Thematische Bibliographien / Depolarization wave propagation

Inhaltsverzeichnis

Zeitschriftenartikel
Dissertationen
Buchteile
Konferenzberichte

Auswahl der wissenschaftlichen Literatur zum Thema „Depolarization wave propagation“

Autor: Grafiati

Veröffentlicht am 28. Juni 2021

Zuletzt aktualisiert am 14. Februar 2022

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an

Wählen Sie eine Art der Quelle aus:

Machen Sie sich mit den Listen der aktuellen Artikel, Bücher, Dissertationen, Berichten und anderer wissenschaftlichen Quellen zum Thema "Depolarization wave propagation" bekannt.

Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.

Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.

Zeitschriftenartikel zum Thema "Depolarization wave propagation"

Ben-Shimol, Y., N. Blaunstein und M. Sergeev. „DEPOLARIZATION EFFECTS OF RADIO WAVE PROPAGATION IN VARIOUS LAND BUILT–UP ENVIRONMENTS“. Informatsionno-upravliaiushchie sistemy (Information and Control Systems) 74, Nr. 1 (Februar 2015): 68–76. http://dx.doi.org/10.15217/issn1684-8853.2015.1.68.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Momose-Sato, Yoko, Naohisa Miyakawa, Hiraku Mochida, Shinichi Sasaki und Katsushige Sato. „Optical Analysis of Depolarization Waves in the Embryonic Brain: A Dual Network of Gap Junctions and Chemical Synapses“. Journal of Neurophysiology 89, Nr. 1 (01.01.2003): 600–614. http://dx.doi.org/10.1152/jn.00337.2002.

Der volle Inhalt der Quelle

Annotation:

Correlated neuronal activity plays a fundamental role in the development of the CNS. Using a multiple-site optical recording technique with a voltage-sensitive dye, we previously described a novel type of depolarization wave that was evoked by cranial or spinal nerve stimulation and spread widely over the whole brain region in the chick embryo. We have now investigated developmental expression and neuronal network mechanisms of this depolarization wave by applying direct stimulation to the brain stem or upper cervical cord of E5–E11 embryos, which elicited wave activity similar to that evoked by nerve stimulation. Spatial distribution patterns of the depolarization wave changed dynamically with development, and this change appeared to be related to the regional differences in neuronal differentiation. The depolarization wave was completely eliminated by application of either gap junction blockers or an N-methyl-d-aspartate (NMDA)-receptor antagonist, indicating that functions of both gap junctions and NMDA receptors are indispensable for wave propagation. A possible interpretation of the results is that dual networks of gap junctions and chemical synaptic coupling mediate large-scale depolarization waves in the developing chick CNS.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Santos, Edgar, Renán Sánchez-Porras, Oliver W. Sakowitz, Jens P. Dreier und Markus A. Dahlem. „Heterogeneous propagation of spreading depolarizations in the lissencephalic and gyrencephalic brain“. Journal of Cerebral Blood Flow & Metabolism 37, Nr. 7 (25.01.2017): 2639–43. http://dx.doi.org/10.1177/0271678x16689801.

Der volle Inhalt der Quelle

Annotation:

In the recently published article, “Heterogeneous incidence and propagation of spreading depolarizations,” it is shown, in vivo and in vitro, how KCl-induced spreading depolarizations in mouse and rat brains can be highly variable, and that they are not limited, as once thought, to a concentric, isotropic, or homogenous depolarization wave in space or in time. The reported results serve as a link between the different species, and this paper contributes to changing the way in which SD expansion is viewed in the lissencephalic brain. Here, we discuss their results with our previous observations made in the gyrencephalic swine brain, in computer simulations, and in the human brain.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Bayguinov, Orline, Sean M. Ward, James L. Kenyon und Kenton M. Sanders. „Voltage-gated Ca2+ currents are necessary for slow-wave propagation in the canine gastric antrum“. American Journal of Physiology-Cell Physiology 293, Nr. 5 (November 2007): C1645—C1659. http://dx.doi.org/10.1152/ajpcell.00165.2007.

