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Sample records for vestibular nuclei neurons

  1. Otolith-Canal Convergence in Vestibular Nuclei Neurons

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    Dickman, J. David

    1996-01-01

    During manned spaceflight, acute vestibular disturbances often occur, leading to physical duress and a loss of performance. Vestibular adaptation to the weightless environment follows within two to three days yet the mechanisms responsible for the disturbance and subsequent adaptation are still unknown In order to understand vestibular system function in space and normal earth conditions the basic physiological mechanisms of vestibular information co coding must be determined. Information processing regarding head movement and head position with respect to gravity takes place in the vestibular nuclei neurons that receive signals From the semicircular canals and otolith organs in the vestibular labyrinth. These neurons must synthesize the information into a coded output signal that provides for the head and eye movement reflexes as well as the conscious perception of the body in three-dimensional space The current investigation will for the first time. determine how the vestibular nuclei neurons quantitatively synthesize afferent information from the different linear and angular acceleration receptors in the vestibular labyrinths into an integrated output signal. During the second year of funding, progress on the current project has been focused on the anatomical orientation of semicircular canals and the spatial orientation of the innervating afferent responses. This information is necessary in order to understand how vestibular nuclei neurons process the incoming afferent spatial signals particularly with the convergent otolith afferent signals that are also spatially distributed Since information from the vestibular nuclei is presented to different brain regions associated with differing reflexive and sensory functions it is important to understand the computational mechanisms used by vestibular neurons to produce the appropriate output signal.

  2. Time constants of vestibular nuclei neurons in the goldfish: a model with ocular propioception.

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    Allum, J H; Graf, W

    1977-12-22

    A simple model of the vestibular-ocular reflex with a proprioceptive eye velocity feedback loop is used to simulate recent data on the vestibular responses of neurons in the vestibular nuclei of spinal goldfish. The data support the hypothesis that a proprioceptive feedback loop elongates the vestibular nucleus time constant to equal that of the slow phase eye movements of vestibular nystagmus.

  3. Presynaptic and postsynaptic ion channel expression in vestibular nuclei neurons after unilateral vestibular deafferentation.

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    Shao, Mei; Popratiloff, Anastas; Hirsch, June C; Peusner, Kenna D

    2009-01-01

    Vestibular compensation refers to the recovery of function occurring after unilateral vestibular deafferentation, but some patients remain uncompensated. Similarly, more than half of the operated chickens compensate three days after unilateral vestibular ganglionectomy (UVG), but the rest remain uncompensated. This review focuses on the studies performed on the principal cells of the chick tangential nucleus after UVG. The tangential nucleus is a major avian vestibular nucleus whose principal cells are all second-order, vestibular reflex projection neurons participating in the vestibuloocular and vestibulocollic reflexes controlling posture, balance, and eye movements. Using whole-cell patch-clamp approach in brain slice preparations, spontaneous spike firing, ionic conductances, and spontaneous excitatory postsynaptic currents (sEPSCs) are recorded in principal cells from controls and operated chickens three days after UVG. In compensated chickens, the proportion of spontaneous spike firing principal cells and their spike discharge rate are symmetric on the lesion and intact sides, with the rates increased over controls. However, in the uncompensated chickens, the spike discharge rate increases on the lesion side, but not on the intact side, where only silent principal cells are recorded. In all the experimental groups, including controls, silent principal cells are distinguished from spontaneous spiking cells by smaller persistent sodium conductances and higher activation thresholds for the fast sodium channel. In addition, silent principal cells on the intact side of uncompensated chickens have larger dendrotoxin-sensitive potassium conductances, with a higher ratio of immunolabeling for surface/cytoplasmic expression of a dendrotoxin-sensitive, potassium channel subunit, Kv1.1. Finally, in compensated chickens, sEPSC frequency is symmetric bilaterally, but in uncompensated chickens sEPSC frequency increased only on the lesion side, where the expression of Kv1

  4. Central vestibular system: vestibular nuclei and posterior cerebellum.

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    Barmack, Neal H

    2003-06-15

    The vestibular nuclei and posterior cerebellum are the destination of vestibular primary afferents and the subject of this review. The vestibular nuclei include four major nuclei (medial, descending, superior and lateral). In addition, smaller vestibular nuclei include: Y-group, parasolitary nucleus, and nucleus intercalatus. Each of the major nuclei can be subdivided further based primarily on cytological and immunohistochemical histological criteria or differences in afferent and/or efferent projections. The primary afferent projections of vestibular end organs are distributed to several ipsilateral vestibular nuclei. Vestibular nuclei communicate bilaterally through a commissural system that is predominantly inhibitory. Secondary vestibular neurons also receive convergent sensory information from optokinetic circuitry, central visual system and neck proprioceptive systems. Secondary vestibular neurons cannot distinguish between sources of afferent activity. However, the discharge of secondary vestibular neurons can distinguish between "active" and "passive" movements. The posterior cerebellum has extensive afferent and efferent connections with vestibular nuclei. Vestibular primary afferents are distributed to the ipsilateral uvula-nodulus as mossy fibers. Vestibular secondary afferents are distributed bilaterally. Climbing fibers to the cerebellum originate from two subnuclei of the contralateral inferior olive; the dorsomedial cell column and beta-nucleus. Vestibular climbing fibers carry information only from the vertical semicircular canals and otoliths. They establish a coordinate map, arrayed in sagittal zones on the surface of the uvula-nodulus. Purkinje cells respond to vestibular stimulation with antiphasic modulation of climbing fiber responses (CFRs) and simple spikes (SSs). The modulation of SSs is out of phase with the modulation of vestibular primary afferents. Modulation of SSs persists, even after vestibular primary afferents are destroyed by a

  5. Responses of neurons of lizard's, Lacerta viridis, vestibular nuclei to electrical stimulation of the ipsi- and contralateral VIIIth nerves.

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    Richter, A; Precht, W; Ozawa, S

    1975-03-22

    Field and intracellular potentials were recorded in the vestibular nuclei of the lizard following stimulation of the ipsi- and contralateral vestibular nerves. The field potentials induced by ipsilateral VIIIth nerve stimulation consisted of an early negative or positive-negative wave (presynaptic component) followed by a slow negativity (transsynaptic component). The spatial distribution of the field potential complex closely paralleled the extension of the vestibular nuclei. Mono- and polysynaptic EPSPs were recorded from vestibular neurons after ipsilateral VIIIth nerve stimulation. In some neurons early depolarizations preceded the EPSPs. These potentials may be elicited by electrical transmission. Often spikelike partial responses were superimposed on the EPSPs. It is assumed that these potentials represent dendritic spikes. Contralateral VIIIth nerve stimulation generated disynaptic and polysynaptic IPSPs in some neurons and EPSPs in others. The possible role of commissural inhibition in phylogeny is discussed. In a group of vestibular neurons stimulation of the ipsilateral VIIIth nerve evoked full action potentials with latencies ranging from 0.25-1.1msec. These potentials are caused by antidromic activation of neurons which send their axons to the labyrinth.

  6. Receptors of glutamate and neurotrophin in vestibular neuronal functions.

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    Chan, Y S; Chen, L W; Lai, C H; Shum, D K Y; Yung, K K L; Zhang, F X

    2003-01-01

    The last decade has witnessed advances in understanding the roles of receptors of neurotrophin and glutamate in the vestibular system. In the first section of this review, the biological actions of neurotrophins and their receptors in the peripheral and central vestibular systems are summarized. Emphasis will be placed on the roles of neurotrophins in developmental plasticity and in the maintenance of vestibular function in the adult animal. This is reviewed in relation to the developmental expression pattern of neurotrophins and their receptors within the vestibular nuclei. The second part is focused on the functional role of different glutamate receptors on central vestibular neurons. The developmental expression pattern of glutamate receptor subunits within the vestibular nuclei is reviewed in relation to the potential role of glutamate receptors in regulating the development of vestibular function. Copyright 2003 National Science Council, ROC and S. Karger AG, Basel

  7. Intrinsic membrane properties of central vestibular neurons in rodents.

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    Eugène, Daniel; Idoux, Erwin; Beraneck, Mathieu; Moore, L E; Vidal, Pierre-Paul

    2011-05-01

    Numerous studies in rodents have shown that the functional efficacy of several neurotransmitter receptors and the intrinsic membrane excitability of central vestibular neurons, as well as the organization of synaptic connections within and between vestibular nuclei can be modified during postnatal development, after a lesion of peripheral vestibular organs or in vestibular-deficient mutant animals. This review mainly focuses on the intrinsic membrane properties of neurons of the medial vestibular nuclei of rodents, their postnatal maturation, and changes following experimental or congenital alterations in vestibular inputs. It also presents the concomitant modifications in the distribution of these neurons into different neuron types, which has been based on their membrane properties in relation to their anatomical, biochemical, or functional properties. The main points discussed in this review are that (1) the intrinsic membrane properties can be used to distinguish between two dominant types of neurons, (2) the system remains plastic throughout the whole life of the animal, and finally, (3) the intracellular calcium concentration has a major effect on the intrinsic membrane properties of central vestibular neurons.

  8. Synaptic plasticity in the medial vestibular nuclei: role of glutamate receptors and retrograde messengers in rat brainstem slices.

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    Grassi, S; Pettorossi, V E

    2001-08-01

    The analysis of cellular-molecular events mediating synaptic plasticity within vestibular nuclei is an attempt to explain the mechanisms underlying vestibular plasticity phenomena. The present review is meant to illustrate the main results, obtained in vitro, on the mechanisms underlying long-term changes in synaptic strength within the medial vestibular nuclei. The synaptic plasticity phenomena taking place at the level of vestibular nuclei could be useful for adapting and consolidating the efficacy of vestibular neuron responsiveness to environmental requirements, as during visuo-vestibular recalibration and vestibular compensation. Following a general introduction on the most salient features of vestibular compensation and visuo-vestibular adaptation, which are two plastic events involving neuronal circuitry within the medial vestibular nuclei, the second and third sections describe the results from rat brainstem slice studies, demonstrating the possibility to induce long-term potentiation and depression in the medial vestibular nuclei, following high frequency stimulation of the primary vestibular afferents. In particular the mechanisms sustaining the induction and expression of vestibular long-term potentiation and depression, such as the role of various glutamate receptors and retrograde messengers have been described. The relevant role of the interaction between the platelet-activating factor, acting as a retrograde messenger, and the presynaptic metabotropic glutamate receptors, in determining the full expression of vestibular long-term potentiation is also underlined. In addition, the mechanisms involved in vestibular long-term potentiation have been compared with those leading to long-term potentiation in the hippocampus to emphasize the most significant differences emerging from vestibular studies. The fourth part, describes recent results demonstrating the essential role of nitric oxide, another retrograde messenger, in the induction of vestibular

  9. Development of the brain stem in the rat. II. Thymidine-radiographic study of the time of origin of neurons of the upper medulla, excluding the vestibular and auditory nuclei.

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    Altman, J; Bayer, S A

    1980-11-01

    Groups of pregnant rats were injected with two successive daily doses of 3H-thymidine from gestational days 12 and 13 (E12 + 13) until the day before birth (E21 + 22). In radiographs from adult progeny of these rats the proportion of neurons generated on specific days was determined in the major nuclei of the upper medulla, with the exception of the vestibular and auditory nuclei. The neurons of the motor nuclei are generated over a brief period. Neurons of the retrofacial nucleus are produced first, with more than 60% of the cells arising on day E11 or earlier. Peak generation time of abducens neurons is day E12 and of the neurons of the facial nucleus is day E13. In contrast, the neurons of the superior salivatory nucleus are produced late, predominantly on day E15 and some on day E16. The generation of the (sensory relay) neurons of the nucleus oralis of the trigeminal complex takes place over an extended period between days E12 and E15; the last generated cells include the largest neurons of this nucleus. Neurons of the raphe magnus are produced between days E11 and E14, the neurons of the rostral medullary reticular formation between days E12 and E15. The latest generated neurons of the upper medulla (excluding the cochlear nuclei) belong to a structure identified as the granular layer of the raphe. Combining these results with those of the preceding paper (Altman and Bayer, '80a) and with additional data, it is postulated that the laterally and ventrally situated motor nucleus of the trigeminal, the facial nucleus, and the nucleus ambiguous form a single longitudinal zone of branchial motor neurons with a rostral-to-caudal cytogenetic gradient. In contrast, the medially and dorsally situated (juxtaventricular) hypoglossal nucleus and abducens nucleus (together with the other nuclei of the ocular muscles) form a longitudinal somatic motor zone with a caudal-to-rostral gradient. The dorsal nucleus of the vagus and the superior salivatory nucleus may constitute

  10. Connections of the vestibular nuclei in the rabbit

    NARCIS (Netherlands)

    A.H. Epema

    1990-01-01

    textabstractThis thesis descnbes the afferent, efferent and intrinsic connections of the vestibular nuclei in the Dutch belted rabbit. Different anatomical tracing techniques were used to study these projections. A description of the vestibular complex was added, since recent data for the rabbit

  11. [Neuronal plasticity of otolith-related vestibular system].

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    Lai, Suk-King; Lai, Chun-Hong; Zhang, Fu-Xing; Ma, Chun-Wai; Shum, Daisy K Y; Chan, Ying-Shing

    2008-12-01

    This review focuses on our effort in addressing the development and lesion-induced plasticity of the gravity sensing system. After severance of sensory input from one inner ear, there is a bilateral imbalance in response dynamics and spatial coding behavior between neuronal subpopulations on the two sides. These data provide the basis for deranged spatial coding and motor deficits accompanying unilateral labyrinthectomy. Recent studies have also confirmed that both glutamate receptors and neurotrophin receptors within the bilateral vestibular nuclei are implicated in the plasticity during vestibular compensation and development. Changes in plasticity not only provide insight into the formation of a spatial map and recovery of vestibular function but also on the design of drugs for therapeutic strategies applicable to infants or vestibular disorders such as vertigo and dizziness.

  12. Vestibular nucleus neurons respond to hindlimb movement in the decerebrate cat.

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    Arshian, Milad S; Hobson, Candace E; Catanzaro, Michael F; Miller, Daniel J; Puterbaugh, Sonya R; Cotter, Lucy A; Yates, Bill J; McCall, Andrew A

    2014-06-15

    The vestibular nuclei integrate information from vestibular and proprioceptive afferents, which presumably facilitates the maintenance of stable balance and posture. However, little is currently known about the processing of sensory signals from the limbs by vestibular nucleus neurons. This study tested the hypothesis that limb movement is encoded by vestibular nucleus neurons and described the changes in activity of these neurons elicited by limb extension and flexion. In decerebrate cats, we recorded the activity of 70 vestibular nucleus neurons whose activity was modulated by limb movements. Most of these neurons (57/70, 81.4%) encoded information about the direction of hindlimb movement, while the remaining neurons (13/70, 18.6%) encoded the presence of hindlimb movement without signaling the direction of movement. The activity of many vestibular nucleus neurons that responded to limb movement was also modulated by rotating the animal's body in vertical planes, suggesting that the neurons integrated hindlimb and labyrinthine inputs. Neurons whose firing rate increased during ipsilateral ear-down roll rotations tended to be excited by hindlimb flexion, whereas neurons whose firing rate increased during contralateral ear-down tilts were excited by hindlimb extension. These observations suggest that there is a purposeful mapping of hindlimb inputs onto vestibular nucleus neurons, such that integration of hindlimb and labyrinthine inputs to the neurons is functionally relevant. Copyright © 2014 the American Physiological Society.

  13. How Vestibular Neurons Solve the Tilt/Translation Ambiguity: Comparison of Brainstem, Cerebellum, and Thalamus

    OpenAIRE

    Dora E. Angelaki; Yakusheva, Tatyana A.

    2009-01-01

    The peripheral vestibular system is faced by a sensory ambiguity, where primary otolith afferents respond identically to translational (inertial) accelerations and changes in head orientation relative to gravity. Under certain conditions, this sensory ambiguity can be resolved using extra-otolith cues, including semicircular canal signals. Here we review and summarize how neurons in the vestibular nuclei, rostral fastigial nuclei, cerebellar nodulus/uvula, and thalamus respond during combinat...

  14. The normal distribution and projections of constitutive NADPH-d/NOS neurons in the brainstem vestibular complex of the rat.

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    Saxon, D W; Beitz, A J

    2000-09-11

    The vestibular system is a highly conserved sensory system in vertebrates that is largely responsible for maintenance of one's orientation in space, posture, and balance and for visual fixation of objects during motion. In light of the considerable literature indicating an involvement of nitric oxide (NO) in sensory systems, it is important to determine whether NO is associated with vestibular pathways. To study the relationship of NO to vestibular pathways, we first examined the normal distribution of constitutive NADPH-diaphorase (NADPH-d), a marker for nitric oxide synthase (NOS), in the vestibular complex (VC) and then examined its association with selected vestibular projection neurons. Survey of the four major vestibular nuclei revealed that only the medial vestibular nucleus contained significant numbers of perikarya stained for NADPH-d/NOS. By contrast, all the vestibular nuclei contained a network of fine processes that stained positive for NADPH-d, although the density of this network varied among the individual nuclei. To determine whether NADPH-d/NOS neurons project to vestibular efferent targets, injections of the retrograde tracer Fluoro-Gold were made into known targets of second-order vestibular neurons. Vestibular neurons containing constitutive NADPH-d/NOS were found to project predominantly to the oculomotor nucleus. A small number of neurons also participate in vestibulothalamic and intrinsic vestibular connections. These results indicate that NADPH-d/NOS neurons are prevalent in the MVN and that a subpopulation of these neurons project to the oculomotor complex. Nitric oxide is probably released locally from axons located throughout the vestibular complex but may play a particularly important role in vestibulo-ocular pathways. Copyright 2000 Wiley-Liss, Inc.

  15. Neuronal nitric oxide synthase immunopositive neurons in cat vestibular complex: a light and electron microscopic study.

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    Papantchev, V; Paloff, A; Hinova-Palova, D; Hristov, S; Todorova, D; Ovtscharoff, W

    2006-11-01

    Nitric oxide is a unique neurotransmitter, which participates in many physiological and pathological processes in the organism. Nevertheless, there are little data about the neuronal nitric oxide synthase immunoreactivity (nNOS-ir) in the vestibular complex of a cat. In this respect, the aims of this study were to: (1) demonstrate nNOS-ir in the neurons and fibers, from all major and accessory vestibular nuclei; (2) describe their light microscopic morphology and distribution; (3) investigate and analyze the ultrastructure of the NOS I-immunopositive neurons, fibers, and synaptic boutons. For demonstration of the nNOS-ir, the peroxidase-antiperoxidase-diaminobenzidin method was applied. Immunopositive for nNOS neurons and fibers were present in all major and accessory vestibular nuclei. On the light microscope level, the immunopositive neurons were different in shape and size. According to the latter, they were divided into four groups--small (with diameter less than 15 microm), medium-sized (with diameter from 15 to 30 microm), large type I (with diameter from 30 to 40 microm), and large type II (with diameter greater than 40 microm). On the electron microscope level, the immunoproduct was observed in neurons, dendrites, and terminal boutons. According to the ultrastructural features, the neurons were divided into three groups--small (with diameter less than 15 microm), medium-sized (with diameter from 15 to 30 microm), and large (with diameter greater than 30 microm). At least two types of nNOS-ir synaptic boutons were easily distinguished. As a conclusion, we hope that this study will contribute to a better understanding of the functioning of the vestibular complex in cat and that some of the data presented could be extrapolated to other mammals, including human.

  16. Coding of Velocity Storage in the Vestibular Nuclei

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    Sergei B. Yakushin

    2017-08-01

    Full Text Available Semicircular canal afferents sense angular acceleration and output angular velocity with a short time constant of ≈4.5 s. This output is prolonged by a central integrative network, velocity storage that lengthens the time constants of eye velocity. This mechanism utilizes canal, otolith, and visual (optokinetic information to align the axis of eye velocity toward the spatial vertical when head orientation is off-vertical axis. Previous studies indicated that vestibular-only (VO and vestibular-pause-saccade (VPS neurons located in the medial and superior vestibular nucleus could code all aspects of velocity storage. A recently developed technique enabled prolonged recording while animals were rotated and received optokinetic stimulation about a spatial vertical axis while upright, side-down, prone, and supine. Firing rates of 33 VO and 8 VPS neurons were studied in alert cynomolgus monkeys. Majority VO neurons were closely correlated with the horizontal component of velocity storage in head coordinates, regardless of head orientation in space. Approximately, half of all tested neurons (46% code horizontal component of velocity in head coordinates, while the other half (54% changed their firing rates as the head was oriented relative to the spatial vertical, coding the horizontal component of eye velocity in spatial coordinates. Some VO neurons only coded the cross-coupled pitch or roll components that move the axis of eye rotation toward the spatial vertical. Sixty-five percent of these VO and VPS neurons were more sensitive to rotation in one direction (predominantly contralateral, providing directional orientation for the subset of VO neurons on either side of the brainstem. This indicates that the three-dimensional velocity storage integrator is composed of directional subsets of neurons that are likely to be the bases for the spatial characteristics of velocity storage. Most VPS neurons ceased firing during drowsiness, but the firing

  17. Coding of Velocity Storage in the Vestibular Nuclei

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    Yakushin, Sergei B.; Raphan, Theodore; Cohen, Bernard

    2017-01-01

    Semicircular canal afferents sense angular acceleration and output angular velocity with a short time constant of ≈4.5 s. This output is prolonged by a central integrative network, velocity storage that lengthens the time constants of eye velocity. This mechanism utilizes canal, otolith, and visual (optokinetic) information to align the axis of eye velocity toward the spatial vertical when head orientation is off-vertical axis. Previous studies indicated that vestibular-only (VO) and vestibular-pause-saccade (VPS) neurons located in the medial and superior vestibular nucleus could code all aspects of velocity storage. A recently developed technique enabled prolonged recording while animals were rotated and received optokinetic stimulation about a spatial vertical axis while upright, side-down, prone, and supine. Firing rates of 33 VO and 8 VPS neurons were studied in alert cynomolgus monkeys. Majority VO neurons were closely correlated with the horizontal component of velocity storage in head coordinates, regardless of head orientation in space. Approximately, half of all tested neurons (46%) code horizontal component of velocity in head coordinates, while the other half (54%) changed their firing rates as the head was oriented relative to the spatial vertical, coding the horizontal component of eye velocity in spatial coordinates. Some VO neurons only coded the cross-coupled pitch or roll components that move the axis of eye rotation toward the spatial vertical. Sixty-five percent of these VO and VPS neurons were more sensitive to rotation in one direction (predominantly contralateral), providing directional orientation for the subset of VO neurons on either side of the brainstem. This indicates that the three-dimensional velocity storage integrator is composed of directional subsets of neurons that are likely to be the bases for the spatial characteristics of velocity storage. Most VPS neurons ceased firing during drowsiness, but the firing rates of VO

  18. The medial vestibular nuclei, a vulnerable target in thiamine deficiency.

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    Kattah, Jorge C; Guede, Cindy; Hassanzadeh, Bahareh

    2018-01-01

    Bilateral medial vestibular nuclei (MVN) is a common target in thiamine depletion and results in acute vestibular failure. Involvement of the MVN was present in 27 out of 38 brainstem sections reported in the largest thiamine deficiency autopsy cohort with Wernicke's encephalopathy. Serial clinical, imaging and vestibulo-ocular reflex gain measured with the video head impulse (vHIT) in one patient with acute thiamine deficiency. Low horizontal VOR gain correlated with an abnormal manual head impulse and with MRI evidence of MVN in an alcohol-dependent patient with low thiamine levels. The vertical VOR gain was either normal or mildly abnormal. Thiamine replacement and normal diet restored the VOR gain and MRI signal changes to normal. This single case study provides clinical-imaging correlation for symmetric MVN compromise in thiamine deficiency, its effect on the VOR gain and the favorable response to thiamine and diet replacement when identified early.

  19. Nonphosphorylated neurofilament protein is expressed by scattered neurons in the vestibular and precerebellar brainstem.

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    Baizer, Joan S

    2009-11-17

    Vestibular information is essential for the control of posture, balance, and eye movements. The vestibular nerve projects to the four nuclei of the vestibular nuclear complex (VNC), as well as to several additional brainstem nuclei and the cerebellum. We have found that expression of the calcium-binding proteins calretinin (CR) and calbindin (CB), and the synthetic enzyme for nitric oxide synthase (nNOS) define subdivisions of the medial vestibular nucleus (MVe) and the nucleus prepositus (PrH), in cat, monkey, and human. We have asked if the pattern of expression of nonphosphorylated neurofilament protein (NPNFP) might define additional subdivisions of these or other nuclei that participate in vestibular function. We studied the distribution of cells immunoreactive to NPNFP in the brainstems of 5 cats and one squirrel monkey. Labeled cells were scattered throughout the four nuclei of the VNC, as well as in PrH, the reticular formation (RF) and the external cuneate nucleus. We used double-label immunofluorescence to visualize the distribution of these cells relative to other neurochemically defined subdivisions. NPNFP cells were excluded from the CR and CB regions of the MVe. In PrH, NPNFP and nNOS were not colocalized. Cells in the lateral vestibular nucleus and RF colocalized NPNFP and a marker for glutamatergic neurons. We also found that the cholinergic cells and axons of cranial nerve nuclei 3, 4, 6, 7,10 and 12 colocalize NPNFP. The data suggest that NPNFP is expressed by a subset of glutamatergic projection neurons of the vestibular brainstem. NPNFP may be a marker for those cells that are especially vulnerable to the effects of normal aging, neurological disease or disruption of sensory input.

  20. IDENTIFICATION OF VESTIBULOOCULAR PROJECTION NEURONS IN THE DEVELOPING CHICKEN MEDIAL VESTIBULAR NUCLEUS

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    Gottesman-Davis, Adria; Peusner, Kenna D.

    2010-01-01

    Biocytin was injected into the oculomotor, trochlear, or abducens nucleus on one side using isolated chicken brainstem preparations or brain slices to identify the medial vestibular nucleus (MVN) neurons projecting to these targets. Oculomotor nucleus injections produced retrogradely labeled neurons in the contralateral ventrolateral MVN (MVNVL), with few labeled neurons in the ipsilateral MVNVL, and rarely in the dorsomedial MVN on either side. Labeled MVNVL neurons were identified as stellate (95%) and elongate cells (5%). Trochlear nucleus injections produced a similar pattern of MVN neuron labeling. Abducens nucleus injections resulted in retrogradely labeled stellate (87%) and elongate (13%) neurons in the MVNVL which had smaller cell bodies than those projecting to the oculomotor nucleus. Anteroposteriorly, labeled MVNVL neurons were coextensive with the tangential nucleus, with neurons projecting to the oculomotor nucleus distributed lateral to and intermixed with the more medially situated neurons projecting to the abducens nucleus. The fundamental pattern of vestibuloocular projecting neurons was similar at both embryonic ages studied, E16 and E13. In contrast to mammals, where most vestibuloocular projection neurons reside within the MVN, the majority of retrogradely labeled neurons in these chicken preparations were found within the ventrolateral vestibular, descending vestibular, and tangential nuclei. The morphological identification and mapping of vestibuloocular projection neurons in the chicken MVN described here represents the first step in a systematic evaluation of the relationship between avian vestibuloocular neuron structure and function. PMID:19705454

  1. Developmental maturation of ionotropic glutamate receptor subunits in rat vestibular nuclear neurons responsive to vertical linear acceleration.

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    Lai, Suk-King; Lai, Chun-Hong; Tse, Yiu-Chung; Yung, Ken K L; Shum, Daisy K Y; Chan, Ying-Shing

    2008-12-01

    We investigated the maturation profile of subunits of ionotropic glutamate receptors in vestibular nuclear neurons that were activated by sinusoidal linear acceleration along the vertical plane. The otolithic origin of Fos expression in these neurons was confirmed as a marker of functional activation when labyrinthectomized and/or stationary control rats contrasted by showing sporadically scattered Fos-labeled neurons in the vestibular nuclei. By double immunohistochemistry for Fos and one of the receptor subunits, otolith-related neurons that expressed either alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate or N-methyl-d-aspartate subunits were first identified in the medial vestibular nucleus, spinal vestibular nucleus and Group x by postnatal day (P)7, and in the lateral vestibular nucleus and Group y by P9. No double-labeled neurons were found in the superior vestibular nucleus. Within each vestibular subnucleus, these double-labeled neurons constituted approximately 90% of the total Fos-labeled neurons. The percentage of Fos-labeled neurons expressing the GluR1 or NR2A subunit showed developmental invariance in all subnuclei. For Fos-labeled neurons expressing the NR1 subunit, similar invariance was observed except that, in Group y, these neurons decreased from P14 onwards. For Fos-labeled neurons expressing the GluR2, GluR2/3, GluR4 or NR2B subunit, a significant decrease was found by the adult stage. In particular, those expressing the GluR4 subunit showed a two- to threefold decrease in the medial vestibular nucleus, spinal vestibular nucleus and Group y. Also, those expressing the NR2B subunit showed a twofold decrease in Group y. Taken together, the postsynaptic expression of ionotropic glutamate receptor subunits in different vestibular subnuclei suggests that glutamatergic transmission within subregions plays differential developmental roles in the coding of gravity-related vertical spatial information.

  2. Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons

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    Holstein, G. R.; Friedrich, V. L. Jr; Martinelli, G. P.

    2001-01-01

    Nitric oxide is an unstable free radical that serves as a novel messenger molecule in the central nervous system (CNS). In order to understand the interplay between classic and novel chemical communication systems in vestibular pathways, the staining obtained using a monoclonal antibody directed against L-citrulline was compared with the labeling observed using more traditional markers for the presence of nitric oxide. Brainstem tissue from adult rats was processed for immunocytochemistry employing a monoclonal antibody directed against L-citrulline, a polyclonal antiserum against neuronal nitric oxide synthase, and/or NADPH-diaphorase histochemistry. Our findings demonstrate that L-citrulline can be fixed in situ by vascular perfusion, and can be visualized in fixed CNS tissue sections by immunocytochemistry. Further, the same vestibular regions and cell types are labeled by NADPH-diaphorase histochemistry, by the neuronal nitric oxide synthase antiserum, and by our anti-L-citrulline antibody. Clusters of L-citrulline-immunoreactive neurons are present in subregions of the vestibular nuclei, including the caudal portion of the inferior vestibular nucleus, the magnocellular portion of the medial vestibular nucleus, and the large cells in the ventral tier of the lateral vestibular nucleus. NADPH-diaphorase histochemical staining of these neurons clearly demonstrated their multipolar, fusiform and globular somata and long varicose dendritic processes. These results provide support for the suggestion that nitric oxide serves key roles in both vestibulo-autonomic and vestibulo-spinal pathways.

  3. Age-Related Neurochemical Changes in the Vestibular Nuclei

    Directory of Open Access Journals (Sweden)

    Paul eSmith

    2016-03-01

    Full Text Available There is evidence that the normal aging process is associated with impaired vestibulo-ocular (VOR and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa’s ganglion and the vestibular nucleus complex (VNC, it is not entirely consistent. Whatever structural and functional changes occur in the VNC as a result of aging, either to cause vestibular impairment or to compensate for it, neurochemical changes must underlie them. However, the neurochemical changes that occur in the VNC with aging are poorly understood because the available literature is very limited. This review summarises and critically evaluates the available evidence relating to the noradrenaline, serotonin, dopamine, glutamate, GABA, glycine, and nitric oxide neurotransmitter systems in the aging VNC. It is concluded that, at present, it is difficult, if not impossible, to relate the neurochemical changes observed to the function of specific VNC neurons and whether the observed changes are the cause of a functional deficit in the VNC or an effect of it. A better understanding of the neurochemical changes that occur during aging may be important for the development of potential drug treatments for age-related vestibular disorders. However, this will require the use of more sophisticated methodology such as in vivo microdialysis with single neuron recording and perhaps new technologies such as optogenetics.

  4. Age-Related Neurochemical Changes in the Vestibular Nuclei.

    Science.gov (United States)

    Smith, Paul F

    2016-01-01

    There is evidence that the normal aging process is associated with impaired vestibulo-ocular reflexes (VOR) and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa's ganglion and the vestibular nucleus complex (VNC), it is not entirely consistent. Whatever structural and functional changes occur in the VNC as a result of aging, either to cause vestibular impairment or to compensate for it, neurochemical changes must underlie them. However, the neurochemical changes that occur in the VNC with aging are poorly understood because the available literature is very limited. This review summarizes and critically evaluates the available evidence relating to the noradrenaline, serotonin, dopamine, glutamate, GABA, glycine, and nitric oxide neurotransmitter systems in the aging VNC. It is concluded that, at present, it is difficult, if not impossible, to relate the neurochemical changes observed to the function of specific VNC neurons and whether the observed changes are the cause of a functional deficit in the VNC or an effect of it. A better understanding of the neurochemical changes that occur during aging may be important for the development of potential drug treatments for age-related vestibular disorders. However, this will require the use of more sophisticated methodology such as in vivo microdialysis with single neuron recording and perhaps new technologies such as optogenetics.

  5. Convergence of Linear Acceleration and Yaw Rotation Signals on non-Eye Movement Neurons in the Vestibular Nucleus of Macaques.

    Science.gov (United States)

    Newlands, Shawn D; Abbatematteo, Ben; Wei, Min; Carney, Laurel H; Luan, Hongge

    2017-10-04

    Roughly half of all vestibular nucleus neurons without eye movement sensitivity respond to both angular rotation and linear acceleration. Linear acceleration signals arise from otolith organs and rotation signals arise from semicircular canals. In the vestibular nerve, these signals are carried by different afferents. Vestibular nucleus neurons represent the first point of convergence for these distinct sensory signals. This study systematically evaluated how rotational and translational signals interact in single neurons in the vestibular nuclei: multisensory integration at the first opportunity for convergence between these two independent vestibular sensory signals. Single-unit recordings were made from the vestibular nuclei of awake macaques during yaw rotation, translation in the horizontal plane, and combinations of rotation and translation at different frequencies. The overall response magnitude of the combined translation and rotation was generally less than the sum of the magnitudes in responses to the stimuli applied independently. However, we found that under conditions in which the peaks of the rotational and translational responses were coincident, these signals were approximately additive. With presentation of rotation and translation at different frequencies, rotation was attenuated more than translation, regardless of which was at a higher frequency. These data suggest a non-linear interaction between these two sensory modalities in the vestibular nuclei, in which coincident peak responses are proportionally stronger than other, off-peak interactions. These results are similar to those reported for other forms of multisensory integration, such as audio-visual integration in the superior colliculus. Copyright © 2017, Journal of Neurophysiology.

  6. Neural network model of vestibular nuclei reaction to onset of vestibular prosthetic stimulation

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    Jack eDigiovanna

    2016-04-01

    Full Text Available The vestibular system incorporates multiple sensory pathways to provide crucial information about head and body motion. Damage to the semicircular canals, the peripheral vestibular organs that sense rotational velocities of the head, can severely degrade the ability to perform activities of daily life. Vestibular prosthetics address this problem by using stimulating electrodes that can trigger primary vestibular afferents to modulate their firing rates, thus encoding head movement. These prostheses have been demonstrated chronically in multiple animal models and acutely tested in short-duration trials within the clinic in humans. However, mainly due to limited opportunities to fully characterize stimulation parameters, there is a lack of understanding of ‘optimal’ stimulation configurations for humans. Here we model possible adaptive plasticity in the vestibular pathway. Specifically, this model highlights the influence of adaptation of synaptic strengths and offsets in the vestibular nuclei to compensate for the initial activation of the prosthetic. By changing the synaptic strengths, the model is able to replicate the clinical observation that erroneous eye movements are attenuated within 30 minutes without any change to the prosthetic stimulation rate. Although our model was only built to match this time-point, we further examined how it affected subsequent pulse rate and pulse amplitude modulation. Pulse amplitude modulation was more effective than pulse rate modulation for nearly all stimulation configurations during these acute tests. Two non-intuitive relationships highlighted by our model explain this performance discrepancy. Specifically the attenuation of synaptic strengths for afferents stimulated during baseline adaptation and the discontinuity between baseline and residual firing rates both disproportionally boost pulse amplitude modulation. Co-modulation of pulse rate and amplitude has been experimentally shown to induce both

  7. How vestibular neurons solve the tilt/translation ambiguity. Comparison of brainstem, cerebellum, and thalamus.

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    Angelaki, Dora E; Yakusheva, Tatyana A

    2009-05-01

    The peripheral vestibular system is faced by a sensory ambiguity, where primary otolith afferents respond identically to translational (inertial) accelerations and changes in head orientation relative to gravity. Under certain conditions, this sensory ambiguity can be resolved using extra-otolith cues, including semicircular canal signals. Here we review and summarize how neurons in the vestibular nuclei, rostral fastigial nuclei, cerebellar nodulus/uvula, and thalamus respond during combinations of tilt and translation. We focus primarily on cerebellar cortex responses, as nodulus/uvula Purkinje cells reliably encode translation rather than net gravito-inertial acceleration. In contrast, neurons in the vestibular and rostral fastigial nuclei, as well as the ventral lateral and ventral posterior nuclei of the thalamus represent a continuum, with some encoding translation and some net gravito-inertial acceleration. This review also outlines how Purkinje cells use semicircular canal signals to solve the ambiguity problem and how this solution fails at low frequencies. We conclude by attempting to bridge the gap between the proposed roles of nodulus/uvula in tilt/translation discrimination and velocity storage.

  8. Vestibular nucleus neurons respond to hindlimb movement in the conscious cat

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    Miller, Derek M.; DeMayo, William M.; Bourdages, George H.

    2016-01-01

    The limbs constitute the sole interface with the ground during most waking activities in mammalian species; it is therefore expected that somatosensory inputs from the limbs provide important information to the central nervous system for balance control. In the decerebrate cat model, the activity of a subset of neurons in the vestibular nuclei (VN) has been previously shown to be modulated by hindlimb movement. However, decerebration can profoundly alter the effects of sensory inputs on the activity of brain stem neurons, resulting in epiphenomenal responses. Thus, before this study, it was unclear whether and how somatosensory inputs from the limb affected the activity of VN neurons in conscious animals. We recorded brain stem neuronal activity in the conscious cat and characterized the responses of VN neurons to flexion and extension hindlimb movements and to whole body vertical tilts (vestibular stimulation). Among 96 VN neurons whose activity was modulated by vestibular stimulation, the firing rate of 65 neurons (67.7%) was also affected by passive hindlimb movement. VN neurons in conscious cats most commonly encoded hindlimb movement irrespective of the direction of movement (n = 33, 50.8%), in that they responded to all flexion and extension movements of the limb. Other VN neurons overtly encoded information about the direction of hindlimb movement (n = 27, 41.5%), and the remainder had more complex responses. These data confirm that hindlimb somatosensory and vestibular inputs converge onto VN neurons of the conscious cat, suggesting that VN neurons integrate somatosensory inputs from the limbs in computations that affect motor outflow to maintain balance. PMID:27440244

  9. Nonphosphorylated neurofilament protein is expressed by scattered neurons in the vestibular and precerebellar brainstem

    OpenAIRE

    Baizer, Joan S.

    2009-01-01

    Vestibular information is essential for the control of posture, balance, and eye movements. The vestibular nerve projects to the four nuclei of the vestibular nuclear complex (VNC), as well as to several additional brainstem nuclei and the cerebellum. We have found that expression of the calcium-binding proteins calretinin (CR) and calbindin (CB), and the synthetic enzyme for nitric oxide synthase (nNOS) define subdivisions of the medial vestibular nucleus (MVe) and the nucleus prepositus (Pr...

  10. Lack of biocytin transfer at gap junctions in the chicken vestibular nuclei.

    Science.gov (United States)

    Arabshahi, A; Giaume, C; Peusner, K D

    1997-06-01

    In vivo experiments were designed to test for functional gap junctions at 'mixed' synapses that were morphologically characterized between the large-diameter, primary vestibular fibers and second-order vestibular neurons in the chicken, Gallus gallus. In previous intracellular recordings and dye injections into these neurons from brain slice preparations of chick embryos (E15/16) and also newborn hatchlings (HI-2), no evidence was obtained for functional gap junctions. Therefore, biocytin, a low molecular weight tracer that permeates gap junction channels, was extracellularly applied to either the ampullary nerves or to the vestibular ganglion of 3-6 day old hatchlings and adult chickens (9 months). This procedure resulted in the uptake of the dye and heavy staining of both the thick and thin fibers composing the vestibular nerve and in loading of vestibular efferent neurons. However, no dye transfer was observed between the large-diameter, primary vestibular fibers and second-order vestibular neurons. This observation, which was performed using a relatively non-invasive approach on intact animals, suggests that the gap junctions at these mixed synapses are probably not functional under the conditions of these experiments.

  11. Fos expression in neurons of the rat vestibulo-autonomic pathway activated by sinusoidal galvanic vestibular stimulation

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    Gay R Holstein

    2012-02-01

    Full Text Available The vestibular system sends projections to brainstem autonomic nuclei that modulate heart rate and blood pressure in response to changes in head and body position with regard to gravity. Consistent with this, binaural sinusoidal galvanic vestibular stimulation (sGVS in humans causes vasoconstriction in the legs, while low frequency (0.02-0.04 Hz sGVS causes a rapid drop in heart rate and blood pressure in anesthetized rats. We have hypothesized that these responses occur through activation of vestibulo-sympathetic pathways. In the present study, c-Fos protein expression was examined in neurons of the vestibular nuclei and rostral ventrolateral medullary region (RVLM that were activated by low frequency sGVS. We found c-Fos-labeled neurons in the spinal, medial and superior vestibular nuclei (SpVN, MVN and SVN, respectively and the parasolitary nucleus. The highest density of c-Fos-positive vestibular nuclear neurons was observed in MVN, where immunolabeled cells were present throughout the rostro-caudal extent of the nucleus. C-Fos expression was concentrated in the parvocellular region and largely absent from magnocellular MVN. C-Fos-labeled cells were scattered throughout caudal SpVN, and the immunostained neurons in SVN were restricted to a discrete wedge-shaped area immediately lateral to the IVth ventricle. Immunofluorescence localization of c-Fos and glutamate revealed that approximately one third of the c-Fos-labeled vestibular neurons showed intense glutamate-like immunofluorescence, far in excess of the stain reflecting the metabolic pool of cytoplasmic glutamate. In the RVLM, which receives a direct projection from the vestibular nuclei and sends efferents to preganglionic sympathetic neurons in the spinal cord, we observed an approximately 3-fold increase in c-Fos labeling in the sGVS-activated rats. We conclude that localization of c-Fos protein following sGVS is a reliable marker for sGVS-activated neurons of the vestibulo

  12. Neurotransmitters in the vestibular system.

    Science.gov (United States)

    Balaban, C D

    2016-01-01

    Neuronal networks that are linked to the peripheral vestibular system contribute to gravitoinertial sensation, balance control, eye movement control, and autonomic function. Ascending connections to the limbic system and cerebral cortex are also important for motion perception and threat recognition, and play a role in comorbid balance and anxiety disorders. The vestibular system also shows remarkable plasticity, termed vestibular compensation. Activity in these networks is regulated by an interaction between: (1) intrinsic neurotransmitters of the inner ear, vestibular nerve, and vestibular nuclei; (2) neurotransmitters associated with thalamocortical and limbic pathways that receive projections originating in the vestibular nuclei; and (3) locus coeruleus and raphe (serotonergic and nonserotonergic) projections that influence the latter components. Because the ascending vestibular interoceptive and thalamocortical pathways include networks that influence a broad range of stress responses (endocrine and autonomic), memory consolidation, and cognitive functions, common transmitter substrates provide a basis for understanding features of acute and chronic vestibular disorders. © 2016 Elsevier B.V. All rights reserved.

  13. Age-Related Neurochemical Changes in the Vestibular Nuclei

    OpenAIRE

    Paul eSmith

    2016-01-01

    There is evidence that the normal aging process is associated with impaired vestibulo-ocular reflexes (VOR) and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa’s ganglion and ...

  14. Exogenous glutamate induces short and long-term potentiation in the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Frondaroli, A; Pessia, M; Pettorossi, V E

    2001-08-08

    In rat brain stem slices, high concentrations of exogenous glutamate induce long-term potentiation (LTP) of the field potentials evoked in the medial vestibular nuclei (MVN) by vestibular afferent stimulation. At low concentrations, glutamate can also induce short-term potentiation (STP), indicating that LTP and STP are separate events depending on the level of glutamatergic synapse activation. LTP and STP are prevented by blocking NMDA receptors and nitric oxide (NO) synthesis. Conversely, blocking platelet-activating factor (PAF) and group I metabotropic glutamate receptors only prevents the full development of LTP. Moreover, in the presence of blocking agents, glutamate causes transient inhibition, suggesting that when potentiation is impeded, exogenous glutamate can activate presynaptic mechanisms that reduce glutamate release.

  15. Mechanotransduction and hyperpolarization-activated currents contribute to spontaneous activity in mouse vestibular ganglion neurons

    Science.gov (United States)

    Horwitz, Geoffrey C.; Risner-Janiczek, Jessica R.

    2014-01-01

    The hyperpolarization-activated, cyclic nucleotide–sensitive current, Ih, is present in vestibular hair cells and vestibular ganglion neurons, and is required for normal balance function. We sought to identify the molecular correlates and functional relevance of Ih in vestibular ganglion neurons. Ih is carried by channels consisting of homo- or heteromeric assemblies of four protein subunits from the Hcn gene family. The relative expression of Hcn1–4 mRNA was examined using a quantitative reverse transcription PCR (RT-PCR) screen. Hcn2 was the most highly expressed subunit in vestibular neuron cell bodies. Immunolocalization of HCN2 revealed robust expression in cell bodies of all vestibular ganglion neurons. To characterize Ih in vestibular neuron cell bodies and at hair cell–afferent synapses, we developed an intact, ex vivo preparation. We found robust physiological expression of Ih in 89% of cell bodies and 100% of calyx terminals. Ih was significantly larger in calyx terminals than in cell bodies; however, other biophysical characteristics were similar. Ih was absent in calyces lacking Hcn1 and Hcn2, but small Ih was still present in cell bodies, which suggests expression of an additional subunit, perhaps Hcn4. To determine the contributions of hair cell mechanotransduction and Ih to the firing patterns of calyx terminals, we recorded action potentials in current-clamp mode. Mechanotransduction currents were modulated by hair bundle defection and application of calcium chelators to disrupt tip links. Ih activity was modulated using ZD7288 and cAMP. We found that both hair cell transduction and Ih contribute to the rate and regularity of spontaneous action potentials in the vestibular afferent neurons. We propose that modulation of Ih in vestibular ganglion neurons may provide a mechanism for modulation of spontaneous activity in the vestibular periphery. PMID:24638995

  16. Role of nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Grassi, S; Pettorossi, V E

    2000-01-01

    In rat brainstem slices, we investigated the role of nitric oxide in long-term potentiation induced in the ventral portion of the medial vestibular nuclei by high-frequency stimulation of the primary vestibular afferents. The nitric oxide scavenger [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide ] and the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester were administered before and after induction of potentiation. Both drugs completely prevented long-term potentiation, whereas they did not impede the potentiation build-up, or affect the already established potentiation. These results demonstrate that the induction, but not the maintenance of vestibular long-term potentiation, depends on the synthesis and release into the extracellular medium of nitric oxide. In addition, we analysed the effect of the nitric oxide donor sodium nitroprusside on vestibular responses. Sodium nitroprusside induced long-term potentiation, as evidenced through the field potential enhancement and unit peak latency decrease. This potentiation was impeded by D, L-2-amino-5-phosphonopentanoic acid, and was reduced under blockade of synaptosomal platelet-activating factor receptors by ginkgolide B and group I metabotropic glutamate receptors by (R,S)-1-aminoindan-1, 5-dicarboxylic acid. When reduced, potentiation fully developed following the washout of antagonist, demonstrating an involvement of platelet-activating factor and group I metabotropic glutamate receptors in its full development. Potentiation induced by sodium nitroprusside was also associated with a decrease in the paired-pulse facilitation ratio, which persisted under ginkgolide B, indicating that nitric oxide increases glutamate release independently of platelet-activating factor-mediated presynaptic events. We suggest that nitric oxide, released after the activation of N-methyl-D-aspartate receptors, acts as a retrograde messenger leading to an enhancement of glutamate release to a

  17. Synaptic plasticity in medial vestibular nucleus neurons: comparison with computational requirements of VOR adaptation.

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    John R W Menzies

    Full Text Available BACKGROUND: Vestibulo-ocular reflex (VOR gain adaptation, a longstanding experimental model of cerebellar learning, utilizes sites of plasticity in both cerebellar cortex and brainstem. However, the mechanisms by which the activity of cortical Purkinje cells may guide synaptic plasticity in brainstem vestibular neurons are unclear. Theoretical analyses indicate that vestibular plasticity should depend upon the correlation between Purkinje cell and vestibular afferent inputs, so that, in gain-down learning for example, increased cortical activity should induce long-term depression (LTD at vestibular synapses. METHODOLOGY/PRINCIPAL FINDINGS: Here we expressed this correlational learning rule in its simplest form, as an anti-Hebbian, heterosynaptic spike-timing dependent plasticity interaction between excitatory (vestibular and inhibitory (floccular inputs converging on medial vestibular nucleus (MVN neurons (input-spike-timing dependent plasticity, iSTDP. To test this rule, we stimulated vestibular afferents to evoke EPSCs in rat MVN neurons in vitro. Control EPSC recordings were followed by an induction protocol where membrane hyperpolarizing pulses, mimicking IPSPs evoked by flocculus inputs, were paired with single vestibular nerve stimuli. A robust LTD developed at vestibular synapses when the afferent EPSPs coincided with membrane hyperpolarization, while EPSPs occurring before or after the simulated IPSPs induced no lasting change. Furthermore, the iSTDP rule also successfully predicted the effects of a complex protocol using EPSP trains designed to mimic classical conditioning. CONCLUSIONS: These results, in strong support of theoretical predictions, suggest that the cerebellum alters the strength of vestibular synapses on MVN neurons through hetero-synaptic, anti-Hebbian iSTDP. Since the iSTDP rule does not depend on post-synaptic firing, it suggests a possible mechanism for VOR adaptation without compromising gaze-holding and VOR

  18. Vestibular mechanisms.

    Science.gov (United States)

    Precht, W

    1979-01-01

    It is apparent from this and other reviews of the subject that our knowledge of vestibular function is most complete for the primary canal and otolithic afferents. Relatively little progress has been made in the understanding of receptor mechanisms and the functional importance of the efferent vestibular system. Since most of it has been summarized previously the latter were not considered here. Considerably more knowledge has accumulated in the field of central vestibular mechanisms, particularly those related to eye movements. Recent advances in functional synaptology of direct and indirect vestibuloocular pathways are described. It appears that the indirect pathways are essential for the central integration of the peripheral head velocity into a central eye position signal. Candidates for the neural integrator are presented and discussed and their connectivity described both for the horizontal and the relatively poorly studied vertical eye movement system. This field will certainly be studied extensively during the next years. Another interesting field is the role of the cerebellum in the control the vestibuloocular reflex. Recent data and hypotheses, including the problem of cerebellar plasticity, are summarized and evaluated. That the vestibular nuclei are by no means a simple relay system for specific vestibular signals destined for other sensory or motor centers is evidenced in this review by the description of multiple canal-canal, canalotolith, and visual-vestibular convergence at the nuclear level. Canal-otolith and polysensory convergence in vestibular neurons enables them to correct for the inherent inadequacies of the peripheral canal system in the low frequency range. The mechanisms of polysensory interaction in the central vestibular system will undoubtedly be an important and interesting field for future research.

  19. Differential central projections of vestibular afferents in pigeons

    Science.gov (United States)

    Dickman, J. D.; Fang, Q.

    1996-01-01

    The question of whether a differential distribution of vestibular afferent information to central nuclear neurons is present in pigeons was studied using neural tracer compounds. Discrete tracing of afferent fibers innervating the individual semicircular canal and otolith organs was produced by sectioning individual branches of the vestibular nerve that innervate the different receptor organs and applying crystals of horseradish peroxidase, or a horseradish peroxidase/cholera toxin mixture, or a biocytin compound for neuronal uptake and transport. Afferent fibers and their terminal distributions within the brainstem and cerebellum were visualized subsequently. Discrete areas in the pigeon central nervous system that receive primary vestibular input include the superior, dorsal lateral, ventral lateral, medial, descending, and tangential vestibular nuclei; the A and B groups; the intermediate, medial, and lateral cerebellar nuclei; and the nodulus, the uvula, and the paraflocculus. Generally, the vertical canal afferents projected heavily to medial regions in the superior and descending vestibular nuclei as well as the A group. Vertical canal projections to the medial and lateral vestibular nuclei were observed but were less prominent. Horizontal canal projections to the superior and descending vestibular nuclei were much more centrally located than those of the vertical canals. A more substantial projection to the medial and lateral vestibular nuclei was seen with horizontal canal afferents compared to vertical canal fibers. Afferents innervating the utricle and saccule terminated generally in the lateral regions of all vestibular nuclei in areas that were separate from the projections of the semicircular canals. In addition, utricular fibers projected to regions in the vestibular nuclei that overlapped with the horizontal semicircular canal terminal fields, whereas saccular afferents projected to regions that received vertical canal fiber terminations. Lagenar

  20. Target neurons of floccular middle zone inhibition in medial vestibular nucleus.

    Science.gov (United States)

    Sato, Y; Kanda, K; Kawasaki, T

    1988-04-19

    Unitary activities of 288 neurons were recorded extracellularly in the medial vestibular nucleus (MV) in anesthetized cats. In 19 neurons, located in the rostral part of the MV adjacent to the stria acustica, floccular middle zone stimulation resulted in cessation of spontaneous discharges. Systematic microstimulation in the brainstem during recording of 16 of 19 target neurons of floccular middle zone inhibition revealed that the target neurons projected to the ipsilateral abducens nucleus (ABN), and not to the contralateral ABN nor the oculomotor nucleus. The conjugate ipsilateral horizontal eye movement elicited by middle zone stimulation may be mediated by this pathway to motoneurons and internuclear neurons in the ipsilateral ABN. In additional experiments, the MV neurons responding antidromically to ipsilateral ABN stimulation and orthodromically to ipsilateral 8 nerve stimulation were recorded extracellularly. In only 7 of 36 recorded neurons, middle zone stimulation depressed the orthodromic and spontaneous activities. Many neurons were free of floccular inhibition. As to the route of floccular inhibitory control over the vestibulo-ocular reflex (VOR) during visual-vestibular stimulation, we propose that the interaction of target and VOR relay neurons takes place at the ipsilateral ABN and modulates the VOR, in addition to well known Ito's proposal that the interaction of the floccular output and the VOR takes place at secondary vestibular neurons and modulates the VOR.

  1. Mechanisms of vestibular compensation: recent advances.

    Science.gov (United States)

    Dutia, Mayank B

    2010-10-01

    This article reviews recent studies that have provided experimental evidence for mechanisms of neural and synaptic plasticity in the brain during vestibular compensation, the behavioural recovery that takes place following peripheral vestibular lesions. First, experimental evidence from animal studies indicates that an unbalanced vestibular commissural system is a fundamental cause of the syndrome of oculomotor and postural deficits after unilateral labyrinthectomy. Second, recent studies suggest the involvement of both GABAergic and glycinergic commissural neurons. In addition gliosis and reactive neurogenesis in the ipsilesional vestibular nuclei appear to be involved in compensation. Third, evidence from cerebellar-deficient mutant mice demonstrates an important role for cerebellum-dependent motor learning in the longer term. Factors such as stress steroids and neuromodulators such as histamine influence these plasticity mechanisms and may thus contribute to the development of compensation in patients. Vestibular compensation involves multiple, parallel plastic processes at various sites in the brain. Experimental evidence suggests that adaptive changes in the sensitivity of ipsilesional vestibular neurons to the inhibitory neurotransmitters GABA and glycine, changes in the electrophysiological excitability of vestibular neurons, changes in the inhibitory control of the brainstem vestibular networks by the cerebellum, gliosis and neurogenesis in the ipsilesional vestibular nuclei, and activity-dependent reorganization of the synaptic connectivity of the vestibular pathways are mechanisms involved in compensation.

  2. Plasticity of Scarpa’s ganglion neurons as a possible basis for functional restoration within vestibular endorgans

    Directory of Open Access Journals (Sweden)

    Cécile eTravo

    2012-06-01

    Full Text Available In a previous study (Brugeaud et al., 2007, we observed spontaneous restoration of the vestibular function in young adult rodents following excitotoxic injury of the neuronal network of vestibular endorgans. The functional restoration was supported by a repair of synaptic contacts between hair cells and primary vestibular neurons. This process was observed in 2/3 of the animals studied and occurred within five days following the synapse insult. To assess whether structural plasticity is a fundamental trait of altered vestibular endorgans and to decipher the cellular mechanisms that support such a repair process, we studied the neuronal regeneration and synaptogenesis in co-cultures of vestibular epithelia and Scarpa’s ganglion from young and adult rodents. We demonstrate that under specific culture conditions, primary vestibular neurons from young mice or rats exhibit robust ability to regenerate nervous processes. When co-cultured with vestibular epithelia, primary vestibular neurons were able to establish de novo contacts with hair cells. Under the present paradigm, these contacts displayed morphological features of immature synaptic contacts. This reparative capacity remained in older mice although to a lesser extent. Identifying the basic mechanisms underlying the repair process may provide a basis for novel therapeutic strategies to restore mature and functional vestibular synaptic contacts following damage or loss.

  3. Efferent Vestibular Neurons Show Homogenous Discharge Output But Heterogeneous Synaptic Input Profile In Vitro.

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    Miranda A Mathews

    Full Text Available Despite the importance of our sense of balance we still know remarkably little about the central control of the peripheral balance system. While previous work has shown that activation of the efferent vestibular system results in modulation of afferent vestibular neuron discharge, the intrinsic and synaptic properties of efferent neurons themselves are largely unknown. Here we substantiate the location of the efferent vestibular nucleus (EVN in the mouse, before characterizing the input and output properties of EVN neurons in vitro. We made transverse serial sections through the brainstem of 4-week-old mice, and performed immunohistochemistry for calcitonin gene-related peptide (CGRP and choline acetyltransferase (ChAT, both expressed in the EVN of other species. We also injected fluorogold into the posterior canal and retrogradely labelled neurons in the EVN of ChAT:: tdTomato mice expressing tdTomato in all cholinergic neurons. As expected the EVN lies dorsolateral to the genu of the facial nerve (CNVII. We then made whole-cell current-, and voltage-clamp recordings from visually identified EVN neurons. In current-clamp, EVN neurons display a homogeneous discharge pattern. This is characterized by a high frequency burst of action potentials at the onset of a depolarizing stimulus and the offset of a hyperpolarizing stimulus that is mediated by T-type calcium channels. In voltage-clamp, EVN neurons receive either exclusively excitatory or inhibitory inputs, or a combination of both. Despite this heterogeneous mixture of inputs, we show that synaptic inputs onto EVN neurons are predominantly excitatory. Together these findings suggest that the inputs onto EVN neurons, and more specifically the origin of these inputs may underlie EVN neuron function.

  4. BASIC CONCEPTS IN UNDERSTANDING RECOVERY OF FUNCTION IN VESTIBULAR REFLEX NETWORKS DURING VESTIBULAR COMPENSATION

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    Kenna ePeusner

    2012-02-01

    Full Text Available Unilateral peripheral vestibular lesions produce a syndrome of oculomotor and postural deficits with the symptoms at rest, the static symptoms, partially or completely normalizing shortly after the lesion due to a process known as vestibular compensation. The symptoms are thought to result from changes in the activity of vestibular sensorimotor reflexes. Since the vestibular nuclei must be intact for recovery to occur, many investigations have focused on studying these neurons after lesions. At present, the neuronal plasticity underlying early recovery from the static symptoms is not fully understood. Here we propose that knowledge of the reflex identity and input-output connections of the recorded neurons is essential to link the responses to animal behavior. We further propose that the cellular mechanisms underlying vestibular compensation can be sorted out by characterizing the synaptic responses and time course for change in morphologically-defined subsets of vestibular reflex projection neurons. Accordingly, this review focuses on the perspective gained by performing electrophysiological and immunolabeling studies on a specific subset of morphologically-defined, glutamatergic vestibular reflex projection neurons, the principal cells of the chick tangential nucleus. Reference is made to pertinent findings from other studies on vestibular nuclei neurons, but no comprehensive review of the literature is intended since broad reviews already exist. From recording excitatory and inhibitory spontaneous synaptic activity in principal cells, we find that the rebalancing of excitatory synaptic drive bilaterally is essential for vestibular compensation to proceed. This work is important for it defines for the first time the excitatory and inhibitory nature of the changing synaptic inputs and the time course for changes in a morphologically-defined subset of vestibular reflex projection neurons during early stages of vestibular compensation.

  5. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling.

    Science.gov (United States)

    Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi; Rajguru, Suhrud M

    2014-09-15

    Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. Copyright © 2014 the American Physiological Society.

  6. 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.

    Science.gov (United States)

    Matsuno, Hitomi; Kudoh, Moeko; Watakabe, Akiya; Yamamori, Tetsuo; Shigemoto, Ryuichi; Nagao, Soichi

    2016-01-01

    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. The FL P-cell axonal boutons were distributed in the magnocellular MVN and in the border region of parvocellular MVN and prepositus hypoglossi (PrH). In the magnocellular MVN, the FL-P cell axons mainly terminated on somata and proximal dendrites. On the other hand, in the parvocellular MVN/PrH, the FL P-cell axonal synaptic boutons mainly terminated on the relatively small-diameter (cells and those of vestibular nerve on the neurons of the parvocellular MVN/PrH, we added injections of biotinylated dextran amine into the semicircular canal and anterogradely labeled vestibular nerve axons in some mice. The MVN dendrites receiving the FL P-cell axonal synaptic boutons often closely apposed vestibular nerve synaptic boutons in both LM and EM studies. Such a partial overlap of synaptic boutons of FL P-cell axons with those of vestibular nerve axons in the distal dendrites of MVN neurons suggests that inhibitory synapses of FL P-cells may influence the function of neighboring excitatory synapses of vestibular nerve in the parvocellular MVN/PrH neurons.

  7. Latency of vestibular responses of pursuit neurons in the caudal frontal eye fields to whole body rotation.

    OpenAIRE

    Akao, Teppei; Saito, Hiroshi; Fukushima, Junko; Kurkin, Sergei; Fukushima, Kikuro

    2007-01-01

    The smooth pursuit system and the vestibular system interact to keep the retinal target image on the fovea by matching the eye velocity in space to target velocity during head and/or whole body movement. The caudal part of the frontal eye fields (FEF) in the fundus of the arcuate sulcus contains pursuit-related neurons and the majority of them respond to vestibular stimulation induced by whole body movement. To understand the role of FEF pursuit neurons in the interaction of vestibular and pu...

  8. Three-dimensional analysis of vestibular efferent neurons innervating semicircular canals of the gerbil

    Science.gov (United States)

    Purcell, I. M.; Perachio, A. A.

    1997-01-01

    Anterograde labeling techniques were used to examine peripheral innervation patterns of vestibular efferent neurons in the crista ampullares of the gerbil. Vestibular efferent neurons were labeled by extracellular injections of biocytin or biotinylated dextran amine into the contralateral or ipsilateral dorsal subgroup of efferent cell bodies (group e) located dorsolateral to the facial nerve genu. Anterogradely labeled efferent terminal field varicosities consist mainly of boutons en passant with fewer of the terminal type. The bouton swellings are located predominately in apposition to the basolateral borders of the afferent calyces and type II hair cells, but several boutons were identified close to the hair cell apical border on both types. Three-dimensional reconstruction and morphological analysis of the terminal fields from these cells located in the sensory neuroepithelium of the anterior, horizontal, and posterior cristae were performed. We show that efferent neurons densely innervate each end organ in widespread terminal fields. Subepithelial bifurcations of parent axons were minimal, with extensive collateralization occurring after the axons penetrated the basement membrane of the neuroepithelium. Axonal branching ranged between the 6th and 27th orders and terminal field collecting area far exceeds that of the peripheral terminals of primary afferent neurons. The terminal fields of the efferent neurons display three morphologically heterogeneous types: central, peripheral, and planum. All cell types possess terminal fields displaying a high degree of anisotropy with orientations typically parallel to or within +/-45 degrees of the longitudinal axis if the crista. Terminal fields of the central and planum zones predominately project medially toward the transverse axis from the more laterally located penetration of the basement membrane by the parent axon. Peripheral zone terminal fields extend predominately toward the planum semilunatum. The innervation

  9. Suprachiasmatic nuclei and Circadian rhythms. The role of suprachiasmatic nuclei on rhythmic activity of neurons in the lateral hypothalamic area, ventromedian nuclei and pineal gland

    Science.gov (United States)

    Nishino, H.

    1977-01-01

    Unit activity of lateral hypothalamic area (LHA) and Ventromedian nuclei (VMN) was recorded in urethane anesthetized male rats. A 5 to 10 sec. a 3-5 min and a circadian rhythmicity were observed. In about 15% of all neurons, spontaneous activity of LHA and VMN showed reciprocal relationships. Subthreshold stimuli applied at a slow rate in the septum and the suprachiasmatic nuclei (SCN) suppressed the rhythms without changing firing rates. On the other hand, stimulation of the optic nerve at a rate of 5 to 10/sec increased firing rates in 1/3 of neurons of SCN. Iontophoretically applied acetylcholine increased 80% of tested neurons of SCN, whereas norepinephrine, dopamine and 5 HT inhibited 64, 60 and 75% of SCN neurons respectively. These inhibitions were much stronger in neurons, the activity of which was increased by optic nerve stimulation. Stimulation of the SCN inhibited the tonic activity in cervical sympathetic nerves.

  10. Signal processing in the vestibular system during active versus passive head movements.

    Science.gov (United States)

    Cullen, Kathleen E; Roy, Jefferson E

    2004-05-01

    In everyday life, vestibular receptors are activated by both self-generated and externally applied head movements. Traditionally, it has been assumed that the vestibular system reliably encodes head-in-space motion throughout our daily activities and that subsequent processing by upstream cerebellar and cortical pathways is required to transform this information into the reference frames required for voluntary behaviors. However, recent studies have radically changed the way we view the vestibular system. In particular, the results of recent single-unit studies in head-unrestrained monkeys have shown that the vestibular system provides the CNS with more than an estimate of head motion. This review first considers how head-in-space velocity is processed at the level of the vestibular afferents and vestibular nuclei during active versus passive head movements. While vestibular information appears to be similarly processed by vestibular afferents during passive and active motion, it is differentially processed at the level of the vestibular nuclei. For example, one class of neurons in vestibular nuclei, which receives direct inputs from semicircular canal afferents, is substantially less responsive to active head movements than to passively applied head rotations. The projection patterns of these neurons strongly suggest that they are involved in generating head-stabilization responses as well as shaping vestibular information for the computation of spatial orientation. In contrast, a second class of neurons in the vestibular nuclei that mediate the vestibuloocular reflex process vestibular information in a manner that depends principally on the subject's current gaze strategy rather than whether the head movement was self-generated or externally applied. The implications of these results are then discussed in relation to the status of vestibular reflexes (i.e., the vestibuloocular, vestibulocollic, and cervicoocular reflexes) and implications for higher

  11. Nitric oxide modulation of the spontaneous firing of rat medial vestibular nuclear neurons.

    Science.gov (United States)

    Kim, Hoo Won; Park, Jong-Seong; Jeong, Han-Seong; Jang, Myung Joo; Kim, Byeong-Chae; Kim, Myeong-Kyu; Cho, Ki-Hyun; Kim, Tae Sun; Park, Sung Wook

    2004-10-01

    Modulation of the spontaneous activity of rat medial vestibular nuclear neurons by nitric oxide was investigated using the whole-cell patch-clamp technique. The spike frequency was increased by sodium nitroprusside (SNP), a nitric oxide liberating agent, and it was also increased by another nitric oxide liberating agent, sodium-nitroso-N-acetylpenicillamine. L-Arginine, the substrate of nitric oxide synthase, increased the firing of the neurons. The increased SNP-induced firing was inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinozalin-1-one (ODQ), a specific inhibitor of guanylate cyclase. These results suggest that nitric oxide increases the neuronal excitability of the neurons by a cGMP-dependent mechanism.

