Huberman LabUse Sleep to Enhance Learning, Memory & Emotional State | Dr. Gina Poe
EVERY SPOKEN WORD
150 min read · 30,042 words- 0:00 – 2:52
Dr. Gina Poe
- AHAndrew Huberman
(music plays) Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today my guest is Dr. Gina Poe. Dr. Gina Poe is a professor in the Department of Integrative Biology and Physiology at the University of California Los Angeles. Her laboratory and research focuses on the relationship between sleep and learning, in particular, how specific patterns of brain activity that are present during specific phases of sleep impact our ability to learn and remember specific types of information. For instance, procedural information, that is, how to perform specific cognitive or physical tasks, as well as encoding of emotional memories and discarding emotional memories. Indeed, her research focuses on how specific phases of sleep can act as its own form of trauma therapy, discarding the emotional tones of memories. In addition, her laboratory focuses on how specific phases of sleep impact things like the release of growth hormone. Growth hormone, of course, plays critical roles in metabolism and tissue repair, including brain tissue repair, and therefore has critical roles in vitality and longevity. Today you will learn many things about the relationship between sleep, learning, emotionality, and growth hormone. One basic but very important takeaway that you'll learn about today, which was news to me, is that it's not just the duration and depth of your sleep that matter, but actually getting to sleep at relatively the same time each night ensures that you get adequate growth hormone release in the first hours of sleep. In fact, if you require, let's say, eight hours of sleep per night, but you go to sleep two hours later than your typical bedtime on any given night, you actually miss the window for growth hormone release. That's right. Getting growth hormone release in sleep, which is absolutely critical to our immediate and long-term health, is not a prerequisite of getting sleep even if we are getting enough sleep. As Dr. Poe explains, there are critical brain circuits and endocrine, that is, hormone circuits, that regulate not just the duration and depth and quality and timing of sleep, but when we place our bout of sleep, that is, when we go to sleep each night, plus or minus about a half hour or so, strongly dictates whether or not we will experience all the health promoting, including mind promoting, benefits of sleep. Today's episode covers that and a lot more in substantial detail. You will learn, for instance, how to use sleep in order to optimize learning as well as forgetting for those things that you would like to forget. So during today's episode, Dr. Gina Poe shares critical information about not just neuroscience but physiology and the hormone systems of the brain and body that strongly inform mental health, physical health, and performance. So by the end of today's episode, you'll be far more informed about sleep and how it works, the different roles it performs, and you'll have several new actionable steps that you can take in order to improve your mental health, physical health,
- 2:52 – 6:58
LMNT, Helix Sleep, Eight Sleep, Momentous
- AHAndrew Huberman
and performance. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is LMNT. LMNT is an electrolyte drink that has everything you need and nothing you don't. That means plenty of salt, magnesium, and potassium, the so-called electrolytes, and no sugar. Now, the electrolytes are critical to the function of every cell in your body, in particular, the neurons, the nerve cells. As I've talked about before on this podcast, neurons, nerve cells require adequate sodium and potassium as well as magnesium in order to fire action potentials, which are the electrical signals that allow neurons to do everything from generate focus and attention, allow you to learn, and generate neuromuscular connection and allow you to exercise or train or do any kind of skilled activity with a high degree of output. I take LMNT about two or three times per day, typically once in the morning and again after or during my bout of exercise each day, and sometimes an additional one if I've sat in a hot sauna and sweat a lot or if the weather is very hot. If you'd like to try LMNT, you can go to Drink LMNT, that's L-M-N-T.com/huberman to claim a free LMNT sample pack with your purchase. Again, that's Drink LMNT, L-M-N-T.com/huberman to claim a free sample pack. Today's episode is also brought to us by Helix Sleep. Helix Sleep makes mattresses and pillows that are of the absolute highest quality. Now, sleep is the foundation of mental health, physical health, and performance. When we are sleeping well, all of those things excel. And when we are not sleeping well, all of those things suffer. Now, the surface that you sleep on, that is, the mattress that you sleep on, is critical. And Helix understands that everybody has slightly different sleep needs. So if you were to go to the Helix site, which I invite you to do, and take their brief two-minute quiz, it will match your body type and sleep preferences to the perfect mattress for you. It will ask you questions, for instance, do you sleep on your back or your side or your stomach? Do you tend to run hot or cold during the night? Or maybe you don't know the answers to those questions. I went and took the sleep quiz at Helix and it matched me to the so-called Dusk mattress, D-U-S-K. I started sleeping on a Dusk mattress over a year ago and it's the best sleep that I've ever had. It's completely transformed the depth and duration and quality of my sleep in ways that make me feel far better during the daytime. If you're interested in upgrading your mattress, you can go to helixsleep.com/huberman, take their two-minute sleep quiz, and they'll match you to a customized mattress and you'll get up to $350 off any mattress order and two free pillows. Again, if interested, go to helixsleep.com/huberman for up to $350 off and two free pillows. Today's episode is also brought to us by Eight Sleep. Eight Sleep makes smart mattress covers with cooling, heating, and sleep tracking capacity.Now, again, sleep is the foundation of mental health, physical health, and performance, but what many people don't realize is that in order to fall and stay asleep, your core body temperature has to drop by about one to three degrees. Conversely, in order to wake up each morning and feel refreshed, your body temperature actually has to increase by one to three degrees. Therefore, controlling the temperature of your sleeping environment is absolutely key. With Eight Sleep, that's very easy to do. Depending on whether or not you typically run too cold or too hot during the night, you can program your Eight Sleep mattress cover so that it's the optimal temperature, not just for you, but for each phase, the early, middle, and late phase of your sleep and for waking up in the morning. In fact, you can even control the temperature of your Eight Sleep mattress cover differentially across the mattress if you're sleeping alongside somebody else. If you'd like to try Eight Sleep, you can go to EightSleep.com/Huberman and check out their Pod Pro Cover and save $150 at checkout. Eight Sleep currently ships in the USA, Canada, UK, and select countries in the EU and Australia. Again, that's EightSleep.com/Huberman to save $150 at checkout. The Huberman Lab Podcast is now partnered with Momentous Supplements. To find the supplements we discuss on the Huberman Lab Podcast, you can go to Live Momentous, spelled O-U-S, LiveMomentous.com/Huberman. And I should just mention that the library of those supplements is constantly expanding. Again, that's LiveMomentous.com/Huberman. And now for my discussion with Dr.
- 6:58 – 10:32
Sleep Phases, Perfect Night’s Sleep
- AHAndrew Huberman
Gina Po. Dr. Gina Po, welcome.
- GPGina Poe
Thank you.
- AHAndrew Huberman
I've really been looking forward to this conversation because I'm familiar with your work, and I know that many people are going to be excited to learn about your work as it relates to sleep, as it relates to problem-solving, creativity, addiction and craving, relapse-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... and a number of other important topics. So-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... to start things off, I would love for you to educate us a bit about this thing that we are all familiar with and yet very few of us understand, which is sleep.
