Today, you’ll learn about how high blood pressure can reduce the gray matter in your brain, why scientists think the surface of Mercury is covered in diamonds, and how while we have gene pairs from both parents, our bodies will use one parent’s gene over the other’s depending on the circumstances.
Today, you’ll learn about how high blood pressure can reduce the gray matter in your brain, why scientists think the surface of Mercury is covered in diamonds, and how while we have gene pairs from both parents, our bodies will use one parent’s gene over the other’s depending on the circumstances.
50 Shades of Gray Matter
Diamonds a Plenty
Mom and dad genes aren’t just at the mall.
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Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/blood-pressures-mercurys-crusty-diamonds-dad-or-mom-genes
NATE: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. Time flies when you’re learnin’ super cool stuff. I’m Nate.
CALLI: And I’m Calli. If you’re dropping in for the first time, welcome to Curiosity, where we aim to blow your mind by helping you to grow your mind. If you’re a loyal listener, welcome back!
NATE: Today, you’ll learn about how high blood pressure can reduce the gray matter in your brain, why scientists think the surface of Mercury is covered in diamonds, and how while we have gene pairs from both parents, our bodies will use one parent’s gene over the other’s depending on the circumstances.
CALLI: Without further ado, let’s satisfy some curiosity!
[SFX: Whoosh/Intro Music]
CALLI: You know what raises my blood pressure?
NATE: Um...thinking about your blood pressure running high?
CALLI: Yep! And not only that - but thinking about how high blood pressure can severely impact your brain and alter its structure.
NATE: I might cover my ears for this. I’d like to have my brain’s structure stay the same, thank you.
CALLI: Hands off ears, Nate! It’s better to know! A new study shows that people whose overall blood pressure has increased from early adulthood to middle age have less gray matter in their brains.
NATE: This doesn’t sound good. Which one is the gray matter again?
CALLI: It’s the part of the brain responsible for body movements, memory retention, and regulating our emotions.
NATE: I’m freaking out, Calli. I have to get this under control.
CALLI: Not to make it worse but the study also showed that elevated blood pressure correlated to worse results on cognitive tests. But don’t worry there is some good news.
NATE: Phew! What did you find out?
CALLI: The first bit of good news is that the data from the study is pretty solid. A team from the University of Alabama at Birmingham started it all the way back in 1983. Taking a group of five thousand, one hundred and fifteen healthy people between the ages of eighteen and thirty - the scientists would periodically check in on their health.
NATE: This already sounds pretty extensive. How many years did the checks go on for?
CALLI: All the way up to 2016. So, over thirty years. Of the roughly four-and-half-thousand participants still alive, just under nine-hundred agreed to have MRI scans done. The scans were done in 2011 and 2016, and some of the participants had scans done both years. At that point in the study, the average age of the participants was about fifty years old. Okay, this is where we get to the second bit of good news.
NATE: The anticipation is killing me. Or at least decreasing my gray matter.
CALLI: When the team collected all their data, they measured the pressure in the large arteries of the participants throughout a cardiac cycle.
NATE: Cardiac cycle. That sounds like a science term for a heartbeat.
CALLI: That’s because it is!
NATE: Nice!
CALLI: Okay, so that measurement is called the mean arterial pressure, or MAP. It’s basically a more invasive but also more useful way of measuring blood pressure. They found that an increase in MAP showed a higher likelihood of low gray matter volume as compared to white matter.
NATE: That doesn’t sound like good news! Now white matter’s involved!?
CALLI: Hang on, Nate. When surveying the study as a whole it was found that this increased blood pressure history was actually pretty rare.
NATE: Phew. Now I can relax. You could’ve started with that fact.
CALLI: I wanted to be thorough.
NATE: I think you wanted to stress me out.
CALLI: Maybe a little. Kinda fun to watch you squirm. Okay, but in the study - sixty five percent of people did not have any kind of high blood pressure. Another twenty-three percent had high but stable blood pressure. The group hit by those gray matter effects was just twelve percent of the total. Which is about the same as the average rate of people in the U.S. under fifty with high blood pressure or “hypertension”.
NATE: So it’s pretty unlikely that I’ll even develop high blood pressure?
CALLI: Yeah. Whether someone began the study with hypertension, or developed it throughout the tests - they both scored lower on tests for verbal memory as well as brain functions involving planning, organizing, and self-control.
NATE: Are there any theories as to why this damage is happening?
CALLI: They’re still pretty in the dark on it. But some think that elevated blood pressure gets in the way of our brains and cardiovascular systems working together. And the increased pressure might be affecting the small blood vessels involved in brain development.
NATE: Great so if we get high blood pressure we’re doomed. Calli!
