Sleep 'cleans' the brain by flushing out toxins

Scientists have discovered the brain has its own 'waste removal system' that carries out toxins as we sleep

The brain uses sleep to clean away waste toxins that have collected during the day, a new study has shown. 

The brain uses the time we spend asleep to remove all the waste that builds up when we are awake, much like a "garbage removal system", the US based scientists found.

A team at the University of Rochester Medical Center (URMC) for Translational Neuromedicine now believe this waste removal system is one of the fundamental reasons for why we sleep.

The study, published today in the journal Science, reveals that the brain’s unique method of waste removal also clears away toxins responsible for Alzheimer’s disease and other neurological disorders.

Scientists studied images of the brains of mice, looking at the brain 'plumbing system' used to transport waste material out of pipes while we sleep, known as the glymphatic system.

The glyphatic system was ten times more active when the mice were asleep, as opposed to when they were awake.

Researchers found that when asleep, the brain's cells reduce in size, making it easier for waste to be removed effectively.

To flush waste toxins out of the brain, cerebral spinal fluid (CSF) is pumped through the brain's tissue, where it makes its way into the blood circulation system before reaching the liver.

However, pumping CSF fluid requires a large supply of energy. Researchers speculated that the process of cleaning may not be compatible with the functions the brain must perform when awake and actively processing information.

Activity in the brain is much higher in the glymphatic system when it is asleep

Dr Maiken Nedergaard, lead author of the article explained: “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.

“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.”

The new findings have significant implications for treating  'dirty brain' diseases such as Alzheimer's,  Dr Nedergaard added.

 “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,” she said.

News
newsGlobal index has ranked the quality of life for OAPs - but the UK didn't even make it into the top 10
News
people
News
people
News
peopleStella McCartney apologises over controversial Instagram picture
PROMOTED VIDEO
Life and Style
Laid bare: the Good2Go app ensures people have a chance to make their intentions clear about having sex
techCould Good2Go end disputes about sexual consent - without being a passion-killer?
Arts and Entertainment
Richard Burr remains the baker to beat on the Great British Bake Off
tvRichard remains the baker to beat as Chetna begins to flake
News
i100
Sport
footballArsenal 4 Galatasaray 1: Wenger celebrates 18th anniversary in style
Arts and Entertainment
Amazon has added a cautionary warning to Tom and Jerry cartoons on its streaming service
tv
News
people
News
The village was originally named Llansanffraid-ym-Mechain after the Celtic female Saint Brigit, but the name was changed 150 years ago to Llansantffraid – a decision which suggests the incorrect gender of the saint
newsA Welsh town has changed its name - and a prize if you can notice how
News
ebooksAn unforgettable anthology of contemporary reportage
Arts and Entertainment
Kristen Scott Thomas in Electra at the Old Vic
theatreReview: Kristin Scott Thomas is magnificent in a five-star performance of ‘Electra’
News
Destructive discourse: Jewish boys look at anti-Semitic graffiti sprayed on to the walls of the synagogue in March 2006, near Tel Aviv
peopleAt the start of Yom Kippur and with anti-Semitism flourishing, one Jew can no longer ignore his identity
Life and Style
Couples who boast about their relationship have been condemned as the most annoying Facebook users
tech
Arts and Entertainment
Hayley Williams performs with Paramore in New York
musicParamore singer says 'Steal Your Girl' is itself stolen from a New Found Glory hit
News
i100
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Science Teacher

£100 - £110 per day: Randstad Education Group: Key stage 3 and 4 Teacher requi...

RE Teacher

£120 - £162 per day: Randstad Education Hull: Teacher of Religious Education ...

A Level Chemistry Teacher

£120 - £162 per day: Randstad Education Hull: A Level Chemistry Teacher - Humb...

NQT Secondary Teachers

£100 - £130 per day: Randstad Education Hull: Randstad Education is actively r...

Day In a Page

Italian couples fake UK divorce scam on an ‘industrial scale’

Welcome to Maidenhead, the divorce capital of... Italy

A look at the the legal tourists who exploited our liberal dissolution rules
Tom and Jerry cartoons now carry a 'racial prejudice' warning on Amazon

Tom and Jerry cartoons now carry a 'racial prejudice' warning on Amazon

The vintage series has often been criticised for racial stereotyping
An app for the amorous: Could Good2Go end disputes about sexual consent - without being a passion-killer?

An app for the amorous

Could Good2Go end disputes about sexual consent - without being a passion-killer?
Llansanffraid is now Llansantffraid. Welsh town changes its name, but can you spot the difference?

Llansanffraid is now Llansantffraid

Welsh town changes its name, but can you spot the difference?
Charlotte Riley: At the peak of her powers

Charlotte Riley: At the peak of her powers

After a few early missteps with Chekhov, her acting career has taken her to Hollywood. Next up is a role in the BBC’s gangster drama ‘Peaky Blinders’
She's having a laugh: Britain's female comedians have never had it so good

She's having a laugh

Britain's female comedians have never had it so good, says stand-up Natalie Haynes
Sistine Chapel to ‘sing’ with new LED lights designed to bring Michelangelo’s masterpiece out of the shadows

Let there be light

Sistine Chapel to ‘sing’ with new LEDs designed to bring Michelangelo’s masterpiece out of the shadows
Great British Bake Off, semi-final, review: Richard remains the baker to beat

Tensions rise in Bake Off's pastry week

Richard remains the baker to beat as Chetna begins to flake
Paris Fashion Week, spring/summer 2015: Time travel fashion at Louis Vuitton in Paris

A look to the future

It's time travel fashion at Louis Vuitton in Paris
The 10 best bedspreads

The 10 best bedspreads

Before you up the tog count on your duvet, add an extra layer and a room-changing piece to your bed this autumn
Arsenal vs Galatasaray: Five things we learnt from the Emirates

Arsenal vs Galatasaray

Five things we learnt from the Gunners' Champions League victory at the Emirates
Stuart Lancaster’s long-term deal makes sense – a rarity for a decision taken by the RFU

Lancaster’s long-term deal makes sense – a rarity for a decision taken by the RFU

This deal gives England a head-start to prepare for 2019 World Cup, says Chris Hewett
Ebola outbreak: The children orphaned by the virus – then rejected by surviving relatives over fear of infection

The children orphaned by Ebola...

... then rejected by surviving relatives over fear of infection
Pride: Are censors pandering to homophobia?

Are censors pandering to homophobia?

US film censors have ruled 'Pride' unfit for under-16s, though it contains no sex or violence
The magic of roundabouts

Lords of the rings

Just who are the Roundabout Appreciation Society?