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Specification Of V2b And Ka Neurons In The Zebrafish Spinal Cord., Liwia Anna Andrzejczuk

Dissertations - ALL

Spinal cord contains different types of neurons. A vast majority of these neurons are interneurons. Therefore, a better understanding of how interneurons in the spinal cord develop is particularly important, as it will hopefully enable researchers to establish better treatments for spinal cord injury patients. In this thesis, I used zebrafish to study development of two classes of spinal cord neurons - KA cells (which correspond to cerebrospinal fluid-contacting neurons, CSF-cNs) and V2b cells. Both KA and V2b neurons are functionally important in vertebrate locomotor circuitry.

Development of functional neurons involves progression of genetic cascades that lead to correct cell …

Ethanol Exposure During Synaptogenesis In A Mouse Model Of Fetal Alcohol Spectrum Disorders: Acute And Long-Term Effects On Gene Expression And Behaviour, Morgan L. Kleiber

Electronic Thesis and Dissertation Repository

Alcohol is a neuroactive molecule that is able to exert variable and often detrimental effects on the developing brain, resulting in a broad range of physiological, behavioural, and cognitive phenotypes that characterize ‘fetal alcohol spectrum disorders’ (FASD). Factors affecting the manifestation of these phenotypes include alcohol dosage, timing of exposure, and pattern of maternal alcohol consumption; however, the biological processes that are vulnerable to ethanol at any given neurodevelopmental stage are unclear, as is how their disruption results in the emergence of specific pathological phenotypes later in life.

The research included in this thesis utilizes a C57BL/6J (B6) mouse model …

The Role Of Connexins And Pannexins In Mammary Gland Development And Tumorigenesis, Michael K. G. Stewart

Electronic Thesis and Dissertation Repository

The identification of key regulators of breast cancer onset and progression is critical for the development of targeted therapies. Connexins and pannexins are characterized by their ability to form large-pore channels and are frequently dysregulated in cancer. However, their role in breast cancer progression remains poorly understood due to a lack of in vivo models capable of assessing the proposed and opposing roles of connexins and pannexins as both tumor suppressors and/or facilitators in multiple stages of the disease. Using 2 previously uncharacterized genetically-modified mice, connexin43 (Cx43) and connexin26 (Cx26) were evaluated for their role in normal mammary gland development …

Evolutionary Developmental Leaf Morphology Of The Plant Family Araceae, Claudia Liliana Henriquez

Arts & Sciences Electronic Theses and Dissertations

Studying the evolutionary developmental morphology of leaves using next-generation phylogenetics, a candidate gene approach and comparative developmental studies in the plant family Araceae is the overarching theme of the dissertation.

The plant family Araceae is an ancient lineage from the Early Cretaceous and belongs to the monocotyledons. Members of Araceae display striking variation in leaf development; such variation contradicts traditional models of monocot leaf development. Additionally, dissected leaves, which are rare in monocots, seem to have evolved independently multiple times in Araceae by various developmental mechanisms.

Despite extensive efforts to elucidate the evolutionary history of Araceae, phylogenetic ambiguity in the …

Microengineering The Neural Tube, Christopher Demers

Electronic Theses and Dissertations

Early embryonic development is a complex and highly regulated orchestra of instructive cues that collectively guide naïve stem cells towards progressively more specialized fates. In the neural tube, the precursor structure to the brain and spinal cord, these signals emanate from ‘organizing centers’ surrounding the neural tube. These organizing centers send out soluble cues or morphogens that diffuse tens to hundreds of microns to recipient cells residing in the neural tube. Re-creating this dynamic landscape of cues in vitro is impossible using standard cell culture tools and techniques. However, microfluidics is perfectly suited to fill this gap, allowing precise control …

In Vivo Significance Of The Mdm4 And P73 Interaction During Development And Tumorigenesis, Mehrnoosh Tashakori

Dissertations & Theses (Open Access)

The tumor suppressor protein p53 is negatively regulated by Mdm4 protein. The significance of such regulation was determined from mouse models. Mdm4-deficient mice are embryonic lethal at E7.5 in a p53-dependent manner. p73, a member of the p53-family, is a transcription factor with tumor suppressor activity. In vitro studies show that Mdm4 binds to p73 and, further, comprehensive biochemical studies revealed that Mdm4 has higher affinity for p73 than p53. However, little is known about the significance of the Mdm4 and p73 interaction in vivo. This study aimed to elucidate the biological consequences of this interaction during embryogenesis …

How Gains And Losses Influence The Brain And Behavior: Relations To Age, Risk For Depression, And Individual Differences, Katherine R. Luking

