The amount of neurotransmitter released from the presynaptic terminal in response to a single action potential depends, in part, on _____. A) the amount of Ca²⁺ that enters the presynaptic terminal B) the amount of Na⁺ that enters the presynaptic terminal C) the size of the synaptic vesicles D) the length of the axon

Question

Quizplus · Accepted Answer

The amount of neurotransmitter released from the presynaptic terminal in response to a single action potential depends on the amount of Ca2+ that enters the presynaptic terminal. When an action potential arrives at the presynaptic terminal, it triggers the opening of voltage-gated Ca2+ channels, allowing Ca2+ ions to enter the terminal. The Ca2+ ions then bind to specific proteins that trigger the fusion of synaptic vesicles with the presynaptic membrane and the release of neurotransmitters into the synaptic cleft. Therefore, the amount of Ca2+ that enters the terminal determines the amount of neurotransmitter released.

The Amount of Neurotransmitter Released from the Presynaptic Terminal in Response