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What Does Your Brain Do While You Are Sleeping?

Have you ever heard some ersatz over-achiever say, “sleep is over-rated”? He was wrong. If anything, sleep is underrated. There is abundant research to prove it. Like a lot of other stuff, we’ve learned what lack of sleep can do the hard way by not getting enough of it.

You’ll Get a Dirty Brain if You Don’t Sleep Enough
Dr. Maiken Nedergaard and associates at the University of Rochester Medical Center discovered a system that drains waste from the brain. While we sleep of course. Surrounding our spinal column and brain is cerebrospinal fluid. This clear fluid flows through channels in the brain, and the channels are controlled by glial cells. While we sleep, the glial cells move the fluid around and, among other things, it seems to remove beta-amyloid from brain tissue. If “beta-amyloid” rings a bell, it’s because some researchers think it is involved in Alzheimer’s disease. We clearly want that to be removed. If we don’t get sufficient sleep, we are letting the sludge build up.
More bad news: according to a Harvard study, after a short period of sleep deprivation, longer sleep (e.g.-10 hours) helps recovery. But sustained stretches of reduced time of sleep, say, for shift workers who have a hard time sleeping during the day, can’t be offset by a period of longer sleep. From the report abstract: “Thus, the extended wake during the circadian night reveals the cumulative detrimental effects of chronic sleep loss on performance, with potential adverse health and safety consequences”.

Your Memory Won’t Be Very Good Either
A research paper from the Department of Radiology at Brigham and Women’s Hospital, Harvard Medical School in Boston, published in Nature Neuroscience reported: “Evidence indicates that sleep after learning is critical for the subsequent consolidation of memory.”
The paper went on to say:
These results demonstrated that an absence of prior sleep substantially compromises the neural and behavioral capacity for committing new experiences to memory. It therefore appears that sleep before learning is critical in preparing the human brain for next-day memory formation-a worrying finding considering society’s increasing erosion of sleep time.
There is a lot of complexity around how the brain stores and retrieves memories. But adequate sleep is clearly involved.

It Just Gets Worse
And from Dr. JoAnn Manson, “We know that getting adequate sleep is linked to a lower risk of having diabetes, insulin resistance, obesity, cardiovascular disease, and even stress and depression”.

You Are a Diurnal Circadian
Humans are circadian. That is, we operate on twenty-four hour cycles. That is generally true even if there is no light; however, our systems work a whole lot better when we are exposed to light at the right time.
We are also diurnal-active during the day. To get the circadian “rhythms” set correctly, exposure to sunlight in the morning to wake us up, and then darkness to make us sleepy’. There are some other artificial lights that do a good job of awakening us as well. Similarly, to get our body clocks set on the right circadian time, we need darkness.
Summary: our brains are busy while we sleep with cleaning and maintenance, memory organization, and regulation of other body systems. There aren’t any sleep shortcuts – we need seven or more hours; infants, children and teenagers even more.
In our next blog post, we’ll provide some tips on getting a good night’s sleep.

From our book The Big Brain Place Guide to a Better Brain, coming this fall. offers a variety of merchandise to help build better brains.



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