Ionic Waves Research Articles

Measurement and Characterization of the Electrical Properties of Actin Filaments.

Actin filaments, as key components of the cytoskeleton, have aroused great interest due to their numerous functional roles in eukaryotic cells, including intracellular electrical signaling. The aim of this research is to characterize the alternating current (AC) conduction characteristics of both globular and polymerized actin and quantitatively compare their values to those theoretically predicted earlier. Actin filaments have been demonstrated to act as conducting bionanowires, forming a signaling network capable of transmitting ionic waves in cells. We performed conductivity measurements for different concentrations of actin, considering both unpolymerized and polymerized actin to identify potential differences in their electrical properties. These measurements revealed two relevant characteristics: first, the polymerized actin, arranged in filaments, has a lower impedance than its globular counterpart; second, an increase in the actin concentration leads to higher conductivities. Furthermore, from the data collected, we developed a quantitative model to represent the electrical properties of actin in a buffer solution. We hypothesize that actin filaments can be modeled as electrical resistor-inductor-capacitor (RLC) circuits, where the resistive contribution is due to the viscous ion flows along the filaments; the inductive contribution is due to the solenoidal flows along and around the helix-shaped filament and the capacitive contribution is due to the counterion layer formed around each negatively charged filament.

Neuronal dynamics direct cerebrospinal fluid perfusion and brain clearance.

The accumulation of metabolic waste is a leading cause of numerous neurological disorders, yet we still have only limited knowledge of how the brain performs self-cleansing. Here we demonstrate that neural networks synchronize individual action potentials to create large-amplitude, rhythmic and self-perpetuating ionic waves in the interstitial fluid of the brain. These waves are a plausible mechanism to explain the correlated potentiation of the glymphatic flow1,2 through the brain parenchyma. Chemogenetic flattening of these high-energy ionic waves largely impeded cerebrospinal fluid infiltration into and clearance of molecules from the brain parenchyma. Notably, synthesized waves generated through transcranial optogenetic stimulation substantially potentiated cerebrospinal fluid-to-interstitial fluid perfusion. Our study demonstrates that neurons serve as master organizers for brain clearance. This fundamental principle introduces a new theoretical framework for the functioning of macroscopic brain waves.

Theoretically modeling oscillations and waves (EEG and MEG signals) of the brain neuronal fluids and extracellular fluids, using plasma hydrodynamics

Introduction: Ionic oscillations and waves of the brain neurons are mostly analyzed and recorded by EEG (electroencephalography) and (or) MEG (magnetoencephalography). In principle EEG and MEG signals arise from the same neuronal sources. The traditional models of EEG and MEG do not involve natural excitations and attenuations, encodings (decodings), displacement currents of the brain neuronal electromagnetic signals, nor active pumps and passive channels of biological ions. Besides, we have not found any published research at an ionic level to theoretically describe the mechanisms how oscillations and waves of the brain neuronal fluids and extracellular fluids are excited, attenuated and maintained in the both natural and forced modes. Methods and Results: We introduce the plasma physics into brain theory; based on plasma hydrodynamic equations and published data of the brain or neuron sciences and molecular biology, at an ionic level, we model the mechanisms of the complete procedures of excitations, attenuations, propagations (oscillations and waves) of the brain neuronal fluids and extracellular fluids in the both natural and forced modes; our models include active pumps and passive channels of biological ions. Moreover, we also elucidate frequency and amplitude modulations (encodings), displacement currents, as well as effective values of the alternating electric current densities, electric and magnetic fields and voltages, based on the modeling results of the brain neuronal and extracellular plasma waves (oscillations). Conclusion: Our modeling results are qualitatively consistent with the published data of brain neuroscience as well as EEG and MEG.

