Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immediate early response genes have been shown to be inducible in the central nervous system after a variety of stimuli. Induction of these transcription factors in cerebral cortex by a physiological stimulus had not previously been demonstrated. In this study, tactile stimuli induced multiple transcription factors in the somatosensory cortex. Adult male rats were lightly anesthetized with urethane. Tactile stimuli was delivered by a paint brush gently stroking an animals whiskers on one side of its face for a 15 min period. Two h later, the animals were sacrificed. Cortex contralateral to the stimulation was compared with ipsilateral cortex using antibodies raised against immediate early response gene products NGFI-A, NGFI-B, and c-fos. The different transcription factors showed slightly different patterns of response to the tactile stimulus. However, the induction of immunohistochemical staining was most prominent in layer 4 with all antibodies under study. This increase in the number of cell bodies stained was less robust than that seen in the somatosensory cortex after a seizure, and showed more of a predominance in layer 4 cells. These data demonstrate that physiologic stimulation can induce immediate early response genes in cortical cells, and that multiple immediate early response genes react to a stimulus.
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PMID:Induction of transcription factors in somatosensory cortex after tactile stimulation. 131 99

krox 20 is an inducible immediate early response gene. To determine if krox 20 has a physiological role in the adult central nervous system (CNS), this study sought to demonstrate the presence of krox 20 in adult rat brain. RNA analysis showed the presence of krox 20 transcripts in the CNS, including the cortex. Polyclonal antibodies to a Krox 20 fusion protein demonstrated 79 and 55 kDa antigens in nuclear CNS homogenates. Neither RNA nor protein analysis was able to demonstrate an induction of krox 20 by a seizure at times when other immediate early response genes are known to be induced. Immunohistochemical analysis revealed staining at several levels throughout the nervous system. This staining was predominantly nuclear, consistent with the role of krox 20 as a transcription factor. These data show that krox 20 is present in the adult CNS, yet differs in response to stimuli as compared to other related transcription factors with a zinc finger motif, such as NGFI-A and NGFI-C.
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PMID:krox 20 messenger RNA and protein expression in the adult central nervous system. 132 8

The nerve growth factor-induced clone C (NGFI-C) gene encodes a zinc-finger transcription factor that is rapidly induced by nerve growth factor in rat pheochromocytoma PC12 cells and by seizure in brain. NGFI-C is closely related to the previously described early response genes, nerve growth factor-induced clone A (NGFI-A or EGR1), EGR2, and EGR3. These four early response (immediate early) proteins all contain very similar zinc-finger DNA binding domains; in addition, analysis of the non-zinc-finger region revealed that they share an additional five highly homologous subdomains, four of which are within the amino terminus. The 5' flanking region of NGFI-C contains several cAMP response elements but does not contain any serum-response elements or CArG boxes [CC(A/T)6GG], cis-acting elements commonly involved in early response gene regulation. NGFI-C mRNA was detected in neural tissues of postnatal animals, but no expression was found in rat embryos. In situ hybridization demonstrated that NGFI-C is rapidly induced in the dentate gyrus of the hippocampus after seizure, but in contrast to NGFI-A, increases in NGFI-C mRNA were not detected in the overlying cortex. By using fluorescence in situ hybridization, NGFI-C was localized to human chromosome 2p13. This region contains a constitutive fragile site that is associated with chromosomal breakpoints and translocations characteristic of some chronic lymphocytic leukemias.
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PMID:Neural-specific expression, genomic structure, and chromosomal localization of the gene encoding the zinc-finger transcription factor NGFI-C. 163 Nov 70

