Neurosciences Commons^™

Active Dna Demethylation Promotes Cell Fate Specification And The Dna Damage Response, Dongpeng Wang, Wei Wu, Elsa Callen, Raphael Pavani, Nicholas Zolnerowich, Srikanth Kodali, Dali Zong, Nancy Wong, Santiago Noriega, William J Nathan, Gabriel Matos-Rodrigues, Raj Chari, Michael J Kruhlak, Ferenc Livak, Michael Ward, Keith Caldecott, Bruno Di Stefano, André Nussenzweig

Faculty, Staff and Students Publications

Neurons harbor high levels of single-strand DNA breaks (SSBs) that are targeted to neuronal enhancers, but the source of this endogenous damage remains unclear. Using two systems of postmitotic lineage specification-induced pluripotent stem cell-derived neurons and transdifferentiated macrophages-we show that thymidine DNA glycosylase (TDG)-driven excision of methylcytosines oxidized with ten-eleven translocation enzymes (TET) is a source of SSBs. Although macrophage differentiation favors short-patch base excision repair to fill in single-nucleotide gaps, neurons also frequently use the long-patch subpathway. Disrupting this gap-filling process using anti-neoplastic cytosine analogs triggers a DNA damage response and neuronal cell death, which is dependent on TDG. …

Apoe Genetics Influence Murine Gut Microbiome, Diana J. Zajac, Stefan J. Green, Lance A. Johnson, Steven Estus

Sanders-Brown Center on Aging Faculty Publications

Apolipoprotein E (APOE) alleles impact pathogenesis and risk for multiple human diseases, making them primary targets for disease treatment and prevention. Previously, we and others reported an association between APOE alleles and the gut microbiome. Here, we evaluated effects of APOE heterozygosity and tested whether these overall results extended to mice maintained under ideal conditions for microbiome analyses. To model human APOE alleles, this study used APOE targeted replacement (TR) mice on a C57Bl/6 background. To minimize genetic drift, homozygous APOE3 mice were crossed to homozygous APOE2 or homozygous APOE4 mice prior to the study, and the resulting …

Sex Differences In The Disease Progression Of Ftd Vs Ad, Abigail Mitchell, Danielle Frances, Chase Metzger

Science University Research Symposium (SURS)

Abigail Mitchell, Danielle Frances, Chase Metzger

Sex Differences in the Disease Progression of FTD vs AD.

Abstract

Neurodegenerative diseases are on the rise in aging populations due to the upper tier of the population getting larger in that age group (Zheng & Chen, 2022). Knowing this, there is great benefit in more accurate and early diagnosis of conditions like frontotemporal dementia (FTD) and Alzheimer’s disease (AD). Particularly, it is important to understand which variables may contribute to differences in disease burden and progression of associated sequalae, with one of those variables being biological sex. The current study investigated sex differences …

Utilizing The 3d Environment To Facilitate Learning Of Complex Visual Neural Pathways In The Avian Brain, Parker Straight

Graduate Theses and Dissertations

Neuroanatomical pathways are difficult to study often due to the limit of methods used to visualize the anatomical and physiologic characteristics. In many studies, a neural pathway is presented using 2D representations for structural connectivity. A problem is deciding which of three planes: coronal, sagittal, or horizontal is best for visualizing the pathway’s components clearly and spatially precise for those wanting to learn and utilize that information. A 3D environment would be imperative in solving this issue. We therefore attempted to develop a means of accurately presenting detailed anatomical structures within the 3D regions they occurred. It is our hope …

Single Low-Dose Targeted Bevacizumab Infusion In Adult Patients With Steroid-Refractory Radiation Necrosis Of The Brain: A Phase Ii Open-Label Prospective Clinical Trial, Shervin R. Dashti, Robert J. Kadner, Bradley S. Folley, Jason P. Sheehan, Dong Y. Han, Richard J. Kryscio, Mary B. Carter, Lisa B. E. Shields, Brian M. Plato, Renato V. La Rocca, Aaron C. Spalding, Tom L. Yao, Justin F. Fraser

Sanders-Brown Center on Aging Faculty Publications

OBJECTIVE There is an unmet need for safe and rapidly effective therapies for refractory brain radiation necrosis (RN). The aim of this prospective single-arm phase II trial was to evaluate the safety and efficacy of a single low-dose targeted bevacizumab infusion after blood-brain barrier disruption (BBBD) in adult patients with steroid-refractory brain RN.

