Nighttime alertness probed

Washington, Aug 27 (ANI): A new study, conducted by researchers in the U.S., has shown that the circadian system is not the only pathway involved in determining alertness at night – red light, which does not stimulate the circadian system, is just as effective at increasing nighttime alertness as blue light, which does.

Mariana Figueiro from Rensselaer Polytechnic Institute, New York, and colleagues examined the effects of the different lighting conditions.

“It is now well accepted that the circadian system is maximally sensitive to short-wavelength (blue) light and is quite insensitive to long-wavelength (red) light. We’ve shown that a moderate level of red light impacts alertness, an effect that must occur via a pathway other than the circadian system,” she said.

Circadian rhythms are roughly 24-hour cycles in various biological processes, such as core body temperature, melatonin synthesis and sleep-wake behavior, that repeat approximately every 24 hours and are synchronized most strongly by the light-dark cycle in the environment.

Bright light is known to increase alertness at night, but it has never been completely clear whether this light-induced alertness can arise from neural pathways other than those involved in the circadian system.

“There is previous compelling evidence that light-induced stimulation of the circadian system increases alertness at night, but our results suggest that this effect is mediated not only by the circadian system, but also through other mechanisms,” Figueiro added.

The research has been described in the open access journal BMC Neuroscience. (ANI)

How changing light could help people with dementia, other diseases

Washington, May 13 (ANI): Periods of blue-light, like daylight, produced from the blue-white lamp prototypes developed by GE scientists, could help people suffering from dementia and other health problems, according to researchers from Case Western Reserve University.

For the study, the researchers removed some standard fluorescent lighting and installed new blue-white lamp prototypes at the GE’s Nela Park campus, where daylight, which has proven health benefits, is not readily available.

They hypothesized that periods of blue light, like daylight, can help regulate the sleep-wake rhythm, which is a behavioural pattern linked to the 24-hour biochemical circadian cycle of the hormone melatonin. The levels of the hormone determine if people are awake or sleepy.

And by increasing exposure to blue-white light during the day, and yellow-white light in the evening, the researchers hope to help patients regulate their sleep-wake cycles so that they are more awake during the day and more asleep at night.

According to Patricia Higgins, associate professor at the Bolton School of Nursing and one of the lead investigators, the project may prove to be especially beneficial for people suffering from dementia.

In a recent study with five male patients, each person suffering from dementia and living in a long-term care facility, the researchers installed the blue-white lights in an activities room where most residents gathered for meals and daytime activities.

“We wanted to see whether lighting could affect the participants’ sleep-wake rhythms. While the group was small, the results show promise in raising activity levels during daytime hours and increasing sleep at nighttime,” said Higgins.

And they saw one unexpected side effect of the lighting- once adjusted to the blue-white light most employees claimed that they liked the new lighting conditions.

The researchers said that the new lighting used in the test changes the colour without overpowering individuals with brightness.

“Why waste light if you can tune it to the right colour and maximize the amount of useful light,” said Mariana Figueiro, who worked on the study.

“Light is a good stimulus for the circadian system, which regulates your sleep-wake cycles,” says Thomas Hornick, another worker on the study.

He said that it is known that certain drugs do better when given at the appropriate time in the circadian cycle.

Also, the researchers are hoping to apply the study’s findings as a safe, non-pharmacological intervention to change the lighting in hospitals where patients may have a speedier recovery or improved quality of life with a good night’s rest. (ANI)

Special ‘hotel’ in Sydney to help scientists study sleep disorders

Melbourne, February 7 (ANI): Aussie scientists have created a special “hotel” in Sydney as part of their new research project to study sleep disorders, wherein people will be locked away from the world for days, and monitored around the clock.

Their aim will to be gain fresh insights into how the body reacts to shift work, jet lag, sleep disorders, and even space travel.

The country’s first large-scale Time Isolation Research Unit was built as part of the 10 million-dollar co-location of the Woolcock Institute of Medical Research.

The subjects of the study will be kept totally away from external factors like sunlight and noise.

Professor Ron Grunstein has revealed that the multi-room facility has been insulated from the ground, which is why the subjects will not by alerted even by an early morning garbage truck.

“It’s like a hotel for research … (but) the rooms are completely sound-proofed to levels far greater than the best hotels,” the Daily Telegraph quoted Professor Grunstein, who is the institute’s head of sleep and circadian research, as saying.

“If a garbage truck goes past they won’t feel any vibration,” the researcher added.

The scientists will have total control over light, air temperature and what the test subject sees, eats and hears.

They will also take care to prevent any clue that may indicate time of day, even down to the bathroom habits of the researchers.

“The male staff either don’t shave or they shave at odd times and they don’t wear watches … if you really want to do this properly you have to have that attention to detail,” Professor Grunstein says.

This is the fourth time that such a facility has been established in the world. Opened in Glebe, this is said to be the most advanced in the southern hemisphere.

Professor Grunstein said that future work could include testing how a person’s circadian rhythms would be affected by the “completely different lighting conditions than they would experience on earth.”

The institute, which is affiliated to the University of Sydney, will soon take out ads inviting volunteers to participate in its research.

Test subjects can’t be claustrophobic, and they have to deal with almost total isolation for a week or even a month.

“A lot of the people who volunteer for these longer studies have a specific project they want to do. They are quite happy to be isolated – they are writing a book, or some report, or they want to read 10 novels,” Professor Grunstein said. (ANI)