Neuroscience and Neurobiology Commons^™

Changes In Postural Sway Behavior Across The Life Span, Maria M B N R Santos

Graduate Student Theses, Dissertations, & Professional Papers

The present study aimed to investigate human balance control by assessing postural sway on three groups representing three stages of life (6-12, 19-40 and 65-74 years old). There were 14 individuals in each group and they were tested during upright bipedal stance with either eyes open or closed. Focus was given to multiple sway indices representing multi-dimensional features of postural sway in quiet stance and included: the center of pressure area, amplitude, root mean square (RMS), velocity, jerkiness, and sample entropy. Results confirmed that children and seniors swayed more (p<.004), faster (p<.001) and their body sway was shakier (p<.001) than young adults. Seniors also presented faster (p<.006) and shakier (p<.001) sway than children and a more unpredictable pattern of body sway in time (p<.002) than children and young adults. In addition, children presented a more random anterior-posterior sway (p<.034) and a more regular medio-lateral sway (p<.043) than young adults, and a higher synchronization between anterior-posterior and medio-lateral body sway (p<.012) than young adults and seniors. We also observed that postural control of children and young adults becomes relatively more challenged in experimental situations when eyes were closed for most postural indices. In conclusion, this study suggests that multi-dimension posturography is sensitive to detect subtle age-related changes in the postural behavior and each stage of life may have their own signature patterns of postural behavior. Therefore, we expect that quantifications of this nature may be used to assess not only postural instability and fall risk but also to aid the testing of the efficacy of balance interventional protocols.

Quantification Of Brain-Region Specific Alterations In Insulin-Like Growth Factor-1 Expression During Developmental Hypothyroidism, Cari Lee Graber-Feesl

All Graduate Theses, Dissertations, and Other Capstone Projects

Insufficient thyroid hormone (TH) during development results in permanent neurological deficits. These deficits are the result of perturbed TH-mediated brain development. Interestingly, insufficient insulin-like growth factor 1 (Igf-1) during development results in neurological deficits that are similar to those reported for developmental hypothyroidism. This observation suggests that deficits associated with low TH during development may be the result of altered Igf-1 expression in the developing brain. To test this, timed-pregnant mice were treated with thyroid gland inhibitors from gestational day 16 (GD16) until postnatal day 21 (P21) to induce a hypothyroid state. A parallel set of untreated timed-pregnant mice were …

The Default Mode Network And Executive Function: Influence Of Age, White Matter Connectivity, And Alzheimer’S Pathology, Christopher A. Brown

Theses and Dissertations--Neuroscience

The default mode network (DMN) consists of a set of interconnected brain regions supporting autobiographical memory, our concept of the self, and the internal monologue. These processes must be maintained at all times and consume the highest amount of the brain’s energy during its baseline state. However, when faced with an active, externally-directed cognitive task, the DMN shows a small, but significant, decrease in activity. The reduction in DMN activity during the performance of an active, externally-directed task compared to a baseline state is termed task-induced deactivation (TID), which is thought to ‘free-up’ resources required to respond to external demands. …

Identification Of Novel Sleep Related Genes From Large Scale Phenotyping Experiments In Mice, Shreyas Joshi

Theses and Dissertations--Biology

Humans spend a third of their lives sleeping but very little is known about the physiological and genetic mechanisms controlling sleep. Increased data from sleep phenotyping studies in mouse and other species, genetic crosses, and gene expression databases can all help improve our understanding of the process. Here, we present analysis of our own sleep data from the large-scale phenotyping program at The Jackson Laboratory (JAX), to identify the best gene candidates and phenotype predictors for influencing sleep traits.

