Axonal pathways and projection levels of anterior semicircular canal nerve-activated vestibulospinal neurons in cats

2006 ◽  
Vol 406 (1-2) ◽  
pp. 1-5 ◽  
Author(s):  
Naoharu Kitajima ◽  
Akemi Sugita-Kitajima ◽  
Rishu Bai ◽  
Mitsuyoshi Sasaki ◽  
Hitoshi Sato ◽  
...  
Keyword(s):  
Semicircular Canal ◽  
Anterior Semicircular Canal ◽  
Vestibulospinal Neurons

Neurodynamic response analysis of anterior semicircular canal afferents in the pigeon

1980 ◽  
Vol 43 (6) ◽  
pp. 1746-1770 ◽  
Author(s):  
J. P. Landolt ◽  
M. J. Correia
Keyword(s):  
Time Constant ◽  
Semicircular Canal ◽  
Angular Acceleration ◽  
Neural Response ◽  
Response Analysis ◽  
Torsion Pendulum ◽  
Generator Potential ◽  
Pendulum Model ◽  
Anterior Semicircular Canal ◽  
Semicircular Canal Afferents

1. The neurodynamic responses to sinusoidal and pulse angular accelerations were studied in anterior semicircular canal afferents in the barbiturate-anesthetized pigeon. 2. The resting discharge frequency, aS, varied from 7.4 to 149.0 impulses/s. For most units, aS remained fairly constant for long periods of time during the experiment. 3. The neural-response harmonic distortion, resulting from stimulation by sinusoidal angular accelerations, varied in different units. Percent distortions from as low as 3% to those as high as 57% were determined. 4. Intensity-function plots of peak first harmonic neural response as a function of the peak sinusoidal angular acceleration (with frequency, f, as a parameter) are of two types: one has a linear relationship between the variables; the other demonstrates pronounced nonlinearities ("saturation," particularly for low values of f). In saturation-type units, the data of which fit a power law function, the exponent of the function is frequency dependent, becoming closer and closer to unity with increasing f. 5. Data for all units fit the transfer function, G'(s) = Csk/(tauLS + 1), where G'(s) relates the unit response to angular acceleration, C is a gain constant, 0 < k < 1, and tauL is the so-called long time constant of the classical torsion pendulum model. tauL varied from 4.45 to 22.17 S (mean +/- SE = 10.24 +/- 1.20 S). This may be interpreted as an indication of a regional distribution of tauL'S within the neuroepithelium. Arguments are advanced to show that this is consistent with our present understanding of the ampullary end organ. 6. The degree of regularity of the spontaneous discharge (as determined by the coefficient of variation, CV) was significantly correlated with the parameter k in G'(S). The larger the CV, the larger is the corresponding k. Further work indicated that the larger the value of k, the more adaptation a unit exhibited (k varied from 0.017 to 0.66). 7. The time-domain response of G(S) = G'(S)/(tauSS + 1) to different durations of pulse angular acceleration stimuli agreed well with the neural response to these stimuli (tauS = 2.27 ms is the short time constant of the torsion pendulum model). 8. The term Sk was decomposed into an expression containing a series of polynomials in S in the numerator and denominator. The first term in this expansion K0tau1S/(tau1S + 1), has previously been shown to describe so-called adaptation properties in the dynamics of the semicircular canals. A mean (+/-SE) tau1 = 71.56 (+/-10.01) S was determined. Evidence is presented that Sk probably represents a relaxation phenomenon comprised of a time-varying intracellular Na+/K+-transport process, components of which are summed with the generator potential in the afferent terminal(S) of the receptor hair cell.

Evolution of Treatment Maneuvers for Benign Paroxysmal Positional Vertigo

2016 ◽  
Author(s):  
Robert W. Baloh
Keyword(s):  
21St Century ◽  
Semicircular Canal ◽  
Benign Paroxysmal Positional Vertigo ◽  
Posterior Semicircular Canal ◽  
Initial Examination ◽  
Positional Vertigo ◽  
Anterior Semicircular Canal ◽  
Paroxysmal Positional Vertigo

Near the turn of the 21st century, as more physicians began performing the Epley and Semont maneuvers for treatment of benign paroxysmal positional vertigo (BPPV), it became apparent that the procedures could be done at the time of initial examination without the need for sedation or vibration. Furthermore, modified versions of the maneuvers evolved that were more effective and easier to perform. There are clear similarities in these modified repositioning maneuvers. BPPV nearly always results from otoconial debris within the posterior semicircular canal because this is the canal in which it is most easily trapped. Although less common, there are horizontal and anterior semicircular canal variants of BPPV, and otolithic debris can become attached to the cupula, producing a true cupulolithiasis. The nystagmus is in the plane of the affected canal; the nystagmus is transient when the debris is freely floating and persistent when debris is attached to the cupula.

