Neurosciences Commons^™

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

University of 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 …

Validation Of Minimally-Invasive Sample Collection Methods For Measurement Of Telomere Length, Stephanie A. Stout, Jue Lin, Natalie Hernandez, Elysia Poggi Davis, Elizabeth Blackburn, Judith E. Carroll, Laura M. Glynn

Psychology: Faculty Scholarship

Objective: The discovery of telomere length (TL) as a biomarker of cellular aging and correlate of age-related disease has generated a new field of research in the biology of healthy aging. Although the most common method of sample collection for TL is venous blood draw, less-invasive DNA collection methods are becoming more widely used. However, how TL relates across tissues derived from these sample collection methods is poorly understood. The current study is the first to characterize the associations in TL across three sample collection methods: venous whole blood, finger prick dried blood spot and saliva.

Methods: TL …

Higher And Lower Order Factor Analyses Of The Temperament In Middle Childhood Questionnaire., Yuliya Kotelnikova, Thomas M Olino, Daniel N Klein, Sarah V M Mackrell, Elizabeth P Hayden

Brain and Mind Institute Researchers' Publications

The Temperament in Middle Childhood Questionnaire (TMCQ) is a widely used parent-report measure of temperament. However, neither its lower nor higher order structures has been tested via a bottom-up, empirically based approach. We conducted higher and lower order exploratory factor analyses (EFAs) of the TMCQ in a large ( N = 654) sample of 9-year-olds. Item-level EFAs identified 92 items as suitable (i.e., with loadings ≥.40) for constructing lower order factors, only half of which resembled a TMCQ scale posited by the measure's authors. Higher order EFAs of the lower order factors showed that a three-factor structure (Impulsivity/Negative Affectivity, Negative …

Hippocampal Gaba Enables Inhibitory Control Over Unwanted Thoughts, Taylor W. Schmitz, Marta M. Correia, Catarina S. Ferreira, Andrew P. Prescot, Michael C. Anderson

Brain and Mind Institute Researchers' Publications

© 2017 The Author(s). Intrusive memories, images, and hallucinations are hallmark symptoms of psychiatric disorders. Although often attributed to deficient inhibitory control by the prefrontal cortex, difficulty in controlling intrusive thoughts is also associated with hippocampal hyperactivity, arising from dysfunctional GABAergic interneurons. How hippocampal GABA contributes to stopping unwanted thoughts is unknown. Here we show that GABAergic inhibition of hippocampal retrieval activity forms a key link in a fronto-hippocampal inhibitory control pathway underlying thought suppression. Subjects viewed reminders of unwanted thoughts and tried to suppress retrieval while being scanned with functional magnetic resonance imaging. Suppression reduced hippocampal activity and memory …

Contributions Of Appetitive And Aversive Motivational Systems To Decision-Making, Heather E. Soder

USF Tampa Graduate Theses and Dissertations

Optimal decision-making entails outcome evaluation, comparing received costs and benefits with predicted costs and benefits. The anterior cingulate cortex (ACC), a brain area with major connections to the appetitive and aversive motivation systems, may provide the neural substrate of this evaluation process. One way to measure the relative contribution of these systems on decision-making is to measure individual differences in risk-taking behaviors. For individuals who make risky choices, this evaluation step may be biased: some show a preference for immediate, short-term rewards (increased appetitive system), while devaluing the long-term consequences of their choices (decreased aversive system). However, most studies supporting …

Family Income, Cumulative Risk Exposure, And White Matter Structure In Middle Childhood, Alexander J. Dufford, Pilyoung Kim

Psychology: Faculty Scholarship

Family income is associated with gray matter morphometry in children, but little is known about the relationship between family income and white matter structure. In this paper, using Tract-Based Spatial Statistics, a whole brain, voxel-wise approach, we examined the relationship between family income (assessed by income-to-needs ratio) and white matter organization in middle childhood (N = 27, M = 8.66 years). Results from a non-parametric, voxel-wise, multiple regression (threshold-free cluster enhancement, p < 0.05 FWE corrected) indicated that lower family income was associated with lower white matter organization [assessed by fractional anisotropy (FA)] for several clusters in white matter tracts involved in cognitive and emotional functions including fronto-limbic circuitry (uncinate fasciculus and cingulum bundle), association fibers (inferior longitudinal fasciculus, superior longitudinal fasciculus), and corticospinal tracts. Further, we examined the possibility that cumulative risk (CR) exposure might function as one of the potential pathways by which family income influences neural outcomes. Using multiple regressions, we found lower FA in portions of these tracts, including those found in the left cingulum bundle and left superior longitudinal fasciculus, was significantly related to greater exposure to CR (β = -0.47, p < 0.05 and β = -0.45, p < 0.05).

