Hello, and welcome to Ask a Scientist, the podcast for kids and adults to ask scientists questions about anything they want to know. There are so many scientists out there doing a lot of cool scientific research. In the news, we’re constantly hearing about scientists and their ideas and where these ideas are going to take us in the future. But just who are those scientists? In this podcast, we will learn a little more about who they are and what inspires them as scientists.
I’m your host, Victoria Crystal. Every other week, I’ll sit down and ask a different scientist questions written by you, the listeners, and by students from classrooms throughout the country.
Victoria:
Hello listeners. Welcome back to the next episode of Ask a Scientist. Our guest this week is Dr. Heather Brown. She is a biologist who studies the brain and the spinal cord.
Dr. Brown, thank you so much for being with us today.
Dr. Brown:
Thank you for having me. I’m happy to be here.
Victoria:
We are so excited to hear all of your answers, but before we jump into the questions, would you explain a little bit about who you are and what your research is?
Dr. Brown:
I would love to. So my undergraduate degree is in Basic Biological Sciences. And then from there, I actually worked at Chobani, the yogurt company, doing microbiology work and quality assurance where you’re basically testing the yogurt throughout the production process to make sure that there’s no contamination, and that it’s safe to sell. From there, I really became interested in that process of doing science for real-world application. Because we’re testing this product, the yogurt to see, you know, is it safe to sell? Is there contamination in it? And I really liked being a part of that link between science and the real world.
And so that really led me to wanting to go to graduate school, to become a scientist so that I could do this on different projects for, as my career. And so I was looking at graduate programs and seeing, you know, different programs that were out there and types of research to study. And I, also tidbit about me, I’m an identical twin. And so for my whole life, I’ve really been interested in embryology and how, you know, our bodies form and our organs form. And that brought me to the University of Colorado, where I joined the lab of Dr. Lee Niswander. And her lab studies the formation of the brain and spinal cord, and so my project stemmed from her lab, or I studied a specific genes and the environmental interactions that are required for the brain and spinal cord to form correctly. So the overarching topic that I studied to get my doctorate degree was the formation of the embryonic brain and spinal cord.
So we all have a brain and spinal cord, so we can relate on that level. Right? And so our brain and spinal cords started off as a flat sheet of cells. And these flat sheet of cells has to communicate with the cells around it in order to roll up and fuse together to form a tube. This tube is called the neural tube, and this neural tube continues to develop into the brain and the spinal cord, which then becomes your central nervous system for the rest of your life, as it develops into different cell types and nerves.
So, my research focused on one gene that is important for that flat sheet of cells to roll up and fuse together. And so this one gene is called Snx3, S N X three, and this gene is important for trafficking proteins throughout a cell. So what does that mean? Basically the Snx3, I like to think of it as a school bus, so there’s the cell and then inside the cell, this Snx3 is acting as a school bus to quote unquote, drive around the cell and pick up different proteins like a school bus would pick up different kids, and then it stops at its final destination to unload the proteins that it has picked up throughout the cell, just like a school bus when unload kids at the school. And so this gene that traffics that protein around the cell to a specific location is extremely important for that flat sheet of cells to roll up and fuse together to become the neural tube, and then the brain and spinal cord.
So here I am today, talking with you about that.
Victoria:
(Chris – What does the spinal cord do?)
Awesome. Well, we have so many questions about that school bus. And most of these questions were submitted by listeners through emails and on social media, and by students at Bromwell Elementary.
And so we will start off with this question, this good introductory question from Chris. What does the spinal cord do?
Dr. Brown:
Yeah, that’s a great question. So your brain and spinal cord are what makes up the central nervous system of our bodies. So the brain is kind of like the master command center, if you will. And then your spinal cord acts as that pathway or the highway for the messages from your brain to get sent throughout the rest of your body. And so our brain and spinal cord can take in stimulus from the, from, you know, our surroundings or within our bodies and send those messages throughout our entire body, from our toes to our nose, and everywhere in between.
Victoria:
(Kelly – Why is it a cord?)
Awesome.
And this is a really good follow-up question from Kelly. Why is it a chord?
Dr. Brown:
Great question. So it’s a chord because from that very early on stage in development, the brain and spinal cord starts off as that flat sheet of cells. And this flat sheet of cells rolls up and fuses together to form a tube. And then that tube that later develops into the cord. And so really it’s a cord because initially that flat sheet rolls up, just like you roll up a piece of paper.
Victoria:
Cool. And do you know why it rolls up or is that just, just what it does.
