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Pupil and dopamine

Christopher M Warren, Eran Eldar, Ruud L van den Brink, Klodianna-Daphne Tona, Nic J van der Wee, Eric J Giltay, Martijn S van Noorden, Jos A Bosch, Robert C Wilson, Jonathan D Cohen, Sander Nieuwenhuis
UNLABELLED: Neurophysiological evidence suggests that neuromodulators, such as norepinephrine and dopamine, increase neural gain in target brain areas. Computational models and prominent theoretical frameworks indicate that this should enhance the precision of neural representations, but direct empirical evidence for this hypothesis is lacking. In two functional MRI studies, we examine the effect of baseline catecholamine levels (as indexed by pupil diameter and manipulated pharmacologically) on the precision of object representations in the human ventral temporal cortex using angular dispersion, a powerful, multivariate metric of representational similarity (precision)...
May 25, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Yoshiaki Omura, Dominic Lu, Marilyn K Jones, Ahdallah Nihrane, Harsha Duvvi, Yasuhiro Shimotsuura, Motomu Ohki
A brief historical background on Autism & some of the important symptoms associated with Autism are summarized. Using strong Electro Magnetic Field Resonance Phenomenon between 2 identical molecules with identical weight (which received U.S. Patent) non-invasively & rapidly we can detect various molecules including neurotransmitters, bacteria, virus, fungus, metals & abnormal molecules. Simple non- invasive measurement of various molecules through pupils & head of diagnosed or suspected Autism patients indicated that in Autism patients following changes were often found: 1) Acetylcholine is markedly reduced; 2) Alzheimer's disease markers (i...
2015: Acupuncture & Electro-therapeutics Research
Chiara Varazzani, Aurore San-Galli, Sophie Gilardeau, Sebastien Bouret
Motivation determines multiple aspects of behavior, including action selection and energization of behavior. Several components of the underlying neural systems have been examined closely, but the specific role of the different neuromodulatory systems in motivation remains unclear. Here, we compare directly the activity of dopaminergic neurons from the substantia nigra pars compacta and noradrenergic neurons from the locus coeruleus in monkeys performing a task manipulating the reward/effort trade-off. Consistent with previous reports, dopaminergic neurons encoded the expected reward, but we found that they also anticipated the upcoming effort cost in connection with its negative influence on action selection...
May 20, 2015: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Rachel D Plak, Cornelia A T Kegel, Adriana G Bus
In this randomized controlled trial, 508 5-year-old kindergarten children participated, of whom 257 were delayed in literacy skills because they belonged to the lowest quartile of a national standard literacy test. We tested the hypothesis that some children are more susceptible to school-entry educational interventions than their peers due to their genetic makeup, and thus whether the dopamine receptor D4 gene moderated intervention effects. Children were randomly assigned to a control condition or one of two interventions involving computer programs tailored to the literacy needs of delayed pupils: Living Letters for alphabetic knowledge and Living Books for text comprehension...
February 2015: Development and Psychopathology
Neal T Sweeney, Hannah Tierney, David A Feldheim
There are ∼20 types of retinal ganglion cells (RGCs) in mice, each of which has distinct molecular, morphological, and physiological characteristics. Each RGC type sends axon projections to specific brain areas that execute light-dependent behaviors. Here, we show that the T-box transcription factor Tbr2 is required for the development of several RGC types that participate in non-image-forming circuits. These types are molecularly distinct, project to non-image-forming targets, and include intrinsically photosensitive RGCs...
April 16, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Amanda N French, Regan S Ashby, Ian G Morgan, Kathryn A Rose
Recent epidemiological evidence suggests that children who spend more time outdoors are less likely to be, or to become myopic, irrespective of how much near work they do, or whether their parents are myopic. It is currently uncertain if time outdoors also blocks progression of myopia. It has been suggested that the mechanism of the protective effect of time outdoors involves light-stimulated release of dopamine from the retina, since increased dopamine release appears to inhibit increased axial elongation, which is the structural basis of myopia...
September 2013: Experimental Eye Research
Lara Phillips, David Robertson, Mark R Melson, Emily M Garland, Karen M Joos
PURPOSE: To report the ophthalmic findings in young patients with dopamine β-hydroxylase deficiency and to assess them in the context of other reports in an attempt to discern if ophthalmic criteria may assist in early detection of this debilitating, yet treatable, disorder. DESIGN: Prospective, observational case series. METHODS: An ophthalmic examination, including measuring intraocular and systemic blood pressures while supine, sitting, and standing, and eyelid function and pupillary function testing, was completed on 3 young patients with recently documented dopamine β-hydroxylase deficiency at a single institution...
