scholarly journals Cortical responses to vagus nerve stimulation are modulated by ongoing oscillatory activity associated with different brain states in non-human primates

2021 ◽  
Author(s):  
Irene Rembado ◽  
David K. Su ◽  
Ariel Levari ◽  
Larry E. Shupe ◽  
Steve Perlmutter ◽  
...  

AbstractVagus nerve stimulation (VNS) is tested as therapy for several brain disorders and as a means to modulate brain plasticity. Cortical effects of VNS, manifesting as vagal-evoked potentials (VEPs), are thought to arise from activation of ascending cholinergic and noradrenergic systems. However, it is unknown whether those effects are dependent on oscillatory brain activity underling different brain states. In 2 freely behaving macaque monkeys, we delivered trains of left cervical VNS, at different pulsing frequencies (5-300 Hz), while recording local field potentials (LFP) from sites in contralateral prefrontal, sensorimotor and parietal cortical areas, continuously over 11-16 hours. Different brain states were inferred from oscillatory components of LFPs and the presence of overt movement: active awake, resting awake, REM sleep and NREM sleep. VNS elicited VEPs comprising early (<70 ms), intermediate (70-250 ms) and late (>250 ms) components in all sampled cortical areas. The magnitude of only the intermediate and late components was modulated by brain state and pulsing frequency. These findings have implications for the role of ongoing brain activity in shaping cortical responses to peripheral stimuli, for the modulation of vagal interoceptive signaling by cortical states, and for the calibration of VNS therapies.

2021 ◽  
Vol 15 ◽  
Author(s):  
Kathrin Machetanz ◽  
Levan Berelidze ◽  
Robert Guggenberger ◽  
Alireza Gharabaghi

ObjectivesTranscutaneous auricular vagus nerve stimulation (taVNS) modulates brain activity and heart function. The induced parasympathetic predominance leads to an increase of heart rate variability (HRV). Knowledge on the corresponding cortical activation pattern is, however, scarce. We hypothesized taVNS-induced HRV increases to be related to modulation of cortical activity that regulates the autonomic outflow to the heart.Materials and MethodsIn thirteen healthy subjects, we simultaneously recorded 64-channel electroencephalography and electrocardiography during taVNS. Two taVNS stimulation targets were investigated, i.e., the cymba conchae and inner tragus, and compared to active control stimulation in the anatomical vicinity, i.e., at the crus helicis and outer tragus. We used intermitted stimulation bursts of 25 Hz applied at a periodicity of 1 Hz. HRV was estimated with different time-domain methodologies: standard deviation of RR (SDNN), the root mean squares of successive differences (RMSSD), the percentage of RR-intervals with at least 50 ms deviation from the preceding RR-interval (pNN50), and the difference of consecutive RR intervals weighted by their mean (rrHRV).ResultsThe stimulation-induced HRV increases corresponded to frequency-specific oscillatory modulation of different cortical areas. All stimulation targets induced power modulations that were proportional to the HRV elevation. The most prominent changes that corresponded to HRV increases across all parameters and stimulation locations were frontal elevations in the theta-band. In the delta-band, there were frontal increases (RMSSD, pNN50, rrHRV, SDNN) and decreases (SDNN) across stimulation sites. In higher frequencies, there was a more divers activity pattern: Outer tragus/crus helicis stimulation increased oscillatory activity with the most prominent changes for the SDNN in frontal (alpha-band, beta-band) and fronto-parietal (gamma-band) areas. During inner tragus/cymba conchae stimulation the predominant pattern was a distributed power decrease, particularly in the fronto-parietal gamma-band.ConclusionNeuro–cardiac interactions can be modulated by electrical stimulation at different auricular locations. Increased HRV during stimulation is correlated with frequency-specific increases and decreases of oscillatory activity in different brain areas. When applying specific HRV measures, cortical patterns related to parasympathetic (RMSSD, pNN50, rrHRV) and sympathetic (SDNN) modulation can be identified. Thus, cortical oscillations may be used to define stimulation locations and parameters for research and therapeutic purposes.


2021 ◽  
Vol 14 (6) ◽  
pp. 1593-1594
Author(s):  
Cecilia Brambilla Pisoni ◽  
Emma Muñoz Moreno ◽  
Anna Vázquez Oliver ◽  
Rafael Maldonado Lopez ◽  
Antoni Ivorra Cano ◽  
...  

