Figure 4. Increased oxidative damage in the hippocampus 7 d after Aβ 1-42 administration. Representative photomicrographs of the CA1 and CA3 of the hippocampus from WT mice (A, D) injected with Aβ1-42 that show numerous robustly nitrotyrosine-immunoreactive cells compared with Aβ1-42-injected COX-1-/- mice (B, E). Scale bar: A-C, 100 μm; D-F, 50 μm.