Neurosciences Commons^™

Usability Of Abattoir-Acquired Pig Eyes For Refractive Excimer Laser Research, Marius Topka, Yao Zhang, Antonia Bock, Peter Riedel, Johannes Lörner, Alexander Hammer, Eva Maier, Friedrich Paulsen, Christian M Hammer

Faculty, Staff and Student Publications

The purpose of this study was to elucidate, under which conditions abattoir-acquired pig eyes are suitable for refractive excimer laser experiments. Porcine eyes from tunnel-scalded (n = 5) and tank-scalded (n = 10) pigs were compared to unscalded eyes (n = 5) and to eyes scalded in the laboratory (n = 5). The corneal epithelium was removed before an excimer laser was used to perform a - 8.0 D photoablation. Corneal thickness was measured by optical coherence topography before and after photoablation. The ablation depth was determined with a contour measuring station, the morphology of the ablated areas was characterized …

A Comparison Of Machine Learning Classifiers For Pediatric Epilepsy Using Resting-State Functional Mri Latency Data, Ryan D Nguyen, Matthew D Smyth, Liang Zhu, Ludovic P Pao, Shannon K Swisher, Emmett H Kennady, Anish Mitra, Rajan P Patel, Jeremy E Lankford, Gretchen Von Allmen, Michael W Watkins, Michael E Funke, Manish N Shah

Faculty, Staff and Student Publications

Epilepsy affects 1 in 150 children under the age of 10 and is the most common chronic pediatric neurological condition; poor seizure control can irreversibly disrupt normal brain development. The present study compared the ability of different machine learning algorithms trained with resting-state functional MRI (rfMRI) latency data to detect epilepsy. Preoperative rfMRI and anatomical MRI scans were obtained for 63 patients with epilepsy and 259 healthy controls. The normal distribution of latency z-scores from the epilepsy and healthy control cohorts were analyzed for overlap in 36 seed regions. In these seed regions, overlap between the study cohorts ranged from …

Exogenous Inter-Α Inhibitor Proteins Prevent Cell Death And Improve Ischemic Stroke Outcomes In Mice, Louise D Mccullough, Meaghan Roy-O'Reilly, Yun-Ju Lai, Anthony Patrizz, Yan Xu, Juneyoung Lee, Aleah Holmes, Daniel C Kraushaar, Anjali Chauhan, Lauren H Sansing, Barbara S Stonestreet, Liang Zhu, Julia Kofler, Yow-Pin Lim, Venugopal Reddy Venna

Faculty, Staff and Students Publications

Inter-α inhibitor proteins (IAIPs) are a family of endogenous plasma and extracellular matrix molecules. IAIPs suppress proinflammatory cytokines, limit excess complement activation, and bind extracellular histones to form IAIP-histone complexes, leading to neutralization of histone-associated cytotoxicity in models of sepsis. Many of these detrimental processes also play critical roles in the pathophysiology of ischemic stroke. In this study, we first assessed the clinical relevance of IAIPs in stroke and then tested the therapeutic efficacy of exogenous IAIPs in several experimental stroke models. IAIP levels were reduced in both ischemic stroke patients and in mice subjected to experimental ischemic stroke when …

Deep Learning-Based Mixed-Dimensional Gaussian Mixture Model For Characterizing Variability In Cryo-Em, Muyuan Chen, Steven J Ludtke

Faculty, Staff and Students Publications

Structural flexibility and/or dynamic interactions with other molecules is a critical aspect of protein function. Cryogenic electron microscopy (cryo-EM) provides direct visualization of individual macromolecules sampling different conformational and compositional states. While numerous methods are available for computational classification of discrete states, characterization of continuous conformational changes or large numbers of discrete state without human supervision remains challenging. Here we present e2gmm, a machine learning algorithm to determine a conformational landscape for proteins or complexes using a three-dimensional Gaussian mixture model mapped onto two-dimensional particle images in known orientations. Using a deep neural network architecture, e2gmm can automatically resolve the …

