Directional coding of three-dimensional movements by the vestibular semicircular canals

1999 ◽  
Vol 80 (6) ◽  
pp. 417-431 ◽  
Author(s):  
Richard D. Rabbitt
Keyword(s):  
Three Dimensional ◽  
Semicircular Canals ◽  
Directional Coding

Interstitial Nucleus of Cajal Encodes Three-Dimensional Head Orientations in Fick-Like Coordinates

2007 ◽  
Vol 97 (1) ◽  
pp. 604-617 ◽  
Author(s):  
Eliana M. Klier ◽  
Hongying Wang ◽  
J. Douglas Crawford
Keyword(s):  
Coordinate System ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Head Rotation ◽  
Head Orientation ◽  
Interstitial Nucleus Of Cajal ◽  
The Gaze ◽  
Behavioral Constraints ◽  
The Right

Two central, related questions in motor control are 1) how the brain represents movement directions of various effectors like the eyes and head and 2) how it constrains their redundant degrees of freedom. The interstitial nucleus of Cajal (INC) integrates velocity commands from the gaze control system into position signals for three-dimensional eye and head posture. It has been shown that the right INC encodes clockwise (CW)-up and CW-down eye and head components, whereas the left INC encodes counterclockwise (CCW)-up and CCW-down components, similar to the sensitivity directions of the vertical semicircular canals. For the eyes, these canal-like coordinates align with Listing’s plane (a behavioral strategy limiting torsion about the gaze axis). By analogy, we predicted that the INC also encodes head orientation in canal-like coordinates, but instead, aligned with the coordinate axes for the Fick strategy (which constrains head torsion). Unilateral stimulation (50 μA, 300 Hz, 200 ms) evoked CW head rotations from the right INC and CCW rotations from the left INC, with variable vertical components. The observed axes of head rotation were consistent with a canal-like coordinate system. Moreover, as predicted, these axes remained fixed in the head, rotating with initial head orientation like the horizontal and torsional axes of a Fick coordinate system. This suggests that the head is ordinarily constrained to zero torsion in Fick coordinates by equally activating CW/CCW populations of neurons in the right/left INC. These data support a simple mechanism for controlling head orientation through the alignment of brain stem neural coordinates with natural behavioral constraints.

Three-Dimensional Analysis of Vestibular Efferent Neurons Innervating Semicircular Canals of the Gerbil

1997 ◽  
Vol 78 (6) ◽  
pp. 3234-3248 ◽  
Author(s):  
I. M. Purcell ◽  
A. A. Perachio
Keyword(s):  
Basement Membrane ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Central Zone ◽  
Semicircular Canals ◽  
Peripheral Zone ◽  
Longitudinal Axis ◽  
Open Loop ◽  
Response Dynamics ◽  
Efferent Neurons

Purcell, I. M. and A. A. Perachio. Three-dimensional analysis of vestibular efferent neurons innervating semicircular canals of the gerbil. J. Neurophysiol. 78: 3234–3248, 1997. 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° 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 areas of efferent terminal fields display a trend from smallest to largest for the central, peripheral, and planum types, respectively. Neurons that innervate the central zone of the crista do not extend into the peripheral or planum regions. Conversely, those neurons with terminal fields in the peripheral or planum regions do not innervate the central zone of the sensory neuroepithelium. The central zone of the crista is innervated preferentially by efferent neurons with cell bodies located in the ipsilateral group e. The peripheral and planum zones of the crista are innervated preferentially by efferent neurons with cell bodies located in the contralateral group e. A model incorporating our anatomic observations is presented describing an ipsilateral closed-loop feedback between ipsilateral efferent neurons and the periphery and an open-loop feed-forward innervation from contralateral efferent neurons. A possible role for the vestibular efferent neurons in the modulation of semicircular canal afferent response dynamics is proposed.

scholarly journals Reassessment of the phylogenetic relationships of the late Miocene apes Hispanopithecus and Rudapithecus based on vestibular morphology

2021 ◽  
Vol 118 (5) ◽  
pp. e2015215118
Author(s):  
Alessandro Urciuoli ◽  
Clément Zanolli ◽  
Sergio Almécija ◽  
Amélie Beaudet ◽  
Jean Dumoncel ◽  
...  
Keyword(s):  
Late Miocene ◽  
Phylogenetic Relationships ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Great Apes ◽  
Great Ape ◽  
Ongoing Debate ◽  
Evolutionary Patterns ◽  
Geometric Morphometric ◽  
Morphometric Analyses

