The dynamics of the "prion-like" features of Parkinson’s disease (PD) has never been experimentally studied in primates phylogenetically close to humans. We injected 37 baboons in the striatum with picograms of two distinct α-synuclein proteopathic seeds purified from PD brains, differentiating by their size (large or small). After neuropathological examination of the baboon’s brain, we also performed mass spectrometry-based proteomics of baboons’ putamen and entorhinal cortex to study the temporal and spatial response (local and distant) to α-synuclein seeds injections.