monoaminergic

Monoaminergic refers to neurons, circuits, or signaling processes that use monoamine neurotransmitters. The principal monoamines in the brain are dopamine, norepinephrine (noradrenaline), serotonin, and histamine, with epinephrine playing a major role in the peripheral nervous system. Monoaminergic signaling relies on specific synthetic pathways, transporter proteins (DAT, NET, SERT, and VMAT2 for storage), receptor subtypes, and metabolic enzymes such as monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT).

Major systems include dopaminergic pathways originating in the substantia nigra and ventral tegmental area projecting to the striatum and cortex; noradrenergic neurons from the locus coeruleus innervating broad brain regions; serotonergic neurons from the dorsal raphe nuclei reaching widespread cortical and subcortical areas; and histaminergic neurons in the tuberomammillary nucleus projecting broadly to influence arousal and wakefulness.

Monoaminergic transmission is involved in regulation of mood, reward, attention, learning, memory, sleep, and autonomic function. Receptors are diverse and typically G protein–coupled, with autoreceptors modulating release and feedback control of signaling.

Clinical relevance includes associations between monoaminergic dysregulation and depression, anxiety disorders, schizophrenia, ADHD, and Parkinson's disease. Therapeutic strategies commonly target monoaminergic systems, including serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), other antidepressants, monoamine oxidase inhibitors (MAOIs), and dopamine precursors such as L-DOPA.