Cosmonaut brains are "rewired" during long spaceflights

A new study has identified structural connectivity changes that “rewire” the brains of cosmonauts during space missions. To study the changing of the human brain due to spaceflight, the scientists studied brain images created using fiber tractography. 

The research was a collaboration between the European Space Agency (ESA) and Roscosmos led by Dr. Floris Wuyts.

“Fiber tractography gives a sort of wiring scheme of the brain. Our study is the first to use this specific method to detect changes in brain structure after spaceflight,” explained Wuyts. 

“From previous studies, we know that these motor areas show signs of adaptation after spaceflight. Now, we have a first indication that it is also reflected at the level of connections between those regions,”

The research team studied images of the brains of 12 male cosmonauts before and immediately after spaceflight, as well as eight scans seven months after the flight. All of the cosmonauts were on long flights, averaging 172 days. 

Motor function control in the brain seemed to adjust over time, to compensate for weightlessness. Even seven months after a return to earth, these changes in the brain were still visible. There were also changes in anatomy seen immediately after spaceflight that the researchers were able to explain. 

“We initially thought to have detected changes in the corpus callosum, which is the central highway connecting both hemispheres of the brain,” explained Wuyts. “The structural changes we initially found in the corpus callosum are actually caused by the dilation of the ventricles that induce anatomical shifts of the adjacent neural tissue.”

“Where initially it was thought that there are real structural changes in the brain, we only observe shape changes. This puts the findings in a different perspective.”

The research shows one small piece of how humans change during spaceflight, something important to understand if we continue to explore space into the future. 

“These findings give us additional pieces of the entire puzzle. Since this research is so pioneering, we don’t know how the whole puzzle will look yet. These results contribute to our overall understanding of what’s going on in the brains of space travelers,” said Wuyts.

“It is crucial to maintain this line of research, looking for spaceflight induced brain changes from different perspectives and using different techniques.”

The study is published in the journal Frontiers in Neural Circuits. 

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By Zach Fitzner, Earth.com Staff Writer