The original knockout mouse project (KOMP) was a worldwide collaborative effort to produce embryonic stem (ES) cell lines with one of …

Neuropathological And Genetic Correlates Of Survival And Dementia Onset In Synucleinopathies: A Retrospective Analysis, David J. Irwin, Murray Grossman, Daniel Weintraub, Howard I. Hurtig, John E. Duda, Sharon X. Xie, Edward B. Lee, Vivianna M. Van Deerlin, Oscar L. Lopez, Julia K. Kofler, Peter T. Nelson, Gregory A. Jicha, Randy Woltjer, Joseph F. Quinn, Jeffery Kaye, James B. Leverenz, Debby Tsuang, Katelan Longfellow, Dora Yearout, Walter Kukull, C. Dirk Keene, Thomas J. Montine, Cyrus P. Zabetian, John Q. Trojanowski

Sanders-Brown Center on Aging Faculty Publications

Background

Great heterogeneity exists in survival and the interval between onset of motor symptoms and dementia symptoms across synucleinopathies. We aimed to identify genetic and pathological markers that have the strongest association with these features of clinical heterogeneity in synucleinopathies.

Methods

In this retrospective study, we examined symptom onset, and genetic and neuropathological data from a cohort of patients with Lewy body disorders with autopsy-confirmed α synucleinopathy (as of Oct 1, 2015) who were previously included in other studies from five academic institutions in five cities in the USA. We used histopathology techniques and markers to assess the burden of …

Immunotherapy Against Drugs Of Abuse, Gianna Raimondi (Class Of 2017)

Writing Across the Curriculum

Current treatments for drug addiction involve classical pharmacological therapy, involving the use of competitive or noncompetitive agonists (full, partial, or inverse) and antagonists. Drugs of abuse enter the brain after crossing the blood-brain barrier rapidly and binding to the proper receptor(s). They are able to do so because they are small and lipid soluble, and produce reinforcing effects by increasing levels of dopamine in brain areas associated with reward. This occurs in specific systems associated with addiction. In the mesolimbic system, neuron cell bodies originate in the ventral tegmental area (VTA) and project to the nucleus accumbens (NAc), amygdala, hippocampus, …

At Risk Of Being Risky: The Relationship Between “Brain Age” Under Emotional States And Risk Preference, Marc D. Rudolph, Oscar Miranda-Domínguez, Alexandra O. Cohen, Kaitlyn Breiner, Laurence Steinberg, Richard J. Bonnie, Elizabeth S. Scott, Jason Chein, Kim Taylor-Thompson, Karla C. Fettich, Jennifer A. Richeson, Danielle V. Dellarco, Adriana Galván, B.J. Casey, Damien A. Fair

Faculty Scholarship

Developmental differences regarding decision making are often reported in the absence of emotional stimuli and without context, failing to explain why some individuals are more likely to have a greater inclination toward risk. The current study (N = 212; 10–25y) examined the influence of emotional context on underlying functional brain connectivity over development and its impact on risk preference. Using functional imaging data in a neutral brain-state we first identify the “brain age” of a given individual then validate it with an independent measure of cortical thickness. We then show, on average, that “brain age” across the group during the …

Mitochondrial Transplantation After Spinal Cord Injury: Effects On Tissue Bioenergetics And Functional Neuroprotection, Jenna L. Gollihue

Theses and Dissertations--Physiology

Contusion spinal cord injury (SCI) results in devastating life-long debilitation in which there are currently no effective treatments. The primary injury site presents a complex environment marked by subsequent secondary pathophysiological cascades involving excessive reactive oxygen and nitrogen species (ROS/RNS) production, glutamate-induced excitotoxicity, calcium dysregulation, and delayed neuronal apoptosis. Many of these cascades involve mitochondrial dysfunction, thus a single mitochondrial-centric therapy that targets a variety of these factors could be far reaching in its potential benefits after SCI. As such, this dissertation examines whether transplantation of exogenous mitochondria after SCI can attenuate secondary injury cascades to decrease the spread and …

Rules And Mechanisms For Efficient Two-Stage Learning In Neural Circuits, Tiberiu Teşileanu, Bence Ölveczky, Vijay Balasubramanian

Publications and Research

Trial-and-error learning requires evaluating variable actions and reinforcing successful variants. In songbirds, vocal exploration is induced by LMAN, the output of a basal ganglia-related circuit that also contributes a corrective bias to the vocal output. This bias is gradually consolidated in RA, a motor cortex analogue downstream of LMAN. We develop a new model of such two-stage learning. Using stochastic gradient descent, we derive how the activity in ‘tutor’ circuits (e.g., LMAN) should match plasticity mechanisms in ‘student’ circuits (e.g., RA) to achieve efficient learning. We further describe a reinforcement learning framework through which the tutor can build its teaching …

