Brown adipose tissue (BAT) serves as a crucial thermogenic organ, extracting glucose and lipids from circulation to generate heat. Enhancing BAT activity holds potential as a therapy for treating metabolic diseases, such as obesity and diabetes. The sympathetic nervous system (SNS) is the main regulator of BAT activity by increasing extraction and oxidation of substrates. However, the SNS role in metabolic disorders is complex. In obesity, there is increased sympathetic tone, yet reduced BAT responsiveness. Furthermore, increasing systemic sympathetic tone in individuals already at heightened cardiovascular risk leads to adverse complications, as demonstrated by recent clinical trials. As a result, BAT’s impact on overall health in humans has been challenged in recent years, largely due to the lack of methods to selectively activate BAT without affecting other organs. Here, I used chemogenetics and retrograde viral injections in the interscapular BAT (iBAT) of mice to selectively activate only the neurons projecting to this tissue. Targeted activation of BAT did increase thermogenesis and improved glucose homeostasis. Leveraging on the single-cell RNA sequencing from our laboratory, we identified two sympathetic populations innervating iBAT: one primarily targets the small arterioles, while the other innervates the parenchyma. These populations mediate non-overlapping sympathetic-functions in iBAT: activating only the vascular projecting neurons lowers blood glucose without affecting thermogenesis, while activating the other population results in increased energy expenditure, local thermogenesis, and blood flow, with no effect on glycemia. The findings from this work could pave the way to the development of targeted strategies against metabolic disorders characterized by hyperglycemia, highlighting the potential of selectively activating specific SNS components to normalize blood glucose levels.

Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, 2013 / Electromagnetic fields are present wherever electricity is created. The frequency range of these electromagnetic fields is from extremely low to extremely high. The fields present in domestic areas fall within the extremely low frequency range. These fields are created by domestic electrical appliances and telecommunication. There has been much debate on the effect of exposure to these fields on human health. Research has not yet been able to prove adverse effect of these fields on human health. In fact, the benefits of magneto therapy has been recognized and used for several decades. Recently a specific electromagnetic signal has been under investigation for its ability to stimulate the immune response. This signal is produced by a patented generator, called Immunent Activator. Studies performed with the Immunent Activator signal on farm animals revealed increased feed conversion and decreased intestinal lesions of animals with intestinal infections. Most of the research was performed on fish and fowls and evidence of similar findings in mammals is lacking. In the current study, mice were exposed to the Immunent BV signal for seven days, after which immune cell counts were performed and compared to the immune cell counts of a control group of mice which received no electromagnetic exposure. It was found that the T-lymphocyte population of immune cells in the exposed group of mice was statistically significantly higher than that of the control group. The neutrophil count was statistically significantly lower in the exposed group compared to the control group. These findings revealed evidence of immune stimulation in the mice which were exposed to the Immunent Activator signal. Suggestions for further research could be made with regard to specific mechanisms of immune stimulation. The findings of this and other related studies hold benefits for the farming and health industry.

It is of interest to understand how new neurons incorporate themselves into the existing circuitry of certain neuronal populations. One such population of neurons is that which are born in the subventricular zone (SVZ) and migrate to the olfactory bulb where they differentiate into granule cells. Another area of interest is the role of brain-derived neurotrophic factor (BDNF) on the survival and overall health of these neurons. This study aimed to test whether or not BDNF is a survival factor for adult-born granule cells. Here were utilized a transgenic mouse model over-expressing BDNF under the α- calcium/calmodulin-dependent protein kinase II (CAMKIIα) promoter, and tested its effect on olfactory granule cells under sensory deprived conditions. Results from this experiment indicated that there was no significant difference in cell death or cell survival when comparing transgenic and wild type animals. We concluded that BDNF is not a survival factor for adult-born granule cells. