12 ms·

Brains Sweep Themselves Clean of Toxins During Sleep (2013)

445 points by Practicality 11y ago

alexholehouse 11y ago
Related discussion from a few weeks ago; https://news.ycombinator.com/item?id=9895094 https://news.ycombinator.com/item?id=9895094
david_shaw 11y ago
The engineer in me has to wonder: is this something we can synthesize? If it were possible to induce this "dishwasher-like" surge of cerebrospinal fluid in the brain during waking hours, would we be able to live off of significantly less (or no) sleep? I'm not saying that it's necessarily a good idea, but it would have a plethora of practical applications -- pilots, truckers, etc. would be able to stay awake in a healthful way, rather than by ingesting stimulants. I've been interested in the science of sleep for a while -- I wrote a side project, http://sleepyti.me http://sleepyti.me, that actually gets quite a bit of traffic -- but neuroscience is mostly lost on me.
- Practicality 11y ago
  A quote from the article: "It's probably not possible for the brain to both clean itself and at the same time [be] aware of the surroundings and talk and move and so on," So it would be the equivalent of a forced sleep, since you can't be conscious at the same time, but that might still be useful.
  - mmastrac 11y ago
    Perhaps we could do a half-brain sleep like Dolphins? https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep
    - jotm 11y ago
      I wonder how cognitive functions and our personality would be affected? Two halfs make a whole, yin and yang and all that, if half the brain is asleep, would we even be able to think straight?
      - vorg 11y ago
        Maybe that can be the 8 hours a day people do their office jobs.
      - fixermark 11y ago
        So the tradeoff might be that you can operate while half your brain is asleep, but your coworkers might think you're acting a bit crazy? (Not sure precisely how different that is from the experience of most office workers ;) ).
      - qiqing 11y ago
        Hemispherectomy (removal of one half of the brain) is a treatment for Rasmussen's encephalitis when it's sufficiently severe (or the seizures are not responding to drugs). If done very early in life, the plasticity of brain makes it such that those patients grow up to be normally functioning adults. We believe this is because the regions that specialize for different tasks are able to combine their function on the same half. Think of, for instance, the "language" areas (Broca's area and Wernicke's area). (The following over-simplified explanation assumes typical right-hand dominant individuals for the sake of brevity.) If you inactivate that area in the left hemisphere (using drugs or transcranial magnetic stimulation), you'll lose "language" processing of data that occurs around 1 Hz (in English, this corresponds to individual words, phonemes; in tonal languages, this includes tones of lexical significance). If you inactivate that area in the right hemisphere instead, you'll lose "language" processing of data that occurs an order of magnitude slower than that (in most languages, this corresponds to pitch and volume changes over the level of the sentence, and can convey prosody information such as speaker intent as well as speaker identity). Due to specializations like this, hemispherectomies are not performed later in life. You would get symptoms similar to stroke patients. But for all areas, not just language.
  - zardo 11y ago
    Sleep has been shown to be a factor in learning, so functions that happen during sleep could be related to learning disabilities. So yeah, being able to induce this state might be very useful for treating some conditions.
  - vidarh 11y ago
    If we could accelerate the process and/or control duration and/or induce it at will it would have major implications even if we're unable to remove the need to sleep fully.
- ksenzee 11y ago
  "The team discovered that this increased flow was possible in part because when mice went to sleep, their brain cells actually shrank, making it easier for fluid to circulate. When an animal woke up, the brain cells enlarged again and the flow between cells slowed to a trickle." So no, probably not.
  - amelius 11y ago
    I can't help but wonder if perhaps "dreaming" serves no function but is just a side-effect of our brain-cells shrinking (?)
    - metasean 11y ago
      Or to 'entertain'/'occupy' the still operational brain-cells during the flushing period (like tv shows and movies during long flights or dialysis).
      - Terr_ 11y ago
        Brains are metabolically costly, if it were frivolous is probably wouldn't happen. I'd wager it's more like keeping an engine idling because it's less expensive/dangerous than turning it all the way off and restarting it.
      - Retra 11y ago
        From what I've read, the brain partially 'compartmentalizes' it's communications at regular intervals, and dreaming is what happens when this process finishes: the different compartments start communicating, synthesizing multiple independent thought processes into a cohesive whole. (Which would explain why they can be seemingly random and also relevant of recent events.)
    - qiqing 11y ago
      There is some evidence that dreaming is a side effect of defragging the memories of the day into long-term storage format.
- dingbat 11y ago
  neurologists at UCLA Alzheimers center have developed a formulation of Curcumin called "Longvida" which appears to reduce the accumulation of this brain plaque: http://alzheimer.neurology.ucla.edu/Curcumin.html http://alzheimer.neurology.ucla.edu/Curcumin.html Curcumin and Alzheimer’s disease. Our group has tested curcumin in several models and found that it not only reduces oxidative damage and inflammation (as expected), but also reduces amyloid accumulation and synaptic marker loss while promoting both amyloid phagocytosis and clearance. In in vitro studies, we found curcumin worked to prevent synaptic marker and cognitive deficits caused by amyloid peptide infusion and abeta oligomer toxicity. Our work on curcumin and AD is discussed in detail in our publications its important to note that it is only the Longvida formulation of Curcumin which effect because it crosses the blood-brain barrier, although other types seem beneficial for other conditions.
  - will_work4tears 11y ago
    It seems more that Curcumin that isn't passed into the kidneys can pass the blood-brain barrier[0], and you can help prevent that by taking it with piperine; most formulations, at least on Amazon, have piperine in it, if it doesn't take it with some black peppercorns. It appears the only difference between most formulations and Longvida is that they pair it with coconut oil? That's what I could gather from their formulation, they don't even list piperine. I'm skeptical of the brand in particular, not in the sense that it's bio-available, but their claim that only their brand crosses the blood-brain barrier[1][2]. [0] a lot of sites mention this in passing, but here's a study that shows 7 days of supplementation crosses the blood-brain barrier, at least in mice: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781139/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781139/ [1] http://news.vanderbilt.edu/2015/01/curcumin%E2%80%99s-ability-to-fight-alzheimer-studied/ http://news.vanderbilt.edu/2015/01/curcumin%E2%80%99s-abilit... [2] http://www.petesplacenutritionalsupplementblog.com/2014/09/curcuwin-curcumin-vs-longvida.html http://www.petesplacenutritionalsupplementblog.com/2014/09/c...
- mbreedlove 11y ago
  I use sleepyti.me almost every day, thanks for making it available!
- JoshTriplett 11y ago
  It seems rather likely that other neurological functions occur during that time as well. Unless we have the ability to simulate all of them, we shouldn't assume that the ones we ignore aren't important. It would be especially harmful if we ended up suppressing the processes that make you feel sleepy when you need sleep, while the harmful effects of sleeplessness remained.
  - fapjacks 11y ago
    It makes me wonder then about drugs like Modafinil.
    - mtgx 11y ago
      Or coffee.
      - matznerd 11y ago
        Caffeine directly effects the adenosine receptors [1] which are what regulates sleep and wakefulness [2]. [1] http://www.ncbi.nlm.nih.gov/pubmed/20164566 http://www.ncbi.nlm.nih.gov/pubmed/20164566 [2] http://www.sciencedirect.com/science/article/pii/S030100820400125X http://www.sciencedirect.com/science/article/pii/S0301008204...
