Study On The Improvement Of Learning And Memory Ability Of AD Rats By RTMS

BackgroundAlzheimer's disease(AD)is a degenerative disease of the central nervous system(CNS),characterized by memory and cognitive dysfunction,abnormal behavior and personality.Research shows that the demyelination changes in the white matter of AD patients can cause axonal degeneration,the disorder of nerve impulse transmission,the reduction of neural network synchronous.Electroencephalogram(EEG)can detect abnormal connection of neural network.Recent studies have shown that repetitive transcranial magnetic stimulation(rTMS)can promote the growth of oligodendrocyte and myeline repairment.Therefore,it is of great significance for the prevention and treatment of AD that research on therapeutic effect and mechanism of rTMS on AD white matter injury.Objective1.The effects of repetitive transcranial magnetic stimulation(rTMS)on the learning and memory of Alzheimer's disease(AD)rats.2.To discuss the advantages of nonlinear dynamic analysis in AD rat EEG processing over the power spectrum estimation of AR model.3.From the perspective of pathology and digital signal processing explaining the mechanism of effects of rTMS on learning and memory ability in AD rats.Methods1.After eliminating unqualified rats by water maze experiment,100 Sprague-Dawley(SD)rats were randomly divided into group(rTMS+AD),group AD and control group,30 rats in each group,and the remaining were used as spare rats.2.To establish the AD rat model whose bilateral hippocampal area were injected with A beta amyloid protein(A?1-42),and to evaluate the model using Morris water maze.3.10 Hz rTMS was conducted on the group(rTMS+AD),and pseudo stimulation was done on the group AD and normal group for 14 consecutive days.4.Morris water maze was used to test the learning and memory ability of rats in each group,and scalp EEG of AD rats was obtained by Cerebus 64 channel electrophysiological signal recording system for 7 consecutive days,the distribution of MBP in brain tissue of rats was observed by immunohistochemistry.5.The energy spectrum and LZ complexity of EEG signal in each group were acquired by MATLAB,and using SPSS software for statistically analysing of EEG and water maze data,and the rat brain slices were observed using electron microscope.Results1.The escape latency of group AD was longer than that of normal group,and the average distance of group AD from the platform was longer than that of normal group,and the difference was statistically significant(P<0.05);The escape latency of group(rTMS+AD)was shorter than that of the AD group,and the average distance of group(rTMS+AD)from the platform was closer than that of the AD group,and the difference was statistically significant(P<0.05).2.The energy ratio of low frequency(delta+theta)and high frequency(alpha+beta)of group AD was higher than that of normal group.The difference of channel 21(left temporal lobe),25(left parietal lobe),26(right parietal lobe)and 30(frontal lobe)was statistically significant(P < 0.05),and channel 18(pillow leaf)and 22(right temporal lobe)was not statistical significance(P > 0.05);The energy ratio of low frequency(delta+theta)and high frequency(alpha+beta)of group(r TMS+AD)was lower than that of group AD in occipital lobe,left temporal lobe,right temporal lobe and frontal lobe.In left parietal lobe and right parietal lobe,that is the opposite.Only the difference of left temporal lobe was statistically significant(P<0.05).3.The LZ complexity of group(rTMS+AD)was higher than that of the AD group,the LZ complexity of group AD was lower than that of normal group,and the difference was statistically significant(P<0.05).4.The results of HE staining:the brain tissue cells of normal rats are in good shape,they arranged in order,and their outline is clear;the brain tissue cells of AD rats are atrophied,they arranged in random,and their outline is blurred;Compared with the AD group,cellular atrophy of the brain tissue cells in the(rTMS+AD)rats was reduced.5.MBP distribution: In normal rats,the distribution of MBP was uniform and orderly;In AD rats,the distribution of MBP was disordered and the nerve fiber tangles;Compared with the AD group,in(rTMS+AD)rats,the situation that the distribution of MBP was disordered and the nerve fiber tangles are reduced.Conclusions1.rTMS can improve the learning and memory ability of AD rats and increase the LZ complexity of its EEG signal.2.LZ complexity is more suitable for objectively diagnosing of AD and evaluating the effect of rTMS on EEG signal in AD rats than the power spectrum estimation based on AR model.3.The LZ complexity of AD group was lower than that in normal group,and water maze experiment showed that the learning and memory ability of AD group decreased compared with normal group.The results showed that the information contained in EEG of AD group was lower than that of normal group,and the memory ability of the rats was decreased.4.The LZ complexity of(rTMS+AD)group was higher than that in AD group,and water maze experiment showed that the learning and memory ability of(rTMS+AD)group increased compared with AD group.The results showed that the information contained in EEG of(rTMS+AD)group was more than that of normal group,and the memory ability of the rats was increased.5.rTMS could reduce the atrophy of brain cells in AD group,and make the MBP distribution on the synapses tended to be uniform.