Transcript

Brain Balls | Radiolab Podcast

From Radiolab · Episode page · Watch on YouTube

· 41 min · 7,241 words · 222 timestamped sections

This is the full, timestamped transcript of "Brain Balls | Radiolab Podcast", an episode of Radiolab published January 20, 2026 (41 min, about 7,241 words). It mentions 7 people, works and ideas, including Brett Kagan, Sergio Pasca, Jurgen Kenobick, Nature, Wild Cornell Medical Center.

What this episode is about

The content explores the story of Dr. Meline Lancaster, a scientist who, while conducting a gene screening experiment on mouse neural stem cells in a Vienna lab, improvised by using an unconventional glue-like protein to facilitate her research. This decision leads to unexpected discoveries and raises questions about the implications of scientific experimentation and innovation.

Key takeaways

  • Scientists sometimes stumble upon breakthroughs while trying to make things stick—literally.
  • In the lab, a 'happy accident' can yield better results than following the protocol.
  • Cells can think outside the box—literally forming structures when left to their own devices.
  • Improv in research can lead to unexpected innovations that defy textbook teachings.
  • It turns out that what we think are failures can be exciting steps toward scientific discovery.

Who speaks in this episode?

What is discussed, and when

  1. – 15:00: Jurgen Kenobick, Sergio Pasca, Nature
  2. – 20:00: Nature, Wild Cornell Medical Center
  3. – 25:00: Sergio Pasca
  4. – 30:00: Brett Kagan, Cortical Labs
  5. – 40:00: Nature, Life's Edge: The Search for What It Means to Be Alive

Notable quotes from "Brain Balls | Radiolab Podcast"

  • Now in 2013 they team up with a bunch of other researchers and publish a paper in the journal nature. In that paper they describe how this disorder microphille develops in a…
    about Nature · at
  • What would you see? So one example is a there's a scientist at Stanford named Sergio Pasca and he studied a very rare disease called Timothy syndrome.
    about Sergio Pasca · at
  • And this is his lab at the Wild Cornell Medical Center where he studies brain cancer.
    about Wild Cornell Medical Center · at
  • The question they had was, can brain cells in a dish do anything at all that we might want them to do?
    about Brett Kagan · at
  • Of life and what it means to be alive, Carl Zimmer has a terrific book out all about this stuff. It's called Life's Edge: The Search for What It Means to Be Alive. Get it at your local bookstore.
    about Life's Edge: The Search for What It Means to Be Alive · at

Who and what is mentioned in this episode?

People

  • Brett Kagan — Person · Interviewed technologist / neuro-computing proponent · 1 mention · first at
    Introduces the most provocative application: interfacing neurons/organoids with computers (e.g., Pong; CL1) and the consciousness-adjacent concerns.
  • Sergio Pasca — Person · Referenced researcher / exemplar user of organoids · 2 mentions · first at
    Cited for disease modeling (Timothy syndrome) and for building multi-organoid “assembloids” to study pain pathways.
  • Jurgen Kenobick — Person · Referenced collaborator (paper co-author / lab lead in story) · 1 mention · first at
    Presented as Lancaster’s boss and co-author who helps publish the 2013 Nature paper that popularizes cerebral organoids.
    Movie, right? Totally off limits. But 2013, Maline and Jurgen published their paper and boom, we could watch human progenitor brain cells give rise to parts of the brain.

Books & papers

Companies & orgs

Full transcript with timestamps

Oh, wait. You're listen Okay. All right. Okay. All right. You're listening to Radio Lab Lab.

Radio Lab from Wy. Okay, Lulu. Yeah. We're going to start today. Mhm. Back in 2010 in a lab in Vienna.

Oh, jumping right in. Yeah. Just picture sort of a lab with microscopes computers experiments and off in one corner, Hello.

Hi. How's it going? Okay. Wearing glasses and a white lab coat is this scientist named Dr. Meline Lancaster.

Call me Meline. Okay. Maline has just finished her PhD and moved to Austria. Just joined the lab to start her posttock research.

I was still sort of making friends, still trying to make a good impression, getting to know people, you know.

And one of the first things her boss asked her to do was something called a screen. just basically looking for specific genes in mouse neural stem cells.

So that's like baby brain cells of mice. Yeah. Now, she hadn't done exactly this kind of gene screen before.

And that's probably why I didn't really, you know, I was kind of naive about it all.

