Which of the following statements best describes the role of calcium in the release of a neurotransmitter substance from the presynaptic nerve terminal?
A)Calcium entry into the presynaptic terminal prevents the release of the neurotransmitter
B)Calcium entry into the presynaptic terminal is necessary for the release of the neurotransmitter
C)Calcium induces the opening of calcium-dependent sodium channels on the presynaptic terminal
D)Calcium entry into the presynaptic terminal results in the formation of cyclic adenosine monophosphate, which induces a conformational change in the presynaptic sodium channel that leads to the release of neurotransmitter

Question

Quizplus · Accepted Answer

Calcium entry into the presynaptic terminal is necessary for the release of the neurotransmitter. When an action potential reaches the presynaptic terminal, it depolarizes the membrane, causing voltage-gated calcium channels to open. The entry of calcium ions triggers the fusion of neurotransmitter-containing vesicles with the presynaptic membrane, releasing the neurotransmitter into the synaptic cleft. Therefore, without calcium entry, neurotransmitter release cannot occur.

Which of the Following Statements Best Describes the Role of Calcium