    - matznerd 11y ago
      Modafinil is designed for narcoleptics, people who are theoretically getting too much sleep. It is not actually intended for people to use to stay up beyond the recommended range. If you stay up for multiple days you are increasing the build up of these plaques, because the brain is not able to clear them out while you are awake.
      - qiqing 11y ago
        +1. For some normal* people, taking modafinil increases the risk of major depression as well. * not diagnosed with narcolepsy or depression already
- csbrooks 11y ago
  It feels like since we evolved under conditions of sleeping for a third of our lives, there are probably lots of other biological mechanisms that depend on sleep happening to work.
  - marincounty 11y ago
    I've wondered about that for years. I've always felt the body/mind heals/repairs itself during sleep. It's too bad our economic society doesn't value sleep? Never understood having to arrive at most jobs before 10 a.m. I've had so many jobs that want employees there the job site at 7 a.m.? I show up, but I'm not truly working until afer 10 a.m., and I'm not the only one? Then again--I have honestly never been a morning person.
    - vectorjohn 11y ago
      Seems like a different issue. Nothing about the start time says anything about how much sleep you get. On the other hand people sleep better in the dark so if your start time implies you're going to bed when it's light out it could cause problems. Unless you use a prosthetic night (curtains).
      - developer1 11y ago
        >> On the other hand people sleep better in the dark I don't understand how people manage this. I fall asleep in less than 5 minutes if I lie down while the Sun is up in the morning, and stay solidly asleep until an appropriate number of hours have passed. Going to bed in the dark, I can toss and turn for anywhere from 30-120 minutes before finally dozing off. Night owlism is real, and it's seriously debilitating to be required to conform to working a 9-5/10-6 job. It's Friday night, so I get to live my weekend hours. It's 2:30am now, and I'll be up another few hours. Whenever I am on vacation, or between jobs, I instantly swap to a nocturnal schedule. It is extremely painful to have to work during the day, to the point where I burn out after 12-18 months at a job. For the first time in a decade, I've almost made it 2 years at a single employer. That time is running out. I need a reversion back to my normal hours for a while. :(
- jusben1369 11y ago
  In general I agree with the other comments that discuss that lack of sleep might have other issues so "work arounds" designed to help pilots and truckers probably aren't a good idea. However and in particular connection to this article there might be people who are at risk for Alzheimer's where it makes sense to "sweep" the brain more than once a day? So normal sleep + another process around 2pm? Not sure if it would work like that but that was what I wondered when reading this/
  - qiqing 11y ago
    Like a nap. ;)
    - jusben1369 11y ago
      Hey you don't have to tell me twice! But it sounds like sleeping disorders might make that tough?
      - qiqing 11y ago
        Some people have difficulty falling asleep, and other people have trouble staying asleep (often waking up really early in the morning). The latter is much more common amongst older people, even though the amount of sleep they "need" has not decreased -- they just have a hard time staying asleep for long periods of time. In that scenario (when falling asleep is not the hard part), a nap is probably a pretty good idea.
- matznerd 11y ago
  This shows the importance of sleep, but also adds to the question of what we can do to facilitate this process while awake. It seems the best we can do when we are awake, is to use neuroprotective substances to prevent the build-up of the plaques or to sequester them for easier breakdown while sleeping. For example, Noopept, the di-peptide form of the nootropic piracetam, has been shown to lower levels of amyloid plaques via "hydrophobic interactions with toxic amyloid oligomers, [which] prompts their rapid sequestration into larger fibrillar amyloid aggregates." In the linked study, researchers concluded that the "mitigating effect of noopept against amyloid oligomeric cytotoxicity may offer additional benefits to the already well-established therapeutic functions of this new pharmaceutical."[1] The abilities of substances like this to protect the brain as we age, are examples of why we need to move major parts of the medical field to focus on preventative and rejuvenating medicine, instead of just treatment for the final symptoms of a disease that has been in progress for decades... Background info: This is a process of what is now called the glymphatic system. The scientest quoted in the article (M. Nedergaard), previously coined the term "glymphatic" in her paper[2] "The Garbage Truck." She was a follow-on author on the paper referenced in the NPR story, "Sleep Drives Metabolite Clearance from the Adult Brain." It is a pretty interesting paper and I have a full-text copy available in my private research vault [3]. [1] http://nootroo.com/researchvault/neuroprotective-and-nootropic-drug-noopept-rescues-a-synuclein-amyloid-cytotoxicity/ http://nootroo.com/researchvault/neuroprotective-and-nootrop... [2] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749839/pdf/nihms500661.pdf http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749839/pdf/nihm... [3] http://nootroo.com/researchvault/sleep-drives-metabolite-clearance-from-the-adult-brain/ http://nootroo.com/researchvault/sleep-drives-metabolite-cle...
- api 11y ago
  If it were easy, think of the evolutionary advantage: you're never vulnerable to predators and you get twice as much working time per day. The fact that sleep still exists seems to suggest that this is hard and involves some nasty tradeoffs between the "dishwasher mode" and more operational neurological states. It's also likely that more than just this occurs, and that sleep is used to take care of a whole laundry list of housekeeping operations. We have "pausing GC"... heh.
  - vidarh 11y ago
    > you're never vulnerable to predators Except prior to artificial light sources, you would still be forced to stay sheltered or spend your time huddled up with weapons at the ready. > and you get twice as much working time per day. Until our work consisted of something other than hunting and gathering this would likely not have been all that much of a benefit. On evolutionary timescales it would seem most of our evolution has happened in conditions where we were severely constrained with respect to what we could safely do during the night anyway, and so there'd be relatively little benefit to working around whatever the problems of avoiding sleep are. I don't doubt that cutting sleep will pose all kinds of challenges we're not even aware of yet, though.
    - themusicgod1 11y ago
      On the evolutionary timescale that modern sleep became available, I don't think we're talking weapons.
  - agumonkey 11y ago
    > We have "pausing GC"... heh. :) The evolutionary argument is nice but maybe we're just stuck in an old 'branch' local minima. Think of axolotl limb regeneration. We only have partial regeneration but somehow nature felt it was more efficient not to regenerate full limbs and try to survive crippled. Long sleep may have been necessary, but maybe that's not the case anymore.
- profinger 11y ago
  I've used sleepyti.me a lot when trying to pick bed times for 1 off events. Thank you for your help in waking up at the proper interval!
- etrautmann 11y ago
  There's reason to believe that there are other processes that would have to co-occur, like an increase in the extracellular space to allow for clearance of these toxins, AB proteins, etc.
- chjohasbrouck 11y ago
  This might be a weird compliment but I really like your font color choices.
- roflmyeggo 11y ago
  It's not so simple as simply increasing the amount of CSF influx into the brain, but also increasing interstitial space via adrenergic receptor inhibition. The clearance of beta-amyloid, etc. is largely linked to the state of sleeping that would be tough to isolate without inducing sleeping itself.
- dcgoss 11y ago
