When an object conditioned stimulus (CS) is paired with a food unconditioned stimulus (US), anticipatory goal-directed action directed at the US location (goal tracking) is accompanied by behavior directed at the object CS (sign tracking). Sign-tracking behavior appears to be compulsive and habit-like and predicts increased vulnerability to the addictive potential of drugs in animal models. A large body of the literature also suggests that environmental enrichment protects against the development of addiction-prone phenotypes. Thus, we investigated whether compulsive-like sign tracking develops in environmentally enriched rats trained directly in their enriched home environment. We demonstrate that adolescent enriched-housed male Sprague-Dawley rats readily sign track a 5% ethanol bottle CS in their home environment and at a rate higher than adolescent standard-housed rats. We also show that enriched adolescent rats sign track less than enriched adult-trained rats and that acute isolation stress affects sign- and goal-tracking performance of adolescents and adults differently. Sign tracking increased more in the adult than the adolescent rats. Whereas the younger rats showed a decrease in goal tacking after the final stressor manipulation, the adults showed increased goal tracking. Our results are consistent with recent studies, which suggest that although sign tracking performance is compulsive-like, it is not as inflexible and habit-like as previously assumed. Testing in an enriched home environment with object CSs having greater affordance than “neutral” lever CSs may provide greater ecological relevance for investigating the development and expression of adaptive and compulsive-like behaviors in translational research.

当对象条件刺激 (CS) 与食物无条件刺激 (US) 配对时，针对美国位置的预期目标导向动作（目标跟踪）伴随着针对对象 CS 的行为（标志跟踪）。迹象跟踪行为似乎是强迫性的和习惯性的，并预测动物模型对药物成瘾潜力的脆弱性增加。大量文献还表明，环境丰富可以防止容易成瘾的表型的发展。因此，我们调查了直接在丰富的家庭环境中训练的环境丰富的大鼠是否会出现强迫性标志跟踪。我们证明了青少年富集雄性 Sprague-Dawley 大鼠很容易在其家庭环境中跟踪 5% 乙醇瓶 CS，并且其速率高于青少年标准饲养大鼠。我们还表明，富集的青少年大鼠的体征跟踪少于受过富集的成年训练的大鼠，并且急性隔离压力对青少年和成年人的体征和目标跟踪表现的影响不同。与青春期大鼠相比，成年大鼠的体征追踪增加更多。在最后一次压力源操作后，年轻的老鼠表现出目标跟踪的减少，而成年老鼠则表现出目标跟踪的增加。我们的结果与最近的研究一致，这表明虽然标志跟踪表现类似于强迫症，但它并不像以前假设的那样僵化和习惯性。