Non-invasive study of nerve fibres using laser interference microscopy

Brazhe, Alexey; Brazhe, Nadezda A.; Rodionova, N. N.; Yusipovich, A. I.; Ignatyev, Pavel S.; Максимов, Г. В.; Mosekilde, Erik; Sosnovtseva, Olga

doi:10.1098/rsta.2008.0107

Cited by 18 publications

(8 citation statements)

References 37 publications

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“…It is important to realize that myelin is a dynamic structure and always observed either in one of its steady states or during transition from one state to another [15,16]. There is a balance between the processes of aggregation and splitting of myelin layers, especially in the paranode -node -paranode regions, which together with the Schmidt -Lanterman incisures are the most labile and complex regions of the fibre [17].…”

Section: Activity-dependent Changes In Myelin Structurementioning

confidence: 99%

Excitation block in a nerve fibre model owing to potassium-dependent changes in myelin resistance

et al. 2010

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The myelinated nerve fibre is formed by an axon and Schwann cells or oligodendrocytes that sheath the axon by winding around it in tight myelin layers. Repetitive stimulation of a fibre is known to result in accumulation of extracellular potassium ions, especially between the axon and the myelin. Uptake of potassium leads to Schwann cell swelling and myelin restructuring that impacts the electrical properties of the myelin. In order to further understand the dynamic interaction that takes place between the myelin and the axon, we have modelled submyelin potassium accumulation and related changes in myelin resistance during prolonged high-frequency stimulation. We predict that potassium-mediated decrease in myelin resistance leads to a functional excitation block with various patterns of altered spike trains. The patterns are found to depend on stimulation frequency and amplitude and to range from no block (less than 100 Hz) to a complete block (greater than 500 Hz). The transitional patterns include intermittent periodic block with interleaved spiking and non-spiking intervals of different relative duration as well as an unstable regime with chaotic switching between the spiking and non-spiking states. Intermittent conduction blocks are accompanied by oscillations of extracellular potassium. The mechanism of conductance block based on myelin restructuring complements the already known and modelled block via hyperpolarization mediated by the axonal sodium pump and potassium depolarization.

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Section: Activity-dependent Changes In Myelin Structurementioning

confidence: 99%

Excitation block in a nerve fibre model owing to potassium-dependent changes in myelin resistance

et al. 2010

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“…It is known, that myelin sheath of peripheral nerve fibers consists of multiple layers of Schwann cell (SC) membranes, wrapped around the axon [ 1 , 2 ]. Emerging data suggests that specific interactions between axon and SC govern neuronal function [ 1 ].…”

Section: Introductionmentioning

confidence: 99%

Study of the Peripheral Nerve Fibers Myelin Structure Changes during Activation of Schwann Cell Acetylcholine Receptors

2016

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In the present paper we consider a new type of mechanism by which neurotransmitter acetylcholine (ACh) regulates the properties of peripheral nerve fibers myelin. Our data show the importance of the relationship between the changes in the number of Schwann cell (SC) acetylcholine receptors (AChRs) and the axon excitation (different intervals between action potentials (APs)). Using Raman spectroscopy, an effect of activation of SC AChRs on the myelin membrane fluidity was investigated. It was found, that ACh stimulates an increase in lipid ordering degree of the myelin lipids, thus providing evidence for specific role of the “axon-SC” interactions at the axon excitation. It was proposed, that during the axon excitation, the SC membrane K+- depolarization and the Ca2+—influx led to phospholipase activation or exocytosis of intracellular membrane vesicles and myelin structure reorganization.

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“…Popescu et al, 2005;Popescu et al, 2006;Rappaz et al, 2007;Rappaz et al, 2008;Rappaz et al, 2009;Yusipovich, I et al, 2009;Yusipovich et al, 2011), fibroblasts (Dunn & Zicha, 1995), lymphocytes (Tychinsky et al, 2012), neurons (Rappaz et al, 2005;Yusipovich et al, 2006), nerve fibers (see e.g. Bibineyshvili et al, 2013;Brazhe et al, 2008;LaPorta & Kleinfeld, 2012;Maksimov et al, 2001), mast cells (Bondarenko et al, 2013), any microbiological objects (Tychinskii et al, 2007;Yusipovich et al, 2012;Zhurina et al, 2013) and others. In these work we propose a new assay for estimation a number of non-activated, activated and dead isolated peritoneal macrophages in a sample in vitro based on cell phase images.…”

Section: Introductionmentioning

confidence: 99%

Application of Phase Images for Estimation of Peritoneal Macrophages State

Yusipovich¹,

Baizhumanov²,

Казакова³

et al. 2015

IJB

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Procedure based on phase images obtained by the method of Laser Interference Microscopy (LIM) for detection of number non-activated, activated and dead isolated peritoneal macrophages in a sample in vitro was provided. The phase images provide quantitative estimates of the optical path difference (OPD) in each point of object. The OPD varies with cell thickness and concentration of cellular substances. Therefore, it provides useful information on cell structure, localization of subcellular structures, local concentrations of substances and dry mass of cell. In these work we propose a new assay for estimation a number of non-activated, activated and dead isolated peritoneal macrophages in a sample in vitro based on cell phase images. The results were compared with phagocytic index, which was evaluated using latex beads, and the percentage of cells with damaged membranes (dead cells). It was shown that with increasing time after the isolation, the percentage of dead macrophages estimated by LIM was similar to that of the cells with damaged membranes. However, the percentage of activated cells calculated using latex beads exceeded the percentage calculated using the phase images significantly.

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Non-invasive study of nerve fibres using laser interference microscopy

Cited by 18 publications

References 37 publications

Excitation block in a nerve fibre model owing to potassium-dependent changes in myelin resistance

Excitation block in a nerve fibre model owing to potassium-dependent changes in myelin resistance

Study of the Peripheral Nerve Fibers Myelin Structure Changes during Activation of Schwann Cell Acetylcholine Receptors

Application of Phase Images for Estimation of Peritoneal Macrophages State

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