Neurosciences Commons^™

White Matter Correlates Of Domain-Specific Working Memory, Autumn Horne, Junhua Ding, Tatiana T Schnur, Randi C Martin

Faculty, Staff and Student Publications

Prior evidence suggests domain-specific working memory (WM) buffers for maintaining phonological (i.e., speech sound) and semantic (i.e., meaning) information. The phonological WM buffer's proposed location is in the left supramarginal gyrus (SMG), whereas semantic WM has been related to the left inferior frontal gyrus (IFG), the middle frontal gyrus (MFG), and the angular gyrus (AG). However, less is known about the white matter correlates of phonological and semantic WM. We tested 45 individuals with left hemisphere brain damage on single word processing, phonological WM, and semantic WM tasks and obtained T1 and diffusion weighted neuroimaging. Virtual dissections were performed for …

Xcvatr: Detection And Characterization Of Variant Impact On The Embeddings Of Single -Cell And Bulk Rna-Sequencing Samples, Arif Harmanci, Akdes Serin Harmanci, Tiemo J Klisch, Akash J Patel

Duncan NRI Faculty and Staff Publications

Background: RNA-sequencing has become a standard tool for analyzing gene activity in bulk samples and at the single-cell level. By increasing sample sizes and cell counts, this technique can uncover substantial information about cellular transcriptional states. Beyond quantification of gene expression, RNA-seq can be used for detecting variants, including single nucleotide polymorphisms, small insertions/deletions, and larger variants, such as copy number variants. Notably, joint analysis of variants with cellular transcriptional states may provide insights into the impact of mutations, especially for complex and heterogeneous samples. However, this analysis is often challenging due to a prohibitively high number of variants and …

Transcranial Direct Current Stimulation Of Frontal/Occipital Cortices Modulates Neural Correlates Of Cognition In Healthy Young Adults, Yasra Arif

Theses & Dissertations

An exponential rise in the use of transcranial direct current stimulation (tDCS) to modify the human brain and behavior has been observed over the last 20 years, with studies often yielding mixed outcomes. Such heterogeneity is partially attributed to the lack of a concise understanding of the underlying mechanisms. Though considered to exert modulatory effects by changing neuronal membrane polarization and synaptic efficacy, the interactive effects of offline tDCS and the neural underpinnings of cognition, both at the regional and network-level, are yet to be fully understood. Using High-Definition tDCS (HD-tDCS), Magnetoencephalography (MEG), a range of well-established cognitive paradigms, and …

The Use Of Kernig’S And Brudzinski’S Sign In Determining Meningitis: A Review, Crystal T. Duong, Ashton Hughes, Kerem Yilmaz

Physician Assistant Capstones, 2020-current

Objective: Assess the diagnostic value of Kernig’s and Brudzinski’s signs in determining meningitis among individuals aged 18 to 64. Design: Systematic literature review. Methods: Searches done in PubMed utilizing the terms Kernig and Brudzinski. In PubMed, studies were excluded if not in English, older than 2000 or done on animals, and meta-analyses. Results: Three studies were found including Nakao JH, et al, Thomas KE, et al, and Waghdhare S, et al. Conclusion: Kernig’s and Brudzinski’s signs have high specificity but yield a low sensitivity in determining meningitis. They are great tools to be utilized by medical providers, but only support …

Empowering Nurses To Recognize Post-Stroke Depression In The African American Community, Deidra Frisbie, Robin Simon

Doctor of Nursing Practice Projects

African Americans (AA) have the highest prevalence of stroke and death compared to other racial groups in the United States. Post-stroke depression (PSD) affects approximately 1/3 of all stroke patients and is underdiagnosed in the African American community.

Aim: By using a mHealth mobile app and a Psychiatry provider list at discharge, PSD can be identified, and interventions initiated, thus decreasing the sequela of PSD in AA.

