Neurosciences Commons^™

Exploring The Biological Basis For Exercise Neuroprotection In Parkinson’S Disease: A Cross-Sectional Study Of Exercise And Physical Activity On Inflammatory Cytokines And Neurotrophins, Leah Isabelle P. Alegre, Jacob M. Brewer, Adeline Florschutz, Kate E. Hamiltonthompson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Regular exercise and physical therapy are known to increase production of neurotrophins, including brain-derived neurotrophic factor (BDNF), and anti-inflammatory cytokines. These changes combine to theoretically protect and slow the progressive loss of neurons in Parkinson’s disease (PD). The purpose of this study was to examine the effect of exercise and physical activity on various anti-inflammatory and pro-inflammatory cytokines and neurotrophins in people with PD (PwP). This was a cross-sectional design involving PwP (n=37), aged 43-85 years, who participated in two 30-minute bouts of exercise (with brief rest breaks during and pre/post blood draws) separated by a week. Measures collected prior …

Effectiveness Of Cognitive Stimulation Therapy On The Quality Of Life Of Adults With Dementia: A Secondary Analysis, Evelyn Airam

UNLV Theses, Dissertations, Professional Papers, and Capstones

This secondary analysis study evaluated the effectiveness of Cognitive Stimulation Therapy (CST) on quality of life (QoL), depressive symptoms, and cognitive function in 108 community-dwelling older adults with cognitive impairments, including dementia. Outcomes involved Quality of Life (QoL) measured by the Quality of Life in Alzheimer’s Disease (QoL-AD), symptoms of depression by the Cornell Scale for Depression in Dementia (CSDD), and cognitive function using the Saint Louis University Mental Status (SLUMS). After the CST, significant improvements were observed in QoL (p = .004), depressive symptoms (p = .002), and cognitive function (p < .001), with small effect sizes. Additionally, a significant interaction between sex and dementia diagnosis status was found in predicting cognitive changes, suggesting that the relationship between dementia diagnosis and cognitive improvement differs by sex. No between-group differences were found for QoL or depression. Findings support CST as a multidimensional, non-pharmacological intervention that improves cognitive, psychological, and social outcomes. Although effects were small, consistent improvements are clinically meaningful given the progressive nature of dementia. This study extends existing literature by demonstrating CST’s effectiveness in a community-based setting and reinforces its alignment with occupational therapy’s emphasis on participation and holistic care. Results highlight the need for early intervention and expanded access to CST programs to enhance quality of life in this population.

Acute And Chronic Effects Of Neuroinflammation On Hippocampus And Anterior Cingulate Cortex Network Dynamics, Lauren A. Crew

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neuroinflammation has emerged as a critical modulator of cognitive function and neural circuit dynamics, yet the distinct contributions of acute and chronic neuroinflammation to brain function remain poorly defined. This dissertation examines how inflammation independently alters large-scale neural activity and behavior, focusing on interactions between the hippocampus (HPC) and anterior cingulate cortex (ACC), regions essential for memory and executive processes. Using in vivo electrophysiological techniques in a rodent model, this study compares the effects of short-term (acute) and prolonged (chronic) neuroinflammatory states, induced via Poly I:C, on neural oscillations, regional coherence, and spatial coding. Findings reveal that even transient inflammation …

The Speech-To-Song Illusion Across Development And The Effects Of High-Level Expectations, Rodica R. Constantine

UNLV Theses, Dissertations, Professional Papers, and Capstones

The typical listener can readily categorize auditory stimuli as either speech or song even though these structures share many acoustic similarities. These musical and linguistic categories may nevertheless take time to develop as children acquire language- and music-specific knowledge. In the Speech-to-Song (STS) illusion, multiple repetitions of a natural spoken utterance can give rise to a perceptual switch wherein the stimulus begins to sound song-like to the listener. While the STS illusion has been well-researched in adult listeners, it had yet to be investigated in children. In our study, we examined whether children experience the STS illusion by presenting participants …

Exploring The Processing Of Objects, Settings, And Global Properties In Natural Auditory Scenes, Margaret A. Mcmullin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Our auditory system has a remarkable ability to make sense of complex environments, allowing us to identify what we are hearing and where sounds come from. This process of auditory scene analysis is essential for situational awareness, decision-making, and effective communication in daily life. While much is known about how listeners segregate and identify individual sound sources (e.g., voices), less is understood about how global properties of a scene (e.g., openness, naturalness) contribute to perception. This dissertation examined how object- and setting-level information in natural auditory scenes are processed, and whether they rely on distinct or overlapping mechanisms. In Experiment …

