Answer:
When the action potential reaches the end of axon at the axon terminal Release of neurotransmitter occur from pre synaptic nerve ending.
Step-by-step explanation:
Action potential is an important process that help the generation and propagation of nerve impulse transmission from one neuron to the next one.
When the action potential reaches the axon terminal it help in the liberation of neurotransmitter which may be either excititory or inhibitory.
The released neurotransmitter binds to the surface receptor of post synaptic membrane causing either deplarization or hyperpolarization depending on the nature of neurotransmitter .