Medicine and Health Sciences Commons^™

The Relationship Of Plantar Sensation With Standing Balance And Gait Post-Stroke, Stephen Parsons

Electronic Thesis and Dissertation Repository

Gait and balance dysfunction after stroke limit independence and quality of life. Numerous contributing factors have been investigated but the role of sensation deficits has received little attention. This thesis investigated the relationship between plantar cutaneous sensation and 1) standing balance, 2) gait, and 3) use of vision to compensate for sensory loss with a secondary analysis of data from individuals with subacute stroke. Associations between standing balance, gait and sensation were investigated with Spearman correlations. Individuals classified as impaired or intact sensation were compared on gait and standing balance measures. This thesis found plantar sensation is related to standing …

Genetic And Chemical Dissection Of Bloodbrain Barrier Development In Zebrafish, Robyn Anne Umans

Theses and Dissertations (ETD)

The blood-brain barrier (BBB) maintains a homeostatic environment as well as prohibits the entrance of xenobiotics into the brain. Because of these qualities, drug delivery is a fundamental challenge for the treatment of many diseases of the central nervous system (CNS). Along with limiting the access of therapeutics into the brain, the BBB is also impaired in CNS pathologies. Understanding the molecular cues that are essential for healthy BBB development and integrity may reveal targets for drug delivery leading to decreased progression or possible treatment of many detrimental CNS diseases. While the central features of the BBB have been accepted, …

Hemispheric Asymmetry In The Perception Of Musical Pitch Structure, Matthew Adam Rosenthal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Both the left and right hemispheres contribute to the perception of pitch structure

in music. Music researchers have attempted to explain the observed asymmetries in the perception of musical pitch structure by characterizing the dominant processing style of each hemisphere. However, no existing characterizations have been able to account for all of the empirical findings. To better explain existing empirical findings, this dissertation characterizes the left hemisphere as dominant in temporal pitch processing (i.e. with respect to the sequential ordering of pitches) and the right hemisphere as dominant in non-temporal pitch processing (i.e. without respect to the sequential ordering of …

Postural Sway And Brain Hemispheric Power Spectral Density Under Different Attentional Focus Conditions, Sharon Jalene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the differences, if any, in the root mean square error (RMSE) of postural sway and hemispheric power spectral density (PSD) in the alpha and beta bands (8-12Hz and 12-25Hz) during different conditions of attentional focus (i.e., internal focus (IF), and external focus (EF) and a control condition (C)). Previous studies have shown that the adoption of IF and EF significantly alter motor performance and that EF promotes automaticity (Wulf, 2013). Sports performance and balance studies utilizing EEG spectral analyses report increased alpha oscillations during expert performance and stable balance and increased beta …

The Effects Of Sensory Integration On Short Term Memory In College Students, Chelsea B. Tolliver

Chancellor’s Honors Program Projects

No abstract provided.

Measuring The Role Of Inhibition In Auditory Discrimination In Mice, Tazima Nur

Graduate Theses and Dissertations

Understanding how inhibitory neurons affect sensory information processing in the cerebral cortex is an ongoing goal of both neuroscience and statistical physics research. In this master's thesis research project, an experimental system has been designed and built for studying how auditory dynamic range depends on inhibitory neurons, based on observations of mouse behavior. In this thesis, firstly, the topic of inhibition and information processing has been introduced. Then two papers related to inhibition and dynamic range has been reviewed in detail. One of the papers is an experimental work that analyzes the affect of inhibition on dynamic range. The other …

Quantitative Mri Correlates Of Hippocampal And Neocortical Pathology In Intractable Temporal Lobe Epilepsy, Maged Goubran

Electronic Thesis and Dissertation Repository

Intractable or drug-resistant epilepsy occurs in over 30% of epilepsy patients, with many of these patients undergoing surgical excision of the affected brain region to achieve seizure control. Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to investigate histopathological correlates of quantitative relaxometry and DTI from hippocampal and neocortical specimens of intractable TLE patients. To achieve this goal I developed and evaluated a pipeline for histology to in-vivo MRI …