Assessing The Effects Of Streptozotocin-Induced Hyperglycemia On Amyloid Beta Accumulation And Cognitive Behavior In A Mouse Model Of Alzheimer’S Disease-Related Pathology, Andrew Adonay Ortiz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s disease (AD) is an irreversible and devastating neurodegenerative disease characterized by progressive synaptic, dendritic, glial, and neuronal loss, collectively leading to impairments in learning, memory, and deterioration of cognitive and behavioral functions. AD is the most common form of dementia accounting for 60-80% of all cases. AD affects approximately 7 million Americans and is the 6th leading cause of death in the US. Furthermore, by 2050, the US is projected to spend over $1.1 trillion on AD-related treatments. Pathological hallmarks of AD include beta-amyloid (Aβ) plaques, intracellular neurofibrillary tangles (NFTs), and chronic neuroinflammation, which can promote and exacerbate both …

Alteration Of Peripheral Cytokines In Alzheimer’S Disease, Zhengshi Yang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s disease (AD) is a progressive neurodegenerative disease with the clinical symptoms of gradual cognitive decline and memory loss. Biologically, abnormal accumulation of Aβ (Aβ) plaque and tau tangles in the brain are the core pathological hallmarks in AD. Although inflammatory response is not specific to AD, emerging evidence suggests that the disrupted innate immune system within the central nervous system, particularly microglial activation, might act as the bridge linking Aβ aggregation to pathological phosphorylation and aggregation of tau. The inflammatory response was suggested to initially have a neuroprotective role of attempting to clear Aβ plaques, and then become neurotoxic …

Delineating Genetic Influences On Neurodegenerative Disorders And Infectious Diseases Through Advanced Computational Methods, Xiaowei Zhuang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Genetics plays a critical role in understanding the molecular mechanisms underlying neurodegenerative disorders and pathogen evolution in infectious diseases. For example, identifying genetic variants associated with a disease phenotype uncovers functional pathways that could lead to potential drug targets and therapeutic interventions. In addition, tracking the genetic evolution of pathogens enables early detection and warning of infectious disease outbreaks. In both applications, given the large amount of genetic data, advanced computational methods, including longitudinal and multivariate models, could significantly boost the statistical power and capture interrelationships among traits, environmental factors and genetic influences. This dissertation focuses on four applications of …

The Effects Of Non-Invasive Brain Stimulation On Excitability Of The Primary Motor Cortices And Complex Motor Task Learning, Erik Woodruff Wilkins

UNLV Theses, Dissertations, Professional Papers, and Capstones

Transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) are promising non-invasive brain stimulation techniques, particularly for clinical applications involving altered or impaired motor function, such as in stroke and Parkinson’s disease. Although tDCS and tACS are different modalities, both forms of stimulation operate on the same principle - weak electrical currents are delivered through electrodes placed on the scalp in specific configurations known as “montages”. The most commonly used montage for targeting the primary motor cortex (M1) is the M1-SO configuration. This montage leverages the established observation that cortical regions directly beneath the anode generally increase in …

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 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 …

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 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

Purpose

Adolescence 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 …

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 …

The Genetic Relationship Between Peripheral Inflammation And Alzheimer’S Disease, Davis Cammann

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alzheimer’s disease (AD) is the leading cause of dementia worldwide, and has become an ever-present problem in aging populations. An increasing body of evidence suggests that neuroinflammation is one of the key drivers of AD pathology. One overlooked contributor to this burden is peripheral inflammation throughout the body. Due to increased permeability of the blood-brain-barrier (BBB) in older age, inflammatory plasma proteins and immune cells infiltrate the CNS and drive neuroinflammation through interactions with neurons and glia. In addition, age-related changes in the composition of gut microbiome taxa lead to increased gut permeability and inflammatory burden. Because inflammatory factors are …

Systems Dynamics Of The Anterior Cingulate Cortex And Hippocampus In Behavioral Switching, Spatial Working Memory, And Disease, Ryan Wirt

UNLV Theses, Dissertations, Professional Papers, and Capstones

The electrophysiological properties of the hippocampus (HC) and anterior cingulate cortex (ACC) are the central focus of research on learning, memory, and neurological disease. Previous research has shown that HC is essential for forming new memories, spatial navigation, and temporal processing. While the function of ACC, located within the medial prefrontal cortex, remains controversial, it has a role in long-term memory recall, processing pain, monitoring current state, learning, schema updates, and information integrations. Interactions between the ACC and HC occur during social memory, spatial working memory performance, and long-term memory recall. Notably, the HC and ACC are among the first …

Markers Of Neuroinflammatory And Degenerative Processes In Professional Athletes With Traumatic Encephalopathy Syndrome, Brooke Conway Kleven

