Sleeping squirrels may harbour key to treating strokes

SQUIRRELS could hold the key to helping stroke patients avoid brain damage, scientists believe.

Researchers in the US have discovered that when squirrels hibernate a protective process occurs in their cells which allows their brain to function with reduced blood flow and oxygen.

When they awaken the animals suffer no ill-effects despite being deprived of essential nutrients.

During an ischemic stroke the blood supply, containing sugar and oxygen, is cut off to the brain, causing cells to die, which often leads to paralysis and speech problems.

Scientists from the National Institute of Neurological Disorders and Stroke (NINDS) believe that creating a drug which could trigger the same cellular changes of hibernating squirrels could prevent that brain damage.

“If we could only turn on the process hibernators appear to use to protect their brains, we could help protect the brain during a stroke and ultimately help people recover,” said Joshua Bernstock, first author and a graduate student at NINDS. Around 100,000 people have strokes each year in Britain, and 85 per cent will suffer ischemic strokes, with almost two thirds of the survivors leaving hospital with a disability.

There are 1.2million people living in the UK with the after-effects of a stroke. Currently, the only way to minimise stroke-induced cell death is to remove a clot as soon as possible.

Researchers found that a cellular process called Sumoylation goes into overdrive when squirrels hibernate, protecting their

‘If we could only turn on the process hibernators use to protect their brains’

cells. They found that process could be boosted by the enzyme ebselen.

When ebselen was injected into animal brain cells they stayed alive, even when deprived of blood and oxygen. Mr Bernstock said: “As a physician-scientist, I really like to work on projects that have clear relevance for patients,” he added.

The research was published in The FASEB Journal, the journal of the Foundation of American Societies for Experimental Biology.