The release of neurotransmitter from axon terminals into the synaptic cleft depends on:
A)The inflow of chloride ions
B)The opening of nodes of Ranvier
C)Reversal of the sodium-potassium pump
D)The entry of calcium ions from the extracellular fluid

Question

Quizplus · Accepted Answer

The release of neurotransmitter from axon terminals into the synaptic cleft depends on the entry of calcium ions from the extracellular fluid. When an action potential reaches the axon terminal, it causes the opening of voltage-gated calcium channels, allowing calcium ions to flow into the axon terminal. This increased calcium concentration triggers the release of neurotransmitters into the synaptic cleft.

The Release of Neurotransmitter from Axon Terminals into the Synaptic