A group of Fife scientists believe they have moved a step closer to finding a cure for Alzheimer's disease.
The number of people with Alzheimer's is expected to rise
St Andrews University biologists claim to have developed a compound which has successfully prevented the disease killing brain cells.
It also appeared to improved memory and learning ability already damaged.
Working with US researchers they developed man-made compounds capable of blocking a nerve cell interaction known to lead to the symptoms of the disease.
The results of the study - carried out in the laboratory using a model of the disease - have prompted the Alzheimer's Research Trust to help fund a further three years research.
Trust chief executive Rebecca Wood described the findings as "exciting".
"A drug that can stop Alzheimer's disease from killing brain cells is a holy grail for researchers working to overcome the devastating condition which affects more than 500,000 people in the UK," she said.
The number of sufferers is expected to double to more than one million with the general ageing of the population over the next generation.
Alzheimer's is linked to the build-up of amyloid protein, which eventually forms "senile plaques".
The amyloid protein inflicts damage by interacting with an enzyme called amyloid beta alcohol dehydrogenase (ABAD) and releasing toxic substances which kill brain cells.
Researchers at St Andrews University initially focused on developing the three-dimensional shape of ABAD and understanding how amyloid attaches itself to the structure.
Dr Frank Gunn-Moore, senior lecturer at the university's school of biology, said: "Alzheimer's sufferers produce too much amyloid and ABAD in their brains.
"Based on our knowledge of ABAD, we produced an inhibitor that can prevent amyloid attaching to it in a living model."
Dr Gunn-Moore, who led the research, added: "We have shown that it is possible to reverse some of the signs associated with Alzheimer's disease.
"The work is now being continued to try and refine the inhibitor into a potential drug.
"Our research holds a possible key for the treatment of Alzheimer's disease, particularly in its early stages."
Dr Susanne Sorensen, head of research, Alzheimer's Society, said: "The study provides another important piece in the puzzle for understanding Alzheimer's disease and points toward a possible new treatment target, which has so far been unexplored."
Jim Jackson, chief executive of Alzheimer Scotland, also welcomed the results of the study, although he cautioned that more research was required.