Digital Commons Network^™

How The Manipulation Of The Ras Homolog Enriched In Striatum Alters The Behavioral And Molecular Progression Of Huntington’S Disease, Franklin A. Lee

University of New Orleans Theses and Dissertations

Huntington’s disease is an incurable, progressive neurological disorder characterized by loss of motor control, psychiatric dysfunction, and eventual dystonia leading to death. Despite the fact that this disorder is caused by a mutation in one single gene, there is no cure. The mutant Huntingtin (mHtt) protein is expressed ubiquitously throughout the brain but frank cell death is limited to the striatum. Recent work has suggested that Rhes, Ras homolog enriched in striatum, which is selectively expressed in the striatum, may play a role in Huntington’s disease neuropathology. In vitro studies have shown Rhes to be an E3 ligase for the …

The Feedforward And Feedback Controls On Gait In Adults With Diabetes, Chun-Kai Huang

Theses & Dissertations

There are nearly 26 million people with diabetes mellitus (DM) in the US, and half of chronic DMs develop somatosensory deficits due to diabetic polyneuropathy or diabetic peripheral neuropathy (DPN). The absence or impaired somatosensory feedback (e.g. touch sensation or joint proprioception) resulted from the damage of large nerve fiber, and motor deficits such as attenuated muscle strength and abnormal plantar pressure of lower extremity have been identified in DPN, and these sensorimotor impairments lead to an increased number of falls. To reduce the risk of falling, a well-coordinated and adapted limb movement driven by the feedforward (anticipatory) and feedback …

Serotonergic System And Gait: Dorsal Raphe Nucleus As A Control System For Gait, Nahal Farhani

Electronic Thesis and Dissertation Repository

In advanced stages of Parkinson Disease (PD), gait and postural abnormalities emerge. These symptoms are not prominent at early stages of PD despite significant dopaminergic neuronal loss. Gait abnormalities are largely not responsive to levodopa. Therefore, other types of neurons might be responsible for gait abnormalities of the PD.

Since the reticulospinal tract (RET) is mainly implicated in the control of axial muscles, the degeneration of this pathway or populations of neurons controlling this pathway might be responsible for axial symptoms. However, there is limited data about the neurons controlling the RET. Our aim in this study is to delineate …

Cardiovascular Regulation And Effects Of Respiratory Motor Training In Patients With Chronic Spinal Cord Injury., Bonnie Legg Ditterline

Electronic Theses and Dissertations

This dissertation attempts to discover the mechanisms between cardiovascular and respiratory motor control post spinal cord injury (SCI): in normal, non-injured (NI) persons, cardiovascular regulation is dependent upon respiration, but there is nothing that suggests the mechanism for this relationship post-SCI. Thus we hoped to evaluate various aspects of cardiovascular regulation to further illustrate how this relationship is changed or unchanged by SCI. Chapter I describes the anatomy and physiology of the spine, respiratory system, and cardiovascular system in a NI person, and then describes how the function of these systems is changed by SCI. In addition, we describe therapies …

Neurophysiological Activity Related To Speech Production: An Erp Investigation, Adithya Chandregowda

USF Tampa Graduate Theses and Dissertations

The event related potential (ERP) technique is enjoying widespread application in neurophysiological research due to its fine temporal resolution. Of relevance to this study are ERPs related to voluntary movements. The precision with which movement related processes could be recorded using the ERP technique was demonstrated by Gilden, Vaughan and Costa (1966) and Kutas and Donchin (1974, 1977, and 1980) who found that the readiness potential (RP) immediately preceding hand movement was larger over the hemisphere contralateral to the responding hand. Given that left hemisphere controls right hand movements and vice versa, their findings confirmed that the lateralized readiness potential …

An Animal Model Of Flashbulb Memory: Insights Into The Time-Dependent Mechanisms Of Memory Enhancement, Laura Ashley Bullard

USF Tampa Graduate Theses and Dissertations

The vivid memory of an emotional event, as well as memory for incidental details associated with the arousing event, has been referred to collectively as a “flashbulb memory”. An important aspect of flashbulb memory in people is that an emotional event enhances memory of contextual details, such as the weather, or clothes one was wearing at the time of the event. Therefore, an emotional event not only produces a detailed memory of the event, itself, but also enhances memory for contextual details that would otherwise not be remembered. The first goal of this work is to describe the development of …

