Medicine and Health Sciences Commons^™

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 …

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 …

Acetaminophen Associated Neurotoxicity And Its Relevance To Neurodevelopmental Disorders, Seol-Hee Kim

USF Tampa Graduate Theses and Dissertations

Autism is a lifelong neurodevelopmental disorder. The etiology of autism still remains unclear due to the heterogeneous and complex nature of the disorder, however synergistic actions between genetic components and environmental factors have been suggested. Acetaminophen (APAP) is one of the most popular over-the-counter drugs that possess antipyretic and analgesic effects. It is considered a relatively safe and effective within therapeutic doses. Recently, early exposure to APAP has been suggested to be one of the underlying cause of autism. Children are often prescribed APAP to lessen fever or irritability after vaccination during the first year, and APAP may adversely affect …

Neuropeptide Modulation Of The Large Conductance Potassium (Bk) Channel In The Auditory System: Therapeutic Implications For Age-Related Hearing Loss, Ellliott James Brecht

USF Tampa Graduate Theses and Dissertations

The auditory temporal processing deficits associated with age-dependent hearing decline have been increasingly attributed to issues beyond peripheral hearing loss. Age-related hearing loss (ARHL), also known as presbycusis, is linked with changes in the expression of both excitatory and inhibitory neurotransmitters in the central auditory system. There are also age-related changes in the expression and function of the ion channels which mediate action potential firing. The slow, Ca²⁺ activated, K⁺ channels of the BK-type are essential in controlling both neurotransmitter release and neural communication via alteration of action potential durations, firing frequency, and neural adaptation. There are many …

The Potential Role Of Antiretroviral Efavirenz In Hiv Associated Neurocognitive Disorders, Lecia Ashanna Moya Brown

USF Tampa Graduate Theses and Dissertations

The prevalence of milder forms of HIV-associated neurocognitive disorders (HAND) is rising despite combination antiretroviral therapy (cART). Efavirenz (EFV) is among the most commonly used antiretroviral drugs globally, but causes neurological symptoms that may interfere with adherence and reduce tolerability, and may have central nervous system (CNS) effects that contribute in part to HAND in patients on cART. Thus we evaluated a commonly used EFV containing regimen: EFV/zidovudine (AZT)/lamivudine (3TC) in murine N2a cells transfected with the human “Swedish” mutant form of amyloid precursor protein (SweAPP N2a cells) to assess for promotion of amyloid-beta (Aβ) production (Chapter 3). Treatment with …

Tau-Directed Immunotherapy For Alzheimer’S Disease, Sulana Kay Schroeder

USF Tampa Graduate Theses and Dissertations

Alzheimer’s disease (AD) is the leading cause of dementia, accounting for 50 to 80 percent of dementia cases, and the prevalence of the disease is projected to increase significantly with time. AD is characterized by severe cognitive decline with age, ultimately requiring continued caregiving and eventually death. The pathology of AD is characterized by the presence of extracellular amyloid plaques, intracellular neurofibrillary tangles (NFT) composed of hyperphosphorylated tau protein, neuron loss, and evidence of inflammation indicated by the presence of reactive microglia and astrocytes. Frontotemporal Lobe Dementia (FTLD) is a rare form of dementia that is related to AD, most …

Mass-Spectrometry Based Proteomics Of Age-Related Changes In Murine Microglia, Antwoine Flowers

USF Tampa Graduate Theses and Dissertations

The last century has seen a steady increase in the extension of the average lifespan. This has concomitantly produced higher incidences of age-related chronic degenerative diseases like Alzheimer’s and Parkinson’s diseases. Age is the single greatest risk factor for the development of not just these degenerative conditions but cancer as well. The aged niche undergoes a number of maladaptive changes that allow underlying conditions to present and progress. Exactly which changes, contribute to the progression of which disease is currently an area of intense study. However, these answers often present therapeutic targets for disease prevention. Age is characterized by a …

The Effects Of Synthetic And Dietary Therapeutics On Learning, Memory, Motor Coordination, And Seizure In An Angelman Syndrome Mouse Model, Stephanie Lynn Ciarlone

USF Tampa Graduate Theses and Dissertations

Angelman syndrome (AS) is a rare genetic and neurological disorder presenting with severe developmental delay, ataxia, epilepsy, and lack of speech. AS is associated with a neuron-specific loss of function of the maternal UBE3A allele, a gene encoding an E3 ubiquitin ligase. Currently, no cure exists for this disorder; however, recent research using an AS mouse model suggests that pharmacological intervention is plausible, and can alleviate some of the detrimental phenotypes reported in AS patients.

Although there is no curative treatment for AS, seizure medication and behavioral therapies are most commonly prescribed in order to minimize symptoms. However, these options …

Hypercapnic Hyperoxia Increases Free Radical Production And Cellular Excitability In Rat Caudal Solitary Complex Brain Slice Neurons, Geoffrey Edward Ciarlone

USF Tampa Graduate Theses and Dissertations

The caudal solitary complex (cSC) is a cardiorespiratory integrative center in the dorsal medulla oblongata that plays a vital role in the central CO₂-chemoreceptive network. Neurons in this area respond to hypercapnic acidosis (HA) by a depolarization of the membrane potential and increase in firing rate, however a definitive mechanism for this response remains unknown. Likewise, CO₂-chemoreceptive neurons in the cSC respond to hyperoxia in a similar fashion, but via a free radical mediated mechanism. It remains unknown if the response to increased pO₂ is merely an increase in redox signaling, or if it’s the …

Regulation Of Palmitoylation Enzymes And Substrates By Intrinsically Disordered Regions, Krishna D. Reddy

USF Tampa Graduate Theses and Dissertations

Protein palmitoylation refers to the process of adding a 16-carbon saturated fatty acid to the cysteine of a substrate protein, and this can in turn affect the substrate’s localization, stability, folding, and several other processes. This process is catalyzed by a family of 23 mammalian protein acyltransferases (PATs), a family of transmembrane enzymes that modify an estimated 10% of the proteome. At this point in time, no structure of a protein in this family has been solved, and therefore there is poor understanding about the regulation of the enzymes and their substrates. Most proteins, including palmitoylation enzymes and substrates, have …

Hormone Replacement Therapy (Hrt) Modulates Peripheral And Central Auditory System Processing With Aging, Tanika Williamson

USF Tampa Graduate Theses and Dissertations

After the findings were reported for the Women’s Health Initiative (WHI) study in the past decade, there has been a significant decline in the overall use of hormone replacement therapy (HRT) among women. However, there are still millions of middle-aged, menopausal women in the U.S. who are currently undergoing hormone therapy. Their reasons for continuing treatment include relief of severe menopausal symptoms, aid in the management of osteoporosis and reduction in the risk of colon cancer (Ness et al., 2005). The purpose of the following investigation was to evaluate the impact of HRT on the central and peripheral auditory systems …

Intraocular Pressure Sensing And Control For Glaucoma Research, Simon Antonio Bello

USF Tampa Graduate Theses and Dissertations

Animal models of ocular hypertension are important for glaucoma research but come with experimental costs. Available methods of intraocular pressure (IOP) elevation are not always successful, the amplitude and time course of IOP changes are unpredictable and irreversible, and IOP measurement by tonometry is laborious. This dissertation focuses on the development and implementation of two novel systems for monitoring and controlling IOP without these limitations. The first device consists of a cannula implanted in the anterior chamber of the eye, a pressure sensor that continually measures IOP, and a bidirectional pump driven by control circuitry that can infuse or withdraw …

Designing The Haptic Interface For Morse Code, Michael Walker

USF Tampa Graduate Theses and Dissertations

Two siblings have a muscular degenerative condition that has rendered them mostly blind, deaf and paraplegic. Currently, the siblings receive communication by close range sign language several feet in front of their vision. Due to the degenerative nature of their condition, it is believed that the siblings will eventually become completely blind and unable to communicate in this fashion. There are no augmented communication devices on the market that allow communication reception for individuals who cannot see, hear or possess hand dexterity (such as braille reading). To help the siblings communicate, the proposed communication device will transmit Morse code information …

The Concerted Regulation Of Intracellular Signaling By Amyloid Precursor Protein And Aβ Peptide, Lisa Kirouac

USF Tampa Graduate Theses and Dissertations

It is widely accepted that A-beta (Aβ) generated from amyloid precursor protein (APP) oligomerizes and fibrillizes to form neuritic plaques in the Alzheimer’s disease (AD) brain, yet little is known about the contribution of APP preceding AD pathogenesis. Our data presented here suggest that APP has a functional role in cell cycle regulation and proliferation. First, we demonstrat that APP is pathologically phosphorylated at Thr₆₆₈ and that P-APP localizes to the centrosomes. Furthermore, P-APP is proteolytically processed in a cell cycle -dependent manner to generate its pathogenic metabolites. Using Stable Isotope Labeling by Amino Acids in Culture (SILAC) and …

