keyword
MENU ▼
Read by QxMD icon Read
search

Nodes of ranvier

keyword
https://www.readbyqxmd.com/read/29664415/model-based-optimal-multipolar-stimulation-without-a-priori-knowledge-of-nerve-structure-application-to-vagus-nerve-stimulation
#1
Melissa Dali, Olivier Rossel, David Andreu, Laure Laporte, Alfredo Hernandez, Jeremy Laforet, Eloi Marijon, Albert Hagège, Maureen Clerc, Christine Henry, David Guiraud
OBJECTIVE: Multipolar cuff electrode can selectively stimulate areas of peripheral nerves and therefore enable to control independent functions. However, the branching and fascicularization are known for a limited set of nerves and the specific organization remains subject-dependent. This paper presents a general modeling and optimization methods in the context of multipolar stimulation using a cuff electrode without a priori knowledge of the nerve structure. Vagus nerve stimulation experiments based on the optimization results were then investigated...
April 17, 2018: Journal of Neural Engineering
https://www.readbyqxmd.com/read/29615864/molecular-neuropathology-of-astrocytes-and-oligodendrocytes-in-alcohol-use-disorders
#2
REVIEW
José J Miguel-Hidalgo
Postmortem studies reveal structural and molecular alterations of astrocytes and oligodendrocytes in both the gray and white matter (GM and WM) of the prefrontal cortex (PFC) in human subjects with chronic alcohol abuse or dependence. These glial cellular changes appear to parallel and may largely explain structural and functional alterations detected using neuroimaging techniques in subjects with alcohol use disorders (AUDs). Moreover, due to the crucial roles of astrocytes and oligodendrocytes in neurotransmission and signal conduction, these cells are very likely major players in the molecular mechanisms underpinning alcoholism-related connectivity disturbances between the PFC and relevant interconnecting brain regions...
2018: Frontiers in Molecular Neuroscience
https://www.readbyqxmd.com/read/29525575/signal-propagation-along-the-axon
#3
REVIEW
Sylvain Rama, Mickaël Zbili, Dominique Debanne
Axons link distant brain regions and are usually considered as simple transmission cables in which reliable propagation occurs once an action potential has been generated. Safe propagation of action potentials relies on specific ion channel expression at strategic points of the axon such as nodes of Ranvier or axonal branch points. However, while action potentials are generally considered as the quantum of neuronal information, their signaling is not entirely digital. In fact, both their shape and their conduction speed have been shown to be modulated by activity, leading to regulations of synaptic latency and synaptic strength...
March 8, 2018: Current Opinion in Neurobiology
https://www.readbyqxmd.com/read/29497094/conditional-knockout-of-na-v-1-6-in-adult-mice-ameliorates-neuropathic-pain
#4
Lubin Chen, Jianying Huang, Peng Zhao, Anna-Karin Persson, Fadia B Dib-Hajj, Xiaoyang Cheng, Andrew Tan, Stephen G Waxman, Sulayman D Dib-Hajj
Voltage-gated sodium channels NaV 1.7, NaV 1.8 and NaV 1.9 have been the focus for pain studies because their mutations are associated with human pain disorders, but the role of NaV 1.6 in pain is less understood. In this study, we selectively knocked out NaV 1.6 in dorsal root ganglion (DRG) neurons, using NaV 1.8-Cre directed or adeno-associated virus (AAV)-Cre mediated approaches, and examined the specific contribution of NaV 1.6 to the tetrodotoxin-sensitive (TTX-S) current in these neurons and its role in neuropathic pain...
March 1, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29467340/saltatory-conduction-as-an-electrostatic-compressional-wave-in-the-axoplasm
#5
Tetsuya Akaishi
Saltatory conduction is an essential phenomenon to facilitate the fast conduction in myelinated nerves. The conventional conductive models assumed electric circuits with local current along the axonal membrane to explain the nerve conduction in unmyelinated nerves. However, whether such models with local current can be also applied to the saltatory conduction in myelinated nerves is unknown. In this report, I propose a new model of saltatory conduction by focusing on the behavior of electric charges in the axoplasm, not limited to the membrane...