Role Of The Slingshot-Cofilin And Ranbp9 Pathways In Alzheimer's Disease Pathogenesis, Jung A Woo

USF Tampa Graduate Theses and Dissertations

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by two major pathological hallmarks, amyloid plaques and neurofibrillary tangles. The accumulation of amyloid-β protein (Aβ) is an early event associated with synaptic and mitochondrial damage in AD. Therefore, molecular pathways underlying the neurotoxicity and generation of Aβ represent promising therapeutic targets for AD. Recent studies have shown that actin severing protein, Cofilin plays an important role in synaptic remodeling, mitochondrial dysfunction, and AD pathogenesis. However, whether Cofilin is an essential component of AD pathogenesis and how Aβ induced neurotoxicity impinges its signals to Cofilin are unclear.

In my dissertation studies, we …

“Principal Component Analysis And The Cumulative Gait Index: Translational Tools To Assess Gait Impairments In Rats With Olivocerebellar Ataxia”, Chase Lambert

USF Tampa Graduate Theses and Dissertations

Numerous studies suggest that modulation of the cholinergic system through the use of nicotinic agonists can improve motor function in humans or animals with motor disorders. Specifically, although there are no approved therapeutics for patients with ataxia, the nicotinic receptor agonist varenicline has demonstrated efficacy to improve coordination and gait in several groups of patients with different subtypes of ataxia. Importantly, the mechanism underlying the varenicline’s mechanism of action to improve motor function remains to be elucidated. Thus, the purpose of these experiments was to first quantify gait impairments in rats with olivocerebellar ataxia utilizing an objective treadmill-based system to …

A Neurobiological Pathway That Mediates Stress-Induced Drug Use, Oliver Vranjkovic

Dissertations (1934 -)

Cocaine addiction represents a tremendous health and financial burden on our society and the high rate of relapse to cocaine use in abstinent addicts represents a major barrier to effective therapy. Thus, understanding the factors that contribute to relapse and the underlying neurobiological processes is important for guiding the development of treatment for addiction. Stressful life events often trigger drug use in recovering addicts. The contribution of stress to drug use is problematic due to the unpredictable and often uncontrollable nature of stress. A growing literature indicates that norepinephrine and corticotropin releasing factor (CRF) in the brain play key roles …

The Relationship Of Spasticity And Impairments In Force Regulation And Neuromuscular Fatigue Post Stroke, Reivian Berrios Barillas

Dissertations (1934 -)

Hyperreflexia that causes muscle spasticity may contribute to limitations in force regulation and walking ability post stroke. Additionally, neuromuscular fatigue may reduce force regulation, which is important because fatigue can assist to strengthen muscles that control walking. Hyperreflexia may be caused by cortical disinhibition that allows Ia afferents to amplify excitatory synaptic inputs to motoneuron pools. Cortical disinhibition is presumably caused by stroke-related motor cortex damage. Although, other excitatory synaptic sources to motoneurons contribute to motor control, hyperreflexia may be one contributor that affects stroke survivors. However, hyperreflexia is reported infrequently to effect force regulation post stroke. The goal was …

Relationships Between Age And White Matter Integrity In Children With Phenylketonuria, Erika M. Wesonga

Arts & Sciences Electronic Theses and Dissertations

Objective: Phenylketonuria (PKU) is a hereditary metabolic disorder associated with cognitive compromise. Diffusion tensor imaging (DTI) has allowed detection of poorer microstructural white matter integrity in children with PKU, with decreased mean diffusivity (MD) in comparison with healthy children. However, very little research has been conducted to examine the trajectory of white matter development in this population. The present study investigated potential differences in the developmental trajectory of MD between children with early- and continuously-treated PKU and healthy children across a range of brain regions.

Methods: Children with PKU (n = 31, mean age = 12.2 years) were …

The Role Of Glutaminase 1 In Hiv-1 Associated Neurocognitive Disorders And In Brain Development, Yi Wang

Theses & Dissertations

Glutaminase is the enzyme that converts glutamine into glutamate, which serves as a key excitatory neurotransmitter and one of the energy providers for cellular metabolism. Glutamate is essential for proper brain functioning but at excess levels, it is neurotoxic and has a key role in the pathogenesis of various neurodegenerative diseases, including HIV-1 associated neurocognitive disorders (HAND). However, the detailed mechanism of glutamate-mediated neurotoxicity remains unclear. In part I, we identified the regulation of glutaminase 1 (GLS1) in the central nervous system (CNS) of HAND animal models including HIV-Tat transgenic (Tg) mouse and HIVE-SCID mouse, since GLS1 is the dominant …