Temperature relaxation and generalized Coulomb logarithm in two-temperature dense plasmas relevant to inertial confinement fusion implosions

Detailed knowledge of energy exchange between electrons and ions is of fundamental importance for the description of temperature relaxation and also other nonequilibrium physics in Inertial Confinement Fusion (ICF). We present a theoretical model for the temperature relaxation rate and the related generalized Coulomb logarithm based on the Quantum Lenard–Balescu (QLB) kinetic equation, where no special cutoffs are needed to be introduced. To describe the collective modes characterizing the ionic acoustic waves, a single-pole approximation is introduced for the ionic dielectric response. The proposed model for the generalized Coulomb logarithm is examined over a wide range of plasma conditions for electron temperatures between 102 and 105 eV and electron densities between 1022 and . The values of the generalized Coulomb logarithm are demonstrated to be in excellent agreement with the ones evaluated using the original QLB kinetic approach but with much less computational cost. Comparisons with molecular dynamics simulations and other theoretical approaches are presented. For further applications of our model, we present results for the recently measured experimental Coulomb logarithm. Compared to other widely applied models such as the Landau–Spitzer Coulomb logarithm, our model provides more consistent descriptions for the results of molecular dynamics simulations and also for the experimental outcomes. Our model for the generalized Coulomb logarithm is easy to calculate and can benefit efficient and reliable simulations for the ICF implosions.

Investigation of solitary wave structures for the stochastic Nizhnik–Novikov–Veselov (SNNV) system

The current study deals with the stochastic Nizhnik–Novikov–Veselov (SNNV) system analytically under the multiplicative noise effect. The Nizhnik–Novikov–Veselov equation is an extension of the KdV equation with applications in shallow-water waves, ionic acoustic waves in plasma, long internal waves in density-stratified oceans, and sound waves on crystal networks. The stochastic wave structures are constructed with the help of the Sardar subequation method. The different solutions are extracted which are in the form of solitons and solitary wave structures in the noise effect. Additionally, the stochastic behavior appears in the 3-dim, 2-dim, and their corresponding contour representations by the various selection of parameters.

Chirped modulated wave excitations in an electrical model of microtubules

Inspired by standard electrophysiological models of microtubules (MTs), we consider a relatively large one-dimensional spatial array of nonlinear electrical transmission network with a negative nonlinear resistance. Employing the reductive perturbation approach in the semi-discrete approximation, we show that the evolution of ionic waves in this electrical circuit model of microtubules is described by a nonlinear Schrödinger (NLS) equation with a dissipative/amplification term in the presence of an external linear potential. The modulational instability analysis of the amplitude equation shows that the derived NLS equation suitably describes the dynamics of our lattice of biochemical units as an excitable medium. Based on exact and approximate solutions of the amplitude equation, we investigate analytically the existence of modulated chirped solitonic waves along microtubules. We suggest possible biological implications of these nonlinear modulated waves. Our system is found to amplify significantly the amplitude of the input signal, confirming thus known experimental results on MTs. Nevertheless, a proper choice of various parameters of the negative nonlinear resistance is required for further validation of our theoretical results.

Soliton solutions, Lie symmetry analysis and conservation laws of ionic waves traveling through microtubules in live cells

This study explores a fourth-order nonlinear symmetric solution to ionic waves in living microtubules. Lie group analysis and the new extended direct algebraic approach are used to build solitary wave solutions. We reduce the partial differential equation based on symmetry into ordinary differential equations. Solved equations yield novel single wave patterns. For physical explanation, specific solitary wave structures are visually shown. The solutions include the anti-kink, kink shape, the absolute value of the spike shape, singular kink wave shape, and dark-singular soliton solution. Utilizing the multiplier technique, we establish the equation’s local conservation laws. Some solution sketches depict the model’s vision.

Exact and numerical solutions for the nanosoliton of ionic waves propagating through microtubules in living cells

In this article, the Paul–Painleve approach (PPA) which was formulated recently and built on the balance role has been used perfectly to achieve new impressive solitary wave solutions to the nanosoliton of ionic waves (NSOIW) propagating along the microtubules in the living cells. In addition, variational iteration method (VIM) has been applied in the same vein and parallel to establish numerical solutions of this model.

