ABSTRACT
Objective:To investigate the effect of electroacupuncture (EA) on synaptic plasticity and the expression of autophagy-related proteins in the hippocampus in Alzheimer′s disease (AD). To explore how EA might improve cognition in AD.Methods:Healthy male Sprague-Dawley rats were randomly divided into a sham operation group, a model group and an EA group. The rat model of AD was established by injecting Aβ1-42 into the bilateral CA1 area of the hippocampus. The sham operation group was injected with an equal amount of normal saline at the same site. Starting the day after the successful modelling, the EA group received 20 minutes of EA treatment at the Baihui (DU20) and bilateral Shenshu (BL23) acupoints once a day, 6 times a week for 2 weeks. The rats′ learning and memory were then tested using a Morris water maze. The long-term potentiation (LEP) in the hippocampus was assessed using a MED64 microelectrode array and any ultrastructural changes of autophagosomes were detected using an electron microscope. The expression of the autophagy-related proteins Beclin-1 and microtubule associated protein light chain 3 (LC3) in the hippocampus were determined using western blotting.Results:The escape latency was significantly shorter and the times crossing the platform increased significantly in the EA group compared with the model group. The average amplitude of the postsynaptic excitatory field potentials in the EA group was significantly higher than among the model group. There were many autophagosomes in the hippocampal neurons of the model group, significantly more than in the EA group. The LC3II/LC3I ratio and Beclin-1 protein expression decreased significantly in the EA group compared to the model group.Conclusions:EA can improve learning and memory and restore LEP in the hippocampus of rats modeling AD. The mechanism may be related to its regulation of autophagy in hippocampal neurons.