Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels

Calcium release from intracellular stores plays a key role in the regulation of a variety of cellular activities. In various cell types this release occurs through inositol-triphosphate (IP3) receptors which are Ca2+ channels whose open probability is modulated by the cytosolic Ca2+ concentration it...

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Autores principales:	Solovey, Guillermo, Ponce Dawson, Silvina
Publicado:	2008
Materias:	Calcium Concentration (process) Enzyme activity Semiconductor doping Sugars Ca2+ releases Calcium releases Cell types Cellular activities Cluster regions Coarser grids Cytosolic Fine grids Intracellular stores Large ranges Localized events Mathematical modeling Numerical simulations Open channels Optical techniques Point sources Reaction-diffusion systems Relative locations Simplified models Spatio temporals Temporal scales Triphosphate Xenopus laevis oocytes Probability distributions
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15393755_v78_n4_p_Solovey http://hdl.handle.net/20.500.12110/paper_15393755_v78_n4_p_Solovey
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_15393755_v78_n4_p_Solovey
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spelling	paper:paper_15393755_v78_n4_p_Solovey2023-06-08T16:20:37Z Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels Solovey, Guillermo Ponce Dawson, Silvina Calcium Concentration (process) Enzyme activity Semiconductor doping Sugars Ca2+ releases Calcium releases Cell types Cellular activities Cluster regions Coarser grids Cytosolic Fine grids Intracellular stores Large ranges Localized events Mathematical modeling Numerical simulations Open channels Optical techniques Point sources Reaction-diffusion systems Relative locations Simplified models Spatio temporals Temporal scales Triphosphate Xenopus laevis oocytes Probability distributions Calcium release from intracellular stores plays a key role in the regulation of a variety of cellular activities. In various cell types this release occurs through inositol-triphosphate (IP3) receptors which are Ca2+ channels whose open probability is modulated by the cytosolic Ca2+ concentration itself. Thus, the combination of Ca2+ release and Ca2+ diffusion evokes a variety of Ca2+ signals depending on the number and relative location of the channels that participate of them. In fact, a hierarchy of Ca2+ signals has been observed in Xenopus laevis oocytes, ranging from very localized events (puffs and blips) to waves that propagate throughout the cell. In this cell type channels are organized in clusters. The behavior of individual channels within a cluster cannot be resolved with current optical techniques. Therefore, a combination of experiments and mathematical modeling is unavoidable to understand these signals. However, the numerical simulation of a detailed mathematical model of the problem is very hard given the large range of spatial and temporal scales that must be covered. In this paper we present an alternative model in which the cluster region is modeled using a relatively fine grid but where several approximations are made to compute the cytosolic Ca2+ concentration ([Ca2+]) distribution. The inner-cluster [Ca2+] distribution is used to determine the openings and closings of the channels of the cluster. The spatiotemporal [Ca2+] distribution outside the cluster is determined using a coarser grid in which each (active) cluster is represented by a point source whose current is proportional to the number of open channels determined before. A full reaction-diffusion system is solved on this coarser grid. © 2008 The American Physical Society. Fil:Solovey, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ponce Dawson, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15393755_v78_n4_p_Solovey http://hdl.handle.net/20.500.12110/paper_15393755_v78_n4_p_Solovey
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Calcium Concentration (process) Enzyme activity Semiconductor doping Sugars Ca2+ releases Calcium releases Cell types Cellular activities Cluster regions Coarser grids Cytosolic Fine grids Intracellular stores Large ranges Localized events Mathematical modeling Numerical simulations Open channels Optical techniques Point sources Reaction-diffusion systems Relative locations Simplified models Spatio temporals Temporal scales Triphosphate Xenopus laevis oocytes Probability distributions
spellingShingle	Calcium Concentration (process) Enzyme activity Semiconductor doping Sugars Ca2+ releases Calcium releases Cell types Cellular activities Cluster regions Coarser grids Cytosolic Fine grids Intracellular stores Large ranges Localized events Mathematical modeling Numerical simulations Open channels Optical techniques Point sources Reaction-diffusion systems Relative locations Simplified models Spatio temporals Temporal scales Triphosphate Xenopus laevis oocytes Probability distributions Solovey, Guillermo Ponce Dawson, Silvina Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels
topic_facet	Calcium Concentration (process) Enzyme activity Semiconductor doping Sugars Ca2+ releases Calcium releases Cell types Cellular activities Cluster regions Coarser grids Cytosolic Fine grids Intracellular stores Large ranges Localized events Mathematical modeling Numerical simulations Open channels Optical techniques Point sources Reaction-diffusion systems Relative locations Simplified models Spatio temporals Temporal scales Triphosphate Xenopus laevis oocytes Probability distributions
description	Calcium release from intracellular stores plays a key role in the regulation of a variety of cellular activities. In various cell types this release occurs through inositol-triphosphate (IP3) receptors which are Ca2+ channels whose open probability is modulated by the cytosolic Ca2+ concentration itself. Thus, the combination of Ca2+ release and Ca2+ diffusion evokes a variety of Ca2+ signals depending on the number and relative location of the channels that participate of them. In fact, a hierarchy of Ca2+ signals has been observed in Xenopus laevis oocytes, ranging from very localized events (puffs and blips) to waves that propagate throughout the cell. In this cell type channels are organized in clusters. The behavior of individual channels within a cluster cannot be resolved with current optical techniques. Therefore, a combination of experiments and mathematical modeling is unavoidable to understand these signals. However, the numerical simulation of a detailed mathematical model of the problem is very hard given the large range of spatial and temporal scales that must be covered. In this paper we present an alternative model in which the cluster region is modeled using a relatively fine grid but where several approximations are made to compute the cytosolic Ca2+ concentration ([Ca2+]) distribution. The inner-cluster [Ca2+] distribution is used to determine the openings and closings of the channels of the cluster. The spatiotemporal [Ca2+] distribution outside the cluster is determined using a coarser grid in which each (active) cluster is represented by a point source whose current is proportional to the number of open channels determined before. A full reaction-diffusion system is solved on this coarser grid. © 2008 The American Physical Society.
author	Solovey, Guillermo Ponce Dawson, Silvina
author_facet	Solovey, Guillermo Ponce Dawson, Silvina
author_sort	Solovey, Guillermo
title	Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels
title_short	Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels
title_full	Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels
title_fullStr	Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels
title_full_unstemmed	Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels
title_sort	simplified model of cytosolic ca2+ dynamics in the presence of one or several clusters of ca2+ -release channels
publishDate	2008
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15393755_v78_n4_p_Solovey http://hdl.handle.net/20.500.12110/paper_15393755_v78_n4_p_Solovey
work_keys_str_mv	AT soloveyguillermo simplifiedmodelofcytosolicca2dynamicsinthepresenceofoneorseveralclustersofca2releasechannels AT poncedawsonsilvina simplifiedmodelofcytosolicca2dynamicsinthepresenceofoneorseveralclustersofca2releasechannels
_version_	1768541911373578240

Simplified model of cytosolic Ca2+ dynamics in the presence of one or several clusters of Ca2+ -release channels

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