by Stefanie P.C. Czerwinski. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader. / Sjèogren's Syndrome (SS) is a chronic, inflammatory autoimmune disease affecting mostly the exocrine cells of lacrimal and salivary glands, leading to diminished secretory function and resulting in keratoconjunctivitis sicca (dry eye disease) and/or stomatitis sicca (dry mouth disease). Despite several decades of studies focusing on autoimmune diseases and dry eye diseases, the exact etiology and mechanisms of SS remain unknown. Besides the fact that SS is often unreported, unrecognized and untreated, today's therapies rely exclusively on treating the symptoms after disease progression; there exists neither prevention therapy nor cure for SS. In addition, SS has been diagnosed predominantly in post-menopausal women with the female to male ratio reaching 9:1, suggesting a role of ovarian sex hormones in the pathogenesis of SS. However, not all postmenopausal women develop SS, indicating the contribution of other factors such as a genetic background to the onset of SS. In the present study, ovariectomized (OVX) NOD.B10.H2b mice provide a model of menopause with a genetic predisposition to SS, as compared to non-predisposed C57BL/10 mice. Both strands of mice were either sham operated, OVX, OVX and treated with 17(Sb (Bestradiol (E2), or OVX and treated with dihydrotestosterone (DHT). Lacrimal glands were collected 3, 7, 21, and 30 days after surgery and processed for RNA analysis by rt-qPCR and protein assays by ELISA to evaluate cytokine expression and concentrations of IL- 1\U+fffd\, TNF-a, IFN-(Sd(B, IL-10, and IL-4 on a timeline. Overall, our results showed a significant increase in IL-1\U+fffd\ TNF-a, IL-10, and IL-4 expression and levels in the lacrimal glands of OVX NOD.B10.H2b mice as compared to sham operated animals, and treatment with E2 or DHT at time of OVX prevented the increase in cytokine expression and levels.

In conclusion, the results suggested the important role of Ncl in driving the optic vesicle formation during early eye development. / The eye is a complex sense organ. It develops from different embryonic origins that including neural ectoderm, surface ectoderm, neural crest and paraxial mesoderm. Morphogenetic waves occur during eye development involve timely interactions of transcription factors and inductive signaling to ensure the correct temporal and spatial development of different components. Genetic studies of congenital eye defects, especially mutation screening and gene targeting, have provided the information about the molecular regulation in the complex processes of eye development. However, our knowledge of the basic genetic pathways that regulate the normal embryonic eye formation is incomplete. / Though the developing eye is believed to be highly specialized extension from the developing neural tube, the formation of major eye structure involves independent coordination of inductive interactions and regional specifications; formation of neural connections between retina and optic tectum; and maturation to a functional eye. There is not much information about eye-specific expression in early embryonic period. In this study, microarray was used to profile the molecular changes occurring in the developing mouse eye between the stage of optic vesicle evagination at E9.5 and completion of basic eye formation at P0. Differentially expressed transcription factor and signaling molecules, including nucleolin gene (Ncl), in the early developing eye were displayed. Temporal expression patterns were confirmed by quantitative real time PCR and spatial expressions patterns were confirmed by the whole-mount in situ hybridization. siRNA and overexpression vector targeting nucleolin transcript was designed to study their roles in the early eye morphogenesis during mouse embryogenesis in vitro. The loss of function phenotype after nucleolin knockdown was demonstrated by the absence of early optic vesicles with normal neural tube in the developing mouse embryos. Ectopic optic vesicle in developing mouse embryo was resulted under overexpression of Ncl . With the aim to study the biological roles of Ncl in mouse embryonic eye development in vivo, both conventional and conditional knockout techniques were attempted. The expression and functional studies revealed that a new neural tube independent signaling pathway regulated in the induction and formation of optic vesicles in the early eye formation. / Tang, Ling Yin. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3294. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 138-146). / 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.

