Neuroscience and Neurobiology Commons^™

Endocytic Trafficking Of The Amyloid Precursor Protein In Rat Cortical Neurons, Sahily Reyes

Dissertations and Theses (Open Access)

Amyloid-beta (Aβ) aggregation and deposition into extracellular plaques is a hallmark of the most common forms of dementia, including Alzheimer’s disease. The Aβ-containing plaques result from pathogenic cleavage of amyloid precursor protein (APP) by secretases resulting in intracellular production of Aβ peptides that are secreted and accumulate extracellularly. Despite considerable progress towards understanding APP processing and Aβ aggregation, the mechanisms underlying endosomal production of Aβ peptides and their secretion remain unclear. Using endosomes isolated from cultured primary neurons, we determined that the trafficking of APP from the endosomal membrane into internal vesicles of late endosome/multivesicular bodies (MVB) is dependent on …

Targeting Mitochondrial Dysfunction In Cns Injury Using Methylene Blue; Still A Magic Bullet?, Hemendra J. Vekaria, Lora Talley Watts, Ai-Ling Lin, Patrick G. Sullivan

Spinal Cord and Brain Injury Research Center Faculty Publications

Complex, multi-factorial secondary injury cascades are initiated following traumatic brain injury, which makes this a difficult disease to treat. The secondary injury cascades following the primary mechanical tissue damage, are likely where effective therapeutic interventions may be targeted. One promising therapeutic target following brain injury are mitochondria. Mitochondria are complex organelles found within the cell, which act as powerhouses within all cells by supplying ATP. These organelles are also necessary for calcium cycling, redox signaling and play a major role in the initiation of cell death pathways. When mitochondria become dysfunctional, there is a tendency for the cell to loose …

Morphogenesis And Growth Driven By Selection Of Dynamical Properties, Yuri Cantor

Dissertations, Theses, and Capstone Projects

Organisms are understood to be complex adaptive systems that evolved to thrive in hostile environments. Though widely studied, the phenomena of organism development and growth, and their relationship to organism dynamics is not well understood. Indeed, the large number of components, their interconnectivity, and complex system interactions all obscure our ability to see, describe, and understand the functioning of biological organisms.

Here we take a synthetic and computational approach to the problem, abstracting the organism as a cellular automaton. Such systems are discrete digital models of real-world environments, making them more accessible and easier to study then their physical world …

Study Of Regulated Cell Death In Two Systems: Pd-1 In Natural Killer Cells And Rip3 In Neurons, Yu Huang

Dissertations and Theses (Open Access)

Cell death is not only an essential phenomenon in normal development and homeostasis, but also crucial in various pathologies. It is now clear that many types of cell death can be regulated by pharmacological or genetic interventions. These were largely achieved by identifying the molecular mechanisms underlying the regulated cell death (RCD). While in the immune system, RCD needs to be facilitated to help the clearance of pathogens and tumors, in healthy cells, especially the terminally differentiated neurons in the nervous system, it is more desirable to protect cells from dying due to stress under pathological conditions. Thus, understating the …

Chaperoning Ef Hands That Shape Calcium Response: Ncald, Hpca And S100b, Jingyi Zhang

Graduate School of Biomedical Sciences Theses and Dissertations

All organisms have an internal clock with a defined period between repetitions of activities. The period for circadian clock in human is 24.5 hours, while in mouse and rat, it is 23.5 hours. However, all organisms are forced to be in synchronization with their environment. A major environmental force that resets the internal clock to 24 hours is light. This phenomenon is defined as “light entrainment” or “phase-setting”. It is unclear how this entrainment process occurs. Studies from this laboratory indicate a role for two neuronal calcium sensor proteins: Neurocalcin  (NCALD) and S100B. For these two genes, mRNA as …

Investigating The Synergistic Effects Of Cisplatin And Two Curcuminoid Compounds On Cancer, Denis Hodzic

Mahurin Honors College Capstone Experience/Thesis Projects

Cisplatin is an anti-cancer drug effective against several cancers which can produce the serious side-effect of hearing loss. Curcumin, a natural plant compound, can increase the activity of cisplatin against cancer and counteract cisplatin’s effect against hearing. Because curcumin exhibits poor bioavailability, there is considerable interest in developing synthetic curcumin analogs (curcuminoids) that are more soluble and which retain anti-cancer activity and otoprotective function. This study investigated whether two curcuminoids, EF-24 and CLEFMA, increase the cytotoxic and ototoxic effects of cisplatin against the lung cancer cell line, A549, and the colorectal cancer cell line, Caco2. Cytotoxicity was measured by using …

