-Objective:As axon outgrowth and dentate granule cell neurogenesis are hallmarks of hippocampal development and are also the two morphologic changes in the structure of the dentate gyrus after status epilepticus (SE), we hypothesized that molecules involved in normal development may also play a role during epileptogenesis. Method: Using in situ hybridization, we have characterized mRNA expression of myocytespecific enhancer binding factor 2C (MEF2C) in the dentate gyrus during development (P0, P3, P7, P14 and P28) and at multiple time points following pilocarpine-induced SE (3, 7, 14, 28 days after SE). Results: It was demonstrated that MEF2C is up-regulated during development (P0, P3, P7, P14 and P28) and in the adult rat dentate gyrus following SE (3, 7, 14, 28 days after SE). Conclusions: The molecules controlling cell-fate decisions in the developing dentate gyrus are also operative during epileptogenesis.KEY WORDS: rat, hippocampus, epilepsy, status epilepticus, MEF2C.
Realce miócito específico ligado a expressão do fator 2C (MEF2C) no giro denteado durante o desenvolvimento e após uso de pilocarpina induzindo status epilepticus: estudo preliminarResumo -Objetivo: Como o crescimento axonal e a neurogênese do giro denteado são características intrínsecas do hipocampo durante o processo de desenvolvimento, e também são duas alterações morfológicas na estrutura do giro denteado após o status epilepticus (SE), nós hipotetizamos que as moléculas envolvidas no processo normal do desenvolvimento hipocampal também podem participar do processo de epileptogênese. Método: Utilizando hibridização in situ, caracterizamos a expressão do RNAm do fator de transcrição myocyte-specific enhancer binding factor 2C (MEF2C) no giro denteado durante o desenvolvimento (P0, P3, P7, P14 e P28) e em diferentes períodos após o SE (3, 7, 14, 28 dias após SE). Resultados: Foi demonstrado um aumento da expressão de MEF2C no giro denteado durante o desenvolvimento e no giro denteado de animais adultos após o SE. Conclusão: As moléculas que controlam o destino celular durante o processo de desenvolvimento também estão operativas durante o processo de epileptogênese. PALAVRAS-CHAVE: rato, hipocampo, epilepsia, status epilepticus, MEF2C. Epilepsy is the commonest serious neurological condition. Temporal lobe epilepsy (TLE), the most common epilepsy in adults, is generally intractable and is suspected to be the result of recurrent excitation or inhibition circuitry 1 . TLE is defined by recurring partial complex seizures arising from limbic structures of the temporal lobes, including the hippocampus, dentate gyrus, amygdala and associated temporal neocortex 1 . The study of mechanisms of the epilepsies requires employment of animal models. In these lines, the pilocarpine model is the most useful TLE model that reflects the human condition 2 . In brief, the systemic administration of the cholinergic agonist pilocarpine to rats promotes sequential behavioural and electrographic changes that can be divided into three distinct