The unique aspect of norepinephrine (NE) release is that

Question

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Norepinephrine (NE) is released from axonal varicosities, which are swollen regions along the axons of neurons. These varicosities contain small vesicles filled with neurotransmitter molecules, including NE. When an action potential reaches the varicosity, the vesicles release NE into the synaptic cleft, where it can then bind to and activate receptors on postsynaptic neurons or other target cells. Choice B is incorrect because NE release does require the entry of calcium ions, which trigger the fusion of the vesicles with the presynaptic membrane. Choice C is correct, as black widow spider venom can block the release of NE and other neurotransmitters by preventing the fusion of vesicles with the presynaptic membrane. Choice D is incorrect, as amphetamine can enhance NE release by promoting its release from vesicles and inhibiting its reuptake. Choice E is incorrect, as NE is not known to be released from glial cells.

The Unique Aspect of Norepinephrine (NE) Release Is That