MicroRNAs grease the cell's circadian clockwork
Most of our cells possess an internal clock, a group of genes displaying a cyclic expression pattern that reaches a peak once a day. A large number of circadian
genes are expressed by organs such as the liver, whose activity needs to be precisely regulated over the course of the day. A team of res...
Two new studies on circadian rhythms
Hanover, NHDartmouth Medical School geneticists have made new inroads into understanding the regulatory circuitry of the biological clock that synchronizes the ebb and flow of daily activities, according to two studies published May 15.
Research on the relationship between clocks and temperat...
UNC study: Tinkering with the circadian clock can suppress cancer growth
CHAPEL HILL Researchers at the University of North Carolina at Chapel Hill have shown that disruption of the circadian
clock the internal time-keeping mechanism that keeps the body running on a 24-hour cycle can slow the progression of cancer.
The study disputes some of the most recent rese...
Research finds that circadian rhythms dominate all life functions
New research from Colorado State University shows that the function of all genes in mammals is based on circadian
-- or daily -- rhythms. The study, publishing in PLoS Computational Biology on June 15, refutes the current theory that only 10 percent to 15 percent of all genes were affected by natu...
New fruit fly protein illuminates circadian response to light
Researchers at the University of Pennsylvania School of Medicine have identified a new protein required for the circadian
response to light in fruit flies. The discovery of this protein ?named JET ?brings investigators one step closer to understanding the process by which the body's internal clock ...
A resetting signal keeps circadian rhythm on track in Drosophila fruit flies
A Brandeis University study published this week in Nature shows for the first time that a molecular signal maintains coherence among brain clock cells that regulate daily activity of Drosophila melanogaster (fruit flies). The two key groups of neurons control morning and evening activity and are ma...
A novel method to measure circadian cycles
Everyone knows morning people and late-night owls. The variation in individual circadian
rhythms is an anecdotal as well as experimentally verified fact. But, until now, to systematically study circadian
differences (and thereby hope to rout out the underlying genetic causes), scientists have had ...
Temperature regulates circadian clock in zebrafish
The biological clock controls the circadian
rhythms of a wide range of physiological and behavioral processes, from fluctuating hormone levels to sleep-wake cycles and feeding patterns. While it's well known that circadian
clock elements sense and respond to light cycles, much less is known about h...
Gene controlling circadian rhythms linked to drug addiction
The gene that regulates the body's main biological clocks also may play a pivotal role in drug addiction, researchers at UT Southwestern Medical Center have found.
The Clock gene not only controls the body's circadian
rhythms, including sleep and wakefulness, body temperature, hormone levels, bl...
The circadian clock: Understanding nature's timepiece
A cluster of brain cells less than half the size of a pencil eraser tells you when to wake up, when to be hungry and when it's time to go to sleep. The same cells also cause you to be disoriented after you've flown across multiple time zones.
The human circadian
clock, comprised of about 20,000 ...
After a time-shift, mixed signals from the circadian clock Circadian
rhythms in mammalian behavior, physiology, and biochemistry are controlled by the central clock within a brain structure known as the suprachiasmatic nucleus (SCN). The clock is synchronized to environmental cycles of light and dark. It is well known, from everyday experience, that adjust...
A biological basis for the 8-hour workday?
... PHILADELPHIA - The circadian
clock coordinates physiological and behavioral pro... or 8 hours, indicating that shorter cycles of the circadian
rhythm are also biologically encoded. Using a nove...ons for better understanding disruptions to normal circadian
rhythms that contribute to a host of pathologies s...
How your body clock avoids hitting the snooze button
...ocks to reset themselves on a molecular level.
clocks regulate the daily fluctuations of many phy...ges in the length of the day mean that an animal's circadian
clock often has to reset itself on a molecular lev...hool of Biological and Chemical Sciences study the circadian
clocks of Drosophila, a type of fruit fly. Writing...
What happens when we sleep
Sleep is regulated by processes in the brain in response to how long we are awake in addition to the light/dark cycle controlled by the circadian
rhythm. With Drs. Oum Hassani and Maan Gee Lee, Dr. Barbara Jones at the MNI were studying a structure in the brain called the lateral hypothalamus (...
