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At least 19 recordsLinked to original sources
PubMedDate not supplied

[The interoceptive properties of the vestibular apparatus (a systems analysis of vestibular-oculomotor interaction)].

Modern views about physiological functions of vestibular system are submitted, their contradictions are picked out. The result of development of experimental and clinical vestibulometry till last decades at the foundation of critical estimation of effectiveness of different methods of vestibular receptor's stimulation are summed up. It is proposed to consider vestibular apparatus only as structural sensory element of eye's moving functional system at the foundation of cybernetics' principles of physiological function's regularity. It is proposed to estimate vestibular function as a part of the whole afferent stream in system, which hasn't their own way at effector neurone once which determines together with proprioceptive afferentation internal system's status. Methodological principles of further research of vestibular apparatus and vestibular function are determined.

Animals↗
PubMed1981

[Participation of the vestibular apparatus in regulating shivering].

Participation of the vestibular apparatus in the control of bioelectrical activity and function of muscle motor units was studied in experiments on cats with cold shivering. It was shown that the shivering was suppressed by limitation of the vestibulospinal effects whereas stimulation of the vestibular apparatus enhanced it. Suppression of the shivering after delabyrinthation manifested both in the increased frequencies of impulses in the active motor units and in the recruitment of new units, previously "silent". Participation of the vestibular apparatus in cold shivering control and the mechanism by which the animal's posture is formed thereby restricting the heat-release surface are discussed.

Animals↗
PubMed1991

Blood flow in the cochlea, vestibular apparatus and facial nerve.

Blood flow in the cochlea, vestibular apparatus and facial nerve was investigated in the 12 temporal bones of 6 guinea pigs using non-radioactive microspheres. The cochlear blood flow volume was 1.80 +/- 0.82 microliters/min and the blood flow volume of the vestibular apparatus was 0.43 +/- 0.16 microliters/min. The blood flow volume of the facial nerve in the temporal bone was 0.29 +/- 0.17 microliter/min. Regarding these blood flow volumes, the difference between the right and left was not significant, although there were large interanimal differences. The distribution of the blood flow in the cochlea, vestibular apparatus and facial nerve is also described.

Animals↗
PubMedDate not supplied

[The physiological functions of the vestibular apparatus].

Physiological functions of the vestibular apparatus were considered in terms of functional systems, permanent physiological activity and robot theories. A working hypothesis is assumed on vestibular receptor as a sensory detector of some functional systems of the body which enables creation of the internal coordinate system together with proprioreceptors of ocular, cervical, trunk and limb muscles, articular and tendinous receptors for adequate spacial perception via ocular and tactile analyzers; extrapolation of somatic responses. Vestibular reactions in disease and experiment are believed to be systemic responses primarily of functional and oculomotor systems. Isolation of vestibular afferentation from the total afferent flow is impossible already at the level of vestibular nuclei. Perspectives of further usage of rotatory and caloric tests for investigation of vestibular function are outlined.

Eye Movements↗
PubMed1983

The surface structures of the human vestibular apparatus.

The surface of the human vestibular apparatus has been examined in the scanning electron microscope following early post mortem fixation. Preservation of the fine structures of the maculae is good but of the cristae of the semi-circular canals is only fair. The surface features of the maculae do not differ from those seen in experimental animals. There appears to be an age related loss of ciliated sensory cells from the cristae. This might explain some of the age related changes in vestibular function.

Acoustic Maculae↗
PubMed1980

Origin of efferent fibers of the vestibular apparatus in goldfish. A horseradish peroxidase study.

After injecting a horseradish peroxidase (HRP) solution into the vestibular apparatus in goldfish (Carassius auratus), cells in the medulla oblongata exhibited retrogradely transported HRP reaction product. These labeled cells were confined to 3 nuclei, i.e. the nucleus motorius tegmenti of Bartelmez (with the most prominent labeled cell groups), the ventral vestibular nucleus (Dieter's nucleus) and the medial vestibular nucleus. We consider these labeled cells to be the origin of the efferent innervation to the vestibular apparatus in goldfish. Neurons providing efferent innervation to the sensory periphery in the nucleus motorius tegmenti have, as yet, not been described.

Animals↗
PubMedDate not supplied

The structural and functional organization of the vestibular apparatus of rats exposed to weightlessness for 20 days on board the Sputnik "Kosmos-782".