Neurovascular Regulation In Diabetic Retinopathy And Emerging Therapies, Liyang Ji, Hong Tian, Keith A Webster, Wei Li

Faculty, Staff and Students Publications

Diabetic retinopathy (DR) is the leading cause of vision loss in working adults in developed countries. The disease traditionally classified as a microvascular complication of diabetes is now widely recognized as a neurovascular disorder resulting from disruption of the retinal neurovascular unit (NVU). The NVU comprising retinal neurons, glia and vascular cells coordinately regulates blood flow, vascular density and permeability to maintain homeostasis. Disturbance of the NVU during DR can lead to vision-threatening clinical manifestations. A limited number of signaling pathways have been identified for intercellular communication within the NVU, including vascular endothelial growth factor (VEGF), the master switch for …

Therapeutic Efficacy Of A Potent Anti-Venezuelan Equine Encephalitis Virus Antibody Is Contingent On Fc Effector Function, Vanja Krneta-Stankic, Mark E Corkins, Adriana Paulucci-Holthauzen, Malgorzata Kloc, Andrew B Gladden, Rachel K Miller

Faculty, Staff and Student Publications

E-cadherin junctions facilitate assembly and disassembly of cell contacts that drive development and homeostasis of epithelial tissues. In this study, using Xenopus embryonic kidney and Madin-Darby canine kidney (MDCK) cells, we investigate the role of the Wnt/planar cell polarity (PCP) formin Daam1 (Dishevelled-associated activator of morphogenesis 1) in regulating E-cadherin-based intercellular adhesion. Using live imaging, we show that Daam1 localizes to newly formed cell contacts in the developing nephron. Furthermore, analyses of junctional filamentous actin (F-actin) upon Daam1 depletion indicate decreased microfilament localization and slowed turnover. We also show that Daam1 is necessary for efficient and timely localization of junctional …

Intermittent Hypoxia And Effects On Early Learning/Memory: Exploring The Hippocampal Cellular Effects Of Pediatric Obstructive Sleep Apnea, Arvind Chandrakantan, Adam C Adler, Mehmet Tohsun, Farrah Kheradamand, Russell S Ray, Steven Roth

Faculty, Staff and Students Publications

This review provides an update on the neurocognitive phenotype of pediatric obstructive sleep apnea (OSA). Pediatric OSA is associated with neurocognitive deficits involving memory, learning, and executive functioning. Adenotonsillectomy (AT) is presently accepted as the first-line surgical treatment for pediatric OSA, but the executive function deficits do not resolve postsurgery, and the timeline for recovery remains unknown. This finding suggests that pediatric OSA potentially causes irreversible damage to multiple areas of the brain. The focus of this review is the hippocampus, 1 of the 2 major sites of postnatal neurogenesis, where new neurons are formed and integrated into existing circuitry …

Deciphering An Agrp-Serotoninergic Neural Circuit In Distinct Control Of Energy Metabolism From Feeding, Yong Han, Guobin Xia, Dollada Srisai, Fantao Meng, Yanlin He, Yali Ran, Yang He, Monica Farias, Giang Hoang, István Tóth, Marcelo O Dietrich, Miao-Hsueh Chen, Yong Xu, Qi Wu

Children’s Nutrition Research Center Staff Publications

Contrasting to the established role of the hypothalamic agouti-related protein (AgRP) neurons in feeding regulation, the neural circuit and signaling mechanisms by which they control energy expenditure remains unclear. Here, we report that energy expenditure is regulated by a subgroup of AgRP neurons that send non-collateral projections to neurons within the dorsal lateral part of dorsal raphe nucleus (dlDRN) expressing the melanocortin 4 receptor (MC4R), which in turn innervate nearby serotonergic (5-HT) neurons. Genetic manipulations reveal a bi-directional control of energy expenditure by this circuit without affecting food intake. Fiber photometry and electrophysiological results indicate that the thermo-sensing MC4RdlDRN neurons …

