The mammalian brain contains dedicated circuits for both the learned expression and suppression of fear. These circuits require precise coordination to facilitate the appropriate expression of fear behavior, but the mechanisms underlying this coordination remain unclear. Using a combination of chemogenetics, activity-based neuronal-ensemble labeling and in vivo electrophysiology, we found that fear extinction learning confers on parvalbumin-expressing (PV) interneurons in the basolateral amygdala (BLA) a dedicated role in the selective suppression of a previously encoded fear memory and BLA fear-encoding neurons. In addition, following extinction learning, PV interneurons enable a competing interaction between a 6-12 Hz oscillation and a fear-associated 3-6 Hz oscillation within the BLA. Loss of this competition increases a 3-6 Hz oscillatory signature, with BLA→medial prefrontal cortex directionality signaling the recurrence of fear expression. The discovery of cellular and oscillatory substrates of fear extinction learning that critically depend on BLA PV interneurons could inform therapies aimed at preventing the pathological recurrence of fear following extinction learning.

中文翻译：

---

恐惧消灭学习的细胞和振荡底物。

哺乳动物的大脑包含专门的电路，用于学习表达和抑制恐惧。这些回路需要精确的协调，以促进恐惧行为的适当表达，但这种协调的基础机制仍不清楚。结合使用化学遗传学，基于活动的神经元整体标记和体内电生理学，我们发现恐惧绝灭的学习赋予基底外侧杏仁核（BLA）中表达小白蛋白（PV）的中间神经元，这在选择性抑制先前的抑制作用中起着重要作用。编码的恐惧记忆和BLA恐惧编码神经元。此外，在消光学习之后，PV中子使BLA内6-12 Hz振荡与恐惧相关的3-6 Hz振荡之间发生竞争性相互作用。这种竞争的丧失会增加3-6 Hz的振荡信号，而BLA→内侧前额叶皮层的方向性表明恐惧表达的再次出现。严重依赖于BLA PV中间神经元的恐惧消灭学习的细胞和振荡底物的发现可以为旨在防止消灭学习后恐惧的病理性复发的疗法提供参考。