(ANOVA, P < 0.05). Therefore, the duration of ICa(spark) contributes to the amplitude of STOCs. This relationship implies that (a) activation kinetics plays a role in determining the amplitude of STOCs and (b) additional recruitment of BK channels is possible by longer duration of Ca2+ sparks. To corroborate our findings on the relationships between Ca2+ sparks and STOCs shown in Figs. 1–3, we decided to directly visualize RYRs and BK channels in these cells as addressed below.
