Medicine and Health Sciences Commons^™

Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy

University of New Orleans Theses and Dissertations

The model of basal ganglia function proposed by Albin, Young and Penney (1989) describes two anatomically independent motor pathways, the direct and indirect. However, under normal conditions striatal dopamine (DA) is required for the expression of motor behavior, and DAergic control of the two pathways (via D1 and D2 receptors, respectively) is dependent on co-activation. We tested for a possible breakdown of D1/D2 synergism using transgenic R6/1 mice bearing the human huntingtin allele (Htt). Motor stereotypy, observed prior to the onset of HD-related symptoms, was rated on a 5-point scale following activation of: A) D1 receptors alone, B) D2 receptors …

Novel Therapeutic Approaches For Juvenile Neuronal Ceroid Lipofuscinosis (Cln3), Megan Elizabeth Bosch

Theses & Dissertations

Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) is a lysosomal storage disease caused by autosomal recessive mutations in CLN3. Neuronal loss is thought to occur via glutamate excitotoxicity; however, little is known about neuron-astrocyte glutamate regulation in JNCL. We discovered that Cln3^Δex7/8 astrocytes have significantly lower basal spontaneous Ca²⁺ oscillations and decreased responses to glutamate, indicating a disrupted signaling network. Cln3^Δex7/8 astrocytes also displayed significantly lower basal mitochondrial respiration and ATP production, suggesting impaired metabolic functions. Concurrent with diminished astrocyte metabolism and Ca²⁺ signaling, Cln3^Δex7/8 neurons were hyper-responsive to glutamate stimulation. These studies suggest that CLN3 …

Neuronal Correlates For Neuroendocrine Habituation To Repeated Stress, Sara Matovic

Electronic Thesis and Dissertation Repository

One way that the body actively responds to an impending stressor is by increasing systemic glucocorticoids through the activation of the hypothalamic-pituitary-adrenal (HPA) axis. While it is essential for short-term adaptation to stress, the sustained activation of the HPA axis during chronic stress can be detrimental and is linked to stress-related psychiatric conditions such as anxiety and depression. Therefore, it is important that the HPA axis adapts, or habituates, during chronic stress to minimize the negative consequences. Corticotropin releasing hormone (CRH) neurons in the paraventricular nucleus of the hypothalamus (PVN) function to assimilate incoming information from the stress circuitry and …

Analysis Of Diagnostic, Preventive, And Disease-Modifying Therapeutic Measures Of Alzheimer’S Disease, Ghazal Habib Havoutis

HCNSO Student Capstones

Alzheimer’s disease (AD) is the most common late-onset neurodegenerative disorder and cause of dementia, characterized by the formation of neurofibrillary tangles and senile plaque deposits. The heterogeneous nature of the disease (both genetically and environmentally) makes it difficult to prevent or cure. Without prevention, the prevalence of AD is expected to triple by 2050. However, because the diagnosis of AD is usually preceded by years of cognitive impairment, early detection may aid in reducing prevalence. Thus, there is a need for validated diagnostic measures for early and improved diagnosis and prevention. In this review, current and ongoing classifiers of early …

Neuroanatomical And Morphological Properties Of Neurons That Generate Inspiratory Related Breathing Rhythm And Influence Respiratory Motor Pattern In Mice, Victoria Akins

Dissertations, Theses, and Masters Projects

The relationship between neuron morphology and function is a perennial issue in neuroscience. Information about synaptic integration, network connectivity, and the specific roles of neuronal subpopulations can be obtained through morphological analysis of key neurons within any given microcircuit. Breathing is essential behavior for humans and all mammals, yet the neural microcircuit that governs respiration is not completely understood. The respiratory neural microcircuit resides within the ventral respiratory column located in the medulla. Within the respiratory column, the site of respiratory rhythm generation is the bilaterally distributed preBötzinger complex (preBötC). Rhythm-generating neurons in the preBötC are derived from a single …

Habituation And Dishabituation In The Olfactory Bulb: From Neural Responses To Behavior, Mary Cameron Ogg

Theses and Dissertations (ETD)

Habituation and dishabituation modulate the neural resources and behavioral significance allocated to incoming stimuli across the sensory systems. The purpose of the research presented in this dissertation was to characterize these processes in the mouse olfactory bulb (OB) and to determine if OB acetylcholine (ACh) has a role in physiological and behavioral olfactory dishabituation. Calcium imaging was used to determine the timecourse and magnitude of habituation in different parts of the OB during and after a prolonged odor presentation. Widefield imaging of the dendritic, or glomerular, response of OB output cells demonstrated that prolonged odor input habituates glomerular responses during …

