Circadian Rhythm News and Research

Latest Circadian Rhythm News and Research

New insights into sleep difficulties among older people

A new study of the brain's master circadian clock - known as the suprachiasmatic nucleus, or SCN - reveals that a key pattern of rhythmic neural activity begins to decline by middle age. The study, whose senior author is UCLA Chancellor Gene Block, may have implications for the large number of older people who have difficulty sleeping and adjusting to time changes.

20 Jul 2011

Arabidopsis thaliana helps scientists to solve puzzles in human health

A tiny plant called Arabidopsis thaliana just helped scientists unearth new clues about the daily cycles of many organisms, including humans. This is the latest in a long line of research, much of it supported by the National Institutes of Health, that uses plants to solve puzzles in human health.

14 Jul 2011

Eating at wrong time of the day reduces fertility in fruit flies

Dieticians will tell you it isn't healthy to eat late at night: it's a recipe for weight gain. In fruit flies, at least, there's another consequence: reduced fertility.

8 Jun 2011

Abnormal clock gene coordination observed in tissues of Alzheimer's patients

Twenty-four hour cycles, known as circadian rhythms, are important for proper body functions, including for normal brain function and mental health. Disruptions of circadian rhythms and sleep-wake cycles have been observed in patients with Alzheimer's disease. A new study by Douglas Institute researchers unravels a possible basis for these perturbations.

28 Apr 2011

Heart attacks more severe in the morning: Study

Heart attacks are more dangerous in the morning than at any other time of day, research has shown. The study has shown that compared with other times, patients who had an attack between 6am and noon suffered around 20% more damage to their hearts. Researchers say this pattern is thought to be linked to circadian rhythms, the 24-hour “body clock” processes that influence many biological functions including blood pressure.

28 Apr 2011

Astrocytes regulate circadian system that controls normal sleep patterns

The circadian system that controls normal sleep patterns is regulated by a group of glial brain cells called astrocytes, according to a study published online on April 14th in Current Biology, a Cell Press publication. Neuroscientists from Tufts University School of Medicine found that disruption of astrocyte function in fruit flies ( Drosophila) led to altered daily rhythms, an indication that these star-shaped glial cells contribute to the control of circadian behavior.

15 Apr 2011

Nurses use ineffective strategy for adapting circadian clocks to night-time schedule

As many as 25 percent of hospital nurses go without sleep for at least 24 hours in order to adjust to working on the night shift, which is the least effective strategy for adapting their internal, circadian clocks to a night-time schedule.

15 Apr 2011

Obesity impacts gene clock of cardiovascular system

Obese individuals typically suffer more medical problems than their leaner counterparts. They are more likely to be diagnosed with insulin resistance, diabetes, increased stress hormones, hypothyroidism, and sleep apnea. Researchers at the Georgia Health Sciences University in Augusta have also found the potential for something else, using an animal model.

12 Apr 2011

Blood pressure's internal circadian rhythm does not appear to increase morning heart attacks

The internally-driven daily cycle of blood pressure changes doesn't appear to be linked to the known increase in morning heart attacks, according to a study in Circulation Research: Journal of the American Heart Association.

8 Apr 2011

Vanda to initiate tasimelteon Phase IIb/III clinical trial in Major Depressive Disorder

Vanda Pharmaceuticals Inc. today announced its plans to initiate a Phase IIb/III clinical trial of tasimelteon in patients with Major Depressive Disorder (MDD). The trial is expected to begin during the second half of 2011. Tasimelteon is currently being evaluated in Phase III clinical trials for the treatment of Non-24-Hour Sleep/Wake Disorder (N24HSWD) in blind individuals without light perception.

31 Mar 2011

New findings help explain why toxoplasmosis causes serious disease

Providing clues into why the severity of a common parasitic infection can vary greatly from person to person, a new Johns Hopkins study shows that each one of three strains of the cat-borne parasite Toxoplasma gondii sets off a unique reaction in the nerve cells it invades.

15 Mar 2011

LRC professors develop daylighting design guide for school students

The body's internal clock is responsible for regulating the timing of our sleep and other daily biological cycles, called circadian rhythms. During school months, however, teenagers miss out on essential morning light needed to stimulate the 24-hour biological clock.

15 Mar 2011

Loss of 'twenty-four' gene makes it harder to wake up

Northwestern University scientists have discovered a new mechanism in the core gears of the circadian clock. They found the loss of a certain gene, dubbed "twenty-four," messes up the rhythm of the common fruit fly's sleep-wake cycle, making it harder for the flies to awaken.

17 Feb 2011

Mathematical models to predict fatigue could reduce risk of accidents

Washington State University sleep researchers have determined that the air traffic controller in the crash of a Lexington, Ky., commuter flight was substantially fatigued when he failed to detect that the plane was on the wrong runway and cleared it for takeoff.

24 Jan 2011

Scripps Research receives NIH grant to develop therapies for circadian rhythm disorders

The Scripps Research Institute has been awarded $3.17 million over four years to develop compounds that will counteract disruptions of the human biological clock - the circadian rhythm that regulates our patterns of activity and rest over a 24-hour daily cycle.

19 Jan 2011

Bright light therapy for the aged depressed: Study

A new study shows that exposure to bright light may ease symptoms of depression in elderly people. The researchers tried three weeks of bright light therapy using specially designed light boxes and saw that it improved symptoms of depression by as much as 54% in older adults with depression. The light therapy also improved sleep and optimized levels of the neurotransmitter serotonin. Low levels of serotonin are associated with depression and often targeted by antidepressant drugs. This is the first study of its kind to show a beneficial effect of bright light therapy on treating depression in the elderly with non-seasonal major depressive disorder.

5 Jan 2011

Study: Multitude of genes are linked to adult height

As much as 90 percent of variation in adult height may be caused by genetic inheritance, but a multitude of genes are involved. Most of these have yet to be discovered.

4 Jan 2011

Fungus may provide clue about human response to changes in circadian rhythm

Humans are not the only species ruled by a circadian rhythm. Even simple organisms like moulds are governed by an inner clock. Studying red bread mould may teach us how our own internal clock works. This is exactly what the Centre for Organelle Research at the University of Stavanger, Norway is doing.

30 Dec 2010

Interaction of light with circadian systems

In a new paper published this week in the Proceedings of the National Academy of Sciences, Aziz Sancar, MD, PhD, the Sarah Graham Kenan Professor of Biochemistry and Biophysics in the UNC School of Medicine, and his colleagues have taken an important step in understanding the underlying molecular signals that influence a broad array of biological processes ranging from the sleep-wake cycle to cancer growth and development.

30 Dec 2010

Inserting plant's clock gene could replace circardian clock defect in humans

A gene that controls part of the 'tick tock' in a plant's circadian clock has been identified by UC Davis researchers. And not only is the plant gene very similar to one in humans, but the human gene can work in plant cells and vice versa.

2 Dec 2010