METHODS Ten adults with steroid-refractory, imaging-confirmed brain RN were enrolled between November 2016 and January 2018 and followed for 12 months after treatment. Bevacizumab 2.5 mg/kg was administered as a one-time targeted intra-arterial infusion immediately after BBBD. Primary outcomes included safety and > 25% decrease in lesion volume. …

Dimensionality Of Natural Auditory Scene Perception: A Factor Analysis Study, Margaret A. Mcmullin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Theories of auditory and visual scene analysis suggest the perception of scenes relies on the identification and segregation of objects within it, resembling a detail-oriented processing style, but it is possible that a global-oriented process also occurs while evaluating auditory scenes. There is evidence for global properties that enable rapid recognition of visual scenes, even without recognizing the individual objects comprising the scene. It is our understanding that a similar line of research has not been explored in the auditory domain; therefore, we evaluated the contributions of high-level global and low-level acoustic information to auditory scene perception. A secondary aim …

Author Correction: Entorhinal Cortex Directs Learning-Related Changes In Ca1 Representations, Christine Grienberger, Jeffrey C Magee

Faculty, Staff and Students Publications

No abstract provided.

Effects Of Ethanol On Glun1/Glun2a And Glun1/Glun2b Nmda Receptor-Ion Channel Gating Kinetics, Robert W. Peoples, Hong Ren

Biomedical Sciences Faculty Research and Publications

Background

The N-methyl-D-aspartate receptor (NMDAR) is a major molecular target of alcohol action in the central nervous system, yet many aspects of alcohol's modulation of the activity of this ion channel remain unclear. We and others have shown that ethanol inhibition of NMDAR involves alterations in gating, especially a reduction in mean open time. However, a full description of ethanol's effects on NMDAR kinetics, including fitting them to a kinetic model, has not been reported.

Methods

To determine ethanol's effects on NMDAR kinetics, we used steady-state single-channel recording in outside-out patches from HEK-293 cells transfected with recombinant GluN1/GluN2A or …

Reorganization Of The Functional Connectome From Rest To A Visual Perception Task In Schizophrenia And Bipolar Disorder, Philipp Riedel, Junghee Lee, Christopher G Watson, Amy M Jimenez, Eric A Reavis, Michael F Green

Faculty, Staff and Student Publications

Functional connectome organization is altered in schizophrenia (SZ) and bipolar disorder (BD). However, it remains unclear whether network reorganization during a task relative to rest is also altered in these disorders. This study examined connectome organization in patients with SZ (N = 43) and BD (N = 42) versus healthy controls (HC; N = 39) using fMRI data during a visual object-perception task and at rest. Graph analyses were conducted for the whole-brain network using indices selected a priori: three reflecting network segregation (clustering coefficient, local efficiency, modularity), two reflecting integration (characteristic path length, global efficiency). Group differences were limited …

Markers Of Neuroinflammatory And Degenerative Processes In Professional Athletes With Traumatic Encephalopathy Syndrome, Brooke Conway Kleven

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: The clinical criteria for Traumatic encephalopathy syndrome (ccTES) were developed to improve the diagnosis of Chronic traumatic encephalopathy (CTE). This study aimed to determine whether there was an association between a clinical diagnosis of Traumatic encephalopathy syndrome (TES) and changes in serum biomarkers, balance, neuroimaging, and cognition among athletes in the Professional Athletes Brain Health Study (PABHS).Methods: Of the cohort, 130 professional fighters met age or retirement criteria and went to a consensus conference, with 52 fighters (40%) meeting the criteria for TES. A generalized linear model with generalized estimating equations was utilized to assess the odds of disease …

Benefits Of Early Treatment With Natalizumab: A Real-World Study., Daniel Ontaneda, Ellen M Mowry, Scott D Newsome, Robert T Naismith, Jacqueline Nicholas, Elizabeth Fisher, Carl De Moor, Justin Bohn, Pei-Ran Ho, Al Sandrock, Richard Rudick, James R Williams

Ambulatory and Primary Care Articles

BACKGROUND: The impact of early versus later high-efficacy disease-modifying therapy (DMT) in patients with multiple sclerosis (MS) is uncertain. This study reported the association of early versus later natalizumab treatment with real-world clinical outcomes in MS patients.