This investigation of the vestibular apparatus of rats exposed for 20 days to weightlessness on board an earth satellite and to acceleration during take-off and landing has revealed a set of changes in the structural and functional organization, such as adjoinment of the otolith to the utricle receptor surface and peripheral localization of the nucleoli inside the receptor cells' nuclei. Destruction of some receptor cells, apparently due to increased swelling of the vestibular apparatus tissue and alteration of the shape and structure of the otoconia were observed. In the horizontal crista, detachment of the cupula took place.

Acceleration↗
PubMed1992

On the capability of the vestibular apparatus to perceive sound stimuli.

This paper discusses the capacity of sound perception in 5 profoundly deaf subjects in whom a "fenestra" was previously formated on the lateral semicircular canal. The ability of sound and vibration perception after fenestra formation in profoundly deaf subjects with normal function of the vestibular apparatus has been described previously. The experiments for this procedure were done on pigeons by Wit & Bleeker. The subjects aged from 22 to 34 years. Causes of deafness varied. Their hearing threshold was bilaterally higher than 95 dB HL and their vestibular apparatus was of normal excitability bilaterally when tested with a caloric test. In all 5 patients the ear conduction hearing threshold remained the same, but the ability of vibration perception improved significantly, and ranged postoperatively between 30 and 45 dB HL. The frequency dynamic range was from 125 to 2,000 Hz in 4 subjects, and from 125 to 4,000 Hz in 1 subject. The patients claimed to have perceived higher intensities, but with a variable dynamic range from frequency to frequency. The intensity range amounted to between 15 and 40 dB. The obtained data of vibration perception ability are discussed.

Adult↗
PubMed2003

Contribution of the vestibular apparatus to postural control when rising from a chair.

OBJECTIVE: The everyday act of rising from a chair is known to require the combined angular control of a number of the body's joints, especially those within the pitch plane. Precisely how this control is exerted, however, remains controversial. The aim of this study was to obtain a better understanding of the contribution made by the vestibular apparatus to postural control of the body and head when an individual rises from a chair. MATERIAL AND METHODS: A total of 24 healthy controls and 38 patients with varying degrees of vestibular dysfunction were examined. Electromagnetic motion sensors were used to analyze the angular control of the head and body as subjects rose from a chair with their eyes open or closed. RESULTS: We found that unilateral vestibular dysfunction caused fixation of the head with respect to the body, resulting in a loss of spatial stability of the head which was not compensated for by visual input. Visual input did appear to compensate for bilateral vestibular loss, enabling patients with bilateral vestibular apparatus impairment or central disorders to fix the position of their head in space. CONCLUSION: The act of rising from a chair is normally controlled by vestibular and proprioceptive input; the head is aligned according to the gravitational reference so as to obtain stable visual information. In patients with unilateral vestibular hypofunction, posture is still controlled by these two inputs, although the ability to align the head is diminished. In patients with bilateral vestibular hypofunction or a central disorder, head alignment is maintained using visual input, although it may not be the sole or predominant stabilizing force.

Adult↗
PubMed1981

Changes in the microstructure of the vestibular apparatus of tadpoles (Rana temporaria) developed in simulated weightlessness.

The vestibular apparatus of tadpoles (Rana temporaria) exposed to simulated weightlessness was examined by electron microscopy. Extended exposure to simulated weightlessness is followed by significant alterations in the sensory epithelia and also in the otolith membrane. Large vacuoles, filled with necrobiotic mitochondria and fragments of endoplasmic reticulum, were concentrated in the region where an otolith membrane covers the hair cells but were mostly absent in zones of the epithelia with undifferentiated cells. The number of otoconia in the otolith membrane was diminished. The results were compared with data from space flight experiments and some concordance was noted. The possible connection between some unusual behavior of the tadpoles after weightlessness simulation and the structural alterations in the gravitational sensors was discussed.

Animals↗
PubMed1996

Vestibular symptoms in otosclerosis--correlation of otosclerotic involvement of vestibular apparatus and Scarpa's ganglion cell count.