Astaxanthin Attenuates Mptp Induced Neurotoxicity And Modulates Cognitive Function In Aged Mice, Beth Grimmig

USF Tampa Graduate Theses and Dissertations

Parkinson’s disease is the second common neurodegenerative disease and is most frequently diagnosed in individuals over 60. There are no available medications that can prevent or restore the loss of neurons that correspond to motor impairments in patients. Identifying novel therapeutic compounds that are capable of slowing and reversing the extensive neurodegeneration that occurs in PD remains an important goal of the field. While basic research has identified potential therapeutic agents, studies often use young model organisms to demonstrate efficacy of the target compound. This approach ignores the impact of the aged CNS on the disease process, and likely contributes …

Modeling Post Stroke Respiratory Dysfunction, Apneas And Cognitive Decline, Anthony Patrizz

Dissertations & Theses (Open Access)

Modeling Post Stroke Respiratory Dysfunction,

Apneas and Cognitive Decline

Anthony Patrizz, B.A.

Advisory Professor: Louise McCullough M.D., Ph.D.

Stroke is a major cause of mortality and the leading cause of long-term disability in the US. More than 60% of individuals suffering a first time stroke develop respiratory dysfunction, prolonging recovery and increasing mortality. Post-stroke cognitive decline is a major contributor to disability and nursing home placement, therefore the cognitive consequences of Stroke Induced Respiratory Dysfunction (SIRD) need to be explored if we hope to enhance functional recovery. The first step towards treatment of the negative consequences of SIRD is the …

Exercise, Learning And Emotional Health: Interdisciplinary Approaches To Translational Action, Tessa L. Koschel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Exercise positively effects physical, psychological and neurological wellbeing. Though the population at large is becoming increasingly aware of the multi-faceted benefits of exercise, the majority of people fail to meet daily exercise recommendations. Largely, demands of everyday life such as work, school and family take priority over fitness. The issue therefore becomes a matter of time. In a world of media multi-tasking and immediate gratification, the challenge to health professionals becomes incorporation and manipulation of these consistencies to improve exercise uptake and adherence. Focus must shift from the idea of making additional time for exercise, to adding exercise to time …

Contributions Of Appetitive And Aversive Motivational Systems To Decision-Making, Heather E. Soder

USF Tampa Graduate Theses and Dissertations

Optimal decision-making entails outcome evaluation, comparing received costs and benefits with predicted costs and benefits. The anterior cingulate cortex (ACC), a brain area with major connections to the appetitive and aversive motivation systems, may provide the neural substrate of this evaluation process. One way to measure the relative contribution of these systems on decision-making is to measure individual differences in risk-taking behaviors. For individuals who make risky choices, this evaluation step may be biased: some show a preference for immediate, short-term rewards (increased appetitive system), while devaluing the long-term consequences of their choices (decreased aversive system). However, most studies supporting …

Role Of Dbx1-Derived Pre-Bötzinger Complex Interneurons In Breathing Behaviors Of Adult Mice, Nikolas C. Vann

Dissertations, Theses, and Masters Projects

Breathing is a rhythmic motor behavior essential to sustain homeostasis and life itself in humans and all terrestrial mammals. A specialized neuronal network is responsible for generating and controlling the rhythm and pattern for breathing. The core rhythm-generating microcircuit in particular is located within a site dubbed the preBötzinger complex (preBötC). The preBötC is a heterogeneous region containing neurons with both respiratory and non-respiratory activity that express excitatory and inhibitory transmitters, peptide transmitters and peptide receptors. More recently, preBötC neurons have been characterized by molecular genetics. The markers historically used to define the respiratory CPG within the preBötC intersect with …

A Longitudinal Study Of The Effects Of Cognitive Awareness Training On Transaction Processing Accuracy: An Introduction To The Ace Theoretical Construct, John Townsend

USF Tampa Graduate Theses and Dissertations

This study examines the impact of Cognitive Awareness training on transaction processing accuracy rates within the US Financial Services Industry. Grounded in the theories of Inattentional Blindness and Error Management Culture, this paper supports and extends both theories through the development of a new theoretical construct. The ACE Construct is a novel approach that combines cognitive science, organizational development, and operational efficiency practices into a single approach designed to improve transaction processing accuracy. The study involved the design and implementation of a novel training program, with performance data observations sampled over seven months, to evaluate the impact of Cognitive Awareness …

Functional Magnetic Resonance Imaging As An Assessment Tool In Critically Ill Patients, Loretta Norton