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Establishing appropriate animal models for the study of human memory is paramount to the development of memory disorder treatments. Damage to the hippocampus, a medial temporal lobe brain structure, has been implicated in the memory loss associated with Alzheimer’s disease and other dementias. In humans, the role of the hippocampus is largely defined; yet, its role in rodents is much less clear due to conflicting findings. To investigate these discrepancies, an extensive review of the rodent literature was conducted, with a focus on studies that used the Novel Object Recognition (NOR) paradigm for testing. The total amount of time the objects were explored during training and the delay imposed between training and testing seemed to determine hippocampal recruitment in rodents. Male C57BL/6J mice were implanted with bilateral dorsal CA1 guide cannulae to allow for the inactivation of the hippocampus at discrete time points in the task. The results suggest that the rodent hippocampus is crucial to the encoding, consolidation and retrieval of object memory. Next, it was determined that there is a delay-dependent involvement of the hippocampus in object memory, implying that other structures may be supporting the memory prior to the recruitment of hippocampus. In addition, when the context memory and object memory could be further dissociated, by altering the task design, the results imply a necessary role for the hippocampus in the object memory, irrespective of context. Also, making the task more perceptually demanding, by requiring the mice to perform a two-dimensional to three-dimensional association between stimuli, engaged the hippocampus. Then, in the traditional NOR task, long and short training exploration times were imposed to determine brain region activity for weak and strong object memory. The inactivation and immunohistochemistry findings imply weak object memory is perirhinal cortex dependent, while strong object memory is hippocampal-dependent. Taken together, the findings suggest that mice, like humans, process object memory on a continuum from weak to strong, recruiting the hippocampus conditionally for strong familiarity. Confirming this functional similarity between the rodent and human object memory systems could be beneficial for future studies investigating memory disorders. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Conclusion. The present results indicate that, baicalein with optimal dosage of 30 muM suppressed collagen deposition in AngII stimulated SHR CF cultures. In animal model of hypertension, high dose of baicalein feeding for 12 week showed optimal antifibrotic effect in hypertensive hearts. (Abstract shortened by UMI.) / For in-vivo study, comparing to control group, HW/BW (x1000) of SHR was significantly reduced in 12 weeks-high dose baicalein and (-0.78+/-0.23, p=0.014) 12 weeks-Valsartan group (-0.71+/-0.22, p=0.021), however, no significant change was observed in the LW/BW ratio. / In Blood pressure control, no effects on attenuation of SBP were observed after 4 weeks and 12 weeks daily administration of baicalein, only 12 weeks feeding of Valsartan significantly down-regulated the systolic blood pressure by -19.25+/-10.09 mmHg, p=0.049. / In the in-vivo study, SHR was used as a model of genetic hypertension. The objectives were: firstly, to determine the efficacy of baicalein in the prevention of myocardial fibrosis (interstitial fibrosis) in SHR, & compared with WKY rats as normal controls. Secondly, to determine if over-expression of pro-collagen I (and III, if any) gene in the ventricles could be normalized by baicalein. Thirdly, to determine if left ventricular hypertrophy in SHR is improved by baicalein. Furthermore, to determine if blood pressure and blood biochemistry parameters (plasma level of brain natriuretic peptides (BNP), and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) level could be alternated by baicalein. Besides, to determine the body weight (BW), heart weight to body ratio (HW/BW), liver weight to body weight ratio (LW/BW), serum AST and ALT level could be alternated by baicalein. Finally to evaluate by echocardiography if there are changes of ivss and ivsd in SHR after administration of baicalein. / Keywords. baicalein, wogonin, collagen, cardiac fibrosis, hypertension / Objectives. In the in-vitro study, cardiac fibroblast culture was prepared from neonatal SHR and WKY rats. The objectives were multi-fold: firstly, to determine over-expression of pro-collagen I mRNA (and III, if any) in cardiac fibroblasts cultures could be normalized by baicalein and wogonin after AngII activation. Secondly, to evaluate the efficacy of baicalein and wogonin on the suppression of total collagen protein production in cardiac fibroblasts cultures after AngII activation. Thirdly, to evaluate the mechanism (in protein level) of baicalein and wogonin on regulating collagen deposition in cardiac fibroblasts after AngII activation. Furthermore, to determine if there were any effects on cytotoxicity and membrane integrity of baicalein and wogonin towards cardiac fibroblasts cultures. Finally, to determine the optimal concentration of baicalein and wogonin for the above actions in-vitro. / Results. For in-vitro study, incubation of AngII resulted in significant up-regulation of COL-I and COL-III mRNA and total collagen protein production. Addition of either baicalein or wogonin significantly suppressed the mRNA synthesis and total collagen protein in CF with an optimal dosage of 30 muM. No effects on viability and membrane integrity were observed on baicalein and wogonin towards cardiac fibroblasts cultures. / Kong, Kam Chuen Ebenezer. / Advisers: Cheuk-Man Yu; Gabriel W. K. Yip. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0242. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 176-204). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

