Medicine and Health Sciences Commons^™

Slo2.1 Channels: A New Molecular Mechanism To Regulate Uterine Excitability, Juan Jose Ferreira

Arts & Sciences Electronic Theses and Dissertations

At the end of pregnancy, the uterus transitions from a non-contractile state to a highly contractile state. Two processes primarily drive this transition. First, from the 28th week of pregnancy until labor, the resting membrane potential of uterine (myometrial) smooth muscle cells (MSMCs) gradually becomes more positive (depolarizes) (Parkington et al. 1999). Second, at the end of pregnancy, MSMCs express more oxytocin receptors and become more sensitive to oxytocin (Kimura et al. 1996). However, the detailed mechanisms by which these processes occur have not been determined. My central hypothesis was that the Na+-activated K+ channel SLO2.1 plays a key role …

Influence Of Focal Activity On Macroscale Brain Dynamics In Health And Disease, Zachary Pollack Rosenthal

Arts & Sciences Electronic Theses and Dissertations

Macroscopic recordings of brain activity (e.g. fMRI, EEG) are a sensitive biomarker of the neural networks supporting neurocognitive function. However, it remains largely unclear what mechanisms mediate changes in macroscale networks after focal brain injuries like stroke, seizure, and TBI. Recently, optical neuroimaging in animal models has emerged as a powerful tool to begin addressing these questions. Using widefield imaging of cortical calcium dynamics in mice, this dissertation investigates the mechanisms by which focal disruptions in activity alter brain-wide functional dynamics. In two chapters, I demonstrate 1) that focal sensory stimulation elicits state-dependent, global slow waves propagating from primary somatosensory …

An Investigation Of Sensory Percepts Elicited By Macro-Sieve Electrode Stimulation Of The Rat Sciatic Nerve, Nikhil Shiva Chandra

McKelvey School of Engineering Theses & Dissertations

Intuitive control of conventional prostheses is hampered by their inability to replicate the rich tactile and proprioceptive feedback afforded by natural sensory pathways. Electrical stimulation of residual nerve tissue is a promising means of reintroducing sensory feedback to the central nervous system. The macro-sieve electrode (MSE) is a candidate interface to amputees’ truncated peripheral nerves whose unique geometry enables selective control of the complete nerve cross-section. Unlike previously studied interfaces, the MSE’s implantation entails transection and subsequent regeneration of the target nerve. Therefore, a key determinant of the MSE’s suitability for this task is whether it can elicit sensations at …

Identification Of Multi-Tissue Protein Quantitative Trait Loci And Causal Inference Of Protein Effects In Neurological And Other Complex Human Diseases Via Mendelian Randomization, Chengran Yang

Arts & Sciences Electronic Theses and Dissertations

Alzheimer disease (AD) is the most common neurodegenerative disease, affecting 6.2 million people mostly aged 65 years or older in the United States as of early 2021. AD has been widely studied and characterized worldwide, but there is still no effective treatment or cure. Even the latest FDA-approved treatment, Aducanumab, cannot stop decline or improve cognition. To develop a truly effective treatments, researchers keep discovering genetic and molecular mechanisms underlying the disease. Protein biomarkers are keys to bridge the mechanisms to disease. Here, I first used a high-throughput proteomic dataset from three tissues (CSF, plasma, and brain) with array-based genotype …

Influence Of Aging And Cerebrovascular Disease On Neuroimaging Measures Of Alzheimer Disease, Lauren Nicole Koenig

Arts & Sciences Electronic Theses and Dissertations

The overall goal of this dissertation is to gain a better understanding of how Alzheimer disease relates to normal aging and cerebrovascular disease to impact neuroimaging measures in a clinically meaningful way. Both aging and cerebrovascular disease are known to influence measures of Alzheimer disease, making it difficult to separate what changes are attributable specifically to Alzheimer disease. We hypothesize that a better understanding of these relationships will allow future studies to appropriately take these factors into account. In Chapters 2 and 3 we attempt to separate out the influences of normal aging and Alzheimer disease on measures of atrophy. …

Genetic Risk Factors For Neurodevelopmental Disorders: Insights From Hipsc-Cerebral Organoids, Michelle L. Wegscheid