  12. The effects of bilateral vestibular loss on hippocampal volume, neuronal number and cell proliferation in rats

    Directory of Open Access Journals (Sweden)

    Yiwen eZheng

    2012-02-01

    Full Text Available Previous studies in humans have shown that bilateral loss of vestibular function is associated with a significant bilateral atrophy of the hippocampus, which correlated with the patients’ spatial memory deficits. More recently, patients who had recovered from unilateral vestibular neuritis have been reported to exhibit a significant atrophy of the left posterior hippocampus. Therefore, we investigated whether bilateral vestibular deafferentation (BVD would result in a decrease in neuronal number or volume in the rat hippocampus, using stereological methods. At 16 months post-BVD, we found no significant differences in hippocampal neuronal number or volume compared to sham controls, despite the fact that these animals exhibited severe spatial memory deficits. By contrast, using bromodeoxyuridine (BrdU as a marker of cell proliferation, we found that the number of BrdU-labelled cells significantly increased in the dentate gyrus of the hippocampus between 48 h and 1 week following BVD. Although a substantial proportion of these cells survived for up to 1 month, the survival rate was significantly lower in BVD animals when compared with that in sham animals. These results suggest a dissociation between the effects of BVD on spatial memory and hippocampal structure in rats and humans, which cannot be explained by an injury-induced increase in cell proliferation.

  13. Reconsidering the role of neuronal intrinsic properties and neuromodulation in vestibular homeostasis

    Directory of Open Access Journals (Sweden)

    Mathieu eBeraneck

    2012-02-01

    Full Text Available The sensorimotor transformations performed by central vestibular neurons (2°VN constantly adapt as the animal faces conflicting sensory information or sustains injuries. In order to ensure the homeostasis of vestibular-related functions, neural changes could in part rely on the regulation of 2°VN intrinsic properties. Here, we review evidence which demonstrates modulation and plasticity of 2°VN intrinsic properties. We first present partition of rodents 2°VN into distinct subtypes, namely type A and type B. Then, we focus on the respective properties of each type and their putative roles in vestibular functions. The intrinsic properties of 2°VN can be swiftly modulated by a wealth of neuromodulators, to adapt rapidly, for example, to temporary changes of the ecophysiological surroundings. To illustrate how intrinsic excitability can rapidly be modified in physiological conditions and therefore be targeted in the clinic, we present the modulation of vestibular reflexes in relation to the neuromodulatory fluctuation of the sleep/wake cycle. On the other hand, intrinsic properties can also be slowly yet deeply modified in response to major perturbations as is the case following a unilateral labyrinthectomy (UL. We revisit the experimental evidence which demonstrate that drastic alterations of the 2°VN intrinsic properties occur following UL, however with a slow dynamic, more on par with the compensation of dynamic deficits than static ones. Data are interpreted in the framework of a distributed process which progress from the global, large scale coping mechanisms (e.g. changes in behavioural strategies to the local, small scale ones (e.g. changes in intrinsic properties. Within this framework, the compensation of dynamic deficits improves with time as deeper modifications are engraved within the finer parts of the vestibular-related networks. Finally, we propose perspectives and working hypotheses to pave the way for future research aiming at

  14. 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.

    Directory of Open Access Journals (Sweden)

    Hitomi Matsuno

    Full Text Available 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. The FL P-cell axonal boutons were distributed in the magnocellular MVN and in the border region of parvocellular MVN and prepositus hypoglossi (PrH. In the magnocellular MVN, the FL-P cell axons mainly terminated on somata and proximal dendrites. On the other hand, in the parvocellular MVN/PrH, the FL P-cell axonal synaptic boutons mainly terminated on the relatively small-diameter (< 1 μm distal dendrites of MVN neurons, forming symmetrical synapses. The majority of such parvocellular MVN/PrH neurons were determined to be glutamatergic by immunocytochemistry and in-situ hybridization of GFP expressing transgenic mice. To further examine the spatial relationship between the synapses of FL P-cells and those of vestibular nerve on the neurons of the parvocellular MVN/PrH, we added injections of biotinylated dextran amine into the semicircular canal and anterogradely labeled vestibular nerve axons in some mice. The MVN dendrites receiving the FL P-cell axonal synaptic boutons often closely apposed vestibular nerve synaptic boutons in both LM and EM studies. Such a partial overlap of synaptic boutons of FL P-cell axons with those of vestibular nerve axons in the distal dendrites of MVN neurons suggests that inhibitory synapses of FL P-cells may influence

  15. Glutamate and GABA in vestibulo-sympathetic pathway neurons

    Directory of Open Access Journals (Sweden)

    Gay R Holstein

    2016-02-01

    Full Text Available The vestibulo-sympathetic reflex actively modulates blood pressure during changes in posture. This reflex allows humans to stand up and quadrupeds to rear or climb without a precipitous decline in cerebral perfusion. The vestibulo-sympathetic reflex pathway conveys signals from the vestibular end organs to the caudal vestibular nuclei. These cells, in turn, project to pre-sympathetic neurons in the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively. The present study assessed glutamate- and GABA-related immunofluorescence associated with central vestibular neurons of the vestibulo-sympathetic reflex pathway in rats. Retrograde FluoroGold tract tracing was used to label vestibular neurons with projections to RVLM or CVLM, and sinusoidal galvanic vestibular stimulation was employed to activate these pathways. Central vestibular neurons of the vestibulo-sympathetic reflex were identified by co-localization of FluoroGold and cFos protein, which accumulates in some vestibular neurons following galvanic stimulation. Triple-label immunofluorescence was used to co-localize glutamate- or GABA- labeling in the identified vestibulo-sympathetic reflex pathway neurons. Most activated projection neurons displayed intense glutamate immunofluorescence, suggestive of glutamatergic neurotransmission. To support this, anterograde tracer was injected into the caudal vestibular nuclei. Vestibular axons and terminals in RVLM and CVLM co-localized the anterograde tracer and vesicular glutamate transporter-2 signals. Other retrogradely-labeled cFos-positive neurons displayed intense GABA immunofluorescence. Vestibulo-sympathetic reflex pathway neurons of both phenotypes were present in the caudal medial and spinal vestibular nuclei, and projected to both RVLM and CVLM. As a group, however, triple-labeled vestibular cells with intense glutamate immunofluorescence were located more rostrally in the vestibular nuclei than the GABAergic neurons. Only the

  16. The thalamocortical vestibular system in animals and humans.

    Science.gov (United States)

    Lopez, Christophe; Blanke, Olaf

    2011-06-24

    The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex." The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data from electrophysiology and neuroanatomy in animals by comparing them with data from neuroimagery and neurology in humans. Multiple thalamic nuclei are involved in vestibular processing, including the ventroposterior complex, the ventroanterior-ventrolateral complex, the intralaminar nuclei and the posterior nuclear group (medial and lateral geniculate nuclei, pulvinar). These nuclei contain multisensory neurons that process and relay vestibular, proprioceptive and visual signals to the vestibular cortex. In non-human primates, the parieto-insular vestibular cortex (PIVC) has been proposed as the core vestibular region. Yet, vestibular responses have also been recorded in the somatosensory cortex (area 2v, 3av), intraparietal sulcus, posterior parietal cortex (area 7), area MST, frontal cortex, cingulum and hippocampus. We analyze the location of the corresponding regions in humans, and especially the human PIVC, by reviewing neuroimaging and clinical work. The widespread vestibular projections to the multimodal human PIVC, somatosensory cortex, area MST, intraparietal sulcus and hippocampus explain the large influence of vestibular signals on self-motion perception, spatial navigation, internal models of gravity, one's body perception and bodily self-consciousness. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Postsynaptic mechanisms underlying the excitatory action of histamine on medial vestibular nucleus neurons in rats

    Science.gov (United States)

    Zhang, Xiao-Yang; Yu, Lei; Zhuang, Qian-Xing; Peng, Shi-Yu; Zhu, Jing-Ning; Wang, Jian-Jun

    2013-01-01

    Background and Purpose Anti-histaminergic drugs have been widely used in the clinical treatment of vestibular disorders and most studies concentrate on their presynaptic actions. The present study investigated the postsynaptic effect of histamine on medial vestibular nucleus (MVN) neurons and the underlying mechanisms. Experimental Approach Histamine-induced postsynaptic actions on MVN neurons and the corresponding receptor and ionic mechanisms were detected by whole-cell patch-clamp recordings on rat brain slices. The distribution of postsynaptic histamine H1, H2 and H4 receptors was mapped by double and single immunostaining. Furthermore, the expression of mRNAs for H1, H2 and H4 receptors and for subtypes of Na+–Ca2+ exchangers (NCXs) and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels was assessed by quantitative real-time RT-PCR. Key Results A marked postsynaptic excitatory effect, co-mediated by histamine H1 and H2 receptors, was involved in the histamine-induced depolarization of MVN neurons. Postsynaptic H1 and H2 rather than H4 receptors were co-localized in the same MVN neurons. NCXs contributed to the inward current mediated by H1 receptors, whereas HCN channels were responsible for excitation induced by activation of H2 receptors. Moreover, NCX1 and NCX3 rather than NCX2, and HCN1 rather than HCN2-4 mRNAs, were abundantly expressed in MVN. Conclusion and Implications NCXs coupled to H1 receptors and HCN channels linked to H2 receptors co-mediate the strong postsynaptic excitatory action of histamine on MVN neurons. These results highlight an active role of postsynaptic mechanisms in the modulation by central histaminergic systems of vestibular functions and suggest potential targets for clinical treatment of vestibular disorders. Linked Articles This article is part of a themed issue on Histamine Pharmacology Update. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2013.170.issue-1 PMID:23713466

  18. Effects of galvanic vestibular stimulation on postural limb reflexes and neurons of spinal postural network.

    Science.gov (United States)

    Hsu, L-J; Zelenin, P V; Orlovsky, G N; Deliagina, T G

    2012-07-01

    Quadrupeds maintain the dorsal side up body orientation due to the activity of the postural control system driven by limb mechanoreceptors. Binaural galvanic vestibular stimulation (GVS) causes a lateral body sway toward the anode. Previously, we have shown that this new position is actively stabilized, suggesting that GVS changes a set point in the reflex mechanisms controlling body posture. The aim of the present study was to reveal the underlying neuronal mechanisms. Experiments were performed on decerebrate rabbits. The vertebral column was rigidly fixed, whereas hindlimbs were positioned on a platform. Periodic lateral tilts of the platform caused postural limb reflexes (PLRs): activation of extensors in the loaded and flexing limb and a decrease in extensor activity in the opposite (unloaded and extending) limb. Putative spinal interneurons were recorded in segments L4-L5 during PLRs, with and without GVS. We have found that GVS enhanced PLRs on the cathode side and reduced them on the anode side. This asymmetry in PLRs can account for changes in the stabilized body orientation observed in normal rabbits subjected to continuous GVS. Responses to platform tilts (frequency modulation) were observed in 106 spinal neurons, suggesting that they can contribute to PLR generation. Two neuron groups were active in opposite phases of the tilt cycle of the ipsi-limb: F-neurons in the flexion phase, and E-neurons in the extension phase. Neurons were driven mainly by afferent input from the ipsi-limb. If one supposes that F- and E-neurons contribute, respectively, to excitation and inhibition of extensor motoneurons, one can expect that the pattern of response to GVS in F-neurons will be similar to that in extensor muscles, whereas E-neurons will have an opposite pattern. We have found that ~40% of all modulated neurons meet this condition, suggesting that they contribute to the generation of PLRs and to the GVS-caused changes in PLRs.

  19. Latency of vestibular responses of pursuit neurons in the caudal frontal eye fields to whole body rotation.

    Science.gov (United States)

    Akao, Teppei; Saito, Hiroshi; Fukushima, Junko; Kurkin, Sergei; Fukushima, Kikuro

    2007-03-01

    The smooth pursuit system and the vestibular system interact to keep the retinal target image on the fovea by matching the eye velocity in space to target velocity during head and/or whole body movement. The caudal part of the frontal eye fields (FEF) in the fundus of the arcuate sulcus contains pursuit-related neurons and the majority of them respond to vestibular stimulation induced by whole body movement. To understand the role of FEF pursuit neurons in the interaction of vestibular and pursuit signals, we examined the latency and time course of discharge modulation to horizontal whole body rotation during different vestibular task conditions in head-stabilized monkeys. Pursuit neurons with horizontal preferred directions were selected, and they were classified either as gaze-velocity neurons or eye/head-velocity neurons based on the previous criteria. Responses of these neurons to whole body step-rotation at 20 degrees/s were examined during cancellation of the vestibulo-ocular reflex (VOR), VOR x1, and during chair steps in complete darkness without a target (VORd). The majority of pursuit neurons tested (approximately 70%) responded during VORd with latencies smooth pursuit. The shortest latency to the onset of target motion during smooth pursuit was 80 ms and the modal value was 95 ms. The time course of discharge rate difference of the two groups of neurons between VOR cancellation and x1 was predicted by the discharge modulation associated with smooth pursuit. These results provide further support for the involvement of the caudal FEF in integration of vestibular inputs and pursuit signals.

  20. Vestibular Neuronitis

    Science.gov (United States)

    ... up to several months. People do not have tinnitus (ringing in the ears), and hearing is usually ... as prednisone Intravenous fluids if vomiting persists Physical therapy Treatment of vertigo is done only to relieve ...

  1. Sympathetic and parasympathetic neurons are likely to be absent in the human vestibular and geniculate ganglia: an immunohistochemical study using elderly cadaveric specimens.

    Science.gov (United States)

    Yamauchi, Masato; Yamamoto, Masahito; Kitamura, Kei; Kasahara, Masaaki; Matsunaga, Satoru; Murakami, Gen; Abe, Shin-Ichi

    2016-01-01

    The vestibular and geniculate ganglia of the ear in experimental animals carry both of the tyrosine hydroxylase (TH)-positive sympathetic neurons and the neuronal nitric oxide synthase (nNOS)-positive parasympathetic neurons. With an aid of immunohistochemistry, we examined these ganglia as well as the horizontal part of the facial nerve using specimens from 10 formalin-fixed elderly cadavers. The submandibular ganglion from the same cadavers was used for the positive control for both markers. Although there was a nonspecific reaction in nuclei for the present antibody of nNOS, these ganglia were unlikely to contain either nNOS- or TH-positive neurons. However, we did not deny a possibility that the absence was a result of degeneration with aging. In contrast, the facial nerve horizontal part consistently contained both of TH-positive- and nNOS-positive fibers. These fibers might regulate blood supply to the facial nerve and the dysregulation leads to edema to elevate pressure on the nerve within its osseous canal.

  2. Differential Inhibitory Control of Semicircular Canal Nerve Afferent-Evoked Inputs in Second-Order Vestibular Neurons by Glycinergic and GABAergic Circuits

    National Research Council Canada - National Science Library

    Stefan Biesdorf; David Malinvaud; Ingrid Reichenberger; Sandra Pfanzelt; Hans Straka

    2008-01-01

    ... (2°VN) sum with disynaptic inhibitory postsynaptic potentials (IPSPs) that originate from the thickest afferent fibers of the same nerve branch and are mediated by neurons in the ipsilateral vestibular nucleus...

  3. Betahistine produces post-synaptic inhibition of the excitability of the primary afferent neurons in the vestibular endorgans.

    Science.gov (United States)

    Soto, E; Chávez, H; Valli, P; Benvenuti, C; Vega, R

    2001-01-01

    Betahistine has been used to treat several vestibular disorders of both central and peripheral origin. The objective of this work was to study the action of betahistine in the vestibular endorgans. Experiments were done in wild larval axolotl (Ambystoma tigrinum). Multiunit extracellular recordings were obtained from the semicircular canal nerve using a suction electrode. Betahistine (10 microM to 10 mM; n = 32) inhibited the basal spike discharge of the vestibular afferent neurons with an IC50 of 600 microM. To define the site of action of betahistine, its interactions with the nitric oxide synthase inhibitor NG-nitro-L-arginine (3 microM) and with the cholinergic antagonists atropine (10 microM; n = 3) and d-tubocurarine (10 microM; n = 3) were studied. The action of betahistine when co-administered with these drugs was the same as that in control experiments, indicating that its effects did not include nitric oxide production or the activation of cholinergic receptors. In contrast, 0.01-1 mM betahistine reduced the excitatory action of kainic acid (10 microM; n = 6) and quiscualic acid (1 microM; n = 13). These results indicate that the action of betahistine on the spike discharge of afferent neurons seems to be due to a post-synaptic inhibitory action on the primary afferent neuron response to the hair cell neurotransmitter.

  4. Response of pontomedullary reticulospinal neurons to vestibular stimuli in vertical planes. Role in vertical vestibulospinal reflexes of the decerebrate cat

    Science.gov (United States)

    Bolton, P. S.; Goto, T.; Schor, R. H.; Wilson, V. J.; Yamagata, Y.; Yates, B. J.

    1992-01-01

    1. To investigate the neural substrate of vestibulospinal reflexes in decerebrate cats, we studied the responses of pontomedullary reticulospinal neurons to natural stimulation of the labyrinth in vertical planes. Our principal aim was to determine whether reticulospinal neurons that terminate in, or are likely to give off collaterals to, the upper cervical segments had properties similar to those of the vestibulocollic reflex (VCR). 2. Antidromic stimulation was used to determine whether the neurons projected to the neck, lower cervical, thoracic, or lumbar levels. Dynamics of the responses of spontaneously firing neurons were studied with sinusoidal stimuli delivered at 0.05-1 Hz and aligned to the plane of body rotation, that produced maximal modulation of the neuron (response vector orientation). Each neuron was assigned a vestibular input classification of otolith, vertical canal, otolith + canal, or spatial-temporal convergence (STC). 3. We found, in agreement with previous studies, that the largest fraction of pontomedullary reticulospinal neurons projected to the lumbar cord, and that only a small number ended in the neck segments. Neurons projecting to all levels of the spinal cord had similar responses to labyrinth stimulation. 4. Reticulospinal neurons that received only vertical canal inputs were rare (1 of 67 units). Most reticulospinal neurons (48%) received predominant otolith inputs, 18% received otolith + canal input, and only 9% had STC behavior. These data are in sharp contrast to the results of our previous studies of vestibulospinal neurons. A considerable portion of vestibulospinal neurons receives vertical canal input (38%), fewer receive predominantly otolith input (22%), whereas the proportion that have otolith + canal input or STC behavior is similar to our present reticulospinal data. 5. The response vector orientations of our reticulospinal neurons, particularly those with canal inputs (canal, otolith + canal, STC) were predominantly in

  5. Projection of secondary vestibular neurons to the abducens nucleus in the carpet shark Cephaloscyllium isabella.

    Science.gov (United States)

    Montgomery, J C; Cotton, P

    1985-01-01

    The abducens nucleus in carpet sharks is not a discrete delimited nucleus, as the dendrites of the motoneurons extend into the reticular formation and the medial longitudinal fasciculus. Injections of horseradish peroxidase (HRP) designed to trace the inputs to these neurons are therefore difficult to confine to this system alone. Despite this problem a consistent finding from injection of HRP in the area of the abducens nucleus is the retrograde labelling of a column of cells in the contralateral octaval nuclei. The column of cells is predominantly in the ventral portion of the descending octaval nucleus, but does straddle the entrance of nerve VIII, extending into the caudal part of the ascending octaval nucleus. Labelled cells correspond in location and morphology to those cells receiving input from horizontal canal afferent fibers, confirming the trineuronal nature of the horizontal vestibulo-ocular reflex arc in elasmobranch fishes.

  6. Octavolateral neurons projecting to the middle and posterior rhombencephalic reticular nuclei of larval lamprey: a retrograde horseradish peroxidase labeling study.

    Science.gov (United States)

    González, M J; Manso, M J; Anadón, R

    1997-08-04

    The octavolateral area of lampreys, which receives primary fibers from the octaval and lateral line nerves, is involved in the premotor organization of body movements through secondary projections to the reticular formation. Here, the typology of neurons of the three octavolateral nuclei (ventral, medial, and dorsal) that putatively project to the middle and posterior rhombencephalic reticular nuclei were studied by retrograde transport of horseradish peroxidase (HRP) applied to these reticular nuclei. Several types of neurons were labeled in the ventral nucleus, both ipsilateral and contralateral to the site of HRP application. Some of these neurons showed a rather simple morphology (octavomotor neurons, monopolar cells), but most had more- or less-branched dendrites that were associated with one, or several, fields of terminal fibers in the octavolateral area. Unlike those of the ventral nucleus, labeled neurons of the medial nucleus were homogeneous in appearance (mostly pear-shaped). The dorsal nucleus was scarcely developed in larvae, as judged from the very simple and small labeled cells. The presence of terminal or "en-passant" boutons of secondary octavolateral fibers in the reticular area and the commissural nature of these fibers were also investigated by means of application of HRP or indocarbocyanine dye to the octavolateral nuclei. In addition, neurons of other alar plate nuclei that were labeled by the HRP application to the reticular nuclei (trigeminal descending root nucleus and solitary nucleus) were also characterized. The functional significance of these results is discussed.

  7. nuclei

    Directory of Open Access Journals (Sweden)

    Minkov N.

    2016-01-01

    Full Text Available We study the effects of quadrupole-octupole deformations on the energy and magnetic properties of high-K isomeric states in even-even heavy and superheavy nuclei. The neutron two-quasiparticle (2qp isomeric energies and magnetic dipole moments are calculated within a deformed shell model with the Bardeen-Cooper- Schrieffer (BCS pairing interaction over a wide range of quadrupole and octupole deformations. We found that in most cases the magnetic moments exhibit a pronounced sensitivity to the octupole deformation, while the 2qp energies indicate regions of nuclei in which the presence of high-K isomeric states may be associated with the presence of octupole softness or even with octupole deformation. In the present work we also examine the influence of the BCS pairing strength on the energy of the blocked isomer configuration. We show that the formation of 2qp energy minima in the space of quadrupole-octupole and eventually higher multipolarity deformations is a subtle effect depending on nuclear pairing correlations.

  8. Light microscopical study of nitric oxide synthase I-positive neurons, including fibres in the vestibular nuclear complex of the cat.

    Science.gov (United States)

    Papantchev, Vassil; Paloff, Adrian; Christova, Tatiana; Hinova-Palova, Dimka; Ovtscharoff, Wladimir

    2005-01-01

    Nitric oxide is a gaseous neurotransmitter that is synthesized by the enzyme nitric oxide synthase I (NOS I). At present, little is known of NOS I-positive neurons in the vestibular nuclear complex of the cat (VNCc). The aim of the present study was to examine the morphology, distribution patterns and interconnections of NOS I-positive neurons, including fibres in the VNCc. Five adult cats were used as experimental animals. All cats were anaesthetized and perfused transcardially. Brains were removed, postfixed, cut on a freezing microtome and stained in three different ways. Every third section was treated with the Nissl method, other sections were stained either histochemically for NADPH diaphorase or immunohistochemically for NOS I. The atlas of Berman (1928) was used for orientation in the morphometric study. NOS I-positive neurons and fibres were found in all parts of VNCc: medial vestibular nucleus (MVN); lateral vestibular nucleus (LVN); superior vestibular nucleus (SVN); inferior vestibular nucleus (IVN); X, Y, Z groups and Cajal's nucleus. The NOS I-positive neurons were classified according to their size (small, medium-sized, large neurons type I and type II) and their shape (oval, fusiform, triangular, pear-shaped, multipolar and irregular). In every nucleus, a specific neuronal population was observed. In SVN, a large number of interconnections between NOS I-positive neurons were identified. In MVN, chain-like rolls of small neurons were found. Tiny interconnections between MVN and mesencephalic reticular formation were present. Our data provide information on the morphology, distribution patterns and interconnections of NOS I-positive neurons in the VNCc and can be extrapolated to other mammals.

  9. 3D Segmentations of Neuronal Nuclei from Confocal Microscope Image Stacks

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    Antonio eLaTorre

    2013-12-01

    Full Text Available In this paper, we present an algorithm to create 3D segmentations of neuronal cells from stacks of previously segmented 2D images. The idea behind this proposal is to provide a general method to reconstruct 3D structures from 2D stacks, regardless of how these 2D stacks have been obtained. The algorithm not only reuses the information obtained in the 2D segmentation, but also attempts to correct some typical mistakes made by the 2D segmentation algorithms (for example, under segmentation of tightly-coupled clusters of cells. We have tested our algorithm in a real scenario --- the segmentation of the neuronal nuclei in different layers of the rat cerebral cortex. Several representative images from different layers of the cerebral cortex have been considered and several 2D segmentation algorithms have been compared. Furthermore, the algorithm has also been compared with the traditional 3D Watershed algorithm and the results obtained here show better performance in terms of correctly identified neuronal nuclei.

  10. Different contributions of platelet-activating factor and nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

    Science.gov (United States)

    Pettorossi, V E; Grassi, S

    2001-01-01

    In rat brainstem slices, we investigated the differential role of nitric oxide (NO) and platelet-activating factor (PAF) in long-term potentiation (LTP) induced in the ventral portion of the medial vestibular nuclei (MVN) by high-frequency stimulation (HFS) of the primary vestibular afferents. The NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) and the PAF receptor antagonist ginkgolide B (BN-52021) were administered before and after induction of potentiation. The effect of carboxy-PTIO was to completely prevent LTP. By contrast, BN-52021 only reduced the amplitude of HFS potentiation, which could develop fully at the drug washout or decline to zero, becoming a short-term phenomenon, in the case of long-lasting PAF receptor block. Both drugs, when given after HFS, had no effect on the already established potentiation, but whilst BN-52021 showed an influence within 5 min of the LTP induction, carboxy-PTIO did not affect the response once HFS was delivered. Moreover, we showed that the NO donor, sodium nitroprusside, and methylcarbamyl PAF (mc-PAF) induced LTP which was associated with an increase in glutamate release as shown by reduction in the paired-pulse facilitation ratio. The mc-PAF LTP was prevented by the NO scavenger, while NO LTP was only reduced by BN-52021. We suggest that NO and PAF are implicated as retrograde messengers in two different phases of vestibular LTP: NO in the induction phase; and PAF in the full expression phase.

  11. Intravenous CDP-choline activates neurons in supraoptic and paraventricular nuclei and induces hormone secretion.

    Science.gov (United States)

    Eyigor, Ozhan; Coskun, Cenk; Cavun, Sinan; Savci, Vahide

    2012-02-10

    The aim of the present study was to assess the effects of intravenous (i.v.) cytidine-5'-diphosphate (CDP)-choline administration on the activation of oxytocin and vasopressin neurons in the supraoptic (SON) and paraventricular nuclei (PVN), using the immunohistochemical identification of c-Fos expression as a marker of neuronal activation and to correlate this with the plasma hormone levels. Rats were catheterized under sevofluorane anesthesia and experiments were conducted 24h later. Blood samples were withdrawn from arterial catheter at 2, 5, 10, 20, 40 and 60 min after CDP-choline (0.5, 1.0 and 2.0 g/kg; i.v.) or saline (1.0 ml/kg; i.v.) for the measurement of plasma oxytocin and vasopressin levels by radioimmunoassay. Animals were sacrificed 90 min after CDP-choline administration for dual immunohistochemistry which was performed on paraformaldehyde-fixed vibratome sections. Dual immunohistochemistry for c-Fos and oxytocin or vasopressin revealed that CDP-choline activates these neurons in a dose-dependent manner. Light microscopic analyses showed that, about 41%, 75% or 87% of the oxytocin neurons and about 18%, 46% or 82% of the vasopressin neurons in SON express c-Fos, thus activated, by the dosages of 0.5, 1.0 or 2.0 g/kg CDP-choline, respectively. Increases in c-Fos expression were about 29%, 62% or 81% for the oxytocin neurons and about 38%, 70% or 78% for the vasopressin neurons in PVN with the dosages of 0.5, 1.0 or 2.0 g/kg CDP-choline, respectively. When compared to the control groups (8% and 7% oxytocin or 2% and 5% vasopressin neuronal activation in SON or PVN, respectively), these increases were found to be statistically significant (p<0.05). In the PVN most of the magnocellular neurons were activated while less number of parvocellular neurons expressed c-Fos in response to CDP-choline challenge. In correlation with c-Fos data, CDP-choline increased plasma oxytocin and vasopressin levels both dose- and time-dependently. Results of the present

  12. Damage to the vestibular inner ear causes long-term changes in neuronal nitric oxide synthase expression in the rat hippocampus.

    Science.gov (United States)

    Zheng, Y; Horii, A; Appleton, I; Darlington, C L; Smith, P F

    2001-01-01

    times following unilateral peripheral vestibular lesions, using western blotting and radioenzymatic assays. We found a decreased expression of neuronal nitric oxide synthase in the ipsilateral dentate gyrus at 2 weeks following the vestibular damage and not before, that may be related to the long-term effects of the loss of vestibular input on hippocampal function. These results support the hypothesis that head movement and position information derived from the vestibular inner ear may be important for the normal function of the hippocampus.

  13. Drug therapy for peripheral vestibular vertigo

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    L. M. Antonenko

    2017-01-01

    Full Text Available The choice of effective treatments for vestibular vertigo is one of the important problems, by taking into account the high prevalence of peripheral vestibular diseases. Different drugs, such as vestibular suppressants for the relief of acute vertigo attacks and vestibular compensation stimulants for rehabilitation treatment, are used to treat vestibular vertigo. Drug therapy in combination with vestibular exercises is effective in patients with vestibular neuronitis, Meniere's disease, so is that with therapeutic maneuvers in patients with benign paroxysmal positional vertigo. The high therapeutic efficacy and safety of betahistines permit their extensive use for the treatment of various vestibular disorders.

  14. Vestibular evoked myogenic potential

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    Felipe, Lilian

    2012-01-01

    Full Text Available Introduction: The Vestibular Evoked Myogenic Potential (VEMP is a promising test for the evaluation of the cholic descending vestibular system. This reflex depends of the integrity from the saccular macula, from the inferior vestibular nerve, the vestibular nuclei, the vestibule-spinal tract and effectors muscles. Objective: Perform a systematic review of the pertinent literature by means of database (COCHRANE, MEDLINE, LILACS, CAPES. Conclusion: The clinical application of the VEMP has expanded in the last years, as goal that this exam is used as complementary in the otoneurological evaluation currently used. But, methodological issues must be clarified. This way, this method when combined with the standard protocol, can provide a more widely evaluation from the vestibular system. The standardization of the methodology is fundamental criterion for the replicability and sensibility of the exam.

  15. Synaptic long-term potentiation and depression in the rat medial vestibular nuclei depend on neural activation of estrogenic and androgenic signals.

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    Mariangela Scarduzio

    Full Text Available Estrogenic and androgenic steroids can be synthesised in the brain and rapidly modulate synaptic transmission and plasticity through direct interaction with membrane receptors for estrogens (ERs and androgens (ARs. We used whole cell patch clamp recordings in brainstem slices of male rats to explore the influence of ER and AR activation and local synthesis of 17β-estradiol (E2 and 5α-dihydrotestosterone (DHT on the long-term synaptic changes induced in the neurons of the medial vestibular nucleus (MVN. Long-term depression (LTD and long-term potentiation (LTP caused by different patterns of high frequency stimulation (HFS of the primary vestibular afferents were assayed under the blockade of ARs and ERs or in the presence of inhibitors for enzymes synthesizing DHT (5α-reductase and E2 (P450-aromatase from testosterone (T. We found that LTD is mediated by interaction of locally produced androgens with ARs and LTP by interaction of locally synthesized E2 with ERs. In fact, the AR block with flutamide prevented LTD while did not affect LTP, and the blockade of ERs with ICI 182,780 abolished LTP without influencing LTD. Moreover, the block of P450-aromatase with letrozole not only prevented the LTP induction, but inverted LTP into LTD. This LTD is likely due to the local activation of androgens, since it was abolished under blockade of ARs. Conversely, LTD was still induced in the presence of finasteride the inhibitor of 5α-reductase demonstrating that T is able to activate ARs and induce LTD even when DHT is not synthesized. This study demonstrates a key and opposite role of sex neurosteroids in the long-term synaptic changes of the MVN with a specific role of T-DHT for LTD and of E2 for LTP. Moreover, it suggests that different stimulation patterns can lead to LTD or LTP by specifically activating the enzymes involved in the synthesis of androgenic or estrogenic neurosteroids.

  16. Molecular and behavioral profiling of Dbx1-derived neurons in the arcuate, lateral and ventromedial hypothalamic nuclei.

    Science.gov (United States)

    Sokolowski, Katie; Tran, Tuyen; Esumi, Shigeyuki; Kamal, Yasmin; Oboti, Livio; Lischinsky, Julieta; Goodrich, Meredith; Lam, Andrew; Carter, Margaret; Nakagawa, Yasushi; Corbin, Joshua G

    2016-05-21

    Neurons in the hypothalamus function to regulate the state of the animal during both learned and innate behaviors, and alterations in hypothalamic development may contribute to pathological conditions such as anxiety, depression or obesity. Despite many studies of hypothalamic development and function, the link between embryonic development and innate behaviors remains unexplored. Here, focusing on the embryonically expressed homeodomain-containing gene Developing Brain Homeobox 1 (Dbx1), we explored the relationship between embryonic lineage, post-natal neuronal identity and lineage-specific responses to innate cues. We found that Dbx1 is widely expressed across multiple developing hypothalamic subdomains. Using standard and inducible fate-mapping to trace the Dbx1-derived neurons, we identified their contribution to specific neuronal subtypes across hypothalamic nuclei and further mapped their activation patterns in response to a series of well-defined innate behaviors. Dbx1-derived neurons occupy multiple postnatal hypothalamic nuclei including the lateral hypothalamus (LH), arcuate nucleus (Arc) and the ventral medial hypothalamus (VMH). Within these nuclei, Dbx1 (+) progenitors generate a large proportion of the Pmch-, Nesfatin-, Cart-, Hcrt-, Agrp- and ERα-expressing neuronal populations, and to a lesser extent the Pomc-, TH- and Aromatase-expressing populations. Inducible fate-mapping reveals distinct temporal windows for development of the Dbx1-derived LH and Arc populations, with Agrp(+) and Cart(+) populations in the Arc arising early (E7.5-E9.5), while Pmch(+) and Hcrt(+) populations in the LH derived from progenitors expressing Dbx1 later (E9.5-E11.5). Moreover, as revealed by c-Fos labeling, Dbx1-derived cells in male and female LH, Arc and VMH are responsive during mating and aggression. In contrast, Dbx1-lineage cells in the Arc and LH have a broader behavioral tuning, which includes responding to fasting and predator odor cues. We define a novel

  17. Development and organization of polarity-specific segregation of primary vestibular afferent fibers in mice.

    Science.gov (United States)

    Maklad, Adel; Kamel, Suzan; Wong, Elaine; Fritzsch, Bernd

    2010-05-01

    A striking feature of vestibular hair cells is the polarized arrangement of their stereocilia as the basis for their directional sensitivity. In mammals, each of the vestibular end organs is characterized by a distinct distribution of these polarized cells. We utilized the technique of post-fixation transganglionic neuronal tracing with fluorescent lipid soluble dyes in embryonic and postnatal mice to investigate whether these polarity characteristics correlate with the pattern of connections between the endorgans and their central targets; the vestibular nuclei and cerebellum. We found that the cerebellar and brainstem projections develop independently from each other and have a non-overlapping distribution of neurons and afferents from E11.5 on. In addition, we show that the vestibular fibers projecting to the cerebellum originate preferentially from the lateral half of the utricular macula and the medial half of the saccular macula. In contrast, the brainstem vestibular afferents originate primarily from the medial half of the utricular macula and the lateral half of the saccular macula. This indicates that the line of hair cell polarity reversal within the striola region segregates almost mutually exclusive central projections. A possible interpretation of this feature is that this macular organization provides an inhibitory side-loop through the cerebellum to produce synergistic tuning effects in the vestibular nuclei. The canal cristae project to the brainstem vestibular nuclei and cerebellum, but the projection to the vestibulocerebellum originates preferentially from the superior half of each of the cristae. The reason for this pattern is not clear, but it may compensate for unequal activation of crista hair cells or may be an evolutionary atavism reflecting a different polarity organization in ancestral vertebrate ears.

  18. Transforming the vestibular system one molecule at a time: the molecular and developmental basis of vertebrate auditory evolution.

    Science.gov (United States)

    Duncan, Jeremy S; Fritzsch, Bernd

    2012-01-01

    We review the molecular basis of auditory development and evolution. We propose that the auditory periphery (basilar papilla, organ of Corti) evolved by transforming a newly created and redundant vestibular (gravistatic) endorgan into a sensory epithelium that could respond to sound instead of gravity. Evolution altered this new epithelia's mechanoreceptive properties through changes of hair cells, positioned the epithelium in a unique position near perilymphatic space to extract sound moving between the round and the oval window, and transformed its otolith covering into a tympanic membrane. Another important step in the evolution of an auditory system was the evolution of a unique set of "auditory neurons" that apparently evolved from vestibular neurons. Evolution of mammalian auditory (spiral ganglion) neurons coincides with GATA3 being a transcription factor found selectively in the auditory afferents. For the auditory information to be processed, the CNS required a dedicated center for auditory processing, the auditory nuclei. It is not known whether the auditory nucleus is ontogenetically related to the vestibular or electroreceptive nuclei, two sensory systems found in aquatic but not in amniotic vertebrates, or a de-novo formation of the rhombic lip in line with other novel hindbrain structures such as pontine nuclei. Like other novel hindbrain structures, the auditory nuclei express exclusively the bHLH gene Atoh1, and loss of Atoh1 results in loss of most of this nucleus in mice. Only after the basilar papilla, organ of Corti evolved could efferent neurons begin to modulate their activity. These auditory efferents most likely evolved from vestibular efferent neurons already present. The most simplistic interpretation of available data suggest that the ear, sensory neurons, auditory nucleus, and efferent neurons have been transformed by altering the developmental genetic modules necessary for their development into a novel direction conducive for sound

  19. Vestibular migraine

    DEFF Research Database (Denmark)

    Lempert, Thomas; Olesen, Jes; Furman, Joseph

    2012-01-01

    This paper presents diagnostic criteria for vestibular migraine, jointly formulated by the Committee for Classification of Vestibular Disorders of the Bárány Society and the Migraine Classification Subcommittee of the International Headache Society (IHS). The classification includes vestibular...... migraine and probable vestibular migraine. Vestibular migraine will appear in an appendix of the third edition of the International Classification of Headache Disorders (ICHD) as a first step for new entities, in accordance with the usual IHS procedures. Probable vestibular migraine may be included...... in a later version of the ICHD, when further evidence has been accumulated. The diagnosis of vestibular migraine is based on recurrent vestibular symptoms, a history of migraine, a temporal association between vestibular symptoms and migraine symptoms and exclusion of other causes of vestibular symptoms...

  20. Evaluation of the areas of neuronal cell bodies and nuclei in the myenteric plexus of the duodenum of adult rats

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    MIRANDA-NETO MARCILÍO H.

    2000-01-01

    Full Text Available This study compared the areas of cell body and nucleus profiles of the myenteric neurons in the antimesenteric and intermediate regions of the duodenum of adult rats. Five male rats were used. The duodenum was removed and dissected to whole-mount preparations, which were stained by the Giemsa technique. The areas of cell body and nucleus profiles of 100 neurons, 50 from each region, of each animal, were assessed with image analyser. Based on the global mean±SD of the areas of cell body profiles, neurons were labelled as small, medium or large. It was observed that the neurons did not differ significantly in size or incidence between the antimesenteric and intermediate regions. However, the nuclei of the small and medium neurons were significantly smaller in the latter region. It is discussed that the smaller nuclear size could be related to the cell bodies being slightly smaller on this region and to a possible smaller biosynthetic activity which would influence nuclear size.

  1. New Insights into Pathophysiology of Vestibular Migraine

    Science.gov (United States)

    Espinosa-Sanchez, Juan M.; Lopez-Escamez, Jose A.

    2015-01-01

    Vestibular migraine (VM) is a common disorder in which genetic, epigenetic, and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropeptides in the perivascular afferent terminals of these trigeminal fibers support the involvement of the trigemino-vascular system. The neurogenic inflammation triggered by activation of the trigeminal-vestibulocochlear reflex, with the subsequent inner ear plasma protein extravasation and the release of inflammatory mediators, can contribute to a sustained activation and sensitization of the trigeminal primary afferent neurons explaining VM symptoms. The reciprocal connections between brainstem vestibular nuclei and the structures that modulate trigeminal nociceptive inputs (rostral ventromedial medulla, ventrolateral periaqueductal gray, locus coeruleus, and nucleus raphe magnus) are critical to understand the pathophysiology of VM. Although cortical spreading depression can affect cortical areas involved in processing vestibular information, functional neuroimaging techniques suggest a dysmodulation in the multimodal sensory integration and processing of vestibular and nociceptive information, resulting from a vestibulo-thalamo-cortical dysfunction, as the pathogenic mechanism underlying VM. The elevated prevalence of VM suggests that multiple functional variants may confer a genetic susceptibility leading to a dysregulation of excitatory–inhibitory balance in brain structures involved in the processing of sensory information, vestibular inputs, and pain. The interactions among several functional and structural neural networks could explain the pathogenic mechanisms of VM

  2. New insights into pathophysiology of vestibular migraine

    Directory of Open Access Journals (Sweden)

    Juan Manuel Espinosa-Sanchez

    2015-02-01

    Full Text Available Vestibular migraine (VM is a common disorder in which genetic, epigenetic and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropeptides in the perivascular afferent terminals of these trigeminal fibers support the involvement of the trigemino-vascular system. The neurogenic inflammation triggered by activation of the trigeminal-vestibulocochlear reflex, with the subsequent inner ear plasma protein extravasation and the release of inflammatory mediators, can contribute to a sustained activation and sensitization of the trigeminal primary afferent neurons explaining VM symptoms. The reciprocal connections between brainstem vestibular nuclei and the structures that modulate trigeminal nociceptive inputs (rostral ventromedial medulla, ventrolateral periaqueductal grey, locus coeruleus and nucleus raphe magnus are critical to understand the pathophysiology of VM. Although cortical spreading depression can affect cortical areas involved in processing vestibular information, functional neuroimaging techniques suggest a dysmodulation in the multimodal sensory integration and processing of vestibular and nociceptive information, resulting from a vestibulo-thalamo-cortical dysfunction, as the pathogenic mechanism underlying VM. The elevated prevalence of VM suggests that multiple functional variants may confer a genetic susceptibility leading to a dysregulation of excitatory-inhibitory balance in brain structures involved in the processing of sensory information, vestibular inputs and pain. The interactions among several functional and structural neural networks could explain the pathogenic

  3. Internal models and neural computation in the vestibular system

    OpenAIRE

    Green, Andrea M.; Dora E. Angelaki

    2010-01-01

    The vestibular system is vital for motor control and spatial self-motion perception. Afferents from the otolith organs and the semicircular canals converge with optokinetic, somatosensory and motor-related signals in the vestibular nuclei, which are reciprocally interconnected with the vestibulocerebellar cortex and deep cerebellar nuclei. Here, we review the properties of the many cell types in the vestibular nuclei, as well as some fundamental computations implemented within this brainstem–...

  4. Role of the medial medullary reticular formation in relaying vestibular signals to the diaphragm and abdominal muscles

    Science.gov (United States)

    Mori, R. L.; Bergsman, A. E.; Holmes, M. J.; Yates, B. J.

    2001-01-01

    Changes in posture can affect the resting length of respiratory muscles, requiring alterations in the activity of these muscles if ventilation is to be unaffected. Recent studies have shown that the vestibular system contributes to altering respiratory muscle activity during movement and changes in posture. Furthermore, anatomical studies have demonstrated that many bulbospinal neurons in the medial medullary reticular formation (MRF) provide inputs to phrenic and abdominal motoneurons; because this region of the reticular formation receives substantial vestibular and other movement-related input, it seems likely that medial medullary reticulospinal neurons could adjust the activity of respiratory motoneurons during postural alterations. The objective of the present study was to determine whether functional lesions of the MRF affect inspiratory and expiratory muscle responses to activation of the vestibular system. Lidocaine or muscimol injections into the MRF produced a large increase in diaphragm and abdominal muscle responses to vestibular stimulation. These vestibulo-respiratory responses were eliminated following subsequent chemical blockade of descending pathways in the lateral medulla. However, inactivation of pathways coursing through the lateral medulla eliminated excitatory, but not inhibitory, components of vestibulo-respiratory responses. The simplest explanation for these data is that MRF neurons that receive input from the vestibular nuclei make inhibitory connections with diaphragm and abdominal motoneurons, whereas a pathway that courses laterally in the caudal medulla provides excitatory vestibular inputs to these motoneurons.

  5. Unilateral horizontal semicircular canal occlusion induces serotonin increase in medial vestibular nuclei: a study using microdialysis in vivo coupled with HPLC-ECD.

    Science.gov (United States)

    Zhang, Ke; Li, Qian; Xu, Jia; Liu, Junxiu; Ke, Jia; Kang, Wei; Li, Tao; Ma, Furong

    2015-06-07

    Unilateral single semicircular canal occlusion (USSCO) is an effective treatment for some cases of intractable vertigo. All patients suffer behavioural imbalance caused by surgery, and then recover with a resumption of vestibular function. However, the compensation mechanism has not been fully evaluated. Findings suggest that serotonin (5-HT) is released from nerve terminals, and plays a vital role in the plasticity of the central nervous system. In this study, we performed surgery of unilateral single semicircular canal occlusion (USSCO) on guinea pigs, and investigated the change of 5-HT by in vivo microdialysis of the medial vestibular nucleus (MVN) coupled with high-performance liquid chromatography and electrochemical detection (HPLC-ECD). A total of 12 guinea pigs were divided randomly into two groups, namely the USSCO group and the control group. Animals in the USSCO group underwent surgery of lateral horizontal semicircular canal occlusion, and those in the control group experienced the same operation but just to expose the horizontal semicircular canal without occlusion. Vestibular disturbance symptoms were observed in the case of the USSCO group, e.g. head tilting, and forced circular movements and spontaneous nystagmus at postoperative days 1 and 3. The basal level of 5-HT was determined to be 316.78 ± 16.62 nM. It elevated to 448.85 ± 24.56 nM at one day following occlusion (P = 0.001). The increase was completely abolished with the vestibular dysfunction recovery. The results showed that unilateral horizontal semicircular canal occlusion could increase the 5-HT level in MVN. 5-HT may play a significant role in the process of central vestibular compensation with residual vestibular function.

  6. Eye movements in vestibular disorders.

    Science.gov (United States)

    Kheradmand, A; Colpak, A I; Zee, D S

    2016-01-01

    The differential diagnosis of patients with vestibular symptoms usually begins with the question: is the lesion central or is it peripheral? The answer commonly emerges from a careful examination of eye movements, especially when the lesion is located in otherwise clinically silent areas of the brain such as the vestibular portions of the cerebellum (flocculus, paraflocculus which is called the tonsils in humans, nodulus, and uvula) and the vestibular nuclei as well as immediately adjacent areas (the perihypoglossal nuclei and the paramedian nuclei and tracts). The neural circuitry that controls vestibular eye movements is intertwined with a larger network within the brainstem and cerebellum that also controls other types of conjugate eye movements. These include saccades and pursuit as well as the mechanisms that enable steady fixation, both straight ahead and in eccentric gaze positions. Navigating through this complex network requires a thorough knowledge about all classes of eye movements to help localize lesions causing a vestibular disorder. Here we review the different classes of eye movements and how to examine them, and then describe common ocular motor findings associated with central vestibular lesions from both a topographic and functional perspective. © 2016 Elsevier B.V. All rights reserved.

  7. Ultrastructure of projections to the oculomotor nucleus and inferior olive from vestibular and cerebellar neurons involved in compensatory eye movements

    NARCIS (Netherlands)

    P.R. Wentzel (Pierre)

    1998-01-01

    textabstractEarly in the evolution of vertebrates eye movements were strictly primitive reflexes that were predominantly controlled by vestibular and visual sensory stimuli. Later during phylogeny, along with the development of the fovea of the retina, vertebrates acquired the ability to make

  8. Is Vestibular Neuritis an Immune Related Vestibular Neuropathy Inducing Vertigo?

    Directory of Open Access Journals (Sweden)

    A. Greco

    2014-01-01

    Full Text Available Objectives. To review the current knowledge of the aetiology of vestibular neuritis including viral infections, vascular occlusion, and immunomediated mechanisms and to discuss the pathogenesis with relevance to pharmacotherapy. Systematic Review Methodology. Relevant publications on the aetiology and treatment of vestibular neuritis from 1909 to 2013 were analysed. Results and Conclusions. Vestibular neuritis is the second most common cause of peripheral vestibular vertigo and is due to a sudden unilateral loss of vestibular function. Vestibular neuronitis is a disorder thought to represent the vestibular-nerve equivalent of sudden sensorineural hearing loss. Histopathological studies of patients who died from unrelated clinical problems have demonstrated degeneration of the superior vestibular nerve. The characteristic signs and symptoms include sudden and prolonged vertigo, the absence of auditory symptoms, and the absence of other neurological symptoms. The aetiology and pathogenesis of the condition remain unknown. Proposed theories of causation include viral infections, vascular occlusion, and immunomediated mechanisms. The management of vestibular neuritis involves symptomatic treatment with antivertiginous drugs, causal treatment with corticosteroids, and physical therapy. Antiviral agents did not improve the outcomes.

  9. Spatial Analysis of the Neuronal Density of Aminergic Brainstem Nuclei in Primary Neurodegenerative and Vascular Dementia: A Comparative Immunocytochemical and Quantitative Study Using a Graph Method

    Directory of Open Access Journals (Sweden)

    Yan Yang

    1999-01-01

    Full Text Available A graph method was employed to analyse spatial neuronal patterns of pontine nuclei with ascending aminergic projections to the forebrain (nucleus centralis superior (NCS, raphes dorsalis (NRD and locus coeruleus (LC, in Alzheimer disease (AD, Huntington disease (HD, and vascular (VD as well as “mixed‐type” (VA dementia, compared with non‐demented controls (CO and a small sample of brains from schizophrenics (“dementia praecox” (DP. The quantitative evaluations by the “minimal spanning tree (MST” were complemented by rough neurofibrillary tangle (NFT counts and by semiquantitative immunohistochemical assessment of amyloid deposition, neuritic plaque formation, and cellular gliosis. The AD cases showed a significant decline of neuronal density in all nuclei examined, as compared with controls and DP. Neuronal loss was not significant in VD, while the mixed cases with both vascular and Alzheimer‐type pathology exhibited pronounced changes of neuronal density. Amyloid deposition occurred almost exclusively in AD and VA, as a rule, being of moderate degree, except for two presenile AD cases where it was marked. NFT were significantly increased in all nuclei in AD and in the VA cases, while they only occasionally appeared beyond age 55 in HD, DP and CO. The four HD cases showed in the NCS and NRD neuronal loss as severe as in AD. This neuronal loss implicates impairment of serotoninergic and noradrenergic neuromodulation as one basic mechanism promoting dementia in AD, VA and perhaps in HD.

  10. Medial vestibular connections with the hypocretin (orexin) system

    Science.gov (United States)

    Horowitz, Seth S.; Blanchard, Jane; Morin, Lawrence P.

    2005-01-01

    The mammalian medial vestibular nucleus (MVe) receives input from all vestibular endorgans and provides extensive projections to the central nervous system. Recent studies have demonstrated projections from the MVe to the circadian rhythm system. In addition, there are known projections from the MVe to regions considered to be involved in sleep and arousal. In this study, afferent and efferent subcortical connectivity of the medial vestibular nucleus of the golden hamster (Mesocricetus auratus) was evaluated using cholera toxin subunit-B (retrograde), Phaseolus vulgaris leucoagglutinin (anterograde), and pseudorabies virus (transneuronal retrograde) tract-tracing techniques. The results demonstrate MVe connections with regions mediating visuomotor and postural control, as previously observed in other mammals. The data also identify extensive projections from the MVe to regions mediating arousal and sleep-related functions, most of which receive immunohistochemically identified projections from the lateral hypothalamic hypocretin (orexin) neurons. These include the locus coeruleus, dorsal and pedunculopontine tegmental nuclei, dorsal raphe, and lateral preoptic area. The MVe itself receives a projection from hypocretin cells. CTB tracing demonstrated reciprocal connections between the MVe and most brain areas receiving MVe efferents. Virus tracing confirmed and extended the MVe afferent connections identified with CTB and additionally demonstrated transneuronal connectivity with the suprachiasmatic nucleus and the medial habenular nucleus. These anatomical data indicate that the vestibular system has access to a broad array of neural functions not typically associated with visuomotor, balance, or equilibrium, and that the MVe is likely to receive information from many of the same regions to which it projects.

  11. The thalamocortical vestibular system in animals and humans

    OpenAIRE

    LOPEZ, Christophe; Blanke, Olaf

    2011-01-01

    The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex." The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data fro...

  12. Lateral medullary syndrome following injury of the vestibular pathway to the core vestibular cortex: Diffusion tensor imaging study.

    Science.gov (United States)

    Yeo, Sang Seok; Jang, Sung Ho; Kwon, Jung Won

    2017-12-05

    The parieto-insular vestibular cortex (PIVC) is a core region of vestibular input into regions of the cortex. The vestibular nuclei have reciprocal connections with the PIVC. However, little is known about injury of the core vestibular pathway to the PIVC in patients with dorsolateral medullary infarctions. In this study, using diffusion tensor tractography (DTT), we investigated injury of the neural connections between the vestibular nuclei and the PIVC in patients with typical central vestibular disorder. Eight consecutive patients with lateral medullary syndrome and 10 control subjects were recruited for this study. To reconstruct the core vestibular pathway to the PIVC, we defined the seed region of interest (ROI) as the vestibular nuclei of the pons and the target ROI as the PIVC. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. The core vestibular pathway to the PIVC showed significantly lower tract volume in patients compared with the control group (p0.05). In conclusion, injury of the core vestibular pathway to the PIVC was demonstrated in patients with lateral vestibular syndrome following dorsolateral medullary infarcts. We believe that analysis of the core vestibular pathway to the PIVC using DTT would be helpful in evaluating patients with lateral medullary syndrome. Copyright © 2017. Published by Elsevier B.V.

  13. K+ Currents in Isolated Vestibular Afferent Calyx Terminals

    National Research Council Canada - National Science Library

    Dhawan, Ritu; Mann, Scott E; Meredith, Frances L; Rennie, Katherine J

    2010-01-01

    Vestibular hair cells transduce mechanical displacements of their hair bundles into an electrical receptor potential which modulates transmitter release and subsequent action potential firing in afferent neurons...

  14. Memory trace of motor learning shifts transsynaptically from cerebellar cortex to nuclei for consolidation.

    Science.gov (United States)

    Shutoh, F; Ohki, M; Kitazawa, H; Itohara, S; Nagao, S

    2006-05-12

    Adaptation of ocular reflexes is a prototype of motor learning. While the cerebellum is acknowledged as the critical site for motor learning, the functional differences between the cerebellar cortex and nuclei in motor memory formation are not precisely known. Two different views are proposed: one that the memory is formed within the cerebellar flocculus, and the other that the memory is formed within vestibular nuclei. Here we developed a new paradigm of long-term adaptation of mouse horizontal optokinetic response eye movements and examined the location of its memory trace. We also tested the role of flocculus and inferior olive in long-term adaptation by chronic lesion experiments. Reversible bilateral flocculus shutdown with local application of 0.5 microl-5% lidocaine extinguished the memory trace of day-long adaptation, while it very little affected the memory trace of week-long adaptation. The responsiveness of vestibular nuclei after week-long adaptation was examined by measuring the extracellular field responses to the electrical stimulation of vestibular nerve under trichloroacetaldehyde anesthesia. The amplitudes and slopes of evoked monosynaptic field response (N1) of week-long adapted mice were enhanced around the medial vestibular nucleus compared with those of control mice. Chronic flocculus or inferior olive lesions abolished both day and week-long adaptations. These results suggest that the functional memory trace of short-term adaptation is formed initially within the cerebellar cortex, and later transferred to vestibular nuclei to be consolidated to a long-term memory. Both day and week-long adaptations were markedly depressed when neural nitric oxide was pharmacologically blocked locally and when neuronal nitric oxide synthase was ablated by gene knockout, suggesting that cerebellar long-term depression underlies both acquisition and consolidation of motor memory.

  15. Maturation of canal-related brainstem neurons in the detection of horizontal angular acceleration in rats.

    Science.gov (United States)

    Lai, Chun-Hong; Yiu, Christina N S; Lai, Suk-King; Ng, Ka-Pak; Yung, Ken K L; Shum, Daisy K Y; Chan, Ying-Shing

    2010-05-15

    We examined the functional maturation of canal-related brainstem neurons in Sprague-Dawley rats at postnatal day (P)1 to adult. Conscious animals were subjected to cycles of angular acceleration and deceleration so as to selectively activate hair cells of the horizontal semicircular canals. Brainstem neurons were monitored for c-fos expression by immuno-hybridization histochemistry as an indicator of neuronal activation. Fos-immunoreactive canal-related neurons were identifiable from P4 onwards in the vestibular nucleus and downstream vestibular relay stations, prepositus hypoglossal nucleus, and inferior olive. In the vestibular nucleus and prepositus hypoglossal nucleus, the number of canal-related neurons increased progressively with age, reaching the adult level by P21. Those in the inferior olive increased in number from P4 to P14 but decreased significantly afterwards until adulthood. The topography was not clear in the vestibular nucleus and prepositus hypoglossal nucleus. Canal-related neurons in P4-7 rats were spread throughout the rostrocaudal length of each subnucleus but clusters of canal-related neurons tended to form within specific subnuclei by P21. These were concentrated in the caudal halves of medial and spinal vestibular nuclei and the rostral parts of superior vestibular nucleus and prepositus hypoglossal nucleus. In the inferior olive, the topography was evident early in the course of development. Canal-related neurons were exclusively located in four subnuclei: dorsal medial cell column, dorsal cap, subnucleus A, and subnucleus C, but not in other subnuclei. Taken together, our data revealed the developmental profile of neuronal subpopulations within the horizontal canal system, thus providing an internal neural representation for postnatal coding of horizontal head rotations in spatial perception. (c) 2009 Wiley-Liss, Inc.

  16. Brainstem processing of vestibular sensory exafference: implications for motion sickness etiology.

    Science.gov (United States)

    Oman, Charles M; Cullen, Kathleen E

    2014-08-01

    The origin of the internal "sensory conflict" stimulus causing motion sickness has been debated for more than four decades. Recent studies show a subclass of neurons in the vestibular nuclei and deep cerebellar nuclei that respond preferentially to passive head movements. During active movement, the semicircular canal and otolith input ("reafference") to these neurons are canceled by a mechanism comparing the expected consequences of self-generated movement (estimated with an internal model-presumably located in the cerebellum) with the actual sensory feedback. The un-canceled component ("exafference") resulting from passive movement normally helps compensate for unexpected postural disturbances. Notably, the existence of such vestibular "sensory conflict" neurons had been postulated as early as 1982, but their existence and putative role in posture control and motion sickness have been long debated. Here, we review the development of "sensory conflict" theories in relation to recent evidence for brainstem and cerebellar reafference cancelation, and identify some open research questions. We propose that conditions producing persistent activity of these neurons, or their targets, stimulate nearby brainstem emetic centers-via an as yet unidentified mechanism. We discuss how such a mechanism is consistent with the notable difference in motion sickness susceptibility of drivers as opposed to passengers, human immunity to normal self-generated movement and why head restraint or lying horizontal confers relative immunity. Finally, we propose that fuller characterization of these mechanisms and their potential role in motion sickness could lead to more effective, scientifically based prevention and treatment for motion sickness.

  17. The Impact of Chronic Sleep Restriction on Neuronal Number and Volumetric Correlates of the Dorsal Respiratory Nuclei in a Rat Model.

    Science.gov (United States)

    Kamali, Ali-Mohammad; Noorafshan, Ali; Karimi, Fatemeh; Karbalay-Doust, Saied; Nami, Mohammad

    2017-08-01

    Sleep restriction can result in a range of neurophysiological consequences in the brain including some brain stem nuclei. This study aimed to evaluate the effects of chronic sleep restriction (CSR) on quantitative aspects of brain stem respiratory centers using stereological methods. Male rats were randomly assigned into experimental group (CSR through a modified multiple platform apparatus), corresponding apparatus-control group (grid-floor control) and cage controls. In the grid-floor control group, animals were placed on wire-mesh grids positioned upon CSR apparatus and were then allowed to retain the opportunity to sleep. On day 21, all rats were euthanized with their brains removed for stereological assessments. The nuclei which are known to be involved in respiration rhythm including nucleus tractus solitarius (NTS), parabrachial nuclei (PB), and Kölliker-Fuse nucleus (KF) were evaluated. Compared to the control groups, stereological findings in CSR rats revealed a decrease by 5.2 ± 0.01%, 7.1 ± 0.007%, 3.9 ± 0.004%, and 6.3 ± 0.002% (mean ± standard error of the mean [SEM], p < .01 for all) in the volume of NTS, medial PB, lateral PB, and KF nuclei, respectively. Also, the total neuronal number of NTS, medial PB, lateral PB, and KF showed a significant decrease by 10.2 ± 21.4%, 6.3 ± 5.2%, 11.8 ± 8.6%, and 9.3 ± 2.5% (mean ± SEM, p < .05 for all), respectively. CSR may potentially induce neuronal loss and structural changes in the dorsal respiratory nuclei.

  18. Vestibular compensation following vestibular neurotomy.

    Science.gov (United States)

    Devèze, A; Montava, M; Lopez, C; Lacour, M; Magnan, J; Borel, L

    2015-09-01

    Four studies assessing vestibular compensation in Menière's disease patients undergoing unilateral vestibular neurotomy, using different analysis methods, are reviewed, with a focus on the different strategies used by patients according to their preoperative sensory preference. Four prospective studies performed in a university tertiary referral center were reviewed, measuring the pattern of vestibular compensation in Menière's disease patients before and after unilateral vestibular neurotomy on various assessment protocols: postural syndrome assessed on static posturography and gait analysis; perceptual syndrome assessed on subjective visual vertical perception; and oculomotor syndrome assessed on ocular cyclotorsion. Vestibular compensation occurred at variable intervals depending on the parameter investigated. Open-eye postural control and gait/walking returned to normal one month after neurotomy. Fine balance analysis found that visual perception of the vertical and ocular cyclotorsion impairment persisted at long-term follow-up. Clinical postural disturbance persisted only when visual afferents were cut off (eyes closed). These impairments were the expression of a postoperative change in postural strategy related to the new use of visual and non-visual references. Understanding pre-operative interindividual variation in balance strategy is critical to screening for postural instability and tailoring vestibular rehabilitation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Cerebellar nuclei neurons show only small excitatory responses to optogenetic olivary stimulation in transgenic mice: in vivo and in vitro studies

    Directory of Open Access Journals (Sweden)

    Huo eLu

    2016-03-01

    Full Text Available To study the olivary input to the cerebellar nuclei (CN we used optogenetic stimulation in transgenic mice expressing channelrhodopsin-2 (ChR2 in olivary neurons. We obtained in vivo extracellular Purkinje cell (PC and CN recordings in anesthetized mice while stimulating the contralateral inferior olive (IO with a blue laser (single pulse, 10 - 50 ms duration. Peri-stimulus histograms were constructed to show the spike rate changes after optical stimulation. Among 29 CN neurons recorded, 15 showed a decrease in spike rate of variable strength and duration, and only 1 showed a transient spiking response. These results suggest that direct olivary input to CN neurons is usually overridden by stronger Purkinje cell inhibition triggered by climbing fiber responses. To further investigate the direct input from the climbing fiber collaterals we also conducted whole cell recordings in brain slices, where we used local stimulation with blue light. Due to the expression of ChR2 in Purkinje cell axons as well as the IO in our transgenic line, strong inhibitory responses could be readily triggered with optical stimulation (13 of 15 neurons. After blocking this inhibition with GABAzine, only in 5 of 13 CN neurons weak excitatory responses were revealed. Therefore our in vitro results support the in vivo findings that the excitatory input to CN neurons from climbing fiber collaterals in adult mice is masked by the inhibition under normal conditions.

  20. Sustained and Transient Vestibular Systems: A Physiological Basis for Interpreting Vestibular Function.

    Science.gov (United States)

    Curthoys, Ian S; MacDougall, Hamish G; Vidal, Pierre-Paul; de Waele, Catherine

    2017-01-01

    Otolithic afferents with regular resting discharge respond to gravity or low-frequency linear accelerations, and we term these the static or sustained otolithic system. However, in the otolithic sense organs, there is anatomical differentiation across the maculae and corresponding physiological differentiation. A specialized band of receptors called the striola consists of mainly type I receptors whose hair bundles are weakly tethered to the overlying otolithic membrane. The afferent neurons, which form calyx synapses on type I striolar receptors, have irregular resting discharge and have low thresholds to high frequency (e.g., 500 Hz) bone-conducted vibration and air-conducted sound. High-frequency sound and vibration likely causes fluid displacement which deflects the weakly tethered hair bundles of the very fast type I receptors. Irregular vestibular afferents show phase locking, similar to cochlear afferents, up to stimulus frequencies of kilohertz. We term these irregular afferents the transient system signaling dynamic otolithic stimulation. A 500-Hz vibration preferentially activates the otolith irregular afferents, since regular afferents are not activated at intensities used in clinical testing, whereas irregular afferents have low thresholds. We show how this sustained and transient distinction applies at the vestibular nuclei. The two systems have differential responses to vibration and sound, to ototoxic antibiotics, to galvanic stimulation, and to natural linear acceleration, and such differential sensitivity allows probing of the two systems. A 500-Hz vibration that selectively activates irregular otolithic afferents results in stimulus-locked eye movements in animals and humans. The preparatory myogenic potentials for these eye movements are measured in the new clinical test of otolith function-ocular vestibular-evoked myogenic potentials. We suggest 500-Hz vibration may identify the contribution of the transient system to vestibular controlled

  1. Hydroxyurea Treatment and Development of the Rat Cerebellum: Effects on the Neurogenetic Profiles and Settled Patterns of Purkinje Cells and Deep Cerebellar Nuclei Neurons.