Lam Tsz Yan. / Thesis submitted in: October 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract (English) --- p.i / 論文摘要 --- p.iv / Acknowledgements --- p.vi / Publications --- p.vii / Abbreviations --- p.ix / Contents --- p.x / Chapter 1. --- General Introduction --- p.1 / Chapter 1.1. --- Obesity --- p.1 / Chapter 1.1.1. --- Overview --- p.1 / Chapter 1.1.2. --- Pathophysiology --- p.1 / Chapter 1.1.3. --- Central obesity --- p.3 / Chapter 1.2. --- Diabetes --- p.7 / Chapter 1.2.1. --- Overview --- p.7 / Chapter 1.2.2. --- Pathophysiology --- p.8 / Chapter 1.3. --- Lipolysis --- p.9 / Chapter 1.3.1. --- Proteins participating in triglyceride lipolysis --- p.10 / Chapter 1.3.1.1. --- Hormone-sensitive lipase (HSL) --- p.10 / Chapter 1.3.1.2. --- Adipose triglyceride lipase (ATGL) --- p.10 / Chapter 1.3.1.3. --- Perilipins --- p.11 / Chapter 1.3.2. --- Abnormal regulation of lipolysis in obesity --- p.11 / Chapter 1.3.3. --- Disturbed lipolysis in insulin resistance --- p.13 / Chapter 1.4. --- Pharmacotherapy --- p.13 / Chapter 1.4.1. --- Obesity --- p.13 / Chapter 1.4.1.1. --- Orlistat --- p.13 / Chapter 1.4.1.2. --- Sibutramine --- p.14 / Chapter 1.4.1.3. --- Others --- p.15 / Chapter 1.4.2. --- Diabetes --- p.15 / Chapter 1.4.2.1. --- Modulation of the β-cells functions --- p.15 / Chapter 1.4.2.2. --- Control of glucose output --- p.16 / Chapter 1.4.2.3. --- Modulation of carbohydrate absorption --- p.16 / Chapter 1.4.2.4. --- Thiazolidinediones (TZDs) --- p.16 / Chapter 1.5. --- Animal models used in type 2 diabetes and obesity research --- p.17 / Chapter 1.6. --- Aim of study --- p.18 / Chapter 2. --- β-Adrenoceptors (β-ARs) --- p.21 / Chapter 2.1. --- Introduction --- p.21 / Chapter 2.1.1. --- Hormonal control of lipolysis --- p.21 / Chapter 2.1.1.1. --- Catecholamines --- p.21 / Chapter 2.1.1.2. --- Insulin --- p.23 / Chapter 2.1.2. --- Folic acid (folate) --- p.23 / Chapter 2.1.2.1. --- Physiological roles of folate --- p.23 / Chapter 2.1.2.2. --- Folate deficiency and its consequences --- p.24 / Chapter 2.1.2.3. --- Hyperhomocysteinemia --- p.24 / Chapter 2.1.2.4. --- Pleiotropic effects of folate --- p.25 / Chapter 2.1.2.5. --- Role of folate in type 2 diabetes and obesity --- p.26 / Chapter 2.1.3. --- Lingzhi --- p.28 / Chapter 2.1.3.1. --- Triterpenoids --- p.29 / Chapter 2.1.3.2. --- Polysaccharides --- p.30 / Chapter 2.2. --- Materials and methods --- p.32 / Chapter 2.2.1. --- Materials --- p.32 / Chapter 2.2.1.1. --- Composition of physiological salt solution --- p.32 / Chapter 2.2.1.2. --- Materials used in lipolysis experiment --- p.32 / Chapter 2.2.1.3. --- Materials used in reverse transcription polymerase chain reaction (RT-PCR) --- p.34 / Chapter 2.2.1.4. --- Materials used in Western blotting --- p.34 / Chapter 2.2.2. --- Methods --- p.36 / Chapter 2.2.2.1. --- Lipolysis experiment --- p.36 / Chapter 2.2.2.1.1. --- Animals --- p.36 / Chapter 2.2.2.1.2. --- Drug administration --- p.36 / Chapter 2.2.2.1.3. --- Isolation of adipocytes --- p.37 / Chapter 2.2.2.1.4. --- Lipolysis measurement --- p.37 / Chapter 2.2.2.1.5. --- Data analysis --- p.38 / Chapter 2.2.2.2. --- RT-PCR --- p.38 / Chapter 2.2.2.2.1. --- Tissue preparation --- p.39 / Chapter 2.2.2.2.2. --- RNA extraction --- p.39 / Chapter 2.2.2.2.3. --- Reverse transcription (RT) --- p.40 / Chapter 2.2.2.2.4. --- Polymerase chain reaction (PCR) --- p.40 / Chapter 2.2.2.2.5. --- Agarose gel electrophoresis --- p.41 / Chapter 2.2.2.2.6. --- Data representation and analysis --- p.41 / Chapter 2.2.2.3. --- Western blotting --- p.42 / Chapter 2.2.2.3.1. --- Tissue preparation --- p.42 / Chapter 2.2.2.3.2. --- Protein extraction --- p.42 / Chapter 2.2.2.3.3. --- Western blotting --- p.42 / Chapter 