StarTalk Radio - Epigenetics & The Full Story of Inheritance with Bianca Jones Marlin

Episode Date: September 6, 2024

Was Lamarckian evolution actually right? Neil deGrasse Tyson, Chuck Nice, & Gary O’Reilly learn about the new field of epigenetics and how the lived experiences of past generations can get passed down genetically with neuroscientist & epigeneticist Bianca Jones Marlin.NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free here:https://startalkmedia.com/show/epigenetics-the-full-story-of-inheritance-with-bianca-jones-marlin/Thanks to our Patrons Takwa Southerland, Harvey Davidson, Shawn D., Bob Race, Gabe Knuth, Carol Schutt, Micheal Ryan, Longman Foner, Christy Summersett, Cameron Bellamy, Colette, and Dee Tandas for supporting us this week. Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

So Gary, Chuck, I love me some neuroscience. Good. I think I'd be a neuroscientist if I were not an astrophysicist. Really? Yeah, I think so. What would your catchphrase be? Because you can't use keep looking up. Keep looking within.

All right, there you go. Keep thinking about it. No, it's just there's so many frontiers. We learned that trauma in one generation can manifest in generations yet to be born. Yeah. You can only learn that by studying the brain. Or my family. All that coming up on StarTalk Special Edition.

Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk. Neil deGrasse Tyson, your personal astrophysicist. And today it's special edition. You know what that means. We've got Gary O'Reilly.

Gary. Hey, Neil. How you doing, man? Former soccer pro. Allegedly. Chuck. Yeah, man. What's up, man? All right, man. Good. You know, I'm loving these special editions because what they all have in common is something about the human condition. Yeah. What it is to be human or what it is to no longer be human because a machine is going to replace

our mind, body, and soul. All of that is in special edition. Yeah. So today's topic, all of that is in special edition yeah so today's topic epigenetics and you gary set the stage here uh okay plenty of great ideas start with a question and podcasts for that matter right and that question would be what if so using what if the stresses and traumas experienced by your grandparents could affect your genetic makeup generations later? I don't want that to be the case. All right, hold that thought. I already know that's the case. Right?

You have to be my grandparents. They wouldn't let me forget that their stresses and traumas actually are affecting. That's a verbal doubling down. But even though those stresses and traumas will have taken place long before you were conceived, yeah, we're back on an epigenetic trail, but this time our destination is transgenerational,

not intergenerational. So it's transgenerational epigenetic inheritance. Yes, it's for real, it's a thing, and we may have found the sharpest blade at the cutting edge of epigenetic research. So having said all of that, please, Neil, introduce our guest. Are you saying we have a sharp blade sitting among us?

In a metaphoric way. I'm glad to know right now that the orderlies have said that that's not allowed. Dr. Bianca Jones-Marlon, welcome to StarTalk. Thank you for having me. Yeah, you're just right up the Thank you for having me. Yeah. You're just right up the street here at Columbia University. Yes. Oh, my gosh.

Good stuff. At the Zuckerman Institute. What goes on at the Zuckerman Institute? We study the mind, the brain, and the behavior of humans, of model organisms, and how the world works. What's a model organism? Model organisms. There's the ones that we really like that work really well for our genetic questions, like mice,

flies, non-human primates, like rhesus macaque and monkeys. But we also have non-non-model organisms, like naked mole rat, for example. Oh, a naked mole rat? You can't beat that. What's the difference between a naked mole rat and a...

New York City rat. A lot. One's brilliant. New York City rats are clones. One will steal your wallet. They're clones. No, no. You'll never see a naked mole rat with a piece of pizza in his mouth going down some stairs.

They're like, ew. Pizza mole rat. Right. So what makes the mole rat a different category of animal to study relative to the list you just gave? Yes, it's because we're looking at model organisms because we have a question that can pretty much generalize amongst organisms. When you have a non-model organism, like my good friend, Dr. Ishmael Abdu-Sabour, who studies as naked mole rats at Columbia, he's looking at pain. And the cool thing about them, they don't feel pain. They don't feel pain.

They also don't get cancer, and they live kind of forever. So they're outside of the paradigm of what you're investigating. I did not know that. They're also precious, but it allows us to ask different questions that we can't ask in my diet within two years. Your background is in neuroscience as it specifically applies in these challenges.

So first, let's just set the stage. We need to know what epigenetics is. And I know what an epicenter is. It is, you know, the part of the earth above, directly above where the earthquake took place. Okay, epidermis is the skin above all your body and organs. So what is epigenetics? Is something sitting above your genes?

Perfect, on the nose. No, I don't want to be the one who explains it. You did it so well. You just did. I don't want to woman-splain you what you just said to me. Oh, that's awesome. I want you to woman-splain me. No, no.

What did I leave? Surely there's missing content there. Go. Yes. And so our genetic code, this is our DNA. This stays the same. And the cool part, it's the same in every cell. Our genetic code is the same in every cell.

But we have eye cells, we have liver cells. We don't have eye cells growing in our liver, hopefully, and vice versa. And this is because we have epigenetic markers, same as the epicenter and the epidermis. Epi means above. So epigenetics means above the genome. These are big proteins, big markers that sit on the genome. And they say, nope, don't read this part of the genome or come read this part above the genome. These are big proteins, big markers that sit on the genome. And they say, nope, don't read this part of the genome or come read this part of the genome. And they change the way that DNA is wrapped around histones or sit in a space.

