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:Few studies have assessed the patterns of parasite populations of rodents over a longitudinal gradient in Chile. In this work, the gastrointestinal helminthic fauna of invasive rodents in Chile was examined to assess the association between their presence/absence and abundance with latitude, host sex, and host body condition, and to assess the coexistence and correlation of the abundance between parasite species. Rodents were obtained from 20 localities between 33 and 43°S. Helminths were extracted from the gastrointestinal tract and identified morphologically. Overall, 13 helminth taxa were obtained. The most frequently identified parasite species was Heterakis spumosa, and the most abundant was Syphacia muris, while Physaloptera sp. was the most widely distributed. No locality presented with a coexistence that was different from that expected by chance, while the abundance of five helminthic species correlated with the abundance of another in at least one locality, most likely due to co-infection rather than interaction. Host sex was associated with parasite presence or abundance, and female sex-biased parasitism was notably observed in all cases. Body condition and latitude presented either a positive or negative association with the presence or abundance of parasites depending on the species. It is notable that the likely native Physaloptera sp. is widely distributed among invasive rodents. Further, gravid females were found, suggesting spillback of this species to the native fauna. The low frequency and abundance of highly zoonotic hymenolepid species suggest that rodents are of low concern regarding gastrointestinal zoonotic helminths.