Abstract
In this paper we consider a model for intracellularCa2+ waves where the ion channels (excitability) is distributed in spatially distinctclusters. We report that channel noise in conjunction with spatial clusteringcan result in the onset of spatially and temporally extremely coherentCa2+ signals at levels of stimulant well below the threshold ofCa2+ oscillations for homogeneously distributed channels. The physiologicalsignificance of this phenomenon is strongly enhanced cellularCa2+-signallingcapability with few agonist molecules binding.
Highlights
Calcium ions are ubiquitous in cells as intracellular messengers [1]
We have demonstrated dramatic changes in intracellular calcium signalling patterns due to clustering of the IP3 receptors
The dynamic behaviour of Ca2+ release from internal stores predicted for homogeneous distributions of IP3 receptors is altered most dramatically at low concentrations of the second messenger IP3
Summary
Calcium ions are ubiquitous in cells as intracellular messengers [1]. Ca2+ participates in a wide range of processes such as triggering the development and differentiation of cells after fertilization, contracting muscle cells and triggering injury response in epithelia cells to name but a few. The intracellular Ca2+ waves are widely simulated by approximating the Ca2+ channels as deterministic and spatially continuous source terms [17]–[19] These reaction– diffusion models explain the observed Ca2+ patterns as nonlinear waves in an excitable, oscillatory, or bistable medium. The observation of localized stochastic Ca2+ puffs created by the cluster of a few tens of IP3Rs [8]–[10], suggests that stochastic effects are relevant for Ca2+ wave propagation and need to be taken into account Several such models with stochastic and spatially discrete IP3R sources have been proposed. This phenomenon may be related to Ca2+ wave nucleation [27]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
