生物透過發展複雜的嗅覺系統以區分生存環境中多樣的氣味並生存下來。在果蠅的嗅覺系統中，氣味分子被終止於觸角葉中51個不同嗅小球的嗅覺受體神經元接收。接著，氣味的訊息通過投射神經元到達三種不同的Kenyon細胞，這些Kenyon細胞形成的蘑菇體被認為是學習和記憶的中心。先前的研究利用電生理採樣的數據發現，每顆Kenyon細胞都會整合來自嗅小球隨機組合的輸入。但在解剖學和發育的分析表明，每種Kenyon細胞與來自單顆嗅小球投射神經元的軸突末端分別占據蕈狀體花萼中不同的空間分佈，這代表投射神經元與Kenyon細胞之間存在著某些模式和規律性。在本篇研究我們透過分析開放資源的電子顯微鏡結果，發現單顆嗅小球的投射神經元幾乎會連接到所有的Kenyon 細胞，但可能更偏向連接某些特定的Kenyon細胞。利用跨突觸標定的基因工具－trans-Tango追蹤物理性的連通性，我們證實了投射神經元與Kenyon細胞之間偏好性連通原理，特別是在具有性別二態性的DA1嗅小球投射神經元與不同類型的Kenyon細胞之間的連結性尤其明顯。透過光遺傳學激活DA1嗅小球的投射神經元，這種非典型的聯通性模式也反映在Kenyon細胞的鈣離子功能性影像中。總體來說，我們的證據表明不同嗅覺投射神經元與不同種類的Kenyon細胞之間的連通性，在個體間表現出一定程度的規則性。

Animals develop complex olfactory system to distinguish various odorants in the environment for survival. In Drosophila, odorants are detected by populations of olfactory receptor neurons (ORNs) terminated at 51 distinct olfactory glomeruli within the antennal lobe (AL). The signals from each glomerulus then delivered via stereotyped projection neurons (PNs) to three distinct families of Kenyon cells (KCs) which together form the mushroom body (MB), the learning and memory center. Electrophysiological sampling data suggests that each KC integrates inputs from a random combination of glomeruli. However, anatomical and developmental analysis show that dendritic arbors of each type of KCs and axonal terminals of PNs from a single AL glomerulus occupied distinct subdomains in the MB calyx, respectively, suggesting the existence of certain patterns and regularities between PN-to-KC connectivity. Here, we analyze the electron microscopy data derived from open source reveals that an individual PN links to all families of KCs but may prefer certain KC connections. Tracing physical connectivity with the trans-synaptic trans-Tango labeling, we substantiated the connectivity principle of PN-to-KC preference, especially evident in the case of sexual dimorphism DA1-PNs. This atypical connectivity pattern is also reflected in calcium functional imaging of KCs after optogenetic activation of DA1-PNs. Together, our data show that the connectivity between different olfactory glomeruli of PNs and different families of KCs exhibits a certain degree of stereotype across individuals.

中文摘要 i
Abstract ii
致謝 iii
Table of Contents iv
List of Tables v
List of Illustrations vi
1 Introduction 1
2 Materials and Methods 6
2.1 Fly strains 6
2.2 Sample Preparation and Immunohistochemistry Staining 7
2.3 Confocal Imaging and Post-Recording Imaging Processing 8
2.4 In vivo GCaMP Functional Imaging and Imaging Processing 8
3 Result 10
3.1 Strategy Analysis 10
3.2 EM Results Revealed Preferred Connections between PNs and KCs 10
3.3 Trans-Synaptic Labeling from Different Types of Uni-Glomerular PNs (iACT) to KCs 11
3.4 Physical Connectivity from Uni-Glomerular PNs to KCs 12
3.5 Functional Connectivity from DA1-PNs to KCs 13
4 Discussion 15
4.1 Highly stereotyped glomeruli are related to innate behaviors 15
4.2 Stereotypy or randomness 16
4.3 Differences between trans-Tango and EM data 17
4.4 Future application of trans-Tango and EM data 18
5 Reference 21
6 Tables 23
7 Figures 25
8 Appendix 29

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