Despite that the RGC axons closely associated with astrocytes, the role of astrocytes in RGC regeneration was uncertain. In view of this, the effect of cultured adult astrocytes on RGC regeneration through an extensive ON lesion segment was studied. Adult ON astrocytes were prepared by sub-culturing of cells migrating out of ON explants. A small hole in the ON was punctured by 27G needle and about 0.5 to 1.0mul (1000 cells) cultured astrocytes was injected into the extensive ON lesion segment. We found that cultured adult astrocytes promoted significant RGC axon regeneration in the extensive ON lesion. / Finally, co-transplantation of intravitreal PN followed by transplantation of astrocytes into the extensive lesion has a synergistic effect on the regrowth of RGC axons, as indicated by the maximum distance achieved by regenerating axons and integrated intensity of staining of the CTB-labeled axons. Transplanatation of VPN+AST, VPN+NAST and NPN+AST as 3.9, 2.5 and l.9 times more potent in inducing regeneration than that of NPN+NAST as shown by integrated intensity measurement. However, co-transplantation of PN and astrocytes could not enhance RGC survival. (Abstract shortened by UMI.) / In this study, we have established an extensive lesion paradigm to study the behavior of injured retinal ganglion cell (RGC) axons after ON crush in adult golden hamster. We found that RGC axons regenerated in the extensive lesion for 406.8mum at 1 week post-crush to 1174.0mum at 4 weeks post-crush. RGC axons were able to regenerate the entire lesion segment but they terminated precisely at the interface between the lesion and the distal segment of the ON. Regrowing axons were intimately associated with astrocytes which repopulated the lesion segment. Repopulated oligodendrocytes were scattered in the lesion segment and myelin debris was significantly decreased in the lesion segment with time. / It is commonly believed that central nervous system (CNS) neurons are unable to regenerate after injury. Recently, there have been several lines of evidence showing that damaged CNS neurons can undergo axonal regeneration under appropriate conditions. Since the retina and optic nerve (ON) are regarded as part of the CNS, therefore, they are used as a model to study CNS regeneration. / Kong Wai Chi. / "July 2005." / Adviser: Y.P. Cho. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3616. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 96-115). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Ho Yi-Fong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 120-131). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Figures --- p.ix / List of Tables --- p.xi / Abbreviations --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Corticosteroids in ophthalmology --- p.1 / Chapter 1.1.1 --- History of the clinical use of corticosteroids --- p.1 / Chapter 1.1.2 --- Administration --- p.1 / Chapter 1.1.3 --- General biological effects of corticosteroids --- p.4 / Chapter 1.1.4 --- Application of corticosteroids in ocular diseases --- p.5 / Chapter 1.1.5 --- Side effects of ocular corticosteroid treatment --- p.6 / Chapter 1.1.6 --- General introduction to commonly used corticosteroids in ophthalmology --- p.6 / Chapter 1.1.6.1 --- Hydrocortisone --- p.6 / Chapter 1.1.6.2 --- Dexamethasone --- p.7 / Chapter 1.1.6.3 --- Triamcinolone --- p.7 / Chapter 1.1.6.4. --- Chemical structures and relative anti-inflammatory potencies --- p.8 / Chapter 1.1.7 --- Cytotoxicity of triamcinolone --- p.12 / Chapter 1.2 --- Retinal ganglion cells --- p.13 / Chapter 1.2.1 --- Basic structures of the eye --- p.13 / Chapter 1.2.2 --- Anatomical structure of retina --- p.13 / Chapter 1.2.3 --- Functions of retinal ganglion cells --- p.18 / Chapter 1.2.4 --- Culture models to study RGCs --- p.20 / Chapter 1.3 --- Aim of study --- p.25 / Chapter