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otolithic projections

Catherine A McCormick, Shannon Gallagher, Evan Cantu-Hertzler, Scarlet Woodrick
The nucleus medialis is the main first-order target of the mechanosensory lateral line (LL) system. This report definitively demonstrates that mechanosensory LL inputs also terminate in the ipsilateral dorsal portion of the descending octaval nucleus (dDO) in the goldfish. The dDO, which is the main first-order auditory nucleus in bony fishes, includes neurons that receive direct input from the otolithic end organs of the inner ear and project to the auditory midbrain. There are two groups of such auditory projection neurons: medial and lateral...
2016: Brain, Behavior and Evolution
Derek M Miller, James F Baker, W Zev Rymer
OBJECTIVE: 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. METHODS: 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...
April 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Thomas Chartrand, Gin McCollum, Douglas A Hanes, Richard D Boyle
Sensory contribution to perception and action depends on both sensory receptors and the organization of pathways (or projections) reaching the central nervous system. Unlike the semicircular canals that are divided into three discrete sensitivity directions, the utricle has a relatively complicated anatomical structure, including sensitivity directions over essentially 360° of a curved, two-dimensional disk. The utricle is not flat, and we do not assume it to be. Directional sensitivity of individual utricular afferents decreases in a cosine-like fashion from peak excitation for movement in one direction to a null or near null response for a movement in an orthogonal direction...
February 2016: Journal of Mathematical Biology
Michel Toupet, Christian Van Nechel, Alexis Bozorg Grayeli
OBJECTIVE: The aim of this study was to evaluate the effect of initial rod position on the subjective visual vertical (SVV) tilt and to investigate the effect of sex and age on the SVV tilt induced by this initial position. STUDY DESIGN: Prospective cross-sectional study. SETTING: Tertiary referral center. PATIENTS: The study included 6598 consecutive patients with a large range of vestibular disorders and 333 control subjects...
July 2015: Otology & Neurotology
Joanne Rimmer, Mitesh Patel, Kiran Agarwal, Claire Hogg, Qadeer Arshad, Jonny Harcourt
HYPOTHESIS: Patients with primary ciliary dyskinesia (PCD) have absent or reduced otoconial function compared to the normal population. BACKGROUND: Investigations in zebrafish show that ciliation is important for the development of the otolith organs, but this has never been evaluated in humans. PCD is a congenital defect of ciliary structure. We undertook a pilot study to determine whether patients with PCD have absent or reduced otoconial function compared to the normal population...
April 2015: Otology & Neurotology
Rommel H Maneja, R Dineshram, Vengatesen Thiyagarajan, Anne Berit Skiftesvik, Andrea Y Frommel, Catriona Clemmesen, Audrey J Geffen, Howard I Browman
Elevated anthropogenic pCO2 can delay growth and impair otolith structure and function in the larvae of some fishes. These effects may concurrently alter the larva's proteome expression pattern. To test this hypothesis, Atlantic herring larvae were exposed to ambient (370 μatm) and elevated (1800 μatm) pCO2 for one-month. The proteome structure of the larvae was examined using a 2-DE and mass spectrometry. The length of herring larvae was marginally less in the elevated pCO2 treatment compared to the control...
September 15, 2014: Marine Pollution Bulletin
Michel Toupet, Christian Van Nechel, Alexis Bozorg Grayeli
The subjective visual vertical (SVV) is an indicator of vestibular otolithic function and mainly processed by the nondominant parietal cortex. We investigated the hypothesis that recovery from SVV tilt after vestibular neuritis can be influenced by the body's lateral preference. This prospective cohort follow-up study included 254 consecutive adult patients with vestibular neuritis. The recovery from SVV tilt was faster in patients with a left hand or eye dominance than in those with a right dominance. While in left-handers the side of the neuritis did not affect the speed of recovery, in right-handed subjects, the recovery from a right-sided neuritis was significantly slower than from a left-sided affection...
2014: Audiology & Neuro-otology
Fred W Mast, Nora Preuss, Matthias Hartmann, Luzia Grabherr
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...
2014: Frontiers in Integrative Neuroscience
Ian S Curthoys, Vedran Vulovic, Ann M Burgess, Leonardo Manzari, Ljiljana Sokolic, Jacob Pogson, Mike Robins, Laura E Mezey, Samanthi Goonetilleke, Elaine D Cornell, Hamish G MacDougall
Extracellular single neuron recording and labelling studies of primary vestibular afferents in Scarpa's ganglion have shown that guinea-pig otolithic afferents with irregular resting discharge are preferentially activated by 500 Hz bone-conducted vibration (BCV) and many also by 500 Hz air-conducted sound (ACS) at low threshold and high sensitivity. Very few afferent neurons from any semicircular canal are activated by these stimuli and then only at high intensity. Tracing the origin of the activated neurons shows that these sensitive otolithic afferents originate mainly from a specialized region, the striola, of both the utricular and saccular maculae...
May 2014: Clinical and Experimental Pharmacology & Physiology
N P M Todd, A C Paillard, K Kluk, E Whittle, J G Colebatch
Todd et al. (2014) have recently demonstrated the presence of vestibular dependent changes both in the morphology and in the intensity dependence of auditory evoked potentials (AEPs) when passing through the vestibular threshold as determined by vestibular evoked myogenic potentials (VEMPs). In this paper we extend this work by comparing left vs. right ear stimulation and by conducting a source analysis of the resulting evoked potentials of short and long latency. Ten healthy, right-handed subjects were recruited and evoked potentials were recorded to both left- and right-ear sound stimulation, above and below vestibular threshold...
