Immunohistochemistry was performed using the avidin-biotin-peroxidase complex techniques as previously reported9 (link). Mice were overdosed with sodium pentobarbital and underwent transcardiac perfusion with 4% paraformaldehyde (PFA). Subsequently, brains were harvested, kept in 4% PFA overnight, and immersed in 30% sucrose at 4°C. OCT compound embedded brains were sliced into 18 μm sections on a cryostat microtome, dried and preserved at −80°C. The primary antibodies were polyclonal rabbit anti-DARPP-32 (dopamine- and cAMP-regulated phosphoprotein, Mr 32 kDa, Cell Signaling, 1:400), monoclonal rat anti-MOMA-2 (monocyte + macrophage antibody, Abcam, ab33451, 1:200), polyclonal rabbit anti-HO-1(heme oxygenase-1, Enzo, SPA-895-F, 1:500). Negative controls were executed by eliminating primary antibody.