Medicine and Health Sciences Commons^™

Epithelial-To-Mesenchymal Transition Leads To Disease-Stage Differences In Circulating Tumor Cell Detection And Metastasis In Pre-Clinical Models Of Prostate Cancer, Lori E. Lowes, David Goodale, Ying Xia, Carl Postenka, Matthew M. Piaseczny, Freeman Paczkowski, Alison L. Allan

Anatomy and Cell Biology Publications

Metastasis is the cause of most prostate cancer (PCa) deaths and has been associated with circulating tumor cells (CTCs). The presence of >= 5 CTCs/7.5mL of blood is a poor prognosis indicator in metastatic PCa when assessed by the CellSearch (R) system, the "gold standard" clinical platform. However, similar to 35% of metastatic PCa patients assessed by CellSearch (R) have undetectable CTCs. We hypothesize that this is due to epithelial-to-mesenchymal transition (EMT) and subsequent loss of necessary CTC detection markers, with important implications for PCa metastasis. Two pre-clinical assays were developed to assess human CTCs in xenograft models; one comparable …

Two Years Of Relationship-Focused Mentoring For First Nations, Metis, And Inuit Adolescents: Promoting Positive Mental Health, Claire Crooks, Deinera Exner-Cortens, Sarah B. Burm, Alicia Lapointe, Debbie G. Chiodo Ms.

Journal Articles

First Nations, Métis, and Inuit (FNMI) youth are disproportionately affected by a range of negative health outcomes including poor emotional and psychosocial well-being. At the same time, there is increasing awareness of culturally-specific protective factors for these youth, such as cultural connectedness and identity. This article reports the findings of a mixed-methods, exploratory longitudinal study on the effects of a culturally-relevant school-based mentoring program for FNMI youth that focuses on promoting mental well-being and the development of cultural identity. Participants included a cohort of FNMI adolescents whom we tracked across the transition from elementary to secondary school. We utilized data …

Level Of Clinical Evidence Presented At The Open And Closed American Shoulder And Elbow Surgeons Annual Meeting Over 10 Years (2005-2014), Jeffrey Kay, Muzammil Memon, Darren De Sa, Nicole Simunovic, George S. Athwal, Asheesh Bedi, Olufemi R. Ayeni

Bone and Joint Institute

© 2016 The Author(s). Background: The American Shoulder and Elbow Surgeons (ASES) annual scientific meetings are premier forums whereby orthopaedic surgeons are informed of the latest research advances in shoulder and elbow surgery. The purpose of the present study was to assess the Level of evidence (LOE) in the clinical papers presented at both the open and closed ASES annual scientific meetings from 2005 to 2014. Secondarily, the study evaluated whether there were any changes in the distribution of LOE over this period of time. Methods: Two reviewers independently evaluated the abstracts of 532 paper presentations at either the open …

Radiation Oncology Quality And Safety Considerations In Low Resource Settings: A Medical Physics Perspective, Jacob Van Dyk, Ahmed Meghzifene

Oncology Publications

The last few years have seen a significant growth of interest in the global radiation therapy crisis. Various organizations have quantified the need and are providing aid in support of addressing the shortfalls existing in many low-to-middle income countries (LMICs). With the tremendous demand for new facilities, equipment and personnel, it is very important to recognize the quality and safety challenges and to address them directly. An examination of publications on quality and safety in radiation therapy indicates a consistency in a number of the recommendations; however, these authoritative reports were generally based on input from high-resourced contexts. Here we …

Positive Allosteric Modulator Of Gabab Receptor Alters Behavioral Effects But Not Afterdischarge Progression Induced By Partial Hippocampal Kindling., L Stan Leung, Miao Jin, Liangwei Chu, Jingyi Ma

