Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038220 (status epilepticus)
 7,272 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In various chemoconvulsant models of human temporal lobe epilepsy, the induction of epileptogenesis by a prolonged period of continuous seizure activity is accompanied by significant changes in hippocampal structure. These changes include an increase in neurogenesis within the proliferative subgranular zone (SGZ) of the dentate gyrus and induction of mossy fiber sprouting in mature dentate granule cells. As dentate granule cell neurogenesis and axon outgrowth are also hallmarks of hippocampal development, we hypothesized that molecules involved in normal development may also play a role in similar changes associated with epileptogenesis. To begin to test this hypothesis, we have analyzed the expression patterns of multiple members of the basic helix-loop-helix (bHLH) family of transcription factors in both normal and epileptic adult rats. bHLH protein expression has been found recently in dentate granule cells at specific developmental stages, and analysis of developmental models suggests specific neural differentiation functions for these molecules. We show that mRNA expression of all seven bHLH family members examined in this study, as well as the divergent homeobox protein Prox1, is present in the adult. Patterns of expression varied considerably between family members, ranging from the limited expression of Mash1 in the neurogenic SGZ of the dentate gyrus to the scattered, widespread profile of Hes5 throughout the dentate gyrus and the hippocampus proper. Moreover, these varied profiles of expression were differentially regulated following status epilepticus, with some increasing (Mash1, Id2), some falling (Hes5, Prox1), and others remaining mostly unchanged (NeuroD/BETA2, NeuroD2/NDRF, Id3, Rath2/Nex1). While the function of these molecules in the adult brain remains to be characterized, our findings support the idea that molecules controlling cell-fate decisions in the developing dentate gyrus are also operative during seizure-induced neurogenesis and plasticity.
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PMID:Differential regulation of basic helix-loop-helix mRNAs in the dentate gyrus following status epilepticus. 1156 18

Enhanced neurogenesis in the dentate gyrus of the hippocampus following seizure activity, especially status epilepticus, is associated with ectopic residence and aberrant integration of newborn granule cells. Hilar ectopic granule cells may be detrimental to the stability of dentate circuitry by means of their electrophysiological properties and synaptic connectivity. We hypothesized that status epilepticus also increases ectopic granule cells in the molecular layer. Status epilepticus was induced in male Sprague-Dawley rats by intraperitoneal injection of pilocarpine. Immunostaining showed that many doublecortin-positive cells were present in the molecular layer and the hilus 7 days after the induction of status epilepticus. At least 10 weeks after status epilepticus, the estimated number of cells positive for both prospero homeobox protein 1 and neuron-specific nuclear protein in the hilus was significantly increased. A similar trend was also found in the molecular layer. These findings indicate that status epilepticus can increase the numbers of mature and ectopic newborn granule cells in the molecular layer.
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PMID:Status epilepticus increases mature granule cells in the molecular layer of the dentate gyrus in rats. 2520 5