Arts & Sciences Electronic Theses and Dissertations

Behavioral and neural response to rewards and punishments has been the subject of a growing literature with particular interest within developmental, psychopathology, and individual difference domains. There is now mounting evidence suggesting that adolescents show heightened response to reward relative to adults, and that adolescents with Major Depressive Disorder (MDD), elevated depressive symptoms, or at high-risk for depression show reduced response to reward. However, it is unclear whether similar relations between response to incentives and development/psychopathology are observed during childhood. Here we examine behavioral, neural (functional magnetic resonance imaging - fMRI), and self-reported responsiveness to gain and loss of rewards …

Effects Of The Developmental Environment On Oxidative Damage And Antioxidants In Red-Eared Slider Turtle ( Trachemys Scripta Elegans ) Hatchlings, Lisa Allison Treidel

Theses and Dissertations

Developmental environments influence many individual phenotypes. However, currently we have a limited understanding of how the developmental environment influences oxidative stress resistance phenotypes. Oxidative stress is defined as a physiological state during which the production of harmful free radicals exceeds the protective capabilities of antioxidants. Variations among adults in susceptibility to oxidative stress can have important consequences for life history strategies and fitness related traits. Our work was aimed at providing insight in to the role that the developmental environment plays on oxidative stress phenotypes in the model oviparous reptile the red-eared slider turtle (Trachemys scripta elegans). Here, we conducted …

Role Of Non-Muscle Myosin Ii And Calcium In Zebrafish Midbrain-Hindbrain Boundary Morphogenesis, Srishti Upasana Sahu

Theses and Dissertations

Elucidating the molecular mechanisms that play a role in cellular morphogenesis is critical to our understanding of brain development and function. The midbrain-hindbrain boundary (MHB) is one of the first folds in the vertebrate embryonic brain and is highly conserved across species. We used the zebrafish MHB as a model for determining the molecular mechanisms that regulate these cell shape changes. Cellular morphogenesis is tightly regulated by signaling pathways that rearrange the cytoskeleton and produce mechanical forces that enable changes in cell and tissue morphology. The generation of force within a cell often depends on motor proteins, particularly non-muscle myosins …

The Effects Of Propofol, Sodium Pentobarbital, And Ketamine Hydrochloride On In Vitro Mouse Embryonic Development, Tyler C. Balak

Theses and Dissertations in Biomedical Sciences

Every year more than 75,000 pregnant women are exposed to teratogenic medications or general anesthesia during non-obstetric surgery in the US,1-4 and embryonic effects of general anesthesia are of particular interest in laboratory research and veterinary medicine. The mouse system is used to screen potential toxic effects of anesthetics used in egg retrieval for in vitro fertilization (IVF), or those of pharmacologic agents which may come in contact with the egg or early embryo. Mouse preimplantation 2-cell embryos were exposed in vitro to incremental concentrations of common general anesthetics within and exceeding the normal clinical dosage range for mice (propofol …

The Neurophysiology Of Intersensory Selective Attention And Task Switching, Jeremy W. Murphy

Dissertations, Theses, and Capstone Projects

Our ability to selectively attend to certain aspects of the world and ignore others is fundamental to our day-to-day lives. The need for selective attention stems from capacity limitations inherent in our perceptual and cognitive processing architecture. Because not every elemental piece of our environment can be fully processed in parallel, the nervous system must prioritize processing. This prioritization is generally referred to as selective attention. Meanwhile, we are faced with a world that is constantly in flux, such that we have to frequently shift our attention from one piece of the environment to another and from one task to …

Analyzing The Interactions Of Kdm5/Lid And Sin3 In Drosophila Melanogaster, Ambikai Gajan

Wayne State University Dissertations

SIN3, the scaffold protein of a histone modifying complex is conserved from yeast to mammals. Drosophila SIN3 associates with both a histone deactylase RPD3 and a histone demethylase dKDM5/LID. Immunopurification of dKDM5/LID verifies a previously observed interaction with SIN3 and RPD3. Furthermore, deficiency of dKDM5/LID phenocopies deficiency of SIN3 in many cellular and developmental processes. Knockdown of both Sin3A and lid hinder cell proliferation in Drosophila cultured cells and developing flies. Knockdown of these genes also results in a curved wing phenotype implicating a role in wing development. Analysis of underlying gene expression changes upon decreased expression of SIN3, dKDM5/LID …

Impact Of Development On Freshwater Turtle Populations Of Coastal South Carolina: An Examination Of Land Use And Road Density, Andre Dominguez