- GPGina Poe
(laughs)
- AHAndrew Huberman
And if you would, could you describe the various phases of sleep that exist, what distinguished them, and perhaps frame this within the context of what would a perfect night sleep look like?
- GPGina Poe
Okay.
- AHAndrew Huberman
How long would it last, more or less?
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
And what would the biology look like? What, w- what is a perfect night's sleep?
- GPGina Poe
Oh, yeah. That's a great question. All right, so sleep is really different from wakefulness and, in fact, can't be replaced by any state of wakefulness that we've been able to come up with so far. Um, our brain chemistry is completely different, and in the different stages of sleep, which there are, there's non-REM and REM are the two major states of sleep, and every animal we've studied so far seems to have both of those states. Um, anyway, those two states are entirely different from one another too, and even within non-REM, there are three states. Stage one, which is what you slip into when you're first falling asleep. It's dozing, there's kind of an interesting rhythm that goes on in the brain that's kind of a fast gamma rhythm. And then there's stage two, which is a really cool state. We sort of used to ignore, sleep researchers, because it was a transient state between wakefulness and the deep stage three slow wave sleep, which is the most impressively different, and then, a- and between that and REM sleep. So stage two, I'll talk a little bit more about, and then the deep slow wave sleep state, which is when big slow waves sweep through our brain and now we realize that it cleans our brain. Um, one of the things that those big slow waves do is cleans our brain and does other really important things to restore us, um, from a day of wakefulness. And then REM sleep, which is the most popular because that's where we have the most active dreams, and, um, when you wake up someone out of REM sleep, they'll almost always report having dreamed something really bizarre. That's called REM sleep, rapid eye movement sleep. So, those are the four states of sleep, of human sleep, and we cycle through them every 90 minutes or so. When we go to sleep, say, 10:00, 10:30, 11:00, um, our first REM sleep period comes about 105 minutes after we fall asleep and, um, lasts about 20 minutes. Actually, it comes about 95 minutes and lasts 10 or 15 minutes, and then, uh, we start over again. And we have about five of those per night for a perfect night's sleep, four or five, something like that. So, a perfect night's sleep is seven and a half, eight hours. There was a really great study that, um, put people in a semi-darkened room with nothing but the bed for 12 hours every day for a month and what people did initially is because, because we're in a sleep-deprived nation is that they slept a lot more than usual, like 10 or 11 hours of the 12, and then they leveled off after a week or two to about eight hours and 15 minutes of sleep. So, you actually can't oversleep. I mean, they had nothing else to do but sleep-
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
... and they would round off to, on average, eight hours and 15 minutes a night and then they spend the rest of the time twiddling their thumbs, humming tunes, you know-
- AHAndrew Huberman
Interesting.
- GPGina Poe
... daydreaming.
- 10:32 – 14:50
Can You Oversleep?
- GPGina Poe
- AHAndrew Huberman
I want to get back to the contour of a perfect night's sleep-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... but I'm intrigued by this idea that people can't oversleep. I'm often asked whether or not we can get too much sleep-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... and whether or not sleeping too log, long, excuse me, can make us groggy the next day.
- GPGina Poe
Right.
- AHAndrew Huberman
Um, is there anything to that?
- GPGina Poe
Okay.
- AHAndrew Huberman
Um, and how does one determine how long they should sleep-
- GPGina Poe
Right.
- AHAndrew Huberman
... on average?
- GPGina Poe
On average, yeah. Well, that's interesting because different people need, seem to need different amounts of sleep, but we don't really even know exactly what sleep is for. So what they need is, you know, kind of, it's, ye- you know, mercury- murky. Um, so we do know a lot of things that sleep do, does now for us, but we don't know how long those things take. So, how long, uh, we need to sleep is also just a big question mark. But some people don't feel rested until they've slept nine hours and some people don't feel rested after three or four and a half. Um, but most people, if they consistently deprive themselves of sleep so that they're only sleeping four, four and a half hours a night, build up...... a cognitive deficit that just builds up over time. The more nights you have with sleep depr- deprivation, the more cognitive deficit you have. And so, you need sleep again, to sleep more to recover. Now, the question you had about, um...
- AHAndrew Huberman
Can you overs-
- GPGina Poe
Can you oversleep? Right.
- AHAndrew Huberman
Can you sleep to the point where it's too much, you know, that we, I-
- GPGina Poe
Yeah.
- AHAndrew Huberman
Growing up, um, uh, when I was in high school, uh, my girlfriend's dad-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... had this belief that no one should sleep in past 6:00 AM. So he would, he'd wake all the, there were two children-
- GPGina Poe
(laughs)
- AHAndrew Huberman
... in that home. He would wake up the kids in that house. He had this thing against oversleeping-
- GPGina Poe
(laughs)
- AHAndrew Huberman
... regardless of when people went-
- GPGina Poe
Right.
- AHAndrew Huberman
... went to sleep. And I always thought that was, um, an interesting mentality.
- GPGina Poe
Yeah.
- AHAndrew Huberman
Um, I don't-
- GPGina Poe
It's not terrible actually, because what that will do is it'll put you, make you sleepier the next night to get to bed on time. So-
- AHAndrew Huberman
Mm-hmm.
- 14:50 – 19:01
Sleep Cycles, Sleep Spindles, “Falling” Asleep, Dreams & Memories
- AHAndrew Huberman
Um, but to return this i- to this idea of the architecture of a perfect night's sleep.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
So you said, um, we fall asleep, the first 90 minutes of sleep, REM sleep, rapid eye movement sleep will arrive at about 95 minutes in.
- GPGina Poe
Yeah.
- AHAndrew Huberman
Does that mean that the rest of that 90 minutes is consumed with slow wave sleep?
- GPGina Poe
Yeah, non-REM sleep.
- AHAndrew Huberman
Okay. And what about the sleep where we are lightly asleep-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... and we might have a dream that has us somehow thinking about movement or that we jolt ourselves awake?
- GPGina Poe
Yeah. Yeah.
- AHAndrew Huberman
That often happens early in the night, right?
- GPGina Poe
Yeah. Yeah. That's the first stage, stage one and stage two of sleep, and stage two of sleep is really cool because that has something called sleep spindles and K-complexes. And what sleep spindles are, are, um, a little brr of activity that's 10 to 15 hertz in frequency. It's a conversation between the thalamus and the cortex. The ga- thalamus is the gateway to consciousness and the neocortex, you know, processes all our cognition. And, um, so it's, it's these spindles, they're called sleep spindles, and if you wake up out of that state, you will often report a dream, like a hallucination style dream. It won't be a long dream report like you have out of REM sleep, but it will be some hallucination state.