  Was just about to go to bed, when I saw you mentioned that you wrote http://sleepyti.me http://sleepyti.me. Got up to go to my computer to say that I use it all the time!! Thanks for the awesome tool.
- conceit 11y ago
  The heart is a muscle that needs rest, as well.
omarchowdhury 11y ago
All is one; during sleep the undistracted soul is absorbed into this unity; in the waking state, being distracted, it distinguishes diverse beings. (Chuang Tzu)
- orik 11y ago
  I thought you were TempleOS at first glance.
deleted 11y ago
[deleted]
- jws 11y ago
  Perhaps you could make an infomercial selling a dietary supplement that cleanses your brain from toxins. Then with the money you earn from that you can fund an actual drug that really does it?
- matznerd 11y ago
  There are already substances out there that can protect against the build of up of amyloid plaques...but it is something that people and companies SHOULD spend a lot more money on. Most pharmaceutical companies do not focus on creating preventative treatments, they focus on treatments for the symptoms of existing conditions.
pizza 11y ago
I can't help but imagine that if this is the case then increased water intake (prior to bed or simply throughout the day) would help intercellular water flow. Anyone know anything about drinking water improving sleep quality? Or generally well-informed sources that describe which bodily processes improve when you drink more water?
- Mz 11y ago
  I don't have sources at my fingertips. I have done a lot of reading. This process of clearing wastes from the brain during sleep is not news to me. They are talking about the lymphatic system, which is the general waste removal system for the body. For your musculoskeletal system, lymph flow increases dramatically with physical activity. So walking more is really helpful. But the brain is on a separate system and lymph gets cleared by sleep. I have a serious incurable condition that interferes with, among other things, oils and salts in my body. What I have figured out over the past 14-ish years (since getting diagnosed) is that hydration is not just about how much fluid you take in. Just like you can oil something to protect it from water, oil in the body helps keep water in. And salt and other electrolytes also matter. There are also other brain chemicals involved in helping modulate the waking and sleeping cycle of the brain, chiefly melatonin and co-q-10. I took lots and lots of co-q-10 to heal my sleep disordered brain after getting off the boatload of prescription drugs that fried it and messed up my ability to sleep. I sleep a lot better than I used to. I am better hydrated than I used to be. But hydration is not merely a matter of drinking water. There are a lot of other chemical things going on there. But I would agree that proper hydration helps (with sleep, brain function, and general lymphatic processes). Water alone does not get you to proper hydration.
  - matznerd 11y ago
    As a note, they are talking about the "glymphatic" system and not the "lymphatic" system. The name is a play on the lymphatic system, but it is specific to the brain. Another paper by the author cited in the NPR story, is my favorite paper on the system: "The Glymphatic System: A Beginner’s Guide" http://www.ncbi.nlm.nih.gov/pubmed/25947369 http://www.ncbi.nlm.nih.gov/pubmed/25947369 In it, they do not mention melatonin or CoQ10, but norepinephrine as a major regulator of wakefulness. (Although I do take 400 mg a day of the reduced form of Coq10 called Ubiquinol).
stdgy 11y ago
The brain continues to fascinate. I wonder how the brain acts while under anesthesia or induced to sleep through sleep aids? Is it different than naturally falling asleep? More particularly, it sounds like brain cells (At least in mice) shrink during sleep and then enlarge during wakeful consciousness. That shrinking mechanism may play a role in the cerebrospinal fluid recycling/cleaning process, which itself may play a role in ridding the brain of harmful plaques. Does an Alzheimer's patient not show the same level of growth and shrinkage? Could forced sleep improve their outcomes? (IE: Could forced sleep lead to a more normal growth/shrink cycle?) I am, unfortunately, ignorant on most of the medical science at play here. Any biologists, doctors or hobbyists have any thoughts?
- qiqing 11y ago
  Former neuroscientist here (though I did not work directly on Alzheimer's or sleep). Anesthesia and sleep are different states, though there are some similarities. Here's a figure that illustrates what 'typical' EEG looks like in these various states: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162622/figure/F1/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162622/figure/F... A smattering of other differences off the top of my head: you can feel pain when you're asleep, but not under anesthesia. It is possible to wake up a sleeping subject or patient with sounds or shaking, but not one under anesthesia. Also you'll feel refreshed after you sleep, but not after anesthesia.
  - XorNot 11y ago
    Also you'll feel refreshed after you sleep, but not after anesthesia. When I had general anesthesia for my wisdom teeth I definitely felt refreshed afterwards. I'm wondering if this idea isn't so well grounded, since we mostly anesthetize and then do violent surgery on people - and so you mostly wake up feeling that.
saalweachter 11y ago
The claim may or may not be true, but for me the word "toxins" has been so thoroughly poisoned by woo that I get a knee-jerk reaction just reading the title. The bar for anyone talking about cleansing toxins is like 200% higher because of all the bullshit that's been spouted over the last few decades.
- rqebmm 11y ago
  This came out a little while ago, but presaged the increasing understanding we have of the brain's lymphatic system.
- ksenzee 11y ago
  I think we can trust a professor of neurosurgery at the University of Rochester not to be spouting woo in her study in _Science_.
  - DanBC 11y ago
    Of course we can. The fact that a trustworthy document from a real scientist in a real journal is initially seen as less reputable because a journalist uses the word toxins shows how devalued the word has become.
- ggchappell 11y ago
  Indeed. But there is also an easy test that can be applied to people that talk about "toxins": see if they can name a toxin. And both the article and the original paper[1] discuss beta-amyloid. In any case, it appears that the blame for the suspect terminology lies primarily with the NPR writer, not the researchers. For example, the word "toxin" does not actually appear in the paper[1], which is titled "Sleep Drives Metabolite Clearance from the Adult Brain". [1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880190/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880190/
pwagle 11y ago
Has anyone determined which stages of sleep this occurs?
clumsysmurf 11y ago
Its possible that sleeping on your side allows the glymphatic pathway to clear waste more efficiently. http://www.futurity.org/side-sleeping-brains-979872/ http://www.futurity.org/side-sleeping-brains-979872/
akilism 11y ago
I just read two really good neuroscience articles over on nautil.us. This stuff is super interesting. http://nautil.us/issue/27/dark-matter/heres-why-your-brain-seems-mostly-dormant http://nautil.us/issue/27/dark-matter/heres-why-your-brain-s... http://nautil.us/issue/27/dark-matter/the-neurons-secret-partner http://nautil.us/issue/27/dark-matter/the-neurons-secret-par...
akilism 11y ago
I just read two really good neuroscience articles over on nautil.us. This stuff is super interesting. http://nautil.us/issue/27/dark-matter/heres-why-your-brain-seems-mostly-dormant http://nautil.us/issue/27/dark-matter/heres-why-your-brain-s... http://nautil.us/issue/27/dark-matter/the-neurons-secret-partner http://nautil.us/issue/27/dark-matter/the-neurons-secret-par...
johndevor 11y ago
I'd be curious to know if anything similar happens during meditation. I often feel just as refreshed from meditating briefly as I do from a quick nap.
roymurdock 11y ago