Methods: Nurses were provided education on PSD, expressions of depression in African-Americans, cultural humility, implicit bias, and the importance of the nurse's role in developing a therapeutic relationship.

Results: Quantitative analysis revealed the …

Frequency And Burden Of Neurological Manifestations Upon Hospital Presentation In Covid-19 Patients: Findings From A Large Brazilian Cohort, Milena Soriano Marcolino, Fernando Anschau, Luciane Kopittke, Magda Carvalho Pires, Izabela Guimarães Barbosa, Daniella Nunes Pereira, Lucas Emanuel Ferreira Ramos, Luís Fernando Israel Assunção, André Soares De Moura Costa, Matheus Carvalho Alves Nogueira, Helena Duani, Karina Paula Medeiros Prado Martins, Leila Beltrami Moreira, Carla Thais Cândida Alves Da Silva, Neimy Ramos De Oliveira, Patricia Klarmann Ziegelmann, Milton Henriques Guimarães-Júnior, Mauro Oscar Soares De Souza Lima, Rubia Laura Oliveira Aguiar, Luanna Silva Monteiro Menezes, Talita Fischer Oliveira, Maíra Dias Souza, Bárbara Lopes Farace, Christiane Corrêa Rodrigues Cimini, Amanda De Oliveira Maurílio, Silvana Mangeon Mereilles Guimarães, Silvia Ferreira Araújo, Guilherme Fagundes Nascimento, Daniel Vitório Silveira, Karen Brasil Ruschel, Thainara Conceição De Oliveira, Alexandre Vargas Schwarzbold, Luiz Antônio Nasi, Maiara Anschau Floriani, Veridiana Baldon Dos Santos, Carolina Marques Ramos, Joice Coutinho De Alvarenga, Ana Luiza Bahia Alves Scotton, Euler Roberto Fernandes Manenti, Gabriela Petry Crestani, Joanna D'Arc Lyra Batista, Daniela Ponce, Juliana Machado-Rugolo, Adriana Falangola Benjamin Bezerra, Petrônio José De Lima Martelli, Heloisa Reniers Vianna, Luís César De Castro, Cássia Regina Gotler Medeiros, Giovanna Grunewald Vietta, Elayne Crestani Pereira, José Miguel Chatkin, Mariana Frizzo De Godoy, Polianna Delfino-Pereira, Antonio Lucio Teixeira

Faculty, Staff and Student Publications

BACKGROUND: Scientific data regarding the prevalence of COVID-19 neurological manifestations and prognosis in Latin America countries is still lacking. Therefore, the study aims to understand neurological manifestations of SARS-CoV 2 infection and outcomes in the Brazilian population.

METHODS: This study is part of the Brazilian COVID-19 Registry, a multicentric cohort, including data from 37 hospitals. For the present analysis, patients were grouped according to the presence of reported symptoms (i.e., headache; anosmia and ageusia; syncope and dizziness) vs. clinically-diagnosed neurological manifestations (clinically-defined neurological syndrome: neurological signs or diagnoses captured by clinical evaluation) and matched with patients without neurological manifestations by …

Detection Of Stroke With Retinal Microvascular Density And Self-Supervised Learning Using Oct-A And Fundus Imaging, Samiksha Pachade, Ivan Coronado, Rania Abdelkhaleq, Juntao Yan, Sergio Salazar-Marioni, Amanda Jagolino, Charles Green, Mozhdeh Bahrainian, Roomasa Channa, Sunil A Sheth, Luca Giancardo

Faculty, Staff and Student Publications

Acute cerebral stroke is a leading cause of disability and death, which could be reduced with a prompt diagnosis during patient transportation to the hospital. A portable retina imaging system could enable this by measuring vascular information and blood perfusion in the retina and, due to the homology between retinal and cerebral vessels, infer if a cerebral stroke is underway. However, the feasibility of this strategy, the imaging features, and retina imaging modalities to do this are not clear. In this work, we show initial evidence of the feasibility of this approach by training machine learning models using feature engineering …

