ABSTRACT
Aim To study the effect of rhynchophylline on NMDA receptor 2B subunit(NR2B) mRNA expression in the nucleus accumbens(NAc) and amygdala(Amy) of amphetamine-induced condictioned place preference(CPP) rats.Method 56 male SPF grade Sprague-Dawley rats were randomly divided into control group,amphetamine-induced model group,model group with ketamine,model group with low,middle,high dose of rhynchophylline,and control group with rhynchophylline(n=8 for each group) The time of rats' staying in white compartment was measured in the 5th day,then NR2B mRNA expression in NAc and Amy of each rat was detected with in situ hybridization technology.Results The rats exhibited CPP after treated with 2 mg?kg-1?d-1 amphetamine for 4 d.Ketamine and rhynchophylline eliminated CPP effect,and the effect of rhychophylline showed a dose-dependence.In amphetamine-induced model group,NR2B mRNA expression in NAc and AMY of rats was significantly increased.Ketamine,middle and high dose of rhynchophylline blocked the increase of NR2B mRNA expression induced by amphetamine.Rhynchophylline had no effect on the basal level of RN2B mRNA expression in normal rats.Conclusion Inhibition of NR2B mRNA expression in NAc and AMY may contribute to the antagonistic effect of rhychophylline on amphetamine-induced CPP.