Boston: Pregnancy may rejuvenate a mother’s brain, scientists at the Tufts University School of Medicine, have discovered following experiments on mice.

Stem cells from growing mouse foetuses migrate to the brains of their mothers and mature into cells that carry out different tasks.

If, as researchers expect, the process also occurs in humans, it could lead to the treatment of brain damage caused by strokes or Alzheimer’s by injection of stem cells from aborted foetuses.

It is well known that during pregnancy a small number of foetal stem cells pass through the placenta and into the mother’s bloodstream, a phenomenon called microchimerism. They can survive for decades in parts of the body including the liver, spleen and skin, and can repair damage.

The process makes evolutionary common sense as the foetus has a better chance of survival if the mother is fit and healthy both during and after pregnancy. However, this effect has never been recorded for brain cells.

Diana Bianchi, professor of pediatrics, obstetrics and gynecology at Tufts University School of Medicine in Boston, and a leading authority on microchimerism, told New Scientist magazine: “This is the first study to show conclusively that foetal cells cross the blood-brain barrier.”