From ear to eye? No effect of transcutaneous vagus nerve stimulation on human pupil dilation: A report of three studies

Burger, Alan E.; Does, Willem van der; Brosschot, J. F.; Verkuil, Bart

doi:10.1016/j.biopsycho.2020.107863

Cited by 59 publications

(67 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result could be especially useful during 'transcutaneous' VNS (t-VNS) [38], which involves electrically stimulating the nerve's cervical or auricular branches close to the surface of the skin. However, it was recently reported that t-VNS through its auricular branch did not affect pupil size [39][40][41]. The discrepancy between these findings and ours suggests that the transcutaneous protocol in those studies likely insufficiently stimulated the vagus nerve, perhaps due to the site of stimulation (auricular vs cervical branches), the chosen stimulation parameters (pulse amplitude, width, rate) or stimulation duration.…”

Section: Discussioncontrasting

confidence: 82%

Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve

Mridha

Gee

Shi

et al. 2019

Preprint

View full text Add to dashboard Cite

Vagus nerve stimulation (VNS) is thought to alter the state of the brain by recruiting global neuromodulators. VNS is used in treatment-resistant epilepsy, and is increasingly being explored for other brain disorders, such as depression, and as a cognitive enhancer. However, the promise of VNS is only partially fulfilled due to a lack of mechanistic understanding of the transfer function between stimulation parameters and neuromodulatory response, together with a lack of biosensor for assaying stimulation efficacy in real time. We here develop an approach to VNS in head-fixed mice on a treadmill, and use it to show that pupil dilation is a biosensor for VNS-evoked cortical neuromodulation. In a 'goldilocks' zone of stimulation parameters, current leakage and off-target effects are minimized and the extent of pupil dilation tracks VNS-evoked basal-forebrain cholinergic axon activity in auditory cortex. Thus, pupil dilation is a sensitive readout of the moment-by-moment titratable effects of VNS on brain state.

show abstract

Section: Discussioncontrasting

confidence: 82%

Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve

Mridha

Gee

Shi

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…This result could be especially useful during "transcutaneous" VNS (t-VNS) 38 , which involves electrically stimulating the nerve's cervical or auricular branches close to the surface of the skin. However, it was recently reported that t-VNS through its auricular branch did not affect pupil size [39][40][41] . The discrepancy between these findings and ours suggest that the transcutaneous protocol in those studies likely insufficiently stimulated the vagus nerve, perhaps due to the site of stimulation (auricular vs cervical branches), the chosen stimulation parameters (pulse amplitude, width, rate), or stimulation duration.…”

Section: Discussionmentioning

confidence: 95%

Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve

et al. 2021

View full text Add to dashboard Cite

Vagus nerve stimulation (VNS) is thought to affect neural activity by recruiting brain-wide release of neuromodulators. VNS is used in treatment-resistant epilepsy, and is increasingly being explored for other disorders, such as depression, and as a cognitive enhancer. However, the promise of VNS is only partially fulfilled due to a lack of mechanistic understanding of the transfer function between stimulation parameters and neuromodulatory response, together with a lack of biosensors for assaying stimulation efficacy in real time. We here develop an approach to VNS in head-fixed mice on a treadmill and show that pupil dilation is a reliable and convenient biosensor for VNS-evoked cortical neuromodulation. In an ‘optimal’ zone of stimulation parameters, current leakage and off-target effects are minimized and the extent of pupil dilation tracks VNS-evoked basal-forebrain cholinergic axon activity in neocortex. Thus, pupil dilation is a sensitive readout of the moment-by-moment, titratable effects of VNS on brain state.

show abstract

“…It is not clear whether DCCS demands more flexible attention than NLT, and whether the difference between the two could only be observed because tVNS evokes a stronger release of norepinephrine, engaging α-1 receptors that were necessary for the DCCS but less so for the NLT. Hence, it is recommended for future studies to address the possible specific efficacy of tVNS by considering an on-line measurement of norepinephrine such as pupillary responses (Warren et al, 2018;Keute et al, 2019b;Burger et al, 2020). This approach might complement and further specify the hypotheses based on the neurovisceral integration model (Thayer et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Transcutaneous Vagus Nerve Stimulation May Enhance Only Specific Aspects of the Core Executive Functions. A Randomized Crossover Trial

et al. 2020

View full text Add to dashboard Cite

Background: Individuals are able to perform goal-directed behaviors thanks to executive functions. According to the neurovisceral integration model, executive functions are upregulated by brain areas such as the prefrontal and cingulate cortices, which are also crucially involved in controlling cardiac vagal activity. An array of neuroimaging studies already showed that these same brain areas are activated by transcutaneous vagus nerve stimulation (tVNS). Despite evidence toward effects of tVNS on specific executive functions such as inhibitory control, there have been no studies investigating what type of inhibition is improved by tVNS by systematically addressing them within the same experiment. Furthermore, the effect of tVNS on another core executive function, cognitive flexibility, has not yet been investigated. Objective: We investigated the effects of tVNS on core executive functions such as inhibitory control and cognitive flexibility. Methods: Thirty-two participants (nine women, M age = 23.17) took part in this study. Vagally mediated heart rate variability parameters (root mean square of successive differences, RMSSD, and high frequency, HF) were measured while participants performed four different cognitive tasks that mainly rely on different aspects of both the aforementioned executive functions. Results: Despite clear conflict effects in the four tasks, only performance on the task used to measure set-shifting paradigm was improved by tVNS, with switch costs being lower during tVNS than during sham stimulation. Furthermore, HF increased during each of the cognitive flexibility tasks, although HF during tVNS did not differ from HF during sham stimulation. Conclusion: The results indicate for the first time (a) that tVNS can increase cognitive flexibility in a set-shifting paradigm, and (b) that tVNS may exert a stronger effect on

show abstract

From ear to eye? No effect of transcutaneous vagus nerve stimulation on human pupil dilation: A report of three studies

Cited by 59 publications

References 88 publications

Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve

Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve

Graded recruitment of pupil-linked neuromodulation by parametric stimulation of the vagus nerve

Transcutaneous Vagus Nerve Stimulation May Enhance Only Specific Aspects of the Core Executive Functions. A Randomized Crossover Trial

Contact Info

Product

Resources

About