    Science.gov (United States)

    Martí, Joaquín; Santa-Cruz, M C; Serra, Roger; Hervás, José P

    2016-11-01

    The current paper analyzes the development of the male and female rat cerebellum exposed to hydroxyurea (HU) (300 or 600 mg/kg) as embryo and collected at postnatal day 90. Our study reveals that the administration of this drug compromises neither the cytoarchitecture of the cerebellar cortex nor deep nuclei (DCN). However, in comparison with the saline group, we observed that several cerebellar parameters were lower in the HU injected groups. These parameters included area of the cerebellum, cerebellar cortex length, molecular layer area, Purkinje cell number, granule cell counts, internal granular layer, white matter and cerebellar nuclei areas, and number of deep cerebellar nuclei neurons. These features were larger in the rats injected with saline, smaller in those exposed to 300 mg/kg of HU and smallest in the group receiving 600 mg/kg of this agent. No sex differences in the effect of the HU were observed. In addition, we infer the neurogenetic timetables and the neurogenetic gradients of PCs and DCN neurons in rats exposed to either saline or HU as embryos. For this purpose, 5-bromo-2'-deoxyuridine was injected into pregnant rats previously administered with saline or HU. This thymidine analog was administered following a progressively delayed cumulative labeling method. The data presented here show that systematic differences exist in the pattern of neurogenesis and in the spatial location of cerebellar neurons between rats injected with saline or HU. No sex differences in the effect of the HU were observed. These findings have implications for the administration of this compound to women in gestation as the effects of HU on the development of the cerebellum might persist throughout their offsprings' life.

  2. Nitric oxide increases the spontaneous firing rate of rat medial vestibular nucleus neurons in vitro via a cyclic GMP-mediated PKG-independent mechanism.

    Science.gov (United States)

    Podda, Maria Vittoria; Marcocci, Maria Elena; Oggiano, Leonardo; D'Ascenzo, Marcello; Tolu, Eusebio; Palamara, Anna Teresa; Azzena, Gian Battista; Grassi, Claudio

    2004-10-01

    The effects of nitric oxide (NO) on the discharge rate of medial vestibular nucleus neurons (MVNn) were investigated in rat brainstem slices. The NO-donor sodium nitroprusside (SNP, 200 microM) caused a marked enhancement (+36.7%) of MVNn spontaneous firing rate, which was prevented by the NO-scavenger, carboxy-PTIO (300 microM). The SNP effects were not modified (+37.4%) by synaptic uncoupling, suggesting that NO influences intrinsic membrane properties of MVNn rather than the synaptic input they receive. The excitatory action of SNP was virtually abolished by slice pretreatment with the soluble guanylyl cyclase inhibitor, ODQ (10 microM), and it was mimicked (+33.1%) by the cGMP analogue 8-Br-cGMP (400 microM). Protein kinase G (PKG) and cAMP/protein kinase A (PKA) were both excluded as downstream effectors of the NO/cGMP-induced excitation. However, the cyclic nucleotide-gated (CNG) channel blockers, L-cis-diltiazem (LCD, 100 microM) and Sp-8-Br-PET-cGMPS (100 microM), significantly reduced the firing rate increase produced by 8-Br-cGMP. Moreover, LCD alone decreased spontaneous MVNn firing (-19.7%), suggesting that putative CNG channels may contribute to the tonic control of resting MVNn discharge. 8-Br-cAMP (1 mM) also elicited excitatory effects in MVNn (+40.8%), which occluded those induced by 8-Br-cGMP, indicating that the two nucleotides share a common target. Finally, nested-polymerase chain reaction assay revealed the expression of CNG channel alpha subunit transcript in MVNn. Our data provide the first demonstration that NO/cGMP signalling modulates MVNn spontaneous firing through a mechanism that is independent of PKG or PKA and probably involves activation of CNG channels.

  3. Compensation following bilateral vestibular damage

    Directory of Open Access Journals (Sweden)

    Bill J Yates

    2011-12-01

    Full Text Available Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have shown that nonlabyrinthine inputs to the vestibular nuclei are rapidly amplified following the onset of BVH, which may explain the recovery of postural stability and orthostatic tolerance that occurs within 10 days. However, the loss of the vestibulo-ocular reflex and degraded spatial cognition appear to be permanent in animals with BVH. Current concepts of the compensatory mechanisms in humans with BVH are largely inferential, as there is a lack of data from patients early in the disease process. Translation of animal studies of compensation for BVH into therapeutic strategies and subsequent application in the clinic is the most likely route to improve treatment. In addition to physical therapy, two types of prosthetic devices have been proposed to treat individuals with bilateral loss of vestibular inputs: those that provide tactile stimulation to indicate body position in space, and those that deliver electrical stimuli to branches of the vestibular nerve in accordance with head movements. The relative efficacy of these two treatment paradigms, and whether they can be combined to facilitate recovery, is yet to be ascertained.

  4. Compensation following bilateral vestibular damage.

    Science.gov (United States)

    McCall, Andrew A; Yates, Bill J

    2011-01-01

    Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH) produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have shown that non-labyrinthine inputs to the vestibular nuclei are rapidly amplified following the onset of BVH, which may explain the recovery of postural stability and orthostatic tolerance that occurs within 10 days. However, the loss of the vestibulo-ocular reflex and degraded spatial cognition appear to be permanent in animals with BVH. Current concepts of the compensatory mechanisms in humans with BVH are largely inferential, as there is a lack of data from patients early in the disease process. Translation of animal studies of compensation for BVH into therapeutic strategies and subsequent application in the clinic is the most likely route to improve treatment. In addition to physical therapy, two types of prosthetic devices have been proposed to treat individuals with bilateral loss of vestibular inputs: those that provide tactile stimulation to indicate body position in space, and those that deliver electrical stimuli to branches of the vestibular nerve in accordance with head movements. The relative efficacy of these two treatment paradigms, and whether they can be combined to facilitate recovery, is yet to be ascertained.

  5. Afferent diversity and the organization of central vestibular pathways.

    Science.gov (United States)

    Goldberg, J M

    2000-02-01

    This review considers whether the vestibular system includes separate populations of sensory axons innervating individual organs and giving rise to distinct central pathways. There is a variability in the discharge properties of afferents supplying each organ. Discharge regularity provides a marker for this diversity since fibers which differ in this way also differ in many other properties. Postspike recovery of excitability determines the discharge regularity of an afferent and its sensitivity to depolarizing inputs. Sensitivity is small in regularly discharging afferents and large in irregularly discharging afferents. The enhanced sensitivity of irregular fibers explains their larger responses to sensory inputs, to efferent activation, and to externally applied galvanic currents, but not their distinctive response dynamics. Morphophysiological studies show that regular and irregular afferents innervate overlapping regions of the vestibular nuclei. Intracellular recordings of EPSPs reveal that some secondary vestibular neurons receive a restricted input from regular or irregular afferents, but that most such neurons receive a mixed input from both kinds of afferents. Anodal currents delivered to the labyrinth can result in a selective and reversible silencing of irregular afferents. Such a functional ablation can provide estimates of the relative contributions of regular and irregular inputs to a central neuron's discharge. From such estimates it is concluded that secondary neurons need not resemble their afferent inputs in discharge regularity or response dynamics. Several suggestions are made as to the potentially distinctive contributions made by regular and irregular afferents: (1) Reflecting their response dynamics, regular and irregular afferents could compensate for differences in the dynamic loads of various reflexes or of individual reflexes in different parts of their frequency range; (2) The gating of irregular inputs to secondary VOR neurons could

  6. Central projections of vestibular afferents from the horizontal semicircular canal in the carpet shark Cephaloscyllium isabella.

    Science.gov (United States)

    Housley, G D; Montgomery, J C

    1983-12-01

    This study utilizes anterograde axonal transport of cobaltous-lysine and conventional silver-staining techniques to study the central projections of the horizontal semicircular canal branch of the VIII nerve within the vestibular nuclei of the carpet shark Cephaloscyllium isabella. Two major terminating axon fields were observed, one caudal and one rostral to the entrance of the VIII nerve, corresponding to the ventral vestibular nucleus and superior vestibular nucleus, respectively. Both fields appear to be located within the ventral portion of the nuclei indicating an apparent subdivision of the VIII nerve projections within the brainstem. The resolution of the sensitive cobalt tracer indicates the presence of both dendritic and pericellular termination of these primary afferent fibres. In the area immediately caudal to the entrance of the VIII nerve a number of labelled primary afferent fibres project to the ventral region of the intermediate nucleus. Other fibres follow the visceral sensory root VII and terminate proximal to the sulcus limitans of His within the dendritic field of the neurons of the nucleus magnocellularis. Some fibres turn ventromedially from the main group of the ascending fibres and terminate in the area of the inferior reticular formation.

  7. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity

    Science.gov (United States)

    Holstein, Gay R.

    2003-01-01

    The goal of this research project was to identify the neurons and circuits in the vestibular nuclei and nucleus prepositus hypoglossi that utilize nitric oxide (NO) for intercellular signaling during gravity-induced plasticity. This objective was pursued using histochemical and immunocytochemical approaches to localize NO-producing neurons and characterize the fine morphology of the cells in ground-based studies of normal rats, rats adapted to hypergravity, and rats adapted to hypergravity and then re-adapted to the 1G environment. NO-producing neurons were identified and studied using four methodologies: i) immunocytochemistry employing polyclonal antibodies directed against neuronal nitric oxide synthase (nNOS), to provide an indication of the capacity of a cell for NO production; ii) immunocytochemistry employing a monoclonal antibody directed against L-citrulline, to provide an indirect index of the enzyme's activity; iii) histochemistry based on the NADPH-diaphorase reaction, for fuI1 cytological visualization of neurons; and iv) double immunofluorescence to co-localize nNOS and L-citrulline in individual vestibular nuclei (VN) and neurons.

  8. Non-linear Galilean vestibular receptive fields.

    Science.gov (United States)

    Bennequin, D; Berthoz, A

    2011-01-01

    We present a set of formulas for the receptive fields of the vestibular neurons that are motivated by Galilean invariance. We show that these formulas explain non-trivial data in neurophysiology, and suggest new hypothesis to be tested in dynamical 3D conditions. Moreover our model offers a way for neuronal computing with 3D displacements, which is reputed to be hard, underlying the vestibular reflexes. This computation is presented in a Bayesian framework. The basis of the model is the necessity of living bodies to work invariantly in space-time, allied to the necessary discreteness of neuronal transmission.

  9. Effects of Sound on the Vestibular System

    Science.gov (United States)

    1976-03-01

    receptors and directly affects central nervous system nuclei. Visual, olfactory, and gustatory responses would be expected if sound directly affected the...AMRL-TR-75-89 EFFECTS OF SOUND ON THE VESTIBULAR SYSTEM MIAMI UNIVERSITY NO OXFORD, OHIO 45056 MARCH 1976 | j...Approvedrfor public release: distribution unlimited AEROSPACE MEDICAL RESEARCH LABORATORY AEROSPACE MEDICAL DMSION Air Force Systems Command Wright.Patterson

  10. Interactions between Stress and Vestibular Compensation - A Review.

    Science.gov (United States)

    Saman, Yougan; Bamiou, D E; Gleeson, Michael; Dutia, Mayank B

    2012-01-01

    Elevated levels of stress and anxiety often accompany vestibular dysfunction, while conversely complaints of dizziness and loss of balance are common in patients with panic and other anxiety disorders. The interactions between stress and vestibular function have been investigated both in animal models and in clinical studies. Evidence from animal studies indicates that vestibular symptoms are effective in activating the stress axis, and that the acute stress response is important in promoting compensatory synaptic and neuronal plasticity in the vestibular system and cerebellum. The role of stress in human vestibular disorders is complex, and definitive evidence is lacking. This article reviews the evidence from animal and clinical studies with a focus on the effects of stress on the central vestibular pathways and their role in the pathogenesis and management of human vestibular disorders.

  11. Interactions between stress and vestibular compensation – a review

    Directory of Open Access Journals (Sweden)

    Yougan eSaman

    2012-07-01

    Full Text Available Elevated levels of stress and anxiety often accompany vestibular dysfunction, while conversely complaints of dizziness and loss of balance are common in patients with panic and other anxiety disorders. The interactions between stress and vestibular function, and plasticity have been investigated both in animal models and in clinical studies. Evidence from animal studies indicates that vestibular symptoms are effective in activating the stress axis, and that the acute stress response is important in promoting compensatory synaptic and neuronal plasticity in the vestibular system and cerebellum. The role of stress in human vestibular disorders is complex, and definitive evidence is lacking. This article reviews the evidence from animal and clinical studies with a focus on the effects of stress on the central vestibular pathways and their role in the pathogenesis and management of human vestibular disorders.

  12. Interactions between Stress and Vestibular Compensation – A Review

    Science.gov (United States)

    Saman, Yougan; Bamiou, D. E.; Gleeson, Michael; Dutia, Mayank B.

    2012-01-01

    Elevated levels of stress and anxiety often accompany vestibular dysfunction, while conversely complaints of dizziness and loss of balance are common in patients with panic and other anxiety disorders. The interactions between stress and vestibular function have been investigated both in animal models and in clinical studies. Evidence from animal studies indicates that vestibular symptoms are effective in activating the stress axis, and that the acute stress response is important in promoting compensatory synaptic and neuronal plasticity in the vestibular system and cerebellum. The role of stress in human vestibular disorders is complex, and definitive evidence is lacking. This article reviews the evidence from animal and clinical studies with a focus on the effects of stress on the central vestibular pathways and their role in the pathogenesis and management of human vestibular disorders. PMID:22866048

  13. CONTRIBUTION OF THE AUDIOLOGICAL AND VESTIBULAR ASSESSMENT TO THE DIFFERENTIAL AND ETIOLOGICAL DIAGNOSIS OF PERIPHERIC VESTIBULAR SYNDROMES

    Directory of Open Access Journals (Sweden)

    Loreta Ungureanu

    2012-09-01

    Full Text Available Scope of the study: Vestibular pathology is a complex one, requiring a minute clinical evaluation, as well as numerous paraclinical investigations. The present study analyzes the contribution of the modern methods of vestibular and auditive investigation to the diagnosis of dizziness. Materials and method: The results of the investigations performed on 84 patients with peripheric vestibular syndrome, on whom a complete audiological and vestibular assessment had been also made, have been retrospectively analyzed. Results: Anamnestic data and the results of evaluation permitted classification of peripheric vestibular pathology according to topo-lesional and etiological criteria. The most frequently diagnosed diseases were: benign paroxysmal positional vertigo, Ménière syndrome and vestibular neuronitis. Conclusions: Testing of the vestibulo-ocular and vestibulo-spinal reflexes through videonystagmoscopy and, respectively, computerized dynamic posturography, besides tonal vocal audiometry and precocious auditive potentials, is especially important for a positive diagnosis and etiological differentiation of vestibular syndromes.

  14. Stress-induced activation of nitric oxide-producing neurons in the rat brain.

    Science.gov (United States)

    Krukoff, T L; Khalili, P

    1997-01-27

    Nitric oxide (NO) is a gaseous neurotransmitter that may mediate a decrease in sympathetic output to the periphery. This implication predicts that NO-producing neurons in the brain are activated in animals experiencing increased levels of sympathetic activity. To test this prediction, we subjected three groups of experimental rats to differing levels of environmental stimulation for 1 hour: minimal stimulation, moderate stimulation, and restraint stress. NO-producing neurons were histochemically visualized in sections of the brain, and activation of these neurons was assessed according to the neuronal expression of the immediate early gene c-fos. Constitutive activation of NO-producing neurons was found in the hypothalamus (paraventricular and supraoptic nuclei), dorsal raphe nuclei, and spinal nucleus of the trigeminal nerve of minimally stimulated rats. When animals were subjected to a novel environment (moderate stimulation), additional NO-producing neurons were activated in the medial septum, medial amygdala, hypothalamic nuclei (lateral, periventricular, and posterior), colliculi, nucleus raphe obscurus, medial vestibular nucleus, nucleus of the tractus solitarius, and several components of the ventrolateral medulla. Restraint stress caused the activation of NO-producing neurons in all of these areas, often in increasing numbers, and the activation of additional NO-producing neurons in the diagonal band of Broca, lateral and medial preoptic areas, basomedial and basolateral amygdalar nuclei, hypothalamic nuclei (dorsomedial, retrochiasmatic supraoptic, and circularis), nucleus raphe pontus, lateral parabrachial nucleus, and pontine nuclei. Expressed as a proportion of NO-producing neurons per section, the largest percentages (>20%) of double-stained neurons were found in the basolateral amygdala (46%), hypothalamic paraventricular nucleus (35%), corpora quadrigemina (estimated at 40%), dorsal raphe (45%), nuclei raphe pontus (33%) and obscurus (63%), lateral

  15. Peripheral Vestibular System Disease in Vestibular Schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Hansen, Søren; Caye-Thomasen, Per

    2015-01-01

    that this may be caused by both cochlear and retrocochlear mechanisms. Multiple mechanisms may also be at play in the case of dizziness, which may broaden perspectives of therapeutic approach. This study presents a systematic and detailed assessment of vestibular histopathology in temporal bones from patients...... with VS. METHODS: Retrospective analysis of vestibular system histopathology in temporal bones from 17 patients with unilateral VS. The material was obtained from The Copenhagen Temporal Bone Collection. RESULTS: Vestibular schwannomas were associated with atrophy of the vestibular ganglion, loss of fiber...... density of the peripheral vestibular nerve branches, and atrophy of the neuroepithelium of the vestibular end organs. In cases with small tumors, peripheral disease occurred only in the tissue structures innervated by the specific nerve from which the tumor originated. CONCLUSION: Vestibular schwannomas...

  16. Nitric oxide in the rat vestibular system.

    Science.gov (United States)

    Harper, A; Blythe, W R; Zdanski, C J; Prazma, J; Pillsbury, H C

    1994-10-01

    Nitric oxide is known to function as a neurotransmitter in the central nervous system. It is also known to be involved in the central nervous system excitatory amino acid neurotransmission cascade. Activation of excitatory amino acid receptors causes an influx of calcium, which activates nitric oxide synthase. The resulting increase in intracellular nitric oxide activates soluble guanylate cyclase, leading to a rise in cyclic guanosine monophosphate. The excitatory amino acids glutamate and aspartate are found in the vestibular system and have been postulated to function as vestibular system neurotransmitters. Although nitric oxide has been investigated as a neurotransmitter in other tissues, no published studies have examined the role of nitric oxide in the vestibular system. Neuronal NADPH-diaphorase has been characterized as a nitric oxide synthase. This enzyme catalyzes the conversion of L-arginine to L-citrulline, producing nitric oxide during the reaction. We used a histochemical stain characterized by Hope et al. (Proc Natl Acad Sci 1991;88:2811) as specific for neuronal nitric oxide synthase to localize the enzyme in the rat vestibular system. An immunocytochemical stain was used to examine rat inner ear tissue for the presence of the enzyme's end product, L-citrulline, thereby demonstrating nitric oxide synthase activity. Staining of vestibular ganglion sections showed nitric oxide synthase presence and activity in ganglion cells and nerve fibers. These results indicate the presence of active nitric oxide synthase in these tissues and suggest modulation of vestibular neurotransmission by nitric oxide.

  17. Molecular aging of the mammalian vestibular system.

    Science.gov (United States)

    Brosel, Sonja; Laub, Christoph; Averdam, Anne; Bender, Andreas; Elstner, Matthias

    2016-03-01

    Dizziness and imbalance frequently affect the elderly and contribute to falls and frailty. In many geriatric patients, clinical testing uncovers a dysfunction of the vestibular system, but no specific etiology can be identified. Neuropathological studies have demonstrated age-related degeneration of peripheral and central vestibular neurons, but the molecular mechanisms are poorly understood. In contrast, recent studies into age-related hearing loss strongly implicate mitochondrial dysfunction, oxidative stress and apoptotic cell death of cochlear hair cells. While some data suggest that analogous biological pathomechanisms may underlie vestibular dysfunction, actual proof is missing. In this review, we summarize the available data on the molecular causes of vestibular dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Changes in outflow to respiratory pump muscles produced by natural vestibular stimulation.

    Science.gov (United States)

    Rossiter, C D; Hayden, N L; Stocker, S D; Yates, B J

    1996-11-01

    1. Activity was recorded from abdominal (expiratory) and phrenic (inspiratory) nerves during natural vestibular stimulation in multiple vertical planes and the horizontal plane in decerebrate cats. Vestibular stimulation was produced by rotating the head in animals whose upper cervical dorsal roots were transected to remove inputs from neck receptors; the upper airway and carotid sinus were denervated, and the vagus nerves were transected to assure that the head rotations did not elicit visceral or pulmonary inputs. 2. The plane of head rotation that produced maximal modulation of respiratory nerve activity (response vector orientation) was measured at one or more frequencies between 0.05 and 0.5 Hz. The dynamics of the response were then studied with sinusoidal (0.05-2 Hz) stimuli aligned with this orientation. In some animals, sinusoidal horizontal rotations of the head at 0.5 and 1 Hz or static head tilts in the pitch and roll planes were also delivered. 3. Typically, maximal modulation of abdominal nerve outflow was elicited by head rotations in a plane near pitch; nose-up rotations produced increased outflow, and nose-down rotations reduced nerve discharges. The gains of the responses (relative to stimulus position) remained relatively constant across stimulus frequencies, and the phases were consistently near stimulus position, like regularly firing otolith afferents. Static nose-up tilt produced elevated abdominal nerve activity throughout the stimulus period, providing further evidence that pitch-sensitive otolith receptors contribute to the response. Horizontal head rotations had little influence on abdominal nerve discharges. 4. The abdominal nerve responses to head rotation were abolished by chemical or aspiration lesions of the medial and inferior vestibular nuclei, which is concordant with the responses resulting from activation of vestibular receptors. Transections of axons arising from bulbospinal neurons in the ventral respiratory group, which are

  19. Nitric oxide producing neurones in the rat medulla oblongata that project to nucleus tractus solitarii.

    Science.gov (United States)

    Esteves, F O; McWilliam, P N; Batten, T F

    2000-11-01

    The production of nitric oxide in neurones of the rat medulla oblongata that project to the nucleus tractus solitarii (NTS) was examined by simultaneous immunohistochemical detection of nitric oxide synthase (NOS) and of cholera toxin B-subunit (CTb), which was injected into the caudal zone of the NTS. Neurones immunoreactive for CTb and neurones immunoreactive for NOS were widely co-distributed and found in almost all the anatomical divisions of the medulla. Dual-labelled cells, containing both CTb and NOS immunoreactivities were more numerous ipsilaterally to the injection sites. They were concentrated principally in the more rostral zone of the NTS, raphé nuclei, dorsal, intermediate and lateral reticular areas, spinal trigeminal and paratrigeminal nuclei and the external cuneate and medial vestibular nuclei. Isolated dual-labelled neurones were also scattered throughout most of the divisions of the reticular formation. These observations indicate that many areas of the medulla that are known to relay somatosensory and viscerosensory inputs contain NOS immunoreactive neurones that project to the NTS, and may, therefore, contribute to the dense NOS-immunoreactive innervation of the NTS. The release of nitric oxide from the axon terminals of these neurones may modulate autonomic responses generated by NTS neurones in relation to peripheral sensory stimuli, and thus ultimately regulate sympathetic and/or parasympathetic outflow.

  20. The effects of vestibular lesions on hippocampal function in rats.

    Science.gov (United States)

    Smith, Paul F; Horii, Arata; Russell, Noah; Bilkey, David K; Zheng, Yiwen; Liu, Ping; Kerr, D Steve; Darlington, Cynthia L

    2005-04-01

    Interest in interaction between the vestibular system and the hippocampus was stimulated by evidence that peripheral vestibular lesions could impair performance in learning and memory tasks requiring spatial information processing. By the 1990s, electrophysiological data were emerging that the brainstem vestibular nucleus complex (VNC) and the hippocampus were connected polysynaptically and that hippocampal place cells could respond to vestibular stimulation. The aim of this review is to summarise and critically evaluate research published in the last 5 years that has seen major progress in understanding the effects of vestibular damage on the hippocampus. In addition to new behavioural studies demonstrating that animals with vestibular lesions exhibit impairments in spatial memory tasks, electrophysiological studies have confirmed long-latency, polysynaptic pathways between the VNC and the hippocampus. Peripheral vestibular lesions have been shown to cause long-term changes in place cell function, hippocampal EEG activity and even CA1 field potentials in brain slices maintained in vitro. During the same period, neurochemical investigations have shown that some hippocampal subregions exhibit long-term changes in the expression of neuronal nitric oxide synthase, arginase I and II, and the NR1 and NR2A N-methyl-D-aspartate (NMDA) receptor subunits following peripheral vestibular damage. Despite the progress, a number of important issues remain to be resolved, such as the possible contribution of auditory damage associated with vestibular lesions, to the hippocampal effects observed. Furthermore, although these studies demonstrate that damage to the vestibular system does have a long-term impact on the electrophysiological and neurochemical function of the hippocampus, they do not indicate precisely how vestibular information might be used in hippocampal functions such as developing spatial representations of the environment. Understanding this will require detailed

  1. Development and regeneration of vestibular hair cells in mammals.

    Science.gov (United States)

    Burns, Joseph C; Stone, Jennifer S

    2017-05-01

    Vestibular sensation is essential for gaze stabilization, balance, and perception of gravity. The vestibular receptors in mammals, Type I and Type II hair cells, are located in five small organs in the inner ear. Damage to hair cells and their innervating neurons can cause crippling symptoms such as vertigo, visual field oscillation, and imbalance. In adult rodents, some Type II hair cells are regenerated and become re-innervated after damage, presenting opportunities for restoring vestibular function after hair cell damage. This article reviews features of vestibular sensory cells in mammals, including their basic properties, how they develop, and how they are replaced after damage. We discuss molecules that control vestibular hair cell regeneration and highlight areas in which our understanding of development and regeneration needs to be deepened. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Internal models and neural computation in the vestibular system.

    Science.gov (United States)

    Green, Andrea M; Angelaki, Dora E

    2010-01-01

    The vestibular system is vital for motor control and spatial self-motion perception. Afferents from the otolith organs and the semicircular canals converge with optokinetic, somatosensory and motor-related signals in the vestibular nuclei, which are reciprocally interconnected with the vestibulocerebellar cortex and deep cerebellar nuclei. Here, we review the properties of the many cell types in the vestibular nuclei, as well as some fundamental computations implemented within this brainstem-cerebellar circuitry. These include the sensorimotor transformations for reflex generation, the neural computations for inertial motion estimation, the distinction between active and passive head movements, as well as the integration of vestibular and proprioceptive information for body motion estimation. A common theme in the solution to such computational problems is the concept of internal models and their neural implementation. Recent studies have shed new insights into important organizational principles that closely resemble those proposed for other sensorimotor systems, where their neural basis has often been more difficult to identify. As such, the vestibular system provides an excellent model to explore common neural processing strategies relevant both for reflexive and for goal-directed, voluntary movement as well as perception.

  3. Common Vestibular Disorders

    OpenAIRE

    Balatsouras, Dimitrios G

    2017-01-01

    The three most common vestibular diseases, benign paroxysmal positional vertigo (BPPV), Meniere's disease (MD) and vestibular neuritis (VN), are presented in this paper. BPPV, which is the most common peripheral vestibular disorder, can be defined as transient vertigo induced by a rapid head position change, associated with a characteristic paroxysmal positional nystagmus. Canalolithiasis of the posterior semicircular canal is considered the most convincing theory of its pathogenesis and the ...

  4. Central Vestibular Dysfunction in an Otorhinolaryngological Vestibular Unit: Incidence and Diagnostic Strategy

    Directory of Open Access Journals (Sweden)

    Mostafa, Badr E.

    2014-03-01

    Full Text Available Introduction Vertigo can be due to a variety of central and peripheral causes. The relative incidence of central causes is underestimated. This may have an important impact of the patients' management and prognosis. Objective The objective of this work is to determine the incidence of central vestibular disorders in patients presenting to a vestibular unit in a tertiary referral academic center. It also aims at determining the best strategy to increase the diagnostic yield of the patients' visit. Methods This is a prospective observational study on 100 consecutive patients with symptoms suggestive of vestibular dysfunction. All patients completed a structured questionnaire and received bedside and vestibular examination and neuroimaging as required. Results There were 69 women and 31 men. Their ages ranged between 28 and 73 (mean 42.48 years. Provisional videonystagmography (VNG results were: 40% benign paroxysmal positional vertigo (BPPV, 23% suspicious of central causes, 18% undiagnosed, 15% Meniere disease, and 4% vestibular neuronitis. Patients with an unclear diagnosis or central features (41 had magnetic resonance imaging (MRI and Doppler studies. Combining data from history, VNG, and imaging studies, 23 patients (23% were diagnosed as having a central vestibular lesion (10 with generalized ischemia/vertebra basilar insufficiency, 4 with multiple sclerosis, 4 with migraine vestibulopathy, 4 with phobic postural vertigo, and 1 with hyperventilation-induced nystagmus. Conclusions Combining a careful history with clinical examination, VNG, MRI, and Doppler studies decreases the number of undiagnosed cases and increases the detection of possible central lesions.

  5. Interaction between vestibular compensation mechanisms and vestibular rehabilitation therapy: ten recommendations for optimal functional recovery

    Directory of Open Access Journals (Sweden)

    LACOUR eMichel

    2015-01-01

    Full Text Available This review questions the relationships between the plastic events responsible for the recovery of vestibular function after a unilateral vestibular loss (vestibular compensation, which has been well described in animal models in the last decades, and the vestibular rehabilitation (VR therapy elaborated on a more empirical basis for vestibular loss patients. The main objective is not to propose a catalogue of results but to provide clinicians with an understandable view on when and how to perform VR therapy, and why VR may benefit from basic knowledge and may influence the recovery process. With this perspective, 10 major recommendations are proposed as ways to identify an optimal functional recovery. Among them are the crucial role of active and early VR therapy, coincidental with a post-lesion sensitive period for neuronal network remodelling, the instructive role that VR therapy may play in this functional reorganisation, the need for progression in the VR therapy protocol, which is based mainly on adaptation processes, the necessity to take into account the sensorimotor, cognitive and emotional profile of the patient to propose individual or à la carte VR therapies, and the importance of motivational and ecologic contexts. More than 10 general principles are very likely, but these principles seem crucial for the fast recovery of vestibular loss patients to ensure good quality of life.

  6. Interaction between Vestibular Compensation Mechanisms and Vestibular Rehabilitation Therapy: 10 Recommendations for Optimal Functional Recovery.

    Science.gov (United States)

    Lacour, Michel; Bernard-Demanze, Laurence

    2014-01-01

    This review questions the relationships between the plastic events responsible for the recovery of vestibular function after a unilateral vestibular loss (vestibular compensation), which has been well described in animal models in the last decades, and the vestibular rehabilitation (VR) therapy elaborated on a more empirical basis for vestibular loss patients. The main objective is not to propose a catalog of results but to provide clinicians with an understandable view on when and how to perform VR therapy, and why VR may benefit from basic knowledge and may influence the recovery process. With this perspective, 10 major recommendations are proposed as ways to identify an optimal functional recovery. Among them are the crucial role of active and early VR therapy, coincidental with a post-lesion sensitive period for neuronal network remodeling, the instructive role that VR therapy may play in this functional reorganization, the need for progression in the VR therapy protocol, which is based mainly on adaptation processes, the necessity to take into account the sensorimotor, cognitive, and emotional profile of the patient to propose individual or "à la carte" VR therapies, and the importance of motivational and ecologic contexts. More than 10 general principles are very likely, but these principles seem crucial for the fast recovery of vestibular loss patients to ensure good quality of life.

  7. Vestibular Function in the Temporal and Parietal Cortex: Distinct Velocity and Inertial Processing Pathways

    Directory of Open Access Journals (Sweden)

    Jocelyne eVentre-Dominey

    2014-07-01

    Full Text Available A number of behavioural and neuroimaging studies have reported converging data in favour of a cortical network for vestibular function, distributed between the temporo-parietal cortex and the prefrontal cortex in the primate. In this review, we focus on the role of the cerebral cortex in visuo-vestibular integration including the motion sensitive temporo-occipital areas i.e. the middle superior temporal area (MST and the parietal cortex. Indeed these two neighbouring cortical regions, though they both receive combined vestibular and visual information, have distinct implications in vestibular function. In sum, this review of the literature leads to the idea of two separate cortical vestibular sub-systems forming (1 a velocity pathway including MST and direct descending pathways on vestibular nuclei. As it receives well defined visual and vestibular velocity signals, this pathway is likely involved in heading perception and rapid top-down regulation of eye/head coordination and (2 an inertial processing pathway involving the parietal cortex in connection with the subcortical vestibular nuclei complex responsible for velocity storage integration. This vestibular cortical pathway would be implicated in high order multimodal integration and cognitive functions, including world space and self- referential processing.

  8. Vestibular function in the temporal and parietal cortex: distinct velocity and inertial processing pathways

    Science.gov (United States)

    Ventre-Dominey, Jocelyne

    2014-01-01

    A number of behavioral and neuroimaging studies have reported converging data in favor of a cortical network for vestibular function, distributed between the temporo-parietal cortex and the prefrontal cortex in the primate. In this review, we focus on the role of the cerebral cortex in visuo-vestibular integration including the motion sensitive temporo-occipital areas i.e., the middle superior temporal area (MST) and the parietal cortex. Indeed, these two neighboring cortical regions, though they both receive combined vestibular and visual information, have distinct implications in vestibular function. In sum, this review of the literature leads to the idea of two separate cortical vestibular sub-systems forming (1) a velocity pathway including MST and direct descending pathways on vestibular nuclei. As it receives well-defined visual and vestibular velocity signals, this pathway is likely involved in heading perception and rapid top-down regulation of eye/head coordination and (2) an inertial processing pathway involving the parietal cortex in connection with the subcortical vestibular nuclei complex responsible for velocity storage integration. This vestibular cortical pathway would be implicated in high-order multimodal integration and cognitive functions, including world space and self-referential processing. PMID:25071481

  9. Vestibular perception following acute unilateral vestibular lesions.

    Directory of Open Access Journals (Sweden)

    Sian Cousins

    Full Text Available Little is known about the vestibulo-perceptual (VP system, particularly after a unilateral vestibular lesion. We investigated vestibulo-ocular (VO and VP function in 25 patients with vestibular neuritis (VN acutely (2 days after onset and after compensation (recovery phase, 10 weeks. Since the effect of VN on reflex and perceptual function may differ at threshold and supra-threshold acceleration levels, we used two stimulus intensities, acceleration steps of 0.5°/s(2 and velocity steps of 90°/s (acceleration 180°/s(2. We hypothesised that the vestibular lesion or the compensatory processes could dissociate VO and VP function, particularly if the acute vertiginous sensation interferes with the perceptual tasks. Both in acute and recovery phases, VO and VP thresholds increased, particularly during ipsilesional rotations. In signal detection theory this indicates that signals from the healthy and affected side are still fused, but result in asymmetric thresholds due to a lesion-induced bias. The normal pattern whereby VP thresholds are higher than VO thresholds was preserved, indicating that any 'perceptual noise' added by the vertigo does not disrupt the cognitive decision-making processes inherent to the perceptual task. Overall, the parallel findings in VO and VP thresholds imply little or no additional cortical processing and suggest that vestibular thresholds essentially reflect the sensitivity of the fused peripheral receptors. In contrast, a significant VO-VP dissociation for supra-threshold stimuli was found. Acutely, time constants and duration of the VO and VP responses were reduced - asymmetrically for VO, as expected, but surprisingly symmetrical for perception. At recovery, VP responses normalised but VO responses remained shortened and asymmetric. Thus, unlike threshold data, supra-threshold responses show considerable VO-VP dissociation indicative of additional, higher-order processing of vestibular signals. We provide evidence of

  10. Vestibular Compensation in Unilateral Patients Often Causes Both Gain and Time Constant Asymmetries in The VOR

    Directory of Open Access Journals (Sweden)

    Mina eRanjbaran

    2016-03-01

    Full Text Available The vestibulo-ocular reflex (VOR is essential in our daily life to stabilize retinal images during head movements. Balanced vestibular functionality secures optimal reflex performance which can be distorted in case of peripheral vestibular lesions. Luckily, vestibular compensation in different neuronal sites restores VOR function to some extent over time. Studying vestibular compensation gives insight into the possible mechanisms for plasticity in the brain.In this work, novel experimental analysis tools are employed to reevaluate the VOR characteristics following unilateral vestibular lesions and compensation. Our results suggest that following vestibular lesions, asymmetric performance of the VOR is not only limited to its gain. Vestibular compensation also causes asymmetric dynamics, i.e. different time constants for the VOR during leftward or rightward passive head rotation. Potential mechanisms for these experimental observations are provided using simulation studies.

  11. Molecular mechanisms of vestibular compensation in the central vestibular system--review.

    Science.gov (United States)

    Kitahara, T; Takeda, N; Kiyama, H; Kubo, T

    1998-01-01

    Vestibular compensation consists of two stages: the inhibition of the contralesional medial vestibular nucleus (contra-MVe) activities at the acute stage after unilateral labyrinthectomy (UL) and the recovery and maintenance of the ipsilesional MVe (ipsi-MVe) spontaneous activities at the chronic stage after UL. In this paper, we reviewed molecular mechanisms of vestibular compensation in the central vestibular system using several morphological and pharmacological approaches in rats. Based on our examinations, we propose the following hypotheses: i) at the acute stage after UL, the activated neurons in the ipsi-MVe project their axons into the flocculus to inhibit the contra-MVe neurons via the NMDA receptor, nitric oxide (NO) and/or GABA-mediated signalling, resulting in the restoration of balance between intervestibular nuclear activities. ii) At the chronic stage after UL, the flocculus depresses the inhibitory effects on the ipsi-MVe neurons via protein phosphatase 2A (PP2A) beta, protein kinase C (PKC) and glutamate receptor (GluR) delta-2, to help the recovery and maintenance of ipsi-MVe activities.

  12. Convergence of vestibular and visual self-motion signals in an area of the posterior sylvian fissure

    Science.gov (United States)

    Chen, Aihua; DeAngelis, Gregory C.; Angelaki, Dora E.

    2011-01-01

    Convergence of visual motion information (optic flow) and vestibular signals is important for self-motion perception, and such convergence has been observed in the dorsal medial superior temporal (MSTd) and ventral intraparietal (VIP) areas. In contrast, the parieto-insular vestibular cortex (PIVC), a cortical vestibular area in the sylvian fissure, is not responsive to optic flow. Here we explore optic flow and vestibular convergence in the visual posterior sylvian area (VPS) of macaque monkeys. This area is located at the posterior end of the sylvian fissure, is strongly interconnected with PIVC, and receives projections from MSTd. We found robust optic flow and vestibular tuning in more than one-third of VPS cells, with all motion directions being represented uniformly. However, visual and vestibular direction preferences for translation were mostly opposite, unlike in area MSTd where roughly equal proportions of neurons have visual/vestibular heading preferences that are congruent or opposite. Overall, optic flow responses in VPS were weaker than those in MSTd, whereas vestibular responses were stronger in VPS than in MSTd. When visual and vestibular stimuli were presented together, VPS responses were dominated by vestibular signals, in contrast to MSTd, where optic flow tuning typically dominates. These findings suggest that VPS is proximal to MSTd in terms of vestibular processing, but distal to MSTd in terms of optic flow processing. Given the preponderance of neurons with opposite visual/vestibular heading preferences in VPS, this area may not play a major role in multisensory heading perception. PMID:21832191

  13. Deregulated genes in sporadic vestibular schwannomas

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Helweg-Larsen, Rehannah Holga Andrea; Stangerup, Sven-Eric

    2010-01-01

    In search of genes associated with vestibular schwannoma tumorigenesis, this study examines the gene expression in human vestibular nerve versus vestibular schwannoma tissue samples using microarray technology....

  14. Central vestibular disorder due to ischemic injury on the parieto-insular vestibular cortex in patients with middle cerebral artery territory infarction: Observational study.

    Science.gov (United States)

    Yeo, Sang Seok; Jang, Sung Ho; Kwon, Jung Won

    2017-12-01

    Central vestibular disorder is common after middle cerebral artery (MCA) territory infarction. The MCA supplies blood to the parieto-insular vestibular cortex (PIVC), a core region of central vestibular symptoms. We report on patients that sustained injuries of the core vestibular pathway to the PIVC with central vestibular disorder following MCA territory infarction, demonstrated on diffusion tensor imaging (DTI). Nineteen patients with MCA territory infarction and 12 control subjects were recruited. To reconstruct the core vestibular pathway to the PIVC, we defined seed region of interest (ROI) as vestibular nuclei of pons and target ROI as the PIVC. Fractional anisotropy (FA), mean diffusivity, and tract volume were measured. In the affected hemisphere, FA value of the core vestibular pathway to the PIVC revealed significant difference between all patient groups and the control group (P territory infarction. Analysis of the core vestibular pathway to the PIVC using DTI would be beneficial in clinical evaluation and management of patients with MCA territory infarction. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  15. Central projections of the vestibular nerve: a review and single fiber study in the Mongolian gerbil.

    Science.gov (United States)

    Newlands, Shawn D; Perachio, Adrian A

    2003-06-15

    The primary purpose of this article is to review the anatomy of central projections of the vestibular nerve in amniotes. We also report primary data regarding the central projections of individual horseradish peroxidase (HRP)-filled afferents innervating the saccular macula, horizontal semicircular canal ampulla, and anterior semicircular canal ampulla of the gerbil. In total, 52 characterized primary vestibular afferent axons were intraaxonally injected with HRP and traced centrally to terminations. Lateral and anterior canal afferents projected most heavily to the medial and superior vestibular nuclei. Saccular afferents projected strongly to the spinal vestibular nucleus, weakly to other vestibular nuclei, to the interstitial nucleus of the eighth nerve, the cochlear nuclei, the external cuneate nucleus, and nucleus y. The current findings reinforce the preponderance of literature. The central distribution of vestibular afferents is not homogeneous. We review the distribution of primary afferent terminations described for a variety of mammalian and avian species. The tremendous overlap of the distributions of terminals from the specific vestibular nerve branches with one another and with other sensory inputs provides a rich environment for sensory integration.

  16. Distinct vestibular effects on early and late somatosensory cortical processing in humans

    NARCIS (Netherlands)

    Pfeiffer, C.; van Elk, M.; Bernasconi, F.; Blanke, O.

    2016-01-01

    In non-human primates several brain areas contain neurons that respond to both vestibular and somatosensory stimulation. In humans, vestibular stimulation activates several somatosensory brain regions and improves tactile perception. However, less is known about the spatio-temporal dynamics of such

  17. Isolated vestibular nuclear infarction: report of two cases and review of the literature.

    Science.gov (United States)

    Kim, Hyo-Jung; Lee, Seung-Han; Park, Jae Han; Choi, Jung-Yoon; Kim, Ji-Soo

    2014-01-01

    Cerebral infarction presenting with isolated vertigo remains a diagnostic challenge. To define the clinical characteristics of unilateral infarctions restricted to the vestibular nuclei, two patients with isolated unilateral vestibular nuclear infarction had bedside and laboratory evaluation of the ocular motor and vestibular function, including video-oculography, bithermal caloric irrigation, the head impulse test (HIT) using magnetic scleral coils, and cervical and ocular vestibular-evoked myogenic potentials (VEMPs). We also reviewed the literature on isolated vertigo from lesions restricted to the vestibular nuclei, and analyzed the clinical features of seven additional patients. Both patients showed spontaneous torsional-horizontal nystagmus that beat away from the lesion side, and direction-changing gaze-evoked nystagmus. Recording of HIT using a magnetic search coil system documented decreased gains of the vestibular-ocular reflex for the horizontal and posterior semicircular canals on both sides, but more for the ipsilesional canals. Bithermal caloric tests showed ipsilesional canal paresis in both patients. Cervical and ocular VEMPs showed decreased or absent responses during stimulation of the ipsilesional ear. Initial MRIs including diffusion-weighted images were normal or equivocal, but follow-up imaging disclosed a circumscribed acute infarction in the area of the vestibular nuclei. Infarctions restricted to the vestibular nuclei may present with isolated vertigo with features of both peripheral and central vestibulopathies. Central signs should be sought even in patients with spontaneous horizontal-torsional nystagmus and positive HIT. In patients with combined peripheral and central vestibulopathy, a vestibular nuclear lesion should be considered especially when hearing is preserved.

  18. Vestibular rehabilitation for unilateral peripheral vestibular dysfunction.

    Science.gov (United States)

    Hillier, Susan L; McDonnell, Michelle

    2011-02-16

    This is an update of a Cochrane Review first published in The Cochrane Library in Issue 4, 2007.Unilateral peripheral vestibular dysfunction (UPVD) can occur as a result of disease, trauma or postoperatively. The dysfunction is characterised by complaints of dizziness, visual or gaze disturbances and balance impairment. Current management includes medication, physical manoeuvres and exercise regimes, the latter known collectively as vestibular rehabilitation (VR). To assess the effectiveness of vestibular rehabilitation in the adult, community-dwelling population of people with symptomatic unilateral peripheral vestibular dysfunction. We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ISRCTN and additional sources for published and unpublished trials. The most recent search was 1 July 2010, following a previous search in March 2007. Randomised trials of adults living in the community, diagnosed with symptomatic unilateral peripheral vestibular dysfunction. We sought comparisons of VR versus control (placebo etc.), other treatment (non-VR, e.g. pharmacological) or another form of VR. We considered the outcome measures of frequency and severity of dizziness or visual disturbance; changes in balance impairment, function or quality of life; and measure/s of physiological status with known functional correlation. Both authors independently extracted data and assessed trials for risk of bias. We included 27 trials, involving 1668 participants, in the review. Trials addressed the effectiveness of VR against control/sham interventions, medical interventions or other forms of VR. Individual and pooled data showed a statistically significant effect in favour of VR over control or no intervention. The exception to this was when movement-based VR was compared to physical manoeuvres for benign

  19. Enlarged Vestibular Aqueducts and Childhood Hearing Loss

    Science.gov (United States)

    ... Infections, and Deafness Enlarged Vestibular Aqueducts and Childhood Hearing Loss On this page: What are vestibular aqueducts? How ... How are enlarged vestibular aqueducts related to childhood hearing loss? Research suggests that most children with enlarged vestibular ...

  20. [Therapy of vestibular vertigo].

    Science.gov (United States)

    Hamann, K F

    1993-05-01

    The non-surgical treatment of vestibular disorders must be based on current knowledge of vestibular pathophysiology. It is generally accepted that after vestibular lesions a self-repair mechanism exists that allows a more or less complete recovery. In cases of persisting vestibular complaints the physician's duty consists in stimulation of these pre-existing mechanisms. This can be done by physical exercises, as has been recommended since the work of Cawthorne and Cooksey in 1946. This concept is meanwhile supported by modern neurophysiological research. This article describes a short training program consisting of exercises for fixation during rotations, smooth pursuit, optokinetic nystagmus and motor learning mechanisms. Physical exercises can be reinforced by nootropic drugs.

  1. Angiogenesis in vestibular schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Werther, Kim; Nalla, Amarnadh

    2010-01-01

    Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) are potent mediators of tumor angiogenesis. It has been demonstrated that vestibular schwannoma VEGF expression correlates with tumor growth pattern, whereas knowledge on the expression of MMPs is lacking. This study...

  2. Modification of tenascin-R expression following unilateral labyrinthectomy in rats indicates its possible role in neural plasticity of the vestibular neural circuit.

    Science.gov (United States)

    Gaal, Botond; Jóhannesson, Einar Örn; Dattani, Amit; Magyar, Agnes; Wéber, Ildikó; Matesz, Clara

    2015-09-01

    We have previously found that unilateral labyrinthectomy is accompanied by modification of hyaluronan and chondroitin sulfate proteoglycan staining in the lateral vestibular nucleus of rats and the time course of subsequent reorganization of extracellular matrix assembly correlates to the restoration of impaired vestibular function. The tenascin-R has repelling effect on pathfinding during axonal growth/regrowth, and thus inhibits neural circuit repair. By using immunohistochemical method, we studied the modification of tenascin-R expression in the superior, medial, lateral, and descending vestibular nuclei of the rat following unilateral labyrinthectomy. On postoperative day 1, tenascin-R reaction in the perineuronal nets disappeared on the side of labyrinthectomy in the superior, lateral, medial, and rostral part of the descending vestibular nuclei. On survival day 3, the staining intensity of tenascin-R reaction in perineuronal nets recovered on the operated side of the medial vestibular nucleus, whereas it was restored by the time of postoperative day 7 in the superior, lateral and rostral part of the descending vestibular nuclei. The staining intensity of tenascin-R reaction remained unchanged in the caudal part of the descending vestibular nucleus bilaterally. Regional differences in the modification of tenascin-R expression presented here may be associated with different roles of individual vestibular nuclei in the compensatory processes. The decreased expression of the tenascin-R may suggest the extracellular facilitation of plastic modifications in the vestibular neural circuit after lesion of the labyrinthine receptors.

  3. Vestibular function testing.

    LENUS (Irish Health Repository)

    Lang, E E

    2010-06-01

    Vestibular symptoms of vertigo, dizziness and dysequilibrium are common complaints which can be disabling both physically and psychologically. Routine examination of the ear nose and throat and neurological system are often normal in these patients. An accurate history and thorough clinical examination can provide a diagnosis in the majority of patients. However, in a subgroup of patients, vestibular function testing may be invaluable in arriving at a correct diagnosis and ultimately in the optimal treatment of these patients.

  4. Common Vestibular Disorders

    Directory of Open Access Journals (Sweden)

    Dimitrios G. Balatsouras

    2017-01-01

    Full Text Available The three most common vestibular diseases, benign paroxysmal positional vertigo (BPPV, Meniere's disease (MD and vestibular neuritis (VN, are presented in this paper. BPPV, which is the most common peripheral vestibular disorder, can be defined as transient vertigo induced by a rapid head position change, associated with a characteristic paroxysmal positional nystagmus. Canalolithiasis of the posterior semicircular canal is considered the most convincing theory of its pathogenesis and the development of appropriate therapeutic maneuvers resulted in its effective treatment. However, involvement of the horizontal or the anterior canal has been found in a significant rate and the recognition and treatment of these variants completed the clinical picture of the disease. MD is a chronic condition characterized by episodic attacks of vertigo, fluctuating hearing loss, tinnitus, aural pressure and a progressive loss of audiovestibular functions. Presence of endolymphatic hydrops on postmortem examination is its pathologic correlate. MD continues to be a diagnostic and therapeutic challenge. Patients with the disease range from minimally symptomatic, highly functional individuals to severely affected, disabled patients. Current management strategies are designed to control the acute and recurrent vestibulopathy but offer minimal remedy for the progressive cochlear dysfunction. VN is the most common cause of acute spontaneous vertigo, attributed to acute unilateral loss of vestibular function. Key signs and symptoms are an acute onset of spinning vertigo, postural imbalance and nausea as well as a horizontal rotatory nystagmus beating towards the non-affected side, a pathological headimpulse test and no evidence for central vestibular or ocular motor dysfunction. Vestibular neuritis preferentially involves the superior vestibular labyrinth and its afferents. Symptomatic medication is indicated only during the acute phase to relieve the vertigo and nausea

  5. In cat four times as many lamina I neurons project to the parabrachial nuclei and twice as many to the periaqueductal gray as to the thalamus

    NARCIS (Netherlands)

    Klop, EM; Mouton, LJ; Hulsebosch, R; Boers, J; Holstege, G

    2005-01-01

    The spinothalamic tract, and especially its fibers originating in lamina 1, is the best known pathway for transmission of nociceptive information. On the other hand, different studies have suggested that more lamina I cells project to the parabrachial nuclei (PBN) and periaqueductal gray (PAG) than

  6. Deregulated genes in sporadic vestibular schwannomas

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Helweg-Larsen, Rehannah Holga Andrea; Stangerup, Sven-Eric

    2010-01-01

    In search of genes associated with vestibular schwannoma tumorigenesis, this study examines the gene expression in human vestibular nerve versus vestibular schwannoma tissue samples using microarray technology.......In search of genes associated with vestibular schwannoma tumorigenesis, this study examines the gene expression in human vestibular nerve versus vestibular schwannoma tissue samples using microarray technology....

  7. Convergence of Vestibular and Neck Proprioceptive Sensory Signals in the Cerebellar Interpositus

    Science.gov (United States)

    Luan, Hongge; Gdowski, Martha Johnson; Newlands, Shawn D.; Gdowski, Greg T.

    2013-01-01

    The cerebellar interpositus nucleus (IN) contributes to controlling voluntary limb movements. We hypothesized that the vestibular signals within the IN might be transformed into coordinates describing the body’s movement, appropriate for controlling limb movement. We tested this hypothesis by recording from IN neurons in alert squirrel monkeys during vestibular and proprioceptive stimulation produced during (1) yaw head-on-trunk rotation about the C1–C2 axis while in an orthograde posture and (2) lateral side-to-side flexion about the C6 –T3 axis while in a pronograde posture. Neurons (44/67) were sensitive to vestibular stimulation (23/44 to rotation and translation, 14/44 to rotation only, 7/44 to translation only). Most neurons responded during contralateral movement. Neurons (29/44) had proprioceptive responses; the majority (21/29) were activated during neck rotation and lateral flexion. In all 29 neurons with convergent vestibular and neck proprioceptive input those inputs functionally canceled each other during all combined sensory stimulation, whether in the orthograde or pronograde posture. These results suggest that two distinct populations of IN neurons exist, each of which has vestibular sensitivity. One population carries vestibular signals that describe the head’s movement in space as is traditional for vestibular signals without proprioceptive signals. A second population of neurons demonstrated precise matching of vestibular and proprioceptive signals, even for complicated stimuli, which activated the semicircular canals and otolith organs and involved both rotation and flexion in the spine. Such neurons code body (not head) motion in space, which may be the appropriate platform for controlling limb movements. PMID:23325256

  8. Vestibular rehabilitation with visual stimuli in peripheral vestibular disorders

    OpenAIRE

    Manso, Andréa; Ganança, Mauricio Malavasi; Caovilla, Heloisa Helena

    2016-01-01

    ABSTRACT INTRODUCTION: Visual stimuli can induce vestibular adaptation and recovery of body balance. OBJECTIVE: To verify the effect of visual stimuli by digital images on vestibular and body balance rehabilitation of peripheral vestibular disorders. METHODS: Clinical, randomized, prospective study. Forty patients aged between 23 and 63 years with chronic peripheral vestibular disorders underwent 12 sessions of rehabilitation with visual stimuli using digital video disk (DVD) (experimental...

  9. Perspectives on Aging Vestibular Function

    National Research Council Canada - National Science Library

    Anson, Eric; Jeka, John

    2016-01-01

    Much is known about age related anatomical changes in the vestibular system. Knowledge regarding how vestibular anatomical changes impact behavior for older adults continues to grow, in line with advancements in diagnostic testing...

  10. Optimal duration of therapy in the recovery period of vestibular diseases

    Directory of Open Access Journals (Sweden)

    M. V. Zamergrad

    2014-01-01

    Full Text Available Dizziness is a common symptom in neurological and general medical practice. In most cases it is caused by diseases of the central or peripheral vestibular system. The most common vestibular system diseases include benign paroxysmal postural vertigo, dizziness, Meniere's disease, vestibular neuronitis, and cerebrovascular diseases. One of the main treatments for the diseases accompanied by dizziness is vestibular rehabilitation that is a complex of exercises, the goal of which is to stimulate vestibular compensation. Adequate vestibular compensation allows a patient to get rid of dizziness and unsteadiness even though vestibular system injury is irreversible. Some medications are able to enhance the efficiency of vestibular rehabilitation. At the same time, the optimal duration of treatment for the most common vestibular disorders has not beenadequately explored. The paper gives the results of an observational program, whose purpose was to determine the optimal duration of vestibular rehabilitation in combination with the use of tanakan in patients with non-progressive unilateral peripheral vestibular disorder.Patients and methods. Data on 46 patients aged 19 to 70 years who underwent vestibular rehabilitation and took tanakan for vertigo caused by vestibular neuronitis (n = 44, labyrinthitis (n =1, or Ramsay Hunt syndrome (n = 1 were analyzed. All the patients were examined four times. The symptoms were recorded and the histories of disease were considered. The degree of vestibular disorders, including vertigo, was assessed when collecting complaints. The symptoms of vertigo were objectivized using its vertigo rating scale and five-point subjective rating scale for vertigo. All the patients underwent standard somatic and neurological examinations and videonystagmography. During the first visit after diagnosis, vestibular exercises were chosen for the patients and tanakan was used in a dose of 40 mg thrice daily to accelerate

  11. Vestibular contributions to high-level sensorimotor functions.

    Science.gov (United States)

    Medendorp, W Pieter; Selen, Luc J P

    2017-10-01

    The vestibular system, which detects motion and orientation of the head in space, is known to be important in controlling gaze to stabilize vision, to ensure postural stability and to provide our sense of self-motion. While the brain's computations underlying these functions are extensively studied, the role of the vestibular system in higher level sensorimotor functions is less clear. This review covers new research on the vestibular influence on perceptual judgments, motor decisions, and the ability to learn multiple motor actions. Guided by concepts such as optimization, inference, estimation and control, we focus on how the brain determines causal relationships between memorized and visual representations in the updating of visual space, and how vestibular, visual and efferent motor information are integrated in the estimation of body motion. We also discuss evidence that these computations involve multiple coordinate representations, some of which can be probed in parietal cortex using neuronal oscillations derived from EEG. In addition, we describe work on decision making during self-motion, showing a clear modulation of bottom-up acceleration signals on decisions in the saccadic system. Finally, we consider the importance of vestibular signals as contextual cues in motor learning and recall. Taken together, these results emphasize the impact of vestibular information on high-level sensorimotor functions, and identify future directions for theoretical, behavioral, and neurophysiological investigations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Replacing semicircular canal function with a vestibular implant.

    Science.gov (United States)

    Merfeld, Daniel M; Lewis, Richard F

    2012-10-01

    To summarize the recent progress in the development of vestibular implants. The review is timely because of the recent advances in the field and because MED-EL has recently announced that they are developing a vestibular implant for clinical applications. The handicap experienced by patients suffering from bilateral vestibulopathy has a strong negative impact on physical and social functioning that appears to justify a surgical intervention. Two different surgical approaches to insert electrodes to stimulate ampullary neurons have been shown to be viable. The three-dimensional vestibulo-ocular reflex in rhesus monkeys produced with a three-dimensional vestibular implant showed gains that were relatively normal during acute stimulation. Rotation cues provided by an implant interact with otolith cues in a qualitatively normal manner. The brain appears to adapt plastically to the cues provided via artificial electrical stimulation. Research to date includes just a few human studies, but available data from both humans and animals support the technological and physiological feasibility of vestibular implants. Although vestibular implant users should not expect normal vestibular function - any more than cochlear implant users should expect normal hearing - data suggest that significant functional improvements are possible.

  13. Vestibular tributaries to the vein of the vestibular aqueduct

    DEFF Research Database (Denmark)

    Hansen, Jesper Marsner; Qvortrup, Klaus; Friis, Morten

    2010-01-01

    CONCLUSION: The vein of the vestibular aqueduct drains blood from areas extensively lined by vestibular dark cells (VDCs). A possible involvement in the pathogenesis of an impaired endolymphatic homeostasis can be envisioned at the level of the dark cells area. OBJECTIVES: The aim of this study...... was to investigate the vascular relationship between the vein of the vestibular aqueduct and the vestibular apparatus, with focus on the VDCs. METHODS: Sixteen male Wistar rats were divided into groups of 6 and 10. In the first group, 2 µm thick sections including the vein of the vestibular aqueduct, utricle...... relation to the VDCs in the utricle and the crista ampullaris of the lateral semicircular canal in the vestibular apparatus. One major vein emanated from these networks, which emptied into the vein of the vestibular aqueduct. Veins draining the saccule and the common crus of the superior and posterior...

  14. Dyscalculia and vestibular function.

    Science.gov (United States)

    Smith, P F

    2012-10-01

    A few studies in humans suggest that changes in stimulation of the balance organs of the inner ear (the 'vestibular system') can disrupt numerical cognition, resulting in 'dyscalculia', the inability to manipulate numbers. Many studies have also demonstrated that patients with vestibular dysfunction exhibit deficits in spatial memory. It is suggested that there may be a connection between spatial memory deficits resulting from vestibular dysfunction and the occurrence of dyscalculia, given the evidence that numerosity is coupled to the processing of spatial information (e.g., the 'spatial numerical association of response codes ('SNARC') effect'). The evidence supporting this hypothesis is summarised and potential experiments to test it are proposed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. The challenge of vestibular migraine.

    Science.gov (United States)

    Sargent, Eric W

    2013-10-01

    Migraine is a common illness and migraine-related dizziness occurs in up to 3% of the population. Because the diagnosis is controversial and may be difficult, many patients go undiagnosed and untreated. This review summarizes current understanding of the taxonomy and diagnosis of vestibular migraine, the relation of vestibular migraine to labyrinthine disease, and the treatment of the condition in adults and children. The categories of migraine accepted by the International Headache Society do not reflect the complex presentations of patients suspected of having vestibular migraine. In clinical practice and research, criteria are increasingly accepted that divide patients suspected of vestibular migraine into 'definite vestibular migraine' and 'probable vestibular migraine.' Because vertigo itself may trigger migraine, patients with vestibular migraine should be suspected of having vestibular end-organ disease until proven otherwise. Treatment remains controversial because of a notable lack of randomized controlled studies of vestibular migraine treatment. For now, the best strategy for the treatment of suspected vestibular migraine patients is dietary/lifestyle modification, antinausea/antiemetics for acute vertigo, and preventive medication for patients who have continued disruptive symptoms. Patients with vestibular migraine should be monitored regularly for the development of latent audiovestibular end-organ disease.

  16. Comparison of the vascular innervation of the rat cochlea and vestibular system.

    Science.gov (United States)

    Lyon, M J; Payman, R N

    2000-03-01

    In order to gain a better understanding of the neuronal and local control of inner ear blood flow, the vascular innervation to the rat cochlea and vestibular system was examined. Specimens were removed in toto beginning at the basilar artery extending to the anterior inferior cerebellar artery, labyrinthine artery, common cochlear artery, modiolar artery and anterior vestibular artery. When possible the vessels were dissected in continuity through the cribrose area. The vestibular endorgans were also removed. Specimens were examined using immunohistochemical techniques for the presence of vasoactive intestinal peptide, neuronal nitric oxide synthase, neuropeptide-Y, substance P and calcitonin gene related peptide. Results show that the vasculature to the cochlea and vestibular portion of the inner ear receive similar types of nonadrenergic innervation, that within the vestibular endorgans, only CGRP and SP were found in the neuroepithelium or in association with vessels, and that within the vestibular system, the majority of the vascular innervation appears to stop at or near the cribrose area. In the cochlea however, it extends to include the radiating arterioles. These findings suggest that cochlear blood flow is under finer control and that neuronally induced changes in blood flow may have a more global effect in the vestibular periphery.

  17. Evidence for reduced nitric oxide synthase (NOS) activity in the ipsilateral medial vestibular nucleus and bilateral prepositus hypoglossi following unilateral vestibular deafferentation in the guinea pig.

    Science.gov (United States)

    Anderson, T V; Moulton, A R; Sansom, A J; Kerr, D R; Laverty, R; Darlington, C L; Smith, P F

    1998-03-23

    The aim of the present study was to examine, using a radioenzymatic assay technique, nitric oxide synthase (NOS) activity in the bilateral medial vestibular nuclei (MVN) and prepositus hypoglossi (PH), during the development of vestibular compensation for unilateral vestibular deafferentation (UVD) in the guinea pig. In the MVN ipsilateral to the UVD, and bilaterally in PH, NOS activity decreased following UVD compared to sham controls and did not recover significantly up to 50 h later, when a substantial degree of behavioural vestibular compensation had occurred. These results suggest that UVD causes a decrease in NOS activity in the ipsilateral MVN and the bilateral PH, and that a consequent decrease in NO may be responsible for some of the ocular motor and postural symptoms of UVD. Copyright 1998 Elsevier Science B.V.

  18. Characterization of Cochlear, Vestibular and Cochlear-Vestibular Electrically Evoked Compound Action Potentials in Patients with a Vestibulo-Cochlear Implant

    Directory of Open Access Journals (Sweden)

    T. A. K. Nguyen

    2017-11-01

    Full Text Available The peripheral vestibular system is critical for the execution of activities of daily life as it provides movement and orientation information to motor and sensory systems. Patients with bilateral vestibular hypofunction experience a significant decrease in quality of life and have currently no viable treatment option. Vestibular implants could eventually restore vestibular function. Most vestibular implant prototypes to date are modified cochlear implants to fast-track development. These use various objective measurements, such as the electrically evoked compound action potential (eCAP, to supplement behavioral information. We investigated whether eCAPs could be recorded in patients with a vestibulo-cochlear implant. Specifically, eCAPs were successfully recorded for cochlear and vestibular setups, as well as for mixed cochlear-vestibular setups. Similarities and slight differences were found for the recordings of the three setups. These findings demonstrated the feasibility of eCAP recording with a vestibulo-cochlear implant. They could be used in the short term to reduce current spread and avoid activation of non-targeted neurons. More research is warranted to better understand the neural origin of vestibular eCAPs and to utilize them for clinical applications.

  19. The vestibular body: Vestibular contributions to bodily representations.

    Science.gov (United States)

    Ferrè, Elisa Raffaella; Haggard, Patrick

    2016-01-01

    Vestibular signals are integrated with signals from other sensory modalities. This convergence could reflect an important mechanism for maintaining the perception of the body. Here we review the current literature in order to develop a framework for understanding how the vestibular system contributes to body representation. According to recent models, we distinguish between three processes for body representation, and we look at whether vestibular signals might influence each process. These are (i) somatosensation, the primary sensory processing of somatic stimuli, (ii) somatoperception, the processes of constructing percepts and experiences of somatic objects and events and (iii) somatorepresentation, the knowledge about the body as a physical object in the world. Vestibular signals appear to contribute to all three levels in this model of body processing. Thus, the traditional view of the vestibular system as a low-level, dedicated orienting module tends to underestimate the pervasive role of vestibular input in bodily self-awareness.

  20. Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis

    Science.gov (United States)

    ... vestibular schwannoma is key to preventing its serious consequences. There are three options for managing a vestibular ... Disorders Balance Problems and Disorders - National Institute on Aging Enlarged Vestibular Aqueducts and Childhood Hearing Loss Genetics ...

  1. Spatial cognition, body representation and affective processes: the role of vestibular information beyond ocular reflexes and control of posture.

    Science.gov (United States)

    Mast, Fred W; Preuss, Nora; Hartmann, Matthias; Grabherr, Luzia

    2014-01-01

    A growing number of studies in humans demonstrate the involvement of vestibular information in tasks that are seemingly remote from well-known functions such as space constancy or postural control. In this review article we point out three emerging streams of research highlighting the importance of vestibular input: (1) Spatial Cognition: Modulation of vestibular signals can induce specific changes in spatial cognitive tasks like mental imagery and the processing of numbers. This has been shown in studies manipulating body orientation (changing the input from the otoliths), body rotation (changing the input from the semicircular canals), in clinical findings with vestibular patients, and in studies carried out in microgravity. There is also an effect in the reverse direction; top-down processes can affect perception of vestibular stimuli. (2) Body Representation: Numerous studies demonstrate that vestibular stimulation changes the representation of body parts, and sensitivity to tactile input or pain. Thus, the vestibular system plays an integral role in multisensory coordination of body representation. (3) Affective Processes and Disorders: Studies in psychiatric patients and patients with a vestibular disorder report a high comorbidity of vestibular dysfunctions and psychiatric symptoms. Recent studies investigated the beneficial effect of vestibular stimulation on psychiatric disorders, and how vestibular input can change mood and affect. These three emerging streams of research in vestibular science are-at least in part-associated with different neuronal core mechanisms. Spatial transformations draw on parietal areas, body representation is associated with somatosensory areas, and affective processes involve insular and cingulate cortices, all of which receive vestibular input. Even though a wide range of different vestibular cortical projection areas has been ascertained, their functionality still is scarcely understood.