Chapter 2 --- Methodology --- p.26 / Chapter 2.1 --- Intravitreal injection of TA (IVTA) --- p.26 / Chapter 2.1.1 --- Materials --- p.26 / Chapter 2.1.1.1 --- Animals --- p.26 / Chapter 2.1.1.2 --- Chemicals --- p.26 / Chapter 2.1.1.3 --- Instruments --- p.26 / Chapter 2.1.2 --- Procedures --- p.26 / Chapter 2.2 --- Peripheral Nerve - Optic Nerve Grafting (PN-ON) Procedure --- p.27 / Chapter 2.3 --- Retrograde Labeling of regenerating RGCs --- p.27 / Chapter 2.3.1 --- Materials --- p.27 / Chapter 2.3.2 --- Procedures --- p.27 / Chapter 2.3.3 --- Statistical analysis --- p.28 / Chapter 2.4 --- Immunohistochemistry --- p.28 / Chapter 2.4.1 --- Materials --- p.28 / Chapter 2.4.2 --- Procedures --- p.29 / Chapter 2.4.3 --- Statistical analysis --- p.29 / Chapter 2.5 --- Histology --- p.29 / Chapter 2.5.1 --- Materials --- p.29 / Chapter 2.5.2 --- Procedures --- p.29 / Chapter 2.6 --- Primary rat retinal ganglion cell culture --- p.30 / Chapter 2.6.1 --- Materials --- p.30 / Chapter 2.6.1.1 --- Animals --- p.30 / Chapter 2.6.1.2 --- Chemicals --- p.30 / Chapter 2.6.1.3 --- Solutions and buffers --- p.30 / Chapter 2.6.1.4 --- Instruments --- p.31 / Chapter 2.6.2 --- Preparations --- p.31 / Chapter 2.6.2.1 --- Working media --- p.31 / Chapter 2.6.2.2 --- Plate coating --- p.32 / Chapter 2.6.3 --- Cell culture process --- p.32 / Chapter 2.6.3.1 --- Dissection of retinal tissues --- p.32 / Chapter 2.6.3.2 --- Purification of RGCs --- p.33 / Chapter 2.6.3.3 --- Culture condition and cell seeding --- p.34 / Chapter 2.7 --- Corticosteroid treatment --- p.34 / Chapter 2.7.1 --- Materials --- p.34 / Chapter 2.7.2 --- Preparations --- p.34 / Chapter 2.7.3 --- Treatment --- p.35 / Chapter 2.8 --- Cell viability assay and morphometric study --- p.36 / Chapter 2.8.1 --- Materials --- p.36 / Chapter 2.8.2 --- Calcein-AM staining --- p.36 / Chapter 2.8.3 --- Cell viability --- p.37 / Chapter 2.8.4 --- Morphometry study --- p.37 / Chapter 2.9 --- TUNEL Assay --- p.38 / Chapter 2.9.1 --- Materials --- p.38 / Chapter 2.9.2 --- Procedure --- p.38 / Chapter 2.9.3 --- Statistical analysis --- p.39 / Chapter 2.10 --- Quantitative Reverse transcription - Polymerase Chain Reaction (qRT-PCR) --- p.39 / Chapter 2.10.1 --- Materials --- p.39 / Chapter 2.10.1.1 --- "Chemicals, reagents, and kits" --- p.39 / Chapter 2.10.1.2 --- Primers --- p.40 / Chapter 2.10.1.3 --- Equipment --- p.41 / Chapter 2.10.1.4 --- Software --- p.41 / Chapter 2.10.2 --- Procedures --- p.41 / Chapter 2.10.2.1 --- Cell collection and RNA isolation --- p.41 / Chapter 2.10.2.2 --- Reverse Transcription --- p.42 / Chapter 2.10.2.3 --- Real-time PCR --- p.43 / Chapter 2.10.3 --- Statistical analysis --- p.43 / Chapter 2.11 --- Western blotting --- p.44 / Chapter 2.11.1 --- Sample preparation --- p.44 / Chapter 2.11.1.1 --- Materials --- p.44 / Chapter 2.11.1.1.1 --- Chemicals and materials --- p.44 / Chapter 2.11.1.1.2 --- Equipment --- p.44 / Chapter 2.11.1.2 --- Procedures --- p.44 / Chapter 2.11.2 --- Protein assay --- p.45 / Chapter 2.11.2.1 --- Materials --- p.45 / Chapter 2.11.2.1.1 --- Chemicals and materials --- p.45 / Chapter 2.11.2.1.2 --- Equipment and software --- p.46 / Chapter 2.11.2.2 --- Procedures --- p.46 / Chapter 2.11.3 --- SDS-polyacrylamide gel electrophoresis (SDS-PAGE) --- p.46 / Chapter 2.11.3.1 --- Materials --- p.46 / Chapter 2.11.3.1.1 --- Chemicals and reagents --- p.46 / Chapter 2.11.3.1.2 --- Equipment --- p.46 / Chapter 2.11.3.1.3 --- Solutions and buffers --- p.47 / Chapter 2.11.3.2 --- Gel preparation --- p.48 / Chapter 2.11.3.3 --- Electrophoresis --- p.49 / Chapter 2.11.3.4 --- Transblotting (semi-dry transfer) --- p.49 / Chapter 2.11.3.5 --- Band visualization --- p.49 / Chapter 2.11.4 --- Immunostaining --- p.50 / Chapter 2.11.4.1 --- Materials --- p.50 / Chapter 2.11.4.1.1 --- Antibodies --- p.50 / Chapter 2.11.4.1.2 --- Chemicals and reagents --- p.50 / Chapter 2.11.4.1.3 --- Equipment --- p.50 / Chapter 2.11.4.2 --- Procedures --- p.50 / Chapter 2.12 --- Gas-chromatography-electron-capture negative-ion mass spectrometry (GC-NCI-MS) --- p.51 / Chapter 2.12.1 --- Standard and reagents --- p.51 / Chapter 2.12.2 --- Chromatography and mass spectrometry --- p.52 / Chapter 2.12.3 --- Sample collection --- p.52 / Chapter 2.12.3 --- Standard and sample preparation --- p.53 / Chapter 2.12.4 --- Validation --- p.54 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Effect of triamcinolone on RGCs in vivo --- p.55 / Chapter 3.2 --- Cell viability of RGCs after IVTA plus PN-ON grafting --- p.55 / Chapter 3.3 --- Abnormal retinal morphology under different IVTA conditions --- p.59 / Chapter 3.4 --- Cell viability assay --- p.66 / Chapter 3.4.1 --- Effects of triamcinolone on RGC viability --- p.66 / Chapter 3.4.2 --- Effects of dexamethasone on RGC viability --- p.68 / Chapter 3.4.3 --- Effects of hydrocortisone on RGC viability --- p.70 / Chapter 3.4.4 --- Effects of filtered fraction of triamcinolone on RGC viability --- p.72 / Chapter 3.5 --- Morphometric study analysis of RGCs --- p.74 / Chapter 3.5.1 --- Percentage of RGCs showing neurite outgrowth --- p.74 / Chapter 3.5.2 --- Average neurite length --- p.77 / Chapter 3.5.3 --- Neurite spanning area --- p.77 / Chapter 3.5.4 --- Neurite count --- p.80 / Chapter 3.5.5 --- Neurite branching --- p.83 / Chapter 3.6 --- Determination of concentration of TA in culture media by GC-NCI-MS --- p.85 / Chapter 3.7 --- TUNEL assay --- p.90 / Chapter 3.8 --- Real-time quantitative Reverse transcription - Polymerase Chain Reaction --- p.93 / Chapter 3.9 --- Western blot --- p.99 / Chapter Chapter 4 --- Discussion --- p.102 / Chapter Chapter 5 --- References --- p.120

Quatre microélectrodes ont été insérées dans le ganglion stellaire gauche (GS) de préparations canines in vivo pour évaluer la décharge des potentiels d’action dans les neurones situés dans ce ganglion périphérique durant un état cardiovasculaire stable et suivant des injections systémiques et locales de nicotine. Durant les périodes de contrôle, des changements mineurs ont été observés dans la pression artérielle systolique, dans le rythme cardiaque et dans le temps de conduction atrio-ventriculaire. L’activité générée par les neurones du GS est demeurée relativement constante à l’intérieure de chaque chien, mais variait entre les préparations. L’administration de nicotine systémique a altéré les variables physiologiques et augmenté l’activité neuronale. Même si différents changements au niveau des variables physiologiques ont été observés entre les animaux, ces changements demeuraient relativement constants pour un même animal. La dynamique de la réponse neuronale était similaire, mais l’amplitude et la durée variaient entre et au sein des chiens. L’injection de nicotine dans une artère à proximité du GS a provoqué une augmentation marquée des potentiels d’action sans faire changer les variables physiologiques. La technique d’enregistrement permet donc de suivre le comportement de multiples populations de neurones intrathoraciques situés dans le GS. La relation entre l’activation neuronale du GS et les changements physiologiques sont stables pour chaque chien, mais varient entre les animaux. Cela suggère que le poids relatif des boucles de rétroaction impliquées dans la régulation cardiovasculaire peut être une caractéristique propre à chaque animal. / Four micro-electrodes were inserted in the left stellate ganglion (SG) of in vivo canine preparations to evaluate the firing of neuronal somata located in this peripheral ganglion during stable cardiovascular state and following local and systemic injection of nicotine. During control periods, minor changes were observed in systolic arterial pressure, the heart rhythm and