title: Calcium waves in a model with a random spatially discrete distribution of Ca2+ release sites.
abstract: We study the propagation of intracellular calcium waves in a model that features Ca2+ release from discrete sites in the endoplasmic reticulum membrane and random spatial distribution of these sites. The results of our simulations qualitatively reproduce the experimentally observed behavior of the waves. When the level of the channel activator inositol trisphosphate is low, the wave undergoes fragmentation and eventually vanishes at a finite distance from the region of initiation, a phenomenon we refer to as an abortive wave. With increasing activator concentration, the mean distance of propagation increases. Above a critical level of activator, the wave becomes stable. We show that the heterogeneous distribution of Ca2+ channels is the cause of this phenomenon.
authors.affiliation: Department of Chemistry and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02254-9110, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Bugrim
authors.forename: A M
authors.initials: AM
authors.lastname: Zhabotinsky
authors.forename: I R
authors.initials: IR
authors.lastname: Epstein
mesh_terms: D000818:Animals; D001665:Binding Sites; D055592:Biophysical Phenomena; D001703:Biophysics; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D003198:Computer Simulation; D004058:Diffusion; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007424:Intracellular Fluid / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D017136:Ion Transport; D007700:Kinetics; D008954:Models, Biological; D009865:Oocytes / Q000378:metabolism; D014981:Xenopus
chemical_list: D015220:Calcium Channels; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium