Today, you’ll learn about a new study that shows drugs like Ritalin aren’t so smart after all, how frozen rat kidneys could lead to a medical revolution, and a new study that shows how people with curly hair are extra cool.
Today, you’ll learn about a new study that shows drugs like Ritalin aren’t so smart after all, how frozen rat kidneys could lead to a medical revolution, and a new study that shows how people with curly hair are extra cool.
Find episode transcripts here: https://curiosity-daily-4e53644e.simplecast.com/episodes/smart-drugs-frozen-organ-transplant-curly-hair-cool
Smart Drugs
Frozen Organ Transplant
Curly Hair Cool
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[SFX: INTRO MUSIC/WHOOSH]
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 a new study that shows drugs like Ritalin aren’t so smart after all, how frozen rat kidneys could lead to a medical revolution, and a new study that shows how people with curly hair are extra cool.
CALLI: Without further ado, let’s satisfy some curiosity!
[SFX: WHOOSH]
NATE: There’s a million stories out there about how anxious teens and college students who are totally stretched thin are doing anything they can to make the grade - including taking so-called brain-booster drugs.
CALLI: So I’ve heard about people in like stressful jobs taking prescription drugs like Ritalin to try to stay sharp and like get ahead.
NATE: Yeah well…a new study has some pretty surprising news for those people: not only do those drugs not help - they might actually make your performance worse.
CALLI: Wow. So… So much for a magic pill that can make you smarter and more successful, huh?
NATE: Yeah exactly! So these drugs, Ritalin, modafinil, and dextroamphetamine, are usually prescribed to people with attention deficit hyperactivity disorder - ADHD - and for narcolepsy. They work by boosting neurotransmitters like serotonin and dopamine in the brain. And for those conditions, the drugs can be a total game changer. But…if you don’t have those conditions…not so much.
CALLI: Okay tell me about the study.
NATE: Researchers at the University of Melbourne gave test subjects either a placebo or one of these drugs and then tested them using something called the knapsack problem. Basically, imagine you’re asked to fill a backpack with some combination of different sized items. Some of the items are worth more than others, and your goal is to make the backpack as valuable as possible without overloading it.
CALLI: This sounds like the theme of a gameshow from the ‘70s.
NATE: I’d probably watch it. It’s a cool test because you have to evaluate not only the value of the objects, but the size as well. It takes some pretty complex strategizing to figure it out.
CALLI: So I’m guessing the people who took the drugs didn’t do any better than the people who took the placebo.
NATE: Nope. In fact, they did worse.
CALLI: Wait? No way.
NATE: Yes way. Dr. Elizabeth Bowman - who was the lead researcher and a neuroscientist from the University of Melbourne in Australia - said that the only real positive effect of the drugs was that it made the test subjects more eager to solve the problem.
CALLI: That feels like a paradox. Because it seems like motivation is half the battle, right? Like…if people who take these drugs when they shouldn’t are too tired or overworked, what they’re really looking for is that little motivational boost these drugs give them. So what am I missing?
NATE: Well yeah. That is what you’d think. And previous studies have shown that these drugs can improve memorization skills and reaction time. But those aren’t exactly the skills that most people prioritize at the office.
CALLI: Ha. Mr. Senior VP in charge of quickly memorizing stuff.
NATE: It’s a very coveted position I’ve heard.
CALLI: I know!
NATE: It’s not! Just to clarify. Not really. So the complexity of this study seemed more like the typical work or school environment. And the thing is, the subjects were eager to get to work, but they actually took much longer to solve the problem - and they did worse at solving it. The drugs just gave them more energy to be bad at what they were doing.
CALLI: Oh my goodness! Imagine taking a medicine that actually does the exact opposite of what you wanted it to do. It’s like taking a heart medication that gives you a heart attack.
NATE: Right. It’s why taking medications for anything other than what they’re meant to treat is just a terrible idea. But on the bright side, another researcher said that there is a more effective way to get back the kind of productive focus that users of these drugs are looking for.
CALLI: Is it some new miracle drug?
NATE: Um…No. Unless you are diagnosed with ADHD or narcolepsy and these drugs will genuinely help you, you’ll find way better results if you just get some sleep and do a little bit of exercise.
CALLI: And at least that option doesn’t cost a thing!
NATE: Yeah! And it’s uh…legal.
