Objective:To investigate the effects of puerarin on learning and memory ability after hypoxia-ischemia brain damage and to understand the underlying mechanisms.Methods:A total of 102 S-D rats(P7)were randomly assigned to three groups(n=34):sham group

Con group

and puerarin group.At 8 weeks after birth

learning and memory ability were tested by Morris water maze.At 3

4

8 weeks after birth

expressions of NR2A and NR2B were detected in the CA1 region of the hippocampus by immunohistochemistry.Results:①The average time of escape latency was significantly longer and the number of platform location crossing was less in Con group than these in sham group(P<0.05

P<0.01).Compared with Con group

the average time of escape latency was significantly shorter(P<0.05)and the number of platform location crossing was more(P<0.05)in puerarin group.②The expression levels of NR2A and NR2B in hippocampal CA1 areas in the Con group were less than those in the sham-operated rats at any time points(P<0.01).These levels of NR2A were significantly increased in the puerarin group when the rats were 3 w and 8 w of age

compared with the Con group(P<0.05).These levels of NR2B were significantly increased in the puerarin group when the rats were 3 w and 4 w of age

compared with the Con group(P<0.05).Conclusion:Puerarin can improve learning and memory in hypoxia-ischemia brain damage rats.This protection may be associated with the increased NR2A and NR2B in the CA1 region of hippocampus.