News / Health

Sleep Cleanses Brain of Waste, Study Says

Study Shows Sleep Helps Keep Brains Healthyi
X
October 21, 2013 10:19 PM
Why do we need sleep? Scientists have found a possible answer to this age-old question. And, as VOA's Carol Pearson reports, the answer may lead to new treatments for neurological disorders such as Alzheimer's or Parkinson's disease.
Related report by Carol Pearson

Related Articles

Global Rise in Dementia Creates Caregiver Shortage

Report says number of old people dependent on care as a result of mind-robbing Alzheimer's disease is set to hit 277 million by 2050

Peanut Butter Sniff Test Could Diagnose Alzheimer's

Smell sensitivity can be one of the first things to be affected in cognitive decline
VOA News
While we’re asleep, our brains are doing more than recharging for the next day.  They’re also tidying up, using a cleaning process scientists hope could lead to treatments for ‘dirty brain’ diseases like Alzheimer’s.

Sleep can flush toxins from the brain that accumulate during the course of the day according to a study which may change understanding about the biological purpose of sleep.

“This study shows that the brain has different functional states when asleep and when awake,” said Maiken Nedergaard, M.D., D.M.Sc., co-director of the University of Rochester Medical Center (URMC) Center for Translational Neuromedicine and lead author of the article. “In fact, the restorative nature of sleep appears to be the result of the active clearance of the by-products of neural activity that accumulate during wakefulness.”

Researchers said the study revealed that the brain’s unique method of waste removal – dubbed the glymphatic system – is highly active during sleep, clearing away toxins responsible for Alzheimer’s disease and other neurological disorders. Furthermore, the researchers found that during sleep the brain’s cells reduce in size, allowing waste to be removed more effectively.

Since the lymphatic system, which is responsible for disposing cellular waste from the rest of the body, does not extend to the brain, scientists had long puzzled about how the brain cleaned itself.

Using two-photon miscroscopy to study mice brains, the researchers discovered what they call a “plumbing system that “piggybacks” on the brain’s blood vessels and pumps cerebral spinal fluid (CSF) through the brain’s tissue, flushing waste back into the circulatory system and onto the liver for filtering.

The accumulation of waste in the brain can lead to diseases such as Alzheimer’s disease.

The researchers said that since pumping CSF demands a great deal of energy, it might perhaps be better to do it when the brain is not occupied with processing information during waking hours

“The brain only has limited energy at its disposal and it appears that it must choice between two different functional states – awake and aware or asleep and cleaning up,” said Nedergaard. “You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can’t really do both at the same time.”

Researchers also found that cells in the brain “shrink” by 60 percent during sleep. They said the contraction allows more space between the cells, which allows the CSF to flow through more freely.

“These findings have significant implications for treating ‘dirty brain’ disease like Alzheimer’s,” said Nedergaard. “Understanding precisely how and when the brain activates the glymphatic system and clears waste is a critical first step in efforts to potentially modulate this system and make it work more efficiently.”

The study was published in the journal Science.

Here's a short video on the findings:

You May Like

Tired of Waiting, South Africans Demand Change ‘Now’

With chronic poverty and lack of basic services largely fueling recent xenophobic attacks, many in Rainbow Nation say it’s time for government to act More

Challenges Ahead for China's Development Plans in Pakistan

Planned $46 billion in energy and infrastructure investments in Pakistan are aimed at transforming the country into a regional hub for trade and investment More

'Forbidden City' Revisits Little Known Era of Asian-American Entertainment

Little-known chapter of entertainment history captured in 80s documentary is revisited in new digitally remastered format and book More

This forum has been closed.
Comment Sorting
Comments
     
by: PermReader
October 23, 2013 9:19 AM
Other researchers were interested in the intellectual functions of the sleeping brain, so it looked strange - the sleep of the brainless insects.

by: Yoshi from: Sapporo
October 21, 2013 4:48 AM
Interesting story! We spend almost one third of the whole life span in sleep so that it has good reason anyone is interested in the purpose of sleep. It is usual that the older ppl get, the shorter sleeping time becomes. It would be the cause of senile dementia with the accumulation of β-amyloid due to its decreased clearance in brain. Thank you.

by: Onifade, 'Muyiwa from: Nigeria
October 20, 2013 5:47 PM
Really, sleep is very good for healthy condition of the entire body whose brain is the remote control.

by: Ramnarayan from: Florida, USA
October 20, 2013 4:00 PM
This is amaziing. All tissues need a cleaning/ detoxification mechanism. For the brain it has been a challenge to document this. The current generation science and technology seems to hold lot of clues to life. As a scientist and an educator, I am thrilled to see VOA actively put such stories in the limelight.
Contrary to to an another writter, this is not a sham. To take such an attitutde over a scientific discovery is crude. Let us look at this observation for what it is; the secrets of brain untangled.

by: jam from: snapper
October 18, 2013 6:01 PM
Purge the waste from TV. Movies. video games. newspapers. Hollywood trash.rap music and politics.

by: Dr. Barry Marr from: USa
October 18, 2013 4:18 PM
As long as our so-called "government" is putting FLUORIDE in the tap water, and MERCURY in all the vaccines, and GMO in the foods, one only needs to read the comment in the article re how "pollution causes cancer" to know that, this article is a sham, and that cancer and cognitive disorders are manufactured by our own government eugenics monsters. Time to wake up people.

