Organisms must learn new strategies to adapt to changing environments. Activity in different neurons often exhibits synchronization that can dynamically enhance their communication and might create flexible brain states that facilitate changes in behavior. We studied the role of gamma-frequency (~40 Hz) synchrony between prefrontal parvalbumin (PV) interneurons in mice learning multiple new cue–reward associations. Voltage indicators revealed cell-type-specific increases of cross-hemispheric gamma synchrony between PV interneurons when mice received feedback that previously learned associations were no longer valid. Disrupting this synchronization by delivering out-of-phase optogenetic stimulation caused mice to perseverate on outdated associations, an effect not reproduced by in-phase stimulation or out-of-phase stimulation at other frequencies. Gamma synchrony was specifically required when new associations used familiar cues that were previously irrelevant to behavioral outcomes, not when associations involved new cues or for reversing previously learned associations. Thus, gamma synchrony is indispensable for reappraising the behavioral salience of external cues.

生物体必须学习新的策略来适应不断变化的环境。不同神经元的活动通常表现出同步性，可以动态地增强它们的沟通，并可能创造灵活的大脑状态，促进行为的变化。我们研究了前额叶小清蛋白 (PV) 中间神经元之间伽玛频率 (~40 Hz) 同步在学习多种新提示-奖励关联的小鼠中的作用。当小鼠收到先前学到的关联不再有效的反馈时，电压指示器显示 PV 中间神经元之间的跨半球伽马同步性的细胞类型特异性增加。通过提供异相光遗传学刺激来破坏这种同步，导致小鼠坚持过时的关联，这是其他频率的同相刺激或异相刺激无法重现的效果。当新关联使用以前与行为结果无关的熟悉线索时，特别需要伽玛同步，而不是当关联涉及新线索或逆转以前学到的关联时。因此，伽玛同步对于重新评估外部线索的行为显着性是必不可少的。