Mostra el registre d'ítem simple
Minimal model for calcium alternans due to SR release refractoriness
dc.contributor.author | Rodríguez Cantalapiedra, Inma |
dc.contributor.author | Álvarez Lacalle, Enrique |
dc.contributor.author | Peñaranda Ayllón, Angelina |
dc.contributor.author | Echebarría Domínguez, Blas |
dc.contributor.other | Universitat Politècnica de Catalunya. Departament de Física |
dc.date.accessioned | 2017-10-06T18:40:16Z |
dc.date.available | 2017-10-06T18:40:16Z |
dc.date.issued | 2017-09-07 |
dc.identifier.citation | Rodriguez Cantalapiedra, I., Alvarez-Lacalle, E., Peñaranda, A., Echebarria, B. Minimal model for calcium alternans due to SR release refractoriness. "Chaos", 7 Setembre 2017, vol. 27, núm. 9, p. 093928-1-093928-13. |
dc.identifier.issn | 1054-1500 |
dc.identifier.uri | http://hdl.handle.net/2117/108494 |
dc.description.abstract | In the heart, rapid pacing rates may induce alternations in the strength of cardiac contraction, termed pulsus alternans. Often, this is due to an instability in the dynamics of the intracellular calcium concentration, whose transients become larger and smaller at consecutive beats. This alternation has been linked experimentally and theoretically to two different mechanisms: an instability due to (1) a strong dependence of calcium release on sarcoplasmic reticulum (SR) load, together with a slow calcium reuptake into the SR or (2) to SR release refractoriness, due to a slow recovery of the ryanodine receptors (RyR2) from inactivation. The relationship between calcium alternans and refractoriness of the RyR2 has been more elusive than the corresponding SR Ca load mechanism. To study the former, we reduce a general calcium model, which mimics the deterministic evolution of a calcium release unit, to its most basic elements. We show that calcium alternans can be understood using a simple nonlinear equation for calcium concentration at the dyadic space, coupled to a relaxation equation for the number of recovered RyR2s. Depending on the number of RyR2s that are recovered at the beginning of a stimulation, the increase in calcium concentration may pass, or not, over an excitability threshold that limits the occurrence of a large calcium transient. When the recovery of the RyR2 is slow, this produces naturally a period doubling bifurcation, resulting in calcium alternans. We then study the effects of inactivation, calcium diffusion, and release conductance for the onset of alternans. We find that the development of alternans requires a well-defined value of diffusion while it is less sensitive to the values of inactivation or release conductance. |
dc.language.iso | eng |
dc.publisher | Institute of Physics (IOP) |
dc.rights | Attribution-NonCommercial-NoDerivs 3.0 Spain |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
dc.subject | Àrees temàtiques de la UPC::Física |
dc.subject.lcsh | Phase transformations (Statistical physics) |
dc.subject.lcsh | Stochastic processes |
dc.subject.lcsh | Statistical mechanics |
dc.subject.other | Diseases and conditions Phase transitions Stochastic processes Subcellular structures Statistical mechanics models Ionic models Ventricular arrhythmias Calcium alternans |
dc.title | Minimal model for calcium alternans due to SR release refractoriness |
dc.type | Article |
dc.subject.lemac | Transformacions de fase (Física estadística) |
dc.subject.lemac | Processos estocàstics |
dc.subject.lemac | Mecànica estadística |
dc.contributor.group | Universitat Politècnica de Catalunya. GICITED - Grup Interdiciplinari de Ciència i Tecnologia en l'Edificació |
dc.contributor.group | Universitat Politècnica de Catalunya. BIOCOM-SC - Grup de Biologia Computacional i Sistemes Complexos |
dc.identifier.doi | 10.1063/1.5000709 |
dc.relation.publisherversion | http://aip.scitation.org/doi/10.1063/1.5000709 |
dc.rights.access | Open Access |
local.identifier.drac | 21554537 |
dc.description.version | Postprint (author's final draft) |
local.citation.author | Rodriguez Cantalapiedra, I.; Alvarez-Lacalle, E.; Peñaranda, A.; Echebarria, B. |
local.citation.publicationName | Chaos |
local.citation.volume | 27 |
local.citation.number | 9 |
local.citation.startingPage | 093928-1 |
local.citation.endingPage | 093928-13 |
Fitxers d'aquest items
Aquest ítem apareix a les col·leccions següents
-
Articles de revista [190]
-
Articles de revista [2.206]
-
Articles de revista [226]