Could a trip to Mars addle your brains? Some scientists say it might, based on a study of high-energy radiation’s effects on mouse neurons. But an advocate for Red Planet missions says the study overstates the effects.

The report, published Friday in the open-access journal Science Advances, found that mice who were exposed to radiation similar to galactic cosmic rays showed degradations in their brain cells, and didn’t do as well on cognitive tasks.

“This is surprising, and it suggests that NASA has a new complication to consider when they send astronauts into deep space,” senior study author Charles Limoli, a professor of radiation oncology at the University of California at Irvine’s School of Medicine, told NBC News.