Spending a long time in space appears to cause brain damage. This is shown by
a study of five Russian cosmonauts who had stayed on the International Space
Station (ISS). Researchers at the University of Gothenburg are among those now
presenting the results.
The study is published in the scientific journal JAMA Neurology. Its
co-authors at the University, scientists from the Institute of Neuroscience
and Physiology at Sahlgrenska Academy, wrote it jointly with colleagues in
Moscow and Munich.
The scientists followed five male Russian cosmonauts working on the
permanently manned International Space Station (ISS), which is in orbit 400
km from Earth’s surface.
The adverse effects on the body of long periods in space have been known for
some time. The negative changes include atrophic muscles, decreasing bone
mass, deteriorating vision and altered bacterial flora in the gut.
Evidence of brain damage
Blood samples were taken from the cosmonauts 20 days before their departure
to the ISS. On average, they then stayed in space for 169 days
(approximately five and a half months). The participants’ mean age was 49.
After their return to Earth, follow-up blood samples were taken on three
occasions: one day, one week, and about three weeks respectively after
landing. Five biomarkers for brain damage were analyzed. They were
neurofilament light (NFL), glial fibrillary acidic protein (GFAP), total tau
(T-tau), and two amyloid beta proteins.
For three of the biomarkers — NFL, GFAP and the amyloid beta protein Aβ40 —
the concentrations were significantly elevated after the space sojourn. The
peak readings did not occur simultaneously after the men’s return to Earth,
but their biomarker trends nonetheless broadly tallied over time.
“This is the first time that concrete proof of brain-cell damage has been
documented in blood tests following space flights. This must be explored
further and prevented if space travel is to become more common in the
future,” says Henrik Zetterberg, professor of neuroscience and one of the
study’s two senior coauthors.
Several studies underway
”To get there, we must help one another to find out why the damage arises.
Is it being weightless, changes in brain fluid, or stressors associated with
launch and landing, or is it caused by something else? Here, loads of
exciting experimental studies on humans can be done on Earth,” he continues.
The notion that the changes concerned may have a bearing on brain function
is substantiated by changes also seen in magnetic resonance imaging (MRI) of
the brain after space travel. Further support is provided by clinical tests
of the men’s brain function that show deviations linked to their assignments
in space. However, the present study was too small to investigate these
associations in detail.
Zetterberg and his coauthors at the University, scientist Nicholas Ashton
and Professor Kaj Blennow, are currently discussing follow-up studies with
their other fellow researchers involved in the study, and also with national
and international space research institutes.
“If we can sort out what causes the damage, the biomarkers we’ve developed
may help us find out how best to remedy the problem,” Zetterberg says.
Reference:
Peter zu Eulenburg, Judith-Irina Buchheim, Nicholas J. Ashton, Galina
Vassilieva, Kaj Blennow, Henrik Zetterberg, Alexander Choukér. Changes in
Blood Biomarkers of Brain Injury and Degeneration Following Long-Duration
Spaceflight. JAMA Neurology, 2021;
DOI: 10.1001/jamaneurol.2021.3589
No comments:
Post a Comment