Using Stem Cells to Cure Autism, Epilepsy & Schizophrenia | Dr. Sergiu Pașca

27:13Although I think schizophrenia is more prominent at the toward the polls where you have harsher winters as opposed to around the equator, but someone needs to check me those on that because those statistics might have melted away with more careful analysis. I don't know. The other thing is that you'll nowadays hear a growing interest in populations for which a given disease is very rare. So one of the things that circulating out there now that's related to the vaccine debate. And by the way, I'm just going to all myself go on record. I don't think there's any solid evidence that vaccines cause autism.

27:45And there's not epidemiologically, there's not. There's not. I mean, there's this open question as to whether or not vaccines of all kinds can increase inflammation. And there might be things downstream of inflammation, but for the record, right now, there are no published papers that have not been retracted that support the vaccine autism link. I think those papers are being re -investigated under the new administration, but let's leave that aside for now. People will say, well, you have groups like Amish populations where the incidence of autism is significantly lower. Turns out it does exist.

28:19I looked at these data, but it's significantly lower. And then people will say, well, it's the absence of food dies. It's the absence of vaccines, perhaps, et cetera. But then as a genetic disease, you could say, well, there's also There's a tendency for people in the Amish community to reproduce with other people in the Amish community So it's a more restricted genetic pool Yeah, and so that could explain as well and I raised this not to create any additional arguments There enough out there between people But just because I think the correlative nature of all this is what kind of raises the opportunity for anything that's observed like a fever they get better.

28:57But as you said, healthy kids without profound autism also talk more when they have a fever. And so there's been so much made of autism in the various conditions that could create it. And I think it's been very confusing for the general public. Even as a trained scientist, it's been very confusing for me. I feel like every six months or so every year we have a new hypothesis. But nothing's really except for these genetic data, nothing really is rock solid. Right. And then of course, the other issue is also that this conditions are disorders of the human brain. So if you think about it, even talking about schizophrenia, hallucinations, or phenomena, they're very difficult to study.

29:38And of course, we don't know this. We know that schizophrenia is present in almost every population that we know of, even isolated population at 1%. And again, it's a little bit easier because it's done in adults. right? I think in children is much more difficult and in fact many of the genes that were early on identify for autism were identified in this populations and the Amish populations for instance there is a very classic example of a gene that is associated with severe epilepsy and autism that was identified there for the first time is present in other places as well. So yeah I think of course the complexity of the problem is that you also want to make Make sure that you don't just associate something, you also want to reverse it in a way, right?

30:20So you want to do the other experiment where you change it and it goes away, but you can never do that in the human brain. We can just turn things on and off to see whether they're truly causal. And then of course, human brain development also takes an incredibly long period of time. If anything, it seems that the human nervous system has done everything possible to slow down that process. I mean, we milynate all the way to the third decade. right? Like neurons are born and migrating through the nervous system into early postnatal years. Wait, you're telling me that our neurons continue to get myelinated, which of course for those that don't know is the building of the enshiefment that allows electrical signals to be passed down neurons more more efficiently until we're 30 years old.

31:04Yes, there's evidence that myelination, especially in the frontal areas of the brain, are continuing up to the third Thank you. Our, unfortunately now deceased former colleague Ben Barris, he's to shout at people in lab meetings. Yeah. When they say something he didn't like, he'd say, what do you know? You're not even myelinated. Exactly. So he was right. He was absolutely right. Okay, so if you're in a disagreement with somebody younger than 30 and you happen to be older than 30, you can leverage the argument. What do you know? You're not even myelinated yet. Completely myelinated yet. All kidding aside, before we get into the incredible experiments that you're doing in the direction that you're taking to tackle these really hard diseases, I have to ask two questions.

31:43First, is the incidence of autism also increasing outside of the United States, or is this something unique to the United States and Northern Europe? I don't know, we always pair those two. Yes. I should just be fair to the United States and Australia or whatever. Or is there something going on in the United States in particular that autism is increasing faster here? Yeah, I know this the you know the so like the prevalence for autism You know has been actually reported to be higher in other countries even before this some of the early reports many years ago So that in Korea for instance, you know the the prevalence was very high Now that the studies are done Also like in Scandinavian countries it shows that it's probably around the same You know kind of great one in 30 to one in 40 so somewhere between Okay, so it can't be whatever is attached to whenever United States specific conditions.

32:40I mean, yeah, well, because you hear these arguments, oh, you know, it's the glyphosates in the crops in the United States. And while I don't favor that argument, I do think we need to be cautious about what's in the food supply. But those same people often will leverage the argument that well, in Europe, they're not using these things. Well, if the incidence of autism is the same and rising, that sort of does away with that. Right, at least a clean logic to that. And perhaps another argument, which is very important to, you know, bring is that we find the same mutations, right? I mean, the same mutations, if we're talking, let's say, a mutation in a specific calcium channel, you know, you'll find it in a patient in Denmark, right?

33:17As well as like one in Africa or in, let's say, Australia. So I think some of these genetic mutations are sort of like the same. Could we briefly talk about gene therapy and CRISPR? just briefly because I think in the context of a discussion about these neurologic diseases for which currently there aren't perfect cures or even cures in many cases. Gene therapy does hold some promise. In simple terms that I and everyone else can understand, could you just explain what CRISPR allows physicians potentially to do? In other words, can genes be fixed in adulthood? do they have to be fixed in the embryo?

33:59It just give your thoughts generally about CRISPR and gene therapy, because I think most people have heard of it. Yeah, but I think most people don't have an intuitive sense for how it works. So gene therapy is a rather actually broad term, and it covers many ways in which you can correct generally a gene or a genetic defect that we think it's causal. So on one extreme, for instance, you can envision a gene is broken, has a mutation. So what you want to do is you want to put it back. So those were some of the early efforts where you would put it in a virus and deliver it to the patient and adult.

34:37In an adult or in a child depending on like the condition, with the idea is that the gene is not there or like there's not enough of it. So I'm just going to deliver more. That's one extreme. Does it inject into the blood or do you have to go into the specific cell type that's lacking the Many of the studies were done for blood disorders, of course, because it was easier, so you would inject them. Of course, the other possibility is sometimes you don't want to put the gene, you want to put the protein already made. And then it's the case for many conditions where an enzyme, so a protein that does some interesting chemical reactions that are essential to a cell is missing.

35:14So sometimes you just make that enzyme and then you deliver that. It's not always working, but in some cases actually works really well. Now the other thing that you can do is you can try to correct that defect directly. That means you need to operate at the DNA level. So somehow you need to get into every single cell that is affected and correct that. And that's where CRISPR comes into play where presumably you could at one point deliver the guides, so the tiny pieces of nucleic acid that tell you where to go on the DNA, and then an enzyme that will do the cutting and then the putting back, or various other versions of this that you would correct.

35:57Of course, there are challenges with that. Where do you put it? For sickle cell anemia, I know they've essentially reverse sickle cell anemia using CRISPR technology. That's in the blood. It's in the blood. It's of the blood. But if for instance we know about a genetic defect of let's say we'll talk more about the soon but a mutate calcium channel that disrupts heart function and brain function and you come in with CRISPR, you know what the what gene is mutated, you have the healthy gene that potentially you can put back where do you put it? Do you inject it? I mean injecting into the heart is possible.

36:29Yeah. Into the blood supply obviously easier. Getting it directed to the bone marrow but to the brain is hard. Yeah, well presumably you could inject into the brain as well, right? There are ways in which you can inject through their surgery or through an injection in the spinal canal interethically, so that's certainly one way and which you can do it. It is very challenging though because of course the brain has a lot of cell types and You know you very often the way you deliver this like through a virus or through other modalities You know there's only so much of That virus that you can actually put inside the nervous system and the efficiency is not yet like very hot So another way is to go like one level down so that gene will produce an RNA that will produce a protein.

37:14So perhaps we don't have to correct the DNA everywhere, but perhaps we can correct something that happens downstream. And that's so like being the strategy that we've been using primarily, just mostly because at this point, and probably in the future it will be possible, who knows, like in 10 years or maybe even earlier, will be able to deliver very effectively some of this genetic therapies using CRISPR. Because certainly in non -human primate models, things like color blindness have been rescued by introducing a gene through a... When we talk about viruses, people often will think, oh goodness, why would I want to get injected with a virus?

37:50But we should just mention there are things like adenoviruses, which cold viruses are adenoviruses, that can be engineered so that they don't make you sick, but they can carry a cargo,

38:05like So when we say using viruses to deliver genes, it's of the benevolent type or at least benevolent motivation We think that those adenoviruses can live in our body for a long time without causing additional trouble And they're very often modified to make sure that they don't cause disease Of course another limitation of that is that if the gene is really large It simply won't fit in a virus So for instance that will be the case if you think about a calcium channel calcium channel is a gigantic gene will be very difficult to fit inside a virus. Then of course, the other thing is like with this virus is very often, especially with the denoviruses or AAVs, is that you will have one shot, meaning that you have to inject once and hopefully would work.

38:47Because next time you may have an immune reaction, you'll produce antibodies and so you won't be able to deliver again. So again, they're all kind of challenges that people are working really hard to solve. And I have no doubt that in the next decade we'll see therapies or perhaps even cures for some of these conditions. Of course, and I think you're bringing this up, one of the challenges is like when we do this. Because especially for disorders of the brain, neurodevelopmental disorders or autism and other neurodevelopmental disorders, the question is always how early it is too late. You know, how much damage has it done, has it been done, and how much can I actually correct?

39:28And that's one of the things that, you know, we're only now starting to really explore as we're thinking about some of the first clinical trials in the space. Despite shock you a bit, but folks in the quote unquote biohacking community, not me, are getting, I know something I've gotten, folistatin gene therapy as a body enhancement thing. Is there leaving the country because you can't do it in the United States and literally getting an injection of a, of a folistatin gene therapy to, I guess, muscle to improve that. I wouldn't do it personally. Also, I like working out, so I don't need to fall a stat in gene therapy, but it's interesting to note that people are doing this, and I'm raising this as a segue into a discussion about stem cells, because people around the world are getting injected with stem cells in the United States.

40:20It's It's still not allowed by FDA for most things. But I think gene therapy has started. It certainly begun. But it's not the sort of thing that your physician offers up early. It's still very experimental for most things. And then for gene therapies, again, in the context of what you're mentioning is some of this, again, they're irreversible. So once you put the gene in, it goes into a cell, let's say through a lentivirus that will integrate, you can take it out anymore. That will be very difficult. It will get inactivated over time. But so that's what we have to be extra careful with some of this therapies and make sure that we don't do more harm.

