BRISTOL University scientists have made a discovery they hope will improve the chances of recovery for stroke victims.

A research team from the university has found that some nerve cells in the brain have developed a way of protecting themselves from the drop in blood supply and nutrients they suffer during a stoke, where blood vessels in the head rupture.

It has raised hope of new ways of treating what is the third largest killer in the United Kingdom and can lead to the loss of speech and movement in people who survive.

Dr Jack Mellor of the university's school of physiology and pharmacology, who led the research, said: "We hope that if we can understand why some nerve cells are resistant to stroke damage we may be able to develop strategies to protect those cells that are sensitive.

"Historically, stroke has been very difficult to treat because of its unpredictability and the need to administer drugs within minutes of the onset of a stroke. These problems will not be overcome by our research but our findings do reveal a natural protection mechanism in some nerve cells, which may be useful in developing treatments to protect other nerve cell types."

The research, published in the Journal of Neuroscience today, compared two types of nerve cell in the hippocampus, the area of the brain linked to memory and navigation, during a lab test.

Of these cell types, one is highly susceptible to damage after stroke whereas the other has a way of reducing its susceptibility to damage. The researchers believe the resistant cells can protect themselves against the effects of a brain chemical called glutamate, which is released in large quantities during strokes.

Dr Sharlin Ahmed, from The Stroke Association, said: "This is a very important piece of research as it was previously thought that brain cells damaged by stroke died or were dependent on surrounding cells adopting the functions of the damaged ones."