scholarly journals Human organ donor-derived vagus nerve biopsies allow for well-preserved ultrastructure and high-resolution mapping of myelinated and unmyelinated fibers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leif A. Havton ◽  
Natalia P. Biscola ◽  
Esther Stern ◽  
Plamen V. Mihaylov ◽  
Chandrashekhar A. Kubal ◽  
...  
Keyword(s):  
High Resolution ◽  
Vagus Nerve ◽  
Functional Organization ◽  
Adjunctive Treatment ◽  
Vagus Nerves ◽  
Human Organ ◽  
Ultrastructural Studies ◽  
Unmyelinated Fibers ◽  
Unmyelinated Axons ◽  
Myelinated And Unmyelinated Fibers

AbstractThe vagus nerve provides motor, sensory, and autonomic innervation of multiple organs, and electrical vagus nerve stimulation (VNS) provides an adjunctive treatment option for e.g. medication-refractory epilepsy and treatment-resistant depression. The mechanisms of action for VNS are not known, and high-resolution anatomical mapping of the human vagus nerve is needed to better understand its functional organization. Electron microscopy (EM) is required for the detection of both myelinated and unmyelinated axons, but access to well-preserved human vagus nerves for ultrastructural studies is sparse. Intact human vagus nerve samples were procured intra-operatively from deceased organ donors, and tissues were immediately immersion fixed and processed for EM. Ultrastructural studies of cervical and sub-diaphragmatic vagus nerve segments showed excellent preservation of the lamellated wall of myelin sheaths, and the axolemma of myelinated and unmyelinated fibers were intact. Microtubules, neurofilaments, and mitochondria were readily identified in the axoplasm, and the ultrastructural integrity of Schwann cell nuclei, Remak bundles, and basal lamina was also well preserved. Digital segmentation of myelinated and unmyelinated axons allowed for determination of fiber size and myelination. We propose a novel source of human vagus nerve tissues for detailed ultrastructural studies and mapping to support efforts to refine neuromodulation strategies, including VNS.

Optical Approaches to Functional Organization of Glossopharyngeal and Vagal Motor Nuclei in the Embryonic Chick Hindbrain

2002 ◽  
Vol 88 (1) ◽  
pp. 383-393 ◽  
Author(s):  
Katsushige Sato ◽  
Hiraku Mochida ◽  
Itaru Yazawa ◽  
Shinichi Sasaki ◽  
Yoko Momose-Sato
Keyword(s):  
Vagus Nerve ◽  
Developmental Stages ◽  
Functional Organization ◽  
Signal Amplitude ◽  
Optical Recording ◽  
Single Peak ◽  
Motor Nucleus ◽  
Vagus Nerves ◽  
Dorsal Motor Nucleus ◽  
Motor Nuclei

We investigated the functional organization of the glossopharyngeal and vagal motor nuclei during embryogenesis using multiple-site optical recording with a fast voltage-sensitive dye. Intact brain stem preparations with glossopharyngeal and vagus nerves were dissected from 4- to 8-day-old chick embryos. Electrical responses evoked by glossopharyngeal/vagus nerve stimulation were optically recorded from many loci of the stained preparations. In 4- to 6-day-old preparations, action potential-related fast spikelike signals were detected from the nucleus of the glossopharyngeal nerve and the dorsal motor nucleus of the vagus nerve. Contour line maps of the signal amplitude showed multiple-peak patterns, suggesting that the neurons and/or their activity were not uniformly distributed within the nuclei at early developmental stages. As development proceeded from 4 to 6 days, the peaks fused with each other and the number of peaks decreased gradually. In most 7- and 8-day-old preparations, only a single peak was identified in the nuclei, and the distribution of the signal amplitude formed a layered pattern surrounding the peak-signal area. These results suggest that functional organization of the motor nuclei in the embryonic hindbrain changes dynamically with development, resulting in a rearrangement of functional nuclear cores from multiple-peaks to a single peak.

scholarly journals The Anatomical Substratum of Pain Evidence Derived from Morphometric Studies on Peripheral Nerve

