Figure 2

Effects of rotenone exposure on the number of Tyrosine Hydroxylase (TH⁺) neurons in the SNpc and motor function of alpha-synuclein knockout (ASYN-KO) and Wild-type (WT) mice. (A–F) Representative confocal microscopy images showing TH + neurons in the SNpc, labeled in red. (A) WT Vehicle, (B) ASYN KO Vehicle 4 M, (C) ASYN-KO Rotenone 4 M, (D) ASYN-KO Vehicle 2 M, (E) ASYN-KO Rotenone 2 M. (F) Graphic showing the average number of TH⁺ neurons in the SNpc in the different treatment groups of ASYN-KO mice. (1-way ANOVA: F = 0.8964; P = 0.4645, two-tailed unpaired Student’s ttests: P > 0.05 for each comparison; ASYN KO: n = 5, WT: n = 4) (G) Graphic showing the average rotarod performance across 4 months of Rotenone or Vehicle exposure. Treatment did not influence the motor performance of the mice at any timepoint (2-way ANOVA: F = 0.03337; v= 0.8581) (H) Graphic showing the Rotarod performance of ASYN-KO mice groups vs WT mice at timepoint 0. WT mice were able to spend significantly more time on rod compared to ASYN-KO mice, independent of treatment (two-tailed unpaired Student’s ttest: mean diff. = 18.57 ± 5.554; P = 0.0021; ASYN KO: n = 7 per group, WT: n = 6), *P < 0.05; **P < 0.01.