The Dark Side of Neuroplasticity

and brain disease. It will allow adults of any age to learn new languages with the aptitude of a young child. But that's not why I've injected you with it. No, we've we've romanticized neuroplasticity. You see, we forget the importance of neuro stability. As children, we have an amazing ability to adapt to any environment, any language, were open to the world. We're also open to trauma. But then everything has to settle. We put aside those childish things and

we become by a man doctors, secret agents. What do you want from me? Why? I want to change your life? Hans Rob the film Weight What what are you showing me? Jessup a YouTube playlist. Oh please, hours upon hours of let's call it informative content from some of the platforms leading personality No, not thish influencers. I'll tell you anything. For medians, no commentates, unboxes. No. Welcome to Stuff to Blow your Mind from how Stuff Works dot com. Hey,

welcome to Stuff to blow your mind. My name is Robert Lamb and I'm Joe McCormick. And today we're gonna be talking about another topic, sort of a follow up from Robert's visit this year to the World Science Festival. We're gonna be talking about neuroplasticity. That's right. This, uh, this particular panel that that I attended, and this one is also available online. Will make sure there's a link to the YouTube video on the landing page for this

episode Acceptable in your Mind dot com. Uh. The particular

panel was called Nuts and Bolts of Better Brains. It was hosted by Guy mccon, neurosurgeon, neuroscientist, Alvero Pascal Leoni, neuroscientist, uh Nim Tottenham developmental or psychologist, and Carlas Shots, a neuroscientist, and they discussed neuroplasticity, which is something that we've we've touched on on the show before, and I think a lot of people have kind of a general concept of Yeah, neuroplasticity is one of those words that I think has

suffered a lot of abuse in the press um because I mean, there are words that have a good meaning in science, and there's nothing wrong with the concept itself. But in today's neuroscience, neuroplasticity does have a meaning, and it does have a useful meaning. But you see it in a lot of hype and bs on the internet. Yeah, Like I noticed, when when you do a search for neuroplasticity you want to read things about it, you get

mostly content at one of two levels. Either content for experts and neuroscientists, like actual scientific literature that the average reader can't penetrate, and then you get also a whole lot of hype and bs that is telling you about I don't know, about how you're going to revolutionize your brain and you'll become like a child again and become

a master of your own abilities. Yeah, I mean it's already become something of a buzzword, for instance, with with certain uh like supplement manufacturers, and take this neuroplasticity vitamin Yeah, okay, thanks, But but the neuroplasticity is a real thing. It is you can think of it simply as the brain's ability to adapt, and humans most incredible powers of neuroplasticity, especially during the so called critical periods of early childhood. Yeah.

One of the things to think about this kind of weird is um how well humans adapt to such different life conditions. Like if you take most animals out of the environment and condition conditions that they're best adapted to, they don't do very well. There are some exceptions, but most of the time an animal has evolved to have certain instincts. It's got sort of like pretty hardwired behaviors.

It can live, you know, it can be born where it is supposed to be born and live encountering the kind of stimuli it would normally encounter, and you know, it can do its thing that nature has shaped it for. But humans can do all kinds of stuff. We can live in the snow, we can live in the desert, we can live in cities, we can live in it plans. We can be farmers, we can be doctors. We can do so many different kinds of things with our brains.

And there are no other animals like this really. Yeah, the in the talk, they brought up the example of the loggerhead turtle as an example of a creature that is not a paragon of neuroplasticity but neuro stability. A creature that, upon birth is just ready to go and do a very specific thing exceedingly well in a very specific environment. But if you put some major obstacles in that turtle's way, the turtle probably would not find a way to adapt to those obstacles and survive around them.

It would probably just not survive to adulthood, right, I mean in the turtle is a good example of that, because I mean with with with various sea turtles, we've seen examples of how just artificial lighting can screw up a very particular approach to going about its life cycle. Yeah, but so your brain. One of the reasons your brain is so powerful compared to the brains of animals is that it can be adapted to so many different scenarios and so many different types of tasks depending on what

sorts of environments you're exposed to when you're very young. Yeah, language is of course one of the great examples, and I think everyone has at least some awareness of this. Certainly anybody out there who's a parent has has read

about this or experience this with their own children. Is that during certain critical periods, they have an amazing ability to not only pick up a language, but to just perfectly pick it up, to just breathe it in and and and become fluent in it without without any of the challenges that are generally encountered by adults trying to

learn a second language. I mean, one of the ways that it's often put is that with great effort, and adult can learn to speak a language they don't already speak, but they will pretty much always speak it with an accent. Children can learn to speak all kinds of and can learn to speak multiple languages at the same time, and

