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https://www.readbyqxmd.com/read/28065606/neurons-responsive-to-global-visual-motion-have-unique-tuning-properties-in-hummingbirds
#1
Andrea H Gaede, Benjamin Goller, Jessica P M Lam, Douglas R Wylie, Douglas L Altshuler
Neurons in animal visual systems that respond to global optic flow exhibit selectivity for motion direction and/or velocity. The avian lentiformis mesencephali (LM), known in mammals as the nucleus of the optic tract (NOT), is a key nucleus for global motion processing [1-4]. In all animals tested, it has been found that the majority of LM and NOT neurons are tuned to temporo-nasal (back-to-front) motion [4-11]. Moreover, the monocular gain of the optokinetic response is higher in this direction, compared to naso-temporal (front-to-back) motion [12, 13]...
December 29, 2016: Current Biology: CB
https://www.readbyqxmd.com/read/28053039/complex-visual-motion-representation-in-mouse-area-v1
#2
Ganna Palagina, Jochen F Meyer, Stelios M Smirnakis
: Rodent visual cortex has a hierarchical architecture similar to that of higher mammals (Coogan and Burkhalter, 1993; Marshel et al., 2011; Wang et al., 2012). Although notable differences exist between the species in terms or receptive field sizes and orientation map organization (Dräger, 1975; Gattass et al., 1987; Van den Bergh et al., 2010), mouse V1 is thought to respond to local orientation and visual motion elements rather than to global patterns of motion, similar to V1 in higher mammals (Niell and Stryker, 2008; Bonin et al...
January 4, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28050212/otoneurological-abnormalities-in-patients-with-friedreich-s-ataxia
#3
Bianca Simone Zeigelboim, Juliana Cristina Mesti, Vinicius Ribas Fonseca, João Henrique Faryniuk, Jair Mendes Marques, Rafaella Cardosa Cardoso, Hélio Afonso Ghizoni Teive
Introduction Friedreich's ataxia is a neurodegenerative disease and progressive by nature. It has autosomal recessive inheritance and early onset in most cases. Nystagmus and hearing loss (in some cases) make up some of the common symptoms seen in this disorder. Objective The objective of this study is to examine vestibular disorders in patients with Friedreich ataxia. Methods We conducted a retrospective cross-sectional study. We evaluated 30 patients with ages ranging from six to 72 years (mean age of 38...
January 2017: International Archives of Otorhinolaryngology
https://www.readbyqxmd.com/read/27989457/bk-channels-are-required-for-multisensory-plasticity-in-the-oculomotor-system
#4
Alexandra B Nelson, Michael Faulstich, Setareh Moghadam, Kimberly Onori, Andrea Meredith, Sascha du Lac
Neural circuits are endowed with several forms of intrinsic and synaptic plasticity that could contribute to adaptive changes in behavior, but circuit complexities have hindered linking specific cellular mechanisms with their behavioral consequences. Eye movements generated by simple brainstem circuits provide a means for relating cellular plasticity to behavioral gain control. Here we show that firing rate potentiation, a form of intrinsic plasticity mediated by reductions in BK-type calcium-activated potassium currents in spontaneously firing neurons, is engaged during optokinetic reflex compensation for inner ear dysfunction...
January 4, 2017: Neuron
https://www.readbyqxmd.com/read/27942855/functional-neuroimaging-of-visuo-vestibular-interaction
#5
R E Roberts, H Ahmad, Q Arshad, M Patel, D Dima, R Leech, B M Seemungal, D J Sharp, A M Bronstein
The brain combines visual, vestibular and proprioceptive information to distinguish between self- and world motion. Often these signals are complementary and indicate that the individual is moving or stationary with respect to the surroundings. However, conflicting visual motion and vestibular cues can lead to ambiguous or false sensations of motion. In this study, we used functional magnetic resonance imaging to explore human brain activation when visual and vestibular cues were either complementary or in conflict...
