Sell Stacy L, Dillon Ashlee M, Cunningham Kathryn A, Thomas Mary L
Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77550-1031, USA.
Behav Brain Res. 2005 Jun 3;161(1):69-74. doi: 10.1016/j.bbr.2005.01.004. Epub 2005 Feb 3.
In rats, individual differences in vulnerability to self-administration of drugs of abuse can be predicted by individual locomotor responses to a novel environment. This phenomenon has been well described for male rats, however very little information is available with regard to female rats and the added complication of estrous cycle hormone changes influencing activity levels. This study was designed to explore the relationship between individual responsiveness to exposure to a novel environment, the estrous cycle, and the response to cocaine in intact, cycling female rats. Locomotor activity of naive female rats was measured upon exposure to a novel environment followed by determination of estrous cycle stage and level of circulating estradiol. Rats were identified as high-responder (HR; 15% most active) or low-responder (LR; 15% least active) rats based on the locomotor response. Hyperactivity in response to cocaine was greater in HR than in LR rats. These data in combination with evaluation of the stage of estrous suggest that the estrous cycle interacts with individual phenotypic characteristics to modify the sensitivity to cocaine in female animals.
在大鼠中，对滥用药物自我给药的易感性个体差异可通过个体对新环境的运动反应来预测。这种现象在雄性大鼠中已有充分描述，然而，关于雌性大鼠以及发情周期激素变化影响活动水平这一附加复杂性的信息却非常少。本研究旨在探讨完整的、处于发情周期的雌性大鼠对新环境暴露的个体反应性、发情周期与对可卡因反应之间的关系。在将未接触过新环境的雌性大鼠暴露于新环境后，测量其运动活性，随后确定发情周期阶段和循环雌二醇水平。根据运动反应，将大鼠分为高反应者（HR；最活跃的15%）或低反应者（LR；最不活跃的15%）。HR大鼠对可卡因的反应性亢进程度高于LR大鼠。这些数据与发情阶段的评估相结合表明，发情周期与个体表型特征相互作用，以改变雌性动物对可卡因的敏感性。
Zotero 插件