Scientists seek drug to ‘rewire’ adult brain after stroke

Adults who have experienced a stroke may one day be able to take a drug to help their brain “rewire” itself, so that tasks once carried out by now-damaged areas can be taken over by other regions, researchers have claimed.
The ability for the brain to rewire, so-called “brain plasticity”, is thought to occur throughout life; however, while children have a high degree of brain plasticity, adult brains are generally thought to be less plastic.
Research looking at children and young adults who had a stroke as a baby – a situation thought to affect at least one in 4,000 around the time of their birth – has highlighted the incredible ability of the young brain to rewire.

Elissa Newport, a professor of neurology at Georgetown University school of medicine in Washington DC, detailed a new study involving 12 such individuals, aged between 12 and 25.

“What you see is the right hemisphere, which is never in control of language in anyone who is healthy, is apparently capable of taking over language if you lose left hemisphere,” said Newport, who presented the findings at a meeting of the American Association for the Advancement of Science in Austin, Texas. “This does not happen in adults,” she added.

Using brain imaging the team found that the regions in the right hemisphere of the brain that took over were in the mirror image location to those used on the left side of the brain in healthy people. That, she said, emphasises that it is not just any area of the brain that takes over a function should a region become damaged.

Newport said that by understanding what underpins the brain plasticity seen in youngsters, scientists might be able to come up with ways to make the adult brain more plastic, potentially offering hope to adults who have had a stroke.

While less of a priority, the same kind of mechanisms that might help reorganise language areas in those who have had a stroke could work in healthy people to help them learn a second language, Newport admitted.

Takao Hensch, a professor of molecular and cell biology at Harvard University, who was also speaking at the meeting, said that his research in mice showed that by blocking certain molecules in the adult brain that hinder plasticity, it was possible to increase its ability to rewire.

“The baseline of the brain is plastic, to rewire itself. Through evolution it is necessary to layer on brake-like factors to prevent too much rewiring from happening after a certain point,” he said. “This offers novel therapeutic possibilities. If we could judiciously lift the brakes later in life perhaps we could reopen this window.”

Source: theguardian