Modeling 3d Retinogenesis In Mouse Embryonic Stem Cells Following Crispr-Mediated Crx Knockdown, Pooja Prasad

Dissertations, Masters Theses, Capstones, and Culminating Projects

An emerging technology known as three-dimensional (3D) tissue engineering has allowed scientists to mimic tissues found in vivo. Previous studies indicate that it is possible to differentiate dissociated mouse embryonic stem cells (mESCs) into 3D retinal tissues in vitro (Bertacchi, 2015; Eiraku, 2012). The newly differentiated retinal tissues are said to encompass all of the major components found in retinal tissues. The generation of in vitro 3D tissues holds great potential in terms of patient-specific disease modeling. Although various diseases have been well-studied in animal models, there are limitations with regards to patient-specificity. The generation of animal models to study …

Investigating Localization And Activity-Dependent Translation Of Astrocyte Mrna, Rohan Khazanchi

Senior Honors Papers / Undergraduate Theses

Over the past two and a half years, I have studied fundamental aspects of astrocyte biology by investigating the existence and mechanism of astrocyte local translation peripherally around tripartite synapses consisting of pre- and post-synaptic neuron terminals and an associated astrocyte. Astrocytes are critical components of central nervous system synapses (which are predominately tripartite in nature); thus, it is important to consider how astrocyte dysregulation and dysfunction could contribute to the pathogenesis of diseases of synaptic connectivity such as autism spectrum disorders, Alzheimer’s disease, seizure disorders, and more. Overall, my projects involved the development of novel methods to identify astrocyte-specific …

Role Of Trpv4 In Astrocyte Extracellular Matrix Production, Abby Terlouw

Biomedical Engineering Undergraduate Honors Theses

Traumatic Brain Injury (TBI) is an alteration of brain pathology following damage of the central nervous system (CNS) by an external force. In the CNS, glial scar formation often occurs following TBI, and astrocytes are widely believed to contribute to this scar formation. While the role of astrocytes in extracellular matrix (ECM) production is known, the exact mechanism(s) for this event remain unclear. One possible method is the activation of transient receptor potential vanilloid 4 (TRPV4). TRPV4 is a channel protein found in the astrocyte membrane which has been shown to generate intracellular calcium ions following mechanical stimulation. Previous research …

Molecular Mechanisms Of Inward And Outward Budding From Multivesicular Endosomes, Monica Gireud Goss

Dissertations and Theses (Open Access)

Regulating the residence time of membrane proteins (e.g. transporters, ion channels, receptors) on the cell surface can modify their response to extracellular cues and allow for cellular adaptation to environmental conditions. The fate of membrane proteins that are internalized from the plasma membrane and arrive at the limiting membrane of the late endosome/multivesicular body (MVB) is dictated by whether they remain on the limiting membrane, bud into internal MVB vesicles, or bud outwardly from the membrane. The molecular details underlying the disposition of membrane proteins that transit this pathway and the mechanisms regulating these trafficking events are unclear. We established …

Human Neuroblastoma Adaptation To Cobalt Chloride-Induced Hypoxia, Conor Mcauliffe

Seton Hall University Dissertations and Theses (ETDs)

Hypoxia is a frequent characteristic of the solid tumor microenvironment, which occurs when cancer cells lack adequate access to oxygen. By selecting for cells that can adapt to and grow in low oxygen conditions, tumor hypoxia contributes to a more aggressive and invasive cancer phenotype that portends a poor clinical outcome. While many aspects of the cellular response to hypoxia have been explored, the roles of some factors have not been fully explained. Cell signaling factors, including signal transducer and activator of transcription 3 (STAT3), the mu opioid receptor (MOR), and the delta opioid receptor (DOR), as well as changes …

Mechanotransduction Current Is Essential For Stability Of The Transducing Stereocilia In Mammalian Auditory Hair Cells, A. Catalina Vélez-Ortega, Mary J. Freeman, Artur A. Indzhykulian, Jonathan M. Grossheim, Gregory I. Frolenkov

