Medical Sciences Commons^™

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 …

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

Characterization Of Sensory And Shelter Enrichment In The Rodent Research Habitat, Amber M. Paul, Yasaman Shirazi-Fard, America Reyes, Moniece Lowe, Margareth Cheng-Campbell, Sungshin Choi, Eduardo Almeida, April Ronca, Ruth K. Globus

Publications

The ISS provides a platform for conducting Rodent Research (RR) in microgravity and 9 missions have been successfully conducted. The results from these experiments have begun to provide new insights into the effects of spaceflight on mammalian physiological systems. After RR-1-4, the Flight IACUC required inclusion of additional cage enrichment into the Rodent Habitats (RH) to “enhance animal well-being by providing animals with sensory and motor stimulation, through structures and resources that facilitate the expression of species typical behaviors”. A Hut, in the form of a rigid, mesh igloo-like shelter was implemented beginning with RR-5. The potential influence of the …

Effects Of Dabigatran In Mouse Models Of Aging And Cerebral Amyloid Angiopathy, Neethu Michael, Mher Mahoney Grigoryan, Kelley Kilday, Rachita K. Sumbria, Vitaly Vasilevko, Joanne Van Ryn, David H. Cribbs, Annlia Paganini-Hill, Mark J. Fisher

Pharmacy Faculty Articles and Research

Oral anticoagulants are a critical component of stroke prevention, but carry a risk of brain hemorrhage. These hemorrhagic complications tend to occur in elderly individuals, especially those with predisposing conditions such as cerebral amyloid angiopathy (CAA). Clinical evidence suggests that non-vitamin K antagonist oral anticoagulants are safer than traditional oral anticoagulants. We analyzed whether the anticoagulant dabigatran produces cerebral microhemorrhage (the pathological substrate of MRI-demonstrable cerebral microbleeds) or intracerebral hemorrhage in aged mice with and without hemorrhage-predisposing angiopathy. We studied aged (22 months old) Tg2576 (a model of CAA) and wild-type (WT) littermate mice. Mice received either dabigatran etexilate (DE) …

Sciatic Nerve Cut And Repair Using Fibrin Glue In Adult Mice, Erica T. Akhter, Travis M. Rotterman, Arthur W. English, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Peripheral nerve injury (PNI) is an excellent model for studying neural responses to injury and elucidating the mechanisms that can facilitate axon regeneration. As such, several animal models have been employed to study regenerative mechanisms after PNI, including Aplysia, zebrafish, rabbits, cats and rodents. This protocol describes how to perform a sciatic nerve injury and repair in mice, one of the most frequently used models to study mechanisms that facilitate recovery after PNI, and that takes advantage of the availability of many genetic models. In this protocol, we describe a method for using fibrin glue to secure the proximal …

Influence Of Social Isolation During Prolonged Simulated Weightlessness By Hindlimb Unloading, Candice G.T. Tahimic, Amber M. Paul, Ann-Sofie Schreurs, Samantha M. Torres, Linda Rubinstein, Sonette Steczina

Publications

The hindlimb unloading (HU) model has been used extensively to simulate the cephalad fluid shift and musculoskeletal disuse observed in spaceflight with its application expanding to study immune, cardiovascular and central nervous system responses, among others. Most HU studies are performed with singly housed animals, although social isolation also can substantially impact behavior and physiology, and therefore may confound HU experimental results. Other HU variants that allow for paired housing have been developed although no systematic assessment has been made to understand the effects of social isolation on HU outcomes. Hence, we aimed to determine the contribution of social isolation …

Cannabidiol Is Beneficial In Management Of Drug-Resistant Dravet Syndrome, Nikita Desai

Clinical Research in Practice: The Journal of Team Hippocrates

A critical appraisal and clinical application of Devinsky O, Cross H, Laux L, et al. Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome. N Engl J Med. 2017;376(21):2011-2020. doi: 10.1056/NEJMoa1611618.

