Fig. 4

Loss of gangliosides in substantia nigra of PD patients and with normal ageing. Levels of GM1a (a,b), GD1a (c,d), GD1b (e,f) and GT1b (g,h) were determined in substantia nigra from control subjects and PD patients with NP-HPLC. Data were analysed using Pearson correlation analysis (a,c,e,g) (n = 18–20 per group) and 2-way ANOVA (b,d,f,h) (n = 8–10 per cohort; * = p < 0.05). i Pearson correlation analysis of the sum of GM1a + GD1a + GD1b + GT1b levels in substantia nigra from control subjects (n = 20) and PD patients (n = 18). j Comparison of ganglioside levels in 70s-cohort vs. 80s-cohort of control subjects and PD patients (n = 8–10 per cohort, ** = p < 0.01, 2-way ANOVA). k Pearson correlation analysis of the sum of GlcCer + LacCer + GM1a + GD1a + GD1b + GT1b levels in substantia nigra from control subjects (n = 20) and PD patients (n = 18) shows that PD is associated with increased GSL load with age. i Comparison of total GSL levels in 70s-cohorts vs. 80s-cohorts of control subjects and PD patients (n = 8–10 per cohort, *** = p < 0.001, 2-way ANOVA). PD patients identified as GBA mutation carriers are shown in grey (a,c,e,g,i,k). Bar graphs are presented as mean ± SEM