9 Groundbreaking Discoveries About Sleep

  • Added:  3 months ago
  • There's a lot about sleep that we don't understand, like why we even sleep in the first place, for example. Here are some amazing discoveries biologists have made while trying to solve the mystery of sleep.

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    Brain activity

    Brain centers




    Blue light


  • Video CategoriesEducation
  • Runtime: 10:35
  • Tags for this video:  SciShow  science  Hank  Green  education  learn  sleep  fatal familial insomnia  insomnia  thalamus  human body  health  memory  brain  rem  eeg  brain wave  constantin von economo  brain stem  hypothalamus  sleep science  biology  narcolepsy  chronic pain  fibromyalgia  sleep deprivation  blue light  wavelength  melatonin  light  astrocytes  spinal fluid  medicine  alzheimers  

Comments: 1 502

  • The Trident Gamer
    The Trident Gamer 29 minutes ago

    Was the host wearing a TRIFORCE t-shirt?

  • James August
    James August 7 days ago

    after seeing the background pic at 6:05, insomnia may be a problem tonight.. Also, Uberman? Where does that fit? I read somewhere where people were on that schedule for 6 months+

  • Fresh M3
    Fresh M3 7 days ago

    Sleep = memory consolidation, and astrocytes cleaning out your brain because you know... the BBB is pretty tight. Generally everything else that you stated in this video is in response to this. Hopes this helps people that like facts. Sleep doesn't use a pain system, you have a little guy in your brain that paralyzes you PAG, Periaquaductal Gray I think (been a while since 1st year of medical school)... Everything uses the same pain system because it uses your pain fibers and your pain tract. Until you get into the CNS pain that you have to use weird things for... but I'm going on a tangent.... Memory consolidation, astrocytes. Just go with that and no one in science/medicine will ever question what you say.

    Edit: I just got to number 8.... and realized he said Astrocytes lol... Whoops...

  • Plum_ Pie
    Plum_ Pie 8 days ago

    whenever go hiking and i only get like 4gours of sleep in the forest i wake up feeling more rested then i wuld ahve if i was at hme gettig 8hours

  • Tha Spectator
    Tha Spectator 13 days ago

    Guys I'm very close to dying I got to sleep at 1:00 and wakeup at 5am. No wonder why I can't remember shit and I have Chronic Neck Pain. I'm going to sleep before it becomes my last time.
    *Good Night*

  • PrettyLittleArii
    PrettyLittleArii 14 days ago

    Lmao and im watching this video at 3am...

  • Tagger Tag
    Tagger Tag 14 days ago

    The horrible shit we humans did to animals for science.. We owe Rats in particular an apology. God will punish us all.

  • 3majsie maciek
    3majsie maciek 15 days ago

    10:05 Milking a cow!? Did I guessed it?

  • Kiwi Blood
    Kiwi Blood 15 days ago

    "-a region of the brain called the hippocampus."
    First thing I think of
    I actually didn't know we had hippocampi in our head.
    Hmm... I'm calling mine Rainbow.

  • Tsen Animation
    Tsen Animation 15 days ago

    my friend believed that his classmate can be awake for a month without sleeping

  • 8000 cats
    8000 cats 16 days ago

    Lmao, when I first clicked on this video, I thought it said "9 Groundbreaking Discoveries About SHEEP" Counting sheep lol?

  • Saadman Yasar
    Saadman Yasar 17 days ago

    Rats everywhere

  • jeaniebird
    jeaniebird 17 days ago

    I didn't sleep for 6 months straight, once. I went insane, eventually landing in the local loony bin. It was hell. Doctors never figured out, or never admitted, why. I'm positive it's because they kept trying new drugs on me and I just kept reacting badly. After 3 months I had to start refusing because I just couldn't take the side effects, anymore. 3 months after that, I finally slept... Hmm

  • jeaniebird
    jeaniebird 17 days ago

    I had to reschedule a back tattoo I had going once, because I didn't get any sleep the night before. It was ten times more painful than usual. After an hour, I just couldn't take it anymore. I was shocked how much of a difference that made.

