For a long period of time, scientists have been figuring out the negative effects of space travel. Many serious "space diseases" have been found: muscle atrophy, bone changes and deterioration of vision, etc. In a new study, German scientists from Ludwig-Maximilian University of Munich, with the support of colleagues from the University of Gothenburg and the Institute for Medical and Biological Problems of the Russian Academy of Sciences, have identified signs of brain cell damage from blood samples. The researchers monitored five Russian cosmonauts from 2016 to 2020, who spent an average of no more than 169 days on the ISS. Blood samples from the station crew members were taken 20 days before the start of a long space flight, as well as a day, a week and 21-25 days after returning to Earth. It was found that the concentration of neurofilament, glial fibrillary acidic protein and beta-amyloid Aβ40 was significantly increased in men, whose average age was 49 years, after a long stay in space. The first provides structural support for long neuronal sprouts and regulates axon diameter, which affects nerve conduction velocity. The second is the main structural protein of astrocytes of the central nervous system and is considered a biomarker of astroglial pathology in neurological diseases. The third tends to form toxic plaques in the brain, and such accumulations of β-amyloid peptide are a biological sign and factor in the development of dementia and Alzheimer's disease.
"This is the first time concrete evidence of brain cell damage has been recorded in blood tests in humans after spaceflight. Our results should be studied and taken into account if space travel becomes more common in the future," says Professor Henrik Zetterberg.
According to scientists, such changes are caused by a fluid shift, which affected the blood-brain barrier between the circulatory system and the central nervous system. The assumption that the changes described above may be related to brain dysfunction is supported by changes that were also detected by magnetic resonance imaging after space travel. But further research will be needed to understand what is causing the damage.
"If we can figure out the cause of the abnormality, the biomarkers we find will help us understand how best to solve the problem," Zetterberg shares