There's been a lot buzz about Zika virus lately. Last week, we talked about how the scientists created a 3D model of Zika virus, which could help them understand how it infects human cells. And on Monday, the US Centers for Disease Control and Prevention held a press conference where they emphasized the need for more research into treatments and vaccines for the virus.

Now, a paper published this week in the journal Science shows how Zika virus infects developing brain cells. It's the strongest direct evidence so for that Zika could cause microrephaly, a condition where babies are born with abnormally small heads and brains that don't fully develop.

In March, researchers at Johns Hopkins University and Florida State University showed that the virus may target and infect neural stem cells, or NSCs, the cells that divide to create neurons and other brain cells. And this week, researchers at the D'Or Institute for Research and Education in Brazil independently found the same results. They also learned that Zika virus affects neural cell growth and survival.

To mimic embryonic brain development, the researcher grew some NSCs in the lab in two different forms. In one experiment, the scientists infected some of the neural stem cells with Zika virus and grew them as neurospheres, flat circular clusters that contain NSCs and other brain cells. After 6 days, the uninfected NSCs grew into hundreds of healthy, round neurospheres. But the infected neurospheres were all strangely lopsided with jagged edges. The cells started separating from each other, and most of them died. 

Another experiment involved cerebral organoids, which are these apple-seed-sized, mini-brains that kinda look and act like the brain of a first-trimester fetus. They infected 6 of these organoids with Zika and left 6 uninfected. When they measured the organoids after 11 days, the infected ones were only about 60% as bug as the uninfected ones. These results help explain how, over many months, the Zika infection could cause a lot of damage to developing brain cells, and potentially lead to malformed brain condition like microrephaly.

To help make sure that it's only Zika virus that's causing this sort of damage though, the scientists ran a third set of experiments; they compared neural stem cells infected with Zika to cells infected with dengue virus 2. See, dengue and Zika are genetically similar, they're both in the Flavivirus genus. So comparing them could provide evidence that it's Zika, specifically, that affect brain cells, and that it's not a flavivirus thing. And it did provide that evidence. The dengue-infected neurospheres survived and grew almost as well as uninfected ones, and much better than the cells infected with Zika virus. Plus, the brain organoids infected with dengue still grew almost normally.

So now we know how Zika virus targets and attacks developing brain cells. But there's still a lot more research to be done to fully understand what Zika does to humans, and how to stop it. 

Now, all this Zika research is being done by trained researchers in laboratories. And you would think quantum physics, the study of the tiniest particles and the strange ways they interact, would be done by highly qualified scientists as well.

But this week, researcher at Aarhus University in Denmark and the University of Turku in Finland announced that they'd developed a way for non-experts to help solve quantum physics problems. And in the process, these non-experts are helping develop quantum computers, which use tiny particles and the principles of quantum physics to store and process information. 

Having lots of people work on scientific research like this can be useful, because humans are a lot better than computers at certain types of problems, like ones that involve looking at images, or spatial puzzle solving. That's why some scientists use gamification, where they turn their research problems into playable computer games, to crowdsource solutions. 

The researchers here designed a game called Quantum Moves, which has human players work on some of the quantum computing problems that have come up as they try to build a quantum computer. Part of their quantum computer's design involves moving atoms around quickly and accurately using a focused laser beam. The less time it takes to move an atom, the better the computer works. But it's hard to program computers to calculate the shortest possible time it would take for an atom-moving operation to go perfectly, because it depends on a lot of different factors. And that is where citizen scientist come in. 

One of the challenges, for example, is called BringHomeWater, where players move the laser beam to collect water, which represents the atoms the quantum computer would be moving. The goal is to move the water to a highlighted area as fast as possible, without "spilling it", which would mean losing the atom. Over hundreds of thousands of plays from thousands of different players, they've been able to find faster, better solutions to moving atoms than the best computer-based algorithms scientist have been using up until now.

And gamers could do all of this without a physics background or sophisticated math, just some creativity, persistence, and experimentation. If you want to try the game out for yourself, there's a link to the game in the description. 

Thank you for watching this episode of SciShow, which is brought to you by our President of Space, who has been challenged me to pronounce his last name correctly, Morgan Lizop. I'm gonna guess. Morgan is currently riding his bike across the US from west to east raising money for the YouTube content he loves, like us here at SciShow and CrashCourse. You can follow his journey at thebigtryhard.com. Thank you and good luck Morgan.

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