can generally learn to speak them without an accent. But then, of course it goes beyond this too, because there there's so many other things that are being absorbed during childhood, you know, the social norms, cultural norms, just how one interacts with your environment, and that has enabled humans to thrive all over the world, you know, obviously with technological aids in many cases, but still it it underlies the

diversity and success of our species. Then again, there are some reasons to think that you don't want the brain to be sort of infinitely plastic, right, because if we consider plasticity the ability of the brain to adapt to new scenarios and change itself to work better, you also need cases where the brain knows what to do and does it instead of keeps being influenced and changing right right,

and knows where to where to where to stop. You know what, what avenues to stop exploring because basically what happens is their neural circuitry branches out to master the skills necessary for survival. And then uh, and then after it does this, after you know, some of the branches have been prune back. Uh. You can think of it like a you know, like one of those shrub sculptures from the Shining from you know, the original novel. If you've read that, you know you you you prune everything down,

cut it away until it's the appropriate shape. Yeah. It's an interesting thing that the speakers in this event talk about is that the idea of pruning in childhood, how it starts off with way more connections than it needs, and then through this process it sort of pairs back the stuff that says, Okay, it looks like I'm not

going to need that in life. We can just sever all those Yeah, I mean it kind of matches up with the cliche of the child who can grow up to be anything, right, which you know, obviously any given child can't grow up to be absolutely anything. But there is a there. There is a lot of room for specialization and and and and diverse growth there. Yeah, we have natural tendencies and natural potentials, and some of that is genetic. But then also we were extremely adaptable as children, right.

But then of course in neural stability has to kick in. That's important too, a necessary balance in the human brain. Um, you're going to grow up and become this thing we call an adult. But what if I am Peter Pan and I don't want to grow up and be an adult because growing up and being in a delt and having neuro stability limits my potential. What if I decide I don't want to be somebody who only speaks English. I want to be somebody who speaks Chinese and speaks

French and speaks the click languages. And you know what if I want to speak all those languages without an accent, why can't I do that. Yeah, I want to have infinite potential again. I want to go back to I want to be able to grow up to be anything.

You know. I think we've all had moments like that where we we we we look at where we are and we think, well, if I could go back and open myself up to this language or this ability or what have you, then I would love to do that, you know, or or just the idea that nobody wants to. You don't want to feel stagnant. You want to feel like you're continuing to grow and uh and you know,

keep up with the young ones. And so scientists have continually looked to possible ways of essentially rewidening the doorways of of neuroplasticity. That's one of the metaphors it's often used, right, is that when you're a child out the door is open, the window is open for you to grasp onto anything. But then depending on who's throwing the metaphor round, you can say, well it closes when you become an adult,

but it doesn't really closes. It gets sort of like it gets almost closed, right, it narrows, And so we've looked to ways to to widen it in adulthood, and and it goes beyond this mirror um, you know, intellectual vanity as well. Right, it's not just Peter Pan saying

I want this, I want that. There's also the idea of treating problems in the adult brain by reintroducing plasticity, right, it would it would give us a way to treat various neurodegenerative disorders, anxiety, depression, even post traumatic stress disorder. Like anytime there's a there's a potential for for growth and change, positive growth and change in the brain to help with a given condition. Neuroplasticity is often brought up as a as a potential cure. But it's a challenge

to do this sort of thing. As a Columbia University develop antal psychologist Dr Nim Totenham, who we were referenced already, as she stated in the in that World Science Festival discussion, the brain actually extends, expends a lot of energy to keep critical periods from reopening. Yeah, we there there seems to be some logic underlying this, this move the evolution took right, it says, you know, you don't stay a plastic child forever. At some point the brain needs to

figure out what to be and be that right. And that's one of the reasons we're calling this episode the Dark Side of neuroplasticity. Not that neuroplasticity he necessarily has this deep, dark underbelly, but the sort of public awareness tends to lean so heavily towards neuroplastics is just an absolute good. I want as much of it as I can get. We want to counter the hype. Neuroplasticity is a good thing, but it's also not in uh, it's not a good thing in every possible case, in every

possible sense. Right, And towards the end of the episode, Will will speculate a little bit and look at some some speculation from experts about some of the possible pitfalls could be. What are some and even what are some of the black mirror esque possibilities in a world full of neuroplasticity inducing drugs? Yeah, now the question about these drugs, though, is still wide open. I mean it's sort of uh.

I hate to use the metaphor the wild West. What's a better metaphor for an arena in which there is still much much new ground being forged? Welcome to the jungle Baby. How about some spelunking. We're spelunking. Yeah, those are close confines, though, I guess okay, I think I think wild West is still pretty good. Well whatever it is.