2017 ◽  
Vol 27 (04) ◽  
pp. 1650048 ◽  
Author(s):  
Simon Wostyn ◽  
Willeke Staljanssens ◽  
Leen De Taeye ◽  
Gregor Strobbe ◽  
Stefanie Gadeyne ◽  
...  

The mechanism of action of vagus nerve stimulation (VNS) is yet to be elucidated. To that end, the effects of VNS on the brain of epileptic patients were studied. Both when VNS was switched “On” and “Off”, the brain activity of responders (R, seizure frequency reduction of over 50%) was compared to the brain activity of nonresponders (NR, seizure frequency reduction of less than 50%). Using EEG recordings, a significant increase in P300 amplitude for R and a significant decrease in P300 amplitude for NR were found. We found biomarkers for checking the efficacy of VNS with accuracy up to 94%. The results show that P300 features recorded in nonmidline electrodes are better P300 biomarkers for VNS efficacy than P300 features recorded in midline electrodes. Using source localization and connectivity analyses, the activity of the limbic system, insula and orbitofrontal cortex was found to be dependent on VNS switched “On” versus “Off” or patient group (R versus NR). The results suggest an important role for these areas in the mechanism of action of VNS, although a larger patient study should be done to confirm the findings.


2017 ◽  
Vol 10 (2) ◽  
pp. 526
Author(s):  
T. Polak ◽  
C. Stelzer ◽  
A. Katzorke ◽  
J.B.M. Zeller ◽  
M.J. Herrmann

2021 ◽  
Vol 15 ◽  
Author(s):  
Philipp Ruhnau ◽  
Tino Zaehle

No matter how hard we concentrate, our attention fluctuates – a fact that greatly affects our success in completing a current task. Here, we review work from two methods that, in a closed-loop manner, have the potential to ameliorate these fluctuations. Ear-EEG can measure electric brain activity from areas in or around the ear, using small and thus portable hardware. It has been shown to capture the state of attention with high temporal resolution. Transcutaneous auricular vagus nerve stimulation (taVNS) comes with the same advantages (small and light) and critically current research suggests that it is possible to influence ongoing brain activity that has been linked to attention. Following the review of current work on ear-EEG and taVNS we suggest that a combination of the two methods in a closed-loop system could serve as a potential application to modulate attention.


2019 ◽  
Vol 28 (4) ◽  
pp. 1381-1387
Author(s):  
Ying Yuan ◽  
Jie Wang ◽  
Dongyu Wu ◽  
Dahua Zhang ◽  
Weiqun Song

Purpose Severe dysphagia with weak pharyngeal peristalsis after dorsal lateral medullary infarction (LMI) requires long-term tube feeding. However, no study is currently available on therapeutic effectiveness in severe dysphagia caused by nuclear damage of vagus nerve after dorsal LMI. The purpose of the present investigation was to explore the potential of transcutaneous vagus nerve stimulation (tVNS) to improve severe dysphagia with weak pharyngeal peristalsis after dorsal LMI. Method We assessed the efficacy of 6-week tVNS in a 28-year-old woman presented with persisting severe dysphagia after dorsal LMI who had been on nasogastric feeding for 6 months. tVNS was applied for 20 min twice a day, 5 days a week, for 6 weeks. The outcome measures included saliva spitted, Swallow Function Scoring System, Functional Oral Intake Scale, Clinical Assessment of Dysphagia With Wallenberg Syndrome, Yale Pharyngeal Residue Severity Rating Scale, and upper esophagus X-ray examination. Results After tVNS, the patient was advanced to a full oral diet without head rotation or spitting. No saliva residue was found in the valleculae and pyriform sinuses. Contrast medium freely passed through the upper esophageal sphincter. Conclusion Our findings suggest that tVNS might provide a useful means for recovery of severe dysphagia with weak pharyngeal peristalsis after dorsal LMI. Supplemental Material https://doi.org/10.23641/asha.9755438


2021 ◽  
Vol 3 (1) ◽  
pp. e14-e15
Author(s):  
Mark C Genovese ◽  
Yaakov A Levine ◽  
David Chernoff

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