Locus coeruleus (LC)

The **locus coeruleus** (Latin for "blue spot") is a small, pigmented nucleus located in the dorsal pons of the brainstem, distinguished by its melanin-rich neurons[1][3][4]. It is the principal source of norepinephrine (noradrenaline) in the brain, comprising the locus coeruleus-noradrenergic (LC-NA) system[1][2][5]. The LC has wide-reaching projections throughout the central nervous system, affecting nearly all brain regions except the striatum[4]. Its physiological roles include the regulation of arousal, attention, memory, stress, and the sleep-wake cycle, as well as fine-tuning cognitive and behavioral responses[1][2][5][9]. The LC is functionally heterogeneous, composed of distinct modules of noradrenergic neurons with specific projection patterns and roles[2][5]. Dysfunction or degeneration of the LC and its noradrenergic output has been implicated in several neurological and psychiatric conditions, notably mood and neurodegenerative disorders[2][4][5][9]. While it plays a central neurobiological role, the locus coeruleus itself is a brain region (nucleus), not a molecular drug target such as a receptor, enzyme, or transporter.

Other names

locus caeruleuslocus ceruleusblue spotnucleus pigmentosus pontis