Learn about stem cell “mini brains” that grew eyes and how the FDA prevented an epidemic of birth defects in the 1960s. Scientists grew stem cell 'mini brains' that developed mini-eyes on their own by Cameron Duke Gabriel, E., Albanna, W., Pasquini, G., Ramani, A., Josipovic, N., Mariappan, A., Schinzel, F., Karch, C. M., Bao, G., Gottardo, M., Suren, A. A., Hescheler, J., Nagel-Wolfrum, K., Persico, V., Rizzoli, S. O., Altmüller, J., Riparbelli, M. G., Callaini, G., Goureau, O., & Papantonis, A. (2021). Human brain organoids assemble functionally integrated bilateral optic vesicles. Cell Stem Cell. https://doi.org/10.1016/j.stem.2021.07.010 Starr, M. (2021). Scientists Grew Stem Cell “Mini Brains”. Then, The Brains Sort-of Developed Eyes. ScienceAlert. https://www.sciencealert.com/scientists-used-stem-cells-to-make-mini-brains-they-grew-rudimentary-eyes The FDA never approved thalidomide, and that saved American babies by Briana Brownell James, A. J. (2021, August 17). How a “stubborn” Canadian saved thousands of American babies from birth defects. Nationalpost; National Post. https://nationalpost.com/news/canada/how-a-stubborn-canadian-saved-thousands-of-american-babies-from-birth-defects Phillips, S. (2020, March 9). How a courageous physician-scientist saved the U.S. from a birth-defects catastrophe. Uchicagomedicine.org; UChicago Medicine. https://www.uchicagomedicine.org/forefront/biological-sciences-articles/courageous-physician-scientist-saved-the-us-from-a-birth-defects-catastrophe Office of the Commissioner. (2019). Frances O. Kelsey. U.S. Food and Drug Administration. https://www.fda.gov/about-fda/fda-history-exhibits/frances-oldham-kelsey-medical-reviewer-famous-averting-public-health-tragedy McNeill, L. (2017, May 8). The Woman Who Stood Between America and a Generation of “Thalidomide Babies.” Smithsonian Magazine; Smithsonian Magazine. https://www.smithsonianmag.com/science-nature/woman-who-stood-between-america-and-epidemic-birth-defects-180963165/ Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Learn about stem cell “mini brains” that grew eyes and how the FDA prevented an epidemic of birth defects in the 1960s.
Scientists grew stem cell 'mini brains' that developed mini-eyes on their own by Cameron Duke
The FDA never approved thalidomide, and that saved American babies by Briana Brownell
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/mini-brains-that-grew-eyes-and-how-the-fda-saved-babies
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about how scientists grew stem cell “mini brains” that developed mini-eyes of their own; and how the FDA saved American babies from an epidemic of birth defects in the 1960s.
CODY: Let’s satisfy some curiosity.
Scientists recently announced that they had grown mini-brains in a lab — and got those mini-grains to grow their own mini-eyes. I know, it sounds like we’re a little early for Halloween, but the result will help us to better understand how eyes develop and how to treat and prevent certain eye diseases.
Technically, these little lab-grown brains are called brain organoids. They’re made from human pluripotent stem cells, which are cells that can turn into almost any other type of cell in the body. So like, in the basal layer of your skin, you have what are called multipotent stem cells. Those can develop into different types of cells — as long as they’re types of skin cells. Scientists figured out how to make multipotent stem cells behave like pluripotent stem cells so they could develop into basically whatever they told it to — nerves, skin, or in this case, brain tissue.
But I want to stress the word “tissue.” Brain organoids are a far cry from growing sentient brains in a jar, so don’t worry about that. Instead, they’re just bits of brain tissue grown in a dish, and they don’t think or feel things the way a normal brain would. These “mini-brains” are often used for experiments that, if performed on a living human brain, would be ethically dubious at best. We’re talking stuff like testing the effects of certain drugs on neural tissue, or seeing how cells develop in really bad conditions.
In this case, the researchers were using brain organoids to study eye development. Essentially, they were able to use specific chemicals to coax brain organoids into developing two little optic cups, or the beginnings of eyes. In a mammal embryo, eye development begins first by developing the optic cup, and then the eye that will live in it. These organoids began developing the eye cups about 50 days into development, right on schedule with when a human embryo would begin developing them.
So, what we have is really a tiny, almost brain with tiny, almost eyes. This is a big deal because it gives researchers the ability to explore diseases of eye and retina development through experimentation, which wasn’t possible before. They can give organoids mutations that cause certain degenerative diseases, watch how the eyes develop, and potentially learn how to treat or mitigate those diseases during development. These brains might be mini, but their potential is huge.
The Food and Drug Administration, or FDA, is the U.S. government agency responsible for making sure that medical products are safe to use. FDA approval means that a new drug has to pass scientific scrutiny and show evidence of both effectiveness and safety. And it was thanks to one “stubborn” data-demanding doctor at the FDA that allowed the United States to avoid an epidemic of birth defects in the 1960’s.
That doctor was Canadian-born Dr. Frances Oldham Kelsey. After an illustrious career, she’d been recently hired to an extremely competitive position at the FDA in Washington, DC. She was tasked with reviewing 300 applications a year for new products, with only the help of a handful of other medical officers.
It was only her second New Drug Approval application that gave her pause: a treatment for morning sickness called thalidomide made by the drug manufacturer Merrell. Thalidomide had been approved by 20 other countries and had already been prescribed to 20,000 patients, so the pressure was on to approve the medication.
But Merrell’s application was lacking. It was mostly based on physician testimonials Instead of rigorous clinical trials. And of the clinical trials they did include, Dr. Kelsey and the other reviewers agreed that they did not show that the drug was safe and effective. They asked Merrell for more data on the drug’s safety, which really delayed its approval.
Executives at Merrell were furious. They launched an assault of constant faxes (that’s right, angry faxes), phone calls, and surprise in-person appearances at the FDA offices in an attempt to push through an approval.
But, Dr. Kelsey and the rest of the team would not be rushed.
And it turns out that they made the right call. Soon after, medical reports about thalidomide started to crop up. There were stories of serious side effects, like nerve damage in the hands and feet. Not only that, but the safety of the drug during pregnancy was also in question. Thanks to Dr. Kelsey’s previous research, she knew that some drugs were able to make it through a pregnant woman’s placenta and end up in the fetus. She wondered whether thalidomide might be one such case. If there were serious side effects in adults, could something worse happen to a fetus?
Dr. Kelsey’s insight turned out to be right. Soon, a series of extremely disturbing reports came out. By the end of 1961, many mothers who had taken thalidomide during pregnancy had given birth to babies with missing or malformed limbs. Merrell withdrew their application.
All-told, around the world, 10,000 children were born with significant birth defects, and another 100,000 were lost before birth due to thalidomide. The number in the US? Just 17. And it’s thanks to a bureaucrat insisting on rigorous safety data at the FDA.
Let’s recap today’s takeaways
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ASHLEY: Today’s writers were Cameron Duke and Briana Brownell.
CODY: Our managing editor is Ashley Hamer.
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!