字幕表 動画を再生する 英語字幕をプリント Why do we have to sleep? I am losing valuable life hours here! Anthony here for DNews, and I have always wondered just why exactly we have to sleep. Do you know how much I can do if I never got tired. Scientists wonder about it too. Every animal participates in some form of sleep, even though it puts us all in an incredibly vulnerable state; Anything can get you, seems wasteful. So, it must perform some function that is so important it is worth the trade-off of being killed by a predator who is on a slightly different work schedule. There are a few theories. One is that it gives us more time to repair our muscles and cells. One is that it lowers the amount of energy we need and less energy means less meals, means less hunting and gathering, which we can't really do in the dark anyway. One of the recent and most popular theories has to do with memory consolidation. when we sleep, our brain takes everything we have seen and done throughout the day and filters through it. Looks for patterns, sifts through what it finds an essential and decides what to turn into a memory. And some experts think that dreams are a sort of representation of that; It's like a nightly clean up. We've seen evidence of it. Studies show that if you get sleep right after practicing something that takes fine motor skills, like typing or playing an instrument, it helps you retain that knowledge faster. Missing a night of sleep can mess with attention, awareness reasoning, problem solving skills. But the super weird thing is that even without sleep body repair happens. So where is the big benefit? Researchers from the University of Rochester think they found it. Turns out sleep isn't just a mental house cleaning for your brain, it's a physical one. Your body has got a great system for flushing all the unneeded stuff out that piles up; It's called the Lymphatic System. But the Lymphatic system does not extend to your brain. And your think box keeps itself locked up behind something called the Blood Brain Barrier, which tightly regulates everything that comes in and out. Your brain controls everything so it keeps itself in a high security area where it can't be contaminated. But it has to get rid of its waste products somehow, but we have never actually been able to see how. But using new technology called Two Photon Microscopy, the Rochester researchers were able to see the brain's disposal system. They're calling it The Glymphatic System. It's this plumbing system that pumps cerebral spinal fluid through brain tissue and then flushes it into your circulatory system and the Lymphatic system just takes it from there. And here is where sleep comes in. The Glymphatic system seem to be about ten time more active during sleep in mice. It seems like pushing all that CSF through its system requires a lot of energy, so your brain makes a choice: Run your body or clean itself. That seems to be why our brain uses as much energy when we are asleep as it does when we are awake. Not only that, it looks like brain cells shrink up to 60% during sleep, so all that CSF can wash over it faster. So what makes this flushing process more important that cell repair or forming memories? Well, build up of waste is linked to serious brain diseases, like Alzheimer's. If you don't shut down every night, your brain can't clean itself out properly enough. I don't know, are you guys getting enough sleep? Let me know down below, but don't brag and subscribe for more DNews.