Noradrenergic neurotransmission

Noradrenergic neurotransmission refers to the physiological process by which the catecholamine norepinephrine (noradrenaline) acts as a chemical messenger to transmit signals across synapses in the central and peripheral nervous systems. This system originates primarily in the locus coeruleus of the brainstem and projects widely throughout the brain, where it plays a critical role in regulating arousal, attention, mood, and the stress response. In the periphery, it is the primary mediator of the sympathetic nervous system's fight-or-flight response, influencing heart rate, blood pressure, and energy mobilization. Dysregulation of noradrenergic signaling is implicated in a variety of psychiatric and neurological conditions, including major depressive disorder, ADHD, and chronic anxiety. Pharmacological intervention typically targets the norepinephrine transporter (NET) to prolong signaling or specific adrenergic receptor subtypes (alpha-1, alpha-2, and beta receptors) to either stimulate or inhibit downstream physiological effects.

Other names

Norepinephrine systemAdrenergic signalingNoradrenaline neurotransmissionSympathetic neurotransmission

Drugs modulate this system by inhibiting the norepinephrine transporter (NET) to increase synaptic levels, acting as agonists or antagonists at alpha- and beta-adrenergic receptors, or inhibiting metabolic enzymes like monoamine oxidase (MAO).