As exogenously administered RA suppressed the expression of the RA synthesizing enzymes, further investigation on whether this would lead to deficiency in endogenous RA concentrations was conducted. Results showed that exogenously administered RA significantly reduced the endogenous RA level in the head region with C57 embryos showing a greater reduction than ICR embryos. / In addition, detailed morphological and histological studies were conducted to determine if RA treatment caused early embryonic changes with strain difference. When compared with ICR embryos, C57 embryos exhibited more pronounced responses to RA, including developmental retardation, underdevelopment of the anterior neural plate and absence of or smaller optic pit/optic vesicle formation. However, RA treatment did not cause abnormal apoptosis in the early stages in both strains. / Since the teratogenic effect of RA is highly developmental stage-dependent, it is possible that there is a difference in the developmental stage between these 2 mouse strains at the time of RA injection. Indeed, it was found that the developmental stage of ICR embryos was approximately 6 hours ahead of C57 embryos. However, the role that this factor plays in the differential strain susceptibility to RA can be excluded since C57 fetuses were still 3 times more susceptible to developing anophthalmia/microphthalmia than ICR fetuses that were subject to RA treatment at equivalent developmental stages. Comparison of susceptibility to RA-induced anophthalmia/microphthalmia was also made among heterozygous fetuses obtained from reciprocal matings between C57 and ICR male and female mice, and those in homozygous ICR and C57 fetuses. Results showed that the C57 strain has conferred both genetic predisposition and maternal effects in increasing the embryo's susceptibility to RA-induced ocular defects. / Since the type of RA-induced ocular defects mimic those that developed in Raldh2 null mutant embryos, the effect of RA treatment on the expression of RA synthesizing enzymes, Raldh2 and Raldh3, and the RA-inducible gene Cyp26a1, as well as some early eye development genes were examined. Exogenously administered RA reduced the mRNA expression levels of Raldh2, Raldh3 and Cyp26a1 in the head region, with C57 embryos showing a greater reduction than ICR embryos. / Taken together, results of this thesis suggest that there is a strain difference in susceptibility to RA-induced ocular defects in which exogenously applied RA suppresses the expression of RA synthesizing enzymes and leads to endogenous RA deficiency. This finding may shed light on understanding why both excess and deficiency of RA can lead to similar types of ocular defects. / To determine if there are strain differences in the susceptibility to RA-induced ocular defects, two mouse strains were used. They are C57BL/6J (C57), mice that spontaneously develop ocular defects and ICR mice, which are not prone to developing ocular defects. Detailed time and dose response studies were conducted and eye defects were examined in near-term fetuses. C57 fetuses were found to be significantly more susceptible to RA-induced anophthalmia/microphthalmia than ICR fetuses. / Vitamin A (retinol) and its most active metabolite, all- trans retinoic acid (RA) is essential for vision in the adult and for eye development in the embryo. It is well documented that in humans, excess intake or deficiency of vitamin A or RA is associated with congenital ocular defects such as microphthalmia. However, the underlying mechanism remains unclear. The aim of this study is to examine the pathogenic mechanism of RA-induced developmental ocular defects. / Lau, Wing Sze Josephine. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0240. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 186-211). / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

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.

Baicalin, which is a flavonoid, was previously shown to exert neuroprotective effects against ischemic injury and oxidative insults. In this study, baicalin was found to induce neuronal differentiation on both C17.2 NSC and primary mouse NSC originated from hippocampuses of E14.5 mouse embryos. The baicalin-mediated differentiation of C17.2 NSC was noted in dose- and time-dependent manners. Baicalin-treated NSC displayed long processes of neurites. The gene expression of neuronal markers, NF-L, TUBB3 and MAP2 was also significantly increased after treated with 20 to 50 muM baicalin on C17.2 NSC. Treating C17.2 NSC with baicalin significantly increased the number of TUBB3 positive cells by 300%. A significant increase in the gene expression of TUBB3 was also observed on primary NSC upon baicalin treatment at 5 to 10 muM. The number of TUBB3 positive cells was increased by 100% after treating with 10 muM baicalin. C17.2 NSC treated with baicalin also increased the gene expression of GABAergic and serotonergic neuronal subtype specific enzymes GAD1 and TPH1. / Nature provides a vast pool of natural compounds with neuroprotection and neurotrophism. A few of these compounds can induce the differentiation of neural stem cells (NSC). There are ample opportunities to discover more natural compounds with differentiation inducing