Journal articles: 'Ganglion spiral'

1

Cho, Chang Hyun. "Survival of Spiral Ganglion." Korean Journal of Otorhinolaryngology-Head and Neck Surgery 52, no. 11 (2009): 869. http://dx.doi.org/10.3342/kjorl-hns.2009.52.11.869.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Anniko, M., W. Arnold, T. Stigbrand, and A. Ström. "The Human Spiral Ganglion." ORL 57, no. 2 (1995): 68–77. http://dx.doi.org/10.1159/000276714.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Whitlon, Donna S. "Introduction: Spiral ganglion neurons." Hearing Research 278, no. 1-2 (August 2011): 1. http://dx.doi.org/10.1016/j.heares.2011.06.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Xu, Helen, Natasha Pollak, Sebahattin Cureoglu, and Michael M. Paparella. "S240 – Human Cochlear Implant Histopathology." Otolaryngology–Head and Neck Surgery 139, no. 2_suppl (August 2008): P155. http://dx.doi.org/10.1016/j.otohns.2008.05.415.

Full text

Abstract:

Objectives 1) To exam the histopathology of multichannel cochlear implant temporal bones. 2) To evaluate the relationship of residual spiral ganglion cell counts to clinical hearing performance. Methods 8 temporal bones from 4 cochlear implant patients were examined histologically. Paired comparisons were made between implanted and nonimplanted temporal bones. Clinical performance data was obtained from patient charts. Results There were varying amounts of inflammation (fibrosis and ossification) in the basal turn of the cochlear in all implanted temporal bones. Trauma to the facial nerve at facial recess site was noticed in 1 case. Compared with nonimplanted ears, 2 implanted bones with less than 10-year duration of implantation had no significant changes of spiral ganglion cell population. One case with prolong implant duration (15 years) showed about 36% decrease of spiral ganglion cells at the implanted site. The case with best speech recognition (89% with CID sentence) had the highest residual spiral ganglion cells (30% of normal spiral ganglion cell population). 2 cases with poor clinical performance (< 10% with CID sentence) had the residual spiral ganglion cells at 11% and 22%. The case with moderate clinical performance (30% with CID sentence) had 14% of normal spiral ganglion cell population. Surviving dendrites varied from 5% to 30% among 4 cases with no relationship to clinical performance. Conclusions Our findings suggest prolonged implantation may affect spiral ganglion cell population. There is no reverse relationship between residual spiral ganglion cells in implanted temporal bones to clinical speech performance observed from our limited cases.

APA, Harvard, Vancouver, ISO, and other styles

5

Ariyasu, Laurence, Frank R. Galey, Raymond Hilsinger, and Frederick M. Byl. "Computer-Generated Three-Dimensional Reconstruction of the Cochlea." Otolaryngology–Head and Neck Surgery 100, no. 2 (February 1989): 87–91. http://dx.doi.org/10.1177/019459988910000201.

Full text

Abstract:

Computer-generated three-dimensional reconstructions of the nerve fibers from the organ of Corti to the spiral ganglion were used to determine the optimum maximal length of the cochlear implant electrode. The spiral ganglion within the modiolus is much shorter than the organ of Corti. The spiral ganglion has turns and reaches no higher than the middle of the second turn of the organ of Corti, which has turns. The spiral ganglion is concentric and basal with respect to the organ of Corti. The spiral ganglion dendrites within the osseous spiral lamina of the basal turn project radially, nearly perpendicular to the central axis of the modiolus. Upon entering the modiolus, they turn basally at an angle of approximately 120 degrees. The projection of dendrites within the osseous spiral lamina became increasingly oblique as the ganglion extended apically. The organization of the cochlear nerve results from the spiraling of the ganglion. These findings are in agreement with previous reports. Implications of these findings and their possible relevance to the optimum length of the cochlear implant electrode are discussed with reference to cochlear damage resulting from longer electrodes.

APA, Harvard, Vancouver, ISO, and other styles

6

Khan, Aayesha M., Ophir Handzel, Donald K. Eddington, Doris Damian, and Joseph B. Nadol. "Effect of Cochlear Implantation on Residual Spiral Ganglion Cell Count as Determined by Comparison with the Contralateral Nonimplanted Inner Ear in Humans." Annals of Otology, Rhinology & Laryngology 114, no. 5 (May 2005): 381–85. http://dx.doi.org/10.1177/000348940511400508.

