Objective To observe and compare the depression and anxiety-like behaviors of experimental mice of different ages.
Methods Twenty-seven male C57BL/6 mice were divided into young group (3 months old, n = 9), middle-aged group (10 months old, n = 9) and old group (18 months old, n = 9). , respectively, the tail suspension test, forced swimming test, elevated plus maze test, open field test and sugar water preference test were performed to observe the depression and anxiety-like behaviors of mice. 6 Serum serotonin content of mice.
Results The mice in the middle-aged group had longer tail suspension immobility time than the mice in the old group (P<0.05); the immobility time of the mice in the young group, middle-aged group and the old group was significantly decreased in forced swimming, and the mice in the young group were swimming. The immobility time of the mice in the middle-aged group was significantly longer than that of the mice in the middle-aged group (P<0.001) and the mice in the aged group (P<0.001). 01); the mice in the middle-aged group had a higher preference rate of sugar water at 12 hours than the mice in the old group (P < 0.05), and the mice in the young group had a higher preference rate of sugar water at 12, 36, 48, and 60 hours than the mice in the old group (P<0.05). < 0. 05); compared with the middle-aged group and the young group, the mice in the old group had a longer arm opening time (P< 0. 05), and the mice in the young group had more probes than the middle-aged group (P< 0. 01). ); the mice in the young group moved longer in the open field than in the old group (P< 0.05); the serum 5-HT content of the mice in the old, middle-aged and young groups showed a decreasing trend, and the young group showed a decreasing trend. The serum 5-HT in mice was significantly lower than that in the middle-aged group (P<0.05) and the aged group (P<0.01).
Conclusion Overall, under the same stimulation, the younger the mice are, the more likely they are to exhibit depression and anxiety-like behaviors, and the lower the serum 5-HT level.