Analyzing A-Series Gangliosides In Neurons Following Exposure To Glutamate, Dae Hee Park

Electronic Thesis and Dissertation Repository

Neurons within different brain regions have varying levels of vulnerability to external stress and therefore respond differently to injury. A potential reason to explain this may lie within a key lipid class of the cell’s plasma membrane called gangliosides. These glycosphingolipid species have been shown to play various roles in the maintenance of neuronal viability. The purpose of this study is to use electrospray ionization mass spectrometry (ESI-MS) technique and immunohistochemistry to evaluate the temporal changes in the expression profiles of various ganglioside species during the course of neurodegeneration in rat primary cortical neurons exposed to glutamate toxicity. Primary embryonic …

Metabolic Profiling Of Prions In The Gastro-Intestinal Tract, Uffaf Khan

Dissertations & Theses (Open Access)

Metabolic profiling of prions in the gastro-intestinal tract

Uffaf Khan, B.S.

Thesis Advisor: Claudio Soto, Ph.D.

Abstract

Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of debilitating neurodegenerative disorders that affect both humans and animals. They can be spread by horizontal transmission as seen in chronic wasting disease in deer and elk population. In addition, transmission to humans has also been documented which includes bovine spongiform encephalopathy in cattle to variant Creutzfeldt-Jakob disease in humans due to consumption of contaminated meat. The most probable natural route of transmission is by oral consumption of infectious material. Even …

The Effect Of Sleep On Perceptual Learning And Memory Consolidation, Vanessa Claire Irsik

UNLV Theses, Dissertations, Professional Papers, and Capstones

An ability to segregate speech accurately is essential given that most auditory environments contain other overlapping conversations or environmental noise. While perceiving speech among background noise can be difficult in and of itself, those with hearing impairments can experience considerable difficulty. While training has been shown to benefit perceptual segregation of trained sounds, it is unclear how such training transfers to sounds not included in a training regimen. The current study aimed to address this question by training listeners on a portion of sounds during a vowel segregation task, and subsequently testing on both the trained sounds and untrained sounds. …

Contribution Of The Dorsolateral Prefrontal Cortex To Attentional And Mnemonic Processes In Visual Search, Brandon Belbeck

Electronic Thesis and Dissertation Repository

A key characteristic of selective visual attention is that it may be deployed on the basis of our knowledge or goals of the task at hand. Here, we used cryogenic deactivation to investigate the contribution of the dorsolateral PFC to cognitive flexibility and working memory, as well as their relation to the deployment of attention. Macaque monkeys performed visual search tasks requiring them to foveate a target in an array of stimuli. These included a feature search, a constant-target conjunction search, a variable-target search and variable-target with delay search task, with each being more cognitively demanding than the last. Bilateral …

Effects Of Cocaine Sensitization On Drug Self-Administration, Mesocorticolimbic Sapap Levels, And Prefrontal Ionotropic Glutamate Receptors, Kyle Christopher Summers

Theses and Dissertations (ETD)

Towards the goal of improving the knowledge base of how drugs of abuse function to create addicts and using currently uninvestigated areas of this knowledge base, we focused our research studies the male albino rat, and strived to explain how cocaine sensitization alters particular molecular mechanisms in the mesocorticolimbic system related to glutamate receptors, SAPAPs, and affects drug self-administration. Taking all the previously discussed research studies into consideration, we hypothesized that low-dose cocaine self-administration would yield a significant elevation in drug seeking behavior for psychostimulant sensitized animals. For specific changes at the PSD, we hypothesized that acute cocaine exposure and/or …

Neural Plasticity In Response To Intervention In Adolescents With Autism Spectrum Disorders, Sheryl Jayne Stevens

Dissertations (1934 -)

Current theories of Autism Spectrum Disorders (ASD) suggest that they may develop from the transactional interaction between biological risk factors and environmental processes (Dawson et al., 2009). Due to the brain’s experience-expectant nature, one’s degree of social exposure may have a significant impact on their brain development and behavioral presentation. In addition to the primary critical neurodevelopmental period identified in early childhood, recent research has demonstrated a second period of substantial neurodevelopment during the adolescent period (Sisk & Foster, 2004). This study investigated the neural and behavioral impact of participation in an empirically validated behavioral intervention (The Program for the …

