FIGURE 1.

“Logarithmic” and “normal” diffusion of Ca²⁺ from the point source. Shown are the time-dependent profiles of Ca²⁺ concentration, which were obtained from Eqs. 8 and 7, describing the fast (a) and the normal (b) diffusion, respectively. In both cases, the effective diffusion coefficient was 40 μm²/s and the same amplitude of point source was used. The inset (top) shows the approximation of “total [Ca²⁺]” term in Eqs. 4 and 5 by logarithm. Panels a and b depict [Ca²⁺] changes, and panels c and d present normalized spatial derivatives as indicators of the fronts of Ca²⁺ concentration.