system, with being crucial component. Therefore, electrical might have potential modify—most time probably in non-physiological way—the signal transmission within axis, potentially influencing progression or symptoms AD. This review explores interaction percutaneous emphasizing its effects on It examines various aspects, such as specific brain regions, gut microbiota composition, maintenance intestinal environmental homeostasis, inflammatory responses, plasticity, hypothalamic–pituitary–adrenal (HPA) regulation. suggests that tVNS could serve effective strategy modulate intervene treatment future.

Language: Английский

Citations

13
Transcutaneous Auricular Vagus Nerve Stimulation Does Not Accelerate Fear Extinction: A Randomized, Sham‐Controlled Study DOI Open Access
Martina D’Agostini,

Lucas Vanden Bossche,

Andreas M. Burger

et al.

Psychophysiology, Journal Year: 2025, Volume and Issue: 62(1)

Published: Jan. 1, 2025

ABSTRACT Transcutaneous auricular vagus nerve stimulation (taVNS) has been tested as a strategy to facilitate fear extinction learning based on the hypothesis that taVNS increases central noradrenergic activity. Four studies out of six found enhance especially at beginning extinction. Facilitatory effects were mainly observed in US expectancy, less fear‐potentiated startle (FPS), and not skin conductance response (SCR). Suboptimal parameters may explain reported mixed results. Also, variability selected conditioning paradigms statistical power impedes comparability between studies. This study sought further test whether accelerates indexed by FPS, SCR. Similar most previous studies, we employed differential paradigm. The left ear 79 healthy participants was stimulated with either sham (earlobe) or (cymba concha) during learning. To maximize beneficial taVNS, cymba concha administered continuously maximum level below pain threshold. Results pre‐registered frequentist exploratory Bayesian analyses indicate did accelerate any outcomes. null results commonly used does reliably optimize More research is needed if protocol determines efficacy optimizing

Language: Английский

Citations

1
Short bursts of transcutaneous auricular vagus nerve stimulation enhance evoked pupil dilation as a function of stimulation parameters DOI
Martina D’Agostini, Andreas M. Burger,

Mathijs Franssen

et al.

Cortex, Journal Year: 2022, Volume and Issue: 159, P. 233 - 253

Published: Dec. 17, 2022

Language: Английский

Citations

37
Evidence for a modulating effect of transcutaneous auricular vagus nerve stimulation (taVNS) on salivary alpha-amylase as indirect noradrenergic marker: A pooled mega-analysis DOI Creative Commons
Manon Giraudier, Carlos Ventura‐Bort, Andreas M. Burger

et al.

Brain stimulation, Journal Year: 2022, Volume and Issue: 15(6), P. 1378 - 1388

Published: Sept. 30, 2022

Language: Английский

Citations

33
Phasic, Event-Related Transcutaneous Auricular Vagus Nerve Stimulation Modifies Behavioral, Pupillary, and Low-Frequency Oscillatory Power Responses DOI Creative Commons
Christian Wienke, Marcus Grueschow, Aiden Haghikia

et al.

Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 43(36), P. 6306 - 6319

Published: Aug. 17, 2023

Transcutaneous auricular vagus nerve stimulation (taVNS) has been proposed to activate the locus ceruleus-noradrenaline (LC-NA) system. However, previous studies failed find consistent modulatory effects of taVNS on LC-NA biomarkers. Previous suggest that phasic may be capable modulating biomarkers such as pupil dilation and alpha oscillations. it is unclear whether these extend beyond pure sensory vagal responses. Critically, potential pupillary light reflex an additional biomarker not explored so far. Here, we applied active sham in 29 subjects (16 female, 13 male) while they performed emotional Stroop task (EST) a passive (PLRT). We recorded size brain activity dynamics using combined Magnetoencephalography (MEG) pupillometry design. Our results show significantly increased performance during EST. During PLRT, reduced delayed constriction. In MEG, frontal-midline theta power EST, whereas occipital was both EST PLRT. findings provide evidence systematically modulates behavioral, pupillary, electrophysiological parameters cognitive processing. Moreover, demonstrate for first time can used simple effective proxy efficacy. These have important implications development noninvasive neuromodulation interventions various clinical applications.SIGNIFICANCE STATEMENT gained increasing attention technique widely nonclinical research. Nevertheless, exact mechanism action yet fully understood. By assessing physiology behavior response conflict healthy humans, successful application phasic, improve control modulate markers noradrenergic Understanding mechanisms could optimize future applications lead better treatments mental disorders associated with dysfunction. addition, present new taVNS-sensitive measure representing easy-to-use studies.

Language: Английский

Citations

22
Short-term transcutaneous vagus nerve stimulation increases pupil size but does not affect EEG alpha power: A replication of Sharon et al. (2021, Journal of Neuroscience) DOI Creative Commons
Beth Lloyd, Franz Wurm, Roy de Kleijn

et al.

Brain stimulation, Journal Year: 2023, Volume and Issue: 16(4), P. 1001 - 1008

Published: June 20, 2023

Transcutaneous auricular vagus nerve stimulation (taVNS) has been tested as a potential treatment for pharmaco-resistant epilepsy and depression. Its clinical efficacy is thought to depend on taVNS-induced activation of the locus coeruleus other neuromodulator systems. However, unlike invasive VNS in rodents, there little evidence an effect taVNS noradrenergic activity.We attempted replicate recently published findings by Sharon et al. (2021), showing that short bursts transiently increased pupil size decreased EEG alpha power, two correlates central activity.Following original study, we used single-blind, sham-controlled, randomized cross-over design. Human volunteers (n = 29) received short-term (3.4 s) at maximum level below pain threshold, while collected resting-state pupil-size data. To analyze data, scripts provided colleagues.Consistent with dilation was significantly larger during than sham (p .009; Bayes factor supporting difference 7.45). failed power .37); data were four times more likely under null hypothesis (BF10 0.28).Our support effectiveness inducing transient dilation, correlate phasic activity. recent finding (2021) attenuates Overall, this study highlights need continued research neural mechanisms underlying its option conditions. It also direct replications influential studies.

Language: Английский

Citations

20
Auricular Transcutaneous Vagus Nerve Stimulation Specifically Enhances Working Memory Gate Closing Mechanism: A System Neurophysiological Study DOI Creative Commons

Anyla Konjusha,

Shijing Yu, Moritz Mückschel

et al.

Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 43(25), P. 4709 - 4724

Published: May 23, 2023

Everyday tasks and goal-directed behavior involve the maintenance continuous updating of information in working memory (WM). WM gating reflects switches between these two core states. Neurobiological considerations suggest that catecholaminergic GABAergic are likely involved dynamics. Both neurotransmitter systems underlie effects to auricular transcutaneous vagus nerve stimulation (atVNS). We examine atVNS on dynamics their underlying neurophysiological neurobiological processes a randomized crossover study design healthy humans both sexes. show specifically modulates gate closing thus neural mechanisms enabling WM. opening were not affected. through modulation EEG alpha band activity. This was case for clusters activity signal referring stimulus information, motor response fractions carrying stimulus-response mapping rules during closing. EEG-beamforming shows modulations fronto-polar, orbital, inferior parietal regions associated with effects. The data because (noradrenaline) system as indicated by lack modulatory pupil diameter dynamics, inter-relation saliva markers noradrenaline Considering other findings, it appears central effect cognitive processing refers stabilization circuits, putatively mediated via system.SIGNIFICANCE STATEMENT Goal-directed depends how well short-term can be flexibly updated but also shielded from distraction. These functions guarded gate. an increasingly popular brain techniques enhances ability close shield what physiological anatomic aspects

Language: Английский

Citations

17