I mean, we're still trying to figure out what kinds of drugs might do this, what side effects they might have, if they are effective at doing it, And we'll talk more later in the episode about what some of these specific drugs might be. Yeah, because to master neuroplus this day, we're going to have to establish the molecules that close

the doors. I mean, the thing is, it is possible to extend critical periods and manipulate them, and experts do, in fact think that we'll one day be able to do this with a pill, with some sort of medication. So it's not a question of of if. It's a question of when the groundwork is already being laid for this. Uh, it's just how are we gonna be ready for it

when it happens. Well, I think we should take a quick break and then when we come back we will discuss a few things about the history of the idea of neuroplasticity. Than alright, we're back. So Charles Darwin actually offered some thoughts about how the brain changes in response to the environment. In his book The Descent of Man, which published in eighteen seventy four, and though we should note that he did not use the term plasticity, he did sort of write about the idea of of the

brain adapting. He wrote, quote, I have shown that the brains of domestic rabbits are considerably reduced in bulk in comparison with those of the wild rabbit or hair, and this may be attributed to their having been closely confined during many generations, so that they have exerted their intellect, instincts, senses,

and voluntary movements. But little uh note that he's imagining this adaptation of the brain taking place over multiple generations through inheritance, which is very different from the kind of plasticity that we're talking about, which takes place within a single body within a single lifetime. But he is at least offering an image they're of saying like, Okay, maybe the brain can kind of be molded to what it

best does given its environmental circumstances. Right if you if you're a wild hair, and you need to be crafty and wily and use all your senses to survive out in the brush. Uh, you you will grow these bulky brains. But if you're a domestic hair and all you do is sit around and get fed, then you don't need all that stuff and the brain will adapt. This touches on a fact that we've discussed before, and that is that that the that the brain like evolution is a

miser and that's cheap. Yeah, it's it's cheap. It wants the most economic model for functionality. It is. It is the Ebenezer Scrooge of the body. No, the whole body is cheap. Actually, you know it makes sense. You don't want wasting energy in an environment where energy is hard to come by. Living in a world of technology and abundance. Uh, you know, we should stop to think, how, you know, if if you have food to eat, if you're not wondering where your next meal comes from, you should think

about how lucky you are. But you should also think about how, in many ways your body and the bodies of every other creature in the world, we're sort of designed for scenarios where you would be constantly living on the edge of starvation. But back to neuro plasticity. So the term plasticity emerged from the work of American psychologist William James who lived eighteen forty two to nineteen ten,

and James defined it the following way. He said, it's quote the possession of a structure weak enough to yield an influence, but strong enough not to yield all at once. Yeah, I mean that makes sense. It's ideal for a young child to be open to their environment and not so open that they're just completely overwhelmed. Right, So I want to read a quote from William James from his from his seminal work on psychology, where he started deposit that the brain might have some kind of might have some

kind of like changeable structure. So he says, quote, if habits are due to the plasticity of materials to outward agents, we can immediately see to what outward influences, if to any, the brain matter is plastic, not too mechanical pressures, not to thermal changes, not to any of the forces to which all the other organs of our body are exposed. For nature has so blanketed and wrapped the brain about that the only impressions that can be made upon it are through the blood on the one hand, and the

sensory nerve roots on the other. And it is to the infinitely attenuated currents that pour in through these latter channels that the hemispherical cortex shows itself to be so peculiarly susceptible. The currents, once in, must find a way out. In getting out, they leave their traces in the paths which they take. The only thing they can do, in short, is to deepen old paths or to make new ones.

And the whole plasticity of the brain sums itself up in two words when we call it an organ in which currents pouring in from the sense organs make with extreme facility paths which do not easily disappear. For, of course, a simple habit, like every other nervous event, the habit of snuffling, for example, or putting one's hands into one's pockets or biting one's nails, is mechanically nothing but a reflex discharge, and its anatomical substratum must be a path

in the system. The most complex habits, as we shall presently see more fully, are from the same point of view, nothing but concatenated discharges of the nerve centers, due to the presence there of systems of reflex paths so organized as to wake each other up successively, the impression produced by one muscular contraction serving as a stimulus to provoke the next, until a final impression inhibits the process and closes the chain. So that was very forward thinking on

William James's part. He's so, he's got a very rudimentary nineteenth century understanding of brain function here, but it does get some some interesting basic insights right. One of them is that habits or tendencies of the brain consist of a kind of reinforcing of pathways of activities. Another is that complex brain functions are built out of many less

complex brain functions happening together in sequence. Another is that the potential and predispositions of an individual brain like your brain, can be changed based on repeated interaction with chemicals in the blood or with the data of the senses. And that last part is just as a tangent one of those utterly mundane facts that I often have to stop and force myself to be amazed by over and over again, Like,

think about this. It sounds kind of stupid to say, but by making acoustic vibrations in the air with my mouth that you can hear or by like drawing a picture on a chalkboard and putting it in front of your eyes. I can literally change the physical configuration of your brain. I make changes inside your skull by doing things you can see in here. Isn't that bizarre? Yeah?