2.2.2.3.4. --- Data representation and analysis --- p.43 / Chapter 2.3. --- Results --- p.43 / Chapter 2.3.1. --- Studies on the β-adrenoceptor-mediated lipolytic response in +m/+db and +db/+db mice --- p.43 / Chapter 2.3.1.1. --- Effect of β2-adrenoceptor agonist on lipolysis --- p.43 / Chapter 2.3.1.2. --- Effect of β3-adrenoceptor agonists and their antagonists on lipolysis --- p.44 / Chapter 2.3.1.3. --- Effect of non-selective β-adrenoceptor agonists and their antagonists on lipolysis --- p.45 / Chapter 2.3.1.4. --- Effect of modulators of intracellular cyclic nucleotide monophosphate on lipolysis --- p.46 / Chapter 2.3.1.5. --- Effect of exogenously delivered nitric oxide on lipolysis --- p.47 / Chapter 2.3.1.6. --- Gene expression of β-adrenoceptors in white adipose tissue --- p.47 / Chapter 2.3.1.7. --- Protein expression of β-adrenoceptors in white adipose tissue --- p.47 / Chapter 2.3.2. --- Effect of folic acid treatment on lipolysis --- p.48 / Chapter 2.3.2.1. --- Determination of body weight --- p.48 / Chapter 2.3.2.2. --- Effect of β2-adrenoceptor agonist on lipolysis --- p.48 / Chapter 2.3.2.3. --- Effect of β-adrenoceptor agonists on lipolysis --- p.49 / Chapter 2.3.2.4. --- Effect of non-selective β-adrenoceptor agonist on lipolysis --- p.50 / Chapter 2.3.2.5. --- Effect of modulators of intracellular cyclic nucleotide monophosphate on lipolysis --- p.51 / Chapter 2.3.2.6. --- Effect of exogenously delivered nitric oxide on lipolysis --- p.52 / Chapter 2.3.2.7. --- Gene expression of β-adrenoceptors in white adipose tissue --- p.52 / Chapter 2.3.2.8. --- Protein expression of β-adrenoceptors in white adipose tissue --- p.53 / Chapter 2.3.3. --- Effect of Lingzhi (water-extract) treatment on lipolysis --- p.54 / Chapter 2.3.3.1. --- Determination of body weight --- p.54 / Chapter 2.3.3.2. --- Lipolytic effect of forskolin --- p.54 / Chapter 3. --- Peroxisome Proliferator-Activated Receptor-y (PPAR-γ) --- p.91 / Chapter 3.1. --- Introduction --- p.91 / Chapter 3.1.1. --- Peroxisome proliferator-activated receptors --- p.91 / Chapter 3.1.1.1. --- Peroxisome proliferator-activated receptor-γ --- p.91 / Chapter 3.1.1.1.1. --- "PPAR-γ in obesity, lipid metabolism and type 2 diabetes" --- p.91 / Chapter 3.1.1.1.2. --- PPAR-γ in inflammation and atherosclerosis --- p.92 / Chapter 3.1.1.2. --- PPAR-γ and thiazolidinediones --- p.93 / Chapter 3.2. --- Materials and method --- p.95 / Chapter 3.2.1. --- Materials --- p.95 / Chapter 3.2.1.1. --- Composition of physiological salt solution --- p.95 / Chapter 3.2.1.2. --- Materials used in lipolysis experiment --- p.95 / Chapter 3.2.1.3. --- Materials used in RT-PCR --- p.95 / Chapter 3.2.1.4. --- Materials used in Western blotting --- p.95 / Chapter 3.2.2. --- Methods --- p.96 / Chapter 3.2.2.1. --- Lipolysis experiment --- p.96 / Chapter 3.2.2.2. --- RT-PCR --- p.96 / Chapter 3.2.2.3. --- Western blotting --- p.97 / Chapter 3.3. --- Results --- p.97 / Chapter 3.3.1. --- Effect of PPAR-γ agonists on lipolysis --- p.97 / Chapter 3.3.2. --- Gene expression of PPAR-γ in white adipose tissue --- p.97 / Chapter 3.3.3. --- Protein expression of PPAR-γ in white adipose tissue --- p.97 / Chapter 4. --- 3-Hydoxy-3-MethylgIutaryl Coenzyme A (HMG-CoA) Reductase --- p.106 / Chapter 4.1. --- Introduction --- p.106 / Chapter 4.1.1. --- Cholesterol metabolism and cardiovascular diseases --- p.106 / Chapter 4.1.2. --- Statins --- p.106 / Chapter 4.1.2.1. --- Modes of action --- p.107 / Chapter 4.1.2.2. --- Therapeutic efficacy of statins --- p.108 / Chapter 4.1.2.2.1. --- Diabetes --- p.108 / Chapter 4.1.2.2.2. --- Coronary artery disease --- p.109 / Chapter 4.1.3. --- Distribution and expression of HMG-CoA reductase --- p.109 / Chapter 