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PubMedDate not supplied

Three-dimensional organization of cytoskeletons in the vestibular sensory cells.

The cytoskeletal organization of the guinea pig vestibular sensory cells was investigated employing the saponin perfusion method using scanning electron microscopy as well as immunohistochemical technique. The intermediate filaments were demonstrated in the sensory cells. They were usually seen surrounding the nucleus and extending through the cytoplasm which connected the nuclear membrane to the plasma membrane, cuticular plate or other cytoorganelles. These findings may suggest that the intermediate filaments provide mechanical support to the cell and its nucleus. Microtubules were found mainly in the supranuclear portion of the cells and run parallel to the main axis of the cell body, which is directly connected to the cuticular plate. These findings may suggest that the microtubules provide mechanical support to the cell and may be closely related to the sensory cell transduction system. The actin filaments were densely packed in the site of the cuticular plate. They also distributed throughout the cytoplasm, which appeared as a dense network in the periphery region. These findings support the idea that the actin filaments could be responsible for sensory cell transduction as well as to give mechanical strength to the surface of the cell and enable the cell to change its shape and move.

Actins↗
PubMed1994

High-resolution scanning electron microscopic study of cell organelles of the chick's vestibular ganglion.

The fine intracellular structures of the chick's vestibular ganglion were studied three-dimensionally using the scanning electron microscope (SEM) after freeze-fracturing with 50% dimethyl sulfoxide solution and placement in 0.1% osmium oxide solution. Three patterns of perikaryal myelination could be distinguished in the vestibular ganglion cells: heavily myelinated, lightly myelinated and unmyelinated. Intracellular organelles such as the Golgi apparatus, endoplasmic reticulum and mitochondria could be demonstrated clearly. The stereoscopic structures of the Schwann cells and nerve fibers were also clearly demonstrated.

Animals↗
PubMedDate not supplied

[The vestibular organ throughout history].

AIMS AND DEVELOPMENT: Our aim is to attempt to create a chronologically ordered and coherent corpus of the apparently scarce information that exists about the history of the vestibular organ, a component of the inner ear situated on both sides of the head in the petrous temporal bone. Its job, at least in humans, is to transmit sensory information about movements of the head to components of the central nervous system. Some of its more common disorders lead to syndromes that implicitly entail balance disorders, such as the case of the syndrome described by Prosper Meni re in the 19th century. Without ruling out the possible ancestral knowledge of the vertiginous processes associated with the inner ear, our objective is to review some of the aspects that anatomists, physiologists and prominent physicists have been involved in throughout history, i.e. elements that appeared between the 18th and mid 20th century and which have led to a fuller understanding of the morphological and functional aspects of the fundamental apparatus involved in the detection of gravity and inertia, shared by vertebrates: the vestibular organ.

History, 18th Century↗
PubMed1997

Effects of vestibular rehabilitation on postural control.

We evaluated the effects of vestibular rehabilitation on postural instability in 2 patients with unilateral and bilateral reduced vestibular function. Another patient with unilateral vestibular disorder was treated with drugs without vestibular rehabilitation. The outcome of postural control in these 3 patients was measured using an EquiTest. With this apparatus, improvement of postural stability and change of postural strategy were measured under the condition eyes closed and platform movement was dependent on the subject's anterior-posterior sway. The observations suggest that the vestibular rehabilitation had a positive effect not only on postural stability but also on postural strategy.

Adult↗
PubMed1976

Construction of a practical and inexpensive air stimulator for caloric vestibular testing.

An inexpensive and practical method for delivering air into the aural canal at a selected stable temperature is described. A water-air heat exchanger utilizing the external circulation of a constant-temperature water bath brings the temperature of the air stream to a chosen value. Measurements indicate stable air outflow temperatures are maintained when proper nozzle design and air flow rates are employed. The apparatus is easy to construct and has proven convenient and effective when used in the clinical vestibular laboratory.

