The brains of astronauts adapt to the space environment, but it is not yet known how much. In this pioneering study, researchers were able to discover how connections can change after a stay on the ISS.
Life in space undeniably has an impact on the body of astronauts. Their bones are put to the test and this is one of the reasons why Thomas Pesquet had to learn to walk again upon his return to Earth. But what about the impact of extreme space environment on the brain?
New data have been obtained using a novel technique of ‘diffusion imaging’ tractography. In French, these are scanners that make it possible to highlight, with high precision, the structure and connections within the human brain. These are 12 astronauts (men) who were followed with these scans, carried out before then several times after their stay in the international space station — stay which lasted 172 days on average for these participants.
The results, the fruit of a collaboration between the European Space Agency and the Russian agency Roscomos, were published on February 18, 2022. What exactly do they show us about the brains of these astronauts?
Changes in brain connections are significant
« We found changes in neural connections between several motor areas of the brain », note the authors in a communicated. Thanks to the scans carried out with these 12 astronauts, the researchers discovered that the brain evolves significantly in certain connections. They also observed changes in fluid distribution and shapes. Those are ” significant micro-structural changes “, write the authors.
There is nothing surprising in itself that the environment has such an influence: the plasticity of the brain is known, and it is thanks to it that we constantly learn, that memories are constantly added. Likewise, we already knew that space affects the brain (a study of April 2020 was talking about it). But since this research mobilizes innovative scanner technology, the researchers were able to go further in exploring the impacted neural circuits. As a result, these changes caused by the space environment are described like ” very new and very unexpected ».
How to explain these reconnections? Physics and kinesthesia (perception of movement) are different in the spatial environment. This changes the representation and control of the body. What happens in the brain therefore comes reflect this altered sensorimotor function in space ».
The way we move has an impact on our brain: we are also “wired” according to how we move. ” Motor areas are brain centers where movement commands are initiated. In weightlessness, an astronaut must drastically adapt his movement strategies in relation to the Earth. Our study shows that their brains are, so to speak, rewired “, explain the authors.
That motor areas show signs of adaptation after spaceflight is therefore not surprising, but with this study, “ we have a first indication that this is also reflected in the connections between these regions “. And this is just the beginning of research into the effects of the environment on our bodies and our brains.