the atrioventricular conduction time. The activity generated by SG neurons remained relatively constant within each dog, but the firing rate was variable among the preparations. Systemic nicotine administration altered the physiological variables and increased the neuronal activity. Although different patterns of physiological changes were observed among the preparations, it remained invariant upon successive injections in each animal. The behaviour of the neuronal response was similar but varies in amplitude and duration both within and between the dogs. Local injections of nicotine in an artery close to the SG induced a brief and huge burst of neuronal firing, but did not influence the physiological response. The recording technique thus permit to follow the behaviour of multiple intrathoracic neuronal populations located in the SG. The relation between the SG firing and the physiological changes is stable in each dog, but differed between the animals. It suggests that the weight of the different feedback loops involved in the cardiovascular regulation might be a characteristic feature of each animal and/or the position of the electrodes in the SG is critical, since different neuronal populations are present and could react differently.

[Truncated abstract] Microenvironmental changes associated with apoptotic neural degeneration may instruct a proportion of newly transplanted donor cells to differentiate towards the fate of the deteriorating host cellular phenotype. In the work described in this thesis, this hypothesis was tested by inducing apoptotic retinal ganglion cell (RGC) death in neonatal and adult rats and mice, and then examining whether intravitreally grafted cells from a range of sources of donor neural tissue became incorporated into these selectively depleted retinae. Donor tissues were: a postnatal murine cerebellar-derived immortalised neural precursor cell line (C17.2); an adult rat hippocampal-derived clonal stem-like line (HCN/GFP); mouse embryonic day 14 (E14) primary dissociated retinal cells (Gt[ROSA]26); and adult mouse ciliary pigmented margin-derived primary neurospheres (Gt[ROSA]26). In neonates, rapid RGC death was induced by removal of the contralateral superior colliculus (SC), and in adults, delayed RGC death was induced by unilateral optic nerve (ON) transection. Some adult hosts received ON transection coupled with an autologous peripheral nerve (PN) graft. Donor cells were injected intravitreally 6-48 h after SC ablation (neonates) or 0, 5, 7 or 14 days after ON injury (adults). Cells were also injected into non-RGC depleted neonatal and adult retinae. At 4 or 8 weeks, transplanted cells were identified, quantified and their differentiation fate within host retinae was assessed. Transplanted male C17.2 cells were identified in host retinae using a Y-chromosome marker and in situ hybridisation, or by their expression of the lacZ reporter gene product Escherichia coli beta-galactosidase (beta-gal) using Xgal histochemistry or a beta-gal antibody. No C17.2 cells were identified in axotomised adult-injected eyes undergoing delayed RGC apoptosis (n = 16). Donor cells were, however, stably integrated within the retina in 29% (15/55) of mice that received C17.2 cell injections 24 h after neonatal SC ablation; 6-31% of surviving cells were found in the RGC layer (GCL). These NSC-like cells were also present in intact retinae, but on average there were fewer cells in GCL. In SC-ablated mice, most grafted cells did not express retinal-specific markers, although occasional donor cells in the GCL were immunopositive for beta-III tubulin (TUJ1), a protein highly iii expressed by, but not specific to, developing RGCs. Targeted rapid RGC depletion thus increased C17.2 cell incorporation into the GCL, but grafted C17.2 cells did not appear to differentiate into an RGC phenotype.