Immunocytochemistry with specific antisera was used to assess regional levels of six immediate early gene encoded proteins (KROX-24, c-FOS, FOS B, c-JUN, JUN B and JUN D) in the rat hippocampus after 15 min of bicuculline-induced seizures. Serial sections of the dorsal hippocampus were examined at various postictal recovery periods up to 24 h. The results demonstrate a complex temporal and spatial pattern of immediate early gene synthesis and accumulation. Three major categories of immediate early gene products could best be distinguished in the dentate gyrus: KROX-24 and c-FOS showed a concurrent rapid rise with peak levels at 2 h and a return to baseline levels within 8 h after seizure termination. FOS B, c-JUN and JUN B levels increased more gradually with peak intensities in the dentate gyrus reached at 4 h. These immediate early gene products showed above normal levels in various hippocampal subpopulations up to 24 h. JUN D exhibited the most delayed onset combined with a prolonged increase of seizure-induced immunoreactivity. Irrespective of this differential temporal expression profile of individual transcription factors, the sequence of induction in the hippocampal subpopulations was identical for all immediate early gene-encoded proteins examined: first in the dentate gyrus granule cells followed by CA1 and CA3 neurons, respectively. Our data indicate an asynchronous synthesis of several immediate early gene-encoded proteins in the brain after status epilepticus. FOS and JUN proteins act via homo- or heterodimer complexes at the AP-1 and other DNA binding sites. The different time-courses for individual immediate early gene products strongly suggest, that at different time-points after status epilepticus, different AP-1 complexes are effective. In vitro studies have shown that different AP-1 complexes possess different DNA binding affinities as well as different transcriptional regulatory effects. Our results suggest that these molecular mechanisms are also effective in vivo.
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PMID:Induction of immediate early gene encoded proteins in the rat hippocampus after bicuculline-induced seizures: differential expression of KROX-24, FOS and JUN proteins. 160 23

Kindling is a phenomenon in which brief afterdischarges (ADs) evoked by periodic electrical stimulation of the brain eventually result in generalized clonic motor seizures. Once present, the enhanced sensitivity to electrical stimulation is lifelong. The mechanism by which brief ADs produce this long-lasting effect may involve a change in gene expression. To begin to investigate changes in gene expression that occur during kindling, we used in situ hybridization histochemistry to examine the time course of expression of mRNAs of the immediate early genes (IEGs) c-fos, c-jun, NGFI-A, and c-myc within the dorsal hippocampus of rats following a kindling AD. Three principal findings resulted from this study. First, the expression of all mRNAs except c-myc was significantly increased (P less than 0.05) within discrete neuronal populations. Second, the time course of expression of the IEGs differed markedly within the same neuronal population. Third, for a given IEG, the time course and anatomic pattern of expression were strikingly different among different neuronal populations of the hippocampus. The prolonged and distinctly different patterns of IEG expression suggest that target genes are differentially regulated in these neuronal populations for prolonged periods following a kindling AD.
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PMID:Differential expression of immediate early genes in the hippocampus in the kindling model of epilepsy. 166 8

We have cloned NGFI-C, a nerve growth factor-induced early-response gene which encodes a Cys2/His2 zinc finger protein. RNA blot analysis demonstrates that NGFI-C mRNA is induced within minutes of stimulation of PC12 cells by nerve growth factor and is similarly activated in brain after a Metrazol-induced seizure. The cDNA sequence predicts a protein that contains three zinc fingers which show striking homology to the DNA-binding regions of three previously reported zinc finger proteins, NGFI-A, Krox-20, and the Wilms' tumor gene product. NGFI-C binds to the previously described DNA-binding site of these three proteins, which is GCGGGGGCG. Cotransfection experiments revealed that NGFI-C strongly activates transcription from this site in mammalian cells. The isolation of another early-response gene that encodes a member of the G(C/G)G or GSG element-binding family should provide an opportunity to investigate the relative contributions of a family of transcription factors to the cell's response to changes in its environment.
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PMID:The early response gene NGFI-C encodes a zinc finger transcriptional activator and is a member of the GCGGGGGCG (GSG) element-binding protein family. 207 95

Antibodies are used to localize the NGFI-A protein in the rat brain. The protein is found in a wide variety of neurons. However, not all neurons are stained. The protein is either absent or present at undetectable levels in glial cells. Neuronal nuclei stain intensely, cytoplasmic staining is lighter. Seizures cause a detectable increase in the intensity of staining.
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PMID:Localization of the NGFI-A protein in the rat brain. 216 69