Der volle Inhalt der Quelle

Annotation:

Electrical slow waves determine the timing and force of peristaltic contractions in the stomach. Slow waves originate from a dominant pacemaker in the orad corpus and propagate actively around and down the stomach to the pylorus. The mechanism of slow-wave propagation is controversial. We tested whether Ca2+ entry via a voltage-dependent, dihydropyridine-resistant Ca2+ conductance is necessary for active propagation in canine gastric antral muscles. Muscle strips cut parallel to the circular muscle were studied with intracellular electrophysiological techniques using a partitioned-chamber apparatus. Slow-wave upstroke velocity and plateau amplitude decreased from the greater to the lesser curvature, and this corresponded to a decrease in the density of interstitial cells of Cajal in the lesser curvature. Slow-wave propagation velocity between electrodes impaling cells in two regions of muscle and slow-wave upstroke and plateau were measured in response to experimental conditions that reduce the driving force for Ca2+ entry or block voltage-dependent Ca2+ currents. Nicardipine (0.1–1 μM) did not affect slow-wave upstroke or propagation velocities. Upstroke velocity, amplitude, and propagation velocity were reduced in a concentration-dependent manner by Ni2+ (1–100 μM), mibefradil (10–30 μM), and reduced extracellular Ca2+ (0.5–1.5 mM). Depolarization (by 10–15 mM K+) or hyperpolarization (10 μM pinacidil) also reduced upstroke and propagation velocities. The higher concentrations (or lowest Ca2+) of these drugs and ionic conditions tested blocked slow-wave propagation. Treatment with cyclopiazonic acid to empty Ca2+ stores did not affect propagation. These experiments show that voltage-dependent Ca2+ entry is obligatory for the upstroke phase of slow waves and active propagation.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Tryba, Andrew K., Edward M. Merricks, Somin Lee, Tuan Pham, SungJun Cho, Douglas R. Nordli, Tahra L. Eissa et al. „Role of paroxysmal depolarization in focal seizure activity“. Journal of Neurophysiology 122, Nr. 5 (01.11.2019): 1861–73. http://dx.doi.org/10.1152/jn.00392.2019.

Der volle Inhalt der Quelle

Annotation:

We analyze the role of inhibition in sustaining focal epileptic seizure activity. We review ongoing seizure activity at the mesoscopic scale that can be observed with microelectrode arrays as well as at the macroscale of standard clinical EEG. We provide clinical, experimental, and modeling data to support the hypothesis that paroxysmal depolarization (PD) is a critical component of the ictal machinery. We present dual-patch recordings in cortical cultures showing reduced synaptic transmission associated with presynaptic occurrence of PD, and we find that the PD threshold is cell size related. We further find evidence that optically evoked PD activity in parvalbumin neurons can promote propagation of neuronal excitation in neocortical networks in vitro. Spike sorting results from microelectrode array measurements around ictal wave propagation in human focal seizures demonstrate a strong increase in putative inhibitory firing with an approaching excitatory wave, followed by a sudden reduction of firing at passage. At the macroscopic level, we summarize evidence that this excitatory ictal wave activity is strongly correlated with oscillatory activity across a centimeter-sized cortical network. We summarize Wilson–Cowan-type modeling showing how inhibitory function is crucial for this behavior. Our findings motivated us to develop a network motif of neurons in silico, governed by a reduced version of the Hodgkin–Huxley formalism, to show how feedforward, feedback, PD, and local failure of inhibition contribute to observed dynamics across network scales. The presented multidisciplinary evidence suggests that the PD not only is a cellular marker or epiphenomenon but actively contributes to seizure activity. NEW & NOTEWORTHY We present mechanisms of ongoing focal seizures across meso- and macroscales of microelectrode array and standard clinical recordings, respectively. We find modeling, experimental, and clinical evidence for a dual role of inhibition across these scales: local failure of inhibition allows propagation of a mesoscopic ictal wave, whereas inhibition elsewhere remains intact and sustains macroscopic oscillatory activity. We present evidence for paroxysmal depolarization as a mechanism behind this dual role of inhibition in shaping ictal activity.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Smith, T. K., J. B. Reed und K. M. Sanders. „Effects of membrane potential on electrical slow waves of canine proximal colon“. American Journal of Physiology-Cell Physiology 255, Nr. 6 (01.12.1988): C828—C834. http://dx.doi.org/10.1152/ajpcell.1988.255.6.c828.