My friends and I were up late on a road trip once. We started to argue about how long it would take someone to die from lack of sleep. Initially, I held the position that sleep was probably more important than eating food, and that you would die from sleep deprivation before you died from starvation. We looked it up, and learned about a disease called fatal familial insomnia. A mutated protein causes the onset of permanent insomnia, and there is no cure. It affects about 100 individuals worldwide. [1] The average life expectancy of a patient is 18 months after the onset of symptoms. The first 9 months is a worsening case of insomnia, where the patient will experience paranoia, panic attacks, and hallucinations. Sleeping pills and barbiturates have been shown to worsen the clinical manifestations and hasten the onset of the disease. The individual then becomes completely unable to sleep, and will enter a state of dementia before becoming completely mute and unresponsive. This second state of permanent insomnia lasts for 9 months. So ultimately, we learned that you can go for 9 months without sleeping before you die. I'm not sure at what point you'll suffer irreversible brain damage, but that was an interesting finding for me nonetheless. [1] https://en.wikipedia.org/wiki/Fatal_familial_insomnia https://en.wikipedia.org/wiki/Fatal_familial_insomnia
- jquery 11y ago
  From the article: > Non REM Stages 1 and 2: Light sleep NREM-sleep > Non REM Stages 3 and 4: Deep slow wave sleep (SWS) > REM-sleep when dreams occur > FFI patients cannot go past stage 1 It appears they are getting sleep, but only stage 1 sleep. That might be what keeps them alive for 9 months. If stage 1 was blocked, I venture to guess their survival duration would be much lower.
  - tim333 11y ago
    Here's some other research data. In Guamtanamo they kept prisoners awake 11 days and found "surprisingly, little seem[s] to go wrong with the subjects physically." In rat experiments they all died by 32 days. I'm guessing full sleep depravation in humans would have a similar result to rats though thankfully no one seems to have tried that. http://www.slate.com/articles/news_and_politics/explainer/2009/05/can_you_die_from_lack_of_sleep.html http://www.slate.com/articles/news_and_politics/explainer/20...
asciimo 11y ago
>If this proves to be true in humans as well... Wake me up when they publish that paper.
jeffdavis 11y ago
So why does a lion need to sleep for 18 hours then?
lxfontes 11y ago
brain: longest garbage collection cycle ever
vlunkr 11y ago
It's fascinating to me that we still don't know why we sleep. We spend 1/3 of our lives in a self induced coma-like state and we aren't sure why, except that if you don't you start to go crazy. It will be interesting to see how this develops!
rudolf0 11y ago
>In Guantanamo they kept prisoners awake 11 days Somewhat off-topic, but how could anyone possibly argue this is not torture?
- Kenji 11y ago
  Is anyone arguing that torture is not something that happens in Guantanamo? By now it should be common knowledge that it's a torture camp. Obama promised to shut it down but he didn't.
  - rudolf0 11y ago
    I don't think anyone on HN has argued that, but many people in the general public still insist that "enhanced interrogation" like what's done in Guantanamo is not actually torture. Or at least they used to, until Obama finally admitted people have been tortured; though some still insist it isn't torture. My question was more hypothetical. That seems like the very definition of torture.
    - georgemcbay 11y ago
      Those people know it is really torture, they are just able to handwave it away because the people it is happening to believe in a slightly different god than they do.
    - gclaramunt 11y ago
      Is not torture when the good guys do it! Specially when there's a ticking bomb
  - rancur 11y ago
    I'm sorry, were you one of those silly students I was in college with who thought he would?
- guelo 11y ago
  Like Mengele, there's interesting science that can be conducted when you have no morals.
carsongross 11y ago
WHY? WHY IN GODS NAME?!?! Why would such a preposterously dangerous state, complete defenselessness, not be engineered around by darwinian pressure?!?
- gress 11y ago
  Because it isn't.
tim333 11y ago
There's a nice gif on Wikipedia showing something like fluid flow in question: https://en.wikipedia.org/wiki/Cerebrospinal_fluid#Circulation https://en.wikipedia.org/wiki/Cerebrospinal_fluid#Circulatio...
cthyon 11y ago
Does anyone know if there is research about whether this at all impacts/plays a part in causing dreams?
rebootthesystem 11y ago
Many years ago, during a stupid-er time in my life, I stayed up three nights in a row. I was working on a robotics paper to present at a conference. My first. It was a massive project and things had fallen behind schedule. With just three days left until I was supposed to be on a plane I had no choice but to work on the thing continuously and get it done. It was a solid three days of writing code and building/testing boards. I got done and packed with a couple of hours to spare before having to go to the airport. For some reason I could not sleep on the flight from Los Angeles to Seattle. Once I got to the room at the hotel I pretty much collapsed on the bed. My talk was scheduled for the next morning. I figured I could sleep a solid 12 hours and have a couple to get ready for the talk/presentation. Somewhere in the middle of the night I woke up. I have no clue how long I slept up to that point. I had lost all sense of time. I went to the bathroom. And that's when the nightmare started. I washed my face and almost immediately my ears started to buzz. It was something like a 1kHz sine wave. It started at a low level and got louder and louder. Scary. At a certain point, my field of vision started to turn milky white. The tone got louder and all I could see was a bright white light engulfing my entire field of view. I was blind and deaf and in the worst possible circumstances I could imagine. I have no clue how long it all lasted. It felt like somewhere around 15 minutes. It could have been just thirty seconds but I had no sense of time and I was freaking out. All I could do was sit on the bathroom floor, hold on to something and think through the worst possible scenarios. After what I guess was about fifteen minutes my vision started to slowly come back and the tone started to fade away. That must have taken another 5 to 15 minutes. I was drenched in sweat and scared like I had never been in my life. I've never done drugs or alcohol. I imagined this had to be like a grade-A drug addict overdose experience, or worst. All I could do was go back to sleep after that. I was exhausted. The next day I asked to have my talk re-scheduled and went to see a doctor. He told me I was an idiot and lucky not to have ended-up in the ER with brain damage. That was the last time I worked on anything overnight. I know tech companies have a culture of working long hours to get things done. Be sure you are not killing yourself to crank out another 100 lines of meaningless code. The world can wait. And if your VC's don't understand you'd like to live a long an healthy life, well, fuck them.
roflmyeggo 11y ago
Yet another reason to get a good nights sleep. Many of these metabolic degradation products (not just beta-amyloid) of neuronal cell activities should readily be cleared quickly and efficiently from the interstitial space of the brain due to the highly sensitive nature of neuronal cells to their environment. Some negative effects documented from these byproducts include: negatively effecting synaptic transmission[1], decreasing cytosolic Ca2+ concentrations[2] (Ca2+ is one of the final players in the triggering the release of neurotransmitters into the synapse between neurons to facilitate messages), and irreversible neuronal injury[3]. [1] - K. Parameshwaran, M. Dhanasekaran, V. Suppiramaniam, Amyloid beta peptides and glutamatergic synaptic dysregulation. Exp. Neurol. 210, 7–13 (2008) [2] - K. V. Kuchibhotla, S. T. Goldman, C. R. Lattarulo, H. Y. Wu, B. T. Hyman, B. J. Bacskai, Abeta plaques lead to aberrant regulation of calcium homeostasis in vivo resulting in structural and functional disruption of neuronal networks. Neuron 59, 214–225 (2008) [3] - M. P. Mattson, Calcium and neuronal injury in Alzheimer’s disease. Contributions of beta-amyloid precursor protein mismetabolism, free radicals, and metabolic compromise. Ann. N. Y. Acad. Sci. 747, 50–76 (1994)
brad3378 11y ago
I have a harder time controlling my appetite if I don't get enough sleep. Could these toxins be related?
- Strom 11y ago
  Perhaps, as serotonin does regulate both sleep & appetite.
bjd2385 11y ago
This is fascinating!

