title: Puff-wave transition in an inhomogeneous model for calcium signals.
abstract: In many cell types, calcium ion channels on the endoplasmic reticulum membrane occur in a clustered distribution. The channels generate either localized puffs, each comprising channels of only one cluster, or global calcium waves. In this work we model the calcium system as a two-dimensional lattice of active elements distributed regularly in an otherwise passive space. We address an important feature of the puff-wave transition, which is the difference in lifetime of puffs at a few hundred milliseconds and long-lived global waves with periods of several seconds. We show that such a lifetime difference between puffs and waves can be understood with strongly reduced ordinary differential equations modified by a time-scale factor that takes into account the coupling strength of active and passive regions determined by the Ca2+ diffusion coefficient. Furthermore, we show that the point model can also describe very well the dependence of Ca2+ oscillation characteristics on the cluster-cluster distance in the case of large diffusivity.
authors.affiliation: Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005, China. jianweishuai@xmu.edu.cn
authors.forename: J W
authors.initials: JW
authors.lastname: Shuai
authors.forename: Y D
authors.initials: YD
authors.lastname: Huang
authors.forename: S
authors.initials: S
authors.lastname: Rüdiger
mesh_terms: D002021:Buffers; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002477:Cells / Q000378:metabolism; D004058:Diffusion / Q000187:drug effects; D004533:Egtazic Acid / Q000494:pharmacology; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D008954:Models, Biological; D009068:Movement / Q000187:drug effects
chemical_list: D002021:Buffers; D053496:Inositol 1,4,5-Trisphosphate Receptors; D004533:Egtazic Acid; D002118:Calcium