Air↗
PubMed1997

Postural stability of diabetic patients with and without cutaneous sensory deficit in the foot.

Postural stability was measured in 50 patients classified into two diabetic groups: insulin-dependent diabetes mellitus (IDDM: n = 27), and diabetic patients with bilateral cutaneous sensory deficit in the foot (CD: n = 23). All patients were matched to 50 non-diabetic controls on age, weight and gender variables. The integrity of cutaneous sensory information at the foot was assessed using a monofilament test. Static and dynamic balance was evaluated using an objective balance test involving computer-controlled dual force platforms enclosed by a visual surround. The apparatus provided six test conditions designed to systematically manipulate or eliminate visual, vestibular or somatosensory information. Scores for the six tests, and a derived composite balance score together with movement strategy scores were used for data analysis. For all six tests and composite score CD patients revealed significant postural instability compared to controls. Additionally, the CD group recorded reduced strategy scores indicating an atypical shift from ankle to hip strategy movement as postural control was stressed. IDDM patient test scores were not significantly different from control data on any pairwise comparison. Results indicated significant balance loss associated with CD putting the individual at increased risk for falling and compromising foot mechanics.

Adult↗
PubMed2003

Electrical stimulation (ES) in the management of sexual pain disorders.

We performed an open study to investigate the use of electrical stimulation (ES) on the vestibular area and vaginal introitus in women with sexual pain disorders. We recruited 29 women (age range 20-45 years) from among the patients at our Reproductive Psychobiology Unit to participate in the present study. They each experienced vestibular pain, inducing dyspareunia and vaginism. We performed ES with an ECL43400 apparatus (Elite, EssediEsse srl, Milan, Italy) once a week for 10 weeks. To evaluate the muscular activity of the perineal floor and sexual function, we employed the same apparatus with a vaginal probe for recording myoelectrical activity (muV), we employed a VAS scale for evaluating pain, and we administered the Female Sexual Function Index (FSFI; Rosen et al., 2000) before and after the study protocol. We analyzed data by parametric and nonparametric comparisons and correlations, as appropriate. Our major findings were as follows: (a) the contractile ability of pelvic floor muscles (p < 0.001), as well as the resting ability (p < 0.001), significantly improved following ES; (b) the current intensity tolerated significantly increased (p < 0.001) throughout the study, from 41.3 +/- 7.4 mA at the start of the study to 50 +/- 7.4 mA at the end of the stimulation protocol; (c) the Visual Analogic Scale (VAS) for pain significantly declined (p < 0.001), whereas FSFI pain scores (p < 0.001) and full scale scores (p < 0.001) significantly improved following ES, and 4 out of 9 women with vaginism went back to coital activity; (d) FSFI pain score and the current intensity tolerated, both before (R = .59; p < 0.006) and at the end (R = .53; p < 0.02) of the stimulation protocol, positively correlated. ES may be effective in the management of sexual pain disorders. Further controlled studies are necessary to standardize stimulation protocols according to the severity of pain and to better clarify the long-term clinical effects of ES.

Adult↗
PubMed1989

Neurotransmitter effects on inhibitory burst neurons in the cat.

The present experiment was designed to determine which neurotransmitter influences the burst pattern in the firing of the inhibitory burst neurons (IBN) during vestibular nystagmus. Cats were anesthetized with ether and mounted in a stereotaxic apparatus on a turntable, implanted stimulation electrodes, removed occipital bone and aspirated the vermal part of cerebellum. After the operation ether was discontinued. The recordings took place with the cats in an alert condition created by upper cervical cord transsection, artificial respiration and local anesthesia by infiltrating 0.5% lidocaine into the semilunar ganglions every two hours. We also employed iontophoretic application of the various drugs: GABA, muscimol, glycine, serotonin (5-HT) and bicuculline through seven-barrelled glass micropipettes. GABA or muscimol did not influence nystagmus rhythm, but both chemicals caused strong suppression of burst activities in IBN. Since this inhibitory effect of GABA was suppressed by the simultaneous application of bicuculline, IBNs appear to be controlled by GABAA receptor. Glycine and 5-HT did not change the firing pattern of IBN. Application of bicuculline itself caused an increase of tonic discharges of IBN. These findings suggest that IBN receive inhibitory impulses from the higher GABAergic neurons.

