Final answer:
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated calcium channels. This allows calcium ions to enter the cell and initiate the release of neurotransmitter molecules through exocytosis.
Step-by-step explanation:
When an action potential reaches the axon terminal, the membrane depolarizes and opens voltage-gated Ca2+ channels. When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated calcium channels. This allows calcium ions to enter the cell and initiate the release of neurotransmitter molecules through exocytosis.
This depolarization allows Ca2+ ions to enter the cell, initiating a signaling cascade that leads to the fusion of synaptic vesicles with the presynaptic membrane. This fusion allows the release of neurotransmitter molecules into the synaptic cleft through exocytosis.