4.2. --- Materials and method --- p.110 / Chapter 4.2.1. --- Materials --- p.110 / Chapter 4.2.1.1. --- Composition of physiological salt solution --- p.110 / Chapter 4.2.1.2. --- Materials used in lipolysis experiment --- p.110 / Chapter 4.2.1.3. --- Materials used in RT-PCR --- p.110 / Chapter 4.2.1.4. --- Materials used in Western blotting --- p.110 / Chapter 4.2.2. --- Methods --- p.110 / Chapter 4.2.2.1. --- Lipolysis experiment --- p.110 / Chapter 4.2.2.2. --- RT-PCR --- p.111 / Chapter 4.2.2.3. --- Western blotting --- p.111 / Chapter 4.3. --- Results --- p.112 / Chapter 4.3.1. --- Effect of statins on lipolysis --- p.112 / Chapter 4.3.2. --- Gene expression of HMG-CoA reductase in various internal organs --- p.112 / Chapter 4.3.3. --- Protein expression of HMG-CoA reductase in various internal organs --- p.113 / Chapter 5. --- Discussion --- p.122 / Chapter 5.1. --- β-adrenoceptor-mediated lipolysis --- p.122 / Chapter 5.2. --- Studies on peroxisome proliferator-activated receptor-γ --- p.140 / Chapter 5.3. --- Studies on HMG-CoA reductase --- p.142 / Chapter 5.4. --- Further studies --- p.147 / Chapter 5.5. --- Conclusions --- p.148 / Chapter 6. --- References --- p.152

Chiu, Wang Kei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 95-110). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Contents --- p.v / Acknowledgements --- p.viii / Abbreviations --- p.ix / List of tables --- p.xii / List of figures --- p.xii / Chapter 1. --- Literature Review --- p.1 / Chapter 1.1 --- Cell cycle and chromosome replication --- p.1 / Chapter 1.2 --- Telomere-associated proteins --- p.4 / Chapter 1.3 --- Telomere repair protein --- p.6 / Chapter 1.4 --- Function of telomere --- p.9 / Chapter 1.5 --- Telomerase --- p.10 / Chapter 1.6 --- Factors affecting telomere length --- p.14 / Chapter 1.7 --- Stress and telomere length --- p.14 / Chapter 1.8 --- Definition of Stress --- p.16 / Chapter 1.9 --- Central nervous system components involved in stress response --- p.17 / Chapter 1.10 --- Glucocorticoid --- p.17 / Chapter 1.11 --- Physiological effects under the activation of stress system --- p.19 / Chapter 1.12 --- Effects of chronic hyperactivation of the stress system --- p.20 / Chapter 1.13 --- Hypothesis --- p.23 / Chapter 2. --- Materials and Methods --- p.24 / Chapter 2.1 --- Materials --- p.24 / Chapter 2.2 --- Experiment animals --- p.25 / Chapter 2.3 --- Methods --- p.26 / Chapter 2.3.1 --- Treatment schedule --- p.26 / Chapter 2.3.2 --- Organ extraction and serum preparation --- p.27 / Chapter 2.4 --- Serum corticosteroid assay --- p.27 / Chapter 2.5 --- Telomere length assay --- p.30 / Chapter 2.5.1 --- Genomic DNA extraction --- p.30 / Chapter 2.5.2 --- Genomic DNA digestion --- p.31 / Chapter 2.5.3 --- Southern blotting procedure --- p.32 / Chapter 2.6 --- Telomeric Repeat Amplification Protocol (TRAP) assay --- p.37 / Chapter 2.6.1 --- Extract preparation and protein concentration quanititation --- p.38 / Chapter 2.6.2 --- Real-time PCR reaction --- p.39 / Chapter 2.6.3 --- Melt Curve --- p.41 / Chapter 2.7 --- Detection of mouse telomerase reverse transcriptase component (mTERT) mRNA expression by reverse transcriptase- polymerase chain reaction (RT-PCR) --- p.42 / Chapter 2.7.1 --- Total RNA extraction --- p.42 / Chapter 2.7.2 --- RT-PCR --- p.44 / Chapter 2.7.3 --- Agarose gel electrophoresis of RT-PCR products --- p.45 / Chapter 2.8 --- Detection of mouse TERT (mTERT) by Western blotting --- p.46 / Chapter 2.8.1 --- Nuclear protein extraction --- p.46 / Chapter 2.8.2 --- Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) --- p.47 / Chapter 2.9 --- Statistics --- p.49 / Chapter 3. --- Results --- p.51 / Chapter 3.1 --- Body and spleen weights of study animals --- p.51 / Chapter 3.2 --- Serum corticosterone level --- p.54 / Chapter 3.3 --- Telomere lengths of spleen --- p.54 / Chapter 3.4 --- Telomerase activity of spleen tissue --- p.58 / Chapter 3.5 --- Correlation between serum corticosterone level and telomere length --- p.65 / Chapter 3.6 --- Correlation between serum corticosterone level and telomerase activity --- p.66 / Chapter 3.7 --- Correlation between telomere length and telomerase activity --- p.67 / Chapter 3.8 --- Detection of telomerase reverse transcriptase component (mTERT) mRNA expression by RT-PCR --- p.69 / Chapter 3.9 --- Detection of mTERT by Western blotting --- p.72 / Chapter 3.10 --- Correlation between serum corticosterone level and mTERT mRNA /protein expression --- p.75 / Chapter 4. --- Discussion --- p.77 / Chapter 4.1 --- Serum corticosterone level in mice --- p.78 / Chapter 4.2 --- Mice body weight and spleen weight --- p.80 / Chapter 4.3 --- Telomere lengths in the spleen tissue --- p.83 / Chapter 4.4 --- Telomerase activity in spleens --- p.84 / Chapter 4.5 --- Correlation between serum corticosterone level and telomere length --- p.87 / Chapter 4.6 --- Correlation between serum corticosterone level and telomerase activity --- p.89 / Chapter 4.7 --- Mouse telomerase reverse transcriptase component (mTERT) mRNA expression --- p.89 / Chapter 4.8 --- Expression of mTERT protein --- p.90 / Chapter 4.9 --- Conclusion --- p.92 / Chapter 5. --- References --- p.95 / Chapter 6. --- Appendix --- p.111

Orientador: Jean Leandro dos Santos / Banca: Chung, Man Chin / Banca: Simone Kashima Haddad / Resumo: A reativação da expressão gênica de gama-globina e consequente produção de hemoglobina fetal (HbF) por mecanismos epigenéticos é uma valiosa intervenção terapêutica na anemia falciforme. Estudos recentes mostram que a inibição da enzima Histona Deacetilase (HDAC), principalmente HDAC-1 e HDAC-2, mostrou ser uma estratégia promissora em promover o aumento da expressão gênica de gama-globina e a produção de HbF sem causar alteração no ciclo e proliferação celular. Neste trabalho foram planejadas por modelagem molecular novos compostos inibidores de HDAC 1 e 2. Os estudos de ancoragem molecular revelaram a forma como estes compostos interagem com a HDAC-2, sendo a subunidade N-(2-aminofenil)benzamida responsável por interagir com o átomo de zinco presente no sítio ativo. Durante o processo de otimização das estruturas, os valores de docking score passaram de -9,8 para - 12,3, indicando melhores interações com o receptor. Onze compostos inéditos foram sintetizados e caracterizados por métodos analíticos. Os estudos enzimáticos mostraram atividade inibitória dos novos compostos variaram de 83 à 96% para HDAC-1, 83 à 94% para HDAC-2 e 82 à-89% para HDAC-3. O composto (22) (4-(4-aminofenetil)-N-(2-aminofenil)benzamida) foi um dos mais ativos apresentando, na concentração de 10 μM, atividade inibitória contra as HDACs 1 e 2 com valores superiores a 90%. Estes resultados mostram que os compostos planejados neste trabalho são potenciais inibidores de HDAC, sendo a molécula (22) a mais ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Reactivation of gamma-globin gene expression and fetal hemoglobin (HbF) production through epigenetic mechanisms are valuable strategy to sickle cell anemia treatment. Early studies have demonstrated that histone deacetylase inhibition, especially HDAC-1 and HDAC-2, is a promising strategy to increase gamma-globin gene expression and HbF production without alteration in cell cycle or cell proliferation. At this work it was designed, by molecular modeling, new compounds HDAc 1 and 2 inhibitors. The molecular modeling studies has demonstrated how these compounds interacts with HDAC-2, being