445 points by Practicality 11y ago

Related discussion from a few weeks ago; https://news.ycombinator.com/item?id=9895094 https://news.ycombinator.com/item?id=9895094

david_shaw 11y ago

The engineer in me has to wonder: is this something we can synthesize? If it were possible to induce this "dishwasher-like" surge of cerebrospinal fluid in the brain during waking hours, would we be able to live off of significantly less (or no) sleep? I'm not saying that it's necessarily a good idea, but it would have a plethora of practical applications -- pilots, truckers, etc. would be able to stay awake in a healthful way, rather than by ingesting stimulants. I've been interested in the science of sleep for a while -- I wrote a side project, http://sleepyti.me http://sleepyti.me, that actually gets quite a bit of traffic -- but neuroscience is mostly lost on me.

Practicality 11y ago
A quote from the article: "It's probably not possible for the brain to both clean itself and at the same time [be] aware of the surroundings and talk and move and so on," So it would be the equivalent of a forced sleep, since you can't be conscious at the same time, but that might still be useful.
- mmastrac 11y ago
  Perhaps we could do a half-brain sleep like Dolphins? https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep
  - jotm 11y ago
    I wonder how cognitive functions and our personality would be affected? Two halfs make a whole, yin and yang and all that, if half the brain is asleep, would we even be able to think straight?
    - vorg 11y ago
      Maybe that can be the 8 hours a day people do their office jobs.
    - fixermark 11y ago
      So the tradeoff might be that you can operate while half your brain is asleep, but your coworkers might think you're acting a bit crazy? (Not sure precisely how different that is from the experience of most office workers ;) ).
    - qiqing 11y ago
      Hemispherectomy (removal of one half of the brain) is a treatment for Rasmussen's encephalitis when it's sufficiently severe (or the seizures are not responding to drugs). If done very early in life, the plasticity of brain makes it such that those patients grow up to be normally functioning adults. We believe this is because the regions that specialize for different tasks are able to combine their function on the same half. Think of, for instance, the "language" areas (Broca's area and Wernicke's area). (The following over-simplified explanation assumes typical right-hand dominant individuals for the sake of brevity.) If you inactivate that area in the left hemisphere (using drugs or transcranial magnetic stimulation), you'll lose "language" processing of data that occurs around 1 Hz (in English, this corresponds to individual words, phonemes; in tonal languages, this includes tones of lexical significance). If you inactivate that area in the right hemisphere instead, you'll lose "language" processing of data that occurs an order of magnitude slower than that (in most languages, this corresponds to pitch and volume changes over the level of the sentence, and can convey prosody information such as speaker intent as well as speaker identity). Due to specializations like this, hemispherectomies are not performed later in life. You would get symptoms similar to stroke patients. But for all areas, not just language.
- zardo 11y ago
  Sleep has been shown to be a factor in learning, so functions that happen during sleep could be related to learning disabilities. So yeah, being able to induce this state might be very useful for treating some conditions.
- vidarh 11y ago
  If we could accelerate the process and/or control duration and/or induce it at will it would have major implications even if we're unable to remove the need to sleep fully.
ksenzee 11y ago
"The team discovered that this increased flow was possible in part because when mice went to sleep, their brain cells actually shrank, making it easier for fluid to circulate. When an animal woke up, the brain cells enlarged again and the flow between cells slowed to a trickle." So no, probably not.
- amelius 11y ago
  I can't help but wonder if perhaps "dreaming" serves no function but is just a side-effect of our brain-cells shrinking (?)
  - metasean 11y ago
    Or to 'entertain'/'occupy' the still operational brain-cells during the flushing period (like tv shows and movies during long flights or dialysis).
    - Terr_ 11y ago
      Brains are metabolically costly, if it were frivolous is probably wouldn't happen. I'd wager it's more like keeping an engine idling because it's less expensive/dangerous than turning it all the way off and restarting it.
    - Retra 11y ago
      From what I've read, the brain partially 'compartmentalizes' it's communications at regular intervals, and dreaming is what happens when this process finishes: the different compartments start communicating, synthesizing multiple independent thought processes into a cohesive whole. (Which would explain why they can be seemingly random and also relevant of recent events.)
  - qiqing 11y ago
    There is some evidence that dreaming is a side effect of defragging the memories of the day into long-term storage format.
dingbat 11y ago
neurologists at UCLA Alzheimers center have developed a formulation of Curcumin called "Longvida" which appears to reduce the accumulation of this brain plaque: http://alzheimer.neurology.ucla.edu/Curcumin.html http://alzheimer.neurology.ucla.edu/Curcumin.html Curcumin and Alzheimer’s disease. Our group has tested curcumin in several models and found that it not only reduces oxidative damage and inflammation (as expected), but also reduces amyloid accumulation and synaptic marker loss while promoting both amyloid phagocytosis and clearance. In in vitro studies, we found curcumin worked to prevent synaptic marker and cognitive deficits caused by amyloid peptide infusion and abeta oligomer toxicity. Our work on curcumin and AD is discussed in detail in our publications its important to note that it is only the Longvida formulation of Curcumin which effect because it crosses the blood-brain barrier, although other types seem beneficial for other conditions.
- will_work4tears 11y ago
  It seems more that Curcumin that isn't passed into the kidneys can pass the blood-brain barrier[0], and you can help prevent that by taking it with piperine; most formulations, at least on Amazon, have piperine in it, if it doesn't take it with some black peppercorns. It appears the only difference between most formulations and Longvida is that they pair it with coconut oil? That's what I could gather from their formulation, they don't even list piperine. I'm skeptical of the brand in particular, not in the sense that it's bio-available, but their claim that only their brand crosses the blood-brain barrier[1][2]. [0] a lot of sites mention this in passing, but here's a study that shows 7 days of supplementation crosses the blood-brain barrier, at least in mice: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781139/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781139/ [1] http://news.vanderbilt.edu/2015/01/curcumin%E2%80%99s-ability-to-fight-alzheimer-studied/ http://news.vanderbilt.edu/2015/01/curcumin%E2%80%99s-abilit... [2] http://www.petesplacenutritionalsupplementblog.com/2014/09/curcuwin-curcumin-vs-longvida.html http://www.petesplacenutritionalsupplementblog.com/2014/09/c...
mbreedlove 11y ago
I use sleepyti.me almost every day, thanks for making it available!
JoshTriplett 11y ago
It seems rather likely that other neurological functions occur during that time as well. Unless we have the ability to simulate all of them, we shouldn't assume that the ones we ignore aren't important. It would be especially harmful if we ended up suppressing the processes that make you feel sleepy when you need sleep, while the harmful effects of sleeplessness remained.
- fapjacks 11y ago
  It makes me wonder then about drugs like Modafinil.
  - mtgx 11y ago
    Or coffee.
    - matznerd 11y ago
      Caffeine directly effects the adenosine receptors [1] which are what regulates sleep and wakefulness [2]. [1] http://www.ncbi.nlm.nih.gov/pubmed/20164566 http://www.ncbi.nlm.nih.gov/pubmed/20164566 [2] http://www.sciencedirect.com/science/article/pii/S030100820400125X http://www.sciencedirect.com/science/article/pii/S0301008204...
  - matznerd 11y ago
