果蠅處理視覺訊號之原腦橋區域神經網路圖譜

A Comprehensive Wiring Diagram of the Protocerebral Bridge for Visual Information Processing in the Drosophila Brain

林志勇(Chih-Yung Lin)

指導教授 ： 江安世

國立清華大學/生命科學院/生物科技研究所/博士(2013年)

https://doi.org/10.6843/NTHU.2013.00574

摘要

大腦如何理解接外部的感官訊息並進一步產生有意義行動關鍵是隱藏在腦中無數神經網路。原腦橋是昆蟲腦內中央複合體的主要組成部位之一，而中央複合體在解剖學與發育上則與人類的基底神經節可能系出同源。本研究先藉由逐一拆解數百個與原腦橋區域相關的單一神經元結構，再將其全部組合並置入於具有三維空間的中央複合體立體架構內，重構出以前腦橋區域為主體的完整神經網路圖譜，其中並載明 神經網路圖譜，其中並載明各神經元極性與訊息傳遞的可能路徑。藉由分析本研究 發現之一百九十四顆不同種類原腦橋神經元的結果，可進一步揭露出，中央複合體各不同組成部位間，其彼此訊息傳遞是由一個高度規律的處理系統負責。此系統包含多項不同的神經網路排列特性，諸如鏡像式、聚合發散散諸如鏡像式、 聚合式、 發散式、瓦蓋交疊式、回饋式以及平行放大等；同時本論文也深入探討這些特性在功能及演化上的重要性。藉此神經網路圖譜為藍本，研究者將可進一步探討果蠅大腦如何處理外部的感官訊號，例如視覺，以表達出適當的行為反應。

關鍵字

中央複合體 ； 原腦橋神經元

並列摘要

How the brain perceives sensory information and generates meaningful behavior depends critically on its underlying circuitry. The protocerebral bridge (PB) is a major part of the insect central complex (CX), a pre-motor center may be analogous to the human basal ganglia. Here, by deconstructing hundreds of PB single neurons and reconstructing them into a common 3D framework, we have constructed a comprehensive map of PB circuits with labeled polarity and predicted directions of information flow. Our analysis reveals a highly-ordered information processing system that involves directed information flow among CX subunits through 194 distinct PB neuron types. Circuitry properties such as mirror, convergence, divergence, tiling, reverberation and parallel signal propagation were observed; their functional and evolutional significances were discussed. This layout of PB neuronal circuitry may provide guidelines for further investigations on transformation of sensory (e.g. visual) input into locomotion command in fly brains.

並列關鍵字

central complex ； protocerebral bridge

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