Adults Can Grow Brain Cells

For the first time, researchers have found evidence that adults can grow new brain cells. The finding is expected to generate new studies into what stimulates brain cell growth. Doctors hope the information eventually can help patients who have Alzheimer's or Parkinson's disease, illnesses in which neurons have been lost. CBS News Correspondent Dr. Emily Senay reports.
A study published in the November issue of the British journal Nature Medicine reports that, contrary to previous theories, brain cells do grow in adult humans.
Researchers at the Salk Institute in California studied the brains of five terminal cancer patients who had received a chemical "tag" that marks DNA in newly-divided cells. After the patients died from cancer, tissues from their brains were studied. The researchers found that new neurons had been generated in the patients' brains before they died.

The brain cells grew on their own; the researchers did not induce the growth. The scientists do not know whether the cells were functional.

The belief that neurons could not be generated in adults was widely held. Brain cells are complicated structures, with spiderlike tentacles. Scientists did not think they could divide to become new cells.

The study found that the adult cells do not have to divide, but that premature brain neurons are held in reserve. Doctors believe that the cells are somehow triggered to divide and mature in the adult brain.

Scientists hope that the research will be the first step toward learning more about how brain cells reproduce and develop in adults. The findings may lead to discoveries on how to artificially stimulate the growth of brain cells in people who have lost neurons.

Reported By Dr. Emily Senay