RESUMO
Objective:To study the effect of modified Suanzaoren Tang on the expression of excitatory amino acids receptor（EAARs） in hippocampus of rats with chronic depression， and to explore the anti-depressant mechanism of modified Suanzaoren Tang based on excitatory amino acids receptor. Method:Sixty SD rats were randomly divided into normal group，model group，and low，middle and high-dose modified Suanzaoren Tang groups，and ketamine group，with 10 rats in each group．Except normal group，the depression model of rats was prepared by using chronic restraint stress（CRS）.The normal group and model group were intragastrically（ig） given normal saline．the modified Suanzaoren Tang groups were intragastrically given corresponding herbal drugs 6，12，24 g·kg-1， ketamine group group were given ketamine 0.015 g·kg-1 through intraoeritoneal injection，for 21 days，once a day．Then the depressive behaviors of rats were observed by Morris water maze and novelty feeding experiment.Western blot was used to detect the levels of DAR1，NMDAR2A，NMDAR2B，GluR1，mGluR1，CaMKⅡα and CaMKⅡβ protein expression in rat hippocampus tissue. Result:Compared with normal group，the time of novel ingestion and escape latencywere prolonged significantly（P<0.01）， and the time of space exploration was shortened significantly（P<0.01）.The levels of NMDAR1，NMDAR2A，NMDAR2B，mGluR1 and CaMKⅡβ expression were increased significantly（P<0.01），while the levels of GluR1 and CaMKⅡα expression were decreased significantly（P<0.01）in model group. Compared with model group，the time of novel ingestion and escape latency were shortened significantly （P<0.01）， and the time of space exploration was prolonged significantly（P<0.01）.The levels of NMDAR1，NMDAR2A，NMDAR2B，mGluR1 and CaMKⅡβ protein expression were decreased significantly（P<0.01），but the levels of GluR1 and CaMKⅡα expression were increased decreased significantly（P<0.01）in middle and high-dose modified Suanzaoren Tang groups. Conclusion:Modified Suanzaoren Tang can improve the behavior of chronic depression rats effectly. Its mechanism may be related with reduction the expression of NMDAR1，NMDAR2A，NMDAR2B，mGluR1 and CaMKⅡβ protein ，increase the expression of GluR1and CaMKⅡα protein.