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
And during, while we're falling asleep, one of the reasons we call it falling asleep is because in stage one and stage two, our muscles are relaxing-
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
... and if there's part of our brain that's conscious enough to sort of recognize that relaxation, we'll feel like we're falling and we'll jerk awake. So often that hallucination, it's called hypnagogic hallucination, we'll feel like... It'll be, include some falling aspect that we'll wake up out of.
- AHAndrew Huberman
That's really interesting to me.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
I've long felt that sensation of almost like dropping back into my head.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, so much so that if I elevate my s- feet just slightly and I tilt my head back-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... just slightly-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... um, in order to go to sleep, I find that I fall asleep mus- much faster.
- GPGina Poe
Interesting.
- AHAndrew Huberman
But it does feel as if I'm going to fall, like almost going to do a backward somersault.
- GPGina Poe
That's fascinating.
- AHAndrew Huberman
I actually really like the, the sensation-
- GPGina Poe
(laughs)
- 19:01 – 22:05
Tool: Growth Hormone Release & Sleep
- AHAndrew Huberman
So, um, there's a number of different hormones associated with the different stages of sleep. We know that melatonin is a hormone that-
- GPGina Poe
Of nighttime.
- AHAndrew Huberman
... of nighttime that makes us sleepy.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, what about growth hormone release? When does that occur during sleep?
- GPGina Poe
So, growth hormone release happens all day long and all night long, but the deep slow wave sleep that you get the very first sleep cycle, um, is when you get a big bolus of growth hormone release and in men and women equally. And if you miss that first deep slow wave sleep period, you also miss that big bolus of growth hormone release, and you might get ultimately across the day just as much overall growth hormone release, but endocrinologists will tell you that big boluses do different things than a little bit eked out over time. So, that is what we know. There's also a big push to synthesize prot- proteins. Um, so that's when the protein synthesis part that builds memories, for example, in our brain happens in that first cycle of sleep. So you don't want to miss that, especially if you've learned something really big and needs, needs more synaptic space to encode it.
- AHAndrew Huberman
How would somebody miss that first 90 minutes?
- GPGina Poe
Sleep-depriving themselves. Yeah, so you could-
- AHAndrew Huberman
So let's say I normally go to sleep at, um, 10:00 PM.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, and then from 10:00 to 11:30 would be this first phase of sleep and that's when the growth hor- big bolus-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... of growth hormone would be released. Does that mean that if I go to sleep instead at 11:30 or midnight that I miss that first phase of sleep?
- GPGina Poe
Yeah.
- AHAndrew Huberman
Why is it not the case that I get that first phase of sleep just simply starting later?
- GPGina Poe
It is a beautiful clock that we have in our body that knows when things should happen and it's every cell in our body has a clock and all those clocks are normally synchronized and the circadi- circadian clocks are synchronized. And so our cells are ready to respond to that growth hormone release at a particular time and if we miss it, and it's a time in relation to me- melatonin also, so if you miss it, yeah, you might get some growth hormone release but it's occurring at a time when that, your clock is already moved to the next phase. And so it's, it's just a clock thing.
- AHAndrew Huberman
Yeah. I don't think, um, we can overstate the importance of what you just described.
- GPGina Poe
Mm-mm.
- AHAndrew Huberman
And to be honest, despite knowing a bit about the sleep research and circadian biology-
- GPGina Poe
Mm.
- AHAndrew Huberman
... this is the very first time that I've ever heard this, that if you normally go to sleep at a particular time and growth hormone is released in that first phase of sleep, that you can't simply initiate your sleep bout later and expect to capture that first phase of sleep.
- GPGina Poe
Yeah.
- AHAndrew Huberman
That's incredible.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
And I think important.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
And, um, as many listeners are probably realizing, also highly actionable. So what this means is that we should have fairly consistent bedtimes-
- GPGina Poe
Yes.
- AHAndrew Huberman
... in addition to fairly consistent wake times.
- GPGina Poe
Yes.
- 22:05 – 24:55
Adolescence; Early Sleep, Alcohol & Sleep Spindles
- AHAndrew Huberman
Okay. Um, I don't want to backtrack but I did write down something that I think is, um, important for me to resolve, um, or for you to resolve.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
So I'm going to ask this. Um, people that sleep nine hours or more, perhaps that reflecting an issue, some underlying issue perhaps.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Is being a teenager or an adolescent and undergoing a stage of, of, of development where there's a lot of bodily and brain growth an exception to that because-
- GPGina Poe
Yes.
- AHAndrew Huberman
... I don't recall sleeping a ton when I was a teenager. I had a ton of energy.
- GPGina Poe
Yeah.
- AHAndrew Huberman
But I know a few teenagers, um, and they sleep a lot.
- GPGina Poe
Yeah. Yeah.
- AHAndrew Huberman
Like they'll just sleep and sleep and sleep and sleep.
- GPGina Poe
Yeah.
- AHAndrew Huberman
Should we let them sleep and sleep and sleep?
- GPGina Poe
Yes.
- AHAndrew Huberman
Okay.
- GPGina Poe
Let them sleep. (laughs)
- AHAndrew Huberman
Okay. So that's the one exception. What about if-
- GPGina Poe
Just like babies.
- AHAndrew Huberman
Okay.
- GPGina Poe
Eh, when, when you're developing something in your brain or the rest of your body, you really need sleep to help organize that. I mean, sleep is doing really hard work in organizing our brains and, and making it develop right. And if we deprive ourselves of sleep, we will actually also just ha- like, like I said, we have a daily clock, we also have a developmental clock and we can miss a developmental window if we don't let ourselves sleep extra like we need to.
- AHAndrew Huberman
What other things inhibit growth hormone release or other components of this first stage of sleep? In other words, if I go to sleep religiously every night at 10:00 PM-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... are there things that I perhaps do in the preceding hours or the preceding day, like ingest caffeine or alcohol, that can make that first stage of sleep less effective even if I'm going to sleep at the same time?
- GPGina Poe
Alcohol definitely will do that because alcohol is a REM sleep suppressant and it even suppresses some of that stage two transition to REM with those sleep spindles. And those sleep spindles, we didn't talk about their function yet, but they're really important for moving memories, um, to our cortex. It's a unique time when our hippocampus, the sort of like the RAM of our brains, um, writes it to a hard disk and, uh, which is the cortex. And they're, it's a unique time when they're connected. So if you don't want to miss that, you don't want to miss REM sleep when ch- is also a part of the consolidation process and, um, schema changing process and alcohol in there, you know, before we go to sleep will do that. Until we've metabolized alcohol and put it out of our bodies, it will affect our sleep, uh, badly.
- AHAndrew Huberman
So probably fair to say no ingestion of alcohol within the four to six hours preceding sleep?
