Space attacks the human body in several possible ways. Radiation, whose prolonged exposure has negative effects, microgravity, which affects the bones and spine. The lack of gravity, therefore, weakens the bone system, also causes weight loss and even vision problems, among other effects of space.
Now, then, a new study in the journal Science Advances analyzed the brain fluid of 11 cosmonauts (Russian astronauts) who traveled to the ISS (International Space Station). The brain is quite plastic to changes – and the study, which scanned the cosmonauts’ brains, showed this neuroplasticity in great detail.
“With the techniques we use, we can clearly see that there are microstructural changes in three main areas of the brain that are involved in motor processing,” said lead author Steven Jillings, a neuroscientist at the University of Antwerp, Belgium, when The Guardian.
Scientists scanned the brains of cosmonauts at three different times. They are: before flights, nine days after returning to Earth and six to seven months after returning. The method used is called diffusion-weighted magnetic resonance (dMRI), and creates a map of the diffusivity of water molecules present in tissues. The average mission time was 171 days.
General findings of the effects of space
The cerebrospinal fluid (CSF), which bathes the brain in the surroundings, has been redistributed in microgravity. In this process, then, the liquid pushes the brain to the top of the skull. This is possibly associated, above all. loss of clarity in vision, due to the effects of repositioning the brain in some cavities in the brain.
CSF helps protect the brain (such as a mattress or shock absorber). In addition, it plays an important role in cleaning nerve tissue residues.
Effects on brain ventricles, which produce and help CSF flow, are responsible for vision problems. More precisely, obstacles to normal fluid circulation. It is not something like an increase in brain pressure, but it does affect vision somehow.
Miscellaneous structural changes
The main microstructural changes are in the primary motor cortex, responsible for signs of movement, as its name suggests; the cerebellum, whose role is in balance and fine movements and in the basal ganglia, responsible, among several tasks, for actions related to the motor system.
Although the brain adapts again to Earth, some of the changes were still present even after the seven months were back on Earth. That is, cosmonauts and astronauts do not “heal” completely.
“What we see makes a lot of sense. It is a sign of the complex situation that cosmonauts are in and that they are learning to adapt to this extreme environment ”, says the senior author, Floris Wuyts, to the The Guardian. “Something so different in space is the lack of gravity. If there is a lack of gravity, you will have to relearn how to move properly ”.
“Seven months after the space mission, most of the initial post-flight changes recovered to pre-flight levels, although ventricular enlargement persisted and the GM or WM tissue remained increased to some degree in the sensory-motor brain areas.” explains the team in the study.
Jillings became interested in the subject when his supervisor, Wuyts, senior author of this new study, proposed, in 2009, MRI scans to study brain neuroplasticity. In 2013 the project starts and Jillings joins the group in 2016. In 2017, at last, the researchers finished their preparations, with enough statisticians for the main part of the study – the tests with cosmonauts.
In this way, new magnetic resonance techniques used in future studies will bring new details and new responses to the effects of space on the brain. The organ always impresses with such plasticity, governed by the current situation.
The study was published in the journal Science Advances. With information from Space.com and The Guardian.