Night Janitors of the Brain

you really wake up feeling refreshed. I was able to get a pretty good night's sleep myself last night because I slept alone on the couch, um, because the toddlers is it still has a cold and ends up sleeping in the bed, and so you get the night migration. Yeah. And then of course once the toddlers in the bed, they just kind of like turn like a like a turbine all night. Um. And then this case also coughing, So I knew I had the podcast hit the couch.

Full night's sleep. Woke up so much, so much better, like actually able to to think about the topics that we were recording today and to some degree articulate those thoughts. Yeah. I'm always amazed by what the sort of powers that can bestow upon you when you have a good night's sleep, and sometimes I wake up thinking, oh I'm back. Oh yeah you hey you Julie, I know you. Yeah. It really were a different person when we've had a full night's sleep. We were we're in a since our best person.

Like I think back to times where I would try to do something either um mentally intense or creatively intense, by staying up ridiculously late at night to work on it. Be it like you know, school project or you know, a bit of fiction I was trying to write. And now nowadays I I just I look back and just complete disbelief, Like why would I try and do that on the last remaining bit of energy that I had in my my noggin when I could have had a full night's sleep, woken up and tackle the fresh Because

you're young and foolish. Exactly, That's just what it goes. Um. I actually was thinking about those, thinking about how we humans require so much sleep. In some ways, it feels really ridiculous, right because we're these apex predators. So far, we're we're dominating out there among other species. And then I think I wonder if tiny dust mites with their tiny sharpie scrawl things on my head while I'm sleeping at night, like I just pooped on this apex predator's

head ha ha ha and laugh at us. Why does this giant being needs so much sleep? It rules the planet, and yet it decides to just shut its eyes and drift off into La la land for a large portion of its time here on Earth. Yeah, in a very vulnerable position. Right, You're immobile, You're vulnerable, and this for our ancestors would have been pretty risky business. Yeah. I mean, you get into believe we're discussed in the past, like

the theories about our dreams about falling. It's a leftover from days when when falling from your your your perch of slumber in the trees would probably mean something would eat you. I love that theory. I think it's really interesting. Um so, yeah, I mean does bring up this idea that is there more to sleep than meets the eye, just then consolidating some of our memories or making us feel refreshed, as there's something going on in the background

that is essential to survival. Yeah, and I mean, and clearly it's essential. We've talked before about you know, can we have a cure for sleep? Are their ways to artificially achieve what sleep does for us. And the hard answer is no, you can sort of, you can kick that can down the street a little bit, but eventually you're gonna have to go to sleep or the consences are going to grow more and more dire, leading up

to hallucinations and death right. As we will discover, there is no substitute for the night janitors of the brain and what they do, and we'll talk about that in a minute, but before we get into that, let's talk about the awe inspiring an energy draining splendor that is the human brain. What sets us apart, why we need to rest so much, because if you think about it,

um our brain is taking up about the energy. So if you equate that with like the world energy sources, we'd be like the brain would be like the U S and China. Yeah, just glowing there in the night. Yeah yeah, yeah. To think about the mammalian brain is specifically the human brain. I love the analogy that we've touched on in the past of the ice cream cun You have the basic brain as the scoop of gray matter up there on the cone and and for you know,

most creatures, that's that's all you need. It takes care of all ther your your basic functions, but for us, humans especially, we need a little more. We need a little extra scoop on top of that. Yeah, it's true.

If we trace the brains evolution from fish to amphibians, too, reptiles, to mammals and finally humans, we see that the parts of the brain that have grown the most and human beings are the neo cortex, specifically the prefrontal cortex, and mammals were given this upgrade, the second scoop, if you will, that neo cortex, so we could deal with all sorts of things parenting, mathematics, language, and humans. So it's really

important to our survival. So now think about this. As reported in the journal Science, researchers who have examined preserved samples of cerebral cortex from humans and several species of a report that in particular region, in a particular region of the prefrontal cortex. Now this is the area that

contributes to abstract thinking again sophisticated cognition. Neurons have more space between them in the human brain than in the brains of apes, and this extra space allows for more room for connections between neurons and Why is that important because we have about I don't know, two hundred billion nerve cells which are connected to one another via hundreds of trillions of synapsis. Yeah, and these are essentially microprocessors.