December 10, 2016: Brain Structure & Function
https://www.readbyqxmd.com/read/27941319/the-vigabatrin-induced-retinal-toxicity-is-associated-with-photopic-exposure-and-taurine-deficiency-an-in-vivo-study
#6
Ye Tao, Jixue Yang, Zhao Ma, Zhongjun Yan, Ce Liu, Jianjie Ma, Yunqin Wang, Zhen Yang, Yi Fei Huang
BACKGROUND/AIMS: Retinal toxicity is one of the most commonly discussed and concerning adverse effects of vigabatrin (VGB). The present study explored the relationship between the VGB elicited retinal toxicity, photopic exposure, and taurine deficiency, aiming at screening for risk factors to minimize the adverse effects of VGB. METHODS: The effects of VGB on function and morphology of mouse retinas were examined via a series of in vivo tests, including electroretinography (ERG), Spectral domain optical coherence tomography (SD-OCT), and optokinetic testing...
2016: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/27924617/cxcl12-sdf-1-dependent-retinal-migration-of-endogenous-bone-marrow-derived-stem-cells-improves-visual-function-after-pharmacologically-induced-retinal-degeneration
#7
Volker Enzmann, Stéphanie Lecaudé, Anna Kruschinski, Axel Vater
Mobilized bone marrow-derived stem cells (BMSC) have been discussed as an alternative strategy for endogenous repair. Thereby, different approaches for BMSC mobilization have been pursued. Herein, the role of a newly discovered oligonucleotide for retinal homing and regeneration capability of BMSCs was investigated in the sodium iodate (NaIO3) model of retinal degeneration. Mobilization was achieved in GFP-chimera with NOX-A12, a CXC-motif chemokine ligand 12 (CXCL12)/stromal cell-derived factor 1 (SDF-1)-neutralizing L-aptamer...
December 6, 2016: Stem Cell Reviews
https://www.readbyqxmd.com/read/27894470/effectiveness-of-a-placebo-intervention-on-visually-induced-nausea-in-women-a-randomized-controlled-pilot-study
#8
Veronika Müller, Kirsten Remus, Verena Hoffmann, Matthias H Tschöp, Karin Meissner
OBJECTIVE: Improvement of nausea by placebo interventions has recently been demonstrated in clinical trials and experimental settings. However, many questions regarding placebo effects on nausea remain unanswered. For example, nausea reduction in women could only be achieved when the placebo intervention was "enhanced" by conditioning, while men responded primarily to verbally suggested improvement. It is unclear whether these findings are generalizable or were due to situational variables...
December 2016: Journal of Psychosomatic Research
https://www.readbyqxmd.com/read/27832268/an-active-efficient-coding-model-of-optokinetic-nystagmus
#9
Chong Zhang, Jochen Triesch, Bertram E Shi
Optokinetic nystagmus (OKN) is an involuntary eye movement responsible for stabilizing retinal images in the presence of relative motion between an observer and the environment. Fully understanding the development of OKN requires a neurally plausible computational model that accounts for the neural development and the behavior. To date, work in this area has been limited. We propose a neurally plausible framework for the joint development of disparity and motion tuning in the visual cortex and of optokinetic and vergence eye-movement behavior...
November 1, 2016: Journal of Vision
https://www.readbyqxmd.com/read/27802139/visual-resolution-and-contrast-sensitivity-in-two-benthic-sharks
#10
Laura A Ryan, Nathan S Hart, Shaun P Collin, Jan M Hemmi
Sharks have long been described as having 'poor' vision. They are cone monochromats and anatomical estimates suggest they have low spatial resolution. However, there are no direct behavioural measurements of spatial resolution or contrast sensitivity. This study estimates contrast sensitivity and spatial resolution of two species of benthic sharks, the Port Jackson shark, Heterodontus portusjacksoni, and the brown-banded bamboo shark, Chiloscyllium punctatum, by recording eye movements in response to optokinetic stimuli...
