Neurosciences Commons^™

Effects Of Balance Training On Spinal Reflexive Excitability Modulation, Corticospinal Excitability, And Balance Performance In Individuals With Chronic Ankle Instability, Sunghoon Chung

Rehabilitation Sciences Theses & Dissertations

Chronic ankle instability (CAI) is a neurophysiologic deficit resulting in diverse sensorimotor impairments. Following acute ankle sprains, pain, mechanical instability, and joint deafferentation reduce sensory input to the central nervous system (CNS). In response, the CNS sends altered motor signals to lower extremity muscles. These CNS changes contribute to various neuromuscular impairments in CAI patients, the most common of which is reduced balance performance. Specifically, CAI patients struggle to modulate spinal reflex excitability of the soleus muscle when progressing from simpler to more complex balance tasks. This overreliance on spinal reflexes results in inconsistent activation of the ankle stabilizing muscle. …

Signaling Mechanisms Underlying Activity-Dependent Integration Of Adult-Born Neurons In The Mouse Olfactory Bulb, Suyang Bao, Juan M Romero, Benjamin D W Belfort, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

Adult neurogenesis has fascinated the field of neuroscience for decades given the prospects of harnessing mechanisms that facilitate the rewiring and/or replacement of adult brain tissue. The subgranular zone of the hippocampus and the subventricular zone of the lateral ventricle are the two main areas in the brain that exhibit ongoing neurogenesis. Of these, adult-born neurons within the olfactory bulb have proven to be a powerful model for studying circuit plasticity, providing a broad and accessible avenue into neuron development, migration, and continued circuit integration within adult brain tissue. This review focuses on some of the recognized molecular and signaling …

Promoting Diverse Perspectives: Addressing Health Disparities Related To Alzheimer's And All Dementias, Gladys Maestre, Carl Hill, Percy Griffin, Stephen Hall, William Hu, Jason Flatt, Ganesh Babulal

School of Medicine Publications

Dementia research lacks appropriate representation of diverse groups who often face substantial adversity and greater risk of dementia. Current research participants are primarily well-resourced, non-Hispanic White, cisgender adults who live close to academic medical centers where much of the research is based. Consequently, the field faces a knowledge gap about Alzheimer's-related risk factors in those other groups. The Alzheimer's Association hosted a virtual conference on June 14–16, 2021, supported in part by the National Institute on Aging (R13 AG072859-01), focused on health disparities. The conference was held entirely online and consisted of 2 days of core programming and a day …

Suboptimal Self-Reported Sleep Efficiency And Duration Are Associated With Faster Accumulation Of Brain Amyloid Beta In Cognitively Unimpaired Older Adults, Louise N. Pivac, Belinda M. Brown, Kelsey R. Sewell, James D. Doecke, Victor L. Villemagne, Vincent Doré, Michael Weinborn, Hamid R. Sohrabi, Samantha L. Gardener, Romola S. Bucks, Simon M. Laws, Kevin Taddei, Paul Maruff, Colin L. Masters, Christopher Rowe, Ralph N. Martins, Stephanie R. Rainey-Smith

Research outputs 2022 to 2026

Introduction: This study investigated whether self-reported sleep quality is associated with brain amyloid beta (AB) accumulation. METHODS: Linear mixed effect model analyses were conducted for 189 cognitively unimpaired (CU) older adults (mean ± standard deviation 74.0 ± 6.2; 53.2% female), with baseline self-reported sleep data, and positron emission tomography-determined brain AB measured over a minimum of three time points (range 33.3–72.7 months). Analyses included random slopes and intercepts, interaction for apolipoprotein E (APOE) 4 allele status, and time, adjusting for sex and baseline age.

Results: Sleep duration < 6 hours, in APOE 4 carriers, and sleep efficiency < 65%, in the whole sample and APOE 4 non-carriers, is associated with faster accumulation of brain AB. DISCUSSION: These findings suggest a role for self-reported suboptimal sleep efficiency and duration in the accumulation of Alzheimer's disease (AD) neuropathology in CU individuals. Additionally, poor sleep efficiency represents a potential route via which individuals at lower genetic risk may progress to preclinical AD. Highlights: In cognitively unimpaired older adults self-report sleep is associated with brain amyloid beta (AB) accumulation. Across sleep characteristics, this relationship differs by apolipoprotein E (APOE) genotype. Sleep duration < 6 hours is associated with faster brain AB accumulation in APOE 4 carriers. Sleep efficiency < 65% is associated with faster brain AB accumulation in APOE 4 non-carriers. Personalized sleep interventions should be studied for potential to slow AB accumulation.

