Objective      To investigate the effect of repeated anodal transcranial direct current stimulation (tDCS) on the learning and memories abilities in rat model of Alzheimer’s disease (AD).      Methods      Sprague-Dawley rats were randomly allocated to a sham group

an AD group

a 20 μA tDCS group

a 60 μA tDCS group

a 100 μA tDCS group and a 200 μA tDCS group. The hippocampi of the rats in the AD group and the tDCS groups was subjected to Aβ

1-40

injection to establish AD models. In postoperative 2 weeks

repeated a

nodal tDCS was applied to the frontal cortex of the rats in the tDCS groups

while the rats in the AD group and the sham group received sham stimulation. After tDCS

the learning and memory abilities of the rats was assessed by Morris water maze and Y-maze tests

and Nissl staining was performed to reveal morphological changes of hippocampus neurons.      Results      The Morris water maze test results showed that

compared with the AD group

the 60 μA tDCS group

100 μA tDCS group and 200 μA tDCS group showed significant decrease of the escape latency (P0.05)

but there were no significant changes in the platform-crossing times and swimming time in platform quadrant (P0.05). The Y-maze test results showed that

tDCS with current intensity of 100 μA and 200 μA significantly improved the learning and memory performance of the AD rats (P0.05). tDCS could increase the Nissl body number and deepen staining.      Conclusion      Repeated anodal tDCS may alleviate learning and memory dysfunction in the rat models of AD.