RESUMEN
<p><b>OBJECTIVE</b>To clarify if programmed cell death mechanisms induced by seizures take part in the necrotic process of neurons.</p><p><b>METHODS</b>Seizure was induced by pilocarpine (P) in Sprague-Dawley adult rats which were allowed to recover for 24 or 72 hours before perfusion-fixation. Neuronal death was assessed by light microscopy with the hematoxylin-eosin (HE) staining and with in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Bax and Bcl-2 protein expression were examined by histochemistry.</p><p><b>RESULTS</b>Twenty-four and 72 hours after seizures, neuronal death in hippocampus CA1 region was morphologically necrotic. TUNEL-positive and morphologically necrotic cells increased in the hippocampal CA1 region at 72 hours after seizures, there was significant difference compared with controls (P < 0.001). Bax expression was also increased in the hippocampal CA1 region at 72 hours after seizures (P < 0.001), but Bcl-2 expression did not increase, while Bcl-2/Bax ratio decreased.</p><p><b>CONCLUSION</b>Seizures induced late-onset neuronal necrosis was accompanied by programmed cell death mechanisms.</p>