Physiology Faculty Publications

Mechanotransducer channels at the tips of sensory stereocilia of inner ear hair cells are gated by the tension of 'tip links' interconnecting stereocilia. To ensure maximal sensitivity, tip links are tensioned at rest, resulting in a continuous influx of Ca²⁺ into the cell. Here we show that this constitutive Ca²⁺ influx, usually considered as potentially deleterious for hair cells, is in fact essential for stereocilia stability. In the auditory hair cells of young postnatal mice and rats, a reduction in mechanotransducer current, via pharmacological channel blockers or disruption of tip links, leads to stereocilia shape changes and shortening. …

P32. Altered Sensory Processing In Response To Novel Dreadd-Induced Inactivation Of Gaba In Pedunculopontine Tegmental Nucleus, Niveen Fulcher

Western Research Forum

Niveen Fulcher¹, Cleusa De Oliveira², & Susanne Schmid^1,2

¹Schulich School of Medicine & Dentistry, University of Western Ontario

²Anatomy and Cell Biology, University of Western Ontario

Altered sensory processing in response to novel DREADD-induced inactivation of GABA in pedunculopontine tegmental nucleus

Background: Sensory processing deficits are associated with certain psychiatric illnesses, such as schizophrenia and autism spectrum disorder (ASD). Sensory filtering and sensorimotor gating are evolutionarily conserved preattentive responses that filter and block redundant sensory stimuli that would otherwise overwhelm our brains. To date, underlying mechanisms of these deficits are undefined. Prepulse …

Adaptor Protein 2 (Ap-2) Complex Is Essential For Functional Axogenesis In Hippocampal Neurons, Jae Won Kyung, In Ha Cho, Sukmook Lee, Woo Keun Song, Timothy A. Ryan, Michael B. Hoppa, Sung Hyun Kim

Dartmouth Scholarship

The complexity and diversity of a neural network requires regulated elongation and branching of axons, as well as the formation of synapses between neurons. In the present study we explore the role of AP-2, a key endocytic adaptor protein complex, in the development of rat hippocampal neurons. We found that the loss of AP-2 during the early stage of development resulted in impaired axon extension and failed maturation of the axon initial segment (AIS). Normally the AIS performs two tasks in

concert, stabilizing neural polarity and generating action potentials. In AP-2 silenced axons polarity is established, however there is a …

Origins Of Thalamic And Cortical Projections To The Posterior Auditory Field In Congenitally Deaf Cats., Blake E Butler, Nicole Chabot, Andrej Kral, Stephen G Lomber

Psychology Publications

Crossmodal plasticity takes place following sensory loss, such that areas that normally process the missing modality are reorganized to provide compensatory function in the remaining sensory systems. For example, congenitally deaf cats outperform normal hearing animals on localization of visual stimuli presented in the periphery, and this advantage has been shown to be mediated by the posterior auditory field (PAF). In order to determine the nature of the anatomical differences that underlie this phenomenon, we injected a retrograde tracer into PAF of congenitally deaf animals and quantified the thalamic and cortical projections to this field. The pattern of projections from …

Alpha-Synuclein: Insight Into The Hallmark Of Parkinson's Disease As A Target For Quantitative Molecular Diagnostics And Therapeutics, Baggio A. Evangelista

Honors Undergraduate Theses

Parkinson’s disease (PD) is the second-most common neurodegenerative disease after Alzheimer’s disease. With 500,000 individuals currently living with Parkinson’s and nearly 60,000 new cases diagnosed each year, this disease causes significant financial burden on the healthcare system - amassing to annual expenditures totaling 200 billion dollars; predicted to increase through 2050. The disease phenotype is characterized by a combination of a resting tremor, bradykinesia, muscular rigidity, and depression due to dopaminergic neuronal death in the midbrain. The cause of the neurotoxicity has been largely discussed, with strong evidence suggesting that the protein, alpha-Synuclein, is a key factor. Under native conditions, …

Transposon-Mediated Stable Suppression Of Gene Expression In The Developing Chick Retina, Masaru Nakamoto, Chizu Nakamoto

Biology Faculty Publications

The embryonic chick has long been a favorite model system for in vivo studies of vertebrate development. However, a major technical limitation of the chick embryo has been the lack of efficient loss-of-function approaches for analyses of gene functions. Here, we describe a methodology in which a transgene encoding artificial microRNA sequences is introduced into embryonic chick retinal cells by in ovo electroporation and integrated into the genome using the Tol2 transposon system. We show that this methodology can induce potent and stable suppression of gene expression. This technique therefore provides a rapid and robust loss-of-function approach for studies of …

