| Objective:Alzheimer’s disease(AD)is a slow progressive development of cognitive,behavioral disorders and dysfunctional neurological diseases,which is the most common type of dementia.Although some progresses have been made in the pathogenesis and treatment of Alzheimer’s disease,the current method of treating AD is still unclear.In this study,we investigated the effects of electroacupuncture with different frequencies on the rats with Alzheimer’s disease to test their learning and memory ability,synaptic morphology and related proteins,glycogen synthase kinase-3β and β-amyloid.We also revealed some possible mechanism of electroacupuncture with different frequencies for AD.Methods:168 healthy wistar rats were randomly divided into seven groups with24 rats in each group,normal,sham operation,model,hand acupuncture,2Hz electroacupuncture,30 Hz electroacupuncture and 50 Hz electroacupuncture.There are Aβ1-42 was injected into the lateral cerebral ventricles to establish the AD model.The acupoints,“baihui”and“shenshu”,were selected to be treated by electroacupuncture once for a day,which lasted consecutively for two weeks.We selected continuous wave mode,the frequency of2 Hz,30Hz,50 Hz,current 1m A,20 min for each treatment time.The learning and memory abilities of rats were tested in the Morris water maze after the treatment.Immunohistochemistry and western blotting were adopted to detect the expression of GAP-43 and GSK-3β.The expression of Aβ and its related proteins were detected by western blotting and enzyme-linked immunosorbent assay.Result:1.Morris Water Maze tests showed that the average escape latency significantly increased in model group compared with normal group and sham operation group(P < 0.01).The first time of spatial probing the former platform was shorter and the number of spanning the former platform significantly increased(P < 0.01).The average escape latency in the electroacupuncture groups were shorter than the model group(P <0.01).Compared to the model group,the first time of spatial probing the former platform were shorter(P < 0.05)and the number of spanning the former platform increased(P < 0.05).The average escape latency of 50 Hz electroacupuncture group was significantly shorter than 2Hz and 30 Hz electro-acupuncture groups(P<0.05).The first time of spatial probing the former platform were shorter and the number of spanning the former platform increased(P<0.05).2.The electron microscope showed that the synaptic number in the hippocampus and cortical Tissue of three electroacupuncture groups increased significantly compare with the model(P < 0.01),the synaptic density was improved obviously.The synaptic number of 50 Hz electroacupuncture group increased remarkably compare with 2Hz and 30 Hz electro-acupuncture group(P<0.05).3.The expression levels of GSK-3β and GSK-3β-Tyr216 in the hippocampus and Cortical tissue of three electroacupuncture group decreased significantly compared with the model group(P < 0.01).And there was a significant decrease in the expression of GSK-3 β and GSK-3β-Tyr216 in the 50 Hz electro-acupuncture group compare to that of 2Hz and 30Hz electroacupuncture group(P<0.05).The expression levels of GAP-43 and GSK-3β-Ser9 in the hippocampus in electroacupuncture groups increased significantly compare with the model group(P<0.01).Compared with 2Hz and30 Hz electroacupuncture group,the expression levels of GAP-43 and GSK-3β-Ser9 in the 50 Hz electroacupuncture group increased remarkably(P<0.05).4.The expression levels of APP in the hippocampus and cortical tissue of three electroacupuncture groups decreased significantly compared with the model group(P<0.01),and there was a significant decrease in the expression of APP in the 50 Hz electroacupuncture group compare to that of 2Hz and 30 Hz electroacupuncture groups(P<0.05).The expression levels of Aβ1-40 and Aβ25-35 in the hippocampus and cortical tissue of three electroacupuncture group decreased significantly compared with the model group(P<0.01),and there was a significant decrease in the expression of Aβ1-40 and Aβ25-35 in the 50 Hz electroacupuncture group compare to that of 2Hz and 30 Hz electroacupuncture groups(P<0.05).Conclusion:1.The electroacupuncture can improve the behavioral changes in the pathogenesis of AD rats,shorten the average escape latency and the time of first crossing the platform,increase the number of times across the platform.The 50 Hz electroacupuncture group is better than 2Hz,30 Hz electroacupuncture group.The results showed that electroacupuncture could improve the learning and memory abilities of AD model rats.2.The electroacupuncture can improve the synaptic morphological changes and improve the learning and memory abilities of AD rats by increasing the number of synapses in the brain of AD rats,increasing synaptic density,repairing synaptic injury and promoting synaptic regeneration.The curative effect of50 Hz electroacupuncture group is better than that of 2Hz and30 Hz electroacu-puncture groups.3.The electroacupuncture can improve the synaptic morphological changes the learning and memory abilities of AD rats by increasing the number of synapses synaptic densityin the brain of AD rats,repair synaptic injury and promot synaptic regeneration.50 Hz EA group is better than 2Hz,30 Hz treatment groups.4.The electroacupuncture can decrease the expression levels of Tyr216-GSK-3β,inhibit the activity of GSK-3β,reduce synaptic injury and improve the learning and memory abilities of AD rats.50 Hz electroacupuncture group is better than 2Hz,30 Hz electroacupuncture groups.5.The electroacupuncture can inhibit the expression levels of GSK-3β and decrease the expression of Aβ-related proteins APP,Aβ1-40 and Aβ25-35,prevent over-accumulation of Aβ,reduce the damage of neurotoxicityand improve the role of learning and memory ability of the AD model rats.The 50 Hz electroacupuncture group is better than 2Hz,30 Hz electroacupuncture groups.The synaptic morphological changes are the neurophysiological basis of learning and memory ability,which is closely related to the pathogenesis of Alzheimer’s disease.GSK-3β is a key signal factor of Wnt signaling pathway,which plays a key role in synaptic plasticity.In this study,it is possible to effectively inhibit the activity of GSK-3β with different frequency electroacupuncture,but also by inhibiting the activity of GSK-3β indirectly,decrease the expression of Aβ and its related protein,reduce synaptic injury,promote synaptic injury repair andto achieve the purpose of prevention and treatment of AD. |
