NASA Study Reveals Shifts in Astronaut Brains During Spaceflight

Research shows the human brain doesn't remain static in zero gravity, with implications for long-term space travel health

Mar. 28, 2026 at 5:52am

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A new study led by Dr. Rachael Seidler at the University of Florida, published in the Proceedings of the National Academy of Sciences, demonstrates that the human brain shifts and deforms within the skull during and after spaceflight. This discovery has significant implications for the long-term health of astronauts and our understanding of neurological adaptation to the unique conditions of space.

Why it matters

The observed brain shift raises concerns about potential neurological consequences, as the compression of upper brain regions could potentially impair the glymphatic system responsible for clearing waste products. Understanding these effects is crucial for mitigating risks associated with long-duration space travel to the Moon and Mars.

The details

The study analyzed MRI scans of 26 astronauts, taken both before and after space missions ranging from weeks to over a year in duration. Researchers meticulously measured the distance the brain moved within the skull and divided the brain into 130 distinct regions to track movement patterns. The research showed a consistent upward and backward shift of the brain following spaceflight, with astronauts who spent approximately one year on the International Space Station experiencing a movement of over 2mm in some upper brain regions.

  • The study was published in the Proceedings of the National Academy of Sciences on March 28, 2026.
  • The research analyzed MRI scans of astronauts before and after space missions ranging from weeks to over a year in duration.

The players

Dr. Rachael Seidler

A Professor at the University of Florida, specializing in the neural control of movement and the effects of spaceflight on the brain. She is also the Deputy Director of the UF Astraeus Space Institute.

University of Florida

The institution where Dr. Seidler's research team is based and where the study was conducted.

NASA

The U.S. space agency that provided funding and support for the research.

National Space Biomedical Research Institute (NSBRI)

An organization that also provided funding and support for the research on the effects of spaceflight on the human brain.

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What they’re saying

“The observed brain shift raises concerns about potential neurological consequences. The compression of the upper brain regions could potentially impair the glymphatic system, which is responsible for clearing waste products from the brain.”

— Dr. Rachael Seidler, Professor, University of Florida

“Understanding these effects is crucial for mitigating risks associated with long-duration space travel to the Moon and Mars.”

— Dr. Rachael Seidler, Professor, University of Florida

What’s next

Researchers plan to conduct further investigations into the long-term effects of the observed brain shifts, as well as develop countermeasures to protect astronaut health during future missions to the Moon and Mars.

The takeaway

This research highlights the importance of understanding how the human body, particularly the brain, adapts to the unique challenges of space travel. The findings could have broader implications for neurological conditions on Earth, as studying the brain's plasticity and adaptation mechanisms could inform treatments for fluid imbalances or pressure-related issues.