41:01Which I guess it's always what we try. Absolutely. I'd like to take a quick break and acknowledge our sponsor, AG1. AG1 is a vitamin mineral probiotic drink that also includes prebiotics and adaptogens. As many of you know, I've been taking AG1 for more than 13 years now. I discovered it way back in 2012 long before I ever had a podcast and I've been drinking it every day since. For the past 13 years, AG1 has been the same original flavor. They've updated the formulation, but the flavor has always remained the same. And now, for the first time, AG1 is available in three new flavors, berry, citrus, and tropical.

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42:11Right now, AG1 is giving away an AG1 welcome kit that includes 5 free travel packs and a free bottle of vitamin D3K2. Again, go to drinkag1 .com slash huberman to claim the special welcome kit of 5 free travel packs and a free bottle of vitamin D3K2. Today's episode is also brought to us by BetterHelp. BetterHelp offers professional therapy with a licensed therapist carried out entirely online. I personally have been doing therapy for well over 35 years. I find it to be an extremely important component to overall health. In fact, I consider doing regular therapy just as important as getting regular exercise, including cardiovascular exercise and resistance training, which of course I also do every week.

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43:23Interestingly, in a recent survey, 72 % of better help members reported a reduction in negative symptoms as a result of their better -help therapy sessions. If you'd like to try better help, you can go to betterhelp .com slash Huberman to get 10 % off your first month. Again, that's betterhelp .com slash Huberman. Let's talk about stem cells, organoids and assemblids, and you'll explain what those are. But let's wait into this through the way it happened chronologically. Most people have heard of stem cells, cells that could become other things. when I was a postdoc, any laboratory that worked on human stem cells worked on human embryonic stem cells.

44:07Literally cells that were collected from aborted fetuses. This was and given for medical study. There was an incredible discovery, which you'll tell us about, which basically made that technology obsolete and also allowed scientists to bypass a lot of the ethical considerations. Serious ethical considerations. Regardless of where you sit on that debate. I mean, you're using the tissue from a human embryo to study things. You could say some people will support that, some people won't. But then a new technology comes along and basically makes that technology obsolete, allowing you and others to do the work on stem cells and assemblots and so forth without having to take cells from human embryos, which is spectacular.

44:51So could you please tell us about that discovery of the stem cell technology that really changed the entire game and did away with this ethical serious ethical battle? Let's call it what it was. Let's start first with stem cells and what they are because I think it's also important to define them. So stem cells are cells that have two properties. First of all, they in principle can become other cells. And if they are of the most potent type, they will be totally potent. So they can make everything. If they're pluripotent, they can miss almost everything. And then of course, there are, you know, lower levels of potency for the cells.

45:32So we all carry stem cells in us, right? Not in the brain or fewer in the brain for sure. But in the liver and in other organs like in the gut as we renew the gut You know every few weeks that is done primarily through the stem cells, but those are restricted They can make everything they can make mostly that specialized cell type for which they have been so like primed Now the earliest earliest of stem cells like those pluripotent there are very important those are present at early stages of development of the embryo and And of course, that happens post -conception. So the challenge has been that you have to remove them from fertilized egg.

46:11And if conception, if life starts at conception, then of course you're an interface. I think a lot of the ethical debates have started because of that. But you know in early days, even if you were to do that, you wouldn't be able to keep those cells. It turns out that the cells are very difficult to maintain. And this brings us actually to the second property of the cells, which is that in principle, they can be maintained forever. If you provide the right conditions, they will divide and stay the same forever. Those are the two properties. So you can keep them forever, you can freeze them down, put them in a liquid nitrogen, bring them out anytime, and they'll start exactly where they left.

46:50And then with the right guidance, they can become other cell types. So only around 1998, that when we could actually maintain some of the cells in a dish, somebody figured out a soup of chemicals that you can add and this cells will survive because after that point it was not possible. So that triggered, of course, the promise of this field that now would be able to take those cells and derive various organs, right, perhaps transplant them, replace organs. Of course that ended up being much more complicated and of course there were all this ethical debates related to the source of those cells and what does it actually mean to use this embryonic stem cells?

47:32And yet we've learned a lot about those cells in early days, what are the properties of those cells? And then almost 20 years ago, Shinya Yamanaka, a scientist in Japan at the UCSF, came up with an absolutely brilliant idea. You know, we were always thought that the development, the development of the human or of any... it's a one -way street. Once you go down development, you never come back. So once you start making a stem cell that is more restricted, and then at the end, you make, let's say, a liver cell, you can never go back and become that clueless stem cell again. And that generally starts to be useful to protect us from cancer or any other sort of, we don't have parts of our hands differentiating into something else.

48:22and he thought that maybe you could do that, not in a natural way, in an artificial way, and that, of course, would be very useful. So what he did is he went and he looked at the genes that are expressed in pluripotent stem cells at very, very high levels, very, very high levels. And it almost as gene therapy, because we were talking about gene therapy. He took like the top couple of dozens of these genes and then started adding them inside skin cells. So he took skin cells initially from mice and then from human and then started adding them one by one two by two three by three four by four five by five six by six To see whether any of those cells Once they have this combination of Jesus are expressing to report and stem cells would somehow get confused And think that they're actually a pluripotent stem cell and then go back in time and actually become a pluripotent stem cells And he's shown indeed that a combination of four is enough.

49:15Of course you can have six And that ended up being what we today called the Yamannaka factor. In a way it was like, it was almost like alchemy, right? Where you sort of like, you know, transform something into something else, right? You make out of this metal, you make gold. It was pretty much like that. It was like the essence of alchemy. And it turns out that that discovery was so profound, because suddenly you could take a skin cell from anybody and put those genetic factors in, turn those cells into pluripotent stem cells that we'd later on learn, they're almost identical to those embryonic stem cells.

49:53And now I have those cells from any of us and use them for various purposes, perhaps for, let's say, making blood cells in the future or perhaps to, you know, model something outside of the body. And I was finishing my clinical training around that time. And I remember even seeing that paper. And of course, in my naivete at that time, I thought, what, this is it? This is going to be the entry point for studying human neuroscience. I was doing experiments at that time, studying actually the cortex and recording from animals, electrical activity of those neurons and always like that. It's like, I thought this disconnect between what I was seeing in the clinic, which were the spations with severe profound autism, and then recordings from the brain and thinking, we're never going to be able to do that.

50:39How are we going to understand this complex disorder of the brain if we cannot even listen to the activity of those cells' life? And then suddenly, like seeing that discovery, you know, again, naïve at that time, thought, well, that could be perhaps the way in which we could make neurons from any patient. And so very soon after I came to Stanford, which I guess is where we met, with sort of like this idea in mind that we will be able to make neurons from this patient and rebuild maybe some of the cells or some of the circuits of the brain outside of the body without doing any harm because we're not doing the biopsy of the brain or anything invasive, just essentially creating a replica of some of those cells outside of the body and then finally study them at will in a dish and do all kind of experiments with you remove things and add things and perhaps a one day even develop therapeutics.

51:31And here we are, 16 years later, since that process really started, took a long time. But now for the first time, we've gotten such a good understanding of some of these conditions. And one of them, in particular, that actually a therapeutic is insight, and we're preparing for the first clinical trial, that is really arising exclusively through studies done with this human stem cell models, without actually using any animal models, just essentially creating, recreating cells and circuits it's outside of the brain of those patients. It's amazing because it allows you to study human cells, which has immense benefit.

52:10They're essentially limitless in number because all you need is one fiberglass, one skin cell or some cell that you can provide these Yamannaka factors to and essentially grow other cells. And we'll talk about what those cells that you create are capable of becoming not just cells, but circuits, in a few moments. But I know it's going to be in the back of people's minds, and certainly in the back of my mind. This idea that when one has a baby that you should keep the umbilical cord because the umbilical cord contains stem cells, usually I think the umbilical cord is discarded. Maybe some people keep it, I don't know.

52:53What is the current thinking on stem cells that reside in the umbilical cord? People pay a lot of money to freeze those and most people don't have a minus 80 freezer around. So they pay to do that. What is the potential for umbilical stem cells in the future? Is it something that parents... I don't want to say should invest in, but if they have the disposable income that they would be wise to do that? So those cells that are collected from the umbilical cord are stem cells, but they're already quite restricted in what they can make. So their applications are also restricted mostly to blood disorders.

53:33So I think it's important to keep in mind that they're not so like a universal solution to anything that would ever involve to report in stem cells in the future or stem cell therapies in the future. So again, I think it's important to know that while they have certain applications and there've been quite clear cases where the availability of those cells were useful in a blood disorder in that child later on. There certainly not, you know, the half of this universal uses as maybe sometimes they're being advertised. When we hear about people typically leaving the US to get, quote, stem cell injections, where are those stem cells coming from?

54:12Are they coming from those patients? And I should mention that there was a clinic down in Florida that was offering stem cell injections into the eye for people with macular degeneration. And that clinic was shut down and all stem cell injections in the United States, to my knowledge, all were shut down because of those patients. Not only did it fail to rescue their vision, it actually made them go blind very quickly. So the FDA shut down commercial stem cell injections. I think there's still places where they do a kind of work around. Yeah, and it's worth mentioning that PRP platelet -rich plasma is FDA approved It does not contain many if any stem cells despite what you might read But what are your thoughts on like when people go down to Columbia?

55:00It seems like they go down to Columbia Yeah, or elsewhere to get or Mexico to get stem cell injections assuming the conditions are clean Yeah And I say that because I know of at least one patient who was paralyzed from an injection of stem cells into their spinal disc, paralyzed, almost died. Fortunately, it's doing better now, and it was because it went septic, the way that got infected. Well, that's one of the problems. Very often, we don't even know what is being injected. I think that is like a very important aspect. We don't know what is, sometimes are the cells from the patient that are being collected, sometimes some of this umbilical cell, sometimes we don't even know what cells are being injected.

55:38Like it could be cells from somebody else. Yeah, there are incredibly risky procedures. Of course, they've never really been observed. there have been very few of any clinical trials trying to really address it in a very systematic way. And very often, that's also the case, you know, that's also because they're not really justified. So in the context of autism, this is very often like done, you know, and it's not just in South America, sometimes there are places in Europe where you can get an injection of some stem cells for autism. Wait, parents are taking their kids to these clinics and getting them injected with stem cells that come from some other patients.

56:11Some cells that are collected, they did it from the patient. It depends a little bit on where it's done and how it's actually done. But again, even from a biological point of view, what are those stem cells, presumably doing, let's say in autism? We don't think that there is a cell that is missing in the brain, so it's not like those cells can go. And I think as I was mentioning before, most of the cells already restricted in their potential. They can no longer make any cell types. So, you know, the idea that you take this for important stem cells and you just inject them, let's say, in the knee and it will, like, miraculously grow, you know, cartilage.