So it turns them on and off. Is that a way to think about it that way? Yes, I think you can. So the expression of the gene itself is dependent upon the epigenetic determination how much is expressed

and when it is expressed depends on the epigenetic epigenetic environment so here we have transgenerational epigenetic inheritance

how does that get inherited oh my goodness I mean if we all knew how it got inherited like that quickly

I think you'd be addressing me in my Nobel Prize. But since we're not there yet, but there are questions surrounding that. The problem is here, when you get your Nobel Prize, you're coming back here on the show. Okay. All right. Girl Scouts honor. Okay.

So there's many questions that are left unanswered when it comes to how transgenerational epigenetic inheritance works. I think we're at the space now in neuroscience where we are observing that intergenerational inheritance of an experience is pretty much canon now. We can say with my studies as well as others that an experience in a parent will change the way the offspring develop. And I'll be pretty specific with this. Experience in a parent. Experience in a parent.

Even before the child is conceived. Exactly. Before the child is conceived. So not a pregnant model organism. Because we heard that that can be influenced. You can envision a way. If you have a pregnant person that's pregnant with a female, the eggs of their granddaughter could be inside of them.

So you pretty much can be talking to three generations in one space. Okay, well, catch me up on Bio 101. So I knew that a girl born has all the eggs she'll ever drop. Yes. But how does the egg that she drops have eggs? Which means she has the genetics of her granddaughter, who will then make up the body and the eggs of the granddaughter inside of those eggs that's inside of the mom.

So it's basically like a Russian doll. Okay. All right. All right. I got two Russian dolls here. Okay. Pass me my Russian doll.. Okay. All right. All right. I got two Russian dolls here. Okay. Pass me my Russian doll. Oh, okay.

Oh, she's got a space station. Whose office do you think you're in? Why are you surprised? Here in the Haiti Planetarium, Neil deGrasse Tyson's office. Because it was a Russian doll. I turned around and expected to see, like, I don't know, like a babushka. Yes, this is the International Space Station. That's cool.

And inside there is Soyuz. Soyuz. That's how they get there. Okay, so each of these is sort of a genetic expression within the previous one. So is the left one. She wants me to keep going. The one inside of there. So let's say mom's space station had like stressful experience.

Yes. And then baby, what's on baby? This is Soyuz. Baby Soyuz. Yes. Yeah, baby Soyuz is probably going to be stressed. But baby Soyuz was there in the ether, right? Now we're talking about grandbaby. what's on Baby? This is Soyuz. Baby Soyuz. Yes. Yeah, Baby Soyuz is probably going to be stressed, but Baby Soyuz was there in the ether, right? Okay.

Now we're talking about Grandbaby. Who's Grandbaby? Okay, I don't know what this thing is. Nor do I. It's sci-fi to me. Okay. So this is now Grandchild. Okay.

It sits well with, I don't know. That's how messed up she was. This is way too transgenerational. We're not talking about Great Grandchild. I don't know anything about this yet. All right. So then the last one here, we're now four generations in. Yeah.

And guess what that is? Oh. Sputnik. Sputnik. And it's Russian all the way through. Oh, look at that. That's a good one.

So you're telling me that some parts, some elements of all of our behavior is not our fault. Ooh. I'm saying that in some

model organisms. She was like, ooh. Okay. So'm saying that in some model organisms... She was like, ooh. Okay, so listen. Because my kids are listening to this, okay? Like, no, that's on you. Wait, wait. Let me not be so negative. Are you suggesting that some components

of our character, personality, demeanor, and the like is traceable to forces that occurred outside of the lives we've lived? What I'm saying is that in some model organisms, there's an experience that can happen in a parent that leads to epigenetic changes, that leads to changes in development of offspring. Now, we've demonstrated this in worms.

My lab specifically looks at mice. When it comes to humans, the best study surrounding, the most studied topic surrounding intergenerational and transgenerational inheritance comes from after World War II, the most studied topic surrounding intergenerational and transgenerational inheritance comes from after World War II, the Dutch hunger winter. So this is a period of time where the Netherlands were cut off from food and it led to a man-made famine. So this is also, I think, something pretty particular. We're not talking about it. Really? Yeah, 1944 to 1945.

Yes. And then the generations were suffering from serious medical conditions, diabetes. Diabetes, hypertension, even schizophrenia. Not just for the children. And we're speaking about young children who were starved, but were not pregnant, were not procreating, were starved. They went on to have children, who went on to have children, which is our generation now. Like the generation of these people are alive now. And what we observed is that, what other studies have observed, this is not generation now. The generation of these people are alive now. And what we observed is that, what

other studies have observed, this is not what my lab particularly does, is that there's an increase in hypertension, diabetes, schizophrenia. And I also think it's very particular to... I think the Dutch were black. I was just going to go there. This is a man-made famine. This is not something that's tracking with

the environment in a way that all things are aligned. This is a man-made famine. This is not something that's tracking with the environment in a way that all things are aligned. This is a man-made famine. So you can envision a space where you have a man-made famine, a man-made decrease in food, increase only in salted food because that's all you have access to. Salt reserves food. Yes, exactly, yeah. Plus a lot of stress, I would assume,

if we're talking about the black population prior to the 1900s, and then introduce food deserts and access to low-quality food. We can envision an epigenetic space. Yeah, so a food desert is a common terminology that we use for a space in which there's not fresh food available in like an X-block radius,

like a walking radius. That's a food desert, okay? You can get McDonald's before you can get broccoli. Okay? Chuck has defined the food desert. I'm Ali Khan Hemraj, and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson. So you've got this Dutch winter famine in 44-45 as a real-time observation.

