Prevalence of stochasticity in experimentally observed responses of pancreatic acinar cells to acetylcholine.
Calcium ions play an important role in both intra- and intercellular signaling. In pancreatic acinar cells intracellular Ca(2+) regulates exocytotic secretion and fluid secretion. In this paper we study the typical experimental traces of Ca(2+) responses in pancreatic acinar cells obtained in response to the physiological agonist acetylcholine. To determine whether they are stochastic or deterministic in nature, we analyze the traces with methods of nonlinear time series analysis. In particular, by performing surrogate data tests and employing a determinism test for short time series, we show that the responses of pancreatic acinar cells to acetylcholine are stochastic with only faintly expressed deterministic features. Presented results thus corroborate the notion that mathematical models should take stochasticity explicitly into account when describing intra- and intercellular processes, and that indeed further efforts should be directed toward this subject.
Perc
Matjaz
M
Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia. matjaz.perc@uni-mb.si
Rupnik
Marjan
M
Gosak
Marko
M
Marhl
Marko
M
D000109:Acetylcholine / Q000494:pharmacology*; D000465:Algorithms; D000818:Animals; D001683:Biological Clocks / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology*; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D009991:Oscillometry / Q000379:methods*; D046790:Pancreas, Exocrine / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013269:Stochastic Processes
D000109:Acetylcholine