Vestibular Ganglion Cells Research Articles

Three-dimensional reconstruction of the Golgi apparatus and the endoplasmic reticulum of the vestibular ganglion cell.

Three-dimensional reconstruction of the Golgi apparatus and the endoplasmic reticulum of the vestibular ganglion cell.

Immunocytochemical evidence for an afferent GABAergic neurotransmission in the guinea pig vestibular system

To implicate γ-aminobutyric acid (GABA) as an afferent neurotransmitter (AN), the localization of GABA synthesizing and degradation enzymes; l-glutamate decarboxylase (GAD) and GABA transminase (GABA-T) was investigated by light and electron microscopy immunocytochemistry in guinea pig vestibular cristae and ganglion cells (GC). GAD-like immunoreactivity was exclusively confined to the sensory hair cell (HC) cytoplasm, suggesting that GAD synthesizes GABA in the HC. GABA-like immunoreactivity was found within HC, nerve calyces, nerve fibers, and GC, suggesting its participation in terminating transmitter action. These results demonstrate the existence of a GABAergic system in the guinea pig vestibule and strongly support GABA as a vestibular AN.

Preprotachykinin A mRNA detected by in situ hybridization in guinea pig vestibular ganglion

In situ hybridization histochemistry was conducted to examine the expression of mRNA oncoding preprotachykinin A (PPTA), the precursor of the neuropeptide substance P (SP) and neurokinin A (NKA), in guinea pig vestibular ganglion. Signals for PPTA mRNA moderately accumulated on most ganglion cells. SP and NKA are thus confirmed to be present in vestibular ganglion cells of the guinea pig.

Immunohistochemical studies on the guinea pig's vestibular ganglion cell--with reference to the distribution of substance P and neurofilament

The immunocytochemical distribution and morphological characteristics of substance P and neurofilament in vestibular end organs and the vestibular ganglion of the guinea pig were investigated. The effect of capsaicin on substance P-like immunoreactivity was also evaluated in this study. Substance P-like immunoreactivity was found in the peripheral region of vestibular end organs and in small or medium size vestibular ganglion cells. Approximately 85% of vestibular ganglion cells showed substance P-like immunoreactivity. Although substance P-like immunoreactivity was depleted in the nasal mucosa and trigeminal ganglion by capsaicin treatment, substance P distributed in the primary vestibular neurons was not affected. In contrast to the distribution of substance P, neurofilament was also found in the primary afferent neurons in the central regions of vestibular end organs. Neurofilament immunoreactive cells, which were larger in size than cells without neurofilament-like immunoreactivity comprised about 34% of vestibular ganglion cells. These immunocytochemical findings suggest that vestibular ganglion cells can be classified on the basis of size and immunocytochemical characteristics.

Experimental Viral Infection in Vestibular Ganglia of Rats

Viral infection has been suggested to be one of the causative agents of vestibular neuronitis. It is probable that reactivation of herpes simplex virus (HSV) in the vestibular ganglia may lead to vestibular dysfunction, causing vertigo and/or disequilibrium.In this study, rats were innoculated with HS V-I through the middle ear. We first examined the vestibular ganglia in the acute phase with an immunofluorescent (IF) method. We detected viral antigens in some vestibular ganglion cells. Second, we used the polymerase chain reaction (PCR) to detect virus DNA in vestibular gang-lia of rats in the latent phase. We found virus DNA in about 60% of vestibular ganglia on the innoculated side only. Third, we used reverse transcript-PCR (RT-PCR) to detect latency-asso-ciated transcripts (LAT), one of the mRNA of HSV-I . We found LAT in the vestibular gang-lion on the innoculated side only in the latent phase.These data indicate that HSV-I infects vesti-bular ganglia in the acute phase and establishes a latent infection. Only in the latent phase, LA T are transcripted in vestibular ganglia as in trigeminal ganglia.

Distribution of tyrosine hydroxylase-like immunofluorescence in guinea pig vestibular ganglia and sensory areas.

The distribution of tyrosine hydroxylase (TH)-like immunofluorescence was analyzed in the guinea pig vestibular ganglia and end organs using a monoclonal antibody to TH. TH was chosen as a marker for the sympathetic fibers because TH regulates the first step of catecholamine synthesis by converting tyrosine to dopa. In the vestibular ganglia, there were TH-positive nerve fibers having distinct varicosities surrounding the vestibular ganglion cells. In the sensory areas, there was a sympathetic plexus in the subepithelial tissue of the saccule, the utricle, and the crista ampullaris. We speculated that the sympathetic innervation has a direct influence on the vestibular ganglion cells and diffuse influence on the capillary permeability.

