Inferior collicular seizure generalization produces site-selective cortical induction of cyclooxygenase 2 (COX-2).

Given the potential role of mitogen-inducible cyclooxygenase (COX-2) in CNS damage, patterns of COX-2 induction were determined both before and after seizure generalization from the inferior collicular cortex into the forebrain. With midbrain seizures, no change was found in COX-2-like immunoreactivity, even at the site of seizure genesis. However, upon forebrain seizure generalization, dramatic, ipsilateral increases in COX-2-like immunoreactivity were found in layers II and II of perirhinal, entorhinal and temporal cortex, just dorsal to the perirhinal fissure, coursing from the level of the medial geniculate to the level of the inferior colliculus. No changes in COX-2-like immunoreactivity were found in contralateral cortical regions, retrosplenial cortex, dentate gyrus, subiculum, tenia tectum or inferior colliculus. Thus, initial seizure generalization into the forebrain induces COX-2 expression in a highly specific area of the cerebral cortex.