Hepatobiliary Surg Nutr. 2024 Oct 1;13(5):891-893. doi: 10.21037/hbsn-24-516. Epub 2024 Sep 26.

NO ABSTRACT

PMID:39507731 | PMC:PMC11534763 | DOI:10.21037/hbsn-24-516

Front Aging Neurosci. 2024 Oct 23;16:1444703. doi: 10.3389/fnagi.2024.1444703. eCollection 2024.

ABSTRACT

BACKGROUND: Previous studies have evaluated the safety and efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) for the treatment of Parkinson’s disease (PD). However, the mechanism underlying the effect of taVNS on PD remains to be elucidated. This study aimed to investigate the immediate effects of taVNS in PD patients.

METHODS: This crossover self-controlled study included 50 PD patients. Each patient underwent three sessions of resting-state functional magnetic resonance imaging (rs-fMRI) under three conditions: real taVNS, sham taVNS, and no taVNS intervention. We analyzed whole-brain amplitude of low-frequency fluctuations (ALFF) from preprocessed fMRI data across different intervention conditions. ALFF values in altered brain regions were correlated with clinical symptoms in PD patients.

RESULTS: Forty-seven participants completed the study and were included in the final analysis. Real taVNS was associated with a widespread decrease in ALFF in the right hemisphere, including the superior parietal lobule, precentral gyrus, postcentral gyrus, middle occipital gyrus, and cuneus (voxel p < 0.001, GRF corrected). The ALFF value in the right superior parietal lobule during real taVNS was negatively correlated with the Unified Parkinson’s Disease Rating Scale Part III (r = -0.417, p = 0.004, Bonferroni corrected).

CONCLUSION: TaVNS could immediately modulate the functional activity of brain regions involved in superior parietal lobule, precentral gyrus, postcentral gyrus, middle occipital gyrus, and cuneus. These findings offer preliminary insights into the mechanism of taVNS in treating PD and bolster confidence in its long-term therapeutic potential. TaVNS appears to reduce ALFF values in specific brain regions, suggesting a potential modulation mechanism for treating PD.

PMID:39507202 | PMC:PMC11537911 | DOI:10.3389/fnagi.2024.1444703

Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2024 Oct;46(5):776-782. doi: 10.3881/j.issn.1000-503X.15872.

ABSTRACT

The joints have abundant sensory nerves and sympathetic nerve fibers,which convert physical and chemical stimuli in the joints into nerve impulses that are transmitted to the central nervous system and participate in the hypersensitivity reactions of inflammatory joint diseases such as osteoarthritis (OA).This paper summarizes the distribution and functional characteristics of intra-articular nerves and focuses on the mechanism of the vagus-sympathetic autonomic circuit in regulating the immune microenvironment in joints in the case of OA.In addition,intra-articular inflammatory cytokines represented by tumor necrosis factor-α and interleukin-6 directly or indirectly induce sensory nerve action potential and activate the pain transduction pathway from the local joint to the central nervous system.The sensory nerves in the joints in the case of OA are also involved in the recruitment of immune cells and inflammatory cytokines.This neuro-immune interaction model not only provides a variety of new targets for the treatment of OA but also suggests that the treatment of OA should adopt a holistic view with comprehensive consideration of the nerve and immune microenvironment in the bone and joint and their mutual influences.

PMID:39502061 | DOI:10.3881/j.issn.1000-503X.15872

Anaesth Rep. 2024 Nov 4;12(2):e12332. doi: 10.1002/anr3.12332. eCollection 2024 Jul-Dec.

ABSTRACT

A 67-year-old woman with no history of cardiovascular disease, undergoing an elective laparoscopic cholecystectomy, experienced severe bradycardia and cardiac arrest immediately following an alveolar recruitment manoeuvre under general anaesthesia. Prompt cardiopulmonary resuscitation restored cardiac output within 2-3 min. Postoperatively, she remained stable and was discharged following 24 h of monitoring. The cardiac arrest was likely triggered by vagal nerve stimulation and activation of intrinsic cardiac reflexes by the alveolar recruitment manoeuvre. The event emphasises a rare, but significant, risk of the routine management of pulmonary atelectasis.

PMID:39498314 | PMC:PMC11532626 | DOI:10.1002/anr3.12332

Cureus. 2024 Oct 1;16(10):e70613. doi: 10.7759/cureus.70613. eCollection 2024 Oct.

