Brain Shifts in Space: How Length of Mission and Time Between Flights Affect Brain Fluid

Spaceflight can have a significant impact on the human body, and researchers are still trying to understand the details. In a recent study, scientists explored the relationship between the length of space missions and the time between them and the fluid in the human brain. The cerebrospinal fluid, stored in the brain in four pockets called ventricles, protects the brain and helps wash away cellular waste while delivering nutrients.

Research Findings

The study, published by University of Florida neuroscientist Heather McGregor and colleagues, along with researchers from NASA Johnson Space Centre and other US institutions, found that the increase in ventricle size and brain fluid volume depends on certain factors, including the length of time astronauts spend in space and the intervals between their space endeavors. The team discovered that ventricle expansion continues with spaceflight and that its rate of change depends on the duration of missions. The longer the spaceflight, the greater the increase in ventricle size, up to about six months, where the rate of change seems to plateau.

The research also showed that intermission intervals of fewer than three years may not allow sufficient time for the ventricles to recover their compensatory capacity. For astronauts who had a break of fewer than three years between missions, ventricle expansion was not as prominent. The team suggests that this means there’s not enough time for the brain ventricles to shrink and reset themselves to cope with the increases in cerebrospinal fluid.

The scans also showed that the more previous missions an astronaut had done, the less noticeable the increase in ventricle size was after a mission. The researchers suggested that the brains of these astronauts were “less compliant” due to earlier expansions or had maxed out their capacity for coping with the stressors of spaceflight.

Impact on Health

Although the study did not delve into the subsequent health impacts of changes in ventricle size and brain fluid levels, previous research has linked additional cerebrospinal fluid with vision problems for astronauts. With longer missions planned to the Moon and Mars in the coming years, understanding how different bodies and brains are impacted will be essential.

The findings of this study illustrate some potential plateaus and boundaries of human brain changes with spaceflight. As only 636 individuals have ever gone to space, analyzing the effects of spaceflight on larger groups of people is crucial to gain a better understanding of the impact on the human body. With this study, researchers have uncovered how the length of space missions and the time between them impact the brain’s fluid and ventricle size, providing important insights into how the brain shifts in space.