Spaceflight Can Have Long-Lasting Effect On Human Brain

Even before the arrival of the first rocket, men had dreamt of reaching the stars. We do know for a fact that space exploration is going to change our civilization permanently. However, scientists are just beginning to discover the effects outer space would cause to our body.

According to a study released in the academic journal Proceedings of the National Academy of Sciences, bodily changes occurring in the microgravity environment can remain for months after the astronaut returned to Earth. And the part of our body that is most extensively changed by the experience is the brain.

Ventricular Enlargement

Angelique van Ombergen, Ph.D. is a postdoctoral researcher hailing from the University of Antwerp who spearheaded the research. In the process, she and her team found how spaceflight actually alters the way that cerebral spinal fluids move in the brain’s ventricles. They are the hollow cavities within the brain that allow the fluid to flow smoothly.

The microgravity environment astronauts had to deal with throughout a mission cause the fluid to push upward and expand slightly three ventricles out of four within the human’s brain. This is the official finding after sampling 11 cosmonauts. Over an average mission of 169 days, these cavities enlarged by about 11.6% in comparison to ordinary people’s on Earth.

The expanded vessels did gradually shrink back to normal. However, they do it at an extremely slow rate. Even when the cosmonauts had returned to Earth for seven months, their brain’s ventricles were still larger than normal by 6.4%.

Additional Data

Van Ombergen stated that more research needs doing, but she concluded that there could be potentially two consequences.

“No specific neurological investigations were done as part of the twin study to the best of my knowledge, but cognition was checked,” she affirmed that the data that her research had reaped seem to be complementary to the Twin study of NASA.

Astronaut Scott Kelley, after returning from the ISS, underwent a number of studies on his blood, genes, and cells to detect changes. They concluded that his state of health was optimistic and that there didn’t seem to be any permanent or damaging changes to his body.

Van Ombergen’s data added to the existing knowledge on the biological changes of humans in space. Even though extensive tests were conducted on both Scott and Mark Kelley, the results published in April did not include a brain scan or analysis into the brain.

Side-Effects of Ventricle Enlargement

It is common sense that when anything shifted from its ordinary state within the brain, there can be changes to the person and his/her behaviors or functions. Though Van Ombergen considered that this could be a possibility, her paper did not pinpoint exactly what these changes could be.

Her study could explain why an eye condition prevalent in astronauts called Spaceflight Neuro-ocular Syndrome (SANS). This is something that has been troubling NASA and other space agencies for years and it is considered to be one of the barriers to deep space exploration and habitation. SANS manifested itself in the form of degraded vision acuity when the person lived and worked for an extensive period of time in space.

A NASA report from 2017 stated that SANS affected from 37.5% to as many as 51% of astronauts who had conducted mission on the ISS. There were past studies attempting to explain this by proposing that a shift in cerebrospinal fluid can change the pressures on the eyes, resulting in the changes in vision acuity.

Though she didn’t mention explicitly that cerebral fluid shifts are the perpetrator behind SANS. She did say that the enlargement of ventricular volumes in the brain is correlated with degradation of vision in the left eye. It’s a pretty small effect, though it is highly visible in her paper.

Closer to Space

For every astronaut that has returned home safe and sound from space, we learned a little bit more about how the human body would react to space. And although we are still quite a long distance away from discovering all there are to know about the physical consequences of spaceflight or give us answers on bugging questions such as SANS. And with each study like the one Van Ombergen's conducted, we are a little bit closer to conquering space.