Full text

Abstract:

It is generally assumed that at least a minimal number of spiral ganglion cells is essential for successful speech perception with a cochlear implant. Although the insertion of a multichannel cochlear implant frequently results in loss of residual hearing in the implanted ear, this outcome does not imply that significant damage to residual populations of spiral ganglion cells has occurred. The purpose of the current study was to compare spiral ganglion cell counts in implanted and nonimplanted cochleas in 11 patients for whom both temporal bones were available and in whom a multichannel cochlear implant had been placed unilaterally. The temporal bones were processed for light microscopy by standard techniques. The cochleas were reconstructed by 2-dimensional methods. Spiral ganglion cell counts of the implanted and nonimplanted sides were compared by a paired t-test (2-tailed). The mean spiral ganglion cell counts for implanted and nonimplanted ears were not statistically different in the most basal three segments of the cochlea. However, the mean spiral ganglion cell count in segment 4 (apical segment) and the mean total spiral ganglion cell count were lower in the implanted cochleas than in the nonimplanted cochleas (p < .01). The results of this study suggest a modest decrease in the total spiral ganglion cell count in the implanted ears as compared to the nonimplanted ears, principally in the apical segment. Possible interpretations of this finding are discussed.

APA, Harvard, Vancouver, ISO, and other styles

7

Chiong, Charlotte M., Robert J. Glynn, Wen-Zhuang Xu, and Joseph B. Nadol. "Survival of Scarpa's Ganglion in the Profoundly Deaf Human." Annals of Otology, Rhinology & Laryngology 102, no. 6 (June 1993): 425–28. http://dx.doi.org/10.1177/000348949310200603.

Full text

Abstract:

The electrically evoked auditory brain stem response in some cochlear implant patients may be confounded by evoked potentials generated by vestibular neurons. The magnitude of this contribution to the response from the vestibular system is unknown, in part because the survival of cells within Scarpa's ganglion in profoundly deaf humans is unknown. Therefore, we undertook a quantitative study of Scarpa's ganglion in 48 deaf subjects who in life would have been candidates for cochlear implantation and in 5 subjects with normal hearing. The numbers of residual cells in both Scarpa's ganglion and the spiral ganglion in deaf subjects were significantly less than in individuals with normal hearing. Bivariate analysis demonstrated a highly significant positive correlation between cell counts of Scarpa's ganglion and the spiral ganglion. The durations of hearing loss and of profound deafness were negatively correlated with Scarpa's ganglion cell counts. However, in contrast to spiral ganglion cell survival, the cause of profound deafness did not predict the number of Scarpa's ganglion cells. Multiple linear regression analysis using a variety of clinical parameters demonstrated that the best predictor of the number of Scarpa's ganglion cells in profoundly deaf humans was the number of remaining spiral ganglion cells.

APA, Harvard, Vancouver, ISO, and other styles

8

Ramku, Emina, Refik Ramku, Dugagjin Spanca, and Valbona Zhjeqi. "Functional Pattern of Increasing Concentrations of Brain-Derived Neurotrophic Factor in Spiral Ganglion: Implications for Research on Cochlear Implants." Open Access Macedonian Journal of Medical Sciences 5, no. 2 (February 27, 2017): 121–25. http://dx.doi.org/10.3889/oamjms.2017.017.

Full text

Abstract:

BACKGROUND: As previously various studies have suggested application of brain-derived neurotrophic factor (BDNF) may be considered as a promising future therapy for hearing deficits, in particular for the improvement of cochlear neurone loss during cochlear implantation.AIM: The present study's aim was to establish the upper threshold of the concentration of BDNF in Naval Medical Research Institute (NMRI) mice spiral ganglion outgrowth.METHODS: Spiral ganglion explants were prepared from post-natal day 4 (p4) (NMRI) mice of both sexes under the approval and guidelines of the regional council of Hearing Research Institute Tubingen.RESULTS: Spiral ganglion explants were cultured at postnatal days 4 in the presence of different concentrations of BDNF as described under methods. We chose an age of postnatal day (P4) and concentrations of BDNF 0; 6; 12.5; 25 and 50 ƞg/ml. Averaged neurite outgrowth is measured in 4 different cultures that were treated with different concentrations. Results show that with increasing concentrations of BDNF, the neurite density increases.CONCLUSION: The present finding show evidence that BDNF has a clear incremental effect on the number of neurites of spiral ganglia in the prehearing organ, but less on the neurite length. The upper threshold of exogenous BNDF concentration on spiral ganglion explant is 25 ƞg/ml. This means that concentration beyond this level has no further incremental impact. Therefore our suggestion for hydrogel concentration in NMRA mice in future research should be 25 ƞg/ml.

APA, Harvard, Vancouver, ISO, and other styles

9

Yilmaz-Bayraktar, Suheda, Jana Schwieger, Verena Scheper, Thomas Lenarz, Ulrike Böer, Michaela Kreienmeyer, Mariela Torrente, and Theodor Doll. "Decellularized equine carotid artery layers as matrix for regenerated neurites of spiral ganglion neurons." International Journal of Artificial Organs 43, no. 5 (August 22, 2019): 332–42. http://dx.doi.org/10.1177/0391398819868481.