Arts & Sciences Electronic Theses and Dissertations

Neurofibromatosis type 1 (NF1) is a common neurodevelopmental disorder (NDD) characterized by remarkable phenotypic variability, where affected children manifest a spectrum of central nervous system (CNS) abnormalities, including brain tumors, impairments in attention, behavior, learning disabilities, and an increased incidence of autism spectrum disorder (ASD). A significant barrier to the implementation of precision medicine strategies for children with NF1 is a lack of prognostic risk factors to guide clinical management. However, emerging population-based genotype-phenotype association studies have suggested that the germline NF1 gene mutation may represent one clinically actionable risk factor for NF1-associated neurodevelopmental abnormalities. As a critical step in …

Causal Function And Bias Correlation Of The Orbitofrontal Cortex In Economic Choices, Shi Weikang

Arts & Sciences Electronic Theses and Dissertations

Economic choices entail two mental processes, value calculation and value comparison (Niehans, 1990). Studies in the last twenty years have shown that neurons in the orbitofrontal cortex (OFC) could support both processes. Namely, in the studies in which monkeys chose between two juice options with various amounts, three functional cell groups had been found in the OFC: offer value cells encode the value of individual juices, chosen juice cells encode the choice in a binary way and chosen value cells encode the value of the chosen juice (Padoa-Schioppa and Assad, 2006). These results suggest a decision circuit within OFC with …

Mapping Neural Responses Onto Innate And Acquired Behavior: From Insect Olfaction To Realizing A Bio-Hybrid Chemical Recognition System, Rishabh Chandak

McKelvey School of Engineering Theses & Dissertations

In many organisms, the sense of smell, driven by the olfactory system, serves as the primary sensory modality that guides a plethora of behaviors such as foraging for food, finding mates, and evading predators. Using an array of biological sensors, the olfactory system converts volatile chemical inputs from an organism’s environment into well-patterned neural responses that inform downstream motor neurons to drive appropriate behaviors (e.g., moving towards food or away from danger). For many external cues, the elicited neural responses are often determined by the genetic makeup of the organism, which assigns an innate preference, or valence, for these different …

On Arousal And The Internal Regulation Of Brain Function: Theory And Evidence Across Modalities And Species, Ryan Raut

Arts & Sciences Electronic Theses and Dissertations

The brain is an organ. It is subject to the same physiological regulatory processes that engage the rest of the body’s organs, sculpted over hundreds of millions of years to sustain life so effectively. The central message of this thesis is that the holistic functioning of the brain, rather than operating at some level above or independent from these systemic regulatory processes, is deeply related to them. In short, as our limited attention spans might suggest: brain function is internally regulated. I propose that this internal regulation is a primary function of intrinsic brain activity. Chapter 2 provides a theoretical …

The Role Of Neuronal Atp-Sensitive Potassium Channels In Learning And Memory, Shaul Vladimir Yahil

Arts & Sciences Electronic Theses and Dissertations

ATP-sensitive potassium (KATP) channels link cellular metabolism and membrane excitability in many tissues, including brain and pancreas. Gain-of-function (GOF) mutations to KATP channels cause neonatal diabetes, with some patients exhibiting developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome. Diabetic symptoms have been attributed to loss of membrane excitability and insulin secretion in pancreatic β-cells, though the origin of neurological deficits and the effects of neuronal KATP-GOF mutations more generally remain elusive. In this dissertation, I will present evidence that mice expressing KATP-GOF mutations pan-neuronally (nKATP-GOF) demonstrated sensorimotor and cognitive deficits, whereas hippocampus-specific hKATP-GOF mice exhibited predominantly learning and memory deficits. …

(R)-2,5-Dimethoxy-4-Iodoamphetamine [(R)-Doi] Influences Coping Strategies To An Escapable Social Stress, Kevin Thomas Krupp

Dissertations and Theses

Depressive mood disorders are a leading cause of disability worldwide and pharmacological treatments for these disorders are inadequate, requiring new compounds with greater efficacy be investigated. The etiology of depression is heterogeneous; however, it is well established that stress exposure, and the proinflammatory effects of stress have a major role. Psychedelic compounds have rapid and long-lasting anxiolytic and antidepressive effects in humans and animal models of stress induced affective behavior. However, it is not completely understood how these compounds produce such rapid effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A partial agonist with potent anti-inflammatory properties, …

