Using two dyes to observe the competition of Ca2+ trapping mechanisms and their effect on intracellular Ca2+ signals

• Published in: Physical biology 2018-11, Vol.15 (6), p.066006-066006
• Main Authors: Piegari, E, Lopez, L F, Ponce Dawson, S
• Format: Article
• Language: English
• Subjects: calcium buffers; calcium puffs; spatio-temporal distributions
• ISSN: 1478-3975
• DOI: 10.1088/1478-3975/aac922

The specificity and universality of intracellular signals rely on the variety of spatio-temporal patterns that the concentration can display. liberation through inositol 1,4,5-trisphosphate receptors () is key for this variety. In this paper, we study how the competition between buffers of different kinetics affects signals that involve release through . The study also provides insight into the underlying spatial distribution of the channels that participate in the signals. Previous works on the effects of buffers have drawn conclusions 'indirectly' by observing the -bound dye distributions in the presence of varying concentrations of exogenous buffers and using simulations to interpret the results. In this paper, we make visible the invisible by observing the signals simultaneously with two dyes, and , each of which plays the role of a slow or fast buffer, respectively. Our observations obtained for different concentrations of highlight the dual role that fast buffers exert on the dynamics, either reducing the intracluster channel coupling or preventing channel inhibition and allowing the occurrence of relatively long cycles of release. Our experiments also show that signals with relatively high release rates remain localized in the presence of large concentrations, while the mean speed of the elicited waves increases. We interpret this as a consequence of the more effective uncoupling between clusters as the slow dye concentration increases. Combining the analysis of the experiments with numerical simulations, we also conclude that release not only occurs within the close vicinity of the centers of the clearly identifiable release sites ( clusters) but there are also functional in between them.