Full text

Abstract:

Today’s best solution in compensating for sensorineural hearing loss is the cochlear implant, which electrically stimulates the spiral ganglion neurons in the inner ear. An optimum hearing impression is not ensured due to, among other reasons, a remaining anatomical gap between the spiral ganglion neurons and the implant electrodes. The gap could be bridged via pharmacologically triggered neurite growth toward the electrodes if biomaterials for neurite guidance could be provided. For this, we investigated the suitability of decellularized tissue. We compared three different layers (tunica adventitia, tunica media, and tunica intima) of decellularized equine carotid arteries in a preliminary approach. Rat spiral ganglia explants were cultured on decellularized equine carotid artery layers and neurite sprouting was assessed quantitatively. Generally, neurite outgrowth was possible and it was most prominent on the intima (in average 83 neurites per spiral ganglia explants, followed by the adventitia (62 neurites) and the lowest growth on the media (20 neurites). Thus, decellularized equine carotid arteries showed promising effects on neurite regeneration and can be developed further as efficient biomaterials for neural implants in hearing research.

APA, Harvard, Vancouver, ISO, and other styles

10

Nadol, Joseph B., Yi-Shyang Young, and Robert J. Glynn. "Survival of Spiral Ganglion Cells in Profound Sensorineural Hearing Loss: Implications for Cochlear Implantation." Annals of Otology, Rhinology & Laryngology 98, no. 6 (June 1989): 411–16. http://dx.doi.org/10.1177/000348948909800602.

Full text

Abstract:

Ninety-three temporal bones from 66 patients who were profoundly deaf during life were reconstructed by analysis of serial light microscopic sections. The correlations of total and segmental spiral ganglion cell counts with age, duration of hearing loss and profound deafness, and cause of hearing loss were evaluated. Bivariate analysis demonstrated that total spiral ganglion cell count tended to be lower in older than in younger deaf individuals and lower with longer duration of hearing loss and total deafness. However, multiple regression analysis demonstrated that the cause of hearing loss was the single most significant determinant of total spiral ganglion cell count. Patients with deafness due to aminoglycoside toxicity or sudden idiopathic deafness had the highest residual spiral ganglion cell count and patients with deafness due to presumptive postnatal viral labyrinthitis, bacterial labyrinthitis, and congenital or genetic causes had the lowest numbers of residual spiral ganglion cells.

APA, Harvard, Vancouver, ISO, and other styles

11

Jones, Timothy A., Patricia A. Leake, Russell L. Snyder, Olga Stakhovskaya, and Ben Bonham. "Spontaneous Discharge Patterns in Cochlear Spiral Ganglion Cells Before the Onset of Hearing in Cats." Journal of Neurophysiology 98, no. 4 (October 2007): 1898–908. http://dx.doi.org/10.1152/jn.00472.2007.

Full text

Abstract:

Spontaneous neural activity has been recorded in the auditory nerve of cats as early as 2 days postnatal (P2), yet individual auditory neurons do not respond to ambient sound levels <90–100 dB SPL until about P10. Significant refinement of the central projections from the spiral ganglion to the cochlear nucleus occurs during this neonatal period. This refinement may be dependent on peripheral spontaneous discharge activity. We recorded from single spiral ganglion cells in kittens aged P3–P9. The spiral ganglion was accessed through the round window through the spiral lamina. A total of 112 ganglion cells were isolated for study in nine animals. Spike rates in neonates were very low, ranging from 0.06 to 56 spikes/s, with a mean of 3.09 ± 8.24 spikes/s. Ganglion cells in neonatal kittens exhibited remarkable repetitive spontaneous bursting discharge patterns. The unusual patterns were evident in the large mean interval CV (CVi = 2.9 ± 1.6) and burst index of 5.2 ± 3.5 across ganglion cells. Spontaneous bursting patterns in these neonatal mammals were similar to those reported for cochlear ganglion cells of the embryonic chicken, suggesting this may be a general phenomenon that is common across animal classes. Rhythmic spontaneous discharge of retinal ganglion cells has been shown to be important in the development of central retinotopic projections and normal binocular vision. Bursting rhythms in cochlear ganglion cells may play a similar role in the auditory system during prehearing periods.

APA, Harvard, Vancouver, ISO, and other styles

12

Li, Jieying, Yan Chen, Shan Zeng, Chuijin Lai, Yanping Zhang, Liting Zhang, Yuxuan Shi, Tianyu Zhang, Huawei Li, and Peidong Dai. "Contralateral Suppression of DPOAEs in Mice after Ouabain Treatment." Neural Plasticity 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/6890613.

Full text

Abstract:

Medial olivocochlear (MOC) efferent feedback is suggested to protect the ear from acoustic injury and to increase its ability to discriminate sounds against a noisy background. We investigated whether type II spiral ganglion neurons participate in the contralateral suppression of the MOC reflex. The application of ouabain to the round window of the mouse cochlea selectively induced the apoptosis of the type I spiral ganglion neurons, left the peripherin-immunopositive type II spiral ganglion neurons intact, and did not affect outer hairs, as evidenced by the maintenance of the distorted product otoacoustic emissions (DPOAEs). With the ouabain treatment, the threshold of the auditory brainstem response increased significantly and the amplitude of wave I decreased significantly in the ouabain-treated ears, consistent with the loss of type I neurons. Contralateral suppression was measured as reduction in the amplitude of the 2f1−f2 DPOAEs when noise was presented to the opposite ear. Despite the loss of all the type I spiral ganglion neurons, virtually, the amplitude of the contralateral suppression was not significantly different from the control when the suppressor noise was delivered to the treated cochlea. These results are consistent with the type II spiral ganglion neurons providing the sensory input driving contralateral suppression of the MOC reflex.