We've discussed how these work out before. They're they're both memory storage and information processing elements. Uh, uh and uh and they're essential to all this complex uh thoughts, all the all these of all this computation that we're able to achieve, all the uh this this management of information across all of these different parts of the brain. Yeah,

this is crazy. One synapse may contain on the order of one thousand molecular scale switches, and a single human brain has more switches than all the computers and routers and internet connections on Earth. And that's from Stephen Smith, who is a professor of molecular and cellular physiology. So what we're saying there is that that is a lot of electricity going on in the old noggin and a lot of wear and tear. So what is what happens

with all of that use? Yeah? I like to think of think of this in terms of an old house that that hasn't had a lot of electrical upgrades. To it, but the individuals living inside it, their electrical needs have evolved over time. There they have more and more gadgets

they need to be plugged up. They have more and more just just chunks of their entertainment system that need to plug into the wall and plug into this, that and the other, and so eventually get these overpowered uh um outlets where with all these power strips aga into power strips. Uh And because that's essentially one of the things about about the evolution of the human brain, it doesn't as much takeaway old stuff is just pile on more. It's just this this ice cream cone that's uh at

times seems a little toppling. Yeah, and of course you have by products from that, and we'll talk a little bit more about that, but before we do, we're gonna take a quick break, and then we'll find out about this night janitor who's coming to clean away the debris and positively even the disease. The night Genitor is coming for you. All Right, we're back, and I think we all have experienced what happens when we over tax our brains.

Your little nappy poo coming on, or just absolute mental exhaustion. Yeah, you just it's harder to string your thoughts together. It's harder to uh to prepare for a podcast, much less performed one. It's harder to put up with things too. It's hard to be patient with people with toddlers, with though with whatever your circumstances are. You just feel a little more trapped in the maze rather than wandering the labyrinth.

It's harder to learn new things to write, because that's what happens when you're sleeping, and you get the formation of new neuronal connections and the pruning of old ones. So we know that there is a lot of up keep going on, But what about all that mental exercise? Again, those byproducts, because if you look at the human body, the lymphatic system, you will see that when the body's muscles exert sustained energy, they create toxic byproducts in your

muscle cells. And this is according to Maria Konokov reading for The New York Times, the lymphatic system serves as the body's custodian. Whenever waste is form, it sweeps it clean. The brain, however, is out of reach of this system. Yeah, we've we've we've keep adding all of the gear to the old brain. But it's shut off from from the rest of us. It's a it's it's it's not in a position for servicing by the Lympic systems. So what's going to clean it up? Who's going to clean it up?

The old idea is that that the brain rid itself of metabolites and beta amyloids, these are actually associated with Alzheimer's was that it broke it down and recycled it at an individual level. But Mike ken Nindogrod, a Danish biologist who has been leading research into sleep function at the University of Rochester, didn't think that that made sense. She thought, you know, the brain is way too busy

to be recycling all of its own energy. And she suspected that the brain shared the same kind of system that muscles and the lymphatic system have. Yeah, and it's it makes perfect sense, right. Why would uh, why would the brain have a different structure in place? I would have a different system entirely. It seems like you would have a system more in keeping with what the rest of the body is doing to to carry out the same task. But it was a mystery, right because you

know that the brain creates these byproducts. How in the world are they ushered out? And why are they sometimes sitting in your brain and collecting um. So this system that she thought about is again similar to the lymphatic system, but this one is predicated on the rebro spinal fluid and what near de Guard calls the glymphatic system, and that that gly glymphatic system is a nod to the brain's cleil cells, which maintain homeostasis and protect neurons. So