- GPGina Poe
Yeah. (laughs)
- AHAndrew Huberman
Given the half-life?
- GPGina Poe
(laughs) Given the half-life.
- AHAndrew Huberman
Or at all, or at all would be better-
- GPGina Poe
Yeah.
- 24:55 – 30:33
Middle Sleep States & REM, Schema, Waking at Night
- AHAndrew Huberman
second and third 90 minute blocks of sleep? Is there anything that makes those, um, unique? What, what is their signature, uh, besides the fact that they come second and third in the night?
- GPGina Poe
Yeah. There's more and more REM sleep the later in the night we get. Um, there's also a change in hormones, you know, the growth hormone and, um, melatonin levels are starting to decline, but other hormones are picking up. So it is a really different stage that you also don't want to shortchange yourself on. And I think that's the stage many studies are showing that those are the times in sleep when the most creativity can happen.
- AHAndrew Huberman
Hm.
- GPGina Poe
That's when our dreams can incorporate and put together old and new things together into a new way and, um, and our schema are built during that time. So, um, yeah, we can change our minds best during those phases of sleep.
- AHAndrew Huberman
Could you elaborate a little bit more on schema?
- GPGina Poe
Yeah.
- AHAndrew Huberman
Uh, no one... I don't think anyone on this podcast has ever discussed schema.
- GPGina Poe
No.
- AHAndrew Huberman
I'm a little bit familiar with schema from my, um, courses on psychology, but it's been a while, so maybe if you could just refresh mine and everyone, everyone else's memory.
- GPGina Poe
Well, it's, it's still a, a concept.
- AHAndrew Huberman
Sure.
- GPGina Poe
Schema is this concept. (laughs)
- AHAndrew Huberman
How do you define schema?
- GPGina Poe
Right. (laughs) I think of schema as, um, like we have a schema of Christmas, right? We ha- we, we have all kinds of ideas that we sew together and call Christmas. A holiday season in the Northern hemisphere, it's cold. We have Santa Claus and reindeer and jingle bells and even things that are false that, but we normally associate with Christmas, presents, family gathering, when it is, all of this stuff is sewn together into one. There's a thread linking them all and we can just give y- ourselves a list of words and, um, and none of them contain the word Christmas and then ask people later, um, you know, give them another list of words and include the w- word Christmas and they'll say, "Oh yeah, that word was there." Because in their minds, they brought up that word Christmas because it's part of that whole schema. So that's what, it's sort of a related, lot of related concepts, I guess is what I-
- AHAndrew Huberman
When I think about it sort of like on the desktop of my computer, um, would scare some people, but it's just a ton of folders.
- GPGina Poe
Yeah. (laughs)
- AHAndrew Huberman
But each of the folder names mean something-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... very clear and specific to me.
- GPGina Poe
Right.
- AHAndrew Huberman
And inside of those folders are collections of things that-
- GPGina Poe
That's right.
- AHAndrew Huberman
... make sense in terms of how they're batched.
- GPGina Poe
That's right.
- AHAndrew Huberman
Is that kind of one way to think about it?
- GPGina Poe
Exactly. No, that's a great way to think of it. And, and when you're in REM sleep in the later parts of the night and that transition to REM, that's when your computer of your brain is com- opening folders and comparing documents, seeing if there, is there anything the same. These two documents look very much the same, but there's a little bit of difference and it can, it can link those conceptually. So that, that's probably one of the origins of creativity is finding things that are related, maybe just linked a little bit and you can find that link and strengthen it if it-
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
... you know, makes your schema interesting and different. Yeah.
- AHAndrew Huberman
Very interesting.
- GPGina Poe
Mm-hmm.
- 30:33 – 33:22
Deep Sleep, Dreams & Senses
- AHAndrew Huberman
is unique perhaps about the architecture of dreams and sleep in the, let's say, the last third of the night or the-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... or the second half of the night?
- GPGina Poe
Right. Yeah. In the second half of the night, we have longer REM sleep periods, and those are considered the deepest sleep, even though slow wave sleep, big slow waves is considered deep. It is deep, but actually-
- AHAndrew Huberman
Yeah. They call slow wave sleep deep sleep-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... and REM sleep rapid eye movement. But now you're telling me that REM sleep is actually the deeper sleep?
- GPGina Poe
The deepest.
- AHAndrew Huberman
Okay. There needs to be a new nomenclature-
- GPGina Poe
Yeah. (laughs)
- AHAndrew Huberman
... of sleep researchers.
- GPGina Poe
I know. You really shouldn't call it-
- AHAndrew Huberman
Yeah.
- GPGina Poe
... deep or not deep.
- AHAndrew Huberman
No. No. Please.
- GPGina Poe
The reason why you call slow wave sleep deep sleep is because it's difficult to arouse people out of that state. Um, and when you do arouse them out of that state, they're more s- most often confused and just want to go back into sleep and can go back pretty easily. If you arouse someone out of REM sleep, they're more likely to report something that was really kind of almost like wakefulness, it's, it was so vivid. But in fact, if you give someone a non-threatening kind of stimulation, like somebody dropping keys or, um, a ping or something like that, instead of waking... That same volume will wake someone up out of non-REM sleep, but out of REM sleep and instead lengthen the amount of time or make it even more dense, y- rapid eye movements more dense, and often people will incorporate that sound into their dreams. So-
- AHAndrew Huberman
Hmm. So the body and brain are somehow conscious of the, um, of the sound, and I've heard also smells-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... can even make it into our, our dreams-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... in, in REM sleep, but that we, it doesn't arouse us for sleep.
- GPGina Poe
It doesn't arouse us as often. Yeah.
- AHAndrew Huberman
Interesting.
- GPGina Poe
And maybe one of the reasons why REM sleep is deeper is, especially in adults and older people, that deep slow wave sleep goes away. So it's not as deep. It's not as big. The slow waves aren't as large, which is probably problematic, but we are not sure. And so then REM sleep becomes the deepest stage. Actually, in children, it's kind of a toss-up because they... It's really hard to wake them up out of that deep slow wave sleep. And in fact, um, fire alarms don't wake them up, even really loud fire alarms, out of that state of sleep. So that's why they're trying to change fire alarms so that instead of something that the kids don't associate with anything, like the (imitates fire alarm) whatever, they don't associate with, it says their name or something else that may be less loud but more salient to them and will wake them up.
- AHAndrew Huberman
I don't know, having carried sleeping children in from the car-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... I don't know that I want children to start waking up from sleep 'cause-
- GPGina Poe
Yeah. I know.
- AHAndrew Huberman
... that's one of the best things when you get-
- GPGina Poe
Isn't it?