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: The clinical criteria for Traumatic encephalopathy syndrome (ccTES) were developed to improve the diagnosis of Chronic traumatic encephalopathy (CTE). This study aimed to determine whether there was an association between a clinical diagnosis of Traumatic encephalopathy syndrome (TES) and changes in serum biomarkers, balance, neuroimaging, and cognition among athletes in the Professional Athletes Brain Health Study (PABHS).Methods: Of the cohort, 130 professional fighters met age or retirement criteria and went to a consensus conference, with 52 fighters (40%) meeting the criteria for TES. A generalized linear model with generalized estimating equations was utilized to assess the odds of disease …

Dimensionality Of Natural Auditory Scene Perception: A Factor Analysis Study, Margaret A. Mcmullin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Theories of auditory and visual scene analysis suggest the perception of scenes relies on the identification and segregation of objects within it, resembling a detail-oriented processing style, but it is possible that a global-oriented process also occurs while evaluating auditory scenes. There is evidence for global properties that enable rapid recognition of visual scenes, even without recognizing the individual objects comprising the scene. It is our understanding that a similar line of research has not been explored in the auditory domain; therefore, we evaluated the contributions of high-level global and low-level acoustic information to auditory scene perception. A secondary aim …

Cognitive Testing For Sport Concussion: The Immediate Post-Concussion Assessment And Cognitive Testing (Impact), Julia E. Maietta

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sport concussion is among the most common injuries for an athlete to experience during sport participation. Because of the complex pathophysiological process that affects the brain during and after concussion, symptoms can be heterogeneous in presence and severity. Although most acute symptoms (e.g., headache, slowed processing speed, loss of consciousness, irritability, depression, anxiety) resolve within seven to 10 days for most athletes, there is evidence that higher initial symptom burden and other genetically based differences can lead to longer symptom duration and complicated recovery post-concussion. Because structural changes that commonly occur as a result of concussion (e.g., diffuse axonal injury) …

Investigating Conserved Mechanisms For Embryonic Eye Regrowth In Xenopus Laevis, Cindy Kha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Regeneration is a complex process to replace or restore tissue after damage. However, animals vary in their ability to regenerate tissue, and humans are limited in their abilities. Understanding how regeneration occurs in highly regenerative vertebrates, such as in Xenopus laevis frogs will lead to defining common regeneration mechanisms. In recent years, eye regeneration research in Xenopus laevis tadpoles provided new promising insight into the mechanisms necessary for repair of damaged eye tissue. Much progress has been made towards understanding the regenerative capability of the complex eye since Xenopus tadpoles can regenerate mature eye tissues, including: the optic nerve, retina, …

The Effects Of Executive Function Between Anxiety And Math Achievement In Adolescents, Mckenzie Hall

UNLV Theses, Dissertations, Professional Papers, and Capstones

Anxiety in Children can develop into pervasive disorders in adulthood if not treated. Research shows dysfunctional Executive Function (EF) and anxiety are both shown to have a negative impact on math achievement in children and adolescents (Trezise & Reeve, 2018; Kalaycioglu, 2015; Owens, Stevenson, Hadwin & Norgate, 2012). Chung, Weyandt, and Swentosky (2014) found biological and neuropsychological support for EF as a unitary and multifaceted processor for regulating our emotional states as well as our daily procedures. Anderson’s (2002) model of Executive Control System (ECS) allows the factors of EF to be examined using a developmental approach towards EF processes. …

Axon Initial Segment Morphology Across Typical Cortical Development And In Mouse Models Of Neurodevelopmental Disorders With A High Incidence Of Epilepsy, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) are commonly associated with a high incidence of epileptic seizures which result from excessive firing of neurons. The axon initial segment (AIS) is a neuronal compartment essential for the control of activity patterns of neurons. The AIS undergoes important modifications during development, but the molecular mechanisms that affect the development, morphology, and protein composition of the AIS are still not well understood. We examined AIS morphology of medial prefrontal cortex (mPFC) pyramidal neurons in wildtype mice across development and in two mouse models of NDDs. Results indicate restructurings at the AIS during typical development, some of which …

Multiple Approaches To Auditory Rhythm: Development Of Sustained Musical Beat And The Relation To Language, Development Of Rhythmic Categories Via Iterated Production, And A Meta-Analytic Study Of Neural Entrainment To Beat, Karli Marie Nave

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rhythm is ubiquitous to human communication, coordination, and experience of music. In this dissertation, I address three empirical questions through three different methodologies, all of which contribute to the growing body of literature on human auditory rhythm processing. In Chapter 2, I present a registered report detailing the results of independent conceptual replications of Nozaradan, Peretz, Missal, & Mouraux (2011), all using the same vetted protocol. Listeners performed the same tasks as in Nozaradan et al. (2011), with the addition of behavioral measures of perception. In neuroscience, neural correlates to musical beat perception have been identified, yet little to no …

