Here's what paralyzes you during sleep

By Stephanie Pappas
LiveScience

During the most dream-filled phase of sleep, our muscles become paralyzed, preventing the body from acting out what's going on in the brain. Now, researchers have discovered the brain chemicals that keep the body still in sleep.

The findings could be helpful for treating sleep disorders, the scientists report Wednesday (July 18) in The Journal of Neuroscience.

The brain chemicals kick into action during rapid eye movement (REM) sleep, a phase that usually begins about 90 minutes into a night's rest. During REM, the brain is very active, and dreams are at their most intense. But the voluntary muscles of the body — arms, legs, fingers, anything that is under conscious control — are paralyzed.

This paralysis keeps people still even as their brains are acting out fantastical scenarios; it's also the reason people sometimes experience sleep paralysis, or the experience of waking up while the muscles are still frozen. This sensation has been the basis for myths such as the succubus and the incubus, demons said to pin people down in their sleep, usually to have sex with them. [ Top 10 Spooky Sleep Disorders ]

Exactly how the muscles are paralyzed has been a mystery, however. Early studies pegged a neurotransmitter called glycine as the culprit, but paralysis still occurred even when the receptors that read glycine's presence were blocked, disproving that notion.

So University of Toronto researchers Patricia Brooks and John Peever cast a wider net. They focused on two different nerve receptors in the voluntary muscles, one called metabotropic GABAB and one called ionotropic GABAA/glycine. The latter receptor responds to both glycine and a different communication chemical called gamma-aminobutyric acid, or GABA, while the first responds to GABA and not glycine.

The researchers used drugs to "switch off" these receptors in rats and discovered that the only way to prevent sleep paralysis during REM was to shut both types off at the same time. What that means is that glycine alone isn't enough to paralyze the muscles. You need GABA, too.

Understanding this alphabet soup of neurotransmitters is important for people who have sleep disorders, especially an odd condition called REM behavior disorder. In this disorder, people don't become paralyzed during REM sleep. That means they act out their dreams, talking, thrashing and even punching or hitting in their sleep.

Currently, Clonazepam, an antipsychotic drug, is used to treat REM behavior disorder. The new study could point to new treatments for the problem, sleep researcher Dennis McGinty of the University of California, Los Angeles, who was not involved in the study, said in a statement. The researchers hope that the results could help explain the link between REM behavior disorder and more deadly conditions.

"Understanding the precise mechanism behind these chemicals’ role in REM sleep disorder is particularly important because about 80 percent of people who have it eventually develop a neurodegenerative disease, such as Parkinson’s disease," Peever said. "REM sleep behavior disorder could be an early marker of these diseases, and curing it may help prevent or even stop their development." 

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Discuss this post

not so fast here. I actually know 'other stuff'.

    Reply#1 - Tue Jul 17, 2012 6:00 PM EDT

    isn't that like treating the symptom instead of curing the problem?

      Reply#2 - Tue Jul 17, 2012 6:07 PM EDT

      sleep paralysis is no joke, is suffered from that for 2 weeks after a surgery. it was the most bizarre, scary thing ever. being awake while your body is asleep and you can't even turn your head. pretty spooky.

      • 4 votes
      Reply#3 - Tue Jul 17, 2012 7:16 PM EDT

      Sleep paralysis usually only lasts for 5-10 seconds right after you wake up. I've had it happen to me a few times, it's terrifying until you realize what's going on.

      What kind of surgery did you have (if you don't mind me asking)? I'm curious if it was the surgery that triggered the sleep paralysis or some kind of reaction to the anesthesia.

        #3.1 - Tue Jul 17, 2012 8:01 PM EDT

        Or if the surgeon traumatized some major nerves which took about two weeks to recover from the injuries to them during surgery.

          #3.2 - Wed Jul 18, 2012 4:33 AM EDT

          I had that happen to me once and it was awful! I couldn't even talk. My husband was stroking my arm at the time and it was unbearable - my skin was super-sensitive, as well. I tried to tell him to stop, it was that irritating, but I could only make noises - no words.

          Freaky and terrifying, indeed!

          • 2 votes
          #3.3 - Wed Jul 18, 2012 8:22 AM EDT

          I had it happen twice. I think the freakiest part to me was not being in control of my breathing, since it was still 100% on autopilot. It's been quite a while, but I think it may have been during the time I was taking Clonazepam occasionally. Maybe that was the cause?