Electrical Propagation of Condensed and Diffuse Ions Along Actin Filaments.

In this article, we elucidate the roles of divalent ion condensation and highly polarized immobile water molecules on the propagation of ionic calcium waves along actin filaments. We introduced a novel electrical triple layer model and used a non-linear Debye-Huckel theory with a non-linear, dissipative, electrical transmission line model to characterize the physicochemical properties of each monomer in the filament. This characterization is carried out in terms of an electric circuit model containing monomeric flow resistances and ionic capacitances in both the condensed and diffuse layers. We considered resting and excited states of a neuron using representative mono and divalent electrolyte mixtures. Additionally, we used 0.05V and 0.15V voltage inputs to study ionic wavesalong actin filaments in voltage clamp experiments. Our results reveal that the physicochemical properties characterizing the condensed and diffuse layers lead to different electrical conductive mediums depending on the ionic species and the neuron state. This region specific propagation mechanism provides a more realistic avenue of delivery by way of cytoskeleton filaments for larger charged cationic species. A new direct path for transporting divalent ions might be crucial for many electrical processes found in localized neuron elements such as at mitochondria and dendritic spines.

Exact Traveling and Nano-Solitons Wave Solitons of the Ionic Waves Propagating along Microtubules in Living Cells

In this paper, the weakly nonlinear shallow-water wave model is mathematically investigated by applying the modified Riccati-expansion method and Adomian decomposition method. This model is used to describe the propagation of waves in weakly nonlinear and dispersive media. We obtain exact and solitary wave solutions of this model by using the modified Riccati-expansion method then using these solutions to determine the boundary and initial conditions. These conditions are employed to evaluate the semi-analytical wave solutions and calculate the absolute value of error. The values of absolute error show the accuracy of the obtained solutions. Some solutions are sketched to show the perspective view of the solution of this model. Moreover, the novelty of the obtained solutions is illustrated by showing the similarity and differences between our and previous solutions of the model.

Signal transmission through seawater for MHz frequencies and medium distances (0–30 m) using ionic current waves

Electromagnetic (EM) signals can only be transmitted through seawater for short distances (<1 m) for frequencies (>1 MHz). Therefore a new technique, the ionic current wave (ICW), has been developed for signal propagation at MHz frequency. This technique uses the conduction current produced in seawater as a result of thermal ionisation releasing H+ and OH– ions. A small voltage (<1.5 V pk) is applied between two metal electrodes submerged in the seawater to avoid ionisation by the input electrical energy.<br/> A detailed theoretical analysis of the ICW process has shown that ionic currents can be transmitted at MHz frequency over distances of 10 m with low signal loss per decade. For longer propagation distances of 100 m the theory predicts a signal loss of –20 dB per decade.<br/> Propagation experiments have been carried out in Liverpool dock seawater for distances of 2 m–28 m between parallel 0.5 m × 0.3 m electrodes placed vertically in the seawater at a depth of 2 m. Signal frequencies within the range of 1 MHz–8 MHz have been investigated. In each experiment the received propa gated signal power was approximately –67 dBm (well above the dock electrical noise of –140 dBm) and only showed a small power loss over the full range of propagation.<br/> The ICW system will be able to measure longer propagation distances in deep seawater conditions suitable for ship and submarine communications. Its performance is comparable to that of sonar systems.

Hot Quantum Electron-Ion-nonmagnetized Dusty Plasma: ion sound waves and dispersion relation.