Recent studies have demonstrated that the regulation of neuropeptide expression in forebrain neurons is responsive to external influences including changes in physiological activity. This has been demonstrated most clearly in studies of hippocampus where the synthesis and resting levels of several neuropeptides, localized within well-characterized components of hippocampal circuitry, have been shown to be selectively influenced by seizure activity. In studies described here, we examined the influence of recurrent limbic seizures on the expression of enkephalin, dynorphin, cholecystokinin, and neuropeptide Y (NPY) in rat and mouse hippocampus using immunohistochemical, in situ hybridization and blot hybridization techniques. The data demonstrate that seizures differentially influence the expression of each peptide as a part of a broader cascade of changes in genomic expression within individual hippocampal neurons. In particular, seizures increase preproenkephalin mRNA and enkephalin peptide but decrease dynorphin peptide in the dentate gyrus granule cell/mossy fiber system. Seizure-induced decreases in the concentration of preprodynorphin mRNA in the granule cells have been reported by others. Immunoreactivity for CCK, which is codistributed with the opioid peptides in the mossy fiber system of mouse, is also dramatically reduced in the granule cell axons by seizure. Recurrent seizures induce two temporally distinct changes in NPY expression in hippocampus. First, there is an increase in hybridization to preproNPY mRNA within scattered, probable local circuit neurons in all subfields. This is followed by the seemingly novel appearance of preproNPY mRNA within the dentate gyrus granule cells and pyramidal cells of field CA1. Clues about mechanisms of neuropeptide regulation have come from observations of other, more rapid, transcriptional events induced by seizure. Most notably, our results and those of others demonstrate that seizures increase the expression of messenger RNAs from immediate-early genes (c-fos, c-jun, and NGFI-A) which encode proteins that may mediate neuropeptide gene regulation. In addition, mRNA for nerve growth factor is dramatically increased in the dentate gyrus granule cells by seizure; increased production of this trophic factor might mediate the more delayed changes in genomic expression and growth responses observed to occur in hippocampus and other forebrain areas following seizure activity.
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PMID:Seizures, neuropeptide regulation, and mRNA expression in the hippocampus. 220 4

Recent studies in invertebrates indicate that a rapid genomic response to neuronal stimulation has a critical role in long-term changes in synaptic efficacy. Because several of the genes (immediately early genes; IEGs) that respond rapidly to growth factor stimulation of vertebrate cells in vitro are also activated by neuronal stimulation in vivo, attention has focused on the possibility that they play a part in synaptic plasticity in vertebrate nervous systems. Four IEGs thought to encode transcription factors, zif/268 (also termed Egr-1, NGFI-A, Krox 24), c-fos, c-jun, and jun-B are rapidly induced in the brain by seizure activity, and we have now studied the induction of these genes in a well-characterized model of synaptic plasticity in the vertebrate brain--long-term potentiation (LTP) of the perforant pathgranule cell (pp-gc) synapse in vivo. We found that high-frequency (but not low-frequency) stimulation of the pp-gc synapse markedly increases zif/268 messenger RNA (mRNA) levels in the ipsilateral granule cell neurons; mRNA of c-fos, c-jun and jun-B is less consistently increased. The stimulus frequency and intensity required to increase zif/268 mRNA levels are similar to those required to induce LTP, which is also seen only ipsilaterally, and both responses are blocked by NMDA-receptor antagonists as well as by convergent synaptic inhibitory inputs already known to block LTP. Accordingly, zif/268 mRNA levels and LTP seem to be regulated by similar synaptic mechanisms.
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PMID:Rapid increase of an immediate early gene messenger RNA in hippocampal neurons by synaptic NMDA receptor activation. 254 65

The present study examined the response of immediate early genes following kainic acid induced seizures in mice lacking the alpha and delta isoforms of CREB. mRNA levels for c-fos, c-jun, and Krox-24 were measured following limbic seizure activity and were found to be induced in wild type as well as CREB mutant mice. This effect was also seen for these three mRNAs at the protein level as well as for FOS-B. Furthermore the time course of expression of FOS, JUN, KROX-24, and FOS-B proteins were essentially the same in CREB mutant mice as compared to wild-type controls. These data suggest that CREB alpha and delta are not required for the induction of immediate early genes following pharmacologically induced seizures.
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PMID:Effects of kainic acid induced seizures on immediate early gene expression in mice with a targeted mutation of the CREB gene. 755 95


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