Biological Research On Burnout-Depression Overlap: Long-Standing Limitations And On-Going Reflections, Renzo Bianchi, Irvin Sam Schonfeld, Eric Laurent

Publications and Research

In this commentary, we discuss seldom-noticed methodological problems affecting biological research on burnout and depression and make recommendations to overcome the limitations of past studies conducted in this area. First, we suggest that identified subtypes of depression (e.g., depression with melancholic features and depression with atypical features) should be taken into account in future biological research on burnout and depression, given that different subtypes of depression have been associated with distinct autonomic and neuroendocrine profiles. Second, we underline that research on burnout-depression overlap is made difficult by the absence of a consensual conceptualization and operationalization of burnout. In order to …

Variations In Crowding, Saccadic Precision, And Spatial Localization Reveal The Shared Topology Of Spatial Vision, John A. Greenwood, Martin Szinte, Bilge Sayim, Patrick Cavanagh

Dartmouth Scholarship

Visual sensitivity varies across the visual field in several characteristic ways. For example, sensitivity declines sharply in peripheral (vs. foveal) vision and is typically worse in the upper (vs. lower) visual field. These variations can affect processes ranging from acuity and crowding (the deleterious effect of clutter on object recognition) to the precision of saccadic eye movements. Here we examine whether these variations can be attributed to a common source within the visual system. We first compared the size of crowding zones with the precision of saccades using an oriented clock target and two adjacent flanker elements. We report that …

Cx43 Expression Increases In Response To Increased Temperature Incubation In The Developing Chicken Embryonic Brain, Erick A. Barrios

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We used the chicken embryo model to examine whether altered incubation temperature during chicken embryo development would alter the protein expression of heat shock protein 70 (hsp70), hsp90, and connexin 43 (cx43) in the brain. We incubated eggs in either optimal (37.6°C, Con), increased (39.6°C, +2), or decreased (35.6°C, -2) temperature conditions until they reached embryonic day 16 (E16). The -2 condition significantly increased incidence of embryonic mortality. As shown in the literature, the development of the eggs was accelerated or decelerated due to increased or decreased temperature respectively. To control for this, we incubated eggs at optimal temperature (37.6°C) …

Upstream Regulators Of Vrac Activation In Human 1321n1 Astrocytoma Cells, Courtney Elyse Moore

Browse all Theses and Dissertations

Cells rely on a constant volume not only for structural stability but also for normal homeostatic processes to occur. In the brain and CNS, cells can regain their normal volume through a process termed regulatory volume decrease (RVD). A key component of a cells' response to cell swelling is the activation of channel(s) responsible for the efflux of chloride current, ICl,swell. Volume regulated anion channels (VRAC) which mediate ICl,swell have been implicated in controlling cell volume during RVD, but the mechanisms which activate this channel are not completely understood. In this study, I examined the role of G protein-coupled signaling …

Hydrogen Sulfide Regulation Of Kir Channels, Junghoon Ha

Theses and Dissertations

Inwardly rectifying potassium (Kir) channels establish and regulate the resting membrane potential of excitable cells in the heart, brain and other peripheral tissues. Phosphatidylinositol- 4,5-bisphosphate (PIP2) is a key direct activator of ion channels, including Kir channels. Gasotransmitters, such as carbon monoxide (CO), have been reported to regulate the activity of Kir channels by altering channel-PIP2 interactions. We tested, in a model system, the effects and mechanism of action of another important gasotransmitter, hydrogen sulfide (H2S) thought to play a key role in cellular responses under ischemic conditions. Direct administration of sodium hydrogen sulfide (NaHS), as an exogenous H2S source, …

The Hypercapnic Ventilatory Response And Behavior In Ca2+-Activated K+ (Bk) Channel Knock Out Mice And T-Cell Death-Associated Gene 8 (Tdag8) Receptor Knock Out Mice, Christine Annette Ratliff-Rang