December 15, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27760815/beat-to-beat-control-of-human-optokinetic-nystagmus-slow-phase-durations
#11
Carey D Balaban, Joseph M Furman
: This study provides the first clear evidence that the generation of optokinetic nystagmus fast phases (FPs) is a decision process that is influenced by performance of a concurrent disjunctive reaction time task (DRT). Ten subjects performed an auditory DRT during constant velocity optokinetic stimulation. Eye movements were measured in three dimensions with a magnetic search coil. Slow phase (SP) durations were defined as the interval between FPs. There were three main findings. Firstly, human optokinetic nystagmus SP durations are consistent with a model of a Gaussian basic interval generator (a type of biological clock), such that FPs can be triggered randomly at the end of a clock cycle (mean duration: 200-250 ms)...
January 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/27749752/vestibular-involvement-in-patients-with-otitis-media-with-antineutrophil-cytoplasmic-antibody-associated-vasculitis
#12
Yuka Morita, Kuniyuki Takahashi, Shuji Izumi, Yamato Kubota, Shinsuke Ohshima, Arata Horii
OBJECTIVE: Otitis media (OM) with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) is a novel concept of ear disease that is characterized by progressive mixed or sensorineural hearing loss with occasional systemic involvement. Considering the accumulating knowledge about the characteristics of and treatment for auditory dysfunction in OMAAV, the objective of this study was to investigate the vestibular function and symptoms of patients with OMAAV. STUDY DESIGN: Retrospective chart review...
January 2017: Otology & Neurotology
https://www.readbyqxmd.com/read/27732573/cortico-fugal-output-from-visual-cortex-promotes-plasticity-of-innate-motor-behaviour
#13
Bao-Hua Liu, Andrew D Huberman, Massimo Scanziani
The mammalian visual cortex massively innervates the brainstem, a phylogenetically older structure, via cortico-fugal axonal projections. Many cortico-fugal projections target brainstem nuclei that mediate innate motor behaviours, but the function of these projections remains poorly understood. A prime example of such behaviours is the optokinetic reflex (OKR), an innate eye movement mediated by the brainstem accessory optic system, that stabilizes images on the retina as the animal moves through the environment and is thus crucial for vision...
October 20, 2016: Nature
https://www.readbyqxmd.com/read/27711146/distribution-and-structure-of-synapses-on-medial-vestibular-nuclear-neurons-targeted-by-cerebellar-flocculus-purkinje-cells-and-vestibular-nerve-in-mice-light-and-electron-microscopy-studies
#14
Hitomi Matsuno, Moeko Kudoh, Akiya Watakabe, Tetsuo Yamamori, Ryuichi Shigemoto, Soichi Nagao
Adaptations of vestibulo-ocular and optokinetic response eye movements have been studied as an experimental model of cerebellum-dependent motor learning. Several previous physiological and pharmacological studies have consistently suggested that the cerebellar flocculus (FL) Purkinje cells (P-cells) and the medial vestibular nucleus (MVN) neurons targeted by FL (FL-targeted MVN neurons) may respectively maintain the memory traces of short- and long-term adaptation. To study the basic structures of the FL-MVN synapses by light microscopy (LM) and electron microscopy (EM), we injected green florescence protein (GFP)-expressing lentivirus into FL to anterogradely label the FL P-cell axons in C57BL/6J mice...
2016: PloS One
https://www.readbyqxmd.com/read/27698486/similar-contrast-sensitivity-functions-measured-using-psychophysics-and-optokinetic-nystagmus
#15
Steven C Dakin, Philip R K Turnbull
Although the contrast sensitivity function (CSF) is a particularly useful way of characterising functional vision, its measurement relies on observers making reliable perceptual reports. Such procedures can be challenging when testing children. Here we describe a system for measuring the CSF using an automated analysis of optokinetic nystagmus (OKN); an involuntary oscillatory eye movement made in response to drifting stimuli, here spatial-frequency (SF) band-pass noise. Quantifying the strength of OKN in the stimulus direction allows us to estimate contrast sensitivity across a range of SFs...
