scholarly journals Context-independent encoding of passive and active self-motion in vestibular afferent fibers during locomotion in primates

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Isabelle Mackrous ◽  
Jérome Carriot ◽  
Kathleen E. Cullen
Keyword(s):  
Mathematical Modeling ◽  
Vestibular System ◽  
Direct Proof ◽  
Head Motion ◽  
Sensory Coding ◽  
Primate Locomotion ◽  
Afferent Fibers ◽  
Self Motion ◽  
The Brain ◽  
Efferent Vestibular System

AbstractThe vestibular system detects head motion to coordinate vital reflexes and provide our sense of balance and spatial orientation. A long-standing hypothesis has been that projections from the central vestibular system back to the vestibular sensory organs (i.e., the efferent vestibular system) mediate adaptive sensory coding during voluntary locomotion. However, direct proof for this idea has been lacking. Here we recorded from individual semicircular canal and otolith afferents during walking and running in monkeys. Using a combination of mathematical modeling and nonlinear analysis, we show that afferent encoding is actually identical across passive and active conditions, irrespective of context. Thus, taken together our results are instead consistent with the view that the vestibular periphery relays robust information to the brain during primate locomotion, suggesting that context-dependent modulation instead occurs centrally to ensure that coding is consistent with behavioral goals during locomotion.

Vestibular Signals in Self-Orientation and Eye Movement Control

Physiology ◽  
2001 ◽  
Vol 16 (5) ◽  
pp. 234-238 ◽  
Author(s):  
Bernhard J. M. Hess
Keyword(s):  
Signal Processing ◽  
Eye Movement ◽  
Vestibular System ◽  
Retinal Image ◽  
Internal Model ◽  
Movement Control ◽  
Head Position ◽  
Head Motion ◽  
Afferent Information ◽  
The Brain

The central vestibular system receives afferent information about head position as well as rotation and translation. This information is used to prevent blurring of the retinal image but also to control self-orientation and motion in space. Vestibular signal processing in the brain stem appears to be linked to an internal model of head motion in space.

scholarly journals Vestibular implants studied in animal models: clinical and scientific implications

2016 ◽  
Vol 116 (6) ◽  
pp. 2777-2788 ◽  
Author(s):  
Richard F. Lewis
Keyword(s):  
Animal Models ◽  
Vestibular System ◽  
Animal Studies ◽  
Vestibular Function ◽  
Clinical Problem ◽  
Head Motion ◽  
The Past ◽  
New Treatment ◽  
Vestibular Damage ◽  
The Brain

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.

Steps toward recovery of function after hemilabyrinthectomy in frogs

1998 ◽  
Vol 119 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Norbert Dieringer ◽  
Hans Straka
Keyword(s):  
Time Course ◽  
Recovery Of Function ◽  
Behavioral Deficits ◽  
Afferent Fibers ◽  
Vestibular Nuclear Complex ◽  
The Central Nervous System ◽  
Synaptic Changes ◽  
Necessary And Sufficient ◽  
The Brain

Removal of the labyrinthine organs on one side results in a number of severe postural and dynamic reflex deficits. Over time some of these behavioral deficits normalize again. At a chronic stage the brain of frogs exhibits a number of changes in vestibular and propriospinal circuits on the operated side that were studied in vitro. The onset of changes in the vestibular nuclear complex was delayed, became evident only after head posture had recovered by more than 50%, and was independent of the presence or absence of a degeneration of vestibular nerve afferent fibers. The time course of changes measured in the isolated spinal cord paralleled the time course of normalization of head and body posture. Results obtained after selective lesions of individual labyrinthine nerve branches show that unilateral inactivation of utricular afferent inputs is a necessary and sufficient condition to provoke postural deficits and propriospinal changes similar to those after the removal of all labyrinthine organs. The presence of multiple synaptic changes at distributed anatomic sites over different periods of time suggests that different parts of the central nervous system are involved in the normalization of different manifestations of the vestibular lesion syndrome. (Otolaryngol Head Neck Surg 1998;119:27–33.)