- 33:22 – 34:37
AG1 (Athletic Greens)
- AHAndrew Huberman
I'd like to take a quick break and acknowledge one of our sponsors, Athletic Greens. Athletic Greens, now called AG1, is a vitamin mineral probiotic drink that covers all of your foundational nutritional needs. I've been taking Athletic Greens since 2012, so I'm delighted that they're sponsoring the podcast. The reason I started taking Athletic Greens and the reason I still take Athletic Greens once or usually twice a day is that it gets me the probiotics that I need for gut health. Our gut is very important. It's populated by, uh, gut microbiota that communicate with the brain, the immune system, and basically all the biological systems of our body to strongly impact our immediate and long-term health. And those probiotics in Athletic Greens are optimal and vital for microbiotic health. In addition, Athletic Greens contains a number of adaptogens, vitamins, and minerals that make sure that all of my foundational nutritional needs are met and it tastes great. If you'd like to try Athletic Greens, you can go to athleticgreens.com/huberman and they'll give you five free travel packs that make it really easy to mix up Athletic Greens while you're on the road, in the car, on the plane, et cetera, and they'll give you a year's supply of vitamin D3 K2. Again, that's athleticgreens.com/huberman to get the five free travel packs and the year's supply of vitamin D3 K2.
- 34:37 – 36:47
Later Sleep, Paralysis, Sleepwalking, Sleep Talking
- AHAndrew Huberman
So this, um, enhanced volume or, or proportion of, of rapid eye movement sleep in the second half of the night, uh, relates to more elaborate dreams. Uh, we are paralyzed during-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... REM sleep, correct?
- GPGina Poe
Yes.
- AHAndrew Huberman
Yeah.
- GPGina Poe
Normally paralyzed and that's really good because that's the time when we're actively dreaming storyline dreams and we could, um, hurt ourselves. We're actually really cut off from the outside world in terms of, you know, um, responding to, say, this table or window or door, and so different from s- sleepwalking, which is out of slow wave sleep, uh, out of slow wave sleep, that sleepwalking is a mixture between sleep and wakefulness, so you actually will respond to the door. You can cook a full meal, um, drive your car while you're in deep slow wave sleep. It's scary because you never know what you're going to do. You don't have voluntary, voluntary control over it. You have no conscious control over it, but you can actually safely navigate, um, some situations in sleepwalking, um, and actually have a conversation, although it may not make much sense when you're sleep talking. In REM sleep, you're not a-... processing the outside world. And instead, um, when you're acting out your dreams, you could be doing things like walking through a plate glass window or falling off of, you know, down the stairs, um, things like that. So, you really want your muscles to be inactivated during REM sleep. Otherwise, you will act out those dreams and really hurt yourself or your bed partner.
- AHAndrew Huberman
What about sleep talking or talking in sleep?
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, I don't know how many relationships have, um, been saved by sleep talking, but I'm guessing a few have, uh, been destroyed.
- GPGina Poe
(laughs) Yeah.
- AHAndrew Huberman
And I'm guessing that, um, talking in sleep could have meaning or perhaps has no meaning, just as dreams-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... could have meaning or no meaning-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... as we recall them. Yeah.
- GPGina Poe
Yeah. Do not take sleep talking seriously. Um, no matter what people say, it doesn't necessarily reflect truth. So it's not like you're being more truthful when you're sleep talking. Um-
- AHAndrew Huberman
You just saved a number of relationships.
- GPGina Poe
I hope so. (laughs)
- AHAndrew Huberman
(laughs) Um, I'm not directing this at anyone in particular-
- GPGina Poe
(laughs)
- AHAndrew Huberman
... but I, I guarantee you just did.
- GPGina Poe
Yeah.
- AHAndrew Huberman
Um, noted.
- GPGina Poe
(laughs)
- 36:47 – 43:19
Alarm Clock & Grogginess; Sleep Trackers, Brain & Sleep
- GPGina Poe
- AHAndrew Huberman
Um, so as people start to approach morning or the time when they normally would wake up-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... I've heard that it's important to, if possible, complete one of these 90-minute cycles prior to waking up.
- GPGina Poe
Hmm.
- AHAndrew Huberman
That is, if you set your alarm for halfway through one of these 90-minute cycles that come late in the night of sleep, that it can lead to, um, rather groggy patterns of waking.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, so I'll just ask you directly, do you use a, uh, an alarm clock?
- GPGina Poe
I do not. Um, thankfully, I'm in a line of work that doesn't require me normally to do anything at any particular time.
- AHAndrew Huberman
That's great.
- GPGina Poe
I do it when I do it. Um-
- AHAndrew Huberman
Great.
- GPGina Poe
... unless I have to catch a plane, and then I always set my alarm just in case. (laughs)
- AHAndrew Huberman
Well, as a fellow academic, I can tell you there are plenty of punishing features about being an academic scientist that-
- GPGina Poe
(laughs)
- AHAndrew Huberman
... um, that offset the fact that, uh, you don't have to use an alarm clock, but it is nice that you can often set your own schedule.
- GPGina Poe
Yeah. Yeah.
- AHAndrew Huberman
So would you recommend that, if possible, that people not use an alarm clock?
- GPGina Poe
Yeah, absolutely. If you can just listen to your body and wake up when you need to wake up, that would be great. Um, but, um, one of the reasons why we have such grogginess is called sleep inertia. When we wake up out of the wrong state, which is, um, deep slow wave sleep, is because I liken it to, uh, like a washing machine cycle. This 90-minute cycle is like a washing machine cycle. And, and, um, the first part is to add water, right? And, um, then your clothes are soaking wet. You don't want to open the washing machine and try and function, put them on, and wear them around while they're soaking wet and full of soap. So, you have to wait until the cycle is through before you can... Well, actually, that's... Put it in the dryer too-
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
... (laughs) um, before you want to wear them. Um, so, yeah, you can function. It just takes a little while for those clothes, (laughs) that brain to dry out, so you can actually function well. Um, but it's better to wait through the whole cycle is complete. And so that's why you want to set that 90, 90-minute alarm clock. And again, that's around 90 minutes, because the first stage of sleep, the first cycle of sleep is actually a little longer, more like 105, 110 minutes-
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
... but then the second ones and third ones, they get sort of shorter and shorter as the night goes on. And in the last few cycles, you're just doing the N2 REM sleep cycle, which takes less time. And if you wake up out of REM sleep, there's usually no problem cognitively.
- AHAndrew Huberman
Okay.
- GPGina Poe
You're, you're good to go.
- AHAndrew Huberman
Are you a fan of, of sleep trackers?
- GPGina Poe
Uh, sure. Yeah.
- AHAndrew Huberman
Yeah. Do you use one?
- GPGina Poe
I have one on.
- AHAndrew Huberman
Mm-hmm.
- 43:19 – 54:30
Early Slow Wave Sleep & “Washout”, Normal Sleep Cycle & Night Owls
- AHAndrew Huberman
there's one more thing I wanted to ask about the architecture of the night's sleep.
