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Revealed: why we need a good night's sleep

Scientists warn of the dangers of sleepless nights after discovering how brain clears out day's mental rubbish

By Steve Connor, Science Editor

A video portrait of David Beckham sleeping, by the artist Sam Taylor-Wood, shown at the National Portrait Gallery

AP

A video portrait of David Beckham sleeping, by the artist Sam Taylor-Wood, shown at the National Portrait Gallery

To sleep, perchance to dream, said Hamlet. Now scientists have shown that sleep is more about getting rid of the previous day's mental rubbish than it is about dreaming.

A study into slumber has found that the nerve connections built up in the brain during a busy day are pruned back during the night in an attempt to keep the mind from overloading on junk information.

The findings lend support to the idea that a good night's sleep is essential for consolidating important memories of the previous day and getting rid of things that would otherwise clog up the system.

The researchers behind the study said the results showed how important it was for people to get a good night's sleep to be on top form the next day.

"Right now, a lot of people are worried about their jobs and the economy, and some are no doubt losing sleep over these concerns," said one of the authors, Paul Shaw, from the Washington University School of Medicine in St Louis.

"But these data suggest the best thing you can do to make sure you stay sharp and increase your chances of keeping your job is to make getting enough sleep a top priority."

The research was based on analysis of fruit flies. The scientists believe that these simple creatures are a good model of sleep in humans because, like people, flies need between six and eight hours a night and show physical and mental signs of deprivation if they fail to get enough.

Like humans, fruit flies exposed to a busy day's activities need more sleep. Those raised in crowded conditions sleep two or three hours longer than those kept in solitary confinement and flies that are kept active with "mental workouts" sleep longer than those that are not.

Previous studies had shown that sleep promotes learning and memory in animals. The latest research went further by showing that the connections (synapses) between nerve cells in the brain are built up during the day and are pruned after a good night's sleep, Professor Shaw said.

"There are a number of reasons why the brain can't indefinitely add synapses, including the finite spatial constraints of the skull. We were able to track the creation of new synapses in fruit flies during learning experiences, and to show that sleep pushed that number back down," he said.

The scientists kept the fruit flies in a specially designed "fly agitator" with a robot arm that occasionally shook the resting platforms for the flies to prevent them from sleeping. The scientists found physical changes in the brains of these sleep-deprived flies – specifically, a build-up of the proteins that connect one nerve cell to another.

When the scientists analysed the brains of the flies after they had slept, the level of these proteins had dropped, indicating that the nerve connections themselves had become weaker or even eliminated during the night.

"At the end of sleep, the strongest synapses shrink, while the weakest synapses may even disappear," said Chiara Cirelli, from the University of Wisconsin-Madison, another author of the study, published in Science.

"Much of what we learn in a day, we don't really need to remember," she said. "If you have used up all the space, you can't learn more before you clean out the junk that is filling up your brain."

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Comments

[info]iain39 wrote:
Friday, 3 April 2009 at 03:12 am (UTC)
Anyone with more than a few days experience of life on earth will already know that without proper sleep, the next day is a mess. The brain is clearly being managed and cleaned up in the night, and though the Dawkinists would insist this is random and uncontrolled, quite clearly it is not. If the world's best minds struggle to understand how the brain works, what kind of intelligence would be competent to maintain and upgrade it while we sleep?

Perhaps science will soon prove that poking ourselves in the eye is bad for vision, and that breaking an ankle is not, as was previously supposed, good for our health!
[info]l3enz0 wrote:
Friday, 3 April 2009 at 06:23 am (UTC)
Why would Dawkinists insist that ? In fact how have you managed to bring Dawkinists into this at all ? The only random thing here , is your comment .
(no subject) - [info]iain39 - Friday, 3 April 2009 at 08:27 am (UTC) Expand
(no subject) - [info]l3enz0 - Friday, 3 April 2009 at 08:38 am (UTC) Expand
Oi - [info]eetmyne - Friday, 3 April 2009 at 09:33 am (UTC) Expand
Re: Oi - [info]vhawk1951 - Friday, 3 April 2009 at 05:28 pm (UTC) Expand
(no subject) - [info]sara_sense - Friday, 3 April 2009 at 10:30 am (UTC) Expand
god - [info]khi3ar - Friday, 3 April 2009 at 10:54 am (UTC) Expand
Re: god - [info]sara_sense - Friday, 3 April 2009 at 11:41 am (UTC) Expand
Re: god - [info]vhawk1951 - Friday, 3 April 2009 at 05:02 pm (UTC) Expand
Re: god - [info]vhawk1951 - Friday, 3 April 2009 at 06:46 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 01:40 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 05:22 pm (UTC) Expand
House vs Earth - [info]matthewanew - Friday, 3 April 2009 at 05:22 pm (UTC) Expand
Re: House vs Earth - [info]vhawk1951 - Friday, 3 April 2009 at 06:03 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 05:34 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 06:40 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 04:30 pm (UTC) Expand
Sleep
[info]juliandbsmith wrote:
Friday, 3 April 2009 at 08:16 am (UTC)
Sleep is one of the most mysterious and strange things that animals and humans do. We don't know why because our bodies, minds (and that of fruit flies) are extremely complex. Taken a process at a time life's chemistry isn't necessarily mysterious but the interaction of biliions of processes is complex beyond current understanding. For those that don't understand why scientists seem to prove the obvious, nothing is taken for granted in good science. Everything has to be tested before being tied into evidence based knowledge. I fail to see why imagined miltant followers of Dawkin are being brought into this. If you believe in a God then this must be the way sleep works if you don't then this must be the way things are.