Um but so anyway, so she got to work, we put this enzyme on, it just cuts preparing the baby mouse cells.

The cells all become loose and apart from each other. Uh that part she'd actually done before, so you know, easy enough.

Yeah. But then something she hadn't done before, she needed to get those cells to stick flat to the glass bottom of her dish so that she could do that screen.

And to do that, she needed to use special organic proteins as a glue. And I hadn't they hadn't come in yet. I'd ordered them, but they hadn't come in yet.

And instead of just, you know, waiting for them to arrive, I don't know. I was so anxious to do the experiment.

She decided to improvise and so I just kind of like rummaged through the freezer,

found a random tube of glue-like proteins. I don't know how old they were and anyway and I used those

squirted it on the dishes, pipe headed in the cells, popped them in the incubator and went home for the night. next morning

came in, took a look in her petri dishes, hoping to see a nice, clean, clear layer of cells,

like flat on the dish, but instead everything in there was really cloudy, shouldn't be cloudy.

Cloudy means those cells are floating freely around in there, which means that those tubes of protein glue she used,

you know, we're no good. And the cells hadn't stuck. And if the cells aren't stuck in the protein, that means they're probably dead.

Yeah, all the cells are dead. I'll just throw it away. Huh. And I don't know why I did this, but

right before she tossed it, she thought, you know, but I'll check it. I'll just take a peek. Why not? So, she slides these cloudy dishes under the microscope, peers into the eyepiece, and in the circle of light, she sees

these weird blobs. The cells weren't dead. They were alive and healthy and plumped into three or four blobs.

What did they Yeah. Can you as vividly as you can describe him? I mean, they're like a sort of beige color, like an off-white tiny

about the size of a grain of sand. Are these floating balls of cells? And she's like, "Huh,

weird." So, she zeros in on one of these blobs, turns the dial on the microscope to zoom in until she's looking basically inside the blob, and that's when she sees a tube. A tube. Yeah. So, she's like looking down into like one end of the tube. So it looks

almost like a donut shape. Had you ever seen anything like that before? No. No.

Huh. Yeah. I mean, as far as she knew, if the cells weren't in that protein stuff, you know, flat to the bottom, they should sort of die and fall apart and make a big random mess. But these ones seem to be coming together to make this shape. So she gets up from the microscope and starts

sort of going around the lab a little bit subtly at first kind of just like, "Hey, has anybody ever like seen cells do funny things?" You know,

clump up together. And everybody was just sort of like, "Oh, well, if if they're they're supposed to be laying flat. If they're not laying flat, you you screwed it up." Like they they just weren't that interested.

No. So I just kind of like put it in formaldahhide, put it away in the fridge for a little while and was like, "Okay,

let's try this GAN screen again." But this time, no floaty clumps. Going to get those cells to stick flat on the bottom. And eventually she decides to try something new.

This thing that I had read about called Matrael. Basically cellular crazy glue. Like she's not taking any chances.

I'm just going to put a whole bunch in my dish. So she squirts a lot of it on there.

Okay. She puts her cells on top and again pops them in the incubator, crosses her fingers and goes home for the night. She comes back in the morning.

You know, same thing. You go to the incubator, you take it out of the incubator, you look at it, and I was like, "Okay, this is weird."

Once again, there's a bunch of stuff floating in there. Huh. I was like, "Okay, well, the matriel didn't work like it was supposed to."

Again, it seemed like the cells had started clumping together. And that's when I then took them, put them on the tissue culture microscope, looked down the eyepiece, and again,

there they were, funny shaped balls. These ones were also beigish, off-white kind of color,

but they were bigger, and they sort of have like bulges coming off of them. And this time when she looked inside, she saw full-on

architecture. There was a tube, but also a little circle sort of oblongshaped thing

and a fat layer of tightly packed cells all lined up around a space in the middle. They were making structures. They were making things.

Kind of like what cells do as an embryo is developing, which to Meline didn't make any sense. Everybody had always taught me that cells need things coming from other tissues in the body, you know, of the embryo that are necessary for building that embryo. And here was a situation where nothing was telling them what to do because they'd been completely taken out of the embryo.

H and they were like forming structures with no instructions. She's like, "Oh my god, like this is like there are things developing here." But toward what? Well, to Meline, it kind of looked like

they were building a brain. So, these are these are neural stem cells which inside a developing mouse.

