The harp seal, Pagophilus groenlandicus (Erxleben, 1777). XXI. The structure of the vestibular apparatus

1972 ◽  
Vol 50 (11) ◽  
pp. 1357-1361 ◽  
Author(s):  
F. Ramprashad ◽  
K. E. Money ◽  
K. Ronald
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
Harp Seal ◽  
Body Orientation ◽  
Sensory Cells ◽  
Vestibular Apparatus ◽  
Posterior Semicircular Canal ◽  
Pagophilus Groenlandicus ◽  
Sensory Hairs

The structure of the large vestibular apparatus of the harp seal (Pagophilus groenlandicus) is similar to that of other mammals. However, the posterior semicircular canal is the smallest of the three canals and the plane of the lateral is below that of the posterior semicircular canal. An additional sensory end organ (crista neglecta) is present about 0.75 mm from the posterior crista. The neuroepithelium of the crista neglecta is similar to that of the crista of the semicircular canals and consists of large supporting and sensory cells, the sensory hairs of which project into the cupula. No otoconia were seen on the crista neglecta as were present on the otolithic membrane of the maculae utriculi and sacculi. A large macula utriculi and crista neglecta may be necessary for body orientation during diving.

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.

Purine and pyrimidine nucleotide-sensitive phosphoinositidase C in ampulla from frog semicircular canal

1997 ◽  
Vol 272 (1) ◽  
pp. R51-R58 ◽  
Author(s):  
D. Butlen ◽  
C. Bernard ◽  
A. Ammar ◽  
E. Ferrary
Keyword(s):  
Semicircular Canal ◽  
Competitive Inhibition ◽  
Rank Order ◽  
Semicircular Canals ◽  
Disulfonic Acid ◽  
Sensory Cells ◽  
Reactive Blue 2 ◽  
Pyrimidine Nucleotide ◽  
Noncompetitive Inhibitor ◽  
Dose Dependent

A microassay was developed to screen the abilities of ATP analogues to stimulate phosphoinositidase C in single ventral regions (including dark cells and sensory cells) of ampullas microdissected from posterior vertical semicircular canals of Rana ridibundo and labeled with myo-[3H]inositol. ATP induced a dose-dependent and saturable increase of total [3H]linositol phosphate production accompanied by an equivalent decrease in the [3H]phosphoinositide pool. The rank order of analogues revealing agonistic potencies for phosphoinositidase C activation was as follows: uridine 5'-triphosphate > or = adenosine 5'-O-[3-thiophosphate] tetralithium > adenosine 5'-O-[2-thiodiphosphate] trilithium > or = ATP > or = ADP = inosine 5'-triphosphate > or = guanosine 5'-triphosphate > or = 2-methylthio-adenosine 5'-triphosphate tetrasodium > or = 2'-desoxy-thymidine 5'-triphosphate > or = cytidine 5'-triphosphate = (alpha, beta)-methyl ATP > AMP, whereas adenosine 3',5'-cyclic monophosphate and adenosine were almost devoid of activity. For antagonists, 1,4'-diisothiocyanostilbene-2, 2'-disulfonic acid was far more active than suramin for competitive inhibition of ATP-induced enzyme stimulation, whereas reactive blue 2 acted as a noncompetitive inhibitor. Results indicate that the putative P2 receptors triggering phosphoinositidase C activation in ventral ampullary epithelium from frog semicircular canal exhibit mainly the functional properties of P2Y and P2U receptors.

Acute Vestibular Paralysis in Herpes Zoster Oticus

1979 ◽  
Vol 88 (3) ◽  
pp. 303-310 ◽  
Author(s):  
Leonard Proctor ◽  
John Lindsay ◽  
Henry Perlman ◽  
Gregory Matz
Keyword(s):  
Herpes Zoster ◽  
Semicircular Canal ◽  
Disease Process ◽  
Semicircular Canals ◽  
Caloric Test ◽  
Lateral Semicircular Canal ◽  
Posterior Semicircular Canal ◽  
Herpes Zoster Oticus ◽  
Eye Closure

A case of herpes zoster oticus is presented in which the lateral and superior semicircular canals of the labyrinth were affected unilaterally. The results of several electronystagmographic examinations are described and correlated with the patient's description of symptoms. This case study indicates that disease affecting the lateral semicircular canal is reliably detected by the conventional caloric test. However, the fact that the posterior semicircular canal remained intact could not be inferred from the results of the caloric test in this case. Also, the appearance of nystagmus upon eye closure appears to have been a more sensitive index of the state of the disease process than was the caloric test.

