Neuroscience and Neurobiology Commons^™

An Overview Of Dyslexia: Definition, Characteristics, Assessment, Identification, And Intervention, Jane Roitsch, Silvana M. Watson

Communication Disorders & Special Education Faculty Publications

Background: Dyslexia is a developmental brain-based type of learning disability that affects a person's ability to read and spell words. Best estimates place 5 percent to 10 percent of the population with the condition, but the incidence of dyslexia is challenging to pinpoint, as the definition of dyslexia varies throughout research. Objective: The purpose of this article is to provide an overview of dyslexia, its characteristics, assessment and identification, and intervention techniques for the condition. Results: Although the disorder varies from person to person, common characteristics among people with dyslexia include difficulty with phonological skills, low accuracy and fluency of …

Mechanoreceptor Activation In The Treatment Of Drug-Use Disorders: Mechanism And Outcome, Kyle Bills

Theses and Dissertations

The therapeutic benefits attributed to activation of peripheral mechanoreceptors are poorly understood. There is growing evidence that mechanical stimulation modulates substrates in the supraspinal central nervous system (CNS) that are outside the canonical somatosensory circuits. This work demonstrates that activation of peripheral mechnoreceptors via mechanical stimulation (MStim) is sufficient to increase dopamine release in the nucleus accumbens (NAc), alter neuron firing rate in the ventral tegmental area (VTA) and increase membrane translocation of delta opioid receptors (DORs) in the NAc. Further, we demonstrate that these effects are dependent on DORs and acetylcholine receptors. Additionally, MStim can block neuronal markers of …

Missing Female Patients: An Observational Analysis Of Sex Ratio Among Outpatients In A Referral Tertiary Care Public Hospital In India, Mudit Kapoor, Deepak Agrawal, Shamika Ravi, Ambuj Roy, S. V. Subramanian, Randeep Guleria

Journal Articles

Objective: To investigate gender discrimination in access to healthcare and its relationship with the patient's age and distance from the healthcare facility. Design and setting: An observational study based on outpatient data from a large referral public hospital in Delhi, India. Participants: Confirmed clinical appointments. Primary and secondary outcome measures: Estimates from the logistic regression are used to compute sex ratios (male/female) of patient visits with respect to distance from the hospital and age. Missing female patients for each state - a measure of the extent of gender discrimination - is computed as the difference in the actual number of …

The Functional Conservation Of Frazzled In Insects, Benjamin Wadsworth

Graduate Theses and Dissertations

Axons in the developing embryo receive and react to signals that direct their growth to reach target tissues at specified locations. The signal pathways that direct midline crossing of axons during embryonic development have been comprehensively examined in the past years using the Drosophila ventral nerve cord or the spinal cord as a model system. A number of these signaling mechanisms are conserved, however disparities have been found between species in general strategy or the molecular signals controlling the response of axons to guidance cues.

The Netrin-Frazzled pathway has been shown to aid in midline crossing of axons in the …

Reduced Gabaergic Signaling At The Axon Initial Segment Decreases Vigilance State Transitioning, Austin John Boren

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sleep is a highly regulated homeostatic process that is disrupted in an estimated 50-70 million Americans. Regulation of sleep depends upon coordinated signaling of multiple neurotransmitter systems. In particular, inhibitory gamma-aminobutyric acid (GABA) signaling is required to suppress wake-active brain regions in order to initiate and maintain sleep states. GABA type A receptors (GABAARs) are ionotropic receptors with subunit compositions uniquely enriched on subcellular domains of target cells. α2 subunit-containing GABAARs are the primary target of GABA released onto the axon initial segment (AIS), a site critical for phasing the oscillatory activity of cortical cells. α2-containing GABAARs have previously been …

Impact Of Excitation-Inhibition Balance/Imbalance On Dynamics Of Cortical Neural Networks, Vidit Agrawal

Graduate Theses and Dissertations

The purpose of this research is to study the implications of Excitation/Inhibition balance and imbalance on the dynamics of ongoing (spontaneous) neural activity in the cerebral cortex region of the brain.

