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

Video Positive Messaging Helps Revamp Ethiopia's Image

In country once connected with war, poverty, famine, headlines now focus on fast-growing economy, diplomatic reputation More

Russian Activist Thinks Kremlin Ordered Nemtsov's Death

Alexei Navalny says comments of Russian liberals who think government wasn't involved are 'nonsense.' More

Video Land Disputes Rise Amid Uganda Oil Boom

Investors appear to be cashing in by selling parcels of land to multiple buyers 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.
Positive Messaging Transforms Ethiopia's Imagei
X
Marthe van der Wolf
March 03, 2015 9:03 PM
Ethiopia was once known for famine and droughts. Now, headlines more often point to its fast-growing economy and its emergence as a regional peacemaker. How has Addis Ababa changed the narrative? VOA's Marthe van der Wolf reports.
Video

Video Positive Messaging Transforms Ethiopia's Image

Ethiopia was once known for famine and droughts. Now, headlines more often point to its fast-growing economy and its emergence as a regional peacemaker. How has Addis Ababa changed the narrative? VOA's Marthe van der Wolf reports.
Video

Video Cyber War Rages Between Iran, US

A newly published report indicates Iran and the United States have increased their cyber attacks on each other, even as their top diplomats are working toward an agreement to guarantee Iran does not develop a nuclear weapon and to free Iran from international sanctions. The development is part of a growing global trend. VOA’s Al Pessin reports from London.
Video

Video Answers Elude Families of MH370 Passengers

For the families on board Malaysia Airlines flight MH370, an airline official’s statement nearly one year ago that the plane had lost contact with air traffic control at 2:40 AM is the only thing that remains confirmed. William Ide reports.
Video

Video Land Disputes Arise Amid Uganda Oil Boom

Ugandan police say there has been a sharp increase in land disputes, with 10 new cases being reported each day. The claims come amid an oil boom as investors appear to be cashing in by selling parcels of land to multiple buyers. Meanwhile, the people who have been living on the land for decades are chased away, sometimes with a heavy hand. VOA's Serginho Roosblad reports.
Video

Video In Russia, Many Doubt Opposition Leader's Killer Will Be Found

The funeral has been held in Moscow for Boris Nemtsov, the opposition leader who was assassinated late Friday just meters from the Kremlin. Nemtsov joins a growing list of outspoken critics of Russia under the leadership of President Vladimir Putin who are believed to have been murdered for their work. VOA’s Daniel Schearf reports from Moscow.
Video

Video Simulated Astronauts Get Taste of Mars, in Hawaii

For generations, people have dreamed of traveling to Mars to explore Earth's closest planetary neighbor. VOA's Mike O'Sullivan reports that while space agencies like NASA are planning manned missions to the planet, some volunteers in Hawaii are learning how humans will cope with months in isolation on a Mars base.
Video

Video Destruction of Iraq Artifacts Shocks Archaeologists

The city of Mosul was once one of the most culturally rich and religiously diverse cities in Iraq. That tradition is under attack by members of the Islamic State who have made Mosul their capital city. The Mosul Museum is the latest target of the group’s campaign of terror and destruction, and is of grave concern to archaeologists around the world. VOA’s Kane Farabaugh reports.
Video

Video Smartphones May Help in Diagnosing HIV

Diagnosing infections such as HIV requires expensive clinical tests, making the procedure too costly for many poor patients or those living in remote areas. But a new technology called lab-on-a-chip may make the tests more accessible to many. VOA’s George Putic reports.
Video

Video Afghan Refugees Complain of Harassment in Pakistan

Afghan officials have expressed concern over reports of a crackdown on Afghan refugees in Pakistan following the Peshawar school attack in December. Reports of mass arrests and police harassment coupled with fear of an uncertain future are making life difficult for a population that fled its homeland to escape war. VOA’s Ayesha Tanzeem reports from Islamabad.
Video

Video Ukrainian Volunteers Prepare to Defend Mariupol

Despite the ongoing ceasefire in Ukraine, soldiers in the city of Mariupol fear that pro-Russian separatists may be getting ready to attack. The separatists must take or encircle the city if they wish to gain land access to Crimea, which was annexed by Russia early last year. But Ukrainian forces, many of them volunteers, say they are determined to defend it. Patrick Wells reports from Mariupol.
Video

Video Moscow Restaurants Suffer in Bad Economy, Look for Opportunity

As low oil prices and Western sanctions force Russia's economy into recession, thousands of Moscow restaurants are expected to close their doors. Restaurant owners face rents tied to foreign currency, while rising food prices mean Russians are spending less when they dine out. One entrepreneur in Moscow has started a dinner kit delivery service for those who want to cook at home to save money but not skimp on quality. VOA's Daniel Schearf reports.
Video

Video Presidential Hopefuls Battle for Conservative Hearts and Minds

One after another, presumptive Republican presidential contenders auditioned for conservative support this week at the Conservative Political Action Conference held outside Washington. The rhetoric was tough as a large field of potential candidates tried to woo conservative support with red-meat attacks on President Barack Obama and Democrats in Congress. VOA Political Columnist Jim Malone takes a look.
Video

Video Southern US Cities Preserve Civil Rights Heritage to Boost Tourism

There has been a surge of interest in the American civil rights movement of the 1950s and '60s, thanks in part to the Hollywood motion picture "Selma." Five decades later, communities in the South are embracing the dark chapters of their past with hopes of luring tourism dollars. VOA's Chris Simkins reports.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More