The suprachiasmatic nucleus or nuclei, abbreviated SCN, is a tiny region on the brain's midline, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle, using around 20,000 neurons.
The SCN, which is pine cone-shaped and the size of a grain of rice, interacts with many other regions of the brain. It contains several cell types and several different peptides (including vasopressin and vasoactive intestinal peptide) and neurotransmitters.
Read more about Suprachiasmatic Nucleus: Location, Circadian Effects, Circadian Rhythms of Endothermic and Ectothermic Vertebrates, Other Signals From The Retina, Gene Expression, Electrophysiology, Sexual Orientation and The SCN
Famous quotes containing the word nucleus:
“You know that the nucleus of a time is not
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Of the world, the heroic effort to live expressed
As victory. The poet does not speak in ruins
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He shares the confusions of intelligence.”
—Wallace Stevens (1879–1955)