中文摘要：

β-arrestin2是G蛋白偶联受体的负反馈调控蛋白，介导受体的脱敏，此外β—arrestin2还可以通过招募信号分子，介导G蛋白非依赖的信号传导过程。β-arrestin2广泛分布于各重要脑区，参与神经环路的信号传递。本文旨在研究β-arrestin2在可卡因诱导的小鼠奖赏行为中的作用。采用β—arrestin2基因敲除小鼠口rrb2＋），检测了β-arrestin2在不同剂量可卡因诱导的条件性位置偏爱（conditioned place preference，CPP）形成中的作用，还检测了其在可卡因诱导的自主活动性变化中的作用。结果显示，在中等剂量（20mg／kg）和高剂量（30mg／kg）可卡因诱导的CPP实验中，Arrb2＋小鼠比野生型小鼠（Arrb2＋）表现出更强的可卡因诱导的位置偏爱，而在低剂量（10mg／kg）可卡因实验中两者无显著性差异。可卡因诱导的Arrb2-/-小鼠的自主活动性显著低于4rrb2＋小鼠。以上结果提示，β-arresstin2在可卡因诱导的奖赏行为中起重要作用。

英文摘要：

Besides its role in desensitization and internalization of receptors, β-arrestin2 facilitates G protein-independent signaling through its ability to scaffold various signaling molecules. β-arrestin2 is widely distributed in the central nervous system, and mediates signal transduction of brain circuit. The aim of the present study was to investigate the role of β-arrestin2 in reward behaviors induced by cocaine. We assessed the conditioned place preference （CPP） induced by low （10 mg/kg）, moderate （20 mg/kg） and high （30 rag/ kg） doses of cocaine in Arrb2-/- mice and Arrb2＋/＋ controls. In the Arrb2/- mice, moderate and high, but not low, dose of cocaine induced pronounced increases of CPP scores, which were higher than those in the Arrb2＋/＋ mice. Moreover, cocaine-induced locomotor activity was significantly lower in Arrb2-/- mice than that of Arrb2＋/＋ littermate controls. Taken together, our results suggest a potential role of β-arrestin2 in the cocaine-induced rewarding behaviors.