The brain, a homologous organ possessed by most of animals, has many functions. One of the most important brain functions is enabling the animals to react properly to environmental stimuli. To understand how a brain achieves this, mapping the brain’s sensory circuitry becomes essential. The most fruitful work has been the mapping of Drosophila olfactory circuit. Today we have known that: after odorants bind to Drosophila olfactory receptors, the neuronal signals are triggered and relayed by a series of neurons to the higher brain centers including the lateral horn, a brain region involved in non-association behavioral responses to some odorants. For revealing more facts about this brain region, this thesis provides a map of neurons innervating the lateral horn. Also, by analyzing these neurons, it proposes the lateral horn neurons’ possible signal output and input areas in the fly brain, and shows some examples of lateral horn neuron stereotypes. In addition, for helping scientists analyze their image data related to the lateral horn, my colleagues and I have built a representative lateral horn 3D model in a standard brain.

大部分的動物都有「腦」這個演化同源器官。腦有許多複雜的功能，其中非常重要的一項，就是使動物對週遭的刺激做出適當的反應；譬如追尋食物香味來源或是逃離惡臭的環境。如果我們想要了解腦如何執行這項功能，首先要做的就是描繪出腦中感覺訊息傳達的路徑。目前這項工作進展最迅速，成果最豐碩的就是描繪果蠅腦的嗅覺網路。如今我們已知：當氣味分子與果蠅觸角上的嗅覺接受器結合，神經訊號就會被觸發，接下來一連串的神經細胞會將訊號傳遞到腦中更高階的兩個處理中心；其中一個處理中心是果蠅腦的蕈狀體，這個處理中心與果蠅的嗅覺學習記憶能力有關。另外一個處理中心則是側角區，這個區域與果蠅對氣味的直覺反應有關。為了進一步了解側角區，這篇論文提出了果蠅腦側角區的神經細胞圖譜，呈現出許多側角區神經細胞的三維影像資料；同時藉由分析這些影像資料，本文指出側角區神經細胞可能將訊號送往果蠅腦的某幾個區域，以及某幾個可能將訊息送至側角區的果蠅腦區。另外在本論文中，我們也可以在某種程度上看到側角區神經細胞的幾種特定的空間分布型態。最後，我與幾位同僚一同在果蠅標準腦中建立了一個側角區的三維模型，以利日後的研究人員在一個虛擬的標準腦中處理他們所擷取到的側角區神經細胞影像資料。

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