An Improved Mouse Model Of Depression Based On Neurosurgical Treatment Of Chronic Restraint Stress

Objective To compare the effect of constant restrain stress and intermittent restrain stress in establishing mice model of depression,so as to find a better animal model of depression for neurosurgery treatment.Methods Mice were divided randomly into Control(Con)group,Constant Restrain(CR)group and Intermittent Restraint(IR)group.Mice were exposed to different frequency of restrain stress to establish a depression model under the condition of the same total daily restraint time,and were evaluated by behavioral tests and Histological comparison.Behavioral tests included SPT,TST,FST and OFT.Neuron morphology were traced by AAV virus,the expression of PTEN in prefrontal cortex and BDNF in hippocampus were detected by Western blot,and the levels of inflammatory factors were detected by ELISA.Results After 6 weeks of restrain stress,the body weight and SPF of restrained mice decreased,the mean immobility time of FST and TST increased,and central time in OFT increased.Importantly,differences between the two observation groups were detected either in body weight or in four behavioral tests.PTEN expression in IR group was significantly higher than that in CR group.BDNF expression in IR group was lower than that in CR group.The number of synapses in PFC area of IR group was less than that in CR group(P=0.01).The number of microglia in hippocampus of IR group was obviously increased.Conclusion Mice model of depression was successfully established through both intermittent restraint and consistent restrain.Intermittent restraint is more likely to cause depression like behavior in mice compared with constant restrain.