Is there a relationship between sleep-wake rhythm and diabetes?
...level is higher during the day than in the night. Taken together, these new data implicate an association between the sleep-wake rhythm, the so-called circadian
rhythm, and fasting glucose levels, which was not known previously.
Until now an efficient strategy for prevention and for therapies to treat the c...
When it comes to sleep research, fruit flies and people make unlikely bedfellows
...ersity of Missouri-Kansas City have shown that the circadian
rhythms (sleep/wake cycles) of fruit flies and ver...rch is one of only a few possible drug targets for circadian
problems that can lead to seasonal affective disor...ety functions 24 hours a day and has produced more circadian
problems than our ancestors ever faced," said Jeff...
Bright lights, not-so-big pupils
"These melanopsin-containing cells signal light to many different parts of the brain to drive different behaviors, from setting the circadian
clock to affecting mood and movement," says Do. "I want to know how these signals are processed and whether they are abnormal in disorders like season...
Immunity stronger at night than during day
...e known as phagocytosis oscillates with the body's circadian
rhythm, according to Stanford researchers who pres...nger at night, consistent with the hypothesis that circadian
proteins upregulate restorative functions such as ...efine the relationship between innate immunity and circadian
rhythm, which is the oscillating protein clock or ...
Practice as well as sleep may help birds learn new songs
...ges in singing, this discovery provides a compelling hypothesis for how this learning might happen. Juvenile songbirds show a complex, sleep-dependent circadian
patterns of singing that have been observed during developmental vocal learning.
Their songs have less structure each morning and regain their com...
New genes present drug targets for managing cholesterol and glucose levels
...range," said Boehnke, who has studied the genetics of diabetes for more than 15 years.
The gene, called the melatonin receptor, helps regulate the circadian
clock, among other things. The finding strengthens the association between disrupted sleep patterns and diabetes, Boehnke said.
In the glucose stud...
Plants grow bigger and more vigorously through changes in their internal clocks
... same species).
The research team discovered a direct connection between circadian
clock regulators and growth vigor in both hybrids and polyploids. circadian
clocks control growth, metabolism and fitness in plants and animals.
Seasonal affective disorder may be linked to genetic mutation, study suggests
...ology professor who studies the genetics of the body's biological clock, or circadian
Provencio and his colleagues have discovered that melanopsin, a...vision, but are linked to many non-visual responses, such as the control of circadian
rhythms, the control of hormones, the mediation of alertness and the regula...
Gene therapy restores vision to mice with retinal degeneration
...n via the optic nerve, which is formed from the cells' axons. Melanopsin is usually produced in a subset of cells that are involved with establishing circadian
rhythms but not with vision. The MGH team used the standard viral vector adeno-associated virus to deliver the gene encoding melanopsin throughout the...
Brainy genes, not brawn, key to success on mussel beach
... separate, mussels can decrease the chances of such cell damagean advantage in such extreme conditions.
What controls the cycles?
In humans, the circadian
rhythm is also a cycle that involves waves of gene expression, but unlike the mussel cycles, it has consistent intervals regulated by light.
TheVisualMD.com launches new animated 3-D views of human body in action
...dimensional images and animations of both male and female forms which include everything from muscles and skeleton, to the mechanics of digestion, the circadian
rhythms of the heart, and the intricacy of the brain and nerve network.
"With TheVisualMD.com, we've built a new interactive content delivery syst...
Circadian clock may be critical for remembering what you learn, Stanford researchers say
... The circadian
rhythm that quietly pulses inside us all, guiding ...st Norman Ruby has shown that having a functioning circadian
system is critical to the hamsters' ability to rem...environment, as do all animals. But hamsters whose circadian
system was disabled by a new technique Ruby and hi...
Biologists identify genes controlling rhythmic plant growth
... of plant growth hormones, plant light sensors and circadian
rhythms that permit plants to undergo rhythmic gro...dly growing population."