Abstract: The dispersion equation for isothermal ionic sound waves is derived and analyzed for collisionless nonmagnetized dusty plasma consisting of quantum gases of electrons, ions, and dust at hot temperatures. and an exact expression is obtained for the linear velocity of ionic sound. Analysis has been carried out by the method of the Bernoulli pseudopotential. The quantum effects include, Fermi degenerate pressure, and exchange correlation potential. The ranges of phase velocities of periodic ionic sound waves and soliton velocities are determined. It is shown that in the plasma under investigation, the soliton velocity cannot be lower than the linear velocity of ionic sound. A graph should plotted between the frequency and wave number, three region should obtained, solutions in the form of periodic ionic sound waves should be sought precisely in the range of velocities The profiles of physical quantities in a periodic wave and in a soliton are constructed, as well as the dependences of the velocity of sound and the critical velocity on the ionic concentration in the plasma. It is shown that these velocities increase with the ion concentration and the term of dusty plasma as well as term of hot quantum electron and ion may effect on the dispersion relation. The application of this work has been pointed out for laboratory as well as for space dusty plasmas.

Abstract 3724: Molecular mechanisms of TTField action determined by measurements and modelling of electro-conductive properties of microtubules

Abstract Biological effects of AC electric fields at frequencies between 100-300 kHz discovered a decade ago are being applied to cancer cells as a therapeutic modality in the treatment of glioblastoma multiforme (GBM). They are called Tumor Treating Fields (TTFields) as they disrupt cell division. Based on our electro-conductive measurements and modeling, we provide an assessment of possible molecular-level mechanisms. Computer simulations and experimental measurements carried out for microtubules and actin filaments are presented. Charge and dipole values for monomers and dimers as well as polymerized forms of these proteins are summarized. Continuum approximations for cable equations describing actin filaments and microtubules compare favorably to measurements in buffer solutions showing soliton waves and transistor-like amplification of ionic signals, respectively. AC Conductivity and capacitance of tubulin and microtubules have been measured and modeled in the range of frequencies between 1 Hz and 1 MHz. A dramatic change in conductivity occurs when tubulin forms microtubules. In living cells, this signals a conductive phase transition coinciding with mitosis in dividing cells. This process is allowed by TTField penetration into the cleavage furrow in dividing cells and provides the most significant mechanistic explanation of the observed effects. We provide estimates of the forces, energies and power involved in the action of TTFields on microtubules and kinesin motors. These calculations are compared and contrasted with typical values experienced at a cell level and provide strong arguments for real physical effects of TTFields in dividing cells. We also show results of DLS and TEM measurements on microtubules and tubulin oligomers in solution, which allow us to quantify these processes under controlled conditions. In conclusion, the most likely candidates to provide a quantitative explanation of these effects are ionic condensation waves around microtubules as well as dielectrophoretic effects on the dipole moments of microtubules. Citation Format: Aarat P. Kalra, Sahil Patel, Asadullah Bhuiyan, Jordane Preto, Vahid Rezania, John D. Lewis, Karthik Shankar, Jack Tuszynski. Molecular mechanisms of TTField action determined by measurements and modelling of electro-conductive properties of microtubules [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3724.

Exact solitary wavelike solutions in a nonlinear microtubule RLC transmission line.

Analytically, we study the dynamics of ionic waves in a microtubule modeled by a nonlinear resistor, inductor, and capacitor (RLC) transmission line. We show through the application of a reductive perturbation technique that the network can be reduced in the continuum limit to the dissipative nonlinear Schrödinger equation. The processes of the modulational instability are studied and, motivated with a solitary wave type of solution to the nonlinear Schrödinger (NLS) equation, we use the direct method and the Weierstrass's elliptic function method to present classes of solitary wavelike solutions to the dissipative NLS equation of the network. The results suggest that microtubules are the biological structures where short-duration nonlinear waves called electrical envelope solitons can be created and propagated. This work presents a good analytical approach of investigating the propagation of solitary waves through a microtubule modeled by a nonlinear RLC transmission line.

Dynamics of modulated waves in a nonlinear microtubule RLC transmission line

We study the dynamics of modulated ionic waves in a microtubule modeled by a nonlinear RLC transmission line (Tuszynski et al., 2004; Sataric et al., 2009). We show through the application of a reductive perturbation technique that the network can be reduced in the continuum limit to the dissipative nonlinear Schrödinger equation. The processes of the modulational instability and the effects of the dissipative elements of the network on wave propagation are investigated. We perform numerical simulations which confirm analytical predictions and give rise to localized modulated wave formation. The results suggest that microtubules can be biological structures where short-duration nonlinear waves called electrical envelope solitons can be created and propagated.