Browse all Theses and Dissertations

Some acid sensing areas in the brain control the expression of breathing and anxiety/fear including the locus coeruleus (LC) (Redmond & Huang, 1979) and the nucleus tractus solitarius (NTS). It has been found that knocking out T-cell death-associated gene 8 (TDAG8), a chemosensor, attenuates CO2 induced fear phenotypes in mice. However their hypercapnic ventilatory response (HCVR) has not yet been looked at. Also, BK channels are large-conductance, calcium-activated potassium channels that are activated by increases in concentration of intracellular calcium ions. It has been found that BK KO rats have an increase in their HCVR (Patrone et al., 2014) however …

Is Mitochondrial Development Impaired In Hyperoxic Rats And Does This Underpin The Blunting Of The Acute Hypoxic Ventilatory Response?, Tariq Hasan Fayyad

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Carotid body (CB) responses to hypoxia are low at birth and increase over time to mature responses. Using an in vitro rat CB-carotid sinus nerve (CSN) preparation, Kholwadwala and Donnelly (1992) demonstrated that the CSN activity in response to hypoxia increased from low levels to robust adult responses after two weeks. This time course of maturation was paralleled by an increase in TASK channel sensitivity to hypoxia in the O2-sensing Type I cells (Kim et al, 2011). Previous studies have indicated that a fall in Type I cell mitochondrial volume and an increase in the rate of oxidative phosphorylation may …

Measuring The Effects Of High-Fat Diet On Breathing And Oxygen-Sensitivity Of The Carotid Body Type I Cell, Ryan J. Rakoczy

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The carotid bodies (CB), the primary peripheral chemoreceptors, respond to changes in blood gases with neurotransmitter release, thereby increasing carotid sinus nerve firing frequency and ultimately correcting the pattern of breathing. It has previously been demonstrated that acute application of the adipokine leptin caused perturbations of intracellular calcium and membrane ion movement in isolated CB Type I cells (Pye et al, 2015) and augmented the response of the intact CB to hypoxia (Pye et al, 2016). This study's aim was to examine, in-vivo, if elevated leptin modulated CB function and breathing. Rats were fed high-fat chow or control chow for …

Investigating The Role Of An Sk Channel Activator On Survival And Motor Function In The Sod1-G93a, Als Mouse Model, Matthew Thomas Dancy

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Amyotrophic Lateral Sclerosis (ALS) is a fatal, adult-onset progressive degenerative motor neuron disease that is characterized by muscle atrophy and weakness due to the loss of upper and lower motor neurons. Average survival time for individuals diagnosed with the disease is three to five years; currently there is no cure and only one drug approved by the Food and Administration (FDA). Scientists have proposed various theories in order to solve the mystery which surrounds ALS. One of these theories hypothesizes how hyperexcitability and excitotoxicity leads to the death of motor neurons. In this study, we will address ways of combatting …

The Effect Of Cold On The Physiology Of Drosophila Larva Heart And On Synaptic Transmission At Crayfish Neuromuscular Junctions, Yuechen Zhu

Theses and Dissertations--Biology

Ectothermic animals are susceptible to temperature changes such as cold shock with seasons. To survive through a cold shock, ectotherms have developed unique strategies. My interest is focusing on the physiological function of during cold shock and prolonged cold exposure in the fruit fly (Drosophila melanogaster) and crayfish (Procambarus clarkii). I used Drosophila melanogaster as a model system to investigate cardiac function in response to modulators (serotonin, acetylcholine, octopamine, dopamine and a cocktail of modulators) in acute cold shock and chronic cold shock conditions as possible mechanism to regulate heart rate in the cold. To examine if the dampened heart …

Verbal Behaviors During Employment Interviews Of College Students With And Without Asd, Dennis James Bublitz, Katherine Fitzgerald, Maria Alarcon, Joanne D'Onofrio, Kristen Gillespie-Lynch

Publications and Research

BACKGROUND: Even well-educated people with ASD struggle with obtaining employment, partially due to social difficulties during interviews. Although increasing numbers of individuals with ASD are entering college, little research focuses on this population. Particularly little is known about how to help college students with ASD obtain jobs.

OBJECTIVE: This study attempts to identify challenges with verbal communication during employment interviews that are specific to college students with ASD.

METHODS: We administered mock employment interviews to 16 college students with ASD and 14 college students without disabilities. Responses to interview questions were coded for content and timing.

RESULTS: Students with ASD …