Starts out as a sheet of cells and then they fold up and close and form a tube. And then the neural tube elongates and that becomes the spinal cord. One end of it balloons out and that becomes the brain. And that's what it looked like the cells in Meline's dish were doing. It it seemed like these cells on their own were starting to try to make themselves into a mouse brain

at the time. Yeah. At the time I was I was just kind of confused. So she showed some other people around the lab what she'd seen. I showed some of these structures,

tubes, the circles, the lines, but several people in the lab were just kind of I think they were just totally bored.

They were like, I don't know, sometimes things just grow weird. You probably just did the gel wrong. And the director of the lab, her boss was like,

I thought you were going to do a screen. You know, make a flat dish of cells to screen for jeans.

What are you doing? And I was like, don't worry, I'm working on it. H. And so over the next few months, Meline focused on getting a nice flat layer of mouse neural stem cells on the bottom of her petri dishes so she could do those screens.

And so that was like mostly what I was talking about with people in the lab. Yeah. But at the same time,

off by herself in her little corner when no one was paying attention, I was always still playing around with Matriel, growing these weird balls of cells,

tweaking the recipe, trying to make sure I could get it to happen reproducibly.

And then one day, she gets her hands on some human stem cells, cells that come from skin or blood that you can reprogram to an embryionic state.

Where do you get those from? I think these were actually made from discarded human foreskin.

Wow. So specific. Okay. What a detail. All right. Thank you for that. Because it's just bit of tissue that's thrown away.

Yeah. Right. Of course. Of course. Literally thrown away. All right. Okay. So uh Wow.

Yeah. So, anyway, so then with So, she got these human stem cells. She put them in the matriel, swirled them around in this nutrient-rich fluid so they could kind of eat, and she would watch as these formerly foreskin cells started forming into clumpy parts of a human brain.

My god. And then she kept tweaking when and how much of the matriel she would add, and she would just watch these blob shapes over time get bigger.

I mean, they can get as big as like a pencil eraser. Side note, at the time she was pregnant.

Yeah. my oldest, I was pregnant with her. So, she said she had this extra maternal instinct and she was like just really nurturing these little brain balls.

Yeah. And then one day, couple months after, she's been tweaking her ball recipe.

And I looked under the microscope inside. Yeah. On this beige lump, she could see a perfect ring of black pigment. And that was just I looked at that I was like that's a developing eye.

Shut up. And it was growing on a developing human brain. You're like no. What? Yeah.

No, you what? And then then that was then when she went to her weekly lab meeting.

I presented this data. I showed this picture of this beginning of an eye and I remember hearing audible gasps. And then she showed them pictures of the cells forming tubes and loes and

ventricles like an actual brain. Everybody in the lab started to get it. They were like, "Hey, wait a second. It's like you have a version of an early human brain in this dish and you can actually watch the earliest stages of this process of development

that we know almost nothing about." Is that true though? Do we not know anything about early human brain development? I just think you get all these little

like when you're pregnant, you get a scan here, a scan there. Maybe we know something from animal models. But this was literally the first time anyone in human history had ever watched the early brain develop right from the beginning like this.

Yeah. Which is especially important when something in the brain has gone wrong.

Now we can actually watch this process instead of just looking at the end when the person is already severely suffering. we can try to understand how it got there.

So Meline and her boss Jurgen Kenobick who's on board with the whole project now in 2013 they team up with a bunch of other researchers and publish a paper in the journal nature. In that paper they describe how this disorder microphille develops in a fetal brain and they were like oh and to see all of this we use these tiny 3D brain balls which we have decided to call cerebral organoids. That's when like everything changed.

If you were studying human brain development, it was like someone just invented the microscope.

Yes. You can see things that were invisible before. I I don't So, this is Carl Zimmer, science journalist, New York Times columnist, bookw writer.

Ah, you got Zimmer. Yeah. As soon as I heard about this stuff, of course, he's my first phone call and he was all over it.

Sort of like humanoid, organoid, very sci-fi. And the first thing that he pointed out is that there are so many neurological disorders where

the key moments are during development. It's like the key the key plot points are happening when we can't watch the movie,

right? Totally off limits. But 2013, Maline and Jurgen published their paper and boom, we could watch human progenitor brain cells give rise to parts of the brain.

But what would you do with that? Like what would you see? So one example is a there's a scientist at Stanford named Sergio Pasca and he studied a very rare disease called Timothy syndrome.

