Figure 3 AAV vector-mediated EGFP expression in CA1 pyramidal neurons of the rat hippocampus. Representative images of the hippocampal CA1 sector from rats transduced with AAV2/5 vector engineered to express enhanced green fluorescent protein (EGFP) driven by a CMV promoter (AAV2/5-CMV-EGFP). Vector was injected (4 x 109 GC intra-hippocampal injection) two weeks prior to either sham surgery (A) or 10 minutes of transient forebrain ischemia (B). Rats were euthanized one week after injury and brain sections were immunolabeled for the neuronal marker NeuN (red). Robust EGFP fluorescence is observed in the CA1 pyramidal neurons (NeuN-positive) of sham-operated rats (A). However, NeuN-positive cells expressing EGFP are dramatically reduced one week after TFI, which is consistent with delayed necrosis of transduced CA1 pyramidal neurons (B).