Ontogeny of afferents to the fetal rat cerebellum.

Afferents to the fetal rat cerebellum have been studied in fixed tissue with the fluorescent tracer, 1,1'-dioctadecyl-3,3,3',3'tetramethylindocarbocyanine perchlorate (DiI). The dye was applied to the cerebellar anlage at ages from embryonic day (E) 12 to birth (P0). Central processes of vestibular ganglion cells were found to be the first identifiable afferents to the cerebellum, being present at least by E13 and perhaps as early as E12. Ipsilateral spinocerebellar fibres may be labelled from E15, vestibular nuclei (both ipsi- and contralateral) also from E15, while contralateral inferior olivary nuclei could not be retrogradely labelled until E17. Trigeminocerebellar neurons in the interpolaris subnucleus of the nucleus of the trigeminal spinal tract and neurons of the lateral reticular nucleus were not labelled until E22 and P0, respectively. Finally, contralateral pontine nuclei were retrogradely labelled from the cerebellum after birth.

Identification and ultrastructural localization of a calretinin-like calcium-binding protein (protein 10) in the guinea pig and rat inner ear

Calretinin has been identified as a brain specific calcium-binding protein which appears as a prominent protein in the cochlear nucleus. We identified and localized calretinin in the guinea pig and rat inner ear using polyclonal antibodies. Immunoblot analyses of guinea pig and rat auditory nerve homogenates revealed an immunoreactive band migrating with the same molecular weight as the purified protein, at M r = 29k . Immunocytochemistry was carried out at the light and electron microscope levels. In the guinea pig cochlea, inner hair cells, Deiters' cells, Hensen's cells and interdental cells of the spiral limbus were stained. Most of the cochlear ganglion cells were immunostained. In the guinea pig vestibular organs, the staining was exclusively neuronal and localized in large nerve fibers and nerve calices of the apex of the cristae. Only some vestibular ganglion cells were stained. In the rat cochlea, inner hair cells and most of the ganglion neurons were immunoreactive. In the rat vestibule, large nerve fibers and calices were stained as were some type II hairs cells. Only some vestibular ganglion cells were reactive. Electron microscopic observations of immunostained guinea pig cochlea and vestibule showed that the staining was cytosolic. In addition, specific sub-localization was also found in the apical portion of the nerve calices in association with microvesicles. These results describe the discrete localization of calretinin in the cochlea and in the vestibular receptors and suggest a function associated with biochemical regulations at the level of microvesicles in vestibular afferent neurons.

Investigations into the Cause of Vertigo in Sudden Sensorineural Hearing Loss

In this light microscopic study of the temporal bone, an attempt has been made to find a morphologic correlate of vertigo associated with idiopathic sudden sensori-neural hearing loss (ISSHL). Hair cell densities of the three cristae and both maculae, as well as vestibular ganglion cell (neuronal) count estimation, was done in nine ears that had documented histories of ISSHL. There were five ears with vertigo and four without. These quantitative data--i.e., hair cell densities and neuronal counts, of the vertiginous ears (group I) and nonvertiginous ears (group II)--was compared by histograms and statistically. Additionally, in each of the two groups, the data from three opposite normal hearing ears were taken as a control and used for comparison with the ISSHL ears. The differences between the vertiginous, nonvertiginous, and control ears were not significant at the 0.01 level, indicating that the vertigo was not caused by hair cell or neuronal degeneration. Gross morphologic alterations in the vestibular system, such as membrane ruptures, endolymphatic hydrops, etc., were also assessed, but no clear-cut pathology was identified in the vertiginous and nonvertiginous ears. The absence of a light microscopic morphologic correlate for vestibular disturbances associated with ISSHL suggests that the symptoms could result from ultrastructural changes in the hair cells and their synapses or from biochemical alterations in their environment.

Localization of substance P-like immunoreactivity in guinea pig vestibular endorgans and the vestibular ganglion

The immunocytochemical distribution of substance P (SP) in guinea pig vestibular endorgans and the vestibular ganglion was investigated. Two kinds of SP-immunoreactive fibers were distinguished. Most were thick, and found around or beneath sensory hair cells. These SP-immunoreactive fibers were distributed predominantly on the slope of the crista and the peripheral region of the macula. By electron microscopy, we confirmed this type SP-like immunoreactivity to be restricted within primary afferent neurons. Some vestibular ganglion cells also showed SP-like immunoreactivity, suggesting that SP is present in some primary afferent neurons, and is involved in afferent neurotransmission. The characteristic distribution of SP may indicate functional differences within each endorgan. The other group of immunoreactive nerve fibers, varicous thin fibers could be found in the stroma of vestibular endorgans, nerve trunk, vestibular ganglion, and along blood vessels of the vestibular ganglion. These fibers may have a different origin, and have an influence on blood flow and certain other functions.