Dr. Brown:
Yeah. So it needs to roll up because the, so the neural tube is, like I said, originally flat, and if it doesn’t roll up and fuse, then it stays open. And then your brain and spinal cord will develop outside of the body. So imagine that you have a sheet of paper, in the bottom of your paper, that one side of it is one color, and then the top side is a different color. So when it’s laying flat on the desk, all you see is that one, one side. So let’s just say that top side is white. When you roll it up, you see the red side of the paper, the other side of the paper, let’s just pretend it’s red. So after that’s rolled up and it continues to develop in the embryo, that red side will become the skin, and so of the embryo to cover up the spinal cord. So if it’s not rolled up, then you’ll have that white exposed in this analogy. That’s the, the, the cells that make up the spinal cord, and you won’t have that skin layer going over it to keep it inside the body.
Victoria:
Okay. That makes sense.
Dr. Brown:
That’s, okay.
Victoria:
Yeah. Yeah, it does. So, yeah, we’ve got to have our brain and our spinal cord inside and not on the outside.
Dr. Brown:
Yeah.
Victoria:
(Audrey – What makes our brains think? Does the school bus gene help us think?)
Yeah.
All right. This is a fun question, I think, from Audrey. What makes our brains think? Does the school bus gene help us think?
Dr. Brown:
Yeah, that’s a fantastic question. So scientists are still studying what makes us think. But what we know from the research that has been done so far, is that again, our sensory system, so eyes, smell, hear, touch, will take in environmental stimuli, and those stimuli will be sent to our brain. And then our brain that has to synthesize all the information in a coherent way, and our brain uses the different components of our brain structure to work together, to then create thoughts.
Victoria:
Wow. Okay. Yeah. So the school bus gene that is in the individual cells. Is that?
Dr. Brown:
Yep. You’re right. It’s in the cells and really Snx3 or the school bus gene as we’re calling it, it is much more important early on in embryonic development. So when the fetus is still developing inside the mom, that’s really where this gene is more active to initially create the brain and spinal cord.
Victoria:
(Sydney – What does the school bus gene look like? Can you see it?)
Okay. Cool. This is a cool question from Sydney. What does the school bus gene look like? Can you see it?
Dr. Brown:
Yes. I love this question because you can’t see it with the naked eye, but there are ways that we can see it as scientists. So the gene is just double-stranded DNA, and then that DNA is the recipe for the protein that makes, and then this protein is the actual, what we’re calling it, school bus that goes around the cell, picks up other proteins and drops them off.
So we can’t just look at the cells and see this protein with our naked eye. But what we can do is put a little fluorescent tag on these proteins using molecular techniques. And then we use a super strong microscope that allows us to see those fluorescent markers that we’ve essentially attached to our protein, to our school bus gene. And we can see those fluorescent dots moving around within a cell using this really strong microscope.
And so, no, you can’t see it by just looking at it plain, but we’ve developed this method to attach these fluorescent tags on the protein with really strong microscopes so that we can see it.
Victoria:
(Michelle – Do you have to dissect brains to do your work?)
Awesome. That’s cool.
Okay. And this is another question about I guess seeing aspects of your work. Michelle wants to know do you have to dissect brains to do your work?
Dr. Brown:
Yes, I do dissect brains. Most of these brains come from embryo. So I just have to say preface our lab uses the mouse as our model organism to study this gene and to study the process of neural tube closure or the formation of the brain and spinal cord. And so a lot of my dissections are of these embryonic mice as their brains and spinal cords are developing. Also we use the mouse because the, this gene is identical in mouse to humans on the protein level.
Victoria:
(Aaron – What does a brain feel like?)
Cool. And a follow-up to that from Aaron. What does a brain feel like?
Dr. Brown:
So at the stages that I am dissecting them, they really just feel like jello. They’re not super formed yet. It’s just the really early brain that I’m dissecting.
Victoria:
(Limetra – What can you do to ensure your brain and spinal cord stay healthy?)
Interesting.
All right, this next question is from Limetra. What can you do to ensure your brain and spinal cord stay healthy?
Dr. Brown:
That’s a great question. Aspects that help us maintain a healthy brain and spinal cord involve things like getting enough sleep, having a balanced diet, getting enough vitamins and minerals, and then also just using good safety practices. So for example, wearing a helmet when you’re riding a bike, wearing a seatbelt in the car, and things like that to avoid traumatic injury.
Victoria:
(Sierra – What are the conditions called when someone’s brain and/or spinal cord don’t develop properly? And can they be fixed?)
That makes sense.
Okay. This next question is from Sierra. What are the conditions called when someone’s brain and/or spinal cord don’t develop properly? And can they be fixed?
