Calcium transients in (a) the 0.1 μm thick submembrane shell and (b) the cell core of a single dendritic compartment of 4 μm diameter with 4 radial shells. Fast buffer with initial concentration 50 μM, forward rate k+ = 500 μM-1s−1 and backward rate k− = 1000 s−1. Black solid line: fixed buffer. Blue dotted line: mobile buffer with diffusion rate Dbuf = 1 × 10−6 cm2 s−1. Gray dashed line: excess (EBA) approximation. Gray dash-dotted line: rapid (RBA) buffer approximation. Binding ratio κ = 25. All other model parameters as in Figure 6.5.