    Modafinil is designed for narcoleptics, people who are theoretically getting too much sleep. It is not actually intended for people to use to stay up beyond the recommended range. If you stay up for multiple days you are increasing the build up of these plaques, because the brain is not able to clear them out while you are awake.
    - qiqing 11y ago
      +1. For some normal* people, taking modafinil increases the risk of major depression as well. * not diagnosed with narcolepsy or depression already
csbrooks 11y ago
It feels like since we evolved under conditions of sleeping for a third of our lives, there are probably lots of other biological mechanisms that depend on sleep happening to work.
- marincounty 11y ago
  I've wondered about that for years. I've always felt the body/mind heals/repairs itself during sleep. It's too bad our economic society doesn't value sleep? Never understood having to arrive at most jobs before 10 a.m. I've had so many jobs that want employees there the job site at 7 a.m.? I show up, but I'm not truly working until afer 10 a.m., and I'm not the only one? Then again--I have honestly never been a morning person.
  - vectorjohn 11y ago
    Seems like a different issue. Nothing about the start time says anything about how much sleep you get. On the other hand people sleep better in the dark so if your start time implies you're going to bed when it's light out it could cause problems. Unless you use a prosthetic night (curtains).
    - developer1 11y ago
      >> On the other hand people sleep better in the dark I don't understand how people manage this. I fall asleep in less than 5 minutes if I lie down while the Sun is up in the morning, and stay solidly asleep until an appropriate number of hours have passed. Going to bed in the dark, I can toss and turn for anywhere from 30-120 minutes before finally dozing off. Night owlism is real, and it's seriously debilitating to be required to conform to working a 9-5/10-6 job. It's Friday night, so I get to live my weekend hours. It's 2:30am now, and I'll be up another few hours. Whenever I am on vacation, or between jobs, I instantly swap to a nocturnal schedule. It is extremely painful to have to work during the day, to the point where I burn out after 12-18 months at a job. For the first time in a decade, I've almost made it 2 years at a single employer. That time is running out. I need a reversion back to my normal hours for a while. :(
jusben1369 11y ago
In general I agree with the other comments that discuss that lack of sleep might have other issues so "work arounds" designed to help pilots and truckers probably aren't a good idea. However and in particular connection to this article there might be people who are at risk for Alzheimer's where it makes sense to "sweep" the brain more than once a day? So normal sleep + another process around 2pm? Not sure if it would work like that but that was what I wondered when reading this/
- qiqing 11y ago
  Like a nap. ;)
  - jusben1369 11y ago
    Hey you don't have to tell me twice! But it sounds like sleeping disorders might make that tough?
    - qiqing 11y ago
      Some people have difficulty falling asleep, and other people have trouble staying asleep (often waking up really early in the morning). The latter is much more common amongst older people, even though the amount of sleep they "need" has not decreased -- they just have a hard time staying asleep for long periods of time. In that scenario (when falling asleep is not the hard part), a nap is probably a pretty good idea.
matznerd 11y ago
This shows the importance of sleep, but also adds to the question of what we can do to facilitate this process while awake. It seems the best we can do when we are awake, is to use neuroprotective substances to prevent the build-up of the plaques or to sequester them for easier breakdown while sleeping. For example, Noopept, the di-peptide form of the nootropic piracetam, has been shown to lower levels of amyloid plaques via "hydrophobic interactions with toxic amyloid oligomers, [which] prompts their rapid sequestration into larger fibrillar amyloid aggregates." In the linked study, researchers concluded that the "mitigating effect of noopept against amyloid oligomeric cytotoxicity may offer additional benefits to the already well-established therapeutic functions of this new pharmaceutical."[1] The abilities of substances like this to protect the brain as we age, are examples of why we need to move major parts of the medical field to focus on preventative and rejuvenating medicine, instead of just treatment for the final symptoms of a disease that has been in progress for decades... Background info: This is a process of what is now called the glymphatic system. The scientest quoted in the article (M. Nedergaard), previously coined the term "glymphatic" in her paper[2] "The Garbage Truck." She was a follow-on author on the paper referenced in the NPR story, "Sleep Drives Metabolite Clearance from the Adult Brain." It is a pretty interesting paper and I have a full-text copy available in my private research vault [3]. [1] http://nootroo.com/researchvault/neuroprotective-and-nootropic-drug-noopept-rescues-a-synuclein-amyloid-cytotoxicity/ http://nootroo.com/researchvault/neuroprotective-and-nootrop... [2] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749839/pdf/nihms500661.pdf http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749839/pdf/nihm... [3] http://nootroo.com/researchvault/sleep-drives-metabolite-clearance-from-the-adult-brain/ http://nootroo.com/researchvault/sleep-drives-metabolite-cle...
api 11y ago
If it were easy, think of the evolutionary advantage: you're never vulnerable to predators and you get twice as much working time per day. The fact that sleep still exists seems to suggest that this is hard and involves some nasty tradeoffs between the "dishwasher mode" and more operational neurological states. It's also likely that more than just this occurs, and that sleep is used to take care of a whole laundry list of housekeeping operations. We have "pausing GC"... heh.
- vidarh 11y ago
  > you're never vulnerable to predators Except prior to artificial light sources, you would still be forced to stay sheltered or spend your time huddled up with weapons at the ready. > and you get twice as much working time per day. Until our work consisted of something other than hunting and gathering this would likely not have been all that much of a benefit. On evolutionary timescales it would seem most of our evolution has happened in conditions where we were severely constrained with respect to what we could safely do during the night anyway, and so there'd be relatively little benefit to working around whatever the problems of avoiding sleep are. I don't doubt that cutting sleep will pose all kinds of challenges we're not even aware of yet, though.
  - themusicgod1 11y ago
    On the evolutionary timescale that modern sleep became available, I don't think we're talking weapons.
- agumonkey 11y ago
  > We have "pausing GC"... heh. :) The evolutionary argument is nice but maybe we're just stuck in an old 'branch' local minima. Think of axolotl limb regeneration. We only have partial regeneration but somehow nature felt it was more efficient not to regenerate full limbs and try to survive crippled. Long sleep may have been necessary, but maybe that's not the case anymore.
profinger 11y ago
I've used sleepyti.me a lot when trying to pick bed times for 1 off events. Thank you for your help in waking up at the proper interval!
etrautmann 11y ago
There's reason to believe that there are other processes that would have to co-occur, like an increase in the extracellular space to allow for clearance of these toxins, AB proteins, etc.
chjohasbrouck 11y ago
This might be a weird compliment but I really like your font color choices.
roflmyeggo 11y ago
It's not so simple as simply increasing the amount of CSF influx into the brain, but also increasing interstitial space via adrenergic receptor inhibition. The clearance of beta-amyloid, etc. is largely linked to the state of sleeping that would be tough to isolate without inducing sleeping itself.
dcgoss 11y ago
Was just about to go to bed, when I saw you mentioned that you wrote http://sleepyti.me http://sleepyti.me. Got up to go to my computer to say that I use it all the time!! Thanks for the awesome tool.
conceit 11y ago
The heart is a muscle that needs rest, as well.

