Human circadian rhythm in serum melatonin in short winter days and in simulated artificial long days

Burešová, M.; Dvořáková, M; Zvolský, P; Illnerová, Helena

doi:10.1016/0304-3940(92)90042-6

Cited by 33 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The hypothesis that transitions between diurnal and nocturnal periods of circadian rhythms are separately entrained to dawn and dusk was supported by a previously published analysis of data from the experiment in Study 1 (Wehr et al 1993), which suggested that these transitions were separately entrained to lights-on and lights-off (see also Burefsova et al 1992). This finding was confirmed in the present analysis, in which a more appropriate indicator of offset of melatonin secretion was used (Fig.…”

Section: Entrainment To Dawn and Dusksupporting

confidence: 87%

Evidence for a biological dawn and dusk in the human circadian timing system

Wehr

Aeschbach

Duncan

2001

The Journal of Physiology

156

View full text Add to dashboard Cite

Because individuals differ in the phase angle at which their circadian rhythms are entrained to external time cues, averaging group data relative to clock time sometimes obscures abrupt changes that are characteristic of waveforms of the rhythms in individuals. Such changes may have important implications for the temporal organization of human circadian physiology. To control for variance in phase angle of entrainment, we used dual internal reference points ‐ onset and offset of the nocturnal period of melatonin secretion ‐ to calculate average profiles of circadian rhythm data from five previously published studies. Onset and/or offset of melatonin secretion were found to coincide with switch‐like transitions between distinct diurnal and nocturnal periods of circadian rhythms in core body temperature, sleepiness, power in the theta band of the wake EEG, sleep propensity and rapid eye movement (REM) sleep propensity. Transitions between diurnal and nocturnal periods of sleep‐wake and cortisol circadian rhythms were found to lag the other transitions by 1‐3 h. When the duration of the daily light period was manipulated experimentally, melatonin‐onset‐related transitions in circadian rhythms appeared to be entrained to the light‐to‐dark transition, while melatonin‐offset‐related transitions appeared to be entrained to the dark‐to‐light transition. These results suggest a model of the human circadian timing system in which two states, one diurnal and one nocturnal, alternate with one another, and in which transitions between the states are switch‐like and are separately entrained to dawn and dusk. This description of the human circadian system is similar to the Pittendrigh‐Daan model of the rodent circadian system, and it suggests that core features of the system in other mammals are conserved in humans.

show abstract

Section: Entrainment To Dawn and Dusksupporting

confidence: 87%

Evidence for a biological dawn and dusk in the human circadian timing system

Wehr

Aeschbach

Duncan

2001

The Journal of Physiology

156

View full text Add to dashboard Cite

show abstract

“…That melatonin offset, but not onset, changed during the luteal phase and as a consequence of LWT is consistent with a two-oscillator model of melatonin secretion in which onset (evening oscillator) and offset (morning oscillator) are differentially regulated by light (Pittendrigh and Daan, 1976b; 1976a; Vanecek and Illnerova, 1982; Buresova et al, 1992; Elliott and Tamarkin, 1994). Delayed offset, but not onset, of urinary measures of melatonin also characterized depressed postmenopausal women (Tuunainen et al, 2002).…”

Section: Discussionsupporting

confidence: 80%

Late, but not early, wake therapy reduces morning plasma melatonin: Relationship to mood in Premenstrual Dysphoric Disorder

Parry¹,

Meliska²,

Martı́nez³

et al. 2008

Psychiatry Research

View full text Add to dashboard Cite

Wake therapy improves mood in Premenstrual Dysphoric Disorder (PMDD), a depressive disorder in DSM-IV. We tested the hypothesis that the therapeutic effect of wake therapy in PMDD is mediated by altering sleep phase with melatonin secretion.We measured plasma melatonin every 30 minutes (18:00 -09:00 h) in 19 PMDD and 18 normal control (NC) women during mid follicular (MF) and late luteal (LL) menstrual cycle phases, and during LL interventions with early wake therapy (EWT) (sleep 03:00-07:00 h)(control condition) versus late wake therapy (LWT) (sleep 21:00-01:00 h)(active condition).Melatonin offset was delayed and duration was longer in the symptomatic LL vs. asymptomatic MF phase in both NC and PMDD subjects. LWT, but not EWT, advanced offset and shortened duration vs. the LL baseline, although they improved mood equally. Later baseline LL morning melatonin offset was associated with more depressed mood in PMDD patients, and longer melatonin duration in the MF phase predicted greater mood improvement following LWT.That LWT, but not EWT, advanced melatonin offset and shortened duration while they were equally effective in improving mood suggests that decreasing morning melatonin secretion is not necessary for the therapeutic effects of wake therapy in PMDD.

show abstract

“…There is evidence that melatonin signals daylength to human physiology, as it does in other species (Arendt, 1999; Buresova et al, 1992; Wehr et al, 2001). Thus, a change in duration of its secretion might be expected in conditions of extreme daylength.…”

Section: Polar Studiesmentioning

confidence: 93%

Biological Rhythms During Residence in Polar Regions

Arendt¹

2012

Chronobiology International

129

View full text Add to dashboard Cite

At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with “normal” working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within a week, in contrast to temperate zones where complete adaptation rarely occurs. A similar situation occurs on high-latitude North Sea oil installations, especially when working 18:00–06:00 h. Lack of conflicting light exposure (and “social obligations”) is the probable explanation. Many have problems returning to day work, showing circadian desynchrony. Timed light treatment again has helped to restore normal phase/sleep in a small number of people. Postprandial response to meals is compromised during periods of desynchrony with evidence of insulin resistance and elevated triglycerides, risk factors for heart disease. Only small numbers of subjects have been studied intensively in polar regions; however, these observations suggest that suboptimal light conditions are deleterious to health. They apply equally to people living in temperate zones with insufficient light exposure.

show abstract

Human circadian rhythm in serum melatonin in short winter days and in simulated artificial long days

Cited by 33 publications

References 15 publications

Evidence for a biological dawn and dusk in the human circadian timing system

Evidence for a biological dawn and dusk in the human circadian timing system

Late, but not early, wake therapy reduces morning plasma melatonin: Relationship to mood in Premenstrual Dysphoric Disorder

Biological Rhythms During Residence in Polar Regions

Contact Info

Product

Resources

About