The UC Irvine-led study, published in Scientific Reports, adds to a growing body of research on the harmful effects humans may reckon with as they venture out longer and deeper into space, whether on trips to Mars or potentially beyond.
“The most logical conclusion to draw from these studies is that cosmic radiation exposure poses a real and potentially detrimental neurocognitive risk for prolonged deep space travel,” the study authors wrote. “With the growing realization that space is a radioactive environment comes the need to more completely define these risks with more certainty through continued research.”
It’s well-known that radiation can damage neural tissue and hurt cognitive function; cancer patients with brain tumors who need radiotherapy end up with what the study authors called “severe and progressive cognitive deficits.” But it’s not clear exactly what effect space radiation has on the brain because there are different types of radiation and they’re delivered in different doses.
「。。。」The scientists found that even six months after radiation exposure, the rodents still were suffering from brain inflammation and neural damage. Neurons sported fewer dendrites and spines, which meant their neural networks were less interconnected than in a healthy brain.
On behavioral tasks, the rodents exposed to radiation performed poorly on tests of learning and memory. Their ability to suppress unpleasant and stressful associations also declined — an effect that could make someone prone to anxiety over a multiyear trip to the Red Planet and back.
“The inability to moderate reactions to certain unpleasant stimuli could elicit elevated stress, anxiety and otherwise disadvantageous responses in unexpected or emergency situations,” the study authors wrote.