CALLI: Seems a little bit important there.
[SFX: WHOOSH]
CALLI: Scientists at the University of Minnesota are on the verge of a huge medical breakthrough. They have successfully frozen rat kidneys!
NATE: I don’t mean to be judgmental of these scientists but I am pretty confident that I could freeze a rat kidney, if I had one.
CALLI: Yes…but-but…could you let it sit frozen for several days, then unfreeze it, and then put it back into a rat and get it to function properly?
NATE: Oh see no! That part… the function part… up until there I was actually with you. I could pull off those other things. But. So you’re saying that they were able to freeze a kidney but somehow keep it alive?
CALLI: Yeah! Exactly. It’s the kind of suspended-animation we hear about all the time in movies where people travel to distant star systems and then thaw out when they get there, and they’re just fine. Scientists have been trying to accomplish this for decades but keep coming up short.
NATE: It does sound like a sorta crazy Twilight Zone - Black Mirror kinda thing. I gotta say if I know my sci-fi, like there’s going to be some weird complications to this.
CALLI: So that’s the thing! Actually - not really. Animals drop their temperatures in nature all the time. In fact, a few years ago, these teensy microscopic creatures called rotifers actually reproduced after having been suspended in permafrost for… get this…24,000 years.
NATE: Wow! So how did these researchers finally do it in the lab?
CALLI: Well. If you ever want to freeze an organ but keep it intact enough to use again, there are a few problems you have to overcome. First, when something freezes unevenly - like, one part freezes at a different time than another part - it can crack or split or just come out kind of wonky.
NATE: Is uh…is wonky like the scientific term?
CALLI: Yes, Nate. I am now a scientist, okay? It also gets wonky if it thaws unevenly. Not only that, but if it doesn’t freeze at the correct rate - like, too slowly - then ice crystals form, and those can basically shred the organ.
NATE: Have I mentioned how not in a hurry I am to get frozen?
CALLI: That’s probably a good choice. When you freeze cells or organs to keep them in a suspended state, you actually are vitrifying them, which basically means putting them into a kind of glassy state. To do that and to keep them from getting shredded by ice crystals, they first pump the tissue full of cryoprotective agents - kinda like antifreeze. And then they freeze it really fast.
NATE: Imagine getting antifreeze pumped into you.
CALLI: I mean it’s a little more complicated than that, but yeah. But then they have to thaw the tissue, and that has its own challenges. But here’s the thing: there are over 100,000 Americans on the transplant waiting list right now, and as many as 17 people die each day waiting for life-saving organs. There is a huge supply issue, and that has literally EVERYTHING to do with time.
NATE: I’m assuming that’s because organs need to be transplanted pretty quickly after they’re removed from the donor, right?
CALLI: Exactly. Doctors say they need to be fresh. That means that a patient waiting for a kidney needs to be prepared at a moment’s notice to have surgery. And if they do find a kidney for that patient, it had better be close by, because after even a few hours, it’s just no longer viable.
NATE: Okay, wow! So this new technology really could change everything.
CALLI: It absolutely could. If we could freeze transplant organs, a recipient could undergo pre-treatment for weeks to make sure their body is ready to accept the new organ. They could ship organs anywhere to the people who need them. It would be a medical revolution, and that’s not an overstatement.
NATE: Okay. So rat kidneys are one thing, but humans are another, I suppose?
CALLI: Yeah. Not to mention the rat kidneys worked - but they didn’t work quite as well as fresh kidneys. They have a lot of work to do on this technique with animals in the lab - they plan to test this out on pig organs next, which are considerably bigger. But they say it’s going to take another huge medical breakthrough for this to be a viable option for humans.
NATE: So no interstellar space travel for me in the near future?
CALLI: I mean, don’t get me wrong, this is a huge breakthrough. But we’re still years off from it being available to humans. But now there’s at least light at the end of the tunnel…
[SFX: WHOOSH]
NATE: You know how everybody always wants the kind of hair that they don’t have?
CALLI: Oh my gosh, yes! I mean, everyone I know with straight hair wants curls. And everyone with curls spends their life with the straightener.
NATE: Well…it turns out curly hair might actually have an evolutionary advantage.
CALLI: Oh good! My straight haired friends are gonna love this one.
NATE: Right? So scientists at Penn State wanted to know where curly hair comes from.