Rap1 In The Vmh Regulates Glucose Homeostasis, Kentaro Kaneko, Hsiao-Yun Lin, Yukiko Fu, Pradip K Saha, Ana B De La Puente-Gomez, Yong Xu, Kousaku Ohinata, Peter Chen, Alexei Morozov, Makoto Fukuda

Faculty, Staff and Students Publications

The hypothalamus is a critical regulator of glucose metabolism and is capable of correcting diabetes conditions independently of an effect on energy balance. The small GTPase Rap1 in the forebrain is implicated in high-fat diet-induced (HFD-induced) obesity and glucose imbalance. Here, we report that increasing Rap1 activity selectively in the medial hypothalamus elevated blood glucose without increasing the body weight of HFD-fed mice. In contrast, decreasing hypothalamic Rap1 activity protected mice from diet-induced hyperglycemia but did not prevent weight gain. The remarkable glycemic effect of Rap1 was reproduced when Rap1 was specifically deleted in steroidogenic factor-1-positive (SF-1-positive) neurons in the …

The Impact Of Synchrony On Neuronal Coding And Behavior, Natasha Kharas

Dissertations and Theses (Open Access)

Cortical columns represent the elementary functional and computational module of the neocortex. Although much is known about its laminar structure and synaptic connectivity, how patterns of spiking activity propagate within columnar circuits when the state of the brain changes remains poorly understood. We used multi-electrode laminar arrays to reveal that brain state modulates the propagation of neural activity across the layers of early and mid-level visual cortex (areas V1 and V4). We found a high prevalence of neuronal synchrony (vigorous (On) and weak (Off) spiking) in rest but low prevalence of synchrony during wakefulness. We next tested whether propagation of …

Investigating Diffusion Tensor Imaging Correlates Of Cognitive Impairment In Idiopathic Normal Pressure Hydrocephalus And Alzheimer's Disease, Omar Hasan, Omar Hasan

Dissertations and Theses (Open Access)

Modest expansion of the human brain cerebrospinal fluid (CSF)-filled ventricles is normal with aging, and because of this, it can be difficult for physicians to accurately diagnose and treat enlarged ventricles (ventriculomegaly), called hydrocephalus¹ (fluid or water in the brain) Ventriculomegaly occurs due to an obstruction (such as a blood clot or tumor), or a change in CSF absorption². Primary hydrocephalus, also called idiopathic normal pressure hydrocephalus (iNPH), is non-obstructive and may be comorbid with other neurodegenerative diseases such as Alzheimer’s disease (AD) or frontotemporal dementia (FTD). Clinically, it can be difficult to tell whether the pathophysiological …

Obstructive Sleep Apnea And Dementia-Common Gene Associations Through Network-Based Identification Of Common Driver Genes, Hyun-Hwan Jeong, Arvind Chandrakantan, Adam C Adler

Faculty, Staff and Students Publications

BACKGROUND: Obstructive Sleep Apnea (OSA) occurs in 7% of the adult population. The relationship between neurodegenerative diseases such as dementia and sleep disorders have long attracted clinical attention; however, no comprehensive data exists elucidating common gene expression between the two diseases. The objective of this study was to (1) demonstrate the practicability and feasibility of utilizing a systems biology approach called network-based identification of common driver genes (NICD) to identify common genomic features between two associated diseases and (2) utilize this approach to identify genes associated with both OSA and dementia.