Volition And Action In The Human Brain: Processes, Pathologies, And Reasons, Itzhak Fried, Patrick Haggard, Biyu J. He, Aaron Schurger

Psychology Faculty Articles and Research

Humans seem to decide for themselves what to do, and when to do it. This distinctive capacity may emerge from an ability, shared with other animals, to make decisions for action that are related to future goals, or at least free from the constraints of immediate environmental inputs. Studying such volitional acts proves a major challenge for neuroscience. This review highlights key mechanisms in the generation of voluntary, as opposed to stimulus-driven actions, and highlights three issues. The first part focuses on the apparent spontaneity of voluntary action. The second part focuses on one of the most distinctive, but elusive, …

Distinct Patterns Of Reduced Prefrontal And Limbic Gray Matter Volume In Childhood General And Internalizing Psychopathology, Hannah R. Snyder, Benjamin L. Hankin, Curt A. Sandman, Kevin Head, Elysia Poggi Davis

Psychology: Faculty Scholarship

Reduced gray matter volume (GMV) is widely implicated in psychopathology, but scholars have found mostly overlapping areas of GMV reduction across disorders rather than unique neural signatures, potentially due to pervasive comorbidity. GMV reductions may be associated with broader psychopathology dimensions rather than specific disorders. We used an empirically supported bifactor model consisting of common psychopathology and internalizing- and externalizing-specific factors to evaluate whether latent psychopathology dimensions yield a clearer, more parsimonious pattern of GMV reduction in prefrontal and limbic/paralimbic areas implicated in individual disorders. A community sample of children (N = 254, ages 6–10) was used to evaluate …

The Large-Scale Organization Of Shape Processing In The Ventral And Dorsal Pathways, Erez Freud, Jody C. Culham, David C. Plaut, Marlene Behrmann

Brain and Mind Institute Researchers' Publications

Although shape perception is considered a function of the ventral visual pathway, evidence suggests that the dorsal pathway also derives shape-based representations. In two psychophysics and neuroimaging experiments, we characterized the response properties, topographical organization and perceptual relevance of these representations. In both pathways, shape sensitivity increased from early visual cortex to extrastriate cortex but then decreased in anterior regions. Moreover, the lateral aspect of the ventral pathway and posterior regions of the dorsal pathway were sensitive to the availability of fundamental shape properties, even for unrecognizable images. This apparent representational similarity between the posterior-dorsal and lateral-ventral regions was corroborated …

Vocabulary Learning Benefits From Rem After Slow-Wave Sleep., Laura J Batterink, Carmen E Westerberg, Ken A Paller

Brain and Mind Institute Researchers' Publications

Memory reactivation during slow-wave sleep (SWS) influences the consolidation of recently acquired knowledge. This reactivation occurs spontaneously during sleep but can also be triggered by presenting learning-related cues, a technique known as targeted memory reactivation (TMR). Here we examined whether TMR can improve vocabulary learning. Participants learned the meanings of 60 novel words. Auditory cues for half the words were subsequently presented during SWS in an afternoon nap. Memory performance for cued versus uncued words did not differ at the group level but was systematically influenced by REM sleep duration. Participants who obtained relatively greater amounts of REM showed a …

Accumulation Of Non-Numerical Evidence During Nonsymbolic Number Processing In The Brain: An Fmri Study, Tali Leibovich, Daniel Ansari

Brain and Mind Institute Researchers' Publications

Behavioral evidence has shown that when performing a nonsymbolic number comparison task (e.g., deciding which of two dot arrays contains more dots), participants' responses are sensitive to affected by both numerical (e.g., number of items) and non-numerical magnitudes (i.e., area, density, etc.). Thus far it is unclear what brain circuits support this process of accumulating non-numerical variables during nonsymbolic number processing. To investigate this, 21 adult participants were asked to engage in a dot comparison task. To measure the neural correlates of accumulating numerical and non-numerical variables, we manipulated the number of the non-numerical magnitudes that were congruent (correlated with …

Cooperation Not Competition: Bihemispheric Tdcs And Fmri Show Role For Ipsilateral Hemisphere In Motor Learning, Sheena Waters, Tobias Wiestler, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