Exact Solutions with Lie Symmetry Analysis for Nano-Ionic Currents along Microtubules

In this work, the Lie symmetry analysis is tested by its applications to nano-solitons of ionic waves propagation along microtubules in living cells and nano-ionic currents of MTs.

Dynamic Gradient Directed Molecular Transport and Concentration in Hydrogel Films

AbstractMaterials which selectively transport molecules along defined paths offer new opportunities for concentrating, processing and sensing chemical and biological agents. Here, we present the use of traveling ionic waves to drive molecular transport and concentration of hydrophilic molecules entrained within a hydrogel. The traveling ionic wave is triggered by the spatially localized introduction of ions, which through a dissipative ion exchange process, converts quaternary ammonium groups in the hydrogel from hydrophilic to hydrophobic. Through a reaction–diffusion process, the hydrophobic region expands with a sharp transition at the leading edge; it is this sharp gradient in hydrophilicity that drives the transport of hydrophilic molecules dispersed within the film. The traveling wave moved up to 450 μm within 30 min, while the gradient length remained 20 μm over this time. As an example of the potential of molecular concentration using this approach, a 70‐fold concentration of a hydrophilic dye was demonstrated.

Dynamic Gradient Directed Molecular Transport and Concentration in Hydrogel Films.

Materials which selectively transport molecules along defined paths offer new opportunities for concentrating, processing and sensing chemical and biological agents. Here, we present the use of traveling ionic waves to drive molecular transport and concentration of hydrophilic molecules entrained within a hydrogel. The traveling ionic wave is triggered by the spatially localized introduction of ions, which through a dissipative ion exchange process, converts quaternary ammonium groups in the hydrogel from hydrophilic to hydrophobic. Through a reaction-diffusion process, the hydrophobic region expands with a sharp transition at the leading edge; it is this sharp gradient in hydrophilicity that drives the transport of hydrophilic molecules dispersed within the film. The traveling wave moved up to 450 μm within 30 min, while the gradient length remained 20 μm over this time. As an example of the potential of molecular concentration using this approach, a 70-fold concentration of a hydrophilic dye was demonstrated.

Kinetic-Simulation Study of Propagation of Langmuir-Like Ionic Waves in Dusty Plasma

The propagation of ionic perturbations in a dusty plasma is considered through a three-species kinetic simulation approach, in which the temporal evolution of all three elements, i.e., electrons, ions, and dust particles are followed based on the Vlasov equation coupled with the Poisson equation. Two cases are focused upon: first, a fully electron-depleted dusty plasma, i.e., a plasma consisting of ions and dust particles. The second case includes dusty plasmas with large electron-to-ion temperature ratios. The main features of the ionic waves in these two settings, including the dispersion relation and the Landau damping rate, are studied. It is shown that the dispersion relation of the ionic waves perfectly matches the dispersion relation of Langmuir waves and hence is called Langmuir-like ionic waves and can be considered as Langmuir-like ionic waves. These waves can be theoretically predicted by the dispersion relation of the dust-ion-acoustic waves. The transition of ionic waves from dust-ion-acoustic to Langmuir-like waves is shown to be sharp/smooth in first/second case. The Landau damping rates based on simulation results are presented and compared with theoretical predictions wherever possible.

On the freak waves in mesospheric plasma

The nonlinear properties of dusty ionic freak waves have been studied in homogeneous, unmagnetized dusty plasma system containing ions, isothermal electrons, negative and positive grains. By using the derivative expansion method and assuming strongly dispersive medium, the basic model equations are reduced to a nonlinear form of Schrodinger equation (NLSE). One of the solutions of the NLSE in the unstable region is the rational one which is responsible for the creation of the freak profiles. The reliance of freak waves profile on dusty grains charge and carrier wave number are discussed .