2018: Tohoku Journal of Experimental Medicine
https://www.readbyqxmd.com/read/29444299/early-nodal-and-paranodal-disruption-in-autoimmune-optic-neuritis
#6
Aleksandar Stojic, Jovana Bojcevski, Sarah K Williams, Ricarda Diem, Richard Fairless
Disturbances in the nodes of Ranvier are an early phenomenon in many CNS disorders, including the autoimmune demyelinating disease multiple sclerosis (MS). Using an animal model of optic neuritis, a common early symptom of MS, we have investigated nodal and paranodal compartments in the optic nerve during disease progression. Both nodes and paranodes, as identified by immunohistochemistry against sodium channels (Nav) and Caspr, respectively, were observed to increase in length during the late induction phase of the disease, prior to onset of the demyelination and immune cell infiltration characteristic of optic neuritis...
February 10, 2018: Journal of Neuropathology and Experimental Neurology
https://www.readbyqxmd.com/read/29421432/dc-evoked-modulation-of-excitability-of-myelinated-nerve-fibres-and-their-terminal-branches-differences-in-sustained-effects-of-dc
#7
Dominik Kaczmarek, Elzbieta Jankowska
Direct current (DC) evokes long-lasting changes in neuronal networks both presynaptically and postsynaptically and different mechanisms were proposed to be involved in them. Different mechanisms were also suggested to account for the different dynamics of presynaptic DC actions on myelinated nerve fibres stimulated before they entered the spinal grey matter and on their terminal branches. The aim of the present study was to examine whether these different dynamics might be related to differences in the involvement of K+ channels...
February 5, 2018: Neuroscience
https://www.readbyqxmd.com/read/29329312/a-computational-study-of-the-impact-of-inhomogeneous-internodal-lengths-on-conduction-velocity-in-myelinated-neurons
#8
Abby Scurfield, David C Latimer
Age-related decreases in the conduction velocity (CV) of action potentials along myelinated axons have been linked to morphological changes in the myelin sheath. In particular, evidence suggests the presence of segmental demyelination and remyelination of axons. In remyelinated segments, the distance between adjacent nodes of Ranvier is typically shorter, and myelin sheaths are thinner. Both experimental and computational evidence indicates that shortened internodes slows CV. In this computational study, we determine the impact of progressive segmental demyelination and remyelination, modeled by shorter internodes with thinner myelin sheaths interspersed with normal ones, upon the CV...
2018: PloS One
https://www.readbyqxmd.com/read/29323217/node-of-ranvier-as-an-array-of-bio-nanoantennas-for-infrared-communication-in-nerve-tissue
#9
Andrea Zangari, Davide Micheli, Roberta Galeazzi, Antonio Tozzi
Electromagnetic radiation, in the visible and infrared spectrum, is increasingly being investigated for its possible role in the most evolved brain capabilities. Beside experimental evidence of electromagnetic cellular interactions, the possibility of light propagation in the axon has been recently demonstrated using computational modelling, although an explanation of its source is still not completely understood. We studied electromagnetic radiation onset and propagation at optical frequencies in myelinated axons, under the assumption that ion channel currents in the node of Ranvier behave like an array of nanoantennas emitting in the wavelength range from 300 to 2500 nm...
January 11, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29300891/loss-of-cntnap2-causes-axonal-excitability-deficits-developmental-delay-in-cortical-myelination-and-abnormal-stereotyped-motor-behavior
#10
Ricardo Scott, Alberto Sánchez-Aguilera, Kim van Elst, Lynette Lim, Nathalie Dehorter, Sung Eun Bae, Giorgia Bartolini, Elior Peles, Martien J H Kas, Hilgo Bruining, Oscar Marín
Contactin-associated protein-like 2 (Caspr2) is found at the nodes of Ranvier and has been associated with physiological properties of white matter conductivity. Genetic variation in CNTNAP2, the gene encoding Caspr2, has been linked to several neurodevelopmental conditions, yet pathophysiological effects of CNTNAP2 mutations on axonal physiology and brain myelination are unknown. Here, we have investigated mouse mutants for Cntnap2 and found profound deficiencies in the clustering of Kv1-family potassium channels in the juxtaparanodes of brain myelinated axons...