While much is known about the influence of ventricular afferent neurons on cardiovascular function in the dog, identification of the neurochemicals transmitting cardiac afferent signals to central neurons is lacking. Accordingly, we identified ventricular afferent neurons in canine dorsal root ganglia (DRG) and nodose ganglia by retrograde labeling after injecting horseradish peroxidase (HRP) into the anterior right and left ventricles. Primary antibodies from three host species were used in immunohistochemical experiments to simultaneously evaluate afferent somata for the presence of HRP and markers for two neurotransmitters. Only a small percentage (2%) of afferent somata were labeled with HRP. About half of the HRP-identified ventricular afferent neurons in T3 DRG also stained for substance P (SP), calcitonin gene-related peptide (CGRP), or neuronal nitric oxide synthase (nNOS), either alone or with two markers colocalized. Ventricular afferent neurons and the general population of T3 DRG neurons showed the same labeling profiles; CGRP (alone or colocalized with SP) being the most common (30-40% of ventricular afferent somata in T3 DRG). About 30% of the ventricular afferent neurons in T2 DRG displayed CGRP immunoreactivity and binding of the putative nociceptive marker IB4. Ventricular afferent neurons of the nodose ganglia were distinct from those in the DRG by having smaller size and lacking immunoreactivity for SP, CGRP, and nNOS. These findings suggest that ventricular sensory information is transferred to the central nervous system by relatively small populations of vagal and spinal afferent neurons and that spinal afferents use a variety of neurotransmitters.

A la suite d'un traumatisme nerveux les neurones périphériques ont la capacité de régénérer. La repousse est possible grâce à l'environnement permissif et les aptitudes intrinsèques des neurones périphériques à entamer un processus régénératif. Cette capacité intrinsèque se traduit par des remaniements cellulaires et moléculaires induits notamment par la modification de l'expression de nombreux gènes. Ma thèse a porté sur l'étude de l'un d'entre eux : CaMKIα (Calcium-Calmodulin-dependent kinase Iα), dont nous avons montré l'induction de l'expression dans les neurones de ganglions rachidiens dorsaux par une lésion du nerf sciatique. Cette kinase, jamais encore décrite dans le système nerveux périphérique adulte, est impliquée dans le développement neuronal au niveau central. Nous avons établi que l'expression de CaMKIα est spécifiquement induite à la suite de différents types de traumatismes mécaniques du nerf sciatique (sections, compressions chroniques ou aiguës) dans une population restreinte de neurones lésés, majoritairement myélinisés. La localisation subcellulaire de CaMKIα, à la fois dans le corps cellulaire des neurones et dans les fibres du nerf sciatique, évoque un transport axonal de la kinase vers le site de lésion. L'inhibition de la voie de signalisation de CaMKIα par traitement pharmacologique ou l'utilisation de siRNA dirigés contre CaMKIα induit in vitro une chute significative de la vitesse de pousse des neurites des neurones lésés. L'ensemble de ces résultats suggère que l'induction de CaMKIα contribue à la régénération axonale post-lésionnelle des neurones périphériques. / Peripheral neurons have the capacity to regenerate after injury. This regeneration is allowed by thefavorable environment generated by the cellular components of the system and intrinsic aptitudes ofthe peripheral neurons to enter this process. These intrinsic abilities are manifested as cellular changes and molecular alterations including transcriptional and post-transcriptional modifications. Prior to my work, our laboratory carried out transcriptomic analysis on dorsal root ganglia after nerve injury. This allowed us to highlight a set of genes induced in response to peripheral nerve lesion. My thesis focused on one of them: CaMKIα (Calcium-Calmodulin-dependent kinase Iα). This kinase, not previously described in the adult peripheral nervous system, has been shown to be involved in central nervous system neuronal development. We have shown that CaMKIα is specifically induced following different kinds of mechanical lesions of the sciatic nerve (sections and acute or chronic crush) in a restricted, predominantly myelinated, population of injured neurons. The subcellular location of CaMKIα, both in the soma and nerve fibers suggest an axonal transit of the kinase to the injury site. The inhibition of the CaMKIα signaling pathway by a pharmacological compound or RNA silencing in vitro induced a significantly decreased velocity of neurite growth in injured neurons. Taken together, these results suggest that the induction of CaMKIα contributes to the post injury axonal regeneration of peripheral neurons.