CALLI: It’ll be okay, Nate. Some more good news is that while high blood pressure rates can be somewhat genetic, they can also be easily managed and even reversed with the right lifestyle choices like staying away from smoking and alcohol, managing stress levels, and reducing sodium in your diet.
NATE: So I have to cut pizza and french fries out of my diet? That sounds like more bad news.
CALLI: Maybe just a little more moderation with them. What’s more important, Nate - having a few extra slices a week? Or keeping your gray matter intact?
NATE: Hmmm...
CALLI: I don’t understand you sometimes.
NATE: The pizza relieves my stress so it all evens out anyway right?
CALLI: I don’t think that’s how it works!
[SFX: Whoosh]
NATE: Calli, a lot of people impress their partners with beautiful, ornate engagement rings ... but I think I’ve got an idea that would top even that.
CALLI: Are you getting married, Nate?
NATE: Ha, not yet, but always good to plan! My idea though ... you ready for it? ... A space diamond!
CALLI: A space diamond? Where are you going to get one of those?
NATE: Planet Mercury! Researchers think that as much as one third of Mercury’s crust could be made of diamonds.
CALLI: Sounds like Mercury’s got a lot of them!
NATE: Even though the planet is smaller than some moons in our solar system, this finding means it could have more diamonds than Earth, many times over.
CALLI: Wow. I know Mars has been getting a lot of love in the news recently, what with our hopes to visit it, but maybe we should hang a U-y and head to Mercury instead?
NATE: Oh, it's crazy. It's the closest planet to the sun, and since it has no atmosphere, it is absolutely covered in craters from meteorite impacts. All of that happened about 4 billion years ago during the Late Heavy Bombardment, a violent time in our solar system that gave our own moon many of its craters.
CALLI: Oh cute, the Moon and Mercury ... they’re like a pair of guys who got matching tattoos at a bachelor party weekend.
NATE: Not my future bachelor party weekend! No two guys will bond more than the group bonds as a whole!
CALLI: Okay...
NATE: Mercury is also eight-hundred degrees Fahrenheit during the day, and gets down to negative two-ninety at night. And those days and nights are long, while its years are short. It takes the planet fifty-nine earth days to rotate for a single day, but only takes eighty-eight earth days to do a lap around the sun.
CALLI: So, having a bad day on Mercury is a really big deal. Lasts more than half the year!
NATE: Pretty darn close. Mercury is unique in another important way, its surface is covered in a crust of graphite.
CALLI: A carbon crust? Sounds like a horribly burnt pizza to me. Is that what makes it good for diamonds?
NATE: Well let's talk about Earth diamonds first. They form from carbon under immense pressure and temperatures. On Earth that usually happens about a hundred miles beneath the surface, and they only reach the surface when they’re spit out by volcanoes.
CALLI: I wish I belched precious gemstones.
NATE: I’m glad you don’t. Researchers have found that diamonds can form on the surface though. But it only seems to happen when a meteorite strikes and creates a moment of intense pressure and heat. The subsequent stones are called ... ooh, this is a fun one ... shock diamonds.
CALLI: Fiancés-to-be in jewelry stores across the world are hoping they pick out a “shock” diamond too.
NATE: Ha, yes. Well if they wanted to get a real one, Mercury would be the best place to look. Researchers figured if they were on earth, they’re probably on Mercury too… a lot of them. So, they used a computer program to simulate four-point-five billion years of meteorite impacts. They had the meteorites traveling well over twenty-thousand miles per hour, like they do, and simulated the thousand feet of graphite at the top of mercury’s crust.
CALLI: If there aren't diamonds, you could make a fortune in pencils with that much graphite.
NATE: You could make pencils as large as a Mercury day is long! Okay, so the computer software found that the meteorite impacts would make about 16 quadrillion tons of diamonds. A quadrillion is a million billions. That’s a lot of diamonds. As much as 16 times the estimated reserves on Earth.
CALLI: Sitting there in piles on the surface of Mercury? Easy heist ... if we could only get a rocket.
NATE: Researchers think some of these diamonds would be destroyed in subsequent meteorite strikes, but not too many. After all, it takes over 7000 degrees fahrenheit to melt a diamond. That’s over half as hot as the Sun!
CALLI: Sounds like there are still a ton to be had then. So, what do you think? Should we go all Armageddon, space mining? Actually, might not need to mine. I’ve done some volunteer litter pickup, and from the sounds of it, the surface is filthy with gems.
NATE: Sure, there are a lot of diamonds up there, but these likely won’t be the large sparkly gems of our dreams. It’s more likely the planet is covered in dispersed impure diamonds, most of them small, many of them mixed in with graphite. It’ll be a mess.
CALLI: Hey, a girl can dream. When will we be able to confirm?
NATE: Well the joint European-Japanese mission BepiColombo is hoping to do a flyby of the planet in 2025 and will hopefully be able to analyze the planet for diamond’s unique infrared signature.
