β-amyloid oligomers and cellular prion protein in Alzheimer’s disease

Prefibrillar oligomers of the β-amyloid peptide (Aβ) are recognized as potential mediators of Alzheimer’s disease (AD) pathophysiology. Deficits in synaptic function, neurotoxicity, and the progression of AD have all been linked to the oligomeric Aβ assemblies rather than to Aβ monomers or to amyloid plaques. However, the molecular sites of Aβ oligomer action have remained largely unknown. Recently, the cellular prion protein (PrP C ) has been shown to act as a functional receptor for Aβ oligomers in brain slices. Because PrP C serves as the substrate for Creutzfeldt–Jakob Disease (CJD), these data suggest mechanistic similarities between the two neurodegenerative diseases. Here, we review the importance of Aβ oligomers in AD, commonalities between AD and CJD, and the newly emergent role of PrP C as a receptor for Aβ oligomers.