METHODS: The study included 661 participants diagnosed with MS in 1994 or later from 7 US centers participating in the MS Partners Advancing Technology for Health Solutions (MS PATHS) network. Time to natalizumab treatment between diagnosis and first infusion (TTNT) was determined from the Tysabri Outreach: Unified Commitment to Health (TOUCH) registry. Clinical outcomes were defined using neuroperformance tests included in the Multiple …

A Minimal Role For Synonymous Variation In Human Disease, Ryan S Dhindsa, Quanli Wang, Dimitrios Vitsios, Oliver S Burren, Fengyuan Hu, James E Dicarlo, Leonid Kruglyak, Daniel G Macarthur, Matthew E Hurles, Slavé Petrovski

Duncan NRI Faculty and Staff Publications

Synonymous mutations change the DNA sequence of a gene without affecting the amino acid sequence of the encoded protein. Although some synonymous mutations can affect RNA splicing, translational efficiency, and mRNA stability, studies in human genetics, mutagenesis screens, and other experiments and evolutionary analyses have repeatedly shown that most synonymous variants are neutral or only weakly deleterious, with some notable exceptions. Based on a recent study in yeast, there have been claims that synonymous mutations could be as important as nonsynonymous mutations in causing disease, assuming the yeast findings hold up and translate to humans. Here, we argue that there …

Propranolol Modulates Cerebellar Circuit Activity And Reduces Tremor., Joy Zhou, Meike E Van Der Heijden, Luis E Salazar Leon, Tao Lin, Lauren N Miterko, Dominic J Kizek, Ross M Perez, Matea Pavešković, Amanda M Brown, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Tremor is the most common movement disorder. Several drugs reduce tremor severity, but no cures are available. Propranolol, a β-adrenergic receptor blocker, is the leading treatment for tremor. However, the in vivo circuit mechanisms by which propranolol decreases tremor remain unclear. Here, we test whether propranolol modulates activity in the cerebellum, a key node in the tremor network. We investigated the effects of propranolol in healthy control mice and Car8^wdl/wdl mice, which exhibit pathophysiological tremor and ataxia due to cerebellar dysfunction. Propranolol reduced physiological tremor in control mice and reduced pathophysiological tremor in Car8^wdl/wdl mice to control levels. …

Neurobehavioral Deficits And A Progressive Ictogenesis In The Tetrodotoxin Model Of Epileptic Spasms, John T Le, Carlos J Ballester-Rosado, James D Frost, John W Swann

Duncan NRI Faculty and Staff Publications

Objective: Our goal was to determine whether animals with a history of epileptic spasms have learning and memory deficits. We also used continuous (24/7) long-term electroencephalographic (EEG) recordings to evaluate the evolution of epileptiform activity in the same animals over time.

Methods: Object recognition memory and object location memory tests were undertaken, as well as a matching to place water maze test that evaluated working memory. A retrospective analysis was undertaken of long-term video/EEG recordings from rats with epileptic spasms. The frequency and duration of the ictal events of spasms were quantified.

Results: Rats with a history of epileptic spasms …

Development Of Myelinating Glia: An Overview, Carlo D Cristobal, Hyun Kyoung Lee

Duncan NRI Faculty and Staff Publications

Myelin is essential to nervous system function, playing roles in saltatory conduction and trophic support. Oligodendrocytes (OLs) and Schwann cells (SCs) form myelin in the central and peripheral nervous systems respectively and follow different developmental paths. OLs are neural stem-cell derived and follow an intrinsic developmental program resulting in a largely irreversible differentiation state. During embryonic development, OL precursor cells (OPCs) are produced in distinct waves originating from different locations in the central nervous system, with a subset developing into myelinating OLs. OPCs remain evenly distributed throughout life, providing a population of responsive, multifunctional cells with the capacity to remyelinate …

Seizure Count Forecasting To Aid Diagnostic Testing In Epilepsy, Emily T Wang, Sharon Chiang, Stephen Cleboski, Vikram R Rao, Marina Vannucci, Zulfi Haneef

Faculty, Staff and Students Publications

Objective: Epilepsy monitoring unit (EMU) admissions are critical for presurgical evaluation of drug-resistant epilepsy but may be nondiagnostic if an insufficient number of seizures are recorded. Seizure forecasting algorithms have shown promise for estimating the likelihood of seizures as a binary event in individual patients, but methods to predict how many seizures will occur remain elusive. Such methods could increase the diagnostic yield of EMU admissions and help patients mitigate seizure-related morbidity. Here, we evaluated the performance of a state-space method that uses prior seizure count data to predict future counts.

Methods: A Bayesian negative-binomial dynamic linear model (DLM) was …

Implementation Of Systematic Safety Checklists In A Neurocritical Care Unit: A Quality Improvement Study, César E Escamilla-Ocañas, Gabriel Torrealba-Acosta, Pitchaiah Mandava, Muhammad Suhaib Qasim, Bárbara Gutiérrez-Flores, Eric Bershad, Mohammad Hirzallah, Chethan P Venkatasubba Rao, Rahul Damani

Faculty, Staff and Students Publications

Background and objectives: Structured and systematised checklists have been shown to prevent complications and improve patient care. We evaluated the implementation of systematic safety checklists in our neurocritical care unit (NCCU) and assessed its effect on patient outcomes.

