scholarly journals Bio-capacitor consist of insulated myelin-sheath and uninsulated node of Ranvier: a bio-nano-antenna

2020 ◽  
Vol 10 (1) ◽  
pp. 4956-4965
Keyword(s):  
Nerve Cell ◽  
Myelin Sheath ◽  
Electromagnetic Waves ◽  
Node Of Ranvier ◽  
Quantum Effects ◽  
Small Region ◽  
Physiological Data ◽  
Membrane Thickness ◽  
Electrical Wire ◽  
Membrane Bound

Myelin consists of fatty molecules (lipids) which are located in the CNC (central nervous system) and as an insulator around nerve cell axons increases the velocities information to transit from one nerve cell to another tissue like an electrical wire (the axon) with insulating material (myelin) around it. Each axon contains multiple long myelinated parts separated from each other through short gaps called “Nodes of Ranvier” or myelin-sheath gaps. A computational model is presented for the simulation of propagated electromagnetic waves in a critical point between insulated myelin-sheath towards uninsulated node of Ranvier. The QM/MM calculation has been applied for generalizing the node of Ranvier results for computing action potentials and electro chemical behavior of membranes which agree with clusters of voltage-gated ion sodium and potassium channels. The node of Ranvier complexes is an accurate organization of membrane-bound aqueous compartments, and the model presented here represents electrophysiological events with combined realistic structural and physiological data. The quantum effects of different thicknesses in the mixed membranes of GalC/DPPC, have also been specifically investigated. It is shown that quantum effects can appear in a small region of free spaces within the membrane thickness due to the number and type of lipid’s layers. In addition, from the view point of quantum effects by Heisenberg rule, it is shown that quantum tunneling is allowed in some micro positions of membrane capacitor systems, while it is forbidden in other forms.

scholarly journals Bio-Lipid Nano Capacitors: Resonance with Helical Myeline Proteins

2020 ◽  
Vol 10 (6) ◽  
pp. 6695-6705
Keyword(s):  
Lipid Bilayers ◽  
Quantum Effects ◽  
Small Region ◽  
The State ◽  
External Factors ◽  
The Self ◽  
Myelin Proteins ◽  
Membrane Thickness ◽  
Variable Capacitance ◽  
Helical Coils

The model of this work represents electrophysiological occurrences with a combination of some phospholipids such as POPC and galactocerebroside lipid bilayers as variable capacitors. The quantum effects of different thicknesses in the mixed membranes of GalC/POPC, Galc/ POPE, and Galc/DPPC have also explicitly been investigated. It is shown that quantum effects can appear in a small region of free spaces within the membrane thickness due to the number and type of lipid's layers. In the presence of external factors such as protein transmembrane and myelin proteins as a resistance, the forces can influence the state of the membrane, which results in a variable capacitance behavior. This allows introducing a capacitive susceptibility which can be resonating with the self-induction of helical coils in myelin proteins, the resonance of which is the main reason for various biological pulses.

scholarly journals A NMR Study of Sodium/Potassium Pumping System in the Node of Ranvier Myelin-Sheath

2021 ◽  
Vol 11 (6) ◽  
pp. 14260-14277
Keyword(s):  
Action Potentials ◽  
Node Of Ranvier ◽  
Physiological Data ◽  
Sodium Potassium ◽  
Voltage Gated ◽  
Pumping System ◽  
Nmr Study ◽  
Helical Coils ◽  
Membrane Bound ◽  
Sodium And Potassium

The QM/MM calculation has been applied to generalize the node of Ranvier results for computing action potentials and electrochemical behavior of membranes that agree with clusters of voltage-gated ion sodium and potassium channels. Ranvier complexes' node is an accurate organization of membrane-bound aqueous boxes. The model applied here shows an electrophysiological phenomenon with simulated structural and physiological data. The quantum effects of various thicknesses in a selected membrane of Galc /DMPC and Galc/NPGS have also been specifically investigated. This allows introducing a capacitive susceptibility that can resonate with the self-induction of helical coils or ion channels, the resonance of which is the main reason for various biological pulses.

