Biochemistry, Biophysics, and Structural Biology Commons^™

Somatic Inhibition By Microscopic Magnetic Stimulation, Hui Ye

Biology: Faculty Publications and Other Works

Electric currents can produce quick, reversible control of neural activity. Externally applied electric currents have been used in inhibiting certain ganglion cells in clinical practices. Via electromagnetic induction, a miniature-sized magnetic coil could provide focal stimulation to the ganglion neurons. Here we report that high-frequency stimulation with the miniature coil could reversibly block ganglion cell activity in marine mollusk Aplysia californica, regardless the firing frequency of the neurons, or concentration of potassium ions around the ganglion neurons. Presence of the ganglion sheath has minimal impact on the inhibitory effects of the coil. The inhibitory effect was local to the …

Determining The Role Of Methylglyoxal (Mgo) And The Trpa1 Channel In Inducing Astrocyte Senescence And Neurodegeneration, Natalie Hill

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Aging is the largest risk factor for the development of Alzheimer’s disease (AD) and related dementias. A recently proposed driver of age-related pathologies is cellular senescence, a phenotype that consists of cell-cycle arrest and an inflammatory response known as the senescence-associated secretory phenotype (SASP). Although there is a link between the accumulation of senescent cells and neurodegeneration, much remains unknown about how senescent cells arise in the brain. Astrocytes are the most abundant cell type in the brain that serve important roles like supporting neurons and proliferating in response to stress. Methylglyoxal (MGO) is a glycolytic byproduct that can react …

Identifying The Cell Composition And Clonal Diversity Of Supratentorial Ependymoma Using Single Cell Rna-Sequencing, James He

Honors Scholar Theses

Ependymoma is a primary solid tumor of the central nervous system. Supratentorial ependymoma (ST-EPN), a subtype of ependymomas, is driven by an oncogenic fusion between the ZFTA and RELA genes in 70% of cases. We introduced this fusion into neural progenitor cells of mice embryos via in utero electroporation of a non-viral binary piggyBac transposon system containing ZFTA-RELA. From preliminary data in the LoTurco lab, inducing the expression of ZFTA-RELA into different neural progenitor cells produces tumors of varying lethality and cellular composition. To define the cellular composition and subclonal diversity of ST-EPN tumors, we used single cell RNA-sequencing …

Mitochondrial Distribution Of Glycine Receptors In Motor Neuron Cell Lines, Katsiaryna Milashevich

Student Theses and Dissertations

Although non-essential, glycine plays an important role in major metabolic reactions and is most known for its anti-inflammatory effects. An accumulation of contemporary research has shown that glycine is able to stabilize membrane potential using glycine receptors at the cellular level and to protect mitochondrial function directly, whether it is from inflammation, heavy metal poisoning, or ischemia-induced neuroinflammation. In this research, the existence of a hypothetical mitochondrial glycine receptor is examined. Immunofluorescence imaging was used to examine the presence of the glycine receptor subunits alpha 1 and alpha 2 in both non- differentiated and differentiated neuroblastoma cell lines. The preliminary …

Ampa And Kainate Receptor-Potentiating Rna Aptamers, Janet L. Lynch

Legacy Theses & Dissertations (2009 - 2024)

Glutamate receptors act to bring about excitatory transmission in the central nervous system. The receptors are divided into two groups: ionotropic and metabotropic glutamate receptors. Ionotropic glutamate receptors are ion channels which are activated by an agonist such as glutamate or kainate. The main receptors in the ionotropic glutamate receptor family are the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate and N-methyl-D-aspartate (NMDA) receptors. In the central nervous system ionotropic glutamate receptors are found both pre- and postsynaptically. It has been found that most AMPA and NMDA receptors are postsynaptic receptors while the kainate receptors can be pre- or postsynaptic. Underactivity of these …

Long-Term Impacts Of Acute Stressor Exposure On Locus Coeruleus Function And Anxiety-Like Behavior In Rats, Olga Borodovitsyna

Graduate School of Biomedical Sciences Theses and Dissertations

Stress is a physiological state characterized by behavioral arousal that occurs during exposure to harmful or threatening stimuli, and usually facilitates an adaptive behavioral response. The persistence of stress sometimes causes it to become maladaptive, potentially contributing to disease development, including physiological complications with altered neuroendocrine signaling and impaired function of organ systems, and psychological conditions including depression and anxiety. Anxiety disorders in particular are associated with a history of stress and are the most common class of mental disorders, with a lifetime prevalence of 33.7% in the general population. The locus coeruleus (LC) is a major node in the …

