locus ceruleus

physiology

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June 30, 2026

Quick Summary

The locus coeruleus is a small, bluish area within the brainstem. It is characterized by a high concentration of neurons that produce norepinephrine, a neurotransmitter. This region plays a role in various physiological functions, including attention and arousal, by influencing the nervous system. The term "locus coeruleus" literally translates to "dark blue place" in New Latin.12

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sleep
REM sleep
Animal studies have identified the locus ceruleus (or locus coeruleus), a region in the brainstem, as the probable source of that inhibition. When that structure is surgically destroyed in experimental animals, the animals periodically engage in active, apparently goal-directed behaviour during REM sleep, although they still show the unresponsivity to…
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Animal studies have identified the locus ceruleus (or locus coeruleus), a region in the brainstem, as the probable source of that inhibition. When that structure is surgically destroyed in experimental animals, the animals periodically engage in active, apparently goal-directed behaviour during REM sleep, although they still show the unresponsivity to…
Read More

human nervous system
Autonomic tracts
…blue region known as the locus ceruleus; these cells distribute the neurotransmitter norepinephrine to the brain and spinal cord. Fibers from the locus ceruleus descend to spinal levels without crossing and are distributed to terminals in the anterior horn, the intermediate zone, and the dorsal horn. Other noradrenergic cell groups…
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…blue region known as the locus ceruleus; these cells distribute the neurotransmitter norepinephrine to the brain and spinal cord. Fibers from the locus ceruleus descend to spinal levels without crossing and are distributed to terminals in the anterior horn, the intermediate zone, and the dorsal horn. Other noradrenergic cell groups…
Read More