Figure 9

Examples of BrdU incorporation in the SGZ in rats with different infarct distribution. The two first rows (A-D and E-H) are BrdU/ED-1 and NeuN-stained sections from two SHRs with a similar infarct size (120.3 mm³ vs. 117.6 mm³) but with a different infarct distribution. In the last row (I-L), sections are shown from a SD rat with a very small infarct (0.95 mm³) solely confined to the right DG. The magnitude of the BrdU uptake in the right DG was similar in the SHR visualized in A-D and the SD shown in I-L (14840 BrdU⁺ cells vs. 15280 BrdU⁺ cells), whereas the SHR represented in E-H had a much lower BrdU uptake (2800 BrdU⁺ cells). A-C, E-G, and I-J are BrdU/ED-1 double stains. The boxed area on the coronal sections in A, E, and I are shown in B, F and J-K, whereas the boxed area in B and F are depicted in C-D and G-H. D, H, and K-L are NeuN stains that correspond to the BrdU/ED-1 double stain in C, G, and J. Note the infiltration of ED-1⁺-activated microglia in B-C, and J compared with F-G. Correspondingly, neuronal loss was found in D and K-L, but not in H. The presence of activated microglia in the microenvironment around the DG, however, did not seem to compromise the BrdU uptake in the SGZ. The scale bars represent 1 mm (A, E, I), 500 μm (B, F, J, K), 100 μm (C, D, G, H), and 50 μm (L) respectively. BrdU, 5-bromo-2'-deoxy-uridine; DG, dentate gyrus; NeuN, neuronal nuclei; SDs, Sprague-Dawley rats; SGZ, subgranular zone; SHRs, spontaneously hypertensive rats.