title: Rest-activity cycle and melatonin rhythm in blind free-runners have similar periods.
abstract: In the absence of the entraining light-dark cycle, most totally blind humans free-run, albeit with relative coordination to nonphotic zeitgebers. Such blind free-runners (BFRs) often attempt to maintain a 24-h sleep-wake schedule and consequently suffer from recurrent sleep disruption and daytime somnolence. This study was conducted to determine the periods of the free-running melatonin rhythm and of the rest-activity cycle in 16 BFRs. It was found that the non-24-h component of the rest-activity rhythm correlated with the observed period of the circadian pacemaker.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Emens
authors.forename: Alfred J
authors.initials: AJ
authors.lastname: Lewy
authors.forename: Amber L
authors.initials: AL
authors.lastname: Laurie
authors.forename: Jeannie B
authors.initials: JB
authors.lastname: Songer
mesh_terms: D056044:Actigraphy; D000204:Activity Cycles / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001683:Biological Clocks / Q000502:physiology; D001766:Blindness; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D008875:Middle Aged; D017440:Photoperiod; D012146:Rest; D055815:Young Adult
chemical_list: D008550:Melatonin