目的实验选用条件性位置偏爱(CPP)作为记忆模型,考察基底外侧杏仁核的多巴胺受体在吗啡诱导的奖赏记忆巩固中的作用。方法雄性SD大鼠皮下注射5mg·kg^-1的吗啡后,和环境线索匹配3次建立CPP模型,在每次吗啡训练后,向基底外侧杏仁核立即注射D1受体拮抗剂SCH23390(0μg、0.2μg、2μg),或者训练后2h注射SCH23390(2μg)。结果训练后立即注射SCH23390会干扰吗啡CPP记忆的巩固[(143±29)S:(37±27)S,P〈0.05],训练后延迟2h注射则不影响吗啡相关记忆的巩固[(37±27)s:(137±22)s,P〈0.05],且SCH23390本身不产生条件性位置偏爱或厌恶效应(F(2,36)=0.37,P〉0.05)。结论基底外侧杏仁核参与吗啡诱导的条件性趋近行为,多巴胺D1受体在记忆巩固中有重要作用。
Objective To investigate the influence of dopamine receptor in the basolateral amygdala on the consolidation of morphine-induced reward memory with the conditioned place preference (CPP) being used as a memory model. Methods Adult male Sprague-Dawley rats were injected with 5mg · kg^-1 morphine or saline and confined to treatment- or non-treatment-paired compartments for 45 minutes for three days. After every morphine training, rats immediately received intrabasolateral amygdala infusions of D1 antagonist SCH23390(01μg ,0.2 μg or 2μg) or as compared, SCH23390 was injected 2 hours after conditioned training. Results Immediate posttraining injection ( but not delayed 2 hours) of SCH23390 (2 μg) blocked acquisition of m0rphine-induced consolidation of memory for CPP [ ( 143 ± 29 ) s vs ( 37 ± 27 ) s, P 〈 0. 05 ] ; while the 2-hour-ddayed injection of SCH23390 did not[ (37 ± 27)s vs (137 ± 22)s, P 〈 0.05 ]. Furthermore, SCH23390 did not induce CPPor conditioned place aversion( F (2.36〉 = 0.37, P 〉 0.05 ). Conclusion BLA is involved in morphine-induced approaching behavior and dopamine D1 receptor plays an important role in the consolidation of memory.