Aggregates with ubiquitinated proteins are detected upon PGJ2 infusion. A & B. Immunostaining for ubiquitinated proteins (red) and TH-positive neurons (green) was performed four weeks after the last PGJ2 microinjection. Dopaminergic neurons in the SNpc of mice treated with 6.7 μg or 16.7 μg of PGJ2 exhibited clear aggregates (arrows) with ubiquitinated proteins. Nuclear staining (Hoechst) in the mice treated with the two highest doses of PGJ2 also exhibit an apoptotic morphology, i.e. a fragmented and/or condensed appearance (arrowheads). 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 in A and 10 μm in B.