Scientists have documented the effects of space travel on the human brain

With microgravity conditions and other things messing with our physiology from head to toe, space may be an unfavorable environment for the human body, with the skull, of course, being the major worry. Deeper insight into the problem is provided by a recent NASA-funded research. The cerebral ventricles, which are areas in the centre of the brain that store cerebrospinal fluid, significantly expanded in size in astronauts who embarked on missions lasting at least six months aboard the International Space Station (ISS) or NASA space shuttles, according to researchers on Thursday.

This watery, colorless fluid circulates inside of and around the brain and spinal cord. It eliminates waste materials and cushions the brain to help defend against unexpected impacts.

According to studies based on brain scans of 30 astronauts, it takes three years for the ventricles to completely recuperate after such travels, indicating that at least as much of a gap would be prudent between lengthier space missions.

“The brain’s capacity to adapt to fluid fluctuations in microgravity may be impacted if the ventricles don’t have enough time to heal between back-to-back trips. For instance, the ventricles may be less flexible and/or have less room to expand and accommodate fluid shifts during the following mission if they have already grown larger from a prior mission, according to University of Florida neuroscientist Heather McGregor, lead author of the study published in the journal Scientific Reports.

Cognitive impairment may be linked to aging-related ventricular enlargement, which is brought on by brain shrinkage rather than microgravity.

“At this time, it is unknown how ventricular enlargement affects space travelers. There should be more long-term health monitoring. Rachael Seidler, a professor of applied physiology and kinesiology at the University of Florida and the study’s main author, speculated that this ventricular enlargement likely compresses the nearby brain matter.

The brain is altered by the lack of Earth’s gravity.

According to Seidler, “this appears to be a mechanical effect.” “On Earth, we have valves in our circulatory systems that keep all of our fluids from pooling at our feet as a result of gravity. In contrast, fluids go toward the head in microgravity. The brain sits higher inside the skull as a consequence of this fluid shift toward the head, which probably causes ventricular enlargement.

The research included 23 male and 7 female astronauts from the American, Canadian, and European space agencies, with an average age of roughly 47. Eight people made two-week long space shuttle trips. 18 were on ISS trips that lasted around six months, while four were on missions that lasted almost a year.

After brief voyages, astronauts’ ventricular volumes changed very little or not at all. Although there was no difference between astronauts who flew for six months compared to those who did so for a year, enlargement happened after missions lasting six months or longer.

According to McGregor, “this suggests that the majority of ventricle enlargement occurs during the first six months in space, then taper off around the one-year mark.”

It may be good news for future Mars missions where astronauts may spend two years in microgravity throughout the voyage as the growth did not become worse after six months.

This early conclusion is encouraging for astronaut brain health during lengthy trips, but it’s also crucial that we look at MRI data from a wider sample of astronauts and after even longer missions, according to McGregor.

According to Seidler, the lack of enlargement after brief flights was positive news for anyone who may contemplate taking brief space tourism excursions as that business grows.

Because the human body is under less physical strain in microgravity, there are additional physiological impacts that arise. These include cardiovascular abnormalities, problems with the inner ear’s balance system, bone and muscular atrophy, and an eye condition. Another issue is the increased danger of cancer brought on by astronauts’ increased exposure to solar radiation as they go further away from Earth.