The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
James G Colebatch - One of the best experts on this subject based on the ideXlab platform.
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The Contributions of Vestibular Evoked Myogenic Potentials and Acoustic Vestibular Stimulation to Our Understanding of the Vestibular System.
Frontiers in neurology, 2018Co-Authors: Sally M Rosengren, James G ColebatchAbstract:Vestibular-evoked myogenic potentials (VEMPs) are short-latency muscle reflexes typically recorded from the neck or eye muscles with surface electrodes. They are used clinically to assess otolith function, but are also interesting as they can provide information about the Vestibular System and its activation by sound and vibration. Since the introduction of VEMPs more than 25 years ago, VEMPs have inspired animal and human research on the effects of acoustic Vestibular stimulation on the Vestibular organs, their projections and the postural muscles involved in Vestibular reflexes. Using a combination of recording techniques, including single motor unit recordings, VEMP studies have enhanced our understanding of the excitability changes underlying the sound-evoked vestibulo-collic and vestibulo-ocular reflexes. Studies in patients with diseases of the Vestibular System, such as superior canal dehiscence and Meniere's disease, have shown how acoustic Vestibular stimulation is affected by physical changes in the vestibule, and how sound-evoked reflexes can detect these changes and their resolution in clinical contexts. This review outlines the advances in our understanding of the Vestibular System that have occurred following the renewed interest in sound and vibration as a result of the VEMP.
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a utricular origin of frequency tuning to low frequency vibration in the human Vestibular System
Neuroscience Letters, 2009Co-Authors: Neil Mcangus P Todd, Sally M Rosengren, James G ColebatchAbstract:Abstract Recent work has demonstrated that the human Vestibular System displays a remarkable sensitivity to low-frequency vibration. To address the origin of this sensitivity we compared the frequency response properties of Vestibular reflexes to 10 ms bursts of air-conducted sound and transmastoid vibration, which are thought to be differentially selective for the saccule and utricle, respectively. Measurements were made using two separate central pathways: Vestibular evoked myogenic potentials (VEMPs), which are a manifestation of vestibulo-collic projections, and ocular Vestibular evoked myogenic potentials (OVEMPs), which are a manifestation of vestibulo-ocular projections. For both response pathways air-conducted sound and vibration stimuli produced the same patterns of quite different tuning. Sound was characterised by a band-pass tuning with best frequency between 400 and 800 Hz whereas vibration showed a low-pass type response with a largest response at 100 Hz. Our results suggest that the tuning is at least in part due to properties of end-organs themselves, while the 100 Hz best frequency may be a specifically utricular feature.
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tuning and sensitivity of the human Vestibular System to low frequency vibration
Neuroscience Letters, 2008Co-Authors: Neil Mcangus P Todd, Sally M Rosengren, James G ColebatchAbstract:Mechanoreceptive hair-cells of the vertebrate inner ear have a remarkable sensitivity to displacement, whether excited by sound, whole-body acceleration or substrate-borne vibration. In response to seismic or substrate-borne vibration, thresholds for Vestibular afferent fibre activation have been reported in anamniotes (fish and frogs) in the range -120 to -90 dB re 1g. In this article, we demonstrate for the first time that the human Vestibular System is also extremely sensitive to low-frequency and infrasound vibrations by making use of a new technique for measuring Vestibular activation, via the vestibulo-ocular reflex (VOR). We found a highly tuned response to whole-head vibration in the transmastoid plane with a best frequency of about 100 Hz. At the best frequency we obtained VOR responses at intensities of less than -70 dB re 1g, which was 15 dB lower than the threshold of hearing for bone-conducted sound in humans at this frequency. Given the likely synaptic attenuation of the VOR pathway, human receptor sensitivity is probably an order of magnitude lower, thus approaching the seismic sensitivity of the frog ear. These results extend our knowledge of vibration-sensitivity of Vestibular afferents but also are remarkable as they indicate that the seismic sensitivity of the human Vestibular System exceeds that of the cochlea for low-frequencies.
