Protein aggregates and dementia: is there a common toxicity?

This review considers some of the recent advances made in the understanding of the pathogenic proteins known to aggregate and be implicated in neurodegenerative dementing disorders. It concentrates on the two most obvious candidates for the role of toxic protein in Alzheimer's disease (AD)--beta-amyloid peptide and tau--but also considers other proteins in this disorder and in less common but equally devastating diseases.