A key event for the release of neurotransmitter from the presynaptic membrane is the
A) hyperpolarization of the axon membrane.
B) arrival of an action potential at the axon terminal.
C) influx of potassium ions into the axon terminal.
D) activation of the sodium-potassium pumps.
E) opening of ion channels within the microtubules.

Question

Quizplus · Accepted Answer

The arrival of an action potential at the axon terminal triggers the opening of voltage-gated calcium ion channels in the presynaptic membrane. Calcium ions then enter the axon terminal, causing the release of neurotransmitter into the synaptic cleft.

A Key Event for the Release of Neurotransmitter from the Presynaptic