December 28, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/29282769/glial-m6b-stabilizes-the-axonal-membrane-at-peripheral-nodes-of-ranvier
#11
Marie L Bang, Anya Vainshtein, Hyun-Jeong Yang, Yael Eshed-Eisenbach, Jerome Devaux, Hauke B Werner, Elior Peles
Glycoprotein M6B and the closely related proteolipid protein regulate oligodendrocyte myelination in the central nervous system, but their role in the peripheral nervous system is less clear. Here we report that M6B is located at nodes of Ranvier in peripheral nerves where it stabilizes the nodal axolemma. We show that M6B is co-localized and associates with gliomedin at Schwann cell microvilli that are attached to the nodes. Developmental analysis of sciatic nerves, as well as of myelinating Schwann cells/dorsal root ganglion neurons cultures, revealed that M6B is already present at heminodes, which are considered the precursors of mature nodes of Ranvier...
April 2018: Glia
https://www.readbyqxmd.com/read/29138759/identification-of-persistent-and-resurgent-sodium-currents-in-spiral-ganglion-neurons-cultured-from-the-mouse-cochlea
#12
Lorcan Browne, Katie E Smith, Daniel J Jagger
In spiral ganglion neurons (SGNs), the afferent single units of the auditory nerve, high spontaneous and evoked firing rates ensure preservation of the temporal code describing the key features of incoming sound. During postnatal development, the spatiotemporal distribution of ion channel subtypes contributes to the maturation of action potential generation in SGNs, and to their ability to generate spike patterns that follow rapidly changing inputs. Here we describe tetrodotoxin (TTX)-sensitive Na+ currents in SGNs cultured from mice, whose properties may support this fast spiking behavior...
November 2017: ENeuro
https://www.readbyqxmd.com/read/29125128/action-potential-propagation-ion-current-or-intramembrane-electric-field
#13
Albert Martí, Juan J Pérez, Jordi Madrenas
The established action potential propagation mechanisms do not satisfactorily explain propagation on myelinated axons given the current knowledge of biological channels and membranes. The flow across ion channels presents two possible effects: the electric potential variations across the lipid bilayers (action potential) and the propagation of an electric field through the membrane inner part. The proposed mechanism is based on intra-membrane electric field propagation, this propagation can explain the action potential saltatory propagation and its constant delay independent of distance between Ranvier nodes in myelinated axons...
November 10, 2017: General Physiology and Biophysics
https://www.readbyqxmd.com/read/29114096/fingolimod-protects-against-ischemic-white-matter-damage-by-modulating-microglia-toward-m2-polarization-via-stat3-pathway
#14
Chuan Qin, Wen-Hui Fan, Qian Liu, Ke Shang, Madhuvika Murugan, Long-Jun Wu, Wei Wang, Dai-Shi Tian
BACKGROUND AND PURPOSE: White matter (WM) ischemic injury, a major neuropathological feature of cerebral small vessel diseases, is an important cause of vascular cognitive impairment in later life. The pathogenesis of demyelination after WM ischemic damage are often accompanied by microglial activation. Fingolimod (FTY720) was approved for the treatment of multiple sclerosis for its immunosuppression property. In this study, we evaluated the neuroprotective potential of FTY720 in a WM ischemia model...