- GPGina Poe
Yeah.
- AHAndrew Huberman
Um, in terms of early part of the night.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Earlier you mentioned the washout-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... of debris and-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... um, the so-called glymphatic system-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... I think is what you're referring to.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Could you tell us a little bit more about the washout that occurs in the brain during sleep.
- GPGina Poe
Yeah.
- AHAndrew Huberman
What, what that is and what roles it's thought to serve?
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
And perhaps if there are any ways to ensure that it happens or to ensure that it doesn't happen.
- GPGina Poe
Right.
- AHAndrew Huberman
And obviously, we want this to happen.
- GPGina Poe
Yeah, yeah. Um, all right, great question. We talked about the circadian clock and how certain things happen at certain times. Well, one of the things that happens when we're awake and talking to each other is that there's a lot of plasticity. There's something that I'm learning from you today and you're learning from me, and that changes our synapses and it changes the way our proteins are going to be folded and, and changed during sleep. Um, it unfolds. This process actually uses a lot of ATP, the power, um, structure, the fuel of the brain, and, uh, it unfolds also proteins while we're doing this, while we're using them. And so, during that first part of the night, uh, when we first fall asleep in the first 20 minutes or so, we're building that, uh, adenosine back into ATP and that's, uh, probably why power naps are called power naps because we're actually rebuilding the power. And then, um, we're also cleaning out through the deep slow waves of slow wave sleep, we're cleaning out all those misfolded proteins, unfolded proteins, and other things that get broken down and, um, you know, need to be rebuilt when we're asleep because of its use during wakefulness. So, I liken that to, you know, having a big party during wakefulness and you need all those partygoers to leave in order to do the cleanup. And so what I think the mechanism is, and this is still something to be tested, is actually slow waves themselves, which is bad news for us as we get older and those slow waves get smaller and, uh, slow wave sleep goes away. So, um, so what happens when a neuron is firing is that it expands, the membrane expands a little bit. It becomes more translucent. That's how we know, one of the ways we know that neurons expand when they fire and so every action potential, it, the membrane expands a little bit as sodium brings water into the cell. Um, and then when they're silent, they contract. And so, in, during slow waves, the cool thing is that the reason why you can measure them is that all the neurons at the same time, not all of them, but a good portion of them, are firing at the same time and silent at the same time. And so, you think about that as contracting and expanding all at the same time. It's kind of like a bilge pump of the brain. So that can pump out ... Glia are also really important for this, um, in terms of cleaning up debris and transferring it to where it needs to go so, um, so I think of it actually as a bilge pump, um, cleaning out our brain.
- AHAndrew Huberman
Interesting. I've heard about the glymphatic system-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... and glymphatic washout. I've never thought about the mechanical aspects of it before.
- GPGina Poe
Okay.
- AHAndrew Huberman
I always thought that for some reason, that now it's obvious to me there had to be something mechanical-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... but only now that you've e- e- educated me about this.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
I thought that for some reason the, the cerebral spinal fluid just starts washing through, but here you're talking about literally an expansion and a contraction of the neurons in unison.
- GPGina Poe
Mm-hmm.
- 54:30 – 1:01:46
Locus Coeruleus, Learning & REM Sleep
- GPGina Poe
(laughs)
- AHAndrew Huberman
I'd love for you to tell us about REM sleep and the sleep later in the night as it relates to dreams and emotionality.
- GPGina Poe
Yeah.
- AHAndrew Huberman
And this is probably, um, the appropriate time for you to introduce us to this incredible structure in the brain, which is the locus coeruleus.
- GPGina Poe
Oh, yeah.
- AHAndrew Huberman
A difficult, um, structure to spell-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... but a beautiful, a beautifully named structure.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, I find locus coeruleus to be just fascinating, and I know, I, we know a small fraction of what it does, and I'm hoping you're going to educate me and, and our audience about, more about what it does, and hopefully tell us a little bit about its relationship to epinephrine, AKA adrenaline.
- GPGina Poe
Yeah. I'm so glad you brought this up because I can totally geek out on the locus coeruleus.
- AHAndrew Huberman
Please do.
- GPGina Poe
(laughs) Um, locus meaning spot or place and coeruleus meaning blue, so you could just call it the blue spot. Um, that's the easiest. Every, um, animal with a brain has a blue spot, and, um, yeah, and I mean every animal with a brain because of course, uh, there are animals with nervous systems that are not centralized, like jellyfish. Um, but anyway, we're, we're digressing there. (laughs) So, um, the locus coeruleus is filled with neurons that have in them norepinephrine, which is the brain's version of epinephrine or adrenaline. It's also called noradrenaline. And what it does is it, just like adrenaline in the rest of our bodies, it helps prime us to respond to our environment. So when locus coeruleus neurons fire, and fire in a burst, we can switch our attention. Um, and they will fire in a burst if, for example, if a loud noise happens in the middle of your concentrating on something. So you can, it helps, it fires and it helps you switch your attention to that thing and then learn quickly from it. So it's really important in a stress response. It helps us do quick one-trial learning and, um, and then tonic activity during the day when you're just, you know, doing your normal, going about your normal concentration kind of activity- activities is really good for, um, sustained attention. Um, it, it works with the cholinergic system of our basal forebrain, um, which is really important for learning and memory, also to help us learn about things and put things together. Um, but just tonic ale- levels are a signature of wakefulness and alertness. So too much is panic with the locus coeruleus activity. A burst is switching attention and then tonic levels are sustained constant attention. And then when we go to sleep, the locus coeruleus slows and come, goes from about on average, um, two hertz to about one hertz, one cycle per second, um, tonically. Um, and then when we go into REM sleep, it's the only time when it shuts off completely, and it appears that that complete silence is really, really important for a number of things. And the main thing that I think it's important for is the ability to erase and break down synapses that are no longer working for us. So they encode things that are false now or they are encoding things that we, um, learned in the novelty encoding pathway in c- of our, of our brain that have now been consolidated to other pathways. And so we need to now erase them from the novelty encoding pathway, and that is really, really important for being able to continue to learn, um, things all of our lives. So like erasing that RAM, um, or that, I don't know, what do you call those disks that you stick into computers that-
- AHAndrew Huberman
Oh, uh, hard drive? Uh, no.
- GPGina Poe
Or you got a...
- AHAndrew Huberman
Um, thumb drive.
- GPGina Poe
Thumb drives, yeah.
- AHAndrew Huberman
Thumb drives.
- GPGina Poe
You're erasing your thumb drive so you, that thumb drive is what you carry around all day long and then during sleep, you write that thumb drive to the cortex, to the long-term memory structures, and you need to refresh that thumb drive. And that's what happens during REM sleep when the locus coeruleus is off, because whenever it's on and noradrenaline is there, it helps us to put things together, it helps us to learn and strengthen synapses, but it does not allow us to actually weaken synapses that are also a really important part for life, a portant part of lifelong learning. Um, yeah. Uh, so much more I could say about that.