Evolution has really nothing to say about the non-existence or otherwise of a god, what is challenged is the reductionist reading of scripture based faith. Any belief system that focusses solely on scripture (Christian, Muslim or any other belief) is going to be challenged by reality. Scientific enquiry is about the investigation of reality, by definition it cannot be incompatible with faith. Scriptural revelation is accompanied by the evidence of our eyes and ears, if you believe in a rational and positive god then it is inconceivable that scripture will challenge reality.

At the time of writing the holy books had nothing explict to say about cars, mobile phones, or space travel and yet they exist and we use them. It is obvious that it is the interpretation of scripture and it's extension into areas of life where it has little meaning that is the issue. An extension of evolutionary theory into eugenics brought us the Nazi doctrines and its extension into Spencerian economics has brought us the horrors of the unrestrained free market. The invasion of fundumentalist primitive belief into all areas of life will bring us conflict and degrade learning and society to point of non function. We need learning and rationality, whereever it degrades, society crumbles, the evidence is right before us. Rampant fundumentalist beliefs; Nazi, Christian, Muslim or any other, taken to extreme will bring death and destruction.
Re: Sleep - [info]vhawk1951 - Friday, 3 April 2009 at 06:57 pm (UTC) Expand
Ridiculous
[info]nialltubes wrote:
Friday, 3 April 2009 at 08:37 am (UTC)
Yet again, the god-of-the-gaps argument. My poor little brain is too small to understand something so god must've dunnit. It's good we all don't think like that or we'd all still be living in caves cowering from lightning and praying to the sun.
[info]coruscator wrote:
Friday, 3 April 2009 at 04:02 pm (UTC)
Iain39 = Lord of the non-sequitur.

By the way, evolution by natural seletion is a NON-random process; otherwise, it wouldn't work, dickhead.
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 05:12 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 06:17 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Friday, 3 April 2009 at 07:35 pm (UTC) Expand
(no subject) - [info]coruscator - Saturday, 4 April 2009 at 02:25 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Saturday, 4 April 2009 at 02:48 pm (UTC) Expand
(no subject) - [info]coruscator - Saturday, 4 April 2009 at 03:49 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Saturday, 4 April 2009 at 04:13 pm (UTC) Expand
(no subject) - [info]coruscator - Saturday, 4 April 2009 at 04:49 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Saturday, 4 April 2009 at 04:56 pm (UTC) Expand
(no subject) - [info]coruscator - Saturday, 4 April 2009 at 05:08 pm (UTC) Expand
(no subject) - [info]vhawk1951 - Saturday, 4 April 2009 at 05:17 pm (UTC) Expand
(no subject) - [info]coruscator - Saturday, 4 April 2009 at 05:48 pm (UTC) Expand
[info]vhawk1951 wrote:
Friday, 3 April 2009 at 06:37 pm (UTC)
now why did you go and poke that bear?
[info]tonysmyth wrote:
Friday, 3 April 2009 at 04:20 am (UTC)
Quote: If the world's best minds struggle to understand how the brain works, what kind of intelligence would be competent to maintain and upgrade it while we sleep?

Flawed logic in that sentence.
[info]dootster wrote:
Friday, 3 April 2009 at 05:28 am (UTC)
A good night's sleep is good for the brain.

