Long periods of space not only lead to muscle atrophy and reduced bone density, but also have long-lasting effects on the brain, a study suggests.
The study was led by a team of neuroscientists from the University of Antwerp in Belgium and the Ludwig Maximilians University (LMU) in Munich, showed that differential changes in the three main tissue volumes of the brain for at least half a year after the end of their last mission are demonstrable.
"Our results show prolonged changes in the pattern of CSF circulation over a period of at least seven months after returning to Earth," said Professor Peter zu Eulenburg of LMU.
"However, whether the extensive changes in gray are shown or not, and the white matter leading to any changes in cognition, remains unclear at the time." The study, published in the New England Journal of Medicine, was published ten cosmonauts, each of whom spent an average of one month, spent 1
Magnetic resonance imaging (MRI), which was performed in the days after the return to Earth, showed that the volume of gray matter was reduced compared to before starting.
Seven months later, this effect was partially reversed but still detectable.
In contrast, the volume of cerebral and cerebral fluid filling the inner and outer cavities of the brain increased during long-term exposure to microgravity in the cortex.
The tissue volume of the white matter (those parts of the brain that are predominantly Nerve fibers) appeared to be unchanged on examination immediately after landing.
However, the subsequent study at six months showed a widespread volume reduction relative to both previous measurements.
In this case, the team postulated that during a prolonged stay in space, the volume of white matter may be slowly replaced by an influx of cerebrospinal fluid.
On return to Earth, this process is then reversed gradually, which then leads to a relative decrease in the volume of white matter.
According to the researchers, further studies with a wider range of diagnostic methods are considered essential to minimize the risks associated with long-term missions and to characterize clinical findings.