1974 ◽  
Vol 1 (2) ◽  
pp. 92-97 ◽  
Author(s):  
P.K. Thomas
Keyword(s):  
Peripheral Nerves ◽  
Spontaneous Pain ◽  
Spatial And Temporal Patterns ◽  
Unmyelinated Fibers ◽  
Unmyelinated Axons ◽  
Anatomical Basis ◽  
Pain Pathway ◽  
Myelinated And Unmyelinated Fibers ◽  
Nociceptive Pathway ◽  
Specific Receptors

SUMMARYEarlier theories as to the anatomical basis of pain postulated a direct ‘pain pathway’ from specific receptors in the periphery. Anatomical studies linked this with small myelinated and unmyelinated fibers in the peripheral nerves. Subsequently, hypotheses were advanced which postulated that pain depended upon particular spatial and temporal patterns of sensory input into the nervous system rather than upon specific sets of fibers.More recent physiological studies have demonstrated the existence of peripheral receptors that respond exclusively to noxious stimuli and morphometric studies on peripheral neuropathies in man clearly implicate small myelinated and unmyelinated axons in the conduction of pain. Morphometric studies have also shown that spontaneous pain in neuropathies may be associated with a selective loss of small fibers. These observations therefore support the earlier concept of a specific nociceptive pathway involving small caliber fibers in the peripheral nerves. It is evident that this afferent pathway is capable of modification in the spinal cord both by peripheral inputs and by descending impulses. The notion of a ‘pain pathway’ as such is probably best avoided.

Development of myelinated and unmyelinated fibers of human vagus nerve during the first year of life

1992 ◽  
Vol 110 (1-2) ◽  
pp. 107-113 ◽  
Author(s):  
Pedro M. Pereyra ◽  
Weixian Zhang ◽  
Matthias Schmidt ◽  
Laurence E. Becker
Keyword(s):  
Vagus Nerve ◽  
First Year ◽  
Unmyelinated Fibers ◽  
Myelinated And Unmyelinated Fibers ◽  
First Year Of Life

scholarly journals Stain-Free Resolution of Unmyelinated Axons in Transgenic Mice Using Fluorescence Microscopy

2019 ◽  
Vol 78 (12) ◽  
pp. 1178-1180 ◽  
Author(s):  
Suresh Mohan ◽  
Iván Coto Hernández ◽  
Martin K Selig ◽  
Shinsuke Shibata ◽  
Nate Jowett
Keyword(s):  
Sciatic Nerve ◽  
Fluorescence Microscopy ◽  
Transgenic Mice ◽  
Light Microscopy ◽  
High Throughput ◽  
Peripheral Nerves ◽  
Free Resolution ◽  
Unmyelinated Fibers ◽  
Unmyelinated Axons ◽  
Myelinated And Unmyelinated Fibers

Abstract Though unmyelinated fibers predominate axon counts within peripheral nerves, they are frequently excluded in histomorphometric assessment as they cannot be readily resolved by light microscopy. Herein, we demonstrate stain-free resolution of unmyelinated axons in Sox10-Venus mice by widefield fluorescence imaging of sciatic nerve cryosections. Optional staining of cryosections using a rapid and nontoxic myelin-specific dye (FluoroMyelin Red) enables robust synchronous resolution of myelinated and unmyelinated fibers, comprising a high-throughput platform for neural histomorphometry.

High-voltage EM description of the types and distribution of sensory endings in the inner conical body of the rat vibrissal follicle-sinus complex

1990 ◽  
Vol 48 (3) ◽  
pp. 410-411
Author(s):  
Tony M. Mosconi ◽  
Min J. Song ◽  
Frank L. Rice
Keyword(s):  
Mammalian Species ◽  
Dorsal Side ◽  
Hair Shaft ◽  
Sensory Innervation ◽  
Conical Body ◽  
Adult Rats ◽  
Perpendicular Plane ◽  
Ultrastructural Studies ◽  
Unmyelinated Axons ◽  
Sensory Endings