METHODS: This study utilized 2 public databases (PCNet, DisGeNET) …

A Biallelic Pathogenic Variant In The Ogdh Gene Results In A Neurological Disorder With Features Of A Mitochondrial Disease, Zheng Yie Yap, Klaudia Strucinska, Satoshi Matsuzaki, Sukyeong Lee, Yue Si, Kenneth Humphries, Mark A Tarnopolsky, Wan Hee Yoon

Faculty, Staff and Students Publications

2-Oxoglutarate dehydrogenase (OGDH) is a rate-limiting enzyme in the mitochondrial TCA cycle, encoded by the OGDH gene. α-Ketoglutarate dehydrogenase (OGDH) deficiency was previously reported in association with developmental delay, hypotonia, and movement disorders and metabolic decompensation, with no genetic data provided. Using whole exome sequencing, we identified two individuals carrying a homozygous missense variant c.959A>G (p.N320S) in the OGDH gene. These individuals presented with global developmental delay, elevated lactate, ataxia and seizure. Fibroblast analysis and modeling of the mutation in Drosophila were used to evaluate pathogenicity of the variant. Skin fibroblasts from subject # 2 showed a decrease in …

Indications For Inpatient Magnetoencephalography In Children - An Institution's Experience, Michael W Watkins, Ekta G Shah, Michael E Funke, Stephanie Garcia-Tarodo, Manish N Shah, Nitin Tandon, Fernando Maestu, Christopher Laohathai, David I Sandberg, Jeremy Lankford, Stephen Thompson, John Mosher, Gretchen Von Allmen

Faculty, Staff and Student Publications

Magnetoencephalography (MEG) is recognized as a valuable non-invasive clinical method for localization of the epileptogenic zone and critical functional areas, as part of a pre-surgical evaluation for patients with pharmaco-resistant epilepsy. MEG is also useful in localizing functional areas as part of pre-surgical planning for tumor resection. MEG is usually performed in an outpatient setting, as one part of an evaluation that can include a variety of other testing modalities including 3-Tesla MRI and inpatient video-electroencephalography monitoring. In some clinical circumstances, however, completion of the MEG as an inpatient can provide crucial ictal or interictal localization data during an ongoing …

A Preliminary Dti Tractography Study Of Developmental Neuroplasticity 5–15 Years After Early Childhood Traumatic Brain Injury, Elisabeth A Wilde, Ilirjana Hyseni, Hannah M Lindsey, Jessica Faber, James M Mchenry, Erin D Bigler, Brian D Biekman, Laura L Hollowell, Stephen R Mccauley, Jill V Hunter, Linda Ewing-Cobbs, Mary E Aitken, Marianne Macleod, Zili D Chu, Linda J Noble-Haeusslein, Harvey S Levin

Faculty, Staff and Student Publications

Plasticity is often implicated as a reparative mechanism when addressing structural and functional brain development in young children following traumatic brain injury (TBI); however, conventional imaging methods may not capture the complexities of post-trauma development. The present study examined the cingulum bundles and perforant pathways using diffusion tensor imaging (DTI) in 21 children and adolescents (ages 10-18 years) 5-15 years after sustaining early childhood TBI in comparison with 19 demographically-matched typically-developing children. Verbal memory and executive functioning were also evaluated and analyzed in relation to DTI metrics. Beyond the expected direction of quantitative DTI metrics in the TBI group, we …

Ketamine: Neuroprotective Or Neurotoxic?, Divya Choudhury, Anita E Autry, Kimberley F Tolias, Vaishnav Krishnan

Faculty, Staff and Students Publications

Ketamine, a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist, has been employed clinically as an intravenous anesthetic since the 1970s. More recently, ketamine has received attention for its rapid antidepressant effects and is actively being explored as a treatment for a wide range of neuropsychiatric syndromes. In model systems, ketamine appears to display a combination of neurotoxic and neuroprotective properties that are context dependent. At anesthetic doses applied during neurodevelopmental windows, ketamine contributes to inflammation, autophagy, apoptosis, and enhances levels of reactive oxygen species. At the same time, subanesthetic dose ketamine is a powerful activator of multiple parallel neurotrophic signaling cascades …

Cerebellar Coordination Of Neuronal Communication In Cerebral Cortex, Samuel S Mcafee, Yu Liu, Roy V Sillitoe, Detlef H Heck

