Circadian clocks drive rhythmic physiology and metabolism to optimize plant growth and performance under daily environmental fluctuations caused by the rotation of the planet. Photosynthesis is a key metabolic process that must be appropriately timed to the light-dark cycle. The circadian clock contributes to the regulation of photosynthesis, and in turn the daily accumulation of sugars from ph...

In the study of circadian rhythms, it has been a puzzle how a limited number of circadian clock genes can control diverse aspects of physiology. Here we investigate circadian gene expression genome-wide using larval zebrafish as a model system. We made use of a spatial gene expression atlas to investigate the expression of circadian genes in various tissues and cell types. Comparison of genome-...

As most organisms age, their appearance, physiology, and behaviour alters as part of a life history strategy that maximizes their fitness over their lifetime. The passage of time is measured by organisms and is used to modulate these age-related changes. Organisms have an endogenous time measurement system called the circadian clock. This endogenous clock regulates many physiological responses ...

Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term d...

The sleep-wake cycle and circadian rhythmicity both contribute to brain function, but whether this contribution differs between men and women and how it varies across cognitive domains and subjective dimensions has not been established. We examined the circadian and sleep-wake-dependent regulation of cognition in 16 men and 18 women in a forced desynchrony protocol and quantified the separate c...

Circadian rhythms are endogenously generated rhythms with a period length of about 24-hrs. Evidence gathered over the past decade indicates that the circadian timing system develops prenatally and the suprachiasmatic nuclei, the site of a circadian clock, are present by mid-gestation in human and non-human primates. Recent evidence also shows that the circadian system of primate infants is resp...

ARTICLE HISTORY Received 13 February 2017 Accepted 15 February 2017 ABSTRACT Circadian clock ensures coordination of rhythmic biological processes with environmental cycles. Correct matching of internal and external rhythmic cycles maximizes plant fitness and environmental adaptation capability and also ensures efficient energy consumption through circadian gating of a variety of physiological ...

The "master clock" in the suprachiasmatic nucleus (SCN) of the hypothalamus controls most behavioral, physiological, and molecular circadian rhythms in mammals. However, there are other, still unidentified, circadian oscillators that are able to carry out some SCN functions. Here we show that one of these, the methamphetamine-sensitive circadian oscillator (MASCO), which generates behavioral rh...

Bmal1 is an essential transcriptional activator within the mammalian circadian clock. We report here that the suprachiasmatic nucleus (SCN) of Bmal1-null mutant mice, unexpectedly, generates stochastic oscillations with periods that overlap the circadian range. Dissociated SCN neurons expressed fluctuating levels of PER2 detected by bioluminescence imaging but could not generate circadian oscil...

The complex interaction between alcohol and the body's circadian rhythm has become a rapidly expanding area in chronopharmacology. This area has key implications for the field of alcohol research, because understanding alcohol's effects on the body's internal clock will aid scientists in designing medications and behavioral interventions for treating alcohol abuse and dependence. A number of st...