Metabolic And Morphologic Shifts In Neuro2a Cells Cultured In Galactose Medium, Leah Welker

Masters Theses

It has been observed that highly-proliferating cells, such as cancer cells, rely mainly on glycolysis for ATP production, regardless of presence of oxygen. This effect, however, can be reversed by changing the main energy substrate in the medium from glucose to galactose. The oxidation of galactose in glycolysis yields less net ATP, presumably forcing the cell into OXPHOS. This has been established in many cell lines, including HeLA, HepG2, and skeletal muscle cells. As of yet, this has not been reproduced in neuronal cells. Using Neuro2a, a murine neuroblastoma cell line, this study exposes neuronal cells to galactose medium, and …

Effects Of Chromium On Mouse Splenic T Lymphocytes And Effects Of Ethanol Exposure During Early Neurodevelopment On Behaviors In Mice, Lu Dai

Theses and Dissertations--Toxicology and Cancer Biology

The dissertation consists of three major projects with the focus on the immunotoxicity of chromium and the behavior disorders caused by early ETOH exposure respectively.

Hexavalent chromium [Cr(VI)] is widely used in various industrial processes and has been recognized as a carcinogen. As the first line of host defense system, the immune system can be a primary target of Cr(VI). T cell population represents a major arm of the immune system that plays a critical role in host anti-tumor immunity. Dysfunction of T cells compromises host anti-tumor immunity resulting in oncogenesis. Using mouse splenic T cells as an in vitro …

4-Nonylphenol Induces Neurodegeneration By Altering Cytoskeleton, Cynthia Carreon

Open Access Theses & Dissertations

4-nonylphenol (4-NP), an endocrine-disrupting compound (EDC), has been shown to affect brain development and may cause neurodegeneration. In the environment, 4-NP arises as a degradation product of alkylphenol polyethoxylates, compounds widely used as nonionic surfactants in commercial production, as well as in herbicides, pesticides, polystyrene plastics, and paints and has been shown to undergo a high level of accumulation in biological tissues. However, the mechanism by which 4-NP exerts its effect is not understood. Recent results from our laboratory indicate that Gβγ, an important component of the G protein-signaling pathway, induces neuronal outgrowth and differentiation by modulating microtubule (MT) assembly, …

A Rare Case Of Erythema Elevatum Diutinum Presenting As Diffuse Neuropathy, G H. Nguyen, E L. Guo, D Norris

Faculty, Staff and Students Publications

No abstract provided.

Mitogen And Morphogen Signaling Dysregulation: Pathophysiological Influence In Pancreatic Cancer And Alzheimer’S Disease, Eric Cruz

Theses & Dissertations

Although the etiology of a particular disease will vary, there are genetic and epigenetic bottlenecks that frequently converge resulting in dysregulation of mitogenic and morphogenetic signaling. This propensity is acutely experienced in malignancy and neurodegenerative disease.

Here, we have first investigated the role of dysregulated signaling in the context of pancreatic cancer (PC). Morphogenetic signaling has been regarded as a pleiotropic pathway with the potential to promote and inhibit metastatic features. Our investigation of bone morphogenetic protein 2 (BMP-2), an archetypical member of the BMP superfamily, has revealed the presence of extracellular, intracellular, and long non-coding RNA products. Our findings …

Ros Regulation Of Axonal Mitochondrial Transport, Pin-Chao Liao

Open Access Dissertations

Mitochondria perform critical functions including aerobic ATP production and calcium (Ca2+) homeostasis, but are also a major source of reactive oxygen species (ROS) production. To maintain cellular function and survival in neurons, mitochondria are transported along axons, and accumulate in regions with high demand for their functions. Oxidative stress and abnormal mitochondrial axonal transport are associated with neurodegenerative disorders. However, we know little about the connection between these two. Using primaryDrosophila neuronal cell culture and the third instar larval nervous system as in vitro and in vivo models, respectively, we studied mitochondrial transport under oxidative stress conditions. In vitro …

Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker

Graduate Theses and Dissertations

Following injury to the central nervous system, extracellular modulations are apparent at

the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of …

Consensus Paper: Cerebellar Development, K Leto, M Arancillo, Ebe Becker, A Chiang, Et Al.

Faculty, Staff and Students Publications

The development of the mammalian cerebellum is orchestrated by both cell-autonomous programs and inductive environmental influences. Here, we describe the main processes of cerebellar ontogenesis, highlighting the neurogenic strategies used by developing progenitors, the genetic programs involved in cell fate specification, the progressive changes of structural organization, and some of the better-known abnormalities associated with developmental disorders of the cerebellum.