Der volle Inhalt der Quelle

Annotation:

The effects of membrane potential on the waveforms and propagation of slow waves were tested using circular muscles of the canine colon. Studies were conducted with intracellular recording techniques on cross-sectional strips of canine proximal colon. Circular muscle cells near the submucosa generated slow waves that decayed in amplitude as they spread through the circular layer. The membrane potentials of cells were less negative as a function of distance from the submucosal border. Cells near the submucosa were depolarized with elevated external K+ and electrical pulses using the partitioned chamber technique. The waveforms of depolarized submucosal cells were compared with events recorded from cells in the bulk of the circular layer. The waveform changes caused by experimental depolarization were different from the changes in waveform that occur during propagation, suggesting the latter are due to a different mechanism than depolarization. The effects of the membrane potential on syncytial input resistance and length constant were also evaluated. The results of these studies are consistent with the hypothesis that slow-wave propagation across the circular layer in canine proximal colon occurs passively.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Seppey, Dominique, Roger Sauser, Michèle Koenigsberger, Jean-Louis Bény und Jean-Jacques Meister. „Intercellular calcium waves are associated with the propagation of vasomotion along arterial strips“. American Journal of Physiology-Heart and Circulatory Physiology 298, Nr. 2 (Februar 2010): H488—H496. http://dx.doi.org/10.1152/ajpheart.00281.2009.

Der volle Inhalt der Quelle

Annotation:

Vasomotion consists of cyclic arterial diameter variations induced by synchronous contractions and relaxations of smooth muscle cells. However, the arteries do not contract simultaneously on macroscopic distances, and a propagation of the contraction can be observed. In the present study, our aim was to investigate this propagation. We stimulated endothelium-denuded rat mesenteric arterial strips with phenylephrine (PE) to obtain vasomotion and observed that the contraction waves are linked to intercellular calcium waves. A velocity of ∼100 μm/s was measured for the two kinds of waves. To investigate the calcium wave propagation mechanisms, we used a method allowing a PE stimulation of a small area of the strip. No calcium propagation could be induced by this local stimulation when the strip was in its resting state. However, if a low PE concentration was added on the whole strip, local PE stimulations induced calcium waves, spreading over finite distances. The calcium wave velocity induced by local stimulation was identical to the velocity observed during vasomotion. This suggests that the propagation mechanisms are similar in the two cases. Using inhibitors of gap junctions and of voltage-operated calcium channels, we showed that the locally induced calcium propagation likely depends on the propagation of the smooth muscle cell depolarization. Finally, we proposed a model of the propagation mechanisms underlying these intercellular calcium waves.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Kwaku, Kevin F., und Stephen M. Dillon. „Shock-Induced Depolarization of Refractory Myocardium Prevents Wave-Front Propagation in Defibrillation“. Circulation Research 79, Nr. 5 (November 1996): 957–73. http://dx.doi.org/10.1161/01.res.79.5.957.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Blackwell, K. T. „Calcium Waves and Closure of Potassium Channels in Response to GABA Stimulation in Hermissenda Type B Photoreceptors“. Journal of Neurophysiology 87, Nr. 2 (01.02.2002): 776–92. http://dx.doi.org/10.1152/jn.00867.2000.

Der volle Inhalt der Quelle

Annotation:

Classical conditioning of Hermissenda crassicornisrequires the paired presentation of a conditioned stimulus (light) and an unconditioned stimulus (turbulence). Light stimulation of photoreceptors leads to production of diacylglycerol, an activator of protein kinase C, and inositol triphosphate (IP3), which releases calcium from intracellular stores. Turbulence causes hair cells to release GABA onto the terminal branches of the type B photoreceptor. One prior study has shown that GABA stimulation produces a wave of calcium that propagates from the terminal branches to the soma and raises the possibility that two sources of calcium are required for memory storage. GABA stimulation also causes an inhibitory postsynaptic potential (IPSP) followed by a late depolarization and increase in input resistance, whose cause has not been identified. A model was developed of the effect of GABA stimulation on the Hermissenda type B photoreceptor to evaluate the currents underlying the late depolarization and to evaluate whether a calcium wave could propagate from the terminal branches to the soma. The model included GABAA, GABAB, and calcium-sensitive potassium leak channels; calcium dynamics including release of calcium from intracellular stores; and the biochemical reactions leading from GABAB receptor activation to IP3 production. Simulations show that it is possible for a wave of calcium to propagate from the terminal branches to the soma. The wave is initiated by IP3-induced calcium release but propagation requires release through the ryanodine receptor channel where IP3 concentration is small. Wave speed is proportional to peak calcium concentration at the crest of the wave, with a minimum speed of 9 μm/s in the absence of IP3. Propagation ceases when peak concentration drops below 1.2 μM; this occurs if the rate of calcium pumping into the endoplasmic reticulum is too large. Simulations also show that both a late depolarization and an increase in input resistance occur after GABA stimulation. The duration of the late depolarization corresponds to the duration of potassium leak channel closure. Neither the late depolarization nor the increase in input resistance are observed when a transient calcium current and a hyperpolarization-activated current are added to the model as replacement for closure of potassium leak channels. Thus the late depolarization and input resistance elevation can be explained by a closure of calcium-sensitive leak potassium currents but cannot be explained by a transient calcium current and a hyperpolarization-activated current.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Senseman, David M., und Kay A. Robbins. „High-Speed VSD Imaging of Visually Evoked Cortical Waves: Decomposition Into Intra- and Intercortical Wave Motions“. Journal of Neurophysiology 87, Nr. 3 (01.03.2002): 1499–514. http://dx.doi.org/10.1152/jn.00475.2001.

