研究揭示前額小白蛋白在規則轉移學習過程中的功能

研究揭示前額小白蛋白在規則轉移學習過程中的功能

作者：

小柯機器人

發布時間：2020/5/27 14:19:46

美國加州大學Vikaas S. Sohal小組的最新研究，揭示了前額小白蛋白（PV）中間神經元之間的跨半球γ同步在規則轉移學習過程中支持行為適應。相關論文於2020年5月25日發表在《自然—神經科學》雜誌上。

研究人員探究了PV中樞神經元之間的伽馬頻率（~40 Hz）同步在小鼠中的作用，該小鼠學習了多種新的提示-獎賞機制。當小鼠接受反饋而先前學習的關聯不再有效時，電壓指示器顯示PV中神經元之間跨半球γ同步的細胞類型特異性增加。

通過傳遞異相的光遺傳學刺激破壞這種同步時，會導致小鼠對過時關聯表現出持久性；而同相刺激或其他頻率的異相刺激則無法再現這種效果。當新的關聯使用以前與行為結果無關的熟悉線索，而不是當關聯涉及新線索或顛倒先前學習的關聯時，特別需要伽瑪同步。因此，伽馬同步對於重新評估外部線索行為的顯著性必不可少。

據悉，個體必須學習新的策略以適應不斷變化的環境。不同神經元中的活動通常表現出同步性，可以動態增強其交流，並可能創建靈活的大腦狀態，從而促進行為變化。

附：英文原文

Title: Cross-hemispheric gamma synchrony between prefrontal parvalbumin interneurons supports behavioral adaptation during rule shift learning

Author: Kathleen K. A. Cho, Thomas J. Davidson, Guy Bouvier, Jesse D. Marshall, Mark J. Schnitzer, Vikaas S. Sohal

Issue&Volume: 2020-05-25

Abstract: 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 (~40Hz) 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gamma synchrony between PV interneurons when mice received feedback that previously learned associations were no longer valid. Disrupting this synchronization by delivering out-of-phase optogenetic stimulation caused mice to perseverate on outdated associations, an effect not reproduced by in-phase stimulation or out-of-phase stimulation at other frequencies.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.

DOI: 10.1038/s41593-020-0647-1

Source: https://www.nature.com/articles/s41593-020-0647-1