Caspase 8 deficiency protects neurons in in vivo KA-induced seizure mouse model.

<p>(<b>A</b>) Mouse survival was monitored for 24 hours after exposure of control (n = 8) and N<i>casp8</i>^−/− mice (n = 11) to KA. Non-linear x-axis corresponds to time following KA injection. (<b>B</b>) Seizure scores for control and N<i>casp8</i>^−/− mice were determined every 15 min for 2 h and at longer intervals thereafter <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024341#pone.0024341-Yang1" target="_blank">[40] </a><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024341#pone.0024341-Zhang2" target="_blank">[41]</a>. Percentage of TUNEL-positive neurons (<b>C</b>) and density of degenerating neurons (Masson's trichrome stain) (<b>D</b>) were assessed in the hippocampi of the control and N<i>casp8</i>^−/− mice (mean±SEM). <i>P</i> values result from Student's t-test (<b>B</b>: *<i>p</i> = 0.008; <b>C</b>: *<i>p</i> = 0.002; <b>D</b>: *<i>p</i> = 0.005). Colorimetric intensity measurements were applied to Masson's trichrome-stained control (<b>E</b>) and N<i>casp8</i>^−/− (<b>F</b>) hippocampi to obtain density of degenerating neurons in the annotated area (mark-up images). Arrows indicate hippocampal CA3–CA4 sectors and the hilus (<b>E</b>) and the CA3 sector (<b>F</b>). Apoptotic neurons were visualized by TUNEL assay (<b>G, H</b>), and cleaved-caspase 3 immunostaining (<b>I–K</b>) as presented on virtual (<b>I, K</b>) and mark-up (<b>G, H, J</b>) images of the hippocampal regions of the control (<b>G, I, J</b>) and N<i>casp8</i>^−/− (<b>H, K</b>) mice. Brown color (DAB) on digital images and red, orange and yellow pixels on mark-up images denote positive staining. The arrow indicates TUNEL positive neurons in the CA3–CA4 sector.