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 …

Short Amylin Receptor Antagonist Peptides Improve Memory Deficits In Alzheimer’S Disease Mouse Model, Rania Soudy, Ryoichi Kimura, Aarti Patel, Wen Fu, Kamaljit Kaur, David Westaway, Jing Yang, Jack Jhamandas

Pharmacy Faculty Articles and Research

Recent evidence supports involvement of amylin and the amylin receptor in the pathogenesis of Alzheimer’s disease (AD). We have previously shown that amylin receptor antagonist, AC253, improves spatial memory in AD mouse models. Herein, we generated and screened a peptide library and identified two short sequence amylin peptides (12–14 aa) that are proteolytically stable, brain penetrant when administered intraperitoneally, neuroprotective against Aβ toxicity and restore diminished levels of hippocampal long term potentiation in AD mice. Systemic administration of the peptides for five weeks in aged 5XFAD mice improved spatial memory, reduced amyloid plaque burden, and neuroinflammation. The common residue SQELHRLQTY …

The Role Of The Tau N-Terminal Phosphatase-Activating Domain And Phosphorylation At Thr175 In The Formation Of Tau Cytoplasmic Inclusions, Matthew A. Hintermayer

Electronic Thesis and Dissertation Repository

Cytoplasmic inclusions and fibrils of the microtubule-associated protein tau (tau protein) are a key neuropathological hallmark in tauopathies, including Alzheimer’s disease, chronic traumatic encephalopathy, and amyotrophic lateral sclerosis with cognitive impairment. Previous research has demonstrated that the phosphorylation of tau protein at Thr¹⁷⁵ is sufficient for the initiation of fibril formation both in vitro and in vivo. Here we use mutated tau protein constructs to demonstrate that phosphorylation at Thr¹⁷⁵ results in the aberrant exposure of an N-terminal phosphatase-activating domain (PAD). The tau PAD interacts with protein phosphatase 1 (PP1) leading to the activation of glycogen synthase …

Behavioral Responses To Gold Nanoparticle Exposure And H2o2-Induced Oxidative Stress In Caenorhabditis Elegans, Rachel Pride, Ashley Wagner

DePaul Discoveries

Gold nanoparticles (AuNPs) have been utilized in many biomedical disciplines, most notably cancer therapy and drug delivery. Recent research suggests that with specific peptide manipulation, AuNPs can deliver drugs across the blood-brain barrier (BBB), allowing for treatment of neurodegeneration and other neurological afflictions. Neurodegeneration has been shown to be caused by oxidative stress. The present experiment aimed to assess the effects of AuNPs on C. elegans behavior that had undergone H₂O₂-induced oxidative stress. It was predicted that worms exposed to both H₂O₂ and AuNPs would have higher survival, mechanosensation, and thrashing rates than …

Selenomethionine Protects Mutant Tau N27a Cell From Oxidative Stress And Decreases Phosphorylation Of Tau, Madelin Locicero

Celebration of Learning

Alzheimer’s Disease (AD) is neurodegenerative disease characterized by loss of cells and aggregated tau in the hippocampus. Hyperphosphorylated tau causes the misfolding of tau proteins (aggregated tau), which are responsible for proper neuronal activity. Selenium-methionine has been known to decrease the amount of phosphorylated tau within mutant and wild type 3xTg- AD mice. However, selenium can be toxic to cell depending on the type of cells and the concentration of selenium. The purpose of this study is to determine the effect selenium-methionine has on decreasing hyperphosphorylation of tau, protecting cells from oxidative stress, and decreasing the amount of aggregated tau …

Assessment Of Motor Function, Motor Learning, & Olivary Climbing Fiber Distribution Within Developmental Hyperserotonemia Rat Model For Autism Spectrum Disorder, Elizabeth Diane Holland

MSU Graduate Theses

While Autism Spectrum Disorder (ASD) is defined by deficits in social communication, compromised motor function and motor learning have been increasingly reported. Motor deficits could compound social impairment through delayed language acquisition, reduced opportunity for social interaction, and affected nonverbal communication. One area of interest in the investigation of motor dysfunction is the cerebellum, where altered cerebellar structure and connectivity have been reported in those diagnosed with ASD. Morphological and functional changes in cerebellar circuitry could disrupt motor skill development and may be associated with developmental alterations of the serotonergic system. Elevated blood serotonin in perinatal development, developmental hyperserotonemia (DHS), …

