The low dose radiation present in deep space has shown to have adverse neural and behavioral effects on mice.
Researchers at the University of California, Irvine, Stamford University, Colorado State University and the Eastern Virginia School of Medicine, led by Charles Limoli, set out to investigate how deep space travel would impact the nervous system and found radiation exposure hurt cellular signaling in the hippocampus and prefrontal cortex of the brain leading to learning and memory difficulties in the tested mice.
Space Radiation Causes Memory Loss, Anxiety
The researchers, who published their findings in eNeuro, also saw the mice exhibit behaviors associated with anxiety, implying the radiation can harm the amygdala, which is located within the temporal lobes of the brain.
The mice were exposed to a chronic, low dose of radiation for a period of six months. As a result of the study, researchers predicted that one in five astronauts would experience anxiety during a deep space mission, while one in three would have memory impairments. Some of the astronauts could also struggle with making sound decisions, the researchers concluded.
Research on Space's Impact to Astronauts Picking Up Momentum
With NASA preparing to send astronauts to Mars in 2020, a lot of work is being done to limit the impact that deep space has on the minds and bodies of astronauts.
In July, researchers at UT Southwestern Medical Center and Texas Health, Presbyterian Hospital discovered astronauts could overcome fainting and dizzy spells when they land back on earth by exercising in space. The phenomenon known as orthostatic hypotension in the medical world occurs when blood pressure drops temporarily when a person stands up after sitting or lying down. The blood rushes away from the brain, causing dizziness and/or fainting. It can happen to people with health disorder and to astronauts who are in a low gravity environment for a prolonged period of time.
The researchers studied 12 astronauts who spent about six months in space, having them exercise as much as two hours a day during a space flight. When they came back to earth, there was little impact to blood pressure nor did any of the astronauts faint or experience dizziness 24 hours after landing.
Space Radiation May Cause Cancer
NASA has also focused on the impacts of space radiation on humans who are exposed to it. According to NASA that while the amount of space radiation is typically low, the effect is cumulative. Possible health risks included cancer, damage to the central nervous system, cataracts, and risk of acute radiation sickness.
"While uncertainties in predicting the nature and magnitude of space radiation biological risks still remain, data on the amount of space radiation and its composition are becoming more readily available, and research is helping to identify the biological effects of that radiation," NASA wrote in a research report on space radiation.