APA, Harvard, Vancouver, ISO, and other styles

13

Nadol, Joseph B., and Wen-Zhuang Xu. "Diameter of the Cochlear Nerve in Deaf Humans: Implications for Cochlear Implantation." Annals of Otology, Rhinology & Laryngology 101, no. 12 (December 1992): 988–93. http://dx.doi.org/10.1177/000348949210101205.

Full text

Abstract:

Although the parameters that are most important for postoperative speech perception in cochlear implantation have not been identified, it is assumed that the numbers of remaining cochlear neurons and spiral ganglion cells in the implanted deaf ears are critical. In this study, we evaluated the correlation of the maximum diameter of the cochlear and vestibular nerve trunks with the number of spiral ganglion cells in horizontal sections of the temporal bone of 42 patients who were profoundly deaf during life, and in 5 patients with normal hearing. The maximum diameters of the cochlear, vestibular, and eighth cranial nerves were significantly smaller in the deaf population as compared to normal-hearing controls. In addition, the counts of the remaining spiral ganglion cells were significantly correlated with the maximum diameter of the cochlear (p = .0006), vestibular (p = .001), and eighth cranial nerves (p = .0003). The regression equation estimated that 25% of the variance of the spiral ganglion cell count was predicted by the maximum diameter of the eighth nerve. Although the results of this study suggest that preoperative radiographic imaging of the diameter of the eighth nerve may be helpful in predicting the residual spiral ganglion cell count, the wide variability of diameters of the eighth nerve in hearing and deaf subjects militates against this theoretic usefulness.

APA, Harvard, Vancouver, ISO, and other styles

14

Schachern, Patricia A., Michael M. Paparella, Donald A. Shea, and Tae H. Yoon. "Otologic Histopathology of Fabry's Disease." Annals of Otology, Rhinology & Laryngology 98, no. 5 (May 1989): 359–63. http://dx.doi.org/10.1177/000348948909800509.

Full text

Abstract:

Fabry's disease is a rare progressive X-linked recessive disorder of glycosphingolipid metabolism. The accumulation of glycosphingolipids occurs in virtually all areas of the body, including the endothelial, perithelial, and smooth-muscle cells of blood vessels, the ganglion cells of the autonomic nervous system, and the glomeruli and tubules of the kidney. Although otologic symptoms have been described in these patients, to our knowledge there have been no temporal bone histopathologic reports. We describe the clinical histories, audiometric results, and temporal bone findings of two patients with this rare disorder. Both patients demonstrated a bilateral sloping sensorineural hearing loss audiometrically. Middle ear findings of seropurulent effusions and hyperplastic mucosa were seen in all four temporal bones. Strial and spiral ligament atrophy in all turns, and hair cell loss mainly in the basal turns, were also common findings. The number of spiral ganglion cells was reduced in all temporal bones; however, evidence of glycosphingolipid accumulation was not observed in the spiral ganglia.

APA, Harvard, Vancouver, ISO, and other styles

15

Ramírez, Tania, Simona Sacchini, Yania Paz, Rubén S. Rosales, Nakita Câmara, Marisa Andrada, Manuel Arbelo, and Antonio Fernández. "Comparison of Methods for the Histological Evaluation of Odontocete Spiral Ganglion Cells." Animals 10, no. 4 (April 14, 2020): 683. http://dx.doi.org/10.3390/ani10040683.

Full text

Abstract:

Cetaceans greatly depend on their hearing system to perform many vital activities. The spiral ganglion is an essential component of the auditory pathway and can even be associated with injuries caused by anthropogenic noise. However, its anatomical location, characterized by surrounding bony structures, makes the anatomical and anatomopathological study of the spiral ganglion a difficult task. In order to obtain high-quality tissue samples, a perfect balance between decalcification and the preservation of neural components must be achieved. In this study, different methodologies for spiral ganglion sample preparation and preservation were evaluated. Hydrochloric acid had the shortest decalcification time but damaged the tissue extensively. Both formic acid and EDTA decalcification solutions had a longer decalcification time but exhibited better preservation of the neurons. However, improved cell morphology and staining were observed on ears pretreated with EDTA solution. Therefore, we suggest that decalcifying methodologies based on EDTA solutions should be used to obtain the highest quality samples for studying cell morphology and antigenicity in cetacean spiral ganglion neurons.