Der volle Inhalt der Quelle

Annotation:

In the pond turtle, Pseudemys scripta elegans, visually evoked cortical waves propagate at different velocities within the primary visual area compared with waves that pass into the secondary visual area. In an effort to separate intra- and intercortical wave motions, movies of visually evoked cortical waves recorded by high-speed voltage-sensitive dye (VSD) imaging were subjected to Karhunen-Loéve (KL) decomposition. This procedure decomposes the VSD movies into a series of basis images that capture different spatial patterns of coherent activity. Most of the energy of the compound wave motion (>95%) was captured by the three largest basis images, M1,1 , M1,2 , and M2,1 . Based on visual comparison with maps of wave front latency, KL basis image M1,2 appears to capture the spread of depolarization within the primary visual area, whereas KL basis image M2,1 appears to capture the spread of depolarization from the primary into the secondary visual area. The contribution of different basis images to the intra- and intercortical wave motions was tested by reconstructing the response using different combinations of KL basis images. Only KL basis images M1,1 and M1,2 were needed to reconstruct intracortical wave motion, while basis images M1,1 and M2,1 were needed to reconstruct intercortical wave motion. It was also found that the direction and speed of wave propagation could be deduced by visual inspection of the basis image projections on to the original data set. The relative advantage of KL decomposition for the analysis of complex wave motions captured by VSD imaging is discussed.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Mehr Quellen

Dissertationen zum Thema "Depolarization wave propagation"

Kim, Arnold D. „Optical pulse propagation, diffusion and depolarization in discrete random media /“. Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/6770.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Ředina, Richard. „Model fibrilace síní“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442495.

Der volle Inhalt der Quelle

Annotation:

The aim of this master thesis is to create a 3D electroanatomical model of a heart atria, which would be able to perform atrial fibrillation. To control the model, the differential equations of the FitzHugh-Nagumo model were chosen. These equations describe the change of voltage on the cell membrane. The equations have established parameters. The modification of them leads to changes in the behavior of the model. The simulations were performed in the COMSOL Multiphysics environment. In the first step, the simulations were performed on 2D models. Simulations of healthy heart, atrial flutter and atrial fibrillation were created. The acquired knowledge served as a basis for the creation of a 3D model on which atrial fibrillation was simulated on the basis of ectopic activity and reentry mechanism. Convincing results were obtained in accordance with the used literature. The advantages of computational modeling are its availability, zero ethical burden and the ability to simulate even rarer arrhythmias. The disadvantage of the procedure is the need to compromise between accuracy and computational complexity of simulations.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Martinez, Alexandre Souto. „Statistique de polarisation et effet Faraday en diffusion multiple de la lumière“. Grenoble 1, 1993. http://www.theses.fr/1993GRE10082.

Der volle Inhalt der Quelle

Annotation:

Statistique de polarisation et effet faraday en diffusion multiple de la lumiere. L'analyse traditionnelle de la propagation de la lumiere en milieu aleatoire suppose que les ondes sont des champs scalaires et que les diffuseurs sont ponctuels. Nous avons voulu etudier des situations plus realistes. La nature vectorielle du champ electromagnetique et l'anisotropie de diffusion sont explicitement prises en compte par la theorie de mie. Pour realiser cet objectif, nous avons ecrit et mis au point un code de simulation numerique utilisant l'algorithme de monte carlo. Nous nous sommes interesses tout d'abord aux mecanismes de depolarisation de la lumiere en regime de diffusion multiple. Puis nous faisons une etude approfondie de la pertinence des differentes approches du probleme de la diffusion multiple (portant principalement sur l'equation de boltzmann et la methode de monte carlo). Finalement nous etudions analytiquement et numeriquement l'effet faraday en diffusion multiple. Cet effet fait tourner les etats de polarisation entre deux collisions successives brisant la symetrie par reversement du temps. Les interferences de phase qui donnent lieu au cone de retrodiffusion peuvent ainsi etre controlees par l'application d'un champ magnetique

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Buchteile zum Thema "Depolarization wave propagation"

Sanders, Kenton M., und Tamas Ördög. „Properties of Electrical Rhythmicity in the Stomach“. In Handbook of Electrogastrography. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195147889.003.0006.

