What's so mind-boggling about calcium signaling is its diversity. Not only does calcium play different roles in different cell types, it can play various roles within a single cell depending on both how it enters the cell and how much does so. In neuronal cells, calcium may trigger neurotransmitter release, ion channel gating, kinase activation, nitric oxide (NO) production, and gene transcription. It also helps the cell retain a memory of recent action potentials, which can be important for neuronal plasticity. How calcium activates these diverse responses—and how the responses remain distinct—is the subject of intense study.
Scientists have at their disposal a wide range of new and improved tools to monitor and manipulate intracellular calcium levels. Using these tools, they have found that calcium influxes are local events, affecting those channels and receptors that reside nearby. It is the magnitude of the calcium influx, the nature of the channel ...