  • Jon Lopez
    Jon Lopez 19 days ago


    if jmkjn

  • Beef Shishkabob
    Beef Shishkabob 21 day ago

    I don't understand how "we don't know why we sleep" but 30 seconds later he says we sleep so our body can rest. Isn't that the reason why we sleep? Someone please clarify

  • Christian Andrade
    Christian Andrade 21 day ago

    Why are we so mean to rats?

  • KarinARTS
    KarinARTS 22 days ago

    What's funny is that I'm watching this to force myself not to sleep.....

  • Turtletech Inc.
    Turtletech Inc. 22 days ago

    The hippocampus, where all your memories about hippos are stored

  • Techdroid India
    Techdroid India 23 days ago

    You can use blue light filter apps to use your phone during night without disrupting your sleep cycle.😀📱

  • 1 For The People
    1 For The People 23 days ago

    Good video! ?Could you please do a video about dishwashing? Sounds mundane I know, but my partner and I are having controversy over hand dishwashing vs dishwasher machine and the temperature of hot water. I say sterilizing hot water has to be at least 165degrees F in which you could not handwash dishes because it's too hot. However if you handwash the dishes with a good soap well, rinsed in cool water the dishes are just as clean if not better than in a dishwashing machine. Sterilizing dishes in a machine is OK but wouldn't you also have to keep them in a sterilized environment? Thank you for sharing. Keep up the good work.

  • bradOLF pittLER
    bradOLF pittLER 26 days ago

    it'd be hard to discover all of this stuff without animal testing.

  • Saleem Al-Agha
    Saleem Al-Agha 26 days ago

    i think wifi interferes with sleep

  • offspring
    offspring 26 days ago

    watching cat videos in the middle of the night?? meeen i did it sometimes

  • Elizabeth Shaw
    Elizabeth Shaw 27 days ago

    I have horrific iretractable chronic pain which is not fibromyalgia. it is exhausting and I need to take a nap in the afternoon and I need 10 hours sleep at night or the pain explodes beyond what I can stand.

  • alex parada
    alex parada 27 days ago

    I dont sleep cuz sleep is the cousin of death *thug life music and glasses then dies*

  • SirMan McDude
    SirMan McDude 28 days ago

    So being in non-REM sleep is where your brain files away and stores what it deems to be important while REM sleep is the brain saying "Fuck it, let's run some simulations 'cause we're bored"

  • LittleMissGamerGal
    LittleMissGamerGal 29 days ago

    Dont look at devices a few hours before bed... yet im watching this before bed. i wouldnt have learned that unless I was exposed to blue light now..

  • Fernando Alatorre
    Fernando Alatorre 29 days ago

    It seems to me a bit naive to say "we don't know why we sleep" and on the other hand being so certain about all of the counter effects of not sleeping. Could it not just be that your body does that (sleeps) so that those terrible, fatal counter effects don't happen? Could it not be that your body knows (in a very broad sense of the word) that those effects will occur and thus intends to prevent them by sleeping?

    I mean the guy in the video says, we don't know why we sleep... and then immediately after he says, a lack of sleep will literally kill you....

    So maybe we sleep so we don't die?

  • Private X
    Private X 1 month ago

    Ok. Good night.

  • ordinary Oddball
    ordinary Oddball 1 month ago

    I have f.lux on my PC and Night Shift on my iPhone, but I use my iPad the most in bed and it's old enough that it doesn't have a Night Shift. How do I make it do the orange light thing?