  2. Spatial Cognition, Body Representation and Affective Processes: The Role of Vestibular Information beyond Ocular Reflexes and Control of Posture

    Directory of Open Access Journals (Sweden)

    Fred W Mast

    2014-05-01

    Full Text Available A growing number of studies in humans demonstrate the involvement of vestibular information in tasks that are seemingly remote from well-known functions such as space constancy or postural control. In this review article we point out three emerging streams of research highlighting the importance of vestibular input: 1 Spatial Cognition: Modulation of vestibular signals can induce specific changes in spatial cognitive tasks like mental imagery and the processing of numbers. This has been shown in studies manipulating body orientation (changing the input from the otoliths, body rotation (changing the input from the semicircular canals, in clinical findings with vestibular patients, and in studies carried out in microgravity. There is also an effect in the reverse direction; top-down processes can affect perception of vestibular stimuli. 2 Body Representation: Numerous studies demonstrate that vestibular stimulation changes the representation of body parts, and sensitivity to tactile input or pain. Thus, the vestibular system plays an integral role in multisensory coordination of body representation. 3 Affective Processes and Disorders: Studies in psychiatric patients and patients with a vestibular disorder report a high comorbidity of vestibular dysfunctions and psychiatric symptoms. Recent studies investigated the beneficial effect of vestibular stimulation on psychiatric disorders, and how vestibular input can change mood and affect. These three emerging streams of research in vestibular science are – at least in part – associated with different neuronal core mechanisms. Spatial transformations draw on parietal areas, body representation is associated with somatosensory areas, and affective processes involve insular and cingulate cortices, all of which receive vestibular input. Even though a wide range of different vestibular cortical projection areas has been ascertained, their functionality still is scarcely understood.

  3. An electronic prosthesis mimicking the dynamic vestibular function

    Science.gov (United States)

    Shkel, Andrei M.

    2006-03-01

    This paper reports our progress toward development of a unilateral vestibular prosthesis. The sensing element of the prosthesis is a custom designed one-axis MEMS gyroscope. Similarly to the natural semicircular canal, the microscopic gyroscope senses angular motion of the head and generates voltages proportional to the corresponding angular accelerations. Then, voltages are sent to the pulse generating unit where angular motion is translated into voltage pulses. The voltage pulses are converted into current pulses and are delivered through specially designed electrodes, conditioned to stimulate the corresponding vestibular nerve branch. Our preliminary experimental evaluations of the prosthesis on a rate table indicate that the device's output matches the average firing rate of vestibular neurons to those in animal models reported in the literature. The proposed design is scalable; the sensing unit, pulse generator, and the current source can be potentially implemented on a single chip using integrated MEMS technology.

  4. Neuropharmacology of Vestibular System Disorders

    OpenAIRE

    Soto, Enrique; Vega, Rosario

    2010-01-01

    This work reviews the neuropharmacology of the vestibular system, with an emphasis on the mechanism of action of drugs used in the treatment of vestibular disorders. Otolaryngologists are confronted with a rapidly changing field in which advances in the knowledge of ionic channel function and synaptic transmission mechanisms have led to the development of new scientific models for the understanding of vestibular dysfunction and its management. In particular, there have been recent advances in...

  5. Prophylactic treatment of vestibular migraine

    OpenAIRE

    Salmito, Márcio Cavalcante; Duarte, Juliana Antoniolli; Morganti, Lígia Oliveira Golçalves; Brandão, Priscila Valéria Caus; Nakao, Bruno Higa; Villa, Thais Rodrigues; Ganança,Fernando Freitas

    2017-01-01

    Abstract Introduction: Vestibular migraine (VM) is now accepted as a common cause of episodic vertigo. Treatment of VM involves two situations: the vestibular symptom attacks and the period between attacks. For the latter, some prophylaxis methods can be used. The current recommendation is to use the same prophylactic drugs used for migraines, including β-blockers, antidepressants and anticonvulsants. The recent diagnostic definition of vestibular migraine makes the number of studies on its ...

  6. Differential Involvement during Latent Herpes Simplex Virus 1 Infection of the Superior and Inferior Divisions of the Vestibular Ganglia: Implications for Vestibular Neuritis

    Science.gov (United States)

    Lindemann, Anja; Sinicina, Inga; Horn, Anja K. E.; Brandt, Thomas; Strupp, Michael; Hüfner, Katharina

    2017-01-01

    ABSTRACT Controversy still surrounds both the etiology and pathophysiology of vestibular neuritis (VN). Especially uncertain is why the superior vestibular nerve (SVN) is more frequently affected than the inferior vestibular nerve (IVN), which is partially or totally spared. To address this question, we developed an improved method for preparing human vestibular ganglia (VG) and nerve. Subsequently, macro- and microanatomical as well as PCR studies were performed on 38 human ganglia from 38 individuals. The SVN was 2.4 mm longer than the IVN, and in 65% of the cases, the IVN ran in two separate bony canals, which was not the case for the SVN. Anastomoses between the facial and cochlear nerves were more common for the SVN (14/38 and 9/38, respectively) than for the IVN (7/38 and 2/38, respectively). Using reverse transcription-quantitative PCR (RT-qPCR), we found only a few latently herpes simplex virus 1 (HSV-1)-infected VG (18.4%). In cases of two separate neuronal fields, infected neurons were located in the superior part only. In summary, these PCR and micro- and macroanatomical studies provide possible explanations for the high frequency of SVN infection in vestibular neuritis. IMPORTANCE Vestibular neuritis is known to affect the superior part of the vestibular nerve more frequently than the inferior part. The reason for this clinical phenomenon remains unclear. Anatomical differences may play a role, or if latent HSV-1 infection is assumed, the etiology may be due to the different distribution of the infection. To shed further light on this subject, we conducted different macro- and microanatomical studies. We also assessed the presence of HSV-1 in VG and in different sections of the VG. Our findings add new information on the macro- and microanatomy of the VG as well as the pathophysiology of vestibular neuritis. We also show that latent HSV-1 infection of VG neurons is less frequent than previously reported. PMID:28446678

  7. Genetics of peripheral vestibular dysfunction: lessons from mutant mouse strains.

    Science.gov (United States)

    Jones, Sherri M; Jones, Timothy A

    2014-03-01

    A considerable amount of research has been published about genetic hearing impairment. Fifty to sixty percent of hearing loss is thought to have a genetic cause. Genes may also play a significant role in acquired hearing loss due to aging, noise exposure, or ototoxic medications. Between 1995 and 2012, over 100 causative genes have been identified for syndromic and nonsyndromic forms of hereditary hearing loss. Mouse models have been extremely valuable in facilitating the discovery of hearing loss genes and in understanding inner ear pathology due to genetic mutations or elucidating fundamental mechanisms of inner ear development. Whereas much is being learned about hereditary hearing loss and the genetics of cochlear disorders, relatively little is known about the role genes may play in peripheral vestibular impairment. Here we review the literature with regard to genetics of vestibular dysfunction and discuss what we have learned from studies using mutant mouse models and direct measures of peripheral vestibular neural function. Several genes are considered that when mutated lead to varying degrees of inner ear vestibular dysfunction due to deficits in otoconia, stereocilia, hair cells, or neurons. Behavior often does not reveal the inner ear deficit. Many of the examples presented are also known to cause human disorders. Knowledge regarding the roles of particular genes in the operation of the vestibular sensory apparatus is growing, and it is clear that gene products co-expressed in the cochlea and vestibule may play different roles in the respective end organs. The discovery of new genes mediating critical inner ear vestibular function carries the promise of new strategies in diagnosing, treating, and managing patients as well as predicting the course and level of morbidity in human vestibular disease. American Academy of Audiology.

  8. Current concepts of the vestibular system reviewed: 1. The role of the vestibulospinal system in postural control.

    Science.gov (United States)

    Keshner, E A; Cohen, H

    1989-05-01

    This paper reviews the research findings that support the presence of vestibulospinal reflexes in corrections for head and body instability. Studies of the importance of labyrinthine inputs to the central nervous system organization of eye, head, and body movements demonstrate that the vestibular nuclei are more than a simple relay station for labyrinthine activity. At all levels of the vestibular system beyond the primary vestibular afferents, parallel processing of labyrinthine signals occurs with input from other sensory systems. Thus, output of the vestibular nuclear complex (VNC) is not equivalent to the labyrinthine input. It is the VNC output that influences motor behavior. Various sensory inputs are available to the nervous system to detect and correct postural instability. Most notably, vestibular, visual, and proprioceptive signals contribute significantly to the stabilizing responses in humans. The intent of this paper is to review experimental results rather than to discuss treatment interventions. Wherever possible, conclusions are drawn as to the clinical implications of current research findings.

  9. Vestibular end organ injury induced by middle ear treatment with ferric chloride in rats.

    Science.gov (United States)

    Lee, J H; Kim, M S; Park, B R

    2017-02-01

    Sensorineural hearing loss, ataxia, pyramidal signs, and vestibular deficits characterize superficial siderosis of the central nervous system. This study investigated changes in vestibular function, free radical formation, and phosphorylated cJun expression in the vestibular end organs after middle ear treatment with a ferric chloride (FeCl3) solution. A single injection of 70% FeCl3 solution into the unilateral middle ear cavity caused static vestibular symptoms, such as spontaneous nystagmus and head tilt. Asymmetric expression of c-Fos protein was observed in the bilateral vestibular nuclei and prepositus hypoglossal nuclei within 6 h after injection. Histopathologic examinations revealed partial hair cell loss, degeneration of the supporting stroma, and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells in the neuroepithelial layer of the crista ampullaris in FeCl3-treated animals. 5-(And-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester and diaminofluorescein-2 diacetate fluorescence and immunoreactivity for nitrotyrosine increased markedly in the sensory neuroepithelial layer and nerve bundles of the crista ampullaris after 2 h. Strong immunoreactivity for phospho-cJun and cJun was observed in the type I hair cells of the crista ampullaris 120 h after injection. Thus, a single short-term treatment with a high concentration of FeCl3 in the unilateral middle ear cavity can induce activation of intracellular signals for cJun protein and oxidative stress through the formation of reactive oxygen species and nitric oxide in vestibular sensory receptors, resulting in vestibular dysfunction. These results suggest that activation of intracellular signals for cJun protein and oxidative stress may be a key component of the pathogenesis of vestibular deficits in patients with superficial siderosis.

  10. Expression of calcium-binding proteins and nNOS in the human vestibular and precerebellar brainstem.

    Science.gov (United States)

    Baizer, Joan S; Broussard, Dianne M

    2010-03-15

    Information about the position and movement of the head in space is coded by vestibular receptors and relayed to four nuclei that comprise the vestibular nuclear complex (VNC). Many additional brainstem nuclei are involved in the processing of vestibular information, receiving signals either directly from the eighth nerve or indirectly via projections from the VNC. In cats, squirrel monkeys, and macaque monkeys, we found neurochemically defined subdivisions within the medial vestibular nucleus (MVe) and within the functionally related nucleus prepositus hypoglossi (PrH). In humans, different studies disagree about the borders, sizes, and possible subdivisions of the vestibular brainstem. In an attempt to clarify this organization, we have begun an analysis of the neurochemical characteristics of the human using brains from the Witelson Normal Brain Collection and standard techniques for antigen retrieval and immunohistochemistry. Using antibodies to calbindin, calretinin, parvalbumin, and nitric oxide synthase, we find neurochemically defined subdivisions within the MVe similar to the subdivisions described in cats and monkeys. The neurochemical organization of PrH is different. We also find unique neurochemical profiles for several structures that suggest reclassification of nuclei. These data suggest both quantitative and qualitative differences among cats, monkeys, and humans in the organization of the vestibular brainstem. These results have important implications for the analysis of changes in that organization subsequent to aging, disease, or loss of input.

  11. Update on the pharmacotherapy of cerebellar and central vestibular disorders.

    Science.gov (United States)

    Kalla, Roger; Teufel, Julian; Feil, Katharina; Muth, Caroline; Strupp, Michael

    2016-04-01

    An overview of the current pharmacotherapy of central vestibular syndromes and the most common forms of central nystagmus as well as cerebellar disorders is given. 4-aminopyridine (4-AP) is recommended for the treatment of downbeat nystagmus, a frequent form of acquired persisting fixation nystagmus, and upbeat nystagmus. Animal studies showed that this non-selective blocker of voltage-gated potassium channels increases Purkinje cell excitability and normalizes the irregular firing rate, so that the inhibitory influence of the cerebellar cortex on vestibular and deep cerebellar nuclei is restored. The efficacy of 4-AP in episodic ataxia type 2, which is most often caused by mutations of the PQ-calcium channel, was demonstrated in a randomized controlled trial. It was also shown in an animal model (the tottering mouse) of episodic ataxia type 2. In a case series, chlorzoxazone, a non-selective activator of small-conductance calcium-activated potassium channels, was shown to reduce the DBN. The efficacy of acetyl-DL-leucine as a potential new symptomatic treatment for cerebellar diseases has been demonstrated in three case series. The ongoing randomized controlled trials on episodic ataxia type 2 (sustained-release form of 4-aminopyridine vs. acetazolamide vs. placebo; EAT2TREAT), vestibular migraine with metoprolol (PROVEMIG-trial), cerebellar gait disorders (sustained-release form of 4-aminopyridine vs. placebo; FACEG) and cerebellar ataxia (acetyl-DL-leucine vs. placebo; ALCAT) will provide new insights into the pharmacotherapy of cerebellar and central vestibular disorders.

  12. Vestibular pathways involved in cognition

    Directory of Open Access Journals (Sweden)

    Martin eHitier

    2014-07-01

    Full Text Available Recent discoveries have emphasized the role of the vestibular system in cognitive processes such as memory, spatial navigation and bodily self-consciousness. A precise understanding of the vestibular pathways involved is essential to understand the consequences of vestibular diseases for cognition, as well as develop therapeutic strategies to facilitate recovery. The knowledge of the vestibular cortical projections areas, defined as the cortical areas activated by vestibular stimulation, has dramatically increased over the last several years from both anatomical and functional points of view. Four major pathways have been hypothesized to transmit vestibular information to the vestibular cortex: 1 the vestibulo-thalamo-cortical pathway, which probably transmits spatial information about the environment via the parietal, entorhinal and perirhinal cortices to the hippocampus and is associated with spatial representation and self-versus object motion distinctions; 2 the pathway from the dorsal tegmental nucleus via the lateral mammillary nucleus, the anterodorsal nucleus of the thalamus to the entorhinal cortex, which transmits information for estimations of the head direction; 3 the pathway via the nucleus reticularis pontis oralis, the supramammillary nucleus and the medial septum to the hippocampus, which transmits information supporting hippocampal theta rhythm and memory; and 4 a possible pathway via the cerebellum, and the ventral lateral nucleus of the thalamus (perhaps to the parietal cortex, which transmits information for spatial learning. Finally a new pathway is hypothesized via the basal ganglia, potentially involved in spatial learning and spatial memory. From these pathways, progressively emerges the anatomical network of vestibular cognition.

  13. The vestibular implant: Quo vadis?

    Directory of Open Access Journals (Sweden)

    Raymond eVan De Berg

    2011-08-01

    Full Text Available AbstractObjective: to assess the progress of the development of the vestibular implant and its feasibility short-term. Data sources: a search was performed in Pubmed, Medline and Embase. Key words used were vestibular prosth* and vestibular implant. The only search limit was language: English or Dutch. Additional sources were medical books, conference lectures and our personal experience with per-operative vestibular stimulation in patients selected for cochlear implantation.Study selection: all studies about the vestibular implant and related topics were included and evaluated by two reviewers. No study was excluded since every study investigated different aspects of the vestibular implant. Data extraction and synthesis: data was extracted by the first author from selected reports, supplemented by additional information, medical books conference lectures. Since each study had its own point of interest with its own outcomes, it was not possible to compare data of different studies. Conclusion: to use a basic vestibular implant in humans seems feasible in the very near future. Investigations show that electric stimulation of the canal nerves induces a nystagmus which corresponds to the plane of the canal which is innervated by the stimulated nerve branch. The brain is able to adapt to a higher baseline stimulation, while still reacting on a dynamic component. The best response will be achieved by a combination of the optimal stimulus (stimulus profile, stimulus location, precompensation, complemented by central vestibular adaptation. The degree of response will probably vary between individuals, depending on pathology and their ability to adapt.

  14. True incidence of vestibular schwannoma?

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Tos, Mirko; Thomsen, Jens

    2010-01-01

    The incidence of diagnosed sporadic unilateral vestibular schwannomas (VS) has increased, due primarily to more widespread access to magnetic resonance imaging.......The incidence of diagnosed sporadic unilateral vestibular schwannomas (VS) has increased, due primarily to more widespread access to magnetic resonance imaging....

  15. Hypervascular vestibular Schwannoma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ja Young; Yu, In Kyu [Dept. of Radiology, Eulji University Hospital, Daejeon (Korea, Republic of)

    2014-11-15

    Most vestibular schwannoma is hypovascular with well known poor tumor staining in cerebral angiography. However, hypervascular vestibular schwannoma might be observed as a rare subtype with increased risk of bleeding during surgery. Multimodal imaging features which represent hypervascularity of the tumor can be observed in hypervascular vestibular schwannoma. Here we report a case of hypervascular vestibular schwannoma with brief literature review.

  16. Input/output properties of the lateral vestibular nucleus

    Science.gov (United States)

    Boyle, R.; Bush, G.; Ehsanian, R.

    2004-01-01

    This article is a review of work in three species, squirrel monkey, cat, and rat studying the inputs and outputs from the lateral vestibular nucleus (LVN). Different electrophysiological shock paradigms were used to determine the synaptic inputs derived from thick to thin diameter vestibular nerve afferents. Angular and linear mechanical stimulations were used to activate and study the combined and individual contribution of inner ear organs and neck afferents. The spatio-temporal properties of LVN neurons in the decerebrated rat were studied in response to dynamic acceleration inputs using sinusoidal linear translation in the horizontal head plane. Outputs were evaluated using antidromic identification techniques and identified LVN neurons were intracellularly injected with biocytin and their morphology studied.

  17. Vestibular rehabilitation outcomes in the elderly with chronic vestibular dysfunction.

    Science.gov (United States)

    Bayat, Arash; Pourbakht, Akram; Saki, Nader; Zainun, Zuraida; Nikakhlagh, Soheila; Mirmomeni, Golshan

    2012-11-01

    Chronic vestibular dysfunction is a frustrating problem in the elderly and can have a tremendous impact on their life, but only a few studies are available. Vestibular rehabilitation therapy (VRT) is an important therapeutic option for the neuro-otologist in treating patients with significant balance deficits. The purpose of this study was to assess the effect of vestibular rehabilitation on dizziness in elderly patients with chronic vestibular dysfunction. A total of 33 patients older than 60 years with chronic vestibular dysfunction were studied. Clinical and objective vestibular tests including videonystagmography (VNG) and dizziness handicap inventory (DHI) were carried out at their first visit, 2 weeks, and 8 weeks post-VRT. The VRT exercises were performed according to Cawthorne and Cooksey protocols. Oculomotor assessments were within normal limits in all patients. Nineteen patients (57.57%) showed abnormal canal paralysis on caloric testing which at follow-up sessions; CP values were decreased remarkably after VRT exercises. We found a significant improvement between pre-VRT and post-VRT total DHI scores (P < 0.001). This improvement was most prominent in functional subscore. Our study demonstrated that VRT is an effective therapeutic method for elderly patients with chronic vestibular dysfunction.

  18. Presbivértigo: ejercicios vestibulares Presbivertigo: vestibular exercises

    OpenAIRE

    Esther Bernal Valls; Víctor Faus Cuñat; Raquel Bernal Valls

    2006-01-01

    El uso de ejercicios en el tratamiento de pacientes con déficit vestibular crónico está incrementándose de forma notable, lo que evidencia que se trata de un procedimiento que resulta beneficioso para este tipo de pacientes. Los buenos resultados que se obtienen sugieren que los ejercicios vestibulares dan lugar a una estabilidad postural y a una disminución de la sensación de desequilibrio.The use of exercises in the treatment of patients with vestibular deficits is increasing in a represent...

  19. The vestibular system and cognition.

    Science.gov (United States)

    Smith, Paul F

    2017-02-01

    The last year has seen a great deal of new information published relating vestibular dysfunction to cognitive impairment in humans, especially in the elderly. The objective of this review is to summarize and critically evaluate this new evidence in the context of the previous literature. This review will address the recent epidemiological/survey studies that link vestibular dysfunction with cognitive impairment in the elderly; recent clinical investigations into cognitive impairment in the context of vestibular dysfunction, both in the elderly and in the cases of otic capsule dehiscence and partial bilateral vestibulopathy; recent evidence that vestibular impairment is associated with hippocampal atrophy; and finally recent evidence relating to the hypothesis that vestibular dysfunction could be a risk factor for dementia. The main implication of these recent studies is that vestibular dysfunction, possibly of any type, may result in cognitive impairment, and this could be especially so for the elderly. Such symptoms will need to be considered in the treatment of patients with vestibular disorders.

  20. Pharmacology of the vestibular system.

    Science.gov (United States)

    Smith, P F

    2000-02-01

    In the past year significant advances have been made in our understanding of the neurochemistry and neuropharmacology of the peripheral and central vestibular systems. The recognition of the central importance of excitatory amino acids and their receptors at the level of the hair cells, vestibular nerve and vestibular nucleus has progressed further, and the role of nitric oxide in relation to activation of the N-methyl-D-aspartate receptor subtype is becoming increasingly clear. Increasing evidence suggests that excessive N-methyl-D-aspartate receptor activation and nitric oxide production after exposure to aminoglycoside antibiotics is a critical part of hair cell death, and new pharmacological strategies for preventing aminoglycoside ototoxicity are emerging as a result. Conversely, the use of aminoglycosides to lesion the peripheral vestibular system in the treatment of Meniere's disease has been studied intensively. In the vestibular nucleus, new studies suggest the importance of opioid, nociceptin and glucocorticoid receptors in the control of vestibular reflex function. Finally, the mechanisms of action and optimal use of antihistamines in the treatment of vestibular disorders has also received a great deal of attention.

  1. Is the Headache in Patients with Vestibular Migraine Attenuated by Vestibular Rehabilitation?

    OpenAIRE

    Sugaya, Nagisa; ARAI, Miki; Goto, Fumiyuki

    2017-01-01

    Background Vestibular rehabilitation is the most effective treatment for dizziness due to vestibular dysfunction. Given the biological relationship between vestibular symptoms and headache, headache in patients with vestibular migraine (VM) could be improved by vestibular rehabilitation that leads to the improvement of dizziness. This study aimed to compare the effects of vestibular rehabilitation on headache and other outcomes relating to dizziness, and the psychological factors in patien...

  2. Presbivértigo: ejercicios vestibulares Presbivertigo: vestibular exercises

    Directory of Open Access Journals (Sweden)

    Esther Bernal Valls

    2006-12-01

    Full Text Available El uso de ejercicios en el tratamiento de pacientes con déficit vestibular crónico está incrementándose de forma notable, lo que evidencia que se trata de un procedimiento que resulta beneficioso para este tipo de pacientes. Los buenos resultados que se obtienen sugieren que los ejercicios vestibulares dan lugar a una estabilidad postural y a una disminución de la sensación de desequilibrio.The use of exercises in the treatment of patients with vestibular deficits is increasing in a representative way, what evidences this is a profitable process for this kind of patients. The good results suggest that vestibular exercises permit a postural stability and a decrease in the perception of disequilibrium.

  3. Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography.

    Science.gov (United States)

    Becker-Bense, Sandra; Buchholz, Hans-Georg; Baier, Bernhard; Schreckenberger, Mathias; Bartenstein, Peter; Zwergal, Andreas; Brandt, Thomas; Dieterich, Marianne

    2016-01-01

    The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group subtraction analyses and comparisons with healthy controls were performed with Statistic Parametric Mapping for the PET data. A comparison of PET A of acute-stage patients with that of healthy controls showed increases in glucose metabolism in the cerebellum, motion-sensitive visual cortex areas, and inferior temporal lobe, but none in vestibular cortex areas. At the supratentorial level bilateral signal decreases dominated in the thalamus, frontal eye fields, and anterior cingulum. These decreases persisted after clinical recovery in contrast to the increases. The transient activations can be attributed to ocular motor and postural recovery (cerebellum) and sensory substitution of vestibular function for motion perception (visual cortex). The persisting deactivation in the thalamic nuclei and frontal eye fields allows alternative functional interpretations of the thalamic nuclei: either a disconnection of ascending sensory input occurs or there is a functional mismatch between expected and actual vestibular activity. Our data support the view that both thalami operate separately for each hemisphere but receive vestibular input from ipsilateral and contralateral midbrain integration centers. Normally they have gatekeeper functions for multisensory input to the cortex and automatic

  4. Effects of nitric oxide on the vestibular functional recovery after unilateral labyrinthectomy.

    Science.gov (United States)

    Park, J S; Jeong, H S

    2000-12-01

    The effects of nitric oxide on the vestibular function recovery following unilateral labyrinthectomy were studied. Male Sprague-Dawley rats treated with N-omega-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, were subjected to destruction of the unilateral vestibular apparatus and spontaneous nystagmus was observed. To explore the role of nitric oxide on the potassium current, the whole cell patch clamp technique was applied on isolated medial vestibular nuclear neurons. The frequency of spontaneous nystagmus that appeared in L-NAME-treated rats was higher and maintained longer than in control animals. Potassium currents in the isolated medial vestibular nucleus were inhibited by nitric oxide liberating agents, sodium nitroprusside and S-nitroso-N-acetylpenicillamine. After blockade of calcium dependent potassium currents by high EGTA (11 mM)-containing pipette solution, sodium nitroprusside did not inhibit the outward potassium currents. 8-Bromoguanosine 3,5-cyclic monophosphate, a membrane-permeable cGMP analogue, produced similar effects to inhibit the outward potassium currents as sodium nitroprusside. These results suggest that nitric oxide production after unilateral labyrinthectomy would help to facilitate vestibular compensation by inhibiting calcium-dependent potassium currents through increasing intracellular cyclic GMP, thereby increasing excitability in ipsilateral vestibular nuclear neurons.

  5. Task, muscle and frequency dependent vestibular control of posture

    NARCIS (Netherlands)

    Forbes, P.A.; Siegmund, G.P.; Schouten, A.C.; Blouin, J.S.

    2015-01-01

    The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular

  6. Vestibular rehabilitation with visual stimuli in peripheral vestibular disorders.

    Science.gov (United States)

    Manso, Andréa; Ganança, Mauricio Malavasi; Caovilla, Heloisa Helena

    2016-01-01

    Visual stimuli can induce vestibular adaptation and recovery of body balance. To verify the effect of visual stimuli by digital images on vestibular and body balance rehabilitation of peripheral vestibular disorders. Clinical, randomized, prospective study. Forty patients aged between 23 and 63 years with chronic peripheral vestibular disorders underwent 12 sessions of rehabilitation with visual stimuli using digital video disk (DVD) (experimental group) or Cawthorne-Cooksey exercises (control group). The Dizziness Handicap Inventory (DHI), dizziness analog scale, and the sensitized Romberg static balance and one-leg stance tests were applied before and after the intervention. Before and after the intervention, there was no difference between the experimental and control groups (p>0.005) regarding the findings of DHI, dizziness analog scale, and static balance tests. After the intervention, the experimental and control groups showed lower values (p<0.05) in the DHI and the dizziness analog scale, and higher values (p<0.05) in the static balance tests in some of the assessed conditions. The inclusion of visual stimuli by digital images on vestibular and body balance rehabilitation is effective in reducing dizziness and improving quality of life and postural control in individuals with peripheral vestibular disorders. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  7. Vestibular rehabilitation with visual stimuli in peripheral vestibular disorders

    Directory of Open Access Journals (Sweden)

    Andréa Manso

    2016-04-01

    Full Text Available ABSTRACT INTRODUCTION: Visual stimuli can induce vestibular adaptation and recovery of body balance. OBJECTIVE: To verify the effect of visual stimuli by digital images on vestibular and body balance rehabilitation of peripheral vestibular disorders. METHODS: Clinical, randomized, prospective study. Forty patients aged between 23 and 63 years with chronic peripheral vestibular disorders underwent 12 sessions of rehabilitation with visual stimuli using digital video disk (DVD (experimental group or Cawthorne-Cooksey exercises (control group. The Dizziness Handicap Inventory (DHI, dizziness analog scale, and the sensitized Romberg static balance and one-leg stance tests were applied before and after the intervention. RESULTS: Before and after the intervention, there was no difference between the experimental and control groups (p > 0.005 regarding the findings of DHI, dizziness analog scale, and static balance tests. After the intervention, the experimental and control groups showed lower values (p < 0.05 in the DHI and the dizziness analog scale, and higher values (p < 0.05 in the static balance tests in some of the assessed conditions. CONCLUSION: The inclusion of visual stimuli by digital images on vestibular and body balance rehabilitation is effective in reducing dizziness and improving quality of life and postural control in individuals with peripheral vestibular disorders.

  8. Processing of vestibular inputs by the medullary lateral tegmental field of conscious cats: implications for generation of motion sickness

    Science.gov (United States)

    McCall, Andrew A.; Moy, Jennifer D.; DeMayo, William M.; Puterbaugh, Sonya R.; Miller, Daniel J.; Catanzaro, Michael F.

    2013-01-01

    The dorsolateral reticular formation of the caudal medulla, the lateral tegmental field (LTF), participates in generating vomiting. LTF neurons exhibited complex responses to vestibular stimulation in decerebrate cats, indicating that they received converging inputs from a variety of labyrinthine receptors. Such a convergence pattern of vestibular inputs is appropriate for a brain region that participates in generating motion sickness. Since responses of brainstem neurons to vestibular stimulation can differ between decerebrate and conscious animals, the current study examined the effects of whole-body rotations in vertical planes on the activity of LTF neurons in conscious felines. Wobble stimuli, fixed-amplitude tilts, the direction of which moves around the animal at a constant speed, were used to determine the response vector orientation, and also to ascertain whether neurons had spatial–temporal convergence (STC) behavior (which is due to the convergence of vestibular inputs with different spatial and temporal properties). The proportion of LTF neurons with STC behavior in conscious animals (25 %) was similar to that in decerebrate cats. Far fewer neurons in other regions of the feline brainstem had STC behavior, confirming findings that many LTF neurons receive converging inputs from a variety of labyrinthine receptors. However, responses to vertical plane vestibular stimulation were considerably different in decerebrate and conscious felines for LTF neurons lacking STC behavior. In decerebrate cats, most LTF neurons had graviceptive responses to rotations, similar to those of otolith organ afferents. However, in conscious animals, the response properties were similar to those of semicircular canal afferents. These differences show that higher centers of the brain that are removed during decerebration regulate the labyrinthine inputs relayed to the LTF, either by gating connections in the brainstem or by conveying vestibular inputs directly to the region

  9. Responses of primate caudal parabrachial nucleus and Kolliker-fuse nucleus neurons to whole body rotation

    Science.gov (United States)

    Balaban, Carey D.; McGee, David M.; Zhou, Jianxun; Scudder, Charles A.

    2002-01-01

    The caudal aspect of the parabrachial (PBN) and Kolliker-Fuse (KF) nuclei receive vestibular nuclear and visceral afferent information and are connected reciprocally with the spinal cord, hypothalamus, amygdala, and limbic cortex. Hence, they may be important sites of vestibulo-visceral integration, particularly for the development of affective responses to gravitoinertial challenges. Extracellular recordings were made from caudal PBN cells in three alert, adult female Macaca nemestrina through an implanted chamber. Sinusoidal and position trapezoid angular whole body rotation was delivered in yaw, roll, pitch, and vertical semicircular canal planes. Sites were confirmed histologically. Units that responded during rotation were located in lateral and medial PBN and KF caudal to the trochlear nerve at sites that were confirmed anatomically to receive superior vestibular nucleus afferents. Responses to whole-body angular rotation were modeled as a sum of three signals: angular velocity, a leaky integration of angular velocity, and vertical position. All neurons displayed angular velocity and integrated angular velocity sensitivity, but only 60% of the neurons were position-sensitive. These responses to vertical rotation could display symmetric, asymmetric, or fully rectified cosinusoidal spatial tuning about a best orientation in different cells. The spatial properties of velocity and integrated velocity and position responses were independent for all position-sensitive neurons; the angular velocity and integrated angular velocity signals showed independent spatial tuning in the position-insensitive neurons. Individual units showed one of three different orientations of their excitatory axis of velocity rotation sensitivity: vertical-plane-only responses, positive elevation responses (vertical plane plus ipsilateral yaw), and negative elevation axis responses (vertical plane plus negative yaw). The interactions between the velocity and integrated velocity components

  10. Vestibular Contributions to Human Memory

    OpenAIRE

    Smith, Laura; N/A,

    2017-01-01

    The vestibular system is an ancient structure which supports the detection and control of self-motion. The pervasiveness of this sensory system is evidenced by the diversity of its anatomical projections and the profound impact it has on a range of higher level functions, particularly spatial memory. The aim of this thesis was to better characterise the association between the vestibular system and human memory; while many studies have explored this association from a biological perspective f...

  11. Perspectives on aging vestibular function

    Directory of Open Access Journals (Sweden)

    Eric eAnson

    2016-01-01

    Full Text Available Much is known about age related anatomical changes in the vestibular system. Knowledge regarding how vestibular anatomical changes impact behavior for older adults continues to grow, in line with advancements in diagnostic testing. However, despite advancements in clinical diagnostics, much remains unknown about the functional impact that an aging vestibular system has on daily life activities like standing and walking. Modern diagnostic tests are very good at characterizing neural activity of the isolated vestibular system, but the tests themselves are artificial and do not reflect the multi-sensory aspects of natural human behavior. Also, the majority of clinical diagnostic tests are passively applied because active behavior can enhance performance. In this perspective paper we review anatomical and behavioral changes associated with an aging vestibular system and highlight several areas where a more functionally relevant perspective can be taken. For postural control, a multi-sensory perturbation approach could be used to bring balance rehabilitation into the arena of precision medicine. For walking and complex gaze stability, this may result in less physiologically specific impairments, but the trade-off would be a greater understanding of how the aging vestibular system truly impacts the daily life of older adults.

  12. Perspectives on Aging Vestibular Function.

    Science.gov (United States)

    Anson, Eric; Jeka, John

    2015-01-01

    Much is known about age-related anatomical changes in the vestibular system. Knowledge regarding how vestibular anatomical changes impact behavior for older adults continues to grow, in line with advancements in diagnostic testing. However, despite advancements in clinical diagnostics, much remains unknown about the functional impact that an aging vestibular system has on daily life activities such as standing and walking. Modern diagnostic tests are very good at characterizing neural activity of the isolated vestibular system, but the tests themselves are artificial and do not reflect the multisensory aspects of natural human behavior. Also, the majority of clinical diagnostic tests are passively applied because active behavior can enhance performance. In this perspective paper, we review anatomical and behavioral changes associated with an aging vestibular system and highlight several areas where a more functionally relevant perspective can be taken. For postural control, a multisensory perturbation approach could be used to bring balance rehabilitation into the arena of precision medicine. For walking and complex gaze stability, this may result in less physiologically specific impairments, but the trade-off would be a greater understanding of how the aging vestibular system truly impacts the daily life of older adults.

  13. Vestibular findings in fibromyalgia patients

    Directory of Open Access Journals (Sweden)

    Zeigelboim, Bianca Simone

    2011-07-01

    Full Text Available Introduction: Fibromyalgia (FM is a non-inflammatory musculoskeletal chronic syndrome, whose etiology is unknown, characterized by a diffuse pain, increase in palpation sensitivity and such symptoms as tiredness, insomnia, anxiety, depression, cold intolerance and otologic complaints. Objective: Evaluate the vestibular behavior in fibromyalgia patients. Method: A retrospective transversal study was performed. 25 patients aged between 26 and 65 (average age - 52.2 and standard deviation - 10.3 were evaluated and submitted to the following procedures: anamnesis, otorhinolaryngologic and vestibular evaluation by way of vector electronystamography. Results: a The most evident otoneurologic symptoms were: difficulty or pain when moving the neck and pain was spread to an arm or shoulder (92.0% in each, dizziness (84.0% and headache (76.0%. The different clinical symptoms mostly reported were: depression (80.0%, anxiety (76.0% and insomnia (72.0%; b vestibular examination showed an alteration in 12 patients (48.0% in the caloric test; c an alteration in the peripheral vestibular system prevailed, and d deficient peripheral vestibular disorders were prevalent. Conclusion: This study enabled the importance of the labyrinthic test to be verified, thus emphasizing that this kind of people must be studied better, since a range of rheumatologic diseases can cause severe vestibular changes as a result of their manifestations and impairment areas.

  14. Neuropharmacology of vestibular system disorders.

    Science.gov (United States)

    Soto, Enrique; Vega, Rosario

    2010-03-01

    This work reviews the neuropharmacology of the vestibular system, with an emphasis on the mechanism of action of drugs used in the treatment of vestibular disorders. Otolaryngologists are confronted with a rapidly changing field in which advances in the knowledge of ionic channel function and synaptic transmission mechanisms have led to the development of new scientific models for the understanding of vestibular dysfunction and its management. In particular, there have been recent advances in our knowledge of the fundamental mechanisms of vestibular system function and drug mechanisms of action. In this work, drugs acting on vestibular system have been grouped into two main categories according to their primary mechanisms of action: those with effects on neurotransmitters and neuromodulator receptors and those that act on voltage-gated ion channels. Particular attention is given in this review to drugs that may provide additional insight into the pathophysiology of vestibular diseases. A critical review of the pharmacology and highlights of the major advances are discussed in each case.

  15. Ontogenetic development of vestibular reflexes in amphibians

    Directory of Open Access Journals (Sweden)

    Hans Straka

    2016-11-01

    Full Text Available Vestibulo-ocular reflexes ensure gaze stability during locomotion and passively induced head/body movements. In precocial vertebrates such as amphibians, vestibular reflexes are required very early at the onset of locomotor activity. While the formation of inner ears and the assembly of sensory-motor pathways is largely completed soon after hatching, angular and translational/tilt vestibulo-ocular reflexes (VOR display differential functional onsets and mature with different time courses. Otolith-derived eye movements appear immediately after hatching, whereas the appearance and progressive amelioration of semicircular canal-evoked eye movements is delayed and dependent on the acquisition of sufficiently large semicircular canal diameters. Moreover, semicircular canal functionality is also required to tune the initially omnidirectional otolith-derived VOR. The tuning is due to a reinforcement of those vestibulo-ocular connections that are co-activated by semicircular canal and otolith inputs during natural head/body motion. This suggests that molecular mechanisms initially guide the basic ontogenetic wiring, whereas semicircular canal-dependent activity is required to establish the spatio-temporal specificity of the reflex. While a robust VOR is activated during passive head/body movements, locomotor efference copies provide the major source for compensatory eye movements during tail- and limb-based swimming of larval and adult frogs. The integration of active/passive motion-related signals for gaze stabilization occurs in central vestibular neurons that are arranged as segmentally iterated functional groups along rhombomere 1-8. However, at variance with the topographic maps of most other sensory systems, the sensory-motor transformation of motion-related signals occurs in segmentally specific neuronal groups defined by the extraocular motor output targets.

  16. A review of synaptic mechanisms of vestibular efferent signaling in turtles: extrapolation to efferent actions in mammals.

    Science.gov (United States)

    Jordan, Paivi M; Parks, Xiaorong Xu; Contini, Donatella; Holt, J Chris

    2013-01-01

    The vestibular labyrinth of nearly every vertebrate class receives a prominent efferent innervation that originates in the brainstem and ends as bouton terminals on vestibular hair cells and afferents in each end organ. Although the functional significance of this centrifugal pathway is not well understood, it is clear that efferent neurons, when electrically stimulated under experimental conditions, profoundly impact vestibular afferent discharge. Effects range from chiefly excitation in fish and mammalian vestibular afferents to a more heterogeneous mixture of inhibition and/or excitation in amphibians, reptiles, and birds. What accounts for these diverse response properties? Recent cellular and pharmacological characterization of efferent synaptic mechanisms in turtle offers some insight. In the turtle posterior crista, vestibular efferent neurons are predominantly cholinergic and the effects of efferent stimulation on vestibular afferent discharge can be ascribed to three distinct signaling pathways: (1) Hyperpolarization of type II hair cells mediated by α9/α10-nAChRs and SK-potassium channels; (2) Depolarization of bouton and calyx afferents via α4β2*-containing nAChRs; and (3) A slow excitation of calyx afferents attributed to muscarinic AChRs. In this review, we discuss the evidence for these pathways in turtle and speculate on their role in mammalian vestibular efferent actions where synaptic mechanisms are largely unknown.

  17. [Effect of nitric oxide in vestibular compensation].

    Science.gov (United States)

    Jiang, Zi-dong; Zhang, Lian-shan

    2003-10-01

    To study the effect of nitric oxide (NO) in vestibular compensation after unilateral vestibular deafferentation. Eighteen animals were divided into two groups, 6 of group a as control, 12 of group b received gentamicin intratympanic injection in the left ear. Half of the animals were killed respectively after 5 days and 10 days. Vestibular endorgan and brainstem tissue sections were subjected to NADPH-d reactive test of NOS for histochemical examination. In group a, NOS-like reactivity in both sides of vestibular endorgan and nucli. In group b during 5 days, NOS-like reactivity in right side of vestibular endorgan and nucli, those of the left side were negative. During 10 days, NOS-like reactivity only in the right side of vestibular endorgan. Changes of NOS expression in the contralateral vestibular nucli might have played a role in vestibular compensation.

  18. Vestibular control of entorhinal cortex activity in spatial navigation

    Directory of Open Access Journals (Sweden)

    Pierre-Yves eJacob

    2014-06-01

    Full Text Available Navigation in rodents depends on both self-motion (idiothetic and external (allothetic information. Idiothetic information has a predominant role when allothetic information is absent or irrelevant. The vestibular system is a major source of idiothetic information in mammals. By integrating the signals generated by angular and linear accelerations during exploration, a rat is able to generate and update a vector pointing to its starting place and to perform accurate return. This navigation strategy, called path integration, has been shown to involve a network of brain structures. Among these structures, the entorhinal cortex (EC may play a pivotal role as suggested by lesion and electrophysiological data. In particular, it has been recently discovered that some neurons in the medial EC display multiple firing fields producing a regular grid-like pattern across the environment. Such regular activity may arise from the integration of idiothetic information. This hypothesis would be strongly strengthened if it was shown that manipulation of vestibular information interferes with grid cell activity. In the present paper we review neuroanatomical and functional evidence indicating that the vestibular system influences the activity of the brain network involved in spatial navigation. We also provide new data on the effects of reversible inactivation of the peripheral vestibular system on the EC theta rhythm. The main result is that TTX administration abolishes velocity-controlled theta oscillations in the EC, indicating that vestibular information is necessary for EC activity. Since recent data demonstrate that disruption of theta rhythm in the medial EC induces a disorganization of grid cell firing, our findings indicate that the integration of idiothetic information in the EC is essential to form a spatial representation of the environment.

  19. Vestibular control of entorhinal cortex activity in spatial navigation.

    Science.gov (United States)

    Jacob, Pierre-Yves; Poucet, Bruno; Liberge, Martine; Save, Etienne; Sargolini, Francesca

    2014-01-01

    Navigation in rodents depends on both self-motion (idiothetic) and external (allothetic) information. Idiothetic information has a predominant role when allothetic information is absent or irrelevant. The vestibular system is a major source of idiothetic information in mammals. By integrating the signals generated by angular and linear accelerations during exploration, a rat is able to generate and update a vector pointing to its starting place and to perform accurate return. This navigation strategy, called path integration, has been shown to involve a network of brain structures. Among these structures, the entorhinal cortex (EC) may play a pivotal role as suggested by lesion and electrophysiological data. In particular, it has been recently discovered that some neurons in the medial EC display multiple firing fields producing a regular grid-like pattern across the environment. Such regular activity may arise from the integration of idiothetic information. This hypothesis would be strongly strengthened if it was shown that manipulation of vestibular information interferes with grid cell activity. In the present paper we review neuroanatomical and functional evidence indicating that the vestibular system influences the activity of the brain network involved in spatial navigation. We also provide new data on the effects of reversible inactivation of the peripheral vestibular system on the EC theta rhythm. The main result is that tetrodotoxin (TTX) administration abolishes velocity-controlled theta oscillations in the EC, indicating that vestibular information is necessary for EC activity. Since recent data demonstrate that disruption of theta rhythm in the medial EC induces a disorganization of grid cell firing, our findings indicate that the integration of idiothetic information in the EC is essential to form a spatial representation of the environment.

  20. Recovery of Vestibular Ocular Reflex Function and Balance Control after a Unilateral Peripheral Vestibular Deficit

    OpenAIRE

    John eAllum

    2012-01-01

    This review describes the effect of unilateral peripheral vestibular deficit (UPVD) on balance control for stance and gait tests. Because a UPVD is normally defined based on vestibular ocular reflex (VOR) tests, we compared recovery observed in balance control with patterns of recovery in VOR function. Two general types of UPVD are considered; acute vestibular neuritis (AVN) and vestibular neurectomy. The latter was subdivided into vestibular loss after cerebellar pontine angle tumor surgery ...

  1. Interaction between Vestibular Compensation Mechanisms and Vestibular Rehabilitation Therapy: 10 Recommendations for Optimal Functional Recovery

    OpenAIRE

    Lacour, Michel; Bernard-Demanze, Laurence

    2015-01-01

    This review questions the relationships between the plastic events responsible for the recovery of vestibular function after a unilateral vestibular loss (vestibular compensation), which has been well described in animal models in the last decades, and the vestibular rehabilitation (VR) therapy elaborated on a more empirical basis for vestibular loss patients. The main objective is not to propose a catalog of results but to provide clinicians with an understandable view on when and how to per...

  2. Interaction between vestibular compensation mechanisms and vestibular rehabilitation therapy: ten recommendations for optimal functional recovery

    OpenAIRE

    LACOUR eMichel; BERNARD DEMANZE eLaurence

    2015-01-01

    This review questions the relationships between the plastic events responsible for the recovery of vestibular function after a unilateral vestibular loss (vestibular compensation), which has been well described in animal models in the last decades, and the vestibular rehabilitation (VR) therapy elaborated on a more empirical basis for vestibular loss patients. The main objective is not to propose a catalogue of results but to provide clinicians with an understandable view on when and how to p...

  3. Ocular Vestibular Evoked Myogenic Potentials

    Directory of Open Access Journals (Sweden)

    Felipe, Lilian

    2014-01-01

    Full Text Available Introduction Diagnostic testing of the vestibular system is an essential component of treating patients with balance dysfunction. Until recently, testing methods primarily evaluated the integrity of the horizontal semicircular canal, which is only a portion of the vestibular system. Recent advances in technology have afforded clinicians the ability to assess otolith function through vestibular evoked myogenic potential (VEMP testing. VEMP testing from the inferior extraocular muscles of the eye has been the subject of interest of recent research. Objective To summarize recent developments in ocular VEMP testing. Results Recent studies suggest that the ocular VEMP is produced by otolith afferents in the superior division of the vestibular nerve. The ocular VEMP is a short latency potential, composed of extraocular myogenic responses activated by sound stimulation and registered by surface electromyography via ipsilateral otolithic and contralateral extraocular muscle activation. The inferior oblique muscle is the most superficial of the six extraocular muscles responsible for eye movement. Therefore, measurement of ocular VEMPs can be performed easily by using surface electrodes on the skin below the eyes contralateral to the stimulated side. Conclusion This new variation of the VEMP procedure may supplement conventional testing in difficult to test populations. It may also be possible to use this technique to evaluate previously inaccessible information on the vestibular system.

  4. An adaptive vestibular rehabilitation technique.

    Science.gov (United States)

    Crane, Benjamin T; Schubert, Michael C

    2017-05-23

    There is a large variation in vestibular rehabilitation (VR) results depending on type of therapy, adherence, and the appropriateness for the patient's level of function. A novel adaptive vestibular rehabilitation (AVR) program was developed and evaluated. Technology and procedure development, and prospective multicenter trial. Those with complete unilateral vestibular hypofunction and symptomatic at least 3 months with a Dizziness Handicap Inventory (DHI) >30 were eligible. Patients were given a device to use with their own computer. They were instructed to use the program daily, with each session lasting about 10 minutes. The task consisted of reporting orientation of the letter C, which appeared when their angular head velocity exceeded a threshold. The letter size and head velocity required were adjusted based on prior performance. Performance on the task was remotely collected by the investigator as well as a weekly DHI score. Four patients aged 31 to 74 years (mean = 51 years) were enrolled in this feasibility study to demonstrate efficacy. Two had treated vestibular schwannomas and two had vestibular neuritis. Starting DHI was 32 to 56 (mean = 42), which was reduced to 0 to 16 (mean = 11.5) after a month of therapy, a clinically and statistically significant (P VR in terms of cost and customization for patient ability and obtained a major improvement in symptoms. This study demonstrated a clinically and statistically significant decrease in symptoms after 4 weeks of therapy. 2b Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  5. Vestibular damage in chronic ototoxicity: a mini-review.

    Science.gov (United States)

    Sedó-Cabezón, Lara; Boadas-Vaello, Pere; Soler-Martín, Carla; Llorens, Jordi

    2014-07-01

    Ototoxicity is a major cause of the loss of hearing and balance in humans. Ototoxic compounds include pharmaceuticals such as aminoglycoside antibiotics, anti-malarial drugs, loop diuretics and chemotherapeutic platinum agents, and industrial chemicals including several solvents and nitriles. Human and rodent data indicate that the main target of toxicity is hair cells (HCs), which are the mechanosensory cells responsible for sensory transduction in both the auditory and the vestibular system. Nevertheless, the compounds may also affect the auditory and vestibular ganglion neurons. Exposure to ototoxic compounds has been found to cause HC apoptosis, HC necrosis, and damage to the afferent terminals, of differing severity depending on the ototoxicity model. One major pathway frequently involved in HC apoptosis is the c-jun N-terminal kinase (JNK) signaling pathway activated by reactive oxygen species, but other apoptotic pathways can also play a role in ototoxicity. Moreover, little is known about the effects of chronic low-dose exposure. In rodent vestibular epithelia, extrusion of live HCs from the sensory epithelium may be the predominant form of cell demise during chronic ototoxicity. In addition, greater involvement of the afferent terminals may occur, particularly the calyx units contacting type I vestibular HCs. As glutamate is the neurotransmitter in this synapse, excitotoxic phenomena may participate in afferent and ganglion neuron damage. Better knowledge of the events that take place in chronic ototoxicity is of great interest, as it will increase understanding of the sensory loss associated with chronic exposure and aging. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Aging of vestibular function evaluated using correlational vestibular autorotation test

    Directory of Open Access Journals (Sweden)

    Hsieh LC

    2014-09-01

    Full Text Available Li-Chun Hsieh,1,2 Hung-Ching Lin,2,3 Guo-She Lee4,5 1Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan; 2Department of Otolaryngology, Mackay Memorial Hospital, Taipei, Taiwan; 3Department of Audiology and Speech Language Pathology, Mackay Memorial Medical College, Taipei, Taiwan; 4Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; 5Department of Otolaryngology, Taipei City Hospital, Ren-Ai Branch, Taipei, Taiwan Background: Imbalance from degeneration of vestibular end organs is a common problem in the elderly. However, the decline of vestibular function with aging was revealed in few vestibular function tests such as vestibular autorotation test (VAT. In the current VAT, there are drawbacks of poor test–retest reliability, slippage of the sensor at high-speed rotations, and limited data about the effect of aging. We developed a correlational-VAT (cVAT system that included a small, light sensor (less than 20 g with wireless data transmission technique to evaluate the aging of vestibular function. Material and methods: We enrolled 53 healthy participants aged between 25 and 75 years and divided them into five age groups. The test conditions were vertical and horizontal head autorotations of frequencies from 0 to 3 Hz with closed eyes or open eyes. The cross-correlation coefficient (CCC between eye velocity and head velocity was obtained for the head autorotations between 1 Hz and 3 Hz. The mean of the CCCs was used to represent the vestibular function. Results: Age was significantly and negatively correlated with the mean CCC for all test conditions, including horizontal or vertical autorotations with open eyes or closed eyes (P<0.05. The mean CCC with open eyes declined significantly at 55–65 years old and the mean CCC with closed eyes declined significantly at 65–75 years old.Conclusion: Vestibular function evaluated using mean CCC revealed a decline with

  7. Roles of the cerebellum in pursuit-vestibular interactions.

    Science.gov (United States)

    Fukushima, Kikuro

    2003-01-01

    This mini-review focuses on cerebellar roles in on-line control of smooth-pursuit eye movements during vestibular stimulation in primates. The smooth-pursuit system is necessary to track smoothly moving targets and must interact with the vestibular system during movement of the head and/or whole body to maintain the precision of eye movements in space (i.e. gaze movements). This interaction requires calculation of gaze velocity commands that match the eye velocity in space to the actual target velocity. Two cerebellar regions, the floccular lobe that consists of the flocculus and ventral paraflocculus, and the dorsal vermis, are known to be involved in smooth-pursuit. However, potential differences in their involvement are incompletely understood. To understand their roles, in particular whether the output of these regions codes gaze velocity or eye velocity, simple-spike activity of Purkinje (P-) cells was examined during smooth-pursuit and pursuit-vestibular interaction tasks in various directions in head-restrained monkeys. The results showed differences in discharge characteristics of vertical and horizontal P-cells within the floccular lobe and between the floccular lobe and dorsal vermis. These differences and other available evidence suggest that the dorsal vermis is involved more in the control of gaze movement whereas the floccular lobe primarily controls eye movement (in the orbit) as a component of the oculomotor neural integrator. Smooth-pursuit without vestibular stimulation cannot dissociate eye movement from gaze movement. To understand the cerebellar role in various aspects of smooth tracking of targets moving in the three dimensional space, more information is needed particularly on how the above mentioned two regions along with the dorsal paraflocclus and underlying deep cerebellar nuclei are involved in vergence tracking, how the cerebellum is involved in prediction and perception of target motion, and whether complex-spike discharge is involved

  8. [Expressions of c-Fos and NADPH-d in the related brainstem during vestibular compensation].

    Science.gov (United States)

    Jiang, Zi-Dong; Wen, Yan-Hua

    2008-12-01

    To study the mechanism of vestibular compensation and to observe the changes of c-Fos and NADPH-d expressions in the brainstem of the vestibular deafferentation rats in static status or following angular acceleration stimulation. Totally 60 SD rats were randomly divided into control group (labyrinthine intact), complete unilateral vestibular deafferentation (UVD) group, simultaneous complete bilateral vestibular deafferentation (BVD) group (n = 20 in each group). Subgroups (n = 10 in each subgroup) were set for static status or following angular acceleration stimulation in each group. Double labeling with histochemistry-immunohistochemistry was performed to observe c-Fos/NADPH-d neurons. No positive c-Fos/NADPH-d expression was observed in the both sides of medial vestibular nucleus (MVN) and prepositus hypoglossi (PrH) of normal rats in static status and BVD rats whether following canal rotation or not. c-Fos/ NADPH-d expression was observed in the ipsilesional MVN and the contralesional PrH of UVD rats. However, c-Fos/NADPH-d were detected in both sides of MVN and PrH in UVD rats and normal rats following angular acceleration stimulation. In the ipsilesional MVN and the contralesional PrH, c-Fos plays an important role in vestibular compensation, in which nitric oxide acts as a key neurotransmitter.

  9. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno

    2014-01-01

    BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess...... the effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL......; Web of Science; CAB Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the search was 24 July 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) exploring the efficacy of stereotactic radiotherapy compared with observation alone, microsurgical...

  10. The Vestibular System: A Newly Identified Regulator of Bone Homeostasis Acting Through the Sympathetic Nervous System.

    Science.gov (United States)

    Vignaux, G; Besnard, S; Denise, P; Elefteriou, F

    2015-08-01

    The vestibular system is a small bilateral structure located in the inner ear, known as the organ of balance and spatial orientation. It senses head orientation and motion, as well as body motion in the three dimensions of our environment. It is also involved in non-motor functions such as postural control of blood pressure. These regulations are mediated via anatomical projections from vestibular nuclei to brainstem autonomic centers and are involved in the maintenance of cardiovascular function via sympathetic nerves. Age-associated dysfunction of the vestibular organ contributes to an increased incidence of falls, whereas muscle atrophy, reduced physical activity, cellular aging, and gonadal deficiency contribute to bone loss. Recent studies in rodents suggest that vestibular dysfunction might also alter bone remodeling and mass more directly, by affecting the outflow of sympathetic nervous signals to the skeleton and other tissues. This review will summarize the findings supporting the influence of vestibular signals on bone homeostasis, and the potential clinical relevance of these findings.

  11. Distribution of high-conductance calcium-activated potassium channels in rat vestibular epithelia.

    Science.gov (United States)

    Schweizer, Felix E; Savin, David; Luu, Cindy; Sultemeier, David R; Hoffman, Larry F

    2009-11-10

    Voltage- and calcium-activated potassium channels (BK) are important regulators of neuronal excitability. BK channels seem to be crucial for frequency tuning in nonmammalian vestibular and auditory hair cells. However, there are a paucity of data concerning BK expression in mammalian vestibular hair cells. We therefore investigated the localization of BK channels in mammalian vestibular hair cells, specifically in rat vestibular neuroepithelia. We find that only a subset of hair cells in the utricle and the crista ampullaris express BK channels. BK-positive hair cells are located mainly in the medial striolar region of the utricle, where they constitute at most 12% of hair cells, and in the central zone of the horizontal crista. A majority of BK-positive hair cells are encapsulated by a calretinin-positive calyx defining them as type I cells. The remainder are either type I cells encapsulated by a calretinin-negative calyx or type II hair cells. Surprisingly, the number of BK-positive hair cells in the utricle peaks in juvenile rats and declines in early adulthood. BK channels were not found in vestibular afferent dendrites or somata. Our data indicate that BK channel expression in the mammalian vestibular system differs from the expression pattern in the mammalian auditory and the nonmammalian vestibular system. The molecular diversity of vestibular hair cells indicates a functional diversity that has not yet been fully characterized. The predominance of BK-positive hair cells within the medial striola of juvenile animals suggests that they contribute to a scheme of highly lateralized coding of linear head movements during late development.

  12. The cognitive neurology of the vestibular system.

    Science.gov (United States)

    Seemungal, Barry M

    2014-02-01

    The aim is to reappraise the current state about what we know of vestibular cognition. The review focuses on cognition and perception, and hence the stress on human studies. In addition, the cerebral cortex is the main but not exclusive brain region of interest. There is a brief mention of vestibular ocular function if only to demonstrate the differential processing between reflex and perception. The effect of vestibular activation on some aspects of cognition, for example neglect, is not reviewed, as there have been no recent landmark findings in this area. The vestibular cerebellum is pivotal in the differential gating of vestibular perceptual and ocular signals to the cerebral cortex. The neuroanatomical correlates mediating vestibular sensations of self-motion ('am I moving?') and spatial orientation ('where am I now?') are distinct. Vestibular-motion perception is supported by a widespread white matter network. Vestibular activation specifically reduces visual motion cortical excitability, whereas other visual cortical regions show an increase in excitability. As the vestibular ocular reflex (VOR) and self-motion perception can be uncoupled both behaviourally and in neural correlate, deficits underlying vestibular patients' symptoms may not be revealed by simple VOR assessment. Given the pivotal cerebellar role in gating vestibular signals to perceptual regions, modulating mechanisms of cerebellar plasticity, for example by combining training with medication or brain stimulation, may prove fruitful in treating the symptoms of chronic dizzy patients.

  13. Negative emotional stimuli enhance vestibular processing.

    Science.gov (United States)

    Preuss, Nora; Ellis, Andrew W; Mast, Fred W

    2015-08-01

    Recent studies have shown that vestibular stimulation can influence affective processes. In the present study, we examined whether emotional information can also modulate vestibular perception. Participants performed a vestibular discrimination task on a motion platform while viewing emotional pictures. Six different picture categories were taken from the International Affective Picture System: mutilation, threat, snakes, neutral objects, sports, and erotic pictures. Using a Bayesian hierarchical approach, we were able to show that vestibular discrimination improved when participants viewed emotionally negative pictures (mutilation, threat, snake) when compared to neutral/positive objects. We conclude that some of the mechanisms involved in the processing of vestibular information are also sensitive to emotional content. Emotional information signals importance and mobilizes the body for action. In case of danger, a successful motor response requires precise vestibular processing. Therefore, negative emotional information improves processing of vestibular information. (c) 2015 APA, all rights reserved).

  14. Action mechanism of betahistine in the vestibular end organs.

    Science.gov (United States)

    Chávez, H; Vega, R; Valli, P; Mira, E; Benvenuti, C; Guth, P S; Soto, E

    2001-06-01

    Betahistine has been used to treat several vestibular disorders of both central and peripheral origin. The objective of this work was to study the betahistine action mechanism at the vestibular end organs. Experiments were carried out in wild larval axolotl (Ambystoma tigrinum). Multiunit extracellular recordings were obtained from the semicircular canal nerve using a suction electrode. Betahistine (10 microM to 10 mM, n = 32) inhibited the basal spike discharge of the vestibular afferent neurons with an IC50 of 600 microM. To define the site of action of betahistine, its interactions with antagonists of nitric oxide sintethizing enzyme, cholinergic drugs, and excitatory amino acids were studied. Betahistine 1 mM (n = 5) was coadministered with NG-nitro-L-arginine 3 microM. The action of betahistine remained as in control experiments. Betahistine 1 mM reduced the excitatory action of carbachol (200 microM, n = 5) in a 30 +/- 3.4%. Cholinergic antagonists atropine (10 microM, n = 3) and d-tubocurarine (10 microM, n = 3) did not modify betahistine actions. Betahistine 1 mM also reduced kainic acid (10 microM, n = 4) excitatory action in 45.5 +/- 9.8%. These results corroborate that betahistine has a peripheral inhibitory action in the spike discharge of the afferent neurons in the vestibule. This action seems to involve neither NO production nor modifications in the release of acetylcholine from the efferent fibers. The inhibitory action of betahistine seems to be due to a postsynaptic binding site on the afferent neurons.

  15. Perspectival Structure and Vestibular Processing

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2016-01-01

    I begin by contrasting a taxonomic approach to the vestibular system with the structural approach I take in the bulk of this commentary. I provide an analysis of perspectival structure. Employing that analysis and following the structural approach, I propose three lines of empirical investigation...

  16. Nitric oxide synthase localized in a subpopulation of vestibular efferents with NADPH diaphorase histochemistry and nitric oxide synthase immunohistochemistry.

    Science.gov (United States)

    Lysakowski, A; Singer, M

    2000-11-27

    Efferent innervation of the vestibular labyrinth is known to be cholinergic. More recent studies have also demonstrated the presence of the neuropeptide calcitonin gene-related peptide in this system. Nitric oxide is one of a new class of neurotransmitters, the gaseous transmitters. It acts as a second messenger and neurotransmitter in diverse physiological systems. We decided to investigate the anatomical distribution of the synthetic enzyme for nitric oxide, nitric oxide synthase (NOS), to clarify the role of nitric oxide in the vestibular periphery. NADPH diaphorase histochemical and NOS I immunohistochemical studies were done in the adult chinchilla and rat vestibular brainstem; diaphorase histochemistry was done in the chinchilla periphery. Retrograde tracing studies to verify the presence of NOS in brainstem efferent neurons were performed in young chinchillas. Our light microscopic results show that NOS I, as defined mainly by the presence of NADPH diaphorase, is present in a subpopulation of both brainstem efferent neurons and peripheral vestibular efferent boutons. Our ultrastructural results confirm these findings in the periphery. NADPH diaphorase is also present in a subpopulation of type I hair cells, suggesting that nitric oxide might be produced in and act locally upon these cells and other elements in the sensory epithelium. A hypothesis about how nitric oxide is produced in the vestibular periphery and how it may interact with other elements in the vestibular sensory apparatus is presented in the discussion. Copyright 2000 Wiley-Liss, Inc.

  17. Expression of myosin VIIA in the developing chick inner ear neurons.

    Science.gov (United States)

    Nguyen, Kristi; Hall, Amanda L; Jones, Jennifer M

    2015-01-01

    The auditory-vestibular ganglion (AVG) is formed by the division of otic placode-derived neuroblasts, which then differentiate into auditory and vestibular afferent neurons. The developmental mechanisms that regulate neuronal cell fate determination, axonal pathfinding and innervation of otic neurons are poorly understood. The present study characterized the expression of myosin VIIA, along with the neuronal markers, Islet1, NeuroD1 and TuJ1, in the developing avian ear, during Hamburger-Hamilton (HH) stages 16-40. At early stages, when neuroblasts are delaminating from the otic epithelium, myosin VIIA expression was not observed. Myosin VIIA was initially detected in a subset of neurons during the early phase of neuronal differentiation (HH stage 20). As the AVG segregates into the auditory and vestibular portions, myosin VIIA was restricted to a subset of vestibular neurons, but was not present in auditory neurons. Myosin VIIA expression in the vestibular ganglion was maintained through HH stage 33 and was downregulated by stage 36. Myosin VIIA was also observed in the migrating processes of vestibular afferents as they begin to innervate the otic epithelium HH stage 22/23. Notably, afferents targeting hair cells of the cristae were positive for myosin VIIA while afferents targeting the utricular and saccular maculae were negative (HH stage 26-28). Although previous studies have reported that myosin VIIA is restricted to sensory hair cells, our data shows that myosin VIIA is also expressed in neurons of the developing chick ear. Our study suggests a possible role for myosin VIIA in axonal migration/pathfinding and/or innervation of vestibular afferents. In addition, myosin VIIA could be used as an early marker for vestibular neurons during the development of the avian AVG. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Vestibular Stimulation for Stress Management in Students.

    Science.gov (United States)

    Kumar, Sai Sailesh; Rajagopalan, Archana; Mukkadan, Joseph Kurien

    2016-02-01

    Although several methods are developed to alleviate stress among college students, logistic limitations in adopting them have limited their utility. Hence, we aimed to test a very practical approach to alleviate stress among college students by achieving vestibular stimulation using swings. In this study 60 male and female participants were randomly assigned into vestibular stimulation or control groups. Depression, anxiety, stress scores, sleep quality, heart rate, blood pressure, Autonomic functions, respiratory, haematological, cognitive function, Quality of life were recorded before and after 1(st), 7(th), 14(th), 21(st), 28(th) days of vestibular stimulation. STAI S and STAI T scores were significantly improved on day 28(th) following vestibular stimulation. Diastolic and mean arterial blood pressure were significantly decreased and remained within normal limits in vestibular group on day 28(th) following vestibular stimulation. Postural fall in blood pressure was significantly improved on day 14 onwards, following vestibular stimulation. Respiratory rate was significantly improved on day 7 onwards, following vestibular stimulation. PSQI sleep disturbance, PSQI sleep latency, PSQI total score and bleeding time was significantly improved following vestibular stimulation. Our study supports the adoption of vestibular stimulation for stress management. Hence, placement of swings in college campuses must be considered, which may be a simple approach to alleviate stress among college students.

