Increasing transgenic α-Synuclein protein levels in the brain of 3–12 months old D-Line mice. ELISA was used to analyze levels of hα-Syn in brain homogenates. Panels show hα-Syn expression levels of 3, 6, 9 and 12 months old D-Line mice in the hippocampus (A) and striatum (B) and 6 months old non-transgenic littermates. D-Line mice: 3, 9 and 12 months old (n = 6), 6 months (n = 5), ntg (n = 1). Values of one animal were excluded by Grubb’s Outlier test. Striatum ntg value = 0. Data of the non-transgenic mouse were not included in statistical analyses. Graphs show mean ± SEM; one-way ANOVA followed by Bonferroni’s post hoc test. * p < 0.05; ** p < 0.01.