Changes in cognitive ability and serum microRNAs during aging in mice

Mild cognitive impairment (MCI) is considered an early stage leading to dementia. MCI can be reversed, and early diagnosis at the MCI stage is vital to control the progression to dementia. Dementia is currently diagnosed based on interviews and screening tests. However, novel biomarkers must be identified to enable early detection of MCI. Therefore, this study aimed to discover novel biomarkers in the form of blood microRNAs (miRNAs) for the diagnosis of MCI or early dementia. Four-week-old (4w), 8-week-old (8w), 36-week-old (36w) and 58-week-old (58w) mice were used in this study (each n = 4). In this study, mice of various ages were used to search for microRNAs whose expression changes in serum with aging.