Duncan NRI Faculty and Staff Publications

Cognitive processes involve precisely coordinated neuronal communications between multiple cerebral cortical structures in a task specific manner. Rich new evidence now implicates the cerebellum in cognitive functions. There is general agreement that cerebellar cognitive function involves interactions between the cerebellum and cerebral cortical association areas. Traditional views assume reciprocal interactions between one cerebellar and one cerebral cortical site, via closed-loop connections. We offer evidence supporting a new perspective that assigns the cerebellum the role of a coordinator of communication. We propose that the cerebellum participates in cognitive function by modulating the coherence of neuronal oscillations to optimize communications between multiple …

Reversal Of Neurodegeneration By Engineered Monocytes In Alzheimer’S Disease, Chao-Hsien Chen

Dissertations and Theses (Open Access)

The health challenges posed by Alzheimer’s disease (AD) continue to grow as societies age worldwide. Accumulation of Tau-associated pathology correlates with clinical cognitive deterioration in AD. Resident myeloid cells within the central nervous system (CNS) have a limited capacity to uptake and degrade Tau; however, the resulting secretion of proinflammatory cytokines only acts to accelerate neurodegeneration. Therapeutic antibodies can reduce the neurotoxic oligomeric form of Tau (o-Tau), but in doing so they also aggravate inflammation. Attenuating mutation of the antibody Fc region can silence inflammation but also eliminates its capacity to mediate o-Tau clearance by CNS myeloid cells. Thus, there …

Epilepsy Risk Prediction Model For Patients With Tuberous Sclerosis Complex, Laura S Farach, Melissa A Richard, Philip J Lupo, Mustafa Sahin, Darcy A Krueger, Joyce Y Wu, Elizabeth M Bebin, Kit Sing Au, Hope Northrup, Tacern Study Group

Faculty, Staff and Student Publications

BACKGROUND: Individuals with tuberous sclerosis complex are at increased risk of epilepsy. Early seizure control improves developmental outcomes, making identifying at-risk patients critically important. Despite several identified risk factors, it remains difficult to predict. The purpose of the study was to evaluate the combined risk prediction of previously identified risk factors for epilepsy in individuals with tuberous sclerosis complex.

METHODS: The study group (n = 333) consisted of individuals with tuberous sclerosis complex who were enrolled in the Tuberous Sclerosis Complex Autism Center of Excellence Research Network and UT TSC Biobank. The outcome was defined as having an epilepsy diagnosis. …

Social And Leisure Activities Predict Transitions In Cognitive Functioning In Older Mexican Adults: A Latent Transition Analysis Of The Mexican Health And Aging Study, Heather Mary Brown, Stephen A Murray, Hope Northrup, Kit Sing Au, Lee A Niswander

Faculty, Staff and Student Publications

Disruptions in neural tube (NT) closure result in neural tube defects (NTDs). To understand the molecular processes required for mammalian NT closure, we investigated the role of Snx3, a sorting nexin gene. Snx3−/− mutant mouse embryos display a fully-penetrant cranial NTD. In vivo, we observed decreased canonical WNT target gene expression in the cranial neural epithelium of the Snx3−/− embryos and a defect in convergent extension of the neural epithelium. Snx3−/− cells show decreased WNT secretion, and live cell imaging reveals aberrant recycling of the WNT ligand-binding protein WLS and mis-trafficking to the lysosome for degradation. The importance …

Disrupted Hypothalamic Crh Neuron Responsiveness Contributes To Diet-Induced Obesity, Canjun Zhu, Yuanzhong Xu, Zhiying Jiang, Jin Bin Tian, Ryan M Cassidy, Zhao-Lin Cai, Gang Shu, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Qingyan Jiang, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