APA, Harvard, Vancouver, ISO, and other styles

16

Lu, Cindy, Jesse Appler, and Lisa Goodrich. "Axon branching in spiral ganglion neurons." Developmental Biology 319, no. 2 (July 2008): 503. http://dx.doi.org/10.1016/j.ydbio.2008.05.127.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Arnold, Wolfgang. "Myelination of the Human Spiral Ganglion." Acta Oto-Laryngologica 104, sup436 (January 1987): 76–84. http://dx.doi.org/10.3109/00016488709124979.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Sun, Shuohao, Caroline Siebald, and Ulrich Müller. "Subtype maturation of spiral ganglion neurons." Current Opinion in Otolaryngology & Head & Neck Surgery 29, no. 5 (August 18, 2021): 391–99. http://dx.doi.org/10.1097/moo.0000000000000748.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Msiv, Namrata Pai, Carlton J. Zdanski, Christopher W. Gregory, Jiri Prazma, and Vincent Carrasco. "Sodium nitroprusside/nitric oxide causes apoptosis in spiral ganglion cells." Otolaryngology–Head and Neck Surgery 119, no. 4 (October 1998): 323–30. http://dx.doi.org/10.1016/s0194-5998(98)70072-5.

Full text

Abstract:

OBJECTIVE: In the cochlea, excitatory amino acid receptor overstimulation induces toxicity in spiral ganglion neurons by an unknown mechanism. In the central nervous system, excitatory amino acid-induced toxicity is mediated by nitric oxide, which induces apoptosis in neurons. This study tested the hypothesis that cochlear nitric oxide-mediated toxicity is the result of induction of apoptosis in spiral ganglion neurons. METHODS: The cochleas of 15 gerbils randomly assigned to different groups were perfused for 30 minutes with a test solution of 1 mmol/L sodium nitroprusside, a nitric oxide donor, or a control solution of artificial perilymph. Animals were killed at varying times, including 2, 3, 4, 8, and 18 hours after perfusion. DNA fragmentation or in situ terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling analysis was done on cochleas for detection of apoptosis. RESULTS: Analysis by both techniques demonstrated marked apoptotic cell changes in spiral ganglion neurons of sodium nitroprusside-treated cochleas evident 4 to 8 hours after perfusion, as compared with minimal to no evidence of apoptosis in spiral ganglion neurons of control specimens. CONCLUSIONS: Exposure to high levels of nitric oxide induces apoptosis in spiral ganglion neurons. Because apoptosis is a delayed, potentially reversible cell death pathway, this may present an opportunity for intervention to prevent or attenuate hearing damage induced by excitotoxic stimuli.

APA, Harvard, Vancouver, ISO, and other styles

20

Nadol, Joseph B., Barbara J. Burgess, Bruce J. Gantz, Newton J. Coker, Darlene R. Ketten, Isabel Kos, J. Thomas Roland, et al. "Histopathology of Cochlear Implants in Humans." Annals of Otology, Rhinology & Laryngology 110, no. 9 (September 2001): 883–91. http://dx.doi.org/10.1177/000348940111000914.

Full text

Abstract:

The insertion of an intrascalar electrode array during cochlear implantation causes immediate damage to the inner ear and may result in delayed onset of additional damage that may interfere with neuronal stimulation. To date, there have been reports on fewer than 50 temporal bone specimens from patients who had undergone implantation during life. The majority of these were single-channel implants, whereas the majority of implants inserted today are multichannel systems. This report presents the histopathologic findings in temporal bones from 8 individuals who in life had undergone multichannel cochlear implantation, with particular attention to the type and location of trauma and to long-term changes within the cochlea. The effect of these changes on spiral ganglion cell counts and the correlation between speech comprehension and spiral ganglion cell counts were calculated. In 4 of the 8 cases, the opposite, unimplanted ear was available for comparison. In 3 of the 4 cases, there was no significant difference between the spiral ganglion cell counts on the implanted and unimplanted sides. In addition, in this series of 8 cases, there was an apparent negative correlation between residual spiral ganglion cell count and hearing performance during life as measured by single-syllable word recognition. This finding suggests that abnormalities in the central auditory pathways are at least as important as spiral ganglion cell loss in limiting the performance of implant users.

APA, Harvard, Vancouver, ISO, and other styles

21

Robinson, Alan M., Irena Vujanovic, and Claus-Peter Richter. "Minocycline Protection of Neomycin Induced Hearing Loss in Gerbils." BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/934158.