CALLI: So like…why people have curly hair? I’ve never thought it might have some kind of evolutionary reason other than, you know, just being fabulous.
NATE: Well there are theories about it, but the idea is that for the most part, the traits we all exhibit probably gave our early ancestors some kind of advantage or else they would eventually just disappear.
CALLI: There’s also the idea that a trait wasn’t good OR bad, so it just kinda stuck around, right? Like, if it doesn’t make anyone’s life worse, it just comes along for the ride.
NATE: Totally. So…is curly hair one of those neutral traits? Or does it give people an advantage that straight hair doesn’t? To find out…they put a bunch of human wigs on a piece of equipment called a thermal manikin…
CALLI: Oh please tell me that's just a mannequin with a thermometer on it?
NATE: Kinda. It’s spelled m-a-n-i-k-i-n, and it’s surprisingly a specialized piece of tech that’s used to test out protective clothing. But for this experiment…well…human hair. They basically topped this manikin with all kinds of hair and set its surface temp to around 85 degrees, and the temperature around it to about 86 degrees with a relative humidity of 60%.
CALLI: That is oddly specific, right?
NATE: It is - and I will tell you why in a minute. But first, let me tell you about what they found. All hair types - straight, curly, wavy, you name it - protected the scalp from the heat of the sun. But curly hair - especially hair with tight curls - was the clear winner when it came to protecting our heads from heat. Not only did it reduce the amount of radiant heat that made it to the scalp, it reduced the amount of sweat needed to cool the head.
CALLI: Okay... It’s like insulation. So when we say that curly hair is cool, we mean that literally.
NATE: Exactly. But this story does go deeper. So…remember that oddly specific temperature and relative humidity?
CALLI: Uh… 86 degrees and 60% humidity?
NATE: Those are the average conditions in equatorial Africa, where some 2 million years ago homo erectus began its journey into human history. The heat of Africa was a lot to deal with, so our early human ancestors began shedding their fur as a way to handle the heat.
CALLI: Humans are basically naked apes, as some saying goes.
NATE: Well except we’ve got all this hair on our heads. The paradox is that if we shed our body hair to deal with the African heat, why didn’t we shed our coifs? And beyond that, why did our African ancestors select for curly hair?
CALLI: So it has everything to do with how to handle heat?
NATE: They call it thermoregulation, and it’s important for everything alive on the planet. But for humans - and all of our pals in the genus Homo - things got a little extra hot under the collar. First, we started walking upright, which gave us the ability to run - unlike most of our primate cousins. So not only were we overheated from running, but the very tops of our heads now aimed right at old man sunshine.
CALLI: That is a double broiler.
NATE: Well put. To make matters worse, our brains grew. Not only do bigger brains create more heat, they’re more sensitive to the radiant heat of the sun. So we evolved this kinda high-tech cooling system called sweating.
CALLI: I mean it was high tech for a million years ago, anyway.
NATE: Yeah well there’s a problem with sweating, too. Got any guesses?
CALLI: It’s… embarrassing?
NATE: Probably not back then so much. But if you sweat too much, you get dehydrated, then you’ve really got problems.
CALLI: Okay. So back to the study. Early humans had a problem with their heads overheating and a problem with sweating too much. And you’re telling me that curly hair basically took care of it?
NATE: That is basically what this study found. It’s not the only thing that helped us beat the heat. But researchers think curly hair could be one major factor that allowed humans’ brains to grow into the kind of brains that enjoy getting smarter by listening to Curiosity Daily.
CALLI: Nice! So this curly hair theory has gone full circle! It’s really throwing me through a loop! So many twists and turns!
NATE: Anymore bad puns and you’re gonna overheat.
CALLI: Okay, okay. I’ll stop.
[SFX: WHOOSH]
NATE: Let’s recap what we learned today to wrap up. A study found that while prescription drugs meant to increase cognitive function might make users more motivated, they can actually lead to worse performance overall. Cognitive enhancers may not be as effective as initially thought.
CALLI: Researchers have successfully frozen rat organs and reimplanted them in the rats after thawing. They are years away from being able to do this with human organs, but it could have huge implications for people in need of organ transplants.
NATE: A new study has shown that curly hair helps protect scalps from the heat of the sun, while also lessening our need to sweat to keep cool. Researchers think early humans selected for curly hair to keep their cool in the blazing sun of equatorial A