Who'd have thunk it?!
Still, something missing
[info]jwoji wrote:
Friday, 3 April 2009 at 06:50 am (UTC)
If this were entirely true, then people - and there are more than a handful - who remember absolutely everything they have experienced every day, would, apparently, physically explode. Anyone hear a story like that, lately? What is probably happening is our brain is re-prioritizing the memories, perhaps even - through what we are measuring/perceiving as a synapse decrease - redirecting those memories to another area in the brain we have not yet determined. To support this a little further, many people who are hypnotized can remember minor details from daily activities from decades ago. Also, catalysts to our memories, such as smells, can bring up past details that would be otherwise forever suppressed (but apparently not truly forgotten).
God's work interrupted by fly agitator
[info]prof_use wrote:
Friday, 3 April 2009 at 07:09 am (UTC)
Mental downtime or sleep evolved hundreds of millions of years ago in common ancestors and evolutionary pressure has preserved it as it is beneficial. This is not random and uncontrolled. Why does anyone look for a complicated and unnecessary super-being to be making nightly interventions in all brains of all animals? What a stupid god it would be to have to go round to hundreds of billions of fruit flies and clean up their brains every night. What a silly god it would be that would have his or her work interrupted by a 'fly agitator'. Can't you see how irrational this is?

Who previously supposed breaking an ankle was good for health?
Re: God's work interrupted by fly agitator
[info]sara_sense wrote:
Friday, 3 April 2009 at 09:14 am (UTC)
I think they imagine God, much like the BFG, coming round to our rooms every night and giving us little dreams in order to clear out all the nonsense our silly little brains think about every day.

How the god squad have managed to make this about God is quite bizarre. Their self confessed teeny tiny brains with minimal intellect and comprehension logically inferring that God exists 'because we dream' is blasphemy in the highest order.
Re: God's work interrupted by fly agitator - [info]karachi747 - Friday, 3 April 2009 at 11:39 am (UTC) Expand
Re: God's work interrupted by fly agitator - [info]rmcbride05 - Friday, 3 April 2009 at 01:01 pm (UTC) Expand
Re: God's work interrupted by fly agitator - [info]vhawk1951 - Friday, 3 April 2009 at 04:15 pm (UTC) Expand
Re: God's work interrupted by fly agitator - [info]vhawk1951 - Friday, 3 April 2009 at 06:44 pm (UTC) Expand
8 hours for less for adults
[info]famulla wrote:
Friday, 3 April 2009 at 07:14 am (UTC)
To date the science is baffled about the sleep and the dreams. The baldness and the Indian medicine men.
I think you win. To my knowledge and I am none of the above, we need 8 hours under the ages of 25 to 35, more for the kids say 10 and 5 hours above the 50 years. These are the prescribed hours my granny who lived to 104.
I thank you
Firozali A. Mulla
Re: 8 hours for less for adults
[info]eskimokate wrote:
Friday, 3 April 2009 at 10:16 am (UTC)
Thank-you Firozali. You didn't mention how much sleep 35-50 years olds need. Can you elucidate?
Re: 8 hours for less for adults - [info]famulla - Friday, 3 April 2009 at 12:34 pm (UTC) Expand
so whats new?
[info]jaffgyp wrote:
Friday, 3 April 2009 at 08:27 am (UTC)
so whats new- i seem to recall all this stuff being examined years ago?
Sleep
[info]ollyiris wrote:
Friday, 3 April 2009 at 10:31 am (UTC)
If sleep clears out junk information from our brains, and retains the important stuff, by what unconscious process is this done - by an homunculus perhaps? And by what criteria is importance determined? "My mind let's go a thousand things, like dates of wars and deaths of kings. And yet recalls the very hour... the wind shook listlessly... two petals from that wild-rose tree." (Thomas Bailey Aldrich.)
Re: Sleep
[info]rmcbride05 wrote:
Friday, 3 April 2009 at 01:08 pm (UTC)
Importance is subjective surely? That's why I always forget things that are important to others - birthdays, tasks that need doing, names - but not things important to myself - when someone has offended me by mistake or when its my birthday.

Perhaps it is more interesting to ask exactly what a memory is? Is it a "fact" or is it a smell, an image or taste?! For I often remember the most pointless things at random times which appear to have to relation to anything else. But I am not a philosopher so I will leave these questions to soeone else...
now i understand !!!!!!!!!!!!
[info]laserdent wrote:
Friday, 3 April 2009 at 10:38 am (UTC)
so the mystery is solved why after sex the male often falls into a deep happy sleep and in the morning doesnt remember her name
Flies
[info]checkoutexodus wrote:
Friday, 3 April 2009 at 10:44 am (UTC)
Yes, if it's true for flies it must be true for humans, I've heard that flies' minds are actually more complex than a humans.
[info]eurolinguist wrote:
Friday, 3 April 2009 at 12:25 pm (UTC)
So scientists have found out that sleep is important! Whatever next!
[info]rjd8 wrote:
Friday, 3 April 2009 at 12:58 pm (UTC)
What a load of tripe! "If you have used up all the space?" It is well known that short-term memory is severely restricted but no-one has yet established the limits of long-term memory.

