6 ms·

> The process is important because what's getting washed away during sleep are waste proteins that are toxic to brain cells, Nedergaard says. Evolution found a

by mabbo 10y ago

> The process is important because what's getting washed away during sleep are waste proteins that are toxic to brain cells, Nedergaard says. Evolution found a nice little optimum in sleep that works pretty well- use less energy during a time of the day that isn't a very efficient time to be awake while also cleaning out the brain. This could be interesting for future research. Could we find chemical means to remove those waste proteins?

bryondowd 10y ago
There's an interesting concept. I wonder what the trade-off would be. How much efficiency would it cost to clean the brain continually rather than in a dedicated sleep cycle? Would it even be possible to process these toxins while maintaining consciousness? I'm sure there could be huge benefits for many modern lifestyles to trade heavily on reaction speed and/or lightly on IQ for 50% more waking hours. Or even 25% more waking hours, if you just cut the need for sleep in half, over the long term.
- mrzool 10y ago
  Why force things? I don't want 50% more waking hours. I enjoy my sleep tremendously.
  - bmelton 10y ago
    I suspect (but do not know) that you enjoy your sleep because of its restorative effect. If you could obviate the need for the restorative effect, and instead just always feel newly restored, would you still enjoy going to sleep for no reason? Personally, I dislike the need for sleep. I put it off for as long as I can manage, and try to get as little of it as I can get away with. For me, I have a hard time functioning well with less than 4 hours a night, but anything more then 5.5 hours and I feel like I've thrown the day away. The idea of voluntarily checking out from the world isn't as relaxing to me as picking up a book to read, or learning something new, or doing something productive that isn't work/startup-related. Either way, I assume that nobody would force you to take a drug that you didn't want to take.
    - eckza 10y ago
      Oh my god, think of what this would do to commerce, in terms of a capitalist society. Suddenly, you can take a drug that decreases your need for sleep by 50%. People only need 4h of sleep per night now, for a full nights' sleep - 3h, if you're willing to skimp a little, 2h isn't unheard of (in the way that only getting 4h of sleep a night, now, isn't unheard of either). Suddenly, there's a significant advantage in the hands of everyone willing to take this drug. Students are expected to study more and harder, because they don't need 8h of sleep every night. Entrance exams to schools get more difficult. Software developers are now enticed to work longer hours - longer hours than they already are. Labor / shift workers (hospitality / food industry) are expected to work longer shifts, and they have to, because businesses have to be open longer because more people are awake for more of the day. Now, also, you have to consider: this is just sleep, in terms of brain repair. Your body has to put itself back together every night, too - repairing microscopic muscle tears, fixing bruises, etc etc etc. Your body would probably start slowly falling apart on 2-3h of sleep per night, even if your mind was fully rested. I really, really hope this doesn't happen.
      - ChuckMcM 10y ago
        It is entirely possible that it would evolve differently, perhaps given that not everyone would be available during the 'dark' hours you might see a society evolve into dual function, where 8 hours were for 'working' and 8 hours were for 'community/family' with 8 hours split into two 4 hour segments as 'transition times'.
        bmelton 10y ago
        I was thinking this as well. I suspect that it's impossible to predict, but I wouldn't think it unfathomable to imagine a world in which, with all the additional free time, society might evolve towards a more Italian ethos, in which we take longer lunches, and don't mind spending as much overall time 'at the office', though not necessarily working any more while there.
        eckza 10y ago
- clort 10y ago
  some birds (and dolphins?) sleep one hemisphere at a time, so that they can keep flying
- JoshCole 10y ago
