Decreased DA neurons and TH+ fibers in aged VPS35+/− SNpc and STR. A, Immunostaining indicating reduced TH+ neurons and neuronal processes in 12-month-old Vps35+/− SNpc. B, C, Nissl staining indicating decreased neurons in 12-month-old Vps35+/− SNpc. B, Representative images. C, Stereological analysis of cell numbers in SNpc. Data were presented as mean ± SEM (n = 5; *p < 0.05). D, E, Immunostaining showing reduced TH+ neuronal processes in 12-month-old Vps35+/− STR. D, Representative images. E, Quantification of TH optical density (mean ± SEM; n = 4; *p < 0.05). F, G, Immunostaining indicating normal NeuN+ neuronal density in 12-month-old VPS35+/− Hip. F, Representative images. G, Quantification of densities of CA1 neurons (mean ± SEM; n = 4; *p < 0.05).