Full text

Abstract:

This animal study was designed to determine if minocycline ameliorates cochlear damage is caused by intratympanic injection of the ototoxic aminoglycoside antibiotic neomycin. Baseline auditory-evoked brainstem responses were measured in gerbils that received 40 mM intratympanic neomycin either with 0, 1.2, or 1.5 mg/kg intraperitoneal minocycline. Four weeks later auditory-evoked brainstem responses were measured and compared to the baseline measurements. Minocycline treatments of 1.2 mg/kg and 1.5 mg/kg resulted in significantly lower threshold increases compared to 0 mg/kg, indicating protection of hearing loss between 6 kHz and 19 kHz. Cochleae were processed for histology and sectioned to allow quantification of the spiral ganglion neurons and histological evaluation of organ of Corti. Significant reduction of spiral ganglion neuron density was demonstrated in animals that did not receive minocycline, indicating that those receiving minocycline demonstrated enhanced survival of spiral ganglion neurons, enhanced survival of sensory hairs cells and spiral ganglion neurons, and reduced hearing threshold elevation correlates with minocycline treatment demonstrating that neomycin induced hearing loss can be reduced by the simultaneous application of minocycline.

APA, Harvard, Vancouver, ISO, and other styles

22

Huang, Eric J., Wei Liu, Bernd Fritzsch, Lynne M. Bianchi, Louis F. Reichardt, and Mengqing Xiang. "Brn3a is a transcriptional regulator of soma size, target field innervation and axon pathfinding of inner ear sensory neurons." Development 128, no. 13 (July 1, 2001): 2421–32. http://dx.doi.org/10.1242/dev.128.13.2421.

Full text

Abstract:

The POU domain transcription factors Brn3a, Brn3b and Brn3c are required for the proper development of sensory ganglia, retinal ganglion cells, and inner ear hair cells, respectively. We have investigated the roles of Brn3a in neuronal differentiation and target innervation in the facial-stato-acoustic ganglion. We show that absence of Brn3a results in a substantial reduction in neuronal size, abnormal neuronal migration and downregulation of gene expression, including that of the neurotrophin receptor TrkC, parvalbumin and Brn3b. Selective loss of TrkC neurons in the spiral ganglion of Brn3a−/− cochlea leads to an innervation defect similar to that of TrkC−/− mice. Most remarkably, our results uncover a novel role for Brn3a in regulating axon pathfinding and target field innervation by spiral and vestibular ganglion neurons. Loss of Brn3a results in severe retardation in development of the axon projections to the cochlea and the posterior vertical canal as early as E13.5. In addition, efferent axons that use the afferent fibers as a scaffold during pathfinding also show severe misrouting. Interestingly, despite the well-established roles of ephrins and EphB receptors in axon pathfinding, expression of these molecules does not appear to be affected in Brn3a−/− mice. Thus, Brn3a must control additional downstream genes that are required for axon pathfinding.

APA, Harvard, Vancouver, ISO, and other styles

23

Couloigner, Vincent, Michel Fay, Sabri Djelidi, Nicolette Farman, Brigitte Escoubet, Isabelle Runembert, Olivier Sterkers, Gérard Friedlander, and Evelyne Ferrary. "Location and function of the epithelial Na channel in the cochlea." American Journal of Physiology-Renal Physiology 280, no. 2 (February 1, 2001): F214—F222. http://dx.doi.org/10.1152/ajprenal.2001.280.2.f214.

Full text

Abstract:

In the cochlea, endolymph is a K-rich and Na-poor fluid. The purpose of the present study was to check the presence and to assess the role of epithelial Na channel (ENaC) in this organ. α-, β-, and γ-ENaC subunit mRNA, and proteins were detected in rat cochlea by RT-PCR and Western blot. α-ENaC subunit mRNA was localized by in situ hybridization in both epithelial (stria vascularis, spiral prominence, spiral limbus) and nonepithelial structures (spiral ligament, spiral ganglion). The α-ENaC-positive tissues were also positive for β-subunit mRNA (except spiral ganglion) or for γ-subunit mRNA (spiral limbus, spiral ligament, and spiral ganglion), but the signals of β- and γ-subunits were weaker than those observed for α-subunit. In vivo, the endocochlear potential was recorded in guinea pigs under normoxic and hypoxic conditions after endolymphatic perfusion of ENaC inhibitors (amiloride, benzamil) dissolved either in K-rich or Na-rich solutions. ENaC inhibitors altered the endocochlear potential when Na-rich but not when K-rich solutions were perfused. In conclusion, ENaC subunits are expressed in epithelial and nonepithelial cochlear structures. One of its functions is probably to maintain the low concentration of Na in endolymph.

APA, Harvard, Vancouver, ISO, and other styles

24

Ying, Yu-Lan M., and Carey D. Balaban. "R450 – Manganese Superoxide Dismutase in Spiral Ganglion Cells." Otolaryngology–Head and Neck Surgery 139, no. 2_suppl (August 2008): P195—P196. http://dx.doi.org/10.1016/j.otohns.2008.05.606.