I mean if you and if you extend it to written language, you can think, oh, well, somebody who wrote something, uh, inscribed something down a thousand, two thousand, three thousand years ago. They can speak across all those uh, those dead millennia, and they can speak right to our brain and make changes in it. It's unbelievable. Now. I mentioned earlier that the term plasticity in the context of neuroscience had been

used to mean a lot of different things. There was one particular paper I looked at about this by Giovanni Berluki and Henry book Tool from two thousand nine and Experimental Brain Research, and they talk about how the term plasticity has been used over the past century to refer to quote changes in neural organization, which may account for various forms of behavioral modifiability, either short lasting or enduring,

including maturation, adaptation to a mutable environment, specific and unspecific kinds of learning, and compensatory adjustments in response to functional losses from aging or brain damage. So that that's a lot of different meanings encompassed in the idea of plasticity, but it does sort of apply to all of those, so it's subject to generalization. But then also is sort of uh is a turn It sort of refers to

general change in the brain. Yeah, a kind of adaptation that has come to be associated with pressures put on the brain from the environment. Right, So, with modern techniques, we've discovered that the way these pathways are forged and reinforced in the brain depends largely on the crucial element of the synapps or you know, the bridge of space that connects to nerve cells and allows impulses to pass

between the cells. And in eighteen three, the Italian neuropsychiatrist Eugenio Tanzi first proposed that the basis of practiced based learning and associative memory was these connections between nerve cells

in the brain. Because Tanzi knew that there are other scientists who had observed the slowing of the passage of nerve impulses through the gray matter in the brain, and so he hypothesized that maybe what's going on in that slow down is that there's difficulty for the impulses to cross the gaps between neurons, these gaps that we now

call synapses or synaptic fissures. And based on that assumption, Tansi argued that the way the brain adapts, the way it learns through practice and creates associations between things, the way it sort of enacts its plastic potential is by a kind of exercise. When you perform a repetitious activity in the brain, the same pathways of neurons repeatedly communicate with each other, and by doing this you cause a kind of hypertrophy or strengthening of the connections between those

specific neurons. The more you do a certain thing in the brain, the easier than that thing becomes to do in the brain. And then the next year, in eighteen ninety four, the Spanish neuroscientists Santiago Ramonikahal, who I've thought before we should do a whole episode on this guy. Perhaps he also speculated that learning was based on the

creation and strengthening of connections between neurons. I feel like this is something that has been I think over the years, it's just been so well demonstrated or not really demonstrated, but illustrated with animations and and uh and and art that I have it like well ingrained in my head. Like when people talk start talking about synapses firing, I

picture it. And maybe I also kind of think of it in terms of of playing an instrument, like the physical act of playing an instrument, of linking um, you know of finger movements on say a trumpet or French more and to the note that you're playing, and then linking those in order to create uh, the notes in a particular tune, which of course is both literally a synaptic learning exercise but also kind of an illustration of what's going on, like making this, connecting it to that

and then leading onto the next note. Yeah, we we've learned this in the modern age, and so it's easy for us to picture, but we should appreciate how how interesting of an insight this was for for the people at the time, because there were also competing hypotheses in the late nineteenth and early twentieth century, like Berlukian book Toll show that in the first couple of decades of the twentieth century that this idea of the sort of

learning through quote reduced resistance that exercise synapses. Uh that that idea was pretty widely accepted in that first couple of decades, and then for a while it really went into decline. This the synaptic model of plasticity due to arise in the popularity of competing ideas about all this weird stuff about the equipotential whole version of the brain. But anyway, in the late nineteen forties it came back.

It was sort of rehabilitated by scientists like the Polish neuroscientists Jersey Konorski and the Canadian psychologist Donald Hebb, and Hebb was particularly influential, and then experimental evidence accumulated during the twentieth century, especially during the mid and later twentieth century, from the likes of David Hubel and Torsten VISal, Michael Merzenek, and Eleanor McGuire. Now, the work of each of those individuals is is fascinating, and I would love to come

back and look at them in greater detail. There's some wonderful work they're regarding, Uh, you know, how how we see the world. I mean, some of the very basic questions about the human experience. How how do we perceive the world and how is it processed in the brain are explored by by by their work. But the interesting thing is there's still something of a controversy about exactly how plastic the adult human brain is, if much at all.

