Global expression profiling of epileptogenesis has been confounded by variability across laboratories, epilepsy models, tissue sampled and experimental platforms, with the result that very few genes demonstrate consistent expression changes. The present study minimizes these confounds by combining Affymetrix microarray datasets from seven laboratories, using three status epilepticus (SE) models of epilepsy in rats (pilocarpine, kainate, self-sustained SE or SSSE) and the rat kindling model. Total RNA was harvested from laser-captured dentate granule cells from 6 rats at three times during the early-to-mid latent phase that precedes epilepsy symptoms in the SE models (1, 3 and 10 days after SE), or 24 hr after the first stage 2, stage 4 and stage 5 seizure in the kindling model. Each epilepsy model was studied in two independent laboratories except SSSE. The initial goals of this study were to a) identify model-independent transcriptional changes in dentate granule cells that could point to novel intervention targets for epileptogenesis, b) characterize the basal transcriptional profile of dentate granule cells, and c) identify genes that have highly variable expression.
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View SamplesDiffuse infiltrating gliomas are the most common primary brain malignancy found in adults, and Glioblastoma multiforme, the highest grade glioma, is associated with a median survival of 7 months. Transcriptional profiling has been applied to 85 gliomas from 74 patients to elucidate glioma biology, prognosticate survival, and define tumor sub-classes. These studies reveal that transcriptional profiling of gliomas is more accurate at predicting survival than traditional pathologic grading, and that gliomas characteristically express coordinately regulated genes of one of four molecular signatures: neurogenesis, synaptic transmission, mitotic, or extra-cellular matrix. Elucidation of these survival associated molecular signatures will aid in tumor prognostication and define targets for future directed therapy.
Gene expression profiling of gliomas strongly predicts survival.
Sex, Age, Specimen part, Disease stage
View SamplesInformation about the genes that are preferentially expressed during the course of Alzheimers disease (AD) could improve our understanding of the molecular mechanisms involved in the pathogenesis of this common cause of cognitive impairment in older persons, provide new opportunities in the diagnosis, early detection, and tracking of this disorder, and provide novel targets for the discovery of interventions to treat and prevent this disorder. Information about the genes that are preferentially expressed in relationship to normal neurological aging could provide new information about the molecular mechanisms that are involved in normal age-related cognitive decline and a host of age-related neurological disorders, and they could provide novel targets for the discovery of interventions to mitigate some of these deleterious effects.
Gene expression profiles in anatomically and functionally distinct regions of the normal aged human brain.
Sex, Age, Specimen part, Disease, Disease stage, Race
View SamplesIn pevious research we have shown that the disruption of the normal development of the ventral hippocampus in rodents leads to cellular abnormalities in the frontal cortex and behavioral deficits related to schizophenia (Neurotox Res. 2002, 4(5-6):469-475). We propose the use of gene expression analysis to investigate the molecular underpinnings of these processes which may shed light on the molecular processes relevant to human schizophrenia. In addition, we seek to characterize expression differences induced by chronic administration of antipsychotic medications, which may give insight into the molecular processes involved in ameliorating psychotic symptoms.
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View SamplesIt is suggested that the stress induced activation of the HPA axis and associated increases in plasma ACTH and glucocorticoids (corticosterone, B in the rat) are contributing factors in the development of many psychopathologies. However, the circadian fluctuation of the HPA axis activity (characterized by a zenith in the plasma ACTH and B, before the beginning of the active awake state and the nadir during the inactive sleeping period) occurs throughout the life and is important for normal physiological and behavioral functioning. A blunting or enhancement of this rhythm through changes in the trough or in the peak is a characteristic feature of many pathological states. At the CNS level, the circadian fluctuation of the HPA axis activity is associated with changes in the expression profile of structural, functional, and immediate early genes. However, little is known about the specific role of B in the modulation of the circadian pattern of gene regulation in the CNS.
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View SamplesEpilepsy is a major neurological disorder that affects approximately 1% of the population. The processes that lead to the development of epilepsy (epileptogenesis) are largely unknown. Levetiracetam is a novel antiepileptic drug (AED) that in the kindling model inhibits epileptogenesis in addition to being effective in controlling established epilepsy. The mechanisms of action of levetiracetam as an AED and an antiepileptogenic drug are unknown. By identifying the effect of chronic levetiracetam therapy on gene expression in the brain we hope to be able to identify genes that are involved in epileptogenesis. By comparing the gene expression profiles of levetiracetam and phenytoin treatments, we hope to be able to distinguish between genes that are important for the antiepileptic (anti-seizure) effect and genes that are important for the antiepileptogenic effect of levetiracetam. Phenytoin is a well-established AED; its mechanism of action involves inhibition of sodium channels. In contrast to levetiracetam, available data suggest that phenytoin in certain situations may enhance rather than inhibit the development of epilepsy.
Region-specific changes in gene expression in rat brain after chronic treatment with levetiracetam or phenytoin.
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View SamplesMeningiomas are typically considered a benign tumor that can be cured by complete surgical resection; however, a percentage of patients have recurrent disease, even after apparently complete resections. These patients require additional surgeries, radiation therapy, chemotherapy, or a combination of all three. The ability to recognize these patients prior to recurrence would promote earlier use of adjuvant therapy, thus improving overall patient outcome. Unfortunately, identification of meningiomas with this more aggressive phenotype is difficult, and standard histopathological techniques rarely suffice. The identification of genetic and molecular parameters that can help to define these more aggressive tumors would improve prognostication and treatment planning for patients with meningiomas.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
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View SamplesNeurodegenerative brain disorders become more common in the aged. Most of these disorders are associated with or caused by selective death of certain neuronal subpopulations. The mechanisms underlying the differential vulnerability of certain neuronal populations are still largely unexplored and few neuroprotective treatments are available to date. Elucidation of these mechanisms may lead to a greater understanding of the pathogenesis and treatment of neurodegenerative diseases. Moreover, preconditioning by a short seizure confers neuroprotection following a subsequent prolonged seizure. Our goal is to identify pathways that confer vulnerability and resistance to neurotoxic conditions by comparing the basal and preconditioned gene expression profiles of three differentially vulnerable hippocampal neuron populations.
Gene expression changes after seizure preconditioning in the three major hippocampal cell layers.
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View SamplesTraumatic brain injury (TBI) induces a complex cascade of molecular and physiological effects. This study proposes to investigate the gene expression profile in cortex and hippocampus over early time points, following two different injury severities. These results will complement prior knowledge of both metabolic and neuroplastic changes after TBI, as well as serve as a starting point to investigate additional gene families whose expression is altered after TBI.
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