Department of Neural and Behavioral Sciences, The Pennsylvania State University College of Medicine, Hershey, PA 17033, United States; Nutrition and Foods Program, School of Family and Consumer Sciences, Texas State University, San Marcos, TX 78666, United States.
Department of Neural and Behavioral Sciences, The Pennsylvania State University College of Medicine, Hershey, PA 17033, United States.
Brain Res Bull. 2018 Apr;138:80-87. doi: 10.1016/j.brainresbull.2017.09.001. Epub 2017 Sep 9.
Rats avoid intake of an otherwise palatable taste cue when paired with drugs of abuse (Grigson and Twining, 2002). In male rats, avoidance of drug-paired taste cues is associated with conditioned blunting of dopamine in the nucleus accumbens (Grigson and Hajnal, 2007), conditioned elevation in circulating corticosterone (Gomez et al., 2000), and greater avoidance of the drug-paired cue predicts greater drug-taking (Grigson and Twining, 2002). While female rats generally are more responsive to drug than male rats, in this self-administration model, female rats consume more of a cocaine-paired saccharin cue and take less drug than males (Cason and Grigson, 2013). What is not known, however, is whether the same is true when a saccharin cue predicts availability of an opiate, particularly when the amount of drug experienced is held constant via passive administration by the experimenter. Here, avoidance of a saccharin cue was evaluated following pairings with experimenter delivered cocaine or morphine in male and female rats. Results showed that males and females avoided intake of a taste cue when paired with experimenter administered morphine or cocaine, and individual differences emerged whereby some male and female rats exhibited greater avoidance of the drug-paired cue than others. Female rats did not drink more of the saccharin cue than males when paired with morphine in Experiment 1, however, they did drink more of the saccharin cue than male rats when paired with cocaine in Experiment 2. While no pattern with estrous cycle emerged, avoidance of the cocaine-paired cue, like avoidance of a morphine-paired cue (Gomez et al., 2000), was associated with a conditioned elevation in corticosterone in both male and female rats.
当与滥用药物配对时，老鼠会避免摄入原本可口的味道线索（Grigson 和 Twining，2002）。在雄性大鼠中，对药物配对的味觉线索的回避与伏隔核多巴胺的条件性钝化有关（Grigson 和 Hajnal，2007），循环皮质酮的条件性升高（Gomez 等人，2000），以及对药物配对线索的更大回避预示着更大的药物摄取（Grigson 和 Twining，2002）。虽然雌性大鼠通常比雄性大鼠对药物更敏感，但在这种自我给药模型中，雌性大鼠消耗更多与可卡因配对的蔗糖线索，并且比雄性大鼠摄入的药物更少（Cason 和 Grigson，2013）。然而，当蔗糖线索预测阿片类药物的可用性时，情况是否相同尚不清楚，特别是当药物的摄入量通过实验者的被动给药保持不变时。在这里，评估了雄性和雌性大鼠在与实验者给予的可卡因或吗啡配对后对蔗糖线索的回避。结果表明，雄性和雌性大鼠在与实验者给予的吗啡或可卡因配对时避免摄入味觉线索，并且出现了个体差异，一些雄性和雌性大鼠比其他大鼠表现出对药物配对线索的更大回避。在实验 1 中，当与吗啡配对时，雌性大鼠没有比雄性大鼠摄入更多的蔗糖线索，但是当与可卡因配对时，它们比雄性大鼠摄入更多的蔗糖线索。虽然没有出现发情周期的模式，但可卡因配对线索的回避，就像吗啡配对线索的回避一样（Gomez 等人，2000），与雄性和雌性大鼠的皮质酮条件性升高有关。
