Pioglitazone treatment significantly reduces RGC loss, microgliosis, Müller cell activation, and CCL20 expression in the retina. a Representative immunofluorescent images showing RGC (H&E and RBPMS), Iba1 (red), GFAP (green), or CCL20 (bright field) immunoreactivity in the retina with or without PG treatment 7 days after rTBI. Scale bar 100 μm. Inset high magnification images of the boxed areas showing CCL20 expression in the retinal ganglionic cells, scale bar 20 μm. Blue fluorescence shows DAPI. Scale bar 100 μm. b–f Histograms showing average count of RGC (b, c), Iba1-positive cells (d), average fluorescence intensity of GFAP immunoreactivity (e), or CCL20 immunoreactivity (f) as quantitated by ImageJ. *p < 0.01, **p < 0.001, ***p < 0.0001.