CALLI: Well if you can let them know that I’d like a scoop if they decide to land, that’d be great.
NATE: Ha, I’ll let them know. In the meantime, we can just watch some Antiques Roadshow and hope someone brings in their auntie’s jewelry box.
CALLI: Oh, they’re always good for at least one big gem an episode.
NATE: Shock diamonds!
[SFX: Whoosh]
CALLI: Nate, you know how you inherit genes from your parents?
NATE: Sure, yeah. Everybody has two copies of each gene, one inherited from their mom, and one from their dad.
CALLI: Right. And, genes are called on for all sorts of reasons.
NATE: They help do more than pick your eye color?
CALLI: Oh, yeah. They’re used in different bodily functions, producing proteins, and coordinating plenty of other processes. And when your body calls on a gene, it just uses one of the genes in the pair and the other stays dormant.
NATE: Totally. That’s all stuff we knew already, yeah?
CALLI: Yes. And, researchers are still figuring out all the ins and outs of why the body picks one gene over the other. But, new research shows that scientists could potentially predict which gene will be called upon, depending on several factors. Basically, certain processes seem to use the dad’s gene consistently, and other processes use the mom’s. In making proteins or hormones ... even affecting behavior and decision making.
NATE: That’s wild!
CALLI: Yeah! Let’s get into it. Researchers looked at the brains of mice and found that some parts relied exclusively on the copy of the gene from the mother.
NATE: What did those parts of the brain do?
CALLI: They produced a kind of chemical messenger called neurotransmitters.
NATE: So, just the mother’s gene was being used there. What happened to the father’s gene?
CALLI: In these parts of the brain, the gene from the father mice was switched off.
NATE: Switched off? That's crazy.
CALLI: Right? And in the adrenal gland, the body favors the gene from the father when it makes adrenaline. So, what’s even wilder is that, it’s with help from the same gene. Just the dad side this time though, while the mom side is switched off.
NATE: What gene is this that does these two crucial activities?
CALLI: The gene is Dopa Decarboxylase. It helps control our mood and movement.
NATE: Well how do we know this so well? How can we tell which genes are being favored?
CALLI: Great question. Researchers engineered mice to attach a fluorescent tag to the dopa decarboxylase enzyme. They designed it so it would glow red if it was using mom's gene, or glow blue if it was using dad’s. All they had to do was look under a microscope to see what was active.
NATE: That is so cool, glowing genes.
CALLI: Right?
NATE: So the body used one of the genes from the pair within the brain, and the other one from the same pair in the adrenal gland?
CALLI: Right. Continuing down this track, they saw genes from one parent or another being favored in decision-making. They saw some decisions in sons controlled by mom's genes and some decisions in daughters affected by dad's genes. They put mice in food foraging areas where they could go where they wanted and do what they wanted, take risks, move to safety, forage, that kind of thing. To the researchers, it looked random.
NATE: So, then how could they tell which parents’ gene was affecting the behavior?
CALLI: Well, remember they had that information about certain functions favoring one parent over the other, so with that, they applied a machine learning algorithm to look for patterns in the behavior. And it did! They found that some decisions were based on which parent’s gene was in control.
NATE: That's wild.
CALLI: It was enough to show that decisions and actions can be associated with each parent’s copy of the genes.
NATE: Well why would that be? Is there some evolutionary benefit to that?
CALLI: Well, they believe it might be a sort of genetic regulation. There’s more research to be done to test that hypothesis. But, they think from a natural selection standpoint, it may be better for the species to have daughters and sons make different decisions. Like for daughters to stay closer to home and find partners, whereas sons would be better suited to going out and spreading genetic diversity.
NATE: This has to be a big revelation for researchers.
CALLI: Totally, they’re saying it is a whole new untapped region of biology that could help us understand how and why we make certain decisions.
NATE: Too cool.
[SFX: Whoosh]
NATE: Let’s recap what we learned today to wrap up. A long-term study shows a strong correlation between high blood pressure and decreased brain function in young adult to middle age participants. Those with hypertension not only showed less gray matter in the brain, but also difficulty with cognitive tests concerning verbal memory and high brain functions like planning, organizing, and self-control.
CALLI: Scientists expect the planet closest to our Sun, Mercury, might be covered in diamonds. A crust of graphite and a lifetime of meteorite impacts might be just the combination to make a payload of diamonds many times greater than all of Earth’s reserves.
NATE: We inherit genes in pairs, one from each parent, and only one of those genes is used at a time. New research shows that it may be possible to predict which gene of the pair will be used, depending on the situation. In mice, a given process will use the mothers’ gene, while another will use the father’s. This revelation may provide important insight into how the human body functions and even how we make decisions.