Systems Neuroscience Commons^™

Multimodal Neuroimaging Of Hiv And Aging, Brandon Lew

Theses & Dissertations

HIV infection remains a significant contributor to disease burden, and with the success of antiretroviral therapies, the population of people with HIV is aging. A growing literature suggests a relationship between HIV-infection and a profile of age advancement, most notably in molecular studies of epigenetics. However, despite the widely-known high prevalence of HIV-related brain atrophy, functional deficits, and HIV-associated neurocognitive disorder (HAND), epigenetic age advancement has not been linked to HIV-related changes in neuroimaging metrics.

We applied three neuroimaging methods, structural MRI, resting state functional MRI, and resting state MEG, to study the brain structure and function of 121 virally-suppressed …

Cortical Dynamics Of Language, Kiefer Forseth

Dissertations and Theses (Open Access)

The human capability for fluent speech profoundly directs inter-personal communication and, by extension, self-expression. Language is lost in millions of people each year due to trauma, stroke, neurodegeneration, and neoplasms with devastating impact to social interaction and quality of life. The following investigations were designed to elucidate the neurobiological foundation of speech production, building towards a universal cognitive model of language in the brain. Understanding the dynamical mechanisms supporting cortical network behavior will significantly advance the understanding of how both focal and disconnection injuries yield neurological deficits, informing the development of therapeutic approaches.

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 …

Rehabilitative Movement Approaches And Dance Interventions In Parkinson’S Disease, Cecilia Fontanesi

Dissertations, Theses, and Capstone Projects

The scope of this work is to address the functional deficits and symptoms experienced by those living with Parkinson’s Disease through movement interventions.

Chapter 1 offers a brief overview of current pharmacotherapy and rehabilitation approaches in Parkinson’s, focusing on dance in particular as a movement intervention that may be particularly suited to this population.

Chapter 2 focuses on brain plasticity and motor learning in PD, reporting the effects of rTMS applied after the acquisition of a motor skill. In this study, adaptation tested in patients with PD was comparable in the sham and TMS sessions, while retention indices tested on …

The Current Neuroscientific Understanding Of Alzheimer's Disease, Rachel A. Brandes

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Alzheimer’s disease is a degenerative neurological illness characterized by the deterioration of brain regions implicated in memory and cognitive function. While researchers have yet to find a cure or effective treatment, they have gained a better understanding of its pathology and development. Through years of neuroscience research, scientists have discovered much of what happens in the brain during Alzheimer’s disease onset and how this causes its symptoms; many hypotheses regarding this aspect of the illness involve temporal lobe atrophy, neurofibrillary tangles, and amyloid plaques. Although Alzheimer’s disease affects millions of people every day, it seems that most are unaware of …

The Role Of Inter-Enlargement Propriospinal Neurons In Locomotion Following Spinal Cord Injury., Courtney Therese Shepard

Electronic Theses and Dissertations

The focus of this dissertation is to explore the functional role of two anatomically-defined pathways in the adult rat spinal cord before and after spinal cord injury (SCI). To do this, a Tet^On dual virus system was used to selectively and reversibly silence neurons with cell bodies at spinal segment L2 and projections to spinal segment C6 (long ascending propriospinal neurons, LAPNs) and neurons that originate in the C6 spinal segment and terminate at L2 spinal segment (long descending propriospinal neurons, LDPNs). This dissertation is divided into five chapters. Chapter One provides background information regarding spinal cord injury, locomotion, …

Optical Clearing Reveals Tnbs-Induced Morphological Changes Of Vglut2-Positive Nerve Endings In The Colorectum, Shivam Patel

Honors Scholar Theses

Sensitization of colorectal afferents and colorectal hypersensitivity have been observed in a mouse model of post-infectious irritable bowel syndrome via intracolonic treatment of 2,4,6-trinitrobenzenesulfonic acid (TNBS). In this study, we investigated the distribution and morphology of microscopic colorectal afferent endings before and after intracolonic treatment of TNBS. We genetically labeled predominantly extrinsic colorectal afferents using the vesicular glutamate transporter type 2 (VGLUT2) promoter. Then, we used an optical tissue clearing method of whole-mount colorectum to image labeled VGLUT2-nerve endings that are otherwise obscured in untreated samples. We used vector path tracing to quantify the density and degree of curliness of …

Artifact Identification For Blood Pressure And Photoplethysmography Signals In An Unsupervised Environment, Pooi Khoon Lim

Student Works (2020-2029)