Evaluation of Vertical Semicircular Canal Function in Patients With Vestibular Schwannoma

2018 ◽  
Vol 128 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Keishi Fujiwara ◽  
Hiroko Yanagi ◽  
Shinya Morita ◽  
Kimiko Hoshino ◽  
Atsushi Fukuda ◽  
...  
Keyword(s):  
Vestibular Schwannoma ◽  
Semicircular Canal ◽  
Vestibular Function ◽  
Semicircular Canals ◽  
Vestibular Nerve ◽  
Head Impulse Test ◽  
Posterior Semicircular Canal ◽  
Vestibulo Ocular Reflex ◽  
Anterior Semicircular Canal ◽  
Vertical Semicircular Canal

Objectives: The aim of this study was to investigate vertical semicircular canal function in patients with vestibular schwannoma (VS) by video head impulse test (vHIT). Methods: Fifteen patients with VS who had not received any treatment, including surgery or stereotactic radiotherapy, before vHIT examination were enrolled. Vestibulo-ocular reflex gain and catch-up saccade in vHIT were evaluated. Results: Dysfunction of anterior and posterior semicircular canals was detected by vHIT in 26.7% and 60.0%, respectively. Six patients (40.0%) demonstrated abnormalities referable to both vestibular nerve divisions. Abnormalities referable to the superior vestibular nerve were identified in 3 patients (20.0%), while 3 patients (20.0%) demonstrated a pattern indicative of inferior vestibular nerve involvement. Anterior semicircular canal vHIT produced fewer abnormalities than did either horizontal or posterior semicircular canal vHIT. Conclusions: Dysfunction of the semicircular canals, including the vertical canals, in patients with VS was detected by vHIT. The anterior semicircular canal was less frequently involved than the horizontal or posterior semicircular canal. The examination of the vertical canals by vHIT is useful in the evaluation of vestibular function in patients with VS.

Analysis of the coplanarity of functional pairs of semicircular canals using three-dimensional images reconstructed from temporal bone magnetic resonance imaging

2015 ◽  
Vol 129 (5) ◽  
pp. 430-434 ◽  
Author(s):  
D-K Kim ◽  
D-R Kim ◽  
S H Jeong ◽  
G J Kim ◽  
K-H Chang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Temporal Bone ◽  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Normal Subjects ◽  
Magnetic Resonance Images ◽  
Posterior Semicircular Canal ◽  
Horizontal Semicircular Canal ◽  
The Right

AbstractObjectives:This study was conducted to investigate the angles and orientation of semicircular canals, and the coplanarity of functional canal pairs.Methods:Fluid signals in semicircular canals were reconstructed with three-dimensional reconstruction software using 20 temporal bone magnetic resonance images of normal subjects. The angles between each pair of semicircular canals were measured.Results:The mean angles between the anterior and horizontal semicircular canal plane, the horizontal and posterior semicircular canal plane, and the anterior and posterior semicircular canal plane were 83.7°, 82.5° and 88.4°, respectively. Pairs of contralateral synergistic canal planes were formed 15.1° between the right and left horizontal semicircular canal planes, 21.2° between the right anterior and left posterior semicircular canal, and 21.7° between the left anterior and right posterior semicircular canal.Conclusion:Each semicircular canal makes an almost right angle with other canals, but synergistically acting functional canal pairs of both ears do not lie in exactly the same plane.

scholarly journals Unilateral Multicanalicular Vestibular Lithiasis of Right Horizontal and Posterior Semicircular Canals: An Unusual Case

2021 ◽  
Author(s):  
Ajay Kumar Vats
Keyword(s):  
Semicircular Canal ◽  
Unusual Case ◽  
Semicircular Canals ◽  
Posterior Semicircular Canal ◽  
Gelatinous Matrix ◽  
History Of ◽  
Head Roll ◽  
The Individual ◽  
Treatment Priorities ◽  
Torsional Nystagmus