The Australian Multidomain Approach To Reduce Dementia Risk By Protecting Brain Health With Lifestyle Intervention Study (Au-Arrow): A Study Protocol For A Single-Blind, Multi-Site, Randomized Controlled Trial, Samantha L. Gardener, Stephanie J. Fuller, Sharon L. Naismith, Laura Baker, Miia Kivipelto, Victor L. Villemagne, Stuart M. Grieve, Paul Yates, Stephanie R. Rainey-Smith, Juliana Chen, Belinda Thompson, Nicola J. Armstrong, Malika G. Fernando, Carolina B. Castro, Silochna Meghwar, Rema Raman, Andrew Gleason, Catriona Ireland, Roger Clarnette, Kaarin J. Anstey, Kevin Taddei, Manohar Garg, Hamid R. Sohrabi, Ralph N. Martins

Research outputs 2022 to 2026

Introduction: The Finnish Geriatric Intervention Study (FINGER) led to the global dementia risk reduction initiative: World-Wide FINGERS (WW-FINGERS). As part of WW-FINGERS, the Australian AU-ARROW study mirrors aspects of FINGER, as well as US-POINTER.

Method: AU-ARROW is a randomized, single-blind, multisite, 2-year clinical trial (n = 600; aged 55–79). The multimodal lifestyle intervention group will engage in aerobic exercise, resistance training and stretching, dietary advice to encourage MIND diet adherence, BrainHQ cognitive training, and medical monitoring and health education. The Health Education and Coaching group will receive occasional health education sessions. The primary outcome measure is the change in a …

Dissociating Reading And Auditory Comprehension In Persons With Aphasia, Rachael M. Harrington, Sigfus Kristinsson, Janina Wilmskoetter, Natalie Busby, Dirk B. Den Ouden, Chris Rorden, Julius Fridriksson, Leonardo Bonilha

Communication Sciences and Disorders Faculty Articles and Research

Language comprehension is often affected in individuals with post-stroke aphasia. However, deficits in auditory comprehension are not fully correlated with deficits in reading comprehension and the mechanisms underlying this dissociation remain unclear. This distinction is important for understanding language mechanisms, predicting long-term impairments and future development of treatment interventions. Using comprehensive auditory and reading measures from a large cohort of individuals with aphasia, we evaluated the relationship between aphasia type and reading comprehension impairments, the relationship between auditory versus reading comprehension deficits and the crucial neuroanatomy supporting the dissociation between post-stroke reading and auditory deficits. Scores from the Western Aphasia …

Dopamine Lesions Alter The Striatal Encoding Of Single-Limb Gait, Long Yang, Deepak Singla, Alexander K Wu, Katy A Cross, Sotiris C Masmanidis

Faculty, Staff and Student Publications

The striatum serves an important role in motor control, and neurons in this area encode the body's initiation, cessation, and speed of locomotion. However, it remains unclear whether the same neurons also encode the step-by-step rhythmic motor patterns of individual limbs that characterize gait. By combining high-speed video tracking, electrophysiology, and optogenetic tagging, we found that a sizable population of both D1 and D2 receptor expressing medium spiny projection neurons (MSNs) were phase-locked to the gait cycle of individual limbs in mice. Healthy animals showed balanced limb phase-locking between D1 and D2 MSNs, while dopamine depletion led to stronger phase-locking …

Tmem106b Coding Variant Is Protective And Deletion Detrimental In A Mouse Model Of Tauopathy, George A Edwards, Caleb A Wood, Yang He, Quynh Nguyen, Peter J Kim, Ruben Gomez-Gutierrez, Kyung-Won Park, Yong Xu, Cody Zurhellen, Ismael Al-Ramahi, Joanna L Jankowsky

Duncan NRI Faculty and Staff Publications

TMEM106B is a risk modifier of multiple neurological conditions, where a single coding variant and multiple non-coding SNPs influence the balance between susceptibility and resilience. Two key questions that emerge from past work are whether the lone T185S coding variant contributes to protection, and if the presence of TMEM106B is helpful or harmful in the context of disease. Here, we address both questions while expanding the scope of TMEM106B study from TDP-43 to models of tauopathy. We generated knockout mice with constitutive deletion of TMEM106B, alongside knock-in mice encoding the T186S knock-in mutation (equivalent to the human T185S variant), and …