Late Miocene great apes are key to reconstructing the ancestral morphotype from which earliest hominins evolved. Despite consensus that the late Miocene dryopith great apes Hispanopithecus laietanus (Spain) and Rudapithecus hungaricus (Hungary) are closely related (Hominidae), ongoing debate on their phylogenetic relationships with extant apes (stem hominids, hominines, or pongines) complicates our understanding of great ape and human evolution. To clarify this question, we rely on the morphology of the inner ear semicircular canals, which has been shown to be phylogenetically informative. Based on microcomputed tomography scans, we describe the vestibular morphology of Hispanopithecus and Rudapithecus, and compare them with extant hominoids using landmark-free deformation-based three-dimensional geometric morphometric analyses. We also provide critical evidence about the evolutionary patterns of the vestibular apparatus in living and fossil hominoids under different phylogenetic assumptions for dryopiths. Our results are consistent with the distinction of Rudapithecus and Hispanopithecus at the genus rank, and further support their allocation to the Hominidae based on their derived semicircular canal volumetric proportions. Compared with extant hominids, the vestibular morphology of Hispanopithecus and Rudapithecus most closely resembles that of African apes, and differs from the derived condition of orangutans. However, the vestibular morphologies reconstructed for the last common ancestors of dryopiths, crown hominines, and crown hominids are very similar, indicating that hominines are plesiomorphic in this regard. Therefore, our results do not conclusively favor a hominine or stem hominid status for the investigated dryopiths.

scholarly journals Semicircular canal biomechanics in health and disease

2019 ◽  
Vol 121 (3) ◽  
pp. 732-755 ◽  
Author(s):  
R. D. Rabbitt
Keyword(s):  
Time Course ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Head Movements ◽  
Positional Nystagmus ◽  
Neural Encoding ◽  
Range Of Movement ◽  
Stable Vision ◽  
Health And Disease

The semicircular canals are responsible for sensing angular head motion in three-dimensional space and for providing neural inputs to the central nervous system (CNS) essential for agile mobility, stable vision, and autonomic control of the cardiovascular and other gravity-sensitive systems. Sensation relies on fluid mechanics within the labyrinth to selectively convert angular head acceleration into sensory hair bundle displacements in each of three inner ear sensory organs. Canal afferent neurons encode the direction and time course of head movements over a broad range of movement frequencies and amplitudes. Disorders altering canal mechanics result in pathological inputs to the CNS, often leading to debilitating symptoms. Vestibular disorders and conditions with mechanical substrates include benign paroxysmal positional nystagmus, direction-changing positional nystagmus, alcohol positional nystagmus, caloric nystagmus, Tullio phenomena, and others. Here, the mechanics of angular motion transduction and how it contributes to neural encoding by the semicircular canals is reviewed in both health and disease.

Afferent Innervation Patterns of the Pigeon Horizontal Crista Ampullaris

2006 ◽  
Vol 96 (6) ◽  
pp. 3293-3304 ◽  
Author(s):  
Asim Haque ◽  
David Huss ◽  
J. David Dickman
Keyword(s):  
Fiber Type ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Columba Livia ◽  
Fiber Types ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Branch Order ◽  
Innervation Patterns ◽  
Afferent Innervation

The vestibular semicircular canals are responsible for detection of rotational head motion although the precise mechanisms underlying the transduction and encoding of movement information are still under study. In the present investigation, we utilized neural tracers and immunohistochemistry to quantitatively examine the topology and afferent innervation patterns of the horizontal semicircular canal crista (HCC) in pigeons ( Columba livia). Two hundred and eighty-six afferents from five horizontal canal organs were identified of which 92 units were sufficiently labeled and isolated to perform anatomical reconstructions. In addition, a three-dimensional contour map of the crista was constructed. Bouton afferents were located only in the peripheral regions of the receptor epithelium. Bouton afferents had the most complex innervation patterns with significantly longer and more numerous branches as well as a higher branch order than any other fiber type. Bouton fibers also contained significantly more bouton terminals than did dimorph afferents. Calyx afferents were located only in the apex and central planar regions. Calyx fibers had the largest axonal diameters yet the smallest fiber lengths and innervation areas, the fewest number of branches, the lowest branch order, and the fewest total number of terminals of all fiber types. Dimorph afferents were located throughout the central crista with afferent terminations that were larger and more complex than calyx fibers but less so than bouton fibers. Overall, the pigeon HCC morphology and innervation shares many common features with those of other animal classes.

