Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales

Many natural phenomena display "self-organized criticality" (SOC), (Bak et al., 1987). This refers to spatially extended systems for which patterns of activity characterized by different lengthscales can occur with a probability density that follows a power law with pattern size. Different...

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Detalles Bibliográficos
Autores principales:	Sigaut, Lorena, Ponce Dawson, Silvina
Publicado:	2012
Materias:	Calcium signals Percolation Phase transition Puffs Self-organized criticality
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1664042X_v3SEP_n_p_Lopez http://hdl.handle.net/20.500.12110/paper_1664042X_v3SEP_n_p_Lopez
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_1664042X_v3SEP_n_p_Lopez
record_format	dspace
spelling	paper:paper_1664042X_v3SEP_n_p_Lopez2023-06-08T16:25:56Z Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales Sigaut, Lorena Ponce Dawson, Silvina Calcium signals Percolation Phase transition Puffs Self-organized criticality Many natural phenomena display "self-organized criticality" (SOC), (Bak et al., 1987). This refers to spatially extended systems for which patterns of activity characterized by different lengthscales can occur with a probability density that follows a power law with pattern size. Differently from power laws at phase transitions, systems displaying SOC do not need the tuning of an external parameter. Here we analyze intracellular calcium (Ca 2+) signals, a key component of the signaling toolkit of almost any cell type. Ca2+ 2+ signals can either be spatially restricted (local) or propagate throughout the cell (global). Different models have suggested that the transition from local to global signals is similar to that of directed percolation. Directed percolation has been associated, in turn, to the appearance of SOC. In this paper we discuss these issues within the framework of simple models of Ca 2+ signal propagation. We also analyze the size distribution of local signals ("puffs") observed in immature Xenopus Laevis oocytes. The puff amplitude distribution obtained from observed local signals is not Gaussian with a noticeable fraction of large size events. The experimental distribution of puff areas in the spatio-temporal record of the image has a long tail that is approximately log-normal. The distribution can also be fitted with a power law relationship albeit with a smaller goodness of fit. The power law behavior is encountered within a simple model that includes some coupling among individual signals for a wide range of parameter values. An analysis of the model shows that a global elevation of the Ca 2+ concentration plays a major role in determining whether the puff size distribution is long-tailed or not. This suggests that Ca 2+-clearing from the cytosol is key to determine whether IP3-mediated Ca 2+ signals can display a SOC-like behavior or not. © 2012 Lopez, Piegari, Sigaut and Ponce Dawson. Fil:Sigaut, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Dawson, S.P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1664042X_v3SEP_n_p_Lopez http://hdl.handle.net/20.500.12110/paper_1664042X_v3SEP_n_p_Lopez
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 signals Percolation Phase transition Puffs Self-organized criticality
spellingShingle	Calcium signals Percolation Phase transition Puffs Self-organized criticality Sigaut, Lorena Ponce Dawson, Silvina Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
topic_facet	Calcium signals Percolation Phase transition Puffs Self-organized criticality
description	Many natural phenomena display "self-organized criticality" (SOC), (Bak et al., 1987). This refers to spatially extended systems for which patterns of activity characterized by different lengthscales can occur with a probability density that follows a power law with pattern size. Differently from power laws at phase transitions, systems displaying SOC do not need the tuning of an external parameter. Here we analyze intracellular calcium (Ca 2+) signals, a key component of the signaling toolkit of almost any cell type. Ca2+ 2+ signals can either be spatially restricted (local) or propagate throughout the cell (global). Different models have suggested that the transition from local to global signals is similar to that of directed percolation. Directed percolation has been associated, in turn, to the appearance of SOC. In this paper we discuss these issues within the framework of simple models of Ca 2+ signal propagation. We also analyze the size distribution of local signals ("puffs") observed in immature Xenopus Laevis oocytes. The puff amplitude distribution obtained from observed local signals is not Gaussian with a noticeable fraction of large size events. The experimental distribution of puff areas in the spatio-temporal record of the image has a long tail that is approximately log-normal. The distribution can also be fitted with a power law relationship albeit with a smaller goodness of fit. The power law behavior is encountered within a simple model that includes some coupling among individual signals for a wide range of parameter values. An analysis of the model shows that a global elevation of the Ca 2+ concentration plays a major role in determining whether the puff size distribution is long-tailed or not. This suggests that Ca 2+-clearing from the cytosol is key to determine whether IP3-mediated Ca 2+ signals can display a SOC-like behavior or not. © 2012 Lopez, Piegari, Sigaut and Ponce Dawson.
author	Sigaut, Lorena Ponce Dawson, Silvina
author_facet	Sigaut, Lorena Ponce Dawson, Silvina
author_sort	Sigaut, Lorena
title	Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
title_short	Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
title_full	Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
title_fullStr	Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
title_full_unstemmed	Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
title_sort	intracellular calcium signals display an avalanche-like behavior over multiple lengthscales
publishDate	2012
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1664042X_v3SEP_n_p_Lopez http://hdl.handle.net/20.500.12110/paper_1664042X_v3SEP_n_p_Lopez
work_keys_str_mv	AT sigautlorena intracellularcalciumsignalsdisplayanavalanchelikebehaviorovermultiplelengthscales AT poncedawsonsilvina intracellularcalciumsignalsdisplayanavalanchelikebehaviorovermultiplelengthscales
_version_	1768542569770254336

Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales

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