神經元定向遷移是中樞神經系統發育必須進行的過程，遷移中的神經元極化細胞支架和分途徑，以達到神經元兩極性。小腦是腦部的運動神經中心，負責調整身體的平衡和肌肉的協調。蒲金氏細胞 (Purkinje cell)是小腦主要的輸出路線，為小腦必不可少的一員。可是，蒲金氏細胞遷移過程的分子機制和細胞機制仍然認知多。高爾基器(Golgi apparatus)是蛋白分途徑中的早期細胞器，它的再定位移動在大腦和小腦神經元的遷移過程中有發生。但是，高爾基器極性在蒲金氏細胞定向遷移中究竟發揮什麼作用仍然未知。在這文研究，我目標研究高爾基器定位和蒲金氏細胞早期遷移的關係。 / 透過免疫熒光成像分析，我發現在蒲金氏細胞早期遷移過程中，高爾基器重新定位於前導突起頂端的底部，將前導突起頂端突化成軸突。透過超表達一種高爾基器重組蛋白，培養中的蒲金氏細胞失去高爾基器極性和軸突，證明高爾基器的定位對於蒲金氏細胞突化軸突是必要的。在條件性 Smad1/5雙基因剔除小鼠的小腦，一群蒲金氏細胞未能遷移，顯示出隨機和分散的高爾基器定位，並失去軸突突出。總括來說，我的結果顯示出當蒲金氏細胞在進行早期遷移過程時，高爾基器的定位突化蒲金氏細胞的軸突，這可能對蒲金氏細胞遷移有重要作用。此發現揭開蒲金氏細胞遷移過程中的細胞機制，豐富我們對小腦發展過程中其中一件重要事件的認知。 / Neuronal migration is a fundamental process for central nervous system development during which migrating neurons polarize their cytoskeleton and secretory pathway to establish polarity. Cerebellum is the motor center, tuning body balance and muscle coordination. Purkinje cells, as the major output in the cerebellum, play an indispensable role for cerebellar function. However, the migration of Purkinje cells during early embryonic stages with respect to molecular and cellular mechanisms is largely unknown. Golgi apparatus is an early subcellular compartment in the protein secretory pathway. Recent studies show that Golgi reorientates during neocortical and cerebellar neuronal migration. Nevertheless, it is still not clear what role Golgi polarization plays during Purkinje cell migration. Therefore, in my study, I aim to address how Golgi polarization relates to Purkinje cell migration. / By immunofluorescence study, I showed that Golgi located at the base of leading processes during early Purkinje cell migration, which specifies the leading processes into axons. Disruption of Golgi orientation by overexpressing a Golgi stacking protein suppressed axon specification in cultured Purkinje cells, which suggests that Golgi polarization may be necessary for Purkinje cell axon specification. Conditional inactivation of Smad1/5 in the mouse cerebellum resulted in ectopic Purkinje cells which failed to migrate displayed random and dispersed Golgi positioning and an absence of axon protrusions. Overall, the results suggest that Golgi orientation specified axons of Purkinje cells, which may be important for further Purkinje cell migration. This finding identifies the cellular process during Purkinje cell migration and enriches our understanding of one of the critical events during cerebellar development. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Au, Sin Man June. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 98-109). / Abstracts also in Chinese. / Abstract --- p.iii / Acknowledgements --- p.v / Abbreviations --- p.vi / List of Figures --- p.x / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Cerebellum --- p.1 / Chapter 1.1.1 --- Cerebellum development --- p.1 / Chapter 1.1.2 --- Anatomy and cellular components --- p.4 / Chapter 1.2 --- Neuronal polarization and migration --- p.6 / Chapter 1.2.1 --- Axon specification and axon guidance --- p.7 / Chapter 1.3 --- Cerebellar Purkinje cells --- p.8 / Chapter 1.3.1 --- Physiological and morphological development --- p.8 / Chapter 1.3.2 --- Migration of Purkinje cells. --- p.9 / Chapter 1.3.2.1 --- Settling pattern of Purkinje cell populations --- p.9 / Chapter 1.3.2.2 --- Migration before E13.5 --- p.9 / Chapter 1.3.2.3 --- Interaction with radial glia --- p.10 / Chapter 1.3.2.4 --- Molecular mechanisms --- p.11 / Chapter 1.4 --- Golgi in neurons --- p.17 / Chapter 1.4.1 --- Polarized trafficking --- p.17 / Chapter 1.4.2 --- Golgi motility during cell polarization and