What Triggers the Release of Acetylcholine from a Synaptic Terminal

Question

What triggers the release of acetylcholine from a synaptic terminal?
A) release of calcium ions from the synaptic vesicles
B) graded potentials in the synaptic terminal
C) synaptic vesicles fuse to dendrites
D) diffusion of sodium ions out of the synaptic terminal
E) diffusion of calcium ions into the synaptic terminal

Accepted Answer

The release of acetylcholine from a synaptic terminal is triggered by the diffusion of calcium ions into the synaptic terminal. This triggers the fusion of synaptic vesicles with the presynaptic membrane and the subsequent release of acetylcholine into the synaptic cleft.