Fig. 4

Human α-syn overexpression induces dopaminergic neurodegeneration associated with α-syn pathology in young and old marmoset monkeys. a Stereological cell counts of SNpc TH-positive neurons (left panel, n = 8 for young animals and n = 5 for old animals) and mean grey values of striatal TH-positive fibers (right panel) at 11 weeks after surgery. Colors: blue: injected side of young animals; red: injected side of old animals; white and light grey: non-injected side of young and old animals, respectively. Top panels display representative TH immunostaining at SNpc (left) and striatum (right) levels. b Volume quantification of the hα-syn immunostaining at the SNpc level (left panel) and surface quantification of the hα-syn immunostaining at the striatal level (right panel) at 11 weeks after surgery. Top panels display representative hα-syn immunostaining at SNpc (left) and striatum (right) levels. c Volume quantification of the p-α-syn immunostaining at the SNpc level at 11 weeks after surgery. Left panels display representative human p-α-syn immunostaining at SNpc at macroscopic (left) and microscopic (right) levels. d Covariance analysis of each parameter measured in young and old marmosets. Data regarding TH pathway represent a loss of TH fibers or cell bodies. STR: striatum; * p < 0.05 vs non injected side of young animals; # p < 0.05 vs non injected side of old animals; & p < 0.05 vs injected side of young animals. Scales: 1.5 mm for STR, 0.5 mm for SNpc, 250 μm and 20 μm for high magnification pictures of the (c) panel. hα-syn: human α-syn; p-α-syn: S129 phosphorylated α-syn