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.

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.

Responses of pigeon horizontal semicircular canal afferent fibers. I. Step, trapezoid, and low-frequency sinusoid mechanical and rotational stimulation

1989 ◽  
Vol 62 (5) ◽  
pp. 1090-1101 ◽  
Author(s):  
J. D. Dickman ◽  
M. J. Correia
Keyword(s):  
Mechanical Stimulation ◽  
Semicircular Canal ◽  
Action Potentials ◽  
Transfer Functions ◽  
Semicircular Canals ◽  
Primary Afferent ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Best Fit ◽  
Rotational Stimulation

1. The horizontal semicircular canals of anesthetized (barbiturate/ketamine) pigeons were stimulated by rotational and by mechanical stimulation. 2. The mechanical stimulation consisted of making a small (less than 1 mm) fistula in the lateral part of the bony horizontal semicircular canal and, after inserting a probe coupled to a piezoelectric micropusher through the fistula, providing controlled indentation of the exposed membranous horizontal semicircular duct. 3. Extracellular action potentials from single horizontal semicircular canal primary afferent (HCA) fibers were recorded during sinusoidal rotational and during step, ramp, and sinusoidal mechanical stimulation. 4. The mean spontaneous discharge rate of 160 horizontal canal afferents was 86 +/- 4 (SE) spikes/s. This rate was not significantly different from that reported previously for pigeon HCA fibers recorded with the horizontal canal intact (i.e., no fistula introduced). 5. Sinusoidal mechanical indentation of the horizontal semicircular duct produced clearly entrained action potentials on 36 HCA fibers for a range of peak displacements from +/- 0.5 to +/- 30 microns. Action potentials were never modulated on afferents (n greater than 100) identified as innervating the anterior and posterior semicircular canals or the otolith organs during mechanical stimulation of the horizontal semicircular canal, even for displacements as large as 30 microns. 6. Intensity functions relating peak firing frequency (spikes per second) and peak probe displacement (micrometers) for 1.0-Hz sinusoidal mechanical stimulation were linear over the range 1.0-5.0 microns. The most sensitive units (6/36, 17%) showed response saturation as the stimulus magnitude was extended to 7 microns and beyond. 7. In 15 of 36 units, both mechanical and rotational sinusoidal stimulation (1.0 Hz) were applied to the same unit. The duct indentation magnitudes were 1.0, 2.5, 5.0, and 7.0 microns and the rotational velocities were 5, 10, and 20 deg/s. The constant of proportionality found to equate the peak response produced by rotational to that elicited by mechanical stimulation was 7.0 deg.sec-1/1.0 microns. 8. Bode plots and best-fit transfer functions of the frequency response (0.05-10.0 Hz) of 14 HCAs exposed to both mechanical and rotational stimulation were nearly identical. 9. Parameters for best-fit transfer functions, responses to step, and trapezoidal duct displacements were in excellent agreement with previous rotational studies carried out using the pigeon. 10. Although the mechanisms by which focal identation of the horizontal membranous duct produce responses have not yet been determined, primary afferent responses using this method of stimulation are directly comparable with rotatory stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Horizontal canal benign paroxysmal positional vertigo in a fighter pilot

2011 ◽  
Vol 02 (01) ◽  
pp. 080-083
Author(s):  
Su-Jiang Xie ◽  
Jiang-Chang Wang ◽  
Li Ding ◽  
Sun Xi-Qing
Keyword(s):  
Vestibular System ◽  
Semicircular Canal ◽  
Benign Paroxysmal Positional Vertigo ◽  
Posterior Semicircular Canal ◽  
Horizontal Canal ◽  
Common Disorder ◽  
Positional Vertigo ◽  
Paroxysmal Positional Vertigo

ABSTRACTBenign paroxysmal positional vertigo (BPPV) is the most common disorder of the peripheral vestibular system, characterized by intense, positional provoked vertigo. BPPV is thought to occur due to canalithiasis of the posterior semicircular canal. Recently, a new entity of BPPV, known as horizontal canal (HC)-BPPV, has been recognized. Although only 3 to 8% of BPPV is due to horizontal canal involvement, HC-BPPV is not rare. We present a case of a naval fi ghter pilot who had an incident of HC-BPPV on the ground. The pilot aeromedical evaluation and considerations are discussed.

Role of semicircular canals in positional alcohol nystagmus

1965 ◽  
Vol 208 (6) ◽  
pp. 1065-1070 ◽  
Author(s):  
K. E. Money ◽  
W. H. Johnson ◽  
B. M. A. Corlett
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
The Other ◽  
Positional Nystagmus ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Unilateral Labyrinthectomy

Following unilateral labyrinthectomy or inactivation of one horizontal semicircular canal in cats, a horizontal positional nystagmus was observed when the cat, after ingesting alcohol, was held with the head up or with the head down. This nystagmus was toward the operated ear in the head-up position and away from the operated ear in the head-down position. It disappeared following inactivation of the horizontal canal of the other ear. In cats with both horizontal canals discretely inactivated, there was no horizontal alcohol nystagmus in any position, but the vertical and rotary components of positional alcohol nystagmus were still present. It was concluded that positional alcohol nystagmus is initiated by the action of gravity on receptors of the semicircular canals. No conclusion could be drawn concerning the site or mechanism of the action of alcohol.

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.

Changes in monkey horizontal semicircular canal afferent responses after spaceflight

1992 ◽  
Vol 73 (2) ◽  
pp. S112-S120 ◽  
Author(s):  
M. J. Correia ◽  
A. A. Perachio ◽  
J. D. Dickman ◽  
I. B. Kozlovskaya ◽  
M. G. Sirota ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Vestibular Stimulation ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Efferent Connections ◽  
The Central Nervous System ◽  
Afferent Response

Extracellular responses from single horizontal semicircular canal afferents in two rhesus monkeys were studied after recovery from a 14-day biosatellite (COSMOS 2044) orbital spaceflight. On the 1st postflight day, the mean gain for 9 different horizontal canal afferents, tested using one or several different passive yaw rotation waveforms, was nearly twice that for 20 horizontal canal afferents similarly tested during preflight and postflight control studies. Adaptation of the afferent response to passive yaw rotation on the 1st postflight day was also greater. These results suggest that at least one component of the vestibular end organ (the semicircular canals) is transiently modified after exposure to 14 days of microgravity. It is unclear whether the changes are secondary to other effects of microgravity, such as calcium loss, or an adaptive response. If the response is adaptive, then this report is the first evidence that the response of the vestibular end organ may be modified (presumably by the central nervous system via efferent connections) after prolonged unusual vestibular stimulation. If this is the case, the sites of plasticity of vestibular responses may not be exclusively within central nervous system vestibular structures, as previously believed.

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.

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.

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