ABSTRACT
Objective:To study the effect of the three kinds of EE on the cognitive function and the expression of SYN and MAP-2,and the dentritic growth of pyramidal cells of the cerebral cortex in rats.Method:Forty-eight male SD rats were divided into preserving the physique EE group (EE1),preserving the spirit EE group (EE2),preservation for both physique and spirit EE group(EE3) and standard group (SE),12 rats in each group.Rats were put into the three kinds of EE or standard cages after pre-training.The environmental enrollment lasted for 14 days and followed by a 6-days Morris water maze test.After the Morris water maze test,all the rats were sacrificed for histological study,including using the immunohistochemistry method to detect the expression of SYN and MAP-2,and using the Golgi-Cox staining to study the dentritic growth of pyramidal cells in cerebral cortex.Result:In the Morris water maze,the EE3 group exhibited shorter escape latency than the MCAO+SE group (P＜0.05) on day 5,while no significant differences were seen for the time spent in the target quadrant among the 4 groups (P＞ 0.05).The results of immunohistochemical staining of SYN showed that the expression of SYN was the lowest in the SE group,and there was no significant difference between EE1 and EE3 groups but significantly higher than the EE2 group.The expression of MAP-2 was the lowest in the SE group,and there was no significant difference of expression between EE1 and EE2 groups but significantly lower than the EE3 group.The results of Golgi-Cox staining showed that there was no difference of the dentritic branch among groups in mPFC (P＞ 0.05) while the spine density of the EE1 group was significantly greater than that of the SE and EE2 groups (P ＜ 0.05),but significantly lower than that of the EE3 group (P ＜ 0.05).Conclusion:Two weeks of preservation from both physique and spirit EE can improve the cognitive function,and promote the expression of MAP-2 and SYN and the dentritic growth of pyramidal cells in normal rats.