The first research work addresses the question that why among the continuum of Excitation-Inhibition balance configurations, particular configuration should be favored? We calculate the entropy of neural network dynamics by studying an analytically tractable network of binary neurons. Our main result from this work is that the entropy maximizes at regime which is neither excitation-dominant nor inhibition-dominant but at the boundary of both. Along this boundary we see there …

Sex Differences In Circadian Rhythmicity Arise Outside The Hypothalamus, Sneha M. Chaturvedi

Senior Honors Papers / Undergraduate Theses

Most biological processes are regulated by an internal circadian rhythm. This body clock synchronizes daily rhythms in physiology with the environment. Circadian outputs can differ between females and males, but the underlying mechanisms for these differences are unknown. Glucocorticoids, a class of circadian stress hormones in vertebrates, provide a model for studying sexual dimorphisms in circadian timing. Female rodents show a higher mean and peak-to-trough amplitude of corticosterone than males. This is most prevalent during proestrus when estrogen levels are high. To test the hypothesis that male-female differences in daily corticosterone secretion arise within circadian cells in the brain, we …

Melanopsin-Containing Iprgcs Are Resistant To Excitotoxic Injury And Maintain Functional Non-Image Forming Behaviors After Insult In A Diurnal Rodent Model, Garrett M. Fogo, Dorela D. Shuboni-Mulligan, Andrew J. Gall

Faculty Publications

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are critical for the light signaling properties of non-image forming vision. Melanopsin-expressing ipRGCs project to retinorecipient brain regions involved in modulating circadian rhythms. Melanopsin has been shown to play an important role in how animals respond to light, including photoentrainment, masking (i.e., acute behavioral responses to light), and the pupillary light reflex (PLR). Importantly, ipRGCs are resistant to various forms of damage, including ocular hypertension, optic nerve crush, and excitotoxicity via N-methyl-D-aspartic acid (NMDA) administration. Although these cells are resistant to various forms of injury, the question still remains whether or …

Let It Rest: Sleep And Health As Positive Correlates Of Forgiveness Of Others And Self-Forgiveness, Loren Toussaint, Andrew J. Gall, Alyssa Cheadle, David R. Williams

Faculty Publications

Objective: The present study examined forgiveness of others, self-forgiveness, sleep, and health in a nationally representative sample of United States adults. It was hypothesised that sleep would mediate the associations of forgiveness of others and self-forgiveness with health.

Design: A nationally representative survey of 1,423 United States adults.

Main Outcome Measures: Measures included forgiveness of others, self-forgiveness, sleep quantity, sleep quality, psychological distress, life satisfaction, and self-rated physical health.

Results: Forgiveness of others (β = .20, p < .001) and self-forgiveness (β = .11, p < .01) were associated with sleep and forgiveness of others (β = .24, p < .001) and self-forgiveness (β = .27, p < .001) were associated with health. Sleep was associated with health (β = .45, p < .001) and also acted as a mediator of the associations of forgiveness of others (β = .09, p < .01) and self-forgiveness (β = .05, p < .01) with health.

Conclusions: Forgiveness of others and self-forgiveness may attenuate emotions such as anger, regret, and rumination and provide …

Identification Of A Core Amino Acid Motif Within The Α Subunit Of Gabaars That Promotes Inhibitory Synaptogenesis And Resilience To Seizures, Anna J. Nathanson, Yihui Zhang, Joshua L. Smalley, Thomas A. Ollerhead, Miguel A. Rodriguez Santos, Peter M. Andrews, Heike J. Wobst, Yvonne E. Moore, Nicholas J. Brandon, Rochelle M. Hines, Paul A. Davies, Stephen J. Moss

Psychology Faculty Research

The fidelity of inhibitory neurotransmission is dependent on the accumulation of γ-aminobutyric acid type A receptors (GABAARs) at the appropriate synaptic sites. Synaptic GABAARs are constructed from α(1-3), β(1-3), and γ2 subunits, and neurons can target these subtypes to specific synapses. Here, we identify a 15-amino acid inhibitory synapse targeting motif (ISTM) within the α2 subunit that promotes the association between GABAARs and the inhibitory scaffold proteins collybistin and gephyrin. Using mice in which the ISTM has been introduced into the α1 subunit (Gabra1-2 mice), we show that the ISTM is critical for axo-axonic synapse formation, the efficacy of GABAergic …

