Figure 3

Region of interest (ROI)-based and voxel-based morphometric (VBM) analyses of the hippocampal mean diffusivity (MD) from middle cerebral artery occlusion (MCAO) rats. The histological images were obtained from the rat brain atlas (A, [33]). Regions of interest (ROI) for the hippocampal area were defined semi-automatically on diffusion-weighted images by ROI Editor (B: bregma -3.30 to -3.80 mm). The hippocampal MD of the ipsilateral side was calculated for each group (C). All the post-MCAO groups showed a significant decrease. n = 6 for each group. Values are means ± SEM. *P <0.05; **P <0.01 in the t-test versus intact group. ^# P <0.05; ^### P <0.001 in the t-test versus sham-operated group. T-contrast map showing a significant decrease in MD value was observed in the 1 week after MCAO group compared to the intact group (D: uncorrected, P <0.001). The ipsilateral hippocampus and striatum areas showed significant differences. For the groups tested at 3 weeks and 2 months after MCAO, the realignment process could not be performed by the software, because the chronic MCAO brains were too greatly altered. Color bars, t value (Height threshold t = 4.025).