It's caused by a genetic mutation that causes severe neurodedevelopmental problems and he basically created an organoid with that mutation so that he could see how a brain with Timothy syndrome develops like from the beginning.

Yeah. Now you can actually see what Timothy syndrome is about. So and what did he see? So there are certain kinds of cells called interne neurons and they make very important connections between uh different parts of the brain and with kids with Timothy syndrome they just don't they just fail to get where they need to go.

And now that he knew what was going wrong he started testing out some drugs to see if he could fix that.

Yeah. And he and his colleagues actually ended up finding a a small drug that actually did help these uh neurons to find their way.

Ah, in an organoid. So he he cured it in an organoid, right? Huh. And they are on track to actually start uh clinical trials with that drug uh next year.

Wow. And you could imagine that's one disorder. That's right. Uh, a lot of other conditions, epilepsy, schizophrenia, fetal alcohol syndrome, any of these brain conditions that have an issue starting in development or where we might even suspect they might start that early but aren't sure yet. Now you can see it.

You know, a lot of people in the field said, "Wa, I got to try this." This whole field of neural organoids has just totally exploded. There's I think there's thousands of labs actually using these tools now. The study of the brain is is it's fundamentally different. Now

that's what we are doing on radio lab today. We are just Lulu. We're going to jump into the ball pit of brain balls.

Okay. In which there are tons of new opportunities but also confounding questions. Are there thoughts in there? Is there thinking in there? How brainy are these balls? We are going to get there after the break.

All right, here we are. I'm in the 72nd Street subway station and I am walking to go see a fridge full of brains.

Hey, I'm Liv Nasser. I'm Lula Miller. This is Radio Lab. More specifically, a fridge full of brain organoids.

Just before the break, we learned from Meline that now thousands of labs around the world are growing these brain organoids. And it turns out that one of them happens to be just up the street from our studio in New York City. Only when you're recording are you truly conscious of like how much you breathe.

So we sent our producer Mona Mcgaler laboratory caution hazardous materials to check them out.

Where are we entering? So we're entering. So we have special rooms called cell culture rooms where we grow Oops. We grow um the organoids. This is Dr. Howard Fine.

I'm a medical and neurooncologist. And this is his lab at the Wild Cornell Medical Center where he studies brain cancer.

The type of brain tumor known as a glyopblasto. a very bad kind. Probably now the most lethal of all human cancers. The average survival with about 15 or 16 months

and Dr. Dr. Fine says around 15 years ago or so he hit a wall in his research disease we've probably made the least amount of progress with when I was a

he'd been studying glyobblasto mostly of course in mice right and he admits he actually calls this at the time it was the dirty little secret of oncology that for all this research they were basically getting nowhere

whoa but then you know he came across Meline's work on organoids and it was Laran Caster's I read in nature and it's like like a light literally not many times in you know my 37 career did I truly have a light bulb moment and I I read that paper and said this is what we're looking for and even though

and that's when he pivoted away from mice and started making brain organoids. Can I can we see them?

Yeah, we can take a look. Okay, so he's opening the incubator and he's pulling out.

So these are the stem cells. They looked just like Maline described. They're kind of like a beige color. They look like a kidney bean or like a like a nerd candy.

Little beige balls floating in liquid in a dish. Surrounded by a matri and under the microscope

I see like a dark shape and then I see these little bubbles off the side almost like little popcorny shapes.

You can see structure. These um Dr. F these are from specific patients like your patients.

Yes. But the difference between these organoids and Meline's organoids was that these ones had cancer. So the idea is we're going to make a mini brain from an individual patient

and then Oh, these are the gloma cells. Wow. They take cells from that patient's brain tumor.

Almost just looks like sugar that hasn't dissolved in teeth. And then we retroengineer the patient's own gloma stem cells into the mini brain. Basically, they can put a version of your brain tumor on your

version of your brain on a version of your brain and they can basically make a bunch of those.

We can test hundreds or thousands of drugs and then try a bunch of medicines on them

to look for the drugs or combination of drugs that might be most effective. So, you're saying that like you can try every chemotherapy that's out there and decide like which one?

Everything only limited by resources. As you could imagine, these are Oh my god, that is that is beautiful. I mean, that just thinking about a a a way of like a kind of bespoke medical future exploration,

right? Way better than just using mice. Oh my gosh. partly because it also could help us leapfrog one of the biggest reasons on average 90% of clinical trials for neurological drugs fail. And for brain cancer, by the way, that number is even higher, 95%.