AbstractVestibular lithiasis (canalolithiasis as well as cupulolithiasis) commonly exists in monocanalicular forms involving one of the three semicircular canals, frequent posterior, less frequent horizontal, and very rarely anterior. It is treated with canal clearing maneuvers intended to reposition the otoconia from the semicircular canal (where they have inappropriately entered) through the utricular exit in the nonampullary arm of the semicircular canal to the utricle (where they normally remain as a part of utricular gelatinous matrix). The cases of multicanalicular vestibular lithiasis with the involvement of more than one semicircular canal require meticulous identification of the involved canals and multiple different canal-clearing maneuvers for effective treatment. A 70-year-old male patient with no significant history of previous medical or otologic illnesses or head trauma presented with a 1-day history of vertigo with positional aggravation. A one-time performed diagnostic supine head roll test elicited three different patterns of positional nystagmus, each with an accurate localizing and lateralizing value. Diagnosis of unilateral multicanalicular vestibular lithiasis of right horizontal and posterior semicircular canals was entertained based on the pattern of the elicited positional nystagmi on the supine roll test. The upbeating torsional nystagmus that localizes the involvement to the posterior semicircular canal was paradoxically elicited by supine head roll test and not by the Dix–Hallpike test. As horizontal semicircular canalolithiasis causes severe symptoms, its treatment preceded that of concurrent posterior semicircular canalolithiasis. The patient was successfully treated with multiple sessions of canalith repositioning maneuvers (CRMs) spread over 24 hours. It is important to perform both positional tests, namely Dix–Hallpike maneuver, and supine head roll test, in cases suspected to have multicanalicular vestibular lithiasis. The positionings may need to be repeated several times to unveil multiple nystagmi, each with different localizing and lateralizing values. Identifying treatment priorities with CRM for the individual semicircular canals is crucial, and the canal that is liable to cause severe symptoms needs early clearance of the otoconial debris. If a CRM fails to clear a semicircular canal, an alternative maneuver may need to be executed. Clinicians involved in the care of cases with multicanalicular vestibular lithiasis should be well versed with all possible backup maneuvers for clearing each of the three semicircular canals.

Question of Reference Frames: Visual Direction-Selective Neurons in the Accessory Optic System of Goldfish

2009 ◽  
Vol 102 (5) ◽  
pp. 2781-2789 ◽  
Author(s):  
Olivia Andrea Masseck ◽  
Klaus-Peter Hoffmann
Keyword(s):  
Semicircular Canal ◽  
Reference Frames ◽  
Semicircular Canals ◽  
Visual Direction ◽  
Optic System ◽  
Posterior Semicircular Canal ◽  
Accessory Optic System ◽  
Horizontal Canal ◽  
Goldfish Carassius Auratus ◽  
Maximal Activation

We investigated if visual direction-selective neurons in the pretectal area (APT) of goldfish ( Carassius auratus auratus) preferred visual stimuli resulting from rotations around axes corresponding to the best responsive axes of the semicircular canals [optic flow that is consistent to a maximal activation of the horizontal canal pair (yaw), to a maximal activation of the right anterior/left posterior semicircular canal pair (RALP), and to a maximal activation of the left anterior/right posterior semicircular canal pair (LARP)]. Our sample of neurons recorded in the left pretectum had two preferred axes of rotation: first, rotation around the yaw axis and second, rotation around the RALP axis. Both axes of rotation correspond to best responsive axes of the semicircular canals. For this reason, coding in a reference frame defined by the vestibular system or the pulling direction of the eye muscles is suggested. In our population of recorded APT neurons, we did not find segregation of different preferred axes of rotation into different anatomical structures. Furthermore in all axes no bias for clockwise or counterclockwise rotations was obvious. This is particularly noteworthy for the yaw axis because preference for temporo-nasal and naso-temporal rotations was found at the same recording side. Hence we conclude that in fish the accessory optic system may consist of one nucleus on each side of the midbrain only, the APT. Segregation into different nuclei coding for different axes and different senses of rotation probably first developed in amphibians.

Experimental selective posterior semicircular canal laser deafferentation

2005 ◽  
Vol 119 (5) ◽  
pp. 381-384
Author(s):  
Maged B Naguib
Keyword(s):  
Semicircular Canal ◽  
Carbon Dioxide Laser ◽  
Benign Paroxysmal Positional Vertigo ◽  
Semicircular Canals ◽  
The Other ◽  
Posterior Semicircular Canal ◽  
Relative Ease ◽  
Positional Vertigo ◽  
Otolithic Organ ◽  
Paroxysmal Positional Vertigo

In this experimental study, we attempted to perform selective deafferentation of the posterior semicircular canal ampulla of guinea pigs using carbon dioxide laser beam. The results of this study document the efficacy of this procedure in achieving deafferentation of the posterior semicircular canal safely with regards to the other semicircular canals, the otolithic organ and the organ of hearing. Moreover, the procedure is performed with relative ease compared with other procedures previously described for selective deafferentation of the posterior semicircular canal. The clinical application of such a procedure for the treatment of intractable benign paroxysmal positional vertigo in humans is suggested.

Resistant Posterior Semicircular Canal BPPV with Changing Oculomotor Pattern Solved with Mastoid Vibration Application

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Faralli Mario ◽  
Lapenna Ruggero ◽  
Gambacorta Valeria ◽  
Ricci Giampietro ◽  
D'Ascanio Luca
Keyword(s):  
Semicircular Canal ◽  
Posterior Semicircular Canal
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