SNCA and Parkinson disease: Given the fact that the dorsal striatum receives its main afferents from the dopaminergic neurons of the SNpc23 which are susceptible in Parkinson’s disease, we first examined whether all of the three types of injected fibrilar α-Synuclein could affect healthy neurons in interconnected areas away from the injection site in accordance with the recently proposed theory of pathology transmission to explain neurodegenerative disease progression24–26.