Module 6: Figure intercellular Ca2+ wave
Proposed mechanisms of intercellular wave propagation.
There are numerous examples of Ca2+ waves that travel from cell to cell. There is still some debate about the way the wave travels between cells. A. One mechanism proposes that, when the intracellular wave reaches the cell boundary, some low-molecular-mass component, most likely to be Ca2+, diffuses across the gap junction to ignite another intracellular wave in the neighbouring cell. B. An alternative mechanism suggests that the intracellular wave in one cell stimulates the release of ATP through hemichannels, which then diffuses across to ignite a wave in neighbouring cells by acting on P2Y receptors to produce inositol 1,4,5-trisphosphate (InsP3).