migration --- p.19 / Chapter 1.4.2.1 --- Golgi/centrosome positioning in non-neuronal cell polarization and migration --- p.21 / Chapter 1.4.2.2 --- Golgi/centrosome positioning in neuronal polarization --- p.23 / Chapter 1.4.2.3 --- Golgi’s role in dendrite development --- p.26 / Chapter 1.4.2.4 --- Golgi/centrosome positioning in neuronal migration --- p.26 / Chapter 1.4.2.5 --- Opposite views on Golgi/centrosome positioning in cell polarization and migration --- p.28 / Chapter 1.4.3 --- Golgi’s role in microtubule cytoskeleton organization --- p.31 / Chapter 1.4.4 --- Other factors determining Golgi positioning --- p.32 / Chapter 1.5 --- Aims of the study --- p.34 / Chapter Chapter 2 --- Characterization of Lhx1{U+1D33}{U+A7F1}{U+1D3E}, a Lhx1-driven tau-eGFP knock-in transgenic mouse line / Chapter 2.1 --- Introduction --- p.35 / Chapter 2.2 --- Materials --- p.36 / Chapter 2.2.1 --- Tissue preparation --- p.36 / Chapter 2.2.2 --- Immunofluorescence --- p.36 / Chapter 2.3 --- Methods --- p.36 / Chapter 2.4 --- Results --- p.39 / Chapter 2.4.1 --- GFP expression in Lhx1{U+1D33}{U+A7F1}{U+1D3E} mice --- p.39 / Chapter 2.4.2 --- Purkinje cell markers specifically stain GFP-positive cells in Lhx1{U+1D33}{U+A7F1}{U+1D3E} mice --- p.42 / Chapter 2.5 --- Discussion --- p.44 / Chapter Chapter 3 --- Purkinje cell morphology and migration in early embryonic stages / Chapter 3.1 --- Introduction --- p.46 / Chapter 3.2 --- Materials and Methods --- p.47 / Chapter 3.3 --- Results --- p.48 / Chapter 3.3.1 --- Confocal imaging of Lhx1{U+1D33}{U+A7F1}{U+1D3E} embryos --- p.48 / Chapter 3.4 --- Discussion --- p.52 / Chapter Chapter 4 --- Specification of axon by localization of Golgi in Purkinje cells / Chapter 4.1 --- Introduction --- p.54 / Chapter 4.2 --- Materials --- p.57 / Chapter 4.3 --- Methods --- p.59 / Chapter 4.4 --- Results --- p.63 / Chapter 4.4.1 --- Golgi orientation from E12 to E15.5, in postnatal and in adult Lhx1{U+1D33}{U+A7F1}{U+1D3E} mice --- p.63 / Chapter 4.4.2 --- Anteriorly-orientated Golgi locates at the base of axon --- p.70 / Chapter 4.4.3 --- Golgi locates at the base of axon in cultured Purkinje cells at --- p.1DIV.71 / Chapter 4.4.4 --- Purkinje cells with Golgi orientation loss abrogate axon specification --- p.72 / Chapter 4.5 --- Discussion --- p.76 / Chapter Chapter 5 --- Purkinje cells with migration defect lose Golgi polarization and axon specification in Smad1/5 dKO mutants / Chapter 5.1 --- Introduction --- p.79 / Chapter 5.2 --- Materials and Methods --- p.81 / Chapter 5.3 --- Results --- p.83 / Chapter 5.3.1 --- Purkinje cells with migration defect lose Golgi polarization, normal morphology and axon differentiation --- p.83 / Chapter 5.4 --- Discussion --- p.89 / Chapter Chapter --- 6 General discussion, future perspectives and conclusions / Chapter 6.1 --- General discussion --- p.92 / Chapter 6.2 --- Future perspectives --- p.95 / Chapter 6.2.1 --- Golgi polarization in directing Purkinje cell migration --- p.95 / Chapter 6.2.2 --- The signal mediating Purkinje cell early migration and axonogenesis --- p.96 / Chapter 6.3 --- Conclusions --- p.97 / References --- p.98
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328596 |
| Date | January 2012 |
| Contributors | Au, Sin Man June., Chinese University of Hong Kong Graduate School. Division of Life Sciences. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (xi, 109 leaves) : ill. (chiefly col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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