Dr. Brown:
Yes. I love this question as well. And when the brain and spinal cord doesn’t develop correctly in, the context of my project in the disease that I’ve been studying is it’s called a neural tube defect.
And so you all are already familiar with the term neural tube from the beginning of this podcast, where I explained that that layer of cells rolls up and fuses to make a tube called the neural tube that then continues to develop and become the brain and spinal cord.
And so when it doesn’t form correctly, when that tube doesn’t fuse, it’s left open, then that results in a neural tube defect. And in fact, neural tube defects are the second most common birth defect worldwide, occurring in about half to one in a thousand births. And so it’s a really important problem that we study and so that we can understand it so that we can prevent it.
And so there are multiple types of neural tube defects, depending on what point of that tube is open or closed.
Victoria:
And so is that something that, people are born with and can live with or can be fixed?
Dr. Brown:
Yeah. So depending on where that tube is still open, as the embryo continues to develop, you can have one neural tube defect called anencephaly. And that’s when the tube doesn’t close in the cranial region of the embryo. And then the neural tissue is not covered up by skull or skin. It’s just exposed in utero and it gets degraded and that neural tissue is eventually gone. And so that’s lethal. If a baby has a neural tube defect in the cranial region, 100% of them pass away.
But there’s also spina bifida, which most people have heard of. And spina bifida is when that neural tube is open anywhere else along the back, basically along the spinal cord, and it can be lethal, but it also can be managed, or you can live with it. However, these patients are usually in a wheelchair or they have gastrointestinal issues for the rest of their lives, but you can live with it.
Victoria:
(Mackenzie – Is it the misplacement of the proteins that leads to the development of Down syndrome and other similar conditions?)
Interesting. Yeah.
All right, this question is from Mackenzie. Is it the misplacement of the proteins that leads to the development of Down syndrome and other similar conditions?
Dr. Brown:
Down syndrome is actually the duplication of an entire chromosome. And so my project was looking at one gene. But when you’re talking about an entire chromosome, tons and tons and tons and tons of genes live on one chromosome. So if you have a duplication of one chromosome, there’s a duplication of a whole bunch of genes. And so that is going to have more global and more devastating effects, such as Down syndrome, compared to when in my embyros, when just one gene is affected to misplace the proteins. So I imagine that there’s similarities between the two, but I have not looked, I’ve not studied exactly, you know, in Down syndrome which proteins are misregulated.
Victoria:
(Jane – What can a pregnant woman do to help ensure their baby’s brain and spinal cord develop correctly?)
Okay, that makes sense.
This is a good follow-up to all of these questions, I think. Jane wants to know what can a pregnant woman do to ensure their baby’s brain and spinal cord develop correctly.
Dr. Brown:
That’s a great question as well. Maternal nutrition is really important for the correct development of the brain and spinal cord or the neural tube. And so it’s recommended to get a certain amount of folic acid, it’s recommended to get a certain amount of iron and other vitamins that are usually included in prenatal vitamins. So getting correct nutrition is probably the best thing that the mother can do.
However, we do know that gene and environment interactions can be different. So depending on the mom’s and the embryo’s genetics, that might require different dietary requirements to make sure that fetus will grow correctly with a normal brain and spinal cord.
Victoria:
Interesting. And is that something that doctors will test for and tell the mom what to do?
Dr. Brown:
Unfortunately, not yet. So right now there was really just like a global increase, like just tons of folic acid, tons of folic acid, and tons of folic acid.
However, our lab has shown that in the context of specific genetic mutations, and Snx3 or the school bus gene being one of these genes, that over supplementation of folic acid actually results in a defective neural tube. So instead of helping develop correctly, it has the opposite effect and results in the neural tube defect, which is pretty groundbreaking for my project and for our lab. And there’s a couple other genes in our lab that also react to that way. But we know from epidemiological data that neural tube defects have decreased, you know, 30 to 70% depending on which country you look at, with the increase of folic acid.
So looking at epidemiological data, it’s still the best way to prevent neural tube defects. However, we’re showing now that with specific genetic mutations, it’s really the opposite, it’s the opposite, which again, underlines the importance of understanding gene and environment interactions on a personal level when treating a patient.
Victoria:
(Joe – Does the efficiency of the “school bus” decrease as we age causing degradation and disease?)
Oh, interesting.
All right. This next question is from Joe. Does the efficiency of the “school bus” decrease as we age causing degradation and disease?
Dr. Brown:
So Snx3 or that school bus gene, we don’t really know much about it beyond early fetal development. It has never been associated with neurodegenerative diseases.
