How Pregnancy Changes the Brain, and How Lizards Make DIY Scuba Gear
This week’s news roundup explores how the brain is affected by pregnancy, the way “scuba diving” lizards breathe underwater, and much more.
Anaissa Ruiz Tejada/Scientific American
Happy Monday, listeners! Let’s kick off the week by catching up on the latest science news. For Scientific American’s Science Quickly, I’m Rachel Feltman.
First up we’ve got an update on Butch Wilmore and Suni Williams. These two NASA astronauts set out to spend just over a week in space in June, but now they won’t actually be home until around February. Earlier this month—not long after the ill-fated Starliner spacecraft returned to Earth without them onboard—the pair conducted a press release from the International Space Station. Suni said they’re making the most of their extra time in space by being the best crewmates they can be, and both noted that they’re looking forward to voting in the 2024 presidential election from space. They’ve sent in their requests for absentee ballots, which will be encrypted and downlinked to their local county clerks’ offices. Both will have to list their current address as “low-Earth orbit,” which is kind of adorable. So if voting on November 5 means standing in a long line or dealing with other inconvenient logistics, just take a second to look up into the sky and be grateful that you’re not stuck in space for, like, eight months longer than intended.
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Here’s a bit more space news. A study published last Monday suggests that Earth might have once had a cool cosmic fashion accessory: a giant ring like the one surrounding Saturn. The study authors hypothesize that the ring of space rocks might have formed about 466 million years ago when a big ol’ asteroid got too close and succumbed to our planet’s tidal forces. Once it broke apart to form a ring system, it could have blocked enough sunlight to cool the planet—and sent loads of meteorites down to collide with the surface. In fact, the scientists formed this hypothesis to try to explain a period of frequent meteorite strikes some 485 million to 443 million years ago. They’ll need more evidence to solidify their findings, but in the meantime I think it’s pretty cool to imagine our planet with a big, rocky Hula-Hoop.
And speaking of our Pale Blue Dot, a study published last Friday reminds us of just how complex it is. Researchers found that iron stuck to dust carried on the wind from the Sahara all the way to the Atlantic Ocean plays a crucial role in supporting marine life. Not all forms of iron in the environment are “bioreactive,” or accessible to living things. Researchers say that the iron that travels in Saharan dust actually becomes more bioreactive as it blows through the atmosphere, thanks to chemical reactions that take place there, that means that this long-distance delivery is potentially crucial for supporting life in locations like the Amazonian basin and the Bahamas.
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In less thrilling environmental news, last Monday scientists published a report about microplastics found in the human brain. The researchers examined tissue from cadavers, looking specifically at their olfactory bulbs—those are the parts of the brain that begin to process smells, and two of them sit above the nasal cavity. Samples from eight of the 15 cadavers contained bits of plastic ranging in size from 5.5 to 26.4 micrometers. It seems likely that we inhale these microplastics, and some worry this means they could make their way into to the rest of the brain. We do know that some microbes can make that jump. Microplastics have been linked to inflammatory reactions and could potentially be tied to all sorts of health problems. Last Thursday, an international group of experts in marine biology, sustainability, environmental psychology, global plastics policy and risk assessment published an article in the journal Science calling for international action to combat the plastic and microplastic problem. They warned of the risk of “irreversible environmental damage” if we don’t take pains to drastically lower our plastic production, as well as find ways to lower emissions of and environmental pollution from the plastics we continue to use and discard. Their call to action actually coincides with the 20th anniversary of the first-ever study to use the term “microplastics,” which was also published in Science. For more on microplastics check out our June 24 episode.
That’s not the only alarm bell in health news from last week. Last Monday a study published in the Lancet analyzed the rising trend in antimicrobial resistance, or AMR. The study predicts that antimicrobial-resistant infections will kill more than 39 million people over the course of the next 25 years. Previous research has suggested that AMR could potentially become the world’s leading cause of death by 2050. While pathogens naturally evolve over time to become resistant to treatments like antibiotics and antivirals, this process is happening much faster because of our overuse of antimicrobials for treating humans, plants and animals. Leaders at this week’s meeting of the United Nations General Assembly are expected to sign off on global commitments to fight AMR.
Another health study out last week in Nature Neuroscience aims to unlock the secrets of an infamous phenomenon: pregnancy brain—or, more accurately, all the changes in the brain that come along with gestation. For the first time, researchers followed an individual through their first pregnancy to map changes in their brain—starting before conception and ending two years postpartum. The research team says the most pronounced changes occurred in the cortical gray matter, a.k.a. the wrinkly outer section of the brain. As the body made more pregnancy hormones, gray matter volume decreased—a change that persisted for the length of the study. That’s not necessarily a bad thing; the researchers compared it to changes we see as brains transition through puberty and into adulthood. They also saw an increase in white matter, which facilitates communication between different parts of the brain, which peaked during the second trimester and returned to baseline around the time the person gave birth. While we can’t be sure how one person’s experience during pregnancy might compare to the typical neurological changes a pregnant person might go through, the researchers have made their dataset freely available online to encourage further research on the subject.
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Now, you all know I like to end on a fun one when I can, and what’s more fun than an itsy-bitsy, teeny-weeny scuba-diving lizard? I don’t know what, but if you do, email it to me, I want to see it.
Researchers who study semiaquatic lizards called water anoles had previously noted that the animals form funny little bubbles on top of their nostrils when they dive to avoid predators. Now scientists have confirmed that those bubbles are more than just an adorable side effect of taking a quick dip: the lizards are actually using the air pockets to breathe. By treating some lizards with topicals that kept air from sticking to the skin—thus preventing bubble formation—a new study showed that these little diving helmets allow the reptiles to stay underwater for 32 percent longer than they could otherwise. In a press release, study author Lindsey Swierk described anoles as the “chicken nuggets of the forest,” with loads of potential predators. So it’s not surprising that the little guys have evolved a trick that helps them stay underwater for at least 20 minutes to evade animals trying to make a drive-through run.
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That’s all for this week’s news roundup. We’ll be back on Wednesday to talk about new research on PCOS. And on Friday we’ll drop the next episode of our latest Fascination miniseries. If you didn’t catch Episode One last week, you’ve gotta go back and listen ASAP. It’s all about the beautiful, mysterious world of math. This week we’ll be asking a mind-boggling question: Is math even—real? It’s actually a hotter debate than you may think.
Science Quickly is produced by me, Rachel Feltman, along with Fonda Mwangi, Kelso Harper, Madison Goldberg and Jeff DelViscio. This episode was edited by Anaissa Ruiz Tejada. Shayna Posses and Aaron Shattuck fact-check our show. Our theme music was composed by Dominic Smith. Subscribe to Scientific American for more up-to-date and in-depth science news.
For Scientific American, this is Rachel Feltman. Have a great week!
