Life Sciences Commons^™

Changes In The Epigenetic Landscape Of Oligodendrocyte Progenitor Cells With Time, David K. Dansu

Dissertations, Theses, and Capstone Projects

Most neonatal oligodendrocyte progenitors (nOPCs) give rise to myelinating oligodendrocytes during development, while a proportion are retained as proliferative undifferentiated cells in the adult brain (aOPCs). Previous studies have reported distinct properties for those two populations but the molecular mechanisms underlying these intrinsic differences are not well understood. Using RNA-sequencing and unbiased histone proteomics analysis, we identify transcripts and histone marks that are higher in aOPCs than nOPCs. The genome-wide ChIP-sequencing analysis of chromatin from aOPCs compared to nOPCs detects greater occupancy of the H4K8ac mark at loci corresponding to the higher transcript levels of oligodendrocyte-specific transcription factors and lipid …

The Role Of Tbx2 In Germ Layer Suppression And Dorsoventral Patterning During Early Vertebrate Development, Shoshana Reich

Dissertations, Theses, and Capstone Projects

The differentiation of the three primary germ layers is precisely regulated by inductive cues, the intracellular networks through which these signals are transduced, and a broad array of nuclear proteins, such as transcription factors and epigenetic modifiers. Precise regulation of these various factors is crucial to proper development. Members of the T-box family of DNA-binding proteins play a prominent role in the differentiation of the three primary germ layers. VegT, Brachyury, and Eomesodermin function as transcriptional activators, are expressed in the presumptive mesendoderm and, in addition to directly activating the transcription of endoderm- and mesoderm-specific genes, serve variously as regulators …

Targeting Ampa Receptor Modulation During Early Life Adversity: A Mediator For Threat Associated Memories, Roseanna M. Zanca

Dissertations, Theses, and Capstone Projects

Early life adversity (ELA) is the exposure to a single or to multiple traumatic events before the age of 18 that go beyond the child’s coping. These adverse events are often exacerbated during adolescence particularly when cognitive performance is compromised. Adolescents who experienced ELA may show symptoms of post-traumatic stress disorder (PTSD), while not vividly recalling the early life trauma. These individuals show atypical connectivity between prefrontal-amygdala and hippocampus, all of which is associated with an increased risk of experiencing a traumatic event again later in life. While clinical research has increasingly stressed the importance in addressing the long-lasting consequences …

Dietary Development And Nutritional Ontogeny In Gorilla Beringei : A Multi-Layered, -Omics Approach, Emma C. Cancelliere

Dissertations, Theses, and Capstone Projects

In species who consume folivorous diets, immature individuals must contend with the challenges of extracting nutrients from fibrous foods before dietary adaptations and strategies are fully developed. Additionally, immatures have distinct nutritional needs to support their stage-specific metabolic and biophysiological requirements. To meet these stage-specific needs, while constrained by underdeveloped feeding strategies and digestive capacities, immatures may adopt distinct diets better suited to their specific developmental context. However, where dietary modification is constrained by low dietary diversity or landscape homogeneity, it is unclear how immature individuals compensate through alternative strategies. In turn, little is known about the nutritional and life …

The Inter-Subject Correlation Of Eeg In Response To Naturalistic Stimuli, Samantha S. Cohen

Dissertations, Theses, and Capstone Projects

Inter-subject correlation is a measure of the similarity of the brain activity of a group of people as they respond to the same naturalistic stimulus, typically a story or video, meant to simulate a real world experience. This thesis tests the hypothesis that the correlation of the brain responses of a group of people is indicative of stimulus engagement. The rationale is that the content of the stimulus drives brain activity in a consistent manner, while internal thoughts are divergent and result in uncorrelated activity. The inter-subject correlation (ISC) of neural responses have previously been assessed with fMRI, EEG, and …

The Role Of T-Box Proteins In Vertebrate Germ Layer Formation And Patterning, Sushma Teegala

Dissertations, Theses, and Capstone Projects

All of the tissues in triploblastic organisms, with the exception of the germ cells, arise from the three germ layers, ectoderm, mesoderm and the endoderm. The identification of the genes that underlie the differentiation of these layers is crucial to our understanding of development. T-box family proteins are DNA-binding transcriptional regulators that play important roles during germ layer formation in the early vertebrate embryo. Well-characterized members of this family, including the transcriptional activators Brachyury and VegT, are essential for the proper formation of mesoderm and endoderm, respectively. To date, T-box proteins have not been shown to play a role in …

