Objective To explore the correlation between the expression of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in hippocampus and forebrain cortex and depression caused by chronic stress in mice.
Method 58 SPF-grade KM mice and 29 male and female mice were selected. The mice were randomly divided into a control group and an observation group. The mice in the observation group were stimulated with a variety of stress factors such as fasting and electric shock to the sole of the foot. One was randomly selected every day for a total of 20 days. The mice in the control group did not receive the experimental stressor and were raised under the same conditions. The body weight of mice was measured before stress, 10d and 20d after stress. Both groups of mice were tested by morris water maze experiment and open field experiment, and the results were observed and recorded. Measure the expression of BDNF and VEGF in the hippocampus and forebrain cortex of each group of mice, and analyze their correlation.
Results Before the stress, the weight levels of the two groups of mice were not much different (P>0.05). After the stress, the weight of the mice in the observation group was significantly lower than the control group (P<0.01). The escape latency, swimming distance and stay time in the second quadrant of the observation group were significantly higher than those in the control group (P<0.05 or P<0.01), while="" the="" stay="" time="" in="" other="" quadrants="" p="">0.05). The number of modification times and vertical movement scores of the observation group were significantly lower than those of the control group, the stay time in the central area was significantly higher than that of the control group (P<0.01), and="" the="" number="" of="" defecation="" particles="" was="" not="" significantly="" different="" p="">0.05). Compared with the control group, the expression levels of BDNF and VEGF in the hippocampus CA1 area and forebrain cortex of the observation group were significantly reduced (P<0.05), but="" there="" was="" no="" significant="" difference="" in="" bdnf="" the="" ca3="" area="" between="" two="" groups="" p="">0.05).
Conclusion Chronic stress can cause depression-like behaviors in mice, which may be related to the decreased expression of BDNF and VEGF in the hippocampus and forebrain cortex.