  19. Vestibular Findings in Military Band Musicians

    Directory of Open Access Journals (Sweden)

    Zeigelboim, Bianca Simone

    2014-04-01

    Full Text Available Introduction Exposure to music is the subject of many studies because it is related to an individual's professional and social activities. Objectives Evaluate the vestibular behavior in military band musicians. Methods A retrospective cross-sectional study was performed. Nineteen musicians with ages ranging from 21 to 46 years were evaluated (average = 33.7 years and standard deviation = 7.2 years. They underwent anamnesis and vestibular and otolaryngologic evaluation through vectoelectronystagmography. Results The most evident otoneurologic symptoms in the anamnesis were tinnitus (84.2%, hearing difficulties (47.3%, dizziness (36.8%, headache (26.3%, intolerance to intense sounds (21.0%, and earache (15.7%. Seven musicians (37.0% showed vestibular abnormality, which occurred in the caloric test. The abnormality was more prevalent in the peripheral vestibular system, and there was a predominance of irritative peripheral vestibular disorders. Conclusion The alteration in vestibular exam occurred in the caloric test (37.0%. There were changes in the prevalence of peripheral vestibular system with a predominance of irritative vestibular dysfunction. Dizziness was the most significant symptom for the vestibular test in correlation with neurotologic symptoms. The present study made it possible to verify the importance of the labyrinthine test, which demonstrates that this population should be better studied because the systematic exposure to high sound pressure levels may cause major vestibular alterations.

  20. Vestibular findings in military band musicians.

    Science.gov (United States)

    Zeigelboim, Bianca Simone; Gueber, Crislaine; Silva, Thanara Pruner da; Liberalesso, Paulo Breno Noronha; Gonçalves, Claudia Giglio de Oliveira; Faryniuk, João Henrique; Marques, Jair Mendes; Jurkiewicz, Ari Leon

    2014-04-01

    Introduction Exposure to music is the subject of many studies because it is related to an individual's professional and social activities. Objectives Evaluate the vestibular behavior in military band musicians. Methods A retrospective cross-sectional study was performed. Nineteen musicians with ages ranging from 21 to 46 years were evaluated (average = 33.7 years and standard deviation = 7.2 years). They underwent anamnesis and vestibular and otolaryngologic evaluation through vectoelectronystagmography. Results The most evident otoneurologic symptoms in the anamnesis were tinnitus (84.2%), hearing difficulties (47.3%), dizziness (36.8%), headache (26.3%), intolerance to intense sounds (21.0%), and earache (15.7%). Seven musicians (37.0%) showed vestibular abnormality, which occurred in the caloric test. The abnormality was more prevalent in the peripheral vestibular system, and there was a predominance of irritative peripheral vestibular disorders. Conclusion The alteration in vestibular exam occurred in the caloric test (37.0%). There were changes in the prevalence of peripheral vestibular system with a predominance of irritative vestibular dysfunction. Dizziness was the most significant symptom for the vestibular test in correlation with neurotologic symptoms. The present study made it possible to verify the importance of the labyrinthine test, which demonstrates that this population should be better studied because the systematic exposure to high sound pressure levels may cause major vestibular alterations.

  1. Zolpidem, a selective GABA(A) receptor alpha1 subunit agonist, induces comparable Fos expression in oxytocinergic neurons of the hypothalamic paraventricular and accessory but not supraoptic nuclei in the rat

    DEFF Research Database (Denmark)

    Kiss, Alexander; Søderman, Andreas; Bundzikova, Jana

    2006-01-01

    Functional activation of oxytocinergic (OXY) cells in the hypothalamic paraventricular (PVN), supraoptic (SON), and accessory (ACC) nuclei was investigated in response to acute treatment with Zolpidem (a GABA(A) receptor agonist with selectivity for alpha(1) subunits) utilizing dual Fos/OXY immun...

  2. Efficacy of vestibular rehabilitation on chronic unilateral vestibular dysfunction.

    Science.gov (United States)

    Topuz, Oya; Topuz, Bülent; Ardiç, F Necdet; Sarhuş, Merih; Ogmen, Gülsen; Ardiç, Füsun

    2004-02-01

    To assess the efficacy of vestibular rehabilitation exercises on patients with chronic unilateral vestibular dysfunction. Prospective study. Physical Medicine and Rehabilitation Clinic and Otolaryngology Clinic of a tertiary referral hospital. One-hundred and twenty-five patients with unilateral chronic vestibular dysfunction were included in the study. Eight-week, two-staged (clinic and home) vestibular rehabilitation programme with components of Cawthorne-Cooksey and Norre exercises was applied. Dizziness Handicap Inventory (DHI) and visual analogue scale (VAS) were completed three times (at the beginning, end of the second week and end of the treatment). Data for 112 patients in the first stage and 93 patients in the second stage were evaluated because of insufficient compliance of the other patients. The mean DHI score was decreased from 50.42 +/- 24.12 points to 21.21 +/- 15.97 points (p < 0.001) at the end of first two weeks, and to 19.93 +/- 19.33 points at the end of the whole treatment. The mean VAS score was decreased from 5.87 +/- 2.27 to 2.02 +/- 1.75 (p < 0.001) at the end of second week, and to 1.51 +/- 1.29 at the end of eighth week. In respect to both VAS and DHI scores, improvement was noted in 67 patients (77.4%). Age, gender and disability level had no predictive value about therapy outcome. There was a fast recovery in the supervised exercise session, whereas there was no significant difference in the home exercise session. These findings suggest that either supervised exercise is better than home exercise or that 10 supervised sessions are sufficient to get the end result.

  3. The endocannabinoid system: A new player in the neurochemical control of vestibular function?

    Science.gov (United States)

    Smith, Paul F; Ashton, John C; Darlington, Cynthia L

    2006-01-01

    The results of recent clinical trials of medicinal cannabinoid drugs show that dizziness and vertigo are commonly reported adverse side-effects. Cannabinoid CB1 receptors were initially thought to be expressed in very low densities in the vestibular nucleus complex (VNC). Recent immunohistochemical studies have challenged this idea and suggested that CB1 receptors may exist in numbers similar to the granule cell layer of the cerebellum. This, together with evidence that brainstem CB1 receptors have a higher efficacy than those in many other parts of the brain and that application of cannabinoids can elicit potent electrophysiological effects in VNC neurons, suggests that CB1 receptors and their endogenous ligands may be important in central vestibular function. In this review, we consider the potential clinical significance of the endocannabinoid system for the development of vestibular disorders, the effects of recreational cannabis use and the therapeutic use of medicinal cannabinoids. Copyright 2006 S. Karger AG, Basel.

  4. Physical therapy for persons with vestibular disorders.

    Science.gov (United States)

    Whitney, Susan L; Alghwiri, Alia; Alghadir, Ahmad

    2015-02-01

    Persons with vestibular disorders experience symptoms of dizziness and balance dysfunction, resulting in falls, as well as impairments of daily life. Various interventions provided by physical therapists have been shown to decrease dizziness and improve postural control. In the present review, we will focus on the role of physical therapy in the management of vestibular symptoms in patients with peripheral and central vestibular disorders. Persons with both acute and chronic central and peripheral vestibular disorders improve with vestibular rehabilitation. New interventions during the past 5 years have been designed to enhance recovery from problems with balance and dizziness. Examples include the use of virtual reality, vibrotactile feedback, optokinetic flow, YouTube videos, and innovative methods to change the gain of the vestibulo-ocular reflex (VOR). Patients with central and peripheral vestibular disorders benefit from physical therapy interventions. Advances in physical therapy interventions include new methods to stimulate adaptation of the VOR and the vestibulospinal systems.

  5. Personality changes in patients with vestibular dysfunction

    OpenAIRE

    Paul eSmith; Cynthia eDarlington

    2013-01-01

    The vestibular system is a sensory system that has evolved to detect linear and angular acceleration of the head in all planes so that the brain is not predominantly reliant on visual information to determine self-motion. Since the vestibular system first evolved in invertebrate species in order to detect gravitational vertical, it is likely that the central nervous system has developed a special dependence upon vestibular input. In addition to the deficits in eye movement and postural reflex...

  6. Motor development after vestibular deprivation in rats.

    Science.gov (United States)

    Geisler, H C; Gramsbergen, A

    1998-07-01

    This review summarizes the postural development in the rat and the influences of vestibular deprivation from the 5th postnatal day on this development. Vestibular deprivation leads to a delay in motor development. Most probably this delay is caused by a delay in the development of postural control, which is characterized by a retarded EMG development in postural muscles. Our results indicate that the developing nervous system cannot compensate for a vestibular deficit during the early phase of ontogeny.

  7. Changing perspective: The role of vestibular signals

    OpenAIRE

    Deroualle, Diane; Borel, Liliane; Deveze, Arnaud; Lopez, Christophe

    2015-01-01

    Social interactions depend on mechanisms such as the ability to take another person's viewpoint, i.e. visuo-spatial perspective taking. However, little is known about the sensorimotor mechanisms underpinning perspective taking. Because vestibular signals play roles in mental rotation and spatial cognition tasks and because damage to the vestibular cortex can disturb egocentric perspective, vestibular signals stand as important candidates for the sensorimotor foundations of perspective taking....

  8. Influences of Vestibular System on Sympathetic Nervous System. Implications for countermeasures.

    Science.gov (United States)

    Denise, Pr Pierre

    As gravity is a direct and permanent stress on body fluids, muscles and bones, it is not surpris-ing that weightlessness has important effects on cardiovascular and musculo-skeletal systems. However, these harmful effects do not totally result from the removal of the direct stress of gravity on these organs, but are also partially and indirectly mediated by the vestibular sys-tem. Besides its well known crucial role in spatial orientation and postural equilibrium, it is now clear that the vestibular system is also involved in the regulation of other important physi-ological systems: respiratory and cardiovascular systems, circadian regulation, food intake and even bone mineralization. The neuroanatomical substrate for these vestibular-mediated reg-ulations is still poorly defined, but there is much evidence that vestibular system has strong impacts not only on brainstem autonomic centers but on many hypothalamic nuclei as well. As autonomic nervous system controls almost all body organs, bringing into play the vestibular system by hypergravity or microgravity could virtually affects all major physiological func-tions. There is experimental evidence that weightlessness as well as vestibular lesion induce sympathetic activation thus participating in space related physiological alterations. The fact that some effects of weightlessness on biological systems are mediated by the vestibular system has an important implication for using artificial gravity as a countermeasure: artificial gravity should load not only bones and the cardiovascular system but the vestibular system as well. In short-arm centrifuges, the g load at the head level is low because the head is near the axis of rotation. If the vestibular system is involved in cardiovascular deconditioning and bone loss during weightlessness, it would be more effective to significantly stimulate it and thus it would be necessary to place the head off-axis. Moreover, as the otolithic organs are non longer stimu-lated in

  9. Orexinergic fibers are in contact with Kölliker-Fuse nucleus neurons projecting to the respiration-related nuclei in the medulla oblongata and spinal cord of the rat.

    Science.gov (United States)

    Yokota, Shigefumi; Oka, Tatsuro; Asano, Hirohiko; Yasui, Yukihiko

    2016-10-01

    The neural pathways underlying the respiratory variation dependent on vigilance states remain unsettled. In the present study, we examined the orexinergic innervation of Kölliker-Fuse nucleus (KFN) neurons sending their axons to the rostral ventral respiratory group (rVRG) and phrenic nucleus (PhN) as well as to the hypoglossal nucleus (HGN) by using a combined retrograde tracing and immunohistochemistry. After injection of cholera toxin B subunit (CTb) into the KFN, CTb-labeled neurons that are also immunoreactive for orexin (ORX) were found prominently in the perifornical and medial regions and additionally in the lateral region of the hypothalamic ORX field. After injection of fluorogold (FG) into the rVRG, PhN or HGN, we found an overlapping distribution of ORX-immunoreactive axon terminals and FG-labeled neurons in the KFN. Within the neuropil of the KFN, asymmetrical synaptic contacts were made between these terminals and neurons. We further demonstrated that many neurons labeled with FG injected into the rVRG, PhN, or HGN are immunoreactive for ORX receptor 2. Present data suggest that rVRG-, PhN- and HGN-projecting KFN neurons may be under the excitatory influence of the ORXergic neurons for the state-dependent regulation of respiration. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Prosthetic implantation of the human vestibular system.

    Science.gov (United States)

    Golub, Justin S; Ling, Leo; Nie, Kaibao; Nowack, Amy; Shepherd, Sarah J; Bierer, Steven M; Jameyson, Elyse; Kaneko, Chris R S; Phillips, James O; Rubinstein, Jay T

    2014-01-01

    A functional vestibular prosthesis can be implanted in human such that electrical stimulation of each semicircular canal produces canal-specific eye movements while preserving vestibular and auditory function. A number of vestibular disorders could be treated with prosthetic stimulation of the vestibular end organs. We have previously demonstrated in rhesus monkeys that a vestibular neurostimulator, based on the Nucleus Freedom cochlear implant, can produce canal-specific electrically evoked eye movements while preserving auditory and vestibular function. An investigational device exemption has been obtained from the FDA to study the feasibility of treating uncontrolled Ménière's disease with the device. The UW/Nucleus vestibular implant was implanted in the perilymphatic space adjacent to the three semicircular canal ampullae of a human subject with uncontrolled Ménière's disease. Preoperative and postoperative vestibular and auditory function was assessed. Electrically evoked eye movements were measured at 2 time points postoperatively. Implantation of all semicircular canals was technically feasible. Horizontal canal and auditory function were largely, but not totally, lost. Electrode stimulation in 2 of 3 canals resulted in canal-appropriate eye movements. Over time, stimulation thresholds increased. Prosthetic implantation of the semicircular canals in humans is technically feasible. Electrical stimulation resulted in canal-specific eye movements, although thresholds increased over time. Preservation of native auditory and vestibular function, previously observed in animals, was not demonstrated in a single subject with advanced Ménière's disease.

  11. Vestibular perception is slow: a review.

    Science.gov (United States)

    Barnett-Cowan, Michael

    2013-01-01

    Multisensory stimuli originating from the same event can be perceived asynchronously due to differential physical and neural delays. The transduction of and physiological responses to vestibular stimulation are extremely fast, suggesting that other stimuli need to be presented prior to vestibular stimulation in order to be perceived as simultaneous. There is, however, a recent and growing body of evidence which indicates that the perceived onset of vestibular stimulation is slow compared to the other senses, such that vestibular stimuli need to be presented prior to other sensory stimuli in order to be perceived synchronously. From a review of this literature it is speculated that this perceived latency of vestibular stimulation may reflect the fact that vestibular stimulation is most often associated with sensory events that occur following head movement, that the vestibular system rarely works alone, that additional computations are required for processing vestibular information, and that the brain prioritizes physiological response to vestibular stimulation over perceptual awareness of stimulation onset. Empirical investigation of these theoretical predictions is encouraged in order to fully understand this surprising result, its implications, and to advance the field.

  12. Vestibular insights into cognition and psychiatry.

    Science.gov (United States)

    Gurvich, Caroline; Maller, Jerome J; Lithgow, Brian; Haghgooie, Saman; Kulkarni, Jayashri

    2013-11-06

    The vestibular system has traditionally been thought of as a balance apparatus; however, accumulating research suggests an association between vestibular function and psychiatric and cognitive symptoms, even when balance is measurably unaffected. There are several brain regions that are implicated in both vestibular pathways and psychiatric disorders. The present review examines the anatomical associations between the vestibular system and various psychiatric disorders. Despite the lack of direct evidence for vestibular pathology in the key psychiatric disorders selected for this review, there is a substantial body of literature implicating the vestibular system in each of the selected psychiatric disorders. The second part of this review provides complimentary evidence showing the link between vestibular dysfunction and vestibular stimulation upon cognitive and psychiatric symptoms. In summary, emerging research suggests the vestibular system can be considered a potential window for exploring brain function beyond that of maintenance of balance, and into areas of cognitive, affective and psychiatric symptomology. Given the paucity of biological and diagnostic markers in psychiatry, novel avenues to explore brain function in psychiatric disorders are of particular interest and warrant further exploration. © 2013 Elsevier B.V. All rights reserved.

  13. Personality changes in patients with vestibular dysfunction.

    Science.gov (United States)

    Smith, Paul F; Darlington, Cynthia L

    2013-10-29

    The vestibular system is a sensory system that has evolved to detect linear and angular acceleration of the head in all planes so that the brain is not predominantly reliant on visual information to determine self-motion. Since the vestibular system first evolved in invertebrate species in order to detect gravitational vertical, it is likely that the central nervous system has developed a special dependence upon vestibular input. In addition to the deficits in eye movement and postural reflexes that occur following vestibular dysfunction, there is convincing evidence that vestibular loss also causes cognitive and emotional disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and neocortex play in the sense of spatial orientation. Beyond this, however, patients with vestibular disorders have been reported to experience other personality changes that suggest that vestibular sensation is implicated in the sense of self. These are depersonalization and derealization symptoms such as feeling "spaced out", "body feeling strange" and "not feeling in control of self". We propose in this review that these symptoms suggest that the vestibular system may make a unique contribution to the concept of self through information regarding self-motion and self-location that it transmits, albeit indirectly, to areas of the brain such as the temporo-parietal junction (TPJ).

  14. International Clinical Protocol on Vestibular Disorders (Dizziness).

    Science.gov (United States)

    Trinus, Kostiantyn; Claussen, Claus-Frenz

    2017-12-01

    26-28 May at 43 Congress of Neurootological and Equilibriometric Society (Budapest, Hungary) International Clinical Protocol on Vestibular Disorders (Dizziness) being discussed and accepted as Consensus Document. Cochrane reports estimates that dizziness has prevalence of 22.9% in the last 12 months and an incidence of 3.1%. Only 1.8% of adults consulted a physician in the last 12 months. Cochrane reviews suggest that the evidence base for dizziness evaluation is weak, thus necessitates the creation of evidence-based document. Protocol is based at the new concept of vestibular system, which involves the vestibular peripheral sensors, space orientation tetrad, vestibular presentations in the brain cortex and vestibular effectory projections in the brain. Labyrinth consists of sensors, for which six modalities are adequate: 1. acceleration, 2. gravitation, 3. low frequency whole-body vibration, 4. Infrasound, 5. magnetic impulse, 6. metabolic changes. Vestibular system from rhomboid fosse gets the inputs from visual, acoustic, somatosensory organs, integrating them and forming space perception and orientation. Interaction with space is realized through sensory, motor, vegetative and limbic projections. So, vestibular disturbances may manifest as paropsia, tinnitus, numbness. Vestibular evoked potentials (not VEMP) and craniocorpography have highest sensitivity (90% and more). As vestibular dysfunction has recurrent character patients need monitoring.

  15. Vestibular activation, smooth pursuit tracking, and psychosis.

    Science.gov (United States)

    Jones, A M; Pivik, R T

    1985-04-01

    Pursuit tracking and vestibular activation procedures were combined in an investigation to determine if smooth pursuit tracking deficits could be related to abnormalities of visual-vestibular interaction in psychiatric patients. In actively psychotic patients, but not in comparison groups of schizophrenic outpatients with remitted symptomatology or normal controls, a significant failure of visual fixation to suppress caloric nystagmus was related to a higher incidence of disordered tracking during both baseline and postirrigation conditions. Other vestibular irregularities including dysrhythmia and reduced fast phase velocity were observed in these same patients. The results are supportive of a central deficit in visual-vestibular interaction that may contribute to pursuit tracking deficits in psychosis.

  16. The role of the vestibular assessment.

    Science.gov (United States)

    Phillips, J S; FitzGerald, J E; Bath, A P

    2009-11-01

    To evaluate the role of vestibular assessment in the management of the dizzy patient. A retrospective review of case notes and vestibular assessment reports of 100 consecutive patients referred for vestibular assessment. Sixty of the 100 patients had an abnormal vestibular assessment. Eleven patients had benign paroxysmal positional vertigo as the sole diagnosis, of whom nine had not had a Dix-Hallpike manoeuvre performed before referral. Of patients referred for vestibular rehabilitation, 76 per cent had an abnormal electrophysiological assessment. After vestibular assessment, 35 patients were discharged with no further follow-up appointments in the ENT department. All patients should have a Dix-Hallpike manoeuvre performed prior to referral for vestibular assessment. The majority of our patients undergoing vestibular rehabilitation had abnormal test results, although a significant number did not. Prior to referral, it is worth considering the implication of a 'normal' and 'abnormal' result for the management of the patient. Careful consideration should be given to the development of dedicated dizziness clinics run by practitioners with a specialist interest in balance disorders, in order to ensure appropriate requests for vestibular assessment.

  17. Epidemiology and natural history of vestibular schwannomas

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Caye-Thomasen, Per

    2012-01-01

    This article describes various epidemiologic trends for vestibular schwannomas over the last 35 years, including a brief note on terminology. Additionally, it provides information on the natural history of tumor growth and hearing level following the diagnosis of a vestibular schwannoma. A treatm......This article describes various epidemiologic trends for vestibular schwannomas over the last 35 years, including a brief note on terminology. Additionally, it provides information on the natural history of tumor growth and hearing level following the diagnosis of a vestibular schwannoma....... A treatment strategy based on the natural history of tumor growth and hearing also is discussed....

  18. Personality Changes in Patients with Vestibular Dysfunction

    Directory of Open Access Journals (Sweden)

    Paul eSmith

    2013-10-01

    Full Text Available The vestibular system is a sensory system that has evolved to detect linear and angular acceleration of the head in all planes so that the brain is not predominantly reliant on visual information to determine self-motion. Since the vestibular system first evolved in invertebrate species in order to detect gravitational vertical, it is likely that the central nervous system has developed a special dependence upon vestibular input. In addition to the deficits in eye movement and postural reflexes that occur following vestibular dysfunction, there is convincing evidence that vestibular loss also causes cognitive and emotional disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and cortex play in the sense of spatial orientation. Beyond this, however, patients with vestibular disorders have been reported to experience other personality changes that suggest that vestibular sensation is implicated in the sense of self. These are depersonalisation and derealisation symptoms such as feeling ‘spaced out’, ‘body feeling strange’ and ‘not feeling in control of self’. We suggest in this review that these symptoms suggest that the vestibular system may make a unique contribution to the concept of self through the information regarding self-motion and self-location that it transmits, albeit indirectly, to areas of the brain such as the temporo-parietal junction.

  19. 'Nomadic' nuclei of galaxies

    Science.gov (United States)

    Silchenko, O. K.; Lipunov, V. M.

    1985-12-01

    In this paper the authors discuss observational and theoretical arguments in favour of hypothesis on "nomad life" of active nuclei inside and outside galaxies as well as its consequences. It may be the anisotropic collapse of a supermassive star, or the disruption of a supermassive binary system after the collapse of one companion that would give birth to such nuclei. The authors predict the existence of veritable quasi-stellar active objects without any ghost galaxies.

  20. Effects of aging on nitrergic system in human basal nuclei

    Directory of Open Access Journals (Sweden)

    Bruno Lopes dos Santos

    2014-10-01

    Full Text Available Nitric oxide (NO is a gaseous molecule that plays a role in a number of physiologic processes. The available evidence suggests that NO is a major neurotransmitter involved in motor control and emotion/behavior modulation. To investigate the distribution and morphology of the nitrergic system in human basal nuclei, we studied samples from the striatum, globus pallidus, subthalamic nucleus, substantia nigra and pedunculopontine nucleus of 20 human brains from subjects without neurologic/psychiatric diseases. The samples were stained for NADPH-diaphorase using histochemistry and for neuronal NO synthase using immunohistochemistry. We then analyzed the nitrergic neuronal density and its morphometric parameters. Our data demonstrated that: (I the most posterior regions of the striatum exhibit a higher neuronal density; (II the limbic cortex-associated areas of the striatum exhibit higher neuronal density than other functional subdivisions; (III approximately 90% of the neurons in the subthalamic nucleus express NO; (IV the pedunculopontine nucleus exhibits a massive nitrergic neuronal density; (V in the globus pallidus, there is a marked presence of NO neurons in the medial medullary lamina; and (VI nitrergic neurons were not detected in the substantia nigra. Aging did not change the neuronal density or the morphometric parameters of nitrergic neurons in the analyzed nuclei.

  1. Changing perspective: The role of vestibular signals.

    Science.gov (United States)

    Deroualle, Diane; Borel, Liliane; Devèze, Arnaud; Lopez, Christophe

    2015-12-01

    Social interactions depend on mechanisms such as the ability to take another person's viewpoint, i.e. visuo-spatial perspective taking. However, little is known about the sensorimotor mechanisms underpinning perspective taking. Because vestibular signals play roles in mental rotation and spatial cognition tasks and because damage to the vestibular cortex can disturb egocentric perspective, vestibular signals stand as important candidates for the sensorimotor foundations of perspective taking. Yet, no study merged natural full-body vestibular stimulations and explicit visuo-spatial perspective taking tasks in virtual environments. In Experiment 1, we combined natural vestibular stimulation on a rotatory chair with virtual reality to test how vestibular signals are processed to simulate the viewpoint of a distant avatar. While they were rotated, participants tossed a ball to a virtual character from the viewpoint of a distant avatar. Our results showed that vestibular signals influence perspective taking in a direction-specific way: participants were faster when their physical body rotated in the same direction as the mental rotation needed to take the avatar's viewpoint. In Experiment 2, participants realized 3D object mental rotations, which did not involve perspective taking, during the same whole-body vestibular stimulation. Our results demonstrated that vestibular stimulation did not affect 3D object mental rotations. Altogether, these data indicate that vestibular signals have a direction-specific influence on visuo-spatial perspective taking (self-centered mental imagery), but not a general effect on mental imagery. Findings from this study suggest that vestibular signals contribute to one of the most crucial mechanisms of social cognition: understanding others' actions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. [Effectiveness of Self-efficacy Promoting Vestibular Rehabilitation Program for Patients with Vestibular Hypofunction].

    Science.gov (United States)

    Lee, Hyun Jung; Choi-Kwon, Smi

    2016-10-01

    In this study an examination was done of the effect of self-efficacy promoting vestibular rehabilitation (S-VR) on dizziness, exercise selfefficacy, adherence to vestibular rehabilitation (VR), subjective and objective vestibular function, vestibular compensation and the recurrence of dizziness in patients with vestibular hypofunction. This was a randomized controlled study. Data were collected 3 times at baseline, 4 and 8 weeks after beginning the intervention. Outcome measures were level of dizziness, exercise self-efficacy, and level of adherence to VR. Subjective and objective vestibular function, vestibular compensation and the recurrence of dizziness were also obtained. Data were analyzed using Windows SPSS 21.0 program. After 4 weeks of S-VR, there was no difference between the groups for dizziness, subjective and objective vestibular functions. However, exercise self-efficacy and adherence to VR were higher in the experimental group than in the control group. After 8 weeks of S-VR, dizziness (p=.018) exercise self-efficacy (pVR (pVR is effective in reducing dizziness, and improving exercise self-efficacy, subjective vestibular function and adherence to VR. Objective vestibular function and vestibular compensation were also improved in the experimental group at the end of 8 weeks of S-VR.

  3. Swimming behaviour and calcium incorporation into inner ear otoliths of fish after vestibular nerve transection

    Science.gov (United States)

    Edelmann, E.; Anken, R. H.; Rahmann, H.

    2004-01-01

    Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium tracer alizarin complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated. Like most neonate swordtails, Type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal, and the otolithic calcium incorporation in controls of the same batch was symmetric. In Type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetric. These results show that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. In conclusion, the regulation of otolithic calcium incorporation is guided neuronally, in part via the vestibular nerve and, in part, via a further pathway, which remains to be addressed in the course of future investigations.

  4. [Vestibular influences on human locomotion: results obtained using galvanic vestibular stimulation].

    Science.gov (United States)

    Stolbkov, Iu K; Gerasimenko, Iu P

    2014-06-01

    Locomotion is the most important mode of our movement in space. The role of the vestibular system during human locomotion is not well studied, mainly due to problems associated with its isolation stimulation. It is difficult to stimulate this system in isolation during locomotion because the real movement of the head to activate the vestibular end-organs inevitably leads to the activation of other sensory inputs. Galvanic stimulation is not a natural way to stimulate the vestibular system, but it has the advantage providing an isolated stimulation of the vestibular inputs. This technique is relatively novel in the examination of vestibular contributions during human locomotion. In our review we consider the current data regarding the effect of vestibular signals on human locomotion by using galvanic vestibular stimulation.

  5. Reviewing the Role of the Efferent Vestibular System in Motor and Vestibular Circuits

    Directory of Open Access Journals (Sweden)

    Miranda A. Mathews

    2017-08-01

    Full Text Available Efferent circuits within the nervous system carry nerve impulses from the central nervous system to sensory end organs. Vestibular efferents originate in the brainstem and terminate on hair cells and primary afferent fibers in the semicircular canals and otolith organs within the inner ear. The function of this efferent vestibular system (EVS in vestibular and motor coordination though, has proven difficult to determine, and remains under debate. We consider current literature that implicate corollary discharge from the spinal cord through the efferent vestibular nucleus (EVN, and hint at a potential role in overall vestibular plasticity and compensation. Hypotheses range from differentiating between passive and active movements at the level of vestibular afferents, to EVS activation under specific behavioral and environmental contexts such as arousal, predation, and locomotion. In this review, we summarize current knowledge of EVS circuitry, its effects on vestibular hair cell and primary afferent activity, and discuss its potential functional roles.

  6. Reviewing the Role of the Efferent Vestibular System in Motor and Vestibular Circuits.

    Science.gov (United States)

    Mathews, Miranda A; Camp, Aaron J; Murray, Andrew J

    2017-01-01

    Efferent circuits within the nervous system carry nerve impulses from the central nervous system to sensory end organs. Vestibular efferents originate in the brainstem and terminate on hair cells and primary afferent fibers in the semicircular canals and otolith organs within the inner ear. The function of this efferent vestibular system (EVS) in vestibular and motor coordination though, has proven difficult to determine, and remains under debate. We consider current literature that implicate corollary discharge from the spinal cord through the efferent vestibular nucleus (EVN), and hint at a potential role in overall vestibular plasticity and compensation. Hypotheses range from differentiating between passive and active movements at the level of vestibular afferents, to EVS activation under specific behavioral and environmental contexts such as arousal, predation, and locomotion. In this review, we summarize current knowledge of EVS circuitry, its effects on vestibular hair cell and primary afferent activity, and discuss its potential functional roles.

  7. Vestibular Function and Activities of Daily Living

    Directory of Open Access Journals (Sweden)

    Aisha Harun MD

    2015-09-01

    Full Text Available Objective: Vestibular dysfunction increases with age and is associated with mobility difficulties and fall risk in older individuals. We evaluated whether vestibular function influences the ability to perform activities of daily living (ADLs. Method: We analyzed the 1999 to 2004 National Health and Nutrition Examination Survey of adults aged older than 40 years ( N = 5,017. Vestibular function was assessed with the Modified Romberg test. We evaluated the association between vestibular function and difficulty level in performing specific basic and instrumental ADLs, and total number of ADL impairments. Results: Vestibular dysfunction was associated with significantly higher odds of difficulty with nine ADLs, most strongly with difficulty managing finances (odds ratio [ OR ] = 2.64, 95% confidence interval [CI] = [1.18, 5.90]. In addition, vestibular dysfunction was associated with a significantly greater number of ADL impairments (β = .21, 95% CI = [0.09, 0.33]. This effect size was comparable with the influence of heavy smoking (β = .21, 95% CI = [0.06, 0.36] and hypertension (β = .10, 95% CI = [0.02, 0.18] on the number of ADL impairments. Conclusion: Vestibular dysfunction significantly influences ADL difficulty, most strongly with a cognitive rather than mobility-based task. These findings underscore the importance of vestibular inputs for both cognitive and physical daily activities.

  8. Motor development after vestibular deprivation in rats

    NARCIS (Netherlands)

    Geisler, HC; Gramsbergen, A

    This review summarizes the postural development in the rat and the influences of vestibular deprivation from the 5th postnatal day on this development. Vestibular deprivation leads to a delay in motor development. Most probably this delay is caused by a delay in the development of postural control,

  9. Behavior of the oculomotor neurons discharge during sinusoidal lateral tilt in the rabbit.

    Science.gov (United States)

    Favilla, M; Ghelarducci, B; La Noce, A; Mais, V; Starita, A

    1979-10-15

    The characteristics of the control exerted by macular and ampullar vestibular receptors on oculomotor neurons (OMN) have been investigated by submitting unanesthetized, encéphale isolé rabbits to sinusoidal lateral tilts of varying frequencies (0.013-0.2 Hz). The phase of the response exhibited a progressive shift towards head velocity with increasing frequencies of tilt. The sensitivity of the OMN significantly increased at frequencies above 0.025 Hz, corresponding to peak accelerations suprathreshold for canals related vestibular neurons. The convergent action of macular and ampullar vestibular receptors in the control of vertical eye movements is discussed in relation with stimulus frequency.

  10. Vestibular Function and Depersonalization/Derealization Symptoms.

    Science.gov (United States)

    Jáuregui Renaud, Kathrine

    2015-01-01

    Patients with an acquired sensory dysfunction may experience symptoms of detachment from self or from the environment, which are related primarily to nonspecific symptoms of common mental disorders and secondarily, to the specific sensory dysfunction. This is consistent with the proposal that sensory dysfunction could provoke distress and a discrepancy between the multi-sensory frame given by experience and the actual perception. Both vestibular stimuli and vestibular dysfunction can underlie unreal experiences. Vestibular afferents provide a frame of reference (linear and angular head acceleration) within which spatial information from other senses is interpreted. This paper reviews evidence that symptoms of depersonalization/derealization associated with vestibular dysfunction are a consequence of a sensory mismatch between disordered vestibular input and other sensory signals of orientation.

  11. [Vestibular rehabilitation in elderly patients with dizziness].

    Science.gov (United States)

    Zanardini, Francisco Halilla; Zeigelboim, Bianca Simone; Jurkiewicz, Ari Leon; Marques, Jair Mendes; Martins-Bassetto, Jackeline

    2007-01-01

    The aging of the population is a natural process and is manifested by a decline in the functions of several organs. Vestibular rehabilitation (VR) is a therapeutic process that seeks to promote a significant reduction in the symptoms of the labyrinth. To verify the benefits of VR exercises through the application of the Dizziness Handicap Inventory (DHI) questionnaire--Brazilian version--pre and post rehabilitation. Participants of this study were eight elderly patients with dizziness, ages between 63 and 82 years, three male and five female. The following procedures were carried out: medical history, otologic inspection, vestibular evaluation with vectoelectronystagmography (VENG), application of the DHI questionnaire and of the Cawthorne (1944) and Cooksey (1946) VR exercises. Regarding the auditory and vestibular complaints which were referred to in the medical history, the following was observed: presence of tinnitus, hearing loss, postural vertigo and of unbalance. In the evaluation of the vestibular function alterations were observed for all of the participants, mainly in the caloric test, with a prevalence of unilateral and bilateral hypofunction. In the vestibular exam the following was observed: three cases of unilateral peripheral vestibular deficit syndrome, three cases of bilateral peripheral vestibular deficit syndrome, one case of bilateral central vestibular deficit syndrome and one case of irritating bilateral central vestibular syndrome. There was a statistically significant improvement of the following aspects after VR: physical (p=0.00413), functional (p=0.00006) and emotional (p=0.03268). The VR protocol favored the improvement of life quality of the participants and was of assistance in the process of vestibular compensation.

  12. Effects of vibrotactile vestibular substitution on vestibular rehabilitation - preliminary study,

    Directory of Open Access Journals (Sweden)

    Cibele Brugnera

    2015-12-01

    Full Text Available ABSTRACT INTRODUCTION: Some patients with severe impairment of body balance do not obtain adequate improvement from vestibular rehabilitation (VR. OBJECTIVE: To evaluate the effectiveness of Vertiguard(tm biofeedback equipment as a sensory substitution (SS of the vestibular system in patients who did not obtain sufficient improvement from VR. METHODS: This was a randomized prospective clinical study. Thirteen patients without satisfactory response to conventional VR were randomized into a study group (SG, which received the vibrotactile stimulus from Vertiguard(tm for ten days, and a control group (CG, which used equipment without the stimulus. For pre- and post-treatment assessment, the Sensory Organization Test (SOT protocol of the Computerized Dynamic Posturography (CDP and two scales of balance self-perception, Activities-specific Balance Confidence (ABC and Dizziness Handicap Inventory (DHI, were used. RESULTS: After treatment, only the SG showed statistically significant improvement in C5 (p = 0.007 and C6 (p = 0.01. On the ABC scale, there was a significant difference in the SG (p= 0.04. The DHI showed a significant difference in CG and SG with regard to the physical aspect, and only in the SG for the functional aspect (p = 0.04. CONCLUSION: The present findings show that sensory substitution using the vibrotactile stimulus of the Vertiguard(tm system helped with the integration of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance.

  13. Effects of vibrotactile vestibular substitution on vestibular rehabilitation - preliminary study.

    Science.gov (United States)

    Brugnera, Cibele; Bittar, Roseli Saraiva Moreira; Greters, Mário Edvin; Basta, Dietmar

    2015-01-01

    Some patients with severe impairment of body balance do not obtain adequate improvement from vestibular rehabilitation (VR). To evaluate the effectiveness of Vertiguard™ biofeedback equipment as a sensory substitution (SS) of the vestibular system in patients who did not obtain sufficient improvement from VR. This was a randomized prospective clinical study. Thirteen patients without satisfactory response to conventional VR were randomized into a study group (SG), which received the vibrotactile stimulus from Vertiguard™ for ten days, and a control group (CG), which used equipment without the stimulus. For pre- and post-treatment assessment, the Sensory Organization Test (SOT) protocol of the Computerized Dynamic Posturography (CDP) and two scales of balance self-perception, Activities-specific Balance Confidence (ABC) and Dizziness Handicap Inventory (DHI), were used. After treatment, only the SG showed statistically significant improvement in C5 (p=0.007) and C6 (p=0.01). On the ABC scale, there was a significant difference in the SG (p=0.04). The DHI showed a significant difference in CG and SG with regard to the physical aspect, and only in the SG for the functional aspect (p=0.04). The present findings show that sensory substitution using the vibrotactile stimulus of the Vertiguard™ system helped with the integration of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  14. Galvanic vestibular stimulation improves the results of vestibular rehabilitation.

    Science.gov (United States)

    Carmona, Sergio; Ferrero, Antonela; Pianetti, Guillermina; Escolá, Natalia; Arteaga, María Victoria; Frankel, Lilian

    2011-09-01

    Here, we present findings from a three-step investigation of the effect of galvanic vestibular stimulation (GVS) in normal subjects and in subjects undergoing vestibular rehabilitation (VR). In an initial study, we examined the body sway of 10 normal subjects after one minute of 2 mA GVS. The effect of the stimulation lasted for at least 20 minutes in all subjects and up to two hours in 70% of the subjects. We then compared a group of patients who received conventional VR (40 patients) with a group that received a combination of VR and GVS. Results suggest a significant improvement in the second group. Finally, we attempted to establish the optimal number of GVS sessions and to rule out a placebo effect. Fifteen patients received "systematic" GVS: five sessions, once a week. Five patients received "nonsystematic" galvanic stimulation in a sham protocol, which included two stimulations of the clavicle. These data were analyzed with Fisher's exact test and indicated that the best results were obtained after three sessions of GVS and no placebo effect was observed. © 2011 New York Academy of Sciences.

  15. Localization of nitric oxide synthase isoforms (NOS I, II and III) in the vestibular end organs of the guinea pig.

    Science.gov (United States)

    Takumida, M; Anniko, M

    1998-01-01

    The localization of nitric oxide (NO) synthase (NOS) isoforms was investigated in the vestibular organ of the pigmented guinea pig by indirect immunohistochemistry. The cytoplasm of both type I and type II vestibular sensory cells as well as vestibular ganglion cells showed both NOS I and III immunoreactivity, whereas there was no reactivity in their nuclei and sensory hairs. The afferent nerve chalices were usually not stained. NOS III staining was also observed in the nerve fibers contacting type II cells and in the subepithelial tissue. The endothelial lining of the blood vessels displayed reactivity for NOS III. The cytoplasm of fluid transporting cells showed weak staining for NOS I and moderate staining for NOS III. Immunostaining for NOS II did not display any reactivity in general. These findings may suggest that NO is a mediator of neurotransmission in the vestibular system in sensory cells and ganglia. NO in the fluid transporting cells may play an important role for maintaining the endolymph and ion homeostasis, and NOS III in vascular endothelial cells implies regulatory effects of NO on vascular wall tonus and vestibular blood supply.

  16. Multisensory Integration of Visual and Vestibular Signals Improves Heading Discrimination in the Presence of a Moving Object

    Science.gov (United States)

    Dokka, Kalpana; DeAngelis, Gregory C.

    2015-01-01

    Humans and animals are fairly accurate in judging their direction of self-motion (i.e., heading) from optic flow when moving through a stationary environment. However, an object moving independently in the world alters the optic flow field and may bias heading perception if the visual system cannot dissociate object motion from self-motion. We investigated whether adding vestibular self-motion signals to optic flow enhances the accuracy of heading judgments in the presence of a moving object. Macaque monkeys were trained to report their heading (leftward or rightward relative to straight-forward) when self-motion was specified by vestibular, visual, or combined visual-vestibular signals, while viewing a display in which an object moved independently in the (virtual) world. The moving object induced significant biases in perceived heading when self-motion was signaled by either visual or vestibular cues alone. However, this bias was greatly reduced when visual and vestibular cues together signaled self-motion. In addition, multisensory heading discrimination thresholds measured in the presence of a moving object were largely consistent with the predictions of an optimal cue integration strategy. These findings demonstrate that multisensory cues facilitate the perceptual dissociation of self-motion and object motion, consistent with computational work that suggests that an appropriate decoding of multisensory visual-vestibular neurons can estimate heading while discounting the effects of object motion. SIGNIFICANCE STATEMENT Objects that move independently in the world alter the optic flow field and can induce errors in perceiving the direction of self-motion (heading). We show that adding vestibular (inertial) self-motion signals to optic flow almost completely eliminates the errors in perceived heading induced by an independently moving object. Furthermore, this increased accuracy occurs without a substantial loss in the precision. Our results thus demonstrate that

  17. Genetic disorders of the vestibular system.

    Science.gov (United States)

    Eppsteiner, Robert W; Smith, Richard J H

    2011-10-01

    This review highlights the current body of literature related to the genetics of inherited vestibular disorders and provides a framework for the characterization of these disorders. We emphasize peripheral causes of vestibular dysfunction and highlight recent advances in the field, point out gaps in understanding, and focus on key areas for future investigation. The discovery of a modifier gene that leads to a more severe Usher syndrome phenotype calls into question the assumption that Usher syndrome is universally a monogenic disorder. Despite the use of several investigational approaches, the genetic basis of Menière's disease remains poorly understood. Evidence for a vestibular phenotype associated with DFNB1 suggests that mutations in other genes causally related to nonsyndromic hearing loss also may have an unrecognized vestibular phenotype. Our understanding of the genetic basis for vestibular disorders is superficial. Significant challenges include defining the genetics of inherited isolated vestibular dysfunction and understanding the pathological basis of Menière's disease. However, improved characterization of inherited vestibular dysfunction, coupled with advanced genetic techniques such as targeted genome capture and massively parallel sequencing, provides an opportunity to investigate these diseases at the genetic level.

  18. Anatomy of the vestibular system: a review.

    Science.gov (United States)

    Khan, Sarah; Chang, Richard

    2013-01-01

    A sense of proper sensory processing of head motion and the coordination of visual and postural movements to maintain equilibrium is critical to everyday function. The vestibular system is an intricate organization that involves multiple levels of sensory processing to achieve this goal. This chapter provides an overview of the anatomical structures and pathways of the vestibular system. The five major vestibular structures are located in the inner ear and include: the utricle, the saccule, and the lateral, superior, and posterior semicircular canals. Hair cells on the neuroepithelium of the peripheral vestibular organs carry sensory impulses to primary processing centers in the brainstem and the cerebellum. These areas send input via ascending and descending projections to coordinate vital reflexes, such as the vestibuloocular reflex and the vestibulospinal reflex, which allow for the proper orientation of the eyes and body in response to head motion. Specific connections regarding higher level cortical vestibular structures are poorly understood. Vestibular centers in the brainstem, cerebellum, and cerebral cortex function to integrate sensory information from the peripheral vestibular organs, visual system, and proprioceptive system to allow for proper balance and orientation of the body in its environment.

  19. Embryological development and large vestibular aqueduct syndrome.

    Science.gov (United States)

    Pyle, G M

    2000-11-01

    Large vestibular aqueduct syndrome (LVAS) is a significant cause of hearing loss in early childhood. Many theories on the origins and causes of LVAS have been proposed, including arrest or maldevelopment of the vestibular labyrinth in embryonic life. Prior studies have described postnatal and adult vestibular aqueduct anatomy, but none has analyzed aqueduct growth throughout embryonic life. This study was undertaken to characterize the growth of the developing vestibular aqueduct to gain a better understanding of the possible origins of LVAS. Basic science, temporal bone histopathological study. Serial sections from 48 temporal bones from human embryos ranging in age from 5 weeks' gestation to full term were studied with computer image analysis. Measurements of vestibular aqueduct internal and external aperture, midportion diameter, and length were analyzed to obtain a growth model of development. The vestibular aqueduct grows in a nonlinear fashion throughout embryonic life. All parameters fit a similar growth curve and never reached a maximum or began narrowing during development. Growth in one parameter correlated well with growth of another. There was good side-to-side correlation with all but the external aperture. Most of the membranous labyrinth reaches adult size by 20 weeks' gestation, but the vestibular aqueduct grows throughout embryonic life. The measurements and growth model obtained in this study are not consistent with the theory that LVAS results from an arrest in development early in fetal life. The data suggest that LVAS may result from postnatal and early childhood maldevelopment.

  20. Neuropharmacological basis of vestibular system disorder treatment.

    Science.gov (United States)

    Soto, Enrique; Vega, Rosario; Seseña, Emmanuel

    2013-01-01

    This work reviews the neuropharmacology of the vestibular system, with an emphasis on the mechanism of action of drugs used in the treatment of vestibular disorders. Clinicians are confronted with a rapidly changing field in which advances in the knowledge of ionic channel function and synaptic transmission mechanisms have led to the development of new scientific models for the understanding of vestibular dysfunction and its management. In particular, there have been recent advances in our knowledge of the fundamental mechanisms of vestibular system function and of drug action. In this work, drugs acting on vestibular system have been grouped into two main categories according to their primary mechanisms of action: those with effects on neurotransmitters and neuromodulators dynamics and those that act on voltage-gated ion channels. Particular attention is given in this review to drugs that may provide additional insight into the pathophysiology of vestibular diseases. The critical analysis of the literature reveals that there is a significant lack of information defining the real utility of diverse drugs used in clinical practice. The development of basic studies addressing drug actions at the molecular, cellular and systems level, combined with reliable and well controlled clinical trials, would provide the scientific basis for new strategies for the treatment of vestibular disorders.

  1. Electromagnetic structure of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.G.

    1986-07-01

    A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs. (LEW)

  2. Projections from the subdivisions of the fastigial nucleus to the vestibular complex and the prepositus hypoglossal nucleus in the albino rat: an anterograde tracing study using biocytin.

    Science.gov (United States)

    Omori, O; Umetani, T; Sugioka, K

    1997-02-01

    Differential projections from the subdivisions of the fastigial nucleus to the vestibular complex and the prepositus hypoglossal nucleus were investigated by an anterograde tracing method using biocytin in the albino rat. The caudomedial subdivision of the nucleus projected ipsilaterally to the dorsal and medial parts of the superior vestibular nucleus (Su Ve), the dorsomedial part of the lateral vestibular nucleus (LVe), and the dorsal parts of the medial (MVe) and spinal (Sp Ve) vestibular nuclei, and projected contralaterally to the ventrolateral corners of the Su Ve and LVe, the ventral part of the MVe, and the lateral part of the Sp Ve. The bilateral prepositus hypoglossal nuclei received sparse projections from the caudomedial subdivision. The middle subdivision of the fastigial nucleus projected ipsilaterally to the dorsal and/or ventral parts of the Su Ve, the dorsomedial pats of the LVe and Sp Ve, and the dorsolateral part of the MVe, and projected contralaterally to the dorsal margin of the Su Ve, the ventrolateral part of the LVe, and the lateral part of the Sp Ve. The dorsolateral protuberance of the fastigial nucleus projected ipsilaterally to the dorsal margin of the Su Ve, the dorsomedial part of the LVe, the dorsal or lateral parts of the Sp Ve, and the lateral part of the MVe, and projected contralaterally to the ventrolateral part of the LVe and the lateral part of the Sp Ve. The subnuclei x, y, and f, interstitial nucleus of the vestibular nerve, and the infracerebellar nucleus received bilateral or ipsilateral fastigiovestibular projections.

  3. Progress toward development of a multichannel vestibular prosthesis for treatment of bilateral vestibular deficiency.

    Science.gov (United States)

    Fridman, Gene Y; Della Santina, Charles C

    2012-11-01

    This article reviews vestibular pathology and the requirements and progress made in the design and construction of a vestibular prosthesis. Bilateral loss of vestibular sensation is disabling. When vestibular hair cells are injured by ototoxic medications or other insults to the labyrinth, the resulting loss of sensory input disrupts vestibulo-ocular reflexes (VORs) and vestibulo-spinal reflexes that normally stabilize the eyes and body. Affected individuals suffer poor vision during head movement, postural instability, chronic disequilibrium, and cognitive distraction. Although most individuals with residual sensation compensate for their loss over time, others fail to do so and have no adequate treatment options. A vestibular prosthesis analogous to cochlear implants but designed to modulate vestibular nerve activity during head movement should improve quality of life for these chronically dizzy individuals. We describe the impact of bilateral loss of vestibular sensation, animal studies supporting feasibility of prosthetic vestibular stimulation, the current status of multichannel vestibular sensory replacement prosthesis development, and challenges to successfully realizing this approach in clinical practice. In bilaterally vestibular-deficient rodents and rhesus monkeys, the Johns Hopkins multichannel vestibular prosthesis (MVP) partially restores the three-dimensional (3D) VOR for head rotations about any axis. Attempts at prosthetic vestibular stimulation of humans have not yet included the 3D eye movement assays necessary to accurately evaluate VOR alignment, but these initial forays have revealed responses that are otherwise comparable to observations in animals. Current efforts now focus on refining electrode design and surgical technique to enhance stimulus selectivity and preserve cochlear function, optimizing stimulus protocols to improve dynamic range and reduce excitation-inhibition asymmetry, and adapting laboratory MVP prototypes into devices

  4. Reviewing the Role of the Efferent Vestibular System in Motor and Vestibular Circuits

    OpenAIRE

    Mathews, Miranda A.; Camp, Aaron J.; Murray, Andrew J.

    2017-01-01

    Efferent circuits within the nervous system carry nerve impulses from the central nervous system to sensory end organs. Vestibular efferents originate in the brainstem and terminate on hair cells and primary afferent fibers in the semicircular canals and otolith organs within the inner ear. The function of this efferent vestibular system (EVS) in vestibular and motor coordination though, has proven difficult to determine, and remains under debate. We consider current literature that implicate...

  5. Effects of Vestibular Rehabilitation Interventions in the Elderly with Chronic Unilateral Vestibular Hypofunction

    OpenAIRE

    Arash Bayat; Nader Saki

    2017-01-01

    Introduction: Although vestibular rehabilitation therapy (VRT) methods are relatively popular in treating patients with body balance deficits of vestibular origin, only limited studies have been conducted into customized exercises for unilateral vestibular hypofunction (UVH). Furthermore, very little evidence is available on the outcomes of VRT in the elderly population with chronic UVH. Materials and Methods: A total of 21 patients, aged 61 to 74 years, with UVH participated in this study. T...

  6. Potencial evocado miogênico vestibular

    OpenAIRE

    Felipe,Lilian; Kingma, Herman; Gonçalves, Denise Utsch

    2012-01-01

    INTRODUÇÃO: O Potencial Evocado Miogênico Vestibular (VEMP) é um teste promissor para a avaliação do sistema vestíbulo-cólico descendente. Este reflexo depende da integridade da mácula sacular, do nervo vestibular inferior, dos núcleos vestibulares, das vias vestíbulo-espinhais e do músculo efetor. OBJETIVO: Realizar revisão sistemática de literatura pertinente por meio de bases de dados (COCHRANE, MEDLINE, LILACS, CAPES). CONCLUSÃO: A aplicação clínica do VEMP expandiu-se nos últimos anos, c...

  7. Vestibular rehabilitation in a university hospital

    OpenAIRE

    Flávia da Silva Tavares; Maria Francisca Colella dos Santos; Keila Alessandra Baraldi Knobel

    2008-01-01

    A Reabilitação Vestibular visa melhorar o equilíbrio global, a qualidade de vida e orientação espacial dos pacientes com tontura. OBJETIVOS: Traçar o perfil dos pacientes atendidos no Ambulatório de Reabilitação Vestibular do Setor de Otoneurologia de um hospital universitário e verificar os resultados obtidos no período de novembro/2000 a dezembro/2004. MATERIAL E MÉTODO: Levantamento de dados contidos nas fichas dos 93 pacientes submetidos à Reabilitação Vestibular no período. FORMA DE ESTU...

  8. c-Fos induction by a 14T magnetic field in visceral and vestibular relays of the female rat brainstem is modulated by estradiol

    Science.gov (United States)

    Cason, Angie M.; Kwon, Bumsup; Smith, James C.; Houpt, Thomas A.

    2010-01-01

    There is increasing evidence that high magnetic fields interact with the vestibular system of humans and rodents. In rats, exposure to high magnetic fields of 7T or above induces locomotor circling and leads to a conditioned taste aversion if paired with a novel taste. Sex differences in the behavioral responses to magnetic field exposure have been found, such that female rats show more locomotor circling and enhanced conditioned taste aversion compared to male rats. To determine if estrogen modulates the neural response to high magnetic fields, c-Fos expression after 14T magnetic field exposure was compared in ovariectomized rats and ovariectomized rats with estradiol replacement. Compared to sham exposure, magnetic field exposure induced significantly more c-Fos positive cells in the nucleus of the solitary tract and the parabrachial, medial vestibular, prepositus, and supragenualis nuclei. Furthermore, there was a significant asymmetry in c-Fos induction between sides of the brainstem in several regions. In ovariectomized rats, there was more c-Fos expressed in the right side compared to left side in the locus coeruleus and parabrachial, superior vestibular, and supragenualis nuclei; less expression in the right compared to left side of the medial vestibular; and no asymmetry in the prepositus nucleus and the nucleus of the solitary tract. Chronic estradiol treatment modulated the neural response in some regions: less c-Fos was induced in the superior vestibular nucleus and locus coeruleus after estradiol replacement; estradiol treatment eliminated the asymmetry of c-Fos expression in the locus coeruleus and supragenualis nucleus, created an asymmetry in the prepositus nucleus and reversed the asymmetry in the parabrachial nucleus. These results suggest that ovarian steroids may mediate sex differences in the behavioral responses to magnetic field exposure at the level of visceral and vestibular nuclei of the brainstem. PMID:20553875

  9. c-Fos induction by a 14 T magnetic field in visceral and vestibular relays of the female rat brainstem is modulated by estradiol.

    Science.gov (United States)

    Cason, Angie M; Kwon, Bumsup; Smith, James C; Houpt, Thomas A

    2010-08-06

    There is increasing evidence that high magnetic fields interact with the vestibular system of humans and rodents. In rats, exposure to high magnetic fields of 7 T or above induces locomotor circling and leads to a conditioned taste aversion if paired with a novel taste. Sex differences in the behavioral responses to magnetic field exposure have been found, such that female rats show more locomotor circling and enhanced conditioned taste aversion compared to male rats. To determine if estrogen modulates the neural response to high magnetic fields, c-Fos expression after 14 T magnetic field exposure was compared in ovariectomized rats and ovariectomized rats with estradiol replacement. Compared to sham exposure, magnetic field exposure induced significantly more c-Fos positive cells in the nucleus of the solitary tract and the parabrachial, medial vestibular, prepositus, and supragenualis nuclei. Furthermore, there was a significant asymmetry in c-Fos induction between sides of the brainstem in several regions. In ovariectomized rats, there was more c-Fos expressed in the right side compared to left side in the locus coeruleus and parabrachial, superior vestibular, and supragenualis nuclei; less expression in the right compared to left side of the medial vestibular; and no asymmetry in the prepositus nucleus and the nucleus of the solitary tract. Chronic estradiol treatment modulated the neural response in some regions: less c-Fos was induced in the superior vestibular nucleus and locus coeruleus after estradiol replacement; estradiol treatment eliminated the asymmetry of c-Fos expression in the locus coeruleus and supragenualis nucleus, created an asymmetry in the prepositus nucleus and reversed the asymmetry in the parabrachial nucleus. These results suggest that ovarian steroids may mediate sex differences in the behavioral responses to magnetic field exposure at the level of visceral and vestibular nuclei of the brainstem. Copyright 2010 Elsevier B.V. All rights

  10. Changes in Histamine Receptors (H1, H2, and H3 Expression in Rat Medial Vestibular Nucleus and Flocculus after Unilateral Labyrinthectomy: Histamine Receptors in Vestibular Compensation.

    Directory of Open Access Journals (Sweden)

    Liuqing Zhou

    Full Text Available Vestibular compensation is the process of behavioral recovery following peripheral vestibular lesion. In clinics, the histaminergic medicine is the most widely prescribed for the treatment of vertigo and motion sickness, however, the molecular mechanisms by which histamine modulates vestibular function remain unclear. During recovery from the lesion, the modulation of histamine receptors in the medial vestibular nucleus (MVN and the flocculus may play an important role. Here with the means of quantitative real-time PCR, western blotting and immunohistochemistry, we studied the expression of histamine receptors (H1, H2, and H3 in the bilateral MVN and the flocculus of rats on the 1st, 3rd, and 7th day following unilateral labyrinthectomy (UL. Our results have shown that on the ipsi-lesional flocculus the H1, H2 and H3 receptors mRNA and the protein increased significantly on the 1st and 3rd day, with compare of sham controls and as well the contralateral side of UL. However, on the 7th day after UL, this expression returned to basal levels. Furthermore, elevated mRNA and protein levels of H1, H2 and H3 receptors were observed in the ipsi-lesional MVN on the 1st day after UL compared with sham controls and as well the contralateral side of UL. However, this asymmetric expression was absent by the 3rd post-UL. Our findings suggest that the upregulation of histamine receptors in the MVN and the flocculus may contribute to rebalancing the spontaneous discharge in bilateral MVN neurons during vestibular compensation.

  11. Vestibular Restoration and Adaptation in Vestibular Neuritis and Ramsay Hunt Syndrome With Vertigo.

    Science.gov (United States)

    Martin-Sanz, Eduardo; Rueda, Almudena; Esteban-Sanchez, Jonathan; Yanes, Joaquin; Rey-Martinez, Jorge; Sanz-Fernandez, Ricardo

    2017-08-01

    To evaluate vestibular restoration and the evolution of the compensatory saccades in acute severe inflammatory vestibular nerve paralysis, including vestibular neuritis and Ramsay Hunt syndrome with vertigo. Prospective. Tertiary referral center. Vestibular neuritis (n = 18) and Ramsay Hunt syndrome patients with vertigo (n = 13) were enrolled. After treatment with oral corticosteroids, patients were followed up for 6 months. Functional recovery of the facial nerve was scored according to the House-Brackman grading system. Caloric and video head impulse tests were performed in every patient at the time of enrolment. Subsequently, successive video head impulse test (vHIT) exploration was performed at the 1, 3, and 6-month follow-up. Eighteen patients with vestibular neuritis and 13 with Ramsay Hunt syndrome and associated vertigo were included. Vestibular function was significantly worse in patients with Ramsay Hunt syndrome than in those with vestibular neuritis. Similar compensatory saccades velocity and latency values were observed in both groups, in both the caloric and initial vHIT tests. Successive vHIT results showed a significantly higher vestibulo-ocular reflex gain recovery in vestibular neuritis patients than in Ramsay Hunt syndrome patients. A significantly faster reduction in the latency, velocity, and organization of the compensatory saccades was observed in neuritis than in Ramsay Hunt syndrome patients. In addition to the recovery of the vestibulo-ocular reflex, the reduction of latency, velocity and the organization of compensatory saccades play a role in vestibular compensation.

  12. The decay of hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Wozniak, G.J.

    1988-11-01

    The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.

  13. Vestibular system and neural correlates of motion sickness

    Science.gov (United States)

    Miller, Alan D.

    1986-01-01

    Initial studies re-examine the role of certain central nervous system structures in the production of vestibular-induced vomiting and vomiting in general. All experiments were conducted using cats. Since these studies demonstrated that the essential role of various central structures in vestibular-induced vomiting is only poorly understood, efforts were re-directed to study the control of the effector muscles (diaphragm and abdominal muscles) that produce the pressure changes responsible for vomiting, with the goal of determining how this control mechanism is engaged during motion sickness. Experiments were conducted to localize the motoneurons that innervate the individual abdominal muscles and the portion of the diaphragm that surrounds the esophagus. A central question regarding respiratory muscle control during vomiting is whether these muscles are activated via the same brain stem pre-motor neurons that provide descending respiratory drive and/or by other descending input(s). In other experiments, the use of a combination of pitch and roll motions to produce motion sickness in unrestrained cats was evaluated. This stimulus combination can produce vomiting in only the most susceptible cats and is thus not as provacative a stimulus for cats as vertical linear acceleration.

  14. C-terminals in the mouse branchiomotor nuclei originate from the magnocellular reticular formation.

    Science.gov (United States)

    Matsui, Toshiyasu; Hongo, Yu; Haizuka, Yoshinori; Kaida, Kenichi; Matsumura, George; Martin, Donna M; Kobayashi, Yasushi

    2013-08-26

    Large cholinergic synaptic boutons called "C-terminals" contact motoneurons and regulate their excitability. C-terminals in the spinal somatic motor nuclei originate from cholinergic interneurons in laminae VII and X that express a transcription factor Pitx2. Cranial motor nuclei contain another type of motoneuron: branchiomotor neurons. Although branchiomotor neurons receive abundant C-terminal projections, the neural source of these C-terminals remains unknown. In the present study, we first examined whether cholinergic neurons express Pitx2 in the reticular formation of the adult mouse brainstem, as in the spinal cord. Although Pitx2-positive cholinergic neurons were observed in the magnocellular reticular formation and region around the central canal in the caudal medulla, none was present more rostrally in the brainstem tegmentum. We next explored the origin of C-terminals in the branchiomotor nuclei by using biotinylated dextran amine (BDA). BDA injections into the magnocellular reticular formation of the medulla and pons resulted in the labeling of numerous C-terminals in the branchiomotor nuclei: the ambiguous, facial, and trigeminal motor nuclei. Our results revealed that the origins of C-terminals in the branchiomotor nuclei are cholinergic neurons in the magnocellular reticular formation not only in the caudal medulla, but also at more rostral levels of the brainstem, which lacks Pitx2-positive neurons. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. PLCγ-activated signalling is essential for TrkB mediated sensory neuron structural plasticity

    Directory of Open Access Journals (Sweden)

    Rocha-Sanchez Sonia M

    2010-10-01

    Full Text Available Abstract Background The vestibular system provides the primary input of our sense of balance and spatial orientation. Dysfunction of the vestibular system can severely affect a person's quality of life. Therefore, understanding the molecular basis of vestibular neuron survival, maintenance, and innervation of the target sensory epithelia is fundamental. Results Here we report that a point mutation at the phospholipase Cγ (PLCγ docking site in the mouse neurotrophin tyrosine kinase receptor TrkB (Ntrk2 specifically impairs fiber guidance inside the vestibular sensory epithelia, but has limited effects on the survival of vestibular sensory neurons and growth of afferent processes toward the sensory epithelia. We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone guidance induced by brain-derived neurotrophic factor (BDNF, is altered in these animals. In addition, we find that absence of the PLCγ mediated TrkB signalling interferes with the transformation of bouton type afferent terminals of vestibular dendrites into calyces (the largest synaptic contact of dendrites known in the mammalian nervous system on type I vestibular hair cells; the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel KCNQ4 in these cells. Conclusions These results demonstrate a crucial involvement of the TrkB/PLCγ-mediated intracellular signalling in structural aspects of sensory neuron plasticity.

  16. Climbing fibers mediate vestibular modulation of both "complex" and "simple spikes" in Purkinje cells.

    Science.gov (United States)

    Barmack, N H; Yakhnitsa, V

    2015-10-01

    Climbing and mossy fibers comprise two distinct afferent paths to the cerebellum. Climbing fibers directly evoke a large multispiked action potential in Purkinje cells termed a "complex spike" (CS). By logical exclusion, the other class of Purkinje cell action potential, termed "simple spike" (SS), has often been attributed to activity conveyed by mossy fibers and relayed to Purkinje cells through granule cells. Here, we investigate the relative importance of climbing and mossy fiber pathways in modulating neuronal activity by recording extracellularly from Purkinje cells, as well as from mossy fiber terminals and interneurons in folia 8-10. Sinusoidal roll-tilt vestibular stimulation vigorously modulates the discharge of climbing and mossy fiber afferents, Purkinje cells, and interneurons in folia 9-10 in anesthetized mice. Roll-tilt onto the side ipsilateral to the recording site increases the discharge of both climbing fibers (CSs) and mossy fibers. However, the discharges of SSs decrease during ipsilateral roll-tilt. Unilateral microlesions of the beta nucleus (β-nucleus) of the inferior olive blocks vestibular modulation of both CSs and SSs in contralateral Purkinje cells. The blockage of SSs occurs even though primary and secondary vestibular mossy fibers remain intact. When mossy fiber afferents are damaged by a unilateral labyrinthectomy (UL), vestibular modulation of SSs in Purkinje cells ipsilateral to the UL remains intact. Two inhibitory interneurons, Golgi and stellate cells, could potentially contribute to climbing fiber-induced modulation of SSs. However, during sinusoidal roll-tilt, only stellate cells discharge appropriately out of phase with the discharge of SSs. Golgi cells discharge in phase with SSs. When the vestibularly modulated discharge is blocked by a microlesion of the inferior olive, the modulated discharge of CSs and SSs is also blocked. When the vestibular mossy fiber pathway is destroyed, vestibular modulation of ipsilateral CSs and

  17. Idiopathic scoliosis and the vestibular system

    National Research Council Canada - National Science Library

    Hawasli, Ammar H; Hullar, Timothy E; Dorward, Ian G

    2015-01-01

    ... in the etiology of scoliosis. In this article, we discuss putative mechanisms for adolescent idiopathic scoliosis and review the current evidence supporting a role for the vestibular system in adolescent idiopathic...