Differences In Brainstem Level Encoding Of Am And Fm Signals In A Rat Model For Dyslexia, Stephen Anthony Chabot

Open Access Theses

Developmental dyslexia is a language learning disorder that affects a significant portion of the population. Many subjects who suffer from dyslexia show auditory processing deficits as children, some of which persist into adulthood, which impair their ability to learn one or more aspects of language. There is evidence that some types of training can correct the auditory processing deficits and bring the subject to a normal reading or speaking proficiency for their age group. One common rodent model for dyslexia is the cortical freeze lesion model. This model induces a lesion in the rat cortex similar to the microgyria present …

Brain Death Determination, Bethani Knipfer

Nursing Student Class Projects (Formerly MSN)

Patient MR was a seventeen year old female involved in a motor vehicle collision which resulted in a traumatic brain injury leading to declaration of brain death. The pathophysiology behind the traumatic brain injury, the concept and use of a brain tissue monitoring device, and the tests used in the declaration of brain death will be explored. When brain death is determined, the patient has the opportunity to become an organ donor. Thousands of people are waiting for organs to become available. This is a huge healthcare concern that may be decreased if the general public is more educated regarding …

Role Of Astrocyte Network In Edema After Juvenile Traumatic Brain Injury, Andrew Minoru Fukuda

Loma Linda University Electronic Theses, Dissertations & Projects

Juvenile traumatic brain injury (jTBI) is the leading cause of death and disability in young children and adolescents. Despite its lasting detrimental effects on the developing brain, no pharmacological treatment exists. One of the pathological hallmarks of jTBI is edema. Astrocytes play a key role in the edema process, and have been hypothesized that numerous astrocyte networks allow communication and propagation of edema and secondary injury spread. Two key astrocyte proteins are hypothesized to have a central role in the edema process: Aquaporin 4 (AQP4) and Connexin 43 (Cx43). AQP4 is expressed extensively in astrocyte endfeet, which surrounds the blood …

Regulation Of Metabotropic Glutamate Receptor 5 Activity By Ca2+/Calmodulin-Dependent Protein Kinase Iiα, Fitore Raka

Electronic Thesis and Dissertation Repository

The metabotropic glutamate receptor 5 (mGluR5) is a GPCR coupled to the heterotrimeric G protein Ga_q/11 and activates signaling pathways important for excitatory synaptic transmission. Emerging studies reveal that Amyloid b (Ab) acts as an extracellular scaffold for mGluR5. We have identified Ca²⁺/Calmodulin-dependent protein Kinase IIα (CAMKIIα) as an interacting protein of mGluR5. We hypothesize that CaMKIIα plays a role in mGluR5 signaling and Ab produces differential effects on the regulation of mGluR5 by CAMKIIα. We find that overexpression of CAMKIIα significantly impairs mGluR5-mediated ERK1/2 phosphorylation but does not effect inositol phosphate formation or Ca²⁺ release. …

Investigation Of Sox9 Ablation On Neuroplasticity And Recovery After Ischemic Stroke, Bethany Robin Lenore Bass

Electronic Thesis and Dissertation Repository

Neuroplasticity is a key factor in post-stroke functional recovery. A chief inhibitor of post-stroke neuroplasticity is the expression of chondroitin sulfate proteoglycans (CSPGs). Recent research has shown that the transcription factor SOX9 is responsible for upregulating the expression of CSPGs in the injured central nervous system. Accordingly, CSPG levels are significantly lower in mice with the Sox9 gene conditionally knocked out. The purpose of this study was to determine how Sox9 ablation affects neuroplasticity and recovery after stroke. Behavioural test results revealed that Sox9 KO mice exhibited significantly improved functional recovery after stroke compared to controls. This correlated with increased …

The Antisaccade Task: Visual Distractors Elicit A Location-Independent Planning 'Cost', Jesse C. Desimone

