Localization of the serotonergic terminal fields modulating seizures in the genetically epilepsy-prone rat.

Serotonin (5-HT) has been shown to exert antiepileptic effects in a variety of generalized convulsive seizure models, particularly the genetically epilepsy-prone rat (GEPR). The present study was designed to identify the region/site(s) where 5-HT exerts anticonvulsant effects in the GEPR-9, a model in which sound-evoked generalized tonic-clonic seizures (GTCS) are highly sensitive to manipulations in 5-HT concentration. Because the 5-HT reuptake inhibitor, fluoxetine, was known to exert anticonvulsant effects in GEPR-9s via a 5-HT-dependent mechanism, we utilized selective regional 5-HT depletion in combination with systemic fluoxetine administration to find the site where a 5-HT deficit would prevent the anticonvulsant action of fluoxetine.