Eli5: When we sleep, spinal fluid washes waste from our brain. What exactly is “waste” in the brain?
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(Edit: Yes this is not truly a 5 year old explanation but I hope I explained it enough that a high-school student can understand)
Basically some byproducts of metabolism that the brain makes throughout the day. Our nerve cells in the central nervous system use a lot of energy and have complex functions that arise from complicated metabolic processes. There are other cells in the brain called glial cells. Astrocytes are a type of glial cell that are the main supporters for nerve cells in the brain. They are very essential to proper nerve function and do a lot/most of the daily cleaning up throughout the day but there are still “waste” products from metabolism that are not taken care of. Although minor compared to what astroctyes and microglia do in the brain (maybe more important than what is recognized in the literature), this nightly cerebrospinal fluid can help to clear out some of these metabolites, remove potentially toxic molecules that impair brain function, and also potentially redistribute hormone and chemical messengers in the brain. It’s hard to research this though since tagging these molecules and proteins in the central nervous system for imaging is hard. But all in all, another reason why a good night’s sleep is important!
The “waste” in our brain is a protein, specifically a protein called “beta-amyloid”.
The name may sound funny but, if left uncleared, a build up of this protein can cause Alzheimer’s disease. There are studies that show a direct link between lack of sleep and a development of Alzheimer’s disease.
Source: https://www.nih.gov/news-events/nih-research-matters/sleep-deprivation-increases-alzheimers-protein
If you don’t get proper amounts of sleep, cerebrospinal fluid is unable to wash the beta-amyloid proteins from the brain. Source: https://www.nih.gov/news-events/nih-research-matters/how-sleep-clears-brain
More research is being done on the importance of this “washing” mechanism that happens during sleep. They’ve also found a new way to check for Lewy body diseases (such as Lewy body dementia) by sampling cerebrospinal fluid for those proteins. Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2965495/
Lewy body diseases are caused by a protein called “alpha-synuclein”. These proteins may also be “washed” away during sleep and end up in our cerebrospinal fluid which is why we’re able to check for them with a lumbar puncture.
Research is still being done in this area so we don’t have a whole picture idea of what’s actually going on. There may be more proteins and “waste” being “washed” away but scientists will have to test for each individual protein/waste.
Could there ever be a “rinse cycle” developed to help people who are struggling with this process?
Is it thought that the removing of some of this waste is what triggered certain dreams? I recall hearing that somewhere
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Sleep is a superpower. If I have good dreams I wake up energized. I have the best dreams on generic Wellbutrin single release (it’s an antidepressant) which I only take now and then. Doc have it to me to help quit smoking. He asked me later if it worked to stop smoking and I said no, but I’m not depressed about it anymore.
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one time I was half-awake during this process and I swear I could feel the cleaning cycle happening. so soothing. it was like r/powerwashingporn in the mind.
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