"It was known that the circadian
clock confers an adaptive advantage to plants in n...lar interplay of light sensing, plant hormones and circadian
rhythms that leads to a pronounced rhythmic growth...
'Biological clock' genes control plant growth
These rhythmic growth spurts, and the ability of plants to move in response to light, are actually controlled by genes involved in circadian
rhythms the "biological clock" genes that are influenced by light and dark, vary their activity based on time of day, and are increasingly found in b...
Cyanobacterium sequenced features rare linear chromosome
...produce ethanol and hydrogen, and thus some day become an inexpensive renewable energy source.
Cyanobacteria are the only known bacteria to have a circadian
clock. By day, Cyanothece cells increase gene expression for photosynthesis and sugar production; at night, they moonlight, ramping up gene express...
Interdisciplinary volume on biological rhythms serves as both primer and in-depth resource
... sleep. Subsequent sections of the book offer in-depth discussions on specific topics, including genetic and cellular studies aimed at characterizing circadian
mechanisms; systems approaches to understanding physiological, endocrine, and neural networks; and models used for studying mental and physical cycles...
Feats of strength begin a lizard's day
... nocturnal predators.
Scientists disagree on why birds chorus at dawn and dusk: competing ideas range from territorial defense to manifestations of circadian
rhythms (the animal's internal clock). Ord said his work suggests male anoles use their morning displays primarily to mark territory.
"The dawn cho...
Light receptors in eye play key role in setting biological clock, study shows
..." Doyle said. "Our discovery of the switching mechanism in the eye has direct relevance with respect to the eventual development of therapies to treat circadian
and sleep disorders in the visually impaired." ...
Model for angelman syndrome developed by University of Texas at Austin biologists
...e to climb as well up the sides of plastic containers, weren't as able to form long-term memories (of aversive shocks) and were more likely to display circadian
In other words, the flies, says Fischer, suffer from a kind of Angelman syndrome, and should therefore offer a useful model ...
Circadian rhythm-metabolism link discovered
...ne researchers have found a molecular link between circadian
rhythms our own body clock and metabolism. The d...ial protein called CLOCK that regulates the body's circadian
rhythms, works in balance with another protein cal...e-Corsi, one of the world's leading researchers on circadian
rhythms. The study appears in the July 25 issue of...
The first autism disease genes
...y she will highlight new findings on the role of gene mutations, their association with synapse abnormalities, and surprisingly a connection between circadian
rhythms and autism risk. These insights will nurture applied projects on the development of new therapeutic strategies.
Plants in the fourth dimension
...t and reset by environmental signals. In animals, circadian
rhythms are known to be important for maintaining ... right season. However, they also have endogenous circadian
("around the day") rhythms with roughly 24 hour pe...ting the genetic basis and molecular mechanisms of circadian
cycling and regulation in plants. Dr. McClung, of...
A mammalian clock protein responds directly to light
...have been proven to regulate the mechanisms of the circadian
clock. But how they work in humans and animals is ...nts to blue light, the decrease in flavins affects circadian
rhythms differently. The mouse cryptochromes, Mcry1 and Mcry2, interact with key parts of the circadian
clock: mice with these cryptochromes missing exhib...
SEX4, starch and phosphorylation
..., glucanotransferases and amylases, among others-- and that in leaves, their actions are finely tuned to the diurnal changes in photosynthesis and the circadian
rhythms of the plant.
Some of the new proteins that have been identified by Dr. Zeeman and other researchers in the field act as glucan kinases and...
Pitt receives $2.5 million to simulate and analyze brain, immune system activity
...cale measured in submilliseconds, a scale so small that no one can really grasp how short it is. At the same time, the brain manages and abides by the circadian
rhythm, the body's 24-hour cycle.
"If we make a breakthrough on how to map these time scales, it would apply to multiple systems," Rubin added.
Caloric intake negatively influences healthy adults' sleep patterns
...l energy intake and late-night snack energy intake were significantly correlated with apnea-hypopnea index.
Previous studies have demonstrated that circadian
distribution of food intake is capable of modifying endocrine and metabolic patterns during sleep. However, studies of the influence of food intake d...