Like for most of the history of neuroscience, up until very recently, a lot of experts believed that the human adult brain had almost no plasticity, you know, that it was fixed and stable. But at the same time, it's obvious that adults can learn new things and adapt. Yeah, we can change, and then we don't have to undergo you know, catastrophic brain injury for it to happen, right, So, exactly how much potential for change in plasticity is there

in the adult brain and in what areas like? It appears much easier for adults to learn and adapt in some ways than it does in others. Language acquisition, as we've talked about as a classic example, Um, you know, children are just so so much better at learning a language than adults are. Another one is certain aspects of music learning. Have you read about perfect pitch? Probably, yes, Yeah, you have to get it early or you're not gonna

You're not gonna get it later on. Yeah, This is a commonly cited example Robert sing a middle c oh, I I don't. I don't do music like that, Joe. Almost no adults do unless you've you've trained on it before you were you know, roughly six years old. Right, So if you have this skill known as perfect pitch, you should be able to recognize or produce not just tones relative to other tones, but like you could call out a note and the person would know what that

pitch actually was. They could sing it, or they could recognize it in hearing it. Yeah. I My my reaction to that question is the same as the other day when my son asked me what Thursday plus Thursday equals, and it's just like, I can't. That just broke my brain a little bit to even try and answer that question. It sounds like a three key Thursday probably, but yeah. So Supposedly, the idea is if you teach children to recognize pitches in an absolute sense before they're roughly six

years older, so they can potentially acquire this skill. It's just like you've got to You've got to get going within that window. Yeah, I feel like I'm I'm wasting my time reading the hobbit to my my son, we should be we should be working on this pitch thing. Well, there are all kinds of things potentially like this that you don't even know about. That maybe you should be teaching your son at this article age, you know, before

the window doesn't close but gets very narrow. Yeah. Well, I mean there is a lot of there's a lot of discussion of this out there in parenting forums and actual you know, pure viewed uh child rearing material just about Yeah, these are the ages of childhood when you want to throw a bunch of different activities at them. You want them to have some sort of musical training, some sort of uh training in another language, etcetera like this, This is when the this is when the windows are open.

So you want to just throw as much stuff there there as possible. But I mean, wouldn't it be great if you could be like that again as an adult, As we were talking about earlier, the desire to be Peter Pan, aren't are there things that we could do to make the adult brain a learning and adaptation machine like the young child's brain. A lot of people have been asking that question, and so I guess that's what we should explore now. The idea of induced neuroplasticity and adults.

That's right. And as as we said earlier, it's it's generally accepted that we can do this. It's it's what we have to do is figure out exactly how to do it. It's it's basically we want to be neural puppet masters, but we are only just beginning to really understand where all the strings are and then what happens when you pull those strings? And then how do you pull those strings? Do you just yank on them? Or

is it more of a delicate thing. We were trying to to to master an art form of puppetry that is currently beyond us. Right, It's not can we do this at all? We're pretty sure we will be able to do this to some extent. It's how well can you do it? How well can you target it for the kinds of things you want to do with it, how well can you avoid negative side effects coming with it? All that kind of stuff, and what are the best drugs to do it with? Right? And there there have

been some experiments involving induced neuro plasticity and mice. A lot of those yeah, and uh, you know, and those show a lot of promise in my understanding. But then anytime we're looking at experiments with with mice, Yes, mice are are our great stand ins for human physiology, but they are, of course are not humans. So and there are a lot of differences between rodents and humans, especially

in the brain. Yes, so there are a lot of questions that are that are not really going to be answered until we we we better understand what we're doing with the mice and also get more and more into actually testing some of these treatments on humans. Well, let's look at a couple of examples of research on drug induced neuro plasticity. Yeah, and uh, you know, we're certainly

not gonna be able to cover all of it. As you mentioned earlier, a lot of the research out there is either is either the deep end of the pool or the obscenely shallow end of the pool. And uh, and it's sometimes difficult to make sense even for us, of the deeper end of the neuroscientific pool. Well, we'll try to walk you up just to your armpits or so. Yeah,

this first study actually emerged this year. So psychedelic drugs have long been associated with an opening of the mind, right, and a June two, eighteen study published in Cell Press points to evidence of psychedelic induced neuroplasticity in rats and flies, and UM, I have to say, I found this very interesting too, because there's actually a part in Alan Moore's

v for Vendetta, the original graphic novel. I don't think this is represented in the film version, but you see one of the main characters take l s D at the side of a government resettlement camp, UH, kind of opening himself up to the full horror of the place and his connection to it. It's a it's a very powerful scene, but but it doesn't directly relate to this study.