Mitochondrial Transfer From Mesenchymal Stem Cells Improves Neuronal Metabolism After Oxidant Injury In Vitro: The Role Of Miro1, Nancy Tseng, Scott C Lambie, Christopher Q Huynh, Bridget Sanford, Manisha Patel, Paco S Herson, D Ryan Ormond

Faculty, Staff and Students Publications

Stroke-induced cerebral ischemia is a major cause of death and disability. The disruption of blood flow results in neuronal and glial cell death leading to brain injury. Reperfusion restores oxygen to the affected tissue, but can also cause damage through an enhanced oxidative stress and inflammatory response. This study examines mitochondrial transfer from MSC to neurons and the role it plays in neuronal preservation after oxidant injury. We observed the transfer of mitochondria from MSC to mouse neurons in vitro following hydrogen peroxide exposure. The observed transfer was dependent on cell-to-cell contact and led to increased neuronal survival and improved …

Third Harmonic Generation: A Method For Visualizing Myelin In The Murine Cerebral Cortex, Michael Redlich

Dissertations, Theses, and Capstone Projects

Here we present the use of Third Harmonic Generation (THG) for the label-free imaging of myelinated axons in the murine cerebral cortex. Myelin plays an important role in the processes of learning and disease. However, much of the myelin biology research thus far has focused on white matter tracts where myelin is more visible. Much is still unknown, particularly with regard to myelin in gray matter. First, we engage in THG microscopy using an optical parametric oscillator pumped by a titanium-sapphire laser to demonstrate the utility of the technique for imaging myelin in vivo. Second, we investigate the use of …

Regional N-Glycan And Lipid Analysis From Tissues Using Maldi-Mass Spectrometry Imaging, Alexandra E. Stanback, Lindsey R. Conroy, Lyndsay E. A. Young, Tara R. Hawkinson, Kia H. Markussen, Harrison A. Clarke, Derek B. Allison, Ramon C. Sun

Neuroscience Faculty Publications

N-glycans and lipids are structural metabolites that play important roles in cellular processes. Both show unique regional distribution in tissues; therefore, spatial analyses of these metabolites are crucial to our understanding of cellular physiology. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) is an innovative technique that enables in situ detection of analytes with spatial distribution. This workflow details a MALDI-MSI protocol for the spatial profiling of N-glycans and lipids from tissues following application of enzyme and MALDI matrix.

For complete details on the use and execution of this protocol, please refer to Drake et al. (2018) and Andres et al. (2020).

The Effects Of Rolipram, A Selective Phosphodiesterase Inhibitor, On Immortalized Schwann Cell Proliferation, Akap95 And Cyclin D3 Expression, Kyle P. Kenney, Mary Pistack, Angela Asirvatham

Student Research Poster Presentations 2021

Schwann cells are a vital component of the Peripheral Nervous System and aid in the repair of axons following injury. The regulation of Schwann cell growth in vitro is facilitated by heregulin, a neuron-secreted growth factor, and an unknown mitogen that activates the cyclic adenosine monophosphate (cAMP) pathway. The abundance of intracellular cAMP is regulated by a family of enzymes called phosphodiesterases (PDEs). PDE inhibitors such as rolipram have therapeutic potential in various disorders and function by increasing the levels of intracellular cAMP. A-Kinase anchoring proteins (AKAPs), a family of scaffolding proteins that belong to the cAMP/Protein Kinase A (PKA) …

Open Neuroscience Initiative, Austin Lim

College of Science and Health Full Text Publications

The Open Neuroscience Initiative is a free-to-use textbook

This project began as a means to overcoming the financial burden that face undergraduate neuroscience students when buying textbooks. By compiling and writing a completely free-to-access textbook that covers the foundations of a typical college introduction to neuroscience course, students would have one less obstacle to overcome in their educational career, allowing them to focus their valuable time and attention on learning rather than finances. To make this project a reality, I began with a humble tweet in May 2019 that managed to gain a tiny bit of traction among the neuroscience …

Photoreceptor Phosphodiesterase (Pde6): Activation And Inactivation Mechanisms During Visual Transduction In Rods And Cones, Rick H. Cote

Faculty Publications

Rod and cone photoreceptors of the vertebrate retina utilize cGMP as the primary

intracellular messenger for the visual signaling pathway that converts a light stimulus into an electrical response. cGMP metabolism in the signal-transducing photoreceptor outer segment reflects the balance of cGMP synthesis (catalyzed by guanylyl cyclase) and degradation (catalyzed by the photoreceptor phosphodiesterase, PDE6). Upon light stimulation, rapid activation of PDE6 by the heterotrimeric G-protein (transducin) triggers a dramatic drop in cGMP levels that lead to cell hyperpolarization. Following cessation of the light stimulus, the lifetime of activated PDE6 is also precisely regulated by additional processes. This review summarizes …

