Animal models of α-synucleinopathy for Parkinson disease drug development

A major challenge in Parkinson disease (PD) will be to turn an emerging and expanding pipeline of novel disease-modifying candidate compounds into therapeutics. Novel targets need in vivo validation, and candidate therapeutics require appropriate preclinical platforms on which to define potential efficacy and target engagement before advancement to clinical development. We propose that alpha-synuclein (alpha-syn)-based mammalian models will be crucial for this process. Here, we review alpha-syn transgenic mouse models, viral vector models of alpha-syn overexpression and models of 'prion-like' spread of alpha-syn, and describe how each of these model types may contribute to PD drug discovery. We conclude by presenting our opinion on how to use a combination of these models through the late-stage preclinical, proof-of-principle investigation of novel therapeutics.