Normal brain functions depend critically upon circuit connections and synaptic architectures for information processing. Drosophila model system along with its intricate genetic tool box provides an unprecedented opportunity to understand how neural circuits orchestrating complex behaviors. A key step towards this goal is to generate a map of neuron-to-neuron connections. In this study, we begin to develop a technique called “Brainbow” to create a stochastic expression of multiple copies of fluorescence proteins (XFPs) under GAL4/UAS control, yielding combinatorial XFP expressions in the Drosophila central nervous system. We found that strong XFP expression and high detection sensitivity were essential for proper Brainbow imaging. Several proof-of-concept applications to illustrate intricate structures with Brainbow imaging were given. Brainbow technique demonstrated a way not only to discriminate adjacent neurons in defined group of cells but also to trace neural circuits. Our final goal is to reconstruct a neural circuitry map of brainwide connections in Drosophila.

許多在生物體內的功能機制往往是建構在精密的組織結構上，對於神經系統來說更是如此。神經系統有著極為複雜的網路結構，在生物體內負責處理及整合資訊，並且傳遞資訊到各處來協調各區不同的功能性。為了讓我們更容易剖析中樞神經系統的結構及功能性，我們選擇了基因工具非常發達的果蠅來作為模式生物進行實驗。在這篇研究中，我們使用了「彩虹腦」這個基因轉殖技術來區分果蠅體內不同的神經細胞。經由多種不同顏色螢光蛋白的排列組合，我們有機會賦予每一顆細胞不同的顏色，藉此看清楚神經細胞與其他組織的結構及連結性。除此之外，我們也利用多色螢光技術完成追蹤細胞突觸的工作，這是都是使用單色螢光標定難以達到的目標。在未來基因轉殖技術和影像分析軟體的進步下，我們之後的研究目標是利用這個新技術去建構整隻果蠅的神經網路圖譜。

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