Featured Research

from universities, journals, and other organizations

Molecule Helps Sleep-deprived Rebound Mentally

Date:
February 25, 2009
Source:
UT Southwestern Medical Center
Summary:
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, researchers have identified a key molecular mechanism that regulates the brain's ability to compensate mentally for sleep deprivation.

Dr. Robert Greene.
Credit: Image courtesy of UT Southwestern Medical Center

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.


Story Source:

The above story is based on materials provided by UT Southwestern Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Theresa E. Bjorness, Christine L. Kelly, Tianshu Gao, Virginia Poffenberger, and Robert W. Greene. Control and Function of the Homeostatic Sleep Response by Adenosine A1 Receptors. Journal of Neuroscience, 2009; 29 (5): 1267 DOI: 10.1523/JNEUROSCI.2942-08.2009

Cite This Page:

UT Southwestern Medical Center. "Molecule Helps Sleep-deprived Rebound Mentally." ScienceDaily. ScienceDaily, 25 February 2009. <www.sciencedaily.com/releases/2009/02/090224132908.htm>.
UT Southwestern Medical Center. (2009, February 25). Molecule Helps Sleep-deprived Rebound Mentally. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2009/02/090224132908.htm
UT Southwestern Medical Center. "Molecule Helps Sleep-deprived Rebound Mentally." ScienceDaily. www.sciencedaily.com/releases/2009/02/090224132908.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins