Project description:Mechanistic study on the differential responses of the two hippocampal adjoining regions, i.e., CA1 and CA3, to elevated oxidative stress. Keywords: Time course stress response study
Project description:Mechanistic study on the differential responses of the two hippocampal adjoining regions, i.e., CA1 and CA3, to elevated oxidative stress. Experiment Overall Design: Time course study. Involved four time points and comparison of two brain regions.
Project description:Study on selective vulnerability of certain brain regions to oxidative stress. Here we selected 4 brain regions (hippocampal CA1 and CA3, cerebral cortex, and cerebellar granular layer) to study this phenomenon. Experiment Overall Design: Neurons were collected from the 4 regions of the rat brain and subjected to Affymetrix RAE230A analysis, in order to identify genes related to the differential vulnerability of the neurons to oxidative stress.
Project description:Study on selective vulnerability of certain brain regions to oxidative stress. Here we selected 4 brain regions (hippocampal CA1 and CA3, cerebral cortex, and cerebellar granular layer) to study this phenomenon. Keywords: Comparative analysis of different regions of the brain.
Project description:Complete global brain ischemia (CGBI) and reperfusion occur following resuscitation from cardiac arrest. Different brain neurons are selectively vulnerable to CGBI: pyramidal neurons of hippocampal CA3 survive 10 min CGBI but those of CA1 die at 3 days following 10 min CGBI. CA3 neurons are expected to have more robust stress responses and repair responses than CA1 neurons. We used microarrays to compared total and polysome-bound mRNAs in CA1 and CA3 at 8 hr reperfusion after 10 min CGBI in Long Evans male rats to ascertain differences in total vs polysome-bound gene expression. Male Long Evans rats were subjected to (1) sham operation (non-ischemic control, NIC) or normothermic CGBI of 10 min followed by 8 hr reperfusion (8R). Hippocampal CA1 and CA3 were dissected. n = 5 CA1 or CA3 were pooled to give a single replicate and there were 3 or 4 replicates per group. Post-mitochondrial supernatant (PMS) was prepared. Twenty percent of PMS was TRIzol extracted to give total RNA. The remainder was run on a 20% sucrose pad to isolate polysome pellets, which were also TRIzol extracted to give polysome RNA. Total and polysome RNA were then run on Affymetrix Rat Gene 2.0 microarrays.
Project description:Complete global brain ischemia (CGBI) and reperfusion occur following resuscitation from cardiac arrest. Different brain neurons are selectively vulnerable to CGBI: pyramidal neurons of hippocampal CA3 survive 10 min CGBI but those of CA1 die at 3 days following 10 min CGBI. CA3 neurons are expected to have more robust stress responses and repair responses than CA1 neurons. We used microarrays to compared total and polysome-bound mRNAs in CA1 and CA3 at 8 hr reperfusion after 10 min CGBI in Long Evans male rats to ascertain differences in total vs polysome-bound gene expression.
Project description:In this study we used microarray analysis to reveal the gene expression profile of the hippocampal CA1 subregion, which was laser-capture microdissected one week after kainic acid (KA)-induced status epilepticus (SE) in postnatal day 21 (P21) rats. These rats are developmentally roughly comparable to juvenile children, and KA-induced SE leads to selective damage of hippocampal CA1 pyramidal neurons in this age group while saving neurons of the other sub-regions. We searched for alterations in the gene expression pattern during the early epileptogenetic phase, i.e. one week after SE, and compared the results with those of age-matched control rats. To detect specifically changes in the CA1 pyramidal neurons, we used the laser-capture microdissection technique that allows the precise isolation of the region of interest. The RNA of this region was isolated, amplified, and labeled, and then hybridized to Illumina RatRef-12 Expression BeadChip Arrays. The gene expression data generated from the microarray was first normalized by the guantile normalization method, and then filtered by using the empirical Bayes method, and the contrasts were created by using the Limma R/Bioconductor. Finally, the data was clustered by using the non-hierarchical K-means clustering for genes, and the pathway analysis was performed by âGene set testâ, which analyzes the statistical significance of a set of genes simultaneously ranked by p-value and generates the KEGG categories (Chipster manual). The Illumina microarray analysis with the Chipster software v1.1.0 (http://chipster.csc.fi; CSC, Espoo, Finland) generated a total of 1592 differently expressed genes in the CA1 subregion of KA-treated rats compared to control rats. Using the K-means method the genes were classified in 10 different clusters. The subsequent KEGG-test for the probe set over-representation analysis revealed the 15 significantly (p<0.05) changed KEGG-pathways in response to KA-treatment, e.g. oxidative phosphorylation (26 genes changed), and long-term potentiation (LTP; 18 genes changed). Some of the differentially expressed genes were also identified to be involved in Ca2+ homeostasis, gliosis, inflammation, and GABAergic transmission.
Project description:The hippocampal formation is a brain structure essential for higher-order cognitive functions. It has exquisite differences in anatomical organization and cellular composition, and hippocampal sub-regions have different properties and functional roles. Areas CA1 and CA3 in particular, are key sub-regions for learning and memory formation that fulfill complementary but specific functions. The molecular basis for such specific properties and the link to learning and memory remain unknown. Here using a SWATH-MS proteomic approach and bioinformatic tools, we identify a selective proteomic signature in area CA1 and CA3, and reveal their specific dynamics during memory formation. We show that 30% of all quantifiable proteins are differentially expressed in area CA1 and CA3 at baseline, and that each proteome responds differently during the formation of memory for object or object location. Using clustering and cross-correlational analyses, we outline specific temporal proteomic profiles and an increased correlation between both forms of memory within area CA1, but not within area CA3. These results provide new insight into a proteomic basis for hippocampal sub-region molecular and functional specificity.