In the nervous system, calcium ions crossing the gap between these cause a release of acetylcholine
In the nervous system, calcium ions 
crossing the gap between these cause a release of acetylcholine... [DOC] [TLE] Synaptic Transmission - Boundless [PAR] The chemical event is involved in the transmission of the impulse via release, 
diffusion, receptor binding of neurotransmitter molecules and unidirectional 
communication between ... Calcium ions entering the cell initiate a signaling 
cascade.