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Space travel can seriously change your brain

Researchers have found that microgravity can cause the brain to swell and it can deform the pituitary gland.
Researchers have found that microgravity can cause the brain to swell and it can deform the pituitary gland.
(Image: © Ivar Mendez)

It turns out that spending time in space can change your brain (and you might have to be spun around to prevent it). 

Researchers have been exploring how spaceflight can affect human physiology and human health for as long as we have been working to launch people to space. For example, the groundbreaking Twins Study uncovered a multitude of ways that space changes our bodies — even our gene expression!

But one new study suggests that spaceflight could affect the human brain in strange and unusual ways, which could impair astronaut eyesight and last for a long time.

Related: The Human Body in Space: 6 Weird Facts

Since the days of the shuttle program to today, astronauts have reported issues with vision after traveling to space. Medical evaluations on Earth have revealed that astronauts' optic nerves swell and some experience retinal hemorrhage and other structural changes to their eyes. 

Scientists suspect that these vision issues are caused by increased "intracranial pressure," or pressure in the head, during spaceflight. In a new study led by Dr. Larry Kramer, a radiologist at the University of Texas Health Science Center at Houston, researchers have found evidence that this pressure does, in fact, increase in microgravity. 

In this study, the team performed brain MRI (magnetic resonance imaging, a technique that uses specialized scanners to image parts of the body using magnetic fields) on 11 astronauts (10 men and one woman) both before and after they traveled to space and for up to a year after their return. These MRI images showed that, with long-duration exposure to microgravity, the brain swells and cerebrospinal fluid, which surrounds the brain and spinal cord, increases in volume. 

These findings support the theory that spaceflight increases pressure in the head which researchers think could be tied to issues with astronaut vision, Kramer told

Additionally, Kramer and his colleagues found that the pituitary gland, also changes with exposure to microgravity, Kramer said. They found that the gland became compressed, it changed in height and shape which, as Kramer said, this is a sign of increased pressure in the head. 

Related: Astronauts Use 'Smart Shirt' and Ultrasounds to Monitor Health 

The researchers also found that these effects, the swelling of the brain alongside the compressing pituitary gland and the pressure in the head, was still present a year after the astronauts returned from space. That duration suggests that these effects could be long-lasting, Kramer said. However, further study is needed to evaluate exactly how microgravity affects the brain over an astronaut's lifetime and how this might vary between people, Kramer said. 

Scientists have a number of theories about why the brain swells in space, but what Kramer called "one of the most compelling," is that without gravity, the fluids in our body that usually circulate evenly travel up toward the head and away from the feet, he said. "The blood that normally pools in the extremities redistributes toward the head," he said. "It's not something that we normally experience on Earth unless you're sort of standing on your hands."

Researchers are also working to develop what spaceflight experts call "countermeasures," or techniques that could be used to reduce these negative effects. 

To test countermeasures, research subjects are put on bed rest with their heads tilted downward to simulate the fluid shift scientists believe happens in microgravity. In this position, researchers have found that the optic nerve swells and seen other physical effects that are also seen in spaceflight. "If we can prevent those [effects] in the bed-rest studies, then potentially we can prevent those in microgravity," Kramer said.

One of the countermeasures that researchers are experimenting with is reminiscent of the revolving space station in the sci-fi film "2001: A Space Odyssey," Kramer said. The countermeasure would "spin an astronaut around for a certain portion of the day, just moving the blood through the body and back towards the legs," like an artificial gravity, Kramer said. 

Another countermeasure scientists think may help is a specialized suit for the feet and legs that would help to maintain their fluid levels. 

The work is described in a paper published today (April 14) in the journal the Radiological Society of North America. 

Follow Chelsea Gohd on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

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  • newtons_laws
    Yet more evidence that a long duration manned mission to Mars really needs to be investigating and testing artificial gravity designs for the living quarters during the trip.
  • Torbjorn Larsson
    So space tourists will have swollen heads?

    The study is of a limited material and almost exclusively male, and show modest changes - 2 % mean swelling of brain and its fluid and 13 % increased flow velocities (which may be beneficial) which return to baseline after flight. Uncertainty is low, p < 0.001 on everything that was measured on the whole population, but so was the effect strength. Apart from a supposed connection to "spaceflight-associated neuro-ocular syndrome" they don't report any medical effects.

    I don't like their statistics on partial observations, they simply don't model bias. And MRI correlative studies are iffy, you can study "activity" in dead fish brains.

    I do wish they had made more of the possible study material. The international astronauts were divided into two studies, and this was the smaller.
  • kristi276
    Space travel can seriously alter one's brain, or the lack of gravity can really mess with one's mind. The mean population for the study is relatively small because the population is small; as compared to the overall general population. We don't have hundreds of thousands of people traversing through near orbit, we just have a hand full of astronauts going to the ISS. The study has a gender bias due to the fact that the astronaut core is gender and racially biased. The majority of astronauts are white straight men, with a sprinkling of Asian and Black. Native and Latinos make up less than one percent of the astronaut core. This does not diminish the findings of the study that clearly shows that without gravity there are adverse affects on the human physiology. I do believe that these affects will be magnified as we head towards Mars and beyond. We have "microgravity" due to the close proximity to the nearest center of gravity; Earth. Once we venture away from Mother Earth, the less her influence in on a mass of a traveling object. We are no longer rotating around Earth by traversing the inner space of the solar system; waiting to get tugged into the gravitational influence of Mars. It takes six Earth months to get to Mars. How much hang time do you get when there is no gravity at all; not even microgravity? Astronauts float like a butterfly due to microgravity, can astronauts move when there is a total absence of gravity for several months at a time? How much will the human brain swell due to the lack of gravity? Some one told me that once we are away from our mother; we are under the influence of the sun. I guess we would if we were spinning around the sun and not headed towards Mars or Venus. So when will we design ships with gravity in mind; for a mind is a terrible thing to loss.