Electronic Thesis and Dissertation Repository

Little is known about whether residual cognitive function occurs in the earliest stages of brain injury. The overarching goal of the work presented in this dissertation was to elucidate the role of functional neuroimaging in assessing brain activity in critically ill patients. The overall objective was addressed in the following four empirical chapters: In Chapter 2, three versions of a hierarchically-designed auditory task were developed and their ability to detect various levels of auditory language processing was assessed in individual healthy participants. The same procedure was then applied in two acutely comatose patients. In Chapter 3, a hierarchical auditory task …

Aging, Executive Function, Fronto-Parietal Network Cortical Thickness: Insights From Cognitive Reserve, Katherine Reiter

Dissertations (1934 -)

Cognitive reserve (CR) indexes the nonlinear relationship between neurological insult and behavioral change. CR is manifested in both static factors (e.g., childhood environment, education) and modifiable lifestyle factors, (e.g., leisure activities). Detailed investigation of the influence of CR on cortical thickness, which indexes neuropathology, and cognitive functioning could be particularly important in understanding the heterogeneity of Alzheimer’s disease (AD). While memory decline is the hallmark of AD, executive functioning (EF) decline often predates memory changes, making EF an important target for investigating CR influences. The current study examines the relationship of CR and genetic risk for AD (ε4) on EF …

The Neural Encoding Of Reward In The Striatal-Pallidal Circuitry, Chung Lung Chan

Dissertations (1934 -)

Humans and animals are constantly exposed to external stimuli. The ability to process reward value of a stimulus is critical to guiding appropriate behavior and essential for survival. These processes are regulated by neuronal activity and neurochemical signaling in the reward circuitry, particularly in the nucleus accumbens (NAc). The NAc receives dopaminergic inputs from the midbrain ventral tegmental area (VTA) and sends GABAergic projections to the ventral pallidum (VP). Electrophysiological studies have characterized phasic neuronal responses in the NAc that differential encode appetitive and aversive taste stimuli. Exposure to an appetitive taste stimulus evoked predominantly phasic inhibitory responses in the …

An Anatomical Study Of The Hyperpallium Densocellulare In The Pigeon (Columba Livia), Sara Leilani Kellogg

USF Tampa Graduate Theses and Dissertations

The hyperpallium densocellulare (HD) is an avian cerebral structure, the origin of which remains unclear and considered to be critical to the understanding of the non-mammalian forebrain evolution. The main goal of this investigation was to clarify the anatomical characteristics and behavioral implications of HD, which had been assumed to be a homogeneous unitary entity. This project had three specific aims: 1) To identify possible subdivisions of HD in terms of cytoarchitecture, Substance P distribution, and connections based on unpublished (Aim 1a) as well as published data (Aim 1b); 2) To identify the unknown connections of these subdivisions by using …

Force Compensation And Recreation Accuracy In Humans, Benjamin Rigsby

USF Tampa Graduate Theses and Dissertations

As industry becomes increasingly reliant on robotic assistance and human-computer interfaces, the demand to understand the human sensorimotor system’s characteristics intensifies. Although this field of research has been going on for over a century, new technologies push the limits of the human motor system and our knowledge of it. With new technologies come new abilities, and, in the area of medical care and rehabilitation, the need to expand our knowledge of the sensorimotor system comes from both the patient and physician.

Two studies relating to human force interaction are presented in this thesis. The first study

focuses on humans’ ability …

Multi-Scale Spatial Cognition Models And Bio-Inspired Robot Navigation, Martin I. Llofriu Alonso

USF Tampa Graduate Theses and Dissertations

The rodent navigation system has been the focus of study for over a century. Discoveries made lately have provided insight on the inner workings of this system. Since then, computational approaches have been used to test hypothesis, as well as to improve robotics navigation and learning by taking inspiration on the rodent navigation system.

This dissertation focuses on the study of the multi-scale representation of the rat’s current location found in the rat hippocampus. It first introduces a model that uses these different scales in the Morris maze task to show their advantages. The generalization power of larger scales of …

Mindfulness And Law Enforcement: An Effective Approach To Implementing Mindfulness For First Responders, Gina White

Mindfulness Studies Theses

An increasing number of studies show that people employed as first responders in high trauma service jobs tend to experience a high level of stress, at work and after hours. Studies suggest that constant exposure to job related stress leads to both physical and mental dysregulation. This study looks at the effects of implementing mindfulness tools and techniques to those working in law enforcement. Other works on this topic report mindfulness as a successful tool to increase wellbeing to a broad spectrum of populations. The methodology used in this study was designed specifically for first responders. The data findings were …

