Microarray Analysis of MicroRNA Expression Profiles in Newborn and Adult Rats Hippocampus

MicroRNAs (miRNAs) are a functional small non-coding RNA and play essential roles in gene regulation indevelopment, differentiation and proliferation. In order to investigate the miRNAs function in Lewis rat hippocampal development, in this study, newborn and adult hippocampi were deliberately selected to analyze the miRNA expression profiles by microarray. Microarray analyses identified 22 differentially expressed miRNAs (>1.5 fold, intersection of two sets). Of these, 12 were down-regulated and 10 were up-regulated during hippocampus development. DAVID Functional Annotation Cluster (FAC) analysis of the 317 predicted target genes of down-regulated miRNAs revealed confident enrichment scores for cell adhesion and neuron development etc., indicating the functional significance and importance of these miRNAs during hippocampal development. Bioinformatic analyses of the differentially expressed miRNAs have identified a number of miRNAs with putative involvement in the hippocampus developing process. This study lays a solid foundation for further studies to clarify the important regulation function of miRNAs in brain tissue.