Neurosciences Commons^™

Implicit And Explicit Contributions To Statistical Learning., Laura J Batterink, Paul J Reber, Helen J Neville, Ken A Paller

Brain and Mind Institute Researchers' Publications

Statistical learning allows learners to detect regularities in the environment and appears to emerge automatically as a consequence of experience. Statistical learning paradigms bear many similarities to those of artificial grammar learning and other types of implicit learning. However, whether learning effects in statistical learning tasks are driven by implicit knowledge has not been thoroughly examined. The present study addressed this gap by examining the role of implicit and explicit knowledge within the context of a typical auditory statistical learning paradigm. Learners were exposed to a continuous stream of repeating nonsense words. Learning was tested (a) directly via a forced-choice …

Tract-Based Spatial Statistics In Preterm-Born Neonates Predicts Cognitive And Motor Outcomes At 18 Months., E G Duerden, J Foong, V Chau, H Branson, K J Poskitt, R E Grunau, A Synnes, J G Zwicker, S P Miller

Brain and Mind Institute Researchers' Publications

BACKGROUND AND PURPOSE: Adverse neurodevelopmental outcome is common in children born preterm. Early sensitive predictors of neurodevelopmental outcome such as MR imaging are needed. Tract-based spatial statistics, a diffusion MR imaging analysis method, performed at term-equivalent age (40 weeks) is a promising predictor of neurodevelopmental outcomes in children born very preterm. We sought to determine the association of tract-based spatial statistics findings before term-equivalent age with neurodevelopmental outcome at 18-months corrected age.

MATERIALS AND METHODS: Of 180 neonates (born at 24-32-weeks' gestation) enrolled, 153 had DTI acquired early at 32 weeks' postmenstrual age and 105 had DTI acquired later at …

Transient Visual Responses Reset The Phase Of Low-Frequency Oscillations In The Skeletomotor Periphery., Daniel K Wood, Chao Gu, Brian D Corneil, Paul L Gribble, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

We recorded muscle activity from an upper limb muscle while human subjects reached towards peripheral targets. We tested the hypothesis that the transient visual response sweeps not only through the central nervous system, but also through the peripheral nervous system. Like the transient visual response in the central nervous system, stimulus-locked muscle responses (< 100 ms) were sensitive to stimulus contrast, and were temporally and spatially dissociable from voluntary orienting activity. Also, the arrival of visual responses reduced the variability of muscle activity by resetting the phase of ongoing low-frequency oscillations. This latter finding critically extends the emerging evidence that the feedforward visual sweep reduces neural variability via phase resetting. We conclude that, when sensory information is relevant to a particular effector, detailed information about the sensorimotor transformation, even from the earliest stages, is found in the peripheral nervous system.

Pharmacodynamics Of Folic Acid Receptor Targeted Antiretroviral Nanotherapy In Hiv-1-Infected Humanized Mice., Pavan Puligujja, Mariluz Araínga, Prasanta Dash, Diana L. Palandri, R. Lee Mosley, Santhi Gorantla, Larisa Y Poluektova, Joellyn Mcmillan, Howard Gendelman

Journal Articles: Pharmacology & Experimental Neuroscience

Long-acting nanoformulated antiretroviral therapy (nanoART) can sustain plasma drug levels and improve its biodistribution. Cell targeted-nanoART can achieve this and bring drug efficiently to viral reservoirs. However, whether such improvements affect antiretroviral responses remains unknown. To these ends, we tested folic acid (FA)-linked poloxamer407-coated ritonavir-boosted atazanavir (FA-nanoATV/r) nanoparticles for their ability to affect chronic HIV-1 infection in humanized mice. Following three, 100mg/kg FA-nanoATV/r intramuscular injections administered every other week to infected animals, viral RNA was at or below the detection limit, cell-associated HIV-1p24 reduced and CD4+ T cell counts protected. The dosing regimen improved treatment outcomes more than two fold …

The Effect Of Sleep On Perceptual Learning And Memory Consolidation, Vanessa Claire Irsik