Designs And Outcomes Of Transcranial Magnetic Stimulation (Tms) And Repetitive Transcranial Magnetic Stimulation (Rtms) Circuits, Daniel Senda

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis reports the design and outcomes of several circuits intended for transcranial magnetic stimulation (TMS) and repetitive transcranial magnetic stimulation (rTMS) research. In simple terms, TMS circuits are composed of four main blocks: high voltage power source, energy storage bank, control switch, and coil. Each one of these blocks has characteristics that influence how well the circuit will perform for TMS procedures. A successful TMS research circuit must have the ability to emit controlled electromagnetic pulses through a coil connected to it. For the first block, voltages ranging from 50 V to 2 kV were used. In the second …

Development Of A Novel Cognitive-Motor Dual Task Assessment Battery In Neurodegenerative Disease, Jason Longhurst

UNLV Theses, Dissertations, Professional Papers, and Capstones

Automaticity --- the ability to perform a task with directing attentional resources to its completion --- is commonly reduced among individuals with neurodegenerative diseases. These automaticity deficits result in impaired functional and daily activities and are sensitive to subtle, subclinical impairments. However, current measurement of automaticity by dual task paradigms is methodologically limited. In order to gain insight into the current state of the literature regarding cognitive-motor interference in symptomatic and prodromal neurodegenerative disease, the author of this dissertation conducted a scoping review (Chapter 1). To address the methodological limitations of current measurement of automaticity, a new measurement tool was …

Association Between White Matter Hyperintensities, Cortical Thinning, And Clinical Outcomes In Mild Traumatic Brain Injury, Thomas Helmut Knoblauch

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traumatic Brain Injury (TBI) is a global health challenge, with over 4.6 million confirmed cases annually in North America alone. Mild traumatic brain injuries (mTBIs) are the most common and make up approximately 81% of all TBI diagnoses worldwide [1]. Studies indicate that 10–15% of patients suffer from trauma induced symptoms (i.e. headache, loss of balance, cognitive impairments, fatigue, and mental health/affective disorders) as far as 1 year post injury [2]. Prediction and management of these post-traumatic sequalae is complicated by a lack of symptom associated neuroimaging findings. In spite of a “prominent distribution” of frontotemporal WMHs in pediatric subjects …

The Influence Of Cerebellar Transcranial Direct Current Stimulation On Motor Function In Parkinson’S Disease, Lidio Lima De Albuquerque

UNLV Theses, Dissertations, Professional Papers, and Capstones

Parkinson's disease (PD) is the most common movement disorder and the second most common neurodegenerative disorder. PD is characterized by dopaminergic cell loss in the substantia nigra pars compacta, which leads to a reduction in dopamine in the striatum. These physiological mechanisms lead to a number of motor impairments such as bradykinesia, rigidity, tremor, and postural instability that severely limit the ability of individuals with PD to perform many essential daily living activities. Although current pharmacological, surgical, and physical exercise treatment approaches are valuable they are either only mildly effective, expensive, or associated with a variety of side effects. Therefore, …

Restructuring Of The Axon Initial Segment In Mouse Models Of Neurodevelopmental Disorders, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) affect more than 36% of children in countries with low- and middle- incomes (Boivin, 2015; McCoy, 2016). Interestingly, these heterogeneous disorders share a high incidence of epileptic seizures, suggesting a shared pathology. Seizures result when neuronal firing activity becomes disturbed and neurons fire excessively or in unregulated patterns. A key site in the control of neuronal firing patterns is the axon initial segment (AIS), where the local density of proteins and the morphology of the AIS in part determine the firing of neurons. We hypothesized that a disruption in the morphology and/or composition of the AIS can …

Reduced Gabaergic Signaling At The Axon Initial Segment Decreases Vigilance State Transitioning, Austin John Boren

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sleep is a highly regulated homeostatic process that is disrupted in an estimated 50-70 million Americans. Regulation of sleep depends upon coordinated signaling of multiple neurotransmitter systems. In particular, inhibitory gamma-aminobutyric acid (GABA) signaling is required to suppress wake-active brain regions in order to initiate and maintain sleep states. GABA type A receptors (GABAARs) are ionotropic receptors with subunit compositions uniquely enriched on subcellular domains of target cells. α2 subunit-containing GABAARs are the primary target of GABA released onto the axon initial segment (AIS), a site critical for phasing the oscillatory activity of cortical cells. α2-containing GABAARs have previously been …