Inflammatory factors expressed by active microglia/macrophage in peri-infarct areas at four weeks after stroke. A. Double immunostaining shows expression of TNF-α, IL-1β, IL-10 and TGF-β in active microglia (Iba-1). B. Analysis and quantification for co-localization of cytokines and Iba-1 in the microglia/macrophages with Fiji-ImageJ. Representative two-dimensional histogram and scatterplots visualize the correlation of the pixel intensities, over all pixels and voxels in the images with different Li’s ICQ values, generated by Fiji-ImageJ. Statistical bar figures demonstrate the quantification of Li’s ICQ values for co-localization of each cytokine with Iba-1 in vehicle- and minocycline-treated ischemic hemispheres. *P <0.05, **P <0.01 versus V-I. n = 5 in each group. C. Double immunostaining shows little expression of TNF-α and IL-1β in active microglia/macrophage, with extending processes in the peri-infarct areas bordering with intact tissues. Scale bars = 50 μm. D. Double immunostaining shows expression of TGF-β in PDGFR-β-positive pericytes that closely surround the vessels (V). Scale bars = 50 and 100 μm.