The Effect of Canalith Repositioning for Anterior Semicircular Canal Canalithiasis

ORL ◽  
2005 ◽  
Vol 67 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Yoon Kyung Kim ◽  
Jeong Eun Shin ◽  
Jong Woo Chung
Keyword(s):  
Semicircular Canal ◽  
Anterior Semicircular Canal

Involvement of the Anterior Semicircular Canal in Posttraumatic Benign Paroxysmal Positioning Vertigo

2011 ◽  
Vol 32 (8) ◽  
pp. 1285-1290 ◽  
Author(s):  
Julia Dlugaiczyk ◽  
Stefan Siebert ◽  
Dietmar J. Hecker ◽  
Christoph Brase ◽  
Bernhard Schick
Keyword(s):  
Semicircular Canal ◽  
Anterior Semicircular Canal ◽  
Benign Paroxysmal Positioning Vertigo

Properties and axonal trajectories of posterior semicircular canal nerve-activated vestibulospinal neurons

2008 ◽  
Vol 191 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Keisuke Kushiro ◽  
Rishu Bai ◽  
Naoharu Kitajima ◽  
Akemi Sugita-Kitajima ◽  
Yoshio Uchino
Keyword(s):  
Semicircular Canal ◽  
Posterior Semicircular Canal ◽  
Vestibulospinal Neurons

scholarly journals NEUROANATOMÍA DEL SAURÓPODO TITANOSAURIO NARAMBUENATITAN PALOMOI DEL CRETÁCICO SUPERIOR DE PATAGONIA, ARGENTINA.

2020 ◽  
Author(s):  
Ariana Paulina-Carabajal ◽  
Leonardo Filippi ◽  
Fabien Knoll
Keyword(s):  
Semicircular Canal ◽  
Upper Cretaceous ◽  
Semicircular Canals ◽  
Lateral View ◽  
Phylogenetic Position ◽  
Posterior Semicircular Canal ◽  
X Ray ◽  
Anterior Semicircular Canal ◽  
X Ray Computed ◽  
The Brain

this taxon has uncertain phylogenetic relationships within the clade. An X-ray Computed Tomography (CT) scan of the holotypebraincase allowed the first reconstruction of the brain and inner ear of this taxon, making it possible to compare the neuroanatomy with thatof closely related forms. Except for the slightly sigmodal shape of the endocast in lateral view—considered a basal condition—, the brainshows derived titanosaurian traits such as a poorly developed dorsal expansion and a single exit for Cranial Nerve (CN) XII. In contrast, the innerear exhibits slender and long semicircular canals (the anterior semicircular canal is distinctly longer than the posterior semicircular canal), whichis a character present in more basal representatives of the group, such as Sarmientosaurus. We consider, however, the morphology of theinner ear as an unreliable indicator of phylogenetic position. Furthermore, there is a remarkable similarity between the morphology of theendocast of Narambuenatitanand the possible saltasaurid from (FAM 03.064), from the Upper Cretaceous of Fox-Amphoux-Métisson, France,suggesting saltasaurine affinities for the Argentinean taxon.

scholarly journals A New Coordinate System for Magnetic Resonance Imaging of the Vestibular System

2022 ◽  
Vol 12 ◽  
Author(s):  
Weixing Liu ◽  
Gui Chen ◽  
Junyang Xie ◽  
Tianhao Liang ◽  
Chunyi Zhang ◽  
...  
Keyword(s):  
Coordinate System ◽  
Vestibular System ◽  
Semicircular Canal ◽  
Internal Auditory Canal ◽  
Semicircular Canals ◽  
Image Data ◽  
Mean Values ◽  
Medical Software ◽  
Anterior Semicircular Canal ◽  
Imaging Plane

Objectives: To develop and evaluate a new coordinate system for MRI of the vestibular system.Methods: In this study, 53 internal auditory canal MRI and 78 temporal bone CT datasets were analyzed. Mimics Medical software version 21.0 was used to visualize and three-dimensionally reconstruct the image data. We established a new coordinate system, named W–X, based on the center of the bilateral eyeballs and vertex of the bilateral superior semicircular canals. Using the W–X coordinate system and Reid's coordinate system, we measured the orientations of the planes of the anterior semicircular canal (ASCC), the lateral semicircular canal (LSCC), and the posterior semicircular canal (PSCC).Results: No significant differences between the angles measured using CT and MRI were found for any of the semicircular canal planes (p &gt; 0.05). No statistical differences were found between the angles measured using Reid's coordinate system (CT) and the W–X coordinate system (MRI). The mean values of ∠ASCC &amp; LSCC, ∠ASCC &amp; PSCC, and ∠LSCC &amp; PSCC were 84.67 ± 5.76, 94.21 ± 3.81, and 91.79 ± 5.22 degrees, respectively. The angle between the LSCC plane and the horizontal imaging plane was 15.64 ± 3.92 degrees, and the angle between the PSCC plane and the sagittal imaging plane was 48.79 ± 4.46 degrees.Conclusion: A new W–X coordinate system was developed for MRI studies of the vestibular system and can be used to measure the orientations of the semicircular canals.

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