Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify molecule that helps the sleep-deprived to mentally rebound

26.02.2009
Sleep experts know that the mental clarity lost because of a few sleepless nights can often be restored with a good night’s rest. Now, UT Southwestern Medical Center researchers have identified a key molecular mechanism that regulates the brain’s ability to mentally compensate for sleep deprivation.

Working with mice, they found that a molecule called an adenosine receptor is necessary for sleep-restricted animals to attain adequate levels of slow-wave activity in the brain once normal sleep resumes. It is this increase in slow-wave activity, or SWA, during rebound sleep that helps restore normal working memory and attention skills to the sleep-deprived, the scientists report in the Feb. 4 issue of the Journal of Neuroscience.

“Normal society pushes people to burn candles at both ends — going to bed late, getting up early, and somehow performing mentally with lack of adequate sleep,” said senior author Dr. Robert Greene, professor of psychiatry at UT Southwestern. “We need to have our adenosine receptors intact to do that.”

Adenosine receptors on nerve cells, including brain cells, are akin to docking points for the molecule adenosine. Adenosine levels increase in the brain with each hour of waking activity, and “docking” of the molecule with its receptor is shown in this study to help promote the slow-wave activity of sleep. Scientists have known that recovery from sleep deprivation involves not only an increase in sleep time, or rebound sleep, but also an elevation in this slow-wave activity.

To investigate how adenosine receptors and SWA might be linked, Dr. Greene and his team engineered mice that lacked a receptor to pair up with adenosine.

Sleep-restricted mice were kept awake by being placed on a moving treadmill. Researchers then electronically monitored sleep and waking activity of both normal and genetically engineered mice, including monitoring electronically the brain waves of the animals. The mice also traveled a maze with eight paths, each with a piece of chocolate at the end of it.

Electronic measurements showed that, unlike normal mice, the mice lacking the adenosine receptor could not increase the intensity of their slow-wave activity in response to the sleep deprivation. Under normal sleep conditions both the normal and mutant mice were almost error-free on the maze test. However, when sleep-deprived, the engineered mice made significantly more errors on the maze test than their normal counterparts. This type of skills test represents the human equivalent of the attention and working memory needed to multitask or build on tasks already done, such as being given a phone number, reaching for a pen to write it down and recalling the number, said Dr. Greene.

Linking the lack of functioning adenosine receptors to depressed normal SWA rebound response might aid in developing treatments for people with sleep-related cognitive deficits, he said.

The research also further explains the effects of caffeine, which also “docks” to adenosine receptors, preventing the docking of adenosine and keeping the caffeine-drinker awake. Dr. Greene compared the study mice’s behavior response on the maze test to how a person drinking a “permanent cup of coffee” might behave.

“They probably won’t get the regular amount of slow-wave activity or deep sleep as they normally would,” Dr. Greene said. “This is not to say that coffee is bad, but drinking it all the time or in the evening could affect your mental performance the next day.”

The researchers next will investigate the relationship between sleep, adenosine and energy metabolism, a biological process in which adenosine plays a key role.

Other researchers from UT Southwestern involved in the study were lead author Dr. Theresa Bjorness, postdoctoral research fellow in psychiatry, and Virginia Poffenberger, research technician in psychiatry.

The study was funded by the U.S. Department of Veterans Affairs and the National Institutes of Health.

LaKisha Ladson | EurekAlert!
Further information:
http://www.utsouthwestern.org/neurosciences
http://www.utsouthwestern.edu

More articles from Life Sciences:

nachricht The dense vessel network regulates formation of thrombocytes in the bone marrow
25.07.2017 | Rudolf-Virchow-Zentrum für Experimentelle Biomedizin der Universität Würzburg

nachricht Fungi that evolved to eat wood offer new biomass conversion tool
25.07.2017 | University of Massachusetts at Amherst

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>