ABSTRACT

The international healthcare community has encountered several difficulties because of the COVID-19 pandemic brought on by SARS-CoV-2. COVID-19 can lead to an abnormal immune response that features excessive inflammation, so targeting the vagus nerve through non-invasive vagus nerve stimulation (nVNS) may hold promise as an intervention. This meta-analysis aimed to examine the outcomes of using nVNS on different inflammatory biomarkers in COVID-19 patients. Up until May 2023, we performed a review of online databases. We included randomized controlled trials (RCTs) that discussed how nVNS affected patients with COVID-19’s clinical outcomes. Using the Revman 5.4 software (Cochrane, London, United Kingdom), a meta-analysis was carried out to find the pooled mean difference (MD), with 95% confidence intervals (CIs), of nVNS effects on different inflammatory biomarkers, including interleukin-10 (IL-10), C-reactive protein (CRP), IL-6, and cortisol levels. The review included four RCTs involving 180 COVID-19 patients. Following nVNS treatment, there was a significant increase in IL-10 levels (MD = 1.53, 95% CI: 0.77, 2.29; p < 0.001). CRP levels (MD = -2.24, 95% CI: -4.52, 0.05; p = 0.06), IL-6 levels (MD = 4.07, 95% CI: -3.16, 11.32; p = 0.27), cortisol levels (MD = 1.45, 95% CI: -11.67, 14.57; p = 0.83), and D-dimer levels (MD = -0.47, 95% CI: -1.31, 0.38; p = 0.28) did not differ significantly. These findings suggest that nVNS may positively impact certain inflammatory markers in COVID-19 patients, suggesting that nVNS could be a beneficial adjunctive treatment.

PMID:39493183 | PMC:PMC11528624 | DOI:10.7759/cureus.70613

Brain Topogr. 2024 Nov 2;38(1):11. doi: 10.1007/s10548-024-01088-6.

ABSTRACT

Transcutaneous auricular vagus nerve stimulation (taVNS), a non-invasive form of electrical brain stimulation, has shown potent therapeutic potential for a wide spectrum of conditions. How taVNS influences the characterization of motion sickness – a long mysterious syndrome with a polysymptomatic onset – remains unclear. Here, to examine taVNS-induced effects on brain function in response to motion-induced nausea, 64-channel electroencephalography (EEG) recordings from 42 healthy participants were analyzed; collected during nauseogenic visual stimulation concurrent with taVNS administration, in a crossover randomized sham-controlled study. Cortical neuronal generators were estimated from the obtained EEG using exact low-resolution brain electromagnetic tomography (eLORETA). While both sham and taVNS increased insula activation during electrical stimulation, compared to baseline, taVNS additionally augmented middle frontal gyrus neuronal activity. Following taVNS, brain regions including the supramarginal, parahippocampal, and precentral gyri were activated. Contrasting sham, taVNS markedly increased activity in the middle occipital gyrus during stimulation. A repeated-measures ANOVA showed that taVNS reduced motion sickness symptoms. This reduction in symptoms correlated with taVNS-induced neural activation. Our findings provide new insights into taVNS-induced brain changes, during and after nauseogenic stimuli exposure, including accompanying behavioral response. Together, these findings suggest that taVNS has promise as an effective neurostimulation tool for motion sickness management.

PMID:39487878 | DOI:10.1007/s10548-024-01088-6

NeuroSci. 2023 Dec 28;5(1):8-38. doi: 10.3390/neurosci5010002. eCollection 2024 Mar.

ABSTRACT

The twelve cranial nerves play a crucial role in the nervous system, orchestrating a myriad of functions vital for our everyday life. These nerves are each specialized for particular tasks. Cranial nerve I, known as the olfactory nerve, is responsible for our sense of smell, allowing us to perceive and distinguish various scents. Cranial nerve II, or the optic nerve, is dedicated to vision, transmitting visual information from the eyes to the brain. Eye movements are governed by cranial nerves III, IV, and VI, ensuring our ability to track objects and focus. Cranial nerve V controls facial sensations and jaw movements, while cranial nerve VII, the facial nerve, facilitates facial expressions and taste perception. Cranial nerve VIII, or the vestibulocochlear nerve, plays a critical role in hearing and balance. Cranial nerve IX, the glossopharyngeal nerve, affects throat sensations and taste perception. Cranial nerve X, the vagus nerve, is a far-reaching nerve, influencing numerous internal organs, such as the heart, lungs, and digestive system. Cranial nerve XI, the accessory nerve, is responsible for neck muscle control, contributing to head movements. Finally, cranial nerve XII, the hypoglossal nerve, manages tongue movements, essential for speaking, swallowing, and breathing. Understanding these cranial nerves is fundamental in comprehending the intricate workings of our nervous system and the functions that sustain our daily lives.

PMID:39483811 | PMC:PMC11523702 | DOI:10.3390/neurosci5010002

Front Hum Neurosci. 2024 Oct 17;18:1436365. doi: 10.3389/fnhum.2024.1436365. eCollection 2024.

ABSTRACT

INTRODUCTION: A current thrust in neurology involves using exogenous neuromodulation of cranial nerves (e.g, vagus, trigeminal) to treat the signs and symptoms of various neurological disorders. These techniques also have the potential to augment cognitive and/or sensorimotor functions in healthy individuals. Although much is known about the clinical effects of trigeminal nerve stimulation (TNS), effects on sensorimotor and cognitive functions such as learning have received less attention, despite their potential impact on neurorehabilitation. Here we describe the results of experiments aimed at assessing the effects of TNS on motor learning, which was behaviorally characterized using an upper extremity visuomotor adaptation paradigm.

