Experimental Study Of The Effect Of LF-EMFs On TBS/HFS-induced Long-term Potentiation In The CA1 Region Of The Rat Hippocampus

In modern society,devices capable of generating low frequency electromagnetic fields(LF-EMFs)are widely used,and long-term exposure poses a potential risk to human memory and cognitive function.At the same time,LF-EMFs stimulation is also an effective treatment for neurodegenerative diseases such as Alzheimer's disease.Whether as an external influencing factor or as a clinical treatment,its mechanism of action needs to be explored urgently.Synaptic plasticity is the cellular and molecular mechanism of learning and memory.The synaptic plasticity of Schaffer-CA1 pathway in the hippocampus of SD rats is the experimental basis for evaluating the mechanism of learning and memory.Long-term potentiation(LTP)is an important component of synaptic plasticity and has been identified as essential for in vivo memory formation.There are various types of LTP.Among them,LTP formed by Theta burst stimulation(TBS)and high frequency stimulation(HFS)are the most common.The two kind of LTP have been proven to be different in many aspects,but few studies have focused on the differences between the two in terms of LF-EMFs.This paper takes the acutely isolated SD rat hippocampal slices as the experimental object,mainly selects the sinusoidal magnetic field dose 15 Hz/2 m T which can obtain the obvious regulation effect in the previous study as the control means,and records the field excitatory postsynaptic potential(f EPSP)of the brain slices through the multi-electrode array.And the effect of the LF-EMFs on the different forms of LTP represented by TBS-LTP and HFS-LTP was explored.In order to explore the effect of LF-EMFs on LTP,this paper conducted experiments to antagonize NMDA receptors during the application of LF-EMFs,the calculation of induced currents induced by LF-EMFs,and the experiment of applying current to regulate LTP.The results showed that the effect of LF-EMFs on LTP would not be exhausted once,but could maintain at least two LTP induction processes.Secondly,the antagonistic experiments of NMDA receptor proved that NMDA receptor is indeed involved in the regulation of LTP by magnetic field,but it is not the only regulated substance.Finally,this paper calculates the induced currents of LF-EMFs on hippocampal brain slices,and compares the results of LF-EMFs regulation and direct current regulation of LTP.The results show that the relationship between the regulation effect of LF-EMFs and the magnitude of the induced current is most likely not linear.In summary,synaptic plasticity is an important mechanism for learning and memory.This paper focuses on the research about the influence of LF-EMFs stimulation on different types of LTP and the correlation between regulatory effect and NMDA receptor and the correlation between regulatory effect induced current.And this study provides experimental basis for revealing the effect of LF-EMFs on different types of LTP and finding the mechanism of LF-EMFs affecting LTP,and provides guiding significance for the treatment and research of nerve regulation by LF-EMFs in reality.