Abstract：
:Most of the anatomical and molecular substrates of the system that encodes changes in photoperiod in the duration of melatonin secretion, and the receptor molecules that read this signal, have been shown to be conserved in monkeys and humans, and the functions of this system appear to be intact from the level of the retina to the level of the melatonin-duration signal of change of season. While photoperiodic seasonal breeding has been shown to occur in monkeys, it remains unclear whether photoperiod and mediation of photoperiod's effects by melatonin influence human reproduction. Epidemiological evidence suggests that inhibition of fertility by heat in men in summer contributes to seasonal variation in human reproduction at lower latitudes and that stimulation of fertility by lengthening of the photoperiod in spring contributes to the variation at higher latitudes. Parallels between the seasonality of human reproduction and seasonal affective disorder suggest that they may be governed by common biological processes. Historical and experimental evidence indicates that human responses to seasonal changes in the natural photoperiod may have been more robust prior to the Industrial Revolution and that subsequently they have been increasingly suppressed by alterations of the physical environment.
journal_name
J Biol Rhythmsjournal_title
Journal of biological rhythmsauthors
Wehr TAdoi
10.1177/074873001129002060subject
Has Abstractpub_date
2001-08-01 00:00:00pages
348-64issue
4eissn
0748-7304issn
1552-4531journal_volume
16pub_type
杂志文章,评审abstract：:Individuals of the shore crab Carcinus maenas were exposed to artificial cycles, applied in tidal antiphase, of pairs of the three major environmental variables that entrain circatidal rhythmicity in this species: salinity, temperature, and hydrostatic pressure. During entrainment, the observed locomotor activity patt...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049000500405
更新日期：1990-01-01 00:00:00
abstract：:Numerous studies have used the classic van der Pol oscillator, which contains a cubic nonlinearity, to model the effect of light on the human circadian pacemaker. Jewett and Kronauer demonstrated that Aschoff's rule could be incorporated into van der Pol type models and used a van der Pol type oscillator with higher o...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000867
更新日期：1999-12-01 00:00:00
abstract：:Previous research has demonstrated a clear link between late chronotype and depression. The vulnerability factors underpinning this link, however, are unclear. Here the relationship between two specific emotion regulation strategies, cognitive reappraisal and expressive suppression, and chronotype was investigated usi...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730417709111
更新日期：2017-08-01 00:00:00
abstract：:The role of the intergeniculate leaflet of the thalamus (IGL) in photoperiod responsiveness was examined in a laboratory-selected line of photoperiod nonresponsive (NR) Siberian hamsters. NR hamsters fail to exhibit typical winter-type responses (i.e., gonadal regression and development of winter-type pelage) when exp...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730406287996
更新日期：2006-06-01 00:00:00
abstract：:Photic signals affect circadian activity rhythms by both phasic and tonic mechanisms that modulate pacemaker phase and period. In mammals, the effects of light on circadian activity are mediated by the retina, which communicates with the suprahiasmatic nucleus (SCN) by two different anatomical routes: the retino-hypot...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048700200104
更新日期：1987-04-01 00:00:00
abstract：:Although pineal "synaptic" ribbons (SR) are frequently examined by means of quantitative electron microscopy, their functional significance remains unclear. The same is true for related structures--"synaptic" spherules (SPH). In the course of such studies, it has been noted that SR counts may differ from laboratory to...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048800300103
更新日期：1988-04-01 00:00:00
abstract：:Temperature compensation of circadian rhythms in neuronal firing rate was investigated in the suprachiasmatic nucleus (SCN) of ground squirrels and rats in vitro. A reduction in SCN temperature from 37 to 25 degrees C reduced peak firing rates by > 70% in rats but only by approximately 21% in squirrels; trough firing ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049601100205
更新日期：1996-06-01 00:00:00
abstract：:Groups of Syrian hamsters were exposed to LD cycles with twilight transitions and photoperiods simulating natural lighting conditions at the summer solstice (SS), equinox, and winter solstice (WS) at 41 degrees N and at the winter solstice at the Arctic Circle (WS 66 degrees N) but with daytime illuminance truncated a...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730404272907
更新日期：2005-04-01 00:00:00
abstract：:The tau mutation in Syrian hamsters (Mesocricetus auratus) is phenotypically expressed in a period of the circadian rhythm of about 20 h in homozygotes (SS) and about 22 h in heterozygotes (S+). The authors investigate whether this well-defined model for variation in circadian period exhibits associated changes in ene...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049701200503
更新日期：1997-10-01 00:00:00
abstract：:Several authors have suggested that the transcriptional regulatory protein c-Fos might be part of the mechanism for photic entrainment of the circadian pacemaker in the suprachiasmatic nucleus (SCN) to environmental light:dark cycles. This hypothesis has been based on evidence gathered using single light pulses admini...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049601100104
更新日期：1996-03-01 00:00:00
abstract：:Using quantitative autoradiography, 2-(125)I-melatonin binding was investigated throughout the light:dark cycle in the suprachiasmatic nuclei (SCN), paraventricular nuclei (PVT), and pars tuberalis (PT) of adult female Siberian hamsters kept for 10 weeks in either long or short photoperiods (LP or SP, respectively). P...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049601100406
更新日期：1996-12-01 00:00:00
abstract：:Rats anticipate a fixed daily feeding time by entrainment of a component of their multioscillatory circadian system. The range of stimuli capable of entraining this component is little studied. Previous studies suggest that restricted water access is not an effective entrainment stimulus, as measured by general locomo...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049200700206
更新日期：1992-07-01 00:00:00
abstract：:Arctic and subarctic environments are exposed to extreme light: dark (LD) regimes, including periods of constant light (LL) and constant dark (DD) and large daily changes in day length, but very little is known about circadian rhythms of mammals at high latitudes. The authors investigated the circadian rhythms of a su...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730404264200