scholarly journals Perception of the dynamic visual vertical during sinusoidal linear motion

2017 ◽  
Vol 118 (4) ◽  
pp. 2499-2506 ◽  
Author(s):  
A. Pomante ◽  
L. P. J. Selen ◽  
W. P. Medendorp
Keyword(s):  
Vestibular System ◽  
Spatial Orientation ◽  
Linear Acceleration ◽  
The Body ◽  
Body Motion ◽  
Whole Body ◽  
Linear Motion ◽  
Modeling Framework ◽  
Visual Vertical ◽  
The Brain

The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical—as a proxy for the tilt percept—during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s2peak acceleration, 80 cm displacement). While subjects ( n=10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model’s prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical.NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the disambiguation of linear acceleration and spatial orientation. We discuss the dynamics of these illusory percepts in terms of a dynamic Bayesian model that combines uncertainty in the vestibular signals with priors based on the natural statistics of head motion.

scholarly journals Beyond the brain: towards a mathematical modeling of emotions

2021 ◽  
Vol 2090 (1) ◽  
pp. 012119
Author(s):  
Benjamin Ambrosio
Keyword(s):  
Mathematical Modeling ◽  
Dynamical System ◽  
Electromagnetic Waves ◽  
Real Life ◽  
Work Environments ◽  
Mathematical Approach ◽  
Characteristic Frequencies ◽  
Human Psyche ◽  
The Brain ◽  
Psychic State

Abstract This article focuses on a mathematical description of the emotional phenomenon. The key concept is to consider emotions as an energy, and to rely on the analogy with the electromagnetic waves. Our aim is to provide a mathematical approach to characterize the emergence of emotional fluxes in the human psyche. This goes beyond classical pscychological approaches. In this setting, specific emotions correspond to specific frequencies and our psychic state results from the summation of different characteristic frequencies. Our general model of psychic state is a dynamical system whose evolution results from interactions between external inputs and internal reactions. The model provides both qualitative (frequencies) and quantitative (intensity) components. It aims to be applied to real life situations (in particular in work environments) and we provide a typical example which naturally leads to a problem of control.

scholarly journals How multisensory neurons solve causal inference

2021 ◽  
Vol 118 (32) ◽  
pp. e2106235118
Author(s):  
Reuben Rideaux ◽  
Katherine R. Storrs ◽  
Guido Maiello ◽  
Andrew E. Welchman
Keyword(s):  
Motion Estimation ◽  
Causal Inference ◽  
Visual Motion ◽  
Temporal Area ◽  
Medial Superior Temporal ◽  
Electrophysiological Recordings ◽  
Visual Motion Cues ◽  
Integrated Or ◽  
Self Motion ◽  
The Brain

Sitting in a static railway carriage can produce illusory self-motion if the train on an adjoining track moves off. While our visual system registers motion, vestibular signals indicate that we are stationary. The brain is faced with a difficult challenge: is there a single cause of sensations (I am moving) or two causes (I am static, another train is moving)? If a single cause, integrating signals produces a more precise estimate of self-motion, but if not, one cue should be ignored. In many cases, this process of causal inference works without error, but how does the brain achieve it? Electrophysiological recordings show that the macaque medial superior temporal area contains many neurons that encode combinations of vestibular and visual motion cues. Some respond best to vestibular and visual motion in the same direction (“congruent” neurons), while others prefer opposing directions (“opposite” neurons). Congruent neurons could underlie cue integration, but the function of opposite neurons remains a puzzle. Here, we seek to explain this computational arrangement by training a neural network model to solve causal inference for motion estimation. Like biological systems, the model develops congruent and opposite units and recapitulates known behavioral and neurophysiological observations. We show that all units (both congruent and opposite) contribute to motion estimation. Importantly, however, it is the balance between their activity that distinguishes whether visual and vestibular cues should be integrated or separated. This explains the computational purpose of puzzling neural representations and shows how a relatively simple feedforward network can solve causal inference.

