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Radiation disrupts signaling among other processes in the brain. However, previous experiments used short-term, higher dose-rate exposures of radiation, which does not accurately reflect the conditions in space. To investigate how deep space travel could affect the nervous system, Charles Limoli and colleagues at the University of California, Irvine, Stanford University, Colorado State University and the Eastern Virginia School of Medicine exposed mice to chronic, low dose radiation for six months.
Radiation exposure impaired cellular signaling in the hippocampus and prefrontal cortex, resulting in learning and memory impairments. They also observed increased anxiety behaviors, indicating that the radiation also impacted the amygdala. The researchers predict that during a deep space mission approximately one in five astronauts would experience anxiety-like behavior and one in three would experience certain levels of memory impairments. Additionally, the astronauts may struggle with decision-making.
Source: Society for Neuroscience