A data set. Yeah, and I think it is possibly the only one that's been able, sadly, created. famine in 44, 45 as a real-time observation. A data set. Yeah. And I think it is possibly the only one that's been able, sadly, created so far. It is the best study. And this is because the Netherlands took very clean note of who served in the military. So they started to see these data come about. Now we know that there is a Chinese famine that took place. We, of course, can look at the black American and Native American population

and tie food deprivation with stress and look at health outcomes. But this one is well studied in a short period of time. If we take that and use that as a starting point, your research at your Marlin lab... What a coincidence. You work in a lab called the Marlin lab. Voila.

I chose well. I heard the boss there is great. She's fab. What a coincidence. Exactly, yeah. What are the odds of that? So your research covers a number of things, but what about this epigenetic inheritance?

What is your research about? What is it finding? And how are you finding it and going about getting results? Yes, we spoke about the Dutch hunger winter and Black America. And our work is really motivated on how do we make tomorrow better than it is today? What does it mean to be a human in this space and in this place? Have experiences that are both positive but also negative. How that affects the way the brain develops, the body develops.

How that affects offspring, interactions with offspring and how does that affect therefore communities which affect the world that really is the heart of what we do in the Marlin Lab and if you didn't get it, the Marlin Lab is my lab yes, and so I take my passion for figuring out

how we can make tomorrow better than it is today and my love for science biology and neuroscience and bring this together. So although our mission is to aid the world in this way, we use model organisms such as mice and techniques such as studying epigenetic inheritance to get to this answer. So how do you, I mean, okay, if we're back to trauma, what are you sadly doing to mice to inflict trauma and how do you then balance that out to see how these changes take place? Well, first we paint the mice black.

That's the first thing we do. You know what the sad part is? Oh, gosh. They're called C57 Black 6. Those are the name of the mice. It's just like in the name. Every time you write it down, we're like black mouse. Yeah.

Oh, what a shame. But we treat them very well because we really want to see. Except we will not allow them to get a mortgage in certain areas. We do redline them. Time for our first commercial break. We'll be back after we reset. You cut off parts of the maze. A maze with no exit, right?

Just messing with you. a maze with no exit just messing with you because we want to see what is the bare minimum that you could do to create an epigenetic change we really try to do the bare minimum and we also respect the fact that every mouse that is part of

this experiment and experience is a mouse that we're asking them to dedicate their life to this experience so we do take that very seriously did she say she's asking them? they have names after underscore black six they have a name, we give them names we're asking them to dedicate their life to this experience. So we do take that very seriously. Did she say she's asking them? We do. Look, they have names. After underscore black six, they have a name.

We give them names. Okay. There's Tyrone. You're going to get me in trouble here. I am forbidden from saying anything right now. Yeah, you better. Malik is my favorite. Leticia.

Guys, okay. I'm pulling it back. Go ahead. Y'all are going to get me in trouble. All right. So they pretty much have a pretty regular mouse life, right? They hang out in a cage. They get food.

Sometimes they get to have sex. They live their best life. This is what they do. So there's not many dynamic things happening in their life when they're here in the lab. What we do is we place them into a new chamber. So they haven't seen this chamber before. We then introduce an odor, a smell. This is a smell.

It kind of smells like almond. It's called acetophenone. And we present acetophenone for 10 seconds, and then it co-terminates with a light foot shock. We give them a light foot shock on their foot, and they jump back. But in a mouse who pretty much has had the best life of eating, drinking, and hanging out. This is a

terrible thing. Yes. It's a big deal. This is when they find out, oh my god, I'm black. This is the moment. When did you find out you were black? One day I smelled almond. I smelled some almond and I got a shock.

Good shock. So they're like, what is happening? This happens five times in a row. And then we put them back in the cage over the span of 10 minutes. Okay. Oh, wow. We put them back in the cage and we take them out the next day. We put them in the chamber.

You could already tell. Just from the chamber itself. It makes them apprehensive. Yes. They freeze. It's called freezing. Mice do two things. They'll either freeze or run away.

Those are their two responses to stress. So they freeze when they get in. We have not given them the odor. They already know the room is already stressing them out. So then they get kind of chilled with the room, like, okay, nothing's happening, and then we turn on the odor and they freeze again. Of course.

Even before you shock them. Right. And they're counting down for the foot shock. And so they freeze, freeze, freeze when they smell it, and then they jump because they get the foot shock. We do this for 10 minutes a day for three days. There's many things you can use,

many things neuroscientists use to create this pairing, like odor, or we can use sound. We use odor for... Sensory correspondence. Sensory correspondence, yes. And I even said the vision,

like going into the chamber will also make them scared. But we use odor for a very specific reason. And I can either tell you now or you can ask me and I can tell you. What do you want me to do? No, let's do it. Do you know what we got? Keep me guessing. Okay. We use odor because odor is just a really cool sense. The lab studies smell, taste, and sound, these three. In focusing on odor, when you breathe in, you respire,

you're smelling my lovely Aqua de Parma perfume, right? And you'll remember this moment forever because of this. This is how we interact with the world when you breathe in there's some neurons that interact both with the world and with the brain these neurons are called olfactory sensory neurons they're first order neurons that explore the world and also can send a message back to the brain

and I was lucky enough to train under Richard Axel for my postdoc, he won the Nobel Prize for understanding, he along with his postdoc. He won the Nobel Prize for understanding. He, along with his postdoc, Linda Buck, won the Nobel Prize in 2004 for ironing out what it means to have a mammalian sensory system like the nose. What we see in the nose is that every neuron in the nose expresses only one olfactory receptor.