However, other genes that are similar to the school bus gene have been associated with Alzheimer’s and neurodegenerative diseases. And so that’s something that we would want to study further as we continue to investigate what this gene is doing and how it’s acting at all stages of life.
Victoria:
That’s always an answer I like to hear because if the students are interested in that when they grow up, they can be scientists and answer those questions.
Dr. Brown:
We’d love their help.
Victoria:
(Amy – What other than nutrition helps the gene bus run properly?)
This next question comes from Amy. What other than nutrition helps the gene bus run properly?
Dr. Brown:
So from the early part of this podcast, I told you all how the neural tube of the brain and spinal cord starts off as that flat sheet of cells. Right? And so it’s important for those cells to communicate with each other through different cellular signals or cellular messages. And so those cellular signals and messages are another really critical factor to help that school bus gene run correctly.
Victoria:
(Mackenzie – Is the correct functioning of the gene bus more environmental or genetic?)
Okay. Cool.
All right. Switching gears. This is a question from Mackenzie, and this is getting at more of the environmental factors that you mentioned. And Mackenzie wants to know is the correct functioning of the gene bus more environmental or genetic.
Dr. Brown:
I’m going to have to say both and yes to that. And I say this because we have seen in my research in the mouse, when this gene, the school bus gene or Snx3, is deleted, it results in a deformed brain and spinal cord and the embryo does not live. So that’s pretty clear evidence that the genetic part of it is important.
Also in my research, we’ve shown that when mice have one working copy of this gene, so normally we have to have two copies of a gene, one from our mom and one from our dad. We can use a different genetic techniques so that our mice only have one copy. So they have one good copy. And these mice with one good copy of the school bus gene with increased folic acid supplementation, or, you know, other dietary changes can actually also result in a neural tube defect or defective brain and spinal cord. And so that evidence tells us that it is also has a very strong environmental component.
So both the genetics and the environmental components such as folic acid are go hand in hand with the correct functioning of this gene to result in a normal brain and spinal cord.
Victoria:
(Jen – Have there been changes in how our brain and spinal cords develop during human evolution?)
Okay. Yeah, that, that makes sense. You gotta, you gotta have both.
This next question is from Jen. Have there been changes in how our brain and spinal cords developed during human evolution?
Dr. Brown:
That’s a fascinating question, and it’s something that I would love to know more about. I do know that throughout our evolution as humans, our brain has undergone multiple expansions, where over thousands of years, our brain is gets bigger and bigger and bigger, millions of years really, our brain gets bigger and bigger and bigger. And so yes, it has changed. The evolution has changed in the sense that our brain size is much larger and more complex.
However, I’m not an expert on the details of that evolutionary history.
Victoria:
Yeah. There’s a lot of complex concepts in terms of human evolution history.
Another question I just thought of, is this same process unique to human? Well, no, I guess cause, cause you’re talking about mice. Okay. Never mind.
Dr. Brown:
No worries. Yeah. So really quick if I can just nerd out. Every vertebrate with a brain and spinal cord undergoes neural tube closure. And so we all have it. So like different animals can undergo neural tube closure slightly different ways, but overall it’s all a flat sheet that becomes a tube, that becomes the brand spinal cord.
Victoria:
(Sierra – Could global warming effect the development of our brains and other organs? If yes, how do?)
Awesome. That’s so cool. Okay.
This is a really interesting question from Sierra. Could global warming affect the development of our brains and other organs? If yes, how?
Dr. Brown:
This is a fascinating question that I really hope that students like yours or, you know, the students listening to this podcast pursue when they become scientists, because the global climate change is something that we’re all gonna have to face and understand how it’s affecting us on every level of our lives.
So I don’t know for sure how climate change would affect the function of Snx3 or the school bus gene in the formation of our brain and spinal cords directly. But in an indirect way, we’ve seen that global warming and climate change has affected crops and food yield. And so it’s possible that the development of our brains and spinal cords could be affected indirectly through climate change via nutrient deficiencies.
Victoria:
(Sam – What has been the overall effect on human physiology development as a result of pollution?)
Yeah. That’s, that’s going to potentially be a very big problem for humans in the next tens of years.
Okay, this next question is from Sam. What has been the overall effect on human physiology development as a result of pollution?
Dr. Brown:
That’s another fascinating question that I hope these young scientists are inspired to pursue.
I have not studied that personally. But I do know that we have some labs in Boulder and other collaborating institutions that study microplastics and the biodegradation of different materials that humans throw out in the trash or recycle. And microplastics have been found in our brains. And yeah, and in our bloodstream. And so that’s one way where pollution and trash has really affected us as organisms. So it’s in our bodies. And we don’t really know the full effects of that yet.
