The effects of low‐and high‐frequency non‐invasive transcutaneous auricular vagal nerve stimulation (taVNS) on gastric slow waves evaluated using in vivo high‐resolution mapping in porcine

2020 ◽  
Vol 32 (7) ◽  
Author(s):  
Atchariya Sukasem ◽  
Yusuf Ozgur Cakmak ◽  
Prashanna Khwaounjoo ◽  
Armen Gharibans ◽  
Peng Du
Keyword(s):  
High Resolution ◽  
Nerve Stimulation ◽  
High Frequency ◽  
Vagal Nerve ◽  
Slow Waves ◽  
Non Invasive ◽  
Gastric Slow Waves ◽  
High Resolution Mapping ◽  
Resolution Mapping

scholarly journals High-Resolution Mapping of Myeloarchitecture In Vivo: Localization of Auditory Areas in the Human Brain

2014 ◽  
Vol 25 (10) ◽  
pp. 3394-3405 ◽  
Author(s):  
Federico De Martino ◽  
Michelle Moerel ◽  
Junqian Xu ◽  
Pierre-Francois van de Moortele ◽  
Kamil Ugurbil ◽  
...  
Keyword(s):  
High Resolution ◽  
Human Brain ◽  
High Resolution Mapping ◽  
Resolution Mapping

scholarly journals High-resolution mapping of gastric slow-wave recovery profiles: biophysical model, methodology, and demonstration of applications

2017 ◽  
Vol 313 (3) ◽  
pp. G265-G276 ◽  
Author(s):  
N. Paskaranandavadivel ◽  
L. K. Cheng ◽  
P. Du ◽  
J. M. Rogers ◽  
G. O’Grady
Keyword(s):  
Wave Propagation ◽  
Wavelet Transform ◽  
High Resolution ◽  
Slow Wave ◽  
Recovery Phase ◽  
Slow Waves ◽  
Gastric Slow Wave ◽  
High Resolution Mapping ◽  
Resolution Mapping ◽  
Extracellular Potentials

Slow waves play a central role in coordinating gastric motor activity. High-resolution mapping of extracellular potentials from the stomach provides spatiotemporal detail on normal and dysrhythmic slow-wave patterns. All mapping studies to date have focused exclusively on tissue activation; however, the recovery phase contains vital information on repolarization heterogeneity, the excitable gap, and refractory tail interactions but has not been investigated. Here, we report a method to identify the recovery phase in slow-wave mapping data. We first developed a mathematical model of unipolar extracellular potentials that result from slow-wave propagation. These simulations showed that tissue repolarization in such a signal is defined by the steepest upstroke beyond the activation phase (activation was defined by accepted convention as the steepest downstroke). Next, we mapped slow-wave propagation in anesthetized pigs by recording unipolar extracellular potentials from a high-resolution array of electrodes on the serosal surface. Following the simulation result, a wavelet transform technique was applied to detect repolarization in each signal by finding the maximum positive slope beyond activation. Activation-recovery (ARi) and recovery-activation (RAi) intervals were then computed. We hypothesized that these measurements of recovery profile would differ for slow waves recorded during normal and spatially dysrhythmic propagation. We found that the ARi of normal activity was greater than dysrhythmic activity (5.1 ± 0.8 vs. 3.8 ± 0.7 s; P < 0.05), whereas RAi was lower (9.7 ± 1.3 vs. 12.2 ± 2.5 s; P < 0.05). During normal propagation, RAi and ARi were linearly related with negative unit slope indicating entrainment of the entire mapped region. This relationship was weakened during dysrhythmia (slope: −0.96 ± 0.2 vs −0.71 ± 0.3; P < 0.05). NEW & NOTEWORTHY The theoretical basis of the extracellular gastric slow-wave recovery phase was defined using mathematical modeling. A novel technique utilizing the wavelet transform was developed and validated to detect the extracellular slow-wave recovery phase. In dysrhythmic wavefronts, the activation-to-recovery interval (ARi) was shorter and recovery-to-activation interval (RAi) was longer compared with normal wavefronts. During normal activation, RAi vs. ARi had a slope of −1, whereas the weakening of the slope indicated a dysrhythmic propagation.

Transcutaneous auricular vagal nerve stimulation improves functional dyspepsia by enhancing vagal efferent activity

2021 ◽  
Author(s):  
Ying Zhu ◽  
Feng xu ◽  
Dewen Lu ◽  
Peijing Rong ◽  
Jiafei Cheng ◽  
...  
Keyword(s):  
Functional Dyspepsia ◽  
Nerve Stimulation ◽  
Vagal Nerve ◽  
Vagal Nerve Stimulation ◽  
Slow Waves ◽  
Dyspeptic Symptom ◽  
Vagal Activity ◽  
Gastric Accommodation ◽  
Efferent Activity ◽  
Gastric Slow Waves

Objectives: This study was designed to investigate whether transcutaneous auricular vagal nerve stimulation (taVNS) would be able to improve major pathophysiologies of functional dyspepsia (FD) in patients with FD. Methods: Acute: Thirty-six FD patients (21F) were studied in two sessions (taVNS and sham-ES). Physiological measurements, including gastric slow waves, gastric accommodation and autonomic functions, were assessed by the electrogastrogram (EGG), a nutrient drink test and the spectral analysis of heart rate variability derived from the electrocardiogram (ECG), respectively. Chronic: Thirty-six FD patients (25F) were randomized to receive 2-week taVNS or sham-ES. The dyspeptic symptom scales, anxiety and depression scores and the same physiological measurements were assessed at the beginning and the end of the 2-week treatment. Results: Acute: In comparison with sham-ES, acute taVNS improved gastric accommodation (p=0.008), increased the percentage of normal gastric slow waves (%NSW, fasting: p=0.010; fed: p=0.007) and vagal activity (fasting: p=0.056; fed: p=0.026). Chronic：In comparison with baseline, 2-week taVNS but not sham-ES reduced symptoms of dyspepsia (p=0.010), decreased the scores of anxiety (p=0.002) and depression (p<0.001), improved gastric accommodation (p<0.001) and the %NSW (fasting: p<0.05; fed: p<0.05) by enhancing vagal efferent activity (fasting: p=0.015; fed: p=0.048). Compared with the HC, the patients showed increased anxiety (p<0.001) and depression (p<0.001), and decreased gastric accommodation (p<0.001) and %NSW (p<0.001) as well as decreased vagal activity (fasting: p=0.047). Conclusions: The noninvasive taVNS has a therapeutic potential for treating non-severe FD by improving gastric accommodation and gastric pace-making activity via enhancing vagal activity.

Sign in / Sign up

Export Citation Format

Share Document