Figure 13

Microglial activation after PQ (10 mg/kg b.w.) treatment. Iba 1 immunolocalization (microglial marker) in SN, FC and hippocampus (A, B and C respectively; Weil and Davenport's method -- gray scale) in SN, FC and hippocampus (E, F and G respectively). Densitometric analyses of western blots for Iba 1 and Mac1 (microglial activation marker) to assess expression levels in SN, FC and hippocampus (D and H respectively): (A) intensity of Iba 1 immunofluorescence increased in SN of PQ-treated animals; (B, C) intensity of Iba 1 immunofluorescence decreased in FC (B) and hippocampus (C) of PQ-treated animals. (D) Densitometric analyses of western blots: Iba 1 expression increased significantly in SN, decreased in FC and remained unaltered in hippocampus of PQ-treated mice compared to vehicle-treated controls. (E, F and G): Silver staining revealed a reactive phenotype for microglia (red arrow), which appeared in SN as aggregated forms (b) in PQ-treated brain (E). Silver-impregnated microglia decreased in FC of PQ-treated animals (F). Aggregated forms of microglia appeared in hippocampus (G) of PQ-treated brain, but not controls. (H) Densitometric analyses of western blots indicate that Mac1expression increased significantly in SN, decreased significantly in FC and remained unchanged in hippocampus of PQ-treated animals. β-Actin was used as a reference control in western blots. Data are presented as mean ± SEM (n = 3). Asterisks (*) represent significant differences at a level of p < 0.05 (Student's t-test) for densitometric analyses. Magnification of immunofluorescence images is 10× and magnification of silver-stained images is 40×; the scale bars = 40 µm.