Distinct Patterns Of Default Mode And Executive Control Network Circuitry Contribute To Present And Future Executive Function In Older Adults, Christopher A. Brown, Frederick A. Schmitt, Charles D. Smith, Brian T. Gold

Neuroscience Faculty Publications

Executive function (EF) performance in older adults has been linked with functional and structural profiles within the executive control network (ECN) and default mode network (DMN), white matter hyperintensities (WMH) burden and levels of Alzheimer's disease (AD) pathology. Here, we simultaneously explored the unique contributions of these factors to baseline and longitudinal EF performance in older adults. Thirty-two cognitively normal (CN) older adults underwent neuropsychological testing at baseline and annually for three years. Neuroimaging and AD pathology measures were collected at baseline. Separate linear regression models were used to determine which of these variables predicted composite EF scores at baseline …

The Relationship Between Socioeconomic Status And White Matter Microstructure In Pre-Reading Children: A Longitudinal Investigation, Ola Ozernov-Palchik, Elizabeth S. Norton, Yingying Wang, Sara D. Beach, Jennifer Zuk, Maryanne Wolf, John D.E. Gabrieli, Nadine Gaab

Center for Brain, Biology, and Behavior: Faculty Publications

Reading is a learned skill crucial for educational attainment. Children from families of lower socioeconomic status (SES) tend to have poorer reading performance and this gap widens across years of schooling. Reading relies on the orchestration of multiple neural systems integrated via specific white-matter pathways, but there is limited understanding about whether these pathways relate differentially to reading performance depending on SES background. Kindergarten white-matter FA and second-grade reading outcomes were investigated in an SES-diverse sample of 125 children. The three left-hemisphere white-matter tracts most associated with reading, and their right-hemisphere homologs, were examined: arcuate fasciculus (AF), superior longitudinal fasciculus …

Resolving Intravoxel White Matter Structures In The Human Brain Using Regularized Regression And Clustering, Andrea Hart, Brianna Smith, Sean Smith, Elijah Sales, Jacqueline Hernandez-Camargo, Yarlin Mayor Garcia, Felix Zhan, Lori Griswold, Brian Dunkelberger, Michael R. Schwob, Sharang Chaudhry, Justin Zhan, Laxmi Gewali, Paul Oh

Computer Science Faculty Research

The human brain is a complex system of neural tissue that varies significantly between individuals. Although the technology that delineates these neural pathways does not currently exist, medical imaging modalities, such as diffusion magnetic resonance imaging (dMRI), can be leveraged for mathematical identification. The purpose of this work is to develop a novel method employing machine learning techniques to determine intravoxel nerve number and direction from dMRI data. The method was tested on multiple synthetic datasets and showed promising estimation accuracy and robustness for multi-nerve systems under a variety of conditions, including highly noisy data and imprecision in parameter assumptions.

Gene Co-Expression Analysis Of The Human Substantia Nigra Identifies Bmp2 As A Neurotrophic Factor That Can Promote Neurite Growth In Cells Overexpressing Wild-Type Or A53t Α-Synuclein, Susan R. Goulding, Aideen M. Sullivan, Gerard W. O'Keeffe, Louise M. Collins

Department of Biological Sciences Publications

Introduction: α-synuclein-induced degeneration of dopaminergic neurons has been proposed to be central to the early progression of Parkinson's disease. This highlights the need to identify factors that are neuroprotective or neuroregenerative against α-synuclein-induced degeneration. Due to their potent neurotrophic effects on nigrostriatal dopaminergic neurons, we hypothesized that members of the bone morphogenetic protein (BMP) family have potential to protect these cells against α-synuclein. Methods: To identify the most relevant BMP ligands, we used unbiased gene co-expression analysis to identify all BMP family members having a significant positive correlation with five markers of dopaminergic neurons in the human substantia nigra (SN). …

A Quantitative Motor Assessment Linked To Underlying Damage In Traumatic Brain Injury, Paula K. Johnson

