Which step is not part of the sequence of events that triggers synaptic transmission from a neuron to a muscle fiber? A) Entry of Ca²⁺ into the presynaptic terminal B) Release of norepinephrine into the synaptic cleft C) Opening of Ca²⁺ channels in the presynaptic terminal D) Arrival of an action potential at the presynaptic terminal E) Fusion of synaptic vesicles with the presynaptic membrane

Question

Quizplus · Accepted Answer

Norepinephrine is not typically involved in the transmission from a neuron to a muscle fiber. Instead, acetylcholine is the neurotransmitter released into the synaptic cleft at the neuromuscular junction. Therefore, the release of norepinephrine is not part of the sequence of events that triggers synaptic transmission in this context.

Which Step Is Not Part of the Sequence of Events