56:46It's very often not really the case because those cells are not even capable of making cartilage. So, I think there's, you know, very often, you know, a lack of understanding of what this therapy is really are. And then, of course, there is sadly a lack of understanding of what is actually being injected. So, you know, for autism, this is, unfortunately, happening much more often that you would think. So I very often get, like, parents or families that are asking me desperately, you know, with, like, exhausted old resource. We don't know what else to do with try behavioral therapy, with tried this therapy.

57:22Nothing works. And everybody's recommended that we should just go now to South America and do this injection. Should we do it or not? Right? And of course, my answer is always, like, no, because, again, there's no reason that that would work. Some parents come back and of course they report an improvement. And which is generally a temporary to the extent that we know of course it's never really been studied in a very systematic way. Partly, of course there is a very strong placebo effect which you can, you know, especially in parents like by proxy when you have a child who's like very sick, those placebo effects are very strong.

58:00The parents really want those kids to improve. So they will see things that are improving plus those are still developing kids. So week by week, they may acquire new milestones. And then the other thing, which of course could be part of this, is that there is an inflammatory effect very often. And so that's almost like the fever in a way, right? It would increase, perhaps some of the cytokines will create a fever. where perhaps that is associated. We don't really know, but certainly there are dangers associated with like procedures like this that are, you know, lack the rationale first of all.

58:36And then of course, then they lack any regulatory framework. Yeah, I mean, I think the concern is very real for stem cell injections into all tissues, but when it comes to eyes or brain, and of course, eyes are brain, that's where I just, you know, deep breath and hold it and like why do I like oh my goodness no because We don't get new neurons You lose neurons. They're gone. I mean we get a few in the olfactory bulb in the dentate gyro so the hippocampus a few but you know once they're gone That's it right and Inchecking something into the brain that the probability of tumor growth is is incredibly high Absolutely and especially when it is in the brain where there's Not enough space So we know that anything that grows in the cranial cavity will actually push down, right, vital center.

59:27So there aren't certainly risks associated with that. So let's talk about the other approach, which is the one that you've been embarking on. I'll never forget when we were post -docs. Folks, we were post -docs in the same room. It was D2 -2 -2. Yes. We had a lot of pride in that room. We had benches on opposite sides of the room and we sort of took over that room as an empty room. This is you probably couldn't do this anymore. It was like there's an empty room. Let's bring some microscopes in there We just started doing experiments then. I'll never forget when you Started building Organoids you started building nervous systems in a dish and how excited you were and and it's been remarkable to see your arc To from that And it's not lost on me that you were working extremely hard then I've continued to become what really one of the luminaries of this field Tell us what organoids are.

1:00:23Tell us why they're useful and what they're telling us already about how the brain develops and their therapeutic potential. So let's start from the beginning. Around like 15, 16 years ago, we were able for the first time to get some of the cells that are now known as induced fluoropotin stem cells. These are the Yamannaka. Yes. Or IPS cells. So induced because they've been induced to become more important in an artificial way. But again, they stay like that. So you can share them with anybody else like afterwards. So we got some of those first cells in those early days. And now the question was, how do we make neurons?

1:01:04And what you do is you really kind of leverage the everything that is known in developmental biology. So we already know that there are certain molecules that are very important for making neurons. So all you do is you put those cells in a dish, right, then a plastic dish and a beetroot dish. And then you start almost like when you cook, you start adding various molecules on top and you see what happens. And we knew that it's actually quite easy to make neurons. That was already known. There've been a lot of experiments done the decade before that showed that even if you just remove some of the factors that maintain those cells pluripotent, those pluripotent stencils will start out to differentiate and they like to become neural cells.

1:01:44By default. Almost by default. So it's actually not that difficult to make neurons. So in those early days, you know, you take those cells, play them nicely, those proteins themselves in a dish, and then remove some of these factors. And then within a few days, you will see that they'll change shape, and within a few weeks, some of them will really look like neurons. And when you look at them, you can even, to like look at proteins that only neurons will have, you can actually get an electrode inside a cell and listen to the electrical activity. So it was very exciting as maybe you remember in those days.

1:02:18I mean, you know, this bursting curiosity is always sort of like the ATP of the life in the lab, so to speak. Right? I mean, it's just like, I like want to wake up and want to go see what happened to those cells. And it was clear in those days that, you know, we would be able to make those cells, but would we actually see any abnormalities in those cells? I think it was like the question. You know, how would you know if you derive cells from a patient with autism? How would you know that you found anything abnormal? And that was like a question. What you know, we didn't even know what would be abnormal in the brain.

1:02:55And so that's when we decided actually to focus on something that would be relatively predictable. And that was this mutation in a calcium channel, which was discovered just a few years before in very few patients that had essentially one single letter in their entire genome changed. in a gene that makes a protein known as a calcium channel, sits in excitable cells, meaning cardiac cells and brain cells. And every time a cell receives electrical input, this protein opens up and lets calcium go inside the cell. And that's very important because it couples electrical activity of the network with chemical activity inside the cells.

1:03:36And what we knew about that mutation at that point, that it's pretty much all we knew in those early days, is that it probably allows the channel to stay open slightly longer, just a little bit longer. So more calcium would go inside the cells. First, there would be no way to know because you can't get a neuron or cardiac cell from those patients to actually test it. So what we did is essentially, we made, we recruited some of these patients, we flew them to Stanford, then we got a tiny skin biopsy, made this IPS cells, this takes months, This takes already like four or five months. And then we took those cells in a dish, started to deriving neurons, and after about five, six, seven weeks, then we put them on their microscope, and we started looking at the calcium.

1:04:20You can measure calcium inside cells through a microscope and just literally look at it. And I'll never forget that day, you know, when we did that experiment, we was looking down the microscope, and we essentially stimulated the neurons, and you could just see how control cells will go, calcium goes inside the cells and then it goes out. And then in patients that had Timothy syndrome, say in Timothy syndrome derived neurons, you could see how the calcium will go. And then it will stay longer, it takes longer to go out. So it's like the first defect that we saw in patient -derived neurons. They were actually not coming from a biopsy, they were not coming.

1:04:57So that was incredibly exciting as you can imagine. But it was still relatively simplistic, just a few neurons at a bottom of a dish. Of course for me what was particularly frustrating was that we couldn't go very far in development. So think about the cerebral cortex, the outer layer of the brain that presumably makes us human, has multiple layers, a large diversity of neurons. It takes 27 weeks to make all those cells in the cortex, 27 weeks to make all those neurons. We're not even talking about glial cells, the supporting cells that are coming much later for several years afterwards. But just making those cells takes about 27 weeks.

1:05:37And it turns out, something that we discovered in three experiments done in a dish, is that the timing of the development of those cells, it's actually recapitulated in a dish as well. So if you keep the cells in a dish, they'll actually essentially develop at the same pace are not much faster and it's very difficult to keep neurons in a dish for 27 weeks to get all the neurons. Essentially they peel off, you know, every time you start to move them to another plate and at one point they just die. And so then we thought, how about like never letting them to sit down on a surface? How about just essentially aggregating them as balls of cells and then letting those float?

1:06:19And in those early days there was this amazing scientist from Japan, Yoshiki Sasai, who started doing really beautiful experiments where he was already moving some of the studies that he was doing of development in 3D cultures. He showed you can make an optic cup, a part of the eye. And so it was clear it was in the air this revolution of actually moving cells from 2D flat cultures to 3D self -organizing. And that actually unleashed amazing new properties of the cells. So essentially all we did in those days is I ordered from Germany this plate that were counterintuitively coded so the cells never stick.

1:07:01I mean every time we keep cells in a dish you want them to stick, that's the major problem. So they were actually coded so the cells will never stick. And then there were like this balls of cells, they were floating there. And of course I remember talking in the lab and everybody was like, they're not going to survive. It's going to be a couple of weeks and they're going to. And then a week passed and two week passed and then they kept growing and growing. And of course the enthusiasm of every day to see, are they still alive? And then we discover that we can keep them for months. And these three -dimensional cultures are not known as organoids, just perhaps not the most fortunate name because it suggests that it's organ -like.

1:07:39And of course because they're not an entire organ, so they're not a representation of the entire brain, but that's sort of like the term that we refer this day is to anything that is, so like three -dimensional and organizing in some way. And so we started keeping this cultures, and then at one point, that should be discovered that we can pretty much keep them indefinitely. My lab maintained the longest cultures that have ever been reported, like literally going for years, for two, three years in a dish. And at one point in those early days when actually I was running out of funds in the lab and I came one day in lab meeting, I'm really, you know, determined for us to actually like cut costs.

1:08:17So I've told everybody, go into your incubators because we're spending so much money in feeding the cells and everybody throws out 20 % of your cultures. And then people started saying, so should I throw the ones that are like 500 days old? And somebody was like, the ones that are 800 days old, and I said, what, you guys are keeping them for such a long time? Yeah, they're just keep growing during the incubator. So then we actually did the first study and then we had a series of three studies done over the years of like trying to ask how far do they go and development. So if you have a clump of human neurons that you've made from fluripotent stem cells and you keep feeling them in a dish, how far do they go and development?

1:08:50Do they move much faster? Do they move much slower? Are they stuck at one point in development? and it turns out that they actually keep track of development beautifully. To such an extent, that for instance, we discover when they reach nine months of keeping them in a dish. So about the time of birth, they literally switch to a postnatal signature, really, on their own, in a dish, in a dish. So, you know, there's this classic example in development and neurobiology. There's this There's this protein that usually changes around the time of birth. It's an N &D receptor. So maybe some people know about N &D receptors binding glutamate.

1:09:32They're very important. But they change a lot during development. They're made out of different units and the units change. And it was very well known that during early development, so prenatal before birth, you primarily have two B subunits. And then after birth, they're primarily two A. So if you look in brain development, you just see how essentially 2B goes up and then it goes down and 2A goes up and when you look they meet around birth. So very often people thought that it's birth itself, that triggers that switch. That canonical is called a canonical switch because we all thought that it was like so classic.

1:10:08And then you take an organoid that you maintain in the dish for 600 days. And of course we're not inducing birth, we're not changing media, we're not doing anything special. There are no hormones from home. No, almost changes. Like, you know, we keep exactly the same media, which is certainly very simplistic, you know, kind of like soup of chemicals, but we don't change it. And then you just look at this two subunits and you see how like two B goes down and two A goes up and they pretty much made that nine months of keeping them in a dish. It's amazing. So that tells us that there's some sort of intrinsic clock.