Ongoing Study Of The Association Of Apoe Gene Polymorphisms With Cognitive Impairment In The Rio Grande Valley Hispanic Population, Jaime Miguel L. Saveron, Daniela Gamez, Chun Xu

Research Symposium

Background: Alzheimer's disease (AD), a prevalent neurodegenerative disorder, exhibits a significant genetic component. In addition, mild cognitive impairment (MCI) is a key risk factor for AD. While certain demographic factors and genetic variants associated with AD and cognitive impairment have been identified in non-Hispanic populations, limited research exists on this subject within the Hispanic population, particularly in the Rio Grande Valley. This study aims to investigate the relationship between the APOE gene, specifically its ε4 allele, and cognitive impairment in the Hispanic population of the Rio Grande Valley.

Methods: A total of 269 Hispanic subjects, aged 60 and above, with …

Mapping Sca1 Regional Vulnerabilities Reveals Neural And Skeletal Muscle Contributions To Disease, Lisa Duvick, W Michael Southern, Kellie A Benzow, Zoe N Burch, Hillary P Handler, Jason S Mitchell, Hannah Kuivinen, Udaya Gadiparthi, Praseuth Yang, Alyssa Soles, Carrie A Sheeler, Orion Rainwater, Shannah Serres, Erin B Lind, Tessa Nichols-Meade, Yun You, Brennon O'Callaghan, Huda Y Zoghbi, Marija Cvetanovic, Vanessa C Wheeler, James M Ervasti, Michael D Koob, Harry T Orr

Duncan NRI Faculty and Staff Publications

Spinocerebellar ataxia type 1 (SCA1) is a fatal neurodegenerative disease caused by an expanded polyglutamine tract in the widely expressed ataxin-1 (ATXN1) protein. To elucidate anatomical regions and cell types that underlie mutant ATXN1-induced disease phenotypes, we developed a floxed conditional knockin mouse (f-ATXN1146Q/2Q) with mouse Atxn1 coding exons replaced by human ATXN1 exons encoding 146 glutamines. f-ATXN1146Q/2Q mice manifested SCA1-like phenotypes including motor and cognitive deficits, wasting, and decreased survival. Central nervous system (CNS) contributions to disease were revealed using f-ATXN1146Q/2Q;Nestin-Cre mice, which showed improved rotarod, open field, and Barnes maze performance by 6-12 weeks of age. In contrast, …

Tumor Treating Fields Suppress Tumor Cell Growth And Neurologic Decline In Models Of Spinal Metastases, Daniel Ledbetter, Romulo Augusto Andrade De Almeida, Xizi Wu, Ariel Naveh, Chirag B Patel, Queena Gonzalez, Thomas H Beckham, Robert North, Laurence Rhines, Jing Li, Amol Ghia, David Aten, Claudio Tatsui, Christopher Alvarez-Breckenridge

Faculty, Staff and Student Publications

Spinal metastases can result in severe neurologic compromise and decreased overall survival. Despite treatment advances, local disease progression is frequent, highlighting the need for novel therapies. Tumor treating fields (TTFields) impair tumor cell replication and are influenced by properties of surrounding tissue. We hypothesized that bone's dielectric properties will enhance TTFields-mediated suppression of tumor growth in spinal metastasis models. Computational modeling of TTFields intensity was performed following surgical resection of a spinal metastasis and demonstrated enhanced TTFields intensity within the resected vertebral body. Additionally, luciferase-tagged human KRIB osteosarcoma and A549 lung adenocarcinoma cell lines were cultured in demineralized bone grafts …

A Tough Bioadhesive Hydrogel Supports Sutureless Sealing Of The Dural Membrane In Porcine And Ex Vivo Human Tissue, Kyle C Wu, Benjamin R Freedman, Phoebe S Kwon, Matthew Torre, Daniel O Kent, Wenya Linda Bi, David J Mooney