Paul F. Smith - One of the best experts on this subject based on the ideXlab platform.
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effects of electrical stimulation of the rat Vestibular labyrinth on c fos expression in the hippocampus
Neuroscience Letters, 2018Co-Authors: Martin Hitier, Paul F. Smith, Go Sato, Yanfeng Zhang, Stephane BesnardAbstract:Abstract Several studies have demonstrated that electrical activation of the peripheral Vestibular System can evoke field potential, multi-unit neuronal activity and acetylcholine release in the hippocampus (HPC). However, no study to date has employed the immediate early gene protein, c-Fos, to investigate the distribution of activation of cells in the HPC following electrical stimulation of the Vestibular System. We found that Vestibular stimulation increased the number of animals expressing c-Fos in the dorsal HPC compared to sham control rats (P ≤ 0.02), but not in the ventral HPC. c-Fos was also expressed in an increased number of animals in the dorsal dentate gyrus (DG) compared to sham control rats (P ≤ 0.0001), and to a lesser extent in the ventral DG (P ≤ 0.006). The results of this study show that activation of the Vestibular System results in a differential increase in the expression of c-Fos across different regions of the HPC.
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the modulation of hippocampal theta rhythm by the Vestibular System
Journal of Neurophysiology, 2018Co-Authors: Phillip Aitken, Paul F. Smith, Yiwen ZhengAbstract: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 importa...
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the Vestibular System and cognition
Current Opinion in Neurology, 2017Co-Authors: Paul F. SmithAbstract:Purpose of reviewThe 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 litera
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The Vestibular System
The Rat Nervous System, 2014Co-Authors: Pierre-paul Vidal, Kathleen E. Cullen, G. Holstein, E. Idoux, A. Lysakowski, K. Peusner, Alicia Sans, Ian S. Curthoys, Paul F. SmithAbstract:Abstract The survival of vertebrates is dependent on maintaining their body equilibrium in the gravitational field and being capable of orienting themselves in their environment. Studies have demonstrated that well-defined neuronal networks in the central nervous System implement these complex sensorimotor transformations, known as the vestibuloocular, cervical and optokinetic reflexes. In this chapter, the main characteristics of the Vestibular System are described, including the physiologic properties related to the anatomic features of the peripheral and central Vestibular System. Electrophysiological aspects and the neurotransmitters related to each Vestibular nuclei are discussed, focusing on the medial Vestibular nucleus. An understanding of how Vestibular inputs are integrated with multimodal signals to create the internal representation of head direction throughout the Papez circuit is presented. The pharmacology of the central Vestibular System is reviewed, with emphasis on recent studies which pin-point the pharmacological interactions between identified central Vestibular neurons and their inputs in defined circuits. A section on the influences of the brainstem regions involved in homeostatic regulation is included. In the final section, the anatomy of the main Vestibular nuclei is discussed to the extent that they are useful for understanding some important morpho-functional correlations.
Sally M Rosengren - One of the best experts on this subject based on the ideXlab platform.
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The Contributions of Vestibular Evoked Myogenic Potentials and Acoustic Vestibular Stimulation to Our Understanding of the Vestibular System.
Frontiers in neurology, 2018Co-Authors: Sally M Rosengren, James G ColebatchAbstract:Vestibular-evoked myogenic potentials (VEMPs) are short-latency muscle reflexes typically recorded from the neck or eye muscles with surface electrodes. They are used clinically to assess otolith function, but are also interesting as they can provide information about the Vestibular System and its activation by sound and vibration. Since the introduction of VEMPs more than 25 years ago, VEMPs have inspired animal and human research on the effects of acoustic Vestibular stimulation on the Vestibular organs, their projections and the postural muscles involved in Vestibular reflexes. Using a combination of recording techniques, including single motor unit recordings, VEMP studies have enhanced our understanding of the excitability changes underlying the sound-evoked vestibulo-collic and vestibulo-ocular reflexes. Studies in patients with diseases of the Vestibular System, such as superior canal dehiscence and Meniere's disease, have shown how acoustic Vestibular stimulation is affected by physical changes in the vestibule, and how sound-evoked reflexes can detect these changes and their resolution in clinical contexts. This review outlines the advances in our understanding of the Vestibular System that have occurred following the renewed interest in sound and vibration as a result of the VEMP.
