Sub-threshold Ca2+ waves

Abstract

In this paper we consider a model for intracellular Ca2+ waves where the ion channels (excitability) is distributed in spatially distinct clusters. We report that channel noise in conjunction with spatial clustering can result in the onset of spatially and temporally extremely coherent Ca 2+ signals at levels of stimulant well below the threshold of Ca 2+ oscillations for homogeneously distributed channels. The physiological significance of this phenomenon is strongly enhanced cellular Ca2+-signalling capability with few agonist molecules binding.