The Acquisition And Analysis Of Electroencephalogram Data For The Classification Of Benign Partial Epilepsy Of Childhood With Centrotemporal Spikes, Jessica A. Scarborough

Master's Theses

In this thesis, I will expand upon each step in the process of acquiring and analyzing electroencephalogram (EEG) for the classification of benign childhood epilepsy with centrotemporal spikes. Despite huge advancements in the field of health informatics—natural language processing, machine learning, predictive modeling—there are significant barriers to the access of clinical data. These barriers include information blocking, privacy policy concerns, and a lack of stakeholder support. We will see that these roadblocks are all responsible for stunting biomedical research in some way, including my own experiences in acquiring the data for the second chapter of this thesis.

This second chapter …

Rat Hind Limb Nociceptive Withdrawal Response To Heat And Mechanical Stimuli Depends On Initial Position Of The Paw But Not Stimulus Location, Giavanna Verdi

Senior Honors Projects, 2010-2019

Mammals rapidly withdraw their hind limb in response to noxious stimulation, which is a protective movement known as the nociceptive withdrawal response (NWR). The NWR has been previously studied in spinalized, decerebrated and anesthetized non-human and human mammals; however, there is minimal information on the NWR in intact, unanesthetized non-human mammals.

The first specific aim was to identify the factors that determine the direction and magnitude of the NWR in intact, unanesthetized rats. Based on previous studies, we hypothesized that the location of stimulation and the initial position of the paw preceding the NWR will influence the direction and magnitude …

The Psychophysiological Correlates Of Personality, Trauma, Posttraumatic Stress Disorder And Social Support, Meghan E. Pierce

UNLV Theses, Dissertations, Professional Papers, and Capstones

Theories considering the etiology of psychopathy suggest that trauma exposure, specifically childhood maltreatment and sexual abuse, is related to the development of callous-unemotional traits in children and adolescents, which are precursors to psychopathic traits in adulthood. Furthermore, posttraumatic stress disorder has an opposite relationship with many of the emotional and behavioral components of the two-factor model of psychopathy. Specifically, PTSD is positively associated to IA and traits associated with it and negatively associated with FD. Thus, this study sought to expand upon the current theories of a trauma-based etiology of psychopathy by investigating the relationship between trauma, PTSD, and psychopathic …

Neural Processes Underlying Auditory Context Effects, Breanne Yerkes

UNLV Theses, Dissertations, Professional Papers, and Capstones

Auditory information within our natural environments is disorganized and often ambiguous, leaving our auditory systems with a complex task: organizing sound into coherent objects. The auditory system uses both current and prior information to assist in completing this task. The influences of previous context on current perception have been referred to as context effects. A contrastive context effect results in a current perception that is opposite of what is expected based on the physical stimulus properties presented during an immediate context. A facilitative context effect results in a current perception that is the same as the perception during the immediate …

An Evaluation Of Gabab Receptors On Modulating Neuroinflammation In A Non-Transgenic Animal Model Of Alzheimer's Disease, Monica Bolton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and distinct neuropathological hallmarks, including amyloid beta plaques and neurofibrillary tau tangles (NFT). Although the etiology remains to be discovered, several risk factors exist that significantly contribute to developing AD. Diabetes is one of the major risk factors associated with AD and is characterized by disrupted insulin signaling that may contribute to or exacerbate AD pathologies. Furthermore, both disorders result in increased neuroinflammation. Considerable evidence has demonstrated that a chronic inflammatory response, in particular chronic microglia activation, promotes A production as well as the hyperphosphorylation of tau through …

Investigating Localization And Activity-Dependent Translation Of Astrocyte Mrna, Rohan Khazanchi

Senior Honors Papers / Undergraduate Theses

Over the past two and a half years, I have studied fundamental aspects of astrocyte biology by investigating the existence and mechanism of astrocyte local translation peripherally around tripartite synapses consisting of pre- and post-synaptic neuron terminals and an associated astrocyte. Astrocytes are critical components of central nervous system synapses (which are predominately tripartite in nature); thus, it is important to consider how astrocyte dysregulation and dysfunction could contribute to the pathogenesis of diseases of synaptic connectivity such as autism spectrum disorders, Alzheimer’s disease, seizure disorders, and more. Overall, my projects involved the development of novel methods to identify astrocyte-specific …

The Role Of Hsf1 Protein Regulation On Neurodegeneration, Eunhee Kim

Theses and Dissertations (ETD)

