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Bombs & Brain Cells

June 24, 2013

Nuclear testing in the mid 20th century is helping scientists understand how the brain makes new neurons.



Carbon-dating the brain. I’m Bob Hirshon and this is Science Update.

Above-ground nuclear tests were banned in 1963. But the radioactive carbon-14 they released into the atmosphere is now helping scientists understand the brain. When we eat plants and animals, our cells take up carbon. A percentage of it is in the form of carbon-14, according to neuroscientist Jonas Frisen of the Karolinska Institute in Sweden.

JONAS FRISEN (Karolinska Institute, Sweden):

When a cell undergoes cell division and duplicates its DNA, it will integrate carbon-14 with the concentration corresponding to that in the atmosphere at that time point, effectively creating a timestamp in the DNA of cells which we then can measure and infer when a cell was born.


While scientists once thought that adult brains don’t make new neurons, this study revealed that about 1/3 of the brain cells in the hippocampus, a region of the brain involved in learning and memory, get replaced during the human lifetime. I’m Bob Hirshon, for AAAS, the science society.

The research appears in the journal Cell.


Story by Susanne Bard 


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