Electronic Theses and Dissertations

Previous studies (Haxon 2000; Steen and Gibbs 2004; Marchand and Litvaitis 2004; Aresco 2005) have demonstrated that urbanization and development have disproportionally adverse affects on female turtles. In order to test this paradigm I caught 301 turtles (primarily Trachemys scripta scripta) in ten ponds (5 impacted and 5 unimpacted) across coastal South Carolina. Not only do coastal South Carolina turtles not follow the same male biased pattern of many other studies, there was an overall female bias (154:95). Turtle metrics were between the types of sites existed as well, indicating larger/older population of turtles in unimpacted sites. Water quality parameters …

Effects Of Benzo[A]Pyrene And Cyp19a1b Knockdown On Zebrafish Development, Khalid M. Alharthy

Electronic Theses and Dissertations

Benzo[a]pyrene (BaP) is a ubiquitous environmental contaminant that is both an endocrine disruptor and a carcinogen. Aromatase (CYP19) is a key enzyme in steroidogenesis playing a key role in the hypothalamus-pituitary-gonad feedback loop. We hypothesized that BaP would negatively impact cyp19a1b expression in zebrafish, in turn, adversely affecting development and physiology. Here, we consider whether the toxicities observed following BaP exposure are comparable to those following a transient morpholino (MO)-mediated CYP19a1b knockdown or exposure to an aromatase inhibitor (fadrozole) during early development. One-cell zebrafish embryos were injected with a CYP19a1b-MO or control-MO. Other non-injected embryos were exposed to nominal waterborne …

Developing A Gene Editing System To Study Haplodiploidy In The Jewel Wasp, Nasonia Vitripennis, Emily A. Muller

Scripps Senior Theses

Hymenopteran insects, which include all ants, bees and wasps, reproduce through a poorly understood form of reproduction known as haplodiploidy. A promising experimental system for understanding this developmental process is the jewel wasp, Nasonia vitripennis. A critical aspect of using Nasonia as a model is establishing an effective means for editing specific genes of interest so that their functions can be studied through genetic means. For my thesis research, I performed a pilot study of the gene editing method known as CRISPR in Nasonia. I targeted the single heterochromatin protein 1 (HP1) gene present in the Nasonia genome …

Refinement Of Feedforward Projections, Neuronal Density, And Characterization Of Synapsesin Layer 4 Of Ferret Primary Visual Cortex, Violeta Contreras Ramirez

Dissertations and Theses

No abstract provided.

Temporal Localization Of Insulin-Like Growth Factor 1 (Igf1) Positive Cells In Developing Hypothyroid Brain, Shelby Anne Kline

All Graduate Theses, Dissertations, and Other Capstone Projects

Hypothyroidism has been known to result in numerous neuroanatomical defects in the developing brain. To investigate further into the mechanism in which these defects are obtained, local brain insulin-like growth factor 1 (Igf1) was investigated in relation to the hypothyroid brain. There are many similarities between hypothyroidism and the Igf1 deficient brain. Additionally, TH (thyroid hormone) is known to interact with Igf1. Therefore, the purpose of this study was to investigate the effect of induced congenital hypothyroidism on the temporal expression of Igf1-positive cells in the brain. To investigate the relationship between TH and Igf1 in the brain, we inhibited …

Sexual Behavior Of Immature Tibetan Macaques (Macaca Thibetana), Anne Salow, R. Steven Wagner, Mary Radeke, Joseph Lorenz

All Master's Theses

Tibetan macaque sociosexual behavior begins in infancy, and comprises many of their initial interactions with other group members as infants. Tibetan macaques possess a large sociosexual behavioral repertoire, including a behavior called bridging, which involves infants and juveniles, and is found in only four species. Immature macaques differ in the types, rate, and partner preferences across a variety of behaviors. This study compared rates of sexual behavior among four age and sex classes of 26 immature Tibetan macaques at Mt. Huangshan, China. A total of 643 sex behaviors were observed and evaluated for 5 parameters: total sex behavior rates, initiation …

Dual Functions For Insulinoma-Associated 1 In Retinal Development, Marie A. Forbes-Osborne

Theses and Dissertations--Biology

Proper visual system function requires tightly controlled proliferation of a pool of relatively homogeneous retinal progenitor cells, followed by the stepwise specification and differentiation of multiple distinct cell types. These retinal cells, both neuronal and glial, must be generated in the correct numbers, and the correct laminar location to permit the formation of synaptic connections between individual cell types. After synapses are made, constant signaling is required as part of normal retinal function, and to maintain cellular identity and connectivity. These processes rely on both extrinsic and intrinsic signaling, with regulation of gene expression by cascades of transcription factors having …