Stopping the effects of a protein in the brain could reverse some of the memory loss in the early stages of Alzheimer's disease, scientists have said.
Research found that when the tau gene is "switched off", the toxic effect of the corresponding tau protein is mostly eliminated, according to scientists from the Max Planck Research Unit for Structural Molecular Biology.
When the procedure was carried out on mice with a human tau gene, they regained their learning and remembering ability.
Eva Mandelkow, of the institute, said: "The really important discovery here, however, is that the progression of Alzheimer's disease can be reversed in principle - at least at an early stage of the illness before too many neurons have been destroyed."
In other news, a blood test could soon be used to detect Alzheimer's disease years before symptoms first appear.
Research, published in journal Cell, uses synthetic molecules to identify antibodies specific to Alzheimer's disease.