Select the first step for synaptic signaling when the action potential arrives at the axon terminal of a presynaptic neuron.
A) A neurotransmitter is released by exocytosis.
B) Calcium flows into the synaptic knob.
C) The neurotransmitter combines with protein receptor sites on the subsynaptic membrane.
D) The permeability is altered in a postsynaptic neuron.
E) The neurotransmitter is synthesized.

Question

Quizplus · Accepted Answer

When an action potential arrives at the axon terminal, voltage-gated calcium channels are activated and allow calcium ions to flow into the synaptic knob. This influx of calcium triggers the release of neurotransmitter molecules from vesicles within the presynaptic neuron.

Select the First Step for Synaptic Signaling When the Action