更新日期：2004-06-01 00:00:00
abstract：:The frequency demultiplication hypothesis (FDH) posits that circannual rhythms are generated from circadian cycles by frequency transformation to the lower-frequency rhythm. To test the FDH, we determined the periods of the circannual body mass and estrous cycles of golden-mantled ground squirrels with circadian locom...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048600100402
更新日期：1986-01-01 00:00:00
abstract：:Most cyclic biological processes are under control of a circadian molecular timing system that synchronizes these phenomena to the 24-h day. One generic property of circadian-controlled processes is that they operate within a specific temperature range, below which the manifestation of rhythm ceases. Little is known a...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730414537801
更新日期：2014-06-01 00:00:00
abstract：:Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in s...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730413511771
更新日期：2013-12-01 00:00:00
abstract：:Endogenous circadian rhythms are involved in various photoperiodic responses of birds. Investigations involving the mechanisms of photoperiodic time measurement in birds have been confined mainly to temperate zone species using males exclusively. Due to the paucity of experimental evidence on subtropical birds that ha...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049501000405
更新日期：1995-12-01 00:00:00
abstract：:In Drosophila melanogaster, disruption of night by even short light exposures results in degradation of the clock protein TIMELESS (TIM), leading to shifts in the fly molecular and behavioral rhythms. Several lines of evidence indicate that light entrainment of the brain clock involves the blue-light photoreceptor cry...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873040101600303
更新日期：2001-06-01 00:00:00
abstract：:Aging alters numerous aspects of circadian biology, including the amplitude of rhythms generated by the suprachiasmatic nuclei (SCN) of the hypothalamus, the site of the central circadian pacemaker in mammals, and the response of the pacemaker to environmental stimuli such as light. Although previous studies have desc...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730403251802
更新日期：2003-04-01 00:00:00
abstract：:Access to electric light might have shifted the ancestral timing and duration of human sleep. To test this hypothesis, we studied two communities of the historically hunter-gatherer indigenous Toba/Qom in the Argentinean Chaco. These communities share the same ethnic and sociocultural background, but one has free acce...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730415590702
更新日期：2015-08-01 00:00:00
abstract：:In mammals, molecular circadian rhythms are generated by autoregulatory transcriptional-translational feedback loops with PERIOD/CRYPTOCHROME containing complexes inhibiting the transcription of their own genes. Although the major circadian oscillator components seem to be identified, an increasing number of additiona...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730415587407
更新日期：2015-08-01 00:00:00
abstract：:Although overt diurnal rhythms of behavior do not begin until well after birth, molecular studies suggest that the circadian clock may begin much earlier at a cellular level: mouse embryonic fibroblasts, for example, already possess robust clocks. By multiple criteria, we found no circadian clock present in mouse embr...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730410385281
更新日期：2010-12-01 00:00:00
abstract：:The Drosophila clock relies on transcriptional feedback loops that generate daily oscillations of the clock gene expression at mRNA and protein levels. In the evening, the CLOCK (CLK) and CYCLE (CYC) basic helix-loop-helix (bHLH) PAS-domain transcription factors activate the expression of the period (per) and timeless...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730407313817
更新日期：2008-04-01 00:00:00
abstract：:In many animals, the circadian clock plays a role in adapting to the coming season by measuring day length. The mechanism for measuring day length and its neuronal circuits remains elusive, however. Under laboratory conditions, the fruit fly, Drosophila melanogaster, displays 2 activity peaks: one in the morning and o...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730417738612
更新日期：2018-02-01 00:00:00
abstract：:The ventral subparaventricular zone (vSPVZ) receives direct retinal input and influences the daily patterning of activity in rodents, making it a likely candidate for the mediation of acute behavioral responses to light (i.e., masking). We performed chemical lesions aimed at the vSPVZ of diurnal grass rats (Arvicanthi...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730415626251
更新日期：2016-04-01 00:00:00
abstract：:We investigated the extent to which photoperiodic fluctuations synchronize annual thyroid and gonadal rhythmicity in edible dormice. The effects of different daylength manipulations (LD 4:20, LD 6:18, LD 18:6, LD 20:4) were examined during the two critical ascending and regressive phases of the annual plasma testoster...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049100600405
更新日期：1991-01-01 00:00:00
abstract：:Daylight saving time (DST) is a source of circadian disruption impinging on millions of people every year. Our aim was to assess modifications, if any, in the number, type, and outcome of Accident & Emergency (A&E) visits/return visits over the DST months. The study included 366,527 visits and 84,380 return visits to ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730418791097
更新日期：2018-10-01 00:00:00
abstract：:An outstanding unresolved issue in chronobiology is how the level of locomotor activity influences length of the free-running, endogenous circadian period (tau). To address this issue, the authors studied a novel model, 4 replicate lines of laboratory house mice (Mus domesticus) that had been selectively bred for high...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730403256998
更新日期：2003-12-01 00:00:00
abstract：:DEC1 and DEC2-basic helix-loop-helix transcription factors-exhibit a circadian expression in the suprachiasmatic nucleus and other peripheral tissues and seem to play roles in regulating the mammalian circadian rhythm by suppressing the CLOCK/BMAL1-activated promoters of Per1, Dec1, and Dec2. The authors present data ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730405280195
更新日期：2005-10-01 00:00:00
abstract：:To date, it is largely unknown which light settings define the optimum to steer alertness and cognitive control during regular daytime working hours. In the current article, we used a multimeasure approach combined with a relatively large sample size ( N = 60) and a large range of intensity levels (20-2000 lux at eye ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730418796438
更新日期：2018-12-01 00:00:00
