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Oculomotor circuit

Beatriz Benítez-Temiño, María A Davis-López de Carrizosa, Sara Morcuende, Esperanza R Matarredona, Rosa R de la Cruz, Angel M Pastor
Neurotrophins play a principal role in neuronal survival and differentiation during development, but also in the maintenance of appropriate adult neuronal circuits and phenotypes. In the oculomotor system, we have demonstrated that neurotrophins are key regulators of developing and adult neuronal properties, but with peculiarities depending on each neurotrophin. For instance, the administration of NGF (nerve growth factor), BDNF (brain-derived neurotrophic factor) or NT-3 (neurotrophin-3) protects neonatal extraocular motoneurons from cell death after axotomy, but only NGF and BDNF prevent the downregulation in ChAT (choline acetyltransferase)...
December 1, 2016: International Journal of Molecular Sciences
Lisa C Goelz, Fabian J David, John A Sweeney, David E Vaillancourt, Howard Poizner, Leonard Verhagen Metman, Daniel M Corcos
Unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients with Parkinson's disease improves skeletomotor function assessed clinically, and bilateral STN DBS improves motor function to a significantly greater extent. It is unknown whether unilateral STN DBS improves oculomotor function and whether bilateral STN DBS improves it to a greater extent. Further, it has also been shown that bilateral, but not unilateral, STN DBS is associated with some impaired cognitive-motor functions. The current study compared the effect of unilateral and bilateral STN DBS on sensorimotor and cognitive aspects of oculomotor control...
November 14, 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Marie-Hélène Grosbras
A vast literature indicates that small and large saccades, respectively, subserve different perceptual and cognitive strategies and may rely on different programming modes. While it is well-established that in monkeys' main oculomotor brain regions small and large eye movements are controlled by segregated neuronal populations, the representation of saccade amplitude in the human brain remains unclear. To address this question we used functional magnetic resonance imaging to scan participants while they performed saccades toward targets at either short (4°) or large (30°) eccentricity...
2016: Frontiers in Integrative Neuroscience
Jutta Billino, Jürgen Hennig, Karl R Gegenfurtner
The neural circuits involved in oculomotor control are well described; however, neuromodulation of eye movements is still hardly understood. Memory guided saccades have been extensively studied and in particular neurophysiological evidence from monkey studies points to a crucial functional role of prefrontal dopamine activity. We exploited individual differences in dopamine regulation due to the well established COMT (catechol-O-methyltransferase) Val(158)Met polymorphism to explore the link between prefrontal dopamine activity and memory guided saccades in healthy subjects...
October 25, 2016: Vision Research
Cédrick T Bonnet, Sébastien Szaffarczyk, Stéphane Baudry
Previous works usually report greater postural stability in precise visual tasks (e.g., gaze-shift tasks) than in stationary-gaze tasks. However, existing cognitive models do not fully support these results as they assume that performing an attention-demanding task while standing would alter postural stability because of the competition of attention between the tasks. Contrary to these cognitive models, attentional resources may increase to create a synergy between visual and postural brain processes to perform precise oculomotor behaviors...
October 26, 2016: Cognitive Science
Takashi Kodama, Sascha du Lac
UNLABELLED: The optokinetic response (OKR) consists of smooth eye movements following global motion of the visual surround, which suppress image slip on the retina for visual acuity. The effective performance of the OKR is limited to rather slow and low-frequency visual stimuli, although it can be adaptably improved by cerebellum-dependent mechanisms. To better understand circuit mechanisms constraining OKR performance, we monitored how distinct kinematic features of the OKR change over the course of OKR adaptation, and found that eye acceleration at stimulus onset primarily limited OKR performance but could be dramatically potentiated by visual experience...