Electronic Thesis and Dissertation Repository

Prosaccades are rapid eye movements with direct stimulus and response relations and are designed to bring the fovea onto a target or area of interest. In contrast, antisaccades require the inhibition of a prosaccade and the evocation of a saccade to a target’s mirror-symmetrical location. Previous work has shown that a remote (i.e., midline, contralateral) – but not proximal (i.e., ipsilateral) – task-irrelevant distractor relative to a visual target delays prosaccade reaction times (RT) (i.e., remote distractor effect: RDE). To my knowledge, however, no work has examined whether antisaccade RTs are similarly influenced by a RDE. Accordingly, I sought to …

Task-Switching In Oculomotor Control: Systematic Investigations Of The Unidirectional Prosaccade Switch-Cost, Jeffrey Weiler

Electronic Thesis and Dissertation Repository

An antisaccade requires suppressing a stimulus-driven prosaccade (i.e., response suppression) and remapping a target’s spatial location to its mirror-symmetrical position (i.e., vector inversion). Notably, my previous work demonstrated that the successful execution of an antisaccade selectively lengthens the reaction time (RT) of a subsequently completed prosaccade (i.e., the unidirectional prosaccade switch-cost; Weiler & Heath, 2012a; Weiler & Heath, 2012b). Thus, the objective of this dissertation was further investigate, and ultimately provide a mechanistic explanation for the unidirectional prosaccade switch-cost.

In Chapter Two, I demonstrate that the magnitude of the unidirectional prosaccade switch-cost is not dependent of the number of …

Bdnf Maintains Adult Taste Innervation And Is Required For Taste Nerve Regeneration After Injury., Lingbin Meng

Electronic Theses and Dissertations

Brain derived neurotropic factor (BDNF) is required for the gustatory neuron survival,target innervation, and taste bud maintenance during development. However, whether BDNF has any function in the adult gustatory system in normal conditions or after nerve injury is unclear. To address these issues, I inducibly removed BDNF in all cells expressing BDNF in adult mice. In the experimental animals, Bdnf expression decreased to 5% of control mice in the lingual epithelium and geniculate ganglion (p< 0.01) at both two weeks and ten weeks after tamoxifen administration. I found no effect on taste bud morphology at four weeks following Bdnf gene deletion. However, ten weeks following Bdnf gene deletion, P2X3-positive and TUJ1-positive gustatory innervation to individual taste buds was reduced by nearly half (each with p < 0.01) and both taste bud volume and taste cell number decreased 30% (each with p< 0.01). These experiments demonstrate that BDNF is required for maintenance of normal levels of taste innervation and normal taste bud morphology in adulthood. In addition, taste cells expressing PLCß2 (phospholipase C ß2), a marker for taste cells that respond to sweet, bitter and umami, did not decrease after Bdnf gene deletion in the adult. Thus, the missing taste cells are of another type. This indicates that taste cell loss is not uniform across the various taste cell types, even if nearly all taste cell types receive the P2X3 and TUJ1 innervation. Since BDNF is required for initial innervation of the taste system and supports taste bud innervation and size in adulthood, it could also be required for nerve reinnervation after injury. To determine if Bdnf is still expressed following nerve section, the chorda tympani nerve (taste nerve) was sectioned and Bdnf level was detected with Real Time RT-PCR. Bdnf continued to be expressed at normal levels from two days to two months post-surgery in both geniculate ganglion and tongue epithelium. Therefore, BDNF could be involved with chorda tympani regeneration. To determine if this was the case, the Bdnf gene was deleted in adult inducible transgenic mice (under the control of a Ubiquitin promoter) two weeks before chorda tympani nerve section. Taste bud number was reduced by half in all genotypes at two weeks post-surgery (p < 0.01). For the remaining taste buds, gustatory innervation was nearly gone with only a little innervation from the trigeminal nerve remaining in the taste bud (p < 0.01). Taste bud volume (p < 0.01) and taste cell number (p< 0.01) were reduced by half for both control and experimental genotypes. Eight weeks post-surgery, taste bud number recovered in mice without Bdnf gene deletion, but did not recover in mice following Bdnf gene deletion (p < 0.01). Gustatory nerve innervation returned in 70% of the taste buds in control mice (p< 0.01). For those reinnervated taste buds, both taste bud volume and taste cell number increased to normal levels. However, in mice lacking the Bdnf gene, gustatory fibers only reinnervated 7.8% of the taste buds (p < 0.01); for most uninnervated taste buds, both taste bud volume and taste cell number remained small. These experiments demonstrate that BDNF is crucial for promoting regeneration of gustatory nerve fibers in adulthood. Following gustatory nerve section, considerable adult plasticity has been observed on the contralateral side including enlarged taste buds with more cells (Guagliardo and Hill, 2007). To determine if this anatomical change was associated with alter Bdnf expression. I examined Bdnf level in the geniculate ganglion and tongue epithelium on the contralateral side following chorda tympani nerve section. Results showed Bdnf expression increased two fold at two weeks post-surgery in geniculate ganglion on the contralateral side (p < 0.05), indicating BDNF may involve with the observed plastic changes. To determine if the increase in taste bud size was associated with increased innervation and/or regulated by BDNF, the Bdnf gene was then deleted in inducible knockout mice before nerve surgery, and taste bud size and amount of innervation were measured on the contralateral side. The results showed taste bud volume, taste cell number and a marker for nerve fibers all increased on the contralateral side in mice without Bdnf gene deletion at eight weeks post-surgery. This indicates that larger taste buds could be supported by increased TUJ1 positive fibers from trigeminal nerve. In addition, in mice lacking Bdnf, taste bud volume, taste cell number and innervation did not increase on the contralateral side after surgery, which indicates that Bdnf may contribute to larger taste buds on the contralateral side following nerve section by supporting increased innervation to the larger taste buds.

The Effect Of Acute Lps-Induced Immune Activation And Brain Insulin Signaling Disruption In A Diabetic Model Of Alzheimer's Disease, Andrew Scott Murtishaw

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer's disease (AD) is a neurodegenerative disorder marked by progressive cognitive impairments and pathological hallmarks that include amyloid plaques, neurofibrillary tangles, and neuronal loss. Several well-known mutations exist that lead to early-onset familial AD (fAD). However, these cases only account for a small percentage of total AD cases. The vast majority of AD cases are sporadic in origin (sAD) and are less clearly influenced by a single mutation but rather some combination of genetic and environmental risk.

The etiology of sAD remains unclear but numerous risk factors have been identified that increase the chance of developing AD. Among these risk …

Age-Associated Increases In Fkbp51 Facilitate Tau Neurotoxicity, Laura J. Blair

USF Tampa Graduate Theses and Dissertations

Tau is a protein which regulates microtubule stability and is heavily involved in axonal transport. This stability is dynamically controlled in part by over 40 phosphorylation sites across the tau protein which allows for binding and release from the microtubules. However, if abnormal hyperphosphorylation occurs, tau dissociates from the microtubules. Once released, the microtubules become unstable and the aberrant tau mislocalizes from the axon to the somatodendric compartment, where it aggregates. These aggregates are made of many pathological forms of tau including oligomeric species, paired helical filaments, and neurofibrillary tangles, all of which have associated toxicities. Tau pathology is a …

Humor's Effect On Short-Term Memory In Older Adults: An Innovative Wellness Paradigm, Gurinder Singh Bains

Loma Linda University Electronic Theses, Dissertations & Projects

Context: With ageing, the detrimental effects of stress can impair the ability to learn and sustain memory. Humor and the associated mirthful laughter can reduce stress by decreasing the hormone cortisol. Chronic release of cortisol can damage hippocampal neurons leading to impairment of learning and memory. Objectives: To examine the effect of watching a humor video on short term memory in older adults. Design: A randomized, controlled trial. Setting: Loma Linda University, Loma Linda, CA. Participants: 30 subjects: 20 normal healthy, older adults, 11 males and 9 females; 10 Type 2 Diabetic older adults, 6 males and 4 females. Intervention: …

Implications Of Human Umbilical Cord Blood Cells: An Immunotherapeutic Strategy For Alzheimer's Disease, Donna Darlington

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Alzheimer's disease (AD) is the most common progressive age related dementia and the fourth major cause of mortality in the elderly in the United States. AD is pathologically characterized by deposition of amyloid beta (Aβ) plaques in the brain parenchyma and neurofibrillary tangles (NFTs) within the neuronal soma. While pharmacological targets have been discovered, current strategies for the symptomatic or disease-modifying treatment of AD do not significantly slow or halt the underlying pathological progression of the disease. Consequently, more effective treatment is needed. One possibility for amelioration is using human umbilical cord blood cell (HUCBC) therapy. HUCBCs comprise a …

Preliminary Study On How Tumor Suppressor Nf2 Inhibits Transcriptional Coactivators Yap/Taz In The Developing Mouse Brain, Yu He

Theses and Dissertations (ETD)

Normal brain development requires precise coordination of neural progenitor proliferation and differentiation, the mechanism of which is not well known. Recently the tumor suppressor neurofibromatosis 2 (Nf2) was shown to regulate the balance of neural progenitor proliferation and differentiation in the developing mouse brain through the Hippo pathway effectors, transcriptional coactivators Yap/Taz. The molecular mechanism of how Nf2 regulates Yap/Taz is not understood. Here I showed that Nf2 regulated the Yap/Taz activity by decreasing the stability of Yap/Taz. The regulation was independent of Yap-S366 phosphorylation, which is required for Yap degradation. I also showed that Nf2 did not regulate Lats1/2 …

Wirelesseeg: Data Aquisition + Handheld Device, Michael Dylan Snowden, Madeline Threatt, Brent Mcferrin, David Platillero, Karsten Solies, Lindsey Hopf

Chancellor’s Honors Program Projects

No abstract provided.

Eye-Tracking Measures Of Attentional Bias In Cocaine Dependent Subjects, Nadeeka Dias

Dissertations & Theses (Open Access)

Cocaine-dependent (CD) subjects show evidence of attentional bias toward cocaine-related cues, and this measure of cue-reactivity is predictive of craving and relapse. In previous work, cue-reactivity and attentional bias have been assessed by models that present drug-relevant stimuli (e.g., cocaine-specific Stroop task) and measure physiological and behavioral reactivity (e.g., heart rate, reaction times). Studies have indicated competition between the higher-order cortical processes (frontal eye-fields, DLPFC) in voluntary eye control (i.e., anti-saccades) and more reflexive saccades driven by involuntary midbrain (superior colliculus) perceptual input (i.e., pro-saccades). In addition, neuroimaging studies in patients with cocaine dependence have shown activation in frontal regions …

Deep Learning Via Stacked Sparse Autoencoders For Automated Voxel-Wise Brain Parcellation Based On Functional Connectivity, Céline Gravelines

Electronic Thesis and Dissertation Repository

Functional brain parcellation – the delineation of brain regions based on functional connectivity – is an active research area lacking an ideal subject-specific solution independent of anatomical composition, manual feature engineering, or heavily labelled examples. Deep learning is a cutting-edge area of machine learning on the forefront of current artificial intelligence developments. Specifically, autoencoders are artificial neural networks which can be stacked to form hierarchical sparse deep models from which high-level features are compressed, organized, and extracted, without labelled training data, allowing for unsupervised learning. This thesis presents a novel application of stacked sparse autoencoders to the problem of parcellating …

Neuroplasticity And Mindfulness Meditation, Richard Widdett

Honors Theses

My thesis topic of choice was how mindfulness meditation is linked to neuroplasticity in the brain. The brain is an incredibly complex and powerful organ. Each area of the brain serves a specific purpose and is interconnected. Neuroplasticity is the term used to describe the molding and shaping of the brain based on our experiences from the moment we are born. Mindfulness is defined as the “ability to pay total attention to the present moment with a nonjudgmental awareness of the inner and/or outer experiences.” Many studies have been conducted researching the brain and meditation. The findings from these studies …

Ube3a Role In Synaptic Plasticity And Neurodevelopmental Disorders.The Lessons From Angelman Syndrome., Irina Filonova

USF Tampa Graduate Theses and Dissertations

Angelman Syndrome (AS) is a severe neurodevelopmental disorder that affects 1:12000 newborns. It is characterized by mental retardation, delayed major motor and cognitive milestones, seizures, absence of speech and excessive laughter. The majority of AS cases arise from deletions or mutations of UBE3A gene located on the chromosome 15q11-13. UBE3A codes for E3-ubiquitin ligase that target specific proteins for degradation. To date, a wide variety of Ube3a substrates has been identified. The accumulation of Ube3a-dependent proteins and their effect on the multitude of signal transduction pathways are` considered the main cause of the AS pathology. While the majority of research …

Evaluation Of Presynaptic Dopamine Dynamics After: Toluene Inhalation Or Trkb Receptor Activation, Aaron Kwaku Apawu

Wayne State University Dissertations

Dopamine (DA) neurons in the striatum mediate several functions of the brain and have been linked to a host of neurological disorders including Parkinson's disease and addiction, both of which occur as a result of dysfunction in the DA system. In the present study, our first objective was to understand how the striatal DA system adapts to acute and repeated administration of inhalant toluene. The use of toluene as inhalant, like other drugs of abuse, is known to perturb DA neurotransmission in the brain reward pathway. However, the exact mechanism underling toluene's influence on striatal DA neurotransmission is unknown. The …

Alterations In The Mouse Striatum Following Acute And Repeated Ethanol Exposure, Brooke D. Newman

Wayne State University Dissertations

Brain-derived neurotrophic factor (BDNF) is an important neuromodulator that has implicated in regard to several neurological disorders, including alcohol addiction. BDNF is also an important modulator of dopamine (DA), a neurotransmitter that is heavily implicated in addiction with one of the DA rich brain regions being referred to as the reward center of the brain. One of the focuses in alcohol dependence research includes determining risk factors that make an individual more susceptible to becoming dependent. BDNF has been of interest as a risk factor due to its involvement in ethanol consumption and addiction evidenced in a vast number of …

Longitudinal Change In Regional Cortices And Fluid Intelligence, Peng Yuan

Wayne State University Dissertations

Fluid intelligence (Gf) and crystalized intelligence (Gc) are two factors of the general intelligence. They have distinct age-related trajectories of change. Jung and Haier proposed Parieto-Frontal Integration Theory (P-FIT, 2007) to account for the inter-person variance in reasoning intelligence. Some brain regions such as prefrontal, parietal, temporal and anterior cingulate cortices were included in the P-FIT model and were hypothesized to be involved in fluid reasoning task. Therefore, in the current study, we examined latent growth curves (LGC) of longitudinal change in Gf, Gc, prefrontal cortex, parietal cortex, anterior cingulate, temporal cortex and primary visual cortex. Forty-six healthy middle-aged and …

Inattention And Hyperactivity Among Preschool Age Children Born Prematurely, Andrew Heitzer

Wayne State University Theses

A large body of literature shows that compared to children born at term, preterm- children are at increased risk for difficulties with inattention and hyperactivity. Less consistency exists, however, in the limited body of research exploring the contribution of early biological risk to behavioral disinhibition within the population of children born prematurely. Therefore, our goal was to examine perinatal variables that may influence activity level and hyperactivity among preterm preschoolers. Ninety-eight preterm (23.4 - 33.9 weeks gestation) preschoolers (3-4 years) participated in the study. Direct measures of inattention and hyperactivity as well as parental ratings were used to evaluate behavior. …

Endocannabinoid Involvement In Impulsivity And Decision-Making, Christopher P. Norris

Theses and Dissertations (Comprehensive)

Problem gambling is a widespread phenomenon with a prevalence estimate of 2.3% globally (Williams, Volberg, & Stevens, 2012). Although little is known about the neurochemistry underlying this pathological behaviour, evidence suggests that dysregulation of the brain’s endocannabinoid (eCB) system may be implicated in impulsivity and decision-making. For example, chronic cannabis users exhibit impulsive behaviour and impaired decision-making on the Iowa Gambling Task (IGT). The present study sought to further examine the role of the eCB system in problem gambling-related decision-making in laboratory rats using the five-choice serial reaction time task (5-CSRTT), and a recently-developed rodent analogue of the IGT called …