August 2013: American Journal of Ophthalmology
Marlies E van Bochove, Lise Van der Haegen, Wim Notebaert, Tom Verguts
Recent models have suggested an important role for neuromodulation in explaining trial-to-trial adaptations in cognitive control. The adaptation-by-binding model (Verguts & Notebaert, Psychological review, 115(2), 518-525, 2008), for instance, suggests that increased cognitive control in response to conflict (e.g., incongruent flanker stimulus) is the result of stronger binding of stimulus, action, and context representations, mediated by neuromodulators like dopamine (DA) and/or norepinephrine (NE). We presented a flanker task and used the Gratton effect (smaller congruency effect following incongruent trials) as an index of cognitive control...
June 2013: Cognitive, Affective & Behavioral Neuroscience
Joseph R Blasic, R Lane Brown, Phyllis R Robinson
The visual pigment melanopsin is expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs) in the mammalian retina, where it is involved in non-image forming light responses including circadian photoentrainment, pupil constriction, suppression of pineal melatonin synthesis, and direct photic regulation of sleep. It has recently been shown that the melanopsin-based light response in ipRGCs is attenuated by the neurotransmitter dopamine. Here, we use a heterologous expression system to demonstrate that mouse melanopsin can be phosphorylated by protein kinase A, and that phosphorylation can inhibit melanopsin signaling in HEK cells...
2012: PloS One
Jared D Peterson, Jurij R Bilyk, Robert C Sergott
A 44-year-old man presented with acute onset headache and isolated anisocoria. Dilation lag was noted in the smaller pupil and Horner syndrome was suspected despite the lack of eyelid ptosis. Cocaine testing confirmed the clinical diagnosis, and urgent neuroimaging found an internal carotid artery dissection. The patient was managed with systemic anticoagulation with a good final outcome. Horner syndrome should be suspected in any patient with aniscoria and dilation lag, despite the absence of eyelid ptosis or other associated findings...
September 2013: Survey of Ophthalmology
Kerstin Preuschoff, Bernard Marius 't Hart, Wolfgang Einhäuser
Our decisions are guided by the rewards we expect. These expectations are often based on incomplete knowledge and are thus subject to uncertainty. While the neurophysiology of expected rewards is well understood, less is known about the physiology of uncertainty. We hypothesize that uncertainty, or more specifically errors in judging uncertainty, are reflected in pupil dilation, a marker that has frequently been associated with decision making, but so far has remained largely elusive to quantitative models...
2011: Frontiers in Neuroscience
Evangelia Giza, Dimitrios Fotiou, Sevasti Bostantjopoulou, Zoe Katsarou, George Gerasimou, Anna Gotzamani-Psarrakou, Anna Karlovasitou
The purpose of this study was the evaluation of pupil light reflex (PLR) in patients with Parkinson's disease (PD) by using a modern pupillometry system and the investigation of its potential relationship with dopamine transporter imaging (DaTSCAN), which is an objective method for the evaluation of presynaptic dopaminergic system. PLR was evaluated using pupillometry in 35 patients with PD without clinical evidence of autonomic dysfunction and 44 healthy matched controls. PLR was elicited using a fully automated pupillometry system and six parameters were measured...
January 2012: International Journal of Neuroscience
Andrew L Makowski, Kjell Lindgren, James P Locke
INTRODUCTION: Scopolamine/dextroamphetamine has been used to combat motion sickness generated aboard research aircraft for decades. While it has shown to be effective, previous studies differ as to the presence of visual side effects secondary to scopolamine's anticholinergic properties. This study sought to quantify any such effects in order to determine if they are operationally significant. METHODS: Fliers in NASA's Reduced Gravity Program received a weight-based dose of scopolamine/ dextroamphetamine prior to boarding the aircraft...
July 2011: Aviation, Space, and Environmental Medicine
R A Armstrong
Parkinson's disease (PD) is a common disorder of middle-aged and elderly people in which degeneration of the extrapyramidal motor system causes significant movement problems. In some patients, however, there are additional disturbances in sensory systems including loss of the sense of smell and auditory and/or visual problems. This paper is a general overview of the visual problems likely to be encountered in PD. Changes in vision in PD may result from alterations in visual acuity, contrast sensitivity, colour discrimination, pupil reactivity, eye movements, motion perception, visual field sensitivity, and visual processing speeds...