The current obesity epidemic mainly results from high-fat high-caloric diet (HFD) feeding and may also be contributed by chronic stress; however, the neural basis underlying stress-related diet-induced obesity remains unknown. Corticotropin-releasing hormone (CRH) neurons in the paraventricular hypothalamus (PVH), a known body weight-regulating region, represent one key group of stress-responsive neurons. Here, we found that HFD feeding blunted PVH CRH neuron response to nutritional challenges as well as stress stimuli and dexamethesone, which normally produce rapid activation and inhibition on these neurons, respectively. We generated mouse models with the activity of these neurons clamped at high or low levels, both …

Cell Type Composition And Circuit Organization Of Clonally Related Excitatory Neurons In The Juvenile Mouse Neocortex, Cathryn R Cadwell, Federico Scala, Paul G Fahey, Dmitry Kobak, Shalaka Mulherkar, Fabian H Sinz, Stelios Papadopoulos, Zheng H Tan, Per Johnsson, Leonard Hartmanis, Shuang Li, Ronald J Cotton, Kimberley F Tolias, Rickard Sandberg, Philipp Berens, Xiaolong Jiang, Andreas Savas Tolias

Faculty, Staff and Students Publications

Clones of excitatory neurons derived from a common progenitor have been proposed to serve as elementary information processing modules in the neocortex. To characterize the cell types and circuit diagram of clonally related excitatory neurons, we performed multi-cell patch clamp recordings and Patch-seq on neurons derived from Nestin-positive progenitors labeled by tamoxifen induction at embryonic day 10.5. The resulting clones are derived from two radial glia on average, span cortical layers 2–6, and are composed of a random sampling of transcriptomic cell types. We find an interaction between shared lineage and connection type: related neurons are more likely to …

Age Of Acquisition Impacts The Brain Differently Depending On Neuroanatomical Metric, Hannah Claussenius-Kalman, Kelly A Vaughn, Pilar Archila-Suerte, Arturo E Hernandez

Faculty, Staff and Student Publications

Although researchers generally agree that a certain set of brain areas underlie bilingual language processing, there is discrepancy regarding what effect timing of language acquisition has on these regions. We aimed to investigate the neuroanatomical correlates of age of acquisition (AoA), which has been examined previously, but with inconsistent results, likely influenced by methodological differences across studies. We analyzed gray matter density, volume, and thickness using whole-brain linear models in 334 bilinguals and monolinguals. Neuroanatomical correlates of AoA differed depending on gray matter metric. Relative to early bilinguals, late bilinguals had thicker cortex in language processing and cognitive control regions, …

Burden Of Rare Deleterious Variants In Wnt Signaling Genes Among 511 Myelomeningocele Patients, Luke Hebert, Paul Hillman, Craig Baker, Michael Brown, Allison Ashley-Koch, James E Hixson, Alanna C Morrison, Hope Northrup, Kit Sing Au

Faculty, Staff and Student Publications

Genes in the noncanonical WNT signaling pathway controlling planar cell polarity have been linked to the neural tube defect myelomeningocele. We hypothesized that some genes in the WNT signaling network have a higher mutational burden in myelomeningocele subjects than in reference subjects in gnomAD. Exome sequencing data from 511 myelomeningocele subjects was obtained in-house and data from 29,940 ethnically matched subjects was provided by version 2 of the publicly available Genome Aggregation Database. To compare mutational burden, we collapsed rare deleterious variants across each of 523 human WNT signaling genes in case and reference populations. Ten WNT signaling genes were …

Ultrafast Two-Photon Imaging Of A High-Gain Voltage Indicator In Awake Behaving Mice, Vincent Villette, Mariya Chavarha, Ivan K Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J Schnitzer, Guoqiang Bi, Katalin Toth, Jun Ding, Stéphane Dieudonné, Michael Z Lin

Faculty, Staff and Students Publications

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the …

Gna11 Brain Somatic Pathogenic Variant In An Individual With Phacomatosis Pigmentovascularis, Joseph M Sliepka, Sarah C Mcgriff, Linda Z Rossetti, Peyman Bizargity, Haley Streff, Yi-Shan Lee, Hongzheng Dai, Satyamaanasa Polubothu, Grace Lee, Vicky Ren, Jill V Hunter, Daniel J Curry, Fernando Scaglia, Adekunle M Adesina, Irfan Ali, Veronica Kinsler, Lindsay C Burrage, Dana Marafi

Faculty, Staff and Students Publications

OBJECTIVE: To describe the findings of histopathology and genotyping studies in affected brain tissue from an individual with phacomatosis pigmentovascularis (PPV).

