Medical Neurobiology Commons^™

Activated Dorsomedial Hypothalamic Astrocytes Regulate Feeding Behavior, Bella M. Lisenby

Honors Projects

The dorsomedial hypothalamus (DMH) region of the brain has been shown to be important for anticipatory feeding activity and play a role in restricting excessive food intake. In obese animals that overconsume calories, astrocytes within the DMH exhibit intracellular signaling changes indicative of cellular activation. Because astrocytes are known to influence neuronal function, we hypothesize that activated astrocytes regulate behavior. In the current study, we use chemogenetics combined with stereotaxic surgery to assess the contribution of astrocyte activity in the DMH towards metabolic behaviors.

Vergence Task-Based Neural Pathways With Binocularly Normal Vision And Comorbid Persistent Post-Concussive Symptoms -Convergence Insufficiency, Ayushi Sangoi

Dissertations

Binocular dysfunctions are more prevalent in the persistent post-concussive symptoms (PPCS) population than in the general population. The most prevalent binocular disorder is convergence insufficiency (CI), affecting 3-17% of the general population and up to 10 times as many people with PPCS. CI makes it difficult to fuse or maintain fusion on targets at near, and its symptoms include double or blurry vision and headaches when performing close-range tasks such as reading, which can exacerbate PPCS symptoms. Given controversy over the subjectivity and effectiveness of diagnostic tools and symptom surveys for both PPCS and CI, understanding why CI has high …

Rhythms Of Hippocampal Function And Memory After Moderate Prenatal Alcohol Exposure, Lilliana May Sanchez

Psychology ETDs

Fetal Alcohol Spectrum Disorders involve morphologic and neurobiological abnormalities in offspring subjected to prenatal alcohol exposure. Although not as well studied as high exposure, moderate prenatal alcohol exposure represents the most common and undetected form in humans. While learning and memory deficits have been well characterized at the behavioral level in humans with Fetal Alcohol Spectrum Disorders and in animal models of moderate prenatal alcohol exposure, few studies have determined the circuit or systems level mechanisms of the behavioral deficits. A complete understanding of the neural bases of memory deficits after moderate prenatal alcohol exposure is needed to ultimately identify …

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.

Stromal Interaction Molecule (Stim) Proteins In Microglia And The Impact On Store-Operated Calcium Entry (Soce) And Spinal Cord Injury Recovery, Norah G. Hill

College of Arts & Sciences Senior Theses

In spinal cord injury (SCI), worsening functional outcomes are largely because of secondary injury processes and prolonged chronic inflammation. A major contributor of secondary injury is overload of intracellular calcium, causing neuronal overexcitation and persistent inflammatory responses. One of the primary mediators of calcium entry into the cell is store-operated calcium entry (SOCE). In SOCE, sensors detecting calcium depletion from the endoplasmic reticulum stores are called STIM proteins (1-2). When calcium is low in the cell, STIM proteins will activate Orai channels to open, allowing for the influx of calcium into the cell. The purpose of this study was to …

Targeting The Dorsolateral Prefrontal Cortex With Transcranial Direct Current Stimulation To Improve Depression And Anxiety In Parkinson's Disease, Brock Renicks

Honors Theses

The aim of this study is to observe the outcomes of transcranial direct current stimulation (tDCS) as a treatment for Parkinson’s Disease (PD). This study will primarily look at changes in depression and anxiety, as these symptoms are often comorbid with Parkinson’s Disease. Transcranial direct current stimulation is a non-invasive, very low-intensity form of electrical stimulation of the brain. It is being increasingly used as a form of treatment for Parkinson’s Disease and depression and anxiety, however the literature is ambiguous, showing mixed results throughout various studies, with no standardization of tDCS administration. To determine the effect of tDCS on …

Novel Biomarker Discovery In Multiple Sclerosis, Manisha Gangasani

Honors Theses

Multiple Sclerosis (MS) is a chronic neuroinflammatory disorder affecting the brain, spinal cord, and optic nerve. Patients experience cognitive, motor, autonomic, and emotional symptoms that often overlap with other neurological conditions, making early diagnosis challenging. Current diagnostic criteria require evidence of lesions with dissemination in time and space. Racial disparities in MS outcomes are well documented, with Black individuals often exhibiting greater disease severity, higher relapse rates, and increased disability compared to White individuals. These differences likely reflect a combination of genetic, biological, environmental, and healthcare access factors, underscoring the need to improve early diagnosis and reduce inequities in care. …

Use Of Electroencephalography To Evaluate Neural Correlates Of Attention In The Oddball Paradigm, Folsom J. Berry

