Effects Of Low Frequency Repetitive Transcranial Magnetic Stimulation On Learning And Memory And Synaptic Plasticity In Hippocampus Of Vascular Cognitive Impairment Rats

BackgroundWith our country gradually into the aging society,A variety of atherosclerotic diseases(especially cardiovascular and cerebrovascular diseases)has become a serious impact on the health of our elderly people.Vascular dementia is learning and memory of cognitive function obstacle,which made the health of the population and a great impact to the quality of life,which bring heavy disorder to the family and society.Dementia has become an increasingly serious social public health problems,which bring heavy burden to family and society.Until now,there is no still effective drugs and methods in clinical treatment.How to improve the cognitive function has become an important research topic in brain science.Transcranial magnetic stimulation(TMS)is gradually applied in clinical in recent years which can bring an influence and change to the brain function by biological stimulation technology.It have been used in the treatment of a variety of neural mental illness.However,the impact on the improvement of cognitive dysfunction is relatively small,the mechanism of action is unclear.Cognition is a unique feature of the human brain.hippocampus is the most closely related to the cognition.The synaptic plasticity determines the learning and memory function.The long-term potentiation(LTP)phenomenon is the most important form and index of neural synaptic plasticity.We made VCI model rat hippocampus as the research object.From the perspective of macro and micro cell level.We used the Morris water maze and electrophysiological method if the low-frequency magnetic stimulation can increase VCI cognitive function in rats and study its reasons.It brings hope for the treatment of vascular cognitive impairment patients,which can increase the methods to treat the vascular dementia by the new experimental theoretical basis.ObjectivesTo study the effect of the low frequency repetitive transcranial magnetic stimulation(rTMS)on learning and memory of vascular cognitive impairment(VCI)rats.Exploring the molecular mechanism of low frequency transcranial magnetic stimulation in the treatment of VCI rats,in order to provide a theoretical basis for the treatment of vascular cognitive impairment and enrich the treatment method.MethodsSeventy-five male SD rats were randomly divided into normal group,sham-operated group,model group(VCI),control treatment group(VCI+ rTMS).The methord of VCI model rats were treated with intermittent clipping of bilateral carotid arteries with hypotension.The learning and memory ability of rats was measured by Morris water maze.Electrophysiological recordings were conducted to detect the effects of repetitive transcranial magnetic stimulation(rTMS)on phenomena of synaptic LTP in dentate gyrus of hippocampus slices under the high frequency stimulation(HFS).Preparation of rat brain slices,which placed in the perfusion slot with 95% O2 + 5% CO2 mixture gas with artificial cerebrospinal fluid.Stimulating electrode was placed in dentate gyrus of the hippocampus,DS3 electrical stimulator induced by electrical stimulation.The data was analysised by Spike2 analysis software.The result is percentage(%)whose point of each time amplitude and basic amplitude comparison after the high frequency stimulation.Statistical AnalysisThe data were analyzed by SPSS19.0 software.The data were expressed as mean ± standard deviation(x ± s)(P <0.05).The difference between the result of the water maze and the amplitude percentage of the peak potential(PS)in the hippocampus by way of the one-way ANOVA analysis.P<0.05 was statistically significant.ResultsControl group rats and normal rats are not different with statistical significance.Which indicate that simple surgical operation does not cause the cognitive function of rats prepared.The cognitive abilities of learning and memory of VCI model rats decreased obviously.In the Morris water maze test,the learning and memory of model mice and spatial exploration ability decreased,model rats hippocampal dentate gyrus LTP was inhibited.Low frequency rTMS can significantly improve the cognitive learning ability of VCI model rats,increase not only every index of the model rats model but also hippocampus LTP phenomenon.Low frequency rTMS treatment is safe and effective.we find no obvious adverse reaction in the experiments.All group of rats are well tolerated.ConclusionsThe rTMS can safely and effectively improve the learning and memory cognitive function of VCI model rats.The mechanism may be to increase the synaptic plasticity of hippocampus in VCI model rats.