Inter-synaptic variability of Ca²⁺ cooperativity of AP-evoked vesicular release.

<p>(A) Dependency of the average AP-evoked de-staining rate on . Data are mean ± SEM from six independent experiments for each . (B) Cumulative distributions of at different (1 mM, 620 boutons; 2 mM, 550 boutons, and 4 mM, 555 boutons). (C) Ca²⁺ cooperativity of vesicular release is higher in boutons with slow SRC1 de-staining (blue) than in boutons with fast SRC1 de-staining (red): values at different corresponding to cumulative probabilities 0.75 (Fast boutons) and 0.25 (Slow boutons) were normalized to the corresponding de-staining rates at 1 mM and then plotted against the relative amplitude of Ca²⁺ influx (determined as in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001396#pbio-1001396-g007" target="_blank">Figure 7</a>), which was also normalized to its value at 1 mM . Numbers next to the dotted lines connecting the data points correspond to differential Ca²⁺ cooperativity of vesicular release calculated using the equation <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001396#pbio.1001396-Matveev1" target="_blank">[63]</a> (blue, slow boutons; red, fast boutons).