Physiological signals play a significant role in clinical diagnosis, it always acts as a major input of a decision support system. However, the physiological signal is easily corrupted by different factors especially motion artifacts. Several research works have been tried to recover the underlying physiological signal by suppressing the artifact. However, not much attention has been paid to situation where the artifact is too extreme and the artifact suppression is not possible. In this situation, physiological signal quality must be evaluated before any further assessment. In this study, an automated artifact detection algorithm was developed for Blood Pressure and PPG …

Distributions Of Hypothalamic Neuron Populations Co-Expressing Tyrosine Hydroxylase And The Vesicular Gaba Transporter In The Mouse., Kenichiro Negishi, Mikayla Payant, Kayla Schumacker, Gabor Wittman, Rebecca Butler, Ronald Lechan, Harry Steinbusch, Arshad Khan, Melissa Chee

Selected Works Temporary Series

No abstract provided.

Distributions Of Hypothalamic Neuron Populations Co-Expressing Tyrosine Hydroxylase And The Vesicular Gaba Transporter In The Mouse., Negishi, Mikayla Payant, Kayla Schumacker, Gabor Wittman, Rebecca Butler, Ronald Lechan, Harry Steinbusch, Arshad Khan, Melissa Chee

Departmental Papers (Biology)

No abstract provided.

Apoe As A Metabolic Regulator In Humans, Mice, And Astrocytes, Brandon C. Farmer

Theses and Dissertations--Physiology

Altered metabolic pathways appear to play central roles in the pathophysiology of late-onset Alzheimer’s disease (AD). Carrier status of the E4 allele of the APOE gene is the strongest genetic risk factor for late-onset AD, and increasing evidence suggests that E4 carriers may be at an increased risk for neurodegeneration based on inherent metabolic impairments. A new appreciation is forming for the role of APOE in cerebral metabolism, and how nutritional factors may impact this role. In chapter 1, the literature on nutritional interventions in E4 carriers aimed at mitigating disease risk is reviewed. Studies investigating the mechanism by which …

Spinal Motor Neuron Excitability And Balance Control Changes Following Downslope Walking, Nikki Aitcheson-Huehn

Theses and Dissertations (Comprehensive)

Downslope walking (DSW) has been proposed as a rehabilitation tool for people with Multiple Sclerosis (PwMS) although there are mixed findings in young adults (YA) regarding the balance control changes, despite both populations experiencing depressed spinal motor neuron (MN) pool excitability. Our aim was to determine whether YAs could demonstrate improved balance control in conjunction with SOL H reflex depression (estimate of spinal MN excitability) following DSW. We also aimed to determine whether reciprocal inhibition was a potential mechanism for H reflex depression via conditioned SOL H reflexes. Thirty young adults (23±1.4y, 6 males) were assigned to 30-minutes of DSW …

Mechanisms Of Value-Biased Prioritization In Fast Sensorimotor Decision Making, Kivilcim Afacan-Seref

Dissertations and Theses

In dynamic environments, split-second sensorimotor decisions must be prioritized according to potential payoffs to maximize overall rewards. The impact of relative value on deliberative perceptual judgments has been examined extensively, but relatively little is known about value-biasing mechanisms in the common situation where physical evidence is strong but the time to act is severely limited. This research examines the behavioral and electrophysiological indices of how value biases split-second perceptual decisions and the possible mechanisms underlying the process. In prominent decision models, a noisy but statistically stationary representation of sensory evidence is integrated over time to an action-triggering bound, and value-biases …

Characterization Of The Effect Of Exercise Dose And Integrative Nonpharmacological Therapies In The Treatment Of Chronic Pain, Anna M. Polaski

Electronic Theses and Dissertations

Chronic pain includes debilitating conditions affecting large populations of people throughout the world. These diseases are further complicated by comorbid psychological disorders which make chronic pain conditions difficult to treat. Nonpharmacological treatment options have more recently become an important mainstay of effective therapies and are currently being used to supplement or replace traditional pharmacological treatment methods. Exercise-based therapies in particular are of interest due to their demonstrated success in reducing pain symptoms as well as improving psychological outcomes. Dose is an important factor in being able to effectively prescribe treatments in the context of specific exercise interventions and specific pain …

Cognitive And Non-Cognitive Outcomes Associated With Student Engagement In A Novel Brain Chemoarchitecture Mapping Course-Based Undergraduate Research Experience., Christina D'Arcy, Anais Martinez, Arshad Khan, Jeffrey Olimpo

Selected Works Temporary Series

No abstract provided.

Cognitive And Non-Cognitive Outcomes Associated With Student Engagement In A Novel Brain Chemoarchitecture Mapping Course-Based Undergraduate Research Experience., D'Arcy, Anais Martinez, Arshad Khan, Jeffrey Olimpo

Departmental Papers (Biology)

No abstract provided.

