FIGURE 6.

Calculations of the velocity of Ca²⁺ waves due to regenerative Ca²⁺ release from internal stores. The velocities were obtained as the ratios of distances between the release sites and the times needed for a [Ca²⁺] transient to reach the threshold of release at the neighboring site. In panel a the threshold was set to 0.2 μM and the distance between the release sites was varied. In panel b the distance between the release sites was fixed at 1 μm and the threshold was varied. The parameters of intrinsic cytoplasmic buffer were B_o = 1 mM, K_d = 1 μM, and d = 20 μm²/s (mobile buffer). Middle curves in each panel correspond to the case when the concentrations of the mobile and immobile buffers were equal.