Der volle Inhalt der Quelle

Annotation:

Gastric peristaltic contractions are the basis for emptying of solids from the stomach. These events begin in the mid to high corpus region, develop into a ring around the stomach, and spread down the length of the stomach to the pylorus. The pressure wave resulting from gastric peristalsis pushes the contents of the stomach toward the pyloric sphincter, but a nearly simultaneous contraction of the ring of muscle in the pyloric canal and the terminal antrum ultimately forces much of the food in the retrograde direction, toward the body of the stomach. Sheer forces that develop as a result of this forceful retropulsion cause mechanical disruption of solid particles. Repetitive peristaltic contractions (e.g., in the human these events occur about 3 times per minute), over a period of time, reduces ingested foods to small particles. The action of gastric peristalsis in the distal stomach facilitates emptying and the reduced particle diameter aides in chemical digestion of foods in the small intestine. Pathophysiological conditions that disrupt or disorganize gastric peristalsis can impair or delay normal gastric emptying. Gastric peristaltic contractions result from depolarization of the plasma membranes of smooth muscle cells. For many years it has been known that gastric muscles display periodic (or rhythmic) electrical activity in which membrane potential oscillates between negative potentials and more depolarized levels. The oscillations in membrane potential are known as electrical slow waves (see Color Figs. 2.1 and 2.2 in separate color insert). Slow waves are generated within the tunica muscularis of the proximal corpus along the greater curvature of the stomach, and these events spread around the circumference and down the stomach to the pylorus. A greater velocity of propagation around the stomach than down the stomach causes development of a ring of excitation, and this is the electrical basis underlying gastric peristaltic contractions. Studies have shown that electrical slow waves are generated by specialized pacemaker cells, known as interstitial cells of Cajal (ICCs). The main pacemaker ICCs in the stomach form a dense network of electrically coupled cells between the circular and longitudinal muscle layers of the corpus and antrum.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Konferenzberichte zum Thema "Depolarization wave propagation"

Regonesi, E., C. Capsoni und C. Riva. „Radio wave depolarization simulator based on the SC EXCELL model“. In 2016 10th European Conference on Antennas and Propagation (EuCAP). IEEE, 2016. http://dx.doi.org/10.1109/eucap.2016.7481245.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Lostanlen, Y., und T. Tenoux. „Electromagnetic wave depolarization behaviour at different frequencies for various dielectric materials“. In 2nd European Conference on Antennas and Propagation (EuCAP 2007). Institution of Engineering and Technology, 2007. http://dx.doi.org/10.1049/ic.2007.1350.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Ben-Shimol, Y., N. Blaunstein und Ch Christodoulou. „Depolarization effects of radio wave propagation in various land built-up environments“. In 2014 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE, 2014. http://dx.doi.org/10.1109/aps.2014.6904806.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Liu, Changqing, Jinsheng Yang und Weidong Lv. „Depolarization effect of different propagation mechanisms around buildings“. In 2012 5th Global Symposium on Millimeter Waves (GSMM 2012). IEEE, 2012. http://dx.doi.org/10.1109/gsmm.2012.6314025.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Nikolaou, Symeon, Constantinos Eracleous, Christos G. Panayiotou und Marios Milis. „Foliage obstacle detection exploiting scattering and depolarization of 2.4 GHz waves used for communication links“. In 2012 IEEE Antennas and Propagation Society International Symposium and USNC/URSI National Radio Science Meeting. IEEE, 2012. http://dx.doi.org/10.1109/aps.2012.6349188.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Nanbu, Yukihisa, und Mitsuo Tateiba. „The Second Order Moment Equation of Crossly Polarized EM-Waves Due to Depolarization in Propagation Through Continuous Isotropic Random Medium“. In 2018 Progress in Electromagnetics Research Symposium (PIERS-Toyama). IEEE, 2018. http://dx.doi.org/10.23919/piers.2018.8597624.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Wir bieten Rabatte auf alle Premium-Pläne für Autoren, deren Werke in thematische Literatursammlungen aufgenommen wurden. Kontaktieren Sie uns, um einen einzigartigen Promo-Code zu erhalten!