A new study indicates that function can be restored long after stroke damage by stimulating adult stem cells in the brain. Scientists at UC-Irvine found that a natural growth factor called Transforming Growth Factor-alpha (TGF) stimulates adult stem cells in the affected brain to divide, migrate through the brain, and repair the damage. Using a rat model for stroke, they injected the TGF protein directly into the brain as much as 4 weeks after the stroke damage, and found 99% recovery. Darius Gleason, a graduate student who worked on the study, said:

"It's becoming more and more clear that the brain is like any other organ: It has a lot of potential to regenerate. We are just emulating nature by giving a little nudge to what the brain is trying to do itself."

In a new study just published, the group has shown that even nasal administration of TGF can give significant recovery (70%). This non-invasive route could have great therapeutic application. Previously, German researchers showed nasal administration of adult stem cells was an effective delivery method. This new study shows that using only the stimulatory protein can also be very effective at stimulating the existing adult stem cells already present in the brain.

A clinical trial is currently under way in Houston that injects the stroke patient's bone marrow adult stem cells into the circulatory system; the cells seem to migrate to the injured brain and stimulate repair. Early results from this trial are very promising for stroke treatment.