Characterization Of Vesicular Monoamine Transporter 2 And Its Role In Parkinson's Disease Pathogenesis Using Drosophila, Antonio Joel Tito Jr., Sheng Zhang

Dissertations and Theses (Open Access)

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the selective loss of the dopaminergic neurons in the Substantia nigra pars compacta region of the brain. PD is also the most common neurodegenerative disorder and the second most common movement disorder. PD patients exhibit the cardinal symptoms, including tremor of the extremities, rigidity, slowness of movement, and postural instability, after 70-80% of DA neurons degenerate. It is, therefore, imperative to elucidate the underlying mechanisms involved in the selective degeneration of DA neurons. Although increasing numbers of PD genes have been identified, why these largely widely expressed genes induce …

Dopamine Effects Of Stimulant And Non-Stimulant Drugs Used In The Treatment Of Attention Deficit Hyperactivity Disorder, Preeti Chalwadi

Theses and Dissertations

Attention deficit hyperactivity disorder (ADHD) is thought to be associated with dysfunction of ascending catecholamine neuronal systems, particularly dopamine (DA) and norepinephrine (NE). Dysfunction of these catecholamine neurons innervating the prefrontal cortex is hypothesized to underlie impaired executive functions. Dysfunction of the DA neurons innervating the striatum is additionally hypothesized to underlie deficits in motivation and reinforcement learning. However, mechanisms of action of therapeutic drugs used for treating ADHD have mainly focused on catecholamines in the prefrontal cortex and have not adequately addressed the role played by DA signaling in the striatum. Stimulants such as Adderall® and Ritalin® are chemically …

Understanding The Differences Between Neuronal Calcium Sensor Proteins: A Comparison Of Neurocalcin Delta And Hippocalcin, Jeffrey M. Viviano

Graduate School of Biomedical Sciences Theses and Dissertations

Many neuronal functions, including learning and memory are driven by changes in intracellular Ca2+concentrations. The Neuronal Calcium Sensor (NCS) family of proteins is responsible for mediating the response to calcium. They are typically comprised of 4 EF hands; of which EF 2, 3, and 4 bind calcium.

Hypothesis: NCS proteins carry out unique, non-overlapping functions, and that specific characteristics of the family can be mapped to precise regions of the proteins.

Results: The effect on the following properties were investigated primarily on two highly similar NCS proteins, Neurocalcin Delta (NCALD) and Hippocalcin (HPCA): (1) Response to calcium was determined through …

Active Learning Outside The Classroom: Implementation And Outcomes Of Peer-Led Team-Learning Workshops In Introductory Biology, Philip Kudish, Robin Shores, A. Mcclung, Lisa Smulyan , '76, Elizabeth Ann Vallen, Kathleen King Siwicki

Biology Faculty Works

Study group meetings (SGMs) are voluntary-attendance peer-led team-learning workshops that supplement introductory biology lectures at a selective liberal arts college. While supporting all students’ engagement with lecture material, specific aims are to improve the success of underrepresented minority (URM) students and those with weaker backgrounds in biology. Peer leaders with experience in biology courses and training in science pedagogy facilitate work on faculty-generated challenge problems. During the eight semesters assessed in this study, URM students and those with less preparation attended SGMs with equal or greater frequency than their counterparts. Most agreed that SGMs enhanced their comprehension of biology and …

The Role Of Neurovascular Compromise, Autoimmune Antibodies And Neuronal Calcium Sensor Proteins During The Onset And Progression Of Alzheimer's Disease - Linking The Retina With The Brain, Hao Wu

Graduate School of Biomedical Sciences Theses and Dissertations

Alzheimer's disease (AD), the main cause of dementia, is a progressive and irreversible neurodegenerative disease. The pathological hallmarks of the disease include bloodbrain barrier (BBB) breach, neurofibrillary tang les and amyloid plaques. Also, emerging evidence has raised the possibility that instead of a secondary consequence, the neuroinflammation contributes to the development and early progression of AD. However, the mechanism underlying the blood-neural barrier (BNB), chronic inflammation and neuronal degenerative diseases (NDDs) remain to be elucidated.

To explore the role of the chronic inflammation in NDDs and delineate the early steps of these diseases, in vivo drug-induced and transgenic mouse models …