PDF(Pubmed)
Abstract：
It is widely accepted that fear memories are consolidated through protein synthesis-dependent changes in the basolateral amygdala complex (BLA). However, recent studies show that protein synthesis is not required to consolidate the memory of a new dangerous experience when it is similar to a prior experience. Here, we examined whether the protein synthesis requirement for consolidating the new experience varies with its spatial and temporal distance from the prior experience. Female and male rats were conditioned to fear a stimulus (S1, e.g., light) paired with shock in stage 1 and a second stimulus (S2, e.g., tone) that preceded additional S1-shock pairings (S2-S1-shock) in stage 2. The latter stage was followed by a BLA infusion of a protein synthesis inhibitor, cycloheximide, or vehicle. Subsequent testing with S2 revealed that protein synthesis in the BLA was not required to consolidate fear to S2 when the training stages occurred 48 h apart in the same context; was required when they were separated by 14 d or occurred in different contexts; but was again not required if S1 was re-presented after the delay or in the different context. Similarly, protein synthesis in the BLA was not required to reconsolidate fear to S2 when the training stages occurred 48 h apart but was required when they occurred 14 d apart. Thus, the protein synthesis requirement for consolidating/reconsolidating fear memories in the BLA is determined by similarity between present and past experiences, the time and place in which they occur, and reminders of the past experiences.
摘要：
人们普遍认为，恐惧记忆是通过基底外侧杏仁核复合体（BLA）的蛋白质合成依赖性变化来巩固的。然而,最近的研究表明，当一个新的危险经历与以前的经历相似时，蛋白质合成不是巩固记忆所必需的。这里,我们检查了巩固新经验的蛋白质合成要求是否随其与先前经验的时空距离而变化。雌性和雄性大鼠被限制害怕刺激(S1，例如，光)与第一阶段的电击配对；和第二个刺激(S2，例如，音调）在阶段2中的其他S1冲击配对（S2-S1冲击）之前。后一阶段是蛋白质合成抑制剂的BLA输注，环己酰亚胺,或车辆。随后对S2进行的测试显示，当两个训练阶段在相同的背景下相隔48小时时，不需要BLA中的蛋白质合成来巩固对S2的恐惧；当它们被延迟14天分开或在不同的环境中发生时需要；但是如果S1在延迟后或在不同的环境中重新呈现，则再次不需要。同样，当训练阶段相隔48小时时，不需要BLA中的蛋白质合成来重新巩固对S2的恐惧，但当它们相隔14天时被要求。因此，在BLA中巩固/重新巩固恐惧记忆的蛋白质合成需求取决于现在和过去经验之间的相似性，它们发生的时间和地点，提醒过去的经历。意义陈述当基底外侧杏仁核复合体（BLA）中的蛋白质合成与以前的经历相似时，不需要巩固新的危险经历的记忆。这项研究具有重要意义，表明：（1）当延迟或在不同的背景下发生新的体验时，蛋白质合成需求恢复；（2）通过提醒动物先前的经验，可以逆转延迟和上下文转移的影响；（3）延迟影响新经验的重新巩固，就像影响初始巩固一样。因此，记忆背后的神经机制受现在和过去经验之间的相似性/差异性调节，这些经历发生的时间/地点，和提醒过去的经验。
