Oscillations and waves of intracellular calcium

1993) and in a special issue of Cell Calcium (Cuthbertson Cobbold, 1991). The related, spatial aspects of signalling have also been the subject of several reviews (Amundson Clapham, 1993 Berridge Dupont, 1994) and of another special issue of Cell Calcium (Dissing, 

The purpose of this chapter is to examine the experimental aspects and the theoretical modelling of Ca waves and oscillations. 

Drawing an exhaustive list of experimental studies on Ca oscillations is beyond the scope of this chapter the above-mentioned reviews should be consulted to that end. Here, only those references that pertain directly to the elaboration of the models or allow the comparison of theoretical predictions with experimental data are retained. Before we address theoretical aspects, it is useful to briefly recall the main properties of Ca oscillations as determined from a large number of experimental studies pertaining to a variety of different cell types. The spatial aspects of Ca signalling are considered further below, in section 9.6. 

It has been repeatedly observed (Berridge Galione, 1988 Berridge et al., 1988 Jacob et al., 1988 Berridge, 1989,1990 Cuthbertson, 1989 Jacob, 1990a Petersen Wakui, 1990 Tsien Tsien, 1990 Tsunoda, 1991 Fewtrell, 1993) that oscillations occur only in a certain range of 

Stimulation (see fig. 9.3), and that the frequency of Ca spikes increases with the intensity of the stimulus (see fig. 9.2). Besides the induction of oscillations by external signals, it is often possible to ehcit a train of Ca spikes by increasing the level of extracellular or intracellular Ca or the level of inositol 1,4,5-trisphosphate (IP3 see Osipchuk et al, 1990). The latter messenger is synthesized in response to external signals and is known to raise the level of cytosolic Ca through mobilization from intracellular stores (Berridge Irvine, 1989 Berridge, 1993). 

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