On the Mechanisms of Neural Development in the Ventral Telencephalon

To be presented for public examination with the permission of the Faculty of Para a minha família TABLE OF CONTENTS LIST OF ORIGINAL PUBLICATIONS i ABSTRACT ii LIST OF ABBREVIATIONS iv INTRODUCTION 1 1. The development of telencephalon in mouse 1 1.1. Neural development within the telencephalon 2 1.1.1. Neurogenesis and cell migration within the dorsal telencephalon 3 Use of decloaking chamber-based heat-induced epitope retrieval method improves the detection of Olig2-labeled cells in the ventral telencephalon (I) 23 2. NKCC1 regulates cell proliferation in the ventral telencephalon (II) 26 3. GDNF binds to syndecan-3, and promotes the tangential migration of immature interneurons in the ventral telencephalon (III) 29 CONCLUSIONS 32 ACKNOWLEDGEMENTS 33 REFERENCES 34 i LIST OF ORIGINAL PUBLICATIONS This Thesis is based on the following original articles, which are referred to in the text by their Roman numerals: I Magalhães AC and Rivera C. Superior performance of decloaking chamber-based heat-induced epitope retrieval method improves the quantification of Olig2 cells in paraffin-embedded section of embryonic mouse brain (2014) J Neurosci Methods 235: 226–233. II Magalhães AC and Rivera C. In vivo role of NKCC1 in ventral telencephalon cell cycle reentry. Manuscript. III: Planning and performing the experiments, and analyzing the data for figure 6, and contributing to the writing of manuscript (Materials and Methods, Results, and Discussion sections) ii ABSTRACT The time of arrival of interneurons and oligodendrocytes to the neocortex is critical for proper functional brain development. Aberrances in this sequence can be detrimental, and involved in different developmental diseases. Thus, understanding the mechanisms for temporal control of the genesis and migration of neural cells is crucial. In this study we have focused on the ventral telencephalon, a major source of interneurons and oligodendrocytes. We have developed a more sensitive method for detecting and quantifying oligodendrocyte precursor cells, e.g. Olig2. Current immunohistochemistry methods for detection and quantification of this cell type are poor. Optimal immunohistochemistry often requires heat-induced epitope retrieval (HIER) method for improving the staining in paraffin-embedded sections, and therefore helping in quantitative studies. Here, we have developed an immunohistochemistry protocol using the device decloaking chamber for HIER. This method was compared to the microwave oven-based HIER method by studying the labeling of Olig2 marker in paraffin-embedded sections from embryonic mouse brain. We have demonstrated that the decloaking chamber-based HIER method is the most suitable technique for the detection of single Olig2-labeled cells in the ventral telencephalon. This …