Photoreceptor Phosphodiesterase (Pde6): Structure, Regulatory Mechanisms, And Implications For Treatment Of Retinal Diseases, Rick H. Cote, Richa Gupta, Michael J. Irwin, Xin Wang

Faculty Publications

The photoreceptor phosphodiesterase (PDE6) is a member of large family of Class I phosphodiesterases responsible for hydrolyzing the second messengers cAMP and cGMP. PDE6 consists of two catalytic subunits and two inhibitory subunits that form a tetrameric protein. PDE6 is a peripheral membrane protein that is localized to the signaling-transducing compartment of rod and cone photoreceptors. As the central effector enzyme of the G-protein coupled visual transduction pathway, activation of PDE6 catalysis causes in a rapid decrease in cGMP levels that results in closure of cGMP-gated ion channels in the photoreceptor plasma membrane. Because of its importance in the phototransduction …

Novel Roles Of Yy1 In Astrocytes, Karli A. Mockenhaupt

Theses and Dissertations

Astrocytes tile the entire central nervous system, are diverse across brain regions, and perform specialized functions fine-tuned for their neuronal circuit. Initially, astrocyte heterogeneity is generated through intrinsic programs specified by their progenitors. Then, as astrocyte mature, they are specialized by region-specific communication with surrounding cells. The molecular programs that regulate this diversity and allow for the accommodation to the needs of the local environment remains elusive. We explored a ubiquitously expressed zinc finger transcription factor, Yin Yang 1 (YY1), that both activates and represses transcription by regulating loops of active chromatin. This report describes the diverse functions of astrocytic …

Muscarinic Excitation Of Dopamine Neurons In The Ventral Tegmental Area Via Activation Of A Trpc-Like Cation Conductance, Yu Tzu Chen

Theses and Dissertations

Dopaminergic (DA) neurons in the ventral tegmental area (VTA) play a crucial role in reward and motivational behaviors, including the development of drug addictions. VTA DA neurons receive excitatory cholinergic inputs from the mesopontine tegmentum. Blockage of the M5 muscarinic receptor in DA neurons has been shown to attenuate drug-induced DA release and abuse-related behaviors, but the molecular mechanism is unknown. In this study, experiments were designed to identify the electrophysiological effects of muscarinic agonism in the modulation of action potential kinetics and firing patterns in VTA DA neurons of mice. Pharmacology of the muscarinic receptor-evoked current was also characterized. …

The Receptor Basis Of Serotonergic Modulation In An Olfactory Network, Tyler Ryan Sizemore

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulation is a nearly ubiquitous process that endows the nervous system with the capacity to alter neural function at every level (synaptic, circuit, network, etc.) without necessarily adding new neurons. Through the actions of neuromodulators, the existing neural circuitry can be adaptively tuned to achieve flexible network output and similarly dynamic behavioral output. However, despite their near ubiquity in all sensory modalities, the mechanisms underlying neuromodulation of sensory processing remain poorly understood. In this dissertation, I address three main questions regarding the mechanisms of one modulator (serotonin) within one sensory modality (olfaction). I begin by establishing a "functional atlas" of …

Tet1-Mediated Dna Hydroxymethylation Regulates Adult Remyelination In Mice, Sarah Moyon, Rebecca Frawley, Damien Marechal, Dennis Huang, Katy L.H. Marshall-Phelps, Linde Kegel, Boguslawa Sadowski, Yong-Hui Jiang, David A. Lyons, Wiebke Möbius, Patrizia Casaccia

Advanced Science Research Center

The mechanisms regulating myelin repair in the adult central nervous system (CNS) are unclear. Here, we identify DNA hydroxymethylation, catalyzed by the Ten-Eleven- Translocation (TET) enzyme TET1, as necessary for myelin repair in young adults and defective in old mice. Constitutive and inducible oligodendrocyte lineage-specific ablation of Tet1 (but not of Tet2), recapitulate this age-related decline in repair of demyelinated lesions. DNA hydroxymethylation and transcriptomic analyses identify TET1-target in adult oligodendrocytes, as genes regulating neuro-glial communication, including the solute carrier (Slc) gene family. Among them, we show that the expression levels of the Na+/K+/Cl− transporter, SLC12A2, are …

