Researchers close in on method to rewire brain after stroke

The researchers believe it may be possible to reopen the "critical window" of brain plasticity.

Damage caused by a stroke could be repaired by returning the brain to a childlike state so it can rewire itself, experts at Harvard University believe.

Until recently, researchers thought the brain was fixed after adulthood and unable to make new links.

But Harvard scientists believe it may be possible to reopen the "critical window" of brain plasticity which people have in childhood, allowing new connections to form, or even to repurpose different neural areas so they can take over the role of a damaged part. Brain plasticity is what allows children to learn quickly, and explains why it is easier to pick up a language or new skill as a child.

The experts have discovered that as we age the brain is flooded with molecules which turn off the ability to rewire.

They now believe it could be possible to formulate drugs to prevent this happening, taking the brain back to a more malleable state.

Speaking at a meeting of the American Association for the Advancement of Science in Austin, Texas, Dr Takao Hensch, professor of molecular and cell biology at Harvard, said: "This offers novel therapeutic possibilities. If we could judiciously lift the brakes later in life, perhaps we could reopen this window.

"It really has transformed the way we think about incidents like stroke and the opportunities for recovery."

Babies who have strokes at birth are able to completely rewire one side of their brains to take over the damaged language circuits on the other. Despite the catastrophic damage, they show no speech problems when they grow up, and scientists believe this could now be achieved in older stroke victims.

Harvard scientists are working with experts at the Centre for Brain Plasticity and Recovery at Georgetown University in Washington to find out how this works in babies.

Elissa Newport, professor of neurology at Georgetown, found that 12 individuals studied, aged 12 to 25, who had a left-brain perinatal stroke as babies all now use the right side of their brains for language.

"This does not happen in adults. But in kids their language understanding is excellent."

She added: "This is a very important discovery that may have implications in the rehabilitation of adult stroke survivors."