title: Early morning bright light phase advances the human circadian pacemaker within one day.
abstract: One day after a single exposure to bright light from 03.00 to 09.00 h the morning declines in the serum melatonin concentration were phase-advanced in all subjects relative to pre-exposure patterns by 1.2-2.6 h. The evening melatonin rise was phase-advanced in 5 out of 6 subjects by 0.6-2.2 h. The data suggest that an underlying human circadian pacemaker controlling the melatonin rhythm may be phase-advanced within one day; however, the evening melatonin rise and the morning decline do not necessarily phase-shift by the same amount.
authors.affiliation: Institute of Physiology, Czechoslovak Academy of Sciences, Prague.
authors.forename: M
authors.initials: M
authors.lastname: Buresová
authors.forename: M
authors.initials: M
authors.lastname: Dvoráková
authors.forename: P
authors.initials: P
authors.lastname: Zvolský
authors.forename: H
authors.initials: H
authors.lastname: Illnerová
mesh_terms: D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D008027:Light; D008297:Male; D008550:Melatonin / Q000097:blood
chemical_list: D008550:Melatonin