What is the role of ipsilateral motor and premotor areas in motor learning? One view is that ipsilateral activity suppresses contralateral motor cortex and, accordingly, that inhibiting ipsilateral regions can improve motor learning. Alternatively, the ipsilateral motor cortex may play an active role in the control and/or learning of unilateral hand movements. We approached this question by applying double-blind bihemispheric transcranial direct current stimulation (tDCS) over both contralateral and ipsilateral motor cortex in a between-group design during 4 d of unimanual explicit sequence training in human participants. Independently of whether the anode was placed over contralateral or ipsilateral motor cortex, …

General And Emotion-Specific Alterations To Cognitive Control In Women With A History Of Childhood Abuse, Kristen L. Mackiewicz Seghete, Roselinde H. Kaiser, Anne P. Deprince, Marie T. Banich

Psychology: Faculty Scholarship

Background

Although limited, the literature suggests alterations in activation of cognitive control regions in adults and adolescents with a history of childhood abuse. The current study examined whether such alterations are increased in the face of emotionally-distracting as compared to emotionally neutral information, and whether such alterations occur in brain regions that exert cognitive control in a more top-down sustained manner or a more bottom-up transient manner.

Methods

Participants were young adult women (ages 23–30): one group with a history of childhood physical or sexual abuse (N = 15) and one with no trauma exposure (N = 17), as assessed …

Rapid Statistical Learning Supporting Word Extraction From Continuous Speech., Laura J Batterink

Brain and Mind Institute Researchers' Publications

The identification of words in continuous speech, known as speech segmentation, is a critical early step in language acquisition. This process is partially supported by statistical learning, the ability to extract patterns from the environment. Given that speech segmentation represents a potential bottleneck for language acquisition, patterns in speech may be extracted very rapidly, without extensive exposure. This hypothesis was examined by exposing participants to continuous speech streams composed of novel repeating nonsense words. Learning was measured on-line using a reaction time task. After merely one exposure to an embedded novel word, learners demonstrated significant learning effects, as revealed by …

Aging, Executive Function, Fronto-Parietal Network Cortical Thickness: Insights From Cognitive Reserve, Katherine Reiter

Dissertations (1934 -)

Cognitive reserve (CR) indexes the nonlinear relationship between neurological insult and behavioral change. CR is manifested in both static factors (e.g., childhood environment, education) and modifiable lifestyle factors, (e.g., leisure activities). Detailed investigation of the influence of CR on cortical thickness, which indexes neuropathology, and cognitive functioning could be particularly important in understanding the heterogeneity of Alzheimer’s disease (AD). While memory decline is the hallmark of AD, executive functioning (EF) decline often predates memory changes, making EF an important target for investigating CR influences. The current study examines the relationship of CR and genetic risk for AD (ε4) on EF …

Abnormal Dendritic Maturation Of Developing Cortical Neurons Exposed To Corticotropin Releasing Hormone (Crh): Insights Into Effects Of Prenatal Adversity?, Megan M. Curran, Curt A. Sandman, Elysia Poggi Davis, Laura M. Glynn, Tallie Z. Baram

Psychology: Faculty Scholarship

Corticotropin releasing hormone (CRH) produced by the hypothalamus initiates the hypothalamic-pituitary-adrenal (HPA) axis, which regulates the body’s stress response. CRH levels typically are undetectable in human plasma, but during pregnancy the primate placenta synthesizes and releases large amounts of CRH into both maternal and fetal circulations. Notably, placental CRH synthesis increases in response to maternal stress signals. There is evidence that human fetal exposure to high concentrations of placental CRH is associated with behavioral consequences during infancy and into childhood, however the direct effects on of the peptide on the human brain are unknown. In this study, we used a …

Representation Of Multiple Body Parts In The Missing-Hand Territory Of Congenital One-Handers., Avital Hahamy, Scott N Macdonald, Fiona Van Den Heiligenberg, Paullina Kieliba, Uzay Emir, Rafael Malach, Heidi Johansen-Berg, Peter Brugger, Jody C Culham, Tamar R Makin

Brain and Mind Institute Researchers' Publications

Individuals born without one hand (congenital one-handers) provide a unique model for understanding the relationship between focal reorganization in the sensorimotor cortex and everyday behavior. We previously reported that the missing hand's territory of one-handers becomes utilized by its cortical neighbor (residual arm representation), depending on residual arm usage in daily life to substitute for the missing hand's function [1, 2]. However, the repertoire of compensatory behaviors may involve utilization of other body parts that do not cortically neighbor the hand territory. Accordingly, the pattern of brain reorganization may be more extensive [3]. Here we studied unconstrained compensatory strategies under …

Coordinated Pluralism As A Means To Facilitate Integrative Taxonomies Of Cognition, Jacqueline Anne Sullivan

Brain and Mind Institute Researchers' Publications

© 2017 Informa UK Limited, trading as Taylor & Francis Group. The past decade has witnessed a growing awareness of conceptual and methodological hurdles within psychology and neuroscience that must be addressed for taxonomic and explanatory progress in understanding psychological functions to be possible. In this paper, I evaluate several recent knowledge-building initiatives aimed at overcoming these obstacles. I argue that while each initiative offers important insights about how to facilitate taxonomic and explanatory progress in psychology and neuroscience, only a “coordinated pluralism” that incorporates positive aspects of each initiative will have the potential for success.

Sensory Processing In Autism Spectrum Disorders And Fragile X Syndrome-From The Clinic To Animal Models., D Sinclair, B Oranje, K A Razak, S J Siegel, S Schmid

Brain and Mind Institute Researchers' Publications

Brains are constantly flooded with sensory information that needs to be filtered at the pre-attentional level and integrated into endogenous activity in order to allow for detection of salient information and an appropriate behavioral response. People with Autism Spectrum Disorder (ASD) or Fragile X Syndrome (FXS) are often over- or under-reactive to stimulation, leading to a wide range of behavioral symptoms. This altered sensitivity may be caused by disrupted sensory processing, signal integration and/or gating, and is often being neglected. Here, we review translational experimental approaches that are used to investigate sensory processing in humans with ASD and FXS, and …

Online Neural Monitoring Of Statistical Learning., Laura J Batterink, Ken A Paller

Brain and Mind Institute Researchers' Publications

The extraction of patterns in the environment plays a critical role in many types of human learning, from motor skills to language acquisition. This process is known as statistical learning. Here we propose that statistical learning has two dissociable components: (1) perceptual binding of individual stimulus units into integrated composites and (2) storing those integrated representations for later use. Statistical learning is typically assessed using post-learning tasks, such that the two components are conflated. Our goal was to characterize the online perceptual component of statistical learning. Participants were exposed to a structured stream of repeating trisyllabic nonsense words and a …

The Psychophysiological Correlates Of Personality, Trauma, Posttraumatic Stress Disorder And Social Support, Meghan E. Pierce

UNLV Theses, Dissertations, Professional Papers, and Capstones

Theories considering the etiology of psychopathy suggest that trauma exposure, specifically childhood maltreatment and sexual abuse, is related to the development of callous-unemotional traits in children and adolescents, which are precursors to psychopathic traits in adulthood. Furthermore, posttraumatic stress disorder has an opposite relationship with many of the emotional and behavioral components of the two-factor model of psychopathy. Specifically, PTSD is positively associated to IA and traits associated with it and negatively associated with FD. Thus, this study sought to expand upon the current theories of a trauma-based etiology of psychopathy by investigating the relationship between trauma, PTSD, and psychopathic …

Neural Processes Underlying Auditory Context Effects, Breanne Yerkes

UNLV Theses, Dissertations, Professional Papers, and Capstones

Auditory information within our natural environments is disorganized and often ambiguous, leaving our auditory systems with a complex task: organizing sound into coherent objects. The auditory system uses both current and prior information to assist in completing this task. The influences of previous context on current perception have been referred to as context effects. A contrastive context effect results in a current perception that is opposite of what is expected based on the physical stimulus properties presented during an immediate context. A facilitative context effect results in a current perception that is the same as the perception during the immediate …

Bk Channels Mediate Synaptic Plasticity Underlying Habituation In Rats., Tariq Zaman, Cleusa De Oliveira, Mahabba Smoka, Chakravarthi Narla, Michael O Poulter, Susanne Schmid

Brain and Mind Institute Researchers' Publications

Habituation is a basic form of implicit learning and represents a sensory filter that is disrupted in autism, schizophrenia, and several other mental disorders. Despite extensive research in the past decades on habituation of startle and other escape responses, the underlying neural mechanisms are still not fully understood. There is evidence from previous studies indicating that BK channels might play a critical role in habituation. We here used a wide array of approaches to test this hypothesis. We show that BK channel activation and subsequent phosphorylation of these channels are essential for synaptic depression presumably underlying startle habituation in rats, …

Sleep-Based Memory Processing Facilitates Grammatical Generalization: Evidence From Targeted Memory Reactivation., Laura J Batterink, Ken A Paller