  • z9elka
    z9elka 1 month ago

    poor rats :(

  • Riste dzisev
    Riste dzisev 1 month ago

    Man youre crazy i sleep with lights on and my phone on a youtube playlist the whole night with 2 pillows and a giant blanket over my head. Its pretty comfortable and i would much rather have that than pitch black and quiet and listen to my ears rinning and think the monster from russian sleep experiment or the devil with no eyes and blood is staring at me waitting for me to move and shit my pants jesusCHRIST

  • Krishna Vma
    Krishna Vma 1 month ago

    Thank you for this. All my life I've been a chronic sleep avoider, seeing it as wasted time. My loved ones will be happy to hear that you have managed to convince me that sleep really is necessary and mandatory. Cheers! 🙂

  • Amazing Deep House
    Amazing Deep House 1 month ago

    the poor rats

  • lamp 81
    lamp 81 1 month ago

    I really had no idea that fibromyalgia was worsened by lack of sleep. It really does correspond to my pain levels when I cannot sleep and I cannot do much the next day due to pain and fuzzy brain and lack of motivation. This pain builds up if I do exercise during a bad a day and then keeps me awake the next night because I cannot find a comfortable position. So...if I can somehow sleep then I can feel better and break the cycle! Thanks for the info! I am going to have to stop looking at my phone in bed and just listen to audible or white noise and maybe magazines, catalogues or crossword puzzles, even though that means I leave a light while I am fall asleep. Ok, giving this a try. Amazing!

  • Out Of Place Ninja
    Out Of Place Ninja 1 month ago

    Wait, number six, there was somebody who purposely burned mice, then purposely deprived them of sleep for the purpose of "study"? Sounds like some areas of science is where the crazy people hide to stay out of trouble with society and the law lol.

  • Lin He
    Lin He 1 month ago

    Here I am, watching a YouTube video on my iPad right before bed time.

  • Sierra Miranda
    Sierra Miranda 1 month ago

    Don't we sleep because we're tired of doing shit all day???? I thought it as common sense

  • kidego3kgt
    kidego3kgt 1 month ago

    All those dead rats. RIP.

  • Bill Hampton
    Bill Hampton 1 month ago

    Anybody ever tried meth ? Holy fuck! , 80 hours without one wink of sleep . That shit is crazy I don't how people can keep doing that stuff .

  • IAmAgainst
    IAmAgainst 1 month ago

    Am I the only one thinking in the miserable life the rats in those studies had..?

  • Muscle Man
    Muscle Man 1 month ago

    where did you get your shirt?

  • Elena Sucec
    Elena Sucec 1 month ago

    Poor Rats they take so much @&$% so we don't have to. They definitely got the short end of the stick

  • Elena Sucec
    Elena Sucec 1 month ago

    Who else is procrastinateing sleep staying up late watching YouTube videos!

  • Eduardo Paulo
    Eduardo Paulo 1 month ago


  • EatenRibs i-si-u
    EatenRibs i-si-u 1 month ago

    " still running in the family* but they keep reproducing, such genes to protect ...

  • Jim McBride
    Jim McBride 1 month ago

    "Sleeplessness makes pain worse." Seems reason enough for getting sleep, fwiw

  • Dennis Jasperse
    Dennis Jasperse 1 month ago

    So how do you explain most of the time set the alarm clock and most of the time you wake up maybe 5 minutes early!!!!

  • Doug sillig
    Doug sillig 1 month ago

    is it just me or is Hank's voice a little raspy?

  • Notlehs Bulb
    Notlehs Bulb 1 month ago

    Anyone else watching at 3am?

  • Michael Carter
    Michael Carter 1 month ago

    Why are you fidgeting and using hand gestures so much? It's random; like your just fidgeting just to fidget. Plus it's annoying. until you can tone it down, in unsubscribing.

  • Mikael Durbin
    Mikael Durbin 1 month ago

    My wife and two children have FFI. This mutation is trying to take everything I love. Is there any breakthroughs anywhere? Vanderbilt didn't have a clue what we were even talking about. The dr didn't even take the time to google it

  • spartanace13
    spartanace13 1 month ago

    8:05 Wrong kind of cat video, guess again.