耳石器の機能と形態 文献的考察

The function and morphology of the otolith organs was examined with respect to the information transduction of head tilting and linear acceleration.It has generally been accepted that hair cells of the otolith organs are activated when hairs are reflected to the direction of the kinocillium (morphological polarization vector). Head tilting and acceleration stimulate hair cells with the same morphological polarization vector to increase their firing rates. To prove this theory, the correspondence between morphological and functional polarization vectors of otolith hair cells must be demonstrated.The functional polarization vectors of the otolith organs were predicted after physiological investigation of the vestibular ganglion (Scarpa's ganglion) cells. A similarity between the functional polarization vector of the superior vestibular ganglion cells and the morphological polarization vector of the utricular macula was suspected. Likewise a relation between the inferior vestibular ganglion cells and the saccular macula was also suspected. By this method, however, the peripheral innervation pattern of the vestibular ganglion cells could not be identified and the functional role of the differentiation of hair cells (types 1 and 2) as well as the significance of existence of striola remain unknown.

Histological Changes of Vestibular Nerves and Ganglion Cells in the Acoustic Tumor in Relation to Clinical Functions

The superior vestibular nerves and vestibular ganglion cells were observed electron microscopically in acoustic tumors removed surgically from 15 patients. Furthermore, the sensory cells of the vestibular organs were examined. Histological changes of vestibular nerves and ganglion cells were compared with the caloric responses of the patients. In most cases, the degree of degeneration of myelinated nerve fibers was proportional to the reduced responses of vestibular nerves. The myelinated nerve fibers decreased in number and showed some features of demyelination. The alteration of vestibular ganglion cells was unremarkable in comparison with vestibular nerves. In some cases, the number of lipofuscin granules, vacuolar organelles and amorphous materials markedly increased in the ganglion cells. However, the sensory cells of the vestibular organs appeared normal.

Cell Culture Study of the Vestibular Ganglion Cells:Morphology and Immunohistochemical Activity

Incubation of vestibular ganglion cells from the rat fetus and chick embryos was successfully done demonstrating bipolar cells and two types of multipolar cells, small round cells and large cells, in the cell cultures produced. Vestibular ganglion cells were found to be highly irregular in size. Furthermore, the presence of neurotransmitters (choline acetyltransferase and substance P) was confirmed immunohistochemically. Substance P positive cells had many bipolar cells and some multipolar cells. However, choline acetyl transferase positive cells had some small multipolar cells but few bipolar cells. These findings suggest that all vestibular ganglion cells do not have the same function.

Morphology of Human Vestibular Ganglion

Vestibular ganglion cells of mammals have been considered to be myelinated like spiral ganglion cells. Recently, electron microscopic studies reported that the ganglion cells of human vestibular ganglion were mostly unmyelinated unlike in other mammals. The purpose of this study was to find the myelin sheaths of human vestibular ganglion cells by light and laser microscopy.

Horseradish peroxidase labeling of the central pathways in the medulla of the ampullary nerves in the chicken, Gallus gallus