omarchowdhury 11y ago

All is one; during sleep the undistracted soul is absorbed into this unity; in the waking state, being distracted, it distinguishes diverse beings. (Chuang Tzu)

orik 11y ago
I thought you were TempleOS at first glance.

deleted 11y ago

[deleted]

jws 11y ago
Perhaps you could make an infomercial selling a dietary supplement that cleanses your brain from toxins. Then with the money you earn from that you can fund an actual drug that really does it?
matznerd 11y ago
There are already substances out there that can protect against the build of up of amyloid plaques...but it is something that people and companies SHOULD spend a lot more money on. Most pharmaceutical companies do not focus on creating preventative treatments, they focus on treatments for the symptoms of existing conditions.

pizza 11y ago

I can't help but imagine that if this is the case then increased water intake (prior to bed or simply throughout the day) would help intercellular water flow. Anyone know anything about drinking water improving sleep quality? Or generally well-informed sources that describe which bodily processes improve when you drink more water?

Mz 11y ago
I don't have sources at my fingertips. I have done a lot of reading. This process of clearing wastes from the brain during sleep is not news to me. They are talking about the lymphatic system, which is the general waste removal system for the body. For your musculoskeletal system, lymph flow increases dramatically with physical activity. So walking more is really helpful. But the brain is on a separate system and lymph gets cleared by sleep. I have a serious incurable condition that interferes with, among other things, oils and salts in my body. What I have figured out over the past 14-ish years (since getting diagnosed) is that hydration is not just about how much fluid you take in. Just like you can oil something to protect it from water, oil in the body helps keep water in. And salt and other electrolytes also matter. There are also other brain chemicals involved in helping modulate the waking and sleeping cycle of the brain, chiefly melatonin and co-q-10. I took lots and lots of co-q-10 to heal my sleep disordered brain after getting off the boatload of prescription drugs that fried it and messed up my ability to sleep. I sleep a lot better than I used to. I am better hydrated than I used to be. But hydration is not merely a matter of drinking water. There are a lot of other chemical things going on there. But I would agree that proper hydration helps (with sleep, brain function, and general lymphatic processes). Water alone does not get you to proper hydration.
- matznerd 11y ago
  As a note, they are talking about the "glymphatic" system and not the "lymphatic" system. The name is a play on the lymphatic system, but it is specific to the brain. Another paper by the author cited in the NPR story, is my favorite paper on the system: "The Glymphatic System: A Beginner’s Guide" http://www.ncbi.nlm.nih.gov/pubmed/25947369 http://www.ncbi.nlm.nih.gov/pubmed/25947369 In it, they do not mention melatonin or CoQ10, but norepinephrine as a major regulator of wakefulness. (Although I do take 400 mg a day of the reduced form of Coq10 called Ubiquinol).

stdgy 11y ago

The brain continues to fascinate. I wonder how the brain acts while under anesthesia or induced to sleep through sleep aids? Is it different than naturally falling asleep? More particularly, it sounds like brain cells (At least in mice) shrink during sleep and then enlarge during wakeful consciousness. That shrinking mechanism may play a role in the cerebrospinal fluid recycling/cleaning process, which itself may play a role in ridding the brain of harmful plaques. Does an Alzheimer's patient not show the same level of growth and shrinkage? Could forced sleep improve their outcomes? (IE: Could forced sleep lead to a more normal growth/shrink cycle?) I am, unfortunately, ignorant on most of the medical science at play here. Any biologists, doctors or hobbyists have any thoughts?

qiqing 11y ago
Former neuroscientist here (though I did not work directly on Alzheimer's or sleep). Anesthesia and sleep are different states, though there are some similarities. Here's a figure that illustrates what 'typical' EEG looks like in these various states: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162622/figure/F1/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162622/figure/F... A smattering of other differences off the top of my head: you can feel pain when you're asleep, but not under anesthesia. It is possible to wake up a sleeping subject or patient with sounds or shaking, but not one under anesthesia. Also you'll feel refreshed after you sleep, but not after anesthesia.
- XorNot 11y ago
  Also you'll feel refreshed after you sleep, but not after anesthesia. When I had general anesthesia for my wisdom teeth I definitely felt refreshed afterwards. I'm wondering if this idea isn't so well grounded, since we mostly anesthetize and then do violent surgery on people - and so you mostly wake up feeling that.

saalweachter 11y ago

The claim may or may not be true, but for me the word "toxins" has been so thoroughly poisoned by woo that I get a knee-jerk reaction just reading the title. The bar for anyone talking about cleansing toxins is like 200% higher because of all the bullshit that's been spouted over the last few decades.

rqebmm 11y ago
This came out a little while ago, but presaged the increasing understanding we have of the brain's lymphatic system.
ksenzee 11y ago
I think we can trust a professor of neurosurgery at the University of Rochester not to be spouting woo in her study in _Science_.
- DanBC 11y ago
  Of course we can. The fact that a trustworthy document from a real scientist in a real journal is initially seen as less reputable because a journalist uses the word toxins shows how devalued the word has become.
ggchappell 11y ago
Indeed. But there is also an easy test that can be applied to people that talk about "toxins": see if they can name a toxin. And both the article and the original paper[1] discuss beta-amyloid. In any case, it appears that the blame for the suspect terminology lies primarily with the NPR writer, not the researchers. For example, the word "toxin" does not actually appear in the paper[1], which is titled "Sleep Drives Metabolite Clearance from the Adult Brain". [1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880190/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880190/

pwagle 11y ago

Has anyone determined which stages of sleep this occurs?

clumsysmurf 11y ago

Its possible that sleeping on your side allows the glymphatic pathway to clear waste more efficiently. http://www.futurity.org/side-sleeping-brains-979872/ http://www.futurity.org/side-sleeping-brains-979872/

akilism 11y ago

I just read two really good neuroscience articles over on nautil.us. This stuff is super interesting. http://nautil.us/issue/27/dark-matter/heres-why-your-brain-seems-mostly-dormant http://nautil.us/issue/27/dark-matter/heres-why-your-brain-s... http://nautil.us/issue/27/dark-matter/the-neurons-secret-partner http://nautil.us/issue/27/dark-matter/the-neurons-secret-par...

akilism 11y ago

johndevor 11y ago

I'd be curious to know if anything similar happens during meditation. I often feel just as refreshed from meditating briefly as I do from a quick nap.

