Astronauts’ brains can change shape and shift positions during stays in space, according to a new study with implications for NASA’s goals to conduct long-duration missions to the moon and Mars.The study, published Monday in the journal Proceedings of the National Academy of Sciences, found that after spaceflight, astronauts’ brains were tilted upward and shifted up and back in the skull relative to their normal positions on Earth. The affected areas of the brain included sensory-related regions linked to motion sickness, disorientation and loss of balance, the scientists found.The research adds to a growing but still nascent field of aerospace medicine focused on the toll that spaceflight and the microgravity environment take on the human body. Such research is crucial for planning long-term missions as NASA looks to build a base on the moon and send astronauts deeper into the solar system.AdvertisementAdvertisementAdvertisementAdvertisement“We need to understand these changes and their impacts to keep astronauts safe and healthy and protect their longevity,” said Rachael Seidler, a professor in the department of applied physiology and kinesiology at the University of Florida and a co-author of the study.Seidler and her colleagues analyzed MRI scans from 26 astronauts before and after their time in orbit. The time the participants spent in space ranged from a few weeks (for space shuttle flights) to roughly six months — the standard duration for missions aboard the International Space Station. A few individuals studied spent extended, yearlong stints at the space station.“The people who went for a year showed the largest changes,” Seidler said. “There were still some changes evident in people who went for two weeks, but duration seems to be the driving factor.”She added that among astronauts who had stayed in space six months or longer, the upward movement was “pretty extensive,” particularly in structures at the top of the brain.AdvertisementAdvertisementAdvertisementAdvertisement“It’s on the order of a couple of millimeters,” she said, “which doesn’t sound like a big number, but when you’re talking about brain movement, it really is. That kind of change is visible by eye.”Seidler said the brain changes observed sometimes caused “sensory conflicts” for astronauts while in space, manifesting as temporary disorientation or motion sickness. Back on Earth, the shifts can also contribute to balance issues as the astronauts readju …
