The majority of αS inclusions in the substantia nigra of M20 Tg mice neonatally injected with exogenous αS are not in TH positive neurons. M20 Tg mice 8 months after neonatal injection with 21–140 human αS fibrils (fib) (A) or Δ71-82 human αS (B). Double-labeled immunofluorescence analysis for tyrosine hydroxylase (TH; red) labeling the dopaminergic neurons in the substantia nigra area, and pSer129 (green) labeling the hyperphosphorylated αS inclusions show minimal co-localization. The majority of αS inclusions were not found in TH+ cells, except for a few neurons (white arrows). Cell nuclei were counter stained with DAPI. Scale bar = 100 μm.