  I think from the evolutionary perspective, being active during a time of low fitness gets punished. So if there was an adaption that tended to paralyze something when it was dark out, that gets selected for even though obviously given optimal decisions not being paralyzed is better. Which, if you think about it, is kind of what is happening with sleep. So I imagine the trade-off isn't as severe as someone might guess; it's definitely theoretically possible to run entirely without sleep with the right hardware. For example, lets say sleep was fundamental to cognition. If you were willing to have redundant hardware, you could run two brains and just take turns sleeping them [1]. So that probably gives something of an upper-bound to efficiency. The problem is that a lot of stuff is getting built on top of these things. Scheduled downtime is getting used by other adaptions. Things like handling 'garbage collection' or 'waste collection' inline get shunted away to the downtime to improve response times. This keeps happening. Over short periods there are going to be plenty of cases where being paralyzed isn't optimal. What if something shows in the night? Long term though if the creature is continually staying active when its at disadvantage that's really bad. So additional penalties accrue to force the issue. Then the original 'purpose/benefit' starts getting lost. Things get messed up. Enough adaptions end up taking advantage of the fact that the downtime existed that now there is so much benefit to it for reasons unrelated to its initial creation that it starts becoming worth doing even at times where light levels aren't an issue. So now when you try to mess with sleep, you're not just messing with one little thing. You're messing with a whole bunch of different entangled processes. One to reduce activity during periods where the sensors suck. Another to prevent continued activity when the sensors suck. Another that handles waste. Another that starts up ML algorithms during the downtime to take advantage of the freed-up processing. Another that does data backup. The muscles use the downtime to start construction. Basically all over the body everyone is starting to get to work. It's like that tradeoff problem that gwern talks about with using notropics, where each one improves one thing but causes problems in other areas. So basically, it isn't a question of whether or not you need sleep from a theoretical process perspective. You don't, if you had a different design. But now sleep isn't just the reduce activity time because its night adaption. It's all tied up in everything else. You shorten the amount you sleep? You die younger, because you cancelled the bodies maintenance period. [1]: Which dolphins are kind of doing.
- randcraw 10y ago
  I think nature's solution to this kind of inefficiency arises by adopting a new social behavior rather than evolving a new DNA-based physical ability. It's easier and faster for a group of animals to appoint a guard to protect others during sleep than for the species to evolve a superior brain.
Tharkun 10y ago
The blood/brain barrier makes it difficult to deliver chemical means to the brain.
zip1234 10y ago
Or maybe some sort of mechanical pumping system? If it takes too much energy away from the brain to both remain awake and clear those proteins, a mechanical pump that is powered externally could solve that energy problem. (I'm only half joking--we already have mechanical means of replacing other biological functions such as a dialysis machine).
- che_shirecat 10y ago
  Along this line of thinking, if we knew exactly what was happening in the brain during sleep, could we speed up the process with mechanical/chemical means? Could we turn off brain functions to shrink the cells (or co-opt the existing sleep process and do this after one has fallen asleep), do the cleaning process (faster, while keeping the same effect) then wake up for maybe 30 minutes total of "sleep" a day? I personally don't think it's possible, at least for another century or so, because it's attempting to hack a body function and do it better (faster) than the body naturally does it (a dialysis machine is a poor substitute for a real kidney). Is there any example of a biomedical tech advancement where some part or mechanism in our body was augmented/replaced with something works better than the original?
  - twinkletwinkle 10y ago
    The elbow surgery that baseball pitchers sometimes need. There were reports of pitchers throwing better afterwards, which led to young aspiring pitchers with healthy elbows requesting the surgery. I don't know much about the actual process, I was just reading an article about the ethics of operating on a normal elbow in order to gain some competitive advantage.
    - ghthor 10y ago
      This doesn't sound far fetched at all. Small injuries are a way to focus the body to enter a recovery phase where the end result is a bone/tissue configuration that is strong and less likely to be repeat injured. Martial Artists have been practicing this type of body modification for centuries to bones, ligaments, muscles, and minds. I've experienced it through my own personal knee surgeries. And I wouldn't be surprised if in the future we offer body enhancements to healthy indivuals through surgery that will improve performance or long term health.

