Cell apoptosis in the hippocampus or cortex regions were isolated from wild type and <i>chop</i>−/− mice.

<p>Tunicamycin (0.1 mg/ml) were injected in the hippocampus of wild type C57BL/6J and CHOP−/− mouse. Apoptotic cells were performed by the TUNEL staining 5 days after tunicamycin injection. The staining of neuron nuclei in normal control hippocampus was shown on top (A), and the TUNEL positive cells from hippocampus or cortex (B) of wild type C57BL/6J and <i>chop</i>−/− mouse were quantified (C). Data are presented as mean ± S.E.M. for each group (n = 4). **P<0.01 as Tun+wild type versus Tun+<i>chop−/−</i> mice. H: hippocampus; C: cortex.