Hippocampus RNA-sequencing of aging rats with cognitive decline

Aging is an inevitable process for everyone. Aging is mostly characterized by decline of cognitive function. Themechanisms are still not clear. Hippocampus has been shown to participate in cognition process,the basic mechanism of which are involved in molecularalterations in genes expression. Objective of the present research was to find the transcriptomic changes influenced by aging in hippocampus using RNA-sequencing. The 22-monthrats with cognition decline were used as a model system to analyze the changes in transcriptional networks. There were121 differentially expressed genes identified in the hippocampus of aged rats, including 54 genes upregulated and67 genes downregulated. After GO analysis,differentially expressed genes were found to be enriched inprotein hetorotrimerization, positive regulation of kinase activity, multivesicular body,mitochondrial membrane, oxygen binding and protease binding. KEGG analysesshowed thatDEGs were mainly observed at biochemical signaling pathways, containing Neuroactive ligand-receptor interaction (likeAplnr,Htr2a,Nmur2,Rxfp3), Apelin signaling pathway(likeAplnr,Cdh1,Serpine1),Serotonergic synapse（like Htr2a,Tph2）,Tryptophan metabolism（Tph2）,and so on. These DEGsin the hippocampusmay be involved in the formation of learning and memory. At last, quantitative reverse transcription-polymerase chain reaction was applied to verify the RNAsequencing data.Altogether, the above analysis help to identify specific genes in the aging hippocampus, which might be used as potential molecular targets for the prevention and treatment of aging-related cognition disorders. Male,adult (4 months; n = 10) and aged (22 months; n =10) Sprague Dawley rats were used.Cognitive function in both rat groups were evaluated by Morris water maze. After the MWM test, three male rats from each group were randomly selected and the ventral hippocampus was harvested and processed for transcriptome sequencing.