- AHAndrew Huberman
Yeah. Locus coeruleus sounds fascinating.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
So it's connected to the basal forebrain cholinergic system.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, the neurons in locus coeruleus, if I'm not mistaken, release-
- GPGina Poe
Norepinephrine.
- AHAndrew Huberman
... norepinephrine.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Perhaps epinephrine as well?
- GPGina Poe
Uh, n- well, no, the brain's version of epinephrine is norepinephrine.
- AHAndrew Huberman
Mm-hmm. Right.
- 1:01:46 – 1:06:13
Post-Traumatic Stress Disorder (PTSD), Locus Coeruleus & Sleep
- AHAndrew Huberman
- GPGina Poe
Do you want me to talk about norepinephrine and-
- AHAndrew Huberman
Yeah. So what I'd l-
- GPGina Poe
... emotion and-
- AHAndrew Huberman
Yes. Well, what I'd love-
- GPGina Poe
... stress? (laughs)
- AHAndrew Huberman
... what I'd love for you to, um, tell us about is, you know, what role this lack of norepinephrine release during rapid eye movement sleep-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... um, is thought to achieve and w- maybe you could also review some of your work describing conditions under which norepinephrine invades-
- GPGina Poe
Yeah, invades sleep.
- AHAndrew Huberman
... uh, rapid eye movement sleep and other patterns of sleep and how that can be detrimental.
- GPGina Poe
Yeah. So a lot of this is hypothetical, but based on a lot of good evidence that we're sewing together into a schema from which these hypotheses come, so a model, um, schema from which the h- hypotheses come, but one thing that happens to people with post-traumatic stress disorder is that there's a lot of evidence that the locus coeruleus doesn't stop firing in REM sleep. So whereas their, um, levels of norepinephrine might be similar to people without PTSD during the day and even during the first part of the night, um, during the wee hours of the morning and when you measure norepinephrine levels from metabolites, um, in the blood or the s- cerebral spinal fluid, you see that people with PTSD, it's during the wee hours of the morning when you have the most REM sleep that they have, their norepinephrine levels differentiate most from those that don't have PTSD. And so that's evidence that the l- locus coeruleus is not shutting down during REM sleep like it should. Other evidence is heart rate variability. When our locus coeruleus is firing, um, our heart rates are generally a little higher and they don't vary as much as they do when the locus coeruleus is not firing. So during slow wave sleep normally have this big juicy variability in heart rate with every breath in and breath out because our noradrenergic levels, our norepinephrine levels are lower. During REM sleep, that goes away entirely and our heart rate is, is, um, is, um, dominated by, uh, parasympathetic rather than sympathetic activity and also what our brain is driving, you know, what are we dreaming about, for example. If we're dreaming we're running, our heart rates will go up. But norepinephrine levels sh- still should be low or off. So, um, people with PTSD that noradrenergics, uh, we're studying these in rats too. Is it true that our locus coeruleus doesn't, uh, shut off when we have post-traumatic stress disorder and the preliminary evidence is yes, it's true that it doesn't shut off. So what that would do is, um, norepinephrine would act at synapses to prevent that, uh, weakening that you really need, for example, of novelty in coding structures and it keeps memories in that novelty in coding structure even once it's consolidated to the rest of the brain. So in the hippocampus, which is important for remembering things throughout our lives and, and it's that thumb drive, um, we, we need it to be erased so that we can learn new things, uh, once it's been consolidated to the w- the hard drive of our cortex and if, so if we're not able to do that, we fill up that RAM, um, really quickly or that thumb drive really quickly and we're not able to learn new things. So for example, after a trauma, I talked about the locus coeruleus responding in stressful situations. That's great. It's very adaptive, but then you need it to stop. Once you've learned what you need to learn from it and you want to go to sleep, you need the locus coeruleus to calm down and during REM sleep you want it to stop because then when you've consolidated that traumatic memory to the cortex you need to erase it from the novelty in coding structures, for example, in the hippocampus, so that then when you're in the context of safety you can learn those new things, those new contexts and, um, and stop responding to those same stimuli as though you're in that original situation. So if you're not able to erase that thumb drive, you will always feel like that trauma happened that same day, like earlier that same day, and, um, respond as you would to, uh, uh, an early, uh, a recent trauma, which is with beating heart and all of that. Um, so even memories that are years past, if you're never able to downscale that novelty in coding structure and you purge it from that traumatic memory, it will stay fresh and new and then become maladaptive.
- 1:06:13 – 1:07:31
InsideTracker
- AHAndrew Huberman
I'd like to just take a brief moment and thank one of our podcast sponsors, which is InsideTracker. InsideTracker is a personalized nutrition platform that analyzes data from your blood and DNA to help you better understand your body and help you reach your health goals. I've long been a believer in getting regular blood work done for the simple reason that blood work is the only way that you can monitor the markers, such as hormone markers, lipids, metabolic factors, et cetera, that impact your immediate and long-term health. One major challenge with blood work, however, is that most of the time it does not come back with any information about what to do in order to move the values for hormones, metabolic factors, lipids, et cetera, into the ranges that you want. With InsideTracker, changing those values becomes very straightforward because it has a personalized dashboard that you can use to address the nutrition-based, behavior-based, supplement-based approaches that you can use in order to move those values into the ranges that are optimal for you, your vitality, and your longevity. InsideTracker now includes a measurement of apolipoprotein B, so-called ApoB, in their ultimate plan. ApoB is a key marker of cardiovascular health, and therefore there's extreme value to knowing your ApoB levels. If you'd like to try InsideTracker, you can go to insidetracker.com/huberman to get 20% off any of InsideTracker's plans. Again, that's insidetracker.com/huberman to get 20% off.
- 1:07:31 – 1:12:29
Locus Coeruleus, Trauma & Sleep, Antidepressants, Norepinephrine
- AHAndrew Huberman
What approaches are you aware of that can, um, turn down the output of locus coeruleus during these phases of sleep, and for that matter, what things can cause ramping up of locus coeruleus during this phase of sleep?
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
Um, y- we've had a couple podcast episodes, solo episodes and with guests, talking about trauma. We had Dr. Paul Conti-
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
... who's a Stanford-trained, Harvard-trained, um, psychiatrist who talked a lot about trauma, wrote an excellent book on trauma and, um-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... certainly sleep was emphasized as a, as a key thing, like get enough sleep.
- GPGina Poe
Mm-hmm.
- AHAndrew Huberman
But here you're saying even if somebody with trauma gets enough sleep, if locus coeruleus is hyperactive during sleep-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... those traumas are going to persist. And most of the trauma treatments that I'm aware of are everything ranging from cognitive behavioral therapy, talk therapy, drug therapy, EMDR, hypnosis.
