Scientists discover the first real reason we need sleep:
Scientists report that the first major mechanical reason our brain needs sleep – certain cleaning mechanisms in the brain work better when we shut down the brain .
Similar to how dump trucks take to the streets of the city during the predawn hours, because there is less traffic , our brains cleaners also work better when there is less going on.
“This study shows that the brain has different functional states when asleep and when awake ,” said study researcher Maiken Nedergaard of the University of Rochester.
” In fact, the nature of restful sleep seems to be the result of active settlement of the byproducts of neuronal activity that accumulate during wakefulness. ”
We’ve known that our brain memories are consolidated during sleep and perform other important functions.
There are also benefits for the body during sleep – rest allows our muscles , bones and organs to repair themselves .
It also keeps our immune system healthy.
We know that sleep has all these benefits, but until now we did not know any of the specific changes that lead to these benefits of sleep .
All our cells accumulate while working residues and waste products can be toxic. If not removed they can accumulate and kill cells . Throughout the rest of the lymph system these waste products washed away the body, but the brain is cut from these actions because of the blood – brain barrier .
When the brain is asleep, the channels between the cells grow . This allows the fluid in the depths of the brain tissue to remove toxic proteins that accumulate during the day, including the kind that are responsible for neurodegenerative diseases like Alzheimer’s.
Pictured above , from Xie et . al in Science, shows that when mice sleep , the full ( pale blue ) liquid channels between neurons expand and flush out waste .