Center of Alcohol Studies, Rutgers University, Piscataway, NJ 08854, USA.
Pharmacol Biochem Behav. 2012 May;101(3):417-26. doi: 10.1016/j.pbb.2012.01.010. Epub 2012 Jan 20.
Studies of socially housed rodents have provided significant information regarding the consequences of exposure to stressors. Psychosocial stressors are known to alter the ingestion of ethanol and the activity of the dopaminergic neuronal system. Since both stressors and ethanol are known to affect the function of dopaminergic neurons, we employed amphetamine to assess the role of this neural system on the ingestion of ethanol by psychosocially stressed male rats. Male rats housed two per cage were designated as dominant or subdominant rats based on evaluations of agonistic behavior and body weight changes. The dyad-housed rats and a group of single-housed rats were sequentially assessed for ethanol intake after injections of saline or amphetamine (0.3, 0.9 or 2.7 mg/kg i.p.) both prior to dyad housing and subsequently again during dyad-housing. Prior to dyad housing ethanol intake of future subdominant rats was higher than that of future dominant rats. Dyad-housing significantly increased ethanol intake of dominant rats. Pre-dyad the highest dose of amphetamine potently depressed ethanol ingestion. Sensitivity to amphetamine's depressant effect on ethanol intake was higher at the dyad test in all subjects, most prominently in single-housed rats. In contrast to the single-housed rats, the dyad-housed rats displayed saccharin anhedonia. It can be concluded that dopaminergic system modulates, at least partially, the psychosocial stress-induced changes in ethanol intake. Furthermore, the level of ethanol ingestion at the pre-dyad test was predictive of future hierarchical status.
社交笼养啮齿动物的研究为研究应激暴露的后果提供了重要信息。已知心理社会应激源会改变乙醇的摄入和多巴胺能神经元系统的活性。由于应激源和乙醇都已知会影响多巴胺能神经元的功能，我们使用安非他命来评估这个神经网络系统在社交应激雄性大鼠乙醇摄入中的作用。根据攻击行为和体重变化的评估，将每笼饲养两只的雄性大鼠指定为优势或从属大鼠。双笼饲养的大鼠和一组单笼饲养的大鼠在注射盐水或安非他命（0.3、0.9 或 2.7 mg/kg ip）前后分别评估乙醇摄入量，既在双笼饲养之前，也在双笼饲养期间。在双笼饲养之前，未来从属大鼠的乙醇摄入量高于未来优势大鼠。双笼饲养显著增加了优势大鼠的乙醇摄入量。在双笼饲养之前，最高剂量的安非他命强烈抑制了乙醇的摄入。在所有受试者中，在双笼测试中，对安非他命对乙醇摄入的抑制作用的敏感性更高，在单笼饲养的大鼠中更为明显。与单笼饲养的大鼠不同，双笼饲养的大鼠表现出蔗糖快感缺失。可以得出结论，多巴胺能系统至少部分调节了心理社会应激引起的乙醇摄入变化。此外，在双笼饲养之前的测试中摄入的乙醇量可预测未来的等级地位。