They're failing because they're not predicting whether the drug actually works on the disease.

And this is something that Maline told me too. You might have a drug that works really well for treating mouse spinal cord injury.

Like, it's like, okay, great. this is not going to kill you because you've got the animal work to show you that it's safe, but it also doesn't make them better after the spinal cord injury.

But now, sure, they can do a mouse trial for safety, but they can also test that drug to see if it works on a spinal cord organoid, which is, you know, just a tiny version of an actual human spinal cord.

Wait, what? I thought we were talking brain organoids. She Are there Are there spinal cord organoids? Spinal cord spinal cord organoids. Yeah. Okay. So, as Meline was developing her brain organoids independently around the same time, other scientists all over the world are growing

intestinal organoids, lung organoids, liver organoids, muscle organoids, gin organoids,

pancreas organoids, stomach organoids, heart organoids, kidney organoids, uh breast tissue organoids that actually produce milk. Ah, they they can have a breast tissue organoid that can make milk.

Yes. Weird. Has anyone tasted that milk? Uh, I certainly haven't. I've only read about it. I don't know. I don't know. That's a good question. Anyway,

that's science writer Carl Zimmer again. And he says, "Now you can make an organoid of basically any part of the body

and then you can connect them." What? You can like You can Does that work? You can do that. Oh yeah, they call them assemblids.

Assemblids? Yeah. No, like you can Mr. Potato Head assemble. Correct. But then do they attach to each other?

They attach to each other. And do they communicate with each other? They communicate with each other. Yeah.

Okay. And then what? And do what with your charm bracelet human body. So here's an example. So Sergio Pasca neuroscientist at Stanford University

and his colleagues thought can we use an assemblid to study pain the pathway of pain. So they started with

the finger a finger organoid. No no no no sorry just a nerve in the finger. Okay. A sensory organoid. Connect that

like with some other cells in the dish. Another organoid. The spinal cord. Yeah. Just a little teeny piece of spinal cord. Now, we're going to connect that to a brain organoid that is specifically

the phalamus, which is the central hub in the brain that directs signals in all sorts of different ways.

And finally, we're going to connect that one to one more brain organoid, a cortex organoid.

Wa, this is so weird. I mean, it's like Legos. It's like Legos with the human body.

Correct. So, then they took capsain. That's the molecule in in like spicy food. Is that right?

In spicy food and chili peppers. Yeah. very it can be very painful to to the skin.

Okay. And they said, "Okay, let's let's hit it with capsain and see what happens."

Uhhuh. Boom. Immediately the that sensory organoid goes right and starts sending really strong signals.

And those signals, Carl says, zoom right up through this as amloid to the spinal cord, the phalamus to the cortex,

just like it would in your own body. And they can see some kind of registering.

Correct. And when they watch the way the signal travels, which is something that's normally hidden inside a body,

they discovered all sorts of things about what happens when we feel pain that they didn't know about before.

Like for example, signals from different parts of the assembly began firing together in these synchronized waves of signals.

Okay? And the more you know about how those signals work or move, the better chance you have at stopping them. You could, for example, say, "Okay, can I put a molecule into this assemblid that will stop the pain?"

Oh, wow. But, um, so if they're using these things to study pain, is it feeling pain?

No, probably not. These organoids are just little bits of human tissue. In order to feel pain the way we feel pain, there are other parts of the brain that come into play. The assembly is just this super basic circuit that you send a signal through. So like this pain, it seems to be superficially registering it like

and like what is the it I think in that case. No, no, no. I'm the the I'm the first it is this little ball, but is it a thing? Like

what is it? Well, they crackle with electricity. They they form connections called synapses. They replicate parts of the human brain with astonishing accuracy.

But Carl says they're not brains. They're not brains. That's right. Okay. So, if there's like a slider and on one end is brains and then on the other end is just like some neurons in a dish. Where is this on the slider and and how do you Yeah,

I would say that it's closer still for the time being to the neuron end of the slider simply based on numbers.

Our brain has something like 80 billion neurons and the biggest human brain organoids contain about 2 million cells.

That's 0.0025%. Well under 1%. Yeah. And you know, these things don't have blood vessels. So that is a a very important key limiting factor to how big and complex it can get.

Yeah. And they're not in a body, so they can't interact with the world in like a meaningful way.

