By: Jenny Zhou

The swollen chambers in astronauts’ brains may take up to three years to recover after embarking on a space mission which requires the body to adapt to low gravity.

When humans are in space, fluid-filled chambers swell with liquid, helping them adapt to low gravity. However, after returning to Earth, the chambers don’t shrink quickly. In fact, they may even take three years to recover!

There are four chambers in our brains, called ventricles, and extra fluid can build up in there. Many astronauts return home with swollen ventricles. The chambers are filled with liquid that cushions the brain and also clears out cellular wastes. Siedler says the ventricles expand in space as they take in more fluid.

Rachael Seidler, a researcher at the University of Florida examined the MRI scans of 30 astronauts’ brains after space missions. She and her colleagues compared the scans taken before their space missions and the ones taken after. They noticed that the longer the astronauts stayed in space, the more likely it was for three of their ventricles to expand. The fourth ventricle is very small, Seidler notes. Any changes in it are too tiny to see.

Two-week missions in space didn’t have much of an effect. But six-to-12-month missions resulted in larger ventricles. However, during the longer trips, the amount was similar, hinting that the ventricles swell a bit slowly after six months in space.

Astronauts may even need to wait three years before they’re ready to go on their next space mission. Seidler’s research also showed that the time since the astronaut’s last mission also affected the swelling of their ventricles. For the astronauts whose last mission to space was three or more years prior, their ventricles swelled 10 to 25 percent. For the other astronauts who traveled to space less than three years ago, their ventricles didn’t swell much, if at all.

“I’m glad that the [study] authors took the first step and are looking at this question,” says Donna Roberts. She’s a brain-imaging specialist at the Medical University of South Carolina in Charleston. “There are so many variables that could play into the brain changes that we’re seeing,” Roberts says. “It’s hard to sort them out.”

Spaceflight’s effects on the brain are even more pressing now, she notes. NASA aims to send people to Mars, which could be a two-year round trip. “Everybody talks about the rocket technology to get to Mars,” Roberts says. But “the humans — that’s the real challenge.”

Link to article: https://www.snexplores.org/article/swollen-chambers-in-astronauts-brains-may-take-3-years-to-recover