Integration Of Atm, Atr, And Dna-Pkcs Signaling Maintains Genome Integrity During Neurogenesis, Vanessa D. Enriquez-Rios

Theses and Dissertations (ETD)

The DNA damage response (DDR) orchestrates a network of cellular processes such as cell cycle progression, DNA repair, and apoptosis when complex DNA lesions arise to maintain genomic integrity. ATM, ATR, and DNA-PKcs (encoded by PRKDC) are related phosphatidylinositol-3-kinase like serine/threonine kinases (PIKK) that collectively regulate the DDR network. Studies have demonstrated these kinases can phosphorylate many of the same substrates, suggesting a significant potential for functional redundancy. However, deficiencies in these kinases have been linked to distinct neural degenerative and developmental disorders, underscoring their unique functions for maintain genomic integrity during nervous system development.

Here we utilized mouse genetic …

Concussion Education And The Self-Reporting Rate Of Concussion Symptoms Among College Athletes, Brian J. Hyma

Ed.D. Dissertations

This study addressed the effectiveness of a structured concussion education tool in order to increase the knowledge of concussion symptoms among college athletes. Also, efforts were made to determine if the gained knowledge from the education tool would lead to an increase in the self-reporting of acquired concussion symptoms. For the study, pre and postseason surveys were administered to athletes among six universities. Athletes representing the experimental group received pre-season concussion education while the control group did not receive the education. Data concerning the athlete’s history of structured concussion education, retained knowledge of concussion symptoms, along with the rate of …

Estrodial Effects On Age-Related Shifts In Learning And Memory: A Multiple Memory Systems Approach, Luis Castelan

Honors Capstone Projects - All

Many findings from our lab and others suggest that circulating estrogens as well as estrogen replacement after ovariectomy influence cognitive performance. Young female rats trained during proestrus, when estrogens are high, or with acute estradiol (E2) administration after ovariectomy perform better on the hippocampus-sensitive place task but worse on the striatum-sensitive response task (Korol et al., 2004; Korol and Kolo, 2002). Behavioral neuroscience studies tend to use male rodent models to avoid the complexities of the female reproductive cycle, producing a gap in our knowledge about neural mechanisms of learning and memory in females. As a consequence, age-related effects of …

A Comparison Of The Effects Of Different Doses Of Gabab Receptor Ligands On Spatial Learning And Memory And Memory Flexibility, Chelcie Heaney

UNLV Theses, Dissertations, Professional Papers, and Capstones

The principal inhibitory neurotransmitter in the brain, gamma amino-butyric acid (GABA), mediates several types of learning and memory. Of the two main receptor subtypes for GABA, the in vivo role of GABAB receptor in learning and memory is less well characterized and the current data often conflict. Based on the current literature, it is unclear, for instance, whether enhancing GABAergic activity via the GABAB receptor could be beneficial for or detrimental to learning and memory. Hippocampally-dependent learning and memory tasks are of particular interest due to their clinical relevance to patients with schizophrenia or Alzheimer’s disease, who exhibit impaired performance …

Functional Capacity In Schizophrenia: Relationship Among Effort, Reinforcement Learning And Self-Beliefs, Sally J. Vogel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Individuals with schizophrenia exhibit a wide range of complex neurocognitive, psychiatric and behavioral impairments. Recent research suggests that this complex array of symptoms can be at least partially accounted for by dysfunction in more basic mechanisms, such as the ability to learn from positive and negative reinforcement, or the ability to exert adequate effort when completing simple tasks. Evidence also suggests that deficits in these basic mechanisms may contribute to more complex symptoms, such as functional impairment. Also, the relationship between neurocognitive deficits and functional impairment has been found to be mediated by defeatist performance beliefs. However, studies have not …

Mechanisms Of Atf4-Mediated Neuronal Apoptosis, Patrick Swan

Electronic Thesis and Dissertation Repository

Abstract to be provided

Exploring The Structural And Functional Organization Of The Dorsal Zone Of Auditory Cortex In Hearing And Deafness, Melanie A. Kok