Theses and Dissertations

Traumatic brain injury (TBI) is a leading cause of disability in the United States (Coronado et al., 2011). There is a recognized need for better motor assessments to help mitigate these disabilities. Advances in markerless motion capture and in magnetic resonance imaging (MRI) provide an opportunity to improve clinical assessments, and link them to damage measured in MRI scans. The primary aims of this research were to 1) develop a quantitative motor assessment (QMA), and seed a normative database to enable comparison of impaired behavior to unimpaired, 2) test the sensitivity of the QMA, and 3) link QMA results to …

Alpha Oscillations And Feedback Processing In Visual Cortex For Conscious Perception, Tony Ro

Publications and Research

Variability in perception between individuals may be a consequence of different inherent neural processing speeds. To assess whether alpha oscillations systematically reflect a feedback pacing mechanism for cortical processing during visual perception, comparisons were made between alpha oscillations, visual suppression from TMS, visual evoked responses, and metacontrast masking. Peak alpha oscillation frequencies, measured through scalp EEG recordings, significantly correlated with the optimum latencies for visual suppression from TMS of early visual cortex. Individuals with shorter alpha periods (i.e., higher peak alpha frequencies) processed visual information faster than those with longer alpha periods (i.e., lower peak alpha frequencies). Moreover, peak alpha …

Comparison Of Nickel And Cobalt Induced Hypoxic Cell Models Using Cell Proliferation Assay, Melissa Delcasale

Seton Hall University Dissertations and Theses (ETDs)

Hypoxia is an imbalance in oxygen delivery and oxygen consumption, ultimately affecting cell survival. Low levels of oxygen diminish adenosine triphosphate synthesis resulting from a decline in oxidative phosphorylation in the mitochondria, therefore inducing apoptosis and cell death. To create a hypoxia mimicked environment, we used hypoxia mimetic compounds cobalt and nickel to treat human neuroblastoma (NMB) cells. Using hypoxic mimic human neuronal cell models, we examined and compared the effects of compound-induced hypoxia on NMB cell proliferation. The cells were treated with 100mM and 300mM concentrations of each compound at 24- and 48-hour intervals. To investigate cell proliferation, the …

Wrap-Around Services To Older Adults With Dementia: Collaboration, Education, And Prevention As A Model For Integration Of Primary Care And Neurobehavioral Health, Gladys E. Maestre, Francisco Fernandez

School of Medicine Publications

Background: Medical care in the Rio Grande Valley (RGV) is fragmented and difficult to navigate, especially for older adults with cognitive decline and dementia. The communities are eager to have a new healthcare delivery system that integrate community-based aging services to provide integrated, team collaborative better health care in our communities. The University of Texas RGV School of Medicine, in collaboration with its affiliates in the regional healthcare systems, is a partner providing comprehensive care across the life-cycle bridging science, social services and patient care. Our interprofessional team collaborative emphasizes safe, appropriate, and effective neurobehavioral care, employing evidence-based medicine in …

The Dissociable Impact Of Auditory Vs. Visual Emotional Cues On Visual Processing, Emma K. Stewart Bsc, Derek Gv Mitchell Phd

Western Research Forum

Background: Emotional information has privileged access to processing resources, which can cause it to have a distracting or facilitating effect on task performance for reasons that are poorly understood. The sensory modality through which it is presented may be one determining factor. Some findings suggest that auditory stimuli facilitate visual task performance while visual stimuli interfere with it, but there are conflicting findings.

Hypothesis: We hypothesize that emotional content of a different sensory modality from the task improves task-related performance via a general alerting and arousing effect for all stimuli, while emotional content of the same modality disrupts performance when …

Neural Development To Neurodegeneration Through The Mind Of A Worm, Miranda Arnold

Master of Science in Integrative Biology Theses

Defects in the nervous system can impact the normal function of an organism. By examining mutations during neuronal development, we can better understand the significance of specific pathways. The EphR/ephrin pathway is crucial for axonal guidance during development. The simple organism, C. elegans, allow us to study the impact of EphR/ephrin genes on neuronal morphology, synapse connections, and basic behavior. In specific EphR/ephrin mutants, we see change in morphology and loss of synapses in a thermosensory and also a chemosensory circuit. These mutations can also lead to defects in food searching behaviors. These observations lead us to conclude that …