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Bursting, chaos and birhythmicity originating from self-modulation of the inositol 1,4,5-trisphosphate signal in a model for intracellular Ca2+oscillations

✍ Scribed by G. Houart; G. Dupont; A. Goldbeter


Publisher
Springer
Year
1999
Tongue
English
Weight
630 KB
Volume
61
Category
Article
ISSN
1522-9602

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✦ Synopsis


We investigate the various types of complex Ca 2+ oscillations which can arise in a model based on the mechanism of Ca 2+ -induced Ca 2+ release (CICR), that takes into account the Ca 2+ -stimulated degradation of inositol 1,4,5-trisphosphate (InsP 3 ) by a 3-kinase. This model was previously proposed in the course of an investigation of plausible mechanisms capable of generating complex Ca 2+ oscillations (Borghans et al., 1997). Besides simple periodic behavior, this model for cytosolic Ca 2+ oscillations in nonexcitable cells shows complex oscillatory phenomena like bursting or chaos. We show that the model also admits a coexistence between two stable regimes of sustained oscillations (birhythmicity). The occurrence of these various modes of oscillatory behavior is analysed by means of bifurcation diagrams. Complex oscillations are characterized by means of Poincaré sections, power spectra and Lyapounov exponents. The results point to the role of self-modulation of the InsP 3 signal by 3-kinase as a possible source for complex temporal patterns in Ca 2+ signaling.