UNLV Theses, Dissertations, Professional Papers, and Capstones

An ability to segregate speech accurately is essential given that most auditory environments contain other overlapping conversations or environmental noise. While perceiving speech among background noise can be difficult in and of itself, those with hearing impairments can experience considerable difficulty. While training has been shown to benefit perceptual segregation of trained sounds, it is unclear how such training transfers to sounds not included in a training regimen. The current study aimed to address this question by training listeners on a portion of sounds during a vowel segregation task, and subsequently testing on both the trained sounds and untrained sounds. …

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 …

Selective Generation Of Dopaminergic Precursors From Mouse Fibroblasts By Direct Lineage Conversion., Changhai Tian, Yuju Li, Yunlong Huang, Yongxiang Wang, Dapeng Chen, Jinxu Liu, Xiaobei Deng, Lijun Sun, Kristi Anderson, Xinrui Qi, Yulong Li, R. Lee Mosley, Xiangmei Chen, Jian Huang, Jialin C. Zheng

Journal Articles: Pharmacology & Experimental Neuroscience

Degeneration of midbrain dopaminergic (DA) neurons is a key pathological event of Parkinson's disease (PD). Limited adult dopaminergic neurogenesis has led to novel therapeutic strategies such as transplantation of dopaminergic precursors (DPs). However, this strategy is currently restrained by a lack of cell source, the tendency for the DPs to become a glial-restricted state, and the tumor formation after transplantation. Here, we demonstrate the direct conversion of mouse fibroblasts into induced DPs (iDPs) by ectopic expression of Brn2, Sox2 and Foxa2. Besides expression with neural progenitor markers and midbrain genes including Corin, Otx2 and Lmx1a, the iDPs were restricted to …

Halting The Hallmarks: A Cellular Automaton Model Of Early Cancer Growth Inhibition, Jenna Butler, Frances Mackay, Colin Denniston, Mark Daley

Brain and Mind Institute Researchers' Publications

Cancer treatment is a fragmented and varied process, as ‘‘cancer’’ is really hundreds of different diseases. The ‘‘hallmarks of cancer’’ proposed by Hanahan and Weinberg (Cell 100(1):57–70, 2000) are a framework for viewing cancer within a common set of underlying principles—ten properties that are common to almost all cancers, allowing them to grow uncontrollably and ravage the body. We used a cellular automaton model of tumour growth paired with lattice Boltzmann methods modelling oxygen flow to simulate combination drugs targeted at knocking out pairs of hallmarks. We found that knocking out some pairs of cancer-enabling hallmarks did not prevent tumour …

Mir-21 In Extracellular Vesicles Leads To Neurotoxicity Via Tlr7 Signaling In Siv Neurological Disease., Sowmya V. Yelamanchili, Benjamin G. Lamberty, Deborah A. Rennard, Brenda M. Morsey, Colleen G. Hochfelder, Brittney M. Meays, Efrat Levy, Howard S. Fox

Journal Articles: Pharmacology & Experimental Neuroscience

Recent studies have found that extracellular vesicles (EVs) play an important role in normal and disease processes. In the present study, we isolated and characterized EVs from the brains of rhesus macaques, both with and without simian immunodeficiency virus (SIV) induced central nervous system (CNS) disease. Small RNA sequencing revealed increased miR-21 levels in EVs from SIV encephalitic (SIVE) brains. In situ hybridization revealed increased miR-21 expression in neurons and macrophage/microglial cells/nodules during SIV induced CNS disease. In vitro culture of macrophages revealed that miR-21 is released into EVs and is neurotoxic when compared to EVs derived from miR-21-/- knockout …

Toll-Like Receptors And Dectin-1, A C-Type Lectin Receptor, Trigger Divergent Functions In Cns Macrophages, John C. Gensel, Yan Wang, Zhen Guan, Kyle A. Beckwith, Kaitlyn J. Braun, Ping Wei, Dana M. Mctigue, Phillip G. Popovich