June 22, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Paolo A Grasso, Elisabetta Làdavas, Caterina Bertini
Lateralized post-chiasmatic lesions of the primary visual pathway result in loss of visual perception in the field retinotopically corresponding to the damaged cortical area. However, patients with visual field defects have shown enhanced detection and localization of multisensory audio-visual pairs presented in the blind field. This preserved multisensory integrative ability (i.e., crossmodal blindsight) seems to be subserved by the spared retino-colliculo-dorsal pathway. According to this view, audio-visual integrative mechanisms could be used to increase the functionality of the spared circuit and, as a consequence, might represent an important tool for the rehabilitation of visual field defects...
2016: Frontiers in Systems Neuroscience
Marie R Greaney, Ann E Privorotskiy, Kristen P D'Elia, David Schoppik
Both spatial and temporal cues determine the fate of immature neurons. A major challenge at the interface of developmental and systems neuroscience is to relate this spatiotemporal trajectory of maturation to circuit-level functional organization. This study examined the development of two extraocular motor nuclei (nIII and nIV), structures in which a motoneuron's identity, or choice of muscle partner, defines its behavioral role. We used retro-orbital dye fills, in combination with fluorescent markers for motoneuron location and birthdate, to probe spatial and temporal organization of the oculomotor (nIII) and trochlear (nIV) nuclei in the larval zebrafish...
January 1, 2017: Journal of Comparative Neurology
Sebastian J Lehmann, Brian D Corneil
UNLABELLED: Pupillometry provides a simple and noninvasive index for a variety of cognitive processes, including perception, attention, task consolidation, learning, and memory. The neural substrates by which such cognitive processes influence pupil diameter remain somewhat unclear, although cortical inputs to the locus coeruleus mediating arousal are likely involved. Changes in pupil diameter also accompany covert orienting; hence the oculomotor system may provide an alternative substrate for cognitive influences on pupil diameter...
March 30, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Avery H Weiss, John P Kelly, James O Phillips
PURPOSE: Subjects with Down syndrome (DS) have an anatomical defect within the cerebellum that may impact downstream oculomotor areas. This study characterized gaze holding and gains for smooth pursuit, saccades, and optokinetic nystagmus (OKN) in DS children with infantile nystagmus (IN). METHODS: Clinical data of 18 DS children with IN were reviewed retrospectively. Subjects with constant strabismus were excluded to remove any contribution of latent nystagmus...
March 2016: Investigative Ophthalmology & Visual Science
Sung Jun Joo, Leor N Katz, Alexander C Huk
It is well established that ongoing cognitive functions affect the trajectories of limb movements mediated by corticospinal circuits, suggesting an interaction between cognition and motor action. Although there are also many demonstrations that decision formation is reflected in the ongoing neural activity in oculomotor brain circuits, it is not known whether the decision-related activity in those oculomotor structures interacts with eye movements that are decision irrelevant. Here we tested for an interaction between decisions and instructed saccades unrelated to the perceptual decision...
February 16, 2016: Proceedings of the National Academy of Sciences of the United States of America
James J FitzGerald, Chrystalina A Antoniades
PURPOSE OF REVIEW: Deep brain stimulation (DBS) is an established treatment for several neurological conditions, and is most commonly used to treat Parkinson's disease by implanting electrodes in the basal ganglia. Despite the fact that circuits involved in eye movement control traverse the basal ganglia and are thus likely to be affected by DBS, studies combining DBS with eye movement analysis have been infrequent. This review focuses on recent research studies that examine the relationship between DBS and various types of eye movements and which highlight the potential of this approach...
February 2016: Current Opinion in Neurology
Udo Rüb
The stabilization of the images of objects of the visual world onto the central foveal region of the retina enables a clear and stable view of our environment which is achieved by seven different types of eye movements (Table 6.1) (Leigh and Kennard 2004; Leigh and Zee 2006; Rüb et al. 2008b, 2009). The principal aim of these different types of eye movements is either to stabilize gaze to hold images steadily on the central foveal region of the retina or to shift gaze and bring images of objects of the visual world to the retina's fovea independent of head movements...