Physiology and Pharmacology Publications

Hippocampal seizures decreased the function of GABAB receptors, which may further increase seizure susceptibility and contribute to development of schizophrenia-like behaviors. Recent literature indicates that GABAB receptor agonist may normalize schizophrenia-like behaviors and prevent drug-induced behavioral sensitization. We hypothesized that positive modulation of GABAB receptor function during seizure induction will reduce seizure-induced schizophrenia-like behaviors. Using a partial hippocampal kindling model, afterdischarges were induced after injection of saline or dimethyl sulfoxide (vehicle-kindled rats), or a GABAB receptor positive allosteric modulator CGP7930, at 1 mg/kg i.p. (CGP1-kindled) or 5 mg/kg i.p. (CGP5-kindled). The increase in the primary afterdischarge duration during kindling was …

Effect Of Left Atrial Wall Thickness On Radiofrequency Ablation Success., Jiro Inoue, Allan C Skanes, Lorne J Gula, Maria Drangova

Medical Biophysics Publications

INTRODUCTION: Radiofrequency (RF) ablation in thicker regions of the left atrium (LA) may require increased ablation energy in order to achieve effective transmural lesions. Consequently, many cases of recurrent atrial fibrillation (AF) postablation may be due to thicker-than-normal atrial tissue. The aim of this study was to test the hypotheses that patients with recurrent AF have thicker tissue overall and that electrical reconnection is more likely in regions of thicker tissue.

METHODS AND RESULTS: Retrospective analysis was performed on 86 CT images acquired preoperatively from a cohort of 119 patients who had undergone RF ablation for AF. Of these, 33 …

Design And Evaluation Of A Catheter Contact-Force Controller For Cardiac Ablation Therapy., Daniel Gelman, Allan C Skanes, Mohammad A Tavallaei, Maria Drangova

Medical Biophysics Publications

GOAL: Maintaining a constant contact force (CF) of an ablation catheter during cardiac catheter ablation therapy is clinically challenging due to inherent myocardial motion, often resulting in poor ablation of arrhythmogenic substrates. To enable a prescribed contact force to be applied during ablation, a catheter contact force controller (CCFC) was developed.

METHODS: The system includes a hand-held device attached to a commercial catheter and steerable sheath. A compact linear motor assembly attaches to an ablation catheter and autonomously controls its relative position within the shaft of the steerable sheath. A closed-loop control system is implemented within embedded electronics to enable …

Resting-State Network-Specific Breakdown Of Functional Connectivity During Ketamine Alteration Of Consciousness In Volunteers., Vincent Bonhomme, Audrey Vanhaudenhuyse, Athena Demertzi, Marie-Aurélie Bruno, Oceane Jaquet, Mohamed Ali Bahri, Alain Plenevaux, Melanie Boly, Pierre Boveroux, Andrea Soddu, Jean François Brichant, Pierre Maquet, Steven Laureys

Brain and Mind Institute Researchers' Publications

BACKGROUND: Consciousness-altering anesthetic agents disturb connectivity between brain regions composing the resting-state consciousness networks (RSNs). The default mode network (DMn), executive control network, salience network (SALn), auditory network, sensorimotor network (SMn), and visual network sustain mentation. Ketamine modifies consciousness differently from other agents, producing psychedelic dreaming and no apparent interaction with the environment. The authors used functional magnetic resonance imaging to explore ketamine-induced changes in RSNs connectivity.

METHODS: Fourteen healthy volunteers received stepwise intravenous infusions of ketamine up to loss of responsiveness. Because of agitation, data from six subjects were excluded from analysis. RSNs connectivity was compared between absence of …

The Serotonin Transporter Promoter Polymorphism Moderates The Continuity Of Behavioral Inhibition In Early Childhood., Victoria C Johnson, Katie R Kryski, Haroon I Sheikh, Heather J Smith, Shiva M Singh, Elizabeth P Hayden

