Fig. 2. LPS induces IL-4 expression in the microglia in the SN in vivo. (A~D) Immunofluorescence staining of IL-4 in the SN at 1 d (B), 3 d (C), and 7 d (D) after intranigral injection of LPS or PBS as a control (A, 1d). (E~L) At 3 d post injection, the SN tissues were immunostained simultaneously with IL-4 (Red) and TH (E, I; green), CD11b (F, J; green), Iba-1 (G, K; green) or CD68 (H, L; green). (E~H) PBS injected SN. (I~L) LPS injected SN. Arrows indicate IL-4⁺ cells merged with CD11b⁺, Iba-1⁺, and CD68⁺ cells. (M) Quantification of IL-4 expression in TH⁺, CD11b⁺, Iba-1⁺ or CD68⁺cells in the SN. Scale bars: A, E, 250 µm; B, F, 25 µm; C, D, G, H, 50 µm. J, L, N, P, R, T, 500 µm; K, M, O, Q, S, U, 50 µm. SNpc, substantia nigra pars compacta; SNr, substantia nigra reticulata. Data are presented as the means±SEM of four to eight animals per group. ^*p<0.05, ^**p<0.01, significantly different from PBS (ANOVA and Bonferroni analyses). Scale bar: A~D, 100 mm; E~L, 25 mm.