Static And Dynamic Spectral Acuity In Cochlear Implant Listeners For Simple And Speech-Like Stimuli, Benjamin Anderson Russell

USF Tampa Graduate Theses and Dissertations

For cochlear implant (CI) listeners, poorer than normal speech recognition abilities are typically attributed to degraded spectral acuity. However, estimates of spectral acuity have most often been obtained using simple (tonal) stimuli, presented directly to the implanted electrodes, rather than through the speech processor as occurs in everyday listening. Further, little is known about spectral acuity for dynamic stimuli, as compared to static stimuli, even though the perception of dynamic spectral cues is important for speech perception.

The primary goal of the current study was to examine spectral acuity in CI listeners, and a comparison group of normal hearing (NH) …

The Influence Of Motivational Salience On Attention Selection: An Erp Investigation, Constanza De Dios

USF Tampa Graduate Theses and Dissertations

The current study used event-related potentials (ERPs) to investigate how motivational salience in the form of expectation violation influences spatial attention. The medial frontal negativity (MFN) ERP indexes expected value, being negative to unexpected punishments and positive to unexpected rewards. The P1 and N1 ERPs index spatial attention, being larger to stimuli in attended locations. This design attached motivational value to locations by making one visual hemifield economically rewarding (greater probability of a rewarding outcome) and the other punishing (greater probability of a punishing outcome). Keypresses to a dot probe following a reward-signifying stimulus were awarded money if correct, and …

Inhibiting The Interaction Between Grp94 And Myocilin To Treat Primary Open-Angle Glaucoma, Andrew Stothert

USF Tampa Graduate Theses and Dissertations

Glaucoma is a neurodegenerative protein misfolding disorder classified by increases in IOP, damage to retinal ganglion cells (RGCs), optic nerve (ON) head damage, and progressive irreversible blindness. Primary open-angle glaucoma (POAG) is the most common form of glaucoma, constituting over 90% of clinical cases. POAG is observed in patients where normal outflow channels, mainly the trabecular meshwork (TM), are exposed at the angle formed by the iris and cornea. However, due to TM cellular dysfunction, aqueous outflow resistance is increased preventing normal circulation of aqueous humor. Recent studies have shown that in 2-4% of POAG cases, increased intracellular levels of …

The Effects Of Cognitive Training Among Individuals With Neurodegenerative Diseases, Elise Gabriela Valdes

USF Tampa Graduate Theses and Dissertations

With the growing older adult population, neurodegenerative diseases common in old age such as mild cognitive impairment (MCI) or Parkinson’s disease (PD) are becoming increasingly germane areas of research. Pharmacological treatments have thus far been unsuccessful in treating cognitive decline associated with these neurodegenerative disorders. Alternative interventions, such as cognitive training programs, have shown promise. The current dissertation contains three papers examining cognitive interventions in neurodegenerative diseases. The first paper examined the longitudinal effects of cognitive speed of processing training (SPT) among those with PD. Results showed that training gains seen at initial post-test were maintained three months later. The …

Targeting Tau Degradation By Small Molecule Inhibitors For Treatment Of Tauopathies, Mackenzie Martin

USF Tampa Graduate Theses and Dissertations

Tauopathies are neurodegenerative diseases that affect millions of people around the world. Tauopathies include more than 20 neurodegenerative diseases. Some of the most common tauopathies are Alzheimer’s disease (AD), frontotemporal dementia (FTD), chronic traumatic encephalopathy (CTE), Pick’s disease, corticobasal degeneration, progressive supranuclear palsy (PSP), agyrophillic grain disease, and amyotrophic lateral sclerosis (ALS). These diseases can cause significant memory loss, behavioral changes, motor deficits and speech impairments. Tauopathies stem from accumulation of the microtubule associated protein tau (MAPT). Tau stabilizes microtubules and helps with axonal transport. In a disease state tau becomes hyperphosphorylated and truncated leading to its aggregation. More recently …

Leukemia Inhibitory Factor As A Neuroprotective Agent Against Focal Cerebral Ischemia, Stephanie Davis