Spinal Cord and Brain Injury Research Center Faculty Publications

Spinal cord injury (SCI) activates macrophages, endowing them with both reparative and pathological functions. The mechanisms responsible for these divergent functions are unknown but are likely controlled through stochastic activation of different macrophage receptor subtypes. Various danger-associated molecular patterns released from dying cells in the injured spinal cord likely activate distinct subtypes of macrophage pattern recognition receptors, including bacterial toll-like receptors (TLRs) and fungal C-type lectin receptors (e.g., dectin-1). To determine the in vivo consequences of activating these receptors, ligands specific for TLR2 or dectin-1 were microinjected, alone or in combination, into intact spinal cord. Both ligands elicit a florid …

Genomic Copy Number Variation In Mus Musculus., M Elizabeth O Locke, Maja Milojevic, Susan T Eitutis, Nisha Patel, Andrea E Wishart, Mark Daley, Kathleen A. Hill

Brain and Mind Institute Researchers' Publications

BACKGROUND: Copy number variation is an important dimension of genetic diversity and has implications in development and disease. As an important model organism, the mouse is a prime candidate for copy number variant (CNV) characterization, but this has yet to be completed for a large sample size. Here we report CNV analysis of publicly available, high-density microarray data files for 351 mouse tail samples, including 290 mice that had not been characterized for CNVs previously.

RESULTS: We found 9634 putative autosomal CNVs across the samples affecting 6.87% of the mouse reference genome. We find significant differences in the degree of …

Plastin 3 Expression Does Not Modify Spinal Muscular Atrophy Severity In The ∆7 Sma Mouse, Vicki L. Mcgovern, Aurelie Massoni-Laporte, Xueyong Wang, Thanh T. Le, Hao T. Le, Mark M. Rich, Arthur H. M. Burghes

Neuroscience, Cell Biology & Physiology Faculty Publications

Spinal muscular atrophy is caused by loss of the SMN1 gene and retention of SMN2. TheSMN2 copy number inversely correlates with phenotypic severity and is a modifier of disease outcome. The SMN2 gene essentially differs from SMN1 by a single nucleotide in exon 7 that modulates the incorporation of exon 7 into the final SMN transcript. The majority of the SMN2transcripts lack exon 7 and this leads to a SMN protein that does not effectively oligomerize and is rapidly degraded. However theSMN2 gene does produce some full-length SMN and theSMN2 copy number along with how …

Hand Use Predicts The Structure Of Representations In Sensorimotor Cortex., Naveed Ejaz, Masashi Hamada, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Fine finger movements are controlled by the population activity of neurons in the hand area of primary motor cortex. Experiments using microstimulation and single-neuron electrophysiology suggest that this area represents coordinated multi-joint, rather than single-finger movements. However, the principle by which these representations are organized remains unclear. We analyzed activity patterns during individuated finger movements using functional magnetic resonance imaging (fMRI). Although the spatial layout of finger-specific activity patterns was variable across participants, the relative similarity between any pair of activity patterns was well preserved. This invariant organization was better explained by the correlation structure of everyday hand movements than …

Changes In Visual And Sensory-Motor Resting-State Functional Connectivity Support Motor Learning By Observing., Heather R Mcgregor, Paul L Gribble

Brain and Mind Institute Researchers' Publications

Motor learning occurs not only through direct first-hand experience but also through observation (Mattar AA, Gribble PL. Neuron 46: 153-160, 2005). When observing the actions of others, we activate many of the same brain regions involved in performing those actions ourselves (Malfait N, Valyear KF, Culham JC, Anton JL, Brown LE, Gribble PL. J Cogn Neurosci 22: 1493-1503, 2010). Links between neural systems for vision and action have been reported in neurophysiological (Strafella AP, Paus T. Neuroreport 11: 2289-2292, 2000; Watkins KE, Strafella AP, Paus T. Neuropsychologia 41: 989-994, 2003), brain imaging (Buccino G, Binkofski F, Fink GR, Fadiga L, …

Embracing Multiple Definitions Of Learning, Andrew B. Barron, Eileen A. Hebets, Thomas A. Cleland, Courtney L. Fitzpatrick, Mark E. Hauber, Jeffrey R. Stevens

Eileen Hebets Publications

Definitions of learning vary widely across disciplines, driven largely by different approaches used to assess its occurrence. These definitions can be better reconciled with each other if each is recognized as coherent with a common conceptualization of learning, while appreciating the practical utility of different learning definitions in different contexts.