December 2017: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/29114067/regulation-and-dysregulation-of-axon-infrastructure-by-myelinating-glia
#15
REVIEW
Simon Pan, Jonah R Chan
Axon loss and neurodegeneration constitute clinically debilitating sequelae in demyelinating diseases such as multiple sclerosis, but the underlying mechanisms of secondary degeneration are not well understood. Myelinating glia play a fundamental role in promoting the maturation of the axon cytoskeleton, regulating axon trafficking parameters, and imposing architectural rearrangements such as the nodes of Ranvier and their associated molecular domains. In the setting of demyelination, these changes may be reversed or persist as maladaptive features, leading to axon degeneration...
December 4, 2017: Journal of Cell Biology
https://www.readbyqxmd.com/read/29038243/an-%C3%AE-ii-spectrin-based-cytoskeleton-protects-large-diameter-myelinated-axons-from-degeneration
#16
Claire Yu-Mei Huang, Chuansheng Zhang, Daniel R Zollinger, Christophe Leterrier, Matthew N Rasband
Axons must withstand mechanical forces, including tension, torsion, and compression. Spectrins and actin form a periodic cytoskeleton proposed to protect axons against these forces. However, because spectrins also participate in assembly of axon initial segments (AISs) and nodes of Ranvier, it is difficult to uncouple their roles in maintaining axon integrity from their functions at AIS and nodes. To overcome this problem and to determine the importance of spectrin cytoskeletons for axon integrity, we generated mice with αII spectrin-deficient peripheral sensory neurons...
November 22, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29038240/%C3%AE-ii-spectrin-forms-a-periodic-cytoskeleton-at-the-axon-initial-segment-and-is-required-for-nervous-system-function
#17
Claire Yu-Mei Huang, Chuansheng Zhang, Tammy Szu-Yu Ho, Juan Oses-Prieto, Alma L Burlingame, Joshua Lalonde, Jeffrey L Noebels, Christophe Leterrier, Matthew N Rasband
Spectrins form a submembranous cytoskeleton proposed to confer strength and flexibility to neurons and to participate in ion channel clustering at axon initial segments (AIS) and nodes of Ranvier. Neuronal spectrin cytoskeletons consist of diverse β subunits and αII spectrin. Although αII spectrin is found in neurons in both axonal and somatodendritic domains, using proteomics, biochemistry, and superresolution microscopy, we show that αII and βIV spectrin interact and form a periodic AIS cytoskeleton...
November 22, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29030712/calculating-the-consequences-of-left-shifted-nav-channel-activity-in-sick-excitable-cells
#18
Bela Joos, Benjamin M Barlow, Catherine E Morris
Two features common to diverse sick excitable cells are "leaky" Nav channels and bleb damage-damaged membranes. The bleb damage, we have argued, causes a channel kinetics based "leakiness." Recombinant (node of Ranvier type) Nav1.6 channels voltage-clamped in mechanically-blebbed cell-attached patches undergo a damage intensity dependent kinetic change. Specifically, they experience a coupled hyperpolarizing (left) shift of the activation and inactivation processes. The biophysical observations on Nav1.6 currents formed the basis of Nav-Coupled Left Shift (Nav-CLS) theory...
October 14, 2017: Handbook of Experimental Pharmacology
https://www.readbyqxmd.com/read/28968364/chronic-demyelinating-polyneuropathies
#19
Jeffrey A Allen
PURPOSE OF REVIEW: This article reviews the chronic demyelinating neuropathies, with a focus on the diagnosis and treatment of immune-mediated neuropathies and the features that can help differentiate immune-mediated neuropathies from other chronic demyelinating peripheral nerve conditions. RECENT FINDINGS: Advances in clinical phenotyping and outcomes assessment have enabled neurologists to improve disease recognition, treatment, and disease monitoring. Our understanding of the immunopathogenesis of demyelinating neuropathies is evolving...
October 2017: Continuum: Lifelong Learning in Neurology
https://www.readbyqxmd.com/read/28966641/reassembly-of-the-axon-initial-segment-and-nodes-of-ranvier-in-regenerated-axons-of-the-central-nervous-system
#20
Miguel A Marin, Matthew N Rasband
No abstract text is available yet for this article.
August 2017: Neural Regeneration Research
keyword
keyword
97985
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"