Animals↗
PubMed2006

[Head shaking test (HSN) using to diagnose vestibule damage].

INTRODUCTION: There is described a transient nystagmus provoked by shaking the head in the horizontal plane for a few seconds in both normal subjects and patients that is called Head Shaking Test (HSN) as a diagnostic tool for vestibular dysfunction. HSN is generally accepted that is generated by an asymmetrical peripheral vestibular input and a central velocity storage mechanism, which integrate and extend the peripheral vestibular signals. Purposes 1. Creation of own modification method of stimulation and registration HSN 2. Estimation of HSN test value to show asymmetrical function of vestibular system 3. Establish possibility of HSN test to localization of damage vestibular system 4. Verification this test to use it as screening test MATERIAL AND METHODS: Studied group was consisted of 111 subjects that consist of 68 women and 43 men with mean age 52,4 years. All patients and controls were submitted to audiological tests and vestibular examinations According to the results of the otoneurological tests, patients were divided into: 36 with peripheral vestibular disease, 37 with central vestibular disease, 6 with both peripheral and central vestibular disease and 32 control persons. Own modified HSN test was described. Frequency of movements was approximately 2 Hz determined by metronome. HSN was recorded using ENG apparatus produced by Hartmann. RESULTS: In the first study stage incidence of HSN-H and HSN-V related to localization of vestibular organ damage, symmetric and asymmetric reaction in tested. It was observed more incidence of HSN-H and HSN-V in patients with peripheral and central lesion of vestibular system than in control group. Estimation of HSN incidence related to kinetic test--acceleration-deceleration rotary test shows the same HSN frequency in compared groups, with symmetric or asymmetric reaction in rotary test. HSN frequency related to caloric test (canal paresis) showed statistic differences between normal and canal paresis reaction in caloric test. Analysis incidence of HSN-V revealed no significant differences between examined groups. In the second studied stage the sensitivity and specificity were examined. CONCLUSIONS: 1. It is possible to make HSN test using metronome and ENG recording 2. HSN test may be use to reveal asymmetry of vestibular function. 3. HSN is helpful to diagnose peripheral and central lesion to some extent. 4. HSN is not useful as screening test

Adolescent↗
PubMed1975

[Structure of the neurons of the spiral and vestibular ganglia and changes in them under conditions of adequate stimulation].

The ganglionic cells of the eighth nerve ganglia were studied. The cells of the vestibular and spiral ganglion were similar in structure. Changes in the ultrastructure involving the mitochondrial apparatus, and squamous endoplasmic reticulum and the nucleus took place in the ganglionic cells under effects of stimulation (sound, angular accelerations, vibration). These shifts appear to be morphological manifestations of the ganglionic cell metabolism under the influence of a specific stimulus.

Acoustic Stimulation↗
PubMed2003

Combined effect of vestibular and craniomandibular disorders on postural behaviour.

A correlation has been reported in the dental literature between temporomandibular disorders and musculoskeletal abnormalities, however, the question whether they modify body postural sway remains controversial. In the present investigation, the Craniomandibular Index was used to evaluate the clinical extension of temporomandibular joint dysfunction and related problems in 40 patients with normal vestibular function and in 42 patients with peripheral vestibular disorders. Balance function was assessed by static posturography and body sway area was measured in two conditions: i) eye open, and g) eye closed. Data were compared to those of 40 healthy subjects. Postural control showed a significantly different behaviour between groups with an increase in average body sway in patients with craniomandibular disorders as opposed to controls (p < 0.005). Although the involvement of the stomatognathic apparatus was not quantitatively different in the two groups of patients, those also presenting a peripheral vestibular disorder exhibited greater average body sway than patients with only craniomandibular disorders (p < 0.005). The latter showed a greater average body sway than controls only in the trial with eyes closed (p < 0.05). The results demonstrated that craniomandibular alterations could produce moderate postural instability in patients with a normal vestibular function. Conversely, their association with peripheral vestibular disorders becomes a real challenge to the upright quiet stance probably due to a negative effect of somatosensory origin on the vestibulo-spinal reflex impairment.