1:10:41Once you start a development, the cells measure really, really well the time of development. That does not mean that all aspects of development are going to now be recapitulated in a dish. But it tells us that there is this incredible ability of cells, especially in the nervous system, because of course those cells will keep for the rest of our lives. Now, we're never going to renew neurons. It's going to be different for liver cells or gut cells. But for neurons, probably in particular, they will need to keep track of time really, really well. So that was like the first discovery that we saw like made which is still stunning today We still don't know the mechanism.

1:11:15We're still working really hard on figuring out exactly how the cells are keeping track of time Because as you can imagine if we understand what that Molecular machinery is we used to call it the clock. We now call it a timer We think is more of a timer than an actual clock But understanding what the molecular biology of that is will allow us actually to play with that clock So if you want to make neurons that are, you know, 70 years old neuron from a patient with Parkinson, you know, I don't have to wait 70 years in a dish. Could I make it in like a few weeks? Or perhaps could I take an aging neuron and somehow, you know, rejuvenated by playing with that timer?

1:11:53But just to make it clear, we still don't know that we have some clues about like what it may be, but I think it's still early days. And I think that was like one of the first things that this cultures allowed us to do. Just watch development, human brain development, outside of the human body, in a dish, and actually witness that some fundamental aspects of brain development are actually recapitulated even outside of the uterus and of course of the brain. So that was like the first. And then of course, I guess I'm a development and the biologist by trading and I've done a lot of circuit work in early days.

1:12:32Of course, an obsession of mine was that especially for conditions as complex as autism and schizophrenia, we need to recapitulate some of the circuit properties of the brain. So we now know that probably both for schizophrenia and for autism, it is very unlikely based on the evidence that we have so far that there are cells really missing from the brain. You know, we thought for a while that maybe some cells are missing or maybe other cells are in, you know, in excess, but now the studies that have been done, especially with single cell profiling of brains, of patients that have already died, showed us that the composition of the brain of the cortex in particular, it's very, very similar.

1:13:09So it's unlikely that the cells are missing or like, but likely the way they are connected with each other is that makes a difference. And of course, in the beginning, we were just making this clump of cells, they're all for the cortex, but they're like not connected to anything else. So then came the idea of assemblies. Because most of the cells in the brain connect with cells across the nervous system, and in fact, even more interestingly, cells do not reside in the place in which they're born in the nervous system. We have the largest cell diversity of any other organ, almost 2 ,000 cell types.

1:13:44By the end of the first trimester, there are about 600 cell types in the human brain. You know, think about the liver, right? Maybe a couple of dozens. The brain has to make, you know, hundreds of times more. So how do you do that? The only way is to actually make the cell types in different parts of the brain provide local cues there. And then once the cells have been specified, let them move and find their final position. So the first assembly that we've actually made were of a very stereotypical canonical movement of cells in the nervous system, which has to do again with the cortex. So the cortex, again, the outer layer of the brain has both excitatory and inhibitor neurons.

1:14:23It turns out that most inhibitor neurons are not born in the cortex, but they're born deep in the brain. So essentially, all we did is we made two green regions, the ones that has excitatory neurons and the ones that has inhibitor neurons. And the plan was to put them together, hoping that at one point, the cells will so like know what to do. And in fact, that was like one of the first projects in my lab. kind of like planning that. I remember gave to one of the students like this very difficult task of figuring out how we're going to fuse this two cultures. And they're about three millimeters in size.

1:14:55So you can see them by eye. And I thought it was going to be very difficult to put them together. So the student worked for months trying to figure out like biological glues, you know, kind of like using various electrodes and impaling them and everything else until somebody else came one day and said like, it's very simple. You just put them at the bottom of a tiny ependorf tube, which is the tiniest like of tubes that you get. You put them there overnight and next day they're completely fused. But they're not just fused because now if you look inside within a few days, the cells that are supposed to move start to actually point out towards the cortex, they literally smell the chemicals from the cortex and they start to move in this various stereotypical way towards the cortex.

1:15:39And so that was the first assembly made around 2015 and I still remember it was Ben actually Ben was so excited Ben Bears was so excited about like seeing this else. He wanted to look at this movies every day and Then he said I still have this email from him where he was very preoccupied that he kept saying like this new preparation is not an Orgonaut is not a steroid. It's something else He has to find another name. He loved naming things. He loved naming things. And he understood the importance of naming things. Not just for career reasons, although he understood a lot about how to build a career.

1:16:15But because naming like Yamannaka factors made sense to name it after Yamannaka, he got a Nobel and is immortalized that way, like STEM cells immortalized. But I think the naming is essential because otherwise things can get lost in the time Technical details. Yes. So, who came up with the name of sound? So, he kept insisting that I should find the name. So, I made this long list. I still have like the in my notebook. Like I had a long list of about 20. And I would like keep sending Ben one. And you know, like Ben was always awake like 24 hours. Yeah, he didn't sleep much. He never slept. So, I remember after sending many emails going back and forth and he was just like, no, bad name, bad name.

1:16:58I don't like it. And then at one point, I felt, well, always because it's like, and then a symbol because we're assembled the circuits. So I thought, assembly, and I send the senses. Perfect. I love it. So you name the semblance. I name assemblies and then sort of like, blessed it, like one night at like 3 a .m. And so that was the first assembly. And the first assembly was for cells migrating. But then the question was, cells have to find each other and form circuits. And so within a couple of years, we started making assemblies that will have exons. So the long projections of neurons, finding other partners.

1:17:35And you know how, I forgot who said this, must have been Rodolfo Linas, or you know who said that the brain is sort of, you know, the next evolutionary step towards movement. You know, so like the nervous system has been this theory that has evolved as a way of like moving around. That was sharington, sharington. Sure, the final common path is movement. He was a physiologist, he was kind of vague in a statement, but I think that one. I think that one. And I don't doubt that Rudolfo said something about it too. I'm not gonna try and take anything away from Rudolfo. Anyone that knows Rudolfo thinks that he's not somebody you want to piss off.

1:18:10Well, we should check it. Who actually said that? Give him credit. I'd like Rudolfo. But for us, that became the next objective. Can we actually build a circuit that will have a very clear output? So we would know that we've actually built that circuit. So what we did is essentially, we thought about the simplest circuit for movement, which is the cortical spinal tract. So that means that a neuron in deep layers of the cortex sends a long axons all the way to the spinal cord. Finds a motor neuron, makes a connection, then the motor neuron leaves the spinal cord, goes to the muscle. And essentially you only have these two neurons, right?

1:18:47They're connecting with each other with the muscle, two connections, one between the two of them and one with the muscle. So the simplest of circuits that you can have. Now let's me move my big toe. Right, exactly. It's a pretty, pretty long distance. It's a very simple. And of course, like in other species, a little bit more complicated, it turns out that in mice, there is an additional neuron there. So there are some changes that, you know, happen to our evolution. But for us, and in primates, it's as simple as this. So what we did was we essentially made an organo that resembles the cortex and has some of those neurons.

1:19:18And then we made an organo that resembles the spinal cord and has some order neurons in it. And then we made a bowl of human muscle that you can make from a biopsy. You can literally biopsy a muscle. You get the myoblast, you grow them, and you get a nice bowl of muscle. And then of course the challenge was that, you know, the reality is that we don't know how those cells find each other. Like in development, we know some of the molecular cues that they use, but it's we're far from having a comprehensive understanding of how they find each other. And I remember we were sitting down in the lab and thinking I resisted actually doing this as the first assembly in the lab for a while because the probability was like against us.

1:20:00Like those cells in the core coordinate that are less than 5%, the more or less than 10%, the probability that they find each other perfectly and in enough numbers to trigger muscle contraction was close to zero. And yet you do it, you put the three parts together, you let them assemble, and within a few weeks, you can actually now stimulate the cortex with whatever you want to use with an electrode, with light, and then the muscle starts to contract. And in fact, the more you do it, the more reliable the process is. And then of course we went on so like reverse engineering and figured out that indeed the cells have connected in that precise way.

1:20:37So I think what we started actually to realize was that of course a lot of stem cell biology was, you know, I think a lot of biology was based on chemical and physical factors that we were leveraging. But we've never truly leveraged this kind of like next level of law or power in biology, which is self -organization. The ability of a biological system of building itself, if you think about it, the human brain built itself. Of course, there are instructions, but there's no blueprint. There's no plan that the brain constantly looks to make sure that it actually made all the connections properly, right?

1:21:14Instructions are sort of revealed at every step for the next step. And it mostly comes from the cells finding each other. So I think what we also started learning from this was that all we need to do is make the parts. And if we make the parts right, then the parts will come with the instructions, and then the circuits will assemble on their own. And so that has been really the beginning of it. And of course, it became progressively more difficult to build circuits. And so of course if you put two you may think, oh let's make three and if you make three can you make four? So actually we just published a few months ago the first four part of the same fluid That actually now reconstitutes the pathway that processes sensory information in the nervous system So you think about the cortex, you know sends out To control movement and has an output But it receives information from the outside constantly and that happens to neurons that sit close to the spinal cord have projections in the skin where they sense tactile vibrations or pain stimuli, send that information to the spinal cord.

1:22:20From the spinal cord they cross, they go up to the thalamus in the middle of the brain and from the thalamus they go to the cortex. So this is a four -part pathway. So it took us years, first of all, to make the parts and then to put them together. And then again, the beautiful thing about it is that while we still don't know all the rules of assembly, you can make this four part, we call it the sensory assembly or somatosensory assembly. Because it turns out that the sensory neurons that we can make are mostly sensory neurons that sense pain stimuli. And so you can actually put the four parts together.

1:22:53So the sensory, the spinal cord, the thalamus, and the cortex, and you have to put them in that order. If you change the order, the cells will not find each other. So you just have to create the minimal conditions for them, making the right cell types, putting them in the right order, and then they'll find each other. And within a few weeks, so it takes hundreds of days to build a circuit like this, but the beauty of it is that suddenly you look at it and you just see spontaneous activity that arises in the entire pathway. Just starts to flicker, all in sync. Can you use this assembly to study the effects of different pain medications?

1:23:26Yes. So that is certainly one potential. The other thing that you can do in the first application that we've had was for genetic forms of pain conditions. So we very often think that genetic conditions, where you have a very clear cause, or so like entry points, like Rosetta stones for understanding anything. So there are these interesting mutations in a sodium channel, so another channel. But the sodium channel turns out that if the channel is overactive because of a mutation, you'll have excessive pain. So these patients are highly sensitive. But then if the channel is essentially unable to function, then these patients have loss of pain.

