Figure 8

Estimated numbers of BrdU⁺ cells in the SGZ of SDs and SHRs. We found a very large spread in the number of BrdU⁺ cells within both strains and in each of the four groups. Even among sham animals, the number of BrdU⁺ cells in the SGZ could vary ten-fold. We were not able to demonstrate a statistically significant increase in the BrdU incorporation one week after tMCAo. Further, we found no difference between the sham groups from both strains. Interestingly, we saw a marked increase in BrdU uptake in the ipsilateral DG in three animals (2 SHRs and 1 SD) where the ischemic damage involved the hippocampus (Figure 9). We found a statistically significant difference in the response to ischemia between the two strains if these three animals were excluded from the statistical analyses of the BrdU data. This could indicate that SDs have a higher NPC proliferation than SHRs after remote ischemia. SD sham and SD tMCAo are marked with "triangles" and "squares", whereas SHR sham and SHR tMCAo are represented with "diamonds" and "circles". Note that the filled symbols represent right hemispheres, whereas the unfilled symbols represent left hemispheres. Animals with an ischemically injured hippocampus that were excluded from the statistical analyses were marked with "crosses" if they belonged to the SD strain or "stars" if they were SHRs. Mean BrdU⁺ cell numbers are marked with horizontal lines. * indicates p < 0.05, whereas p < 0.01 are marked with #. BrdU, 5-bromo-2'-deoxy-uridine; DG, dentate gyrus; SDs, Sprague-Dawley rats; SGZ, subgranular zone; SHRs, spontaneously hypertensive rats; tMCAo, transient middle cerebral artery occlusion.