Honors Theses

Electroencephalography (EEG) and Event-Related Potentials (ERP) are tools used to study and analyze cognitive processing. EEG measures neuroelectric brain activity from the scalp, while ERPs are time-locked averages that are used to isolate neural responses to stimuli. The P300 (P3) component (positive waveform elicited at 300 milliseconds (ms)) is the primary ERP component. This thesis project had two main objectives. The first objective was to develop conceptual and technical competency in EEG/ERP theory, data acquisition, and processing. The second objective was to implement the visual oddball paradigm through experimental demonstration. This experiment tested the hypothesis that infrequent target stimuli will …

The Effects Of Body Mass Index On Fertility And In Vitro Fertilization, Morgan R. Kidd

Honors College Theses

In-vitro fertilization (IVF) is the most widely used type of assisted reproductive technology for treating infertility arising from a number of conditions. As obesity rates continue to climb in the United States, infertility has been discovered to have a direct correlation. Individuals that fall below or above the healthy body mass index range are found to have disrupted regulation of the hypothalamic-pituitary-gonadal axis, resulting in diminished reproductive health. Those that are diagnosed as infertile due to conditions caused by the effects of low body mass index or high body mass index may seek assisted reproductive technologies to intervene in achieving …

Silver Nanoparticle-Induced Disruption Of Astrocytic Morphology And Synaptic Microarchitecture In Rat Brain, Elli Williams

Theses, Dissertations and Capstones

Silver nanoparticles (AgNPs) are widely incorporated into consumer and medical products due to their antibacterial properties, increasing the potential for chronic exposure. AgNPs can be released into the environment, enter the body through ingestion or inhalation, cross the blood-brain barrier (BBB), and bioaccumulate in brain tissue. Previous in vitro studies demonstrate that AgNP exposure disrupts cytoskeletal organization and induces neurite collapse in neural cells, suggesting vulnerability of cytoskeleton-dependent structures in vivo. Astrocytes, through their perisynaptic astrocytic processes (PAPs) and perivascular endfeet, play critical roles in maintaining synaptic and neurovascular architecture, both of which rely heavily on cytoskeletal integrity. This …

The Effects Of Stress-Related Hormones On Excitatory Synapse Formation, Autumn C. Garvey

Honors Undergraduate Theses

Stress profoundly influences brain function through neuromodulatory hormones that regulate synaptic plasticity, yet how temporal patterns of hormone exposure shape excitatory synapse formation remains poorly understood. This study investigates how exposure to stress hormones, norepinephrine and cortisol, affects excitatory synapse development. While existing research primarily compares concentration models, real-world stress occurs in variable patterns that may produce distinct neural outcomes. To address this gap, differentiated Neuro2A neuronal cells are exposed to norepinephrine or cortisol under a continuous treatment paradigm designed to model chronic stress conditions. Following treatment, immunofluorescence imaging is utilized to quantify excitatory synapse formation through analysis of presynaptic …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

Manuka Honey Modulates Oxidative Stress In Neuro2-A Cells Through Mitochondrial Regulation, Rachel Abramovici

Honors Undergraduate Theses

Manuka honey is known for its vital usage in wound healing, being an agonist towards fighting infections, and is an acting antioxidant [32]. Its main constituents are flavonoids and phenolic compounds, with methyl syringate (MSYR) being a major active ingredient. The specific compounds responsible for these antioxidant effects, particularly in the CNS, remain unclear. It is hypothesized that pre-treatment of mouse neuroblastoma cells with MSYR followed by hydrogen peroxide exposure will activate the AMPK/SIRT1/PGC-1a pathway, due to MSYR’s phenolic structure, and thus reduce oxidative stress and improve mitochondrial biogenesis. Hydrogen peroxide is a standard reactive oxygen species (ROS) treatment to …

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 …

Dual-Task Interaction Between Vestibular Function And Cognitive Processing Using The P300 Event-Related Potential, Laurel Elise Money-Nolan

Graduate Theses and Dissertations (2019 - present)

Previous research has established links between vestibular function and cognitive processing, aging and cognitive function, and aging and vestibular function. Theories of cognitive resource allocation discuss how cognitive resources, such as attention, are devoted towards and divided between tasks when multitasking. This dual-task study, utilizing a balance task and a listening/cognitive task, across the young- and middle-aged adult age range, aimed to evaluate potential relationships between vestibular function, cognition, and age, and to examine how cognitive resources might be allocated under dual-task conditions.

