Influence of electroacupuncture on cAMP/PKA/CREB signal transduction pathways in Aβ25-35 induced Alzheimer's disease model rats

Objective To explore the influence of electroacupuncture on cAMP/PKA/CREB signal transduction pathways in Aβ25-35induced Alzheimers disease(AD)model rats.Methods Forty-eight healthy female SD rats were randomly divided into model group,electroacupuncture group,sham operation group and normal control group,with 12 rats in each group.After AD models were established by injecting Aβ25-35,electroacupuncture group received electroacupuncture stimulation,and model group did not receive electroacupuncture stimulation.Sham operation group was injected the same volume of normal saline into bilateral hippocampus.And normal control group received no treatment.Morris water maze was adopted to observe learning and memory ability and spatial seeking ability in all groups.Superoxide dismutase and malondialdehyde levels were detected by spectrophotometer.The level of hippocampal cAMP was detected by radioimmunaossay.The expressions of hippocampal 5-HT1 AR,PKA and p-CREB proteins were detected by immunohistochemical method.Total content of Tau protein in brain neurons and Tau protein Ser396 phosphorylation sites were tested by Western blot technique.Results Compared with model group,escape latency shortened,frequencies of leaping increased and time spent in the target quadrant extended(P0.05),the contents of superoxide dismutase,5-HT1 AR,PKA and p-CREB increased(P0.05),and levels of malondialdehyde,total Tau protein,pTau-Ser396and c-fos protein decreased(P0.05)in electroacupuncture group,sham operation group and normal control group.The levels of Tau protein,c-fos and PKA were higher in electroacupuncture group than those in sham operation group(P0.05),which showed no significant difference with normal control group(P0.05). Conclusions Electroacupuncture can significantly improve the learning and memory ability and spatial seeking ability of AD rats by antagonism of abnormal expression of cAMP/PKA/CREB signal transduction pathway related proteins.