Abstract: Objective To investigate the behavior effect and the contents change of PSD-95 in the rats' brain under chronic stress. Methods A pure stress(chronic forced swimming) and the MK801 intervention(injection MK801 before forced swimming) chronic stress model was established by chronic forced swimming. The PSD-95 contents in hippocampus, prefrontal and basal ganglia areas of the rats were measured by the method of Western blotting. Results At the 14th day of chronic forced swimming, the body weight gain was less in the pure stress group than the control or the MK801 intervention group, respectively. In the pure stress group, the value of sucrose consumption was less,the motionless time for forced swimming duration was longer, than the control or MK801 intervention group. The PSD-95 contents of hippocampus area, prefrontal area in pure stress group were significantly higher than that in control group and MK801 intervention group, but for the basal ganglia area there was no significant difference among the three groups. Conclusion Chronic forced swimming rat is an effective chronic stress model. Chronic forced swimming can enhance the message delivery function of the receptor-mediated NMDA within brain cells.

Key words: chronic forcing swimming, chronic stress model, postsynaptic density protein 95