  18. Bubble nuclei; Noyaux Bulles

    Energy Technology Data Exchange (ETDEWEB)

    Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-07-22

    For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.

  19. Nuclei in Astrophysics

    Science.gov (United States)

    Penionzhkevich, Yu. E.

    2016-06-01

    This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclearphysics methods for studying cosmic objects and properties of the Universe. The results of investigations in nuclear reactions, induced by radioactive nuclear beams, make it possible to analyze the nucleosynthesis scenario in the region of light elements in a new manner.

  20. Recovery of vestibular ocular reflex function and balance control after a unilateral peripheral vestibular deficit.

    Directory of Open Access Journals (Sweden)

    John eAllum

    2012-05-01

    Full Text Available This review describes the effect of unilateral peripheral vestibular deficit (UPVD on balance control as observed in stance and gait tests. Normally, a UPVD is defined based on vestibular ocular reflex (VOR function. Therefore, we compare recovery observed in balance control over time with similar patterns of recovery or lack thereof in VOR function. Three types of UPVD are considered; acute vestibular neuritis, vestibular loss prior to and after cerebellar pontine angle tumor (CPAT surgery during which a vestibular neurectomy was performed, and vestibular loss following neurectomy to eliminate disabling Ménière’s disease.To measure balance control, body-worn gyroscopes, mounted near the body’s centre of mass, were used for stance and gait tests. Measurement variables were the pitch (anterior-posterior and roll (lateral sway angles and angular velocities of the lower trunk-pelvis. All three groups showed balance deficits during stance tasks on foam, especially with eyes closed when stable control is highly dependent on vestibular inputs. Deficits in balance control during gait were present but were more profound for complex gait tasks such as tandem gait. Differences emerged between the groups concerning the severity of the deficit and its recovery. Generally, the effects of acute neuritis were more severe but recovered rapidly, deficits due to vestibular neurectomy were less severe but longer lasting. These results paralleled deficits in VOR function and raise questions about two modes of neural plasticity occurring in the vestibular system following vestibular loss: one mode being the limited central compensation for the loss, and the second mode being some restoration of peripheral vestibular function. Future work will need to correlate deficits in balance control during stance and gait more exactly with VOR deficits and carefully consider the differences between insufficient central compensation compared to inadequate peripheral

  1. PROJECTIONS OF DORSAL AND MEDIAN RAPHE NUCLEI TO DORSAL AND VENTRAL STRIATUM

    Directory of Open Access Journals (Sweden)

    G. R. Hassanzadeh G. Behzadi

    2007-08-01

    Full Text Available The ascending serotonergic projections are derived mainly from mesencephalic raphe nuclei. Topographical projections from mesencephalic raphe nuclei to the striatum were examined in the rat by the retrograde transport technique of HRP (horseradish peroxidase. In 29 rats stereotaxically injection of HRP enzyme were performed in dorsal and ventral parts of striatum separately. The extent of the injection sites and distribution of retrogradely labeled neuronal cell bodies were drawed on representative sections using a projection microscope. Following ipsilateral injection of HRP into the dorsal striatum, numerous labeled neurons were seen in rostral portion of dorsal raphe (DR nucleus. In the same level the cluster of labeled neurons were hevier through caudal parts of DR. A few neurons were also located in lateral wing of DR. More caudally some labeled neurons were found in lateral, medial line of DR. In median raphe nucleus (MnR the labeled neurons were scattered only in median portion of this nucleus. The ipsilateral injection of HRP into the ventral region of striatum resulted on labeling of numerous neurons in rostral, caudal and lateral portions of DR. Through the caudal extension of DR on 4th ventricle level, a large number of labeled neurons were distributed along the ventrocaudal parts of DR. In MnR, labeled neurons were observed only in median part of this nucleus. These findings suggest the mesencephalic raphe nuclei projections to caudo-putamen are topographically organized. In addition dorsal and median raphe nuclei have a stronger projection to the ventral striatum.

  2. Idiopathic scoliosis and the vestibular system.

    Science.gov (United States)

    Hawasli, Ammar H; Hullar, Timothy E; Dorward, Ian G

    2015-02-01

    Despite its high prevalence, the etiology underlying idiopathic scoliosis remains unclear. Although initial scrutiny has focused on genetic, biochemical, biomechanical, nutritional and congenital causes, there is growing evidence that aberrations in the vestibular system may play a role in the etiology of scoliosis. In this article, we discuss putative mechanisms for adolescent idiopathic scoliosis and review the current evidence supporting a role for the vestibular system in adolescent idiopathic scoliosis. A comprehensive search of the English literature was performed using PubMed ( http://www.ncbi.nlm.nih.gov/pubmed ). Research articles studying interactions between adolescent idiopathic scoliosis and the vestibular system were selected and evaluated for inclusion in a literature review. Eighteen manuscripts of level 3-4 clinical evidence to support an association between adolescent idiopathic scoliosis (AIS) and dysfunction of the vestibular system were identified. These studies include data from physiologic and morphologic studies in humans. Clinical data are supported by animal model studies to suggest a causative link between the vestibular system and AIS. Clinical data and a limited number of animal model studies suggest a causative role of the vestibular system in AIS, although this association has not been reproduced in all studies.

  3. Current treatment options in vestibular migraine

    Directory of Open Access Journals (Sweden)

    Mark eObermann

    2014-12-01

    Full Text Available Approximately 1% of the general population in western industrialized countries suffers from vestibular migraine. However, it remains widely unknown and often under diagnosed even despite the recently published diagnostic criteria for vestibular migraine. Treatment trials that specialize on vestibular migraine are scarce and systematic randomized controlled clinical trials are only now emerging.This review summarizes the knowledge on the currently available treatment options that were tested specifically for vestibular migraine and gives an evidence-based, informed treatment recommendation with all its limitations.To date only two randomized controlled treatment trials provide limited evidence for the use of rizatriptan and zolmitriptan for the treatment of vestibular migraine attacks because of methodological shortcommings. There is an on-going a multicenter randomized placebo-controlled trial testing metoprolol 95 mg vs. placebo (PROVEMIG-trial. Therefore, the therapeutic recommendations for the prophylactic treatment of vestibular migraine are currently widely based on the guidelines of migraine with and without aura as well as expert opinion.

  4. Vestibular function assessment using the NIH Toolbox

    Science.gov (United States)

    Schubert, Michael C.; Whitney, Susan L.; Roberts, Dale; Redfern, Mark S.; Musolino, Mark C.; Roche, Jennica L.; Steed, Daniel P.; Corbin, Bree; Lin, Chia-Cheng; Marchetti, Greg F.; Beaumont, Jennifer; Carey, John P.; Shepard, Neil P.; Jacobson, Gary P.; Wrisley, Diane M.; Hoffman, Howard J.; Furman, Gabriel; Slotkin, Jerry

    2013-01-01

    Objective: Development of an easy to administer, low-cost test of vestibular function. Methods: Members of the NIH Toolbox Sensory Domain Vestibular, Vision, and Motor subdomain teams collaborated to identify 2 tests: 1) Dynamic Visual Acuity (DVA), and 2) the Balance Accelerometry Measure (BAM). Extensive work was completed to identify and develop appropriate software and hardware. More than 300 subjects between the ages of 3 and 85 years, with and without vestibular dysfunction, were recruited and tested. Currently accepted gold standard measures of static visual acuity, vestibular function, dynamic visual acuity, and balance were performed to determine validity. Repeat testing was performed to examine reliability. Results: The DVA and BAM tests are affordable and appropriate for use for individuals 3 through 85 years of age. The DVA had fair to good reliability (0.41–0.94) and sensitivity and specificity (50%–73%), depending on age and optotype chosen. The BAM test was moderately correlated with center of pressure (r = 0.42–0.48) and dynamic posturography (r = −0.48), depending on age and test condition. Both tests differentiated those with and without vestibular impairment and the young from the old. Each test was reliable. Conclusion: The newly created DVA test provides a valid measure of visual acuity with the head still and moving quickly. The novel BAM is a valid measure of balance. Both tests are sensitive to age-related changes and are able to screen for impairment of the vestibular system. PMID:23479540

  5. Vestibular function assessment using the NIH Toolbox.

    Science.gov (United States)

    Rine, Rosemarie M; Schubert, Michael C; Whitney, Susan L; Roberts, Dale; Redfern, Mark S; Musolino, Mark C; Roche, Jennica L; Steed, Daniel P; Corbin, Bree; Lin, Chia-Cheng; Marchetti, Greg F; Beaumont, Jennifer; Carey, John P; Shepard, Neil P; Jacobson, Gary P; Wrisley, Diane M; Hoffman, Howard J; Furman, Gabriel; Slotkin, Jerry

    2013-03-12

    Development of an easy to administer, low-cost test of vestibular function. Members of the NIH Toolbox Sensory Domain Vestibular, Vision, and Motor subdomain teams collaborated to identify 2 tests: 1) Dynamic Visual Acuity (DVA), and 2) the Balance Accelerometry Measure (BAM). Extensive work was completed to identify and develop appropriate software and hardware. More than 300 subjects between the ages of 3 and 85 years, with and without vestibular dysfunction, were recruited and tested. Currently accepted gold standard measures of static visual acuity, vestibular function, dynamic visual acuity, and balance were performed to determine validity. Repeat testing was performed to examine reliability. The DVA and BAM tests are affordable and appropriate for use for individuals 3 through 85 years of age. The DVA had fair to good reliability (0.41-0.94) and sensitivity and specificity (50%-73%), depending on age and optotype chosen. The BAM test was moderately correlated with center of pressure (r = 0.42-0.48) and dynamic posturography (r = -0.48), depending on age and test condition. Both tests differentiated those with and without vestibular impairment and the young from the old. Each test was reliable. The newly created DVA test provides a valid measure of visual acuity with the head still and moving quickly. The novel BAM is a valid measure of balance. Both tests are sensitive to age-related changes and are able to screen for impairment of the vestibular system.

  6. Unilateral Vestibular Loss Impairs External Space Representation

    Science.gov (United States)

    Borel, Liliane; Redon-Zouiteni, Christine; Cauvin, Pierre; Dumitrescu, Michel; Devèze, Arnaud; Magnan, Jacques; Péruch, Patrick

    2014-01-01

    The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss. PMID:24523916

  7. Unilateral vestibular loss impairs external space representation.

    Directory of Open Access Journals (Sweden)

    Liliane Borel

    Full Text Available The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal and far (extrapersonal spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation, and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

  8. Vestibular schwannoma: negative growth and audiovestibular features.

    Science.gov (United States)

    Stipkovits, E M; Graamans, K; Van Dijk, J E

    2001-11-01

    At the University Medical Center Utrecht, non-operative management was used for 44 patients with a unilateral vestibular schwannoma between 1990 and 1997. During that period, consecutive tumor sizes were determined by magnetic resonance imaging. Three of the 44 patients showed an average decrease in tumor size of 16.7% according to American Academy of Otolaryngology-Head and Neck Surgery standards. This study describes the initial vestibular status and audiometric changes measured over up to 10 years in these three patients. Vestibular function was determined once, by means of the bithermal caloric test, the torsion test, the saccade test, the smooth pursuit test, and the registration of spontaneous nystagmus. The three patients had severe vestibular paresis on the affected side. Pure-tone and speech audiometry were performed at regular intervals. Although the size of their tumors decreased, their hearing gradually deteriorated, just as it does in the majority of patients with a growing or stable vestibular schwannoma. The observations presented here suggest that the development of symptoms in a vestibular schwannoma does not differentiate between patients with a stable, growing or shrinking tumor. The development of symptoms may be the result of the same pathogenetic mechanism.

  9. The vestibular contribution to the head direction signal and navigation.

    Science.gov (United States)

    Yoder, Ryan M; Taube, Jeffrey S

    2014-01-01

    Spatial learning and navigation depend on neural representations of location and direction within the environment. These representations, encoded by place cells and head direction (HD) cells, respectively, are dominantly controlled by visual cues, but require input from the vestibular system. Vestibular signals play an important role in forming spatial representations in both visual and non-visual environments, but the details of this vestibular contribution are not fully understood. Here, we review the role of the vestibular system in generating various spatial signals in rodents, focusing primarily on HD cells. We also examine the vestibular system's role in navigation and the possible pathways by which vestibular information is conveyed to higher navigation centers.

  10. Top-down approach to vestibular compensation: translational lessons from vestibular rehabilitation

    Science.gov (United States)

    Balaban, Carey D.; Hoffer, Michael E.; Gottshall, Kim R.

    2012-01-01

    This review examines vestibular compensation and vestibular rehabilitation from a unified translational research perspective. Laboratory studies illustrate neurobiological principles of vestibular compensation at the molecular, cellular and systems levels in animal models that inform vestibular rehabilitation practice. However, basic research has been hampered by an emphasis on ‘naturalistic’ recovery, with time after insult and drug interventions as primary dependent variables. The vestibular rehabilitation literature, on the other hand, provides information on how the degree of compensation can be shaped by specific activity regimens. The milestones of the early spontaneous static compensation mark the re-establishment of static gaze stability, which provides a common coordinate frame for the brain to interpret residual vestibular information in the context of visual, somatosensory and visceral signals that convey gravitoinertial information. Stabilization of the head orientation and the eye orientation (suppression of spontaneous nystagmus) appear to be necessary by not sufficient conditions for successful rehabilitation, and define a baseline for initiating retraining. The lessons from vestibular rehabilitation in animal models offer the possibility of shaping the recovery trajectory to identify molecular and genetic factors that can improve vestibular compensation. PMID:22981400

  11. Clinical Evaluation of the Vestibular Nerve Using Vestibular Evoked Myogenic Potentials.

    Science.gov (United States)

    Bogle, Jamie M

    2018-01-01

    Vestibular evoked myogenic potentials are currently the most clinically accessible method to evaluate the otolith reflex pathways. These responses provide unique information regarding the status of the utriculo-ocular and sacculo-collic reflex pathways, information that has previously been unavailable. Vestibular evoked myogenic potentials are recorded from tonically contracted target muscles known to be innervated by these respective otolith organs. Diagnosticians can use vestibular evoked myogenic potentials to better evaluate the overall integrity of the inner ear and neural pathways; however, there are specific considerations for each otolith reflex protocol. In addition, specific patient populations may require protocol variations to better evaluate atypical function of the inner ear organs, vestibular nerve transmission, or subsequent reflex pathways. This is a review of the clinical application and interpretation of cervical and ocular vestibular evoked myogenic potentials.

  12. Vestibular-related frontal cortical areas and their roles in smooth-pursuit eye movements: representation of neck velocity, neck-vestibular interactions and memory-based smooth-pursuit

    Directory of Open Access Journals (Sweden)

    Kikuro eFukushima

    2011-12-01

    Full Text Available Smooth-pursuit eye movements are voluntary responses to small slow-moving objects in the fronto-parallel plane. They evolved in primates, who possess high-acuity foveae, to ensure clear vision about the moving target. The primate frontal cortex contains two smooth-pursuit related areas; the caudal part of the frontal eye fields (FEF and the supplementary eye fields (SEF. Both areas receive vestibular inputs. We review functional differences between the two areas in smooth-pursuit. Most FEF pursuit neurons signal pursuit parameters such as eye velocity and gaze-velocity, and are involved in cancelling the vestibulo-ocular reflex by linear addition of vestibular and smooth-pursuit responses. In contrast, gaze-velocity signals are rarely represented in the SEF. Most FEF pursuit neurons receive neck velocity inputs, while discharge modulation during pursuit and trunk-on-head rotation adds linearly. Linear addition also occurs between neck velocity responses and vestibular responses during head-on-trunk rotation in a task-dependent manner. During cross-axis pursuit-vestibular interactions, vestibular signals effectively initiate predictive pursuit eye movements. Most FEF pursuit neurons discharge during the interaction training after the onset of pursuit eye velocity, making their involvement unlikely in the initial stages of generating predictive pursuit. Comparison of representative signals in the two areas and the results of chemical inactivation during a memory-based smooth-pursuit task indicate they have different roles; the SEF plans smooth-pursuit including working memory of motion-direction, whereas the caudal FEF generates motor commands for pursuit eye movements. Patients with idiopathic Parkinson’s disease were asked to perform this task, since impaired smooth-pursuit and visual working memory deficit during cognitive tasks have been reported in most patients. Preliminary results suggested specific roles of the basal ganglia in memory

  13. Vestibular-related frontal cortical areas and their roles in smooth-pursuit eye movements: representation of neck velocity, neck-vestibular interactions, and memory-based smooth-pursuit.

    Science.gov (United States)

    Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo

    2011-01-01

    Smooth-pursuit eye movements are voluntary responses to small slow-moving objects in the fronto-parallel plane. They evolved in primates, who possess high-acuity foveae, to ensure clear vision about the moving target. The primate frontal cortex contains two smooth-pursuit related areas; the caudal part of the frontal eye fields (FEF) and the supplementary eye fields (SEF). Both areas receive vestibular inputs. We review functional differences between the two areas in smooth-pursuit. Most FEF pursuit neurons signal pursuit parameters such as eye velocity and gaze-velocity, and are involved in canceling the vestibulo-ocular reflex by linear addition of vestibular and smooth-pursuit responses. In contrast, gaze-velocity signals are rarely represented in the SEF. Most FEF pursuit neurons receive neck velocity inputs, while discharge modulation during pursuit and trunk-on-head rotation adds linearly. Linear addition also occurs between neck velocity responses and vestibular responses during head-on-trunk rotation in a task-dependent manner. During cross-axis pursuit-vestibular interactions, vestibular signals effectively initiate predictive pursuit eye movements. Most FEF pursuit neurons discharge during the interaction training after the onset of pursuit eye velocity, making their involvement unlikely in the initial stages of generating predictive pursuit. Comparison of representative signals in the two areas and the results of chemical inactivation during a memory-based smooth-pursuit task indicate they have different roles; the SEF plans smooth-pursuit including working memory of motion-direction, whereas the caudal FEF generates motor commands for pursuit eye movements. Patients with idiopathic Parkinson's disease were asked to perform this task, since impaired smooth-pursuit and visual working memory deficit during cognitive tasks have been reported in most patients. Preliminary results suggested specific roles of the basal ganglia in memory-based smooth-pursuit.

  14. The continuum in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Liotta, R.J. [Royal Inst. of Tech. Stockholm (Sweden). Dept. of Solid State Electronics

    1995-11-01

    The Green function formalism is used to extend the standard (shell-model) treatment of bound states to processes that occur in the continuum part of nuclear spectra. The Berggren and Mittag-Leffler expansions are introduced and analysed. Applications to single-particle and particle-hole resonances are performed. Giant resonances are studied within the framework of the continuum RPA. In all cases it is found that the expansions agree well with the exact calculation. The mechanisms that induce the clustering of nucleons in nuclei are analysed and the corresponding decay processes are discussed in detail. (orig.)

  15. Active galactic nuclei

    CERN Document Server

    Blandford, RD; Woltjer, L

    1990-01-01

    Starting with this volume, the Lecture Notes of the renowned Advanced Courses of the Swiss Society for Astrophysics and Astronomy will be published annually. In each course, three extensive lectures given by leading experts in their respective fields cover different and essential aspects of the subject. The 20th course, held at Les Diablerets in April 1990, dealt with current research on active galactic nuclei; it represents the most up-to-date views on the subject, presented with particular regard for clarity. The previous courses considered a wide variety of subjects, beginning with ""Theory

  16. Active galactic nuclei

    CERN Document Server

    Beckmann, Volker

    2012-01-01

    This AGN textbook includes phenomena based on new results in the X-Ray domain from new telescopes such as Chandra and XMM Newton not mentioned in any other book. Furthermore, it considers also the Fermi Gamma Ray Space Telescope with its revolutionary advances of unprecedented sensitivity, field of view and all-sky monitoring. Those and other new developments as well as simulations of AGN merging events and formations, enabled through latest super-computing capabilities. The book gives an overview on the current knowledge of the Active Galacitc Nuclei phenomenon. The spectral energy d

  17. Saturation in nuclei

    CERN Document Server

    Lappi, T

    2010-01-01

    This talk discusses some recent studies of gluon saturation in nuclei. We stress the connection between the initial condition in heavy ion collisions and observables in deep inelastic scattering (DIS). The dominant degree of freedom in the small x nuclear wavefunction is a nonperturbatively strong classical gluon field, which determines the initial condition for the glasma fields in the initial stages of a heavy ion collision. A correlator of Wilson lines from the same classical fields, known as the dipole cross section, can be used to compute many inclusive and exclusive observables in DIS.

  18. Click-evoked responses in vestibular afferents in rats

    National Research Council Canada - National Science Library

    Zhu, Hong; Tang, Xuehui; Wei, Wei; Mustain, William; Xu, Youguo; Zhou, Wu

    2011-01-01

    Sound activates not only the cochlea but also the vestibular end organs. Research on this phenomenon led to the discovery of the sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles...

  19. From ear to uncertainty: Vestibular contributions to cognitive function.

    OpenAIRE

    Paul eSmith; Yiwen eZheng

    2013-01-01

    In addition to the deficits in the vestibulo-ocular and vestibulo-spinal reflexes that occur following vestibular dysfunction, there is substantial evidence that vestibular loss also causes cognitive disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and neocortex play in spatial orientation. In this review we summarize the evidence that vestibular loss causes cognitive disorders, espe...

  20. Auditory and Vestibular Issues Related to Human Spaceflight

    Science.gov (United States)

    Danielson, Richard W.; Wood, Scott J.

    2009-01-01

    Human spaceflight provides unique opportunities to study human vestibular and auditory systems. This session will discuss 1) vestibular adaptive processes reflected by pronounced perceptual and motor coordination problems during, and after, space missions; 2) vestibular diagnostic and rehabilitative techniques (used to promote recovery after living in altered gravity environments) that may be relevant to treatment of vestibular disorders on earth; and 3) unique acoustical challenges to hearing loss prevention and crew performance during spaceflight missions.

  1. Interactive Healthcare Systems in the Home: Vestibular Rehabilitation

    DEFF Research Database (Denmark)

    Aarhus, Rikke; Grönvall, Erik; Larsen, Simon Bo

    2010-01-01

    Vestibular dysfunction is a balance disorder, causing dizziness that provokes discomfort and fall situations. This paper discusses early results from a project that aims to develop assistive technologies to support home-based rehabilitation for elderly affected by Vestibular dysfunction.......Vestibular dysfunction is a balance disorder, causing dizziness that provokes discomfort and fall situations. This paper discusses early results from a project that aims to develop assistive technologies to support home-based rehabilitation for elderly affected by Vestibular dysfunction....

  2. Task, muscle and frequency dependent vestibular control of posture

    OpenAIRE

    Forbes, Patrick A.; Gunter P Siegmund; Schouten, Alfred C.; Blouin, Jean-Sébastien

    2015-01-01

    The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in neck muscles they are maintained regardless of the requirement to maintain head on trunk balance. Recent investigations have also shown that the bandwid...

  3. Ascending vestibular drive is asymmetrically distributed to the inferior oblique motoneuron pools in a subset of hemispheric stroke survivors.

    Science.gov (United States)

    Miller, Derek M; Baker, James F; Rymer, W Zev

    2016-04-01

    Aberrant vestibular nuclear function is proposed to be a principle driver of limb muscle spasticity after stroke. Although spasticity does not manifest in ocular muscles, we sought to determine whether altered cortical modulation of ascending vestibuloocular pathways post-stroke could impact the excitability of ocular motoneurons. Nineteen chronic stroke survivors, aged 49-68 yrs. were enrolled. Vestibular evoked myogenic potentials (VEMPs) were recorded from the inferior oblique muscles of the eye using surface EMG electrodes. We assessed the impact of ascending otolith pathways on eye muscle activity and evaluated the relationship between otolith-ocular function and the severity of spasticity. VEMP responses were recorded bilaterally in 14/19 subjects. Response magnitude on the affected side was significantly larger than on the spared side. In a subset of subjects, there was a strong relationship between affected response amplitude and the severity of limb spasticity, as estimated using a standard clinical scale. This study suggests that alterations in ascending vestibular drive to ocular motoneurons contribute to post-stroke spasticity in a subset of spastic stroke subjects. We speculate this imbalance is a consequence of the unilateral disruption of inhibitory corticobulbar projections to the vestibular nuclei. This study potentially sheds light on the underlying mechanisms of post-stroke spasticity. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Longitudinal performance of an implantable vestibular prosthesis.

    Science.gov (United States)

    Phillips, Christopher; Ling, Leo; Oxford, Trey; Nowack, Amy; Nie, Kaibao; Rubinstein, Jay T; Phillips, James O

    2015-04-01

    Loss of vestibular function may be treatable with an implantable vestibular prosthesis that stimulates semicircular canal afferents with biphasic pulse trains. Several studies have demonstrated short-term activation of the vestibulo-ocular reflex (VOR) with electrical stimulation. Fewer long-term studies have been restricted to small numbers of animals and stimulation designed to produce adaptive changes in the electrically elicited response. This study is the first large consecutive series of implanted rhesus macaque to be studied longitudinally using brief stimuli designed to limit adaptive changes in response, so that the efficacy of electrical activation can be studied over time, across surgeries, canals and animals. The implantation of a vestibular prosthesis in animals with intact vestibular end organs produces variable responses to electrical stimulation across canals and animals, which change in threshold for electrical activation of eye movements and in elicited slow phase velocities over time. These thresholds are consistently lower, and the slow phase velocities higher, than those obtained in human subjects. The changes do not appear to be correlated with changes in electrode impedance. The variability in response suggests that empirically derived transfer functions may be required to optimize the response of individual canals to a vestibular prosthesis, and that this function may need to be remapped over time. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Complications of Microsurgery of Vestibular Schwannoma

    Directory of Open Access Journals (Sweden)

    Jan Betka

    2014-01-01

    Full Text Available Background. The aim of this study was to analyze complications of vestibular schwannoma (VS microsurgery. Material and Methods. A retrospective study was performed in 333 patients with unilateral vestibular schwannoma indicated for surgical treatment between January 1997 and December 2012. Postoperative complications were assessed immediately after VS surgery as well as during outpatient followup. Results. In all 333 patients microsurgical vestibular schwannoma (Koos grade 1: 12, grade 2: 34, grade 3: 62, and grade 4: 225 removal was performed. The main neurological complication was facial nerve dysfunction. The intermediate and poor function (HB III–VI was observed in 124 cases (45% immediately after surgery and in 104 cases (33% on the last followup. We encountered disordered vestibular compensation in 13%, permanent trigeminal nerve dysfunction in 1%, and transient lower cranial nerves (IX–XI deficit in 6%. Nonneurological complications included CSF leakage in 63% (lateral/medial variant: 99/1%, headache in 9%, and intracerebral hemorrhage in 5%. We did not encounter any case of meningitis. Conclusions. Our study demonstrates that despite the benefits of advanced high-tech equipment, refined microsurgical instruments, and highly developed neuroimaging technologies, there are still various and significant complications associated with vestibular schwannomas microsurgery.

  6. Visual dependency and dizziness after vestibular neuritis.

    Directory of Open Access Journals (Sweden)

    Sian Cousins

    Full Text Available Symptomatic recovery after acute vestibular neuritis (VN is variable, with around 50% of patients reporting long term vestibular symptoms; hence, it is essential to identify factors related to poor clinical outcome. Here we investigated whether excessive reliance on visual input for spatial orientation (visual dependence was associated with long term vestibular symptoms following acute VN. Twenty-eight patients with VN and 25 normal control subjects were included. Patients were enrolled at least 6 months after acute illness. Recovery status was not a criterion for study entry, allowing recruitment of patients with a full range of persistent symptoms. We measured visual dependence with a laptop-based Rod-and-Disk Test and severity of symptoms with the Dizziness Handicap Inventory (DHI. The third of patients showing the worst clinical outcomes (mean DHI score 36-80 had significantly greater visual dependence than normal subjects (6.35° error vs. 3.39° respectively, p = 0.03. Asymptomatic patients and those with minor residual symptoms did not differ from controls. Visual dependence was associated with high levels of persistent vestibular symptoms after acute VN. Over-reliance on visual information for spatial orientation is one characteristic of poorly recovered vestibular neuritis patients. The finding may be clinically useful given that visual dependence may be modified through rehabilitation desensitization techniques.

  7. Sensorial countermeasures for vestibular spatial disorientation.

    Science.gov (United States)

    Paillard, Aurore C; Quarck, Gaëlle; Denise, Pierre

    2014-05-01

    Spatial disorientation is defined as an erroneous body orientation perceived by pilots during flights. Limits of the vestibular system provoke frequent spatial disorientation mishaps. Although vestibular spatial disorientation is experienced frequently in aviation, there is no intuitive countermeasure against spatial disorientation mishaps to date. The aim of this review is to describe the current sensorial countermeasures and to examine future leads in sensorial ergonomics for vestibular spatial disorientation. This work reviews: 1) the visual ergonomics, 2) the vestibular countermeasures, 3) the auditory displays, 4) the somatosensory countermeasures, and, finally, 5) the multisensory displays. This review emphasizes the positive aspects of auditory and somatosensory countermeasures as well as multisensory devices. Even if some aspects such as sensory conflict and motion sickness need to be assessed, these countermeasures should be taken into consideration for ergonomics work in the future. However, a recent development in aviation might offer new and better perspectives: unmanned aerial vehicles. Unmanned aerial vehicles aim to go beyond the physiological boundaries of human sensorial systems and would allow for coping with spatial disorientation and motion sickness. Even if research is necessary to improve the interaction between machines and humans, this recent development might be incredibly useful for decreasing or even stopping vestibular spatial disorientation.

  8. A review of the interrelationship between vestibular dysfunction ...

    African Journals Online (AJOL)

    problems and dyslexia were also associated with dysfunction of the vestibular system. Different tests evaluating vestibular loss were identified of which some can be used successfully by practitionars. Various programmes and activities were identified to successfully rehabilitate vestibular function. For better understanding ...

  9. Origin of vestibular dysfunction in Usher syndrome type 1B.

    NARCIS (Netherlands)

    Sun, J.; Alphen, A.M. van; Wagenaar, M.; Huygen, P.L.M.; Hoogenraad, C.C.; Hasson, T.; Koekkoek, S.K.; Bohne, B.A.; Zeeuw, C.I. de

    2001-01-01

    It is still debated to what extent the vestibular deficits in Usher patients are due to either central vestibulocerebellar or peripheral vestibular problems. Here, we determined the origin of the vestibular symptoms in Usher 1B patients by subjecting them to compensatory eye movement tests and by

  10. [The research progress of large vestibular aqueduct syndrome].

    Science.gov (United States)

    Abulikemu, Yiming; Tang, Liang; Zhang, Jin

    2012-11-01

    Large vestibular aqueduct syndrome (LVAS) is one of common non-syndromic hearing disorders. With the rapid development of medical imaging, audiology, molecular biology, genetics, cochlear implant surgery, we have made remarkable achievements in the diagnosis and treatment of large vestibular aqueduct syndrome. This article reviewed related researches of the large vestibular aqueduct syndrome.

  11. Vestibular Schwannoma or acoustic neuroma

    Directory of Open Access Journals (Sweden)

    Hekmatara M

    1997-04-01

    Full Text Available Vestibular schwannoma is the most common tumor of the posterior fossa of the skull. Patients referred with the primary otologic symptoms such as hearing loss, tinnitus, vertigo, imbalance, and the cranial nerve palsy. Thirty-three patients were operated and treated by a team of otolaryngologist and neurosurgeon, anudiometrist, and internist. Patients'chiefcomplaint was due to 94% hearing loss and 27% tinnitus. They scarcely complain of vertigo. If a patient refers with the palsy or paralysis of facial nerve preoperation, we must think of the facial nerve schwannoma or hemangioma or congential cholestoma or malignant metastases rather than acoustic neuroma. The best way for preoperative diagnosis is audiometry, ABR (Auditory Brain Response, and SDS (speech discrimination score with 90% success, but computer Tomography (CT scan and MRI (Magnetic Resonance Image are the valuable anatomic diagnostic radiographic devices. The best method of operation is translabirynthine approach (TLA, since it has the advantages such as an easy access to nerve paths and being the nearest path to CPA (Cerebellopontine Angle. Physicians ought to talk to patients about the importance of the microscopic surgery, surgical methods, and their probable diverse effects such as hearing loss, facial nerve palsy, and intracranial problems.

  12. Can a finding of cervical vestibular evoked myogenic potentials contribute to vestibular migraine diagnostics?

    Directory of Open Access Journals (Sweden)

    Tihana Vešligaj

    2016-02-01

    Full Text Available Aim To investigate differences in vestibular evoked myogenic potentials (VEMP results with patients suffering from vestibular migraine and healthy people, taking into consideration values of threshold and latency of occurrence of the characteristic wave complex, size of amplitude, and interaural amplitude ratio. According to the results, determine the importance and usefulness of VEMP in vestibular migraine diagnostics. Methods A total number of 62 subjects were included in the study, 32 of them belonging to a group of patients suffering from vestibular migraine (VM, while other 30 were in a control group of healthy subjects. Information was collected during the diagnostic evaluation. General and otoneurological history of patients and bedside tests, audiological results, videonystagmography and cervical vestibular evoked myogenic potentials (cVEMP were made. Results There was a difference in an interaural ratio of amplitudes in the experimental and control groups, but it was not found to be clinically significant. By ToneBurst 500 Hz method, the interaural amplitude ratio higher than 35% was measured in 46.97% subjects, while the response was totally unilaterally missing in 28.8% patients. Conclusion Even the sophisticated method as cVEMP does not give the ultimate result confirming the vestibular migraine diagnosis, and neither do other diagnostic methods. cVEMP result can contribute to the completion of full mosaic of vestibular migraine diagnostics.

  13. Mutant mice reveal the molecular and cellular basis for specific sensory connections to inner ear epithelia and primary nuclei of the brain.

    Science.gov (United States)

    Fritzsch, Bernd; Pauley, Sarah; Matei, Veronica; Katz, David M; Xiang, Mengqing; Tessarollo, Lino

    2005-08-01

    We review the in vivo evidence for afferent fiber guidance to the inner ear sensory epithelia and the central nuclei of termination. Specifically, we highlight our current molecular understanding for the role of hair cells and sensory epithelia in guiding afferents, how disruption of certain signals can alter fiber pathways, even in the presence of normal hair cells, and what role neurotrophins play in fiber guidance of sensory neurons to hair cells. The data suggest that the neurotrophin BDNF is the most important molecule known for inner ear afferent fiber guidance to hair cells in vivo. This suggestion is based on experiments on Ntf3 transgenic mice expressing BDNF under Ntf3 promoter that show deviations of fiber growth in the ear to areas that express BDNF but have no hair cells. However, fiber growth can occur in the absence of BDNF as demonstrated by double mutants for BDNF and Bax. We directly tested the significance of hair cells or sensory epithelia for fiber guidance in mutants that lose hair cells (Pou4f3) or do not form a posterior crista (Fgf10). While these data emphasize the role played by BDNF, normally released from hair cells, there is some limited capacity for directed growth even in the absence of hair cells, BDNF, or sensory epithelia. This directed growth may rely on semaphorins or other matrix proteins because targeted ablation of the sema3 docking site on the sema receptor Npn1 results in targeting errors of fibers even in the presence of hair cells and BDNF. Overall, our data support the notion that targeting of the afferent processes in the ear is molecularly distinct from targeting processes in the central nuclei. This conclusion is derived from data that show no recognizable central projection deviation, even if fibers are massively rerouted in the periphery, as in Ntf3(tgBDNF) mice in which vestibular fibers project to the cochlea.

  14. Vestibular rehabilitation: useful but not universally so.

    Science.gov (United States)

    Krebs, David E; Gill-Body, Kathleen M; Parker, Stephen W; Ramirez, Jose V; Wernick-Robinson, Mara

    2003-02-01

    Although vestibular rehabilitation (VR) is gaining popularity, few data support its utility in improving locomotor stability, and no good predictors exist of whom will benefit most. A double-blind, placebo-controlled randomized trial of vestibular rehabilitation was conducted at a large tertiary care hospital on 124 patients (59 +/- 18 years old) with unilateral (n = 51) or bilateral (n = 73) vestibular hypofunction, of whom 86 completed a 12-week intervention. Of these 86, 27 returned for long-term (1-year) follow-up testing. The primary outcome measure was locomotor stability. Group A (6 weeks of VR) significantly (P VR; there were no group differences at 1 year. Of the 86 who completed the intervention, 52 (61%) had clear locomotor gains. VR is helpful for most patients in providing locomotor stability, but further work is needed to determine the factors that prevent VR from being effective for all patients with vestibulopathy.

  15. Eye Movements as Indicators of Vestibular Dysfunction.

    Science.gov (United States)

    Menshikova, Galina Ya; Kovalev, Artem I; Klimova, Oxana A; Chernorizov, Alexander M

    2015-01-01

    Virtual reality technologies are in wide use in sport psychology. An advantage of this kind of technology is the possibility to assess sportspeople's readiness to perform complex movements. This study is aimed at developing a method for the evaluation of vestibular function disturbances in young skaters. Such disturbances may occur while skaters are performing rotation movements. To achieve this goal, we induced a vection illusion, accompanied by virtual environment rotation in a CAVE virtual reality system. Vestibular disturbances were tested for two groups-professional skaters and people who had very little or no skating experience. The quantitative evaluation of vestibular dysfunction was based on eye movement characteristics, which were recorded in subjects experiencing a vection illusion. © The Author(s) 2015.

  16. [Effect of JNK signal transduction pathway in intense noise-induced apoptosis of vestibular hair cells in guinea pigs].

    Science.gov (United States)

    Wei, Ming; Wang, Wei-tao; Zhang, Tao; Tu, Ling; Liang, Ying-hong; Liu, Jia; Zhang, Jun-hua; Gong, Yan-jie

    2012-10-01

    To investigate the mechanism of intense noise-induced apoptosis of vestibular hair cells in guinea pigs and the effect of phosphorylated c-Jun N-terminal kinase (JNK) signal transduction pathway in intense noise-induced apoptosis of vestibular hair cells. Thirty-two guinea pigs were randomly and equally divided into 1, 5, and 15 d experimental groups and control group. The guinea pigs in the experimental groups were exposed to 4 kHz narrow-band noise at 120 dB SPL for 4 h and then subjected to measurement of auditory brainstem response at 1, 5, or 15 d after noise exposure. In each group, four guinea pigs were used to prepare paraffin sections of vestibular hair cells, and the rest for extraction of total protein from vestibular hair cells. The apoptosis of vestibular hair cells was detected by terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP nick-end labeling (TUNEL). The expression levels of p-JNK and pc-Jun were measured by immunohistochemistry and Western blot. TUNEL-positive cells were found in the vestibular hair cells in the experimental groups, most in the 1 d experimental group and least in the 15 d experimental group, but no positive cells were found in the control group. The immunohistochemical results showed that p-JNK and pc-Jun were detected in the cell nuclei in the experimental groups, but no p-JNK- and pc-Jun-positive cells were found in the control group. The Western blot showed that p-JNK and pc-Jun were increased and activated quickly at 1d after noise exposure, reached the peak levels at 5 d after noise exposure, and were then decreased gradually, but they were still at relatively high levels at 15 d after noise exposure. Intense noise can cause injury to vestibular hair cells by inducing cell apoptosis, and p-JNK marks the activation of JNK signal transduction pathway, suggesting that JNK signal transduction pathway plays an important role in intense noise-induced apoptosis of vestibular hair cells in guinea pigs.

  17. Vestibular rehabilitation following mild traumatic brain injury.

    Science.gov (United States)

    Gurley, James M; Hujsak, Bryan D; Kelly, Jennifer L

    2013-01-01

    Vertigo, dizziness, and imbalance are a symptom complex that is commonly found following concussion. Early metabolic changes following concussion may lead to worsening of the injury and symptoms in individuals not properly managed from the outset. When symptoms do not recover spontaneously, skilled vestibular rehabilitation can be an effective modality in an attempt to normalize the individual's vestibular responses. The purpose of this review is to appraise the current and accepted methods available to the skilled clinician in quantifying and treating vestibular dysfunction following concussion. Incidence and prognostic indicators will be reviewed along with common barriers to recovery. Vestibular Rehabilitation following concussion utilizes similar tools and techniques employed when treating those solely with peripheral pathology. The clinician must not only have a solid understanding of when and why certain exercises are required, but also be willing to accept that less exercise may be indicated in this population. As injury to the system following mild traumatic brain injury can include both peripheral and central structures, the duration of therapy and the time to recovery may be prolonged. Co-morbidities including cognitive and behavioral issues, visual-perceptual dysfunction, metabolic dysfunction, and autonomic dysfunction may hamper the effectiveness of the traditional Vestibular Rehabilitation approach. As successful treatment does not occur in a vacuum, working closely with other disciplines well versed in treating these co-morbid issues will help the individual to obtain optimal recovery. Vestibular Rehabilitation is an effective modality for managing dizziness, vertigo, and imbalance following concussion. Careful consideration of the acuity of the injury, along with effective management of co-morbid conditions will optimize the result.

  18. RECORDING OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

    Directory of Open Access Journals (Sweden)

    A. A. Sazgar

    2006-05-01

    Full Text Available It has been shown recently that loud clicks evoke myogenic potentials in the tonically contracting sternocleidomastoid muscles. Studies have suggested that these potentials are of vestibular origin, especially of the saccule and inferior vestibular nerve. A pilot study was undertaken in our hospital to record vestibular evoked myogenic potentials (VEMP for the first time in Iran. Eighteen healthy volunteers (32 ears without history of otologic or vestibular disorders were subjected to the VEMP test. Twenty-one patients (26 ears with unilateral (6 patients and bilateral (5 patients high frequency sensorineural hearing loss with unknown etiology, acoustic neuroma (1 patient, Meniere’s disease (4 patients and unilateral low frequency sensorineural hearing loss without vestibular complaint (5 patients were also enrolled in this study. VEMP response to clicks was obtained from 84.4% of ears of healthy subjects. These subjects demonstrated short latency waves to click stimuli during tonic neck flexor activation. Mean latencies of first positive (p13 and first negative (n23 potentials in healthy subjects were 12.45 ± 1.9 ms and 20.8 ± 3.5 ms, respectively. Median latencies of these two potentials were 12.1 and 19.3 ms, respectively. We could record VEMP in 5 patients with unilateral and all patients with high and low frequency sensorineural hearing loss without vestibular complaint. In the patient with acoustic neuroma VEMP was absent on the affected side. This technique may offer a new method to evaluate otolith and sacculocollic pathways in human.

  19. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors) 304 refs., 53 figs., 5 tabs.

  20. Calyx and dimorphic neurons of mouse Scarpa's ganglion express histamine H3 receptors

    Directory of Open Access Journals (Sweden)

    Zucca Gianpiero

    2009-06-01

    Full Text Available Abstract Background Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. The site of action of these drugs however has not been elucidated yet. Recent works on amphibians showed that histamine H3 receptor antagonists, e.g. betahistine, inhibit the afferent discharge recorded from the vestibular nerve. To assess the expression of H3 histamine receptors in vestibular neurons, we performed mRNA RT-PCR and immunofluorescence experiments in mouse Scarpa's ganglia. Results RT-PCR analysis showed the presence of H3 receptor mRNA in mouse ganglia tissue. H3 protein expression was found in vestibular neurons characterized by large and roundish soma, which labeled for calretinin and calbindin. Conclusion The present results are consistent with calyx and dimorphic, but not bouton, afferent vestibular neurons expressing H3 receptors. This study provides a molecular substrate for the effects of histamine-related antivertigo drugs acting on (or binding to H3 receptors, and suggest a potential target for the treatment of vestibular disorders of peripheral origin.

  1. Vestibular implants studied in animal models: clinical and scientific implications.

    Science.gov (United States)

    Lewis, Richard F

    2016-12-01

    Damage to the peripheral vestibular system can result in debilitating postural, perceptual, and visual symptoms. A potential new treatment for this clinical problem is to replace some aspects of peripheral vestibular function with an implant that senses head motion and provides this information to the brain by stimulating branches of the vestibular nerve. In this review I consider animal studies performed at our institution over the past 15 years, which have helped elucidate how the brain processes information provided by a vestibular (semicircular canal) implant and how this information could be used to improve the problems experienced by patients with peripheral vestibular damage. Copyright © 2016 the American Physiological Society.

  2. Patient with headache and peripheral vestibular dysfunction: case report

    OpenAIRE

    Rossi,Tatiane Maria; Luciano,Naonne Santos Camargo; Oricoli, Polliay Freire; Marchiori,Luciana Lozza de Moraes; Melo, Juliana Jandre

    2009-01-01

    TEMA: a Reabilitação Vestibular constitui-se numa opção de tratamento para pacientes portadores de síndrome vestibular periférica e cefaleia. PROCEDIMENTOS: o paciente, do sexo feminino com 26 anos de idade apresentava síndrome vestibular periférica acompanhada de crises de cefaleia. Foi realizada avaliação e terapia fonoaudiológica com exercícios de habituação vestibular além de fisioterapia e dieta recomendada pelo nutricionista. RESULTADOS: no período de 3 meses com reabilitação vestibular...

  3. Rotational alignment in soft nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nojarov, R. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Yadrena Fizika i Yadrena Energetika)

    1983-12-08

    It is shown that in transitional odd-A nuclei, where the rotation-aligned coupling scheme usually takes place, the low collective angular momentum states of the decoupled band are not completely aligned due to core softness. This is illustrated on the example of La-nuclei.

  4. Spectroscopy of heavy fissionable nuclei

    Indian Academy of Sciences (India)

    2015-08-05

    Aug 5, 2015 ... Structural studies of heavy nuclei are quite challenging due to increased competition from fission, particularly at high spins. Nuclei in the actinide region exhibit a variety of interesting phenomena. Recent advances in instrumentation and analysis techniques have made feasible sensitive measurements of ...

  5. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... determine the charge density distributions of short-lived exotic nuclei by elastic electron scattering. The first collision ... Electron scattering of highly unstable nuclei is not easy because it is difficult to produce ... both ends form a mirror potential to keep the ions longitudinally inside the SCRIT device, and the ...

  6. Effects of vestibular rehabilitation therapy on emotional aspects in chronic vestibular patients.

    Science.gov (United States)

    Meli, Annalisa; Zimatore, Giovanna; Badaracco, Carlo; De Angelis, Ezio; Tufarelli, Davide

    2007-08-01

    A strong relationship exists between vestibular dysfunction and anxiety disorders. The aim of this study was to assess the anxiety and depression levels in patients with chronic dizziness and to assess the effects of vestibular rehabilitation (VR) therapy, on the anxiety and depression levels, without a behavioural or pharmacological therapy. Two groups of 40 patients, each affected by chronic vestibular deficit, were studied. The first one underwent VR, and the latter did not. The psychometric tests used were the State-Trait Anxiety Inventory (STAI) and the Centre for Epidemiological Studies Depression Scale (CES-D). Psychological factors influence the level of handicap experienced by chronic dizziness patients, and disequilibrium influences the anxiety and depression levels. STAI and CES-D scales significantly decrease after VR therapy (PVR therapy positively influences the emotional condition of chronic vestibular deficit patients without pharmacological or psychotherapy treatments.

  7. From ear to uncertainty: Vestibular contributions to cognitive function.

    Directory of Open Access Journals (Sweden)

    Paul eSmith

    2013-11-01

    Full Text Available In addition to the deficits in the vestibulo-ocular and vestibulo-spinal reflexes that occur following vestibular dysfunction, there is substantial evidence that vestibular loss also causes cognitive disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and cortex play in spatial orientation. In this review we summarise the evidence that vestibular loss causes cognitive disorders, especially spatial memory deficits, in animals and humans and critically evaluate the evidence that these deficits are not due to hearing loss, problems with motor control, oscillopsia or anxiety and depression. We review the evidence that vestibular lesions affect head direction and place cells as well as the emerging evidence that artificial activation of the vestibular system, using galvanic vestibular stimulation, can modulate cognitive function.

  8. From ear to uncertainty: vestibular contributions to cognitive function.

    Science.gov (United States)

    Smith, Paul F; Zheng, Yiwen

    2013-11-26

    In addition to the deficits in the vestibulo-ocular and vestibulo-spinal reflexes that occur following vestibular dysfunction, there is substantial evidence that vestibular loss also causes cognitive disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and neocortex play in spatial orientation. In this review we summarize the evidence that vestibular loss causes cognitive disorders, especially spatial memory deficits, in animals and humans and critically evaluate the evidence that these deficits are not due to hearing loss, problems with motor control, oscillopsia or anxiety and depression. We review the evidence that vestibular lesions affect head direction and place cells as well as the emerging evidence that artificial activation of the vestibular system, using galvanic vestibular stimulation (GVS), can modulate cognitive function.

  9. Physiological principles of vestibular function on earth and in space

    Science.gov (United States)

    Minor, L. B.

    1998-01-01

    Physiological mechanisms underlying vestibular function have important implications for our ability to understand, predict, and modify balance processes during and after spaceflight. The microgravity environment of space provides many unique opportunities for studying the effects of changes in gravitoinertial force on structure and function of the vestibular system. Investigations of basic vestibular physiology and of changes in reflexes occurring as a consequence of exposure to microgravity have important implications for diagnosis and treatment of vestibular disorders in human beings. This report reviews physiological principles underlying control of vestibular processes on earth and in space. Information is presented from a functional perspective with emphasis on signals arising from labyrinthine receptors. Changes induced by microgravity in linear acceleration detected by the vestibulo-ocular reflexes. Alterations of the functional requirements for postural control in space are described. Areas of direct correlation between studies of vestibular reflexes in microgravity and vestibular disorders in human beings are discussed.

  10. Cavitation inception from bubble nuclei

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2015-01-01

    . The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model......The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years......, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid...

  11. Quarks in Few Body Nuclei

    Directory of Open Access Journals (Sweden)

    Holt Roy J.

    2016-01-01

    Full Text Available Electron scattering at very high Bjorken x from hadrons provides an excellent test of models, has an important role in high energy physics, and from nuclei, provides a window into short range correlations. Light nuclei have a key role because of the relatively well-known nuclear structure. The development of a novel tritium target for Jefferson Lab has led to renewed interest in the mass three system. For example, deep inelastic scattering experiments in the light nuclei provide a powerful means to determine the neutron structure function. The isospin dependence of electron scattering from mass-3 nuclei provide information on short range correlations in nuclei. The program using the new tritium target will be presented along with a summary of other experiments aimed at revealing the large-x structure of the nucleon.

  12. Inferior vestibular neuritis: 3 cases with clinical features of acute vestibular neuritis, normal calorics but indications of saccular failure

    Directory of Open Access Journals (Sweden)

    Økstad Siri

    2006-12-01

    Full Text Available Abstract Background Vestibular neuritis (VN is commonly diagnosed by demonstration of unilateral vestibular failure, as unilateral loss of caloric response. As this test reflects the function of the superior part of the vestibular nerve only, cases of pure inferior nerve neuritis will be lost. Case presentations We describe three patients with symptoms suggestive of VN, but normal calorics. All 3 had unilateral loss of vestibular evoked myogenic potential. A slight, asymptomatic position dependent nystagmus, with the pathological ear down, was observed. Conclusion We believe that these patients suffer from pure inferior nerve vestibular neuritis.

  13. Characterization of Neuronal Populations in the Human Trigeminal Ganglion and Their Association with Latent Herpes Simplex Virus-1 Infection

    OpenAIRE

    Flowerdew, Sarah E.; Desiree Wick; Susanne Himmelein; Anja K E Horn; Inga Sinicina; Michael Strupp; Thomas Brandt; Diethilde Theil; Katharina Hüfner

    2013-01-01

    Following primary infection Herpes simplex virus-1 (HSV-1) establishes lifelong latency in the neurons of human sensory ganglia. Upon reactivation HSV-1 can cause neurological diseases such as facial palsy, vestibular neuritis or encephalitis. Certain populations of sensory neurons have been shown to be more susceptible to latent infection in the animal model, but this has not been addressed in human tissue. In the present study, trigeminal ganglion (TG) neurons expressing six neuronal marker...

  14. Vestibular Dysfunctions in Cochlear Implant Patients; A Vestibular Evoked Myogenic Potential Study

    Directory of Open Access Journals (Sweden)

    Masoud Motasaddi Zarandy

    2011-12-01

    Full Text Available Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years and 30 normal hearing individuals (mean age 24-27 years as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48% from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

  15. Nitric oxide synthase and arginase expression in the vestibular nucleus and hippocampus following unilateral vestibular deafferentation in the rat.

    Science.gov (United States)

    Liu, Ping; Zheng, Yiwen; King, Jaimee; Darlington, Cynthia L; Smith, Paul F

    2003-03-14

    The aim of this study was to investigate the possible relationship between changes in neuronal and endothelial nitric oxide synthase (nNOS and eNOS) and arginase expression in the vestibular nucleus complex and the hippocampus (CA1, CA2/3 and the dentate gyrus (DG) at 10 h or 2 weeks following a unilateral vestibular deafferentation (UVD) in rats. There were no significant differences in nNOS or arginase II expression in the ipsilateral or contralateral VNC at either 10 h or 2 weeks post-UVD. For eNOS, there was only a significant decrease in expression in the ipsilateral VNC at 2 weeks post-UVD (P<0.01). In the hippocampus, the only significant difference in nNOS expression was a decrease in the ipsilateral DG at 2 weeks post-UVD (P<0.05). There was a significant decrease in eNOS expression in the contralateral CA2/3 region at 10 h post-UVD (P<0.01). The only other significant change in eNOS was an increase in the contralateral DG at 10 h post-UVD (P<0.01). Although arginase II was expressed in all regions of the hippocampus, there were no significant differences in arginase II expression at any time point following UVD. These results suggest that the changes in NOS expression that occur in the VNC and hippocampus following UVD are not correlated with one another or with changes in arginase II.

  16. Latent nystagmus: vestibular nystagmus with a twist.

    Science.gov (United States)

    Brodsky, Michael C; Tusa, Ronald J

    2004-02-01

    Latent nystagmus is a horizontal binocular oscillation that is evoked by unequal visual input to the 2 eyes. It develops primarily in humans with congenital esotropia. To investigate the interrelationship between latent and peripheral vestibular nystagmus and their corollary neuroanatomical pathways. Examination of subcortical neuroanatomical pathways producing latent nystagmus and review of the neurophysiological mechanisms by which they become activated in congenital esotropia. The vestibular nucleus presides over motion input from the eyes and labyrinths. Latent nystagmus corresponds to the optokinetic component of ocular rotation that is driven monocularly by nasal optic flow during a turning movement of the body in lateral-eyed animals. Congenital esotropia alters visual pathway development from the visual cortex to subcortical centers that project to the vestibular nucleus, allowing this primitive subcortical motion detection system to generate latent nystagmus under conditions of monocular fixation. Latent nystagmus is the ocular counterpart of peripheral vestibular nystagmus. Its clinical expression in humans proclaims the evolutionary function of the eyes as sensory balance organs.

  17. Vestibular migraine: clinical and epidemiological aspects

    Directory of Open Access Journals (Sweden)

    Ligia Oliveira Gonçalves Morganti

    Full Text Available ABSTRACT INTRODUCTION: Vestibular migraine (VM is one of the most often common diagnoses in neurotology, but only recently has been recognized as a disease. OBJECTIVE: To analyze the clinical and epidemiological profile of patients with VM. METHODS: This was a retrospective, observational, and descriptive study, with analysis of patients' records from an outpatient VM clinic. RESULTS: 94.1% of patients were females and 5.9% were males. The mean age was 46.1 years; 65.6% of patients had had headache for a longer period than dizziness. A correlation was detected between VM symptoms and the menstrual period. 61.53% of patients had auditory symptoms, with tinnitus the most common, although tonal audiometry was normal in 68.51%. Vectoelectronystagmography was normal in 67.34%, 10.20% had hyporeflexia, and 22.44% had vestibular hyperreflexia. Electrophysiological assessment showed no abnormalities in most patients. Fasting plasma glucose and glycemic curve were normal in most patients, while the insulin curve was abnormal in 75%. 82% of individuals with MV showed abnormalities on the metabolism of carbohydrates. CONCLUSION: VM affects predominantly middle-aged women, with migraine headache representing the first symptom, several years before vertigo. Physical, auditory, and vestibular evaluations are usually normal. The most frequent vestibular abnormality was hyperreflexia. Most individuals showed abnormality related to carbohydrate metabolism.

  18. New perspectives on vestibular evoked myogenic potentials.

    Science.gov (United States)

    Rosengren, Sally M; Kingma, Herman

    2013-02-01

    Although the vestibular evoked myogenic potential (VEMP) measured from the cervical muscles (cVEMP, cervical VEMP) is well described and has documented clinical utility, its analogue recorded from the extraocular muscles (oVEMP, ocular VEMP) has been described only recently and is currently emerging as an additional test of otolith function. This review will, therefore, summarize recent developments in VEMP research with a focus on the oVEMP. Recent studies suggest that the oVEMP is produced by otolith afferents in the superior vestibular nerve division, whereas the cVEMP evoked by sound is thought to be an inferior vestibular nerve reflex. Correspondingly, the oVEMP correlates better with caloric and subjective visual vertical tests than sound-cVEMPs. cVEMPs are more complicated than often thought, as shown by the presence of crossed responses and conflicting results of recent vibration studies. Altered inner ear mechanics produced by the vestibular diseases superior semicircular canal dehiscence and Ménière's disease lead to changes in the preferred frequency of the oVEMP and cVEMP. The oVEMP provides complementary diagnostic information to the cVEMP and is likely to be a useful addition to the diagnostic test battery in neuro-otology.

  19. Stereotactic radiation therapy for large vestibular schwannomas

    NARCIS (Netherlands)

    Mandl, Ellen S.; Meijer, Otto W. M.; Slotman, Ben J.; Vandertop, W. Peter; Peerdeman, Saskia M.

    2010-01-01

    Background and purpose: To evaluate the morbidity and tumor-control rate in the treatment of large vestibular schwannomas (VS) after stereotactic radiation therapy in our institution. Material and methods: Twenty-five consecutive patients (17 men, 8 women) with large VS (diameter 3.0 cm or larger),

  20. Parity violation in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, R.G.H.

    1980-01-01

    A summary of parity violating effects in nuclei is given. Thanks to vigorous experimental and theoretical effort, it now appears that a reasonably well-defined value for the weak isovector ..pi..-nucleon coupling constant can be obtained. There is one major uncertainty in the analysis, namely the M2/E1 mixing ratio for the 2.79 MeV transition in /sup 21/Ne. This quantity is virtually impossible to calculate reliably and must be measured. If it turns out to be much larger than 1, then a null result in /sup 21/Ne is expected no matter what the weak interaction, so an experimental determination is urgently needed. The most promising approach is perhaps a measurement of the pair internal conversion coefficient. Of course, a direct measurement of a pure isovector case is highly desirable, and it is to be hoped that the four ..delta..T = 1 experiments will be pushed still further, and that improved calculations will be made for the /sup 6/Li case. Nuclear parity violation seems to be rapidly approaching an interesting and useful synthesis.

  1. Gluon density in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

    1996-10-01

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

  2. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    1997-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author) 270 refs.

  3. Vestibular loss and balance training cause similar changes in human cerebral white matter fractional anisotropy.

    Directory of Open Access Journals (Sweden)

    Nadine Hummel

    Full Text Available Patients with bilateral vestibular loss suffer from severe balance deficits during normal everyday movements. Ballet dancers, figure skaters, or slackliners, in contrast, are extraordinarily well trained in maintaining balance for the extreme balance situations that they are exposed to. Both training and disease can lead to changes in the diffusion properties of white matter that are related to skill level or disease progression respectively. In this study, we used diffusion tensor imaging (DTI to compare white matter diffusivity between these two study groups and their age- and sex-matched controls. We found that vestibular patients and balance-trained subjects show a reduction of fractional anisotropy in similar white matter tracts, due to a relative increase in radial diffusivity (perpendicular to the main diffusion direction. Reduced fractional anisotropy was not only found in sensory and motor areas, but in a widespread network including long-range connections, limbic and association pathways. The reduced fractional anisotropy did not correlate with any cognitive, disease-related or skill-related factors. The similarity in FA between the two study groups, together with the absence of a relationship between skill or disease factors and white matter changes, suggests a common mechanism for these white matter differences. We propose that both study groups must exert increased effort to meet their respective usual balance requirements. Since balance training has been shown to effectively reduce the symptoms of vestibular failure, the changes in white matter shown here may represent a neuronal mechanism for rehabilitation.

  4. Swimming Behavior and Calcium Incorporation into inner Ear Otoliths of Fish after vestibular Nerve Transection

    Science.gov (United States)

    Edelmann, E.; Anken, R.; Rahmann, H.

    Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium-tracer alizarin- complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated: Like neonate swordtails, type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal and the otolithic calcium incorporation in controls of the same batch was symmetrical. In type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetrical. These results stongly suggest that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. Thus, it is assumed that the mechanisms regulating otolith growth and equlibibrium differ in the two types of cichlid fish. This work was financially supported by the German Aerospace Center (DLR) e.V. (FKZ: 50 WB 9997).

  5. Vestibular loss and balance training cause similar changes in human cerebral white matter fractional anisotropy.

    Science.gov (United States)

    Hummel, Nadine; Hüfner, Katharina; Stephan, Thomas; Linn, Jennifer; Kremmyda, Olympia; Brandt, Thomas; Flanagin, Virginia L

    2014-01-01

    Patients with bilateral vestibular loss suffer from severe balance deficits during normal everyday movements. Ballet dancers, figure skaters, or slackliners, in contrast, are extraordinarily well trained in maintaining balance for the extreme balance situations that they are exposed to. Both training and disease can lead to changes in the diffusion properties of white matter that are related to skill level or disease progression respectively. In this study, we used diffusion tensor imaging (DTI) to compare white matter diffusivity between these two study groups and their age- and sex-matched controls. We found that vestibular patients and balance-trained subjects show a reduction of fractional anisotropy in similar white matter tracts, due to a relative increase in radial diffusivity (perpendicular to the main diffusion direction). Reduced fractional anisotropy was not only found in sensory and motor areas, but in a widespread network including long-range connections, limbic and association pathways. The reduced fractional anisotropy did not correlate with any cognitive, disease-related or skill-related factors. The similarity in FA between the two study groups, together with the absence of a relationship between skill or disease factors and white matter changes, suggests a common mechanism for these white matter differences. We propose that both study groups must exert increased effort to meet their respective usual balance requirements. Since balance training has been shown to effectively reduce the symptoms of vestibular failure, the changes in white matter shown here may represent a neuronal mechanism for rehabilitation.

  6. Vestibular evaluation in children with otitis media with effusion.

    Science.gov (United States)

    Kolkaila, E A; Emara, A A; Gabr, T A

    2015-04-01

    Fifty per cent of children with serous otitis media may have some balance disturbances. To evaluate vestibular function in children with otitis media with effusion. The control group comprised 25 children with bilateral normal hearing and middle-ear function. The study group consisted of 30 children with bilateral otitis media with effusion; these were divided into 2 subgroups according to air-bone gap size. Measures included the Arabic Dizziness Handicap Inventory, an imbalance evaluation sheet for children, vestibular bedside tests for children, and air- and bone-conducted vestibular-evoked myogenic potential testing. Arabic Dizziness Handicap Inventory scores and some vestibular bedside test results were significantly abnormal, with normal video-nystagmography results, in children with otitis media with effusion. Air-conducted vestibular-evoked myogenic potentials were recorded in 73 per cent of children with otitis media with effusion, with significantly delayed latencies. Bone-conducted vestibular-evoked myogenic potentials were successfully detected in 100 per cent of children with otitis media with effusion with similar results to the control group. The Arabic Dizziness Handicap Inventory and vestibular bedside tests are valuable tools for detecting vestibular impairment in children. Bone-conducted vestibular-evoked myogenic potentials are useful for vestibular system evaluation.

  7. Adaptive changes in vergence eye movements induced by vergence-vestibular interaction training in monkeys.

    Science.gov (United States)

    Sato, Fumie; Akao, Teppei; Kurkin, Sergei; Fukushima, Junko; Fukushima, Kikuro

    2004-05-01

    Clear vision of objects moving in three-dimensional space near an observer is attained by a combination of smooth-pursuit and vergence eye movements. The two systems must interact with the vestibular system to maintain the image of the object on the fovea. Previous studies showed that training with smooth-pursuit vestibular interactions resulted in adaptive changes in the smooth-pursuit response. Although vergence and smooth-pursuit systems are thought to have separate neural substrates, recent studies indicate that the caudal parts of the frontal eye fields that receive vestibular inputs contain neurons that discharge in response to combinations of smooth-pursuit and vergence. This combination of discharge sensitivities suggests the possibility that adaptive changes may be induced in the vergence system by vestibular inputs during vergence-pursuit training. To explore this possibility, we examined the effects of training with conflicting vestibular and vergence tracking in four head-stabilized monkeys. Animals were rewarded for tracking a laser spot that moved towards or away from them at 1 Hz in phase with sinusoidal whole-body rotation (+/- 5 degrees) in the pitch plane; the spot moved closer when the monkey's nose moved downward. From the monkey's point of view, the spot moved sinusoidally 10-66 cm in front of them along the mid-sagittal plane, requiring symmetrical vergence eye movements of 4.8 degrees for each eye. Eye movements induced by equivalent spot motion at 0.3-1.0 Hz with or without chair rotation were examined before and after training for each session (0.5-1.0 h). Before training, pitch rotation alone in complete darkness did not induce vergence eye movements in any of the monkeys tested. Vergence tracking without chair rotation showed decreased gain and increased phase lag (re vergence target velocity) at frequencies above 0.5 Hz. After training, the vergence response during chair rotation with the spot showed significantly higher gains and

  8. Galvanic vestibular stimulation impairs cell proliferation and neurogenesis in the rat hippocampus but not spatial memory.

    Science.gov (United States)

    Zheng, Yiwen; Geddes, Lisa; Sato, Go; Stiles, Lucy; Darlington, Cynthia L; Smith, Paul F

    2014-05-01

    Galvanic vestibular stimulation (GVS) is a method of activating the peripheral vestibular system using direct current that is widely employed in clinical neurological testing. Since movement is recognized to stimulate hippocampal neurogenesis and movement is impossible without activation of the vestibular system, we speculated that activating the vestibular system in rats while minimizing movement, by delivering GVS under anesthesia, would affect hippocampal cell proliferation and neurogenesis, and spatial memory. Compared with the sham control group, the number of cells incorporating the DNA replication marker, bromodeoxyuridine (BrdU), was significantly reduced in the bilateral hippocampi in both the cathode left-anode right and cathode right-anode left stimulation groups (P ≤ 0.0001). The majority of the BrdU(+ve) cells co-expressed Ki-67, a marker for the S phase of the cell cycle, suggesting that these BrdU(+ve) cells were still in the cell cycle; however, there was no significant difference in the degree of co-labeling between the two stimulation groups. Single labeling for doublecortin (DCX), a marker of immature neurons, showed that while there was no significant difference between the different groups in the number of DCX(+ve) cells in the right dentate gryus, in the left dentate gyrus there was a significant decrease in the cathode left-anode right group compared with the sham controls (P ≤ 0.03). Nonetheless, when animals were tested in place recognition, object exploration and Morris water maze tasks, there were no significant differences between the GVS groups and the sham controls. These results suggest that GVS can have striking effects on cell proliferation and possibly neurogenesis in the hippocampus, without affecting spatial memory. Copyright © 2014 Wiley Periodicals, Inc.

