Figure 4

Neurovascular alterations in cerebral cortex of WT and ApoE−/− mice. A) GFAP staining in the different brain cortical layers in young and old WT and ApoE−/− mice. Immunohistochemistry for GFAP is distributed in a gradient in cortical cross-sections of young and old WT and ApoE−/− mice as previously described. GFAP staining was increased with aging regardless of the mice strain. The increase is higher in the old ApoE−/− mice, with presence of GFAP positive astrocytes throughout all of the cortical layers. Scale bar = 50 μm. B) Quantification of the intensity of the GFAP staining in cortical layers of young and old WT and ApoE−/− mice. Each column represents mean ± SEM (n = 4 per group). * P <0.05 young WT mice vs old ApoE−/− mice and old WT mice vs old ApoE−/− mice. C) AQP4 immunohistochemistry in the cortex of the young and old WT and ApoE−/− mice. AQP4 expression is not increased in old WT. In contrast, in ApoE−/−, the AQP4 labeling is increased in the astrocyte endfeet in contact with the blood vessels. Bar = 40 μm. D) Quantification of the intensity of the AQP4 staining in cortex cross-section of young and old WT and ApoE−/− mice. Each column represents mean ± SEM (n = 4 per group). * P <0.05 ApoE−/− young vs ApoE−/− old. E) Counting of the number of positive laminin staining did not show any significant differences between the WT and ApoE−/− mice and between young and old (n = 6 per group). F) Counting of the number of positive NeuN cells did not show any significant difference between the WT and ApoE−/− mice and between young and old (n = 6 per group).