The dual-task protocol in this study utilized an oddball paradigm with tonal stimuli to measure the P300 …

Mechanisms Of Correlated Neuronal Activity In The Globus Pallidus, Hamza Albawaliz

Electronic Theses and Dissertations

This thesis investigates the mechanisms of correlated neuronal activity in the globus pallidus externus (GPe), a key structure in the basal ganglia. Neuronal activity in the GPe is reportedly decorrelated in healthy subjects but can become highly correlated in Parkinson’s disease. However, high-density neuronal recordings in the GPe of healthy rats reveal a surprising degree of correlated activity. This raises the question of whether intrinsic properties or network connectivity alone can account for such patterns. To explore this, a computational model was developed in which GPe neurons are represented as coupled phase oscillators influenced by experimentally derived phase-response curves and …

Transcriptomic And Epigenomic Profiling Of Immune Cells Responses To Simian Immunodeficiency Virus Infection In The Brain, Xiaoke Xu

Theses & Dissertations

Human immunodeficiency virus type 1 (HIV-1) is an enveloped retrovirus that significantly impairs the human immune system. A common complication of HIV-1 infection is HIV-associated neurocognitive disorder (HAND), which, prior to the introduction of antiretroviral therapy (ART), led to considerable morbidity and mortality due to untreated neuropsychiatric manifestations. Although ART has substantially reduced the incidence of HIV-associated dementia (HAD), approximately 50% of people living with HIV (PLWH) continue to experience milder forms of HAND. The CNS is seeded by HIV during the acute phase of infection. Once in the brain, HIV targets and activates resident immune cells, primarily microglia and …

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 …

Role And Electrophysiological Properties Of Sexually Dimorphic Oxytocin Receptor Expressing Neurons In The Anteroventral Periventricular Nucleus Of The Female Mice, Armita Abdollahi Govar

LSU Doctoral Dissertations

Oxytocin is a neurohypophyseal hormone that plays a crucial role in regulating mother-infant bonding and maternal behavior. Oxytocin modulates sex-specific parental behaviors by binding to the oxytocin receptor (OXTR)-expressing neurons in the brain. This study investigates the sexually dimorphic OXTR neurons in the anteroventral periventricular nucleus (AVPV) to understand how oxytocin modulates behavior in females. Specifically, we explored the behavioral roles, neural projections, and intrinsic electrophysiological characteristics of these neurons in the female mice. Using immunohistochemistry revealed that the number of OXTR-expressing neurons was enhanced in postpartum females compared with virgin females, suggesting that these neurons are involved in female-specific …

Effects Of Altered Somatosensory Input On Gait Kinetics And Kinematics Via Different Footwear In Individuals With Chronic Post-Stroke Hemiparesis, Daniela Casillas, Lesley Ruiz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose/Hypothesis: Individuals with post-stroke hemiparesis walk with significant asymmetries, leading to slow, effortful walking, and a high risk of falls. One contributing factor is altered sensation on the plantar surface. Studies examining altered somatosensory input via insoles, vibration and other tactile stimuli observed improvements in hemiparesis gait. This study investigates whether altering somatosensory input through different footwear can affect kinetics, kinematics and muscle activity during walking post-stroke. We hypothesized the barefoot conditions would have increased dorsiflexion (heel-strike, swing), increased plantarflexion during toe-off, increased muscle activity and kinetics, compared to memory foam conditions.

Participants: 13 individuals with chronic post-stroke hemiparesis (4F/9M, …

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 …

The Endocannabinoid System's Influence And Modulation Of Nociception, Doreen M. Flannery

Honors Thesis

The anatomy and physiology of pain is a well-defined pathway where noxious stimuli is processed by different systems in the brain. The central research question of this review is how can we better understand the neurobiological effects pain has, and assess if there is therapeutic potential in using endocannabinoids to modulate these effects. Endocannabinoids are signaling molecules that play a key role at both the cellular and molecular level in modulating both acute and chronic pain by influencing different processes within each level that affect how the body responds to both internal and external stimuli. The endocannabinoid system is a …

The Impact Of An Iron-Rich Diet On Fatigue In Menstruating Women With Non-Anemic Iron Deficiency, Meagan Seraydar, Lauren Latimer, Sam Miragliatto

Department of Nutrition Student Projects

Fatigue without diagnosed anemia is prevalent in menstruating women, with iron deficiency being a potential contributor. While iron supplementation is a standard intervention, dietary sources of iron may offer a sustainable alternative. This study aims to assess the impact of an iron-rich diet on fatigue levels in menstruating women. A 12-week randomized controlled trial (RCT) will be conducted, assigning participants to either an iron-rich diet group or a control group following their usual diet without specific iron recommendations. Fatigue will be measured using the Fatigue Severity Scale (FSS) at baseline, six weeks, and twelve weeks, alongside iron status biomarkers, including …

Hdac5 Enzymatic Activity Regulates Scn4b Expression To Control Relapse-Like Cocaine Seeking, Daniel J. Wood

