Calcium is necessary for numerous cell-signaling events in a variety of cells. These include receptor trafficking events, apoptosis, and gene transcription. Calcium influx from the extracellular space often triggers Calcium-Induced Calcium Release (CICR) from intracellular calcium stores such as the endoplasmic reticulum or the mitochondria.
How does this occur in excitatory neuron synapses?
Calcium enters excitatory synapses primarily through
receptors acting as coincidence detectors for membrane polarization and neurotransmitter release. Once inside the cytosol, calcium binds ER-localized
receptors, which act as amplifiers by releasing calcium from the ER. This calcium is returned to the ER by the ATP-driven