Aerospace medicine experts have long known that prolonged stays in space, in a low-gravity environment, take their toll on astronauts.
In addition to being more exposed to certain radiation, capable of damaging DNA, your bone mass can be reduced by up to 2% per month and the muscles in your extremities tend to atrophy. Rather, their head swells, causing many severe headaches. Now, a multidisciplinary team of researchers coordinated by scientists from the University of Antwerp, in Belgium, has discovered that, in the same way, your brain also experiences alterations.
“We have found that there are changes in gray matter, white matter and cerebrospinal fluid,” says Angelique Van Ombergen, a specialist in neuroplasticity from the aforementioned Belgian institution, who has participated in this initiative. “Some can be detected up to seven months after their mission has ended,” he stresses.
Persistent changes
To determine this, Van Ombergen and his collaborators asked a group of ten cosmonauts to undergo an MRI study shortly before they left for space, just after their return – on average, they had spent half a year away from Earth. Earth– and, again, seven months later. “In the first phase of the trial, we focused exclusively on the composition of the brain and its anatomical structure; we put aside the analysis of the most functional aspects ”, says the researcher.
In this way, they realized that the scans they had done on their return showed changes in different types of tissue. Steven Jillings, from the Department of Physics at the University of Antwerp, explains: “The volume of gray matter – a type of neural tissue that is related to the processing and interpretation of information – had been reduced throughout the brain. We also detect changes in cerebrospinal fluid, a colorless substance that, among other things, protects the nervous system and removes waste products from the brains. Low gravity causes a redistribution of fluids, so that they reach the astronauts’ heads in greater quantities. There seems to be a disturbance in the flow of the cerebrospinal fluid, something that persists after the mission ”.
Vision problems
After seven months, the cosmonauts went through the scanner again. The gray matter then looked much more like it had before its foray into space, but certain differences were still perceptible. These were still noticeable in the aforementioned cerebrospinal fluid. The authors of this work, who have published in The New England Journal of Medicine , emphasize that it will be necessary to carry out more studies to know what this phenomenon is due to and the possible consequences it could have. In principle, they suggest that it could be related in some way to the visual acuity problems that some astronauts who have spent a long time away from Earth have presented.
Image: NASA
Reference: Brain Tissue – Volume Changes in Cosmonauts . Angelique Van Ombergen et al. The New England Journal of Medicine (2018) . DOI: 10.1056 / NEJMc1809011