Investigating The Role Of Integrin Beta 3 In Dendritic Arborization In The Supragranular Developing Cerebral Cortex, Zachary Logan Holley

Senior Honors Projects, 2010-2019

Integrin subunits have been implicated in axonal and dendritic outgrowth. In particular, a strong positive association has been found between mutations in integrin beta 3 (Itgb3) and autism spectrum disorder, but little is known about neuronal Itgb3 function in vivo. Many forms of autism spectrum disorder are thought to arise from dysfunctional dendritic arborization and synaptic pruning. Global knockout of Itgb3 in mice leads to autistic-like behaviors. Itgb3^-/- mice also have reduced callosal volume, a key neuroanatomical correlate of autism. Here, we test the hypothesis that Itgb3 is required for normal dendritic arborization in layer II/III pyramidal …

Repetitive Mild Traumatic Brain Injury Impairs Performance In A Rodent Assay Of Cognitive Flexibility, Christopher P. Knapp, Doug P. Fox, Ramesh Raghupathi, Laura L. Giacometti, Stan B. Floresco, Barry D. Waterhouse, Rachel L. Navarra

Rowan-Virtua Research Day

Mild traumatic brain injury (mTBI) occurs in almost 80% of the 3 million reported cases of TBI-related emergency department visits each year in the United States. The majority of mTBIs, sometimes classified as concussions, are due to sports-related activities and typically occur repeatedly over the course of an athlete’s career. mTBI symptoms are generally classified as either somatic or neuropsychiatric/cognitive in nature and include impairments in prefrontal cortex mediated functions, including attention, memory, processing speed, reaction times, problem solving, and cognitive flexibility. To date, there remains a major gap in our understanding of the behavioral manifestations, underlying neurobiology, and treatment …

Notch Inhibitors And The Bet Inhibitor Jq-1 Decrease The Growth Of Primary Tumor Cells Derived From A Novel Mouse Model Of C11orf95-Rela Induced Brain Tumor, Ericka Randazzo, Jesse Dunnack, Justin Fang, Joseph Loturco Phd

University Scholar Projects

Brain tumors are the most common childhood solid malignancy, and because of remarkable advances in treating many cancers outside of the brain, they have become the leading cause of cancer mortality in children. Ependymomas are a class of brain tumors which can be further subdivided into three groups based upon their location and genetic features. Of the three classes, supratentorial ependymomas are the only subgroup known to be marked by an oncogenic driver gene, which consists of a fusion mutation between the C11orf95 and RELA genes. C11orf95-RELA positive tumors are the most aggressive and lethal of …

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis has …

Changes In Hippocampal-Anterior Cingulate Cortex Interactions During Remote Memory Recall, Ryan A. Wirt

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spatial memory is an important cognitive process that relies on extensive neural networks throughout the brain. The hippocampus (HC) is important for the formation of these memories but over time, in a process referred to as consolidation, recall becomes increasingly reliant on other brain areas. The anterior cingulate cortex (ACC), a region within the medial prefrontal cortex, is important for spatial learning, spatial working memory, and remote memory recall, but the mechanisms underlying recall processes are still unknown. To better understand the role of the ACC and HC during memory recall, we introduced rodents into a series of spatially and …

Does It Matter Whether You Or Your Brain Did It? An Empirical Investigation Of The Influence Of The Double Subject Fallacy On Moral Responsibility Judgments, Uri Maoz, Kellienne R. Sita, Jeroen J. A. Van Boxtel, Liad Mudrik

Psychology Faculty Articles and Research

Despite progress in cognitive neuroscience, we are still far from understanding the relations between the brain and the conscious self. We previously suggested that some neuroscientific texts that attempt to clarify these relations may in fact make them more difficult to understand. Such texts—ranging from popular science to high-impact scientific publications—position the brain and the conscious self as two independent, interacting subjects, capable of possessing opposite psychological states. We termed such writing ‘Double Subject Fallacy’ (DSF). We further suggested that such DSF language, besides being conceptually confusing and reflecting dualistic intuitions, might affect people’s conceptions of moral responsibility, lessening the …

Probiotic Administration As An Adjuvant Therapeutic Treatment For Anxiety, Depression, And Cognitive Impairment Among Hypothyroid Patients, Erin R. Gorman