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 …

An Analysis Of Taste Neuron Morphological Variability: Influences Of Neuron Type And Plasticity., Lisa Christina Ohman

Electronic Theses and Dissertations

Taste neurons are functionally and molecularly diverse, but their morphological diversity was, until recently, completely unexplored. Taste neurons were considered relay cells, communicating information from taste-transducing cells to the brain without variation in morphology. Instead, individual taste neurons are tremendously morphologically variable. To determine how differences in branching relate to the number and types of taste-transducing cells providing neuronal input, I combined sparse cell genetic labeling with a whole-mount immunohistochemistry and analysis workflow. I found that the maximum number of taste-transducing cells capable of providing convergent input onto individual gustatory neurons varied with a range of 1-22 taste-transducing cells. Consistently, …

Effects Of Chemosensory Experience And Context On Consummatory Behaviors., Saphira M. Chiu

Electronic Theses and Dissertations

Eating food generates associations between odors and tastes (i.e., flavor) that guide future choices. Experience with an odor-taste mixture links an odor with a taste’s quality and hedonic value, resulting in a preference for an odor paired with a palatable taste over an odor paired with an unpalatable taste. However, experience with a neutral stimulus (i.e., latent inhibition) or environment (i.e., context) can influence the formation of conditioned associations. Here, I used a two-bottle brief-access task to determine whether rats display an innate preference between unpaired odors (isoamyl acetate and benzaldehyde), how preexposure to the unpaired odors impacts mixture-dependent consummatory …

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 …

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 …

Contribution Of Retinal Ganglion Cells To Brown-Norway Rat Spatiotemporal Visual Perception And The Electroretinogram, Nicholas P. Johnson

USF Tampa Graduate Theses and Dissertations

Retinal Ganglion Cells (RGCs) are the sole cells through which visual information is transmitted from the eye to the brain. As such, RGC dysfunction has a dramatic effect on vision and perception. Retinal neurodegenerative diseases, such as glaucoma, are one of the leading causes of blindness worldwide. The study of these diseases requires well-characterized models in order to swiftly and effectively develop diagnostic tools and therapeutics. This dissertation aims to characterize specific properties of the visual system of the Brown-Norway rat. First, visual processing was evaluated in awake, freely moving rats. Contrast sensitivities of Brown-Norway rats were characterized by discrimination-driven …

Validation Of Arterial Spin Labeling For Longitudinal Monitoring And Differential Diagnosis Of Frontotemporal Dementia, Tracy Ssali

Electronic Thesis and Dissertation Repository

Frontotemporal dementia (FTD) is a devastating neurodegenerative disease characterized by a rapid decline in behavioural, language, and motor abilities. Advances in the understanding of FTD genetics and pathophysiology, and the subsequent development of novel disease modifying treatments have highlighted the need for tools to assess their efficacy. While structural magnetic resonance imaging (MRI) and functional imaging with ¹⁸F-flurodeoxyglucose (FDG) positron emission tomography (PET) are used for clinical diagnosis, structural changes are subtle at the early stages and PET imaging is expensive and access limited. Given the coupling of cerebral blood flow (CBF) to energy metabolism, an attractive alternative is …

The Impact Of High Intensity Interval Training On Neurogenesis And Angiogenesis In The Dentate Gyrus, Darrin Lenhart

Seton Hall University Dissertations and Theses (ETDs)

BACKGROUND: Exercise is associated with improved neuronal health and longevity, synaptic plasticity, cerebral blood volume, overall brain volume, and neurogenesis which collectively may have the power to forestall neurodegenerative disease.