Duncan NRI Faculty and Staff Publications

Complete sequestration of central nervous system tissue and cerebrospinal fluid by the dural membrane is fundamental to maintaining homeostasis and proper organ function, making reconstruction of this layer an essential step during neurosurgery. Primary closure of the dura by suture repair is the current standard, despite facing technical, microenvironmental, and anatomic challenges. Here, we apply a mechanically tough hydrogel paired with a bioadhesive for intraoperative sealing of the dural membrane in rodent, porcine, and human central nervous system tissue. Tensile testing demonstrated that this dural tough adhesive (DTA) exhibited greater toughness with higher maximum stress and stretch compared with commercial …

Exploring Neuroplasticity Changes In Neurotoxin-Induced Parkinson’S Disease: A Preliminary Analysis Using Transcranial Magnetic Stimulation, Tomas Gomez Jr., Daniel Salinas, Kelsey Potter-Baker, Nawaz Hack, Ramu Vadukapuram

Research Symposium

Background: Parkinson’s disease (PD) is a neurodegenerative condition that affects movement, cognition, gait, and significantly impacts one's quality of life. Studies have suggested that neurotoxin pre-exposure is related to PD pathology and progressive motor/non-motor deficits, though it remains unclear how neurotoxin exposure affects neuroplasticity. The present study aimed to examine neurotoxin–induced PD-associated neuroplasticity changes in relationship to mental acuity and PD motor functionalities.

Methods: 7 voluntary participants experiencing early-stage PD symptoms with self-reported neurotoxin pre-exposure were enrolled in the longitudinal, repeated-measures clinical study; 2 sex-matched, age-matched, and occupation-matched healthy subjects were recruited for controlled comparative analysis (n=9). UTRGV’s Institute …

Gamma-Aminobutyric Acid (Gaba) Neurons And Perineuronal Nets (Pnn) In The Monodelphis Domestica And Relevance To Psychiatric Disorders, Jatziry Z. Luna Escobedo, Mariela Garcia, John L. Vandeberg, Mario Gil

Research Symposium

Background/ Purpose: Gamma-aminobutyric acid (GABA) is an amino acid that serves as the central nervous system’s (CNS) main inhibitory neurotransmitter. By inhibiting nerve transmission, it works to lower neuronal excitability. Altered GABA levels have been associated with a variety of psychiatric disorders, for example Epilepsies, Parkinson’s Disease, and Schizophrenia. Perineuronal nets (PNN) are extracellular molecules that are released by neurons and glial cells that modulate many neuronal and glial functions by encapsulating the inhibitory cells and neurites. Altered PNN levels serve as a potential trigger to synaptic imbalance. The purpose of this study is to quantify and analyze the presence, …

Contribution Of 24-H Blood Pressure Variability To Dementia-Related Disorders In Hispanics, Nura Salhadar, Kristina Vatcheva, Silvia Mejia-Arango Dr., Luis J. Mena, Ney Alliey-Rodriguez, Carlos A. Chavez, Ciro A. Goana, Egle Silva, Gustavo Calmon, Rosa P. Mavarez, Joseph H. Lee, Joseph D. Terwilliger, Jesus D. Melgarejo, Gladys E. Maestre

Research Symposium

Introduction: As the number of people living with dementia is increasing at alarming rates worldwide, there is an urgent need to understand the physiopathology of dementia syndromes. Among the most important preventable risk factors, treatment of vascular risk factors such as high blood pressure (BP) decreases the risk of Alzheimer’s disease and related dementias (ADRD). Recent evidence suggests that examining BP variability provides additional physiopathological and predictive information above the mean BP level. However, studies examining the relationship between 24-h BP variability and ADRD are limited, and evidence of the association with dementia has not been documented yet. Therefore, we …

Brain-Specific Serine/Threonine-Protein Kinase 1 Is A Substrate Of Protein Kinase C Epsilon Involved In Sex-Specific Ethanol And Anxiety Phenotypes, Michael P. Dugan, Rajani Maiya, Caleb Fleischer, Michal Bajo, Angela E. Snyder, Ashwin Koduri, Sathvik Srinivasan, Marisa Roberto, Robert O. Messing

School of Graduate Studies Faculty Publications

Protein kinase C epsilon (PKCε) regulates behavioural responses to ethanol and plays a role in anxiety-like behaviour, but knowledge is limited on downstream substrates of PKCε that contribute to these behaviours. We recently identified brain-specific serine/threonine-protein kinase 1 (BRSK1) as a substrate of PKCε. Here, we test the hypothesis that BRSK1 mediates responses to ethanol and anxiety-like behaviours that are also PKCε dependent. We used in vitro kinase assays to further validate BRSK1 as a substrate of PKCε and used Brsk1−/− mice to assess the role of BRSK1 in ethanol- and anxiety-related behaviours and in physiological responses to ethanol. We …

