scholarly journals Comparison of the efficiency of chopped and non-rectangular electrical stimulus waveforms in activating small vagus nerve fibers

2019 ◽  
Vol 320 ◽  
pp. 1-8 ◽  
Author(s):  
Mélissa Dali ◽  
Chloé Picq ◽  
Olivier Rossel ◽  
Pawel Maciejasz ◽  
Charles-Henri Malbert ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Electrical Stimulus ◽  
Nerve Fibers

scholarly journals Selective stimulation of the ferret abdominal vagus nerve with multi-contact nerve cuff electrodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan A. Shulgach ◽  
Dylan W. Beam ◽  
Ameya C. Nanivadekar ◽  
Derek M. Miller ◽  
Stephanie Fulton ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Nerve Fibers ◽  
The Body ◽  
Evoked Responses ◽  
Gi Tract ◽  
Selective Stimulation ◽  
Nerve Cuff ◽  
Cuff Electrodes ◽  
Nerve Cuff Electrodes ◽  
Stimulation Of

AbstractDysfunction and diseases of the gastrointestinal (GI) tract are a major driver of medical care. The vagus nerve innervates and controls multiple organs of the GI tract and vagus nerve stimulation (VNS) could provide a means for affecting GI function and treating disease. However, the vagus nerve also innervates many other organs throughout the body, and off-target effects of VNS could cause major side effects such as changes in blood pressure. In this study, we aimed to achieve selective stimulation of populations of vagal afferents using a multi-contact cuff electrode wrapped around the abdominal trunks of the vagus nerve. Four-contact nerve cuff electrodes were implanted around the dorsal (N = 3) or ventral (N = 3) abdominal vagus nerve in six ferrets, and the response to stimulation was measured via a 32-channel microelectrode array (MEA) inserted into the left or right nodose ganglion. Selectivity was characterized by the ability to evoke responses in MEA channels through one bipolar pair of cuff contacts but not through the other bipolar pair. We demonstrated that it was possible to selectively activate subpopulations of vagal neurons using abdominal VNS. Additionally, we quantified the conduction velocity of evoked responses to determine what types of nerve fibers (i.e., Aδ vs. C) responded to stimulation. We also quantified the spatial organization of evoked responses in the nodose MEA to determine if there is somatotopic organization of the neurons in that ganglion. Finally, we demonstrated in a separate set of three ferrets that stimulation of the abdominal vagus via a four-contact cuff could selectively alter gastric myoelectric activity, suggesting that abdominal VNS can potentially be used to control GI function.

Endings of the vagus nerve fibers in the mammalian heart

1927 ◽  
Vol 23 (6-7) ◽  
pp. 622-623
Author(s):  
B. I. Lavrent'ev
Keyword(s):  
Methylene Blue ◽  
Vagus Nerve ◽  
Nerve Fibers ◽  
Nerve Cells ◽  
Vagus Nerves ◽  
Mammalian Heart ◽  
Cardiac Ganglia ◽  
Important Study ◽  
Spiral Fibers

In 1893, Prof. V.V. Nikolaev, having cut vagus nerves of a frog, saw under a microscope degeneration of so-called spiral fibers and pericellular apparatuses on nerve cells of intracardiac nodes. Later these observations were thoroughly verified by Prof. D.V. Polumordvinov and fully confirmed by him. I had a chance to look through amazing by technique preparations of the late Prof. Polumordvinov, obtained by methylene blue method, on which decay of pericellular apparatuses in cardiac ganglia of a frog was absolutely clearly visible. D. V-ch, who died untimely in 1919, unfortunately, did not have time to publish in detail his important study; the manuscript and drawings of his work also remained undiscovered.