October 4, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27676762/effect-of-a-vestibular-rehabilitation-protocol-to-improve-the-health-related-quality-of-life-and-postural-balance-in-patients-with-peripheral-vertigo
#16
Salma Jeribi, Abdelmoneem Yahia, Imen Achour, Bouthaina Hammemi, Abdelmoneem Ghorbel, Mohamed Habib Elleuch, Sameh Ghroubi
OBJECTIVE: To determine the effect of completing a vestibular rehabilitation treatment protocol on postural balance, dizziness and quality of life in patients with peripheral vertigo. MATERIAL/PATIENTS AND METHODS: A prospective study concerning patients with instability due to unilateral peripheral vestibular disorder. The patients were evaluated with a clinical examination and a test of static and dynamic balance on the Satel(®) platform in which length, mediolateral (LongX) and anterior-posterior deviations (long Y) were monitored...
September 2016: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/27676757/sensory-information-treatment-during-disturbed-standing-posture-in-chronic-acquired-demyelinating-polyneuropathies-cadp
#17
Clément Provost, Giulia Piccinini, Sophie Tasseel-Ponche, Pierre Lozeron, Bertrand Arnulf, Alain Yelnik
OBJECTIVE: As proposed after stroke, the study of reactions to a sensory stimulation allows to a better understanding of postural strategies. Below, we provide the analysis in chronic acquired demyelinating polyneuropathies (CADP). MATERIAL/PATIENTS AND METHODS: Prospective study of 25 healthy subjects (57±12years, 8M, 17F) and 25 CADP (66±14years, 20M, 5F) on stabilometric platform (Techno-Concept(®), France). Proprioception was disturbed by tendon vibration on Triceps Surae (TS) and Tibialis Anterior (TA)...
September 2016: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/27659732/cisplatin-induced-toxicity-decreases-the-mouse-vestibulo-ocular-reflex
#18
Yasumitsu Takimoto, Takao Imai, Makoto Kondo, Yukiko Hanada, Atsuhiko Uno, Yusuke Ishida, Takefumi Kamakura, Tadashi Kitahara, Hidenori Inohara, Shoichi Shimada
Cisplatin is a chemotherapeutic agent commonly used for the treatment of solid tumors, and its side-effects include vestibulotoxicity. Previous studies have reported cisplatin-induced vestibulotoxicity in various animal models, but no study has investigated in vivo mouse vestibular dysfunction after cisplatin. The aim of this study was to investigate cisplatin-induced vestibulotoxicity in C57BL/6J mice. Vestibular function was assessed by recording the vestibulo-ocular reflex (VOR). This was done during sinusoidal rotations in the horizontal plane at three frequencies (0...
November 16, 2016: Toxicology Letters
https://www.readbyqxmd.com/read/27638062/multisensory-integration-in-balance-control
#19
A M Bronstein
This chapter provides an introduction to the topic of multisensory integration in balance control in, both, health and disease. One of the best-studied examples is that of visuo-vestibular interaction, which is the ability of the visual system to enhance or suppress the vestibulo-ocular reflex (VOR suppression). Of clinical relevance, examination of VOR suppression is clinically useful because only central, not peripheral, lesions impair VOR suppression. Visual, somatosensory (proprioceptive), and vestibular inputs interact strongly and continuously in the control of upright balance...
2016: Handbook of Clinical Neurology
https://www.readbyqxmd.com/read/27617181/feasibility-accuracy-and-repeatability-of-suprathreshold-saccadic-vector-optokinetic-perimetry
#20
Ian C Murray, Lorraine A Cameron, Alice D McTrusty, Antonios Perperidis, Harry M Brash, Brian W Fleck, Robert A Minns
PURPOSE: To evaluate feasibility, accuracy, and repeatability of suprathreshold Saccadic Vector Optokinetic Perimetry (SVOP) by comparison with Humphrey Field Analyzer (HFA) perimetry. METHODS: The subjects included children with suspected field defects (n = 10, age 5-15 years), adults with field defects (n = 33, age 39-78 years), healthy children (n = 12, age 6-14 years), and healthy adults (n = 30, age 16-61 years). The test protocol comprised repeat suprathreshold SVOP and HFA testing with the C-40 test pattern...
August 2016: Translational Vision Science & Technology
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