Researchers reported on eNeuro that long-term, low-dose radiation (ie, deep space conditions) exposure can cause neurological and behavioral damage in mice. These results highlight the urgent need to develop safety measures to protect astronauts from radiation during a space mission to Mars.
It is known that radiation can disrupt signal conduction in other brain processes. However, previous experiments used short-term, higher-dose-rate radiation, which cannot accurately reflect space conditions.
In order to study how space travel affects the nervous system, Charles Limoli of the University of California, Irvine, Stanford University, Colorado State University and Eastern Virginia School of Medicine and his colleagues exposed mice to chronic low-dose radiation for six months. They found that radiation exposure damages cell signaling in the hippocampus and prefrontal cortex, leading to learning and memory impairment. They also observed an increase in anxiety behaviors, indicating that radiation also affected the amygdala.
Researchers predict that when performing deep-space missions, about one-fifth of astronauts will experience anxiety-like behavior, and one-third of astronauts will experience a certain degree of memory impairment. In addition, astronauts may struggle with decision-making.