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a utricular origin of frequency tuning to low frequency vibration in the human Vestibular System
Neuroscience Letters, 2009Co-Authors: Neil Mcangus P Todd, Sally M Rosengren, James G ColebatchAbstract:Abstract Recent work has demonstrated that the human Vestibular System displays a remarkable sensitivity to low-frequency vibration. To address the origin of this sensitivity we compared the frequency response properties of Vestibular reflexes to 10 ms bursts of air-conducted sound and transmastoid vibration, which are thought to be differentially selective for the saccule and utricle, respectively. Measurements were made using two separate central pathways: Vestibular evoked myogenic potentials (VEMPs), which are a manifestation of vestibulo-collic projections, and ocular Vestibular evoked myogenic potentials (OVEMPs), which are a manifestation of vestibulo-ocular projections. For both response pathways air-conducted sound and vibration stimuli produced the same patterns of quite different tuning. Sound was characterised by a band-pass tuning with best frequency between 400 and 800 Hz whereas vibration showed a low-pass type response with a largest response at 100 Hz. Our results suggest that the tuning is at least in part due to properties of end-organs themselves, while the 100 Hz best frequency may be a specifically utricular feature.
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tuning and sensitivity of the human Vestibular System to low frequency vibration
Neuroscience Letters, 2008Co-Authors: Neil Mcangus P Todd, Sally M Rosengren, James G ColebatchAbstract:Mechanoreceptive hair-cells of the vertebrate inner ear have a remarkable sensitivity to displacement, whether excited by sound, whole-body acceleration or substrate-borne vibration. In response to seismic or substrate-borne vibration, thresholds for Vestibular afferent fibre activation have been reported in anamniotes (fish and frogs) in the range -120 to -90 dB re 1g. In this article, we demonstrate for the first time that the human Vestibular System is also extremely sensitive to low-frequency and infrasound vibrations by making use of a new technique for measuring Vestibular activation, via the vestibulo-ocular reflex (VOR). We found a highly tuned response to whole-head vibration in the transmastoid plane with a best frequency of about 100 Hz. At the best frequency we obtained VOR responses at intensities of less than -70 dB re 1g, which was 15 dB lower than the threshold of hearing for bone-conducted sound in humans at this frequency. Given the likely synaptic attenuation of the VOR pathway, human receptor sensitivity is probably an order of magnitude lower, thus approaching the seismic sensitivity of the frog ear. These results extend our knowledge of vibration-sensitivity of Vestibular afferents but also are remarkable as they indicate that the seismic sensitivity of the human Vestibular System exceeds that of the cochlea for low-frequencies.
Kathleen E. Cullen - One of the best experts on this subject based on the ideXlab platform.
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The Vestibular System
The Rat Nervous System, 2014Co-Authors: Pierre-paul Vidal, Kathleen E. Cullen, G. Holstein, E. Idoux, A. Lysakowski, K. Peusner, Alicia Sans, Ian S. Curthoys, Paul F. SmithAbstract:Abstract The survival of vertebrates is dependent on maintaining their body equilibrium in the gravitational field and being capable of orienting themselves in their environment. Studies have demonstrated that well-defined neuronal networks in the central nervous System implement these complex sensorimotor transformations, known as the vestibuloocular, cervical and optokinetic reflexes. In this chapter, the main characteristics of the Vestibular System are described, including the physiologic properties related to the anatomic features of the peripheral and central Vestibular System. Electrophysiological aspects and the neurotransmitters related to each Vestibular nuclei are discussed, focusing on the medial Vestibular nucleus. An understanding of how Vestibular inputs are integrated with multimodal signals to create the internal representation of head direction throughout the Papez circuit is presented. The pharmacology of the central Vestibular System is reviewed, with emphasis on recent studies which pin-point the pharmacological interactions between identified central Vestibular neurons and their inputs in defined circuits. A section on the influences of the brainstem regions involved in homeostatic regulation is included. In the final section, the anatomy of the main Vestibular nuclei is discussed to the extent that they are useful for understanding some important morpho-functional correlations.