And the brain architecture of a fruit fly may be similar to that of the average Labour minister, but I don't accept that the findings extend to the rest of us.
[info]vhawk1951 wrote:
Friday, 3 April 2009 at 06:50 pm (UTC)
i like that- good one:)
Waste of Time
[info]heniasia wrote:
Friday, 3 April 2009 at 01:32 pm (UTC)
I think scientists do waste other people time by publishing such articles in Science journal! I agree with iain39 that the subject is know to the Arab Boudins in the desert thousands of years before even SCIENCE magazine has evolved! They know sleeping clear the brain from daily work rubbish!
[info]pixi_ditzy wrote:
Friday, 3 April 2009 at 01:51 pm (UTC)
You know, reading these comments (well, some of them!) and ones on other articles, i've found that a lot of people who comment on here are very decided in their views. I thought the whole point was to explore the ideas not force your own down other people's throats crudely. I mean, could there not be a less antagonistic way of conveying your thoughts and beliefs. Because surely, as adults, we should all be respectful and open to different ideas. I myself find it difficult to do this sometimes, I'm not being holier than thou but it just seems a shame that some very deep and interesting debates could come out of this but instead people get angry because the other person does not share their view. I have my own views and believe in them firmly but I don't expect other people to believe them too, even when i explain the reasoning behind them because they believe something different.

You probably don't care what an 18 year old girl has to say (most people don't) but I was just so struck by the attacking nature of some of these comments. I'm sorry if i have offended anyone! I was just intrigued, me being a young girl who still has to experience the world! :)
[info]karachi747 wrote:
Friday, 3 April 2009 at 02:59 pm (UTC)
spot on
(no subject) - [info]janebolacha - Friday, 3 April 2009 at 03:10 pm (UTC) Expand
When no-one else will listen or is interested... - [info]tallise - Saturday, 4 April 2009 at 10:10 am (UTC) Expand
Hear, hear! - [info]tallise - Saturday, 4 April 2009 at 10:01 am (UTC) Expand
[info]mede_hincha wrote:
Friday, 3 April 2009 at 02:03 pm (UTC)
Its funny how you people argue about what god is or isnt. God above all else it must be observed and sought in all things. he is not an intellectual exercise it must be experience hence, seek and ye shall find, but you have to believe that you will find it and he is relative to you so only you may be able to see his/its workings. There is no codifying it, there is no limiting it to say its "love" because that is like taking a snap shot of something that is supposed to be infinite which is by definition not capturable by finite concepts. The essential human condition is to constatntly re-examine old thing in new ways constantly progressing and changing our world by changing the way we conceive of it and in that way we are extensions of "god," infinite in our ability to change and adapt to this emergent system to address issues in the best way possible. That is why religion and politics and all these other static systems can never work for long periods of time, because their purpose is not to be efficient for the greater good. but instead to maintain their postions of relative power. What is so bad about the monetary system is that it channel's the human ability to channel "faith" (monetary system) into inhuman, oppressive and regressive ideas, instead of focusing on things that would actually civilize humanity. how do you prove something that is relative anyway?...i guess it depends...
[info]sara_sense wrote:
Friday, 3 April 2009 at 02:47 pm (UTC)
When you say 'you people' I take it you mean 'us people' as you chastise for arguing about what god is (or isn't) and then proceed to tell us what it is and where to find it?!

"What is so bad about the monetary system is that it channel's the human ability to channel "faith" (monetary system) into inhuman, oppressive and regressive ideas" - I guess like any other organised religion then?! ;-)

(no subject) - [info]mede_hincha - Friday, 3 April 2009 at 04:14 pm (UTC) Expand
it doesn't work for Gollum Brown
[info]vhawk1951 wrote:
Friday, 3 April 2009 at 04:27 pm (UTC)
his mental rubbish seems to stick to him like glue
God!
[info]delphicvi wrote:
Friday, 3 April 2009 at 05:41 pm (UTC)
Do fruit flies believe in God?
Re: God!
[info]vhawk1951 wrote:
Friday, 3 April 2009 at 07:42 pm (UTC)
and to sum up:, that about wraps it up for god then

everyone happy now?

you should be- you've all managed to annoy one another no end

me I found it dead entertaining
Revealed: why we need a good night's sleep
[info]kevinbeach wrote:
Saturday, 4 April 2009 at 12:08 am (UTC)
And this is a new discovery? !

Did somebody get paid money for reiterating the wisdom of the ages as though he had invented it?
Back to the dark ages
[info]trymriverman wrote:
Saturday, 4 April 2009 at 01:15 pm (UTC)
An interesting article and the more we find out about how things work the more we'll benefit from medical advances etc. Most intelligent people are naturally curious to know about these things. What a pity though that there is such a small bunch of non-progressive deadbeats who insist on aggressively parading their mindless & superstitious ignorance on these pages. They have never had anything to offer - they are a complete waste of space.