Although several histopathologic studies have shown otosclerotic involvement of the vestibular apparatus in patients with otosclerosis, the pathogenesis of vestibular symptoms in otosclerosis remains unknown. A quantitative study of Scarpa's ganglion was performed in 217 temporal bones from 118 subjects with otosclerosis. Review of clinical records revealed an incidence of vestibular symptoms in 11.9% of these subjects. Scarpa's ganglion cell counts in temporal bones of subjects with otosclerosis and vestibular symptoms were lower than counts in temporal bones of subjects with otosclerosis but without vestibular symptoms and those of normal subjects. This difference in Scarpa's ganglion cell counts, adjusted for age, between the group with otosclerosis and vestibular symptoms and a group of normal subjects was highly significant (p = 0.0015), whereas the difference in Scarpa's ganglion cell count between a group with otosclerosis but without vestibular symptoms and a group of normal subjects was not significant (p = 0.53). There was also a significant correlation between elevation of the average bone-conduction threshold and the presence of vestibular symptoms in these subjects (p = 0.041). The endosteum of the perilymphatic space of the vestibule and the endosteum of the canal for the superior vestibular nerve or its cribrose area were the two most common sites of involvement by otosclerosis. However, there was no significant correlation between the presence of vestibular symptoms and otosclerotic involvement of any single site or the number of involved sites. Histologic examination of the vestibular nerve fibers and end organs subjacent to otosclerotic foci demonstrated no obvious degenerative changes. Thus our findings appear to suggest that the vestibular symptoms present in patients with otosclerosis are more common in patients with elevated bone conduction thresholds and are correlated with degeneration of the vestibular nerve, which appears to be independent of the severity of otosclerotic involvement of the vestibular end organs.

Aged↗
PubMed1991

The vestibular apparatus of the opossum (Didelphis virginiana) prior to and immediately after birth.

The vestibular apparatus of the opossum was examined shortly before and immediately after birth. A band of about 20 sensory cells was observed within the forming utricle by 24 h prior to birth. Stereocilia projecting from the apices of the sensory cells appeared intimately associated with a well-defined population of overlying otoliths. These morphological observations suggest that a functional utricle may be present at the time of birth and together with other senses (tactile, olfaction) may aid the newborn of this species in its migration from the birth canal to the pouch.

Animals↗
PubMedDate not supplied

[Study of the structure of receptor organs of the vestibular apparatus of rats after space flight on "Kosmos-1667"].

The receptor organs of the vestibular apparatus of rats flown for 7 days on Cosmos-1667 were examined. Serial sections were examined by light microscopy, some utriculus sections by electron microscopy, and otolith membranes by scanning electron microscopy. The fixation method used revealed a distinct structural heterogeneity of the receptor epithelium. In the striola area of the utriculus and sacculus as well as in the central apical area of cristae there are receptor cells surrounded by enlarged cup-like nerve endings. The nerve endings occupy over 70% of the cup-receptor cell complex. The area incorporating the enlarged nerve endings differs in size from animal to animal and from left to right ear in the same animal. The flown rat that was the first to be killed after recovery showed a very well pronounced asymmetry: in the right ear enlarged cups were seen all over the epithelium while in the left ear they were located in distinct spots. Since such changes were not identified in the remaining flown and control rats, it is concluded that they were produced by space flight effects but remained reversible and disappeared after recovery. This paper describes the causes responsible of the changes and their structural and functional relevances as well as other structural modifications that should be considered during vestibular studies.

Aerospace Medicine↗
PubMed1992

Quantitative immunoelectron microscopic localization of Na, K-ATPase alpha-subunit in the epithelial cells of rat vestibular apparatus.

Na, K-ATPase was quantitatively localized in the epithelial cells of rat vestibular apparatus such as macula utriculi, macula sacculi and crista ampullaris. Immunogold localization method was carried out at the saturation level of antibody using an affinity purified antibody against the alpha-subunit of rat kidney Na, K-ATPase. Numerous gold particles were found on the basolateral membrane of the dark cells, a small number of gold particles were found on the basolateral membrane of the transitional epithelium cells and hair cells, but the luminal surface membranes of the hair cells, transitional epithelium cells, planum semilunatum cells and dark cells were rarely labeled by gold particles. Significance of the abundant localization of Na, K-ATPase on the basolateral surface of the dark cells in the production of endolymph was discussed.

Animals↗
PubMed1978

[Structural and functional organization of the vestibular apparatus in rats maintained under weightless conditions for 19.5 days aboard the satellite "Cosmos-782"].

Vestibular apparatus was investigated in rats subjected to weightlessness for 19.5 days in the satelite "Cosmos-782" and experienced acceleration on launching and landing. Some structural and functional changes were noted. They were seen in otolith clinging to the utricular receptor surface and in the peripheral arrangement of the nucleolus in the nuclei of the receptor cells. It is also possible that increased edema of the vestibular tissue resulted in destruction of some receptor cells, and within the otolith--changes in the form and structure of otoconia. In the horizontal crista the cupula was separated.

Acceleration↗