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multimodal integration of self motion cues in the Vestibular System active versus passive translations
The Journal of Neuroscience, 2013Co-Authors: Jerome Carriot, Jessica X Brooks, Kathleen E. CullenAbstract:The ability to keep track of where we are going as we navigate through our environment requires knowledge of our ongoing location and orientation. In response to passively applied motion, the otolith organs of the Vestibular System encode changes in the velocity and direction of linear self-motion (i.e., heading). When self-motion is voluntarily generated, proprioceptive and motor efference copy information is also available to contribute to the brain's internal representation of current heading direction and speed. However to date, how the brain integrates these extra-Vestibular cues with otolith signals during active linear self-motion remains unknown. Here, to address this question, we compared the responses of macaque Vestibular neurons during active and passive translations. Single-unit recordings were made from a subgroup of neurons at the first central stage of sensory processing in the Vestibular pathways involved in postural control and the computation of self-motion perception. Neurons responded far less robustly to otolith stimulation during self-generated than passive head translations. Yet, the mechanism underlying the marked cancellation of otolith signals did not affect other characteristics of neuronal responses (i.e., baseline firing rate, tuning ratio, orientation of maximal sensitivity vector). Transiently applied perturbations during active motion further established that an otolith cancellation signal was only gated in conditions where proprioceptive sensory feedback matched the motor-based expectation. Together our results have important implications for understanding the brain's ability to ensure accurate postural and motor control, as well as perceptual stability, during active self-motion.
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the Vestibular System implements a linear nonlinear transformation in order to encode self motion
PLOS Biology, 2012Co-Authors: Corentin Massot, Adam D Schneider, Maurice J Chacron, Kathleen E. CullenAbstract:Although it is well established that the neural code representing the world changes at each stage of a sensory pathway, the transformations that mediate these changes are not well understood. Here we show that self-motion (i.e. Vestibular) sensory information encoded by VIIIth nerve afferents is integrated nonlinearly by post-synaptic central Vestibular neurons. This response nonlinearity was characterized by a strong (∼50%) attenuation in neuronal sensitivity to low frequency stimuli when presented concurrently with high frequency stimuli. Using computational methods, we further demonstrate that a static boosting nonlinearity in the input-output relationship of central Vestibular neurons accounts for this unexpected result. Specifically, when low and high frequency stimuli are presented concurrently, this boosting nonlinearity causes an intensity-dependent bias in the output firing rate, thereby attenuating neuronal sensitivities. We suggest that nonlinear integration of afferent input extends the coding range of central Vestibular neurons and enables them to better extract the high frequency features of self-motion when embedded with low frequency motion during natural movements. These findings challenge the traditional notion that the Vestibular System uses a linear rate code to transmit information and have important consequences for understanding how the representation of sensory information changes across sensory pathways.
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the Vestibular System multimodal integration and encoding of self motion for motor control
Trends in Neurosciences, 2012Co-Authors: Kathleen E. CullenAbstract:Understanding how sensory pathways transmit information under natural conditions remains a major goal in neuroscience. The Vestibular System plays a vital role in everyday life, contributing to a wide range of functions from reflexes to the highest levels of voluntary behavior. Recent experiments establishing that Vestibular (self-motion) processing is inherently multimodal also provide insight into a set of interrelated questions. What neural code is used to represent sensory information in Vestibular pathways? How do the interactions between the organism and the environment shape encoding? How is self-motion information processing adjusted to meet the needs of specific tasks? This review highlights progress that has recently been made towards understanding how the brain encodes and processes self-motion to ensure accurate motor control.