  9. Exhibition of Stochastic Resonance in Vestibular Perception

    Science.gov (United States)

    Galvan-Garza, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Oman, C. M.; Mulavara, A. P.

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz

  10. Functional and anatomic alterations in the gentamicin-damaged vestibular system in the guinea pig

    NARCIS (Netherlands)

    Oei, MLYM; Segenhout, HM; Dijk, T; Stokroos, [No Value; van der Want, TJL; Albers, FWJ

    Hypothesis: The purpose of this study was to investigate the expected functional and morphologic effect of gentamicin on the vestibular system simultaneously by measurement of vestibular evoked potentials and electron microscopic evaluation. Background: Vestibular short-latency evoked potentials to

  11. Partonic Structure of Light Nuclei

    OpenAIRE

    Armstrong, Whitney; Arrington, John; Cloet, Ian; Hafidi, Kawtar; Hattawy, Mohammad; Potteveld, David; Reimer, Paul; Riordan, Seamus; Yi, Z.; Ball, Jacques; Defurne, Maxime; Garcon, Michel; Moutarde, Herve; Procureur, Sebastien; Sabatie, Franck

    2017-01-01

    We propose to study the partonic structure of $^4$He by measuring the Beam Spin Asymmetry (BSA) in coherent Deeply Virtual Compton Scattering (DVCS) and the differential cross-section of the Deeply Virtual Meson Production (DVMP) of the $\\phi$. Despite its simple structure, a light nucleus such as $^4$He has a density and a binding energy comparable to that of heavier nuclei. Therefore, by studying $^4$He nucleus, one can learn typical features of the partonic structure of atomic nuclei. The ...

  12. Clinical vestibular testing assessed with machine-learning algorithms.

    Science.gov (United States)

    Priesol, Adrian J; Cao, Mengfei; Brodley, Carla E; Lewis, Richard F

    2015-04-01

    Dizziness and imbalance are common clinical problems, and accurate diagnosis depends on determining whether damage is localized to the peripheral vestibular system. Vestibular testing guides this determination, but the accuracy of the different tests is not known. To determine how well each element of the vestibular test battery segregates patients with normal peripheral vestibular function from those with unilateral reductions in vestibular function. Retrospective analysis of vestibular test batteries in 8080 patients. Clinical medical records were reviewed for a subset of individuals with the reviewers blinded to the vestibular test data. A group of machine-learning classifiers were trained using vestibular test data from persons who were "manually" labeled as having normal vestibular function or unilateral vestibular damage based on a review of their medical records. The optimal trained classifier was then used to categorize patients whose diagnoses were unknown, allowing us to determine the information content of each element of the vestibular test battery. The information provided by each element of the vestibular test battery to segregate individuals with normal vestibular function from those with unilateral vestibular damage. The time constant calculated from the rotational test ranked first in information content, and measures that were related physiologically to the rotational time constant were 10 of the top 12 highest-ranked variables. The caloric canal paresis ranked eighth, and the other elements of the test battery provided minimal additional information. The sensitivity of the rotational time constant was 77.2%, and the sensitivity of the caloric canal paresis was 59.6%; the specificity of the rotational time constant was 89.0%, and the specificity of the caloric canal paresis was 64.9%. The diagnostic accuracy of the vestibular test battery increased from 72.4% to 93.4% when the data were analyzed with the optimal machine-learning classifier

  13. Understanding the links between vestibular and limbic systems regulating emotions.

    Science.gov (United States)

    Rajagopalan, Archana; Jinu, K V; Sailesh, Kumar Sai; Mishra, Soumya; Reddy, Udaya Kumar; Mukkadan, Joseph Kurien

    2017-01-01

    Vestibular system, which consists of structures in the inner ear and brainstem, plays a vital role is body balance and patient well-being. In recent years, modulating this system by vestibular stimulation techniques are reported to be effective in stress relief and possibly patient's emotional well-being. Emotions refer to an aroused state involving intense feeling, autonomic activation, and related change in behavior, which accompany many of our conscious experiences. The limbic system is primarily involved in the regulation of emotions. Considering the extensive networks between vestibular and limbic system, it is likely that vestibular stimulation techniques may be useful in influencing emotions. Hence, we review here, the possible mechanisms through which vestibular system can influence emotions and highlight the necessary knowledge gaps, which warrants further research to develop vestibular stimulation techniques as a means to treat health conditions associated with emotional disturbances.

  14. Anxiety changes depersonalization and derealization symptoms in vestibular patients.

    Science.gov (United States)

    Kolev, Ognyan I; Georgieva-Zhostova, Spaska O; Berthoz, Alain

    2014-01-01

    Depersonalization and derealization are common symptoms reported in the general population. Objective. The aim of the present study was to establish the relationship between anxiety and depersonalization and derealization symptoms in patients with peripheral vestibular disorders. Twenty-four vestibular patients with anxiety and 18 vestibular patients without anxiety were examined for depersonalization and derealization symptoms. They were also compared to healthy controls. The results revealed that anxiety consistently changes depersonalization and derealization symptoms in vestibular patients. They are more frequent, more severe, and qualitatively different in vestibular patients with anxiety than in those without anxiety. Anxiety has an effect on depersonalization and derealization symptoms in vestibular patients. The various hypotheses about the underlying mechanism of this effect were discussed.

  15. Bionic balance organs: progress in the development of vestibular prostheses.

    Science.gov (United States)

    Smith, Paul F

    2017-09-01

    The vestibular system is a sensory system that is critically important in humans for gaze and image stability as well as postural control. Patients with complete bilateral vestibular loss are severely disabled and experience a poor quality of life. There are very few effective treatment options for patients with no vestibular function. Over the last 10 years, rapid progress has been made in developing artificial 'vestibular implants' or 'prostheses', based on cochlear implant technology. As of 2017, 13 patients worldwide have received vestibular implants and the results are encouraging. Vestibular implants are now becoming part of an increasing effort to develop artificial, bionic sensory systems, and this paper provides a review of the progress in this area.

  16. Evaluation of postural control in unilateral vestibular hypofunction

    Directory of Open Access Journals (Sweden)

    Rafaela Maia Quitschal

    2014-07-01

    Full Text Available INTRODUCTION: Patients with vestibular hypofunction, a typical finding in peripheral vestibular disorders, show body balance alterations. OBJECTIVE: To evaluate the postural control of patients with vertigo and unilateral vestibular hypofunction. METHOD: This is a clinical cross-sectional study. Twenty-five patients with vertigo and unilateral vestibular hypofunction and a homogeneous control group consisting of 32 healthy individuals were submitted to a neurotological evaluation including the Tetrax Interactive Balance System posturography in eight different sensory conditions. RESULTS: For different positions, vertiginous patients with unilateral vestibular hypofunction showed significantly higher values of general stability index, weight distribution index, right/left and tool/heel synchronizations, Fourier transformation index and fall index than controls. CONCLUSION: Increased values in the indices of weight distribution, right/left and tool/heel synchronizations, Fourier transformation and fall risk characterize the impairment of postural control in patients with vertigo and unilateral vestibular hypofunction.

  17. Prediction in the Vestibular Control of Arm Movements.

    Science.gov (United States)

    Blouin, Jean; Bresciani, Jean-Pierre; Guillaud, Etienne; Simoneau, Martin

    2015-01-01

    The contribution of vestibular signals to motor control has been evidenced in postural, locomotor, and oculomotor studies. Here, we review studies showing that vestibular information also contributes to the control of arm movements during whole-body motion. The data reviewed suggest that vestibular information is used by the arm motor system to maintain the initial hand position or the planned hand trajectory unaltered during body motion. This requires integration of vestibular and cervical inputs to determine the trunk motion dynamics. These studies further suggest that the vestibular control of arm movement relies on rapid and efficient vestibulomotor transformations that cannot be considered automatic. We also reviewed evidence suggesting that the vestibular afferents can be used by the brain to predict and counteract body-rotation-induced torques (e.g., Coriolis) acting on the arm when reaching for a target while turning the trunk.

  18. The value of close monitoring in vestibular rehabilitation therapy.

    Science.gov (United States)

    Itani, M; Koaik, Y; Sabri, A

    2017-03-01

    Vestibular rehabilitation therapy is a well-established treatment modality for patients with vestibular problems. Performing vestibular rehabilitation therapy in a closely monitored setting may result in a better outcome than a home exercise programme. A retrospective study was conducted of patients undergoing vestibular rehabilitation therapy between June 2005 and November 2012 in a tertiary university hospital. The Dynamic Gait Index, the main outcome measure, was utilised before and after the rehabilitation programme. The magnitude of improvement for all patients was analysed, mainly to compare the home exercise group with the closely monitored therapy group. Only 32 patients underwent the vestibular rehabilitation therapy programme. In all patients, there was significant improvement in the mean Dynamic Gait Index score (from 11.75 to 17.38; p rehabilitation therapy resulted in improved performance status. More studies are needed to establish the efficiency of vestibular rehabilitation therapy and compare closely monitored therapy with tailored home exercise rehabilitation.

  19. Vestibular Aqueduct Midpoint Width and Hearing Loss in Patients With an Enlarged Vestibular Aqueduct.

    Science.gov (United States)

    Ascha, Mustafa S; Manzoor, Nauman; Gupta, Amit; Semaan, Maroun; Megerian, Cliff; Otteson, Todd D

    2017-06-01

    Elucidating the relationship between vestibular aqueduct size and hearing loss progression may inform the prognosis and counseling of patients who have an enlarged vestibular aqueduct (EVA). To examine the association between vestibular aqueduct size and repeated measures of hearing loss. For this retrospective medical record review, 52 patients with a diagnosis of hearing loss and radiologic diagnosis of EVA according to the Valvassori criterion were included. All available speech reception threshold and word recognition score data was retrieved; mixed-effects models were constructed where vestibular aqueduct size, age at diagnosis of hearing loss, and time since diagnosis of hearing loss were used to predict repeated measures of hearing ability. This study was performed at an academic tertiary care center. Variable vestibular aqueduct size, age at first audiogram, length of time after first audiogram. Speech reception threshold (dB) and word recognition score (%) during routine audiogram. Overall, 52 patients were identified (29 females [56%] and 23 males [44%]; median age at all recorded audiograms, 7.8 years) with a total of 74 ears affected by EVA. Median (range) vestibular aqueduct size was 2.15 (1.5-5.9) mm, and a median (range) of 5 (1-18) tests were available for each patient. Each millimeter increase in vestibular aqueduct size above 1.5 mm was associated with an increase of 17.5 dB in speech reception threshold (95% CI, 7.2 to 27.9 dB) and a decrease of 21% in word recognition score (95% CI, -33.3 to -8.0 dB). For each extra year after a patient's first audiogram, there was an increase of 1.5 dB in speech recognition threshold (95% CI, 0.22 to 3.0 dB) and a decrease of 1.7% in word recognition score (95% CI, -3.08 to -0.22 dB). Hearing loss in patients with an EVA is likely influenced by vestibular aqueduct midpoint width. When considering hearing loss prognosis, vestibular aqueduct midpoint width may be useful for the clinician who counsels patients

  20. Interactions between Stress and Vestibular Compensation – A Review

    OpenAIRE

    Saman, Yougan; Bamiou, D. E.; Gleeson, Michael; Dutia, Mayank B

    2012-01-01

    Elevated levels of stress and anxiety often accompany vestibular dysfunction, while conversely complaints of dizziness and loss of balance are common in patients with panic and other anxiety disorders. The interactions between stress and vestibular function have been investigated both in animal models and in clinical studies. Evidence from animal studies indicates that vestibular symptoms are effective in activating the stress axis, and that the acute stress response is important in promoting...

  1. Static Balance in Patients with Vestibular Impairments: A Preliminary Study

    OpenAIRE

    Hossein Talebi; Mohammad Taghi Karimi; Seyed Hamid Reza Abtahi; Niloofar Fereshtenejad

    2016-01-01

    Aims. Vestibular system is indicated as one of the most important sensors responsible for static and dynamic postural control. In this study, we evaluated static balance in patients with unilateral vestibular impairments. Materials and Methods. We compared static balance control using Kistler force plate platform between 10 patients with unilateral vestibular impairments and 20 normal counterparts in the same sex ratio and age limits (50 ? 7). We evaluated excursion and velocity of center of ...

  2. Anxiety Changes Depersonalization and Derealization Symptoms in Vestibular Patients

    OpenAIRE

    Kolev, Ognyan I.; Georgieva-Zhostova, Spaska O.; Alain Berthoz

    2014-01-01

    Background. Depersonalization and derealization are common symptoms reported in the general population. Objective. The aim of the present study was to establish the relationship between anxiety and depersonalization and derealization symptoms in patients with peripheral vestibular disorders. Methods. Twenty-four vestibular patients with anxiety and 18 vestibular patients without anxiety were examined for depersonalization and derealization symptoms. They were also compared to healthy controls...

  3. Responses evoked by a vestibular implant providing chronic stimulation

    OpenAIRE

    Thompson L.A.; Haburcakova C.; Gong W; Lee D.J.; Wall Iii C.; Merfeld D.M.; Lewis R.F.

    2012-01-01

    Patients with bilateral vestibular loss experience dehabilitating visual, perceptual, and postural difficulties, and an implantable vestibular prosthesis that could improve these symptoms would be of great benefit to these patients. In previous work, we have shown that a one-dimensional, unilateral canal prosthesis can improve the vestibulooccular reflex (VOR) in canal-plugged squirrel monkeys. In addition to the VOR, the potential effects of a vestibular prosthesis on more complex, highly in...

  4. The Moving History of Vestibular Stimulation as a Therapeutic Intervention

    OpenAIRE

    Grabherr, Luzia; Lenggenhager, Bigna; Macauda, Gianluca

    2015-01-01

    Although the discovery and understanding of the function of the vestibular system date back only to the 19th century, strategies that involve vestibular stimulation were used long before to calm, soothe and even cure people. While such stimulation was classically achieved with various motion devices, like Cox’s chair or Hallaran’s swing, the development of caloric and galvanic vestibular stimulation has opened up new possibilities in the 20th century. With the increasing knowledge and recogni...

  5. Vestibular stimulation: A simple but effective intervention in diabetes care

    OpenAIRE

    Sailesh, Kumar Sai; Archana, R.; Mukkadan, J. K.

    2015-01-01

    Despite the complexities of the relationship between vestibular stimulation and endocrine disorders being well known, research efforts to understand these complexities are lacking. Interestingly vestibular stimulation may potentially prevent/delay development/progression of diabetes. Here we review the science behind this concept and highlight the need for necessary translational research in this area. Current evidence supports the use of vestibular stimulation not only as a potential interve...

  6. Virtual vestibular re-education. A new technology.

    Science.gov (United States)

    Boniver, R

    2006-01-01

    This paper will provide an introduction to the use of virtual environments for vestibular re-education. The author illustrates some of the ways in which researchers are using virtual reality to improve therapy for vertigo. Users of virtual reality must make adaptations to avoid mismatches between perception due to virtual reality and that due to vestibular and proprioceptive subsystems. Virtual reality may be an interesting new way of studying vestibular compensation in normal and pathological conditions.

  7. Nitric oxide synthase and arginase expression changes in the rat perirhinal and entorhinal cortices following unilateral vestibular damage: a link to deficits in object recognition?

    Science.gov (United States)

    Liu, Ping; Gliddon, Catherine M; Lindsay, Libby; Darlington, Cynthia L; Smith, Paul F

    2004-01-01

    Previous studies have shown that peripheral vestibular damage causes long-term neurochemical changes in the hippocampus which may be related to spatial memory deficits. Since recent studies have also demonstrated deficits in non-spatial object recognition memory following vestibular lesions, the aim of the present study was to extend these investigations into the perirhinal cortex (PRC), which is known to be important for object recognition, and the related entorhinal cortex (EC). We examined the effects of unilateral vestibular deafferentation (UVD) on the expression of four enzymes associated with neuronal plasticity, neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), arginase I and arginase II (AI and II), in the rat EC and PRC using Western blotting. Tissue was collected at 10 hs, 50 hs and 2 weeks post-UVD. In the EC and PRC, nNOS protein expression decreased on the contralateral side at 2 weeks post-UVD but not before. At the same time, eNOS protein expression increased in both regions on the contralateral side. In the EC, AII protein expression increased on the ipsilateral side at 2 weeks post-UVD. In the PRC, AI increased and decreased on the contralateral and ipsilateral sides (respectively) at 2 weeks post-UVD. AII showed a bilateral increase in the PRC at 2 weeks post-UVD. These results demonstrate changes in NOS and arginase protein expression in the PRC and EC following UVD, which are unlikely to be due to the initial severity of the vestibular syndrome because they develop well after vestibular compensation has taken place. Neurochemical changes in these regions of the medial temporal lobe may be implicated in the development of object recognition deficits that contribute to cognitive dysfunction following peripheral vestibular damage.

  8. The vestibular system: balancing more than just the body.

    Science.gov (United States)

    Lopez, Christophe

    2016-02-01

    The review presents a selection of recent studies in the field of vestibular neuroscience, including how vestibular stimulation modulates space and body perception. Recent neuroimaging studies identified the operculo-insular/retroinsular cortex as the core vestibular cortex and showed how it is reorganized after vestibular dysfunctions. Subliminal galvanic vestibular stimulation (GVS) induces long-term reduction of hemispatial neglect and improves vertical perception in stroke patients, but the underlying mechanisms remain to be identified. Healthy volunteer research suggests that GVS and caloric vestibular stimulation (CVS) modulate visual and somatosensory processing and that beneficial effects of GVS/CVS in stroke patients are not limited to merely rebalancing brain hemispheric activity. Another mechanism would be that GVS/CVS anchors the self to the body, thus promoting an egocentric frame of reference. In addition to 'balancing the body', the vestibular cortical network contributes to modulate space, body and self-awareness. Emerging evidence suggests that the vestibular network expands into dimensions of emotion processing, mental health, and social cognition. Here, the importance of connecting vestibular physiology, affective neuroscience, and social neuroscience to better understand the psychological aspects of vertigo in otoneurology is discussed.

  9. Task, muscle and frequency dependent vestibular control of posture

    Directory of Open Access Journals (Sweden)

    Patrick A Forbes

    2015-01-01

    Full Text Available The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in neck muscles they are maintained regardless of the requirement to maintain head on trunk balance. Recent investigations have also shown that the bandwidth of vestibular input on neck muscles is much broader than appendicular muscles (up to a factor of 3. This result challenges the notion that vestibular reflexes only contribute to postural control across the behavioral and physiological frequency range of the vestibular organ (i.e., 0-20 Hz. In this review, we explore and integrate these task-, muscle- and frequency-related differences in the vestibular system’s contribution to posture, and propose that the human nervous system has adapted vestibular signals to match the mechanical properties of the system that each group of muscles controls.

  10. Task, muscle and frequency dependent vestibular control of posture.

    Science.gov (United States)

    Forbes, Patrick A; Siegmund, Gunter P; Schouten, Alfred C; Blouin, Jean-Sébastien

    2014-01-01

    The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in neck muscles they are maintained regardless of the requirement to maintain head on trunk balance. Recent investigations have also shown that the bandwidth of vestibular input on neck muscles is much broader than appendicular muscles (up to a factor of 3). This result challenges the notion that vestibular reflexes only contribute to postural control across the behavioral and physiological frequency range of the vestibular organ (i.e., 0-20 Hz). In this review, we explore and integrate these task-, muscle- and frequency-related differences in the vestibular system's contribution to posture, and propose that the human nervous system has adapted vestibular signals to match the mechanical properties of the system that each group of muscles controls.

  11. The History and Evolution of Surgery on the Vestibular Labyrinth.

    Science.gov (United States)

    Naples, James G; Eisen, Marc D

    2016-11-01

    The history of surgery on the vestibular labyrinth is rich but sparsely documented in the literature. The story begins over a century ago with the labyrinthectomy in an era that consisted exclusively of ablative surgery for infection or vertigo. Improved understanding of vestibular physiology and pathology produced an era of selective ablation and hearing preservation that includes semicircular canal occlusion for benign paroxysmal positional vertigo. An era of restoration began with a discovery of superior semicircular canal dehiscence and its repair. The final era of vestibular replacement is upon us as the possibility of successful prosthetic vestibular implantation becomes reality. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  12. Bedside examination for vestibular screening in occupational medicine

    Directory of Open Access Journals (Sweden)

    Ewa Zamysłowska-Szmytke

    2015-04-01

    Full Text Available Objectives: The aim of the study was to assess the usefulness of bedside examination for screening of vestibular and balance system for occupational medicine purposes. Study group comprised 165 patients referred to Audiology and Phoniatric Clinic due to vestibular and/or balance problems. Caloric canal paresis of 19% was the cut off value to divide patients into 43 caloric-positive vestibular subjects and 122 caloric-negative patients. The latter group comprised 79 subjects revealing abnormalities of videonystagmographic (VNG oculomotor tests (central group and 43 subjects with normal VNG. Material and Methods: Vestibular and balance symptoms were collected. Five tests were included to bedside examination: Romberg and Unterberger tests, Head Impulse Test (HIT, Dynamic Visual Acuity (DVA and gaze nystagmus assessment. Results: Vestibular and balance symptoms were reported by 82% of vestibular, 73% of central and 40% of VNG-normal patients. Thirteen out of 18 VNG-normal but symptomatic subjects (73% had abnormal tests in clinical assessment. The sensitivity of bedside test set for vestibular pathology was 88% as compared to caloric test and 68% for central pathology as compared to VNG oculomotor tests. Conclusions: The combination of 5 bedside tests reveal satisfactory sensitivity to detect vestibular abnormalities. Bedside examination abnormalities are highly correlated with vestibular/balance symptoms, regardless the normal results of VNG. Thus, this method should be recommended for occupational medicine purposes.

  13. Bedside examination for vestibular screening in occupational medicine.

    Science.gov (United States)

    Zamysłowska-Szmytke, Ewa; Szostek-Rogula, Sylwia; Śliwińska-Kowalska, Mariola

    2015-01-01

    The aim of the study was to assess the usefulness of bedside examination for screening of vestibular and balance system for occupational medicine purposes. Study group comprised 165 patients referred to Audiology and Phoniatric Clinic due to vestibular and/or balance problems. Caloric canal paresis of 19% was the cut off value to divide patients into 43 caloric-positive vestibular subjects and 122 caloric-negative patients. The latter group comprised 79 subjects revealing abnormalities of videonystagmographic (VNG) oculomotor tests (central group) and 43 subjects with normal VNG. Vestibular and balance symptoms were collected. Five tests were included to bedside examination: Romberg and Unterberger tests, Head Impulse Test (HIT), Dynamic Visual Acuity (DVA) and gaze nystagmus assessment. Vestibular and balance symptoms were reported by 82% of vestibular, 73% of central and 40% of VNG-normal patients. Thirteen out of 18 VNG-normal but symptomatic subjects (73%) had abnormal tests in clinical assessment. The sensitivity of bedside test set for vestibular pathology was 88% as compared to caloric test and 68% for central pathology as compared to VNG oculomotor tests. The combination of 5 bedside tests reveal satisfactory sensitivity to detect vestibular abnormalities. Bedside examination abnormalities are highly correlated with vestibular/balance symptoms, regardless the normal results of VNG. Thus, this method should be recommended for occupational medicine purposes. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  14. Periosteal Pedicle Flap Harvested during Vestibular Extension for Root Coverage

    Directory of Open Access Journals (Sweden)

    Shubham Kumar

    2015-01-01

    Full Text Available Root exposure along with inadequate vestibular depth is a common clinical finding. Treatment option includes many techniques to treat such defects for obtaining predictable root coverage. Normally, the vestibular depth is increased first followed by a second surgery for root coverage. The present case report describes a single-stage technique for vestibular extension and root coverage in a single tooth by using the Periosteal Pedicle Flap (PPF. This technique involves no donor site morbidity and allows for reflection of sufficient amount of periosteal flap tissue with its own blood supply at the surgical site, thus increasing the chances of success of root coverage with simultaneous increase in vestibular depth.

  15. Gentamicin perfusion vestibular response and hearing loss.

    Science.gov (United States)

    Light, Joshua P; Silverstein, Herbert; Jackson, Lance E

    2003-03-01

    To compare hearing results as a function of vestibular ablation in the treatment of Ménière's Disease, using gentamicin perfusion. A retrospective review of patients with Ménière's Disease treated by gentamicin perfusion of the inner ear via the MicroWick device. A tertiary otologic referral center. The charts of patients treated with gentamicin perfusion via the MicroWick between the years 1998 and 2000 were reviewed. The results for patients with functional hearing in the affected ear were analyzed and were compared with the results in patients without functional hearing. Audiologic and vestibular test results as well as subjective symptoms. There were 45 patients who met the inclusion criteria. The averages for speech discrimination score and pure tone average before treatment were 92% and 38 dB, and after treatment were 82% and 47 dB. Patients were divided into two groups: Group 1 (20 patients), less than 75% ice air caloric reduced vestibular response (RVR); Group 2 (25 patients), those who reached greater than 75% ice air caloric RVR. There were 8 patients (17.6%) with persistent vertigo; 7 were from Group 1, and 1 was from Group 2, which was statistically significant (p = 0.007)wwww. The pure tone average dropped an average of 3 dB for Group 1 and 15 dB for Group 2. The difference in hearing loss between the two groups was statistically significant (p = 0.01). This study suggests that there is a correlation between the degree of vestibular ablation, the control of vertigo, and the risk of hearing loss. Patients with functional hearing seem to have a similar success rate for vertigo control, compared with patients who already had lost functional hearing before treatment. Future investigation may determine if less than 100% RVR, but greater than 75% RVR, is an alternative end point with adequate vertigo control and reduced risk of hearing loss.

  16. Evidence for neuronal localisation of enteroviral sequences in motor neurone disease/amyotrophic lateral sclerosis by in situ hybridization.

    Science.gov (United States)

    Woodall, C J; Graham, D I

    2004-01-01

    Sequences resembling those of human enterovirus type B sequences have been associated with motor neurone disease/amyotrophic lateral sclerosis. In a previous study we detected enteroviral sequences in spinal cord/brain stem from cases of motor neurone disease/amyotrophic lateral sclerosis, but not controls. Adjacent tissue sections to two of those strongly positive for these sequences by reverse-transcriptase polymerase chain reaction were analyzed by in situ hybridization with digoxigenin-labelled virus-specific antisense riboprobes. In one case, a female aged 83 showing 12 month rapid progressive disease, signal was specifically localized to cells identifiable as motor neurones of the anterior horn. In another case, a male aged 63 with a 60-month history of progressive muscle weakness, dysarthia, dyspnoea and increased tendon reflexes, signal was located to neurones in the gracile/cuneate nuclei of the brain stem tissue block that had been analyzed. This case showed loss of neurones in the anterior horn of the spinal cord by histopathologic examination which would account for clinical signs of motor neurone disease/amyotrophic lateral sclerosis. Dysfunction of the gracile/cuneate nuclei might have been masked by the paralytic disease. These structures are adjacent to the hypoglossal nuclei, and suggest either localised dissemination from hypoglossal nuclei or a possible route of dissemination of infection through the brainstem to the hypoglossal nuclei. These findings provide further evidence for the possible involvement of enteroviruses in motor neurone disease/amyotrophic lateral sclerosis.

  17. Evidence for neuronal localisation of enteroviral sequences in motor neurone disease/amyotrophic lateral sclerosis by in situ hybridization

    Directory of Open Access Journals (Sweden)

    CJ Woodall

    2009-06-01

    Full Text Available Sequences resembling those of human enterovirus type B sequences have been associated with motor neurone disease/ amyotrophic lateral sclerosis. In a previous study we detected enteroviral sequences in spinal cord/brain stem from cases of motor neurone disease/amyotrophic lateral sclerosis, but not controls. Adjacent tissue sections to two of those strongly positive for these sequences by reverse-transcriptase polymerase chain reaction were analyzed by in situ hybridization with digoxigenin-labelled virus-specific antisense riboprobes. In one case, a female aged 83 showing 12 month rapid progressive disease, signal was specifically localized to cells identifiable as motor neurones of the anterior horn. In another case, a male aged 63 with a 60-month history of progressive muscle weakness, dysarthia, dyspnoea and increased tendon reflexes, signal was located to neurones in the gracile/cuneate nuclei of the brain stem tissue block that had been analyzed. This case showed loss of neurones in the anterior horn of the spinal cord by histopathologic examination which would account for clinical signs of motor neurone disease/amyotrophic lateral sclerosis. Dysfunction of the gracile/cuneate nuclei might have been masked by the paralytic disease. These structures are adjacent to the hypoglossal nuclei, and suggest either localised dissemination from hypoglossal nuclei or a possible route of dissemination of infection through the brainstem to the hypoglossal nuclei. These findings provide further evidence for the possible involvement of enteroviruses in motor neurone disease/amyotrophic lateral sclerosis.

  18. Effects of Vestibular Rehabilitation Interventions in the Elderly with Chronic Unilateral Vestibular Hypofunction

    Science.gov (United States)

    Bayat, Arash; Saki, Nader

    2017-01-01

    Introduction: Although vestibular rehabilitation therapy (VRT) methods are relatively popular in treating patients with body balance deficits of vestibular origin, only limited studies have been conducted into customized exercises for unilateral vestibular hypofunction (UVH). Furthermore, very little evidence is available on the outcomes of VRT in the elderly population with chronic UVH. Materials and Methods: A total of 21 patients, aged 61 to 74 years, with UVH participated in this study. The dizziness handicap inventory (DHI) was performed immediately before, and 2 and 8 weeks after treatment. Results: All patients showed a reduction in DHI scores during the study. The average decrease in DHI score was 25.98 points after 2 weeks’ intervention (P0.05). There were no relationships between the scores and gender. Conclusion: Our study demonstrates that VRT is an effective method for the management of elderly patients with UVH, and shows maximal effect on functional aspects. PMID:28819615

  19. Vestibular schwannoma: an unusual post radiotherapy response.

    Science.gov (United States)

    Uddin, Najam; Iqbal, Muhammad; Memon, Muhammad Ali; Farrukh, Salman

    2014-11-01

    Vestibular schwannoma is a relatively uncommon tumor. Although, it is benign but locally expansile and spreads to damage the adjacent structures. Treatment strategy includes surgery, Stereotactic Radiosurgery (SRS) either by standard or hypofractionated protocols. Due to its benign nature, radiation therapy cannot remove the tumor completely, instead radiation therapy halts the growth of vestibular schwannoma and inactivates this benign tumor. Response of radiation in the form of tumor shrinkage is seen 2 - 2.5 years after the radiations. We report a case of vestibular Schwannoma in which residual tumor of 3.1 cm size following subtotal resection was irradiated of the dose of 54 Gy in 30 equal fractions on 3-Dimensional Conformal Radiation Therapy (3-DCRT). A follow-up CT scan brain after 2 months of radiotherapy showed complete disappearance of the disease categorized as complete response. This is an unusual phenomenon and is likely due to the very rarely seen malignant transformation or presence of malignant component in this benign tumor.

  20. Non surgical treatment of vestibular schwannoma.

    Science.gov (United States)

    Arribas, Leoncio; Chust, María L; Menéndez, Antonio; Arana, Estanislao; Vendrell, Juan B; Crispín, Vicente; Pesudo, Carmen; Mengual, José L; Mut, Alejandro; Arribas, Mar; Guinot, José L

    2015-01-01

    To evaluate the results of local control and complications in the treatment of vestibular schwannoma treated with radiation. A retrospective study of 194 patients diagnosed with vestibular schwannoma, treated consecutively with radiation (either stereotactic radiosurgery or fractionated radiotherapy) from 1997 to 2012. We analyze the local control of tumors, as well as secondary complications to treatment with radiation. A total of 132 (68%) tumors 68% are grade I-II tumors of the Koos classification, 40 (19%) are grade III, and 22 (13%) are grade IV. The tumors associated with neurofibromatosis (NF2), are 3.6% (6 tumors in 4 patients). The tumor control for the overall serie is 97% at 5 years, with a median follow-up of 80.4 months. For large tumors the local control is 91% at 5 years. Free survival of chronic complications is 89% at 5 years. Additionally, 50 tumors were subjected to regular follow-up with MRI without treatment, and 28 (58%) did not experienced tumor growth. Radiation and follow up with MRI, are an alternative to surgery in the treatment of vestibular schwannoma, with a low level of complications inside of multidisciplinary approach. Copyright © 2014 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

  1. Molecular studies of vestibular schwannomas: a review.

    Science.gov (United States)

    Welling, D Bradley; Packer, Mark D; Chang, Long-Sheng

    2007-10-01

    To summarize advances in understanding the molecular biology of vestibular schwannomas over the past year. The role of the neurofibromatosis type 2 protein, denoted as merlin or schwannomin, in embryonic development, cellular adherence, and in cell proliferation has become better elucidated in the past year. Likewise, the role of merlin in Schwann cell-axon interaction has been studied. Additionally, two comprehensive analyses of the spectrum of human neurofibromatosis type 2 mutations have been compiled which make up a valuable resource in understanding critical regions of the neurofibromatosis type 2 gene. Neurofibromatosis type 2 screening guidelines for young patients with solitary vestibular schwannomas have been published. The role of electromagnetic radiation via cellular and portable telephones as a predisposing factor to vestibular schwannoma formation has also been the topic of several studies. Based on increased knowledge of the pathways in which merlin functions and the available transgenic and xenograft mouse models, preliminary data regarding directed pharmacotherapy are also summarized. With increased knowledge of the pathologic mechanisms and interacting proteins associated with merlin, the research community is poised to begin trials of targeted interventions in vitro and in the current mouse models.

  2. [Emergency diagnosis of the acute vestibular syndrome].

    Science.gov (United States)

    Tamás, T László; Garai, Tibor; Király, István; Mike, Andrea; Nagy, Csaba; Paukovics, Ágnes; Schmidt, Péter; Szatmári, Ferenc; Tompos, Tamás; Vadvári, Árpád; Szirmai, Ágnes

    2017-12-01

    To diagnose acute vestibular syndrome (AVS) in a prospective study by a new bedside test (providing 1A evidence) based on oculomotor analysis and assessment of hearing loss. To assess the frequency of central and peripheral causes of acute vestibular syndrome in the emergency room. To establish the diagnostic accuracy of acute cranial computed tomography as compared to oculomotor analysis done by video oculography goggles and audiometry. Between 1st March 2016 and 1st March 2017 we documented 125 patients (62 women, 63 men, average age 53 years) in the emergency room of the Petz Aladár County Teaching Hospital using the above bedside and instrumental testing. Diagnosis was verified by cranial magnetic resonance imaging. According to the results of the instrumental examination in AVS in 67% we found a peripheral cause and in 33% a central pathology. In 62% isolated posterior circulation stroke manifested itself by isolated vertigo without additional focal signs and the acute cranial computed tomography showed negative results in 96%. The instrumental examination increased diagnostic accuracy by making the diagnosis of isolated inferior semicircular canal vestibular neuritis possible. The new bedside oculomotor test is suitable for the diagnosis of posterior circulation stroke manifesting with isolated vertigo in early cases, when the routine neuroradiologic methods have a lower sensitivity or are not available. Orv Hetil. 2017; 158(51): 2029-2040.

  3. Laboratory testing of the vestibular system.

    Science.gov (United States)

    Clarke, Andrew H

    2010-10-01

    Recent reports on vestibular testing, relevant to clinical diagnosis, are reviewed.Besides the case history and bedside examination, objective measurement of the vestibuloocular reflex in all of its facets remains the cornerstone in the diagnostic process. In recent years, this has been enhanced considerably by reliable unilateral tests for the otolith organs, most notably by vestibular-evoked myogenic potential recording and estimation of subjective visual vertical. In addition, progress has been made in the investigation of multisensory interaction, involving visual acuity and posturography.Technological developments include improved eye movement measurement techniques, electrotactile and vibrotactile sensory enhancement or substitution, the use of virtual reality devices and motion stimulators such as hexapods and the rediscovery of galvanic vestibular stimulation as a research and diagnostic tool. The recent introduction of new tests, together with the development of novel technologies, is gradually increasing the scope of the physical and bedside examination of the dizzy patient (see chapter 'Medical management of peripheral disorders' in this issue). The use of more complex equipment, such as rotating chairs, linear sleds, hexapods and posturography platforms, is likely to become limited to specialized laboratories and rehabilitation centers in future years. Further, high resolution magnetic resonance tomography (MRT) and computed tomography have allowed insight into the morphology and determination of malformations of the human labyrinth.

  4. Organization of the nitrergic neuronal system in the primitive bony fishes Polypterus senegalus and Erpetoichthys calabaricus (Actinopterygii: Cladistia).

    Science.gov (United States)

    López, Jesús M; Lozano, Daniel; Morona, Ruth; González, Agustín

    2016-06-15

    Cladistians are a group of basal actinopterygian fishes that constitute a good model for studying primitive brain features, most likely present in the ancestral bony fishes. The analysis of the nitrergic neurons (with the enzyme nitric oxide synthase; NOS) has helped in understanding important aspects of brain organization in all vertebrates studied. We investigated the nitrergic system of two cladistian species by means of specific antibodies against NOS and NADPH-diaphorase (NADPH-d) histochemistry, which, with the exception of the primary olfactory and terminal nerve fibers, labeled only for NADPH-d, yielded identical results. Double immunohistochemistry was conducted for simultaneous detection of NOS with tyrosine hydroxylase, choline acetyltransferase, calbindin, calretinin, and serotonin, to establish accurately the localization of the nitrergic neurons and fibers and to assess possible interactions between these neuroactive substances. The pattern of distribution in both species showed only subtle differences in the density of labeled cells. Distinct groups of NOS-immunoreactive cells were observed in pallial and subpallial areas, paraventricular region, tuberal and retromammillary hypothalamic areas, posterior tubercle, prethalamic and thalamic areas, optic tectum, torus semicircularis, mesencephalic tegmentum, interpeduncular nucleus, superior and middle reticular nuclei, magnocellular vestibular nucleus, solitary tract nucleus, nucleus medianus magnocellularis, the spinal cord and amacrine cells in the retina. Large neurons in cranial nerve sensory ganglia were also labeled. The comparison of these results with those from other vertebrates, using a neuromeric analysis, reveals a conserved pattern of organization of the nitrergic system from this primitive fish group to amniotes, including mammals. © 2015 Wiley Periodicals, Inc.

  5. Cavitation inception from bubble nuclei

    Science.gov (United States)

    Mørch, K. A.

    2015-01-01

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid. The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure–time history of the water. A recent model and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes. PMID:26442138

  6. Head movements evoked in alert rhesus monkey by vestibular prosthesis stimulation: implications for postural and gaze stabilization.

    Directory of Open Access Journals (Sweden)

    Diana E Mitchell

    Full Text Available The vestibular system detects motion of the head in space and in turn generates reflexes that are vital for our daily activities. The eye movements produced by the vestibulo-ocular reflex (VOR play an essential role in stabilizing the visual axis (gaze, while vestibulo-spinal reflexes ensure the maintenance of head and body posture. The neuronal pathways from the vestibular periphery to the cervical spinal cord potentially serve a dual role, since they function to stabilize the head relative to inertial space and could thus contribute to gaze (eye-in-head + head-in-space and posture stabilization. To date, however, the functional significance of vestibular-neck pathways in alert primates remains a matter of debate. Here we used a vestibular prosthesis to 1 quantify vestibularly-driven head movements in primates, and 2 assess whether these evoked head movements make a significant contribution to gaze as well as postural stabilization. We stimulated electrodes implanted in the horizontal semicircular canal of alert rhesus monkeys, and measured the head and eye movements evoked during a 100 ms time period for which the contribution of longer latency voluntary inputs to the neck would be minimal. Our results show that prosthetic stimulation evoked significant head movements with latencies consistent with known vestibulo-spinal pathways. Furthermore, while the evoked head movements were substantially smaller than the coincidently evoked eye movements, they made a significant contribution to gaze stabilization, complementing the VOR to ensure that the appropriate gaze response is achieved. We speculate that analogous compensatory head movements will be evoked when implanted prosthetic devices are transitioned to human patients.

  7. The Modulation of Hippocampal Theta Rhythm by the Vestibular System.

    Science.gov (United States)

    Aitken, Phillip; Zheng, Yiwen; Smith, Paul F

    2017-11-22

    The vestibular system is a sensory system that has evolved over millions of years to detect acceleration of the head, both rotational and translational, in three dimensions. One of its most important functions is to stabilize gaze during unexpected head movement; however, it is also important in the control of posture and autonomic reflexes. Theta rhythm is a 3-12 Hz oscillating EEG signal that is intimately linked to self-motion and is also known to be important in learning and memory. Many studies over the last two decades have shown that selective activation of the vestibular system, either using natural rotational or translational stimulation, or electrical stimulation of the peripheral vestibular system, can induce and modulate theta activity. Furthermore, inactivation of the vestibular system has been shown to significantly reduce theta in freely moving animals, which may be linked to its impairment of place cell function as well as spatial learning and memory. The pathways through which vestibular information modulate theta rhythm remain debatable. However, vestibular responses have been found in the pedunculopontine tegmental nucleus (PPTg) and activation of the vestibular system causes an increase in acetylcholine release into the hippocampus, probably from the medial septum. Therefore, a pathway from the vestibular nucleus complex and/or cerebellum to the PPTg, supramammillary nucleus, posterior hypothalamic nucleus and the septum, to the hippocampus, is likely. The modulation of theta by the vestibular system may have implications for vestibular effects on cognitive function and the contribution of vestibular impairment to the risk of dementia. Copyright © 2017, Journal of Neurophysiology.

  8. Direct reactions with exotic nuclei

    Directory of Open Access Journals (Sweden)

    Obertelli A.

    2014-03-01

    Full Text Available Direct reactions have been a unique tool to address the nuclear many-body problem from the experimental side. They are now routinely used in inverse kinematics with radioactive ion beams (RIB. However, weakly bound nuclei have recently raised questions on the applicability of reaction formalisms benchmarked on stable nuclei to the study of single-particle properties and correlations in these unstable systems. The study of the most exotic species produced at low intensity have triggered new technical developments to increase the sensitivity of the setup, with a focused attention to direct reactions such as transfer at low incident energy or knockout at intermediate energies.

  9. Shell Structure of Exotic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Dobaczewski, J. [Warsaw University; Michel, N. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Nazarewicz, Witold [ORNL; Ploszajczak, M. [Grand Accelerateur National d' Ions Lourds (GANIL); Rotureau, J. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2007-01-01

    Theoretical predictions and experimental discoveries for neutron-rich, short-lived nuclei far from stability indicate that the familiar concept of nucleonic shell structure should be considered as less robust than previously thought. The notion of single-particle motion in exotic nuclei is reviewed with a particular focus on three aspects: (i) variations of nuclear mean field with neutron excess due to tensor interactions; (ii) importance of many-body correlations; and (iii) influence of open channels on properties of weakly bound and unbound nuclear states.

  10. International Symposium on Exotic Nuclei

    CERN Document Server

    Sobolev, Yu G; EXON-2014

    2015-01-01

    The production and the properties of nuclei in extreme conditions, such as high isospin, temperature, angular momenta, large deformations etc., have become the subject of detailed investigations in all scientific centers. The main topics discussed at the Symposium were: Synthesis and Properties of Exotic Nuclei; Superheavy Elements; Rare Processes, Nuclear Reactions, Fission and Decays; Experimental Facilities and Scientific Projects. This book provides a comprehensive overview of the newest results of the investigations in the main scientific centers such as GSI (Darmstadt, Germany), GANIL (Caen, France), RIKEN (Wako-shi, Japan), MSU (Michigan, USA), and JINR (Dubna, Russia).

  11. The frog vestibular system as a model for lesion-induced plasticity: basic neural principles and implications for posture control

    Directory of Open Access Journals (Sweden)

    Francois M Lambert

    2012-04-01

    Full Text Available Studies of behavioral consequences after unilateral labyrinthectomy have a long tradition in the quest of determining rules and limitations of the CNS to exert plastic changes that assist the recuperation from the loss of sensory inputs. Frogs were among the first animal models to illustrate general principles of regenerative capacity and reorganizational neural flexibility after a vestibular lesion. The continuous successful use of the latter animals is in part based on the easy access and identifiability of nerve branches to inner ear organs for surgical intervention, the possibility to employ whole brain preparations for in vitro studies and the limited degree of freedom of postural reflexes for quantification of behavioral impairments and subsequent improvements. Major discoveries that increased the knowledge of post-lesional reactive mechanisms in the central nervous system include alterations in vestibular commissural signal processing and activation of cooperative changes in excitatory and inhibitory inputs to disfacilitated neurons. Moreover, the observed increase of synaptic efficacy in propriospinal circuits illustrates the importance of limb proprioceptive inputs for postural recovery. Accumulated evidence suggests that the lesion-induced neural plasticity is not a goal-directed process that aims towards a meaningful restoration of vestibular reflexes but rather attempts a survival of those neurons that have lost their excitatory inputs. Accordingly, the reaction mechanism causes an improvement of some components but also a deterioration of other aspects as seen by spatio-temporally inappropriate vestibulo-motor responses, similar to the consequences of plasticity processes in various sensory systems and species. The generality of the findings indicate that frogs continue to form a highly amenable vertebrate model system for exploring molecular and physiological events during cellular and network reorganization after a loss of

  12. Analysis of signal processing in vestibular circuits with a novel light-emitting diodes-based fluorescence microscope.

    Science.gov (United States)

    Direnberger, Stephan; Banchi, Roberto; Brosel, Sonja; Seebacher, Christian; Laimgruber, Stefan; Uhl, Rainer; Felmy, Felix; Straka, Hans; Kunz, Lars

    2015-05-01

    Optical visualization of neural network activity is limited by imaging system-dependent technical tradeoffs. To overcome these constraints, we have developed a powerful low-cost and flexible imaging system with high spectral variability and unique spatio-temporal precision for simultaneous optical recording and manipulation of neural activity of large cell groups. The system comprises eight high-power light-emitting diodes, a camera with a large metal-oxide-semiconductor sensor and a high numerical aperture water-dipping objective. It allows fast and precise control of excitation and simultaneous low noise imaging at high resolution. Adjustable apertures generated two independent areas of variable size and position for simultaneous optical activation and image capture. The experimental applicability of this system was explored in semi-isolated preparations of larval axolotl (Ambystoma mexicanum) with intact inner ear organs and central nervous circuits. Cyclic galvanic stimulation of semicircular canals together with glutamate- and γ-aminobutyric acid (GABA)-uncaging caused a corresponding modulation of Ca(2+) transients in central vestibular neurons. These experiments revealed specific cellular properties as well as synaptic interactions between excitatory and inhibitory inputs, responsible for spatio-temporal-specific sensory signal processing. Location-specific GABA-uncaging revealed a potent inhibitory shunt of vestibular nerve afferent input in the predominating population of tonic vestibular neurons, indicating a considerable impact of local and commissural inhibitory circuits on the processing of head/body motion-related signals. The discovery of these previously unknown properties of vestibular computations demonstrates the merits of our novel microscope system for experimental applications in the field of neurobiology. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  13. Vestibular Deficits in Neurodegenerative Disorders: Balance, Dizziness, and Spatial Disorientation.

    Science.gov (United States)

    Cronin, Thomas; Arshad, Qadeer; Seemungal, Barry M

    2017-01-01

    The vestibular system consists of the peripheral vestibular organs in the inner ear and the associated extensive central nervous system projections-from the cerebellum and brainstem to the thalamic relays to cortical projections. This system is important for spatial orientation and balance, both of critical ecological importance, particularly for successful navigation in our environment. Balance disorders and spatial disorientation are common presenting features of neurodegenerative diseases; however, little is known regarding central vestibular processing in these diseases. A ubiquitous aspect of central vestibular processing is its promiscuity given that vestibular signals are commonly found in combination with other sensory signals. This review discusses how impaired central processing of vestibular signals-typically in combination with other sensory and motor systems-may account for the impaired balance and spatial disorientation in common neurodegenerative conditions. Such an understanding may provide for new diagnostic tests, potentially useful in detecting early disease while a mechanistic understanding of imbalance and spatial disorientation in these patients may enable a vestibular-targeted therapy for such problems in neurodegenerative diseases. Studies with state of the art central vestibular testing are now much needed to tackle this important topic.

  14. Vestibular Deficits in Neurodegenerative Disorders: Balance, Dizziness, and Spatial Disorientation

    Directory of Open Access Journals (Sweden)

    Thomas Cronin

    2017-10-01

    Full Text Available The vestibular system consists of the peripheral vestibular organs in the inner ear and the associated extensive central nervous system projections—from the cerebellum and brainstem to the thalamic relays to cortical projections. This system is important for spatial orientation and balance, both of critical ecological importance, particularly for successful navigation in our environment. Balance disorders and spatial disorientation are common presenting features of neurodegenerative diseases; however, little is known regarding central vestibular processing in these diseases. A ubiquitous aspect of central vestibular processing is its promiscuity given that vestibular signals are commonly found in combination with other sensory signals. This review discusses how impaired central processing of vestibular signals—typically in combination with other sensory and motor systems—may account for the impaired balance and spatial disorientation in common neurodegenerative conditions. Such an understanding may provide for new diagnostic tests, potentially useful in detecting early disease while a mechanistic understanding of imbalance and spatial disorientation in these patients may enable a vestibular-targeted therapy for such problems in neurodegenerative diseases. Studies with state of the art central vestibular testing are now much needed to tackle this important topic.

  15. Making Sense of the Body: the Role of Vestibular Signals.

    Science.gov (United States)

    Lopez, Christophe

    2015-01-01

    The role of the vestibular system in posture and eye movement control has been extensively described. By contrast, how vestibular signals contribute to bodily perceptions is a more recent research area in the field of cognitive neuroscience. In the present review article, I will summarize recent findings showing that vestibular signals play a crucial role in making sense of the body. First, data will be presented showing that vestibular signals contribute to bodily perceptions ranging from low-level bodily perceptions, such as touch, pain, and the processing of the body's metric properties, to higher level bodily perceptions, such as the sense of owning a body, the sense of being located within this body (embodiment), and the anchoring of the visuo-spatial perspective to this body. In the second part of the review article, I will show that vestibular information seems to be crucially involved in the visual perception of biological motion and in the visual perception of human body structure. Reciprocally, observing human bodies in motion influences vestibular self-motion perception, presumably due to sensorimotor resonance between the self and others. I will argue that recent advances in the mapping of the human vestibular cortex afford neuroscientific models of the vestibular contributions to human bodily self-consciousness.

  16. Long-term hearing preservation in vestibular schwannoma

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Thomsen, Jens; Tos, Mirko

    2010-01-01

    The aim of the present study was to evaluate the long-term hearing during "wait and scan" management of vestibular schwannomas.......The aim of the present study was to evaluate the long-term hearing during "wait and scan" management of vestibular schwannomas....

  17. Evaluation and treatment of vestibular dysfunction in children.

    Science.gov (United States)

    Rine, Rose Marie; Wiener-Vacher, Sylvette

    2013-01-01

    The effect of vestibular dysfunction since birth is more debilitating than that attained later in life, and unlike adults, children with vestibular dysfunction since or shortly after birth do not recover function without intervention. The purpose of this report is to provide an overview of the etiology of vestibular dysfunction in children as well as the related impairments, and to describe testing methods and evidence based interventions to ameliorate the vestibular related impairments in children. In recent years, investigations have revealed that vestibular dysfunction is more common in children than previously thought, with consequent impairments in motor development, balance and reading abilities. The dysfunction may be due to central or peripheral lesions, each with distinct presentation of symptoms and test results. Common etiologies and clinical presentation of vestibular dysfunction in children are reviewed; appropriate screening and diagnostic techniques and efficacious medical and rehabilitation interventions are presented. Despite advances in clinical and diagnostic testing of vestibular function in children and infants, testing of vestibular function is not typically done. Comprehensive testing of signs and symptoms is critical for diagnosis and implementation of appropriate interventions.

  18. Recent Evidence About the Effectiveness of Vestibular Rehabilitation.

    Science.gov (United States)

    Whitney, Susan L; Alghadir, Ahmad H; Anwer, Shahnawaz

    2016-03-01

    Vestibular rehabilitation of persons with peripheral and central vestibular disorders requires a thorough evaluation and a customized plan of care. Collaboration of the various members of the treatment team optimizes outcomes. Early intervention appears to be better than referring patients who have developed chronic symptoms of balance loss, dizziness, anxiety, and depression. There is a body of emerging evidence that supports that the central nervous system has the capability to reweigh sensory inputs in order to improve function. There continues to be a dearth of knowledge related to how to treat persons with otolithic dysfunction as compared to those with semicircular canal damage. With the use of vestibular rehabilitation, patients are less likely to fall, are less dizzy, balance and gait improve, and quality of life is enhanced. Recent Cochrane reviews and a clinical practice guideline support the use of vestibular rehabilitation for persons with vestibular dysfunction. Typical symptoms and their management including dysregulated gait, falling, fear of falling, increased sway in standing, visual blurring, symptoms with complex visual scenes in the periphery, and weakness are all discussed with ideas for intervention. Any patient with a vestibular disorder may benefit from a trial of vestibular rehabilitation. A discussion of recent evidence and innovations related to vestibular rehabilitation is also included.

  19. Paediatric Acquired Recto –Vestibular Fistula: Experience In Accra ...

    African Journals Online (AJOL)

    The association of acquired recto-vaginal fistula (RVF) with the human immunodeficiency virus is increasingly being recognized and reported in the literature Congenital recto - vestibular fistulae associated with imperforate anus is not uncommon, but it is rare to see children with acquired recto - vestibular fistula. From 1997 ...

  20. Vestibular vertigo in emergency neurology and cervical osteochondrosis

    Directory of Open Access Journals (Sweden)

    T S Barykova

    2010-01-01

    had acute peripheral vestibular pathology that required cerebral stroke or hemorrhage to be ruled out according to clinical data in most cases. Intermittent, recurrent, short-term vestibular crisis in the examined group of patients is temporarily or clinically unrelated to an exacerbation of cervical osteochondrosis.

  1. Postoperative management of nasal vestibular stenosis - The custom-made vestibular device

    NARCIS (Netherlands)

    Menger, Dirk-Jan; Lohuis, Peter J. F. M.; Kerssemakers, Steven; Nolst Trenité, Gilbert J.

    2005-01-01

    Objective: To evaluate the effect of a custom-made postoperative vestibular device on the occurrence and severity), of restenosis. Design: This was a retrospective study conducted at the Department of Otorhinolaryngology/Head and Neck Surgery, Center for Facial Plastic and Reconstructive Surgery of

  2.  A Novel V- Silicone Vestibular Stent: Preventing Vestibular Stenosis andPreserving Nasal Valves

    Directory of Open Access Journals (Sweden)

    Rashid Al Abri

    2012-01-01

    Full Text Available  This report presents a novel style of placing nasal stents. Patientsundergoing surgical procedures in the region of nasal vestibuleand nasal valves are at risk of developing vestibular stenosis andlifelong problems with the external and internal nasal valves;sequels of the repair. The objective of the report is to demonstratea simple and successful method of an inverted V- Stent placementto prevent potential complication of vestibular stenosis and nasalvalve compromise later in life. Following a fall on a sharp edge ofa metallic bed, a sixteen month old child with a deep laceratednasal wound extending from the collumellar base toward thetip of the nose underwent surgical exploration and repair of thenasal vestibule and nasal cavity. A soft silicone stent fashioned asinverted V was placed bilaterally. The child made a remarkablerecovery with no evidence of vestibular stenosis or nasal valveabnormalities. In patients with nasal trauma involving the nasalvestibule and internal and external nasal valves stent placementavoids sequels, adhesions, contractures, synechia vestibularstenosis and fibrosis involving these anatomical structures.The advantages of the described V- stents over the traditionalreadymade ridged nasal stents, tubing’s and composite aural graftsare: a technical simplicity of use, b safety, c less morbidity, dmore comfortable, and e economical. To our knowledge, this isthe first report of such a stent for prevention of vestibular stenosisand preserving nasal valves.

  3. Cyto- and chemoarchitecture of the sensory trigeminal nuclei of the echidna, platypus and rat.

    Science.gov (United States)

    Ashwell, Ken W S; Hardman, Craig D; Paxinos, George

    2006-02-01

    We have examined the cyto- and chemoarchitecture of the trigeminal nuclei of two monotremes using Nissl staining, enzyme reactivity for cytochrome oxidase, immunoreactivity for calcium binding proteins and non-phosphorylated neurofilament (SMI-32 antibody) and lectin histochemistry (Griffonia simplicifolia isolectin B4). The principal trigeminal nucleus and the oralis and interpolaris spinal trigeminal nuclei were substantially larger in the platypus than in either the echidna or rat, but the caudalis subnucleus was similar in size in both monotremes and the rat. The numerical density of Nissl stained neurons was higher in the principal, oralis and interpolaris nuclei of the platypus relative to the echidna, but similar to that in the rat. Neuropil immunoreactivity for parvalbumin was particularly intense in the principal trigeminal, oralis and interpolaris subnuclei of the platypus, but the numerical density of parvalbumin immunoreactive neurons was not particularly high in these nuclei of the platypus. Neuropil immunoreactivity for calbindin and calretinin was relatively weak in both monotremes, although calretinin immunoreactive somata made up a large proportion of neurons in the principal, oralis and interpolaris subnuclei of the echidna. Distribution of calretinin immunoreactivity and Griffonia simplicifolia B4 isolectin reactivity suggested that the caudalis subnucleus of the echidna does not have a clearly defined gelatinosus region. Our findings indicate that the trigeminal nuclei of the echidna do not appear to be highly specialized, but that the principal, oralis and interpolaris subnuclei of the platypus trigeminal complex are highly differentiated, presumably for processing of tactile and electrosensory information from the bill.

  4. Regeneration of hair cells in the mammalian vestibular system.

    Science.gov (United States)

    Li, Wenyan; You, Dan; Chen, Yan; Chai, Renjie; Li, Huawei

    2016-06-01

    Hair cells regenerate throughout the lifetime of non-mammalian vertebrates, allowing these animals to recover from hearing and balance deficits. Such regeneration does not occur efficiently in humans and other mammals. Thus, balance deficits become permanent and is a common sensory disorder all over the world. Since Forge and Warchol discovered the limited spontaneous regeneration of vestibular hair cells after gentamicininduced damage in mature mammals, significant efforts have been exerted to trace the origin of the limited vestibular regeneration in mammals after hair cell loss. Moreover, recently many strategies have been developed to promote the hair cell regeneration and subsequent functional recovery of the vestibular system, including manipulating the Wnt, Notch and Atoh1. This article provides an overview of the recent advances in hair cell regeneration in mammalian vestibular epithelia. Furthermore, this review highlights the current limitations of hair cell regeneration and provides the possible solutions to regenerate functional hair cells and to partially restore vestibular function.

  5. Vestibular schwannoma with contralateral facial pain – case report

    Directory of Open Access Journals (Sweden)

    Ghodsi Mohammad

    2003-03-01

    Full Text Available Abstract Background Vestibular schwannoma (acoustic neuroma most commonly presents with ipsilateral disturbances of acoustic, vestibular, trigeminal and facial nerves. Presentation of vestibular schwannoma with contralateral facial pain is quite uncommon. Case presentation Among 156 cases of operated vestibular schwannoma, we found one case with unusual presentation of contralateral hemifacial pain. Conclusion The presentation of contralateral facial pain in the vestibular schwannoma is rare. It seems that displacement and distortion of the brainstem and compression of the contralateral trigeminal nerve in Meckel's cave by the large mass lesion may lead to this atypical presentation. The best practice in these patients is removal of the tumour, although persistent contralateral pain after operation has been reported.

  6. Congenital and compensated vestibular dysfunction in childhood: an overlooked entity.

    Science.gov (United States)

    Weiss, Avery H; Phillips, James O

    2006-07-01

    We report five children with previously unrecognized vestibular dysfunction detected by clinical examination and confirmed by quantitative vestibular testing. Patient 1 presented with fluctuating visual acuity and intermittent nystagmus. Patient 2 had congenital hearing loss associated with imbalance, delayed motor development, and cyclic vomiting. Patient 3 had neurotrophic keratitis with an intermittent head tilt, imbalance, and motor delays. Patient 4 showed ataxia and eye movement abnormalities following traumatic brain injury and had reading difficulties. Patient 5 had episodic vertigo and eye movement abnormalities from infancy. Clinical vestibular testing emphasized spontaneous nystagmus, rapid head thrust, and assessment of post-rotatory nystagmus. Quantitative vestibular testing included the sinusoidal chair rotation and velocity step tests, measurement of dynamic visual acuity, post-head-shake nystagmus, and computerized platform posturography. Pediatric neurologists encounter children with congenital and compensated vestibular dysfunction, which can be recognized on the basis of relevant history and clinical abnormalities of the ocular-ocular reflex.

  7. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world's first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density ...

  8. Cavitation Nuclei: Experiments and Theory

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2009-01-01

    us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character....

  9. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    The pion production processes from nucleons and nuclei at intermediate energies are important tools to study the hadronic structure. The dynamic models of the hadronic structure are used to calculate the various nucleon and transition form factors which are tested by using the experimental data on photo, electro and.

  10. Physics with loosely bound nuclei

    Indian Academy of Sciences (India)

    nuclear physics changed drastically as the new generation of accelerators started providing more and more rare isotopes, which are away from the line of stability. These weakly bound nuclei are found to exhibit new forms of nuclear matter and unprecedented exotic behaviour. The low breakup thresholds of these rare ...

  11. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    The charged current pion production induced by neutrinos in 12C, 16O and 56Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of in the ...

  12. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

    A review of nuclear astrophysics of light nuclei using radioactive beams or techniques developed for radioactive beams is given. We discuss Big Bang nucleosynthesis, with special focus on the lithium problem, aspects of neutrino-physics, helium-burning and finally selected examples of studies...

  13. Vestibular characterization in the menstrual cycle Caracterização vestibular no ciclo menstrual

    Directory of Open Access Journals (Sweden)

    Cintia Ishii

    2009-06-01

    Full Text Available Hormonal disorders in the menstrual cycle can affect labyrinthine fluid homeostasis, causing balance and hearing dysfunctions. STUDY DESIGN: Clinical prospective. AIM: compare the results from vestibular tests in young women, in the premenstrual and postmenstrual periods. MATERIALS AND METHODS: twenty women were selected with ages ranging from 18 to 35 years, who were not using any kind of contraceptive method for at least six months, and without vestibular or hearing complaints. The test was carried out in each subject before and after the menstrual period, respecting the limit of ten days before or after menstruation. RESULTS: there was a statistically significant difference in the menstrual cycle phases only in the following vestibular tests: calibration, saccadic movements, PRPD and caloric-induced nystagmus. We also noticed that age; a regular menstrual cycle; hearing loss or dizziness cases in the family; and premenstrual symptoms such as tinnitus, headache, sleep disorders, anxiety, nausea and hyperacusis can interfere in the vestibular test. CONCLUSION: there are differences in the vestibular tests of healthy women when comparing their pre and postmenstrual periods.As alterações hormonais do ciclo menstrual podem comprometer a homeostase dos fluidos labirínticos, gerando alterações no equilíbrio e na audição. FORMA DO ESTUDO: Clínico prospectivo. OBJETIVO: Comparar os resultados dos testes do exame vestibular em mulheres jovens, nos períodos pré e pós-menstrual. MATERIAL E MÉTODO: Foram selecionadas vinte mulheres, entre dezoito e trinta e cinco anos, que não fizessem uso de qualquer tipo de anticoncepcional, com audição normal e sem queixas vestibulares. O exame vestibular foi realizado em cada participante no período pré e no período pós-menstrual, em ordem aleatória, e respeitando o limite de até dez dias antes do início da menstruação e até dez dias após o início da menstruação. RESULTADO: Foi observada

  14. State Anxiety Subjective Imbalance and Handicap in Vestibular Schwannoma.

    Science.gov (United States)

    Saman, Yougan; Mclellan, Lucie; Mckenna, Laurence; Dutia, Mayank B; Obholzer, Rupert; Libby, Gerald; Gleeson, Michael; Bamiou, Doris-Eva

    2016-01-01

    Evidence is emerging for a significant clinical and neuroanatomical relationship between balance and anxiety. Research has suggested a potentially priming effect with anxiety symptoms predicting a worsening of balance function in patients with underlying balance dysfunction. We propose to show that a vestibular stimulus is responsible for an increase in state anxiety, and there is a relationship between increased state anxiety and worsening balance function. (1) To quantify state anxiety following a vestibular stimulus in patients with a chronic vestibular deficit. (2) To determine if state anxiety during a vestibular stimulus would correlate with the severity of chronic balance symptoms and handicap. Two separate cohorts of vestibular schwannoma (VS) patients underwent vestibular tests (electronystagmography, cervical and ocular vestibular evoked myogenic potentials, and caloric responses) and questionnaire assessments [vertigo handicap questionnaire (VHQ), vertigo symptom scale (VSS), and state-trait anxiety inventory (STAIY)]. Fifteen post-resection VS patients, with complete unilateral vestibular deafferentation, were assessed at a minimum of 6 months after surgery in Experiment 1 (Aim 1). Forty-five patients with VS in situ formed the cohort for Experiment 2 (Aim 2). Experiment 1: VS subjects (N = 15) with a complete post-resection unilateral vestibular deafferentation completed a state anxiety questionnaire before caloric assessment and again afterward with the point of maximal vertigo as the reference (Aim 1). Experiment 2: state anxiety measured at the point of maximal vertigo following a caloric assessment was compared between two groups of patients with VS in situ presenting with balance symptoms (Group 1, N = 26) and without balance symptoms (Group 2, N = 11) (Aim 2). The presence of balance symptoms was defined as having a positive score on the VSS-VER. In Experiment 1, a significant difference (p handicap (p < 0.001). Anxiety

  15. The molecular biology and novel treatments of vestibular schwannomas.

    Science.gov (United States)

    Fong, Brendan; Barkhoudarian, Garni; Pezeshkian, Patrick; Parsa, Andrew T; Gopen, Quinton; Yang, Isaac

    2011-11-01

    Vestibular schwannomas are histopathologically benign tumors arising from the Schwann cell sheath surrounding the vestibular branch of cranial nerve VIII and are related to the NF2 gene and its product merlin. Merlin acts as a tumor suppressor and as a mediator of contact inhibition. Thus, deficiencies in both NF2 genes lead to vestibular schwannoma development. Recently, there have been major advances in our knowledge of the molecular biology of vestibular schwannomas as well as the development of novel therapies for its treatment. In this article the authors comprehensively review the recent advances in the molecular biology and characterization of vestibular schwannomas as well as the development of modern treatments for vestibular schwannoma. For instance, merlin is involved with a number of receptors including the CD44 receptor, EGFR, and signaling pathways, such as the Ras/raf pathway and the canonical Wnt pathway. Recently, merlin was also shown to interact in the nucleus with E3 ubiquitin ligase CRL4(DCAF1). A greater understanding of the molecular mechanisms behind vestibular schwannoma tumorigenesis has begun to yield novel therapies. Some authors have shown that Avastin induces regression of progressive schwannomas by over 40% and improves hearing. An inhibitor of VEGF synthesis, PTC299, is currently in Phase II trials as a potential agent to treat vestibular schwannoma. Furthermore, in vitro studies have shown that trastuzumab (an ERBB2 inhibitor) reduces vestibular schwannoma cell proliferation. With further research it may be possible to significantly reduce morbidity and mortality rates by decreasing tumor burden, tumor volume, hearing loss, and cranial nerve deficits seen in vestibular schwannomas.