Ultracytochemical localization of membrane-bound enzymes in the node of Ranvier

1989 ◽  
Vol 20 (3-4) ◽  
pp. 207-215
Author(s):  
Kenichirou Inomata ◽  
Fumio Nasu ◽  
Kazuhiro Tomiyasu
Keyword(s):  
Node Of Ranvier ◽  
Membrane Bound ◽  
Membrane Bound Enzymes

scholarly journals ISOLATION OF THE PERIAXONAL SPACE OF THE CENTRAL MYELINATED NERVE FIBER WITH REGARD TO THE DIFFUSION OF PEROXIDASE

1969 ◽  
Vol 17 (8) ◽  
pp. 512-516 ◽  
Author(s):  
ASAO HIRANO ◽  
NORWIN H. BECKER ◽  
H. M. ZIMMERMAN
Keyword(s):  
Horseradish Peroxidase ◽  
Nerve Fiber ◽  
Myelin Sheath ◽  
Node Of Ranvier ◽  
Myelinated Nerve Fiber ◽  
Outer Loop ◽  
Myelinated Nerve ◽  
Lateral Loop ◽  
Periaxonal Space

Horseradish peroxidase was implanted into rat forebrains and the distribution with respect to the periaxonal space was examined. The peroxidase filled the extracellular spaces. Usually, however, the flow stopped at the junction of the outer loop and the outermost lamella of the myelin sheath and at the outermost lateral loop at the node of Ranvier. Therefore, in most cases, the periaxonal space was devoid of peroxidase. Occasionally, however, peroxidase in small amounts evidently penetrated the junctions and could sometimes be clearly demonstrated within the periaxonal space.

scholarly journals Oligodendrocytes assist in the maintenance of sodium channel clusters independent of the myelin sheath

2004 ◽  
Vol 1 (3) ◽  
pp. 179-192 ◽  
Author(s):  
JEFFREY L. DUPREE ◽  
JEFFREY L. MASON ◽  
JILL R. MARCUS ◽  
MICHAEL STULL ◽  
ROCK LEVINSON ◽  
...  
Keyword(s):  
Sodium Channel ◽  
Myelin Sheath ◽  
Node Of Ranvier ◽  
Specific Protein ◽  
Adult Onset ◽  
Murine Models ◽  
Present Evidence ◽  
Term Maintenance ◽  
Deficient Mice

To ensure rapid and efficient impulse conduction, myelinated axons establish and maintain specific protein domains. For instance, sodium (Na+) channels accumulate in the node of Ranvier; potassium (K+) channels aggregate in the juxtaparanode and neurexin/caspr/paranodin clusters in the paranode. Our understanding of the mechanisms that control the initial clustering of these proteins is limited and less is known about domain maintenance. Correlative data indicate that myelin formation and/or mature myelin-forming cells mediate formation of all three domains. Here, we test whether myelin is required for maintaining Na+ channel domains in the nodal gap by employing two demyelinating murine models: (1) cuprizone ingestion, which induces complete demyelination through oligodendrocyte toxicity; and (2) ceramide galactosyltransferase deficient mice, which undergo spontaneous adult-onset demyelination without oligodendrocyte death. Our data indicate that the myelin sheath is essential for long-term maintenance of sodium channel domains; however, oligodendrocytes, independent of myelin, provide a partial protective influence on the maintenance of nodal Na+ channel clusters. Thus, we propose that multiple mechanisms regulate the maintenance of nodal protein organization. Finally, we present evidence that following the loss of Na+ channel clusters the chronological progression of expression and reclustering of Na+ channel isoforms during the course of CNS remyelination recapitulates development.

Electromagnetic waves and quantum effects in aluminium

1972 ◽  
Vol 2 (4) ◽  
pp. 629-642 ◽  
Author(s):  
S Balibar ◽  
B Perrin ◽  
A Libchaber
Keyword(s):  
Electromagnetic Waves ◽  
Quantum Effects

scholarly journals Action Potential Propagation and Synchronisation in Myelinated Axons

2019 ◽  
Author(s):  
Helmut Schmidt ◽  
Thomas R. Knösche
Keyword(s):  
White Matter ◽  
Action Potential ◽  
Myelin Sheath ◽  
Action Potentials ◽  
Structural Parameters ◽  
Node Of Ranvier ◽  
Model Parameters ◽  
Mathematical Framework ◽  
Whole Brain ◽  
Action Potential Propagation

