Blue spot; Nucleus pigmentosus pontis
Locus ceruleus (Latin, “place, dark blue”) is a pigmented noradrenergic nucleus located in the dorsorostral pons.
Locus ceruleus (also spelled locus coeruleus) contains 30,000–35,000 neurons and is made up of four subnuclei: central (largest), anterior, ventral, and posterior dorsal. The locus ceruleus is dark blue in sections; melanin granules inside the pigmented cells of locus ceruleus contribute to its blue color. The neurons of the locus ceruleus provide noradrenergic innervations to most regions of the central nervous system. The projections of the locus ceruleus include the spinal cord, brain stem, cerebellum, thalamic relay nuclei, amygdala, basal telencephalon, and cortex. The norepinephrine from the locus ceruleus has an excitatory effect on most of the brain, mediating arousal and attention processing. The locus ceruleus is targeted by several endogenous opioid peptides, e.g., enkephalin, excitatory...