Study of aging using circuit tests and parametric analysis

Mouse development and aging were investigated in 11 tests. The test data were parametrically analysed, normalized, and integrated using principal component analysis (PCA). Changes in the indexing items displayed two trends: power and accuracy in the trials. Power decreased monotonically with age, whereas accuracy peaked at 6 months. Features, such as fear or anxiety, could not have been measured. The noise level and sensitivity of each test were determined. In an open field test that involved a video recording of movement, the noise level was the lowest and the sensitivity was high. This test contributed the most to the PCA axes, and reproduced the two main directions. Significance StatementThe mathematical aspect may have been neglected in behavioural tests. Here, the circuit test data were objectively analysed by focusing on the data distributions during the aging of mice. The test results revealed two clear directions for the data: power, which was gradually reduced, and accuracy, which peaked at sixth months old. Compared with the open field test evaluated using video recordings, the other tests had higher noise levels and weaker signals. Other tests can be improved by using movie recordings and identifying appropriate items.