Plasmon-Polariton Properties in Metallic Nanosphere Chains

2019

Applied Sciences

Self Cite

We address the field of soft plasmonics in finite electrolyte liquid systems ranged by insulating membranes by an analogy to the plasmonics of metallic nanostructures. The confined electrolyte systems can be encountered on a bio-cell organizational level, taking into account that the characteristics of ion plasmons fall to the micrometer size scale instead of the nanometer in metals because of at least three orders of magnitude larger masses of ions in comparison to electrons. The lower density of ions in electrolytes in comparison to density of electrons in metal may also reduce the energy of plasmons by several orders. We provide the fully analytical description of surface and volume plasmons in finite ionic micro-systems allowing for further applications. We next apply the theory of ionic plasmons to plasmon–polaritons in ionic periodic systems. The complete theory of ionic plasmon–polariton kinetics in the chain of micrometer-sized electrolyte spheres, confined by a dielectric membrane, is formulated and solved. The latter theory has next been applied to the explanation of a mysterious and unclear (for several dozen of years) problem of so-called saltatory conduction of the action potential in myelinated axons of nerve cells. Contrary to conventional models of nerve signaling, the plasmon–polariton model pretty well fits to the queer properties of the saltatory conduction. Moreover, the presented application of soft plasmonics to signaling in periodically myelinated axons may allow for identification of a different role in information processing of the white and gray matters in brain and spinal cord. We have outlined some perspectives to utilize the difference between the electricity of myelinated and non-myelinated nerve cells in brain to develop the topological concept of the memory functioning. The proposed ionic plasmon–polariton model of the saltatory conduction differently recognizes the role of the insulating myelin than previously was thought which may be helpful in the development of a better understanding of the demyelination diseases.

Section: Plasmon-polariton Propagation In Linear Periodic Ionic Systemmentioning

confidence: 83%

Plasmons and Plasmon–Polaritons in Finite Ionic Systems: Toward Soft-Plasmonics of Confined Electrolyte Structures

2019

Applied Sciences

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“…Note that for 1 = 4 × 10 6 1/s and a = 50 μ m, the light-cone interference conditions kd − 1 d∕c = 0 and kd + 1 d∕c = 2 are fulfilled for extremely small values of kd and 2 − kd , respectively, (of the order of 10 −6 for d∕a ∈ [2, 2.5] ) and thus are negligible with regard to the plasmon-polariton kinetics [though are important for metals (Jacak et al 2015;Jacak 2014)]. The related singularities on the light-cone induced by the far-and medium-field Fig.…”

Section: Plasmon-polariton Model Of Saltatory Conduction: Fitting Thementioning

confidence: 99%

“…Note that for 1/s and m, the light-cone interference conditions and are fulfilled for extremely small values of kd and , respectively, (of the order of for ) and thus are negligible with regard to the plasmon-polariton kinetics [though are important for metals (Jacak et al. 2015 ; Jacak 2014 )]. The related singularities on the light-cone induced by the far- and medium-field contributions to the dipole interaction are pushed to the borders of the k domain and thus are unimportant for the considered ionic system.…”

Section: Plasmon-polariton Model Of Saltatory Conduction: Fitting Thementioning

confidence: 99%

“…Similarly, the plasmonic size featured by a strong radiation of plasmons is shifted from the nano-scale for electrons to micrometer scale for ions, again just as for the scale of bio-cell organization. The RPA model of ion plasmons has been developed (Jacak 2015b) including the application to synchronized plasmon oscillations in linear periodic alignments of electrolytes confined by membranes (Jacak 2015c) in analogy to plasmonpolaritons in metallic nano-chains (Brongersma et al 2000;Maier and Atwater 2005;Pitarke et al 2007;Huidobro et al 2010;Citrin 2004;Jacak 2013Jacak , 2014Jacak et al 2015).…”

Section: Introductionmentioning

confidence: 99%

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New wave-type mechanism of saltatory conduction in myelinated axons and micro-saltatory conduction in C fibres

2020

Eur Biophys J

We present a new wave-type model of saltatory conduction in myelinated axons. Poor conductivity in the neuron cytosol limits electrical current signal velocity according to cable theory, to 1-3 m/s, whereas saltatory conduction occurs with a velocity of 100-300 m/s. We propose a wave-type mechanism for saltatory conduction in the form of the kinetics of an ionic plasmon-polariton being the hybrid of the electromagnetic wave and of the synchronized ionic plasma oscillations in myelinated segments along an axon. The model agrees with observations and allows for description of the regulatory role of myelin. It explains also the mechanism of conduction deficiency in demyelination syndromes such as multiple sclerosis. The recently observed micro-saltatory conduction in ultrathin unmyelinated C fibers with periodic ion gate clusters is also explained.

“…For more detailed calculations, including also the transverse polarization of plasmon-polariton modes and the formation of a plasmon-polariton wave packet, cf. (17,18,22,37). The bulk plasmon frequency for ions in an electrolyte (19,20) is = 2 4 (we assumed for the model that the ion charge is = 1.6 × 10 −19 C and the ion mass is = 10 4 , where = 9.1 × 10 −31 kg is the mass of an electron) and for a concentration of = 2.1 × 10 14 1/m 3 , we obtain the Mie-type frequency for ionic dipole oscillations, 1 .…”

Section: Mathematical Description Of Plasmon-polariton Kinetics In Thmentioning

confidence: 99%

New plasmon-polariton model of the saltatory conduction

2020

Preprint

We propose a new model of the saltatory conduction in myelinated axons. This conduction of the action potential in myelinated axons does not agree with the conventional cable theory, though the latter has satisfactorily explained the electrosignaling in dendrites and in unmyelinated axons. By the development of the wave-type concept of ionic plasmon-polariton kinetics in axon cytosol we have achieved an agreement of the model with observed properties of the saltatory conduction. Some resulting consequences of the different electricity model in the white and the gray matter for nervous system organization have been also outlined.SIGNIFICANCE Most of axons in peripheral nervous system and in white matter of brain and spinal cord are myelinated with the action potential kinetics speed two orders greater than in dendrites and in unmyelinated axons. A decrease of the saltatory conduction velocity by only 10% ceases body functioning. Conventional cable theory, useful for dendrites and unmyelinated axon, does not explain the saltatory conduction (discrepancy between the speed assessed and the observed one is of one order of the magnitude). We propose a new nonlocal collective mechanism of ion density oscillations synchronized in the chain of myelinated segments of plasmon-polariton type, which is consistent with observations. This model explains the role of the myelin in other way than was previously thought.