The purpose of the present study was to place horseradish peroxidase on the distal processes of the three ampullary nerves in 6-8-week-old chickens so that we could identify the ganglion cells associated with each nerve and trace the specific central pathways taken by each nerve in the brainstem. We are especially interested in the pathways of the colossal vestibular fibers, which may play a role in a fast reflex pathway as suggested by their large caliber and electrotonic mode of transmission in the tangential vestibular nucleus. The cells of origin of each ampullary nerve occupy discrete portions of the vestibular ganglion. Those vestibular ganglion cells giving rise to the posterior ampullary nerve (PAN) occupy the posterior portion of Scarpa's ganglion; the ganglion cells producing the anterior (AAN) and lateral (LAN) ampullary nerves occupy the anterior ganglion, within the dorsal and ventral portions, respectively. Centrally the vestibular fibers occupy discrete portions of the tangential vestibular nucleus before bifurcating into ascending and descending tracts. The tangential nucleus receives afferents from the colossal fibers, which form spoon endings, and also from the fine vestibular fibers, which form small terminals. The ascending fibers of the posterior ampullary nerve are associated with the nucleus piriformis; the ascending fibers of the anterior and lateral ampullary nerves occupy discrete cell groups of the vestibulo-cerebellar nucleus. All three ampullary nerves have descending branches that course through the retrotangential nucleus into the descending vestibular nucleus (DVN). Within the descending vestibular nucleus, the descending fibers of the posterior ampullary nerve run dorsally and centrally, whereas fibers of the anterior ampullary nerve course ventromedially, and the lateral ampullary nerve fibers take a ventrolateral course until all three fiber bundles converge in the posterior tip of the descending vestibular nucleus. The ascending and descending fibers of each ampullary nerve form collaterals that pass to the ventrolateral and dorsomedial parts of the medial vestibular nucleus. These collaterals are derived exclusively from the fine and medium diameter vestibular fibers. Some of these ascending fibers form a distinctive tract that courses posteriorly within medial regions of the dorsomedial part of the medial vestibular nucleus. The colossal vestibular fibers, which are found within all three ampullary nerves, conform to the ampullary pathways as described, excluding the innervation of the medial vestibular nucleus.

Schwann cells associated with vestibular ganglion cells in the aging rat

The purpose of this study was to quantify any age-related change in the components of Schwann cells associated with vestibular ganglion cells: adperikaryonal Schwann cell cytoplasm, myelin bubbles, compact myelin, Schwann cell lipofuscin, or mitochondria in addition to extracellular intraganglionic space. Studies were carried out in young (Y, 3 to 5 months of age, N = 6), old (0, 24 to 26 months of age, N = 3), and very old (VO, 28 to 31 months of age, N = 6) female Wistar rats using point counting stereologic techniques. Recent reports have demonstrated age-related increases in the peripheral nerve counterparts to the following entities: adaxonal Schwann cell cytoplasm, myelin bubble, endoneurial space, and a decrease in Schwann cell mitochondria. Our results indicate no age-related change in the volume fraction of extracellular intraganglionic space (Y, 0.179 ± 0.04; O, 0.174 ± 0.049; VO, 0.205 ± 0.043), adperikaryonal Schwann cell cytoplasm (Y, 0.026 ± 0.008; O, 0.019 ± 0.003; VO; 0.028 ± 0.007), myelin bubble (Y, 0.004 ± 0.003; O, 0.011 ± 0.009; VO, 0.006 ± 0.002), Schwann cell lipofuscin (Y, 0.002 ± 0.001; O, 0.004 ± 0.003; VO, 0.002 ± 0.001), or mitochondria (Y, 0.194 ± 0.019; O, 0.208 ± 0.024; VO, 0.205 ± 0.04). The only age-related change was an increase in compact myelin (Y, 0.006 ± 0.001; O, 0.008 ± 0.006; VO, 0.011 ± 0.004). These findings differ from those of the peripheral nerve. One possible explanation is a difference in the interaction of Schwann cells, vestibular ganglion cells, and/or the “open” environment of the ganglia compared with Schwann cells, peripheral axons, and/or the “closed” environment of the endoneurium during the aging process.

Expression of neurofilament proteins in the vestibular ganglion cells of the rat

Vestibular neurons from adult rats were studied by immunofluorescence microscopy using ten polyclonal and monoclonal antibodies reacting with different subunits of neurofilament (NF) polypeptides. Most antibodies strongly immunolabeled axons and dendrites. With the majority of antibodies the vestibular ganglion cells showed two distinct subpopulations: those with intense immunoreactivity and those without it. The intensely immunoreactive somata, staining with anti-70 kDa and anti-200 kDa NF antibodies but not with anti-150 kDa NF antibodies, comprised 32% of the ganglion cells (range: 27-40%). These cells were larger than the weakly immunoreactive majority of cells. Comparisons of adjacent sections revealed that at least a part of the distinctly immunostained cells were the same regardless of the antibody used. Thus, about one-third of the vestibular ganglion cells seem to form a subpopulation containing 200 kDa and 70 kDa subunits of NF polypeptides. Similar compositions of NF subunits have been demonstrated in such cells as the large dorsal root ganglion cells. The high percentage of neuronal somata with phosphorylated subunits of NF polypeptides demonstrated in this study is exceptional in other normal neurons and has been demonstrated only in experimental models and disease states.

The demonstration of choline acetyltransferase activity in cultured vestibular ganglion cells from the fetal rat

Incubation of vestibular ganglion cells from the rat fetus was successfully done demonstrating bipolar and multipolar cells in the cell cultures produced. Further, the presence of choline-acetyltransferase-positive cells was confirmed immunohistochemically.

