Structural Brain Damage: When we look at MRI of the whole brain, we see large damage to the same brain area that we saw cellular damage to (the hippocampus). Check out the figure: In the top slice is a healthy subject’s brain, arrows point to a thick, healthy hippocampus full of neural tissue. However, when we compare this to a similar brain slice after mild hypoxia, we see that the same region has substantial atrophy: the empty black spaces indicate a shrunken hippocampus volume.