2011: Parkinson's Disease
Marieke Jepma, Jaap Deinum, Christopher L Asplund, Serge Arb Rombouts, Jouke T Tamsma, Nathanja Tjeerdema, Michiel M Spapé, Emily M Garland, David Robertson, Jacques Wm Lenders, Sander Nieuwenhuis
Dopamine-β-hydroxylase (DβH) deficiency is a rare genetic syndrome characterized by the complete absence of norepinephrine in the peripheral and the central nervous system. DβH-deficient patients suffer from several physical symptoms, which can be treated successfully with L-threo-3,4-dihydroxyphenylserine, a synthetic precursor of norepinephrine. Informal clinical observations suggest that DβH-deficient patients do not have obvious cognitive impairments, even when they are not medicated, which is remarkable given the important role of norepinephrine in normal neurocognitive function...
July 2011: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
Frank W Moler, Amy E Donaldson, Kathleen Meert, Richard J Brilli, Vinay Nadkarni, Donald H Shaffner, Charles L Schleien, Robert S B Clark, Heidi J Dalton, Kimberly Statler, Kelly S Tieves, Richard Hackbarth, Robert Pretzlaff, Elise W van der Jagt, Jose Pineda, Lynn Hernan, J Michael Dean
OBJECTIVES: To describe a large cohort of children with out-of-hospital cardiac arrest with return of circulation and to identify factors in the early postarrest period associated with survival. These objectives were for planning an interventional trial of therapeutic hypothermia after pediatric cardiac arrest. METHODS: A retrospective cohort study was conducted at 15 Pediatric Emergency Care Applied Research Network clinical sites over an 18-month study period...
January 2011: Critical Care Medicine
Göran B W Söderlund, Sverker Sikström, Jan M Loftesnes, Edmund J Sonuga-Barke
BACKGROUND: Noise is typically conceived of as being detrimental for cognitive performance; however, a recent computational model based on the concepts of stochastic resonance and dopamine related internal noise postulates that a moderate amount of auditive noise benefit individuals in hypodopaminergic states. On the basis of this model we predicted that inattentive children would be enhanced by adding background white noise while attentive children's performance would deteriorate. METHODS: Fifty-one secondary school pupils carried out an episodic verbal free recall test in two noise conditions...
2010: Behavioral and Brain Functions: BBF
Mario E Guido, Eduardo Garbarino-Pico, Maria Ana Contin, Diego J Valdez, Paula S Nieto, Daniela M Verra, Victoria A Acosta-Rodriguez, Nuria de Zavalía, Ruth E Rosenstein
Daily and annual changes in ambient illumination serve as specific stimuli that associate light with time and regulate the physiology of the organism through the eye. The eye acts as a dual sense organ linking light and vision, and detecting light that provides specific stimuli for non-classical photoreceptors located in the inner retina. These photoreceptors convey information to the master circadian pacemaker, the hypothalamic suprachiasmatic nuclei (SCN). Responsible for sensing the light that regulates several non-visual functions (i...
December 2010: Progress in Neurobiology
Elizabeth L Thorpe, Anthony F Pizon, Michael J Lynch, Jessica Boyer
Although there are no documented cases of serotonin syndrome (SS) following bupropion ingestion alone in the literature, the ability of bupropion to potentiate serotonin levels and lead to SS is known. A 15-year-old boy was found at home hallucinating. He then developed tonic-clonic activity. Upon arrival in the emergency department, he was confused and restless. On exam, he had tachycardia, hypertension, dilated pupils and dry oral mucosa, normal tone and reflexes in his arms, but rigidity and +4 reflexes in his legs with sustained clonus at his ankles...
June 2010: Journal of Medical Toxicology: Official Journal of the American College of Medical Toxicology
Georg Wensing, Claus Haase, Erich Brendel, Michael Friedrich Böttcher
OBJECTIVE: BAY 63-9044 is a new full 5-HT(1A)-agonist with functional dopamine agonist properties aimed for the treatment of Parkinson's disease. This first-in-man study investigated the pharmacodynamics, safety and tolerability as well as the pharmacokinetics of BAY 63-9044 in a randomized, single-blind, placebo-controlled group-comparison dose escalation study. METHODS: 45 healthy men received BAY 63-9044 as an oral solution in single doses of 0.25 mg, 0.5 mg, 1...
December 2007: European Journal of Clinical Pharmacology
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