So it could pretty much only respond to a chemical that binds only to that receptor. Wow. So there's a level of specificity. And speaking about epigenetic inheritance and transgenerational epigenetic inheritance, what does it mean for us to be stressed because of our ancestors? This is what we're missing in the field.

And I'm so proud that my lab has been able to bring this to the field, the level of specificity. Because we're not talking about your feelings getting hurt. We're talking about an odor that only binds and activates this one receptor in this nose. And what we've been able to replicate, because another lab did this first and it came up with a lot of controversy, and then demonstrate to a finer extent, is that those neurons that smell that almond, you take that mouse out, not the moms, only the dads, you breathe them

and you look at the next generation. And those generations are born with a different olfactory sensory. Get the hell out of here. So how do you... That is insane. It's not as if you can look up the nose and say, oh, you've got more, or you've got the same. So how are you testing?

How are you finding your results to prove? Yes, we have a really cool new technique. Thank you, yes. Yes, that is. I mean, that's really... Let me back up just for a minute. Yeah. You described the experiment as though it was written on a tablet somewhere, but you

had to sit down with either yourself or with colleagues and figure out what would make a good test for the hypothesis. Right. That took a lot of time. I just want to give credit. Thank you. It's easy to put them in. No.

Give them all. No, you have to think that through. I mean, that's just tremendous. Okay. And you want it to be simple enough so that there's not a lot of complicating other factors to isolate the causes and effects. Right, right, right.

On the nose. That's so great. And it's not an easy part of the brain to get to. We created techniques and we use techniques now in the lab. We do brain clearings. We can clear the entire tissue. Okay. Yeah, I'm listening. You know, clearing, so we can clear the entire tissue. Okay. Yeah, I'm going to see.

I'm going to listen. And use light-sheet imaging. That is so cool. Brain clearing. Brain clearing and light-sheet. Straight up, they clone Tyrone stuff. That I'm not sure. Transgenerationally, yes.

It's like a little transgenerational Tyrone. So, how exactly and where exactly? That's going to be the name of my first book, like Transgenerational Tyrone. Intergenerational Inheritance of Trauma. So what's the brain clearing though? How do you get to that space? I totally skipped a part because we're seeing that the offspring have a brain that looks like the parent. But I didn't tell you what the parent brain looks like.

We take the animal out of this chamber after three days of odor shock pairing. We actually let them relax. Day 10, they actually get to have a little fun. They breed because we're going to look at those kids later. 21 days later, we ask them to sacrifice their life and then we look at their brain. If you look at the animals that just got an odor

and no shock, or just got a shock and no odor, or got odor and shock but it's not co-terminating at the same time, their brains all look the same. The paired animals, we call it. The animals got the odor co-terminating with the same time, their brains all look the same. The paired animals, we call it. The animals got the odor co-terminating with shock. They have more neurons that respond to that odor. So I want to give a second to give the beauty of biology

that sits there before we even get to the next generation. The brain takes energy to make new things, to change. And we have more neurons. It's an electric device, so it makes sense. So what period of time does it take for this generation of more receptors to actually happen? We are seeing it in the order of 21 days, about a month. Cool part about the main olfactory epithelium, there's stem cells in this area.

That's the part where the smell manifests? Exactly, the neurons that can smell the world and then send information to the main olfactory epithelium. Epithelium. There's another epi. Look at that. Epithelium, good, okay. And so this tissue, it has a stem cell population. There are very few areas of the brain that have stem cells.

One is the hippocampus, an area known for placement and memory. One is the olfactory bulb. This is where these neurons send the information to that go to other parts of the brain. And the mannol factor epithelium. So there's neurons that are there. They're not neurons, I take that back. They're cells that are there.

And they're like, what am I going to be when I grow up? And they usually hang out and they're like, okay, I'm going to be a peppermint cell because that's what my epigenetic modifications will allow me to be. And then we give them this experience, this odor shock pairing. And what we've gone on to demonstrate, what my labigenetic modifications will allow me to be. And then we give them this experience, this odor shock pairing. And what we've gone on to demonstrate,

what my lab has demonstrated, is that these neurons are going to be peppermint. Say, as important as peppermint is, almond's more important. I'm not going to do that. I got to make a detour. I'm going to bias my receptor choice. I got to make a detour

because that's more important for me. Because now I have this experience that becomes a stimuli, basically. It is a stimulus. It's insane. Wow, you're brilliant. Thanks. Just on the same mouse page, how long does it take a newborn mouse to be old enough to have a next generation?

It takes about six weeks. So a mouse is born. Six weeks later, it can get pregnant. Yes. And how long is the gestation period? 21 days. That's why you said 21 days before. It just happens to be a coincidence that also 21 days is a good time in the nose.

And the typical life expectancy of a mouse is a few years? Two years in the lab. Two years. A year and a half, yes. Two years, okay. In the wild, a lot shorter. Yeah, because they're tasty snacks for owls and foxes and things. So I guess what I'm getting at is mice, which are interestingly genetically similar to us

because we're mammals and vertebrates and this sort of thing. I get that. But what would take us decades to manifest as an organism happens in weeks in your lab. So if you need to go through multiple experiments, it's way more efficient. People also study flies and worms, and they can do this seven generations in two weeks.