roymurdock 11y ago

My friends and I were up late on a road trip once. We started to argue about how long it would take someone to die from lack of sleep. Initially, I held the position that sleep was probably more important than eating food, and that you would die from sleep deprivation before you died from starvation. We looked it up, and learned about a disease called fatal familial insomnia. A mutated protein causes the onset of permanent insomnia, and there is no cure. It affects about 100 individuals worldwide. [1] The average life expectancy of a patient is 18 months after the onset of symptoms. The first 9 months is a worsening case of insomnia, where the patient will experience paranoia, panic attacks, and hallucinations. Sleeping pills and barbiturates have been shown to worsen the clinical manifestations and hasten the onset of the disease. The individual then becomes completely unable to sleep, and will enter a state of dementia before becoming completely mute and unresponsive. This second state of permanent insomnia lasts for 9 months. So ultimately, we learned that you can go for 9 months without sleeping before you die. I'm not sure at what point you'll suffer irreversible brain damage, but that was an interesting finding for me nonetheless. [1] https://en.wikipedia.org/wiki/Fatal_familial_insomnia https://en.wikipedia.org/wiki/Fatal_familial_insomnia

jquery 11y ago
From the article: > Non REM Stages 1 and 2: Light sleep NREM-sleep > Non REM Stages 3 and 4: Deep slow wave sleep (SWS) > REM-sleep when dreams occur > FFI patients cannot go past stage 1 It appears they are getting sleep, but only stage 1 sleep. That might be what keeps them alive for 9 months. If stage 1 was blocked, I venture to guess their survival duration would be much lower.
- tim333 11y ago
  Here's some other research data. In Guamtanamo they kept prisoners awake 11 days and found "surprisingly, little seem[s] to go wrong with the subjects physically." In rat experiments they all died by 32 days. I'm guessing full sleep depravation in humans would have a similar result to rats though thankfully no one seems to have tried that. http://www.slate.com/articles/news_and_politics/explainer/2009/05/can_you_die_from_lack_of_sleep.html http://www.slate.com/articles/news_and_politics/explainer/20...

asciimo 11y ago

>If this proves to be true in humans as well... Wake me up when they publish that paper.

jeffdavis 11y ago

So why does a lion need to sleep for 18 hours then?

lxfontes 11y ago

brain: longest garbage collection cycle ever

vlunkr 11y ago

It's fascinating to me that we still don't know why we sleep. We spend 1/3 of our lives in a self induced coma-like state and we aren't sure why, except that if you don't you start to go crazy. It will be interesting to see how this develops!

rudolf0 11y ago

>In Guantanamo they kept prisoners awake 11 days Somewhat off-topic, but how could anyone possibly argue this is not torture?

Kenji 11y ago
Is anyone arguing that torture is not something that happens in Guantanamo? By now it should be common knowledge that it's a torture camp. Obama promised to shut it down but he didn't.
- rudolf0 11y ago
  I don't think anyone on HN has argued that, but many people in the general public still insist that "enhanced interrogation" like what's done in Guantanamo is not actually torture. Or at least they used to, until Obama finally admitted people have been tortured; though some still insist it isn't torture. My question was more hypothetical. That seems like the very definition of torture.
  - georgemcbay 11y ago
    Those people know it is really torture, they are just able to handwave it away because the people it is happening to believe in a slightly different god than they do.
  - gclaramunt 11y ago
    Is not torture when the good guys do it! Specially when there's a ticking bomb
- rancur 11y ago
  I'm sorry, were you one of those silly students I was in college with who thought he would?
guelo 11y ago
Like Mengele, there's interesting science that can be conducted when you have no morals.

carsongross 11y ago

WHY? WHY IN GODS NAME?!?! Why would such a preposterously dangerous state, complete defenselessness, not be engineered around by darwinian pressure?!?

gress 11y ago
Because it isn't.

tim333 11y ago

There's a nice gif on Wikipedia showing something like fluid flow in question: https://en.wikipedia.org/wiki/Cerebrospinal_fluid#Circulation https://en.wikipedia.org/wiki/Cerebrospinal_fluid#Circulatio...

cthyon 11y ago

Does anyone know if there is research about whether this at all impacts/plays a part in causing dreams?

rebootthesystem 11y ago

Many years ago, during a stupid-er time in my life, I stayed up three nights in a row. I was working on a robotics paper to present at a conference. My first. It was a massive project and things had fallen behind schedule. With just three days left until I was supposed to be on a plane I had no choice but to work on the thing continuously and get it done. It was a solid three days of writing code and building/testing boards. I got done and packed with a couple of hours to spare before having to go to the airport. For some reason I could not sleep on the flight from Los Angeles to Seattle. Once I got to the room at the hotel I pretty much collapsed on the bed. My talk was scheduled for the next morning. I figured I could sleep a solid 12 hours and have a couple to get ready for the talk/presentation. Somewhere in the middle of the night I woke up. I have no clue how long I slept up to that point. I had lost all sense of time. I went to the bathroom. And that's when the nightmare started. I washed my face and almost immediately my ears started to buzz. It was something like a 1kHz sine wave. It started at a low level and got louder and louder. Scary. At a certain point, my field of vision started to turn milky white. The tone got louder and all I could see was a bright white light engulfing my entire field of view. I was blind and deaf and in the worst possible circumstances I could imagine. I have no clue how long it all lasted. It felt like somewhere around 15 minutes. It could have been just thirty seconds but I had no sense of time and I was freaking out. All I could do was sit on the bathroom floor, hold on to something and think through the worst possible scenarios. After what I guess was about fifteen minutes my vision started to slowly come back and the tone started to fade away. That must have taken another 5 to 15 minutes. I was drenched in sweat and scared like I had never been in my life. I've never done drugs or alcohol. I imagined this had to be like a grade-A drug addict overdose experience, or worst. All I could do was go back to sleep after that. I was exhausted. The next day I asked to have my talk re-scheduled and went to see a doctor. He told me I was an idiot and lucky not to have ended-up in the ER with brain damage. That was the last time I worked on anything overnight. I know tech companies have a culture of working long hours to get things done. Be sure you are not killing yourself to crank out another 100 lines of meaningless code. The world can wait. And if your VC's don't understand you'd like to live a long an healthy life, well, fuck them.

roflmyeggo 11y ago

Yet another reason to get a good nights sleep. Many of these metabolic degradation products (not just beta-amyloid) of neuronal cell activities should readily be cleared quickly and efficiently from the interstitial space of the brain due to the highly sensitive nature of neuronal cells to their environment. Some negative effects documented from these byproducts include: negatively effecting synaptic transmission[1], decreasing cytosolic Ca2+ concentrations[2] (Ca2+ is one of the final players in the triggering the release of neurotransmitters into the synapse between neurons to facilitate messages), and irreversible neuronal injury[3]. [1] - K. Parameshwaran, M. Dhanasekaran, V. Suppiramaniam, Amyloid beta peptides and glutamatergic synaptic dysregulation. Exp. Neurol. 210, 7–13 (2008) [2] - K. V. Kuchibhotla, S. T. Goldman, C. R. Lattarulo, H. Y. Wu, B. T. Hyman, B. J. Bacskai, Abeta plaques lead to aberrant regulation of calcium homeostasis in vivo resulting in structural and functional disruption of neuronal networks. Neuron 59, 214–225 (2008) [3] - M. P. Mattson, Calcium and neuronal injury in Alzheimer’s disease. Contributions of beta-amyloid precursor protein mismetabolism, free radicals, and metabolic compromise. Ann. N. Y. Acad. Sci. 747, 50–76 (1994)

brad3378 11y ago

I have a harder time controlling my appetite if I don't get enough sleep. Could these toxins be related?

Strom 11y ago
Perhaps, as serotonin does regulate both sleep & appetite.

bjd2385 11y ago

This is fascinating!