- A. Skupin
- M. Falcke
- European Physical Journal - Special Topics
- Eur Phys J-Spec Top 187 (1): 231-240
Calcium is an important and versatile second messenger in eukaryotic cells. External signals are often transmitted to intracellular targets by oscillations of the cytosolic calcium concentration. Recently, we have experimentally shown that these oscillations consist of sequences of random spikes and depend on spatial characteristics of cells. Here, we apply further statistical analysis to experimental data in order to describe the spike generating process and compare spontaneous and agonist-induced oscillations. It turns out that these oscillations exhibit a non-resonant behavior, and, consequently, regular spiking originates by array-enhanced coherent resonance. Moreover, we present a heuristic model based on the probability density of intervals between spikes that takes a positive feedback of a spike to its successor into account. The extended model is analyzed with respect to statistical properties and information content.