So we're dead smack in the middle. It takes a while to get to the transgenerational part. That's why flies and worms show up in these kinds of conversations. You would not do it on Galapagos tortoises because that would just take too long. Zero percent chance. So you conduct this experiment with an adult. Yes. How many generations will this be present, this change? We are observing it right now from parent to

offspring, from sperm of male to offspring. Our preliminary data suggests that this is not carried on to the next generation if you do nothing to the parent. And this makes evolutionary sense. If your parent has gone through a trauma and you have not come across this stressor or trauma in your lifespan, why would you give your offspring anxiety? Why is it that you would pass it on to the next generation if it's not relevant?

Biology is smart. It's smarter than us. And so we sometimes speak about this in a lens of fear. We don't want this. But really, I view it as biology wanting us to survive. Because if you have more neurons in the next generation, you probably can sense this odor

more quickly. It becomes a defense mechanism in a manner of speaking. Adaptive in a way. And I wouldn't call anxiety or stressors in this area adaptive, but I do think biologically, the hope is that it becomes something

that will allow the organism to survive. It gives a defense mechanism that wouldn't otherwise be there. And it needed it for the almonds even though why would you need to defend against almonds except you in your lab gave them the electric shock.

Because that's what the world looks like. The world is dynamic. It's always changing. There may be times where something that originally is neutral becomes something that has to be aversive, and your brain has to learn that. It's the beauty of being able to learn that,

having your genome learn that, and having that be passed on. So if your generations are in the same environment that caused all the trauma and stress for the original parent, and it stays like that, understandable, you've got the mechanisms that you should be able to survive. But what if that environment changes, and you don't long lead surely you've got a slightly maladapted series of offspring

it's the question of maladaptation i cannot create a space in my mind that would describe biology being maladaptive okay because what if that odor did come back right like odor could never come back, and then yes, you probably have a few more neurons, you maybe smell a little bit less peppermint, but what if that odor does come back? Because not smelling peppermint won't kill you, but not smelling almond could. Yes, see that?

And that's evolution right in a nutshell right there. Happening much quicker than we normally would. We describe that, it's not epigenetic, but in the skeptics community, we describe why it is we are so good at seeing patterns, even when there's no pattern there. And it's been plausibly traced back to, if you think you see a lion in the bushes, and you run away, even though there wasn't a lion in the bushes and you run away,

even though there wasn't a lion in the bushes, you live another day. Voila. If you don't think there's one there, and there is, then that's the end of your gene pool. Game over. So there's a benefit to the caution, to be on the cautionary side of all of this.

Let's throw it into the moment. We have a war in Ukraine. We have a war raging in Gaza. Both with huge tolls on the next generation. The stress and trauma must be unimaginable for the likes of me and anyone else I'd imagine.

Are we likely to see future generations experiencing all sorts of issues like we did with the winter famine. It's a scary thought. It's a really sad and heartbreaking scary thought. It would be the new black people of the world.

Yeah. This is generations on generations, right? And I do think, and I would love to add, my hope as a neuroscientist is that biology is adaptive and wants us to survive. And so although there is going to be an element of inheriting the man-made

trauma, right? It's not ethological trauma. It's man-made trauma that we are having. Notice that phrase hasn't become degendered. Man-made trauma. I said what I said. I was going to say that. I didn't stutter.

It's kind of hard to be gendered that way. It's a human-made trauma. Exactly. Political, man-made trauma. You know, deal with it. I would want to finish

the fact that we can still learn. And so my hope is that in understanding what's happening with these mechanisms that the Marlon Lab is studying,

we can also understand a little bit more about what it means to readapt when things are not in a state of trauma. That's what we hope to bring forward. So not all hope is lost. Is there a difference in heritability between the male who experiences the trauma and the female?

The female is carrying eggs, but the male produces sperm. Can we sit on that for a second? This is the part that makes me excited about science. The mannifactored epithelium turns over on the order of 21 days, maybe 40 days. So like there's a neuron, it's born, live your best life, you're dead in 40 days. And a new one comes in. In humans and mammals. Why does it die away?

So for example, maybe if anyone's had COVID over the last few years, you'll come to know you can't smell. But then after a while you begin to smell, right? Because there's a turnover. Or you smell things that you're not smelling, like gas. Okay. I'm sorry you had that. That was my experience. I kept saying, who left the stove on? I'm running around the house like, someone left the stove on.

And they're all looking at me like, what is your problem? Terrifying. We have an electric oven. But now you can smell fine. If you ever, maybe when you played soccer, you probably headbutted a ball. And for a period of time, you probably couldn't smell well or your taste was kind of funny.

But now I can see what you're saying. There's a direct cause and effect. Because those neurons send their dendrites, so the part of the neuron that takes in information, out into this area in the nose. Remind us of the parts of the nerve cell. Yeah, so we have the cell body that's represented here by my well-manicured hand. And then we have the dendrites here.

The dendrites sit out in the ether of our nasal cavity. And so as we breathe in, as we respire, we get these molecules. They bind to the dendrites. And the dendrites are those looking like tentacles coming off of the cell body. Exactly. Go ahead. And then they'll send this message to the cell body that says, okay, there's enough of these molecules that are bound. Let's make this neuron fire electrically because neurons are both chemical and electrical.

And so it'll fire electrically and it sends that electric signal down the axon. And then it ends in what's called the manufactory bulb. So this is when it starts sending information to the brain, to places like the amygdala, which represent emotion, places like the piriform cortex. So this stimulus gets shared with parts of the brain that can take action on it. Yes. Is that a fair way to characterize it?