Interclass Gpcr Heteromerization Affects Localization And Trafficking, Rudy Toneatti

Theses and Dissertations

Class A serotonin (5-hydroxytryptamine) 2A (5-HT_2AR) and class C metabotropic glutamate 2 receptors (mGluR2) are seven transmembrane receptors (7TMRs or G protein-coupled receptors – GPCRs) involved in multiple neuropsychiatric disorders including schizophrenia. Previous findings from our laboratory reported that 5-HT_2AR and mGluR2 are dysregulated in the prefrontal cortex of patients suffering from this psychiatric condition, although 5-HT_2AR’s expression was recovered in antipsychotic-medicated patients. Genome-wide association studies on schizophrenia reported that endosomal trafficking that regulates cell surface abundance of another 7TMR implicated in this disease (dopamine D2 receptor) can be altered. Ligand-activated receptors, including the …

Calcium Dyshomeostasis In Neurodegeneration, Nicholas Emanuel Karagas

Dissertations and Theses (Open Access)

Neurodegenerative diseases, despite constituting a major and growing cause of mortality globally, have few effective treatments. In order to develop novel therapeutics to combat neurodegeneration, a better understanding of the molecular mechanisms underlying these diseases is needed. Neurons rely on Ca²⁺ to mediate many of their unique functions, and aberrant Ca²⁺ signaling has been broadly implicated in neurodegeneration. The goal of this dissertation is to delineate specific examples of Ca²⁺ dyshomeostasis that I have uncovered in Drosophila models of neurodegeneration.

I first define the role a neurodegeneration-associated mutation plays in perturbing presynaptic [Ca²⁺], which is …

Mathematical Modelling Of Temperature Effects On The Afd Neuron Of Caenorhabditis Elegans, Zachary Mobille, Rosangela Follmann, Epaminondas Rosa

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

White Matter Plasticity In Anxiety: Disruption Of Neural Network Synchronization During Threat-Safety Discrimination, Jia Liu, Ekaterina Likhti, A. Duke Shereen, Tracy A. Dennis-Tiwary, Patricia Casaccia

Advanced Science Research Center

Recent evidence highlighted the importance of white matter tracts in typical and atypical behaviors. White matter dynamically changes in response to learning, stress, and social experiences. Several lines of evidence have reported white matter dysfunction in psychiatric conditions, including depression, stress- and anxiety-related disorders. The mechanistic underpinnings of these associations, however, remain poorly understood. Here, we outline an integrative perspective positing a link between aberrant myelin plasticity and anxiety. Drawing on extant literature and emerging new findings, we suggest that in anxiety, unique changes may occur in response to threat and to safety learning and the ability to discriminate between …

Axonal Blockage With Microscopic Magnetic Stimulation, Hui Ye

Biology: Faculty Publications and Other Works

Numerous neurological dysfunctions are characterized by undesirable nerve activity. By providing reversible nerve blockage, electric stimulation with an implanted electrode holds promise in the treatment of these conditions. However, there are several limitations to its application, including poor bio-compatibility and decreased efficacy during chronic implantation. A magnetic coil of miniature size can mitigate some of these problems, by coating it with biocompatible material for chronic implantation. However, it is unknown if miniature coils could be effective in axonal blockage and, if so, what the underlying mechanisms are. Here we demonstrate that a submillimeter magnetic coil can reversibly block action potentials …

Microglia Induced Neuroinflammation Through The Nlrp3 Inflammasome Following Blast Traumatic Brain Injury, Daniel Younger

Dissertations

The incidence of traumatic brain injury (TBI) among military personnel have been steadily increasing with modern conflicts. A recent RAND report estimated 320,000 service members, totaling 20% of deployed forces, suffer from TBI. However, of this population roughly 60% have not seen a medical professional specifically for TBI. Unlike the civilian population, the primary cause of TBI for active-duty military personnel is blast exposure. Blasts now account for over 70% of all US military casualties in operation Iraqi Freedom (OIF) and Operation enduring freedom (OEF) and are the major cause of TBI. Among many pathological mechanisms associated with blast TBI, …

Differential Expression Of Rna In The Rat Peripheral Nervous System Following Nerve Injury And Treatment With Pain-Relieving Celecoxib-Loaded Nanomedicine, Andrea Stevens