1:24:03And that's equally bad. Many of the patients actually will die because they can sense pain at all. Yeah, I think people don't realize that in mutations where people can sense pain, people fail to make the postural adjustments that allow you to stay alive. And because they, unfortunately, they can be resting a little bit too much on their right leg, we normally think, okay, no big deal, but you're constantly making these postural adjustments. If you don't do that, you actually can damage the legs that you're pushing down to hard on. It seems like a trivial amount of weight, your own body weight, but we fail to recognize just how often we're redistributing our position.

1:24:43No, no, no, no, it's absolutely true. Like feedback in general, it's very important, including through this painful stimuli, through all stimuli in general. And it turns out that if you now make essentially a four -part assembloid that cares the mutation that causes excessive pain, Now the sensor neurons are excessively active, so they keep bursting with activity throughout. And then we thought we were going to take it out and of course, in this patient they can fire. It turns out there's not true that they can fire for some reason, there are probably other channels that are helping them compensate, but they fail to engage the rest of the pathway in a synchronized way.

1:25:18So that's why we needed the four parts. And I think that's why assemblies generally are going to be very useful because they're very emergent properties that are arising from the interactions of the cells at distance in the brain, and likely many disorders. And of course, they're very far from understanding complexes or disorders such as autism. But certainly, this interaction's fault interaction set a distance in the circuits are probably going to be, you know, key to understanding the biology of this condition, and hopefully a one point in collecting them. I'd like to take a quick break and acknowledge one of our sponsors, Function.

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1:27:00The problem is blood testing has always been very expensive and complicated. In contrast, I've been super impressed by function simplicity and at the level of cost. It is very affordable. As a consequence, I decided to join their scientific advisory board and I'm thrilled that they're sponsoring the podcast. If you'd like to try function, you can go to functionhealth .com slash huberman. Function currently has a wait list of over 250 ,000 people, but they're offering early access to huberman podcast listeners. Again, that's functionhealth .com slash huberman to get early access to function. So I want to discuss an ethical consideration slash concern.

1:27:37But before we do that, I want to take a step back and just have you reflect. I mean, I will never forget the first time I learned neural development, like sperm meets egg, and then you get cell duplications, and then the embryo figures out what's going to become muscle, what's going to become nervous system. And it's really a humbling thing to be able to realize that we understand even a small bit of that. Yeah, and very little was known until, you know, the early parts of the last century really is where some of the defining tissues and interactions were first discovered. It was relatively young science.

1:28:17Nowadays, I'm even more humbled by it because one only has to see a child that, you know, nine months ago, didn't exist, and you really start, I mean, most people understand how babies are made. and yet it's staggering. And I think what's so staggering about it, what's so miraculous, and it really is a miracle, is the self -organizing aspect of it. And now I'm hearing that the self -organization, knowledge of, the cells own knowledge about what they should do and when is maintained. And I also have to just both highlight again and applaud the fact that regardless of where one stood on the embryonic stem cell debate, you're describing assemblots that were made from essentially taking a fibroblast, a skin cell, exactly.

1:29:10From a patient or from a non -patient, a healthy person that at least doesn't have that mutation, putting them in a dish, reverting them to stemness through the young and aquifactors, then giving them certain things to drive them towards neuronal fates and then other fates, putting them together, and none of this involves the use of aborted tissues. No. May I ask you this? If today you could bank your fiber blasts, turned into a few neurons, would you do it? Knowing that those cells could eventually be used to create any tissue, like I hope you live a very, very long life surgery. But let's say when you're a hundred, your heart has an issue.

1:29:52Humans can do heart transplants. from another human. There are immune rejection issues there. Pig hearts have been transferred into humans, but we could potentially build a heart that is of your cells. No immune rejection. Why wouldn't you bank your cells? I think you can collect them at any time in principle. As long as you can get them on your 99th birthday. I think you can still get them. For sure, it could be an argument. Sometimes folks. Right. It could be an argument made that old cells are going to be aging. So there are going to be some changes happening in those cells. Maybe they have some.

1:30:25Yeah, that could be an argument made about it. On the other hand, what we're also seeing with some of the cell therapies that are just being developed now more broadly is that they don't have to be necessarily personalized. They don't have to be made from your own cells because you can use immunosuppression. That's one way in which you can do it. So you can transplant the cells from somebody else. Of course, that poses more challenges if you think about the brain, replacing large parts of the brain, which certainly is like, far into the future. Who's brain is talking about, yeah, certainly. But in general, you can see how in the future, we may have off the shelf cells that have been made from a generic individual that you transplant with immunosuppression or cells that have been genetically modified.

1:31:17so that they're not rejected by the immune system. So they're compatible with all of us. That, it's much more likely to become a therapy that is broadly used, I think. So that's why I'm not that worried about harvesting my own cells, like right now. Where do you sit on this idea that, at some point in the not too distant future, we will be able to immortalize entire organs within our body, perhaps not ourselves, but our colleague Michael Snyder, or Cherub genetics at Stanford told me that he thinks that at least in my lifetime, I'm a little bit younger than he is, I'm almost 50, forget how old Mike is, almost 70.

1:31:55But he said at least in my lifetime that immortalization of tissues, human tissues will be possible. He doesn't think that's a fantasy. Yeah, I think different people mean different things by immortalizing something. We generally think like for in vitro studies or for an addition study when you immortalize something it means that the cell is maintained forever but it generally involves using a cancer like factor giving them cancer properties. I mean the cells that are immortalized if you think about it are either the stem cells that we talked about or the cancer cells. So we always have to be careful about like what it means to actually immortalize a cell.

1:32:36Rejuvenate cells that's kind of like an interesting concept. will we be able to actually rejuvenate ourselves even if they're aged? So a lot of discussions have been happening lately, whether you can actually use the Yamannaka factors, not to the extent that you completely reprogram a cell, but that you just use them just a little bit, so that you rejuvenate the cells, not fully. But as you can imagine, those are complicated experiments, they're gonna have to be tuned. You need to control very carefully the dial there. microdosing Yominoch effect. Right. Because you would actually, you risk moving into another state, but, you know, that may be possible at one point.

1:33:18Yeah. I thought that at one point, one of the concerns of using Yominoch effectors, and this whole technology therapeutically was that you could set the reversal and age cells back to stem cells. But then how do you stop them there? And also how do you send them? It mean ultimately it's not a stem cell that you want. You want a fully differentiated heart cell or neuron. You want to stop there. I mean the idea being for anyone trying to reverse their age, I mean how far back are you willing to go? Right. Right. And it's true. When you use the Yamannaka factors or a combination of them, because you know we've discovered afterwards that is not just those factors that can do that.

1:34:00There are combinations of other factors they can do the same. So there are various combinations. There is a lot of redundancy in that pathway. And if you hit the right combinations in a cell at the right time, you can push it back in time. Now, of course, the challenge is that, you know, that reprogramming is full in the sense that everything is going to be erased. If the reprogramming is done properly, directly all the medillation, so all this metal groups that you put across DNA that you know accumulate with age are going to be removed. All the signatures of you know are essentially removed so the cell is truly rejuvenated as like in the beginning.

1:34:42And as you mentioned you know perhaps you don't want to do that right fully, can you do it in a way that is partial reprogramming as some people refer to. But certainly that this is still like early days for that, it sort of needs a possibility. I think for most people, if I said, look, scientists are developing engineering eyes that can replace eyes, and people that are blind. Maybe one eye, maybe both. They'd say great. Right. You're curing blindness, for example. And people are trying to do this. Neural link is doing this. E .J. Chisholm -Lisky and Dan Plankert, Stanford are trying to do this.

1:35:20If I said, you know, there are scientists and companies trying to develop chips so that paralyzed people can walk again, or that people who have locked in syndrome can speak again through one modality or another, they'd say, great. But if I said, there are scientists who are building assemblodes in a dish so that maybe you don't have like two hippocampi, you have three. You have a super memory. Yeah. I think most people will be like, whoa, slow down, you're playing God, that's not okay. And as a parallel example, CRISPR gene therapy, which we talked about earlier, was employed by a Chinese scientist to, I think it was to mutate the HIV receptor to modify, yeah, two individuals, two babies.

1:36:14Yeah, so there are at least two babies that were aware of and probably more around the world, but not terribly many who for whom CRISPR was used to make a genetic modification Those babies were carried to term and it wasn't to fix any particular disease It was to confer them with something additional. Yeah to prevent in this case to prevent Presume transmission of HIV from the mother which is not necessarily justified in that case So right Did the mother have HIV? I think the idea was that, yeah, to avoid maternal transmission to the fetus, you would not have that. But there are other ways in which that can actually be avoided.

1:36:54So in this case, it was not perhaps the best choice of a disease to correct. And I think that's why the scientific community has been quite outraged by both gets the rationale and the way the experiment was done, which was not following, certainly. Yeah, yeah, the scientific community, as you said, was very upset about that, which brings us to the question of ethics. Yes. So I'm sure being really familiar with this technology that you've thought about a number of ethical issues that aren't going to occur to me, or perhaps you've heard about things from the general public or from physicians and psychiatrists, what are some of the key ethical issues that come to mind when thinking about how assemblids are going to be implemented as eventually treatments for disease?

1:37:36Yeah, so we think a lot about like the ethical issues and we think this as a group at Stanford this part of like my center We have like hand -grillies a professor of law and an ethicist But actually we've engaged the many ethicists sociologists to religions we're actually gonna have the first meeting at a silamar this November on the ethics of neural organoids assemblies and their transplantation and You know there various ways of classifying the ethical issues the way I So, like, think about it is that on one hand, there are ethical issues that are related to the cells. We are taking cells from a human.

1:38:11And so, you expect that you have received proper consent for the use of those cells, whatever that is. On the other hand, if, for instance, you put them into an animal, then there are ethical issues related to that animal. Are you doing any harm? How do we manage pain in that animal that has been transplanted? And then there are sort of like issues that are at the interface between the two. So for instance, are there any emergent properties that are arising at one point, whether they're like in a dish or maybe perhaps in an animal? How complex can a circuit like this become? Is there any form of learning, of computation?

1:38:49Of course, some people have raised the issue that perhaps there are sentience or awareness, consciousness. Are they feeling pain? So for instance, that has been like one critique for one of the recent work that we've done. Of course, in that case, we know, the emotional component of pain is processed in different brain regions. We don't have those in a dish. So we know that they're not really feeling pain. We have the pathway of pain. But it also speaks to the fact that we need to be very careful about how we communicate this type of research, even just using terms that are trivializing can actually create a lot of confusion.