            #3.4 - Wed Jul 18, 2012 11:03 AM EDT

            I'm trying to figure what the problem is here. What is described in the article is NORMAL! If you don't have what they call "sleep paralysis" then you would actually act out your dreams. In other words, you need to have it so that your dream is just a dream and you stay laying on the bed. Having it for a few seconds after you've awakened never seemed anything other than normal too. It's just part of the waking up process.

            On the other hand, what gets confusing is waking up within a dream as though you've actually woken up. Then when you wake up again you haven't a clue what is going on. It does take a bit longer to get your bearings.

            • 1 vote
            #3.5 - Wed Jul 18, 2012 11:49 AM EDT

            You said it, Biscuit. I've been through more than my share of trauma, but nothing holds a candle to sleep paralysis. You're completely aware, you try to breathe, and you try to scream, but you can't do anything. It only lasts about five seconds (for me), but it's the most terrifying five seconds you'll ever experience.

            • 4 votes
            #3.6 - Wed Jul 18, 2012 12:26 PM EDT

            I to experienced this. I awoke from a terrible dream in which an intruder was in my home. I open my eyes and when I tried to get up I just couldn't move. I was so freaked out.

              #3.7 - Wed Jul 18, 2012 1:11 PM EDT

              I had this happen a few times, really crazy! I couldn't do anything and felt like I had to struggle to get out of that state. It's hard to stay calm too cause you don't realize what's happening until its over.

              • 2 votes
              #3.8 - Wed Jul 18, 2012 2:17 PM EDT
              Reply

              My fiance sent me this link, thinking it would help me I'm sure, but this doesn't answer a thing for me. How do you get it to stop? What causes it to keep happening? This has been happening to me since I was a kid, I'm 28 now and my most recent "episode" was last week. It has to be one of the scariest things I've ever felt. Not being able to move or speak, but being aware of everything around you. I could hear the freaking birds outside my window, my son next to me, and hear my fiance coughing downstairs. It definitely makes you want to not fall back asleep. Everytime I look it up, it always turns to "out of body experiences" and crap... more HELPFUL info would me nice.

              • 2 votes
              Reply#4 - Tue Jul 17, 2012 10:32 PM EDT

              Wikipedia usually helps. I've had a this a few times, and the scariness decreases for me as I become more accustomed to it and more aware of what's going on. Sleeping better (e.g. by having a healthy sleep schedule) also reduces the chances of sleep paralysis.

                #4.1 - Wed Jul 18, 2012 12:19 AM EDT

                I've had chronic sleep paralysis problems since at least puberty. I'm nearly forty. There are some things that help, but nothing is going to keep you from ever having another episode.

                1. Don't lay on your back to sleep. Most sleep paralysis episodes happen when sleeping on your back.
                2. Try to get enough sleep. You're much more likely to have a sleep paralysis episode when you're overtired.
                3. Find out if anything helps you break the sleep paralysis faster. I know sometimes the moment I think "This is just sleep paralysis", I snap out of it. It doesn't always work. But it helps.
                4. If you're having more than one episode a month (I have 3 to 4), get a prescription for low dose clonazepam (aka Klonopin). The article is wrong when classifying it as an antipsychotic. It's actually a benzodiazepine like Xanax that is also used for seizures and anxiety. It has helped me greatly in reducing the number of episodes, but doctors are often skittish about prescribing it.
                • 3 votes
                #4.2 - Wed Jul 18, 2012 5:56 AM EDT

                p s i don't see dr. or md next to stephanies name. sleep disorder causes parkinsons? give me a break if i had a hangnail she'd probably advise cutting off toe or finger

                  #4.3 - Wed Jul 18, 2012 6:39 AM EDT

                  scotfu - she was quoting John Peever, one of the researchers from the University of Toronto. And the article states that REM sleep behavior disorder may be an early indication of neurodegenerative disease, not that it causes it. There's a big difference.

                  Most of the Body Odd articles are laughable, I found this one (with the exception of the misclassification of clonazepam) to actually be informative and well-written.

                  • 2 votes
                  #4.4 - Wed Jul 18, 2012 7:07 AM EDT

                  quoting peever 80% with sleep disorder develope parkinsons? wheres he getting these stats?

                    #4.5 - Wed Jul 18, 2012 7:15 AM EDT

                    That's actually a low percentage. Just google "rem sleep behavior disorder neurodegenerative disease" and you'll find studies that show that it is predictive of neurodegenerative disease between 94 and 100% of the time. Not all patients with neurodegenerative disorders present with REM sleep behavior disorder early on, but nearly all patients who present with REM sleep behavior disorder develop neurodegenerative disease later in life.