METHODS: A retrospective chart review of a 2-year 10-month-old male with a clinical diagnosis of PPV cesiomarmorata (or type V) was performed. Clinical features, brain imaging and histopathology findings, and genotyping studies in his affected brain tissue are summarized.

RESULTS: The proband had a clinically severe neurologic phenotype characterized by global developmental delay, generalized hypotonia, and recurrent episodes of cardiac asystole in the setting of status epilepticus. A somatic pathogenic variant in

CONCLUSIONS: The finding of this variant in …

Modeling Post Stroke Respiratory Dysfunction, Apneas And Cognitive Decline, Anthony Patrizz

Dissertations and Theses (Open Access)

Modeling Post Stroke Respiratory Dysfunction,

Apneas and Cognitive Decline

Anthony Patrizz, B.A.

Advisory Professor: Louise McCullough M.D., Ph.D.

Stroke is a major cause of mortality and the leading cause of long-term disability in the US. More than 60% of individuals suffering a first time stroke develop respiratory dysfunction, prolonging recovery and increasing mortality. Post-stroke cognitive decline is a major contributor to disability and nursing home placement, therefore the cognitive consequences of Stroke Induced Respiratory Dysfunction (SIRD) need to be explored if we hope to enhance functional recovery. The first step towards treatment of the negative consequences of SIRD is the …

Metabolic Profiling Of Prions In The Gastro-Intestinal Tract, Uffaf Khan

Dissertations and Theses (Open Access)

Metabolic profiling of prions in the gastro-intestinal tract

Uffaf Khan, B.S.

Thesis Advisor: Claudio Soto, Ph.D.

Abstract

Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of debilitating neurodegenerative disorders that affect both humans and animals. They can be spread by horizontal transmission as seen in chronic wasting disease in deer and elk population. In addition, transmission to humans has also been documented which includes bovine spongiform encephalopathy in cattle to variant Creutzfeldt-Jakob disease in humans due to consumption of contaminated meat. The most probable natural route of transmission is by oral consumption of infectious material. Even …

Eye-Tracking Measures Of Attentional Bias In Cocaine Dependent Subjects, Nadeeka Dias

Dissertations and Theses (Open Access)

Cocaine-dependent (CD) subjects show evidence of attentional bias toward cocaine-related cues, and this measure of cue-reactivity is predictive of craving and relapse. In previous work, cue-reactivity and attentional bias have been assessed by models that present drug-relevant stimuli (e.g., cocaine-specific Stroop task) and measure physiological and behavioral reactivity (e.g., heart rate, reaction times). Studies have indicated competition between the higher-order cortical processes (frontal eye-fields, DLPFC) in voluntary eye control (i.e., anti-saccades) and more reflexive saccades driven by involuntary midbrain (superior colliculus) perceptual input (i.e., pro-saccades). In addition, neuroimaging studies in patients with cocaine dependence have shown activation in frontal regions …

Network Dynamics Of Visual Naming, Christopher R. Conner

Dissertations and Theses (Open Access)

Recognition and naming of objects and actions are fundamental components of language. They involve several different systems working in coordination to accomplish a complex behavior. During visual naming, sensory and semantic processing are carried out by dedicated cortical substrates in the temporal and occipital lobes, while response selection and articulatory planning are handled by prefrontal cortex. Despite decades of research using lesion analysis, functional MRI and electro-encephalography, the precise dynamics involved remain unknown due to the inadequate spatio-temporal resolution of these methodologies. Of particular interest is the organization of semantic knowledge and the degree of serial and parallel organization of …