1:39:24And the classic example in our field has been to call this preparations, this organitor assemblots, to call them mini -brains. They may seem like as a trivial joke that it can do anything, you know, any harm. But you hear that for the first time, scientists have made mini -brains in a dish. And what do you think? You think, oh, it must be a miniature human brain that they're keeping in a dish, right? Isolated. And of course, that's not true. We have not made the entire nervous system. We can make parts of the nervous system. We can put them in various combinations, but we've never made the entire brain.

1:40:00Actually, I don't know of any scientists who has as a goal to try to build the entire nervous system as an exact replica of the brain. So I think the words matter a lot. And in fact, that has been one of the things that we've done over the years. A few years ago, I thought it would be really important to get most of the scientists this in the field together and start thinking about this term, it's really carefully. And so we got together, created so like an ad hoc consortium. And through many, many calls, one on one in various groups, we came up with one paper which was published in Nature a couple of years ago, which really comes as a nomenclature for the field.

1:40:40We as scientists decided this are so like the way we classify them. These are the terms that we all agreed should be used and not used, not for instance, project, let's say complex terms onto this. We'll never say that an organoid like sees just because there is a retina, right? We'll never say that a cortical organoid has intelligence because that's a property of an entire nervous system. So we think that this is actually quite important, especially in communicating with the public. And that that consortium turned out to be an actually great exercise of getting everybody together and now thinking what are some of the common practices that we should all use when we report this experiment.

1:41:21So we just had a few months ago, another paper that came also as a perspective in science where in nature where we also lay it out so like the framework for the field. I think it's also speaks to the fact that we're entering so like a new year end science where I think, you know, you would say all these labs are working separately, they're competing with each other. And yet we all got together, you know, 25 or so labs, discuss some of these issues, reach some consensus, you know, and I think that moves the field forward. And I think in general in science, we will need more and more of this collaborative efforts.

1:41:54Because the science is getting more complex, biologies, getting really, really complex, and there's no one single app that can solve all of that. Yeah, I completely agree. I think some years back, collaboration became the norm as opposed to the occasional thing. And I always thought that laboratories should be named after projects, missions as opposed to individuals, but that's another story. Well, kudos to you for thinking about these issues so carefully and for gathering people around them in order to come up with nomenclature Going back to this issue of naming what things are called is so critical It's so critical and we see this in the public health sphere You know when people talk about gain a function research now, you know It's rarely mentioned that you know gain a function studies are critical for understanding things that it's not always the case You're mutating a virus.

1:42:42It's like gain a function as a general technology more specificity of language, I think is going to be immensely beneficial. So I appreciate you doing that. And this terms change with time. I think it's also important to like mentioned that our understanding evolves. Science progresses and sometimes there are things that we thought we understood. And then new techniques come and change that. You know, I think it was Sydney Brenner who said that progress in science usually comes from a new technique that will yield new discoveries and that will create new ideas. So, you know, you think you understand something and suddenly you have a new machine that can measure it much better with more precision or let's say you have this technology when you can now recreate some of the circuits and suddenly new ideas come out of it, new discoveries and then we rethink and we adjust and I think that's the beauty of science that in a way itself correcting as we get a better and better understanding of the world around us.

1:43:36Also essential for people to hear because I think whenever Science or medicine comes out and tries to correct itself Often the general public not all but Components in the general public will go up in arms as you know similar to like a teenager realizing that their parents also Did some bad stuff when they were younger and they're like see I shouldn't believe anything you say it turns out Science is it as a whole I think it's a very well intentioned endeavor You get your occasional bad apples, but I think that This notion of self correction is it's fundamental. Just like engineering's gotten better.

1:44:11The phone you use now doesn't look anything like in terms of technology or speed of the phone you use 10 years ago, likewise with any technology. That's why it's so important that both when we communicate as scientists to the public, we use terms that are not trivializing. I think very often we're told, like, try to simplify so that the public understands. The public understands much more than we think. There are always ways in which you can explain something without trivializing it, without using a new term or some comparison so that they understand that. Because very often, analogies can also be dangerous.

1:44:46But I think I always sort of like assume, and that is sort of like being my mantra. That somebody really has, when you explain, even to the general public, that they have zero knowledge and yet infinite intelligence, right? They think as the saying goes in science. So I think there are always ways of explaining science is very simply, but also communicating that science changes over time. There are new understandings that are correcting the science. And we've seen this, of course, in medicine. We've sadly seen it in psychiatry, right? Many, many times by labeling, relabeling, doing treatments that perhaps were like not the most fortunate, right, over time.

1:45:26But I think it's important to tell the public that, you know, we're always trying to move towards. I think most physicians that I know, most psychiatrists that I know are really, motivated by really trying to make their patient better. So let's play a game where if I say if you take two human cortical neurons, we're three, we're five or ten or a thousand that were developed from one of my fiberglass and you put it into a mouse or a non -human primate like a macaque monkey. I think you've still got a mouse harboring a few of my neurons or a macaque monkey harboring a few of my neurons. At what point does that animal no longer become strictly a mouse or strictly a primate?

1:46:17And then the parallel example, of course, is let's say I could get some neurons from fiberglass that were made from you and those were put into my brain. At what point do I become more serious? You like than Andrew like? So how do you think about those questions? And while it might seem too early to consider those, we've learned through history that it's never too early to start thinking about the ethical implications of a technology like this, where there's transplantation involved. No, it is absolutely not too early. Actually, it's the right time to think about this as experiments are actually being planned, not when experiments have been done.

1:46:53Good point. And that's what we've been doing. And that's why actually all experiments that we do undergo ethical approval in Stanford. And I think most major institutions, right, and certainly in the United States, you have to first propose what you're going to do, especially with chloroportin stem cells, and especially with animals. And a committee will decide whether that is acceptable or not. Of course, their experiments that perhaps are not necessarily legal, but when you try to break a new frontier. But I think what it's important to think about like this process of transplanting or transplantation that you take cells and you put them either in another individual or another species is that what really matters a lot we've learned now is the timing when you actually transplant those cells.

1:47:41So turns out that the brain, the adult brain is not very permissive to forming new connections. We don't form them, we may form small connections, there's a lot of plasticity at the connections, but we don't have, let's say in our adult brains, we don't have cells that are moving now across the nervous system. We don't have entire pathways that are being rewired. You're never gonna have a corticone neuron that just simply regrow and now connects to a spinal cord neuron. Which is why injury to the nervous system is so devastating, right? They're so little recovery because the cells are usually not, you know, not essentially rejuvenating.

1:48:16There are no cells that are replenishing them. It's not just that there are no cells to actually replace them. It's also that the cells are just not that eager to connect with other cells as they are early in development. So years ago, we've discovered that, you know, while we can keep some of these cultures in the dish for very long periods of time and connect them in ever more complex assemblots, and now they're like literally like dozens and hundreds of assemblots that people have made and not just in the nervous system, actually even outside of the nervous system, because There's another assemblots of cardiac assemblots and endometrial assemblots.

1:48:49So the concept is like too covert, and I'm glad to talk about it. We're going to have the first conference on assemblots at Kohlspind Harbor this year, which is sort of like to bridge across fields and try to understand complex cells that interactions. But even with this most complex assemblots, we realize that the cells are still missing cues that are present in vitro. So a few years ago, we were doing an experiment looking at some of the neurons that we made in a dish. And you know, these neurons in the cortex are very often called pyramidal because they look like a pyramid. They really have this beautiful triangular shape.

1:49:21We were looking at the neuron and it looked beautiful, exactly like a pyramidal neuron. And then around that time, we got a piece of tissue that was removed from a child who underwent surgery for epilepsy. So when you sometimes have to undergo the surgeries, intractable epilepsy is really severe. Maybe you talked about this like previously. you have to remove some tissue when you remove some of that tissue also have to remove some healthy tissue and so we got some of that healthy tissue and of course we're always like eager to understand how the cells that were made in a dish are similar or dissimilar to the ones in the actual brain it's like need to benchmark before we use that for a therapy or for anything else and we compare one day some of the cells and we realize to our amazement I don't know how we'd never notice it or nobody has really like made a big deal out of it but the neurons that we're making in a dish were about 10 times smaller than the ones in the cortex on average.

1:50:17I mean, there are kind of miniature versions of what was happening. And so it was like, of course, immediately it was like, what is happening in vivo? You know, is there something, you know, as they say, in vivo veritas very often, right? We know this has been the case for immunology that many experiments in vitro have not always panned once you actually studied them in the natural patient. So that's when we actually started to also use transplantation. Meaning we started thinking could we actually put some of the cells in an animal and see whether they acquire new properties or they look much more like the cell.

1:50:49Of course transplantation has been used for four years. Many of these experiences were done before I was born, especially in Sweden, when scientists will actually take various cells and transplant them into animals. And so what we did, we started doing, is like taking actual organoids, corgol organoids, and then transplanting them into a rat, an early born rat, in the somatosensory cortex, so the part of the brain that senses, it receives information from whiskers. And we've done that in the first few days after birth. And it turned out that that was key, because if you do it later, The cells don't really integrate that well.

1:51:31They integrate, but they don't fully integrate. And if you transplant that organoid into the somatosensory cortex of the rat, and then you wait for a few months, that graft starts to grow, the cells become vascularized by the rat. They will even receive microglia, the immune cells of the nervous system of the rat start to populate. And then when you look on an MRI, you now can see that about a third of one hemisphere of the rat is now made up of human cells. So you can see really from on and on, I'm arrived from the ventricle to the pier. Now you may think that that's like an inert piece of tissue that sits there, but it turns out that it is quite well connected to the host.

1:52:09And that happens because the brain is still eager to connect at that early stage of development, but later on is not. And so first, as you can do experiments where you can actually record the activity of human neurons, and at the same time move the whiskers of the rat. So if you move the whiskers of their atom to the opposite side obviously because the pathways crossed then human neurons now start to respond to that. And then the, I think probably the most important consequence of that is that they receive now input, they're now in an environment that is much more physiological. So when we now looked at the cells, it turned out that they're like six to eightfold larger than when we were making the dish.

1:52:46They're not yet identical replica, but they're very, very close. And that for us has actually been key in starting to actually understand the biology of some of these conditions. So, for instance, for Timothy syndrome, there is a very dramatic effect in the size of the neurons. They're almost twice as smaller than a control neuron in the patient. Well, in the patient, only when you transplant the cells, we can see that defect. In a dish, you look at them and they're identical. And then you transplant them and some of them grow really large to control and the patients fail. And that phenotype can only really be seen properly in vivo.