Brain and Mind Institute Researchers' Publications

Persistently elevated behavioral inhibition (BI) in children is a marker of vulnerability to psychopathology. However, little research has considered the joint influences of caregiver and child factors that may moderate the continuity of BI in early childhood, particularly genetic variants that may serve as markers of biological plasticity, such as the serotonin transporter linked polymorphic region (5-HTTLPR). We explored this issue in 371 preschoolers and their caregivers, examining whether parent characteristics (i.e., overinvolvement or anxiety disorder) and child 5-HTTLPR influenced the continuity of BI between ages 3 and 5. Measures were observational ratings of child BI, observational and questionnaire measures …

Multiple-Modality Exercise And Mind-Motor Training To Improve Cardiovascular Health And Fitness In Older Adults At Risk For Cognitive Impairment: A Randomized Controlled Trial, Narlon Cassio Boa Sorte Silva, Micheal A. Gregory, Dawn P. Gill, Robert Petrella

Lifestyle Research Team

Background:The effects of multiple-modality exercise on arterial stiffening and cardiovascular fitness has not been fully explored. Objectives: To explore the influence of a 24-week multiple-modality exercise program associated with a mind-motor training in cardiovascular health and fitness in community-dwelling older adults, compared to multiple-modality exercise (M2) alone.

Methods: Participants (n=127, aged 67.5 [7.3] years, 71% females) were randomized to either M4 or M2 groups. Both groups received multiple-modality exercise intervention (60 min/day, 3 days/week for 24-weeks); however, the M4 group underwent additional 15 min of mind-motor training, whereas the M2 group received 15 min of balance training. Participants …

Quantifying And Comparing The Pattern Of Thalamic And Cortical Projections To The Posterior Auditory Field In Hearing And Deaf Cats., Blake E Butler, Nicole Chabot, Stephen G Lomber

Brain and Mind Institute Researchers' Publications

Following sensory loss, compensatory crossmodal reorganization occurs such that the remaining modalities are functionally enhanced. For example, behavioral evidence suggests that peripheral visual localization is better in deaf than in normal hearing animals, and that this enhancement is mediated by recruitment of the posterior auditory field (PAF), an area that is typically involved in localization of sounds in normal hearing animals. To characterize the anatomical changes that underlie this phenomenon, we identified the thalamic and cortical projections to the PAF in hearing cats and those with early- and late-onset deafness. The retrograde tracer biotinylated dextran amine was deposited in the …

Usage Of Swi (Susceptibility Weighted Imaging) Acquired At 7t For Qualitative Evaluation Of Temporal Lobe Epilepsy Patients With Histopathological And Clinical Correlation: An Initial Pilot Study., Benjamin Y M Kwan, Fateme Salehi, Pavlo Ohorodnyk, Donald H Lee, Jorge G Burneo, Seyed M Mirsattari, David Steven, Robert Hammond, Terry M Peters, Ali R Khan

Brain and Mind Institute Researchers' Publications

OBJECTIVES: Ultra high field MRI at 7T is able to provide much improved spatial and contrast resolution which may aid in the diagnosis of hippocampal abnormalities. This paper presents a preliminary experience on qualitative evaluation of 7T MRI in temporal lobe epilepsy patients with a focus on comparison to histopathology.

METHODS: 7T ultra high field MRI data, using T1-weighted, T2*-weighted and susceptibility-weighted images (SWI), were acquired for 13 patients with drug resistant temporal lobe epilepsy (TLE) during evaluation for potential epilepsy surgery. Qualitative evaluation of the imaging data for scan quality and presence of hippocampal and temporal lobe abnormalities were …

Regulation Of Amyloid Oligomer Binding To Neurons And Neurotoxicity By The Prion Protein-Mglur5 Complex, Flavio H. Beraldo, Valeriy G. Ostapchenko, Fabiana A. Caetano, Andre L. S. Guimaraes, Giulia D. S. Ferretti, Nathalie Daude, Lisa Bertram, Katiane O. P. C. Nogueira, Jerson L. Silva, David Westaway, Neil R. Cashman, Vilma R. Martins, Vania F. Prado, Marco A. M. Prado

