Ca²⁺ release permeability. Permeability, calculated as defined in Eq. 5, during a long-lasting, supramaximal pulse is shown. (A) For cells shown in Figs. 2 and 3, in which the solution in the pipette was EGTA. (B) For cells in Figs. 4 and 5, in which the solution in the pipette was BAPTA. Note how the permeability decays sharply during a pulse in the WT; it either remains elevated or recovers after initially decaying in the Casq KO.