A bidomain threshold model of propagating calcium waves.
We present a bidomain fire-diffuse-fire model that facilitates mathematical analysis of propagating waves of elevated intracellular calcium (Ca(2+)) in living cells. Modeling Ca(2+) release as a threshold process allows the explicit construction of traveling wave solutions to probe the dependence of Ca(2+) wave speed on physiologically important parameters such as the threshold for Ca(2+) release from the endoplasmic reticulum (ER) to the cytosol, the rate of Ca(2+) resequestration from the cytosol to the ER, and the total [Ca(2+)] (cytosolic plus ER). Interestingly, linear stability analysis of the bidomain fire-diffuse-fire model predicts the onset of dynamic wave instabilities leading to the emergence of Ca(2+) waves that propagate in a back-and-forth manner. Numerical simulations are used to confirm the presence of these so-called 'tango waves' and the dependence of Ca(2+) wave speed on the total [Ca(2+)].
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Department of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK. ruediger.thul@nottingham.ac.uk
Smith
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Coombes
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D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D003600:Cytosol / Q000502:physiology; D004058:Diffusion; D004721:Endoplasmic Reticulum / Q000502:physiology; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology*; D017136:Ion Transport; D007700:Kinetics; D008954:Models, Biological; D009865:Oocytes; D012016:Reference Values; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D014982:Xenopus laevis