what did she do? What would any good scientists do? Go grab a bunch of mice and spy on them while they slept. Yeah, that's just what's what they did. They injected UM mice with fluescent tracers right into their cerebro spinal fluids and this allow them to track where the fluids are going during the course of their sleep. Yeah. Now, during the mices waking hours, the cerebro spinal fluid barely

made it into the brain. But once they were asleep and the sleep was induced, of course the brain cells in in the mice shrunk and that made way for a flood of the fluid, essentially hosing down the brain

of waste products. We're talking the waste products or proteins that are toxic to the brain, and so it's turns out that the brain's interstitial space, the fluid filled area between tissue cells that take up about the brain's total volume, is mainly dedicated to physically removing the cells daily waste. So it's essentially a flood moving through just washing out

all the toxins. It's it's it's like the brain is a is an office with drains on the floor, and when everyone goes home in the evening, they just come in with a fire hose and just start just just just hose it completely down. It's true. Have you ever seen the bathrooms that have like a shower and in the toilet in the same area with as you say, the drains. It's just a perfect way to kind of

get rid of all of the waste at the same time. Um. So, I mean it's kind of a big deal because it gives us a better idea of why humans require so much sleep. Okay, it's not just refreshing or memory consolidation, the removal of actual toxins from your brain, right, And it's also a window into better understanding brain related diseases like Alzheimer's because what they've seen at Alzheimer's pay stance is that there is a build up of that beta

amyloid protein in the brains. So is the question, you know, Morshley equals less brain disease. Possibly we don't know this yet, but it is a It really is a big window into this mystery of how the brain rids itself of these toxic um byproducts. And again why sleep is so

incredibly important to our existence? Yeah, and and and again I feel like, um, something we can both attest to is the the arrival of a child in one's life really drives that home for you, especially when you have to to make that choice between should I say that the kid is asleep, should I go to sleep too, or should I try and stay up and carve a little me time out of the remainder of the night. I would find myself early on trying to do that, thinking, oh, I'll just go to bed at you know, an hour

later and have that hour. But then you cut into the amount of sleep you get, any wake up the next morning when the toddler wakes up, When the child wakes up, and uh, and and you're you're behind. It's hard to catch up again. And then you find yourself, just less able to process the world around you, less able to to to tolerate even the little things to

annoy you. It's uh, it's definitely been. One of the big lessons of getting older is that sleep is magnificent and mandatory and and it's so frustrating that the children don't don't understand that and don't want to sleep. They like, they don't want to do it. It's the greatest thing in the world. It's it's the best part of being human. And you can pretty much do it all you want. You can really sleep as much as you want when you're when you're very young, and they inevitably don't want

to do it. It's the truth, because you know, babies, toddlers with their clock in twelve hours or something, they don't even think about it. They just pass out. And then when you're a teenager, no big deal again, twenties, a night of rockest drinking, you can still bound out of bed, but at some point your body is going to be like, I'm adjusting your sleep clock. Everything from here on out matters. Yeah, I'm taking every second time is ticking. So again we we we have to be

thankful for the night janitors. And I do love that image of the night janitors moving in because it sounds just a little creepy, these strange figures that that move in through your brain while you're asleep, and they're they're brushing away all the toxins, and it's it's a pretty thankless job, right, And we take it for granted, right because we think we just wake up at eight am and the building is just happened to be cleaned overnight.

We don't know how it happened. We feel all fresh, but yeah, they've been toiling away flushing out the toxins. All right, So there you have it now. Sleep is something that all of us do. So I know all of our listeners out there have some little bit of personal information to share about this this uh this idea of the night janitors moving through our brains, clearing things out, taking the toxins away, and indeed the mandatory nature of sleep. Uh.

So feel free to share your stories with us. What has happened when you have tried to avoid sleep, or worse yet, U you've found yourself in a vision where you cannot get the sweep that your body needs. Yeah. I read recently that Americans are getting an hour less of sleep a night than they did something like two decades ago, So there's definitely some sleep deprivation going on. So you want to reach out to us, you want to get in touch, well, you can find us at

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