London, May 30 (IANS): A brain protein believed to be a key component in the progress of dementia can cause memory loss in healthy brains even before physical signs of degeneration appear, says a new University of Sussex study.

The study reveals a direct link between the main culprit of Alzheimer's disease and memory loss. Alzheimer's disease is characterized by the formation of amyloid plaques in the brain tissue.

These amyloid plaques are made up of an insoluble protein, 'Amyloid-beta' (Abeta), which forms small structures called 'oligomers' that are important in the disease progression.

Although these proteins are known to be involved in Alzheimer's, little is understood about how they lead to memory loss. Neuroscience researchers have investigated how Abeta affected healthy brains of pond snails (Lymnaea stagnalis) by observing the effect of administering the protein following a food-reward training task.

"Because we understand the memory pathways so well, the simple snail brain has provided the ideal model system to enable us to link the loss of established memory to pure Abeta," said George Kemenes, a neuroscientist at the University of Sussex.

Snails treated with Abeta had significantly impaired memories 24 hours later when tested with the food task, even though their brain tissue showed no sign of damage.

"This demonstrated that Abeta alone is enough to lead to the symptoms of memory loss that are well known in Alzheimer's disease," said lead author Lenzie Ford from the University of Sussex.

The work will provide a platform for a more thorough investigation of the mechanisms and effects on memory pathways that lead to this memory loss.

"It is absolutely essential that we understand how Alzheimer's disease develops in order to find specific targets for therapeutics to combat this disease," said professor Serpell, who is senior author on the study.

The study appeared in the journal Scientific Reports.