Medical Neurobiology 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 …

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 …

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 …

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 …

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 …

Autologous Peripheral Nerve Grafts To The Brain For The Treatment Of Parkinson's Disease, Andrew Welleford

Theses and Dissertations--Neuroscience

Parkinson’s disease (PD) is a disorder of the nervous system that causes problems with movement (motor symptoms) as well as other problems such as mood disorders, cognitive changes, sleep disorders, constipation, pain, and other non-motor symptoms. The severity of PD symptoms worsens over time as the disease progresses, and while there are treatments for the motor and some non-motor symptoms there is no known cure for PD. Thus there is a high demand for therapies to slow the progressive neurodegeneration observed in PD. Two clinical trials at the University of Kentucky College of Medicine (NCT02369003, NCT01833364) are currently underway that …

Dna Methylation Of The Clusterin Promoter: Associations With Alzheimer’S Disease Risk And Related Phenotypes, Madeline Peretti

Theses: Doctorates and Masters

Background

In 2017 approximately 50 million people worldwide were living with dementia. With Alzheimer’s disease (AD), accounting for 50-70% of dementia cases making this debilitating disease, with no current effective prevention, treatment or cure, a critical healthcare concern. Genome wide association studies (GWAS) have identified a number of risk genes for late onset AD (LOAD); Apolipoprotein E (APOE), a gene involved in the cholesterol/lipid pathway is considered the gene with the greatest risk. The third most associated AD risk gene is Clusterin (CLU), is also involved in the cholesterol/lipid pathway. CLU has been implicated in both …