Barbiturates depress vagal motor pathway to ferret trachea at ganglia

1982 ◽  
Vol 53 (1) ◽  
pp. 253-257 ◽  
Author(s):  
B. E. Skoogh ◽  
M. J. Holtzman ◽  
J. R. Sheller ◽  
J. A. Nadel
Keyword(s):  
Neuromuscular Junction ◽  
Vagus Nerve ◽  
Muscle Tension ◽  
Postsynaptic Membrane ◽  
Nerve Fibers ◽  
Motor Pathway ◽  
Parasympathetic Ganglia ◽  
Before And After ◽  
Nerve Muscle

To determine which site in the vagal motor pathway to airway smooth muscle is most sensitive to depression by barbiturates, we recorded isometric muscle tension in vitro and stimulated the vagal motor pathway at four different sites before and after exposure to barbiturates. In isolated tracheal rings from ferrets, we stimulated muscarinic receptors in the neuromuscular junction by exogenous acetylcholine, postganglionic nerve fibers by electrical fluid stimulation, and the postsynaptic membrane in ganglia by 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP). We also developed a tracheal nerve-muscle preparation to stimulate preganglionic fibers in the vagus nerve electrically. Activation of ganglia by DMPP or by vagus nerve stimulation was depressed by barbiturates at 10-fold lower concentrations than those depressing the activation of postganglionic nerves or the neuromuscular junction. These findings suggest that the postsynaptic membrane in parasympathetic ganglia is the site in the vagal motor pathway most sensitive to depression by barbiturates.

Localization of Adductor and Abductor Motor Nerve Fibers to the Larynx

1977 ◽  
Vol 86 (6) ◽  
pp. 770-776 ◽  
Author(s):  
Richard R. Gacek ◽  
Leslie T. Malmgren ◽  
Michael J. Lyon
Keyword(s):  
Vagus Nerve ◽  
Motor Neurons ◽  
Motor Nerve ◽  
Functional Results ◽  
Nerve Fibers ◽  
Nucleus Ambiguus ◽  
Axoplasmic Flow ◽  
Anterograde Degeneration ◽  
Almost All ◽  
The Brain

Knowledge of the location of motor nerve fibers to the adductor and abductor muscles of the larynx may be useful in the diagnosis and treatment of innervation disorders in this organ. Anterograde degeneration and retrograde tracer anatomical techniques have demonstrated the central and peripheral positions of these two groups of motor nerve fibers in the cat. Traditional nerve fiber degeneration methods applied following intracranial transection of the vagus nerve rootlets indicated that: 1) Most of the fibers in the recurrent laryngeal nerve (RLN) are motor; 2) Almost all of these motor fibers leave the brain stem in the most rostral rootlet(s) of the vagus nerve; and 3) Motor fibers to the larynx form a discrete bundle within the trunk of the vagus nerve before forming the RLN. A tracer (horseradish peroxidase) of retrograde axoplasmic flow in motor neurons has been employed to demonstrate: 1) Dorsoventral division of the adductor and abductor neurons in the nucleus ambiguus; and 2) Diffuse arrangement of both adductor and abductor nerve fibers in the vagus nerve but collection of these fibers into abductor and adductor halves of the RLN prior to entering the larynx. These findings dispel theories of differential cord paralysis (Semon's law) based on a vulnerable position of abductor fibers at the periphery of the RLN. Furthermore, the diffuse arrangement of these fiber groups explains the usually mixed functional results obtained following reimplantation of the RLN into a laryngeal muscle.

scholarly journals In vivo visualization of pig vagus nerve ‘vagotopy’ using ultrasound

2020 ◽  
Author(s):  
Megan L. Settell ◽  
Maisha Kasole ◽  
Aaron C. Skubal ◽  
Bruce E. Knudsen ◽  
Evan N. Nicolai ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Motor Nerve ◽  
Nerve Fibers ◽  
Patient Specific ◽  
Neck Muscle ◽  
Therapeutic Effects ◽  
Ultrasound Images ◽  
Anatomical Landmarks ◽  
Novel Approach