effect on NSC. One of the objectives of this project is to look for novel natural compounds showing neurogenic effect on NSC. This project has established a platform for screening medicinal materials and natural compounds with neural differentiation promoting effect on C17.2 mouse neural stem cell line. Screening results identified total Sanqi saponins, total Renshen saponins, Huangqin extracts and baicalin as potent candidates for inducing this differentiation of NSC. / This project also aims at characterizing the mechanisms involved in the neuronal differentiation effect of baicalin on NSC. Annotation from microarray analysis indicated that baicalin treatment on C17.2 NSC is related to development of tissue and nervous system. qPCR study attested the increased gene expression of nerve growth factor-beta, neurotrophin-3, pro-neural transcriptional factors Ngn1, Ngn2 and NeuroD2. Western blotting showed that baicalin activated ERK1/2 MAP kinase but not JNK and p38 MAP kinases. / This project demonstrated the neurogenic potential of natural resources on NSC. A novel neuronal induction effect of baicalin on NSC was also demonstrated with its mechanisms characterized. This project also revealed that baicalin can be used for promoting functional recovery of post-ischemia animals. / This study showed for the first time that baicalin exerts neuronal differentiation inducing effect on NSC. Another objective of this project is to study whether baicalin can promote functional recovery of animals with ischemia brain injury. Mice having undergone transient occlusion of the bilateral common carotid arteries with blood-reperfusion to induce global cerebral ischemia were treated with baicalin and/or EGFP-NSC. Ischemia animals received implantation of EGFP-NSC into the caudate putamen and/or intravenous injection of baicalin on alternate days for two-week on day seven post-ischemia displayed significant improvement of the cognitive function in terms of the incident of error and escape time in the water T-maze task compared to the control arm of ischemia mice. Data of the study suggested that the therapeutic effect of baicalin would be comparable to that of neural stem cell transplant in improving the cognitive function in a mouse ischemic stroke model. / Li, Ming. / Adviser: P. C. Shaw. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 199-232). / 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.

In this study, the brain of senescence accelerated mouse prone 8 (SAMP8) mice model was adopted to investigate PTMs state (especially methylation patterns) of core histones (H2A, H2B, H3 and H4). Seven methylated sites (H3K24, H3K27, H3K36, H3K79, H3R128, H4K20 and H2A R89) were detected by tandem matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) analysis. The methylation of H3K27 and H3K36 demonstrated a modulating relationship and methylated H3K27 might contribute to the hypermethylation state and gene repression in aged brain. Western blotting results showed that mono-methylated H4K20 decreased during SAMP8 mice aging and di-methylated H3K79 decreased in the brain of 12-month-old SAMP8 mice compared with age-matched senescence accelerated-resistant mouse (SAMR1) control. Di-methylated H3K79 could express in neuron cells of cerebral cortex and hippocampus. Whereas, the number of H3K79 methylation negative cells was higher in the cortex of 12-month old SAMP8 mice than that of age-matched control SAMR1 mice. Chromatin immunoprecipitation (ChIP) result indicated homeodomain transcription factor Pbx1 isoform 1 (Pbx1), transcription factors and transcriptional regulator proteins, such as T-box isoform 20, TetR family precursor BAZ2B and ribosomal protein, were recruited to methylated H3K79 site. Therefore, a model of methylated H3K79 on gene transcriptional regulation was proposed. Furthermore, the consequences of decreased H3K79 methylation in Neuro-2a (N2a) cells were investigated via transfection with Dot1 (disruptor of telomeric silencing) siRNA. After transfection, N2a cells displayed shorter neurite and less dendrite. Proteomic change in the N2a cells provided convincing evidence for the multi-function of decreased H3K79 methylation on transcriptional regulation, protein translation and folding, stress response and DNA breaks repair, which would contribute to brain dysfunction during neurodegenerative disease or aging. / Nowadays, many countries including China are experiencing aging populations. Aging has become the major risk factor for many diseases, such as neurodegenerative disease. The studies on the role of epigenetics in the aging process have grown tremendously in recent years. However, no systematic investigations have provided the information on histone post-translational modifications (PTMs) in aged brain and the roles of histone PTMs in brain aging are still unknown. / This study gave a new insight into the link between histone PTMs and brain aging. It could provide the experimental evidence for future studies and help us to better understand aging or neurodegenerative disease at epigenetic level. Furthermore, it could benefit for setting up the strategies for epigenetic therapy to neurodegenerative disease. / Wang, Chunmei. / Adviser: Ngai Saiming. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaf 136). / 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.