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Vestibular System the many facets of a multimodal sense
Annual Review of Neuroscience, 2008Co-Authors: Dora E. Angelaki, Kathleen E. CullenAbstract:Elegant sensory structures in the inner ear have evolved to measure head motion. These Vestibular receptors consist of highly conserved semicircular canals and otolith organs. Unlike other senses, Vestibular information in the central nervous System becomes immediately multisensory and multimodal. There is no overt, readily recognizable conscious sensation from these organs, yet Vestibular signals contribute to a surprising range of brain functions, from the most automatic reflexes to spatial perception and motor coordination. Critical to these diverse, multimodal functions are multiple computationally intriguing levels of processing. For example, the need for multisensory integration necessitates Vestibular representations in multiple reference frames. Proprioceptive-Vestibular interactions, coupled with corollary discharge of a motor plan, allow the brain to distinguish actively generated from passive head movements. Finally, nonlinear interactions between otolith and canal signals allow the Vestibular System to function as an inertial sensor and contribute critically to both navigation and spatial orientation.
Neil Mcangus P Todd - One of the best experts on this subject based on the ideXlab platform.
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a utricular origin of frequency tuning to low frequency vibration in the human Vestibular System
Neuroscience Letters, 2009Co-Authors: Neil Mcangus P Todd, Sally M Rosengren, James G ColebatchAbstract:Abstract Recent work has demonstrated that the human Vestibular System displays a remarkable sensitivity to low-frequency vibration. To address the origin of this sensitivity we compared the frequency response properties of Vestibular reflexes to 10 ms bursts of air-conducted sound and transmastoid vibration, which are thought to be differentially selective for the saccule and utricle, respectively. Measurements were made using two separate central pathways: Vestibular evoked myogenic potentials (VEMPs), which are a manifestation of vestibulo-collic projections, and ocular Vestibular evoked myogenic potentials (OVEMPs), which are a manifestation of vestibulo-ocular projections. For both response pathways air-conducted sound and vibration stimuli produced the same patterns of quite different tuning. Sound was characterised by a band-pass tuning with best frequency between 400 and 800 Hz whereas vibration showed a low-pass type response with a largest response at 100 Hz. Our results suggest that the tuning is at least in part due to properties of end-organs themselves, while the 100 Hz best frequency may be a specifically utricular feature.
-
tuning and sensitivity of the human Vestibular System to low frequency vibration
Neuroscience Letters, 2008Co-Authors: Neil Mcangus P Todd, Sally M Rosengren, James G ColebatchAbstract:Mechanoreceptive hair-cells of the vertebrate inner ear have a remarkable sensitivity to displacement, whether excited by sound, whole-body acceleration or substrate-borne vibration. In response to seismic or substrate-borne vibration, thresholds for Vestibular afferent fibre activation have been reported in anamniotes (fish and frogs) in the range -120 to -90 dB re 1g. In this article, we demonstrate for the first time that the human Vestibular System is also extremely sensitive to low-frequency and infrasound vibrations by making use of a new technique for measuring Vestibular activation, via the vestibulo-ocular reflex (VOR). We found a highly tuned response to whole-head vibration in the transmastoid plane with a best frequency of about 100 Hz. At the best frequency we obtained VOR responses at intensities of less than -70 dB re 1g, which was 15 dB lower than the threshold of hearing for bone-conducted sound in humans at this frequency. Given the likely synaptic attenuation of the VOR pathway, human receptor sensitivity is probably an order of magnitude lower, thus approaching the seismic sensitivity of the frog ear. These results extend our knowledge of vibration-sensitivity of Vestibular afferents but also are remarkable as they indicate that the seismic sensitivity of the human Vestibular System exceeds that of the cochlea for low-frequencies.
