Magnetic Seizure Therapy Improves The Mice With Depression

BackgroundDepression is a common,high-risk,refractory neuropsychiatric disease in modern society.It is characterized by mood disorders such as depression and severe suicidal thoughts and behaviors.Severe and drug-refractory depression has achieved a certain effect with Electroconvulsive Therapy(ECT),but it has greater side effects.Magnetic Seizure Therapy(MST)utilizes Transcranial Magnetic Stimulation(TMS)technology while retaining the non-invasive and accurate application of TMS.The effect of specific frequency of MST on the efficacy of depression and the treatment of depression on the expression of synaptophysin(SYP)has not been reported,and the specific mechanism of action is not clear.ObjectiveUsing C57 mice with CUMS model,the therapeutic effects of ECT and different frequency of MST on mice with depression were compared to explore the mechanism of action of MST on brain neurons.Provide a theoretical basis for MST treatment of depression and improve treatment.Methods1.Experimental design and animal grouping: According to the CUMS modeling method,60 female C57 mice of 1 month old were randomly divided into: normal group(n=10),SHAM group(n=10),25 Hz MST group(n=10),50 Hz MST group(n=10),100 Hz MST group(n=10),ECT group(n=10).Except the normal group,the other 5 groups were modeled as depression mice.Forced swimming and sucrose water preference experiments were performed before,after,and after treatment.Immediately after the end of the behavioral verification experiment,3 groups of typical mice(18 in total)were decapitated and the protein was quantitatively tested by Western blot.2.Preparation of the CUMS model and treatment regimen for MST: Model mice were given different stimulation items daily for 4 weeks.The modeling validation phase of behavior was followed for 5 days.On the 6th day,the MST group was treated at 25 Hz,50 Hz,and 100 Hz for 3 weeks.3.Forced swimming: The mice were placed in a transparent plastic large container.The water depth prevented the hind limbs of the mice from coming into contact with the bottom of the bucket,and the water temperature was consistent.Each mouse was replaced with dirty water in the container immediately after the experiment to avoid the odor caused by the mouse.Pre-experiments should be performed 24 hours prior to the start of the formal experiment.Light,noise,and operator consistency should be maintained for each test environment.Forced swimming for 6 min and recorded the immobility time of the mice within 5 min.4.Sucrose water preference experiment: 8 bottles of 2% sucrose water and tap water were used to ensure that each bottle had 1 bottle of syrup and tap water,and the other 4 bottles were placed on the empty cage to test the water leakage.The mice were banned from water for fasting 24 hours before the start of the experiment.In the experiment,the position of each cage should be adjusted to ensure the objective and fairness of the data.5.Western blotWestern blotting: After the brain cerebrospinal fluid was perfused into the brain,the brain was isolated from the hippocampus.After the mice were labeled,the quantitative results of the target protein were obtained by immuno-hybridization technique,and the gray value was statistically analyzed by ImageJ analysis software.6.Statistical analysis: Differential statistical analysis was performed on the data using SigmaStat software,expressed as mean ± standard deviation.If p< 0.05,the results are considered statistically significant.Results1.Sucrose water preference experiment: 1)There was no difference in the amount of drinking sugar and tap water before the model establishment;2)After 4 weeks of modeling,the drinking water volume of the five model groups was lower than that of the normal group and the self-control(p<0.05);3)After 3 weeks of treatment,the amount of drinking water in the five model groups was significantly higher than that in the normal group and the control group(p<0.05).2.MST: 1)MST is effective for depression mice;2)100Hz MST has comparable therapeutic effect to ECT in CUMS depression mice;3)treatment improvement effect of different frequency MST is positively correlated with stimulation frequency.3.Western blot: 1)Compared with the normal group,the mice in the model group were treated with MST or ECT and the SYP content was increased;2)The depression model Sham treatment group compared with the normal group.The content of Synaptophysin,SYP)is reduced.ConclusionMST has a significant improvement in the treatment of mice in the depression group;Increased expression of SYP in mouse hippocampus when depression is relieved.