科學家繪製出腦幹迴路內各種前肢動作的功能圖譜
作者：
小柯機器人發布時間：2021/1/8 16:25:45
近日，瑞士巴塞爾大學Silvia Arber及其小組繪製出腦幹迴路內各種前肢動作的功能圖譜。該項研究成果於2021年1月6日在線發表在《自然》雜誌上。
研究人員定義了功能圖譜的邏輯，這被用於腦幹外側頭端延髓（latRM）內的熟練前肢運動。通過在自由移動的小鼠中使用體內電生理學，研究人員揭示了將latRM群體調整為獨特前肢動作的神經元代碼。這些包括獲取和食物處理，這兩者都會因興奮性latRM神經元的擾動而受損。通過遺傳學和病毒示蹤的組合使用，研究人員證明了興奮性latRM神經元通過軸突靶標分離成不同的群體，並通過腦幹和脊髓迴路的差異募集起作用。
通過調查投射分層latRM群體的行為潛能，研究人員發現這些群體的光遺傳學刺激可以引起多種前肢運動，並且每種行為均由單個小鼠穩定表現。總而言之，投射分層的腦幹群體編碼動作階段，並共同作為調節複雜前肢運動關鍵特徵的潛在基礎，從而鑑定出熟練前肢行為的腦幹底物。
據悉，腦幹是控制身體運動的關鍵中心。雖然人們已經知道對全身運動至關重要的腦幹細胞類型和迴路的確切性質，但是了解熟練前肢運動神經元基礎的工作主要集中在上腦幹中心和脊髓。
附：英文原文
Title: A functional map for diverse forelimb actions within brainstem circuitry
Author: Ludwig Ruder, Riccardo Schina, Harsh Kanodia, Sara Valencia-Garcia, Chiara Pivetta, Silvia Arber
Issue&Volume: 2021-01-06
Abstract: The brainstem is a key centre in the control of body movements. Although the precise nature of brainstem cell types and circuits that are central to full-body locomotion are becoming known1,2,3,4,5, efforts to understand the neuronal underpinnings of skilled forelimb movements have focused predominantly on supra-brainstem centres and the spinal cord6,7,8,9,10,11,12. Here we define the logic of a functional map for skilled forelimb movements within the lateral rostral medulla (latRM) of the brainstem. Using in vivo electrophysiology in freely moving mice, we reveal a neuronal code with tuning of latRM populations to distinct forelimb actions. These include reaching and food handling, both of which are impaired by perturbation of excitatory latRM neurons. Through the combinatorial use of genetics and viral tracing, we demonstrate that excitatory latRM neurons segregate into distinct populations by axonal target, and act through the differential recruitment of intra-brainstem and spinal circuits. Investigating the behavioural potential of projection-stratified latRM populations, we find that the optogenetic stimulation of these populations can elicit diverse forelimb movements, with each behaviour stably expressed by individual mice. In summary, projection-stratified brainstem populations encode action phases and together serve as putative building blocks for regulating key features of complex forelimb movements, identifying substrates of the brainstem for skilled forelimb behaviours.
DOI: 10.1038/s41586-020-03080-z
Source: https://www.nature.com/articles/s41586-020-03080-z