Development of the rat efferent vestibular system on the ground and in microgravity

2001 ◽  
Vol 128 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Danielle Demêmes ◽  
Claude J Dechesne ◽  
Stéphanie Venteo ◽  
Florence Gaven ◽  
Jacqueline Raymond
Keyword(s):  
Vestibular System ◽  
Efferent Vestibular System

The Efferent Vestibular System

2012 ◽  
pp. 116-134 ◽  
Author(s):  
Jay M. Goldberg ◽  
Victor J. Wilson ◽  
Kathleen E. Cullen ◽  
Dora E. Angelaki ◽  
Dianne M. Broussard ◽  
...  
Keyword(s):  
Vestibular System ◽  
Efferent Vestibular System

Brain stem responses to electrical stimulation of ventral vagal gastric fibers

1989 ◽  
Vol 257 (1) ◽  
pp. G24-G29
Author(s):  
W. D. Barber ◽  
C. S. Yuan
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Time Of Arrival ◽  
Neuronal Responses ◽  
Proximal Stomach ◽  
Afferent Fibers ◽  
Sensory Modalities ◽  
The Mean ◽  
The Brain ◽  
Stimulation Of

The brain stem neuronal responses to electrical stimulation of gastric branches of the ventral vagal trunk serving the proximal stomach were localized and evaluated in anesthetized cats. The responses were equally distributed bilaterally in the region of nucleus solitarius in the caudal brain stem. The mean latency of the response was 289 +/- 46 (SD) ms, which translated into a conduction velocity of less than 1 m/s based on the distance between the stimulating and recording electrodes. The responses consisted of single and multiple spikes that showed slight variability in the latency, indicating orthodromic activation via a synapse in approximately 98% of the responses recorded. Forty two percent of the units tested showed evidence of convergence of input from vagal afferent fibers in different branches of the ventral vagal trunk that served the proximal stomach. The resultant activity pattern of the unitary response appeared to be the product of 1) the gastric sensory input or modality conveyed by the afferent source and 2) the time of arrival and diversity of modalities served by other gastric afferents impinging on the unit. This provides a mechanism capable of responding on the basis of specific sensory modalities that dynamically reflect ongoing events monitored and conveyed by other gastric afferents in the region.

scholarly journals A review of efferent cholinergic synaptic transmission in the vestibular periphery and its functional implications

2020 ◽  
Vol 123 (2) ◽  
pp. 608-629 ◽  
Author(s):  
L. A. Poppi ◽  
J. C. Holt ◽  
R. Lim ◽  
A. M. Brichta
Keyword(s):  
Synaptic Transmission ◽  
Vestibular System ◽  
Cellular Mechanisms ◽  
Cholinergic Synaptic Transmission ◽  
Behavioral Studies ◽  
Functional Implications ◽  
Electrophysiological Studies ◽  
Efferent Vestibular System ◽  
Anatomical Characterization

It has been over 60 years since peripheral efferent vestibular terminals were first identified in mammals, and yet the function of the efferent vestibular system remains obscure. One reason for the lack of progress may be due to our deficient understanding of the peripheral efferent synapse. Although vestibular efferent terminals were identified as cholinergic less than a decade after their anatomical characterization, the cellular mechanisms that underlie the properties of these synapses have had to be inferred. In this review we examine how recent mammalian studies have begun to reveal both nicotinic and muscarinic effects at these terminals and therefore provide a context for fast and slow responses observed in classic electrophysiological studies of the mammalian efferent vestibular system, nearly 40 years ago. Although incomplete, these new results together with those of recent behavioral studies are helping to unravel the mysterious and perplexing action of the efferent vestibular system. Armed with this information, we may finally appreciate the behavioral framework in which the efferent vestibular system operates.

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