Establishment and evaluation of a stress depression model induced by light and dampness on mice

Objective To establish a novel stress-induced depression model by changing the lighting conditions and continuously damping cushion (L-D). Methods The L-D stress depression animal model was established in C57BL / 6 mice with body weight of 18-22 g. Seventy-five mice with the horizontal and vertical scores higher than 30 and less than 120 in open field test were employed.In the research of model construction, mice were randomly divided into three groups: control group (n=9), chronic unpredictable mild stress(CUMS) model group (n=10) and L-D model group (n=9). In the drug intervention experiments, mice were randomly divided into five groups: control group (n=9), chronic unpredictable mild stress(CUMS) model group (n=10), L-D model group (n=9), CUMS+ fluoxetine group (n=10) and L-D model+ fluoxetine group (n=9). Open field test, forced swimming test and sucrose preference test were used to evaluate the degree of depression in animals. Results (1) In the open field test, the horizontal score of CUMS model group (67.20±5.81) and the L-D model group (52.56±19.05) were significantly lower than that of the control group (76.44±9.22) (t=2.645, t=3.387, both P 0.05). Conclusion Changing the lighting conditions and continuously damping cushion is a new method to establish mice model with depression behavior.Shorter modeling duration and simple operation are the main advantages of this model. Key words: Stress-induced depression animal model; Damp cushion; Lighting conditions; Mice