Researchers point to noteworthy difference in American astronauts’ brains
Scientists from the U.S., Europe and Russia are part of a team releasing the results of a large collaborative study involving the effects of long duration spaceflight on the brain. It appears in the Proceedings of the National Academy of Sciences.
The researchers found that while all of the astronauts and cosmonauts they studied had a similar level of cerebrospinal fluid buildup in the brain, along with reduced space between the brain and the surrounding membrane at the top of the head, there was a noteworthy difference when it came to the Americans. They had more enlargement in the perivascular spaces in the brain, passages that serve as a cleaning system during sleep. That’s something the researchers say warrants further investigation.
Donna Roberts, M.D., a neuroradiologist at the Medical University of South Carolina who helped lead the study, said a challenge when it comes to exploring the effects of spaceflight has been that there aren’t many people in the U.S. who have traveled to space. Combining information about NASA astronauts with that of Russian cosmonauts and astronauts from the European Space Agency gave the study depth.
“By putting all our data together, we have a larger subject number. That’s important when you do this type of study. When you’re looking for statistical significance, you need to have larger numbers of subjects.”
The study focused on 24 Americans, 13 Russians and a small, unspecified number of astronauts from the ESA. It used MRI scans of their brains before and after six months on the International Space Station to evaluate changes in the perivascular spaces.
Lead researcher Floris Wuyts, Ph.D., a professor at the University of Antwerp in Belgium, put the scope of the project in perspective. “I think it is one of the largest studies on space data, and for sure, one of the very few studies with NASA, ESA and Roscosmos data. It comprises data of almost 10% of all people who went into space.” Roscosmos is the Russian space corporation.
Fellow researcher and neuroscientist Giuseppe Barisano, M.D., Ph.D., who works at the University of Southern California, said they looked for differences between the crews. “And in this analysis, we found an increased volume of fluid-filled channels in the brain after spaceflight that was more prominent in the NASA crew than in the Roscosmos crew.”
Roberts explained what that might mean. “An important implication of our findings is that the volume of fluid-filled channels in the brain of astronauts is linked to the development of the spaceflight-associated neuro-ocular syndrome, a syndrome characterized by vision changes and whose mechanisms are still not completely clear.”
But space physiologist Elena Tomilovskaya, Ph.D., of the Russian Academy of Sciences, said further study is needed to determine if there are clinical implications for future flights. “We need to understand how specific microgravity-countermeasure usage, exercise regimes, diet and other factors may play a role in the differences we found between crews.”
Roberts agreed. “It is important not to speculate about pathology or brain health problems at this time. The observed effects are very small, but there are significant changes when we compare the post-flight scans with the preflight scans,” she said.
The idea for the large study came about as the scientists gathered at annual meetings held by NASA and ESA. “Independently, we had previously reported similar changes in space crews at post-flight brain MRI, including enlargement of the cerebral ventricles. We discussed our findings and realized how valuable it would be to perform a joint analysis of our data. I would like to point out that Dr. Wuyts, in particular, was instrumental in organizing our group, which met regularly for two years to carry out this analysis,” Roberts said.“I believe it highlights the importance of international cooperation in understanding the effects of long-term spaceflight on the human body. In fact, we believe international cooperation in space medicine research is essential to ensure the safety of our crews as we return to the Moon and on to Mars.”
The study, “The effect of prolonged spaceflight on cerebrospinal fluid and perivascular spaces of astronauts and cosmonauts,” was funded by the Russian Academy of Sciences, NASA, ESA, the Belgian Science Policy Prodex, FWO Flanders and the National Institute of Mental Health at the National Institutes of Health in the U.S.
For more information and to see graphics and photos, please check out our Catalyst news story.
Founded in 1824 in Charleston, MUSC is the state’s only comprehensive academic health system, with a unique mission to preserve and optimize human life in South Carolina through education, research and patient care. Each year, MUSC educates more than 3,000 students in six colleges – Dental Medicine, Graduate Studies, Health Professions, Medicine, Nursing and Pharmacy – and trains more than 850 residents and fellows in its health system. MUSC brought in more than $327.6 million in research funds in fiscal year 2021, leading the state overall in research funding. MUSC also leads the state in federal and National Institutes of Health funding, with more than $220 million. For information on academic programs, visit musc.edu.
As the health care system of the Medical University of South Carolina, MUSC Health is dedicated to delivering the highest quality and safest patient care while educating and training generations of outstanding health care providers and leaders to serve the people of South Carolina and beyond. Patient care is provided at 14 hospitals with approximately 2,500 beds and five additional hospital locations in development; more than 350 telehealth sites, with connectivity to patients’ homes; and nearly 750 care locations situated in all regions of South Carolina. In 2021, for the seventh consecutive year, U.S. News & World Report named MUSC Health the No. 1 hospital in South Carolina. To learn more about clinical patient services, visit muschealth.org.
MUSC and its affiliates have collective annual budgets totaling $4.4 billion. The nearly 25,000 MUSC team members include world-class faculty, physicians, specialty providers, scientists, students, affiliates and care team members who deliver and support groundbreaking education, research, and patient care.