suprachiasmatic nucleus

noun

su·​pra·​chi·​as·​mat·​ic nucleus ˌsü-prə-ˌkī-əz-ˈma-tik- 

: either of a pair of neuron clusters in the hypothalamus situated directly above the optic chiasma that receive photic input from the retina via the optic nerve and that regulate the body's circadian rhythms

Examples of suprachiasmatic nucleus in a Sentence

Recent Examples on the Web

Our circadian rhythms, 24-hour cycles governed by the brain’s suprachiasmatic nucleus, regulate everything from body temperature to hormone release. —Ximena Araya-Fischel, Forbes.com, 12 Apr. 2025

Melatonin from supplements targets the suprachiasmatic nucleus (SCN) of the hypothalamus in your brain to promote sleep. —Elizabeth Barnes, Verywell Health, 19 Mar. 2025

It’s controlled by a part of the brain called the suprachiasmatic nucleus, or SCN, which contains tiny bundles of nerve cells. —Cathy Habas, SELF, 17 Jan. 2025

Your circadian rhythm – the internal clock that dictates the sleep/wake cycle – is controlled by the suprachiasmatic nucleus (SCN). —Michael Williams, Discover Magazine, 30 Aug. 2021

Word History

First Known Use

1938, in the meaning defined above

Rhymes for suprachiasmatic nucleus

• micronucleus

Medical Definition

suprachiasmatic nucleus

noun

: either of a pair of neuron clusters in the hypothalamus situated directly above the optic chiasma that receive photic input from the retina via the optic nerve and that regulate the body's circadian rhythms

—abbreviation SCN