June 2014: Hearing Research
Hans Straka, Robert Baker
Central vestibular neurons form identifiable subgroups within the boundaries of classically outlined octavolateral nuclei in primitive vertebrates that are distinct from those processing lateral line, electrosensory, and auditory signals. Each vestibular subgroup exhibits a particular morpho-physiological property that receives origin-specific sensory inputs from semicircular canal and otolith organs. Behaviorally characterized phenotypes send discrete axonal projections to extraocular, spinal, and cerebellar targets including other ipsi- and contralateral vestibular nuclei...
2013: Frontiers in Neural Circuits
Hui Meng, Pablo M Blázquez, J David Dickman, Dora E Angelaki
A functional role of the cerebellar nodulus and ventral uvula (lobules X and IXc,d of the vermis) for vestibular processing has been strongly suggested by direct reciprocal connections with the vestibular nuclei, as well as direct vestibular afferent inputs as mossy fibres. Here we have explored the types of neurons in the macaque vestibular nuclei targeted by nodulus/ventral uvula inhibition using orthodromic identification from the caudal vermis. We found that all nodulus-target neurons are tuned to vestibular stimuli, and most are insensitive to eye movements...
January 1, 2014: Journal of Physiology
J Kim
Three-dimensional changes in the angular orientation of the head were monitored during galvanic vestibular stimulation (GVS) delivered through electrodes implanted bilaterally in the tensor tympani muscle of the guinea-pig middle ear. Bilateral GVS was delivered by passing current between both ears with the anode situated in one ear and the cathode in the other ear. Unilateral GVS was also delivered between one ear and an indifferent electrode on the skull. Constant-current stimulation caused the head to tilt predominantly within the roll and yaw planes toward an ear stimulated with anodal current and away from an ear stimulated with cathodal current...
December 3, 2013: Neuroscience
A A Tarnutzer, A G Lasker, D S Zee
Sensory input from the semicircular canals (SCC) and otolith organs is centrally combined with signals from other sensory modalities to continuously update the internal estimate of self-motion. Constant velocity vertical on-axis rotation leads to decay of the nystagmus response from the horizontal SCC and of perceived angular velocity (PAV), and when the rotation stops, a similar oppositely directed post-rotatory response occurs. Case reports and electrical stimulation studies suggest an involvement of the temporo-peri-Sylvian vestibular cortex in generating the PAV...
October 2013: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Maya Inoue, Masashi Tanimoto, Yoichi Oda
Hearing and bodily balance are different sensations initiated by a common mechanism. Both sound- and head movement-dependent mechanical displacement are converted into electrical signals by the sensory hair cells. The saccule and utricle inner ear organs, in combination with their central projections to the hindbrain, are considered essential in fish for separating auditory and vestibular stimuli. Here, we established an in vivo method in larval zebrafish to manipulate otolith growth. We found that the saccule containing a large otolith is necessary to detect sound, whereas the utricle containing a small otolith is not sufficient...
2013: Scientific Reports
Amany Mahmoud, Caitlyn Reed, Adel Maklad
Perception of linear acceleration and head position is the function of the utricle and saccule in mammals. Nonmammalian vertebrates possess a third otolith endorgan, the macula lagena. Different functions have been ascribed to the lagena in arboreal birds, including hearing, equilibrium, homing behavior, and magnetoreception. However, no conclusive evidence on the function of the lagena in birds is currently available. The present study is aimed at providing a neuroanatomical substrate for the function of the lagena in the chicken as an example of terrestrial birds...
October 15, 2013: Journal of Comparative Neurology
A Bani, S Poursaeid, V M Tuset
Sagittal otolith shapes were investigated in order to identify three sympatric species of south Caspian gobies (Caspian goby Neogobius caspius, deepwater goby Ponticola bathybius and bighead goby Ponticola gorlap). The sagittal otoliths in P. bathybius have a rectangular shape and are thick, whereas in N. caspius they are relatively round and thin. In P. gorlap, otoliths have an elongated shape and are relatively thick. The noticeable difference among the otoliths of the three species is the presence of one anterior and one posterior projection in the otoliths of N...
April 2013: Journal of Fish Biology
Sun-Young Oh, Ji Soo Kim, Jong-Min Lee, Byoung-Soo Shin, Seung-Bae Hwang, Ki-Chang Kwak, Chanmi Kim, Seul-Ki Jeong, Tae-Woo Kim
OBJECTIVE: The ocular vestibular-evoked myogenic potential (oVEMP), a recently documented otolith-ocular reflex, is considered to reflect the central projections of the primary otolithic afferent fibers to the oculomotor nuclei. The aim of our study is to define air-conducted sound oVEMP abnormality in patients with acute brainstem lesions and to determine the brainstem structures involved in the generation of oVEMPs. METHODS: In response to air-conducted tone burst sounds (ACS), oVEMP was measured in 52 patients with acute brainstem lesions...
April 2013: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Juno Kim
Galvanic vestibular stimulation (GVS) stimulates primary vestibular afferents innervating the semicircular canals (SCCs) and otoliths found in the inner ear of humans and other mammals, including guinea pigs. To determine which pathways contribute to eye movements generated by this artificial vestibular stimulation in guinea pigs, low current intensities of GVS were passed either bilaterally between the tensor-tympani muscles of the two ears (up to 30 μA) or unilaterally between one tensor-tympani electrode and an indifferent on the back of the neck (up to 60 μA)...
January 2013: Brain Research Bulletin
Catherine A McCormick, Abigail C Wallace
The distribution of axons from the saccule, lagena, and utricle to descending octaval nucleus neurons that project to the auditory midbrain in the goldfish is reported. We have divided these auditory projection neurons, located in the dorsal portion of the descending octaval nucleus (dDO), into two groups, medial and lateral, each of which contains several neuronal populations based on morphology and location. At most levels of the dDO, there are three medial and three lateral populations; the rostral dDO contains an additional lateral population...
2012: Brain, Behavior and Evolution
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