Whiskers or vibrissal follicle-sinus complexes (F-SCs) on the snouts of many mammalian species are structures that have complex, dense sensory innervation. The innervation of F-SCs is remarkably similar in all species with the exception of one site - the inner conical body (ICB). The ICB is an elongated cylindrical structure that encircles the hair shaft near the neck of the follicle. This site has received only cursory attention in ultrastructural studies of the F-SCAdult rats were perfused after the method of Renehan and Munger2. F-SCs were quartered longitudinally and embedded separately in Epon-Araldite. Serial 0.25 μm sections were cut in either the longitudinal or perpendicular plane through the ICB and examined with an AEI EM7 1.2 MV HVEM (Albany, NY) at 1000 KV. Sensory endings were reconstructed from serial micrographs through at least 20 μm in the longitudinal plane and through 10 μm in the perpendicular plane.From two to six small superficial vibrissal nerves converge upon the neck of the F-SC and descend into the ICB. The nerves branch into smaller bundles of myelinated and unmyelinated axons along the dorsal side of the hair shaft.

scholarly journals High-resolution ultrasound changes of the vagus nerve in idiopathic Parkinson’s disease (IPD): a possible additional index of disease

2021 ◽  
Author(s):  
F. Sartucci ◽  
T. Bocci ◽  
M. Santin ◽  
P. Bongioanni ◽  
G. Orlandi
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
High Resolution ◽  
Vagus Nerve ◽  
Imaging Modality ◽  
Disease Stage ◽  
Motor Nucleus ◽  
Idiopathic Parkinson’S Disease ◽  
Idiopathic Parkinson's Disease ◽  
Additional Index

Abstract Background and rationale Histopathological studies revealed degeneration of the dorsal motor nucleus of the vagus nerve (VN) early in the course of idiopathic Parkinson’s disease (IPD). Degeneration of VN axons should be detectable by high-resolution ultrasound (HRUS) as a thinning of the nerve trunk. In order to establish if the VN exhibits sonographic signs of atrophy in IPD, we examined patients with IPD compared with age-matched controls. Material and methods We measured the caliber (cross-sectional area, CSA) and perimeter of the VN in 20 outpatients with IPD (8 females and 12 males; mean age 73.0 + 8.6 years) and in age-matched controls using HRUS. Evaluation was performed by blinded raters using an Esaote MyLab Gamma device in conventional B-Mode with an 8–19 MHz probe. Results In both sides, the VN CSA was significantly smaller in IPD outpatients than in controls (right 2.37 + 0.91, left 1.87 + 1.35 mm2 versus 6.0 + 1.33, 5.6 + 1.26 mm2; p <0.001), as well as the perimeter (right 5.06 + 0.85, left 4.78 + 1.74 mm versus 8.87 + 0.86, 8.58 + 0.97 mm; p <0.001). There were no significant correlations between VN CSA and age, the Hoehn and Yahr scale, L-dopa therapy, and disease duration. Conclusion Our findings provide evidence of atrophy of the VNs in IPD patients by HRUS. Moreover, HRUS of the VN represent a non-invasive easy imaging modality of screening in IPD patients independent of disease stage and duration and an interesting possible additional index of disease.

scholarly journals Essential Oil of Croton zehntneri Prevents Conduction Alterations Produced by Diabetes Mellitus on Vagus Nerve

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 893
Author(s):  
Kerly Shamyra Silva-Alves ◽  
Francisco Walber Ferreira-da-Silva ◽  
Andrelina Noronha Coelho-de-Souza ◽  
José Henrique Leal-Cardoso
Keyword(s):  
Diabetes Mellitus ◽  
Essential Oil ◽  
Diabetic Neuropathy ◽  
Vagus Nerve ◽  
Therapeutic Agent ◽  
Specific Treatment ◽  
Compound Action Potential ◽  
Unmyelinated Fibers ◽  
Conduction Velocities ◽  
Compound Action

Autonomic diabetic neuropathy (ADN) is a complication of diabetes mellitus (DM), to which there is no specific treatment. In this study, the efficacy of the essential oil of Croton zehntneri (EOCz) in preventing ADN was evaluated in the rat vagus nerve. For the two fastest conducting myelinated types of axons of the vagus nerve, the conduction velocities and rheobase decreased, whilst the duration of the components of the compound action potential of these fibers increased. EOCz completely prevented these DM-induced alterations of the vagus nerve. Unmyelinated fibers were not affected. In conclusion, this investigation demonstrated that EOCz is a potential therapeutic agent for the treatment of ADN.

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.

Sign in / Sign up

Export Citation Format

Share Document