The unconditioned stimulus pre-exposure effect in preweanling rats in taste aversion learning: Role of the training context and injection cues
The unconditioned stimulus pre-exposure effect in preweanling rats in taste aversion learning: Role of the training context and injection cues
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DOI：
10.1002/dev.21011
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发表时间：
2013-03-01
影响因子：
2.2
通讯作者：
Spear, N. E.
中科院分区：
文献类型：
--
作者：
Revillo, D. A.;Arias, C.;Spear, N. E.
无条件刺激预暴露效应（US-PE）是指由于先前的 US 经验而导致条件反应的获得延迟的干扰范式。大多数分析这种效应背后的心理机制的研究都是在成年老鼠身上进行的。最广泛接受的假设将这种效应解释为上下文阻塞效应。与 US 相关的语境线索会在调节过程中阻止条件刺激 (CS)-US 关联。缺乏独特嗅觉属性的环境的调节作用直到大约 PD23 在大鼠中才能观察到，包括干扰范式的调节，例如潜在抑制或消退。在这项研究中，我们分析了断奶前大鼠的 US-PE 以及训练环境在条件性味觉厌恶准备方面的作用。在调节之前预先暴露于氯化锂可延缓味觉厌恶的获得。在断奶前的大鼠中，在预暴露期间，当受试者暴露于条件环境时，观察到了 US-PE，并且这种效应不会因在熟悉的环境中施用 US（实验 1a）或在预暴露期间存在替代的、更显着的环境（实验 1b）而减弱。此外，当在预暴露阶段和调节阶段之间改变 US 给药途径（实验 2a）以及在调节过程中移除注射提示时（实验 2b），仍然可以观察到 US-PE。这些实验显示断奶前大鼠具有很强的 US-PE，但未能支持背景阻断假说，至少在个体发育的这个阶段是这样。 (c) 2012 年 Wiley periodicals, Inc. Dev Psychobiol 55: 193204, 2013
The unconditioned stimulus pre-exposure effect (US-PE) refers to the interference paradigm in which acquisition of the conditioned response is retarded due to prior experience with the US. Most studies analyzing the psychological mechanisms underlying this effect have been conducted with adult rats. The most widely accepted hypothesis explains this effect as a contextual blocking effect. Contextual cues associated with the US block the conditioned stimulus (CS)-US association during conditioning. The modulatory role of a context devoid of distinctive olfactory attributes is not observable until approximately PD23 in rats, including modulation of interference paradigms such as latent inhibition or extinction. In this study, we analyzed US-PE in preweanling rats along with the role of the training context in this effect in terms of conditioned taste aversion preparation. Pre-exposure to LiCl before conditioning retarded the acquisition of taste aversion. The US-PE was observed in preweanling rats when, during pre-exposure, subjects were exposed to the conditioning context, and this effect was not attenuated either by the administration of the US in a familiar environment (Experiment 1a), or by the presence of an alternative, more salient context during pre-exposure (Experiment 1b). Additionally, the US-PE was still observed when the route by which the US was administered was changed between the pre-exposure and conditioning phases (Experiment 2a) as well as when the injection cues were removed during conditioning (Experiment 2b). These experiments show a strong US-PE in preweanling rats and fail to support the contextual blocking hypothesis, at least in this stage of ontogeny. (c) 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 193204, 2013