1:53:25So that has been actually essential also as we've been developing a therapeutic for this condition. And you start thinking like how do you test a therapeutic? You know, if there's no animal model of disease, you test everything in a dish. You do want to have some safety check, first of all, for making sure that there are no adverse effects. but also you want to make sure that it works in an envi -vo environment. And actually it turns out that this model that we've built was essential. Because now we could take actually the animal and inject the therapeutic into the nervous system of the animal, but look at the effect on human neurons in an envi -vo context.

1:54:04And so I think that's one application for this. But if you do the transplantation at an later stage, like for instance, in an adult, that integration would probably not happen. I see. So it's quite dependent on the species and there's another thing. The farther away the species are, the less likely it is of course that the cells will integrate. So, you know, think about it. It takes just a couple of weeks for the rats to make the cortex. It takes us 20 weeks to make most of the cortical cells. So, the human cells are always behind. The rat is finishing development very quickly. The humans are trying, but they're keeping their pace.

1:54:42So the integration between the two species happens at some level, but it's not perfect. And that's actually not our goal. Our goal has never really been to have perfect integration. All we wanted to do is to have a better system where we can capture aspect of disease that we wouldn't be able to see in another way, or test therapeutics that we wouldn't be able to test in any other way. And so that's where this actually comes in handy and it's been very useful. It's so interesting that for most people, again, I'm making a lot of assumptions here, but for most people, the idea of a chip of a electrode implanted into the brain of a patient, or spinal cord of a patient isn't that disturbing to them.

1:55:22I mean, no one would choose to do that in the absence of a clinical issue, but well, there are some people who are interested in brain augmentation through the implantation of chips to create super memory or to be able to process more bits of information and whatever capacity. But typically it's discussed in the therapeutic context. But as soon as we hear about, for instance, you know, a pig heart or a baboon heart was was transplanted into a human, you know, all of a sudden it gets to some really core things about our humanness. Yeah. And then of course, I can't help but be reminded of all the anecdotes that you hear where, oh, you know, a patient died, had donated their heart to medicine.

1:56:02The heart was transferred and then the person who received it thought that maybe they had adopted some features of person's experience and there's a, you know, you can't really do the control experiment, but there's a lot of interesting questions that border on mystical, but that, you know, given that experience is mapped into the nervous system, it's not inconceivable that you would have memory traces, at least of bodily experiences built into the organ system, although typically we think of that stuff as in the brain. So, you know, as I hear and learn more about these incredible assemblots, I'm very enthusiastic about where this is headed.

1:56:37I also, of course, think that treatment of diseases that is like the primary entry point. This is what, you know, as opposed to building, you know, super humans, which is I think why that CRISPR experiment, mutating the HIV receptor, was also disparaged. There was this idea that maybe the HIV receptor in the absence of HIV is performing other roles related to learning and memory. And so there was this kind of hints of eugenic type approaches. And that raises a question for me. You mentioned that there are many genes that are associated with autism. Yeah. I think most parents or parents to be don't take a test for those genes.

1:57:15There are companies like Orchid in the Bay Area now that will do deep sequencing of embryos in IVF. They'll do, depending on how much you pay, they'll sequence more. This was in the news a few weeks or months ago. Yeah. And people start thinking, oh, this is like eugenics, right? On the other hand, partner selection, who one chooses to have children with, is its own form of genetic selection. You know, say, oh, you know, he's very kind, she's very kind, she's very smart. You know, that there are people are basing their decisions, hopefully according to features that they would like to create in the offspring.

1:57:47It's not always the case. But so I think sometimes the boundary between, you know, what we call eugenics and mate selection and creating offspring in the... purely old -fashioned way, it's blurry, it becomes a continuum. How far off are we from genetic testing of parents as a kind of obligatory thing? Now that we know some of the genes associated with autism, we test parents for things like TASAC, sickle cell anemia, congenital adrenal hyperplasia, things that are almost deterministic Yes. Down syndrome, right? Trisomy. And in some countries, they'll implant embryos that are not as we say you, Floyd, you know, the proper assortment of chromosomes.

1:58:39But in the US, typically that's discouraged. So how do you think about all this? Like, I mean, you're not responsible for deciding for everyone, but you're right at the kind of a leading edge of what's possible, and you can kind of sniff what's going to be possible. I mean, how much information should a person thinking about having a child have in order to make the best informed decisions? So for some of these conditions, it's more straightforward than for others. As you are saying, some of them are very deterministic. So if you have like 321 chromosomes, you're going to have Down syndrome, and that's going to be associated with the very classic presentation.

1:59:22you know, but for others it turns out and I think that's where it's much more complicated than just testing and making a decision is that the what we call in genetics the penetrance of the genetic mutations is variable, meaning that you could have a genetic mutation that in one patient could cause a very severe presentation or phenotype and another would be very mild. It's not the case for a tibetan syndrome, where actually it's quite predictable. Most of the patients that we know, we've never identified a patient who is non -affected and they're very severely affected. But there are other conditions that are much more common.

2:00:01I think the classic one is a deletion that is happening on chromosome 22, the so -called 22 Q11 .2 deletion syndrome. Known by many, many names, Velocardiophacial Syndrome, Dejure Syndrome. known by many names because it's so common. It's actually the most common micro deletion in humans, about one in 3 ,000 births. Now, the condition is associated with cardiac issues, immune conditions, many of which can actually be addressed medically, but it also comes with a 30 % risk for schizophrenia. 30 %? Yeah. So you think the general population is 1%. So this is about 30 times higher. It also comes with the 30 % risk of autism.

2:00:50But you could also not have any of this. There are individuals who are carrying the 22Q11 .2 deletion, which is a large deletion, by the way, there are 60 genes that are gone in the classic deletion. And yet still carry it around and have minimal defector fetal times. Do we test for this 22Q? This is tested generally this days, yes, because it's so common. But I think that the challenge is this problem of penetrance. And in some patients, and we don't know what the context is, each of us has a very complex genetic background. So it could be that, you know, the same mutation to different individuals will have different levels of severity because one of them perhaps compensates much better for whatever reason.

2:01:36There is a lot of sarcastic forces in development. And if a cell, it's much faster at opening the other gene, like the similar gene that is unmutated, and in other case, it wasn't, or maybe there are other environmental factors that are interacting. But the other possibility is that the genetic background that we have is very different. And so we're still in early days of truly understanding what are the effects of the genetic backgrounds in modulating the severity of these conditions. But in itself, it's a very interesting question. and why some individuals can have a massive deletion of 60 genes and yet still move around.

2:02:13So I think that's going to be a lot of interesting biologists to discover behind this. And then of course, we know that there are differences between animals and humans. That we already know that very often a mutation that would be very severe in a human has almost no defect in an animal model, partly because that gene may be plays a different role, or perhaps the genetic background is very different. Speaking of which, what are some of the other diseases that are being modeled and studied with assemblots? So team at the syndrome has sort of like been the first example because partly because it was some of the first neurons that were derived from IPS cells and from patients with neurodevelopmental disorders in those early days.

2:02:56And also partly because it's the disease that we studied so much on all possible angles. First, with two dynorons, then with three d organoids, then with the cymbloids, then at one point. And I like to say that it kind of, a therapy became self -evident, so to speak. I mean, we were honestly not, I was not thinking that we would develop a therapy for a thymid syndrome, like not in the near future. But at one point, we just accumulated enough biological information, that you just look at it and say, oh, this is exactly what we need to do. And it turns out that, and we did about like five years ago, that we understood so well how this channel is processing the cells and what it causes.

2:03:36That at one point we realized that all we need to do is generate this tiny piece of nucleic acid that we can get inside the cells. It will go in, switch the way the channel is actually processed and rescue or reverse the phenotypes. And it turns out that every single defect that we've described over the past 15 years in studies can be rescued by just adding the tiny piece of nucleic acid. It's almost like a gene therapy in a way. It just doesn't involve a virus. And so this is the first disease that we're preparing for a clinical trial. The patients are very rare. So I've been traveling around the world trying to find most patients with hematocentral even try to understand the complexity of the disease, the severity of the disease.

2:04:17And so we now have a large cohort of the patients ready. And we're preparing for the first clinical trial. We already started producing the drug. So it's drugable. We think that it's drugable, but this will be the first therapeutic for psychiatric disease that has been exclusively developed with human stem cell models without anything else. Like to joke, probably you knew very well, Lubers Dryer. He develops the so -called gene chip, early days of evaluating genes in different cells. He passed away recently. He passed away recently. He also, he would bring coffee by. He would bring coffee by. He had their office across our D222, right?

2:04:53So he would come in nine. Anyone who's ever taken biochemistry, the big red biochemistry book, Strier, that's true. That's what it is. I mean, he was an amazing communicator. I think above anything, he was just a larger than a live figure who like, be able to like go with you in a conversation from like a deep molecular mechanism to what does it actually mean? Yeah, very kind person too. So my last conversation with Lubird, which happened I think a month before he passed away, he came to my office at Stanford, we would meet like every few months, he was just like I was so interested about how this is evolving.

2:05:24And I remember he was sitting in my office, and then he wanted to know where are you with Timothy Syndrome? The paper was still under revision and nature was coming in the next few months. And then he said, the saddest thing is I'm not going to see this paper published. I want to see this paper published. And I said, why? And he goes, do you know what you've done? Because you would usually use with that intensity. And I thought, oh my God, maybe he realized we've made the mistakes somewhere in the paper or like, you know, it's going to point out to some flaw. And then he says, no, you've demystified the psychiatric disease.

2:05:59He said, what do you mean? So when you think about psychiatric disorders, they're so esoteric, so complex mental processes in, you know, their rising behavioral changes. And yet you went all the way down to like a molecular defect, a point mutation, figure out the rest. And now you're on a verge of potentially, you know, perhaps not reversing but at least improving some. So he was so excited about this. I think I never kind of think enough perhaps about it, but he was the last one who so like reminded about like how important it is actually to focus on this genetic disorders or which we know more.

2:06:34Of course, this is just one form of disease. There's so many more afterwards but our hope is that just by understanding and learning from this, we're gonna be able to apply to other disorders. So another one, they were studying now are their formals of epilepsy, which are very difficult to study. They are intractable forms of epilepsy. Patient to have some of these genetic mutations, whether they're an ion channel, or in molecules that are important for cells to stick with each other, they can cause 60 seizures a day. So they're really devastating conditions. They're actually causing impairment just by having those seizures every single day for 10, 15 years.

