Alzheimer’s Culprit Causes Memory Loss Before Brain Degeneration

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, according to new research. The findings were published in the journal Scientific Reports.

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. Now, 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.

The results showed that 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. The researchers said this demonstrate that Abeta alone is enough to lead to the symptoms of memory loss that are well known in Alzheimer's disease. Amyloid proteins don't just affect memory by killing neurons of the brain, but target specific molecular pathways necessary for memories to be preserved.
 
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,' the researchers concluded.
 
Based on material originally posted by University of Sussex.