Nuclear testing from the 1960s helps scientist determine whether adult brains generate new neurons

The birth of new neurons in the adult brain sharpens memory in rodents, but whether the same holds true for humans has long been debated. A study published today in the journal Cell reveals that a significant number of new neurons in the hippocampus—a brain region crucial for memory and learning—are generated in adult humans. The researchers used a unique strategy based on the amount of carbon-14 found in humans as a result of above-ground nuclear testing more than half a century ago. The findings suggest that new neurons are born daily in the human hippocampus, offering the tantalizing possibility that they may support cognitive functions in adulthood.