Full text

Abstract:

Problem Manganese superoxide dismutase (Mn SOD2) is a key metabolic anti-oxidant enzyme of the superoxide dismutase family for detoxifying the free radical cascade inside the mitochondria of the cochlea via activation of downstream uncoupling proteins. Copper/zinc superoxide dismutase (Cu/Zn SOD1) is localized in the cytoplasm. This study examined whether the pattern of expression of these SODs in the cochlea is correlated with the differential cellular vulnerability found in basal versus apical turn of the cochlea. Methods Immunohistochemical methods were used to identify the distribution of Mn SOD2 and Cu/Zn SOD1 in paraffin embedded sections of paraformaldehyde fixed formic acid decalcified temporal bones from mice, rats, and macaques; and special archival celloidin-embedded human temporal bone sections. Results In mice, rats and macaques, both the proportion of Mn SOD2 immunopositive type 1 spiral ganglion cells and the intensity of immunoreactivity were elevated near the cochlear apex. Strongly stained Mn SOD2 type 1 spiral ganglion cells were also observed in archival human temporal bone sections. In contrast, the Cu/Zn SOD1 immunopositive type 1 spiral ganglion cells were distributed identically across cochlear turns in rats and macaques. Conclusion These findings suggest that spiral ganglion cellular responses to ROS exposure may vary along the cochlear spiral, with a lower response capacity in the basal turn. Significance Hair cells and spiral ganglion cells appear to be more vulnerable to ototoxins at the base of the cochlea than at the apex. Our data raises the general hypothesis that a lower Mn SOD2 anti-oxidative capacity at the cochlear base could contribute to the high frequency hearing loss seen in presbycusis and ototoxin-induced hearing loss. The conservative pattern of Mn SOD2 immunostaining across species further suggests that it may be a fundamental mechanism in ROS metabolism and signaling. Support PA Lions Hearing Research Foundation, American Otologic Society Research Fellowship.

APA, Harvard, Vancouver, ISO, and other styles

25

Jyung, Robert W., Josef M. Miller, and Stephen C. Cannon. "Evaluation of Eighth Nerve Integrity by the Electrically Evoked Middle Latency Response." Otolaryngology–Head and Neck Surgery 101, no. 6 (December 1989): 670–82. http://dx.doi.org/10.1177/019459988910100610.

Full text

Abstract:

A reliable objective test for estimating the number and distribution of surviving eighth nerve fibers needs to be identified for selection of candidates for cochlear Implantation. Kanamycin and ethacrynic acid administration In guinea pigs resulted In graded amounts of eighth nerve degeneration over time. The electrically-induced middle latency response (EMLR) was acutely recorded in these animals at specific post-drug times, followed by the immediate killing of the animals, histologic preparation, and spiral ganglion cell density determination. Significant progressive spiral ganglion cell loss was noted by 4 weeks that Increased over time. While EMLR threshold remained stable over time, the slope of the EMLR Input/output function decreased with Increasing post-drug intervals in a manner directly correlated with reduction in spiral ganglion cell density.

APA, Harvard, Vancouver, ISO, and other styles

26

Leitmeyer, Katharina, Andrea Glutz, Vesna Radojevic, Cristian Setz, Nathan Huerzeler, Helen Bumann, Daniel Bodmer, and Yves Brand. "Inhibition of mTOR by Rapamycin Results in Auditory Hair Cell Damage and Decreased Spiral Ganglion Neuron Outgrowth and Neurite FormationIn Vitro." BioMed Research International 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/925890.

Full text

Abstract:

Rapamycin is an antifungal agent with immunosuppressive properties. Rapamycin inhibits the mammalian target of rapamycin (mTOR) by blocking the mTOR complex 1 (mTORC1). mTOR is an atypical serine/threonine protein kinase, which controls cell growth, cell proliferation, and cell metabolism. However, less is known about the mTOR pathway in the inner ear. First, we evaluated whether or not the two mTOR complexes (mTORC1 and mTORC2, resp.) are present in the mammalian cochlea. Next, tissue explants of 5-day-old rats were treated with increasing concentrations of rapamycin to explore the effects of rapamycin on auditory hair cells and spiral ganglion neurons. Auditory hair cell survival, spiral ganglion neuron number, length of neurites, and neuronal survival were analyzedin vitro. Our data indicates that both mTOR complexes are expressed in the mammalian cochlea. We observed that inhibition of mTOR by rapamycin results in a dose dependent damage of auditory hair cells. Moreover, spiral ganglion neurite number and length of neurites were significantly decreased in all concentrations used compared to control in a dose dependent manner. Our data indicate that the mTOR may play a role in the survival of hair cells and modulates spiral ganglion neuronal outgrowth and neurite formation.

APA, Harvard, Vancouver, ISO, and other styles

27

Richter, Claus-Peter, Andrew J. Fishman, and Agnella D. Izzo. "Cochlear Nerve Stimulation With Optical Radiation." Otolaryngology–Head and Neck Surgery 139, no. 2_suppl (August 2008): P99. http://dx.doi.org/10.1016/j.otohns.2008.05.519.

