[Establishment and behavioral evaluation of a mouse model of long-term free-choice alcohol drinking].

To establish a model of long-term free drinking mouse by feeding mice with alcohol to simulate the state of human voluntary long-term drinking, and on this basis, to further discuss the evaluation criteria of long-term free drinking mice model in sports, anxiety and cognitive behavior.Forty six-week-old SPF C57BL/6 male mouse were randomly divided into two groups: Long-term free drinking group (n=20) and normal control group (n=20). The two groups were given solid feed normally. The long-term free drinking group was free to take 10% alcohol and water every day, while the normal drinking group only took water every day. The mice were fed for 7 months, and were evaluated by a series of behavioral methods, including Rota-rod test, balance beam test, open filed test, the elevated plus maze, two-box social behavior, new object recognition, Y maze and water maze.With the increase of drinking days, the mice showed significant alcohol addiction in the alcohol preference test. With the increase of alcohol intake, the mice in the long-term free choice drinking group had slightly shiny fur and reduced diet. Compared with the control group, the weight gain began to slow down from the third month, and the weight decreased significantly by the sixth and seventh months (P=0.006, P < 0.001). The mice showed reduced balance locomotion ability (P=0.003, P=0.001) in the rotary bar and balance beam test. In the open field and elevated cross test, the mice had obvious anxiety-like behavior (P < 0.001). The mice showed decreased social ability in the two boxes of social behavior (P < 0.016). In the experiment of new object recognition and Y maze, the exploration of new object decreased (P=0.018, P=0.040). In the water maze, cognitive functions, such as learning and spatial memory were reduced (P < 0.001).The successful establishment of the long-term free drinking mouse model is more convenient for us to carry out further research on the neural mechanism of alcohol addiction, and lays an experimental foundation for exploring the neural mechanism of alcohol addiction and related new targets.