Treatment that allows brain to 'heal itself' may aid stroke victims

Scientists have discovered a new way to make the brain repair itself after a stroke, according to research published yesterday.

In testing, fewer rats who suffered an induced stroke were left paralysed after the treatment, which activated stem cells in the brain, researchers found.

The discovery will raise hopes for new treatments for stroke that use the body's ability to heal itself.

A team of scientists stimulated stem cells in the rats' brains after they were starved of oxygen.

They used proteins to activate a receptor known as the Notch on the stem cells.

The receptor caused a "cascade" effect which created new brain cells after the stroke. The treatment also improved the ability of existing cells to survive the lack of oxygen.

When rats were given the treatment in laboratories, many recovered from the loss of movement they suffered with the stroke.

The discovery will raise hopes for new treatments for a stroke that use the body's own stem cells to aid healing. Other treatments are less successful because implanted cells come under attack from the body's immune system.

The researchers wrote: "New cell therapies based on embryonic stem (ES) cells are supported by work in animal models of human disease. They are difficult to implement, however, because it is hard to grow tissue specific precursors in the laboratory and it is difficult to deliver them to diffuse disease sites in the body without stimulating an immune response.

"The results that we present here suggest a general model of stem cell expansion that applies to many precursor cells of clinical interest and that may lead to strategies that promote regenerative responses through the activation of endogenous cells."

The research, by Ronald McKay from the National Institute of Neurological Disorders and Stroke in Maryland, US, is published in the journal Nature.