So this University of California Davis study examine the effects of several drugs in test tube and animal experience experiments, including M d m A, d m T, l s D, and the ephetamine d o I, and they found that d o I, d m T, and L s D in particular made neurons more likely to branch out and develop. Based on their findings that use, Davis team thinks that UH psychedelic compounds such as DO d O I, d m T analyst may eventually pave the way for prescription

neuroplasticity drugs. It's just all a matter of capitalizing on their ability to expand the very neural circuits observed to atrophy during depression, anxiety, and PTSD, so they observe functional and structural changes in cortical neurons for both vertebrates and invertebrates exposed to psychedelic compounds and isolated activity to the to the protein called brain derived neurotrophic factor or b d n F, and when b d n F was blocked,

the psychedelics lost their ability to promote neural growth. And the case proved to be the same with the m tour signaling pathway, which plays a role in creating proteins for new sign apps formation. If you think of the brain as a complex map, then this research places two key markers on what could one day prove the pathway

to induce neuro plasticity. The judging from what I've read that it seems like there could be a lot of pathway yeah, oh yes, And senior author and UC Davis Assistant chemistry Professor David E. Olsen on this the stresses that there's there's still a lot to learn here and it is team's experiments didn't entail human trials, of course, but it but it is enough to suggest that the mind expanding aspects of psychedelics as we understand them may

one day adis in creating new treatments. So I want to underline that the researchers here are not saying go and take a bunch of LSD and then try and learn Mandarin or develop perfect pitch. They're saying that there are potentially things in these substances that we could utilize to create far better, far more targeted substances in the future. Now, though there are some results indicating the possibility of induced neuroplasticity and adults and adult humans, these are preliminary intentatives.

We want to keep stressing this is one of those areas where I would really expect to continue to see a lot of controversy about the validity of results over the next decade or the next couple of decades or so. UM. I think it's it's important to stress amidst all of the hype and the advertising and all that about neuroplasticity become a master of your brain, that that we're not there yet. This stuff is not ready for prime time. Right.

I can't remember who made this comparison. But I believe it was pointed out that when when we tinker with the with the way our brain and even the way our bodies work, especially with with various pharmaceuticals, it's kind of like trying to change the oil in a car by just dumping the motor oil direct, like opening the hood and dumping it into the engine. Um. You know, things are not nearly as targeted as they as we want them to be. Yeah, that's great, that's a good metaphor.

So I want to cite a few claims a few other claims about induced neuroplasticity and adult humans that have appeared in the press. One is uh one what I've seen referenced a lot is a article and New Scientist by Helen Thompson about neuroplasticity drugs, and one of the research teams that Thompson talks about is led by the

Harvard Professor of Neurology, Takeo. Hench, who has been doing one one line of research, and the basic gist is that one of the physiological changes that appears to close the window of neuroplasticity and children and bring on this period of adult neuro stability is the proliferation of a particular enzyme in the brain, the enzyme histone d A claise or h d a C, and according to Thompson, this enzyme primarily serves to inhibit the activation and deactivation

of genes in our DNA. So we know that genes and the DNA. It's not like all the genes are all doing their thing all at the same time. Genes can be activated and deactivated, turned on and turned off, and apparently the proliferation of the enzyme h D a C prevents this turning on and off. It's like, okay, settle down, stop flipping the switches. So if this enzyme is associated with the end of the neuroplasticity window, what if we could simply inhibit this enzyme right, would plasticity

open back up? So in two thousand ten, Hinge and colleagues found uh found this to be the case in rodents at least. They used a drug called valproate, which is a drug that specifically restricts his stone d c LAS or h d a C and usually valparade is used to treat conditions like epilepsy and bipolar disorder. In this case, it appeared to cure amblyopia in adult rodents, which is often caused by reduced sight in one eye during the period in childhood when the senses are developing.

