Analysis of Differential microRNA Expression in the Hippocampus of Scopolamine-Induced Amnesic Mouse Model.

Amnesia is characterized by memory deficits linked to various neurodegenerative pathologies and can be induced by the administration of scopolamine, a cholinergic antagonist. Scopolamine-induced amnesia is a well-studied pharmacological animal model that simulates memory impairment caused by aging, brain illnesses, neuropathologies, and trauma. However, the molecular mechanism of amnesia, more importantly in terms of microRNA (miRNA) regulation, is not well understood. Therefore, this study aimed to analyze miRNA profiles in the hippocampus of both control mice and those treated with scopolamine (amnesic mice). Initially, a short cDNA library was prepared for each sample and then sequenced on the Illumina platform. Among the total differentially expressed miRNAs, 113 were significantly upregulated and 96 were downregulated in the scopolamine group in comparison to the control group. Ten upregulated and ten downregulated miRNAs were validated to confirm the reliability of the sequencing results using qRT-PCR (quantitative real-time PCR). Furthermore, we performed a target prediction analysis intersecting the results from TargetScan, miRDB (miRNA database), and Miranda to analyze the targets of the dysregulated miRNAs. We also conducted a pathway analysis to investigate the molecular, cellular, and biological functions of these targets. miRNA‒target interactions were found to play roles in various signaling pathways during amnesia. These results provide an initial insight for the contribution of miRNAs to scopolamine-induced amnesia, as well as their possible application as markers of disease pathology.