Editing Suprachiasmatic nucleus (section)

=== Irregular sleep-wake rhythm disorder ===
[[Irregular sleep–wake rhythm|Irregular sleep-wake rhythm (ISWR) disorder]] is thought to be caused by structural damage to the SCN, decreased responsiveness of the circadian clock to light and other stimuli, and decreased exposure to light.<ref name=":3" /><ref>{{Cite journal |last1=Zee |first1=Phyllis C. |last2=Vitiello |first2=Michael V. |date=2009-06-01 |title=Circadian Rhythm Sleep Disorder: Irregular Sleep Wake Rhythm |journal=Sleep Medicine Clinics |series=Basics of Circadian Biology and Circadian Rhythm Sleep Disorders |language=en |volume=4 |issue=2 |pages=213–218 |doi=10.1016/j.jsmc.2009.01.009 |pmid=20160950 |pmc=2768129 |issn=1556-407X}}</ref> People who tend to stay indoors and limit their exposure to light experience decreased nocturnal melatonin production. The decrease in melatonin production at night corresponds with greater expression of SCN-generated wakefulness during night, causing irregular sleep patterns.<ref name=":3" />