  16. Evaluation of Galvanic Vestibular Stimulation System

    Science.gov (United States)

    Kofman, I. S.; Warren, E.; DeSoto, R.; Moroney, G.; Chastain, J.; De Dios, Y. E.; Gadd, N.; Taylor, L.; Peters, B. T.; Allen, E.; hide

    2017-01-01

    Microgravity exposure results in an adaptive central reinterpretation of information from multiple sensory sources to produce a sensorimotor state appropriate for motor actions in this unique environment, but this new adaptive state is no longer appropriate for the 1-g gravitational environment on Earth. During these gravitational transitions, astronauts experience deficits in both perceptual and motor functions including impaired postural control, disruption in spatial orientation, impaired control of locomotion that include alterations in muscle activation variability, modified lower limb kinematics, alterations in head-trunk coordination as well as reduced dynamic visual acuity. Post-flight changes in postural and locomotor control might have adverse consequences if a rapid egress was required following a long-duration mission, where support personnel may not be available to aid crewmembers. The act of emergency egress includes, but is not limited to standing, walking, climbing a ladder, jumping down, monitoring displays, actuating discrete controls, operating auxiliary equipment, and communicating with Mission Control and recovery teams while maintaining spatial orientation, mobility and postural stability in order to escape safely. The average time to recover impaired postural control and functional mobility to preflight levels of performance has been shown to be approximately two weeks after long-duration spaceflight. The postflight alterations are due in part to central reinterpretation of vestibular information caused by exposure to microgravity. In this study we will use a commonly used technique of transcutaneous electrical stimulation applied across the vestibular end organs (galvanic vestibular stimulation, GVS) to disrupt vestibular function as a simulation of post-flight disturbances. The goal of this project is an engineering human-in-the-loop evaluation of a device that can degrade performance of functional tasks (e.g. to maintain upright balance

  17. Neurosonology Accuracy for Isolated Acute Vestibular Syndromes.

    Science.gov (United States)

    Tábuas-Pereira, Miguel; Sargento-Freitas, João; Isidoro, Luís; Silva, Fernando; Galego, Orlando; Nunes, César; Cordeiro, Gustavo; Cunha, Luís

    2017-12-01

    The clinical approach to acute vestibular syndromes is often complex for the physician. Neurosonology offers a noninvasive method to study the cervicocephalic circulation when a vascular etiology is suspected. We aim to evaluate the diagnostic accuracy of a vascular neurosonological exam in isolated acute vestibular syndrome. All patients submitted to cerebrovascular ultrasound and magnetic resonance imaging during the period between 2011 and 2015 with acute isolated vestibular syndrome. Those with any clinical sign of brainstem lesion on presentation were excluded. All patients performed the neuroimaging study (brain computed tomography and magnetic resonance imaging) and neurologic surveillance. Neurosonological exam included all intra- and extracranial segments of the vertebrobasilar circulation. Positive ultrasound exam was defined as the presence of stenotic or occlusive disease in any of these segments related to the infarcted area. A total of 108 patients were included: 60 (53.6%) were males (mean age: 60.75 years (standard deviation, 14.17)). In 27 patients (25.0%) a cerebral ischemic lesion was found to be the cause of the vertigo. Neurosonological assessment showed a sensitivity of 40.7% (95% confidence interval (CI): 22.4; 61.2), specificity of 100% (95% CI: 95.5; 100.0), positive predictive value (PPV) of 100% (95% CI: 71.5; 100.0), and negative predictive value (NPV) of 83.5% (95% CI: 74.6; 90.3). Our study suggests that cerebrovascular ultrasound is a highly specific method for the diagnosis of cerebrovascular vertigo. However, its low sensitivity makes it a poor candidate for screening. © 2017 by the American Institute of Ultrasound in Medicine.

  18. Differential sensitivity to nicotine among hypothalamic magnocellular neurons

    DEFF Research Database (Denmark)

    Mikkelsen, J D; Jacobsen, Julie; Kiss, Adrian Emil

    2012-01-01

    The magnocellular neurons in the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON) either contain vasopressin or oxytocin. Even though both hormones are released after systemic administration of nicotine, the mechanism through which the two populations of neurons are activated...... is not known. This study was carried out in the rat to investigate the effect of increasing doses of nicotine on subsets of magnocellular neurons containing either oxytocin or vasopressin....

  19. Activation of raphe nuclei triggers rapid and distinct effects on parallel olfactory bulb output channels.

    Science.gov (United States)

    Kapoor, Vikrant; Provost, Allison C; Agarwal, Prateek; Murthy, Venkatesh N

    2016-02-01

    The serotonergic raphe nuclei are involved in regulating brain states over timescales of minutes and hours. We examined more rapid effects of raphe activation on two classes of principal neurons in the mouse olfactory bulb, mitral and tufted cells, which send olfactory information to distinct targets. Brief stimulation of the raphe nuclei led to excitation of tufted cells at rest and potentiation of their odor responses. While mitral cells at rest were also excited by raphe activation, their odor responses were bidirectionally modulated, leading to improved pattern separation of odors. In vitro whole-cell recordings revealed that specific optogenetic activation of raphe axons affected bulbar neurons through dual release of serotonin and glutamate. Therefore, the raphe nuclei, in addition to their role in neuromodulation of brain states, are also involved in fast, sub-second top-down modulation similar to cortical feedback. This modulation can selectively and differentially sensitize or decorrelate distinct output channels.

  20. EL SINDROME VESTIBULAR EN EL ADULTO MAYOR

    OpenAIRE

    Suárez, Hamlet; Suárez, Alejo

    2016-01-01

    El vértigo, la inestabilidad y las caídas tienen una incidencia relevante en el adulto mayor, disminuye su calidad de vida y puede ser causa de muerte en esta población. Este artículo describe las presentaciones clínicas y el abordaje de la evaluación de la patología vestibular en este grupo de edad, utilizando diferentes instrumentos para el diagnóstico así como también las reglas generales del tratamiento.

  1. EL SINDROME VESTIBULAR EN EL ADULTO MAYOR

    Directory of Open Access Journals (Sweden)

    Dr. Hamlet Suárez

    2016-11-01

    Full Text Available El vértigo, la inestabilidad y las caídas tienen una incidencia relevante en el adulto mayor, disminuye su calidad de vida y puede ser causa de muerte en esta población. Este artículo describe las presentaciones clínicas y el abordaje de la evaluación de la patología vestibular en este grupo de edad, utilizando diferentes instrumentos para el diagnóstico así como también las reglas generales del tratamiento.

  2. Vestibular schwannoma presenting with sudden facial paralysis.

    Science.gov (United States)

    Wexler, D B; Fetter, T W; Gantz, B J

    1990-04-01

    Facial paralysis is an unusual manifestation of vestibular schwannoma, and generally signifies an advanced stage of tumor growth. We describe a case of eighth-nerve schwannoma that presented initially with rapid-onset complete unilateral facial paralysis. At the time of operation the nerve was found to be electrically intact despite marked compression by tumor. The facial nerve was preserved and facial motion has partially recovered postoperatively. All unexplained persistent facial paralysis should be evaluated by magnetic resonance imaging with paramagnetic contrast enhancement.

  3. Symptomatic recovery in Miller Fisher Syndrome parallels vestibular-perceptual and not vestibular-ocular reflex function

    Directory of Open Access Journals (Sweden)

    Barry M Seemungal

    2011-02-01

    Full Text Available Unpleasant visual symptoms including oscillopsia and dizziness may occur when there is unexpected motion of the visual world across the subject’s retina (‘retinal-slip’ as in an acute spontaneous nystagmus or on head movement with an acute ophthalmoplegia. In contrast, subjects with chronic ocular dysmotility, e.g. congenital nystagmus or CPEO (chronic progressive external ophthalmoplegia, are typically symptom free. The adaptive processes that render chronic patients asymptomatic are obscure but may include a suppression of oscillopsia perception as well as an increased tolerance to perceived oscillopsia. Such chronic asymptomatic patients display an attenuation of vestibular-mediated angular velocity perception, implying a possible contributory role in the adaptive process. In order to assess causality between symptoms, signs (i.e. eye-movements and vestibular perceptual function, we prospectively assessed symptom ratings and ocular-motor and perceptual vestibular function, in a patient with acute but transient ophthalmoplegia due to Miller Fisher Syndrome (as a model of visuo-vestibular adaptation. The data show that perceptual measures of vestibular function display a significant attenuation as compared to ocularmotor measures during the acute, symptomatic period. Perhaps significantly, both symptomatic recovery and normalisation of vestibular perceptual function were delayed and then occurred in a parallel fashion. This is the first report showing that symptomatic recovery of visuo-vestibular symptoms is better paralleled by vestibular-perceptual testing than VOR (vestibular ocular reflex measures. The findings may have implications for the understanding of patients with chronic vestibular symptoms where VOR testing is often unhelpful.

  4. Reabilitação vestibular na criança: estudo preliminar Vestibular rehabilitation in children: preliminary study

    Directory of Open Access Journals (Sweden)

    Roseli S. M. Bittar

    2002-08-01

    Full Text Available Forma de estudo: Clínico prospectivo. Objetivo: O estudo analisa prospectivamente os resultados da Reabilitação Vestibular pelo método de Cawtorne & Cooksey em 22 crianças, portadoras de vestibulopatia periférica, associada ou não a sintomas centrais, com idade média de 8,6 anos. Material e método: Os exames quantitativos da função vestibular utilizados para quantificar a vestibulopatia foram a eletronistagmografia e a prova rotatória pendular decrescente (PRPD, mas a história clínica altamente sugestiva de processo vestibular foi considerada diagnóstica mesmo na presença de exames normais. Resultado: Os resultados apontam a Reabilitação Vestibular como uma opção válida no tratamento das vestibulopatias na infância, uma vez que não houve casos não responsivos ao tratamento.Study design: Clinical prospective. Aim: The authors analyze prospectively 22 children (mean age 8,6 years with vestibulopathy treated with Vestibular Rehabilitation in order to verify its results. Material and methody: Twenty two children with peripheral vestibular disorders associated or not to central symptoms were submitted to vestibular stimulation by the method of Cawthorne & Cooksey. The methods used to quantify the vestibular abnormalities were the electronystagmography and rotational chair testing, but a suggestive history of vestibular disorder was accepted even the exams were normal. Results: All the patients improved and our results suggest that VR is a therapeutic alternative for the treatment of vestibular disorders in the children.

  5. STATE ANXIETY, SUBJECTIVE IMBALANCE AND HANDICAP IN VESTIBULAR SCHWANNOMA

    Directory of Open Access Journals (Sweden)

    Yougan Saman

    2016-07-01

    Full Text Available ABSTRACTEvidence is emerging of a significant clinical and neuro-anatomical relationship between balance and anxiety. Research has suggested a potentially priming effect with anxiety symptoms predicting a worsening of balance function in patients with underlying balance dysfunction. We propose to show that a vestibular stimulus is responsible for an increase in state anxiety and there is a relationship between increased state anxiety and worsening balance function. Aims1.To quantify state anxiety following a vestibular stimulus in patients with a chronic vestibular deficit.2.To determine if state anxiety during a vestibular stimulus would correlate with the severity of chronic balance symptoms and handicap. MethodsTwo separate cohorts Vestibular Schwannoma (VS patients underwent vestibular tests (electronystagmography, cervical and ocular vestibular evoked myogenic potentials and caloric responses and questionnaire assessment (Vertigo handicap Questionnaire, Vertigo Symptom Scale, State Trait Anxiety InventoryFifteen post resection Vestibular schwannoma patients, with complete unilateral vestibular deafferentation, were assessed at a minimum of 6 months after surgery in Experiment 1 (Aim 1. Forty-five patients with VS in-situ and with preserved vestibular function formed the cohort for Experiment 2 (Aim 2. Experiment 1: VS subjects (N=15 with a complete post-resection unilateral vestibular deafferentation completed a State anxiety questionnaire before caloric assessment and again afterwards with the point of maximal vertigo as the reference (Aim 1. Experiment 2: State anxiety measured at the point of maximal vertigo following a caloric assessment was compared between two groups of presenting with balance symptoms (Group 1 N=26 and without balance symptoms (Group 2 N=11 (Aim 2. The presence of balance symptoms was defined as having a positive score on the VSS-VER.ResultsIn experiment 1, a significant difference (p<0.01 was found when comparing

  6. Responses to Gamma-Aminobutyric Acid of Rat Visual Cortical Neurons in Tissue Slices

    Science.gov (United States)

    1986-04-01

    abdominal stretch receptor neuron in crayfish. Factor I was later identified as GABA (Bazemore et al., 1957). The next breakthrough came in 1958, when...Kuffler and Edwards found that GABA mimicked the effects of afferent stimulation of the crayfish stretch receptor neuron, and suggested that GABA...GABAergic efferents arising from the corpus striatum. GABA has also been linked to Parkinson’s disease, olivo-vestibular disorders, and spasticity

  7. Vestibular Rehabilitation Therapy: Review of Indications, Mechanisms, and Key Exercises

    Science.gov (United States)

    Song, Hyun Seok; Kim, Ji Soo

    2011-01-01

    Vestibular rehabilitation therapy (VRT) is an exercise-based treatment program designed to promote vestibular adaptation and substitution. The goals of VRT are 1) to enhance gaze stability, 2) to enhance postural stability, 3) to improve vertigo, and 4) to improve activities of daily living. VRT facilitates vestibular recovery mechanisms: vestibular adaptation, substitution by the other eye-movement systems, substitution by vision, somatosensory cues, other postural strategies, and habituation. The key exercises for VRT are head-eye movements with various body postures and activities, and maintaining balance with a reduced support base with various orientations of the head and trunk, while performing various upper-extremity tasks, repeating the movements provoking vertigo, and exposing patients gradually to various sensory and motor environments. VRT is indicated for any stable but poorly compensated vestibular lesion, regardless of the patient's age, the cause, and symptom duration and intensity. Vestibular suppressants, visual and somatosensory deprivation, immobilization, old age, concurrent central lesions, and long recovery from symptoms, but there is no difference in the final outcome. As long as exercises are performed several times every day, even brief periods of exercise are sufficient to facilitate vestibular recovery. Here the authors review the mechanisms and the key exercises for each of the VRT goals. PMID:22259614

  8. Impedance pattern of vaginal and vestibular mucosa in cyclic goats

    Directory of Open Access Journals (Sweden)

    Ivo Křivánek

    2008-01-01

    Full Text Available The changes of vaginal and vestibular impedance during the oestrous cycle in goats were examined. The onset of oestrus was teased with a buck once a day during the experiment. Impedance was mea­sured by a four-terminal method. The vaginal impedance was recorded under slight pressure of electrodes to the vaginal dorsal wall at the cervix. The vestibular impedance was recorded under slight pressure of electrodes to the vestibular dorsal wall 5 cm from the vulva and at the vulva. The im­pe­dan­ce was measured once a day from 4 days before the expected oestrus to 6 days after onset of oestrus. The vaginal impedance at the cervix decreased during pro-oestrus (P < 0.01 and increased du­ring oestrus (P < 0.01. The vestibular impedance 5 cm from the vulva decreased during pro-oestrus (P < 0.01 and increased after oestrus (P < 0.01. The decrease of vaginal impedance during peri-oestrus was nearly twofold in comparison with the vestibular impedance 5 cm from the vulva. No sig­ni­fi­cant decrease of the vestibular impedance at the vulva was found during the oestrous cycle. The results indicate that the vaginal impedance at the cervix and vestibular impedance 5 cm from the vulva measured by means of a four-terminal method during the oestrous cycle display cyclic changes that are closely related to the oestrous behaviour of goats.

  9. Betahistine treatment in managing vertigo and improving vestibular compensation: clarification.

    Science.gov (United States)

    Lacour, Michel

    2013-01-01

    Betahistine dihydrochloride (betahistine) is currently used in the management of vertigo and vestibular pathologies with different aetiologies. The main goal of this review is to clarify the mechanisms of action of this drug, responsible for the symptomatic relief of vertigo and the improvement of vestibular compensation. The review starts with a brief summary recalling the role of histamine as a neuromodulator/neurotransmitter in the control of the vestibular functions, and the role of the histaminergic system in vestibular compensation. Then are presented data recorded in animal models demonstrating that betahistine efficacy can be explained by mechanisms targeting the histamine receptors (HRs) at three different levels: the vascular tree, with an increase of cochlear and vestibular blood flow involving the H1R; the central nervous system, with an increase of histamine turnover implicating the H3R, and the peripheral labyrinth, with a decrease of vestibular input implying the H3R/H4R. Clinical data from vestibular loss patients show the impact of betahistine treatment for the long-term control of vertigo, improvement of balance and quality of life that can be explained by these mechanisms of action. However, two conditions, at least, are required for reaching the betahistine therapeutic effect: the dose and the duration of treatment. Experimental and clinical data supporting these requirements are exposed in the last part of this review.

  10. Adaptive plasticity in vestibular influences on cardiovascular control

    Science.gov (United States)

    Yates, B. J.; Holmes, M. J.; Jian, B. J.

    2000-01-01

    Data collected in both human subjects and animal models indicate that the vestibular system influences the control of blood pressure. In animals, peripheral vestibular lesions diminish the capacity to rapidly and accurately make cardiovascular adjustments to changes in posture. Thus, one role of vestibulo-cardiovascular influences is to elicit changes in blood distribution in the body so that stable blood pressure is maintained during movement. However, deficits in correcting blood pressure following vestibular lesions diminish over time, and are less severe when non-labyrinthine sensory cues regarding body position in space are provided. These observations show that pathways that mediate vestibulo-sympathetic reflexes can be subject to plastic changes. This review considers the adaptive plasticity in cardiovascular responses elicited by the central vestibular system. Recent data indicate that the posterior cerebellar vermis may play an important role in adaptation of these responses, such that ablation of the posterior vermis impairs recovery of orthostatic tolerance following subsequent vestibular lesions. Furthermore, recent experiments suggest that non-labyrinthine inputs to the central vestibular system may be important in controlling blood pressure during movement, particularly following vestibular dysfunction. A number of sensory inputs appear to be integrated to produce cardiovascular adjustments during changes in posture. Although loss of any one of these inputs does not induce lability in blood pressure, it is likely that maximal blood pressure stability is achieved by the integration of a variety of sensory cues signaling body position in space.

  11. The relationship between senile hearing loss and vestibular activity

    Directory of Open Access Journals (Sweden)

    Hanifi Kurtaran

    Full Text Available Abstract Introduction: A considerable high number of SNHL patients also suffer from dizziness and related vestibular symptoms. Objective: To evaluate the association of vestibular dysfunction and sensorineural hearing loss (SNHL in adult patients. Methods: Prospective, double-blinded, controlled studies composed by 63 adult patients without any vestibular symptoms or diagnosed vestibular diseases. Audiological status was measured with pure tone audiometry and the vestibular system was tested with vestibular evoked myogenic potential (VEMP. Patients were divided into two groups: a study group (patients with SNHL and a control group (patients without SNHL. VEMP results of the groups were calculated and compared. Results: Mean P1 (23.54 and N1 (30.70 latencies were prolonged in the study group (p < 0.001 and the amplitudes of the study group were significantly reduced (p < 0.001. Both parameters of the VEMP test were abnormal in the study group when compared to the control group. Conclusions: These findings suggest that age-related SNHL may be accompanied by vestibular weakness without any possible predisposing factors for vestibulopathy.

  12. Recovery of dynamic visual acuity in bilateral vestibular hypofunction.

    Science.gov (United States)

    Herdman, Susan J; Hall, Courtney D; Schubert, Michael C; Das, Vallabh E; Tusa, Ronald J

    2007-04-01

    To determine the effect of vestibular exercises on the recovery of visual acuity during head movement in patients with bilateral vestibular hypofunction (BVH). Prospective, randomized, double-blinded study. Outpatient clinic, academic setting. Thirteen patients with BVH, aged 47 to 73 years. One group (8 patients) performed vestibular exercises designed to enhance remaining vestibular function, and the other (5 patients) performed placebo exercises. Measurements of dynamic visual acuity (DVA) during predictable head movements using a computerized test; measurement of intensity of oscillopsia using a visual analog scale. As a group, patients who performed vestibular exercises showed a significant improvement in DVA (P = .001), whereas those performing placebo exercises did not (P = .07). Only type of exercise (ie, vestibular vs placebo) was significantly correlated with change in DVA. Other factors examined, including age, time from onset, initial DVA, and complaints of oscillopsia and disequilibrium, were not significantly correlated with change in DVA. Change in oscillopsia did not correlate with change in DVA. Use of vestibular exercises is the main factor involved in recovery of DVA in patients with BVH. We theorize that exercises may foster the use of centrally programmed eye movements that could substitute for the vestibulo-ocular reflex. clinicaltrials.gov Identifier: NCT00411216.

  13. Responses evoked by a vestibular implant providing chronic stimulation.

    Science.gov (United States)

    Thompson, Lara A; Haburcakova, Csilla; Gong, Wangsong; Lee, Daniel J; Wall, Conrad; Merfeld, Daniel M; Lewis, Richard F

    2012-01-01

    Patients with bilateral vestibular loss experience dehabilitating visual, perceptual, and postural difficulties, and an implantable vestibular prosthesis that could improve these symptoms would be of great benefit to these patients. In previous work, we have shown that a one-dimensional, unilateral canal prosthesis can improve the vestibulooccular reflex (VOR) in canal-plugged squirrel monkeys. In addition to the VOR, the potential effects of a vestibular prosthesis on more complex, highly integrative behaviors, such as the perception of head orientation and posture have remained unclear. We tested a one-dimensional, unilateral prosthesis in a rhesus monkey with bilateral vestibular loss and found that chronic electrical stimulation partially restored the compensatory VOR and also that percepts of head orientation relative to gravity were improved. However, the one-dimensional prosthetic stimulation had no clear effect on postural stability during quiet stance, but sway evoked by head-turns was modestly reduced. These results suggest that not only can the implementation of a vestibular prosthesis provide partial restitution of VOR but may also improve perception and posture in the presence of bilateral vestibular hypofunction (BVH). In this review, we provide an overview of our previous and current work directed towards the eventual clinical implementation of an implantable vestibular prosthesis.

  14. Biomimetic smart sensors for autonomous robotic behavior II: vestibular processing

    Science.gov (United States)

    Xue, Shuwan; Deligeorges, Socrates; Soloway, Aaron; Lichtenstein, Lee; Gore, Tyler; Hubbard, Allyn

    2009-05-01

    Limited autonomous behaviors are fast becoming a critical capability in the field of robotics as robotic applications are used in more complicated and interactive environments. As additional sensory capabilities are added to robotic platforms, sensor fusion to enhance and facilitate autonomous behavior becomes increasingly important. Using biology as a model, the equivalent of a vestibular system needs to be created in order to orient the system within its environment and allow multi-modal sensor fusion. In mammals, the vestibular system plays a central role in physiological homeostasis and sensory information integration (Fuller et al, Neuroscience 129 (2004) 461-471). At the level of the Superior Colliculus in the brain, there is multimodal sensory integration across visual, auditory, somatosensory, and vestibular inputs (Wallace et al, J Neurophysiol 80 (1998) 1006-1010), with the vestibular component contributing a strong reference frame gating input. Using a simple model for the deep layers of the Superior Colliculus, an off-the-shelf 3-axis solid state gyroscope and accelerometer was used as the equivalent representation of the vestibular system. The acceleration and rotational measurements are used to determine the relationship between a local reference frame of a robotic platform (an iRobot Packbot®) and the inertial reference frame (the outside world), with the simulated vestibular input tightly coupled with the acoustic and optical inputs. Field testing of the robotic platform using acoustics to cue optical sensors coupled through a biomimetic vestibular model for "slew to cue" gunfire detection have shown great promise.

  15. The relationship between senile hearing loss and vestibular activity.

    Science.gov (United States)

    Kurtaran, Hanifi; Acar, Baran; Ocak, Emre; Mirici, Emre

    A considerable high number of SNHL patients also suffer from dizziness and related vestibular symptoms. To evaluate the association of vestibular dysfunction and sensorineural hearing loss (SNHL) in adult patients. Prospective, double-blinded, controlled studies composed by 63 adult patients without any vestibular symptoms or diagnosed vestibular diseases. Audiological status was measured with pure tone audiometry and the vestibular system was tested with vestibular evoked myogenic potential (VEMP). Patients were divided into two groups: a study group (patients with SNHL) and a control group (patients without SNHL). VEMP results of the groups were calculated and compared. Mean P1 (23.54) and N1 (30.70) latencies were prolonged in the study group (p<0.001) and the amplitudes of the study group were significantly reduced (p<0.001). Both parameters of the VEMP test were abnormal in the study group when compared to the control group. These findings suggest that age-related SNHL may be accompanied by vestibular weakness without any possible predisposing factors for vestibulopathy. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  16. The clinical manifestations of vestibular migraine: A review.

    Science.gov (United States)

    O'Connell Ferster, Ashley P; Priesol, Adrian J; Isildak, Huseyin

    2017-06-01

    To provide an overview of vestibular migraines presentation, pathology, and diagnosis, as well as an update on current diagnostic criteria. A review of the most recent literature on vestibular migraines was performed. Vestibular migraine is a process with significant impact on the quality of life for those afflicted with the disease, with attacks of spontaneous or positional vertigo and migraine symptoms lasting several minutes to 72h. Inner ear disease can co-exist with migraine and the vestibular symptoms occurring with vestibular migraine can mimic inner ear disorders providing a challenge for clinicians in establishing diagnosis. Recent diagnostic criteria for vestibular migraine proposed by a joint committee of the Bárány Society and the International Headache Society provide an important standard for clinical diagnosis and research endeavor. Vestibular migraine is a challenging disease process to both diagnose and treat. Proper diagnosis and treatment requires a thorough understanding of the current literature. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Hyperventilation-induced nystagmus in patients with vestibular schwannoma.

    Science.gov (United States)

    Califano, Luigi; Iorio, Giuseppina; Salafia, Francesca; Mazzone, Salvatore; Califano, Maria

    2015-02-01

    To determine the utility of the hyperventilation test (HVT) in the diagnosis of vestibular schwannoma (VS). A retrospective analysis of hyperventilation-induced nystagmus (HVIN) in 45 patients with unilateral VS. A tertiary referral center. Forty-five patients with VS; 30 patients with chronic vestibular neuritis; 20 healthy subjects with normal hearing and without symptoms or a history of vertigo, migraine, or neurological diseases (control group). Audiological and vestibular examination; "side-stream" measurement of end-tidal CO2 pressure (P(EtCO2)) to standardize the procedure; magnetic resonance imaging (MRI) centered on the cerebellopontine angle. An analysis of HVIN, its patterns, and its appearance threshold via the measurement of P(EtCO2) correlations with the tumor size. HVIN was observed in 40 of 45 cases (88.9%) in the schwannoma group and in 12 of 30 cases (40%) in the chronic vestibular neuritis group; HVIN was not observed in the control group (0/20 cases) (p hyperventilation event causes metabolic changes in the vestibular system and reveals a latent vestibular asymmetry. The presence of an excitatory pattern is the major criterion that suggests VS in patients with signs of unilateral vestibular deficit.

  18. Vestibular animal models: contributions to understanding physiology and disease.

    Science.gov (United States)

    Straka, Hans; Zwergal, Andreas; Cullen, Kathleen E

    2016-04-01

    Our knowledge of the vestibular sensory system, its functional significance for gaze and posture stabilization, and its capability to ensure accurate spatial orientation perception and spatial navigation has greatly benefitted from experimental approaches using a variety of vertebrate species. This review summarizes the attempts to establish the roles of semicircular canal and otolith endorgans in these functions followed by an overview of the most relevant fields of vestibular research including major findings that have advanced our understanding of how this system exerts its influence on reflexive and cognitive challenges encountered during daily life. In particular, we highlight the contributions of different animal models and the advantage of using a comparative research approach. Cross-species comparisons have established that the morpho-physiological properties underlying vestibular signal processing are evolutionarily inherent, thereby disclosing general principles. Based on the documented success of this approach, we suggest that future research employing a balanced spectrum of standard animal models such as fish/frog, mouse and primate will optimize our progress in understanding vestibular processing in health and disease. Moreover, we propose that this should be further supplemented by research employing more "exotic" species that offer unique experimental access and/or have specific vestibular adaptations due to unusual locomotor capabilities or lifestyles. Taken together this strategy will expedite our understanding of the basic principles underlying vestibular computations to reveal relevant translational aspects. Accordingly, studies employing animal models are indispensible and even mandatory for the development of new treatments, medication and technical aids (implants) for patients with vestibular pathologies.

  19. Treating vertigo with vestibular rehabilitation: results in 155 patients.

    Science.gov (United States)

    Bittar, R S M; Pedalini, M E B; Lorenzi, M C; Formigoni, L G

    2002-01-01

    Balance is fundamental to our daily activities and the vestibular system, together with vision and proprioceptive functions, are the main structures involved in this process. Dizziness is the main clinical manifestation of malfunction of these systems. The mechanisms of vestibular compensation are one of the most studied aspects since they play an important role in the patient's everyday activities. In this retrospective description of a series of cases the authors present their results in 155 patients that underwent a program of vestibular rehabilitation (VR). The program, first described by Cawthorne and Coosey, is based on mechanisms of potentiation of the cervico-ocular reflex and substitution of the lost vestibular cues for visual and somatosensory cues. The results were satisfactory (remission or partial cure) in 75.5% of the patients, with an average treatment time of up to 2 months and 5 or fewer sessions performed in most of the cases. The results were somewhat inferior in those cases in which a central vestibular lesion or more than one etiologic factor was present. The results of a subgroup of elderly patients (age > 65 years) were similar to those of the total number of studied subjects. Vestibular rehabilitation, associated to the specific etiological treatment, appears to be a very useful tool in the management of patients suffering from dizziness of all ages, although different clinical responses to the therapy may vary according to the presence of a central or a peripheral vestibular lesion or multiple etiological factors.

  20. Laboratory examinations for the vestibular system.

    Science.gov (United States)

    van de Berg, Raymond; Rosengren, Sally; Kingma, Herman

    2018-02-01

    In the last decades, researchers suggested that clinical assessment of labyrinthine function in detail became easy thanks to video head impulse tests (VHITs), vestibular evoked myogenic potential test (VEMP) and video-oculography (VOG). It has been argued that they can replace electronystagmography, the caloric and rotatory chair tests. This review addresses the latest evaluations of these tests and the opportunities they offer, but also the limitations in clinical practice. The VHIT and suppression head impulse test (SHIMP) are under ideal circumstances able to accurately identify deficits of the VOR in 3D. However, in a relevant part of the patient population, pupil tracking is inaccurate, video-goggles slip and VOR quantification is problematic. The dissociation between the VHIT and caloric test suggests that these tests are complementary. A new 3D-VOG technique claims to quantify eye torsion better than before, opening multiple diagnostic possibilities. VEMPs remain difficult to standardize. Variability in normal cervical vestibular-evoked myogenic potential amplitude is large. VEMPs become smaller or absent with age, raising questions of whether there is a lower normal limit at all. Recent research shows that the labyrinth is directly stimulated in the MRI offering new opportunities for diagnostics and research. In clinical practice, the VHIT, SHIMP, VEMP and new 3D-VOG techniques improve diagnostic power. Unfortunately, technical issues or variability prevent reliable quantitative evaluation in a part of the regular patient population. The traditional caloric and rotatory chair test can still be considered as valuable complementary tests.

  1. Treatment of peripheral vestibular dysfunction using photobiomodulation

    Science.gov (United States)

    Lee, Min Young; Hyun, Jai-Hwan; Suh, Myung-Whan; Ahn, Jin-Chul; Chung, Phil-Sang; Jung, Jae Yun; Rhee, Chung Ku

    2017-08-01

    Gentamicin, which is still used in modern medicine, is a known vestibular toxic agent, and various degrees of balance problems have been observed after exposure to this pharmacologic agent. Photobiomodulation is a candidate therapy for vertigo due to its ability to reach deep inner ear organs such as the cochlea. Previous reports have suggested that photobiomodulation can improve hearing and cochlea function. However, few studies have examined the effect of photobiomodulation on balance dysfunction. We used a rat model to mimic human vestibulopathy resulting from gentamicin treatment and evaluated the effect of photobiomodulation on vestibular toxicity. Slow harmonic acceleration (SHA) rotating platform testing was used for functional evaluation and both qualitative and quantitative epifluorescence analyses of cupula histopathology were performed. Animals were divided into gentamicin only and gentamicin plus laser treatment groups. Laser treatment was applied to one ear, and function and histopathology were evaluated in both ears. Decreased function was observed in both ears after gentamicin treatment, demonstrated by low gain and no SHA asymmetry. Laser treatment minimized the damage resulting from gentamicin treatment as shown by SHA asymmetry and recovered gain in the treated ear. Histology results reflected the functional results, showing increased hair cell density and epifluorescence intensity in laser-treated cupulae.

  2. Galvanic vestibular stimulation speeds visual memory recall.

    Science.gov (United States)

    Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

    2008-08-01

    The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

  3. Cooper pairs in atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, 19716 Delaware (United States); Dussel, G. G. [Departamento de Fisica J.J. Giambiagi, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Dukelsky, J.; Sarriguren, P. [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2008-12-15

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  4. Vestibular and Attractor Network Basis of the Head Direction Cell Signal in Subcortical Circuits

    Directory of Open Access Journals (Sweden)

    Benjamin J Clark

    2012-03-01

    Full Text Available Accurate navigation depends on a network of neural systems that encode the moment-to-moment changes in an animal’s directional orientation and location in space. Within this navigation system are head direction (HD cells, which fire persistently when an animal’s head is pointed in a particular direction (Sharp et al., 2001a; Taube, 2007. HD cells are widely thought to underlie an animal’s sense of spatial orientation, and research over the last 25+ years has revealed that this robust spatial signal is widely distributed across subcortical and cortical limbic areas. Much of this work has been directed at understanding the functional organization of the HD cell circuitry, and precisely how this signal is generated from sensory and motor systems. The purpose of the present review is to summarize some of the recent studies arguing that the HD cell circuit is largely processed in a hierarchical fashion, following a pathway involving the dorsal tegmental nuclei → lateral mammillary nuclei → anterior thalamus → parahippocampal and retrosplenial cortical regions. We also review recent work identifying bursting cellular activity in the HD cell circuit after lesions of the vestibular system, and relate these observations to the long held view that attractor network mechanisms underlie HD signal generation. Finally, we summarize the work to date suggesting that this network architecture may reside within the tegmento-mammillary circuit.

  5. Improving Sensorimotor Function Using Stochastic Vestibular Stimulation

    Science.gov (United States)

    Galvan, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Mulavara, A. P.; Oman, C. M.

    2014-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transition phases. Post flight sensorimotor changes may include postural and gait instability, spatial disorientation, and visual performance decrements, all of which can degrade operational capabilities of the astronauts and endanger the crew. Crewmember safety would be improved if these detrimental effects of spaceflight could be mitigated by a sensorimotor countermeasure and even further if adaptation to baseline could be facilitated. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor performance through stochastic resonance (SR). The SR phenomenon occurs when the response of a nonlinear system to a weak input signal is optimized by the application of a particular nonzero level of noise. Two studies have been initiated to investigate the beneficial effects and potential practical usage of SVS. In both studies, electrical vestibular stimulation is applied via electrodes on the mastoid processes using a constant current stimulator. The first study aims to determine the repeatability of the effect of vestibular stimulation on sensorimotor performance and perception in order to better understand the practical use of SVS. The beneficial effect of low levels of SVS on balance performance has been shown in the past. This research uses the same balance task repeated multiple times within a day and across days to study the repeatability of the stimulation effects. The balance test consists of 50 sec trials in which the subject stands with his or her feet together, arms crossed, and eyes closed on compliant foam. Varying levels of SVS, ranging from 0-700 micro A, are applied across different trials. The subject-specific optimal SVS level is that which results in the best balance performance as measured by inertial

  6. Vestibular syndrome: a change in internal spatial representation.

    Science.gov (United States)

    Borel, L; Lopez, C; Péruch, P; Lacour, M

    2008-12-01

    The vestibular system contributes to a wide range of functions from reflexes to spatial representation. This paper reviews behavioral, perceptive, and cognitive data that highlight the role of changes in internal spatial representation on the vestibular syndrome. Firstly, we review how visual vertical perception and postural orientation depend on multiple reference frames and multisensory integration and how reference frames are selected according to the status of the peripheral vestibular system (i.e., unilateral or bilateral hyporeflexia), the environmental constraints (i.e., sensory cues), and the postural constraints (i.e., balance control). We show how changes in reference frames are able to modify vestibular lesion-induced postural and locomotor deficits and propose that fast changes in reference frame may be considered as fast-adaptive processes after vestibular loss. Secondly, we review data dealing with the influence of vestibular loss on higher levels of internal representation sustaining spatial orientation and navigation. Particular emphasis is placed on spatial performance according to task complexity (i.e., the required level of spatial knowledge) and to the sensory cues available to define the position and orientation within the environment (i.e., real navigation in darkness or visual virtual navigation without any actual self-motion). We suggest that vestibular signals are necessary for other sensory cues to be properly integrated and that vestibular cues are involved in extrapersonal space representation. In this respect, vestibular-induced changes would be based on a dynamic mental representation of space that is continuously updated and that supports fast-adaptive processes.

  7. Superheavy nuclei and fission barriers

    Science.gov (United States)

    Lu, Bing-Nan; Zhao, Jie; Zhao, En-Guang; Zhou, Shan-Gui

    In this chapter, we will present relativistic mean field (RMF) description of heavy and superheavy nuclei (SHN). We will discuss the shell structure and magic numbers in the mass region of SHN, binding energies and α decay Q values, shapes of ground states and potential energy surfaces and fission barriers. We particularly focus on the multidimensionally-constrained covariant density functional theories (CDFT) and the applications of CDFT to the study of exotic nuclear shapes and fission barriers.

  8. Isosorbide delays gentamicin-induced vestibular sensory cell death.

    Science.gov (United States)

    Takumida, Masaya; Anniko, Matti

    2005-01-01

    The efficacy of isosorbide for protection from vestibular sensory cell damage was investigated. The effects of isosorbide on gentamicin-induced production of nitric oxide (NO) and reactive oxygen species (ROS) were studied by means of the fluorescence indicators 4,5-diaminofluorescein diacetate and dihydrotetramethylrosamine. The effect on gentamicin-induced vestibular sensory cell damage was examined by using an in vitro LIVE/DEAD system. Isosorbide inhibited the production of both NO and ROS. Isosorbide limited the vestibular sensory cell damage caused by gentamicin. It is, therefore, suggested that isosorbide may help to treat inner ear disorders.

  9. Diagnosis of acute unilateral vestibular deficit by virtual reality.

    Science.gov (United States)

    Mora, Renzo; Cesarani, Antonio; Meloni, Francesco; Passali, Francesco Maria; Mora, Francesco; Passali, Giulio Cesare; Barbieri, Marco

    2004-01-01

    The aim of our study was to establish a new diagnostic approach, through the use of virtual reality, to the study of the subjective vertical bar in unilateral peripheral vestibular dysfunction. We subjected 174 patients with unilateral peripheral vestibular dysfunction (ages 18-82 years) to vestibular diagnosis with the virtual reality system. We changed the classic configuration of the subjective visual vertical into a subjective visual horizontal bar. This technique revealed values of the subjective visual horizontal outside the normal range in 91% of patients.

  10. Vestibular rehabilitation using a wide field of view virtual environment.

    Science.gov (United States)

    Sparto, P J; Furman, J M; Whitney, S L; Hodges, L F; Redfern, M S

    2004-01-01

    This paper presents a theoretical justification for using a wide field of view (FOV) virtual reality display system for use in vestibular rehabilitation. A wide FOV environment offers some unique features that may be beneficial to vestibular rehabilitation. Primarily, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. If this hypothesis is correct, then wide FOV systems will have an advantage over narrow field of view input devices such as head mounted or desktop displays. Devices that we have incorporated into our system that are critical for monitoring improvement in this clinical population will also be described.

  11. Noisy Neurons

    Indian Academy of Sciences (India)

    IAS Admin

    Nerves are fibres that conduct electrical signals and hence pass on information from and to the brain. Nerves are made of nerve cells called neurons (Figure 1). Instructions in our body are sent via electrical signals that present themselves as variations in the potential across neuronal membranes. These potential differences ...

  12. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...

  13. EMG responses of the vertical eye muscles to dynamic and static natural vestibular stimulation about different axes in alert rabbits.

    Science.gov (United States)

    Favilla, M; Ghelarducci, B; La Noce, A; Starita, A

    1983-12-05

    The EMG responses of the vertical eye muscles have been recorded in alert intact rabbits submitted to both dynamic and static natural vestibular stimulations about different axes. Following dynamic vestibular stimulation, the phase lead of the EMG response with respect to head position as well as its sensitivity increased with stimulus frequency in all the stimulation modalities. This indicates a progressive recruitment by the stimulus of the second-order vestibular neurons related to semicircular canals. The sensitivity of the response was consistently higher in the effective intermediate roll-pitch modality for all the 4 muscles. Following static stimulation, the EMG response showed an asymmetric modulation. The excitatory response was always higher than the inhibitory one and linearly related with the stimulus. Also for the static stimulation the amplitude of the response was significantly higher when the animal was tilted about the effective intermediate roll-pitch axis for all the 4 muscles. The presence of a maximal EMG response in the same modality for both static and dynamic stimulation indicates a similar spatial organization of those subgroups of ampullar and macular receptors projecting to the same eye muscle.

  14. Outcomes after vestibular rehabilitation and Wii® therapy in patients with chronic unilateral vestibular hypofunction.

    Science.gov (United States)

    Verdecchia, Daniel H; Mendoza, Marcela; Sanguineti, Florencia; Binetti, Ana C

    2014-01-01

    Vestibular rehabilitation therapy is an exercise-based programme designed to promote central nervous system compensation for inner ear deficit. The objective of the present study was to analyse the differences in the perception of handicap, the risk of falls, and gaze stability in patients diagnosed with chronic unilateral vestibular hypofunction before and after vestibular rehabilitation treatment with complementary Wii® therapy. A review was performed on the clinical histories of patients in the vestibular rehabilitation area of a university hospital between April 2009 and May 2011. The variables studied were the Dizziness Handicap Inventory, the Dynamic Gait Index and dynamic visual acuity. All subjects received complementary Wii® therapy. There were 69 cases (41 woman and 28 men), with a median age of 64 years. The initial median Dizziness Handicap Inventory score was 40 points (range 0-84, percentile 25-75=20-59) and the final, 24 points (range 0-76, percentile 25-75=10.40), P<.0001. The initial median for the Dynamic Gait Index score was 21 points (range 8-24, percentile 25-75=17.5-2.3) and the final, 23 (range 12-24, percentile 25-75=21-23), P<.0001. The initial median for dynamic visual acuity was 2 (range 0-6, percentile 25-75=1-4) and the final, 1 (range 0-3, percentile 25-75=0-2), P<.0001. A reduction was observed in the Dizziness Handicap Inventory Values. Values for the Dynamic Gait Index increased and dynamic visual acuity improved. All these variations were statistically significant. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

  15. Effects of electrotactile vestibular substitution on rehabilitation of patients with bilateral vestibular loss.

    Science.gov (United States)

    Barros, Camila Giacomo Carneiro; Bittar, Roseli Saraiva Moreira; Danilov, Yuri

    2010-06-07

    The present study evaluated the effectiveness of electrotactile tongue biofeedback (BrainPort((R))) as a sensory substitute for the vestibular apparatus in patients with bilateral vestibular loss (BVL) who did not have a good response to conventional vestibular rehabilitation (VR). Seven patients with BVL were trained to use the device. Stimulation on the surface of the tongue was created by a dynamic pattern of electrical pulses and the patient was able to adjust the intensity of stimulation and spatially centralize the stimulus on the electrode array. Patients were directed to continuously adjust head orientation and to maintain the stimulus pattern at the center of the array. Postural tasks that present progressive difficulties were given during the use of the device. Pre- and post-treatment distribution of the sensory organization test (SOT) composite score showed an average value of 38.3+/-8.7 and 59.9+/-11.3, respectively, indicating a statistically significant improvement (p=0.01). Electrotactile tongue biofeedback significantly improved the postural control of the study group, even if they had not improved with conventional VR. The electrotactile tongue biofeedback system was able to supply additional information about head position with respect to gravitational vertical orientation in the absence of vestibular input, improving postural control. Patients with BVL can integrate electrotactile information in their postural control in order to improve stability after conventional VR. These results were obtained and verified not only by the subjective questionnaire but also by the SOT composite score. The limitations of the study are the small sample size and short duration of the follow-up. The current findings show that the sensory substitution mediated by electrotactile tongue biofeedback may contribute to the improved balance experienced by these patients compared to VR. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Characteristics of human gait related variables in association with vestibular system disorders.

    Science.gov (United States)

    Ishikawa, K; Edo, M; Yokomizo, M; Togawa, K

    1995-01-01

    Gait analysis was performed in patients with vestibular system disorders, using foot switches and electromyography. They were divided into three groups: 11 cases with vestibular neuronitis (VN), 10 cases with large acoustic neuroma (LAN) who had central lesion evidenced by neurotological examinations, and 10 cases with olivopontocerebellar atrophy (OPCA). A total of 14 healthy adults served as controls. Results showed that time from heel strike to forefoot strike was the most sensitive variable to indicate gait abnormality but had no specificity. As for the variables of stance, swing, and time to reach the initial peak of the tibialis anterior's activity from forefoot off, occurrence rate of abnormality was high in the OPCA group, followed by the LAN and VN groups. Concerning the double support period which is related with body weight transfer from one leg to the other, the LAN and OPCA groups showed higher occurrence rate of abnormality than the VN group. These differences among the three groups could reflect different effects to the gait control systems caused by lesion.

  17. [Acute isolated vestibular paralysis. A clinical and electronystagmographic follow-up study in 28 patients].

    Science.gov (United States)

    Reker, U; Rudert, H

    1977-04-01

    Twenty-eight patients with unilateral acute vestibular paralysis (vestibular neuronitis) were examined after a period of 4-140 months. Seventeen of these patients were examined by electronystagmography with caloric stimuli at 44 degrees, 30 degrees, 17 degrees and 0 degrees C. Most were free of subjective symptoms only one-third had slight unsteadiness after sudden head movement. Subjective symptoms were independent of the presence of permanent canal paralysis or partial recovery of caloric excitability. Spontaneous nystagmus of 3-6,6% intensities was found in 11 of 17 patients. The normal limit for physiological spontaneous nystagmus should therefore be below 3 degrees/s. The most reliable parameter was the maximum velocity of the slow phase, as a mean value of the 4 caloric responses (values corrected for spontaneous nystagmus). The results were: 6 patients with persistent canal paralysis; 4 patients with considerable hypoexcitability; and 7 patients with moderate hypoexcitability. In no patient complete restoration of normal caloric response was found. This is attributed to the described method of caloric testing, which permits exact measurement of small side differences in excitability.

  18. The statistics of the vestibular input experienced during natural self-motion differ between rodents and primates.

    Science.gov (United States)

    Carriot, Jérome; Jamali, Mohsen; Chacron, Maurice J; Cullen, Kathleen E

    2017-04-15

    In order to understand how the brain's coding strategies are adapted to the statistics of the sensory stimuli experienced during everyday life, the use of animal models is essential. Mice and non-human primates have become common models for furthering our knowledge of the neuronal coding of natural stimuli, but differences in their natural environments and behavioural repertoire may impact optimal coding strategies. Here we investigated the structure and statistics of the vestibular input experienced by mice versus non-human primates during natural behaviours, and found important differences. Our data establish that the structure and statistics of natural signals in non-human primates more closely resemble those observed previously in humans, suggesting similar coding strategies for incoming vestibular input. These results help us understand how the effects of active sensing and biomechanics will differentially shape the statistics of vestibular stimuli across species, and have important implications for sensory coding in other systems. It is widely believed that sensory systems are adapted to the statistical structure of natural stimuli, thereby optimizing coding. Recent evidence suggests that this is also the case for the vestibular system, which senses self-motion and in turn contributes to essential brain functions ranging from the most automatic reflexes to spatial perception and motor coordination. However, little is known about the statistics of self-motion stimuli actually experienced by freely moving animals in their natural environments. Accordingly, here we examined the natural self-motion signals experienced by mice and monkeys: two species commonly used to study vestibular neural coding. First, we found that probability distributions for all six dimensions of motion (three rotations, three translations) in both species deviated from normality due to long tails. Interestingly, the power spectra of natural rotational stimuli displayed similar structure

  19. Vestibular compensation after vestibular schwannoma surgery: normalization of the subjective visual vertical and disability.

    Science.gov (United States)

    Batuecas-Caletrio, Angel; Santacruz-Ruiz, Santiago; Muñoz-Herrera, Angel; Sousa, Pablo; Otero, Alvaro; Perez-Fernandez, Nicolas

    2013-05-01

    The degree of caloric weakness before surgery influences faster or slower recovery of patients undergoing vestibular schwannoma surgery. The Dizziness Handicap Inventory (DHI) is a good index to show the recovery of patients as it relates directly to an improvement or not of the subjective visual vertical (SVV). To evaluate the process of recovery of patients as measured by the SVV and the DHI after surgical removal of vestibular schwannoma. We studied 24 consecutive patients of the University Hospital of Salamanca who underwent vestibular schwannoma surgery. We assessed age, tumour size, degree of canalicular weakness and preoperative SVV, and their relationship with DHI and SVV at discharge and also at 1, 3 and 6 months postoperatively. Patients with lesser degrees of caloric weakness took longer to normalize SVV than those with a higher caloric weakness before surgery (p < 0.05). There was a significant correlation between DHI and improvements in SVV with time. The differences disappeared in 6 months where all patients, with greater or lesser degree of caloric weakness, had the same results.

  20. The effect of vestibular rehabilitation on adults with bilateral vestibular hypofunction: a systematic review.

    Science.gov (United States)

    Porciuncula, Franchino; Johnson, Connie C; Glickman, Leslie B

    2012-01-01

    Adults with bilateral vestibular hypofunction (BVH) experience significant disability. A systematic review assessed evidence for vestibular rehabilitation (VR). NUMBER OF STUDIES: 14 studies. Search identification of studies based on inclusion criteria: (a) population: adults with BVH of peripheral origin; (b) interventions: vestibular exercises, balance training, education, or sensory prosthetics; (c) comparison: single interventions or compared to another psychophysical intervention, placebo, or healthy population; (d) outcomes: based on International Classification of Functioning, Disability and Health (ICF) Body Functions and Structure, Activity, and Participation; (e) study designs: prospective and interventional, Levels of Evidence I to III per Centre of Evidence-based Medicine grading. Coding and appraisal based on ICF framework and strength of evidence synthesis. Five Level II studies and nine Level III studies: All had outcomes on gaze and postural stability, five with outcomes on gait speed and perceptions of oscillopsia and disequilibrium. (a) Moderate evidence strength on improved gaze and postural stability (ICF-Body Functions) following exercise-based VR; (b) Inadequate number of studies supporting benefit of VR on ICF-Participation outcomes; (c) Sensory prosthetics in early phase of development. Moderate evidence strength in support of VR from an impairment level; clinical practice and research needed to explore interventions extending to ICF-Activity and Participation.

  1. Effects of vestibular rehabilitation and social reinforcement on recovery following ablative vestibular surgery.

    Science.gov (United States)

    Mruzek, M; Barin, K; Nichols, D S; Burnett, C N; Welling, D B

    1995-07-01

    This study investigated the relative effects of vestibular rehabilitation (VR) and social reinforcement (SR) on recovery following ablative vestibular surgery. Twenty-four subjects were randomly assigned to three treatment groups of either VR with SR, VR without SR, or general range of motion (ROM) exercises with SR. Outcome measures included equilibrium scores in dynamic posturography, asymmetry index in rotation testing, motion sensitivity quotient (MSQ), and dizziness handicap inventory (DHI). A multiple comparison of the overall outcome measures showed no significant differences in group performance over an 8-week period. When individual outcome measures were compared, MSQ and DHI results at the end of the 8-week treatment period revealed less motion sensitivity and dizziness handicap in groups who received VR, with or without SR, as compared with the group who received ROM exercises. These results suggest that after a vestibular injury most patients can effectively utilize central compensation mechanisms to recover from such an injury, regardless of the type of therapeutic intervention used. On the other hand, the reduction in motion sensitivity and dizziness handicap for patients who received VR could indicate a more rapid and complete recovery for these patients. This investigation is continuing as a long-term follow-up study to determine whether there are any long-term benefits in participating in a VR program.

  2. Saccadic entropy of head impulses in acute unilateral vestibular loss

    Directory of Open Access Journals (Sweden)

    Li-Chun Hsieh

    2017-10-01

    Conclusion: Entropy and gain analysis of HIT using wireless electro-oculography system could be used to detect the VOR dysfunctions of AUVL and may become effective methods for evaluating vestibular disorders.

  3. Audio-Vestibular Findings in Increased Intracranial Hypertension Syndrome.

    Science.gov (United States)

    Çoban, Kübra; Aydın, Erdinç; Özlüoğlu, Levent Naci

    2017-04-01

    Idiopathic intracranial hypertension (IIH) can be manifested by audiological and vestibular complaints. The aim of the present study is to determine the audio-vestibular pathologies and their pathophysiologies in this syndrome by performing current audio-vestibular tests. The study was performed prospectively on 40 individuals (20 IIH patients, 20 healthy volunteers). Pure tone audiometry, tympanometry, vestibular evoked myogenic potentials, and electronystagmography tests were performed in both groups and the results were compared. The mean age of both groups was found to be 30.2±18.7. There were 11 females and 9 males in each group. The study group patients had significantly worse hearing levels. Pure tone averages were significantly higher in both ears of the study group (pintracranial pressure may affect the inner ear with similar mechanisms as in hydrops.

  4. Natural history of hearing deterioration in intracanalicular vestibular schwannoma

    NARCIS (Netherlands)

    Pennings, R.J.E.; Morris, D.P.; Clarke, L.; Allen, S.; Walling, S.; Bance, M.L.

    2011-01-01

    BACKGROUND: Intracanalicular vestibular schwannomas have a range of treatment options that can preserve hearing: microsurgery, stereotactic radiotherapy, and conservative observation. OBJECTIVE: To evaluate the natural course of hearing deterioration during a period of conservative observation.

  5. Inner ear malformations in siblings presenting with vestibular ...

    African Journals Online (AJOL)

    frequency 's' sounds. ... endolymphatic ducts and sacs, and a type II incomplete partition. (classic Mondini) defect (Figs 3 and 4). ABR/auditory ... MRI confirmed bilateral enlarged vestibular aqueducts and type. II incomplete partition defects. He was ...

  6. Vestibular stimulation: A simple but effective intervention in diabetes care.

    Science.gov (United States)

    Sailesh, Kumar Sai; Archana, R; Mukkadan, J K

    2015-01-01

    Despite the complexities of the relationship between vestibular stimulation and endocrine disorders being well known, research efforts to understand these complexities are lacking. Interestingly vestibular stimulation may potentially prevent/delay development/progression of diabetes. Here we review the science behind this concept and highlight the need for necessary translational research in this area. Current evidence supports the use of vestibular stimulation not only as a potential intervention to prevent or delay the development of diabetes mellitus in at-risk population, but also to use it as supplementary therapy for diabetic patients management. We urge clinicians to recommend vestibular stimulation by simple means like swing as a goal in maintaining a healthy lifestyle.

  7. Probing the human vestibular system with galvanic stimulation

    National Research Council Canada - National Science Library

    Richard C. Fitzpatrick; Brian L. Day

    2004-01-01

    .... This paper examines the electrophysiology and anatomy of the vestibular organs and the effects of GVS on human balance control and develops a model that explains the observed balance responses...

  8. Distinct spontaneous shrinkage of a sporadic vestibular schwannoma

    DEFF Research Database (Denmark)

    Huang, Xiaowen; Cayé-Thomasen, Per; Stangerup, Sven-Eric

    2013-01-01

    We present a case with outspoken spontaneous vestibular schwannoma shrinkage and review the related literature. The patient was initially diagnosed with a left-sided, intrameatal vestibular schwannoma, which subsequently grew into the cerebello-pontine angle (CPA), followed by total shrinkage...... of the CPA component without any intervention over a 12-year observation period. The literature on spontaneous tumor shrinkage was retrieved by searching the subject terms "vestibular schwannoma, conservative management" in PubMed/MEDLINE database, without a time limit. Of the published data, the articles...... on "shrinkage" or "negative growth" or "regression" or "involution" of the tumor were selected, and the contents on the rate, extent and mechanism of spontaneous tumor shrinkage were extracted and reviewed. The reported rate of spontaneous shrinkage of vestibular schwannoma is 5-10% of patients managed...

  9. Vestibulary rehabilitation--election treatment method for compensating vestibular impairment.

    Science.gov (United States)

    Georgescu, Mădălina; Stoian, Sorina; Mogoantă, Carmen Aurelia; Ciubotaru, Gh V

    2012-01-01

    This paper aims to reveal the actual benefit of vestibular rehabilitation (VR) in patients with unilateral vestibular loss. Case report of a young female patient with acute unilateral vestibular loss due to facial nerve schwannoma developed above the internal auditory canal (IAC) from where it seems to have entered the IAC. Betahistine associated to VR treatment was recommended due to persisting imbalance after tumor removal. The benefit of the combined therapy was evaluated objectively (sensory organization test) and subjectively (questionnaires regarding self-perception of the deficit in quality of life). Both evaluations revealed great improvement in stability (SOT scores) as well as in health-related quality of life (HRQoL)--improvement of self-perception scores of disequilibrium in all questionnaires used. Combined recommended treatment (betahistine and VR) improves HRQoL after acute unilateral vestibular loss. It reduces self-perceived disability and intensity of symptoms during usual activities.

  10. [Presbyastasis and application of vestibular rehabilitation in geriatrics].

    Science.gov (United States)

    Costa de Araujo, P; Demanez, L; Lechien, J; Bauvir, P; Petermans, J

    2011-03-01

    Balance disorders can have a major functional impact among the elderly. The main risk is falling. Three elements are implicated in the loss of balance: vision, proprioception and the vestibular system. This article will discuss mainly vestibular damage and its implications. The assessment of balance disorders, particularly in geriatric patients, is based on validated scales composed of several items. These provide scores and are based on the results of chronometric measurements. They can be useful for the application of Vestibular Rehabilitation (VR), a technique improving the adaptation and autonomy of these patients. Vestibular rehabilitation is therefore part of an overall support, the goal of therapy being to improve daily life and to reduce the risk of falls.

  11. Vestibular rehabilitation: clinical benefits to patients with Parkinson's disease.

    Science.gov (United States)

    Zeigelboim, Bianca Simone; Klagenberg, Karlin Fabianne; Teive, Hélio A Ghizoni; Munhoz, Renato Puppi; Martins-Bassetto, Jackeline

    2009-06-01

    To evaluate the effectiveness of the vestibular rehabilitation (VR) exercises by means of an assessment before and after the application of the Brazilian version of the Dizziness Handicap Inventory (DHI) questionnaire. Twelve patients were studied, the following procedures were carried out: anamnesis, otorhinolaryngological and vestibular evaluation, and the application of the DHI before and after the VR. Clinically resting tremors and subjective postural instability were the motor complaints most frequently associated with complaints of vertigo in 12 cases (100%); in the vestibular exam, all the patients presented abnormalities, frequently from the uni and bilateral peripheral vestibular deficiency syndromes in 10 cases (83.3%); there was significant improvement in the physical, functional and emotional aspects of the DHI after the completion of the VR. The VR following the Cawthorne and Cooksey protocol were shown to be useful in managing subjective complaints of several aspects evaluated in this protocol.

  12. Clinical evaluation of elderly people with chronic vestibular disorder

    OpenAIRE

    Juliana Maria Gazzola; Fernando Freitas Ganança; Mayra Cristina Aratani; Monica Rodrigues Perracini; Maurício Malavasi Ganança

    2006-01-01

    A tontura de origem vestibular é comum entre idosos. OBJETIVO: Caracterizar idosos com disfunção vestibular crônica em relação aos dados sociodemográficos, clínico-funcionais e otoneurológicos. MATERIAL E MÉTODO: Estudo de casos que incluiu 120 idosos com disfunção vestibular crônica. Foram realizadas análises descritivas simples. RESULTADOS: A 5,77±amostra apresentou maioria feminina (68,3%), com média etária de 73,40 1,84±anos. O número médio de doenças associadas ao quadro vestibular foi d...

  13. Vestibular dysfunction in a child with embryonic exposure to accutane.

    Science.gov (United States)

    Westerman, S T; Gilbert, L M; Schondel, L

    1994-05-01

    Children with a history of embryonic exposure to Accutane (isotretinoin) are at great risk for major physical malformations, brain malformations, and decreased intelligence. A case is presented of a 4-year 7-month-old black male with a history of embryonic exposure to Accutane who was born with embryopathy that includes bilateral major ear deformities. The child has a significant bilateral conductive hearing loss, and, in addition, a left sided sensorineural loss. Vestibular function testing revealed evidence of peripheral and central vestibular dysfunction. A course of diphenhydramine hydrochloride and Donnatal (phenobarbital, hyoscyamine sulfate, atropine sulfate, and scopolamine hydrobromide) significantly alleviated the symptoms of vestibular dysfunction. Otologic management of these children should include clinical documentation of the external deformities, evaluation of cochlear function, and early auditory habilitation. Vestibular function should also be evaluated in all children with a history of embryonic exposure to isotretinoin.

  14. Metabolic Maturation of Auditory Neurones in the Superior Olivary Complex.

    Directory of Open Access Journals (Sweden)

    Barbara Trattner

    Full Text Available Neuronal activity is energetically costly, but despite its importance, energy production and consumption have been studied in only a few neurone types. Neuroenergetics is of special importance in auditory brainstem nuclei, where neurones exhibit various biophysical adaptations for extraordinary temporal precision and show particularly high firing rates. We have studied the development of energy metabolism in three principal nuclei of the superior olivary complex (SOC involved in precise binaural processing in the Mongolian gerbil (Meriones unguiculatus. We used immunohistochemistry to quantify metabolic markers for energy consumption (Na(+/K(+-ATPase and production (mitochondria, cytochrome c oxidase activity and glucose transporter 3 (GLUT3. In addition, we calculated neuronal ATP consumption for different postnatal ages (P0-90 based upon published electrophysiological and morphological data. Our calculations relate neuronal processes to the regeneration of Na(+ gradients perturbed by neuronal firing, and thus to ATP consumption by Na(+/K(+-ATPase. The developmental changes of calculated energy consumption closely resemble those of metabolic markers. Both increase before and after hearing onset occurring at P12-13 and reach a plateau thereafter. The increase in Na(+/K(+-ATPase and mitochondria precedes the rise in GLUT3 levels and is already substantial before hearing onset, whilst GLUT3 levels are scarcely detectable at this age. Based on these findings we assume that auditory inputs crucially contribute to metabolic maturation. In one nucleus, the medial nucleus of the trapezoid body (MNTB, the initial rise in marker levels and calculated ATP consumption occurs distinctly earlier than in the other nuclei investigated, and is almost completed by hearing onset. Our study shows that the mathematical model used is applicable to brainstem neurones. Energy consumption varies markedly between SOC nuclei with their different neuronal properties

  15. Effect of gravity on vestibular neural development

    Science.gov (United States)

    Ross, M. D.; Tomko, D. L.

    1998-01-01

    The timing, molecular basis, and morphophysiological and behavioral consequences of the interaction between external environment and the internal genetic pool that shapes the nervous system over a lifetime remain important questions in basic neuroscientific research. Space station offers the opportunity to study this interaction over several life cycles in a variety of organisms. This short review considers past work in altered gravity, particularly on the vestibular system, as the basis for proposing future research on space station, and discusses the equipment necessary to achieve goals. It is stressed that, in keeping with the international investment being made in this research endeavor, both the questions asked and the technologies to be developed should be bold. Advantage must be taken of this unique research environment to expand the frontiers of neuroscience. Copyright 1998 Published by Elsevier Science B.V.

  16. Vestibular ataxia and its measurement in man

    Science.gov (United States)

    Fregly, A. R.

    1974-01-01

    Methods involved in and results obtained with a new comprehensive ataxia test battery are described, and definitions of spontaneous and induced vestibular ataxia in man are given in terms of these findings. In addition, the topic of alcohol-induced ataxia in relation to labyrinth function is investigated. Items in the test battery comprise a sharpened Romberg test, in which the subject stands on the floor with eyes closed and arms folded against his chest, feet heel-to-toe, for 60 seconds; an eyes-open walking test; an eyes-open standing test; an eyes-closed standing test; an eyes-closed on-leg standing test; an eyes-closed walk a line test; an eyes-closed heel-to-toe walking test; and supplementary ataxia tests such as the classical Romberg test.

  17. Effect of gravity on vestibular neural development.

    Science.gov (United States)

    Ross, M D; Tomko, D L

    1998-11-01

    The timing, molecular basis, and morphophysiological and behavioral consequences of the interaction between external environment and the internal genetic pool that shapes the nervous system over a lifetime remain important questions in basic neuroscientific research. Space station offers the opportunity to study this interaction over several life cycles in a variety of organisms. This short review considers past work in altered gravity, particularly on the vestibular system, as the basis for proposing future research on space station, and discusses the equipment necessary to achieve goals. It is stressed that, in keeping with the international investment being made in this research endeavor, both the questions asked and the technologies to be developed should be bold. Advantage must be taken of this unique research environment to expand the frontiers of neuroscience. Copyright 1998 Published by Elsevier Science B.V.

  18. Vestibular rehabilitation in elderly patients with dizziness

    OpenAIRE

    Zanardini, Francisco Halilla; Zeigelboim, Bianca Simone [UNIFESP; Jurkiewicz, Ari Leon; Marques, Jair Mendes; Martins-Bassetto,Jackeline

    2007-01-01

    TEMA: o envelhecimento populacional é um processo natural, manifesta-se por um declínio das funções de diversos órgãos. A reabilitação vestibular (RV) é um processo terapêutico que visa promover a redução significativa dos sintomas labirínticos. OBJETIVO: verificar os benefícios dos exercícios de RV por meio da avaliação pré e pós-aplicação do questionário Dizziness Handicap Inventory (DHI) - adaptação brasileira. MÉTODO: participaram deste estudo oito idosos com queixa de tontura, na faixa e...

  19. Treatment of Vestibular Dysfunction Using a Portable Stimulator

    Science.gov (United States)

    2017-04-01

    AWARD NUMBER: W81XWH-14-2-0012 TITLE: Treatment of Vestibular Dysfunction Using a Portable Stimulator PRINCIPAL INVESTIGATOR: Jorge M...PAGE UU 17 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 Treatment of Vestibular...noise over a 2week stimulation paradigm Significant Results of Year 3 1) Research flyers have been posted to aid in recruitment. Fourteen

  20. Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric

    2012-01-01

    To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hear......To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea...