Medicine and Health Sciences Commons^™

Neural Mechanisms Of Estrogen And Inflammation In Female Stress Susceptibility, Samantha Jane Bouknight

Theses and Dissertations

Posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) are highly debilitating psychiatric disorders that notably share stress as an etiological factor. Stress is a common occurrence experienced daily by virtually everyone and, while most people are resilient, a substantial portion of the population exhibit risk factors that yield them susceptible to developing stress-related psychiatric disorders. One prominent factor that has long been known to increase this risk is the female biological sex with women presenting at least twice as often with disorders like PTSD and MDD compared to men. Interestingly, this bias exists distinctly during the reproductive years and …

Combining Repetitive Transcranial Magnetic Stimulation (Rtms) With Corticosteroid Joint Injections (Cji) For The Treatment Of Chronic Axial Pain (Cap): A Pilot Double-Blinded Randomized-Controlled Trial, Anike A. Alarape Ms

Electronic Thesis and Dissertation Repository

Chronic axial pain (CAP) is a debilitating condition impacting millions globally, with traditional treatments providing only short-term relief. This pilot study explored the primary outcomes of feasibility, tolerability, and safety, as well as the secondary outcomes of pain intensity, disability, quality of life, and patients’ perceived response to the combined intervention of repetitive transcranial magnetic stimulation (rTMS) and corticosteroid joint injections (CJI) as a novel approach to address CAP. Sixteen participants from St. Joseph’s Healthcare Pain Clinic were randomized (1:1) to receive 11 active or sham rTMS sessions over 12 weeks, with follow-up until week 24 or their next CJI, …

Differential Effects Of Cannabis Vapour Constituents On Brain Connectivity: Exploring The Long-Term Effects Of Adolescent Exposure, Pedro Marinho

Electronic Thesis and Dissertation Repository

Cannabis use is common in adolescence and there is evidence for sex differences regarding the long-term effect of cannabis use. We aimed to investigate how exposure to 3 types of cannabis vapour in adolescent rats impacts brain development using magnetic resonance imaging. Male and female Sprague Dawley rats were divided into four groups and exposed to high-CBD, high-THC, balanced CBD + THC, or air at post-natal days 28-42 using a vaporizer. In adulthood, rats underwent diffusion and functional MRI. Results indicated sex-dependent differences in the long-term effects of cannabis exposure in the adult brain. In male rats, we found a …

In Vivo Examination Of Peripheral Drivers Of Alzheimer’S Disease, Celso Catumbela

Dissertations & Theses (Open Access)

Alzheimer’s disease (AD) is the leading cause of dementia worldwide, and predominantly affects elderly populations. This disease is well known for its effects on the brain, but a wealth of clinical reports show that dementia can also modify, or be modified by, various peripheral and systemic processes. Yet, the pathological contribution of peripheral comorbidities to AD remains to be fully understood. In an attempt to address some knowledge gaps, we characterized the cerebral and peripheral pathology in mice with history of either liver injury or sepsis. In the former subjects, we found that even in the absence of genetic risk …

Neural Interactions In Bottom-Up Communication, Prashant Chama Raju

Graduate Theses and Dissertations

The visual system’s remarkable ability to process vast amounts of sensory information rapidly and accurately is fundamental to cognitive neuroscience. This study investigates a key aspect of this capability: the compartmentalization of information into feature-specific subspaces during bottom-up communication. My primary question was: does Canonical Correlation Analysis (CCA) reveal a subspace that encodes color and direction of moving dot stimuli? I found that the first canonical component (CC1) does an excellent job decoding the stimuli, despite being one-dimensional while the stimuli were drawn from a two-dimensional space (red-green and up-down plane). I demonstrate that motion features are processed within distinct …

Exploring The Effect Of Combining Repetitive Transcranial Magnetic Stimulation With Functional Electrical Stimulation Cycling On Lower Extremity Function Following Incomplete Spinal Cord Injury, Fereshteh Ghahremani

Electronic Thesis and Dissertation Repository

Spinal cord injury (SCI) is a neurological condition that disrupts lower extremity function, limiting mobility and independence. This dissertation explores the feasibility, acceptability, and safety of combining repetitive transcranial magnetic stimulation (rTMS) with functional electrical stimulation (FES) cycling to improve lower extremity function following motor incomplete SCI (iSCI). This study is a case series pilot study in which participants with iSCI underwent a combined protocol of rTMS and FES cycling for six weeks. The results demonstrate the preliminary feasibility, participant acceptability, and safety of combining rTMS and FES cycling. While results varied between participants, one participant showed improvements in walking …

Self-Harm In Female Youth With Undiagnosed Adhd: Implementing American Academy Of Pediatrics Screening Guidelines, Roselie M. Woodard

Dissertations

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. If undiagnosed or untreated, ADHD can lead to severe psychosocial issues such as academic failure, substance abuse, unplanned pregnancy, and incarceration. The financial burden in the U.S. from diagnostic errors creates an immense, rising fiscal impact. Early diagnosis and management are crucial to prevent these complications.

Females with ADHD, particularly those with the inattentive subtype, often face diagnostic challenges due to symptom masking and over-compensation. This results in poorer cognitive functioning and self-esteem compared to males with ADHD. ADHD is linked to autonomic nervous …

Investigating Synergistic Effects Of Mild Traumatic Brain Injury And Reduced Cholinergic Tone On Attentional Deficits And Alzheimer's-Like Pathology In Haβ And Htau Mice, Elizabeth M. Teasell

Electronic Thesis and Dissertation Repository

Mild traumatic brain injury (mTBI) increases the risk of Alzheimer’s disease. The early cholinergic decline in Alzheimer’s disease and cholinergic damage observed after TBI suggest a distinct role of this neural system in vulnerability to Alzheimer’s disease following TBI. This thesis evaluated the role of repetitive mTBI and cholinergic dysfunction in the development of cognitive deficits, specifically attentional deficits, and Alzheimer’s-related pathology in mice expressing humanized amyloid-beta and tau and a vesicular acetylcholine transporter knockdown to induce a mild cholinergic deficit. Using the rodent continuous performance test, it was shown that repetitive mTBI in the presence of an already vulnerable …

Assessing The Effects Of Repetitive Mild Traumatic Brain Injury On Risk/Reward Decision Making And Catecholamine Associated Proteins, Christopher Knapp

Theses and Dissertations

Mild traumatic brain injury (mTBI) disrupts cognitive processes that influence risk taking behavior; however, the effects of repetitive mild injury (rmTBI) or whether these outcomes are sex specific are unknown. Risk/reward decision making is mediated by the prefrontal cortex (PFC), which is densely innervated by catecholaminergic fibers. Aberrant PFC catecholamine activity has been documented following TBI and may underlie TBI-induced risky behavior. Here, we exposed rats to sham (no injury), single, or three closed-head controlled cortical impact (CH-CCI) injuries to characterize the effects of rmTBI on 1) risk/reward decision making behavior using a probabilistic discounting task (PDT) and 2) levels …

Cognitive Changes In Early Untreated Parkinson's Disease, Kunj Patel

Electronic Thesis and Dissertation Repository

Cognitive impairment is the most common non-motor symptom in Parkinson’s disease (PD), affecting up to one-third of early-stage patients. However, the cognitive profile in early PD remains unclear due to the use of heterogenous samples of disease severity, small sample sizes, and the inclusion of medication effects. This study aims to characterize cognitive deficits in early PD using a large, drug-naive sample. This study examined performance on the Montreal Cognitive Assessment and the Hopkins Verbal Learning Test from the Parkinson’s Progression Markers Initiative dataset (n= 643 patients with PD; n= 240 healthy controls). Patients were restricted to …

Cannabis Exposure During Pregnancy And Neural Mechanisms Of Parenting: Assessing Neural Responses To Infant Cues And Parenting Outcomes, Shannon Powers

Electronic Theses and Dissertations

As legalization of cannabis and cannabinoids spreads in the United States, access and use of cannabis during the prenatal period has increased. There is limited knowledge on the effects of prenatal cannabis use on the parental brain. One way to identify potential effects of cannabis on parenting is through studying parenting brain functions and behavior. Cannabis use disorder (CUD) has been shown to be associated with lower positive parenting and lower sensitivity to infants, but it is unclear by what mechanisms. The following two studies address this gap in knowledge by examining the association between cannabis use during the prenatal …

Quantifying Resting-State Functional Connectivity In Critically Brain-Injured Patients: A Graph-Theoretical Approach With Fnirs, Ira Gupta

Electronic Thesis and Dissertation Repository

Assessment of consciousness in behaviourally unresponsive patients with critical brain injuries continues to be a challenge. There remains a need for robust tools that can accurately characterize preserved cortical function and predict patient outcomes. In the present study, functional near-infrared spectroscopy is employed in conjunction with graph theory and machine learning to quantify resting-state functional connectivity in 16 acutely brain-injured patients and 23 healthy controls. Results revealed significant channel-level differences between the groups for three graph metrics, including degree, clustering coefficient, and local efficiency. Further investigation using machine learning algorithms revealed that these metrics can be used to distinguish between …

Fine-Tuning Gene Expression: A Novel Therapeutic Approach For Rett Syndrome, Yewon Rhee

Master's Theses

Rett Syndrome (RTT) is a neurodevelopmental disorder that is characterized by a myriad of debilitating symptoms impacting nearly every aspect of life, including motor and gait impairment, social and cognitive deficits, as well as seizures and breathing abnormalities. RTT is caused by X-linked de novo loss-of-function mutations in the methyl-CpG binding protein 2 gene (MECP2), which is an essential epigenetic modulator. Any cure for RTT must directly target MECP2, a highly dosage-sensitive gene. This thesis developed a novel MECP2-targeted therapeutic approach using site-blocking antisense oligonucleotides to prevent microRNA-induced repression of MECP2, allowing fine-tuned control of gene expression. Here we report …

Flanker Task Performance In Young And Older Adults: A Behavioral And Erp Study, Fatima Medrano

Dissertations, Theses, and Capstone Projects

Research suggests that as we get older, executive function abilities decline (Hasher & Zacks, 1988; Salthouse, 1996). One affected ability is that of inhibitory control, which aids in monitoring our responses to non-target stimuli or information. Current research on inhibition reveals inconsistencies across studies. Monitoring brain responses during the Flanker (used to measure inhibitory control) task may add valuable insight into the processes underlying group differences behaviorally, by studying the N200 and P300 event-related potentials which have been associated with inhibitory control processes. This study investigated whether there are differences between older and younger adults in inhibitory control and whether …

A Thorough Examination Of Different Elisa Kits To Determine The Concentration Of S100b Linked To Intracranial Hemorrhage, Anthony Phan

University Honors Theses

Background: Traumatic Brain Injuries (TBI) and Intracranial Hemorrhages (ICH) are one of the leading causes of death. Faster diagnosis and treatment positively impact patient outcomes. Two protein markers (UCHL-1 and GFAP) were approved by the FDA as an indicator for prediction indicators of an ICH or moderate TBI.

Methods: In this project, the S100 Calcium Binding Protein B (S100B) was measured by performing an enzyme-linked immunoglobulin assay (ELISA) on the placebo arm of the Prehospital Tranexamic Acid Use for Traumatic Brain Injury" clinical trial. The aim of this project is to compare glial fibrillary acidic protein (GFAP) concentrations that were …

Measurement Of And Contributors To Developmental Coordination Impairment, Jeffrey D. Konrad

WUSM Theses and Dissertations – All Programs

Movement drives childhood development. As motor skills improve across development, a child becomes capable of greater interactions with their physical and social environment. Children with motor impairments miss out on these interaction opportunities and their development across a variety of domains can suffer. There is accumulating evidence that poor motor competence relates to an array of developmental outcomes such as educational achievement, reading skills, social development, and emotional regulation. Two developmentally important motor impairments are poor motor competence and hyperactivity which are associated with Autism Spectrum Disorder (ASD), Developmental Coordination Disorder (DCD), and/or Attention Deficit Hyperactivity Disorder (ADHD). Critical to …

Role Of Dunc-13 Isoforms In Alcohol Sensitivity In Drosophila, Makenzie Havard

Honors Theses

Functional alcohol tolerance is an adaptation made by the nervous system to high doses of alcohol, and is seen by a significant reduction in sensitivity to this drug. This tolerance is a significant contributing factor in the progression to Alcohol Use Disorders. A major goal of alcohol research is to understand how alcohol induces this tolerance. Dunc13 is a presynaptic active zone protein essential in synaptic vesicle docking and priming. Alcohol binds to the C1 domain of Dunc13 at physiological concentrations, which inhibits Dunc13 from binding Diacylglycerol. This inhibition is predicted to reduce Dunc13 activity and presynaptic activity. Yet, genetically …

Addressing Stroke Care Disparities Through Patient Education, Christina Annerino

Honors Capstones

It has been found across current studies and evaluations of stroke care and patient outcomes that there is a disparity in disability and mortality between male and female patients who have experienced stroke. The aforementioned studies did not identify the cause of this disparity, although a number of hypotheses for this phenomenon were provided. This study then conducted a preliminary survey of 130 participants, both men and women, aged 18-80 years old, to evaluate potential barriers to accessing stroke care and receiving treatment effectively. Preliminary survey data demonstrated consistent gaps in knowledge related to stroke risks, stroke symptoms, and when …

Healthy Aging Modulates The Neural Oscillatory Activity Underlying Basic Visual Processing And Verbal Working Memory, Seth D. Springer

Theses & Dissertations

Worldwide economic and medical improvements have led to profound demographic shifts towards an older overall population. Unfortunately, with older age comes a variety of neurological changes which act to decrease individual quality of life and independence. Since the advent of functional neuroimaging, investigation of age-related changes in neural activity has been of particular interest. However, changes in population-level neural dynamics with age remain poorly characterized. Herein, we utilized magnetoencephalography (MEG), comprehensive neuropsychological assessments, and advanced analytical techniques to investigate spectrally-specific changes in neural oscillatory activity in a healthy aging population. First, we examined age-related deficiencies in visual processing using a …

Perinatal Buprenorphine Effects On Offspring Growth, Opioid Withdrawal, And Brain Morphology In Rats, Parker Barnes

Electronic Theses and Dissertations

Opioid use disorder (OUD) impacts 5.6 million people in the US. Buprenorphine (BUP) is a commonly prescribed opioid medication used to treat OUD, including in pregnant women. However, opioid use during pregnancy is associated with poorer infant outcomes including reduced fetal growth, neurodevelopmental deficits, and neonatal opioid withdrawal syndrome (NOWS). Recent clinical data suggests that providing mothers with a lower dose of BUP may result in fewer negative outcomes in infants. Here, a preclinical rodent model of low-dose perinatal BUP exposure was used to study offspring health outcomes in the neonate, juvenile, and adolescent offspring. Dams were given clinically relevant …

Molecular Mechanisms Of Opioid Use Disorder In Human Brain Models, Emily Mendez

Dissertations & Theses (Open Access)

Opioid use disorder (OUD) is a national and global public health crisis with no end in sight. While studies from animal models hint at widespread epigenetic and transcriptomic alterations of opioid drugs, the molecular consequences of long-term exposure to opioid drugs in human brain is still unclear, and human-centered translational models are necessary to discern the human cell type-specific effects of OUD.

Using postmortem brain Brodmann area 9 (BA9) from the UTHealth Brain Collection for Research on Psychiatric Disorders, I identified angiogenic gene networks perturbed in the RNA and protein of OUD subjects, as well as downregulation of many neuron-correlated …

Control Of Muscle Activation In The Lower Limbs During Leg Cycling After A Motor Complete Spinal Cord Injury., Jae Fish

Electronic Theses and Dissertations

Spinal cord injury (SCI) affects the central nervous system (CNS) causing muscle paralysis and autonomic dysfunctions throughout the body. Muscle activation after SCI is essential to facilitate functional recovery and may be produced via remaining input from supraspinal centers, the central pattern generators (CPG), or muscle stretch reflex responses. In this study, assisted leg cycling is evaluated as a tool to identify the neural structure control of muscle activation after motor complete SCI. Eight individuals with a complete or sensory incomplete SCI between C2 and T5 participated in the study. Participants completed leg cycling trials with and without supraspinal intention …

Sex And Age Differences In Near-Infrared Spectroscopy Responses And The Resulting Influences On Cognition, Miranda K. Traylor

<strong> Theses and Dissertations </strong>

Vascular dysfunction is the earliest known marker of neurodegeneration. However, limited research has been conducted to determine if changes in peripheral vascular function track differences in brain health. Therefore, the purpose was to determine if previously reported sex differences in near-infrared spectroscopy (NIRS) vascular occlusion test (VOT) parameters persist across the lifespan and if these differences track age- and sex-related differences in a cognitive task. Ninety-nine healthy, cognitively intact adults (50 women, 49 men) across the adult lifespan (19-81 yrs) were used for analysis. The combination of NIRS-VOT was used to quantify microvascular function. Cognition was defined as the time …

Investigations Into The Relationship Between Menopause And Alzheimer’S Disease Pathology In A Mouse Model With Ovarian Follicle Depletion, Amanda M. Leisgang Osse

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s Disease (AD) currently affects about 6.9 million Americans, with over two-thirds of those individuals being women. Interestingly, changes in the brain indicative of AD coincide with the onset of menopause. Post-menopausal women have significantly higher levels of AD pathologies, including amyloid beta and hyperphosphorylated tau, than pre-menopausal women. To investigate the relationship between AD pathologies and menopause, we induced menopause-like state in an AD mouse model, APP/PS1, by treatment with 4-vinylcyclohexene diepoxide (VCD) to accelerate ovarian follicle depletion. To monitor the transition to menopause, vaginal lavages and cytology was performed to determine if mice reached anestrous. Both female APP/PS1 …

A Low Dose Of Electro-Psychedelic Treatment Increases Neuronal Dendritic Arborization And Filopodic Spine Density, Elaine Aquino Vasquez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neuropsychiatric disorders remain a formidable challenge to the global healthcare system, necessitating innovative treatments to address their complex pathophysiology. Alternative therapeutic approaches, including electroconvulsive treatment (ECT) and psychedelics, have gained attention for their capacity to relieve a broad range of symptoms. ECT is a long-standing effective therapy for patients, especially treatment-resistant ones. Psychedelics, like psilocybin, can induce profound and sustained therapeutic effects. The limited understanding of their mechanisms of action, compounded by the negative stigma surrounding ECT and psilocybin, prevents them from being used as adjunct agents. ECT and psilocybin promote synaptic plasticity and modulate neural remodeling, yet their comparative …

The Mitochondrial Membrane Potential As A Screening Tool For Immunostimulation, Kendra Mcglothen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The rise of neuroinflammatory disorders highlights the importance of early detection and intervention for more effective treatment options. Neuroinflammation is associated with the pathogenesis of many neurological disorders, including Major Depressive Disorder, Alzheimer's disease, and Multiple Sclerosis. There has been a focus on neurons to advance our understanding of the underlying mechanisms of neuroinflammation and its role in neurodegeneration. However, recent studies have highlighted the pivotal role of glial cells, particularly microglia, in neuroinflammation due to their active participation in the immune response. This study investigates glial-specific indicators of morphology, metabolic changes, and drug efficacy in neuroinflammatory conditions. By analyzing …

The Feasibility Of High-Intensity Training To Improve Self-Control And Occupational Participation In At-Risk Adolescents, Tashia Kaplan

UNLV Theses, Dissertations, Professional Papers, and Capstones

PurposeAdolescence is a challenging time navigating self-control and decision-making, creating vulnerability to developing poor habits and unhealthy behaviors. This feasibility study aimed to determine if a high-intensity training program (HIT) would improve self-control, health-related behaviors, and healthy occupational participation in at-risk adolescents in the Real Talk Youth Impact Program (Real Talk), measured by the Occupational Experience Profile (OEP).

Methodology Three at-risk adolescent were recruited via convenience sampling from Real Talk to participate in a twelve-session HIT intervention, one participant completed all sessions. Researchers used a quasi-experimental exploratory sequential mixed-methods design to examine self-control, health-related behaviors, and occupational participation measured …

The Influence Of Bilateral Dual Source Transcranial Direct Current Stimulation On The Progression Of Muscle Fatigue, Eliza Clinton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Transcranial direct current stimulation (tDCS) applied unilaterally to the primary motor cortex (M1) can significantly prolong the time to task failure (TTF) of a fatiguing contraction. The primary purpose of the study was to examine the influence of bilateral dual source tDCS (dstDCS) applied over the left and right M1s (ds-tDCS) on the TTF of a precision grip task. This was accomplished through the utilization of a double-blind, randomized, SHAM-controlled, within-subjects design. Fourteen participants completed two experiments (ds-tDCS and SHAM stimulation conditions) with a seven-day washout period between sessions. Each experiment involved the performance of a sustained isometric fatiguing contraction …

The Influence Of Bihemispheric Transcranial Direct Current Stimulation On Muscle Fatigue, Ananya Singh Chauhan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Unilateral transcranial direct current stimulation (tDCS) using two electrodes placed over the primary motor cortex (M1) and the contralateral supraorbital (SO) region (M1-SO montage) has been shown to decrease the progression of muscle fatigue. The primary purpose was to determine the impact of bihemispheric tDCS (bi-tDCS) applied over the left and right M1s (bi-tDCS) on the time to task failure (TTF) of a precision-grip task. The study implemented a double-blind, randomized, SHAM-controlled, within-subjects design. A total of 20 participants performed two experimental sessions (bi-tDCS and SHAM conditions) separated by a one-week washout. During each experimental session, a fatiguing isometric contraction …

Investigating The Role Of Diet In Modulating Neuroinflammation In Health And Disease, Rasa Valiauga

Dissertations

An estimated 55 million people worldwide suffer from dementia, with the prevalence expected to drastically increase in the coming years as the population ages. Alzheimer’s disease (AD) is the most common form of dementia and the substantial burden associated with AD has been recognized as a growing public health issue. Despite significant advancements in uncovering the mechanisms which play a role in disease pathology, there is currently no cure or effective treatments. AD is highly complex and multifactorial, with accumulation of misfolded protein, oxidative stress, and inflammation among the numerous etiological processes implicated in disease pathogenesis. While genetic risk factors …