To simulate the STOC initiated by Ca2+ release from one RYR cluster, we first determined the distance to all nearby BK channel clusters. This is necessary because each BK cluster is at a different distance from RYRs, and therefore each is exposed to a different Ca(t) profile. Each BK cluster in the simulation possesses its own Po that is driven by its appropriate Ca(t) profile (based on its distance from the RYR). As the simulation runs, the current though each BK channel cluster is calculated as IBK = N × γ × Po × V, where N is the number of BK channels in a cluster (assumed to be 10; see Results), γ is single-channel conductance, V is the driving voltage, and Po is the Po for that specific BK cluster. The currents through all nearby BK channel clusters are then added to generate STOCs.
