Fig. 3

Effects of rmIL-33 treatment on the number of microglial cells in the hippocampal areas. Mice were intrahippocampally injected with rmIL-33 or vehicle solution (PBS-BSA 0.1%) with or without minocycline pretreatment as in Fig. 1a and brain sections analyzed at 48 h. a Representative immunohistochemical staining (Dapi in blue and Iba1 in green) in the hippocampal section from vehicle mouse indicating the injection site (*). Scale bar = 200 μm. The dotted lines indicate the different areas of the hippocampal formation (CA1, CA2, CA3, and DG=Dentate Gyrus). b, c, d Histograms showing the number of Iba1⁺ cells by mm² quantified in each area (CA1/CA2 in b, CA3 in c, and DG in d). Quantification of Iba1⁺ cells was analyzed from 3–5 sections per mouse (n = 3–4 for each group). In rmIL-33-injected mice, the number of microglia was exacerbated in all hippocampal areas. Interestingly, under minocycline treatment, these increases were drastically limited. Data are represented as mean ± SEM. Statistical comparisons were analyzed using Kruskal-Wallis and uncorrected Dunn’s test to generate P values for each paired comparison (each group vs. Sham without minocycline). *P ≤ 0.05