Yes, exactly. And this is important because it turns over every 21 days, 21 to 40 days. So do sperm. Right. Our data has demonstrated that when you mate an animal 40 days after the odor shock pairing,

we still see this change in the next generation. So that's got to be the female. Females are never shocked. We would never do that in the Marlin lab. How does it go beyond? Exactly. It's something happening

that gets down to the sperm. Right. It's being stored. And even new sperm creates the sperm. In the cellular level. Yes. In the gonads. In the gonads.

The epididymis? Is it epididymis? Oh, voila. Epididymis. Yes. In the epididymis. That's a word. Epididymis.

It shouldn't be. Epididymis. It's epididymis. Yeah. It's epi again. It's your epididymis. Don't go technical on me. Epididymis. Epididymis. The epididymis. Don't go technical on me. Epididymis?

Epididymis. That's the what? The thing that creates sperm. The epididymis is an area inside the testes in which immature sperm, so like their sweet baby sperm, they go into the epididymis and they get what's called an epididymisomal payload. This is not the work that we have pioneered. This is work that others have pioneered that demonstrate if you have, for example, low food. So in metabolics, it's been demonstrated.

There is a payload of information that comes from the liver or that's in the liver and also found in the epididymis. And what happens is these sperm go through the epididymis, they mature, they get grown, and they also get this payload, the epididymosome, that says you were starved. And they bring that down to the next generation. Yes. So I, years ago, and maybe you'll know this and I can't, I'm so sorry, but I read a study. You were trying to look it up?

I was trying to look it up, but I was trying to look up the study itself. And it dealt with sperm production and cocaine use in men. Do you know the study I'm talking about? I believe I do. It was done at Penn? Yes. Yeah. Yes. Yes.

And it was fascinating because the men were passing the information on in their sperm that equated back to the cocaine use. Wow. And it was just fascinating too, but this is exactly what we're talking about. So what you're saying there is outside of a stress trauma,

certain environmental circumstances can have an effect on the way the epigenetics are altered. We do know that stress and trauma do exacerbate this. So there's cocaine uses lifestyle. Yes.

There must be all sorts of other things. I'm guessing environmental pollutions and all sorts. So do you have a list? I mean, can you rank list of avoid this because it'll mess up your gonads? Well, we don't want to say mess up. People will respond to that list. It may not be mess up.

It will change. Change is not always bad. That's true. Are you willing to take that experiment on to see if it goes good or bad? All right. So what has risen to the top of people's research efforts are studying the bad effects. So give me an example of something that could be a good effect in the epigenetic transgenerational. Could I give you something that would be an example of a good effect?

I think a good effect is biology saying if it ain't broke, don't fix it. Right? Like it may not be that we need to. So the good effect is the neutral effect. Yeah, the neutral effect is, right, yeah. Now studies are going on. You spend a lot of time on a yacht and your children come out going, what? Oh, damn.

Mom, I'm so terribly, terribly hungry. The starvation threshold is different when you're on a yacht. For example, just as an example, it's long been known that suicide rates are higher

among people who are less traumatized. Suicide rate for black Americans was way lower than for white Americans, especially wealthy white Americans. And black females is the lowest. Of course, those numbers are creeping up a little recently, which is a sign of more equality, I guess. But... Wow. We finally made it! What a metric!

We did it, guys! I was angry as a white male. Okay, cool. I don't know if this question is relevant or even interesting, but as they say, your biggest problem is your biggest problem. So if you're on the yacht and there's a delay in the caviar and you have a big party you're trying to put on, you could be very stressed by that. Don't judge my trauma.

Don't judge my trauma. My trauma is my trauma. To the therapy session, your trauma is your trauma. From a psychologist's lens, yes. The biggest deal in this mouse life is that it got its foot shocked. We all stubbed our toe at some point within this last week. We're not really going to remember.

It happens often. But in the dynamic of this mouse, yes. I'm coordinated, okay? Sorry, I'm not going to apologize. Yes, I can see the biggest problem being the biggest problem. I think when we think about looking at humans, we have to take culture into consideration.

And that's what we separate when we study mice. Why we have a model organism like mouse is because we can control everything else. There are definitely cultures in which the morbidity associated with suicidality is higher. My mother's from Guyana, South America. At some point it had the highest suicidality rate. It no longer does.

I think it's number three now. In the world? In the world, yes. And we saw that there was a trend with the three major populations, which are Indo-Guyanese, Afro-Guyanese, and Chinese-Guyanese, or like Asian-Guyanese, as well as the native population. And it was higher in the Indo-Guyanese. But there are also different cultural aspects of being Indo-Guyanese.

So I think it's harder to parse that out. So you've got to get the basic science in there first before you get sociological. Yes, before you jump hands down. I think it's wise. Interesting. Of course. It's wise and respectful. Otherwise it's a big tangled mess and you don't know what your causes and effects are.

And no one can fix anything. What happens if the shocks were generational and continued? Yes. So right now what we are observing is an intergenerational change. But what if the environment doesn't change even in the next generation or the generation after that? This is when we can start to envision a space where what we're looking at is an actual evolution change, a change in evolution and not just an epigenetic change. Interesting. Because if what, and we have not demonstrated this nor have other labs, but it could be the space in which

for seven generations, you get the odor foot shock. Right. And then you have other labs, but it could be the space in which for seven generations you get the order foot shock. And then you have the eighth, you'll expect to see the change in brain. What if you do nothing to the eighth and then look at the tenth? Is this when it finally has stopped becoming intergenerational and finally overrode? So in that twelfth generation, what we see is the same

expression that we did in the eighth and the seventh, but we created that eighth and seventh. And now it we created that 8th and 7th. And now it's just happening. But wait, wait. But that smells Lamarckian here. People say Lamarckian as if it's like that. Okay, well, okay, let me do right by Lamarck.