2015: Advances in Anatomy, Embryology, and Cell Biology
Valentina Cazzato, Marco Tullio Liuzza, Gian Vittorio Caprara, Emiliano Macaluso, Salvatore Maria Aglioti
Observing someone rapidly moving their eyes induces reflexive shifts of overt and covert attention in the onlooker. Previous studies have shown that this process can be modulated by the onlooker's personality, as well as by the social features of the person depicted in the cued face. Here, we investigated whether an individual's preference for social dominance orientation, in-group perceived similarity (PS), and political affiliation of the cued-face modulated neural activity within specific nodes of the social attention network...
October 2015: European Journal of Neuroscience
Houcheng Liang, Jinxin Song, Di Shen, Ying Qiao, Jingdong Zhang
Simultaneous co-firing of the levator palpebrae (LP) and pterygoid muscles were recorded in Marcus Gann Syndrome (MGS) patients in early clinical studies. "Release hypothesis" proposed an intrinsic masticatory oculomotor neural circuit and this kind circuit, which, however, has been observed only in amphibian. On the other hand, congenital miswiring hypothesis has overwhelmed other interpretations. However, the same phenomenon visualized in MGS cases was unveiled in human subjects without any sign of congenital oculomotor disorder...
July 2015: Journal of Biomedical Research
Robert H Wurtz
The visual and oculomotor systems in the brain have been studied extensively in the primate. Together, they can be regarded as a single brain system that underlies active vision--the normal vision that begins with visual processing in the retina and extends through the brain to the generation of eye movement by the brainstem. The system is probably one of the most thoroughly studied brain systems in the primate, and it offers an ideal opportunity to evaluate the advantages and disadvantages of the series of perturbation techniques that have been used to study it...
September 19, 2015: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
Anders Hougaard
Migraine sufferers with aura often report visual discomfort outside of attacks and many consider bright or flickering light an attack-precipitating factor. The nature of this visual hypersensitivity and its relation to the underlying pathophysiology of the migraine aura is unknown. A useful technology to study these features of migraine with aura (MA) is functional magnetic resonance imaging (fMRI), which has the potential not only to detect, but also to localize hypersensitive cortex. The main objective of this thesis was to investigate the cortical responsivity of patients with MA during visual stimulation using fMRI...
August 2015: Danish Medical Journal
Mark M G Walton, Michael J Mustari
Strabismus is a common disorder, characterized by a chronic misalignment of the eyes and numerous visual and oculomotor abnormalities. For example, saccades are often highly disconjugate. For humans with pattern strabismus, the horizontal and vertical disconjugacies vary with eye position. In monkeys, manipulations that disturb binocular vision during the first several weeks of life result in a chronic strabismus with characteristics that closely match those in human patients. Early onset strabismus is associated with altered binocular sensitivity of neurons in visual cortex...
August 2015: Journal of Neurophysiology
Pablo M Blazquez, Tatyana A Yakusheva
Data from in vitro and anesthetized preparations indicate that inhibition plays a major role in cerebellar cortex function. We investigated the role of GABA-A inhibition in the macaque cerebellar ventral-paraflocculus while animals performed oculomotor behaviors that are known to engage the circuit. We recorded Purkinje cell responses to these behaviors with and without application of gabazine, a GABA-A receptor antagonist, near the recorded neuron. Gabazine increased the neuronal responsiveness to saccades in all directions and the neuronal gain to VOR cancellation and pursuit, most significantly the eye and head velocity sensitivity...
May 19, 2015: Cell Reports
Martin Gorges, Hans-Peter Müller, Dorothée Lulé, Elmar H Pinkhardt, Albert C Ludolph, Jan Kassubek
Patients with Parkinson's disease (PD) present with eye movement disturbances that accompany the cardinal motor symptoms. Previous studies have consistently found evidence that large-scale functional networks are critically involved in eye movement control. We challenged the hypothesis that altered eye movement control in patients with PD is closely related to alterations of whole-brain functional connectivity in association with the neurodegenerative process. Saccadic and pursuit eye movements by video-oculography and 'resting-state' functional MRI (3 Tesla) were recorded from 53 subjects, i...
March 2016: Brain Imaging and Behavior
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