The ability to extinguish conditioned fear memory is critical for adaptive control of fear response, and its impairment is a hallmark of emotional disorders like post-traumatic stress disorder (PTSD). Fear extinction is thought to take place when animals form a new memory that suppresses the original fear memory. However, little is known about the nature and the site of formation and storage of this new extinction memory. Here we demonstrate that a fear extinction memory engram is formed and stored in a genetically distinct basolateral amygdala (BLA) neuronal population that drives reward behaviors and antagonizes the BLA's original fear neurons. Activation of fear extinction engram neurons and natural reward-responsive neurons overlap significantly in the BLA. Furthermore, these two neuronal subsets are mutually interchangeable in driving reward behaviors and fear extinction behaviors. Thus, fear extinction memory is a newly formed reward memory. VIDEO ABSTRACT.

中文翻译：

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杏仁核奖励神经元形成并存储恐惧灭绝记忆。

消除条件性恐惧记忆的能力对于恐惧反应的适应性控制至关重要，而其损害是诸如创伤后应激障碍（PTSD）等情绪障碍的标志。人们认为，当动物形成一种新的记忆来抑制原始的恐惧记忆时，就会发生恐惧绝种。但是，对于这种新的灭绝记忆的性质以及形成和存储的部位知之甚少。在这里，我们证明了恐惧消灭记忆印章的形成并存储在遗传上不同的基底外侧杏仁核（BLA）神经元种群中，该种群驱动奖励行为并拮抗BLA的原始恐惧神经元。在BLA中，恐惧消灭印记神经元和自然奖赏反应性神经元的激活明显重叠。此外，这两个神经元子集在驱动奖励行为和恐惧灭绝行为方面是可以互换的。因此，恐惧消亡记忆是新形成的奖励记忆。视频摘要。