While scientists are still studying the myriad effects prolonged spaceflights can have on the human body, a new study has cast light on how Astronauts’ brains change shape during spaceflight. MRIs obtained before and after space missions point at something really interesting – astronauts’ brains change shape by compressing and expanding during spaceflight.

MRI reveals how Astronauts’ brains change shape during spaceflight
According to a recent study by the University of Michigan, the examination of structural MRIs in 12 astronauts who spent two weeks as shuttle crew members and 14 astronauts who were on-board the International Space Station revealed increases and decreases in gray matter in different parts of the brain. The changes were directly related to the amount of time astronauts spent in space – the longer the astronauts spent in space the more pronounced the changes. Explaining the observed changes in brain shape, Rachael Seidler, principal investigator and University of Michigan Professor of Kinesiology and Psychology, says –
“We found large regions of gray matter volume decreases, which could be related to redistribution of cerebrospinal fluid in space. Gravity is not available to pull fluids down in the body, resulting in the so-called puffy face in space. This may result in a shift of brain position or compression.”
Increase in gray matter volume
The study also cast light on how gray matter volume changes during spaceflight. The researchers found the increase in gray matter volume in specific regions. Regions controlling leg movement and those involved in processing sensory information from the legs showed changes in gray matter volume. These changes were more pronounced in astronauts since their brains were learning and adapting throughout the day. The changes observed were similar to the one you would observe in someone practicing a new skill 24×7. “It’s interesting because even if you love something you won’t practice more than an hour a day. In space, it’s an extreme example of neuroplasticity in the brain because you’re in a microgravity environment 24 hours a day”, adds Seidler.
The new findings are likely to throw more light on new ways of thinking about health conditions, specifically in cases where people are on long-duration bed rest or people with a condition where cerebrospinal fluid accumulates in ventricles in the brain and causes pressure. Seidler is already leading a new long-term study that will determine the effects on cognition and physical performance.