Objectives: This study was designed to test the hypothesis that low-level vagal nerve stimulation (VNS) reduces the ventricular rate (VR) during atrial fibrillation (AF) through the activation of the inferior vena cava (IVC)-inferior atrial ganglionated plexus nerve activity (IAGPNA).
Background: Increased IVC-IAGPNA can suppress atrioventricular node conduction and slow VR in canine models of AF.
Methods: Persistent AF was induced in 6 dogs and the IVC-IAGPNA, right vagal nerve activity, left vagal nerve activity, and an electrocardiogram were recorded. After persistent AF was documented, VNS was programed to 14 s "on" and 1.1 min "off." After 1 week, the VNS was reprogramed to 3 min off and stimulation continued for another week. Neural remodeling of the stellate ganglion (SG) was assessed with tyrosine hydroxylase staining and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling staining.
Results: Average IVC-IAGPNA was increased during both VNS 1.1 min off (8.20 ± 2.25 μV [95% confidence interval (CI): 6.33 to 9.53 μV]; p = 0.002) and 3 min off (7.96 ± 2.03 μV [95% CI: 6.30 to 9.27 μV]; p = 0.001) versus baseline (7.14 ± 2.20 μV [95% CI: 5.35 to 8.52 μV]). VR was reduced during both VNS 1.1 min off (123.29 ± 6.29 beats/min [95% CI: 116.69 to 129.89 beats/min]; p = 0.001) and 3 min off (120.01 ± 4.93 beats/min [95% CI: 114.84 to 125.18 beats/min]; p = 0.001) compared to baseline (142.04 ± 7.93 bpm [95% CI: 133.72 to 150.37]). Abnormal regions were observed in the left SG, but not in the right SG. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling-positive neurons were found in 22.2 ± 17.2% [95% CI: 0.9% to 43.5%] of left SG cells and 12.8 ± 8.4% [95% CI: 2.4% to 23.2%] of right SG cells.
Conclusions: Chronic low-level VNS increases IVC-IAGPNA and damages bilateral stellate ganglia. Both mechanisms could contribute to the underlying mechanism of VR control during AF.
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http://dx.doi.org/10.1016/j.jacep.2018.05.003 | DOI Listing |
iScience
February 2025
Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
The vagus nerve is proposed to enable communication between the gut microbiome and the brain, but activity-based evidence is lacking. We find that mice reared germ-free exhibit decreased vagal tone relative to colonized controls, which is reversed via microbiota restoration. Perfusing antibiotics into the small intestines of conventional mice, but not germ-free mice, acutely decreases vagal activity which is restored upon re-perfusion with intestinal filtrates from conventional, but not germ-free, mice.
View Article and Find Full Text PDFNephrol Dial Transplant
January 2025
Clinica Medica, University Milano-Bicocca and University of Milano-Bicocca, Milan, Italy.
The autonomic nervous system plays a crucial role in regulating physiological processes and maintaining homeostasis through its two branches: the sympathetic nervous system (SNS) and the parasympathetic nervous system. Dysregulation of the autonomic system, characterized by increased sympathetic activity and reduced parasympathetic tone, is a common feature in chronic kidney disease (CKD) and cardiovascular disease. This imbalance contributes to a pro-inflammatory state, exacerbating disease progression and increasing the risk for cardiovascular events.
View Article and Find Full Text PDFPflugers Arch
January 2025
Division of Neurophysiology, Department of Physiology, Hyogo Medical University, Hyogo, 663 8501, Japan.
The nucleus tractus solitarius (NTS) contains neurons that relay sensory swallowing commands information from the oropharyngeal cavity and swallowing premotor neurons of the dorsal swallowing group (DSG). However, the spatio-temporal dynamics of the interplay between the sensory relay and the DSG is not well understood. Here, we employed fluorescence imaging after microinjection of the calcium indicator into the NTS in an arterially perfused brainstem preparation of rat (n = 8) to investigate neuronal population activity in the NTS in response to superior laryngeal nerve (SLN) stimulation.
View Article and Find Full Text PDFMedicina (Kaunas)
January 2025
Department of Neurosurgery, University of Medicine and Pharmacy "Carol Davila", 030147 Bucharest, Romania.
: The Index of Response to Stimulation (IRES) is a new index that we introduce in this study to grade the effectiveness of vagus nerve stimulation in the treatment of drug-resistant epilepsy. We assessed 76 patients at 6, 12, and 18 months after VNS evaluating improvement with the IRES in four key dimensions: seizure duration decrease, seizure intensity decrease, improvement in quality of life, and seizure frequency decrease. This scale goes from 0, meaning no improvement, to 8, meaning maximal improvement, making the scale a really good measure of clinical utility.
View Article and Find Full Text PDFMicroorganisms
January 2025
Department Neuromed & Movement Science, Norwegian University of Science & Technology (NTNU), 7034 Trondheim, Norway.
The rising burden of type 2 diabetes mellitus (T2DM) is a growing global public health problem, particularly prominent in developing countries. The early detection of T2DM and prediabetes is vital for reversing the outcome of disease, allowing early intervention. In the past decade, various microbiome-metabolome studies have attempted to address the question of whether there are any common microbial patterns that indicate either prediabetic or diabetic gut microbial signatures.
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