Figure 2

Substania nigra pars compacta (SNc) tyrosine hydroxylase (TH) + neurons were quantified from multiple bregma levels. Paraquat and poly(I:C) alone caused a modest, but non-significant TH + reduction relative to saline-treated controls. However, pre-treatment with poly(I:C) followed by paraquat induced a significant reduction in TH + neuronal counts at all bregma levels and at all re-exposure intervals. (A) Representative photomicrographs showing the degree of nigral TH + neuron loss in paraquat, poly(I:C), and the combination treatment groups compared with saline-treated controls. (B) Quantification of SNc TH + neuronal counts depicted in bar graphs. *P < 0.05, relative to saline-treated controls. All data expressed as mean ± SEM, n = 4 to 8.