AbstractWith the advent of advanced MRI techniques it has become possible to study axonal white matter non-invasively and in great detail. Measuring the various parameters of the long-range connections of the brain opens up the possibility to build and refine detailed models of large-scale neuronal activity. One particular challenge is to find a mathematical description of action potential propagation that is sufficiently simple, yet still biologically plausible to model signal transmission across entire axonal fibre bundles. We develop a mathematical framework in which we replace the Hodgkin-Huxley dynamics by a spike-diffuse-spike model with passive sub-threshold dynamics and explicit, threshold-activated ion channel currents. This allows us to study in detail the influence of the various model parameters on the action potential velocity and on the entrainment of action potentials between ephaptically coupled fibres without having to recur to numerical simulations. Specifically, we recover known results regarding the influence of axon diameter, node of Ranvier length and internode length on the velocity of action potentials. Additionally, we find that the velocity depends more strongly on the thickness of the myelin sheath than was suggested by previous theoretical studies. We further explain the slowing down and synchronisation of action potentials in ephaptically coupled fibres by their dynamic interaction. In summary, this study presents a solution to incorporate detailed axonal parameters into a whole-brain modelling framework.Author summaryWith more and more data becoming available on white-matter tracts, the need arises to develop modelling frameworks that incorporate these data at the whole-brain level. This requires the development of efficient mathematical schemes to study parameter dependencies that can then be matched with data, in particular the speed of action potentials that cause delays between brain regions. Here, we develop a method that describes the formation of action potentials by threshold activated currents, often referred to as spike-diffuse-spike modelling. A particular focus of our study is the dependence of the speed of action potentials on structural parameters. We find that the diameter of axons and the thickness of the myelin sheath have a strong influence on the speed, whereas the length of myelinated segments and node of Ranvier length have a lesser effect. In addition to examining single axons, we demonstrate that action potentials between nearby axons can synchronise and slow down their propagation speed.

scholarly journals Variations in Velocity and Sensitivity of Electromagnetic Waves in Transmission Lines Configured in Model Piles with Necking Defects Containing Soils

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6541
Author(s):  
Jung-Doung Yu ◽  
Sang Yeob Kim ◽  
Jong-Sub Lee
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Time Domain ◽  
Electromagnetic Waves ◽  
Electrical Wire ◽  
Different Types ◽  
Bored Piles ◽  
Time Domain Reflectometer ◽  
Water Contents ◽  
Soil Water Contents

This study investigates variations in the velocity and sensitivity of electromagnetic waves in transmission lines configured in defective model piles for the detection of necking defects containing soil. Experiments are performed with model piles containing defects filled with different materials, such as air, sands, and clay. Five different types of transmission lines are configured in model piles. The electromagnetic waves are generated and detected using a time domain reflectometer. The velocity of electromagnetic waves is highest when the defect is filled with air, and it decreases with an increase in the water content. The velocity is lowest when the defect is filled with clay. The sensitivity of transmission lines for detecting defects decreases with an increase in soil water contents. The transmission line with a single electrical wire and epoxy-coated rebar exhibits the highest sensitivity, followed by that with three and two parallel electrical wires. Transmission lines with a single electrical wire and uncoated rebar and those with two parallel electrical wires wrapped with a sheath exhibit poor sensitivity when the defect is filled with clay. This study demonstrates that electromagnetic waves can be effective tools for detecting necking defects with wet and conductive soils in bored piles.

scholarly journals Direct- and indirect-driven reactor targets

1993 ◽  
Vol 11 (1) ◽  
pp. 97-107 ◽  
Author(s):  
K. Kiu
Keyword(s):  
Electromagnetic Waves ◽  
Laser Light ◽  
Target Surface ◽  
Small Region ◽  
Large Radius ◽  
Electron Motion ◽  
Target Structure ◽  
Beam Irradiation ◽  
Strong Light ◽  
Phase Mixing

Theoretical and numerical analyses are given for direct- and indirect-driven reactor targets, from which 3-GJ fusion output energy is released. For a reactor target, which has a large radius and long implosion time, supersonic flow of imploding D–T fuel in the converging nozzle (in sphere) is important for adiabatic compression of fuel. For a direct-driven target, pellet gain depends much upon the region where the beam deposits its energy. Phase mixing is also important to increase the absorption rate of irradiating laser light. When a strong light with a phase is concentrated on a small region of target surface, collective electron motion on the target surface radiates electromagnetic waves, which reduce the electron motion. When beam irradiation on the target is not uniform, an indirect-driven target must be used because a direct-driven target is weak for nonuniform irradiation. For an indirect-driven reactor target, which requires a long implosion time, expansion of radiator and absorber layers causes the decrease in radiation temperature. There is the optimum target structure with respect to the aspect ratio (radiation gap distance).

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