Fig 7. Spatio-temporal Ca²⁺ dynamics in the cytoplasm.

A) Linescan of a single Ca²⁺ spark (upper panel) and Ca²⁺ transients at different distances from the dyad centre (lower panel) B) Whole-cell intracellular Ca²⁺ transient (upper panel) and linescan along the longitudinal axis for a single beat (lower panel). C) Temporal snapshots of spatial Ca²⁺ concentration in a 3-D volume of the cell from multiple views: a) whole cell; b) small portion of the cell (1/4 cross section; 1/6 length), corresponding to the highlighted location in (ai); c) cross-sectional 2D slice and; d) 2D slice along the longitudinal axis. The slices in (c) and (d) are illustrated in bi. Triangular markers in (A) indicate the timings of the corresponding panels (Ci-iv)– 0ms, 10ms, 50ms and 200ms relative to the applied stimulus. The purple-yellow colour bar corresponds to all spatial plots. The original reconstructed sarcolemma and TTs (brown contours) are shown for reference. Note that the repeated symmetry in Ca²⁺ concentration structure is a direct result of the whole-cell geometry being created by tessellating a small portion of the cell (see Methods: Creating a whole cell model).