Adult↗
PubMed1992

Streptomycin blocks the afferent synapse of the isolated semicircular canals of the frog.

This study aimed to define the acute electrophysiological effects of the perilymphatic perfusion of streptomycin in the sensory apparatus of the semicircular canals of the frog. The ampullary DC potential, the vestibular nerve multiunit discharge, the nerve DC potential and the unitary EPSP activity were recorded in isolated semicircular canals of the frog (Rana esculenta L). The results demonstrated that perilymphatic microperfusion of streptomycin (0.1, 0.3, 1 and 3 mM) reduced both resting and mechanically evoked afferent discharge, while the response of the hair cells remains unchanged. Intracellular recordings from single afferent axons showed that the reduction of the afferent discharge was mainly due to a reduction of the amplitude, but not the frequency, of the EPSPs. These results indicate that streptomycin, when applied in the fluid bathing the synaptic pole of the sensory cells, can act as an antagonist of the vestibular afferent transmitter at the postsynaptic level.

Afferent Pathways↗
PubMed1988

Familial progressive vestibulocochlear dysfunction.

A kindred is presented in which several members had complaints of head movement-dependent oscillopsia due to acquired vestibular areflexia in combination with progressive hearing loss. History was noncontributory for other neurologic or otologic diseases (including infectious diseases) or use of neuro-ototoxic drugs. The pedigree suggests autosomal dominant inheritance.

Aged↗
PubMed1995

Melanocytes in the stria vascularis and vestibular labyrinth of the Mongolian gerbil (Meriones unguiculatus).

Inner ear melanocytes are mainly present in the cochlea, vestibular organ, and endolymphatic sac, but their exact biological function has not been determined. In this investigation, we study the pigment cells in the membranous labyrinth of the gerbil. The inner ear melanocytes of M. unguiculatus show an irregular dendritic shape with cytoplasmic processes. These cells are disposed following the distribution of strial marginal and vestibular dark cells that have an important metabolic activity. Gerbil inner ear melanocytes are characterized by the presence of melanosomes, which are homogeneously dense organelles, of variable size and shape, that are surrounded by a membrane. In these cells, the Golgi apparatus plays a important role in melanin synthesis. When melanocytes were incubated in L-DOPA solution, the vesicles and cisterns of the Golgi apparatus exhibited a positive tyrosinase reaction. An interesting observation is the relation between melanocytes and inner ear capillaries. Sometimes, near to sensory vestibular areas, the melanocytes were in contact with Schwann cells and with myelinated fibres of vestibular nerve. The ultrastructural findings of this investigation are consistent with the hypothesis that melanocytes may have functional significance in the inner ear.

Animals↗
PubMed1993

The neurons of the human magnocellular septal nuclei: a Golgi study.

The morphology of neurons in the magnocellular septal nuclei (medial septal and diagonal band nucleus) were studied in frontal sections of 15 human brains by means of the Golgi method. We classified neurons in the diagonal band nucleus according to their size and morphology into four types: type I--multipolar neurons, type II--fusiform neurons, type III--triangular neurons and type IV--fusiform multipolar neurons. The neurons of the medial septal nucleus we classified into two types: type I--multipolar neurons and type II--fusiform neurons. Our results indicated greater morphological variability of neurons in the human diagonal band nucleus than in the medial septal nucleus.

Adult↗