A confocal scanning laser ophthalmoscope (CSLO) was used to image the axonal and dendritic aborizations of RGCs in the Thy-1 YFP mice. With quantitative analysis of cell body area, axon diameter, dendritic field, number of terminal branches, total dendritic branch length, branching complexity, symmetry and distance from the optic disc, the morphologies of RGCs and the patterns of axonal and dendritic degeneration were analyzed. After optic nerve crush, RGC damage was observed prospectively to begin with progressive dendritic shrinkage, followed by loss of the axon and the cell body. Similar pattern of RGC degeneration was observed after 90 minutes of retinal ischemia although no morphological changes were detected when the duration of ischemia was shortened to 30 minutes. The rate of dendritic shrinkage was variable and estimated on average 2.0% per day and 11.7% per day with linear mixed modeling, after optic nerve crush and retinal ischemic injury, respectively. RGCs with a larger dendritic field had a slower rate of dendritic shrinkage. / In summary, we demonstrated that dendritic shrinkage could be evident even before axonal degeneration after optic nerve crush and retinal ischemic injury. We have established a methodology for in vivo and direct visualization of RGCs and retinal microglia, which could provide reliable and early markers for neuronal damage. Measuring the rate of dendritic shrinkage and tracking the longitudinal activation of microglia would provide new paradigms to study the mechanism of neurodegenerative diseases and offer new insights in testing novel therapies for neuroprotection. / Progressive neuronal cell death and microglial activation are the key pathological features in most neurodegenerative diseases. While investigating the longitudinal profiles of neuronal degeneration and microglial activation is pertinent to understanding disease mechanism and developing treatment, analyzing progressive changes has been obfuscated by the lack of a non-invasive approach that allows long term, serial monitoring of individual neuronal and microglial cells. Because of the clear optical media in the eye, direct visualization of the retinal ganglion cells (RGCs) and microglia is possible with high resolution in vivo imaging technique. In this study, we developed experimental models to visualize and characterize the cellular morphology of RGCs and retinal microglia in vivo in the Thy-1 YFP and the CX3CR1 +/GFP transgenic mice, described the patterns of axonal and dendritic shrinkage of RGCs, discerned the dynamic profile of microglial activation and investigated the relationship between RGC survival and microglial activation after optic nerve crush and retinal ischemic injury induced by acute elevation of intraocular pressure. / The longitudinal profile of microglial activation was investigated by imaging the CX3CR1GFP/+ transgenic mice with the CSLO. Activation of retinal microglia was characterized with an increase in cell number reaching a peak at a week after optic nerve crush and retinal ischemic injury, which was followed by a gradual decline falling near to the baseline at the 4 th week. The activation of retinal microglia was proportional to the severity of injury. The number of RGCs survival at 4 weeks post-injury was significantly associated with the number of activated retinal microglia. / Li, Zhiwei. / Adviser: Leung Kai Shun. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 50-66). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Chiasm cells, which include glia and neurons, are generated early before any retinal axon arrives at the midline of the mouse ventral diencephalon. These cells have been shown to affect retinal axon growth and patterning in the optic chiasm. In this study, we used EdU (5-ethyny1-2'-deoxyuridine) for birthdating these chiasm cells, aiming to find out when these cells are generated; then we tried to trace their fates at later stages of development. EdU injection at embryonic day (E) 9.5 to El 1 labeled a number of chiasmatic neurons and radial glial cells at E13, which were immunoreactive for SSEA-1 and RC2, respectively. After colocalization studies, we found that most of these neurons were born as early as E9.5, while a large number of radial glial cells were born as from El 1. Both E9.5-born chiasmatic neurons and Ell-born radial glia decreased by E14-E16; the radial glia even disappeared finally from the midline. Furthermore, we found that some chiasmatic neurons underwent apoptotic cell death as from El 4, and that the radial glia likely differentiated into other cell types after finishing their retinal axon guidance mission at the midline. So it is reasonable that some of the earliest born chiasm cells disappear during development. / During development, retinal ganglion cell axons grow from the eye to the ventral diencephalon, where axons from the two eyes converge and segregate into crossed and uncrossed projections, forming the optic chiasm. This pattern is critical for binocular vision. Although significant progress has been obtained over the past decades, how retinal axon growth and guidance are regulated at the chiasm is largely unknown. Our research will focus on those problems. / In the last part of this thesis, we investigated the retinal axon pathway in the ventral diencephalon of the Sox10Dom mutant embryos and gamma-crystallin mutant embryos. Our findings indicate that Sox10 may not contribute to axon guidance in the developing optic pathway whereas gammaA-crystallin may only play a role in the later uncrossed axons. / N-methyl-D-aspartate (NMDA) receptor is one of the ionotropic glutamate receptors, which are important in synaptic plasticity, apart from implications in dendritic spine remodeling, neurite outgrowth, elongation and branching and glutamate neurotoxicity. There are several subtypes of NMDA receptor channel subunits, NR1, NR2A-D, NR3A&B. The functional diversity of NMDA receptor resides in the different assembly of subunits. In this study, we used RT-PCR to analyze the mRNA expression of all the NMDA receptor subunits in mouse embryos. After that we chose the NR1, NR2B and NR3A antibodies to investigate NMDA receptor subunit expression in the optic pathway during mouse optic pathway development. Using immunohistochemistry, we found that NR1, NR2B and NR3A were expressed in the mouse retina and optic pathway as from E13 when the optic chiasm is forming. Expression of the NMDA receptor subunits were found in the inner cell layers and along retinal axons. Colocalization studies showed that NR1, NR2B and NR3A were localized on the ganglion cells and their axons. In the ventral diencephalon, these subunits were expressed extensively, but NR1 and NR3A were particularly strong along the optic nerve and optic tract. Furthermore, to identify the function of NMDA receptor during optic chiasm development, we cultured E14 retinal explants on laminin and poly-D-ornithine in the presence of the NMDA receptor antagonists MK-801 or Dextrorphan-D-tartrate. These two antagonists can significantly inhibit the retinal axon outgrowth, suggesting that the NMDA receptor promotes retinal axon outgrowth in the retinofugal pathway during optic chiasm development. / Li, Jia. / Adviser: Chan Sun On. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 145-158). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Wai-Chi Kong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 83-92). / Acknowledgements --- p.i / Abstract --- p.ii / Abbreviations Frequently Used --- p.v / Chapter Chapter1 --- General Introduction --- p.1 / Chapter Chapter2 --- Long term culture of whole-mount retinal explant --- p.16 / Chapter Chapter3 --- Responses of retinal ganglion cells after peripheral nerve transplantation in vivo and in vitro --- p.46 / Chapter Chapter4 --- Effect of optic nerve or peripheral nerve explants on cultured whole-mount retinal explants --- p.62 / Chapter Chapter5 --- General Discussion --- p.78 / References --- p.83 / Tables --- p.93

Diss. (sammanfattning) Linköping : Univ., 2003. / Härtill 4 uppsatser.