Responses of pigeon vestibulocerebellar neurons to optokinetic stimulation. II. The 3-dimensional reference frame of rotation neurons in the flocculus

1993 ◽  
Vol 70 (6) ◽  
pp. 2647-2659 ◽  
Author(s):  
D. R. Wylie ◽  
B. J. Frost
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Receptive Fields ◽  
Semicircular Canals ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Monocular Stimulation ◽  
Contralateral Eye ◽  
Ipsilateral Stimulation ◽  
Stimulation Of

1. The complex spike activity of Purkinje cells in the flocculus in response to rotational flowfields was recorded extracellularly in anesthetized pigeons. 2. The optokinetic stimulus was produced by a rotating “planetarium projector.” A light source was placed in the center of a tin cylinder, which was pierced with numerous small holes. A pen motor oscillated the cylinder about its long axis. This apparatus was placed above the bird's head and the resultant rotational flow-field was projected onto screens that surrounded the bird on all four sides. The axis of rotation of the planetarium could be oriented to any position in three-dimensional space. 3. Two types of responses were found: vertical axis (VA; n = 43) neurons responded best to visual rotation about the vertical axis, and H-135i neurons (n = 34) responded best to rotation about a horizontal axis. The preferred orientation of the horizontal axis was at approximately 135 degrees ipsilateral azimuth. VA neurons were excited by rotation about the vertical axis producing forward (temporal to nasal) and backward motion in the ipsilateral and contralateral eyes, respectively, and were inhibited by rotation in the opposite direction. H-135i neurons in the left flocculus were excited by counterclockwise rotation about the 135 degrees ipsilateral horizontal axis and were inhibited by clockwise motion. Thus, the VA and H-135i neurons, respectively, encode visual flowfields resulting from head rotations stimulating the ipsilateral horizontal and ipsilateral anterior semicircular canals. 4. Sixty-seven percent of VA and 80% of H-135i neurons had binocular receptive fields, although for most binocular cells the ipsilateral eye was dominant. Binocular stimulation resulted in a greater depth of modulation than did monocular stimulation of the dominant eye for 69% of the cells. 5. Monocular stimulation of the VA neurons revealed that the best axis for the contralateral eye was tilted back 11 degrees, on average, to the best axis for ipsilateral stimulation. For the H-135i neurons, the best axes for monocular stimulation of the two eyes were approximately the same. 6. By stimulating circumscribed portions of the monocular receptive fields of the H-135i neurons with alternating upward and downward largefield motion, it was revealed that the contralateral receptive fields were bipartite. Upward motion was preferred in the anterior 45 degrees of the contralateral field, and downward motion, was preferred in the central 90 degrees of the contralateral visual field.(ABSTRACT TRUNCATED AT 400 WORDS)

Computer-Aided Three-Dimensional Measurement of the Human Vestibular Apparatus

1992 ◽  
Vol 107 (3) ◽  
pp. 405-409 ◽  
Author(s):  
Hiroaki Sato ◽  
Isamu Sando ◽  
Haruo Takahashi
Keyword(s):  
Analysis Of Variance ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Vestibular Apparatus ◽  
Dimensional Measurement ◽  
Surface Areas ◽  
Computer Aided ◽  
Three Dimensional Measurement ◽  
Dimensional Reconstruction ◽  
Temporal Bones

Using a computer-aided three-dimensional reconstruction and measurement method, 12 measurements were made to determine the dimensions of the maculae, cristae ampullares, and semicircular canals in 18 temporal bones from nine pairs of age-matched male and female individuals (1 day to 76 years old). The surface areas of the utricular and saccular maculae were significantly larger in male than in female specimens (two-way analysis of variance, F = 9.00, df = 1, p<0.01; F = 4.57, df = 1, p < 0.05, respectively). The width of the utricular macula and the length of the saccular macula were also significantly greater in male than in female specimens (two-way analysis of variance, F = 5.17, df = 1, p < 0.05; F = 4.33, df = 1, p < 0.05, respectively). Finally, the three semicircular canals were larger in diameter in male vs. female specimens; this difference was statistically significant for the superior semicircular canal (two-way analysis of variance, F = 10.74, df = 1, p < 0.01). By contrast, none of these dimensions of those vestibular structures showed any significant change in size with advancing postnatal age. We propose from these findings that there appears to be sexual dimorphism in the vestibular apparatus.

scholarly journals Endocranial anatomy of the ceratopsid dinosaur Triceratops and interpretations of sensory and motor function

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9888 ◽  
Author(s):  
Rina Sakagami ◽  
Soichiro Kawabe
Keyword(s):  
Olfactory Bulb ◽  
Inner Ear ◽  
Sensory Input ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Lateral Semicircular Canal ◽  
Linear Measurements ◽  
Low Frequencies ◽  
Effective Angle ◽  
Ceratopsian Dinosaurs

