Cosmic radiation, stem cells don’t mix

 
By • Published: February 8th, 2008
Category: Health in a Heartbeat
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In the comics, people exposed to cosmic radiation acquire superpowers.

In reality, exposure to cosmic or solar radiation will not endow space travelers with awesome strength or the ability to fly.

But what will happen to the human body during extended missions into deep space?

In one of the first studies of its kind, a team of researchers from the University of Florida, the Cold Spring Harbor Laboratory in New York and NASA’s Kennedy Space Center found that radiation targets a particular type of brain cell.

Applying a single dose of radiation to mice akin to what astronauts would experience only after a three-year journey to Mars, scientists discovered a “quiet” type of stem cell was exceptionally vulnerable in the hippocampus… an area of the brain believed to be important for learning and mood control.

These special cells exist in relative repose while their daughter cells reproduce in great numbers, repopulating the brain with new cells.

That the quiet cells were targeted was surprising because it is assumed radiation targets the rapidly dividing cells… which is why radiation is used to fight cancer.

The discovery does not present safety issues for the astronaut program because the radiation dose was far beyond radiation levels encountered in existing space travel.

But the exceptional sensitivity of these brain cells suggests that medications or physical shielding to protect astronauts from cosmic radiation will be important for the success of human space missions beyond the Earth’s protective magnetic field.