Fos神經網絡的雙向抑制可塑性
作者:
小柯機器人發布時間:2020/12/10 16:42:50
美國哈佛醫學院Michael E. Greenberg研究團隊的最新研究揭示了Fos神經元網絡的雙向滲透抑制可塑性。2020年11月9日,《自然》在線發表了這一成果。
研究人員發現,當小鼠在新環境空間中探索時,表達小白蛋白的中間神經元對Fos激活的海馬CA1錐體神經元的抑制作用增強,而對表達膽囊收縮素中間神經元的抑制作用則減弱。當破壞FOS轉錄因子複合物的功能時,這種雙向抑制作用便消失。單細胞RNA測序、核糖體相關mRNA譜分析和染色質分析與電生理學相結合表明FOS激活Scg2的轉錄,該基因編碼多個不同的神經肽,以協調這些抑制作用的變化。由於表達小白蛋白和膽囊收縮素的中間神經元介導錐體細胞活性的特徵不同,SCG2依賴性抑制突觸的識別可能會影響體內網絡的功能。
與此預測一致,在沒有Scg2的情況下,海馬γ節律和錐體細胞與θ期的偶聯發生了顯著改變。這些發現揭示了FOS和SCG2通過重新建立局部抑制以形成選擇性調節狀態在建立Fos激活神經元網絡方面的決定作用。作用於不同抑制途徑的相反可塑性機制可能支持隨著時間推移而鞏固記憶的理論。
據介紹,行為經驗會激活稀疏神經元群體中的FOS轉錄因子,這對於編碼和回憶特定事件至關重要。但是,對經驗誘導腦電路重組以建立Fos激活細胞網絡的機制了解有限。尚不知道在這個過程中是否需要FOS來充當最近神經活動的標記;如果是這樣,那麼有待探究那個Fos靶基因充當了迴路重組的基石。
附:英文原文
Title: Bidirectional perisomatic inhibitory plasticity of a Fos neuronal network
Author: Ee-Lynn Yap, Noah L. Pettit, Christopher P. Davis, M. Aurel Nagy, David A. Harmin, Emily Golden, Onur Dagliyan, Cindy Lin, Stephanie Rudolph, Nikhil Sharma, Eric C. Griffith, Christopher D. Harvey, Michael E. Greenberg
Issue&Volume: 2020-12-09
Abstract: Behavioural experiences activate the FOS transcription factor in sparse populations of neurons that are critical for encoding and recalling specific events1,2,3. However, there is limited understanding of the mechanisms by which experience drives circuit reorganization to establish a network of Fos-activated cells. It is also not known whether FOS is required in this process beyond serving as a marker of recent neural activity and, if so, which of its many gene targets underlie circuit reorganization. Here we demonstrate that when mice engage in spatial exploration of novel environments, perisomatic inhibition of Fos-activated hippocampal CA1 pyramidal neurons by parvalbumin-expressing interneurons is enhanced, whereas perisomatic inhibition by cholecystokinin-expressing interneurons is weakened. This bidirectional modulation of inhibition is abolished when the function of the FOS transcription factor complex is disrupted. Single-cell RNA-sequencing, ribosome-associated mRNA profiling and chromatin analyses, combined with electrophysiology, reveal that FOS activates the transcription of Scg2, a gene that encodes multiple distinct neuropeptides, to coordinate these changes in inhibition. As parvalbumin- and cholecystokinin-expressing interneurons mediate distinct features of pyramidal cell activity4,5,6, the SCG2-dependent reorganization of inhibitory synaptic input might be predicted to affect network function in vivo. Consistent with this prediction, hippocampal gamma rhythms and pyramidal cell coupling to theta phase are significantly altered in the absence of Scg2. These findings reveal an instructive role for FOS and SCG2 in establishing a network of Fos-activated neurons via the rewiring of local inhibition to form a selectively modulated state. The opposing plasticity mechanisms acting on distinct inhibitory pathways may support the consolidation of memories over time.
DOI: 10.1038/s41586-020-3031-0
Source: https://www.nature.com/articles/s41586-020-3031-0