20.500.12556/DKUM-69461 Critical and supercritical spatiotemporal calcium dynamics in beta cells A coordinated functioning of beta cells within pancreatic islets is mediated by oscillatory membrane depolarization and subsequent changes in cytoplasmic calcium concentration. While gap junctions allow for intraislet information exchange, beta cells within islets form complex syncytia that are intrinsically nonlinear and highly heterogeneous. To study spatiotemporal calcium dynamics within these syncytia, we make use of computational modeling and confocal high-speed functional multicellular imaging. We show that model predictions are in good agreement with experimental data, especially if a high degree of heterogeneity in the intercellular coupling term is assumed. In particular, during the first few minutes after stimulation, the probability distribution of calcium wave sizes is characterized by a power law, thus indicating critical behavior. After this period, the dynamics changes qualitatively such that the number of global intercellular calcium events increases to the point where the behavior becomes supercritical. To better mimic normal in vivo conditions, we compare the described behavior during supraphysiological non-oscillatory stimulation with the behavior during exposure to a slightly lower and oscillatory glucose challenge. In the case of this protocol, we observe only critical behavior in both experiment and model. Our results indicate that the loss of oscillatory changes, along with the rise in plasma glucose observed in diabetes, could be associated with a switch to supercritical calcium dynamics and loss of beta cell functionality. beta cells islets of Langerhans self-organized criticality intercellular dynamics calcium waves glucose oscillations computational model confocal calcium imaging beta celice Langerhansovi otočki samoorganizirana kritičnost medcelična dinamika kalcijevi valovi oscilacije glukoze računski model true false true Angleški jezik Slovenski jezik Znanstveno delo 2018-01-23 15:27:57 2018-01-23 15:29:12 2022-08-01 17:29:34 2019-07-11 17:33:04 2017 0 0 str. 1-17 Letn. 8 2017 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1664-042X 612.349.7 1218939 512760376 10.3389/fphys.2017.01106 1664-042X URN:SI:UM:DK:L9BI3QYW Frontiers_in_Physiology_2017_Gosak_et_al._Critical_and_Supercritical_Spatiotemporal_Calcium_Dynamics_in_Beta_Cells.pdf Frontiers_in_Physiology_2017_Gosak_et_al._Critical_and_Supercritical_Spatiotemporal_Calcium_Dynamics_in_Beta_Cells.pdf 1 4EA161605A3548418E7DCD104D7CA2CA 323f335af864563ddeb7cd1308905bb90e7e7453ca0e848668dfaeaf913b4b82 9eadadf0-7c0f-11eb-bb7a-00155d0001ca 20.500.12556/dkum/541d2df0-2f56-4270-89c3-ce0c5d6aad34 https://dk.um.si/Dokument.php?lang=slv&id=121524 http://journal.frontiersin.org/article/10.3389/fphys.2017.01106/full 1 https://dk.um.si/Dokument.php?lang=slv&id=121523 Medicinska fakulteta 0 0 0