Triceratops is one of the well-known Cretaceous ceratopsian dinosaurs. The ecology of Triceratops has been controversial because of its unique morphological features. However, arguments based on brain and inner ear structures have been scarce. In this study, two braincases (FPDM-V-9677 and FPDM-V-9775) were analyzed with computed tomography to generate three-dimensional virtual renderings of the endocasts of the cranial cavities and bony labyrinths. Quantitative analysis, including comparison of linear measurements of the degree of development of the olfactory bulb and inner ear, was performed on these virtual endocasts to acquire detailed neuroanatomical information. When compared with other dinosaurs, the olfactory bulb of Triceratops is relatively small, indicating that Triceratops had a reduced acuity in sense of smell. The lateral semicircular canal reveals that the basicranial axis of Triceratops is approximately 45° to the ground, which is an effective angle to display their horns as well as frill, and to graze. The semicircular canals of Triceratops are relatively smaller than those of primitive ceratopsians, such as Psittacosaurus and Protoceratops, suggesting that sensory input for the reflexive stabilization of gaze and posture of Triceratops was less developed than that of primitive ceratopsians. The cochlear length of Triceratops is relatively short when compared with other dinosaurs. Because cochlear length correlates with hearing frequency, Triceratops was likely adapted to hearing low frequencies.

Three-Dimensional Fetal Cephalometry

1996 ◽  
Vol 33 (6) ◽  
pp. 463-467 ◽  
Author(s):  
G., Bettega ◽  
M. Chenin ◽  
H., Sadek ◽  
P. Cinquin ◽  
J. Lebeau ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Growth Stages ◽  
Normal Human ◽  
The Subject ◽  
Spatial Exploration ◽  
Reproducible Analysis ◽  
Cephalometric Study ◽  
Reproducible Manner

Craniofacial growth has been the subject of numerous studies in which different techniques have been elaborated aiming to model this dynamic phenomenon in a rational manner. One of the methods employed is cephalometric analysis applied to the fetus. Generally, however, these studies are confined to the exploration of a single spatial plane (sagittal plane), whose orientation is never defined in a rigorous and perfectly reproducible manner. Thus, none of these analyses offers a formal growth model. This has led us to propose a new method of fetal cephalometric study taking into account criteria for proper reproducible analysis: spatial exploration of the head performed through three-dimensional tomodensitometric images and precise location of landmarks and reproducibility of the orientation of each image, which is assured by reference to the vestibular orientation (based on the external semicircular canals), as has been described by Girard and Perez and further developed by Fenart. When the labyrinth is developed, this orientation does not change during the growth stages of the head, even with craniofacial deformities. This permits application of this orientation on fetuses and the superposition of images of different subjects. The methodology is presented using two normal human fetuses, and the advantages of this computerized tool are discussed.

scholarly journals Automatic Measurement of Inner Ear in Different Mammals1

2020 ◽  
Author(s):  
Yi Du ◽  
Han-dai Qin ◽  
Chen Liu ◽  
Da Liu ◽  
Shuo-long Yuan ◽  
...  
Keyword(s):  
Inner Ear ◽  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Automatic Measurement ◽  
The Body ◽  
Human Data ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Mini Pigs

AbstractObjectiveThe aim of this research is to develop an accurate and automatic measuring method based on the aid of centerline to construct three dimensional models of inner ear in different mammals and to assess the morphological variations.MethodsThree adult healthy mice, three adult guinea pigs, three adult mini pigs and one left temporal bone of human were included in this research. All 18 animal specimens and the human sample were scanned with the use of Micro-CT. After being segmented, three-dimensional models of the inner ear in different mammals were reconstructed using Mimics. A novel method with the use of centerline was established to estimate the properties of 3D models and to calculate the length, volume and angle parameters automatically.ResultsMorphological models of inner ears in different mammals have been built, which describe detailed shape of cochlear, vestibule, semicircular canals and common crus. Mean value of lengths and volumes of the cochlear, lateral semicircular canal, superior semicircular canal and posterior semicircular canal, tended to increase with the body size of the mammals, showed the proximity to the human data in mini pig. The angles between the semicircular canal planes showed differences between mammals. The mean values of semicircular canals of mice and mini pigs closely resembled to human data in numerical assessment.ConclusionThe automatic measurement of the inner ear based on centerline builds an effective way to assess lengths, volumes and angles of three-dimensional structures. This study provides a theoretical basis for mechanical analysis of inner ear in different mammals and proves the similarity between mini pig and human.

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