Okay. Well, but when I was talking to Carl about this, so um he said that a lot of that might no longer be true. Some scientists have, you know, taken organoids from human cells.

Yeah. And have put them into the brains of rats. What? So, basically what they did is they basically took a rat and they like carved out a chunk of its brain,

but they left some of it. They left most of it. And it's almost like it's like, think about it like it's almost like they gave a rat a little human tumor or something. Um, I mean it doesn't

but the tumor is like just brain human brain. It's human brain. Oh my god. human brain

and these human organoids are pretty happy in there. It's sort of wired in. They connect up with the rat neurons. They get supplied by the rat blood system.

So, they have made in a real sense like a new kind of being. Yeah. Yeah. Yeah. That did not exist before this. Correct.

Um, okay. Feels like there should have been a bigger press release, but Okay. Do the do the do the rats act any differently? Are they suddenly like into podcasts and coffee?

When you do studies on these rats, behavioral tests, memory tests, all sorts of things, they're just rats.

There seems to be nothing human about them. Okay. But one thing they did notice, when you tickle its whiskers,

Yeah. you can actually measure signals from the human brain organoid neurons. The human part of the brain lights up. What?

Yeah. So, it's registering the feeling. They are receiving signals from the rat's senses.

I mean, strictly speaking, they are receiving signals from the rat's senses. Are they feeling it? Feeling it gets hard because it's kind of the pain question again.

But yeah, but now they're in a body. I mean, they're in a being. Yes. But they're not the like driving force of that being. They're like a they're like a house guest in the attic.

Okay. Live, would you put make a brain ball brain organoid of your brain cell and put it in a rat?

Um, if I'm being honest, would you? Probably not. Okay. Okay. So, I don't know, but I just think you're more on my side that this is a little scary than you in your little with your reporter's wand are letting on to because yes, uh there's exciting research, but it just feels like every time you try to comfort me with what we know about these things, you then end up not comforting me and then the scientists take it one step further anyway.

Um, okay. Well, it's it's as if you have seen the future and what the next chapter holds. because that exact thing is going to happen. Uh it it's going to get weirder and creepier and stranger and that's all after the break.

Stick with us. Latif Lulu Radio Lab. We are back talking about brain balls. You know bitty brains, boba brains, the brainish in a dish.

Yes. Haha. With all your clever word play. Uh, but you are about to send us into the next existential tail spin about how people are using these things.

It is possible. So, the final thing I was told to do is push record. Record. Yes. That's an important button. Now, tell me who you are.

So, I'm I'm Brett. This is Brett Kagan. He's a neuroscientist. I'm the chief scientific officer here at Cortical Labs.

Cortical Labs. We're a small tech startup here in Melbourne Australia. Did you start it? Did someone else start it?

No. Well, it was founded by uh there was a few of us and I was contacted by Dr. Hong Wang Chong and Andy Kiten and they were looking for a neuroscientist.

Brett had been an academic obsessed with this particular question. How do you get intelligence out of brain cells that are in a dish?

And this company was like, why don't you leave academia and help us find out? The question they had was, can brain cells in a dish do anything at all that we might want them to do?

Huh? Like do what? What better to pick than Pong? Pong? The like '7s computer game?

Yeah, the game with the paddles and the little ball. Why that? Everybody knows Pong. It was one of the first computer games. It was the first thing that machine learning, which people now like to call AI, really was trained on as a big breakout success.

And he figured the brain runs on electricity. And it's also a shared language of silicon computing.

So why wouldn't we be able to get neurons to do something a computer could do? Exactly.

Like play a simple video game. We used some hardware that allowed us to record the activity of the cells, processed that, and then deliver small electrical pulses back into the cultures, and they did it.

Scientists just put pieces of human and mice brain on a plate and wired it to a computer to play pong.

They learned to track the ball and control a paddle. Seriously, this is one of the craziest things I've ever covered. So, here's what's going on with this.

What? No. Yeah. And this wasn't even an organoid. This was just a flat sheet of neurons in a dish.

I mean, how could it possibly be doing that? Like I mean, can can really dumb things do that? Could like a could like a tree do that?

Trees don't have neurons, so I I I don't think a tree could do that. Okay. So So well, what what does this mean? Like are are they learning?

Well, Brett says yes. I called it learning. And I think learning was an incredibly fair definition because what would an improvement over time in a way that would suit a goal be called other than learning. But other people including Maline Lancaster,

I actually remain to be convinced anybody has really shown that say no because it's really hard to interpret the signals coming from the neurons.

