INTRACELLULAR CHANNELS AND CALCIUM SPIKING

The calcium signal in cells is often highly organized in the form of s pikes which develop as a wave spreading outwards from an initiation si te. These spatiotemporal characteristics depend upon the regenerative release of calcium by either inositol trisphosphate (IP3) or ryanodine (RY) receptors. These two intracellular receptors share considerable structural and functional similarities. In particular, they are both s ensitive to calcium and this process of calcium-induced calcium releas e (CICR) can account for the generation of both calcium spikes and pro pagating calcium waves.