Astronauts’ brains “rewired” during space missions

A new study was published in Boundaries in neural circuits He is the first to analyze The structural connectivity that occurs in the brain changes after a long-duration spaceflight. The results show significant changes in the microstructure in many white matter tracts such as the sensory tracts. The study could form the basis for future research into the full range of brain changes during human space exploration.

Our brain can change and adapt in structure and function throughout our lives. With human space exploration reaching new heights, understanding the effects of spaceflight on human brains is crucial. Previous research has shown that spaceflight has the potential to alter the look and function of an adult brain.

Through a collaborative project between the European Space Agency (ESA) and Roscosmos, a team of international researchers led by Dr. Floris Wittes from the University of Antwerp has studied the brains of humans traveling in space.

Wuyts and colleagues have, for the first time, investigated structural changes in the brain after spaceflight at the level of the white matter tracts deep in the brain.

White matter refers to the parts of the brain responsible for communication between gray matter and the body and between different gray matter regions. In short, white matter is the brain’s communication channel and gray matter is where information is processed.

The educated brain

To study the structure and function of the brain after spaceflight, the researchers used a brain imaging technology called fiber optics.

Imaging the tract with fibers gives a kind of wiring diagram of the brain. Our study is the first to use this specific method to detect changes in brain structure after spaceflight, Yates explained.

Wuyts and his team obtained propagation magnetic resonance imaging (dMRI) scans of 12 male astronauts just before and after their spaceflights. They also collected eight follow-up scans, seven months into the spaceflight. The astronauts all participated in long-duration missions with an average length of 172 days.

Researchers have found evidence for the concept of a “learned brain.” In other words, the level of neuroplasticity must adapt to spaceflight. “We found changes in the neural connections between several motor areas in the brain,” said first author Andrei Doroshin from Drexel University. “Motor areas are the centers of the brain where movements orders are initiated. In the state of weightlessness, the astronaut needs to radically adapt their movement strategies, compared to the Earth. Our study shows that their brain is rewired, so to speak.”

Follow-up examinations revealed that seven months after returning to Earth, these changes were still visible.

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

The authors also found an explanation for the anatomical brain shifts observed after spaceflight.

“We initially thought we had detected changes in corpus callosumwhich is the central highway that connects the two hemispheres of the brain,” Wyatt explained corpus callosum They border the brain’s ventricles, a connected network of fluid-filled chambers, which expand due to space travel.

“The structural changes that we initially found in corpus callosum It’s actually caused by the dilation of the ventricles that causes anatomical shifts of neighboring nerve tissue,” Wuyts said. “Where it was initially thought that there were real structural changes in the brain, we only notice shape changes. This puts the results in a different perspective. “

The future of spaceflight research

The study demonstrates the need to understand how spaceflight affects our bodies, specifically through long-term research on the effects on the human brain. Current countermeasures for muscle and bone loss exist, such as exercising for at least two hours a day. Future research may provide evidence that countermeasures are necessary for the brain.

“These results give us additional pieces of the whole puzzle. Because this research is so ground-breaking, we don’t know what the entire puzzle will yet look like. These results contribute to our overall understanding of what’s going on in the brains of space travelers. It’s essential to preserve this line of Research, looking for brain changes caused by spaceflight from different perspectives and using different techniques.

Reference: “Brain connectivity changes in space travelers after a long-duration spaceflight” by Andrei Doroshin, Stephen Gillings, Ben Goresin, Elena Tomilovskaya, Ekaterina Pechenkova, Inna Nosikova, Alina Rumchiskaya, Lyudmila Litvinova, Ilya Rukavishnikov, Chloe Kathuen and Jan Siberis , Viktor Petrovichev, Angelique van Ombergen, Jitka Anen, Stefan Sonnaert, Paul M. Parzel, Valentin Sinitsyn, Peter zu Jullenberg, Karol Osipovich and Floris L. Yates, February 18, 2022, Boundaries in neural circuits.
DOI: 10.3389 / fncir.2022.815838