PURPOSE: This study aims to explore the impact of high intensity interval training on individuals with mild cognitive impairment using a range of cognitive, physiological, and biomechanical measures. Specifically, this study seeks to assess the impact of high intensity interval training on neurogenesis and angiogenesis in the dentate gyrus of individuals with mild cognitive impairment versus healthy age-matched controls, as assessed by urinalysis of BDNF levels, performance on the Rey …

Alterations To The Brain Following Traumatic Brain Injury, Jacqueline Mader

Honors Projects

Traumatic brain injuries (TBIs) have been labeled as a modern-day epidemic, increasing exponentially with the advancement of technology and society. Gaining a better understanding of the cognitive paths, including the chemical and electrical signals of the brain, neural correlates, and possible interventions for TBI patients allows for the best possible outcome for every patient, and allows for the further advancement of care. By revising and reassessing the ways in which TBIs are categorized and described the prognosis for recovery paints a more realistic view for each individual patient case. The symptoms and impairments that may occur post-injury can be monitored …

Apathy And Brain Atrophy During The First Year Of Moderate-Severe Traumatic Brain Injury: A Longitudinal Study, Gulnaz Kudoiarova

Dissertations, Theses, and Capstone Projects

Apathy, defined as disinterest and loss of motivation, is a common complication after moderate-severe traumatic brain injury (msTBI). The existing body of research in various neurological and neurodegenerative disorders suggests that apathetic symptoms may be associated with variation in the volume of the brain regions such as dorsal anterior cingulate cortex and ventral striatum. However, the longitudinal pattern of TBI-induced atrophy in these key regions and its relationship with apathy symptoms remain to be demonstrated. The current study aimed to describe the atrophy pattern in the anterior cingulate gyrus (ACG) and the nucleus accumbens (NAc; part of ventral striatum) after …

Role Of 4r Tau In Astrocyte-Mediated Neuronal Toxicity And The Progression Of Neurodegenerative Disease, Lubov Alexandra Ezerskiy

Arts & Sciences Electronic Theses and Dissertations

The microtubule-binding protein tau is associated with neurodegenerative diseases, including Alzheimer’s disease, progressive supranuclear palsy, and a subset of frontotemporal dementias. In these tauopathies, tau becomes hyperphosphorylated and forms intracellular neurofibrillary tau tangles, contributing to synaptic dysfunction, neuronal death, and severe astrogliosis. Tau can be classified as having a 3-repeat (3R) or 4-repeat (4R) structure, resulting from alternative splicing of exon 10 within the MAPT gene. While the higher deposition of 4R tau characterizes many primary tauopathies, the role of 4R tau in neurodegenerative disease pathogenesis remains unclear. To investigate the role of tau isoforms in disease, we created tau …

Phenotyping And Preclinical Meta-Analysis Of Behavioral Outcomes From Complete Freund’S Adjuvant-Induced Inflammatory Pain In The Rodent Hind-Paw, Dominika J. Burek

Arts & Sciences Electronic Theses and Dissertations

Pain and opioid use disorder prevalence, diagnoses of mental health disorders, and rate of suicide have all skyrocketed over the last 30 years as a matrix of public health crises. Each reduces quality of life and installs risk of the others; together, they have burdened our country with nearly unmanageable healthcare challenges. Although the critical demand for novel and more effective therapeutics has been clear for decades, relatively little progress has been made to address pain and its comorbidities. Repeated clinical trial failures have called into question the preclinical evidence upon which they are based. Preclinical models of pain-induced negative …

Oligodendrocyte Responses After Spinal Cord Injury., George Zach Wei

Electronic Theses and Dissertations

Recent studies demonstrate that neuroprotection strategies targeting the proteostasis network and components of its effector signaling pathways improve cell survival and motor recovery outcomes in several models of neuronal injury and degeneration. However, the individual contributions of these signaling pathways to the pathogenesis of spinal cord injury (SCI), white matter damage, and motor recovery have not yet been determined. Here, I explored the role of the HIF prolyl hydroxylase domain proteins (PHD/EGLN), effectors that can modulate stress responses activated by the proteostasis network, on motor function recovery after SCI. Furthermore, I identified previously unknown candidate mechanisms in an unbiased manner …

Describing Functional Brain Connectivity's Role In The Relationship Of Multimodal Interventions To Improve Cognitive And Physical Function In Vulnerable (Frailty & Mild Cognitive Impairment) Older Adults., Nicholas (Nick) W. Bray