the subunit N-(2-aminophenyl)benzamide responsible for interact with the zinc atom of active site. During the optimization process, the docking score values hava changed from -9,8 to -12,3, which indicates better interactions with the receptor. It was synthesized and characterized eleven new compounds. Enzimatic assays have demonstrated that the enzymatic inhibition of the compounds varied from 83 to 96% against HDAC 1, 83-94% against HDAC 2 and 82-89% of HDAC 3. Compound (22) (4-(4-aminophenetyl)-N-(2-aminophenyl) benzamide was one of the most promisor among all compounds. At 10uM it was able to inhibit HDAC 1 and 2 more than 90%. These data has demonstrated that the design compounds in this work are potencial inhibitors of HDAC, being...(Complete abstract click electronic access below) / Mestre

Title from PDF of title page. / Document formatted into pages; contains 18 pages. / Thesis (Au.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This study examined the effects of genetic background on the acoustic startle response (ASR) and its modulation by prepulse inhibition (PPI) by comparing nine inbred strains of mice. The ASR, a jerk-like motor reflex, is elicited by bursts of noise or tones with sound pressure levels of 80-90 dB and greater. PPI is a type of modulation of the ASR, requires no training, and results in observable response in both mice and humans. Data were obtained from nine inbred mouse strains, sixteen per strain, which were shipped at approximately 3-5 weeks old from The Jackson Laboratory. In general, ASRs were generally smaller when the startle stimulus was less intense. PPI was relatively weak for the 4 kHz prepulse, and stronger with prepulses of 12 kHz and 20 kHz. However, means varied widely across strains for both ASR and PPI, suggesting a strong influence of genetic background on these behaviors. / ABSTRACT: In addition to genetic influences, peripheral hearing loss and central auditory processing factors must be taken into consideration. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Doctorat en sciences psychologiques / info:eu-repo/semantics/nonPublished

MSCAGR (Animal Science) / Department of Animal Science / This study determined the effects of in vitro culture media (Ham’s F10 and TCM199) and assisted hatching techniques (laser or mechanical) on mice embryo survival following cryopreservation. Pure strain C57BL/6 (B6) female (50) and strain BALB /c (C) Male (25) mice were crossed to produce F1 generation of females which were injected for follicular growth and super ovulation at 6 weeks of age and from which embryos were produced 21 h later through in vivo fertilization. Embryos were randomly divided into Petri dishes with different culture media, and the development of embryos was assessed until the morula stage. At the morula stage, selected embryos were assisted to hatch using different techniques, and then cryopreserved in liquid nitrogen using the slow freezing method for a period of 1 week. After 1 week of cryopreservation, the embryos were thawed and cultured in the two different in vitro culture media for 72 hours. Thereafter, the numbers of embryos hatched or survived were recorded after 24 h, 48 h and 72 h. Data was analyzed using ANOVA in Minitab Software Version 16 (2010). Significant difference in embryo quality development was observed between in vitro culture media and stage of embryo development (P<0.05). In the TCM-199 in vitro culture medium, embryo quality development yielded 72, 69 and 69% from day 1 to day 3, while in Ham’s F10 embryo quality development yielded 68, 63 and 60% respectively. Relative to the control (18.1%) assisted hatching improved hatchability significantly (P<0.05) in the order laser (23.6%)>, mechanical (20.8%). There was significant (P<0.01) interaction between assisted hatching techniques and evaluation time, whereby laser assisted hatching was most successful at 48 h (42.0%) while mechanical assisted hatching was most successful at 72 h (36.8%). Cryopreservation reduced the embryo survival compared to fresh embryos. In conclusion laser was the best assisted hatching technique, while TCM-199 was the better medium for in vitro culture of embryo. / NRF