MUSC Theses and Dissertations

Substance Use Disorder (SUD) is a relapsing disorder characterized by repeated seeking and use of psychoactive substances despite negative consequences to the individual. Epigenetic changes within the medium spiny neurons (MSNs) of the nucleus accumbens (NAc) are thought to underly the lasting propensity to relapse in SUD. The epigenetic enzyme histone deacetylase 5 (HDAC5) in NAc MSNs limits the formation of reward-cue associations in rodent models of drug seeking, but not sucrose seeking, leading to decreased relapse-like behavior. However, whether HDAC5 reduces drug seeking behavior through its own deacetylase activity or through the recruitment of co-repressors is unknown. Furthermore, these …

Impact Of Tranexamic Acid On Patient Outcomes In Intracranial Hemorrhage: A Review, William G. Johnson

The PA Department Journal of Medical Science

Introduction: Intracranial hemorrhage is a medical emergency that remains a significant source of death and disability for patients globally. Tranexamic acid has shown promise in treating trauma related bleeding loss in various settings. This study aims to evaluate its role in the management of intracranial hemorrhages.

Methods: A review of data in the PubMed National Library of Medicine was conducted to find relevant and reputable studies related to this topic. Using the search “tranexamic acid AND intracranial hemorrhage*” and the following filters: last 5 years, free full text, English language, including RCTs, meta-analyses, and systematic reviews, 13 results …

Optimizing Decision-Making In A Cerebral Palsy Model Using Reinforcement Learning, Richard Ampah

Pitzer Senior Theses

This study presents an original interdisciplinary investigation into how reinforcement learning (RL) can model motor and cognitive defects and potentially improve motor and cognitive functions in individuals with cerebral palsy (CP), a non-progressive neurological disorder that impairs movement and adaptability. Integrating computational neuroscience and machine learning, the research applies policy gradient methods and Markov Decision Processes (MDPs) to simulate adaptive learning in agents with and without CP-related constraints.

The central aim is to compare the cumulative rewards of optimal policies, derived from value iteration, and human-like learning policies using the REINFORCE algorithm, both with and without the Bellman baseline. The …

Immune Dynamics And B Cell Contributions To Neuroplasticity And Recovery After Stroke, Thomas A. Ujas

Theses and Dissertations--Neuroscience

This dissertation explores the dynamic interplay between the immune system and the brain across stroke and aging using clinical, post-mortem, and pre-clinical models. The immune system plays critical roles in shaping brain function, responding to injury, and mediating recovery. These studies aim to enhance our understanding of neuroimmune dynamics across spatial and temporal dimensions.

In the first part, we conducted longitudinal sampling of aneurysmal subarachnoid hemorrhage (aSAH) patients to track immune cell and cytokine changes at days 3, 5, 7, 10, and 14 post-stroke, with a focus on delayed cerebral ischemia (DCI), a common complication. We observed distinct temporal patterns, …

Comparative Efficacy Of Hallucinogens In Treating Mood Disorders Through A Meta-Analysis Of Symptom Reduction, Dosage, And Duration, John Marco D.F. Muniz

Honors Undergraduate Theses

Background: Hallucinogens including psilocybin, lysergic acid diethylamide (LSD), ketamine, N,N-dimethyltryptamine (DMT) (as ayahuasca), have re-emerged as potential rapid-acting treatments for mood disorders. We conducted a meta-analysis of placebo-controlled trials evaluating their efficacy in depression and anxiety disorders. Methods: A systematic review identified 12 trials (Total ≈ 670) meeting inclusion criteria (randomized, placebo-controlled). Data on Cohen’s d and Hedges’ g effect sizes for depression- and anxiety-related outcomes were extracted. We computed pooled effect sizes (weighted by sample size and inverse variance), performed subgroup analyses by drug, diagnosis, follow-up duration, and outcome measure type, and assessed heterogeneity (I², Q …

Reassessing Hourly Neurological Assessments: A Quality Improvement Initiative, Haley Lynne Johnson

Graduate Theses, Dissertations, and Problem Reports (ETD)

ABSTRACT

Reassessing Hourly Neurological Assessments: A Quality Improvement Initiative

Haley Lynne Johnson, BSN, RN

Background: Stroke and brain injuries remain among the leading causes of mortality in the United States, accounting for 162,890 deaths in 2021 (Centers for Disease Control and Prevention [CDC], 2021). Although frequent neurological assessments are essential for monitoring patient status, limited evidence supports the prolonged use of hourly neuro-checks (LaBuzetta et al., 2022). Excessive neuro-check frequency has been linked to sleep deprivation, an increased risk of delirium, and inefficient resource utilization (Kishore et al., 2021).

Purpose: This project aimed to assess the impact of …