Investigating The Role Of Integrin Beta 3 In Dendritic Arborization In The Supragranular Developing Cerebral Cortex, Zachary Logan Holley

Senior Honors Projects, 2010-2019

Integrin subunits have been implicated in axonal and dendritic outgrowth. In particular, a strong positive association has been found between mutations in integrin beta 3 (Itgb3) and autism spectrum disorder, but little is known about neuronal Itgb3 function in vivo. Many forms of autism spectrum disorder are thought to arise from dysfunctional dendritic arborization and synaptic pruning. Global knockout of Itgb3 in mice leads to autistic-like behaviors. Itgb3^-/- mice also have reduced callosal volume, a key neuroanatomical correlate of autism. Here, we test the hypothesis that Itgb3 is required for normal dendritic arborization in layer II/III pyramidal …

Feedforward And Feedback Signals In The Olfactory System, Srimoy Chakraborty

Graduate Theses and Dissertations

The conglomeration of myriad activities in neural systems often results in prominent oscillations. The primary goal of the research presented in this thesis was to study effects of sensory stimulus on the olfactory system of rats, focusing on the olfactory bulb (OB) and the anterior piriform cortex (aPC). Extracellular electrophysiological measurements revealed distinct frequency bands of oscillations in OB and aPC. However, how these oscillatory fluctuations help the animal to process sensory input is not clearly understood. Here we show high frequency oscillations in olfactory bulb carry feedforward signals to anterior piriform cortex whereas feedback from the aPC is predominantly …

Modeling And Mapping Addiction In The Zebrafish, Danio Rerio, Bradley Serpa

Master of Science in Integrative Biology Theses

Driven by the communication of dopamine, the vertebrate reward system has been evolutionarily conserved to maintain survival and optimize fitness. The neural circuits governing this system integrate sensory stimuli to produce appropriate, self-preserving responses that underlie experience-based learning. In the most primitive vertebrates, dopamine release in neuronal circuits drives homeostatic behaviors, such as seeking nutrients, finding a mate, or avoiding danger. From agnathans to mammals, dopaminergic synthesis and signaling genes and molecules, along with neuronal pathways and reward system-based behaviors, remain highly conserved. Dopamine signaling proteins include two classes of metabotropic G-Protein Receptor Coupled Dopamine Receptors, D1-like (DRD1) and D2-like …

Moderate Prenatal Alcohol Exposure Impairs Performance In An Object-Place-Paired-Associate Task, Lilliana May Sanchez

Psychology ETDs

Memory impairments, including spatial and object processing, are often observed in individuals with Fetal Alcohol Spectrum Disorder. Much attention has been directed towards the hippocampus, which displays significant alterations after moderate prenatal alcohol exposure (PAE). In the present study, we tested a moderate PAE rat model in an object-place-paired-associate (OPPA) task, previously shown to require hippocampal processing. The OPPA task was composed of training rats to discriminate between an identical pair of objects presented in 180° opposite arms of a radial arm maze. Animals were given a total of 10 trials per day over 14 consecutive days of training and …

Review: Do The Different Sensory Areas Within The Cat Anterior Ectosylvian Sulcal Cortex Collectively Represent A Network Multisensory Hub?, M. Alex Meredith, Mark T. Wallace, H. Ruth Clemo

Anatomy and Neurobiology Publications

Current theory supports that the numerous functional areas of the cerebral cortex are organized and function as a network. Using connectional databases and computational approaches, the cerebral network has been demonstrated to exhibit a hierarchical structure composed of areas, clusters and, ultimately, hubs. Hubs are highly connected, higher-order regions that also facilitate communication between different sensory modalities. One region computationally identified network hub is the visual area of the Anterior Ectosylvian Sulcal cortex (AESc) of the cat. The Anterior Ectosylvian Visual area (AEV) is but one component of the AESc that also includes the auditory (Field of the Anterior Ectosylvian …

Neurofeedback With Fmri: A Critical Systematic Review, Robert T. Thibault, Amanda Macpherson, Michael Lifshitz, Raquel R. Roth, Amir Raz

Psychology Faculty Articles and Research

Neurofeedback relying on functional magnetic resonance imaging (fMRI-nf) heralds new prospects for self-regulating brain and behavior. Here we provide the first comprehensive review of the fMRI-nf literature and the first systematic database of fMRI-nf findings. We synthesize information from 99 fMRI-nf experiments—the bulk of currently available data. The vast majority of fMRI-nf findings suggest that self-regulation of specific brain signatures seems viable; however, replication of concomitant behavioral outcomes remains sparse. To disentangle placebo influences and establish the specific effects of neurofeedback, we highlight the need for double-blind placebo-controlled studies alongside rigorous and standardized statistical analyses. Before fMRI-nf can join the …

