Abstracts

RATIONALE: Epilepsy frequently develops as a result of brain insult and the epileptic process can be divided into tree phases: 1) initial insult, 2) latency period (epileptogenesis) and 3) recurrent seizures (epilepsy). The lack of available strategy to prevent the development of epilepsy is due to our limited understanding of events taking place during the latency period. In the present study we aimed at identification of epileptogenesis releated genes using recently developed amygdala stimulation model of temporal lobe epilepsy in which status epilepticus (SE) is followed by a latency period preceading appearance of spontaneous seizures. METHODS: SE was evoked by stimulation of the lateral nucleus of the amygdala. Rats were constantly monitored with video-EEG monitoring system until the end of experiment. Only the animals that had SE but did not have spontanneous seizures were used for the experiment. Fourteen days after induction of SE rats were sacrificed and RNA from the hippocampus was extracted. Radioactive cDNA probe was syntesized by reverse transcription. cDNA probes derived from control or epileptic animals were hybridized to high density cDNA arrays containing over 5000 gene probes (Research Genetics). Results of hybridizations were analysed densitometrically. Subsequently changes in expression of selected genes were confirmed by RT-PCR. RESULTS: Densitometric analysis of arrays revealed that expression of majority of genes did not change. Two-fold or larger increase in expression was observed in 16 genes, and a decrease in 100 genes. CONCLUSIONS: Presented data indicate, that the expression of selected genes is changed during the latent period. Further characterization of genes involved in epileptogenesis may lead to the development of rational antiepileptogenic therapy in the future.