Fig. 4.

Representative photomicrographs of H&E, TUNEL, and ssDNA staining (A) and cell counting study of morphologically damaged, TUNEL-positive, and ssDNA-positive cells (B). Three days after ischemia, most of the CA1 neurons in the Wt animals showed shrunken, triangular-shaped, condensed nuclei on H&E-stained sections; however, many neurons preserved their normal features of the nuclei in the Tg animals. A majority of these damaged neurons became TUNEL- and ssDNA-positive at the same time (A). Cell-counting analyses (n = 6 each) confirmed that ∼85% of the hippocampal CA1 pyramidal neurons in the Wt rats and 45% in the Tg animals underwent delayed death, and most of these cells were positive for TUNEL and ssDNA. The neuronal damage matured by 3 d after ischemia. There was a significant difference between the Wt and Tg groups. *p < 0.01; **p < 0.001. Scale bar, 20 μm.