Increased expression of aquaporin-4 in brain tissue of amygdala-kindled rats

Recurrent epileptic seizures can lead to brain edema, indicating that water regulation may be perturbed by seizures. We hypothesized that the expression of the brain water channel aq-uaporin-4 (AQP-4) may be upregulated in the epileptic brain. In the present study, we estab-lished the amygdala kindling model of epilepsy, and quantified AQP-4 protein and mRNA levels, using reverse transcription-PCR, immunohistochemistry and western blotting, in epileptic and control rats. We found that AQP-4 was overexpressed in the cerebral cortex of rats with epi-lepsy compared with controls. These findings show that AQP-4 is highly expressed in the brain of amygdala-kindled rats, suggesting that repeated seizures affect water homeostasis in the brain.