Automated Seizure Detection Based On State-Space Model Identification, Zhuo Wang, Michael Sperling, Dale Wyeth, Allon Guez

Department of Neuroscience Faculty Papers

In this study, we developed a machine learning model for automated seizure detection using system identification techniques on EEG recordings. System identification builds mathematical models from a time series signal and uses a small number of parameters to represent the entirety of time domain signal epochs. Such parameters were used as features for the classifiers in our study. We analyzed 69 seizure and 55 non-seizure recordings and an additional 10 continuous recordings from Thomas Jefferson University Hospital, alongside a larger dataset from the CHB-MIT database. By dividing EEGs into epochs (1 s, 2 s, 5 s, and 10 s) and …

Case Report: Molecular Profiling Facilitates The Diagnosis Of A Challenging Case Of Lung Cancer With Choriocarcinoma Features, Hui Li, Xin Hu, Matthew S Ning, Gregory N Fuller, John M Stewart, Jared C Gilliam, Jia Wu, Xiuning Le, Ara A Vaporciyan, J Jack Lee, Don L Gibbons, John V Heymach, Andrew Futreal, Jianjun Zhang

Faculty, Staff and Student Publications

Accurate diagnoses are crucial in determining the most effective treatment across different cancers. In challenging cases, morphology-based traditional pathology methods have important limitations, while molecular profiling can provide valuable information to guide clinical decisions. We present a 35-year female with lung cancer with choriocarcinoma features. Her disease involved the right lower lung, brain, and thoracic lymph nodes. The pathology from brain metastasis was reported as "metastatic choriocarcinoma" (a germ cell tumor) by local pathologists. She initiated carboplatin and etoposide, a regimen for choriocarcinoma. Subsequently, her case was assessed by pathologists from an academic cancer center, who gave the diagnosis of …

Novel Lipid Mediator 7s,14r-Docosahexaenoic Acid: Biogenesis And Harnessing Mesenchymal Stem Cells To Ameliorate Diabetic Mellitus And Retinal Pericyte Loss, Yan Lu, Haibin Tian, Hongying Peng, Quansheng Wang, Bruce A. Bunnell, Nicolas G. Bazan, Song Hong

School of Medicine Faculty Publications

Introduction: Stem cells can be used to treat diabetic mellitus and complications. ω3-docosahexaenoic acid (DHA) derived lipid mediators are inflammation-resolving and protective. This study found novel DHA-derived 7S,14R-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-docosahexaenoic acid (7S,14R-diHDHA), a maresin-1 stereoisomer biosynthesized by leukocytes and related enzymes. Moreover, 7S,14R-diHDHA can enhance mesenchymal stem cell (MSC) functions in the amelioration of diabetic mellitus and retinal pericyte loss in diabetic db/db mice. Methods: MSCs treated with 7S,14R-diHDHA were delivered into db/db mice i.v. every 5 days for 35 days. Results: Blood glucose levels in diabetic mice were lowered by 7S,14R-diHDHA-treated MSCs compared to control and untreated MSC groups, accompanied by …

Synchrony In Networks Of Type 2 Interneurons Is More Robust To Noise With Hyperpolarizing Inhibition Compared To Shunting Inhibition In Both The Stochastic Population Oscillator And The Coupled Oscillator Regimes, Roman Baravalle, Carmen C. Canavier

School of Medicine Faculty Publications

Synchronization in the gamma band (25–150 Hz) is mediated by PV+ inhibitory interneurons, and evidence is accumulating for the essential role of gamma oscillations in cognition. Oscillations can arise in inhibitory networks via synaptic interactions between individual oscillatory neurons (mean-driven) or via strong recurrent inhibition that destabilizes the stationary background firing rate in the fluctuation-driven balanced state, causing an oscillation in the population firing rate. Previous theoretical work focused on model neurons with Hodgkin’s Type 1 excitability (integrators) connected by current-based synapses. Here we show that networks comprised of simple Type 2 oscillators (resonators) exhibit a supercritical Hopf bifurcation between …