If you don't fix it during that neuroplastic window in childhood, you're usually stuck with it as an adult. Yeah, and this is something that played into some of those twentieth century uh UM discoveries related to plasticity that I referenced earlier. Yeah, but would this kind of thing actually work in humans? So Hinge work together with Alan Young at King's College, London and some other colleagues to see if this drug could allow adults to acquire a skill it's usually only

acquired during that highly plastic period of childhood. And they went with perfect pitch again uh calling out that that note knowing exactly what the note is not relative to other notes, but just hearing it or being able to

produce it. So they did a study with twenty four men who had no perfect pitch, no musical training, and these men were treated with either valporoid or placebo daily for about two weeks, and during the second half of the treatment period they watched training videos on how to identify absolute musical tones by associating them with names like Sarah and Jimmy. The reason they did names was to rule out any potential pre existing associations that the men

might have with pitches in the note names. But I like the idea of it's like, you know, sing me a middle Jimmy. On the last day of the trial, the group was given a test. They had to listen to eighteen notes and see if they could correctly identify the absolute pitches by name. The control group who took the placebo got an average of about three point five notes, which was performance at chance. The test group who took the valpor it got a little over five notes right

on average, which was significantly better than chance. So this was a small study, maybe kind of small effect, but it caught plenty of attention from other from other researchers, and Thompson reports that there are also neuroplasticity induction trials with drugs like dnepazil, which is used to treat Alzheimer's, or the common antidepressant prozac. So you know, of course, you see a lot of hype in the headlines like you know, learn like a child again, rewire your brain

to be a super learner. But despite these early, kind of promising seeming trials, we should remember to slow down. Even if we didn't know anything except the fact that our bodies were created by natural selection, we could conclude that the brain shuts down its hyperplastic period for a reason. Do we really want to go messing around with the

stability of our brain without a good reason behind it. Yeah, we kind of just trying to solve the lament configuration here without any real understanding of what is going to happen. So let's take another quick break, and when we come back, we will briefly discuss some of the potential downsides of neuroplasticity,

the pros and cons than. All right, we're back, so we we we discussed the idea that neuroplasticity could have not just pros but also cons If you extend neuro plasticity into adulthood, that's not necessarily a perfectly good thing right now, now, certainly that the potential pros are really attractive because we could invoke brief widenings of neuroplasticity to aid in recovery from various illnesses and injuries. We could treat neurological diseases and fight the effects of Alzheimer's, we

could also use it to treat trauma. One of the things I think about is that in his presentation at the World Science Festival, at the beginning of this panel, the con talks about how hard it is to retrain people to walk after they've had some kind of like stroke or brain injury that damages their motor areas. They forget how to walk and they need to learn how to walk again. It's really hard for an adult to learn how to walk, even if your brain is you know,

you're in a healing phase, because walking is difficult. It's like a super hard thing to learn how to do. You're doing all this intuitive math all the time, to keep your balance, to do everything right. It's not easy, but we learn it during this period when our brains

are in this super learning phase as children. So if if you could say, have somebody with a brain injury they need to relearn how to walk, and you could reinduce that kind of childhood motor learning neuro plasticity, then they could potentially have a lot more success and have an easier time getting back on their feet and relearning these kinds of tasks that we take for granted, but of course, the potential for misuse and even abuse is

obviously high. Here neuro plasticity has already become as we've discussed, something of a buzzword in the realm of supplements and self help, and we focus again on this nero definition of neuroplasticity most of the time, the idea that neuroplasticity equals good and assume that any sort of boost here

is a good thing. But indeed, what would the downsides to even therapeutic use be if someone were to take such a drug unregulated to aid and study perhaps or or to work on some purely for some purely recreational purpose. You know, what would be the cost? We again, we don't know for certain, but but there are some possibilities and some of these were discussed in that World Science

Festival panel. What did they talk about, Well, they said, Uh, for one thing, there is this potential link between too much plasticity and say, savant abilities. Uh. Savant syndrome is when individuals with mental disabilities exhibit advanced abilities and specific areas such as recall, calculation or musical skill. So under under their characterizations, savant syndrome could be sort of a

byproduct of of unregulated plasticity in the brain. Yeah, or at the very least, it's a situation where if you're saying, yeah, give me all the plasticity you got, what could go wrong? And they're saying, well, uh, here here is something. Here's an an example of a case where they may be linked to too much plasticity. Yeah. They also say that too much plasticity may yield too much to the environment. Yeah.

How about um, when children are young, they're emotionally vulnerable. Yeah, or it makes me again, think of that v for Vendetta example of a character essentially, you know, tormenting himself by by taking a psychedelic at a at a place of intense historic trauma. Yeah. Now, I can definitely see ways that if you were to say, make my brain sort of a vessel, make it, make it play. Though we can shape it, however, we want the first really bad thing to happen to you while you're in that

state could have really traumatic effects. Yeah. Indeed, I mean ultimately it can make for a more chaotic system of the mind. Uh, in a time, during a time in which you're not supposed to have that much chaos. Also, they point out that autism may be a situation that entails too much neuroplasticity. It's been pointed out that transcranial magnetics stimulation looks it works longer on autistic individuals, so

