FIGURE 7.

Effect of D_CaSR on longitudinal [Ca²⁺]_SR profile during simulated local Ca²⁺-release. Diffusion-reaction model was run to simulate local SR Ca²⁺-release (see Appendix 1). [Ca²⁺]_SR was calculated 250 ms after increasing SR-membrane permeability to 1.35 μM/s in a central 2 μm length of SR. This estimate of D_CaSR (9 μm²/s) supports large and localized SR-depletion, with only small effects on adjacent luminal regions. Higher D_CaSR significantly depletes SR Ca²⁺ from regions beyond the release site. (Dashed line) 5% depletion threshold.