A jab for Alzheimer's?

which they claim could stop the body from killing brain cells by "cutting off" their protein supply, a breakthrough that may soon pave the way for new treatments for Alzheimer's disease.

A team at Leicester University says it has found that by injecting a protein into the brain, it could protect nerve cells in the brains of laboratory mice with prion disease, a condition which normally causes the brain to slowly die.

Because the process by which prion disease affects brains of mice is similar to some degenerative brain conditions in humans, it is hoped the findings could lead to treatments for the most common form of dementia in people.

In each case the death of brain cells is linked to the build-up of misshapen proteins, which form the plaques found in the brains of Alzheimer's sufferers and Lewy bodies in the nerve cells of people with Parkinson's disease.

In the mice with prion disease, the team found that when the faulty proteins begin to accumulate their cells activated a natural defence mechanism which stopped them from producing any more, 'The Daily Telegraph' reported.

The halt ought to be temporary, but in the diseased mice the production of proteins, which are crucial for the survival of cells, did not start up again.

The scientists found that by injecting a different protein which prevents the supply from being "switched off", they could protect the mice's brain cells for longer and extend their lives, the 'Nature' journal reported.

Prof Giovanna Mallucci, who led the research, said it could provide a "way forward in how we treat other disorders".

Prof Roger Morris, of the School of Biomedical Sciences at King's College London, described the findings as a "major breakthrough" and said there were "good reasons" for thinking it could also apply to Alzheimer's.