Tomie Arthur, Silberman Yuval, Williams Kayon, Pohorecky Larissa A
Department of Psychology and Center of Alcohol Studies, Rutgers University, New Brunswick, NJ 08903, USA.
Pharmacol Biochem Behav. 2002 Jun;72(3):507-13. doi: 10.1016/s0091-3057(01)00781-x.
Pavlovian autoshaping conditioned responses (CRs) are complex sequences of conditioned stimulus (CS)-directed skeletal-motor responses that are elicited by CS objects predictive of food unconditioned stimulus (US). Autoshaping CRs are observed under conditions known to be conducive to elevations in plasma corticosterone levels, as, for example, in response to the eating of food as well as in response to signals predictive of food. Two experiments investigated the relationships between Pavlovian autoshaping procedures, the performance of Pavlovian autoshaping CRs, and plasma corticosterone levels in male Long-Evans rats. In Experiment 1, rats in the CS-US paired group (n=30) were given 20 daily sessions of Pavlovian autoshaping training wherein the insertion of a retractable lever CS was followed by the response-independent presentation of the food US. Tail blood samples obtained after the 20th autoshaping session revealed higher plasma corticosterone levels in the CS-US paired group than in the CS-US random control group (n=10). In Experiment 2, rats (n=35) were assessed for basal plasma corticosterone levels 2 weeks prior to autoshaping training. Plasma samples obtained immediately following the first autoshaping session, and prior to the acquisition of lever-press autoshaping CR performance, revealed higher plasma corticosterone levels in the CS-US paired group (n=24) relative to basal levels. This effect was not observed in the CS-US random control group (n=11). Data suggest that corticosterone release is a physiological endocrine Pavlovian CR induced by lever CS-food US pairings during Pavlovian autoshaping procedures, rather than a by-product of autoshaping CR performance. Implications of the link between autoshaping procedures and corticosterone release are discussed.
巴甫洛夫式自动塑造条件反应（CRs）是由预测食物非条件刺激（US）的条件刺激（CS）引导的复杂的骨骼肌运动反应序列。在已知有利于血浆皮质酮水平升高的条件下可观察到自动塑造CRs，例如，对进食食物以及对预测食物的信号的反应。两项实验研究了巴甫洛夫式自动塑造程序、巴甫洛夫式自动塑造CRs的表现与雄性长 Evans 大鼠血浆皮质酮水平之间的关系。在实验1中，CS-US配对组（n = 30）的大鼠每天接受20次巴甫洛夫式自动塑造训练，其中在插入可伸缩杠杆CS后，不依赖反应地呈现食物US。在第20次自动塑造训练后采集的尾血样本显示，CS-US配对组的血浆皮质酮水平高于CS-US随机对照组（n = 10）。在实验2中，在自动塑造训练前2周评估大鼠（n = 35）的基础血浆皮质酮水平。在第一次自动塑造训练后立即采集的血浆样本，以及在获得杠杆按压自动塑造CR表现之前，显示CS-US配对组（n = 24）的血浆皮质酮水平相对于基础水平更高。在CS-US随机对照组（n = 11）中未观察到这种效应。数据表明，皮质酮释放是巴甫洛夫式自动塑造程序中杠杆CS-食物US配对诱导的生理性内分泌巴甫洛夫式CR，而不是自动塑造CR表现的副产品。讨论了自动塑造程序与皮质酮释放之间联系的意义。