Computational methods in neuroscience have advanced our understanding of neuronal regulation of motor behavior and locomotion and have been applied to identify encoding of behavioral features in circuits. The cerebellum has an established role in sensorimotor processing during coordinated movements, referred to as the “head ganglion of the proprioceptive system” (Sherrington, 1906). Increasing evidence also highlights its role in the processing of behaviorally meaningful stimuli that have the potential of guiding adaptative movements relevant to the task and priming downstream targets for action. Yet the extent to which these diverse encodings of signals in complex motor tasks are present in the cerebellar nuclei and their influence on behavior remains unknown. To shed new light on the role of this subcortical region using computational approaches, this thesis begins with an introduction that reviews the circuity of the mammalian cerebellum, highlights its proposed functions in motor behavior, and explores our understanding of its role in locomotion. In the first chapter, I analyze electrophysiological recordings from cerebellar nuclei in a locomotor obstacle avoidance task in mice that involves a rich and diverse set of task relevant features. Given the complexity of and correlations between the behavioral features, statistical modeling is required to attribute the firing rates to the correct combinations. This model enables identifying the encoding of these signals and reporting on the prevalence and degree to which they are present across individual cells in the nuclei. Additionally, this model allows investigation into the encoding of groups of cells that are selective for specific features. Chapter 2 uses network modeling to generate hypotheses about population level activity in two cortical areas, the primary and supplementary motor areas, and differentiate their computations in monkeys performing a cycling task. Finally, in chapter 3 I concentrate on a specific class of recurrent network models in the balanced state and investigate the linkage between connectivity distribution and firing sparsity, which has the potential to further our understanding on the emergence of feature selectivity in excitatory/inhibitory circuits.

Characterizing the cortical representation of sweet and bitter tastes in awake behaving mice has been challenging due to the sheltered location of the gustatory cortex in the insula, which restricts optical and electrophysiological recordings, and the various functions of the insula, complicating conclusions about taste representation. To overcome these obstacles, we developed a brain-wide imaging paradigm that combines functional magnetic resonance imaging (fMRI) with optogenetic and taste receptor knock-out manipulations in mice. This approach allowed us the study the gustatopic map in awake, behaving mice, showing that sweet and bitter tastes are topographically segregated along the rostro-caudal axis of the gustatory cortex, with sweet represented rostrally and bitter caudally. Notably, this map is subject to plasticity following conditioned taste aversion (CTA) for sweet stimuli, resulting in a posterior shift of the sweet taste field—a phenomenon reversible after CTA extinction.