Acupuncture Improves Synaptic Plasticity of SAMP8 Mice through the RhoA/ROCK Pathway

Background: Studies have found synaptic plasticity damage to be an early marker of Alzheimer's disease (AD). RhoA/ROCK pathway is involved in the regulation of synaptic plasticity. Acupuncture can significantly improve the cognitive state of AD.Objective: We aimed to use modern biological technology to detect the changes in synaptic plasticity and RhoA/ROCK pathway in SAMP8 mice, as well as the intervention effect of acupuncture.Methods: Morris water maze and electrophysiological techniques were used in vivo to detect the changes in spatial memory and LTP of mice. Golgi Cox staining and CASEVIEWER2.1 software were used to quantitatively analyze the changes in the morphology and number of dendritic spines in the hippocampus of mice. The activity of RhoA and ROCK2 in the hippocampus of mice was detected, respectively, by pull-down technique and ELISA. WB technique was used to detect the protein expression of ROCK2 and phosphorylation level of MLC2, LIMK2, and CRMP2 in the hippocampus of mice.Results: The neurobehavior and synaptic plasticity of 8-month-old SAMP8 mice were found to be significantly impaired. Acupuncture could improve the spatial learning and memory ability of SAMP8 mice, and partially prevent the reduction in the number of spines on the secondary branches of the apical dendrites in the hippocampus and the attenuation of LTP. The RhoA/ROCK pathway was significantly activated in the hippocampus of 8-month-old SAMP8 mice, and acupuncture had an inhibitory effect on it.Conclusion: Acupuncture can improve synaptic plasticity by inhibiting the abnormal activation of the RhoA/ROCK pathway, and improve the spatial learning and memory ability of AD, so as to achieve the purpose of treating AD.