在果蠅觸角葉 (antennal lobe)，嗅覺訊息從嗅覺神經 (olfactory receptor neurons)傳遞至投射神經 (projection neurons)，形成頻道般的架構，以氣味受體 (odorant receptors)分隔，同類的嗅覺神經及投射神經連結相同嗅球 (glomerulus)。但是嗅球之間並非完全獨立，區域神經 (local interneurons)連結多顆嗅球，構成溝通的橋梁。在過去的研究顯示，嗅覺訊息在嗅覺神經與投射神經並不相同，推測區域神經可能扮演嗅覺訊息計算、處理的角色。我們的研究以真實的區域神經網路為基礎，分析其各項統計特徵，發現區域神經不論在連結數量 (innervation number)還是連結專一 (innervation specificity)，皆呈現其多樣性 (diversity)，此外，區域神經的連結模式與嗅覺神經對氣味的反應之間存在某種相關性。我們的結果顯示觸角葉的神經網路結構極為複雜且無法以現有理論解釋，因此需要重新審視並可能地提出新的理論模型解釋區域神經在觸角葉所負責的功能。

In Drosophila antennal lobe, olfactory receptor neurons (ORNs) of the same receptor type project to the same glomerulus and make synaptic connections with projection neurons (PNs), which project to higher brain center. The ORNs-glomerulus-PNs pathway forms a channel-like structure, which is heavily innervated by local interneurons (LNs). LNs likely play roles in modulating response of PNs to ORN inputs and in exchanging the olfactory information between channels. Using the wiring diagram of LNs, our analysis showed that the innervation number and the innervation specificity of individual LNs are very diverse while they form a specific innervation pattern that correlates with ORN responses to a certain class of odors. Our result suggests that the neural network architecture of the antennal lobe is extremely complex and beyond the explanation of existing theories. Therefore, we need to reexamine the current theories and, possibly, develop a new theory for the functions of LNs in antennal lobe.

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