Anatomy and Cell Biology Publications

The prion protein (PrPC) has been suggested to operate as a scaffold/receptor protein in neurons, participating in both physiological and pathological associated events. PrPC, laminin, and metabotropic glutamate receptor 5 (mGluR5) form a protein complex on the plasma membrane that can trigger signaling pathways involved in neuronal differentiation. PrPC and mGluR5 are co-receptors also for -amyloid oligomers (AOs) and have been shown to modulate toxicity and neuronal death in Alzheimer's disease. In the present work, we addressed the potential crosstalk between these two signaling pathways, laminin-PrPC-mGluR5 or AO-PrPC-mGluR5, as well as their interplay. Herein, we demonstrated that an existing complex …

Structural Conservation And E2f Binding Specificity Within The Retinoblastoma Pocket Protein Family, Tyler J. Liban, Michael J. Thwaites, Frederick A. Dick, Seth M. Rubin

Paediatrics Publications

The human pocket proteins retinoblastoma (Rb), p107, and p130 are critical negative regulators of the cell cycle and contribute to tumor suppression. While strong structural conservation within the pocket protein family provides for some functional redundancy, important differences have been observed and may underlie the reason that Rb is a uniquely potent tumor suppressor. It has been proposed that distinct pocket protein activities are mediated by their different E2F transcription factor binding partners. In humans, Rb binds E2F1–E2F5, whereas p107 and p130 almost exclusively associate with E2F4 and E2F5. To identify the molecular determinants of this specificity, we compared the …

Vacht Overexpression Increases Acetylcholine At The Synaptic Cleft And Accelerates Aging Of Neuromuscular Junctions, Satoshi Sugita, Leland L. Fleming, Caleb Wood, Sydney K. Vaughan, Matheus P. S. M. Gomes, Wallace Camargo, Ligia A. Naves, Vania F. Prado, Marco A. M. Prado, Cristina Guatimosim, Gregorio Valdez

Anatomy and Cell Biology Publications

Background: Cholinergic dysfunction occurs during aging and in a variety of diseases, including amyotrophic lateral sclerosis (ALS). However, it remains unknown whether changes in cholinergic transmission contributes to age-and disease-related degeneration of the motor system. Here we investigated the effect of moderately increasing levels of synaptic acetylcholine (ACh) on the neuromuscular junction (NMJ), muscle fibers, and motor neurons during development and aging and in a mouse model for amyotrophic lateral sclerosis (ALS). Methods: Chat-ChR2-EYFP (VAChTHyp) mice containing multiple copies of the vesicular acetylcholine transporter (VAChT), mutant superoxide dismutase 1 (SOD1G93A), and Chat-IRES-Cre and tdTomato transgenic mice were used in this …

Preterm Neonatal Lateral Ventricle Volume From Three-Dimensional Ultrasound Is Not Strongly Correlated To Two-Dimensional Ultrasound Measurements, Jessica Kishimoto, Sandrine De Ribaupierre, Fateme Salehi, Walter Romano, David S. C. Lee, Aaron Fenster

Anatomy and Cell Biology Publications

The aim of this study is to compare longitudinal two-dimensional (2-D) and three-dimensional (3-D) ultrasound (US) estimates of ventricle size in preterm neonates with posthemorrhagic ventricular dilatation (PHVD) using quantitative measurements of the lateral ventricles. Cranial 2-D US and 3-D US images were acquired from neonatal patients with diagnosed PHVD within 10 min of each other one to two times per week and analyzed offline. Ventricle index, anterior horn width, third ventricle width, and thalamo-occipital distance were measured on the 2-D images and ventricle volume (VV) was measured from 3-D US images. Changes in the measurements between successive image sets …

Global Access To Radiation Therapy For Cervical Cancer: The Cost Of Inaction, Jacob Van Dyk, D Rodin, Timothy Paul Hanna, E Burger, Eduardo Zubizarreta, Mei Ling Yap, Michael Barton, Rifat Atun, Felicia Marie Knaul, Y Lievens, Mary K. Gospodarowicz, D A. Jaffray, M Milosevic

Oncology Publications

No abstract provided.