Cellular protein homeostasis is achieved by a delicate network of molecular chaperones and various proteolytic processes such as ubiquitin–proteasome system (UPS) to avoid a build-up of misfolded protein aggregates. The latter is a common denominator of neurodegeneration. Neurons are found to be particularly vulnerable to toxic stress from aggregation-prone proteins such as α-synuclein. Induction of heat-shock proteins (HSPs), such as through activated heat shock transcription factor 1 (HSF1) via Hsp90 inhibition, is being investigated as a therapeutic option for proteinopathic diseases. HSF1 is a master stress-protective transcription factor which activates genes encoding protein chaperones (e.g. iHsp70) and anti-apoptotic proteins. However, …

Trunk And Respiratory Motor Control In Typically Developing Children And Its Implications In Children With Chronic Spinal Cord Injury., Goutam Singh

Electronic Theses and Dissertations

Independent sitting is a major milestone and is also a prerequisite for optimal performance of activities of daily living (ADLs). Development of sitting posture control is a dynamic process involving control of degrees of freedom of head and trunk. Traditionally, trunk has been modeled as a single unit (segment). However, recent studies have suggested that it is made up multiple spinal units, controlled by a combination of trunk muscles. During typical development, posture control of trunk is different for different trunk segments. This motor development of trunk control is a complex process due to constant interaction between the nervous system …

Persistent Neurobehavioral Traits In A Mouse Model Of Prenatal Ethanol Exposure, Jill M. Lawrence

Neuroscience Honors Papers

Fetal Alcohol Spectrum Disorders (FASD) effect an estimated 2% of the population, causing a range of symptoms: from craniofacial defects to inhibited cortical growth (May, et al., 2009; Murawski, et al., 2015). Impaired medial forebrain function apparent in FASD is associated with lifelong cognitive behavioral deficits, but these consequences may be avoided with early diagnosis and intervention (Streissguth, et al., 2004). Our goal is to identify early neurobehavioral abnormalities that persist into adulthood that could potentially serve as early indicators for FASD. Mouse models of prenatal ethanol exposure were developed using a voluntary drinking paradigm that introduced a sweetened ethanol …

Age-Related Reductions Of Motor Unit Discharge Rates In The Human Hamstrings, Eric A. Kirk

Electronic Thesis and Dissertation Repository

Neuromuscular age-related differences of human limb muscles have been widely described with the notable exception of the hamstring muscles. The purpose was to assess contractile function and spinal motor neuron output expressed as motor unit discharge rates in the hamstrings of 11 young (26 ± 4 y) and 10 old (80 ± 5 y) men. Maximal voluntary isometric contractions (MVC), stimulated contractile properties and motor unit discharge rates from sub-maximal to MVC were recorded from the lateral (biceps femoris) and medial (semimembranosus-semitendinosus) posterior thigh. In the old men, knee extension and flexion at MVC were lower (P < 0.05) and voluntary activation as assessed by the twitch interpolation technique was reduced (P < 0.05) compared with the young. Electrically evoked twitches were lower in amplitude and increased in duration of old hamstrings (P < 0.05) compared with the young. At sub-maximal to maximal contraction intensities the old had lower motor unit discharge rates as compared to the young (P < 0.001). At MVC, mean motor unit discharge rates in the biceps femoris and semimembranosus-semitendinosus of old hamstrings were 15.6 ± 6.4 and 15.3 ± 5.9 Hz, as compared to 26.1 ± 10.1 and 27.9 ±7.8 Hz in the young, respectively (P < 0.001). To date, the hamstrings show the greatest age-related reductions in motor unit discharge rates of any major limb muscle. These findings, in relation to motor unit discharge rates from other flexors and extensors support that in ageing, greater reductions are associated with limb flexor muscles.

Receptor-Associated Protein (Rap) Models In Vivo Reelin Haploinsufficiency: Implications In Schizophrenia, Jamileh Ahmed

USF Tampa Graduate Theses and Dissertations

The “two-hit” schizophrenia hypothesis suggests genetic and environmental abnormalities interrupt early CNS function. This increases vulnerability of a “second hit” and schizophrenia onset. Chronic stress and decreased Reelin signaling are reportedly associated with schizophrenia. Heterozygous Reeler Mice (HRM) show a 50% reduction in Reelin and display major schizophrenia phenotypes. Receptor-Associated Protein (RAP) blocks ligand-association to Reelin receptor Apolipoprotein E receptor 2 (ApoER2). In this study, we sought to replicate major heterozygous reeler mouse (HRM) phenotypes using in vivo RAP studies to establish an experimental in vitro model. Using an in vitro model, we investigated the effects of chronic stress and …