Selected Honors Theses

Hypothyroidism is a form of thyroid dysfunction that occurs when the thyroid gland does not make and secrete enough thyroid hormones to regulate certain processes in the body. Because thyroid hormones take part in many bodily functions, hypothyroidism can cause a large range of symptoms. Current research indicates that some strains of probiotics have beneficial effects on certain neurological and inflammatory diseases, leading to the impression that they can be used therapeutically for effective treatment of different mental health issues such as anxiety, stress, depression, and impaired memory. Because hypothyroidism often leads to such mental symptoms, it may be possible …

Prefrontal Corticotropin-Releasing Factor (Crf) Neurons Act Locally To Modulate Frontostriatal Cognition And Circuit Function., Sofiya Hupalo, Andrea J Martin, Rebecca K Green, David M Devilbiss, Craig W Berridge

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

The PFC and extended frontostriatal circuitry support higher cognitive processes that guide goal-directed behavior. PFC-dependent cognitive dysfunction is a core feature of multiple psychiatric disorders. Unfortunately, a major limiting factor in the development of treatments for PFC cognitive dysfunction is our limited understanding of the neural mechanisms underlying PFC-dependent cognition. We recently demonstrated that activation of corticotropin-releasing factor (CRF) receptors in the caudal dorsomedial PFC (dmPFC) impairs higher cognitive function, as measured in a working memory task. Currently, there remains much unknown about CRF-dependent regulation of cognition, including the source of CRF for cognition-modulating receptors and the output pathways modulated …

The Extreme Effects Of ‘Not-So-Minor’ Concussions: Chronic Traumatic Encephalopathy Literature Review, Alyssa Pierson

Honors Theses

Many of the concerns that people have with chronic traumatic encephalopathy (CTE) have already been researched for almost a century, but recently, there has been a big push in CTE research. Previous research was done on boxing and football and has now expanded to other contact sports and the military. Risk factors for CTE include repetitive head trauma, the Apoe4 allele, and age of first exposure to brain trauma. A wide range of symptoms may present with CTE, from motor impairment to suicidal ideation. It is believed that a biopsychosocial model should be used when approaching the symptoms of CTE …

Systematic Literature Review Of Quetiapine For The Treatment Of Psychosis In Patients With Parkinsonism, Jack J. Chen, Henry Hua, Lilian Massihi, Ivan Portillo, Azita Alipour, William Ondo, Khashayar Dashtipour

Library Articles and Research

Objective:

The purpose of this article was to determine the efficacy and tolerability of quetiapine compared with placebo or other interventions for psychosis in parkinsonism.

Methods:

Participants with a diagnosis of parkinsonism participated in randomized controlled trials (RCTs) investigating the efficacy and tolerability of quetiapine for psychotic symptoms within a defined follow-up period. The authors conducted searches on PubMed, Cochrane Controlled Register of Trials, and EMBASE for articles published from January 1991 to October 2017. Study methodology and patient- and treatment-level data were independently extracted and summarized by using descriptive statistics. Studies underwent quality assessment for risk of bias.

Results: …

Initial Characterization Of The Indole-3-Carboxamide Bic-154 As A Fast Onset And Reversible Orai Channel Blocker, Tetyana Zhelay, Kalina Szteyn, Elisa Liardo, Jae Eun Cheong, Steffi Koerner, Anil Ekkati, Lijun Sun, J. Ashot Kozak

Neuroscience, Cell Biology & Physiology Faculty Publications

Calcium ion elevations are required for human T-lymphocyte proliferation in response to antigen recognition by a T-cell receptor. Calcium influx through the plasma membrane is necessary for efficient T-cell proliferation and effector function. The calcium channels responsible for Ca2+ influx in lymphocytes have been identified and Orai interacting with ER Ca2+ sensor STIM were shown to be crucial for persistent calcium mobilization. Loss-of-function mutations in Orai1 or STIM1 result in severe combined immunodeficiency (SCID) with muscle hypotonia. Suppression of calcium influx through Orai/STIM channels gives rise to various lymphoproliferative defects. Thus, deletion of Orai or STIM in mice results in …