Characterizing The Impacts Of Contaminants On Fish Embryogenesis And Revealing An Alternate Molecular Mechanism Of Ahr Mediated Cardiac Defects, Corinna Singleman

Dissertations, Theses, and Capstone Projects

There is a long history of damage to natural ecosystems from environmental pollution. Many environmental contaminants are man-made and have been released with abandon over the last 100 years including dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs). These chemicals act on similar cellular processes and cause skin lesions, cancer, learning disabilities and reproductive problems in many vertebrates. There are many studies exploring various aspects of TCDD and PCB exposure on model and wild organisms. Few studies however, have compared effects of PCB mixtures on ecosystems to effects of individual PCBs in the lab. The first aim of this thesis is …

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 …

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.

Age-Related Aspects Of Mirror-Use By Bottlenose Dolphins (Tursiops Truncatus), Rachel A. Morrison

Dissertations, Theses, and Capstone Projects

Bottlenose dolphins are neuroanatomically different and evolutionarily divergent from primates yet they exhibit mirror self-recognition (MSR), a rare cognitive ability in non-human animals. This research investigated the developmental and age-related aspects of MSR in this species. During a longitudinal study, a social group of bottlenose dolphins at the National Aquarium, Baltimore, MD were exposed to a mirror and their behavioral responses were recorded to: 1) further confirm the presence of MSR in this species, 2) determine the age of emergence of MSR and 3) draw comparisons with data documenting the emergence of this ability in humans and great ape species. …

Attention Shapes Our Expectations And Perceptions: The Neural Mechanisms Of Top-Down Attention During Adulthood And Development, Snigdha Banerjee

Dissertations, Theses, and Capstone Projects

Top-down attention is the focusing of attention at one's will through knowledge regarding a current task. There is evidence that top-down attention involves the modulation of sensory cortices by higher order regions. However, the mechanisms of top-down attention across sensory modalities, its influence on early sensory inputs, as well as interactions with motivational systems remain unclear. We performed the following set of electrophysiological experiments in typically developed adults and adolescents to examine these areas. 1) The supramodal attentional theory holds that parietally-based attentional mechanisms are shared across sensory modalities. We tested the supramodal theory by examining if lateralized parieto-occipital alpha-band …

Biological Motion Processing In Typical Development And In The Autism Spectrum, Aaron Krakowski

Dissertations, Theses, and Capstone Projects

Biological motion (BM) analysis and interpretation is a fundamental process of human neurocognition that has been only minimally explored neurophysiologically. In addition to its importance in understanding the underlying roots and development of social cognition, BM processing is a prime candidate domain for exploring the underlying etiology of social cognitive disorders such as the autism spectrum.

In an initial experiment, typical adults observed BM point-light displays of a human actor (UM) as well as their spatially scrambled counterparts (SM), in both an unattended distractor task as well as an explicit attention task. Results showed a neurophysiological response manifested as three …

Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson

Dissertations, Theses, and Capstone Projects

The genus Arctomecon (Papaveraceae) is comprised of three narrowly endemic rare species that are largely restricted to gypsum soils of the eastern Mojave Desert. The small, remaining populations of these species have become increasingly isolated by urban development and habitat fragmentation. Arctomecon humilis is federally listed as endangered due to its limited distribution within a ~15 km radius of an actively expanding city. Organizations involved with land management and conservation have called for greater insight into the genetic variation and population structure of the remaining subpopulations as they make important decisions regarding where to focus their efforts and resources.

The …

Glia-Mediated Neurodegeneration In The Drosophila Melanogaster Cns, Ivan J. Santiago

Dissertations and Theses

No abstract provided.

Anatomical Identification Of Primary Auditory Cortex In The Developing Gerbil, Luis Pendola

Dissertations and Theses

Cortical development is an active field of study. The gerbil provides an excellent model for research because at the moment of birth its brain is rather immature, anatomically and functionally. Furthermore, the gerbil auditory cortex is particularly amenable to investigation in that the gerbil's onset of hearing occurs approximately after 14 days of postnatal life. Despite these advantages of the gerbil for auditory cortex development not much is known about the anatomy of the postnatal gerbil auditory cortex. For example, where is the gerbil auditory cortex? Prior to the onset of hearing, sounds cannot be used to localize auditory cortex. …

The Development Of Hearing In Rats; Reliability Of Wave 1 As A Determinant Of Auditory Maturation And Contributions Of Peripheral Structure Progression, Aminat Saliu

Dissertations and Theses

No abstract provided.