AbstractBackgroundPlacement of the clinical vagus nerve stimulating cuff is a standard surgical procedure based on anatomical landmarks, with limited patient specificity in terms of fascicular organization or vagal anatomy. As such, the therapeutic effects are generally limited by unwanted side effects of neck muscle contractions, demonstrated by previous studies to result from stimulation of 1) motor fibers near the cuff in the superior laryngeal and 2) motor fibers within the cuff projecting to the recurrent laryngeal.ObjectiveThe use of patient-specific visualization of vagus nerve fascicular organization could better inform clinical cuff placement and improve clinical outcomes.MethodsThe viability of ultrasound, with the transducer in the surgical pocket, to visualize vagus nerve fascicular organization (i.e. vagotopy) was characterized in a pig model. Ultrasound images were matched to post-mortem histology to confirm the utility of ultrasound in identifying fascicular organization.ResultsHigh-resolution ultrasound accurately depicted the vagotopy of the pig vagus nerve intra-operatively, as confirmed via histology. The stereotypical pseudo-unipolar cell body aggregation at the nodose ganglion was identifiable, and these sensory afferent fascicular bundles were traced down the length of the vagus nerve. Additionally, the superior and recurrent laryngeal nerves were identified via ultrasound.ConclusionsIntraoperative visualization of vagotopy and surrounding nerves using ultrasound is a novel approach to optimize stimulating cuff placement, avoid unwanted activation of motor nerve fibers implicated in off-target effects, and seed patient-specific models of vagal fiber activation to improve patient outcomes.

Preganglionic vagus nerve fibers also enter the greater curvature of the stomach in rats and ferrets

1988 ◽  
Vol 94 (6) ◽  
pp. 1292-1299 ◽  
Author(s):  
Philip E. Donahue ◽  
Junichi Yoshida ◽  
Edward H. Polley ◽  
Lloyd M. Nyhus
Keyword(s):  
Vagus Nerve ◽  
Nerve Fibers ◽  
Greater Curvature

TETRAETHYLAMMONIUM-INDUCED CONTRACTIONS OF FROG'S SKELETAL MUSCLE: II. EFFECTS ON INTRAMUSCULAR NERVE ENDINGS

1967 ◽  
Vol 45 (5) ◽  
pp. 833-844 ◽  
Author(s):  
G. Beaulieu ◽  
G. B. Frank ◽  
F. Inoue
Keyword(s):  
Motor Nerve ◽  
Muscle Fibers ◽  
Electrical Stimulus ◽  
Nerve Fibers ◽  
Ventral Root ◽  
Nerve Endings ◽  
Glass Capillary ◽  
Action Potential Firing ◽  
Low Concentrations ◽  
Potential Firing

By recording simultaneously from muscle fibers and from the ventral root supplying the muscle, it was found that low concentrations of tetraethylammonium (TEA) caused the muscle fibers to fire without antidromic impulses being conducted to the ventral root. Exposing the muscles to higher TEA concentrations induced action potential firing in both the muscle and the ventral root. d-Tubocurarine prevented the muscle fiber activity but did not modify the ventral root firing. The application of a single supramaximal electrical stimulus to the sciatic nerve resulted in an afterdischarge of the muscle fibers either alone or simultaneous with an afterdischarge of fibers in the ventral root. By recording from fine intramuscular motor nerve fibers with extracellular glass capillary microelectrodes while simultaneously recording from the ventral root, it was demonstrated that TEA could cause these fine intramuscular motor nerve fibers to fire without the activity being conducted antidromically to the ventral root. A consideration of the patterns of TEA-induced electrical activity and afterdischarging led to the suggestion that TEA causes these effects by displacing calcium from binding sites on the motor nerve endings, making the latter hyperexcitable and unstable and thereby causing afterdischarging and 'spontaneous' activity.

scholarly journals Sympathetic Nerve Fibers within the Cervical Vagus Nerve Do Not Innervate the Heart

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Allan Migirov ◽  
John Siano ◽  
Eduard I. Dedkov ◽  
Youhua Zhang
Keyword(s):  
Vagus Nerve ◽  
Sympathetic Nerve ◽  
Nerve Fibers ◽  
Sympathetic Nerve Fibers
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