According to a recent study, prolonged exposure to microgravity (weightlessness) leads to structural changes in the brains of astronauts. These changes may be responsible for some of the still unexplained conditions that astronauts experience upon returning from space to Earth.
Study
The researchers examined in detail the images of the brains of 34 astronauts taken before and after they took part in the space mission.
On long missions, usually longer than six months, 18 of the astronauts under study were aboard the International Space Station, and 16 other astronauts participated in short solo flights (approximately two weeks).
Structural changes
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Scans of the astronauts' brains have shown that the brains of most long-term mission participants have undergone several significant structural changes after they returned from the ISS.
Their brains have moved to the apex of the skull and there is much less cerebrospinal fluid inside the skull (cerebrospinal fluid is a clear fluid that circulates in the brain, and is also located in the subarachnoid space of the spinal cord and brain). However, none of the participants in short-duration missions have experienced such changes.
In addition, studies have shown that almost all astronauts who have been on many months of space missions, there was a narrowing of the central sulcus of the brain - the depression that separates the parietal lobes from the frontal lobes. Only 20% of astronauts on short flights have shown this effect.
Effect of microgravity
Despite the fact that scientists have long been aware of the various aspects of the effect of microgravity on the human body, the new study offers one of the most profound and potentially significant assessments of the effect of prolonged stay in space on the human brain.
The structural changes observed in the brains of astronauts, according to scientists, could explain some of the symptoms experienced by astronauts upon returning from the ISS.
In addition, these changes will help scientists in the future create conditions for safer long-term space missions, including manned missions to Mars.
Consequences of being in zero gravity
Scientists hope the results will help them better understand a condition seen in many experienced astronauts known as "intracranial pressure syndrome with visual impairment." Astronauts with this syndrome experience blurred vision, along with swelling of the optic nerve and increased intracranial pressure.
It is not yet clear what exactly leads to the appearance of this state. Three participants in the new study had similar symptoms. At the same time, brain scans of all three showed a narrowing of the central groove of the brain.
The need for further research
The researchers hypothesized that moving the brain to the apex of the skull, along with "pressure" on the tissue, is likely to slow the circulation of cerebrospinal fluid, which in turn increases intracranial pressure and leads to optic nerve tumors. But more research is needed to prove a direct link between structural changes in the brain and "intracranial pressure syndrome with visual impairment." In addition, more research is needed to understand how long these structural changes last.
New research will be able to help researchers determine how permanent and irreversible the changes in the brains of astronauts are, or whether the brains of astronauts eventually return to their usual "earthly" state.
conclusions
Scientists are confident of the need for further research and hope that the new data will help them better study the effects of long-term space travel on the brains of astronauts, as well as help them find effective ways to make even long-term space travel safer. This is necessary so that space expeditions can successfully continue and develop without endangering the health of astronauts.
Hope Chikanchi