Possible Breakdown Of Dopamine Receptor Synergism In A Mouse Model Of Huntington's Disease, Samantha F. Kennedy

LSU New Orleans Theses and Dissertations

The model of basal ganglia function proposed by Albin, Young and Penney (1989) describes two anatomically independent motor pathways, the direct and indirect. However, under normal conditions striatal dopamine (DA) is required for the expression of motor behavior, and DAergic control of the two pathways (via D1 and D2 receptors, respectively) is dependent on co-activation. We tested for a possible breakdown of D1/D2 synergism using transgenic R6/1 mice bearing the human huntingtin allele (Htt). Motor stereotypy, observed prior to the onset of HD-related symptoms, was rated on a 5-point scale following activation of: A) D1 receptors alone, B) D2 receptors …

Disruption Of Hippocampal Multisynaptic Networks By General Anesthetics., Min-Ching Kuo, L Stan Leung

Physiology and Pharmacology Publications

BACKGROUND: Previous studies showed that synaptic transmission is affected by general anesthetics, but an anesthetic dose response in freely moving animals has not been done. The hippocampus provides a neural network for the evaluation of isoflurane and pentobarbital on multisynaptic transmission that is relevant to memory function.

METHODS: Male Long-Evans rats were implanted with multichannel and single electrodes in the hippocampus. Spontaneous local field potentials and evoked field potentials were recorded in freely behaving rats before (baseline) and after various doses of isoflurane (0.25 to 1.5%) and sodium pentobarbital (10 mg/kg intraperitoneal).

RESULTS: Monosynaptic population excitatory postsynaptic potentials at the …

Distinct Combinations Of Premotor Neuronal Activation Encode Multimodal Information And Predict Motor Output, Chris Goldsmith

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

On The Origin Of Sensory Errors, Jonathan R. Flynn

Dissertations and Theses (Open Access)

Estimation of perceptual variables is imprecise and prone to errors. Although the properties of these perceptual errors are well characterized, the physiological basis for these errors is unknown. One previously proposed explanation for these errors is the trial-by-trial variability of the responses of sensory neurons that encode the percept. Initially, it would seem that a complicated electrophysiological experiment would need to be performed to test this hypothesis. However, using a strong theoretical framework, I demonstrate that it is possible to determine statistical characteristics of the physiological mechanism responsible for perceptual errors solely from a behavioral experiment. The basis for this …

P35. Investigating The Effect Of Maternal Immune Activation On Sensory Filtering, Social Behaviour And Attention, Faraj Haddad

Western Research Forum

Background

Altered brain development is associated with many neuropsychiatric disorders like Autism Spectrum Disorder (ASD) and schizophrenia. Environmental insults can interfere with neurodevelopment, and a prominent example is maternal infection during pregnancy. Epidemiological studies show that children born to mothers who were infected during pregnancy display a higher risk of developing ASD and schizophrenia, and this effect is mainly due to the maternal immune response. Polyinosinic-polycytidilic acid (Poly I:C) is a double stranded RNA molecule that mimics viral markers and elicits an immune response. When injected in pregnant rodents, this model produces offspring that exhibit core symptoms of ASD and …

Canine Emotions As Seen Through Human Social Cognition, Miiamaaria V. Kujala

Animal Sentience

It is not possible to demonstrate that dogs (Canis familiaris) feel emotions, but the same is true for all other species, including our own. The issue must therefore be approached indirectly, using premises similar to those used with humans. Recent methodological advances in canine research reveal what dogs experience and what they derive from the emotions perceptible in others. Dogs attend to social cues, they respond appropriately to the valence of human and dog facial expressions and vocalizations of emotion, and their limbic reward regions respond to the odor of their caretakers. They behave differently according to the …

Maguk Scaffolds Organize A Key Synaptic Complex In Horizontal Cell Processes Contacting Photoreceptors, Alejandro Vila, Ph.D.

Dissertations and Theses (Open Access)

Synaptic processes and plasticity of synapses are mediated by large suites of proteins. In most cases, many of these proteins are tethered together by synaptic scaffold proteins. Scaffold proteins have a large number and typically a variety of protein interaction domains that allow many different proteins to be assembled into functional complexes. As each scaffold protein has a different set of protein interaction domains and a unique set of interacting partners, the presence of synaptic scaffolds can provide insight into the molecular mechanisms that regulate synaptic processes. In studies of rabbit retina, we found SAP102 and Chapsyn110 selectively localized in …

Zombies, Predatory Wasps And Consciousness, James K. Peterson

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.