Objective To investigate the effect of electroacupuncture on the P35/P25-cyclin-dependent kinase 5(CDK5)-Tau pathway in rats with Alzheimer's disease(AD)

as well as the mechanism of electroacupuncture in the prevention and treatment of AD. Methods Sprague-Dawley rats were randomly divided into control group

sham-operation group

model group

and electroacupuncture treatment group

with 12 rats in each group. A rat model of AD was established by injection of Aβ_(25-35) into the bilateral hippocampus. The rats in the electroacupuncture treatment group were given electroacupuncture at "Baihui"(GV20) and "Shenshu"(BL23) once a day

15 min each time

for 10 days. Morris water maze was used to evaluate learning and memory abilities

immunohistochemistry was used to measure the distribution and expression of P35/P25

CDK5

and Tau5 in the hippocampus

and Western blot was used to measure the expression of the above mentioned proteins

phosphory-lated Tau(Ser199

Ser202). Results In the visual platform test

there were no significant differences in escape latency and search path between groups(P>0.05). In the hidden platform test

there were no significant differences in escape latency and search path between the control group and the sham-operation group(P>0.05); the model group had significantly longer escape latency and search path than the control group and the sham-operation group(P<0.05). Compared with the model group

the electroacupuncture treatment group had significantly shorter escape latency and search path(P<0.05). In the spatial exploration test

there was no significant difference in the number of platform crossings between the control group and the sham-operation group(P<0.05). The model group had a significantly lower number of platform crossings than the control group and the sham-operation group(P<0.01

P<0.05). The electroacupuncture treatment group had a significantly higher number of platform crossings than the model group(P<0.05). Compared with the control group and the sham-operation group

the model group had significant increases in the protein expression of P35/P25 and CDK5(P<0.001)

and the electroacupuncture treatment group had significant reductions compared with the model group(P<0.001). There was no significant difference in the protein expression of Tau5 between groups(P>0.05). The model group had significantly higher protein expression of phosphorylated Tau(Ser199

Ser202) in the hippocampus than the control group and the sham-operation group(P<0.01

P<0.05). The electroacupuncture treatment group had significantly lower protein expression of phosphorylated Tau(Ser199

Ser202) than the model group(P<0.05

P<0.01). Conclusion Electroacupuncture may delay the progression of AD by affecting the expression of proteins involved in the P35/P25-CDK5-Tau pathway in the hippocampus of rats.