Electronic Thesis and Dissertation Repository

Recent neuroscientific research has focused on cortical plasticity, which refers to the ability of the cerebral cortex to adapt as a consequence of experience. Over the past decade, an increasing number of studies have convincingly shown that the brain can adapt to the loss or impairment of a sensory system, resulting in the expansion or heightened ability of the remaining senses. A particular region in cat auditory cortex, the dorsal zone (DZ), has been shown to mediate enhanced visual motion detection in deaf animals. The purpose of this thesis is to further our understanding of the structure and function of …

Certain General Anesthetics Used In Pediatrics Hinder Neurological Development In Infants, Michael R. Hirschi

Selected Honors Theses

General anesthetics act by either blocking N-methyl-d-aspartate (NMDA) receptors or over stimulating γ-aminobutyric acid (GABA) receptors.^1–3 The actions of these receptors are responsible for the anesthetized state and are also crucial in the neurological development of infants.^2,4–8 Animal studies, although limited, provide vital information about general anesthesia’s neurotoxicity its hindrance of neurological development. Exposure to general anesthesia can severely hinder proper neuronal migration, synaptogenesis, and can drastically increase neuronal apoptosis in infant animals.^9–16 General anesthetics are more neurotoxic to infant animals in combination compared to individually.^10,16,17 Additionally, multiple exposures to general anesthesia tend to have compounding …

The Therapeutic Role Of Turmeric In Treatment And Prevention Of Alzheimer’S Disease, Rylan M. Mcquade

Selected Honors Theses

As a devastating neurological condition that expends millions of lives each year, Alzheimer’s disease (AD) is a subject of intense investigation.¹ Although AD has been known for over a century, the precise mechanisms that underlie AD pathogenesis and development are still poorly understood. The Alzheimer phenotype is typified by extracellular amyloid-beta (Aβ) plaques and intracellular neurofibrillary tangles (NFTs), causing researchers to notice several key enzymes implicated in this process.¹ Most notable are β and γ secretases (which drive Aβ plaque production) and phospholipase

A₂ (which stimulates major cascade activation through the specific cleavage of fatty acyl esters). …

Effect Of The Ketogenic Diet On Behavioral Symptoms Of Autism In The Poly(Ic) Mouse Model, Sierra L. Slade

Senior Theses and Projects

Autism spectrum disorder (ASD) is a neurological disorder characterized by decreased sociability, deficits in communication, and restricted and repetitive behaviors. The ketogenic diet (KD), a high-fat, low-carbohydrate, and moderate-protein diet has been shown to improve these three behavioral symptoms in the BTBR mouse model of autism. However, further research is required to strengthen the body of knowledge surrounding the potential of KD as diet therapy for autism. Epidemiological observations have shown that maternal immune activation (MIA) during pregnancy increases the risk of autism in offspring. Based on these observations, the polyinosinic:polycytidylic acid (poly(IC)) mouse model was developed as an animal …

Individualized Cognitive Rehabilitation For Adults With Acquired Brain Injury, Emily M. Aiken

Senior Theses and Projects

Acquired Brain Injury (ABI) can result from internal factors (e.g. tumor) or external causes (e.g. trauma). Three case studies of Korsakoff’s syndrome, meningioma, and traumatic brain injury (TBI), will be presented to illustrate the variety of cognitive deficits across different individuals with ABI. This study uses cognitive rehabilitation therapies to target individual cognitive symptoms. Results and discussion place emphasis on the use of prospective memory (PM) training for treating Korsakoff’s syndrome. The Memory for Intentions Screening Test (MIST) served as the assessment for PM analysis pre and post rehabilitation. The data from this study will be used as a model …

Unstable Ventilatory Control During Sleep After High Spinal Cord Injury: The Contribution Of Chemosensitivity And Hypoventilation, Amy Therese Bascom

Wayne State University Dissertations

ABSTRACT

UNSTABLE VENTILATORY CONTROL DURING SLEEP AFTER HIGH SPINAL CORD INJURY: THE CONTRIBUTION OF CHEMOSENSITIVITY AND HYPOVENTILATION

by

Amy T. Bascom

May 2015

Advisor: Dr. Harry G. Goshgarian

Major: Anatomy and Cell Biology

Degree: Doctor of Philosophy

A high prevalence of sleep-disordered breathing (SDB) after spinal cord injury (SCI) has been reported in the literature; however, the underlying mechanisms are not well understood. My studies had 2 aims: 1) to determine the effect of the withdrawal of the wakefulness drive to breathe on the degree of hypoventilation in SCI patients and able-bodied controls and 2) to determine the response of …