Cosmic radiation may lead to dementia; $9 million ‘space brain’ study says


A NASA-funded study has established that long term exposure to cosmic radiation, which involves exposure to charged particles resulting from cosmic events including supernova explosion, may end up harming brains of astronauts to an extent that they may suffer from dementia and possibly other cognitive disorders.

With NASA getting serious about finding life on distant worlds and manned mission to Mars, the space agency has been interested in knowing the ill-effects of long-terms space travel and stay.

As a part of this, the space agency funded a $9 million study led by University of California, Irvine professor of radiation oncology Charles Limoli to see how cosmic radiation affects astronauts’ cognition.

It as been established that exposure to dangerous radiation fields in space impair cognitive abilities of rodents implying that astronauts who spend extended time in space may end up suffering from similar disorders including dementia. The NASA funded study decided to look into the behavioral impairments of rodents attributed to space radiation exposure and the underlying causes of these deficits, including studies to quantify the structural and functional alterations to nerve cells.

Through the study dubbed ‘space brain’ the team intends to investigate how cosmic radiation affects astronauts and possibly learn ways to mitigate those effects so as to enable further human exploration of space including manned mission to Mars.

“The space environment poses unique hazards to astronauts, since a range of potential central nervous system complications can result during and after actual space travel,” Limoli said before the commencement of the study. “We plan to conduct a comprehensive series of rodent studies to characterize the neurobiological mechanisms involved with radiation-induced cognitive impairment.”

The Study

Professor Limoli at his colleagues Ivan Soltesz, professor and chair of anatomy & neurobiology; Munjal Acharya, assistant professor of radiation oncology; and Janet Baulch and Vipan Kumar, project scientists in Limoli’s research group found that exposure to highly energetic charged particles – much like those found in the galactic cosmic rays that bombard astronauts during extended spaceflights – cause significant damage to the central nervous system, resulting in cognitive impairments.

For the ‘space brain’ project, rodents were subjected to charged particle irradiation (fully ionized oxygen and titanium) at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory. These rodents were then sent back to Limoli’s Irvine lab.

Limoli said that this particular findings are bad for astronauts who may be deployed on a two- to three-year round trip to Mars. Tests on rodents implicate possibilities of performance decrements, memory deficits, and loss of awareness and focus during spaceflight. This in turn may affect mission-critical activities, and exposure to these particles may have long-term adverse consequences to cognition throughout life, the researchers have warned.

Any solution?

Limoli and the team are still working on the project, but as a partial solution the team proposes specially designed spacecrafts that will include areas of increased shielding – specifically areas where astronauts will rest and sleep.

The team is working on pharmacologic strategies involving compounds that scavenge free radicals and protect neurotransmission.