there is stronger perturbation there. And transcranial magnetic stimulation that just be where you put like a magnetic coil over the head to induce current in the brain, and that sort of stimulates certain brain areas or or actually I think often suppresses or sort of like shuts down certain brain areas. But they're saying that in certain uh, in certain cases, it appears that some individuals with some types of autism are more susceptible to the brain being manipulated

by that kind of thing. Yeah, exactly. And then on the other hand, they say that schizophrenia may, according to some recent studies, be tied to synaptic pruning again the process by which the brain sheds wheat connections between neurons. In other words, that it might be more associated with the brain sort of being the opposite of two neuroplastic

to neurostable. Yeah. Yeah, again, just showing that there is a balance in the There seems to be a balance in the brain, and we really need to know what we're doing before we just erupt it, even for very noble purposes and very targeted purposes um point. For instance, during adolescence and even early adulthood, we see this in the pre frontal cortex, the center of you know, thinking

and planning skills. People with genes that accelerate or at intensify pruning are at higher risk for schizophrenia, according to a two thousand sixteen Columbia University study published in Nature. And then it's worth driving home too that this would in no way be a magic pill. This would not be like some some movie pill where you just take it and oh, I'm suddenly, uh, you know, a complete genius. Suddenly I'm a master of every art I attempt to

take up. Well, yeah, I mean, we should keep in mind we don't want to overstate the effects too much, are over generalized too much. But with the caveat that this is just a metaphor, you should be careful about anything that makes your mind more like the mind of a child. Yeah, that makes your mind more like I mean, there are great things about being a child, but there are also ways in which being a child is a

position of vulnerability. There's a reason we protect children, and who's going to protect you if you're you know, if you're taking a whole bunch of illegally obtained neuroplasticity pills. Like there's there's not a direct comparison to be made here between say potential neuroplasticity drug abuse and say steroid abuse. But but but I think you can you can draw

some very rough comparisons. You know, an individual who who takes too much of this substance in order to artificially bulk up muscles in an inn what is ultimately an unhelpful way, you know, like muscles that are too big to really function for what you you need them for, and then that occurring with with various side effects as well,

both mental and physical. So I feel like we we we risk similar situations, certainly if we're talking about any future abuse of these or even just recreational use of neuro plasticity drugs, as is often the case with with great possibility for rewards comes great possibility for risks. So this is this is something where you should keep an eye on it. This is a field that could have

great promise for really helping people's lives. But but you know, be careful, don't buy into the hype, and definitely don't buy anything somebody selling. Yeah, yeah, be care because there, as was pointed out there, there are already products in the market that are using the neuro plasticity buzzword to to to reach you. Uh. And at the same time, if you're thinking, well, Robert, Joe, I'm getting a little older and I want to I want to stay sharp. I wanna I want to do what I can to

to keep those those doors a little bit wide. I want to I don't want to go into neural stagnation. What can I do? Well, there are safe things that we do know about. In fact, there is one of them is sleep, getting plenty of sleep, exercise and nutrition. Uh. Using your brain, like stimulation of the brain, both intellectually and socially. Yeah. Uh. And and you know your you might think, well, these don't sound very fun, but I hate stimulating. It's like you like keep telling us to

take our vitamins. But in a way, it's like that. It's like we're not talking about magic fixes here, but we're talking about things that that that have done regularly over the course of a lifetime, have been shown to have positive effects. Why can't I just have a pill? I know that's that's what we really want. But but I do think when you when you look at it, like more often than not, it certainly with more complex things related to human physiology and and and certainly the mind,

the quick fixes is not necessarily what we think it is. Yeah, now, I want to come back on what I just said there. I am certainly not somebody who wants to demonize medication of any kind, demonized psychiatric medication or or you know, neurological medication. I that's a thing you sometimes hear people do you know, like, oh, why don't you just you know, you need a pill for that? Why don't you just

whip your life into shape? That That is a fatally reductionist statitude that does not properly understand the way that our bodies and behaviors are controlled by chemicals in the brain. Yes, and certainly all the various differences from brain to brain. Uh yeah, so, uh so I'm very much in the same same boat. I think that the future for neuro plasticity is bright. There there is a lot of good that is going to come of these future treatments and medications.

But it does benefit us to to understand uh, what we're actually talking about and the the the both negative and positive potential of the technology. Yeah, so hold hold the hype, listen to the researchers, all right. So there you have it. Uh. In the meantime, if you want to check out more episodes of Stuff to Blow your Mind, head on over to stuff to Blow your Mind dot com. That's the mother ship. That's where we'll find all the episodes,

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