The Influence Of Unpredictable, Fragmented Parental Signals On The Developing Brain, Laura M. Glynn, Tallie Z. Baram

Psychology Faculty Articles and Research

Mental illnesses originate early in life, governed by environmental and genetic factors. Because parents are a dominant source of signals to the developing child, parental signals - beginning with maternal signals in utero - are primary contributors to children’s mental health. Existing literature on maternal signals has focused almost exclusively on their quality and valence (e.g. maternal depression, sensitivity). Here we identify a novel dimension of maternal signals: their patterns and especially their predictability/unpredictability, as an important determinant of children’s neurodevelopment. We find that unpredictable maternal mood and behavior presage risk for child and adolescent psychopathology. In experimental models, fragmented/unpredictable …

The Promises And Challenges Of Erythropoietin For Treatment Of Alzheimer's Disease, Jiahong Sun, Jan Michelle Martin, Victoria Vanderpoel, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder in the world, and intracellular neurofibrillary tangles and extracellular amyloid-beta protein deposits represent the major pathological hallmarks of the disease. Currently available treatments provide some symptomatic relief but fail to modify primary pathological processes that underlie the disease. Erythropoietin (EPO), a hematopoietic growth factor, acts primarily to stimulate erythroid cell production, and is clinically used to treat anemia. EPO has evolved as a therapeutic agent for neurodegeneration and has improved neurological outcomes and AD pathology in rodents. However, penetration of the blood–brain barrier (BBB) and negative hematopoietic effects are the two …

Neurochemical Factors Associated With The Initial Pathophysiological Reaction To Large Vessel Occlusion Stroke, Sarah R. Martha

Theses and Dissertations--Nursing

Ischemic stroke is the leading cause of disability world-wide and affects over 800,000 people per year in the United States. The majority of these strokes are ischemic due to a blockage of blood flow to the brain. Damage to the brain occurs at the onset of stroke, neuronal cell death is irreversible and therefore, quick treatment to remove blockage is critical factor in the recovery from stroke. Mechanical thrombectomy as a treatment for ischemic stroke provides an ideal opportunity to collect blood distal and proximal to the cerebral thrombus to examine neurochemical changes occurring during stroke.

The purpose of this …

Can Nanotechnology Be The Leading Method In Detecting And Treating Cerebral Tumors?, Daniel D. Singh, Zuri Jules-Culver

OUR Journal: ODU Undergraduate Research Journal

Nanotechnology refers to the manipulation or design of materials and structures with desired features in the 1nm–1000 nm size range. The blood brain barrier (BBB) is a major obstacle that drugs must overcome in order to reach tumor cells. The role of this barrier is to transport essential nutrients while protecting and regulating the internal environment. Nanoparticles have been shown to transport drugs through this barrier and accumulate in tumor cells. This is significant since nanoparticles are drug carriers allowing chemotherapeutic drugs to accumulate in target areas (Sun et al., 2017). This is possible because they are able to be …

Axon Initial Segment Integrity In Aging And Traumatic Brain Injury, Mazen M. Gouda

Theses and Dissertations

According to the Center for Disease Control’s (CDC) report to the Congress, there are 2.2 million emergency department visits; 80,000 hospitalizations; and 50,000 deaths each year due to traumatic brain injury. Adults 65 years and older account substantially for the majority of the hospitalization and deaths. Over 70% of the traumatic brain injuries of the older adults are classified as mild to moderate; however, even with these milder injuries, older adults present with a significantly higher morbidity and mortality compared to all other age groups (LeBlanc et al., 2006). With that in mind, it seems essential to develop a deeper …

Development Of A Functional Testing Platform For The Sensory Segment Of The Neuromuscular Reflex Arc, Alisha Colon

Electronic Theses and Dissertations

Investigations of human biology and disease have been hindered by the use of animal models. The information obtained from such studies often results in clinically irrelevant results and drug trial failures. Additionally, several governing bodies have been formulating legislation to move away from animal models and toward more ethical and efficient testing platforms for drug discovery and cosmetic research. As an answer to these issues, "body-on-a-chip" systems have been a rapidly developing field which easily recapitulates in vivo functionality, providing a more relevant, repeatable, and ethical testing platform to better predict biology. These systems can be used as human-based testing …