Electronic Theses and Dissertations

The neuroinflammatory response to peripheral nerve injury is associated with chronic pain and significant changes in the expression profiles of RNAs in neurons, glia and infiltrating immune cells: a neuro-immune triad. Chronic constriction injury (CCI) of the rat sciatic nerve provides an opportunity to mimic neuropathic injury and quantitatively assess behavior and differential gene expression in individual animals. Macrophages that phagocytose intravenously injected nanoemulsion carrying the non-steroidal anti-inflammatory, NSAID, Celecoxib, naturally accumulate at the site of injury resulting in relief of CCI behavioral hyper-sensitivity. It is not known beyond the inhibition of cyclooxygenase-2 (COX-2) activity and the reduction in prostaglandin …

Effect Of S100b Deletion On Membrane Properties And Localization Of Ncald And Hpca, Natasha Hesketh

Graduate School of Biomedical Sciences Theses and Dissertations

Calcium signaling is particularly important for neuronal function. Neurons utilize a wide range of calcium-binding proteins. Dysregulation of such proteins is linked to neurodegeneration. Neurocalcin delta (NCALD), hippocalcin (HPCA), and S100B are calcium sensors that are expressed in the hippocampus, a brain region essential to memory and severely damaged in Alzheimer’s disease (AD). Despite the potential importance of these proteins, we do not fully understand the physiological significance of their relationship. Because NCALD and HPCA are known to interact with S100B, we hypothesized that the loss of S100B affects NCALD and HPCA localization, and therefore electrical properties, of hippocampal neurons. …

Elevated Cochlear Adenosine Causes Hearing Loss Via Adora2b Signaling, Jeanne Manalo

Dissertations and Theses (Open Access)

Over 538 million people in the world have been diagnosed with hearing loss (HL). Current treatments for the most common type of HL, sensorineural HL, are limited to hearing aids and cochlear implants with no FDA-drugs available. The hearing process demands an abundance of ATP and HL is often attributed to a disruption in this metabolic energy currency. Patients who lack adenosine deaminase (ADA), the enzyme that irreversibly metabolizes adenosine, have high levels of adenosine that yield severe health problems, including HL; however, the pathogenic mechanisms behind HL and adenosine remain elusive. Our lab has found a HL phenotype in …

Investigation Of The Role Of Heparin-Binding Pocket In Amyloid Fibrils Formation Of Fgf-1, I Gusti Ayu Agung Septiari

Graduate Theses and Dissertations

Human acidic fibroblast growth factor (aFGF/hFGF-1) is one of the promising molecules to be investigated to generate an in-depth understanding of the pathological mechanism of Alzheimer's disease (AD) neurodegenerative disorder characterized by the presence of amyloid fibrils. Some in vivo and human brain tissue studies proved the correlation of high-level expression of FGF-1-induced neuroinflammation and the occurrence of AD. The presence of amyloid fibrils as a hallmark of AD can be related to the generic property of the proteins to form amyloid fibrils; High level of FGF-1, in this case, may contribute to the formation of amyloid fibrils. As a …

Circuits With Broken Fibration Symmetries Perform Core Logic Computations In Biological Networks, Ian Leifer, Flaviano Morone, Saulo D. S. Reis, José S. Andrade Jr., Mariano Sigman, Hernán A. Makse

Publications and Research

We show that logic computational circuits in gene regulatory networks arise from a fibration symmetry breaking in the network structure. From this idea we implement a constructive procedure that reveals a hierarchy of genetic circuits, ubiquitous across species, that are surprising analogues to the emblematic circuits of solid-state electronics: starting from the transistor and progressing to ring oscillators, current-mirror circuits to toggle switches and flip-flops. These canonical variants serve fundamental operations of synchronization and clocks (in their symmetric states) and memory storage (in their broken symmetry states). These conclusions introduce a theoretically principled strategy to search for computational building blocks …

Modulating Matrix Metalloproteases And Inflammation In Huntington’S Disease, Alejandro Lopez Ramirez

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Huntington’s disease (HD) is a rare and incurable autosomal neurodegenerative disease affecting 1-10 in every 100,000 people in the world. There is no cure for HD and treatments available alleviate certain symptoms for short periods of time. Evidence suggests that neuropathology of HD begins with the proteolysis of the mutated Huntingtin (mHTT) protein. A variety of proteases, like the matrix metalloproteases, cleave mHTT creating proteinaceous fragments that are thought to be neurotoxic. As these fragments increase in the brain, the damage to neurons also increases, leading to chronic inflammation due to hyper reactive microglia and astrocytes attempting to minimize and …

Nonlinear Control Of Biological Dynamical Systems, Megan J. Morrison

Biology and Medicine Through Mathematics Conference

No abstract provided.