USF Tampa Graduate Theses and Dissertations

Previous publications from this laboratory demonstrated that administration of leukemia inhibitory factor (LIF) (125 µg/kg) to young, male Sprague-Dawley rats at 6, 24, and 48 h after middle cerebral artery occlusion (MCAO) reduced infract volume, improved sensimotor skills, and alleviated damage to white matter at 72 h after the injury. In vitro studies using cultured oligodendrocytes (OLs) showed that LIF (200 ng/ml) also protects against 24 h of oxygen-glucose deprivation through activation of Akt signaling and upregulation of the antioxidant enzymes peroxiredoxin IV and metallothionein III. Other groups have demonstrated that LIF reduces neurodegeneration in animal models of disease, but …

Cell Permeability Studies Of Aapeptides And Novel Molecular Probes For Ad, Ge Bai

USF Tampa Graduate Theses and Dissertations

Alzheimer's diseases(AD) has been discovered and under research for more than 70 years, However there is no cure for these progressive and devastating diseases. Based on the following hypothsis: Aß metabolite problem/over production result in the accumulation, and lead to aggregation is the cause of Alzheimer’s disease. AApeptide and Melatonin derivatives can bind to Aß and block the aggregation of β amyloid monomers, decrease the toxicity of Aß to neurons and slow the progressive of Alzheimer’s diseases. In addition, AApeptide which mimic transmembrane peptide Tat will have similar transmembrane function. We have set up our goals as follows: 1) Using …

Modulation Of Whole Cell Currents In Human Neuroblastoma Cells Via The Hormone Aldosterone: An In Vitro Study, Harish Kumar Chittam

USF Tampa Graduate Theses and Dissertations

Ion channels play a critical role in maintaining homeostasis by moving various ions in and out of cells. The Na⁺-K⁺-2Cl^- or NKCC1 ion channel is involved in the regulation of Na⁺, K⁺, and Cl^- across cell membranes, and plays a key role in many forms of cellular physiology. In the cochlea, NKCC1 is involved in endolymph production and maintenance of the endocochlear potential. Our hypothesis is that blocking NKCC1 channels should directly impact auditory sensitivity causing hearing loss. Our lab has also shown that the hormone aldosterone (ALD) can upregulate …

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 …

Neuroinflammatory Alterations Via Cd-36 In Traumatic Brain Injury, Diana G. Hernandez-Ontiveros

USF Tampa Graduate Theses and Dissertations

Traumatic brain injury (TBI) has become an increasingly unmet clinical need due to intense military conflicts worldwide. Directly impacted brain cells suffer massive death, with neighboring cells succumbing to progressive neurodegeneration accompanied by inflammatory and other secondary cell death events. Subsequent neurodegenerative events may extend to normal areas beyond the core of injury, thereby exacerbating the central nervous system’s inflammatory response to TBI. Recently CD-36 (cluster of differentiation 36/fatty acid translocase (FAT), a class B scavenger receptor of modified low-density lipoproteins (mLDLs) in macrophages, has been implicated in lipid metabolism, atherosclerosis, oxidative stress, and tissue injury in cerebral ischemia, and …

Sigma Receptor Activation Mitigates Toxicity Evoked By The Convergence Of Ischemia, Acidosis And Amyloid-Beta, Adam Alexander Behensky

USF Tampa Graduate Theses and Dissertations

Stroke is the fifth leading cause of death in the United States and a major cause of long-term disability in industrialized countries. The core region of an ischemic stroke dies within minutes due to activation of necrotic pathways. Outside of this core region is the penumbral zone, where some perfusion is maintained via collateral arteries. Delayed cell death occurs in this area due to the triggering of apoptotic mechanisms, which expands the ischemic injury over time. The cellular and molecular events that produce the expansion of the ischemic core continue to be poorly understood. The increases in the amyloid precursor …

Strategies For Preventing Age And Neurodegenerative Disease-Associated Mitochondrial Dysfunction, Vedad Delic

USF Tampa Graduate Theses and Dissertations

Mitochondrial dysfunction plays a pivotal role in the development of aging phenotypes and aging-associated neurodegenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and Amyotrophic lateral sclerosis (ALS). Strategies that restore mitochondrial dysfunction may rescue the deficits of central metabolism in these disorders and improve cell survival. For example, we found that modulating the mTOR signaling pathway in a tissue culture model of aging-induced mitochondrial DNA mutation enhanced mitochondrial function as evidenced by increased oxygen consumption. Our previous melatonin studies also led us to hypothesize that caloric restriction and the hormone melatonin would reverse brain mitochondrial dysfunction in animal …