                    More research needs to be done, but it's a pretty well-documented and studied phenomenon.

                    • 1 vote
                    #4.6 - Wed Jul 18, 2012 8:22 AM EDT

                    Clonazepam is not an antipsychotic drug.

                      #4.7 - Wed Jul 18, 2012 12:02 PM EDT
                      Reply

                      how do you explain sleepwalking, eating etc. ?

                      • 1 vote
                      Reply#5 - Wed Jul 18, 2012 6:06 AM EDT

                      I myself was going to ask about the sleepwalking issue seeing how I have a nephew that sleepwalked while in a deep sleep. Which the article sort of confused me about the paralysis statement.

                      • 1 vote
                      #5.1 - Wed Jul 18, 2012 8:36 AM EDT

                      The kind of sleepwalking your nephew has would be NREM sleepwalking (sleepwalking during deep sleep, stages 3 and 4), which has nothing to do with the information in this article. It is fairly common, and not something to be overly anxious about. My daughter had frequent episodes of NREM sleepwalking, but has now grown out of it (she's 17).

                      REM somnambulism is considered a REM sleep behavior disorder, which is much rarer.

                      • 1 vote
                      #5.2 - Wed Jul 18, 2012 9:55 AM EDT

                      Yes but if the body puts us into a paralyzed state, why then do some people sleep walk? Do they not when in REM but then in later stages, the body does not produce the chemicals for paralysis?

                        #5.3 - Wed Jul 18, 2012 2:23 PM EDT

                        Spybee - The paralysis is only during REM sleep, that is correct. If you can move during REM sleep, something is seriously wrong. Garden variety sleepwalking takes place during NREM sleep (usually stages 3 and 4. Google is your friend.), when the body is not paralyzed.

                        • 1 vote
                        #5.4 - Wed Jul 18, 2012 2:41 PM EDT

                        :) ah ok I see. Thanks for the reply Jaimie!

                          #5.5 - Wed Jul 18, 2012 2:49 PM EDT
                          Reply

                          i've also watched a family member die slowly from alzhiemers and parkinsons. most doctors continually prescribed drug after drug which made matters worse. sleep disorder heres some drugs. grind your teeth while sleeping...heres another drug. lets face it docs are in it for the money like everything else. ive had normal (compared to what?) dreams since a kid. flying, swimming, water, fishing. after doc suggested melatonin i had the most bizzare weird bloody nightmarish dreams so immediately stopped taking it. with most drugs there are bad side effects "they" don't want you to know about because..you guessed it their in it for the money

                          • 1 vote
                          Reply#6 - Wed Jul 18, 2012 6:26 AM EDT

                          I am glad they published this article. It doesn't happen often but I have had this. I'm usually on my back sleeping and I am always dreaming of a terrifying situation, like someone chasing or about to attack me. I try to wake myself up but I can't move. I try to fight off what's after me, but I can't get the strength to move. Because you're kind of awake you can try to think 'this is a dream and you'll eventually wake up' but sometimes that is hard when you think you're about to be killed. Terrifying to say the least. So glad I saw this article.

                          • 1 vote
                          Reply#7 - Wed Jul 18, 2012 10:04 AM EDT

                          Sleep disorders can have a severe affect on your life. Some of my friends work in the nutraceutical industry and certain supplements are known to help. As always, please consult with your physician before starting any of these.

                          Glysom by Ajinomoto is a glycine supplement -

                          Clonazepam and other benzos are also options, but these are highly potent substances that require a prescription. They are especially dangerous when combined with alcohol.

                          Melatonin is a highly potent substance and more than a few recommend avoiding it. The experience of scotfu with melatonin is not unusual.

                          Again, I'm not an MD. If you have sleep disturbances that require medication, then please consult with your physician.

                            Reply#8 - Wed Jul 18, 2012 10:07 AM EDT

                            I've had this off and on over many years. It's the strangest thing I've ever experienced. I'm always thinking, "someone just please touch me to bring me out of this feeling...." I lay there thinking, but not sure, that I'm totally aware of my surroundings, but just can't respond in any way......

                            • 1 vote
                            Reply#9 - Wed Jul 18, 2012 10:15 AM EDT

                            A wetdream will debunk this theory.

                              Reply#10 - Wed Jul 18, 2012 10:35 AM EDT

                              Obviously this affliction affects not only the sleeping. Example given: U.S. Congress!!