Brain and Mind Institute Researchers' Publications

Generalization-the ability to abstract regularities from specific examples and apply them to novel instances-is an essential component of language acquisition. Generalization not only depends on exposure to input during wake, but may also improve offline during sleep. Here we examined whether targeted memory reactivation during sleep can influence grammatical generalization. Participants gradually acquired the grammatical rules of an artificial language through an interactive learning procedure. Then, phrases from the language (experimental group) or stimuli from an unrelated task (control group) were covertly presented during an afternoon nap. Compared to control participants, participants re-exposed to the language during sleep showed larger …

Whose Expertise Is It? Evidence For Autistic Adults As Critical Autism Experts, Kristen Gillespie-Lynch, Steven K. Kapp, Patricia J. Brooks, Jonathan Pickens, Ben Schwartzman

Publications and Research

Autistic and non-autistic adults’ agreement with scientific knowledge about autism, how they define autism, and their endorsement of stigmatizing conceptions of autism has not previously been examined. Using an online survey, we assessed autism knowledge and stigma among 636 adults with varied relationships to autism, including autistic people and nuclear family members. Autistic participants exhibited more scientifically based knowledge than others. They were more likely to describe autism experientially or as a neutral difference, and more often opposed the medical model. Autistic participants and family members reported lower stigma. Greater endorsement of the importance of normalizing autistic people was associated …

Reduction Of Cocaine-Induced Locomotor Effects By Enriched Environment Is Associated With Cell-Specific Accumulation Of Δfosb In Striatal And Cortical Subregions, Audrey Lafragette, Michael T. Bardo, Virginie Lardeux, Marcello Solinas, Nathalie Thiriet

Psychology Faculty Publications

Background: Early exposure to enriched environments has been shown to decrease the locomotor effects induced by repeated injections of cocaine and modify basal and cocaine-induced total protein levels of the transcription factor ΔFosB in the whole striatum of mice. In this study, we aimed at characterizing whether the profile of ΔFosB accumulation induced by enriched environments and cocaine would be similar or different in terms of brain areas and cell type.

Methods: We used mice expressing the eGFP protein in D1 receptor positive (D1R(+)) neurons to determine whether ΔFosB induced by enriched environment or cocaine injections (5×15 mg/kg) would occur …

Adaptable Categorization Of Hands And Tools In Prosthesis Users., Fiona M Z Van Den Heiligenberg, Nick Yeung, Peter Brugger, Jody C Culham, Tamar R Makin

Brain and Mind Institute Researchers' Publications

No abstract provided.

Corrigendum To "Overlapping And Distinct Brain Regions Involved In Estimating The Spatial Position Of Numerical And Non-Numerical Magnitudes: An Fmri Study" [Neuropsychologia 51(5) (2013) 979-989], Stephan E. Vogel, Roland H. Grabner, Michael Schneider, Robert S. Siegler, Daniel Ansari

Brain and Mind Institute Researchers' Publications

No abstract provided.

Quantitative Assessment Of White Matter Injury In Preterm Neonates: Association With Outcomes., Ting Guo, Emma G Duerden, Elysia Adams, Vann Chau, Helen M Branson, M Mallar Chakravarty, Kenneth J Poskitt, Anne Synnes, Ruth E Grunau, Steven P Miller

Brain and Mind Institute Researchers' Publications

OBJECTIVE: To quantitatively assess white matter injury (WMI) volume and location in very preterm neonates, and to examine the association of lesion volume and location with 18-month neurodevelopmental outcomes.

METHODS: Volume and location of WMI was quantified on MRI in 216 neonates (median gestational age 27.9 weeks) who had motor, cognitive, and language assessments at 18 months corrected age (CA). Neonates were scanned at 32.1 postmenstrual weeks (median) and 68 (31.5%) had WMI; of 66 survivors, 58 (87.9%) had MRI and 18-month outcomes. WMI was manually segmented and transformed into a common image space, accounting for intersubject anatomical variability. Probability …

Skilled Adult Readers Activate The Meanings Of High-Frequency Words Using Phonology: Evidence From Eye Tracking., Debra Jared, Katrina O'Donnell

Brain and Mind Institute Researchers' Publications

We examined whether highly skilled adult readers activate the meanings of high-frequency words using phonology when reading sentences for meaning. A homophone-error paradigm was used. Sentences were written to fit 1 member of a homophone pair, and then 2 other versions were created in which the homophone was replaced by its mate or a spelling-control word. The error words were all high-frequency words, and the correct homophones were either higher-frequency words or low-frequency words-that is, the homophone errors were either the subordinate or dominant member of the pair. Participants read sentences as their eye movements were tracked. When the high-frequency …