locus coeruleus
noun
locus coe·ru·le·us
-si-ˈrü-lē-əs 
variants
or less commonly locus ceruleus
: a bluish area of the brain stem with many norepinephrine-containing neurons
Examples of locus coeruleus in a Sentence
Recent Examples on the Web
The researchers also discovered a feedback loop between GH and a brainstem hub called the locus coeruleus, which functions to keep us alert.
—
New Atlas, 8 Sep. 2025
One area in the brain involved in focus is the locus coeruleus–noradrenaline (LC-NA) system, which undergoes changes with age and has been linked in past research to early Alzheimer’s disease.
—Jenny Lehmann, Discover Magazine, 10 July 2025
The locus coeruleus neurons make substances called trophic factors, which promote the building of neural circuits.
—Kelyn Soong, Anchorage Daily News, 3 Feb. 2023
Dysfunction of the locus coeruleus, and the resulting breakdown of organized brain activity, has been related to several conditions, including Alzheimer’s disease and attention deficit hyperactivity disorder.
—Jason S. Tsukahara, Scientific American, 2 June 2021
From there, the vagus nerve’s signals travel to other important brain structures with bewildering Latin names, such as the locus coeruleus and the dorsal raphe nuclei.
—IEEE Spectrum, 29 May 2015
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New Atlas, 8 Sep. 2025
One area in the brain involved in focus is the locus coeruleus–noradrenaline (LC-NA) system, which undergoes changes with age and has been linked in past research to early Alzheimer’s disease.
—Jenny Lehmann, Discover Magazine, 10 July 2025
The locus coeruleus neurons make substances called trophic factors, which promote the building of neural circuits.
—Kelyn Soong, Anchorage Daily News, 3 Feb. 2023
Dysfunction of the locus coeruleus, and the resulting breakdown of organized brain activity, has been related to several conditions, including Alzheimer’s disease and attention deficit hyperactivity disorder.
—Jason S. Tsukahara, Scientific American, 2 June 2021
From there, the vagus nerve’s signals travel to other important brain structures with bewildering Latin names, such as the locus coeruleus and the dorsal raphe nuclei.
—IEEE Spectrum, 29 May 2015
Cite this Entry
“Locus coeruleus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/locus%20coeruleus. Accessed 29 Sep. 2025.
Copy CitationMedical Definition
locus coeruleus
noun
lo·cus coe·ru·le·us
variants
also locus ceruleus
plural loci coerulei also loci cerulei
-lē-ˌī
: a blue area of the brain stem with many norepinephrine-containing neurons
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