@article {Wang014431, author = {Xiao Wang and Yan Hao and Seth H. Weinberg and Gregory D. Smith}, title = {Ca2+-activation kinetics modulate successive puff/spark amplitude, duration and inter-event-interval correlations in a Langevin model of stochastic Ca2+ release}, elocation-id = {014431}, year = {2015}, doi = {10.1101/014431}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Through theoretical analysis of the statistics of stochastic calcium (Ca2+) release (i.e., the amplitude, duration and inter-event interval of simulated Ca2+ puffs and sparks), we show that a Langevin description of the collective gating of Ca2+ channels may be a good approximation to the corresponding Markov chain model when the number of Ca2+ channels per Ca2+ release unit (CaRU) is in the physiological range. The Langevin description of stochastic Ca2+ release facilitates our investigation of correlations between successive puff/spark amplitudes, durations and inter-spark intervals, and how such puff/spark statistics depend on the number of channels per release site and the kinetics of Ca2+-mediated inactivation of open channels. When Ca2+ inactivation/de-inactivation rates are intermediate{\textemdash}i.e., the termination of Ca2+ puff/sparks is caused by the recruitment of inactivated channels{\textemdash}the correlation between successive puff/spark amplitudes is negative, while the correlations between puff/spark amplitudes and the duration of the preceding or subsequent inter-spark interval are positive. These correlations are significantly reduced when inactivation/deinactivation rates are extreme (slow or fast) and puff/sparks terminate via stochastic attrition.}, URL = {https://www.biorxiv.org/content/early/2015/01/27/014431}, eprint = {https://www.biorxiv.org/content/early/2015/01/27/014431.full.pdf}, journal = {bioRxiv} }