You got to do right by Lamarck, okay? Jean-Baptiste Lamarck came maybe half a century before Darwin. You also want to give credit where credit's due. Darwin's work is built upon what Lamarck came half a century before Darwin. You also want to give credit where credit's due. Darwin's work is built upon what Lamarck studied. If I could put that in a nutshell, pretty much what Lamarckian inheritance would describe is a giraffe walking in its giraffe space, and it sees green leaves on top of a tree,

and it's like, okay, I really want these green leaves, so I'm going to hope and wish and stretch and try to get those leaves. And just try to get the leaves. And as you try, your neck gets longer. And then you have a longer neck. Voila. And the next generation is even longer.

Exactly. So it's a quiet characteristic from things that happen. Based on your circumstances or surroundings. Yes. Exactly. All right. Whereas Lamarck, I mean, Darwin says, you were born with a long neck. You eat all the top of the leaves.

All your cousins die with short necks. And now you get to breed more and have a never a long neck. You eat all the top of the leaves. All your cousins die with short necks. And now you get to breed more and have a never as long neck. And you were selected to remain because your neck was suited for eating trees. And everybody else died. And it doesn't mean that it's one or the other. It does not have to be nature versus nurture in this space. It could be an end or. So is this adapt and survive?

Or is that just too broad a stroke? I think this is what comes back to how many generations does the smell continue on? What we can say is that studies that went on after Lamarckian inheritance became a concept where scientists would go in and they would say, okay, well, let's see if Lamarck is real. We're going to go take this mouse.

We're going to cut off its tail. And let's see if the next generation is born with no tail. In fact, let's do it for three generations. We do not do this in the lab. Let me clarify. But for three generations, you cut off the mouse tail. We do it with po tail. In fact, let's do it for three generations. We do not do this in the lab. Let me clarify, right? But for three generations, you cut off the mouse tail and you see...

They do it with poodles. Don't apologize for not doing it to mice. Okay, exactly. And poodles are still born with tails. Yes, with long tails. They cut them short

to make it a little bushy tuft, but... Right. So they said, okay, Lamarck is wrong. But what they didn't study is are the mice now afraid of the scientist

who comes in with the lab coat and scissors? So what are we really focusing our question and answer on? Because that would be a psychological trauma, not just a physical change. Let's turn this around, because we've talked about traumas. We're going to cut the tails off young animals, right? How cute, how wonderful. What if you get exposed an animal to something pleasant and continued that pleasant exposure, do you find that that becomes a more balanced, a happier creature? Kumbaya.

I know, this is not going to happen anyway, right? But is it possible to have other things transferred, not just trauma? If I were to have a conversation with biology, I think what biology would say back to me is like, let's survive so we can thrive. All right. If sugar is good, if flowers smell good,

we're good. But do you have conversations with biology? All the time. All the time. And it speaks back to me. Okay. In the way neurons fire.

Science is so beautiful. All right. But what we think is happening when it comes to a stressor is that there's something called coincidence detection. And we talk about this as electrophysiologists

who record from neurons in the brain when one neuron fires and another neuron hears that firing and also fires, it's coincidence detection. We have an animal who's smelling the environment so those neurons are firing and it gets a shock. That's another pathway that's now firing the same time those olfactory sensory neurons are firing. If we have something pleasant,

we could have the smell of a flower and maybe some dopamine be released and that could be paired. But it may not be... Dopamine makes you feel good. Dopamine's a neurotransmitter that makes you feel good. But would that be enough of a threshold

to say, now let's take all the energy necessary to make sure animals smell flowers more? It's already roped into what the pleasant circuitry looks like. But I think the best way to answer that question would be, let's override it with something really good. Let's give them some good cocaine. Right?

Because it's so good that it's bad. How does that change the next generation? That's the way I would approach that experiment. Is that true with most things? They're so good, they're bad? Well, yeah. I mean, sugar is certainly what, like, you know, we, there are sugar receptors in our stomach, on our tongue, in our brain. But why?

Because it's essential for survival. It's got high calorie density. Exactly. But at one point. Then it gets hijacked. But it was scarce. By candy bar companies. But the scarcity is what allowed it to be, oh, it's so good.

And hey, I got to get this because you're not going to get it. But now that it's abundant, now it's a bad thing, because you can get it all the time. Right. Because it's subject to abuse. Those same receptors have been hijacked by modern civilization. Right. So you would agree or possibly even lament that these features of our adaptability in modern times, if you don't need that adaptation, yet you still have manifestations of it, a clever advertiser or a clever marketing person can hijack those sensory urges. Of course. Yeah.

Absolutely. And whose responsibility is that to fix that? So, we've discussed Chuck's need for sugar. He quite needs to survive. Senses, sight, smell, taste, they're all sensory. So it's all survival.

This whole thing of epigenetic inheritance is... Survive to thrive. A simple umbrella to my mind is survival. Yes. And so therefore it's as necessary as oxygen. Oh, hands down. Hands down.

Sweet. Oxygen to aerobic... Yeah, to aerobic. Yes. They're anaerobic life that doesn't want oxygen, just to be... We're being speciesists. We're just only talking about the important ones.

We're being speciesists. Correct. No isms so let's let's see if we can land this plane this fascinating plane let me be cynic here so what now you understand the phenomenon what are you going to do about it an entire generation of people survived the depression famine uh, racism, slavery. Can you do anything about it other than just come behind us all? Is that, well, here's why you're that way, and then go back to your lab. Meanwhile, Chuck has hypertension. He's got issues. Anxiety, anguish. He's got race issues.

