A prevailing theory of Parkinson disease pathogenesis revolves around the spread of α-synuclein toxicity from the periphery to the brain. In this Review, Blesa and colleagues discuss the idea that, although these bottom-up mechanisms are involved, early neuronal loss in the nigrostriatal system also plays a prominent role.
- Javier Blesa
- Guglielmo Foffani
- Jose A. Obeso