She says when you teach brain cells to play pong, they're, you know, connected to a computer. So what what people do is they use algorithms to sort of decode that message and then send a signal back to neurons. And so you kind of have like two black boxes that you've just hooked up.

It's sort of a collaboration between the brain cells and the computer. And you don't really know what either of them are doing.

Anyway, whatever is happening here, what Brett and his team took away from this is if neurons can do something a computer does, why don't we use neurons as computers? What?

Yeah. Literally a couple months ago, they released their first computer called the CL1. And it is, they don't call it this, but it's it's effectively a biomp computer. It has neurons in it.

Ew. Brain sticky real human brain matter in it. Yeah. It's got like little brain organoids in it. It has 800,000 neurons interfaced with a silicon chip. You can use it to do computer stuff with. Uh, okay. I mean, I can get behind the the brain balls being used for neurological disorder research. Great. You know what? Bespoke cancer treatments. Cool. But why are we hooking up human brain cells to computers to like make money? That to me feels like not worth the risk. Like,

well, think about the problems we are having right now with all of these data centers chugging all this energy, right?

Yes. Absolutely. Wrecking the planet, right? So, our brains are so impressively efficient. Energywise, we have like a dim light bulb like screwed into our heads, right? That's the amount of energy that we need to do all the complex things that we do. If AI or if some supercomput was doing the equivalent, it would need millions of times more power like the difference between a single light bulb and a large town.

It's so flattering. The other thing is that like think about these AIs. You need to train it on the whole internet, right? A human brain is much quicker to learn. If you could harness that energy efficiency, if you could harness that kind of like knowledge efficiency in a computer, you could move mountains.

Okay. But I guess my authentic question at this point is like, okay, you have shown us all this stuff. At this point, it seems pretty clear that they can definitely register input, right? Like they've there's the tickle, the pain, the signal they're getting from pong.

Mhm. Okay. Okay. And then this Pong example at least shows us they are then able based on that input to produce some kind of output.

Yeah. Okay. So let's say it is. Yeah. Okay. So my question is if they can do those things wouldn't they have to have some thrumming level of consciousness?

Uh no actually. No they really don't. Like like like just like a bunch of the things you just talked about AI can do those. Is AI conscious? Even going further than that, like a Roomba can do like navigate a room. Roomba conscious. That's that's a signal in and out.

Yeah. Right. A Roomba is going, "Oh, there's an edge. Let me go this way." That's a signal in and out. When we talk about human consciousness, we mean self-consciousness like you are aware of yourself.

You have a past, you have a future that you're concerned about. There's like that continuity of experience.

This is Dr. Insu Hyan. I'm the director of the center for life sciences at the museum of science in Boston.

He's a bioethicist and he's worked on a bunch of teams with scientists who are studying brain organoids.

We tried to identify what are the emerging scientific and ethical issues. You're like kind of like their conscience. Is that sort of the thing?

You know what I sometimes I feel like a priest in secular clothes. And he says at this point he is not worried about brain organoids having anything like human consciousness.

The brain organoids in the dish don't have that continuity. they don't have all the reges. They don't have the interaction with the outside world.

But when he thinks about the future that Brett and others are trying to create where maybe people start connecting more and more complicated and even more and more structured clumps of human brain cells to computers, maybe you get it might not even be human consciousness, but some kind of consciousness could emerge. just hooked up just to the world.

Yeah. Okay. So, what what about this Latif? I I would, if I may, I I would like to just issue a commandment that all the smart people who are like excited by brain organoids, they all take one year to stop making organoids and use their smarts and their technologies and their labs to like try to understand the consciousness of the organoids that have already been made. You know, like ideally they they could all be in a dark room and just have candles and quietly, meditatively watch for any flickers to understand what's going on. And then and then we have a grand assembly where everyone reports back and we all collectively decide what to do.

But I know that like some of these scientists have this fire inside them to be like how many cures am I not going to find in that year? Like how many people am I not going to help in that year? like the glyopblasto like those people don't have a year

and those people are telling me to just shut up because this is a piece of discarded foreskin.

That's right. If if we have a tool that we don't use Maline Lancaster again and there are millions of actually conscious human beings out there that don't have treatments, but we decide no, we're going to put the value of organoids higher than those people. That would be unethical. It's funny like at the beginning like you asked me like would you make a brain ball of yourself and I said no. And then at some point like my thinking switched where I'm like oh no unless it would save someone's life. Well that's noble. And now I feel even worse saying I don't know that I would. I just I mean yeah okay if it's my own kid.