Victoria:
(Joe – It seems that there is an increase in the frequency of brain cancers. Has something changed in our environment that has caused this to happen?)
Yikes. That is scary, but a lot of very important research to be done. So that’s what we like to hear on this podcast. More opportunities for students when they grow up.
Okay. And this next question is from Joe. It seems that there has been an increase in the frequency of brain cancers. Has something changed in our environment that has caused this to happen?
Dr. Brown:
I’m not aware of an increase in frequency, I guess I would have to look up, you know, on the CDC potentially that’s happening. But I do know that brain cancer occurs in about six in every 100,000, I think, cancer diagnosis. I’d have to double check. I’d have to fact check that. But it is technically a rare cancer in the world, brain cancer is. So I’m not sure if there is an increase or what could be affecting that. But from what I know about environmental and genetic relationships, that it’s definitely possible that things in our environment are contributing to development of brain cancer, as well as genetic risk factors.
Victoria:
(Chris – What degrees do you have?)
Oh man. Yikes.
Well, switching gears a little bit, we’ve got a couple of questions about you and your career. Chris wants to know what degrees do you have?
Dr. Brown:
I got my Bachelor of Science from the State University of New York at Cortland in Basic Biological Sciences with a minor in Chemistry. And then I just defended and received my Doctor of Philosophy from the University of Colorado Anschutz Medical Campus in the Cell Biology, Stem Cells and Development program.
Victoria:
Awesome. Congratulations to you.
Dr. Brown:
Thank you.
Victoria:
(Amy – How did you decide on such specific research?)
Very exciting. And you touched on this a little bit earlier. But if, if you have more information or more details you want to go into. Amy wants to know how did you decide on such specific research?
Dr. Brown:
Great question, Amy. So I am an identical twin. And growing up, we always struggled with different things. So whether that would be a sickness or behaviors, we were so different. But the fact that we have the same exact DNA, because identical twins come from one egg fertilizing one sperm, and then that zygote splits into two and becomes two fetuses. I’m a kid, well not a kid, you know, high school age, thinking about how we have the same DNA, but we have such different issues that we’re dealing with throughout our lives.
And so I was really interested to understand why that is and how that could possibly be when we have the same genes. And so that really steered me to studying something genetic. And then also something in the field of embryology in the human development.
And so when I was researching programs and saw that Lee Niswander was studying the formation of the brain and spinal cord. That was a great marriage of genes, embryology, human development that I was looking for to study and to pursue.
Victoria:
That’s very cool. A great origin story.
Dr. Brown:
Thank you.
Victoria:
(Audrey – What is the one thing you want people to know about genes and the environment?)
All right. And this is our very last question. And I think one of my favorite questions that we’ve ever received. Audrey wants to know what is one thing you want people to know about genes and the environment.
Dr. Brown:
Fantastic question. And that’s a great question to bring our conversation to a close. And I would say the one thing that I want people to take away is that this gene environment relationship can be different for every single variable.
So depending on, you have to look at the gene environment interaction from a bird’s eye view in a big picture way. So depending on whatever gene you’re looking at and whatever environmental interaction, you have to have an open mind to test a variety of hypotheses of how these interactions could be occurring for every set of gene environment interaction that you’re looking at. So it’s important to look at this gene environment concept from a big picture, and to have an open mind to test different hypotheses, and to remember that what you discover for one gene environment interaction is not necessarily true for all of them.
Victoria:
Oh, well, that’s really cool.
All right. And then I, guess I was kind of joking when I said that was our last question. I do have one more question for you. Do you have any questions of your own for the listeners?
Dr. Brown:
Oh yes. Oh my gosh. I love talking to aspiring scientists. So I would want to know what they are interested in. So are they more interested in human diseases, or animal diseases, or are they interested in the climate, or are they interested in geology or volcanoes or deep sea? I would love to know what scientifically peaks their interests.
Victoria:
Awesome. That is a great question for the listeners. And if the listeners want to send in an answer, feel free to send them to our podcast email, askascientistpod@gmail.com or submit your answers on social media @_askascientist on Twitter and @askascientistpod on Instagram and Facebook. So send in your answers to the podcast social media, and I will pass them along to Dr. Brown.
Thank you so much for joining us today. I’ve learned so much in talking to you just now, and I hope the listeners did too.
Dr. Brown:
Well, thank you for having me on the show. It’s really been my pleasure and I’m excited to hear what the listeners are interested in studying.
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