Calbindin D-28k and parvalbumin in the rat nervous system

This paper describes the distribution of structures stained with mono- and polyclonal antibodies to the calcium-binding proteins calbindin D-28k and parvalbumin in the nervous system of adult rats. As a general characterization it can be stated that calbindin antibodies mainly label cells with thin, unmyelinated axons projecting in a diffuse manner. On the other hand, parvalbumin mostly occurs in cells with thick, myelinated axons and restricted, focused projection fields. The distinctive staining with antibodies against these two proteins can be observed throughout the nervous system. Calbindin D-28k is primarily associated with long-axon neurons (Golgi type I cells) exemplified by thalamic projection neurons, strionigral neurons, nucleus basalis Meynert neurons, cerebellar Purkinje cells, large spinal-, retinal-, cochlear- and vestibular ganglion cells. Calbindin D-28k occurs in all major pathways of the limbic system with the exception of the fornix. Calbindin D-28k is, however, also found in some short-axon cells (Golgi type II), represented by spinal cord interneurons in layer II and interneurons of the cerebral cortex. It is also detectable in some ependymal cells and abundantly occurs in vegatative centres of the hypothalamus. The “paracrine core” of the nervous system and its adjunct (1985, Nieuwenhuys, Ghemoarchitecture of the Brain. Springer, Berlin) is very rich in calbindin D-28k. The distribution of calbindin D-28k-positive neurons is very similar to that of the dihydroperydine subtype of calcium channels. Most of the cells containing calbindin D-28k are vulnerable to neurodegenerative processes. Parvalbumin-immunoreactive neurons have a different, and mostly complementary distribution compared with those which react with calbindin D-28k antisera, but in a few cases (Purkinje cells of the cerebellum, spinal ganglion neurons), both calcium-binding proteins co-exist in the same neuron. Many parvalbumin-immunoreactive cells in the central nervous system are interneurons (Golgi type II) and, to a lesser extent, long-axon cells (Golgi type I), whereas conditions are vice versa in the peripheral nervous system. Intrinsic parvalbuminic neurons are prominent in the cerebral cortex, hippocampus, cerebellar cortex and spinal cord. Long-axon parvalbumin-immunoreactive neurons are, for example, the Purkinje cells, neurons of the thalamic reticular nucleus, globus pallidus, substantia nigra (pars reticulata) and a subpopulation among large spinal-, retinal-, cochlear- and vestibular ganglion cells. Parvalbumin is rich in cranial nerve nuclei related to eye movements. In addition to nervous elements, parvalbumin immunoreactivity occurs in a few ependymal cells and in some pillar cells of the organ of Corti. In contrast to calbindin D-28k, parvalbumin is virtually absent from vegetative centres and pathways. Parvalbumin co-exists with GABA in cortical neurons and is, in general, preferentially associated with “fast-firing” neurons. Whole functional systems are revealed by either parvalbumin or calbindin D-28k immunohistochemistry. Parvalbumin, for example, occurs in the whole chain of neurons of the epicritic sensibility in the somatosensory system. Calbindin D-28k, on the other hand, occurs in the whole taste pathway. With antibodies against calbindin D-28k and parvalbumin it is possible to reveal at least two as yet undescribed brain nuclei: one in the hypothalamus (parvalbumin 1), the second in the medulla (calbindin D-28k 1). Calbindin D-28k and parvalbumin are evenly distributed within the various domains of the same neuron, but in some instances their levels vary between soma and cell processes. The immunostaining with calbindin D-28k and parvalbumin antisera show gradations in intensity among neurons belonging to different populations, a phenomenon compatible with the presence of varying concentrations of these proteins. Calbindin D-28k and parvalbumin are excellent new neuroanatomical markers which can be utilized to selectively visualize certain neurons and pathways in the central nervous system and peripheral nervous system.

Mitochondrial Volume Density of Schwann Cells Associated with Rat Vestibular Ganglion Cells

The purpose of this study was to quantitate the mitochondrial volume density (MVD) within Schwann cells associated with vestibular ganglion cells in the female Wistar rat. Results show that this type of Schwann cell (SC) has a significantly higher MVD (19.4% +/- 1.9) than that reported for myelinating SC of peripheral nerve (1-5%). This large difference in SC MVD may be related to the energy requirements needed to maintain the local ion homeostasis around the ganglion cells given the environmental differences created by the different barrier systems of these regions of the nervous system.