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Vagal Nerve (vagal + nerve)

Distribution by Scientific Domains
Life Sciences50%
Medical Sciences33%

Terms modified by Vagal Nerve

  • vagal nerve stimulation
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  • vagal nerve stimulator
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    Selected Abstracts

    Development of the specialized AMPA receptors of auditory neurons

    DEVELOPMENTAL NEUROBIOLOGY, Issue 3 2002
    Steven G. Sugden
    Abstract At maturity, the AMPA receptors of auditory neurons exhibit very rapid desensitization kinetics and high permeability to calcium, reflecting the predominance of GluR3 flop and GluR4 flop subunits and the paucity of GluR2. We used mRNA analysis and immunoblotting to contrast the development of AMPA receptor structure in the chick cochlear nucleus [nucleus magnocellularis (NM)] with that of the slowly desensitizing and calcium-impermeable AMPA receptors of brainstem motor neurons in the nucleus of the glossopharyngeal/vagal nerves. The relative abundance of transcripts for GluRs 1,4 changes substantially in auditory (but not motor) neurons after embryonic day (E)10, with large decreases in GluR2 and increases in GluR3 and GluR4. Relative to the motor neurons, NM neurons show a higher abundance of flop isoforms of GluRs 2,4 at E10, suggesting that auditory neurons are already biased toward expression of flop isoforms before the onset of synaptic function at E11. Immunoreactivities in NM show very distinct developmental patterns from E13 onward: GluR2 declines by >90%, GluR3 increases threefold, and GluR4 remains relatively constant. Our results show that there are a series of critical points during normal development, most occurring after the onset of function, when rapid changes in receptor structure (occurring via both transcriptional and post-transcriptional control mechanisms) produce the specialized AMPA receptor functions that enable auditory neurons to accurately encode acoustic information. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 189,202, 2002 [source]

    Safe and Effective Ablation of Atrial Fibrillation: Importance of Esophageal Temperature Monitoring to Avoid Periesophageal Nerve Injury as a Complication of Pulmonary Vein Isolation

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2009
    TAISHI KUWAHARA M.D.
    Introduction: Catheter ablation on the left atrial posterior wall has been reported to potentially damage the esophagus or periesophageal vagal nerve. The aim of this study was to evaluate the efficacy of esophageal temperature monitoring (ETM) in preventing esophageal or periesophageal vagal nerve injury in patients with atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation. Methods: This study included 359 patients with drug-refractory AF who underwent extensive PV isolation. The first 152 patients were treated without ETM (non-ETM) and the last 207 with ETM. In the ETM group, the esophageal temperature (ET) was measured with a deflectable temperature probe that was placed close to the ablation electrode, and the radiofrequency energy applications were stopped when the ET reached 42°C. Results: In all patients in the ETM group, the ET increased to 42°C in at least one site by 28 ± 14 seconds, mostly along the right side of the left PVs, especially near the left inferior PV. Less energy (6.3 ± 1.9 × 104 J) was required for PV isolation in the ETM group than that in the non-ETM (6.8 ± 1.9 ×104 J, P = 0.03). Gastric hypomotility owing to periesophageal nerve damage was observed in three patients in the non-ETM group, but in none in the ETM (P = 0.02). The recurrence rates of AF did not differ between the two groups (non-ETM, 29%; ETM, 27%). Conclusion: Titration of the duration of the ablation energy delivery while monitoring the ET could prevent periesophageal nerve injury due to the AF ablation, without decreasing the success rate of maintaining sinus rhythm. [source]

