LTP Experiments On Synaptic Plasticity In Rat Hippocampal CA1 Region By ELF-EMFs Of Different Modes

In modern society,the threat of extremely low frequency electromagnetic fields(ELF-EMFs)to people's health is more and more serious,and there are potential risks to human nervous system function and cognitive behavior.At the same time,ELF-EMFs is also closely related to Alzheimer's disease and other related neurocognitive diseases.Schaffer-CA1 synaptic plasticity LTP in the hippocampus is a classic model for studying learning and memory.At present,most domestic and foreign studies on LTP models focus on living animals,but there are many uncertain factors in the biological effects of magnetic exposure of living animals.The study of ELF-EMFs exposure to hippocampal isolated brain slices has the advantages of strong targeting and easy control of radiation dose.Therefore,this paper uses different modes of ELF-EMFs stimulation to explore the mechanism of LTP on synaptic plasticity.In this paper,synapses in the hippocampal CA1 region of SD rats with acute isolation were used as experimental models,and synaptic plasticity was used as the basis for evaluating learning and memory mechanisms.This article first explores the continuous sinusoidal magnetic field stimulation parameters of nine different doses(intensity: 0.5mT,1mT,2mT,frequency: 15Hz,50Hz,100Hz),and records the changes of field excitatory posts synaptic potential(f EPSP)by the multi-electrode array(MEA)system.And further analysis of the effect on long-term potentiation(LTP),the results showed that the experimental effect of the magnetic field dose of 15Hz / 2mT is most obvious.Based on this,three different modes are analyzed and compared,including continuous sinusoidal magnetic field(15Hz / 2mT),continuous pulsed magnetic field(pulse width: 200 ?s;frequency: 15Hz;intensity: 2mT)and rhythmic pulse magnetic field(pulse width: 200 ?s;frequency: 15Hz;intensity: 2mT,interval time: 5 s,10 s,15 s,30 s),and four different time(10 s,20 s,40 s,and 60 s)ELF-EMFs on synaptic plasticity LTP.The results show that ELF-EMFs in all three modes can inhibit the synaptic plasticity LTP to a certain extent.Among them,the continuous sinusoidal magnetic field suppression effect is the most obvious,while the continuous pulse magnetic field and rhythm pulse magnetic field suppression effect is relatively weak,and no significant difference.In addition,this inhibition effect becomes more pronounced as the magnetic field stimulation time increases.Among them,the inhibitory effect of rhythmic pulse ELF-EMFs on synaptic plasticity is not permanent,but reversible,and this effect will gradually disappear after a certain recovery time.In a word,the experimental results of different ELF-EMFs on LTP of synaptic plasticity in Schaffer-CA1 area of hippocampus obtained in this study provide a basis for exploring the mechanism of ELF-EMFs on learning and cognition,and have a certain reference value for the parameter design of ELF-EMFs treatment device in clinical.