- GPGina Poe
Yeah.
- AHAndrew Huberman
Um, nowadays there's a lot of interest and attention on, um, clinical studies on exploring psychedelics-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... high dose psilocybin and MDMA.
- GPGina Poe
Yeah.
- AHAndrew Huberman
The, so there's a vast landscape-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... none of which, as far as I know, is really focused on sleep specifically.
- GPGina Poe
No, they're not. And they should be, because actually psychedelics is a sleep-like state.
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
And, um, it's a REM sleep-like state, although of course there are some major differences. So yeah, (sighs) so much to talk about here. So antidepressants, um, are often noradrenergic or serotonergic reuptake inhibitors. So they leave norepinephrine actually out there in the synapses, and what that does is it inhibits REM sleep. Um, and if you're able to get REM sleep, it would probably be REM sleep with some noradrenergic-
- AHAndrew Huberman
Mm-hmm.
- GPGina Poe
... activity. So actually I think, anyway, I'm not a physician, that, um, antidepressants are counter-indicated. You don't want to take them if you've experienced a trauma and you're experiencing PTSD, because if anything, it's going to make it worse or at least prevent the type of adaptive REM sleep that you really need in order to resolve those emotions and move on. Um-
- AHAndrew Huberman
Is that statement-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... specific to antidepressants that, um, tickle the noradrenergic pathway? So-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... the, the one that comes to mind is, um, bupropio- I can never pronounce it, bupropion which is-
- GPGina Poe
Yeah.
- 1:12:29 – 1:16:22
Locus Coeruleus, Bedtime & Novelty, Estrogen & Trauma
- AHAndrew Huberman
So, if I want to reduce the amount of norepinephrine released from locus coeruleus during rapid eye movement sleep to eliminate the troubling or maybe even traumatic memories-
- GPGina Poe
Yeah.
- AHAndrew Huberman
... um, and allow late stages of sleep each night to have their maximum positive effect-
- GPGina Poe
Mm-hmm. What do you do?
- AHAndrew Huberman
... is there anything that I can do besides avoiding, um, avoiding traumas, avoiding serotonergic or noradrenergic compounds?
- GPGina Poe
Well, I would also avoid anything just prior to going to sleep that might excite those systems.
- AHAndrew Huberman
Hmm.
- GPGina Poe
So, a lot of novelty. Um, a lot of, you know, exciting, um, stress-inducing video games. Um, try and enter sleep with as much calm as you can. So maybe deep breathing exercises. That's a beautiful way to calm your sympathetic fight or flight system is deep breathing. And, um, we haven't been able to test this with rats because we can't ask them to do a deep breathing exercise (laughs) . Um, there might be a way we can do that, but I haven't found out or figured it out yet. Um, but if there's a way you can make your sympathetic system, nervous system calm down before you go to sleep, it might be for you meditation or deep breathing exercises. It might be for some a warm bath or a comforting book. Nothing too exciting, but, um, also nothing too boring perhaps. Um, just something right in the middle which makes you feel happy and calm is what you should do. And if you instead go to sleep while you're anxious or, um, you're hyped up, then your sleep could become maladaptive. Um, another thing that happens in rats that we have yet to know if it happens in women is that female rats have, uh, three phases of their estrus cycle that, um, their locus coeruleus doesn't seem to calm down during REM sleep as much. And we don't know why, but during the high estrogen phases of their estrus cycle, the locus coeruleus shuts down just like it does in male rats. But in the other three phases, it doesn't. So, um, one thing that might work, and in fact there are a few studies that show it, it could work really well, is, um, uh, giving women after a trauma event, um, something that contains estrogen because estrogen somehow is protective against PTSD and they know that through retrospective studies where they, uh, gave women in emergency room either a pill with estrogen in it or without, and those that had the pill with estrogen in it were much less likely to get PTSD from that trauma as measured a year later than those that had the pill without. So, um, there are some really good studies by Bronwyn Graham, she's out of Australia, to really hone in on how much estrogen do you need, and also testosterone, just so you know, gets converted to estrogen in the brain. So testosterone also can be protective because it gets converted to estrogen. Um, but there's something about estrogen that's really helpful and protective about, uh, that from, from the high locus coeruleus firing and this is, again, preliminary data that we don't have full... We don't have all the answers yet and, um, we are looking into it actively right now, but it's, uh, really important. The other thing about women is that we are two to four times more susceptible to anxiety-related mental health disorders including post-traumatic stress disorder. So if we could figure out what's happening to the locus coeruleus during sleep in women, um, that, and then figure out a way to normalize that so the locus coeruleus is silent when it needs to be silent, I think we could go a long way in, in helping women be more resilient to stress-related, uh, disorders.
- 1:16:22 – 1:19:12
Sex Differences & Sleep
- AHAndrew Huberman
What are some other, um, sex differences as they relate to sleep?
- GPGina Poe
Yeah. Yeah, that's a really good question. There have been very few studies unfortunately, uh, of women and sleep. Um, women and estrus cycle or menstrual cycle and sleep and, um, but what we have found which actually largely replicated a study in 1960, um, is that, that women, or females rather, at high estrogen, high hormonal phases of their estrus cycle or menstrual cycle sleep a lot less, but that sleep is more efficient. So that sleep is more dense in those sleep spindles which I haven't gone into what they might do except this connection between the hippocampus and cortex, but it's, those sleep spindles are more dense and more coherent across the brain areas. The theta cycle which is five to 10 hertz in the hippocampus important for when you're learning and also important during REM sleep. It is also bigger and juicier, um, during the high hormonal phases. So even though there's less sleep, it's more efficient and better. Um, but, uh, so, so all of that efficiency seems to be reduced in those other hormonal phases. Um, so even though you might sleep a little more, um, you might need more sleep in fact in order to accomplish the same thing that you can get with that short, um, very efficient sleep of high hormonal phases.
- AHAndrew Huberman
Very interesting.
- GPGina Poe
Yeah.
- AHAndrew Huberman
I think, um, there is a growing trend at least among, uh, NIH-funded grants to, uh, require, um, that, uh, as they refer to it in the grants, biological sex as a variable.
- GPGina Poe
Yes.
- AHAndrew Huberman
Uh, and again, here we're ta- not talking about sex the, um, the verb, although I'm sure there are studies about that too, but biological sex as a variable because there is a dearth of studies exploring sex differences in-
Episode duration: 2:05:40
Install uListen for AI-powered chat & search across the full episode — Get Full Transcript
Transcript of episode BMTt8gSl13s
Get more out of YouTube videos.
High quality summaries for YouTube videos. Accurate transcripts to search & find moments. Powered by ChatGPT & Claude AI.
Add to Chrome