2:07:09And so those are a really big issue right now. So we've been focusing a lot on trying to build now models for this epileptic seizures, either through in vitro studies or after we transplant, and then we study more complex networks in patients. And then of course, intellectual disability, so severe intellectual disability, schizophrenia, forms of schizophrenia. So we've been studying now for almost 12, 13 years, 22Q on one deletion syndrome. We think it's, so like an entry point, it's the highest genetic risk factor that we know of for schizophrenia. So we think it may give us some windows into how molecular defects arise.

2:07:48So I think you can think of most psychiatric and neurological conditions that you can study now, as long as they have a strong biological genetic component. So I think those that have a social component, those that are triggered by social stress, let's say, forms of anxiety, depression, those are much more challenging to study because, of course, we can mimic that social environment. Can I make a request? Please. That someone in your lab tried to tackle dystonia. Yes. I had the experience last year of somebody contacting me. I get contacted a lot for requests to help with horribly sad situations.

2:08:31As one does if you're in the neuroscience field. Typically it's people with visual deficits who've gone blind or losing their vision. And this time it was a mother of a young kid who had a form of dystonia where he was essentially just going from a biol accounts normal appearing and acting kid to having basically no ability to move or do anything, couldn't go to camp, couldn't go to school. And it was just a very, very tragic situation. He had a neurosurgery, I will know soon how he's doing. But I learned that these dystonia's are not super uncommon. I mean, fortunately they're uncommon enough, but you just have to witness one of these stories and turns out there there is a genetic basis for these.

2:09:16So I'm putting in a vote for dystonia for the parent and for the child. It's devastating. And we don't hear from these people very often and they're sociological reasons for that. Certain diseases are underrepresented in the public sphere. Autism we hear a lot about, not just because of the prevalence, but because there's a, we have a certain affinity to kids and that explains that, a discussion for another time. But these dystonia are very hard to witness in a way that has made them kind of veiled to the public. But they're very, very detrimental. And it would be amazing. I know you already have a lot on your plate, but I'm putting in a strong vote for.

2:10:01But we are actually working on on the stonias because they are devastating conditions and there are now genetic mutations that cause really severe forms of dyskinesia and stonias. So really uncontrollable movements in this kids that are really devastating for social functioning and general for development. And so we do know a little bit about the biology behind it. We do know that the basal ganglia, this deep structure into the brain is very important for movements. You know, we very often stimulate that brain region for Parkinson's disease or parts, you know, of those circuitry. So we know it's very important.

2:10:34So we've been trying to rebuild it in a dish. So we now can build some of the circuits. We call them lupa assemblots. We essentially can put a cortex and we've made the strighitum and then you put parts of the mesencephal and the midbrain and the thalamus. And the cells connecting the lup and now they have activity. So you can now induce mutations at various levels of the circuit and see where is that mutation most important. So let's say if you were to develop a gene therapy, where would you deliver that gene? If you were to choose, if you can deliver it in the entire brain. So this are really early days, but I think it can be applied.

2:11:09I think in general, you're mentioning this before about autism, and even the ability of communicating this disorder or how much awareness there is. I think when I refer to autism, I generally refer to the severe forms and profound autism. And as we discussed earlier, there's certainly a continuum and there are many individuals that are high functioning, right? They have high skills. They may lack certain social skills, but they have other skills. They're different. They're productive in society. I am not talking about discovering or developing a therapeutic for any of these individuals. We are talking about the profound forms of autism.

2:11:57The ones that actually the parents are still struggling to even communicate about, right? The kids who may never go to school may never be able to actually live on their own. The same is the case for many of the patients with severe dystonias. So I think it's very important because I think in the case of autism, partly because it's being talked about and I can because it is a spectrum is, you know, it's also part of the identity, right, of a part of the population. And that's absolutely fine. I think perhaps like at one point having different terms. Yeah, that would be useful. It may be useful because we were talking before about terminology, which is so important.

2:12:34So perhaps that would be so like useful at one point to define, you know, the border between profound forms of autism and forms of autism that are not really a disease. Yeah, as well meaning as the psychiatric community is, it's bound by this, you know, DSM, whatever number it happens to be on for understandable reasons, but I think a better nomenclature will really help. It has societal implications. It has to do with how we treat people generally. Actually, just as a quick reflection years ago, I sat down with Bob Desimone, who, you know, world -class neuroscientist, as you know, but he was the head of the National Institute to Mental Health at that time.

2:13:13And he said, to me directly, it was overlaunch. He said, do you know why there's so much more money spent trying to understand autism as opposed to schizophrenia? At least that was the case at the time. And I think it is still now. I said, no, and he said, because the strong genetic link in schizophrenia means that oftentimes the parents are struggling as well. They're not bringing their children in. And with severe nowadays, it's not politically correct to call them schizofrenics. For people with severe schizofrenia, it's scary to be around. Yeah. It's really scary, whereas with autism, even in the profound case, these are children, and as a human species, we naturally have this.

2:13:54We want to care for our young. And it just pulls on us. And he said, you know, so there's been this incredible lobby of the government, and therefore pressure on NIH to direct funds towards studying autism, them far, far less for schizophrenia. It's interesting, you know, in light of the homeless problem in California and elsewhere and the huge amount of mental disease and drug addiction. I think nowadays there's kind of a broader understanding of brain diseases as diseases that people suffer from as opposed to cold mothering or something, like ridiculous theories like that. I definitely wanna talk a little bit about you, not getting too personal here, but I've known you for some years and from the first time I met you, it was clear, you were gonna work on something important, you were gonna figure it out, and your work ethic is like something to behold.

2:14:48Without inflating numbers, how much time are you spending these days, either at the computer working on things related to your science or in the lab or thinking about your science? I mean, of your waking hours, what percentage? Well, I've never seen this as work, so probably all the time. I think about this all the time. I mean, luckily now, of course, I have a lab of incredible scientists and many of them now have their own labs. And we've been teaching so many people around the world now, like more than 350 labs around the world to just implement this technology. Very systematically through courses that we do at Stanford.

2:15:23So I feel we've got like amplified so much. So there's always something happening. But I've never seen it honestly. It's work. I mean, I think it's so fun to think about, you know, the human brain. It's certainly fascinating to think about the biology of this condition. And of course for me, training as a physician, I think seeing firsthand some of the devastating effects of psychiatric disorders was a very strong motivation to actually go into neuroscience. I'll never forget when your first paper was published as a postdoc. You brought in a cake for everyone else. I don't know if you remember that.

2:16:01You brought in cake for everyone else. I don't remember. I guess the first time I've ever observed this, this is awesome. At the time I was eating cake, I don't eat cake anymore. With each successive decade, I get stricter and stricter with my eating. I still enjoy food very much. But it's really speaks to your spirit and your generosity. I feel so blessed that someday I'll be able to say, I can tell you stories from way back when D2 -2 -2, when we took over that room without permission. I think we just did it. I think we just took shade. Which is the way to do it. It's unincorporated. Well, Ben was the one who always said, you know, ask for forgiveness, not permission within the proper context of doing science.

2:16:40He was famous for bringing his experiments to talks as a postdoc, so he wouldn't lose time on his experiments. And then I think at one point, there's a story where someone called it out to him out and said, hey, you know, like, why are you bringing your experiments to seminars? Everyone else is drinking coffee and doing something. He said, because I don't know if your seminar is going to be any good. And I don't want to waste the time on my experiments. You know, he had such an incredible spirit about just ceaseless pursuit of knowledge, which clearly you do as well. Sarah, I am so grateful for you taking time out of your immensely busy schedule to come here and educate us all on this incredible technology that you've developed and that other laboratories are now using.

2:17:21I realized it's a field, but clearly a field that you've been seminal and launching. And, you know, I think for a lot of people, if they were to just hear about organoids in the news or here, okay, we took these neurons and we were able to grow them in addition. They formed some things that resemble circuits and when putting them into mice, they'd say, you know, this sounds a lot like a parlor trick or something that scientists do to keep themselves busy with our tax dollars. But I just want to thank you because you've beautifully illustrated the linear fashion in which you've gone from human disease to building up technologies, one cell type in a dish, two cell types, circuits in a dish, three synapses modeling, using drugs and other approaches, genetic therapies to figure out what actually needs to be fixed, going back into patients, which is super exciting.

2:18:09I'm absolutely convinced this is the way science is going to be done on the brain to cure neurologic and psychiatric diseases. I'm absolutely convinced because animal models, while they have their place, they just can't recapitulate everything we're interested in. And we know that, as you mentioned from other fields. So whatever we have to do to keep you going, you look younger than the last time I saw you, which was a while ago. So you told me before we started, you walk a lot. How many steps a day are you doing? I do more than 12, 15 ,000 for sure. So you're walking to and from work? Yeah, and I walk all the time.

2:18:43I like to walk, especially when I travel. I visit a lot Europe and parts of the world and I love to just walk. And art is the only other thing that I do. Other than science, I love art. I used to paint right now as mostly thinking about art and like what you know I've seen most museums in Europe at this point like several times. Who's art is exciting? You know I'm fascinated by art but who's art are you intrigued by lately? Well I mean I've my favorites have always been impressionist but then I go through phases and so I love all art as an expression and I think that's sort of like you know I walk a lot museums I think you could probably trace like where I've done most of the walking and it's probably done in museums or in California walking at night and so like discussing science with students or others.

2:19:29Fantastic and none of this biohacking nonsense you eat one meal a day that's how you stay so fit. I generally eat one meal a day yeah. How long have you been doing that? years, I think. I mean, I think in medical school, initially as a necessity because I grew up in Romania and I went to medical school there and there wasn't really dedicated time for research. So I had no option but to do my experiments either very early in the morning or very late at night. So there would be very little time to actually eat, to be honest at that time. So I felt that was like running all the time doing experiments or clinical work.

2:20:05Like I said, your vigor seems to be just increasing with time as it's really wonderful. Clearly, you've found the career path for you and it's going to benefit us all it already has. So, please come back and tell us about your progress. Absolutely. In six months a year, whenever the time is right, we'll have you back. And once again, thanks for doing everything you do. You're in this time of hearing so much negative news and thinking like science is so hobbled and all this stuff I really science need support, obviously. But what's that saying? You see on the internet, not all superheroes wear capes.

2:20:40You're doing God's work. So thank you. Thank you so much. Thank you. Thank you for joining me for today's discussion with Dr. Sergio Posca. To learn more about his work, please see the links in the show note captions. If you're learning from Endor and join this podcast, please subscribe to our YouTube channel. That's a terrific zero cost way to support us. In addition, please follow the podcast by clicking the follow button on both Spotify and Apple. And on both Spotify and Apple, you can leave us up to a five star review. And you can now leave us comments at both Spotify and Apple. Please also check out the sponsors mentioned at the beginning and throughout today's episode.

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