Prostate. Prostate. All kinds. Okay? If you can't do anything about it, what good is this? And if you can do something about it, then are you playing God? I think that's a twofold answer. One is for the love and need of understanding science,

and the other one is for the love and need of understanding people. If there was a space in which someone who had gone through trauma, ancestrally, and then are born here in modern day and are suffering from all these elements, even though they eat healthy, they exercise, they still have hypertension, they still feel this anxiety. I believe to have a neuroscientist say to you, you can take that burden off of you. It's not your fault. This is just the way that you've inherited experiences of your ancestors. That validation within itself will probably create a shift for better. So that thing there,

it's not your fault. It's not your fault. I mean, I just heard you talk about sugar, so maybe that one is your fault. It's not your fault. It's not your fault mantra. It's not your fault except the sugar. That part.

That runs deep. That's great. And I think the other is, if we have to understand what's happening in a maladaptive situation, quote unquote, in a bad situation, we have to understand the basics of biology. We can't fix something unless we know how it broke. In the hit series, The Expanse, there's talk of adapting a life form that can just simply live in the vacuum of space. Because that's a new frontier where a lot of people are hanging out in all the time.

because that's a new frontier where a lot of people are hanging out all the time. So I'm just wondering, generally in science, if you understand something, ultimately you can manipulate it and control it. Yes. Is there a plan for that going forward? Where you can go in and nip, tuck, tweak, pinch, and all of these symptoms go away, thereby removing the epigenetic forces operating. If we understand it, can we nip-tuck?

In the same way, if we understand the need for sugar, should we pound it into our food and candy and give it to our children? I think it has to do with the responsibility of scientists to say we now have the ability to do a little nipping and a little tucking, but do we understand how this is going to change generations to come if we take out the ability for you to change this adaptation?

You could doom a future generation to not want sugar and then they won't even have the unintended. Or not smell this smell and not have anxiety but then constantly get slapped up. That's a really good answer. I can't even rebut that. The unintended consequences. Why are you giving me such a good, man, I got nothing to ask you now. You answered my question so good. That's why the good doctor is here.

I know, I know. To give the good answers. So I love everything you've described. Is there any controversy among your colleagues about what you're doing? Are there competitive ideas? Where does your work fit in the landscape of neuroscientists? It is dead smack in the center of the controversy.

And a lot of it has to do, A, with what we're taught in textbooks and what we decide is canon, decide is truth. And then we see that maybe Lamarck wasn't all wrong and that really draws people's brains. So our job as neuroscientists is to say, put your textbook aside, this is the data. Let's look at what our studies have demonstrated and take it from there on a clean slate.

But presumably there are other labs. If you publish what you do, it's then reproducible. So why should anything be so controversial as what is poking mice? I think on a very important note of this reproducibility. Unless you just have special black mice that nobody else gets.

Don't stop. Poor Tyrone. What is your name of Tyrone? Are any't stop. Poor Tyrone. We are. What's your name of Tyrone? Are any of your mice named Tyrone? I can't answer the question now because you know who it is and I can't say it now. So, of course. But I will say that my lab was the first to replicate this study. Okay.

Of the original change in the parent. Fantastic. This study. That's a start. Yes. Brian Diaz and Kerry Russell. They got a lot of fire for it because. They got a lot of fire. They got a lot of fire for it. They got a lot of fire.

I entered into the flames thinking, first things first, can we replicate this? Cleanly, using our brain clearing and using our cool microscopes, we've been able to replicate that. We then built upon it by showing this is the mechanism. I think that, unfortunately, we have to sometimes wiggle our brains out of the old mindset

and just look at the data and see what that looks like. I think that's why shows like this are so important because you're motivating people to think slightly differently and have that little different of a spin. And that can take things in a different direction. The way the cutting edge of neuroscience works. I mean, when you look at addiction, just addiction alone, the work that has been done to prove that addiction

is not a matter of willpower. It's not a matter of desire. It's actually a matter of desire. More going on. It's actually a brain malady. I mean, if you had told somebody that 30 years ago, they'd have laughed at you. They'd have said, you're a quack. And now it's just accepted.

So, yeah, keep going. This is great. That dovetails with the free will question. Right. How much are we actually in control of our body, mind, and soul? Right, and how much of it is a chemical response? Right. And how much of it is man-made?

Right, well, that's where... This is man-made, yeah. You've introduced an entirely new aspect of the conversation. I only bring the data, yeah. I only talk about the data show. So cool. Now, we have to ask,

because we like neuroscience and StarTalk Special Edition, so we're compelled to ask, how much genetic control do you have over your husband? I rely heavily on epigenetics. My relationship with my husband and my children. Completely obedient household. Epigenetics and prayer.

That's so funny. That's so funny. Thank you for sharing your expertise. And you're just up the street in Columbia. Yes, I am. We've got to come back. Yeah, just a couple miles north of here. We're at the American Museum of Natural History.

And you've got your own lab. And there's more research going on in different areas in the Marlin Lab. So we may well be revisiting soon. Okay. All right. Dr. Professor, thank you for joining us. Thank you for having me. Chuck, always good to have you, man.

Always a pleasure. All right. This has Professor, thank you for joining us. Thank you for having me. Chuck, always good to have you, man. Always a pleasure. All right. This has been StarTalk Special Edition. Neil deGrasse Tyson, as always, bidding you keep working up.