by mabbo 10y ago

bryondowd 10y ago

There's an interesting concept. I wonder what the trade-off would be. How much efficiency would it cost to clean the brain continually rather than in a dedicated sleep cycle? Would it even be possible to process these toxins while maintaining consciousness? I'm sure there could be huge benefits for many modern lifestyles to trade heavily on reaction speed and/or lightly on IQ for 50% more waking hours. Or even 25% more waking hours, if you just cut the need for sleep in half, over the long term.

mrzool 10y ago
Why force things? I don't want 50% more waking hours. I enjoy my sleep tremendously.
- bmelton 10y ago
  I suspect (but do not know) that you enjoy your sleep because of its restorative effect. If you could obviate the need for the restorative effect, and instead just always feel newly restored, would you still enjoy going to sleep for no reason? Personally, I dislike the need for sleep. I put it off for as long as I can manage, and try to get as little of it as I can get away with. For me, I have a hard time functioning well with less than 4 hours a night, but anything more then 5.5 hours and I feel like I've thrown the day away. The idea of voluntarily checking out from the world isn't as relaxing to me as picking up a book to read, or learning something new, or doing something productive that isn't work/startup-related. Either way, I assume that nobody would force you to take a drug that you didn't want to take.
  - eckza 10y ago
    Oh my god, think of what this would do to commerce, in terms of a capitalist society. Suddenly, you can take a drug that decreases your need for sleep by 50%. People only need 4h of sleep per night now, for a full nights' sleep - 3h, if you're willing to skimp a little, 2h isn't unheard of (in the way that only getting 4h of sleep a night, now, isn't unheard of either). Suddenly, there's a significant advantage in the hands of everyone willing to take this drug. Students are expected to study more and harder, because they don't need 8h of sleep every night. Entrance exams to schools get more difficult. Software developers are now enticed to work longer hours - longer hours than they already are. Labor / shift workers (hospitality / food industry) are expected to work longer shifts, and they have to, because businesses have to be open longer because more people are awake for more of the day. Now, also, you have to consider: this is just sleep, in terms of brain repair. Your body has to put itself back together every night, too - repairing microscopic muscle tears, fixing bruises, etc etc etc. Your body would probably start slowly falling apart on 2-3h of sleep per night, even if your mind was fully rested. I really, really hope this doesn't happen.
    - ChuckMcM 10y ago
      It is entirely possible that it would evolve differently, perhaps given that not everyone would be available during the 'dark' hours you might see a society evolve into dual function, where 8 hours were for 'working' and 8 hours were for 'community/family' with 8 hours split into two 4 hour segments as 'transition times'.
      - bmelton 10y ago
        I was thinking this as well. I suspect that it's impossible to predict, but I wouldn't think it unfathomable to imagine a world in which, with all the additional free time, society might evolve towards a more Italian ethos, in which we take longer lunches, and don't mind spending as much overall time 'at the office', though not necessarily working any more while there.
        eckza 10y ago
clort 10y ago
some birds (and dolphins?) sleep one hemisphere at a time, so that they can keep flying
JoshCole 10y ago
I think from the evolutionary perspective, being active during a time of low fitness gets punished. So if there was an adaption that tended to paralyze something when it was dark out, that gets selected for even though obviously given optimal decisions not being paralyzed is better. Which, if you think about it, is kind of what is happening with sleep. So I imagine the trade-off isn't as severe as someone might guess; it's definitely theoretically possible to run entirely without sleep with the right hardware. For example, lets say sleep was fundamental to cognition. If you were willing to have redundant hardware, you could run two brains and just take turns sleeping them [1]. So that probably gives something of an upper-bound to efficiency. The problem is that a lot of stuff is getting built on top of these things. Scheduled downtime is getting used by other adaptions. Things like handling 'garbage collection' or 'waste collection' inline get shunted away to the downtime to improve response times. This keeps happening. Over short periods there are going to be plenty of cases where being paralyzed isn't optimal. What if something shows in the night? Long term though if the creature is continually staying active when its at disadvantage that's really bad. So additional penalties accrue to force the issue. Then the original 'purpose/benefit' starts getting lost. Things get messed up. Enough adaptions end up taking advantage of the fact that the downtime existed that now there is so much benefit to it for reasons unrelated to its initial creation that it starts becoming worth doing even at times where light levels aren't an issue. So now when you try to mess with sleep, you're not just messing with one little thing. You're messing with a whole bunch of different entangled processes. One to reduce activity during periods where the sensors suck. Another to prevent continued activity when the sensors suck. Another that handles waste. Another that starts up ML algorithms during the downtime to take advantage of the freed-up processing. Another that does data backup. The muscles use the downtime to start construction. Basically all over the body everyone is starting to get to work. It's like that tradeoff problem that gwern talks about with using notropics, where each one improves one thing but causes problems in other areas. So basically, it isn't a question of whether or not you need sleep from a theoretical process perspective. You don't, if you had a different design. But now sleep isn't just the reduce activity time because its night adaption. It's all tied up in everything else. You shorten the amount you sleep? You die younger, because you cancelled the bodies maintenance period. [1]: Which dolphins are kind of doing.
randcraw 10y ago
I think nature's solution to this kind of inefficiency arises by adopting a new social behavior rather than evolving a new DNA-based physical ability. It's easier and faster for a group of animals to appoint a guard to protect others during sleep than for the species to evolve a superior brain.

Tharkun 10y ago

The blood/brain barrier makes it difficult to deliver chemical means to the brain.

zip1234 10y ago

Or maybe some sort of mechanical pumping system? If it takes too much energy away from the brain to both remain awake and clear those proteins, a mechanical pump that is powered externally could solve that energy problem. (I'm only half joking--we already have mechanical means of replacing other biological functions such as a dialysis machine).

che_shirecat 10y ago
Along this line of thinking, if we knew exactly what was happening in the brain during sleep, could we speed up the process with mechanical/chemical means? Could we turn off brain functions to shrink the cells (or co-opt the existing sleep process and do this after one has fallen asleep), do the cleaning process (faster, while keeping the same effect) then wake up for maybe 30 minutes total of "sleep" a day? I personally don't think it's possible, at least for another century or so, because it's attempting to hack a body function and do it better (faster) than the body naturally does it (a dialysis machine is a poor substitute for a real kidney). Is there any example of a biomedical tech advancement where some part or mechanism in our body was augmented/replaced with something works better than the original?
- twinkletwinkle 10y ago
  The elbow surgery that baseball pitchers sometimes need. There were reports of pitchers throwing better afterwards, which led to young aspiring pitchers with healthy elbows requesting the surgery. I don't know much about the actual process, I was just reading an article about the ethics of operating on a normal elbow in order to gain some competitive advantage.
  - ghthor 10y ago
    This doesn't sound far fetched at all. Small injuries are a way to focus the body to enter a recovery phase where the end result is a bone/tissue configuration that is strong and less likely to be repeat injured. Martial Artists have been practicing this type of body modification for centuries to bones, ligaments, muscles, and minds. I've experienced it through my own personal knee surgeries. And I wouldn't be surprised if in the future we offer body enhancements to healthy indivuals through surgery that will improve performance or long term health.