Progesterone (PROG) reduces microglial/macrophage and astrocytic activation, neutrophil infiltration, and Fluoro-Jade B (FJB)+ cell number after collagenase-induced ICH. (A–C) Immunostaining for Iba1 (A), myeloperoxidase (MPO; B), and glial fibrillary acidic protein (GFAP; C) in the perihematomal region on day 3 after collagenase-induced ICH. Inset represents higher magnification of MPO-positive neutrophil. Scale bar = 50 μm. (D) FJB histological staining of degenerating cells in sections collected 3 days after collagenase injection. Inset represents higher magnification of FJB-positive cell. Scale bar = 25 μm. (E–G) Bar graphs show quantification analysis of activated microglia/macrophages and astrocytes, infiltrating neutrophils, and FJB-positive cells (n=6 mice/group, *p<0.01 or 0.05 versus vehicle-treated group). Values are means ± SD.