                              • 1 vote
                              Reply#11 - Wed Jul 18, 2012 11:12 AM EDT

                              Sleep paralysis seems to be something that those who have never experienced will dismiss it, but those who have experienced it know it's very real and terrifying. I first experienced it during college, and it continues to be an issue and I'm in my mid-40's.

                              I am very thankful for the University of Toronto for their long study on this issue. My doctors dismissed my complaints 20 years ago, and finding their study online was the first real evidence I found to define what I was experiencing. As someone who is predisposed to this issue, I will say that through trial and error I've discovered a way to control the symptoms. For me it's about sticking to a regular sleep schedule and getting enough rest. If I go on too little sleep or alter my schedule, it strikes. Others mentioned that it only lasts between 5 and 10 seconds, but this has not been my experience. Mine will last indefinitely. Once it hits, I have found the only way "out" of it is to try and calm down and go back to sleep. For those of you who don't know what this is like, imagine waking up. You are conscious, you feel the bedsheets beneath you, you hear the noises in the room, you are aware that you are lying in a bed, but you cannot open your eyes, you can't move your body. It feels what you imagine a coma might be like. it's terrifying.

                              Having said that, it's fascinating that they have defined a drug that may help, but if it's possible to control and keep this condition away by regulating sleep, diet, weight, etc. then this would be the best course of action, I think.

                              • 1 vote
                              Reply#12 - Wed Jul 18, 2012 11:13 AM EDT

                              It is very scary and I've not yet met a physician other than my brother who has heard of it. It's frustrating.

                              My episodes last anywhere from a few seconds to an hour. I can rarely get myself to go back to sleep because of the depth of the terror, but I've had some success with forcing myself to wake fully.

                              I have no idea how they could help those of us with sleep paralysis with this knowledge since it doesn't happen every night, and there is a small window of time when those chemicals are working when they shouldn't be. Good news for people with REM sleep behavior disorders though.

                              I really think our only hope is to, as you recommend, try to stay on a healthy sleep schedule and be aware of other triggers like sleeping on your back, etc..

                                #12.1 - Wed Jul 18, 2012 11:38 AM EDT
                                Reply

                                Ive actually experienced sleep paralysis myself however at the time I was unaware if I was dreaming or not... I kinda knew I was awake but I could not even move my body and it all felt numb. It DID last around 10 seconds and afterwards I think I dozed back of to sleep lol... But it isnt a nice feeling at all and yes it is pretty scary when you cant even move....

                                  Reply#13 - Wed Jul 18, 2012 11:54 AM EDT

                                  Wow...you babies are a joke. I have sleep paralyzes, which this article isn't even about but rather why our muscle get paralyzed during REM stage, and it isn't a big issue. If you suffer from SP and make a big deal about it, then you have other things wrong with your life. I always get SP when I take a nap during the day, or try to sleep in. It doesn't last long and you ALWAYS are able to get up eventually, but the better part of SP is if you wait it out you'll actually go into a lucid dream leading to fun dreaming moments. Sleep paralyzes isn't scary.

                                    Reply#14 - Wed Jul 18, 2012 1:20 PM EDT

                                    I kinda disagree and kinda agree. For me, sleep paralysis is scary. But also, for me, scary lucid dreaming is fun! : )

                                      #14.1 - Thu Jul 19, 2012 2:00 PM EDT

                                      If you aren't feeling terror and paranoia during sleep paralysis, there's something wrong with your brain, and you really should see a good neurologist. Or perhaps you're experiencing something other than classic sleep paralysis. Or you do feel paranoid and you're a sociopath, then it's probably okay. Well, as okay as that could be.

                                        #14.2 - Thu Jul 19, 2012 7:35 PM EDT
                                        Reply

                                        "Here's what paralyzes you during sleep"

                                        The knowledge that you have to get up and go to work. For the rest of your life.

                                          Reply#15 - Wed Jul 18, 2012 3:24 PM EDT

                                          Big red flag I noticed in this article: Clonazepam is used to treat the disorder. If anyone tries to give you or a loved one this drug for anything, do some heavy research first. (My ex took it for anxiety.) This drug is highly addictive, is easy to grow a tolerance to so that you need more to get the original effect, and has a boomerang effect so that your original problem is significantly amplified when you try to stop taking it. As a matter of fact, if anyone gives you any drug for any condition, research the drug first, including its addictive qualities and withdrawal. Stay safe!

                                            Reply#16 - Thu Jul 19, 2012 1:58 PM EDT
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