  • Mathy Don
    Mathy Don 1 month ago

    Aw those poor rats, what a way to die. Sleep deprived to death...

  • Wolfpack Q
    Wolfpack Q 1 month ago

    I could use some sleep

  • pete1
    pete1 1 month ago

    If you take one thing from that video it should be: don't get reincarnated as a rat!

  • Ni Enye
    Ni Enye 1 month ago

    eeg isn't a new technique at all. wait.... how did I get here. I need to sleep.

  • Dreterria Maiden
    Dreterria Maiden 1 month ago

    So....we're Rats now ?😂

  • Clarinet Catato
    Clarinet Catato 1 month ago

    Here's what I think are the two most important facts about sleep: The fact that sleep is necessary and how much you should get

  • BvsMAcosh
    BvsMAcosh 1 month ago

    none of this is groundbreaking. Or even new.

  • actsrv9
    actsrv9 1 month ago

    poor lab rats

  • Vio
    Vio 1 month ago

    i have such a shit sleep schedule/cycle i know my brain & body are getting rekt.

  • Lester Stumpf
    Lester Stumpf 1 month ago

    am i the only one who is glad to not be a rat?

  • Graxster
    Graxster 1 month ago

    I guess it's a good thing that I go to sleep every night. Oh wait... I wasn't even worried about it. :D

  • apcolleen
    apcolleen 1 month ago

    what did people blame insomnia on before electricity?

  • Praise Pepe, God of Kek

    Well, that are happy rats

  • edward Andrews
    edward Andrews 1 month ago

    i only sleep for a hour and a half, been this way all my life, ive never had any side affects, i always feel rested and alert, and i even dream, drove my parents nuts when i was a child

  • bnighter
    bnighter 1 month ago

    so my kindle is killing me. softly.

  • icedragonxl4
    icedragonxl4 1 month ago

    There were some incorrect facts in this video that I hope it's okay for me to correct. In the first discovery that says that sleep can kill you is incorrect. The truth is we don't quite actually know if that's the case yet or at all. Yes mice die after a couple of weeks with no sleep but the symptoms that cause them to die don't seem to show in humans I believe; and yes, fatal familial insomnia is deadly and kills those afflicted with it, but again, we don't know if it's the lack of sleep that causes the death or the other symptoms of the disorder. Also, the date in #3 was incorrect as well. The activity of the brain during sleep wasn't discovered until the 1950s at the University of Chicago using electroencephalogram.

  • Ron Josh Ytem
    Ron Josh Ytem 1 month ago

    I wonder if the memory test was affected by the intermittent information gathered while the subjects stayed awake.

  • Eileen Albers
    Eileen Albers 2 months ago

    Fuck those people who kept the rats from sleeping

  • Algore Daemon
    Algore Daemon 2 months ago

    Indeed the correlation between sleep and memory is a very interesting one, particularly how deep-sleep is more related to memory consolidation (or perhaps 'dumping' instead). Now the thing I'm really curious about is the potential relationship between sleep and creativity, possibly also having to do with REM and the rich-associative and cognitive process of dreaming, which hasn't been given much thought in sleep studies at all until now. And this might have more to do with specific hormones but, you can ask any professional artist about their sleeping habits and overall productivity; you can't think and be genuinely creative unless you've had a good night sleep.

  • lovexsqualor
    lovexsqualor 2 months ago

    Wow lots of rat torture going on.

  • Amir Khan
    Amir Khan 2 months ago

    here we are still trying to understand why we sleep in this "advanced age" . and we still able to confidently shun the existence of God . have you any proof ??!

  • William Dwyer
    William Dwyer 2 months ago

    Prior to taming the dog (wolf), people probably had to sleep with "one eye open." Predators larger than us were in great abundance back then. So it wouldn't have been until dogs became common, that people could finally get a good night's sleep.

