Coarse-grained entropy rates quantify fast Ca2+ dynamics modulated by pharmacological stimulation.
Calcium (Ca2+) is an ubiquitous intracellular messenger which regulates cellular processes, such as secretion, contraction, and cell proliferation. A variety of cell types respond to hormonal stimuli with periodic oscillations of the intracellular free Ca2+ concentration ([Ca2+]i) which can be modulated in their frequency in a dose-dependent manner. The period of these well-studied oscillations varies normally between 30 sec and a couple of minutes. Here we study [Ca2+]i oscillations in clonal beta cells (hamster insulin secreting cells, HIT) under pharmacological stimulation. Besides the well-known high-amplitude low frequency oscillations we try to analyze for the first time low-amplitude high frequency oscillations of [Ca2+]i under pharmacological stimulation which have not been explored in experimental approaches to date. Using coarse-grained entropy rates computed from information-theoretic functionals we demonstrate differences in temporal complexity of the fast low-amplitude [Ca2+]i dynamics corresponding to different phases of pharmacological stimulation which are additional to the well-known dose-dependent pattern of low-frequency high amplitude [Ca2+]i dynamics.
Institute of Computer Science, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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D000465:Algorithms; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology* / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D003198:Computer Simulation; D006224:Cricetinae; D019277:Entropy; D007515:Islets of Langerhans / Q000187:drug effects / Q000502:physiology; D007700:Kinetics; D008954:Models, Biological; D009991:Oscillometry; D015290:Second Messenger Systems / Q000502:physiology; D013997:Time Factors
D001127:Arginine Vasopressin; D002118:Calcium