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.

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 Action potential propagation recorded from single axonal arbors using multielectrode arrays

2018 ◽  
Vol 120 (1) ◽  
pp. 306-320 ◽  
Author(s):  
Kenneth R. Tovar ◽  
Daniel C. Bridges ◽  
Bian Wu ◽  
Connor Randall ◽  
Morgane Audouard ◽  
...  
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Hippocampal Neurons ◽  
Detection Threshold ◽  
Physiological Data ◽  
Low Density ◽  
Multielectrode Arrays ◽  
Action Potential Propagation ◽  
Voltage Gated ◽  
Axonal Arbors

We report the presence of co-occurring extracellular action potentials (eAPs) from cultured mouse hippocampal neurons among groups of planar electrodes on multielectrode arrays (MEAs). The invariant sequences of eAPs among coactive electrode groups, repeated co-occurrences, and short interelectrode latencies are consistent with action potential propagation in unmyelinated axons. Repeated eAP codetection by multiple electrodes was widespread in all our data records. Codetection of eAPs confirms they result from the same neuron and allows these eAPs to be isolated from all other spikes independently of spike sorting algorithms. We averaged co-occurring events and revealed additional electrodes with eAPs that would otherwise be below detection threshold. We used these eAP cohorts to explore the temperature sensitivity of action potential propagation and the relationship between voltage-gated sodium channel density and propagation velocity. The sequence of eAPs among coactive electrodes “fingerprints” neurons giving rise to these events and identifies them within neuronal ensembles. We used this property and the noninvasive nature of extracellular recording to monitor changes in excitability at multiple points in single axonal arbors simultaneously over several hours, demonstrating independence of axonal segments. Over several weeks, we recorded changes in interelectrode propagation latencies and ongoing changes in excitability in different regions of single axonal arbors. Our work illustrates how repeated eAP co-occurrences can be used to extract physiological data from single axons with low-density MEAs. However, repeated eAP co-occurrences lead to oversampling spikes from single neurons and thus can confound traditional spike-train analysis. NEW & NOTEWORTHY We studied action potential propagation in single axons using low-density multielectrode arrays. We unambiguously identified the neuronal sources of propagating action potentials and recorded extracellular action potentials from several positions within single axonal arbors. We found a surprisingly high density of axonal voltage-gated sodium channels responsible for a high propagation safety factor. Our experiments also demonstrate that excitability in different segments of single axons is regulated independently on timescales from hours to weeks.

scholarly journals Changes in the Membrane Permeability of Frog's Sartorius Muscle Fibers in Ca-Free EDTA Solution

1963 ◽  
Vol 47 (2) ◽  
pp. 379-392 ◽  
Author(s):  
H. Kimizuka ◽  
K. Koketsu
Keyword(s):  
Membrane Permeability ◽  
Chloride Content ◽  
Chloride Ions ◽  
Sartorius Muscle ◽  
Constant Field ◽  
Sodium Influx ◽  
Sodium Potassium ◽  
Edta Solution ◽  
Frog Sartorius ◽  
Sodium And Potassium

The changes in the membrane permeability to sodium, potassium, and chloride ions as well as the changes in the intracellular concentration of these ions were studied on frog sartorius muscles in Ca-free EDTA solution. It was found that the rate constants for potassium and chloride efflux became almost constant within 10 minutes in the absence of external calcium ions, that for potassium increasing to 1.5 to 2 times normal and that for chloride decreasing about one-half. The sodium influx in Ca-free EDTA solution, between 30 and 40 minutes, was about 4 times that in Ringer's solution. The intracellular sodium and potassium contents did not change appreciably but the intracellular chloride content had increased to about 4 times normal after 40 minutes. By applying the constant field theory to these results, it was concluded that (a) PCl did not change appreciably whereas PK decreased to a level that, in the interval between 10 and 40 minutes, was about one-half normal, (b) PNa increased until between 30 and 40 minutes it was about 8 times normal. The low value of the membrane potential between 30 and 40 minutes was explained in terms of the changes in the membrane permeability and the intracellular ion concentrations. The mechanism for membrane depolarization in this solution was briefly discussed.

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

Cardiovascular and renal effects of hypoxia in conscious carotid body-denervated rats

1993 ◽  
Vol 74 (6) ◽  
pp. 2795-2800 ◽  
Author(s):  
R. Behm ◽  
H. Mewes ◽  
W. H. DeMuinck Keizer ◽  
T. Unger ◽  
R. Rettig
Keyword(s):  
Carotid Body ◽  
Normobaric Hypoxia ◽  
Sodium Potassium ◽  
Water Excretion ◽  
Excretory Function ◽  
Arterial Blood ◽  
Peripheral Arterial ◽  
Renal Responses ◽  
Arterial Po2 ◽  
Sodium And Potassium

The contribution of peripheral arterial chemoreceptors to cardiovascular and renal responses to acute hypocapnic hypoxia is currently not well understood. We compared the effects of normobaric hypoxia on mean arterial blood pressure (MABP), heart rate, glomerular filtration rate (GFR), renal blood flow (RBF), and renal volume and electrolyte excretion in conscious unilaterally nephrectomized carotid body-denervated (n = 10) and sham-operated (n = 10) control rats. Thirty minutes of normobaric hypoxia (12.5% O2) resulted in significant reductions in arterial PO2 and PCO2 as well as decreases in MABP, GFR, RBF, and renal sodium, potassium, and water excretion. These effects occurred more rapidly and/or were significantly more pronounced in carotid body-denervated than in sham-operated rats. These data indicate that moderate acute hypocapnic hypoxia has profound effects on systemic and renal hemodynamics as well as on renal excretory function in conscious rats. We conclude that stimulation of the peripheral arterial chemoreceptors can partially offset the hypoxia-induced decreases in MABP, RBF, GFR, urine flow, and urinary sodium and potassium excretion, thereby helping to maintain cardiovascular as well as fluid and electrolyte homeostasis.