  • Jinx4one
    Jinx4one 2 months ago

    If less sleep is bad, what is the effect of too much sleep?

  • bluebooksky1
    bluebooksky1 2 months ago

    oh my God poor rats. 😞

  • ilikeceral3
    ilikeceral3 2 months ago

    Discovery by me: wow! Getting a full night's rest really DOES help! Too bad I never do it.

  • Trevor Carr
    Trevor Carr 2 months ago

    Scientist's gotta laugh sometimes, we sleep because WE ARE TIRED simple really.

  • Martin Collins
    Martin Collins 2 months ago

    That I'm not getting enough

  • daisy3690
    daisy3690 2 months ago


  • SajoieDeVie
    SajoieDeVie 2 months ago

    I have childhood onset idiopathic insomnia, so I can tell you that not sleeping sucks incredibly. Also, I watch a lot of insomnia related videos just in case one day doctors figure out my specific type of insomnia.

  • Vijay Agrawal
    Vijay Agrawal 2 months ago

    how did they make the rats not go to sleep?

  • Piggy
    Piggy 2 months ago

    so ironic of me to watch this at 3 am

  • vogonsrock
    vogonsrock 2 months ago

    Great video (although in this case didn't tell me anything new) but what I mostly went away with from this was 'gee rodents have *really* suffered in our attempts to figure out sleep'.

    TRUE JUSTICE ALLAH 2 months ago

    Best App for PC in my opinion for blue-light-reduction is; FLUX(f.lux)
    The best for MOBILE are; EasyEyes(easiest), Twilight or flux mobile. I would use easy eyes as Twilight gets a little invasive.

  • ummm...
    ummm... 2 months ago

    3rd of our lives spent sleeping? I average about 5 hours a night and sleep like poo. Guess I'm screwed

  • Abdelgafar El Masry
    Abdelgafar El Masry 2 months ago

    Hank, you're a legend, keep making those videos because you & Micheal are great presenters.

  • 340PD
    340PD 2 months ago

    The amount of calories that Hank Green burns during one of his videos would amaze you.

  • Dari Bluestar
    Dari Bluestar 2 months ago

    Stop comparing rats to humans 1st of all & "a group of researchers" nah fuck dat... conduct your own research.

  • Nathaniel Brigham
    Nathaniel Brigham 2 months ago

    I'm not against testing on rats, but still... Poor rats.

  • Georgia Lloyd
    Georgia Lloyd 2 months ago

    Omg I'm going to die really soon then

  • Srijan Raghunath
    Srijan Raghunath 2 months ago

    ironic because we are watching this on a phone, computer, etc.

  • HAB
    HAB 2 months ago

    Paleo-Sleeping = Awesome!

  • HeyHay
    HeyHay 2 months ago

    currently trying to heal a huge surgical wound going from the bottom of my rib cage to my pelvis. Lots of pain control and healing required. No wonder I sleep so much.

  • Pur
    Pur 2 months ago

    Hmmm wonder why as a teenager we remember things better (I slept 12 hrs a day then) vs as an adult (6 maybe 7)....does this also affect learning new things...."old dogs can't learn new tricks". Just saying...

  • Emmie Knobloch
    Emmie Knobloch 2 months ago

    Fatal Familial Insomnia doesn't actually kill you through lack of sleep - it's caused by misfolded prion proteins, like mad cow disease or Creutzfeld Jakob disease. Insomnia is a symptom of the degradation of the brain tissue in the thalamus, as the prion proteins form aggregates that inhibit brain function. You can die from lack of sleep, but this disease kills you by brain degradation.

  • bret you
    bret you 2 months ago

    they burn rats and deprive them of sleep to study the correlation, nice , who exactly are the vermin again? i hope I'm misunderstanding something here

  • Jason Miller
    Jason Miller 2 months ago

    The shadow from his collar makes it look like he's got some serious chest hair

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