OBJECTIVE: Assessing the effects of TNS on motor learning.

METHODS: Motor learning was behaviorally characterized using an upper extremity visuomotor adaptation paradigm. In Experiment 1, effects of offline TNS using clinically tested frequencies (120 and 60 Hz) were characterized. Sixty-three healthy young adults received TNS before performing a task that involved reaching with perturbed hand visual feedback. In Experiment 2, the effects of 120 and 60 Hz online TNS were characterized with the same task. Sixty-three new participants received either TNS or sham stimulation concurrently with perturbed visual feedback.

RESULTS: Experiment 1 results showed that 60 Hz stimulation was associated with slower rates of learning than both sham and 120 Hz stimulation, indicating frequency-dependent effects of TNS. Experiment 2 however showed no significant differences among stimulation groups. A post-hoc, cross-study comparison of the 60 Hz offline and online TNS results showed a statistically significant improvement in learning rates with online stimulation relative to offline, pointing to timing-dependent effects of TNS on visuomotor learning.

DISCUSSION: The results indicate that both the frequency and timing of TNS can influence rates of motor learning in healthy adults. This suggests that optimization of one or both parameters could potentially increase learning rates, which would provide new avenues for enhancing performance in healthy individuals and augmenting rehabilitation in patients with sensorimotor dysfunction resulting from stroke or other neurological disorders.

PMID:39483193 | PMC:PMC11526447 | DOI:10.3389/fnhum.2024.1436365

Gut Microbes. 2024 Jan-Dec;16(1):2421581. doi: 10.1080/19490976.2024.2421581. Epub 2024 Nov 1.

ABSTRACT

Gastrointestinal (GI) microbiota plays an active role in regulating the host’s immune system and metabolism, as well as certain pathophysiological processes. Diet is the main factor modulating GI microbiota composition and studies have shown that high fat (HF) diets induce detrimental changes (dysbiosis) in the GI bacterial makeup. HF diet induced dysbiosis has been associated with structural and functional changes in gut-brain vagally mediated signaling system, associated with overeating and obesity. Although HF-driven changes in microbiota composition are sufficient to alter vagal signaling, it is unknown if improving microbiota composition after diet-induced obesity has been established can ameliorate gut-brain signaling and metabolic outcomes. In this study, we evaluated the effect of lean gut microbiota transfer in obese, vagally compromised, rats on gut-brain communication, food intake, and body weight. Male rats were maintained on regular chow or 45% HF diet for nine weeks followed by three weeks of microbiota depletion using antibiotics. The animals were then divided into four groups (n = 10 each): LF – control fed regular chow, LF-LF – chow fed animals that received microbiota from chow fed donors, HF-LF – HF fed animals that received microbiota from chow fed donors, and HF-HF – HF fed animals that received microbiota from HF fed donors. HF-LF animals received inulin as a prebiotic to aid the establishment of the lean microbiome. We found that transferring a LF microbiota to HF fed animals (HF-LF) reduced caloric intake during the light phase when compared with HF-HF rats and prevented additional excessive weight gain. HF-LF animals displayed an increase in postprandial activation of both primary sensory neurons innervating the GI tract and brainstem secondary neurons. We concluded from these data that improving microbiota composition in obese rats is sufficient to ameliorate gut-brain communication and restore normal feeding patterns which was associated with a reduction in weight gain.

PMID:39485288 | DOI:10.1080/19490976.2024.2421581

Korean J Physiol Pharmacol. 2024 Oct 31. doi: 10.4196/kjpp.24.266. Online ahead of print.

ABSTRACT

Auricular vagus nerve stimulation (aVNS) is one of the promising neuromodulation techniques due to its non-invasiveness, convenience, and effectiveness. aVNS has been suggested as a potential treatment for neurodegenerative diseases showing impaired cerebrospinal fluid (CSF) dynamics. Improving CSF flow has been proposed as a key mechanism of the therapeutic effect on neurodegenerative diseases. However, aVNS parameters have been set empirically and the effective parameter that maximize the effect remains elusive. Here we show that 30 minutes of low-frequency aVNS increased arterial vasomotion events and enhanced cortical CSF influx along the branches of middle cerebral arteries. By using in vivo two photon imaging or widefield fluorescence microscopy with plasma and CSF tracers for visualizing blood vessels and perivascular spaces, arterial vasomotion and cortical CSF influx dynamics were acquired. The low-frequency (2 Hz) aVNS, but not middleand high-frequency (40 and 100 Hz) aVNS, significantly increased the number of vasomotion events compared to the sham group. Accordingly, in the CSF imaging, 2 Hz of aVNS markedly enhanced the CSF influx. Our findings demonstrate that lowfrequency aVNS is the effective parameter in respect to modulating vasomotion and CSF influx, resulting in brain clearance effect.

PMID:39482237 | DOI:10.4196/kjpp.24.266