Learning is a major focus of research in psychology, neuro- science, behavioral ecology, evolutionary theory, and computer science, as well as in many other disciplines. Despite its conceptual prevalence, definitions of learning differ enormously both within and between these disciplines, and new definitions continue to be proposed [1]. Ongoing disputes …

Dualism And Doctrine, Dov Fox, Alex Stein

Indiana Law Journal

What kinds of harm among those that tortfeasors inflict are worthy of compensation? Which forms of self-incriminating evidence are privileged against government compulsion? What sorts of facts constitute a criminal defendant’s intent? Existing doctrine pins the answer to all of these questions on whether the injury, facts, or evidence at stake are “mental” or “physical.” The assumption that operations of the mind are meaningfully distinct from those of the body animates fundamental rules in our law.

A tort victim cannot recover for mental harm on its own because the law presumes that he is able to unfeel any suffering arising …

Clinical Spectrum And Radiographic Features Of The Syndrome Of The Trephined, Cara L. Sedney, William Dillen, Terrence Julien

Neurosurgery Faculty Publications

OBJECT: Craniectomy is a common neurosurgical procedure. Syndrome of the trephined (ST) occurring after craniectomy results in neurologic symptoms that are reversible with cranioplasty. While well-documented, previous literature consisted of case reports, symptom spectrum and risk factors have not been well characterized.

MATERIALS AND METHODS: A retrospective review of 29 consecutive cases who underwent decompressive craniectomy within a 30-month period was performed. Patients were considered affected by ST if a previously stable neurological deficit improved within 3 weeks after cranioplasty. Prevalence of ST was measured and association with demographic information, clinical symptoms patterns, indication for and size of craniectomy, as …

Neural Plasticity In Response To Intervention In Adolescents With Autism Spectrum Disorders, Sheryl Jayne Stevens

Dissertations (1934 -)

Current theories of Autism Spectrum Disorders (ASD) suggest that they may develop from the transactional interaction between biological risk factors and environmental processes (Dawson et al., 2009). Due to the brain’s experience-expectant nature, one’s degree of social exposure may have a significant impact on their brain development and behavioral presentation. In addition to the primary critical neurodevelopmental period identified in early childhood, recent research has demonstrated a second period of substantial neurodevelopment during the adolescent period (Sisk & Foster, 2004). This study investigated the neural and behavioral impact of participation in an empirically validated behavioral intervention (The Program for the …

Effects Of Cocaine Sensitization On Drug Self-Administration, Mesocorticolimbic Sapap Levels, And Prefrontal Ionotropic Glutamate Receptors, Kyle Christopher Summers

Theses and Dissertations (ETD)

Towards the goal of improving the knowledge base of how drugs of abuse function to create addicts and using currently uninvestigated areas of this knowledge base, we focused our research studies the male albino rat, and strived to explain how cocaine sensitization alters particular molecular mechanisms in the mesocorticolimbic system related to glutamate receptors, SAPAPs, and affects drug self-administration. Taking all the previously discussed research studies into consideration, we hypothesized that low-dose cocaine self-administration would yield a significant elevation in drug seeking behavior for psychostimulant sensitized animals. For specific changes at the PSD, we hypothesized that acute cocaine exposure and/or …

Taranis Functions With Cyclin A And Cdk1 In A Novel Arousal Center To Control Sleep In Drosophila., Dinis J.S. Afonso, Die Liu, Daniel R. Machado, Huihui Pan, James E.C. Jepson, Dragana Rogulja, Kyunghee Koh

Department of Neuroscience Faculty Papers

Sleep is an essential and conserved behavior whose regulation at the molecular and anatomical level remains to be elucidated. Here, we identify TARANIS (TARA), a Drosophila homolog of the Trip-Br (SERTAD) family of transcriptional coregulators, as a molecule that is required for normal sleep patterns. Through a forward-genetic screen, we isolated tara as a novel sleep gene associated with a marked reduction in sleep amount. Targeted knockdown of tara suggests that it functions in cholinergic neurons to promote sleep. tara encodes a conserved cell-cycle protein that contains a Cyclin A (CycA)-binding homology domain. TARA regulates CycA protein levels and genetically …