Norepinephrine storage vesicle

The norepinephrine storage vesicle refers to the specialized intracellular organelles—synaptic vesicles—within sympathetic neurons that store and release the neurotransmitter norepinephrine (also called noradrenaline). These vesicles play a critical role in neurotransmission by enabling the regulated release of norepinephrine during nervous system activity. The norepinephrine storage vesicle, also called the noradrenaline storage vesicle or large dense-cored vesicle, is an organelle in adrenergic neurons that sequesters norepinephrine along with proteins such as chromogranin A and dopamine-β-hydroxylase. Upon depolarization and calcium influx, these vesicles fuse with the neuronal membrane to release norepinephrine into the synaptic cleft, facilitating sympathetic neurotransmission. Dysfunction or pharmacological depletion of vesicular norepinephrine can profoundly impact blood pressure regulation, cardiovascular function, and mood. The vesicle itself is not a receptor, enzyme, transporter, or classic therapeutic target, but its function is central to catecholaminergic neurotransmission and may be affected by drugs acting on vesicular transporters or catecholamine metabolism.

Other names

Noradrenaline storage vesicleCatecholamine storage vesicleSynaptic vesicle (in adrenergic neurons)Large dense-cored vesicle

Inhibition of vesicular monoamine transporter (VMAT) reduces norepinephrine storage within vesicles, depleting synaptic stores (e.g., reserpine's mechanism)