Design/methods: This quality improvement project followed a Plan-Do-Study-Act (PDSA) methodology. A checklist for medication reconciliation, thromboembolic prophylaxis, glycaemic control, daily spontaneous awakening, breathing trial, diet, catheter/lines duration monitoring and antibiotics de-escalation was implemented during daily patient rounds. Main outcomes included the rate of new infections, mortality and NCCU-length of stay (LOS). Intervened patients were compared with historical controls after propensity score and …

K27m In Canonical And Noncanonical H3 Variants Occurs In Distinct Oligodendroglial Cell Lineages In Brain Midline Gliomas, Selin Jessa, Abdulshakour Mohammadnia, Ashot S Harutyunyan, Maud Hulswit, Srinidhi Varadharajan, Hussein Lakkis, Nisha Kabir, Zahedeh Bashardanesh, Steven Hébert, Damien Faury, Maria C Vladoiu, Samantha Worme, Marie Coutelier, Brian Krug, Augusto Faria Andrade, Manav Pathania, Andrea Bajic, Alexander G Weil, Benjamin Ellezam, Jeffrey Atkinson, Roy W R Dudley, Jean-Pierre Farmer, Sebastien Perreault, Benjamin A Garcia, Valérie Larouche, Mathieu Blanchette, Livia Garzia, Aparna Bhaduri, Keith L Ligon, Pratiti Bandopadhayay, Michael D Taylor, Stephen C Mack, Nada Jabado, Claudia L Kleinman

Faculty, Staff and Students Publications

Canonical (H3.1/H3.2) and noncanonical (H3.3) histone 3 K27M-mutant gliomas have unique spatiotemporal distributions, partner alterations and molecular profiles. The contribution of the cell of origin to these differences has been challenging to uncouple from the oncogenic reprogramming induced by the mutation. Here, we perform an integrated analysis of 116 tumors, including single-cell transcriptome and chromatin accessibility, 3D chromatin architecture and epigenomic profiles, and show that K27M-mutant gliomas faithfully maintain chromatin configuration at developmental genes consistent with anatomically distinct oligodendrocyte precursor cells (OPCs). H3.3K27M thalamic gliomas map to prosomere 2-derived lineages. In turn, H3.1K27M ACVR1-mutant pontine gliomas uniformly mirror early ventral …

Facilitation–Inhibition Control Of Motor Neuronal Persistent Inward Currents In Young And Older Adults, Lucas B. R. Orssatto, Gabriel L. Fernandes, Anthony J. Blazevich, Gabriel S. Trajano

Research outputs 2022 to 2026

A well-coordinated facilitation–inhibition control of motor neuronal persistent inward currents (PICs) via diffuse neuromodulation and local inhibition is essential to ensure motor units discharge at required times and frequencies. Present best estimates indicate that PICs are reduced in older adults; however, it is not yet known whether PIC facilitation–inhibition control is also altered with ageing. We investigated the responses of PICs to (i) a remote handgrip contraction, which is believed to diffusely increase serotonergic input onto motor neurones, and (ii) tendon vibration of the antagonist muscle, which elicits reciprocal inhibition, in young and older adults. High-density surface electromyograms were collected …

Hdac2 In Primary Sensory Neurons Constitutively Restrains Chronic Pain By Repressing Α2Δ-1 Expression And Associated Nmda Receptor Activity, Jixiang Zhang, Shao-Rui Chen, Meng-Hua Zhou, Daozhong Jin, Hong Chen, Li Wang, Ronald A Depinho, Hui-Lin Pan

Faculty, Staff and Student Publications

α2δ-1 (encoded by the Cacna2d1 gene) is a newly discovered NMDA receptor-interacting protein and is the therapeutic target of gabapentinoids (e.g., gabapentin and pregabalin) frequently used for treating patients with neuropathic pain. Nerve injury causes sustained α2δ-1 upregulation in the dorsal root ganglion (DRG), which promotes NMDA receptor synaptic trafficking and activation in the spinal dorsal horn, a hallmark of chronic neuropathic pain. However, little is known about how nerve injury initiates and maintains the high expression level of α2δ-1 to sustain chronic pain. Here, we show that nerve injury caused histone hyperacetylation and diminished enrichment of histone deacetylase-2 (HDAC2), …