A theoretical study of cytosolic calcium waves in Xenopus oocytes

Calcium waves have been observed in Xenopus oocytes through the use of confocal fluorescence microscopy. The waves assume many patterns including plane waves, target patterns and spirals. Modification of the membrane model (Jafri et al., 1992) to include diffusion terms in two dimensions reproduces planar and circular propagating waves. A one-dimensional model is used to study the properties of these waves. The model predicts that increasing the buffering capacity of the cytosol decreases the wave amplitude and speed. A decrease in the wave speed is also observed when the net calcium entry rate into the cytosol decreases. The model also predicts that as the diffusion constant is increased, the wave speed increases.