不同背景的同伴强化及催产素处理对雌性棕色田鼠可卡因条件位置偏爱的影响（英文）

Effects of different-context peer reinforcing and oxytocin treatment on cocaine CPP in female mandarin voles

同伴间的社会互作是一种天然奖赏,能够影响成瘾药物使用的敏感性。催产素(Oxytocin,OT)能够调节社会行为,并提高社会互作的奖赏价值。然而不同背景的同伴互作以及与OT合并使用是否对可卡因的奖赏效应有不同的影响尚不清楚。棕色田鼠(Lasiopodomys mandarinus)是一种单配制田鼠,个体间具有较复杂的社会行为。利用雌性棕色田鼠,我们首先检测了可卡因(20 mg/kg)单独强化以及与不同背景关系的同伴(熟悉雌性、陌生雌性和陌生雄性)同时强化诱导的条件位置偏爱(conditioned place preference,CPP)及持续时间;其次检测了实验鼠外周注射OT(1 mg/kg)并给予不同背景同伴强化对可卡因CPP的影响。结果表明,可卡因单独强化时,实验鼠能够形成可卡因CPP并能持续至3周;用熟悉的雌性同伴强化时,实验鼠对可卡因CPP的维持时间缩短;用陌生的雌性或雄性同伴强化时可抑制可卡因CPP的形成。实验鼠注射OT后,用熟悉雌性或陌生雄性同伴分别强化时会抑制或反转可卡因CPP。这些结果表明不同背景关系的同伴强化对可卡因奖赏效应的影响不同。OT可促进同伴强化的奖赏价值,降低动物对可卡因的偏爱,且该效应因强化同伴的背景而不同。

Peer interaction is a substantial natural reward and influences the susceptibility to engage in drug use. Oxytocin （OT） regulates social behavior, thereby enhancing the reward value of social interaction. However, it remains unclear wheth- er different-context peer interaction combined with OT exert different contributions to the rewarding effects of cocaine. Using female mandarin voles （Lzsiopodomys mandarinus）, a monogamous rodent with complex nonsexual social behavior, we first examined the conditioned place preference （CPP） and its persistence when subject voles were conditioned with cocaine （20 mg/kg） alone or conditioned with cocaine versus different peers （e. g. familiar females, unfamiliar females and unfamil- iar males）. Second, the CPP was examined when subjects received peripheral OT （1 mg/kg） treatment and different context peer conditioning. We found that female voles established and maintained long-lasting cocaine preferences for three weeks when conditioned with cocaine alone. The persistence time of cocaine CPP was shortened when simultaneously conditioned to afamiliar female peer, while it was inhibited when simultaneously conditioned to an unfamiliar female or a male peer. The subject voles that received OT inhibited or reversed cocaine CPP when conditioned with familiar or unfamiliar males, respec- tively. These results indicate that different-context peer reinforcing differentially affects rewarding effects of cocaine. OT facilitates reward value of peer reinforcing, thereby contributing to attenuating cocaine preference and this effect varies with peer context.