RESUMO
OBJECTIVE: To find out the differentially expressed genes in the hippocampus of the rats with genetic epilepsy so as to lay a foundation for exploring the pathogenesis of epilepsy by means of cDNA array technology. METHODS: Gene expression patterns in the hippocampus of the genetic epilepsy-prone P77PMC rats and normal Wistar rats were established using the alpha-32P-labeled cDNA probes hybridized with the Atlas Rat cDNA Expression Array, and then were analyzed by an image analysis instrument to get the differentially expressed genes. RESULTS: Fifteen genes were found having differential expression patterns in hippocampus between the P77PMC rats and the Wistar rats, while there may be many other differentially expressed genes left undiscovered due to having no appropriate image analysis software. And among the fifteen genes, the expression levels of twelve genes in the P77PMC rats were higher than those in the Wistar rats, while the expression levels of the other three genes were lower. The results of reverse transcription-polymerase chain reaction(RT-PCR) have demonstrated the reliability of cDNA arrays method. CONCLUSION: cDNA array is a powerful tool for identifying differential expression genes of epilepsy on large scales. There are several differentially expressed genes in hippocampus of the P77PMC rats and the Wistar rats. All these identified genes could play potentially important roles in the pathogenesis of epilepsy.
Assuntos
DNA Complementar/metabolismo , Epilepsia/genética , Perfilação da Expressão Gênica , Hipocampo/metabolismo , Animais , Calmodulina/biossíntese , Calmodulina/genética , DNA Complementar/genética , Predisposição Genética para Doença , Hipocampo/química , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: To characterize the acute and chronic behavioral, electrographic and histological changes of sustained seizures induced by pilocarpine in rats. METHODS: The rats in the study were divided into the experimental group and control group. After status epilepticus (SE) was induced in the experimental rats, the surviving animals were continuously monitored for 6 h-60 days. At different times after the pilocarpine injection, the animals were processed for neo-Timm and Nissl staining to visualize granule cell mossy fiber sprouting and hippocampal cell damage. RESULTS: Of the animals injected with pilocarpine, 87% developed SE, and most of the pilocarpine-induced SE rats (20%-100%) showed recurrent seizures during the chronic period. A widespread cell loss was noted in the hippocampal formation of the rats with pilocarpine-induced SE. The pattern of neo-Timm staining in the inner molecular layer was clearly altered in animals that showed pilocarpine-induced SE. The Neo-Timm staining score of the experimental group was significantly higher than that of the control group. The degree of inner molecular layer mossy fiber terminal staining increased with time after the epileptogenic lesion. CONCLUSION: The temporal lobe epilepsy model induced by pilocarpine in rats can replicate several of the features of human temporal epilepsy (hippocampal cell loss, inner molecular layer mossy fiber sprouting, and spontaneous recurrent seizures), and it may be a useful model for studying this human temporal lobe epilepsy. The results also suggest that structural brain damage insulted by pilocarpine-induced SE may underlie or be associated with recurrent spontaneous seizures in rats.