Sure. I don't care if I'm like a little enslaved human consciousness if it saves my kid. But as you have shown us, the scientists are going to do more. They're going to try new things. They're going to build bigger brains. And like there is a line and we will cross it and we won't know that we've crossed it, you know?

Right. And well, and the thing about these organoids is that they're already crossing all kinds of lines.

You disrupt categories that we thought were so neat and tidy and distinguishable. life non-life human nonhuman human computer. We thought those were pretty clean categories, but this research is kind of upsetting the very foundations of what we think separates these categories apart. Does feel like it's like, oh, we've created a new category of thing like a a new category of thing that is maybe alive. It is alive.

We have created a new category of thing that is alive. That is that is that is that is weird.

Oh, yeah. It's hard. It's hard to actually put it into a category that already exists, I think, because because they're not actual brains that we can say absolutely certainly, but they're also not just a few neurons in a dish either. We almost don't really even have the words for it.

I think it's kind of a new a new thing. Lot of Nasser. This episode was produced by Annie Mchuan, Mona Madgaler, and Pat Walters. It was edited by Alex Nissan and Pat Walters with fact-checking by Natalie Middleton and Rebecca Rand. Special thank you shoutouts to Lynn Levy, Jason Yamata Hamp, David Fagenbomb, Andrew Verstein, Anne Hamilton, Christopher Mason, Maline Mason, Mari Arti, plus Howard Fine, and his whole team at Wild Cornell for hosting us. And if you're looking for more musings on the nature of life and what it means to be alive, Carl Zimmer has a terrific book out all about this stuff. It's called Life's Edge: The Search for What It Means to Be Alive. Get it at your local bookstore.

That's it for us. From our brain balls to yours, see you next week. Okay, start now. I was practicing. No, you don't need to. You don't need to practice anymore. We're recording now.

Hi, I'm Ellie Colms and I'm from Louisville, Kentucky. And here are the staff credits.

And she's Molly's niece. Yeah. Radio Lab is hosted by Lulu Miller and Latif Nasser. Saurin Wheeler is our executive editor. Sarah Sandbach is our executive director. Our managing editor is Pat Walters. Dylan Keefe is our director of sound design. Our staff includes Jeremy Bloom, Wary Fortuna, David Gable, Maria Paz, Gutierrez, Sindu, Nana Sambandon, Matt Guilty, Mona Mad Gaffcar, Annie Mcwin, Alex Nissan, Sara Kari, Anissa Vietz, Arion Wack, Molly Webster, and Jessica Young. With help from Rebecca Rand, our fact checkers are Diane Kelly, Emily Kger, and Natalie Middleton.

I love your giggle. Leadership support for Radio Lab science programming is provided by the Simons Foundation and the John Templeton Foundation. Foundational support for Radio Lab was provided by the Alfred P. Sloan Foundation.

Questions about this episode

Who speaks in "Brain Balls | Radiolab Podcast"?

Lulu Miller (Host), Latif Nasser (Guest), Dr. Meline Lancaster (Guest), Carl Zimmer (Guest), Dr. Howard Fine (Guest), Dr. Insu Hyan (Guest), Brett Kagan (Guest).

What is "Brain Balls | Radiolab Podcast" about?

The content explores the story of Dr. Meline Lancaster, a scientist who, while conducting a gene screening experiment on mouse neural stem cells in a Vienna lab, improvised by using an unconventional glue-like protein to facilitate her research. This decision leads to unexpected discoveries and raises questions about the implications of scientific experimentation and innovation.

What is mentioned in this Radiolab episode?

7 people, works and ideas are mentioned, including Brett Kagan, Sergio Pasca, Jurgen Kenobick, Nature, Wild Cornell Medical Center, Cortical Labs. Each one on this page links to its own page with every episode that mentions it.

How long is "Brain Balls | Radiolab Podcast"?

The episode runs 41 min; the transcript is about 7,241 words in 222 timestamped sections.

More from Radiolab

About this transcript: the episode's spoken words as captioned on YouTube, split into timestamped sections. Reclip.Me locates every person, work and idea in the text, keeps the time it is first named, and quotes the words around it verbatim. Last updated January 24, 2026.