Hockey Fans In Training (Hockey Fit) Pilot Study Protocol: A Gender-Sensitized Weight Loss And Healthy Lifestyle Program For Overweight And Obese Male Hockey Fans, Dawn P. Gill, Wendy Blunt, Ashleigh De Cruz, Brendan Riggin, Kate Hunt, Guangyong Zou, Shannon Sibbald, Karen Danylchuk, Merrick Zwarenstein, Cindy M. Gray, Sally Wyke, Christopher Bunn, Robert J. Petrella

Family Medicine Publications

Background:

Effective approaches that engage men in weight loss and lifestyle change are important because of worldwide increases, including in Canada, in obesity and chronic diseases. Football Fans in Training (FFIT), developed in Scotland, successfully tackled these problems by engaging overweight/obese male football fans in sustained weight loss and positive health behaviours, through program deliveries at professional football stadia.

Methods:

Aims: 1) Adapt FFIT to hockey within the Canadian context and integrate with HealtheSteps™ (evidence-based lifestyle program) to develop Hockey Fans in Training (Hockey FIT); 2) Explore potential for Hockey FIT to help overweight/obese men lose weight and improve other …

Carpal Tunnel Syndrome, Joy C. Macdermid

Bone and Joint Institute

No abstract provided.

Neural Measures Reveal Implicit Learning During Language Processing., Laura J Batterink, Larry Y Cheng, Ken A Paller

Brain and Mind Institute Researchers' Publications

Language input is highly variable; phonological, lexical, and syntactic features vary systematically across different speakers, geographic regions, and social contexts. Previous evidence shows that language users are sensitive to these contextual changes and that they can rapidly adapt to local regularities. For example, listeners quickly adjust to accented speech, facilitating comprehension. It has been proposed that this type of adaptation is a form of implicit learning. This study examined a similar type of adaptation, syntactic adaptation, to address two issues: (1) whether language comprehenders are sensitive to a subtle probabilistic contingency between an extraneous feature (font color) and syntactic structure …

Carotid Artery Atherosclerosis In Patients With Active Rheumatoid Arthritis: Predictors Of Plaque Occurrence And Progression Over 24 Weeks, Janet E Pope, Tatiana Nevskaya, Lillian Barra, Grace Parraga

Medical Biophysics Publications

INTRODUCTION: This study evaluated the prevalence and progression of subclinical carotid artery atherosclerosis in active rheumatoid arthritis (RA).

METHODS: Carotid arteries of RA patients were scanned using 3D ultrasound at baseline and 24 weeks for total plaque area, vessel wall volume, and intima-media thickness (IMT), as well as arterial stiffness measured using pulse wave velocity. Variables related to inflammation, lipids and cardiovascular (CV) risk were assessed for associations with plaque progression. Of 195 screened patients, 31 met inclusion criteria (66 Swollen joint count (SJC) plus 68 Tender joint count (TJC)≥8 OR SJC plus TJC≥4 with elevated acute phase reactants) and …

Synthesis, Self-Assembly, And Immunological Activity Of Α-Galactose-Functionalized Dendron–Lipid Amphiphiles, John Trant, Namrata Jain, D. M. Mazzuca, J Trevor Mcintosh, Bo Fan, S M Mansour Haeryfar, Sebastien Lecommandoux, Elizabeth Gillies

