The intracellular stimulus for secretion of neurotransmitters into the synaptic cleft is an increase in
A)potassium ion levels.
B)chloride ion levels.
C)sodium ion levels.
D)calcium ion levels.
E)acetylcholine levels.

Question

Quizplus · Accepted Answer

The intracellular stimulus for the secretion of neurotransmitters into the synaptic cleft is an increase in calcium ion levels. When an action potential reaches the axon terminal, it triggers the opening of voltage-gated calcium channels, allowing calcium ions to enter the neuron. This influx of calcium ions initiates the fusion of synaptic vesicles with the plasma membrane, leading to the release of neurotransmitters into the synaptic cleft.

The Intracellular Stimulus for Secretion of Neurotransmitters into the Synaptic