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Cinema That Crosses Borders Showcased at Tribeca Film Festivali
X
April 24, 2015 4:09 AM
Among the nearly 100 feature length films being shown at this year’s Tribeca Film Festival in New York City are more than 20 documentaries and features with international appeal, from a film about a Congolese businessman in China, to documentaries shot in Pakistan and diaspora communities in the U.S., to a poetic look at disaffected South African youth. VOA’s Carolyn Weaver has more.
Video

Video Cinema That Crosses Borders Showcased at Tribeca Film Festival

Among the nearly 100 feature length films being shown at this year’s Tribeca Film Festival in New York City are more than 20 documentaries and features with international appeal, from a film about a Congolese businessman in China, to documentaries shot in Pakistan and diaspora communities in the U.S., to a poetic look at disaffected South African youth. VOA’s Carolyn Weaver has more.
Video

Video UN Confronts Threat of Young Radicals

The radicalization and recruitment of young people into Islamist extremist groups has become a growing challenge for governments worldwide. On Thursday, the U.N. Security Council heard from experts on the issue, which has become a potent threat to international peace and security. VOA’s Margaret Besheer reports.
Video

Video Growing Numbers of Turks Discover Armenian Ancestry

In a climate of improved tolerance, growing numbers of people in Turkey are discovering their grandmothers were Armenian. Hundreds of thousands of Armenians escaped the mass deportations and slaughter of the early 1900's by forced conversion to Islam. Or, Armenian children were taken in by Turkish families and assimilated. Now their stories are increasingly being heard. Dorian Jones reports from Istanbul that the revelations are viewed as an important step.
Video

Video Migrants Trek Through Western Balkans to Reach EU

Migrants from Africa and other places are finding different routes into the European Union in search of a better life. The Associated Press followed one clandestine group to document their trek through the western Balkans to Hungary. Zlatica Hoke reports that the migrants started using that route about four years ago. Since then, it has become the second-most popular path into Western Europe, after the option of sailing from North Africa to Italy.
Video

Video TIME Magazine Honors Activists, Pioneers Seen as Influential

TIME Magazine has released its list of celebrities, leaders and activists, whom it deems the world’s “most influential” in 2015. VOA's Ramon Taylor reports from New York.
Video

Video US Businesses See Cuba as New Frontier

The Obama administration's opening toward Cuba is giving U.S. companies hope they'll be able to do business in Cuba despite the continuation of the U.S. economic embargo against the communist nation. Some American companies have been able to export some products to Cuba, but the recent lifting of Cuba's terrorism designation could relax other restrictions. As VOA's Daniela Schrier reports, corporate heavy hitters are lining up to head across the Florida Straits - though experts urge caution.
Video

Video Kenya Launches Police Recruitment Drive After Terror Attacks

Kenya launched a major police recruitment drive this week as part of a large-scale effort to boost security following a recent spate of terror attacks. VOA’s Gabe Joselow reports that allegations of corruption in the process are raising old concerns about the integrity of Kenya’s security forces.
Video

Video Japan, China in Race for Asia High-Speed Rail Projects

A lucrative competition is underway in Asia for billions of dollars in high-speed rail projects. Cambodia, India, Indonesia, Malaysia Thailand and Vietnam are among the countries planning to move onto the fast track. They are negotiating with Japan and the upstart Chinese who are locked in a duel to revolutionize transportation across Asia. VOA Correspondent Steve Herman in Bangkok has details.
Video

Video Scientists: Mosquitoes Attracted By Our Genes

Some people always seem to get bitten by mosquitoes more than others. Now, scientists have proved that is really the case - and they say it’s all because of genes. It’s hoped the research might lead to new preventative treatments for diseases like malaria, as Henry Ridgwell reports from London.
Video

Video Bible Museum Coming to Washington DC

Washington is the center of American political power and also home to some of the nation’s most visited museums. A new one that will showcase the Bible has skeptics questioning the motives of its conservative Christian funders. VOA religion correspondent Jerome Socolovsky reports.
Video

Video Armenia and Politics of Word 'Genocide'

A century ago this April, hundreds of thousands of Armenians of the Turkish Ottoman empire were deported and massacred, and their culture erased from their traditional lands. While broadly accepted by the U.N. and at least 20 countries as “genocide”, the United States and Turkey have resisted using that word to describe the atrocities that stretched from 1915 to 1923. But Armenians have never forgotten.
Video

Video Afghan First Lady Pledges No Roll Back on Women's Rights

Afghan First Lady Rula Ghani, named one of Time's 100 Most Influential, says women should take part in talks with Taliban. VOA's Rokhsar Azamee has more from Kabul.
Video

Video Keeping Washington Airspace Safe Is Tall Order

Being the home of all three branches of the U.S. federal government makes Washington, D.C. the prime target for those who want to make their messages and ideas heard. Unfortunately, many of them choose to deliver them in unorthodox ways, including from the air, as a recent incident clearly showed involving a gyrocopter landing on the Capitol’s West Lawn. VOA's George Putic has more.
Video

Video New Brain Mapping Techniques Could Ease Chronic Pain

From Boulder, Colorado, Shelley Schlender reports that new methods for mapping pain in the brain are providing validation for chronic pain and might someday guide better treatment.
Video

Video Hope, Prayer Enter Fight Against S. Africa Xenophobia

South Africa has been swept by disturbing attacks on foreign nationals. Some blame the attacks on a legacy of colonialism, while others say the economy is to blame. Whatever the cause, ordinary South Africans - and South African residents from around the world - say they're praying for the siege of violence to end. Anita Powell reports from Johannesburg.

VOA Blogs