Contributions Of Semantic And Phonological Working Memory To Narrative Language Independent Of Single Word Production: Evidence From Acute Stroke, Rachel Zahn, Tatiana T Schnur, Randi C Martin

Faculty, Staff and Student Publications

Neuropsychological case studies have provided evidence that individuals with semantic, but not phonological, working memory (WM) deficits have difficulty producing phrases containing several content words. These findings supported the claim of a phrasal scope of planning at the grammatical formulation stage of production, where semantic WM supports the maintenance of lexical-semantic representations as they are inserted into slots in phrasal constituents. Recent narrative production results for individuals at the acute stage of stroke supported the role for semantic WM in phrasal elaboration while suggesting a role for phonological WM at a subsequent phonological encoding stage in supporting fluent, rapid speech. …

Rna Editing Of Microtubule-Associated Protein Tau Circular Rnas Promotes Their Translation And Tau Tangle Formation, Justin Ralph Welden, Giorgi Margvelani, Karol Andrea Arizaca Maquera, Bhavani Gudlavalleti, Sandra C. Miranda Sardón, Alexandre Rosa Campos, Noémie Robil, Daniel C. Lee, Alvaro G. Hernandez, Wang-Xia Wang, Jing Di, Pierre De La Grange, Peter T. Nelson, Stefan Stamm

Sanders-Brown Center on Aging Faculty Publications

Aggregation of the microtubule-associated protein tau characterizes tauopathies, including Alzheimer’s disease and frontotemporal lobar degeneration (FTLD-Tau). Gene expression regulation of tau is complex and incompletely understood. Here we report that the human tau gene (MAPT) generates two circular RNAs (circRNAs) through backsplicing of exon 12 to either exon 7 (12→7 circRNA) or exon 10 (12→10 circRNA). Both circRNAs lack stop codons. The 12→7 circRNA contains one start codon and is translated in a rolling circle, generating a protein consisting of multimers of the microtubule-binding repeats R1–R4. For the 12→10 circRNA, a start codon can be introduced by two …

Genetic Expression Changes And Pathologic Findings Associated With Hyperhomocysteinemia In Human Autopsy Brain Tissue, Erica M. Weekman, Zachary Winder, Colin B. Rogers, Erin L. Abner, Tiffany L. Sudduth, Ela Patel, Adam J. Dugan, Shuling X. Fister, Brandi Wasek, Peter T. Nelson, Gregory A. Jicha, Teodoro Bottiglieri, David W. Fardo, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

Introduction: Vascular contributions to cognitive impairment and dementia (VCID) are a leading cause of dementia. An underappreciated, modifiable risk factor for VCID is hyperhomocysteinemia (HHcy), defined by elevated levels of plasma homocysteine, most often due to impaired B vitamin absorption in aged persons. Studies aimed at identifying neuropathologic features and gene expression profiles associated with HHcy have been lacking.

Methods: A subset of research volunteers from the University of Kentucky Alzheimer’s Disease Research Center longitudinal cohort came to autopsy and had ante mortem plasma homocysteine levels available. Brain tissue and blood plasma drawn closest to death were used to measure …

Nursing Considerations For Post-Traumatic Amnesia After A Traumatic Brain Injury, Hannah Grant

Senior Honors Theses

A period known as post-traumatic amnesia (PTA) often follows a traumatic brain injury (TBI). PTA is characterized by anterograde and retrograde amnesia, confusion, disorientation, and agitation. The duration and severity of PTA is a key indicator of the long-term prognosis after a TBI, so proper assessment and nursing care of a PTA patient is crucial. TBIs range from mild to severe, but primarily affect the fronto-temporal lobes. In PTA, both neural lesions and white matter damage within the parahippocampal region can cause PTA. A nurse must perform a thorough assessment of a TBI patient, but, since PTA is a key …

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 …

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. …

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 …

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 …

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 …

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 …

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 …

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 …