PGJ2 dose-dependent microglia activation in the SN. TH (red, dopaminergic) and IBA1 (green, activated microglia) immunostaining of SN shows a dose-dependent loss of dopaminergic neurons coinciding with microglia activation caused by treatment with the two highest PGJ2 concentrations (6.7 μg or 16.7 μg). No difference was apparent between DMSO-treated mice and mice treated with the lowest PGJ2 concentration (3.4 μg). Panels with brackets depict ipsilateral (infused) and contralateral sections of the same mouse. Scale bar = 20 μm.