Miserendino Mindy J D, Haile Colin N, Kosten Therese A
Sacred Heart University, Fairfield, Conn., USA.
Psychopharmacology (Berl). 2003 May;167(3):281-90. doi: 10.1007/s00213-003-1411-4. Epub 2003 Mar 28.
Locomotor response to novelty predicts locomotor and reinforcing effects of psychostimulant drugs in outbred rats. Among Lewis and Fischer 344 (F344) inbred rats this association is less clear, perhaps due to strain-selective differences in responses to novelty.
We examined responses to novel inescapable and escapable environments and to novel objects in these strains.
Experiment 1 utilized a place conditioning procedure. Rats were confined to one side for 8 days and then allowed access to both this (familiar) and the novel sides. Experiment 2 assessed locomotor response within an inescapable environment. On another occasion, contacts with novel objects within a novel environment were tabulated. Corticosterone levels and fecal boli were measured. Whether these responses predicted amphetamine-induced locomotor activity was determined. To further assess genetic contributions to this association, experiment 3 assessed novelty responses in F1 hybrid Lewis-F344 rats.
Lewis rats showed greater novelty-seeking behavior in the escapable environment but lower locomotor activity in the inescapable environment compared to F344 rats. There were no strain differences in novel object contacts, corticosterone, or fecal boli responses. Baseline corticosterone levels and activity levels in the novel environment were positively correlated with amphetamine activity based on data from all rats. However, novelty and amphetamine-induced activity showed non-significant negative correlations in F344 and Lewis rats. Yet, F1 rats showed a significant positive correlation between these variables, even though some of their other responses were Lewis-like or F344-like.
These data suggest that responses to different novelty situations are strain-dependent.
对新奇事物的运动反应可预测远交系大鼠中精神兴奋药物的运动和强化作用。在近交系Lewis大鼠和Fischer 344（F344）大鼠中，这种关联不太明确，可能是由于对新奇事物反应的品系选择性差异所致。
我们研究了这些品系对新奇不可逃避和可逃避环境以及新奇物体的反应。
实验1采用位置条件反射程序。大鼠被限制在一侧8天，然后允许其进入这一侧（熟悉侧）和新奇侧。实验2评估在不可逃避环境中的运动反应。在另一次实验中，统计在新奇环境中与新奇物体的接触情况。测量皮质酮水平和粪便颗粒。确定这些反应是否能预测苯丙胺诱导的运动活动。为了进一步评估这种关联的遗传贡献，实验3评估了F1杂交Lewis-F344大鼠的新奇反应。
与F344大鼠相比，Lewis大鼠在可逃避环境中表现出更强的新奇寻求行为，但在不可逃避环境中的运动活动较低。在新奇物体接触、皮质酮或粪便颗粒反应方面没有品系差异。根据所有大鼠的数据，新奇环境中的基线皮质酮水平和活动水平与苯丙胺活性呈正相关。然而，在F344大鼠和Lewis大鼠中，新奇反应和苯丙胺诱导的活动呈非显著负相关。然而，F1大鼠在这些变量之间表现出显著正相关，尽管它们的一些其他反应类似Lewis大鼠或F344大鼠。
这些数据表明对不同新奇情境的反应具有品系依赖性。
