You’ve probably heard from various sources already that astronauts grow slightly taller when they’re in space. Or even that their muscles atrophy after a long time in space. But did you know their brains get affected as well when they go on long space missions? A recent study led by a team of neuroscientists from the University of Antwerp in Belgium and Ludwig-Maximilians-University (LMU) of Munich showed that differential changes in the three main volumes of tissue in the brain remain detectable for at least six months after a long space mission is complete.
“Our results point to prolonged changes in the pattern of cerebrospinal fluid circulation over a period of at least seven months following the return to Earth,” commented Prof Peter Zu Eulenburg from the LMU. “However, whether or not the extensive alterations shown in the grey and the white matter lead to any changes in cognition remains unclear at present,” he added.
Reported later in the New England Journal of Medicine, the study was performed on ten cosmonauts right after their return from space. Each of them had spent an average of 189 days aboard the International Space Station, reports Devdiscourse. Results of the magnetic resonance tomography (MRT) scans showed that the volume of grey matter in the central nervous system had reduced compared to before the mission. However, this effect became partly reversed seven months later but remained detectable nonetheless.
On the other hand, the volume of cerebrospinal fluid, which fills the inner and outer cavities of the brain, had increased within the cortex with long-term exposure to microgravity. Six months later, this volume had reduced considerably, leaving the team postulating that the cerebrospinal fluid could have replaced the white matter, which was originally believed to be unchanged after the return from space. The scientists believe that a wider range of diagnostic methods is essential to minimise the risks associated with long-term space missions in the future.