Electronic Thesis and Dissertation Repository

Aging is associated with declining cognitive and physical function. The decline accelerates in older adults diagnosed with mild cognitive impairment (MCI), a pre-dementia state, and frailty, a state of decreased physiological reserve. Previous work shows that frailty modifies the relationship between dementia pathology and clinical symptoms. Functional brain network connectivity (FBNC) refers to brain areas that are anatomically separate but temporally related in their neural signaling; it is believed to enable the completion of complex cognitive and physical functions. FBNC is considered a sensitive biomarker for monitoring the progression of dementia syndromes and investigating the efficacy of interventional strategies. Therefore, …

Early Indicators Of Cognitive Dysfunction: The Role Of Mild Behavioral Impairment, Hillary J. Rouse

USF Tampa Graduate Theses and Dissertations

Older age is associated with an increased risk for cognitively impairing diseases such as dementia. Despite significant research to find ways to cure this disease, there has been little success. However, a critical need when an intervention is discovered is a need to find ways to identify people who are at the greatest risk of developing dementia earlier in the disease process so that interventions can be implemented at that time. This could potentially lessen their risk or delay when they are diagnosed. Using longitudinal data from the National Alzheimer’s Coordinating Center (NACC), the aims of this current dissertation were …

The Balance Of Excitation And Inhibition And Its Influence On Cortical States And Rett Syndrome, Jingwen Li

Graduate Theses and Dissertations

Our brain consists of billions of neurons, properly coordinating to process information and realize brain functions. Among them, there are two types of neurons: excitatory neurons and inhibitory neurons. The firing of excitatory neurons increases the membrane potential of downstream neurons, and thus excites other neurons to fire. The firing of inhibitory neurons, in contrast, decreases the membrane potential of downstream neurons, and thus inhibits other neurons to fire. The interplay of excitatory and inhibitory neurons shape the spiking activity in the population. Thus, the `balance of excitation and inhibition' plays an important role in cortical processing and brain functions. …

Effects Of Genetics And Sex On Hippocampal Gene Expression And Adolescent Behaviors Following Neonatal Ethanol Exposure In Bxd Recombinant Inbred Mice, Jessica A. Baker

Theses and Dissertations (ETD)

Fetal alcohol spectrum disorders (FASD) are the leading preventable neurodevelopmental disorders in the western world. A hallmark symptom of FASD is cognitive and learning deficits that present in early childhood and continue throughout adulthood. Teratogenic effects of alcohol include increased cell death in the hippocampus, a brain region critically important in learning and memory. Genetics have been shown to have a role in the severity of alcohol’s teratogenic effect on the developing brain. Previous work in our lab identified differential vulnerability to ethanol-induced call death in the hippocampus using fourteen BXD strains and the two parental strains. The goal of …

Relationship Between Cognitive Performance, Physical Activity, And Socio-Demographic/ Individual Characteristics Among Aging Americans, Imtiaz Masfique Dowllah

Theses and Dissertations

Despite the attenuation of association following adjustments for covariates, participants who engaged in 3–6 hr/wk of vigorous- and > 1 hr/wk of moderate-intensity PA scored significantly higher in tests that assessed executive function and processing speed domains of cognition compared to inactive peers (η2 = 0.005 & 0.007 respectively, p < 0.05). Also, after adjustment, the effects of 1–3 hr/wk of vigorous-intensity PA became trivial for the delayed recall memory domain test scores (β = 0.33; 95% CI: –0.01, 0.67; η2 = 0.002; p = 0.56). There was no clear dose-response relationship between the cognitive test scores and weekly moderate-intensity PA. Interestingly, higher handgrip strength and higher late-life body-mass-index were associated with a higher performance across all cognitive domains. Observed associations provide evidence linking habitual PA with superior cognition health among older adults. Furthermore, increased muscle strength and higher late-life adiposity may …

Taste Learning In Insular Cortex: Plasticity Is Influenced By Experience Type, Stephanie Marie Staszko

Theses and Dissertations (ETD)

The gustatory cortex (GC) has long been studied as the main cortical area encoding taste stimuli and likely integrates sensory, visceral, and emotional information to guide taste-related behaviors. However, our understanding of cortical taste coding on a single-cell level has only become clear in recent years. The anatomical location of GC on the lateral and ventral surface of the brain makes it difficult to target with traditional imaging methods. Thus, much of what we know about cortical taste coding and cortical taste plasticity has been derived either from multiunit electrode recordings or anesthetized imaging experiments, techniques which lack the ability …