    Medullary motor neurones associated with drinking behaviour of Japanese eels

    JOURNAL OF FISH BIOLOGY, Issue 1 2003
    T. Mukuda
    A fluorescent dye, Evans blue (EB), was injected into the following seven drinking-associated muscles of the Japanese eel Anguilla japonica: the sternohyoid, third branchial, fourth branchial, opercular, pharyngeal, upper oesophageal sphincter and oesophageal body muscles. The sternohyoid muscle promotes ,ingestion', and the remaining muscles contribute to ,swallowing'. All neurones stained by EB were located ipsilaterally in the caudal medulla oblongata (MO) of the Japanese eel. Neurones projecting into the sternohyoid muscle were identified as those in the spino-occipital motor nucleus (NSO), and neurones projecting into the remaining muscles as those in the glossopharyngeal,vagal motor complex (GVC). Within the GVC, the neuronal arrangement was topological, and hence, ,swallowing' will be completed if the GVC neurones ,fire' progressively from rostral to caudal. These neurones in the NSO and GVC may use acetylcholine (ACh) as a neurotransmitter, as the EB-positive neurones in both nuclei were immunoreactive against anticholine acetyltransferase (anti-ChAT) antibody. Besides the MO, some somata in a ganglion of the vagal nerve were also stained by EB injected into the pharyngeal, the upper oesophageal sphincter and the oesophageal body muscles. The localization and the shape of the somata suggest that they are sensory neurones. These sensory neurones were not ChAT-immunoreactive. Combining these results, based on a model for ,swallowing' in mammals, a plausible model for central organization of ,drinking' in the Japanese eel is proposed, which suggests that ,drinking' in the fishes is regulated by the neuronal circuit for ,swallowing' in mammals. [source]

    Esophageal Acid Levels after Pulmonary Vein Isolation for Atrial Fibrillation

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009
    GEORG NÖLKER M.D.
    Background: Pulmonary vein antrum isolation (PVAI) is a potentially curative, nonpharmacologic treatment of atrial fibrillation (AF). Several procedural complications have been described, including esophageal wall lesions ranging from erythema and esophagitis, necrosis and ulcer, to atrio-esophageal fistula. We prospectively studied changes in esophageal acid levels before and after PVAI. Methods: We performed 24-hour pH-metry before and 1.3 ± 1.6 days after PVAI, in 25 patients (mean age = 62 ± 12 years, 17 men) with symptomatic AF. A 2-mm transnasal probe was inserted into the inferior part of the esophagus and into the stomach to measure pH levels at fixed intervals. DeMeester scores, indicating acidic gastro-esophageal reflux, were calculated. Results: The mean number of reflux episodes increased from 89 ± 80 before to 107 ± 94 after PVAI. The mean percentage of time with esophageal pH < 4 was shorter after (108 ± 193 minutes) than before PVAI (159 ± 245 minutes). The mean DeMeester score decreased from 49 ± 68 before to 31 ± 41 after PVAI (P < 0.05). We observed erythema or esophagitis in five patients, necrosis or ulcer in seven, and atrio-esophageal fistula in no patient. Conclusions: Our hypothesis of increased acid levels caused by stimulation of the right vagal nerve during isolation of the right upper pulmonary vein was not verified. [source]

    Effects of right and left vagal stimulation on left ventricular acetylcholine levels in the cat

    ACTA PHYSIOLOGICA, Issue 1 2001
    T. Akiyama
    To test the effectiveness of, and the interactions between, right and left vagal stimulation on left ventricular acetylcholine (ACh) levels, we applied the dialysis technique to the heart of anaesthetized cats. Dialysis probes were implanted in the left ventricular myocardium and perfused with Krebs,Henseleit buffer containing eserine. Dialysate ACh content was measured as an index of ACh release from post-ganglionic vagal nerve terminals in the left ventricular myocardium. We electrically stimulated the right and left cervical vagal nerves separately or together and investigated the dialysate ACh response. In two different regions of the left ventricle, substantial dialysate ACh responses were observed by the stimulation (20 Hz) of both right and left cervical vagal nerves. At stimulation frequencies of both 10 and 20 Hz, the dialysate ACh response to the bilateral vagal stimulation was almost algebraically the calculated sum of the individual dialysate ACh responses to unilateral vagal stimulation. In conclusion, ACh levels in the left ventricle are affected by both right and left vagal nerves and show little evidence of interactions between right and left vagal nerves at the level of the cardiac ganglia. [source]