Effects of Synthetic Atrial Natriuretic Peptides on Sodium-Potassium Transport in Human Erythrocytes

1985 ◽  
Vol 69 (2) ◽  
pp. 223-226 ◽  
Author(s):  
G. A. Sagnella ◽  
D. A. Nolan ◽  
A. C. Shore ◽  
G. A. MacGregor
Keyword(s):  
Loop Diuretic ◽  
Sodium Pump ◽  
Human Erythrocytes ◽  
Atrial Natriuretic Peptides ◽  
Sodium Potassium ◽  
Potassium Ion Transport ◽  
Wide Range ◽  
Natriuretic Effect ◽  
Cotransport System ◽  
Sodium And Potassium

1. The effects of synthetic human and rat atrial peptides on sodium and potassium ion transport has been investigated in intact human erythrocytes. 2. The effects of these peptides have been tested on the active, sodium pump-dependent (ouabain-sensitive) and on the sodium-potassium cotransport system (bumetanide-sensitive) with 86Rb used as a tracer. 3. Human (α-ANP, 28 amino acids) or rat (atriopeptin III) atrial peptides, over a wide range of concentrations, did not influence the uptake of 86Rb in either the ouabain-sensitive or the bumetanide-sensitive transport system. 4. These results suggest that the natriuretic effect of the atrial peptides is not mediated through inhibition of the sodium pump or the loop-diuretic-sensitive Na-K cotransport.

Localization and trafficking of cardiac voltage-gated potassium channels

2007 ◽  
Vol 35 (5) ◽  
pp. 1069-1073 ◽  
Author(s):  
D.F. Steele ◽  
A. Dehghani Zadeh ◽  
M.E. Loewen ◽  
D. Fedida
Keyword(s):  
Potassium Channels ◽  
Molecular Motors ◽  
Action Potentials ◽  
Voltage Gated ◽  
Anchoring Proteins

The proper trafficking and localization of cardiac potassium channels is profoundly important to the regulation of the regionally distinct action potentials across the myocardium. These processes are only beginning to be unravelled and involve modulators of channel synthesis and assembly, post-translational processing, various molecular motors and an increasing number of modifying enzymes and molecular anchors. The roles of anchoring proteins, molecular motors and kinases are explored and recent findings on channel internalization and trafficking are presented.

scholarly journals Statistical field theory of the transmission of nerve impulses

2020 ◽  
Author(s):  
Gianluigi Zangari del Balzo
Keyword(s):  
Field Theory ◽  
Cell Membrane ◽  
Nerve Cell ◽  
Action Potentials ◽  
Demyelinating Diseases ◽  
Voltage Gated ◽  
Nerve Impulses ◽  
Statistical Field ◽  
Statistical Field Theory ◽  
Nerve Cell Membrane

Abstract Background Stochastic processes leading voltage-gated ion channel dynamics on the nerve cell membrane are a sufficient condition to describe membrane conductance through statistical mechanics of disordered and complex systems.Results Voltage-gated ion channels in the nerve cell membrane are described by the Ising model. Stochastic circuital elements called ”Ising machines” are introduced. Action potentials are described as quasi-particles of a statistical field theory for the Ising system.Conclusions The particle description of action potentials is a new powerful tool to describe the generation and propagation of nerve impulses. We thus have the opportunity to exploit another useful point of view to describe the generation and propagation of nerve impulses, especially when classical electrophysiological models break down. Moreover, the particle description allows us to develop new hardware and software devices based on general and theoretical physics to study neurodegenerative and demyelinating diseases as Multiple Sclerosis and Alzheimer’s disease, even integrated by connectomes. It is also suitable for the study of complex networks, quantum computing, artificial intelligence, machine and deep learning, cryptography, ultra-fast lines for entanglement experiments and many other applications of medical, physical and engineering interest.

Hodgkin–Huxley neurons with defective and blocked ion channels

2015 ◽  
Vol 26 (10) ◽  
pp. 1550112 ◽  
Author(s):  
James Christopher S. Pang ◽  
Johnrob Y. Bantang
Keyword(s):  
Ion Channels ◽  
Action Potentials ◽  
Reversal Potential ◽  
Membrane Conductance ◽  
Potassium Ions ◽  
Temporal Response ◽  
Constant Input ◽  
Control Drug ◽  
Channel Control ◽  
Sodium And Potassium

We utilize the original Hodgkin–Huxley (HH) model to consider the effects of defective ion channels to the temporal response of neurons. Statistics of firing rate and inter-spike interval (ISI) reveal that production of action potentials (APs) in neurons is not sensitive to changes in membrane conductance for sodium and potassium ions, as well as to the reversal potential for sodium ions, as long as the relevant parameters do not exceed 13% from their normal levels. We also found that blockage of a critical fraction of either sodium or potassium channels (dependent on constant input current) respectively limits the firing activity or increases spontaneous spiking activity of neurons. Our model may be used to guide experiment designs related to ion channel control drug development.

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