Chemistry Publications

Nanoassemblies presenting multivalent displays of biologically active carbohydrates are of significant interest for a wide array of biomedical applications ranging from drug delivery to immunotherapy. In this study, glycodendron–lipid hybrids were developed as a new and tunable class of dendritic amphiphiles. A modular synthesis was used to prepare dendron–lipid hybrids comprising distearylglycerol and 0 through 4th generation polyester dendrons with peripheral protected amines. Following deprotection of the amines, an isothiocyanate derivative of C-linked α-galactose (α-Gal) was conjugated to the dendron peripheries, affording amphiphiles with 1 to 16 α-Gal moieties. Self-assembly in …

Selectivity Of Conventional Electrodes For Recording Motor Evoked Potentials: An Investigation With High‐Density Surface Electromyography, Alessio Gallina, Sue Peters, Jason L. Neva, Lara A. Boyd, Jayne Garland

Physical Therapy Publications

Introduction

The objective of this study was to determine whether motor evoked potentials (MEPs) elicited with transcranial magnetic stimulation and measured with conventional bipolar electromyography (EMG) are influenced by crosstalk from non-target muscles.

Methods

MEPs were recorded in healthy participants using conventional EMG electrodes placed over the extensor carpi radialis muscle (ECR) and high-density surface EMG (HDsEMG). Fifty MEPs at 120% resting and active motor threshold were recorded. To determine the contribution of ECR to the MEPs, the amplitude distribution across HDsEMG channels was correlated with EMG activity recorded during a wrist extension task.

Results

Whereas the conventional EMG identified …

Impact Of Platelet-Rich Plasma On Arthroscopic Repair Of Small- To Medium-Sized Rotator Cuff Tears: A Randomized Controlled Trial, Richard Holtby, Monique Christakis, Eran Maman, Joy C. Macdermid, Tim Dwyer, George S. Athwal, Kenneth Faber, John Theodoropoulos, Linda J. Woodhouse, Helen Razmjou

Bone and Joint Institute

© 2016, © The Author(s) 2016. Background: Increased interest in using platelet-rich plasma (PRP) as an augment to rotator cuff repair warrants further investigation, particularly in smaller rotator cuff tears. Purpose: To examine the effectiveness of PRP application in improving perioperative pain and function and promoting healing at 6 months after arthroscopic repair of small- or medium-sized rotator cuff tears. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This was a double-blinded randomized controlled trial of patients undergoing arthroscopic repair of partial- or full-thickness rotator cuff tears of up to 3 cm who were observed for 6 months. …

Biallelic Hypomorphic Mutations In A Linear Deubiquitinase Define Otulipenia, An Early-Onset Autoinflammatory Disease, Qing Zhou, Xiaomin Yu, Erkan Demirkaya, Natalie Deuitch, Deborah Stone, Wanxia Li Tsai, Hye Sun Kuehn, Hongying Wang, Dan Yang, Yong Hwan Park, Amanda K. Ombrello, Mary Blake, Tina Romeo, Elaine F. Remmers, Jae Jin Chae, James C. Mullikin, Ferhat Güzel, Joshua D. Milner, Manfred Boehm, Sergio D. Rosenzweig, Massimo Gadina, Steven B. Welch, Seza Özen, Rezan Topaloglu, Mario Abinun, Daniel L. Kastner, Ivona Aksentijevich

Paediatrics Publications

Systemic autoinflammatory diseases are caused by mutations in genes that function in innate immunity. Here, we report an autoinflammatory disease caused by loss-of-function mutations in OTULIN (FAM105B), encoding a deubiquitinase with linear linkage specificity. We identified two missense and one frameshift mutations in one Pakistani and two Turkish families with four affected patients. Patients presented with neonatal-onset fever, neutrophilic dermatitis/panniculitis, and failure to thrive, but without obvious primary immunodeficiency. HEK293 cells transfected with mutated OTULIN had decreased enzyme activity relative to cells transfected with WT OTULIN, and showed a substantial defect in the linear deubiquitination of target molecules. Stimulated patients' …

The Prevalence, Location, Severity, And Daily Impact Of Pain Reported By Youth And Young Adults With Cerebral Palsy., Laura Brunton, Sarah Hall, Adrienne Passingham, Julie Wulff, Rich Delitala

Physical Therapy Publications

PURPOSE: To describe the prevalence, location, severity, and daily impact of pain reported by youth and young adults with cerebral palsy (CP). A secondary aim was to identify any significant associations between the constructs of interest.

