Astronauts heading to Mars soon would face a slew of challenges including exposure to a massive amount of radiation that can potentially cause permanent brain damage. A new study has revealed that rodents exposed to high energy particles developed dementia and cognitive impairments.

Researchers from the University of California, Irvine are now studying these harmful effects of radiation exposure for future human space travel to deep space, especially to Mars. Test results show that exposure to cosmic radiation is one of the greatest threats to astronauts.

According to UCI's School of Medicine Charles Limoli, who is a radiation oncology professor, this not good news for astronauts who will be deployed to Mars on two- to three-year-long round trip missions.

The effects of radiation exposure via high energy particles that are constantly streaming in space include anxiety, memory loss, depression, and cognitive impairments.

In this new study, scientists exposed rodents to fully ionized oxygen and titanium in NASA's Space Radiation Laboratory.

After six months of exposure, brain scans revealed permanent brain damage that includes defective neural dendrites and spines which all connect crucial brain synapses. These defective links can prevent and disrupt the transmission of brain signals which would ultimately prevent normal functioning and peak brain performance.

Tests show that the rodents had forgotten to erase negative memories, which is apparently connected to a neural mechanism known as fear of extinction. Limoli explains that fear of extinction can become very problematic and even dangerous during a three-year mission to Mars.

NASA scientists are developing technology to protect spacecraft and astronauts from these high energy particles. But Limoli says that there may be no way to escape them.

This study has been published in the journal Scientific Reports.