Just recently, experts discovered DNA changes in one astronaut after almost a year in space. Now this new findings say, MRIs before and after space missions reveal that the astronauts' brains compress and expand during spaceflight.
The study conducted by experts at the University of Michigan is the first to examine structural changes that take place in astronauts' brains during spaceflight. They learned that the volume of gray matter
increased or decreased, and the extent of the alteration depended on the length of time spent in space
The top row shows brain changes with long duration bed rest; the bottom row shows brain changes with spaceflight. Orange shows regions of increase; blue = decrease. There is some overlap but also notable differences with spaceflight showing more changes in the cerebellum, a structure that is involved in motor learning. (c) University of Michigan
"We found large regions of gray matter volume decreases, which could be related to redistribution of cerebrospinal fluid in space," Seidler said in a statement
. "Gravity is not available to pull fluids down in the body, resulting in so-called puffy face in space. This may result in a shift of brain position or compression."
For the study, principal investigator Rachael Seidler and her team examined structural MRIs in 12 astronauts who spent two weeks as shuttle crew members, and 14 who spent six months on the International Space Station. All experienced increases and decreases in gray matter in different parts of the brain, with more profound changes the longer the astronauts spent in space.
"In space, it's an extreme example of neuroplasticity in the brain because you're in a microgravity environment 24 hours a day," Seidler said.
The reason behind the changes in the brain isn't yet confirmed. However, experts said they are looking forward to deeper studies about how long the brain changes last, as well as the repercussions on cognition and physical performance.
"The behavior may return to normal, but the way the brain controls the behavior may change," she said.