Project description: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. Each experimental group consists of 6 rats (biological replicates) from one laboratory at a single time point, except for the SSSE group (6 at day 1 after SSSE, 5 controls and at day 3 after SSSE, 4 at day 10). Thus granule cells were harvested from 164 rats.
Project description: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.
Project description:Hippocampal sclerosis (HS) is the most common neuropathological finding of medically intractable cases of mesial temporal lobe epilepsy (MTLE), the most common form of partial epilepsy. Within the dentate gyrus, HS may be associated with granule cell dispersion and aberrant mossy fiber sprouting, and these pathological changes are accompanied by a range of molecular changes. In this study, we analyzed the gene expression profiles of dentate granule cells of MTLE patients with and without HS to show that next-generation sequencing methods can produce interpretable genomic data from RNA collected from small homogenous cell populations and to shed light on the transcriptional changes associated with HS. 12 samples of dentate granule cells from patients with mesial tempora lobe epilepsy, 5 with hippocampal sclerosis and 7 without hippocampal sclerosis. 10 samples had replicates.
Project description:Hippocampal sclerosis (HS) is the most common neuropathological finding of medically intractable cases of mesial temporal lobe epilepsy (MTLE), the most common form of partial epilepsy. Within the dentate gyrus, HS may be associated with granule cell dispersion and aberrant mossy fiber sprouting, and these pathological changes are accompanied by a range of molecular changes. In this study, we analyzed the gene expression profiles of dentate granule cells of MTLE patients with and without HS to show that next-generation sequencing methods can produce interpretable genomic data from RNA collected from small homogenous cell populations and to shed light on the transcriptional changes associated with HS.