SNCA and Parkinson disease: Moreover, enhanced microglial activation was also observed in various PD animal models, including α-synuclein overexpression models, as well as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 6-hydroxydopamine (6-OHDA) and rotenone neurotoxin-induced mice, rats and monkeys (Roca et al., 2011).