METHOD: An observational study of 112 participants with CP to understand their experience of pain through a questionnaire. Participants were 56 males and 55 females with a mean age of 18y 9mo (SD 4y 5mo).

RESULTS: Pain was reported by 75% of males and 89% of females. Both severity and impact of pain were significantly greater in females. In addition, severity and impact of …

Design, Development And Evaluation Of A Compact Telerobotic Catheter Navigation System., Mohammad Ali Tavallaei, Daniel Gelman, Michael Konstantine Lavdas, Allan C Skanes, Douglas L Jones, Jeffrey S Bax, Maria Drangova

Medical Biophysics Publications

BACKGROUND: Remote catheter navigation systems protect interventionalists from scattered ionizing radiation. However, these systems typically require specialized catheters and extensive operator training.

METHODS: A new compact and sterilizable telerobotic system is described, which allows remote navigation of conventional tip-steerable catheters, with three degrees of freedom, using an interface that takes advantage of the interventionalist's existing dexterity skills. The performance of the system is evaluated ex vivo and in vivo for remote catheter navigation and ablation delivery.

RESULTS: The system has absolute errors of 0.1 ± 0.1 mm and 7 ± 6° over 100 mm of axial motion and 360° of …

Response To: Letter To The Editor Regarding: The Expanding Phenotype Of Melas Caused By The M.3291 T > C Trna Mutation E Kelland, C. A. Rupar, Asuri N. Prasad, K. Y. Tay, A. Downie And C. Prasad (1) By Josef Finsterer, Md, Phd [1], Sinda Zarrouk-Mahjoub, Phd [2] [1] Krankenanstalt Rudolfstiftung, Vienna [2] Genomics Platform, Pasteur Institute Of Tunis, Tunisia, E. Kelland, C. A. Rupar, Asuri N. Prasad, K. Y. Tay, A. Downie, C. Prasad

Bone and Joint Institute

No abstract provided.

Probing The Nature Of Deficits In The ‘Approximate Number System’ In Children With Persistent Developmental Dyscalculia, S Bugden, Daniel Ansari

Brain and Mind Institute Researchers' Publications

In the present study we examined whether children with Developmental Dyscalculia (DD) exhibit a deficit in the so-called 'Approximate Number System' (ANS). To do so, we examined a group of elementary school children who demonstrated persistent low math achievement over 4 years and compared them to typically developing (TD), aged-matched controls. The integrity of the ANS was measured using the Panamath (www.panamath.org) non-symbolic numerical discrimination test. Children with DD demonstrated imprecise ANS acuity indexed by larger Weber fraction (w) compared to TD controls. Given recent findings showing that non-symbolic numerical discrimination is affected by visual parameters, we went further and …

A Quantitative Comparison Of The Hemispheric, Areal, And Laminar Origins Of Sensory And Motor Cortical Projections To The Superior Colliculus Of The Cat., Blake E Butler, Nicole Chabot, Stephen G Lomber

Brain and Mind Institute Researchers' Publications

The superior colliculus (SC) is a midbrain structure central to orienting behaviors. The organization of descending projections from sensory cortices to the SC has garnered much attention; however, rarely have projections from multiple modalities been quantified and contrasted, allowing for meaningful conclusions within a single species. Here, we examine corticotectal projections from visual, auditory, somatosensory, motor, and limbic cortices via retrograde pathway tracers injected throughout the superficial and deep layers of the cat SC. As anticipated, the majority of cortical inputs to the SC originate in the visual cortex. In fact, each field implicated in visual orienting behavior makes a …