Full text

Abstract:

Problem Neural prosthetic devices are artificial extensions to the body that restore or supplement nervous system function that was lost during disease or injury. The devices stimulate remaining neural tissue with electric current, providing some input to the nervous system. Hereby, the challenge for neural prostheses is to stimulate remaining neurons selectively. However, electrical current spread does not easily allow stimulation of small neuron populations. In neural prostheses developments, particular success has been realized in the cochlear prostheses development. The devices bypass damaged hair cells in the auditory system by direct electrical stimulation of the auditory nerve. Stimulating discrete spiral ganglion cell populations in cochlear implant users’ ears is similar to the encoding of small acoustic frequency bands in a normal-hearing person's ear. In contemporary cochlear implants, however, the injected electric current is spread widely along the scala tympani and across turns. Consequently, stimulation of spatially discrete spiral ganglion cell populations is difficult. Methods Spiral ganglion cells in guinea pigs were stimulated with laser pulses from an Aculight Capella infrared laser. Results With our experiments we demonstrate that extreme spatially selective stimulation is possible using light. Conclusion Our long-term goal is to develop and build an optical cochlear implant prosthesis to stimulate small populations of spiral ganglion cells. Significance Our long-term goal is to develop and build an optical cochlear implant prosthesis to stimulate small populations of spiral ganglion cells. Support This project has been funded with federal funds from the National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN260-2006-00006-C / NIH No. N01-DC-6-0.

APA, Harvard, Vancouver, ISO, and other styles

28

Bixenstine, Paul J., Mauricio P. Maniglia, Amit Vasanji, Kumar N. Alagramam, and Cliff A. Megerian. "Spiral Ganglion Degeneration Patterns in Endolymphatic Hydrops." Laryngoscope 118, no. 7 (July 2008): 1217–23. http://dx.doi.org/10.1097/mlg.0b013e31816ba9cd.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Anderson, Malin, A. H. Johnston, T. A. Newman, P. D. Dalton, and Helge Rask-Andersen. "Internalization of Nanoparticles into Spiral Ganglion Cells." Journal of Nanoneuroscience 1, no. 1 (June 1, 2009): 75–84. http://dx.doi.org/10.1166/jns.2009.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Bao, Jianxin, and Kevin K. Ohlemiller. "Age-related loss of spiral ganglion neurons." Hearing Research 264, no. 1-2 (June 2010): 93–97. http://dx.doi.org/10.1016/j.heares.2009.10.009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Zhai, S.-Q., W. Guo, Y.-Y. Hu, N. Yu, Q. Chen, J.-Z. Wang, M. Fan, and W.-Y. Yang. "Protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion." Journal of Laryngology & Otology 125, no. 5 (November 16, 2010): 449–54. http://dx.doi.org/10.1017/s0022215110002112.

Full text

Abstract:

AbstractObjective:To explore the protective effects of brain-derived neurotrophic factor on the noise-damaged cochlear spiral ganglion.Methods:Recombinant adenovirus brain-derived neurotrophic factor vector, recombinant adenovirus LacZ and artificial perilymph were prepared. Guinea pigs with audiometric auditory brainstem response thresholds of more than 75 dB SPL, measured seven days after four hours of noise exposure at 135 dB SPL, were divided into three groups. Adenovirus brain-derived neurotrophic factor vector, adenovirus LacZ and perilymph were infused into the cochleae of the three groups, variously. Eight weeks later, the cochleae were stained immunohistochemically and the spiral ganglion cells counted.Results:The auditory brainstem response threshold recorded before and seven days after noise exposure did not differ significantly between the three groups. However, eight weeks after cochlear perfusion, the group receiving brain-derived neurotrophic factor had a significantly decreased auditory brainstem response threshold and increased spiral ganglion cell count, compared with the adenovirus LacZ and perilymph groups.Conclusion:When administered via cochlear infusion following noise damage, brain-derived neurotrophic factor appears to improve the auditory threshold, and to have a protective effect on the spiral ganglion cells.

APA, Harvard, Vancouver, ISO, and other styles

32

Gao, Dongmei, Hong Yu, Bo Li, Li Chen, Xiaoyu Li, and Wenqing Gu. "Cisplatin Toxicology: The Role of Pro-inflammatory Cytokines and GABA Transporters in Cochlear Spiral Ganglion." Current Pharmaceutical Design 25, no. 45 (January 10, 2020): 4820–26. http://dx.doi.org/10.2174/1381612825666191106143743.

Full text

Abstract:

Background: The current study was conducted to examine the specific activation of pro-inflammatory cytokines (PICs), namely IL-1β, IL-6 and TNF-α in the cochlear spiral ganglion of rats after ototoxicity induced by cisplatin. Since γ-aminobutyric acid (GABA) and its receptors are involved in pathophysiological processes of ototoxicity, we further examined the role played by PICs in regulating expression of GABA transporter type 1 and 3 (GAT-1 and GAT-3), as two essential subtypes of GATs responsible for the regulation of extracellular GABA levels in the neuronal tissues. Methods: ELISA and western blot analysis were employed to examine the levels of PICs and GATs; and auditory brainstem response was used to assess ototoxicity induced by cisplatin. Results: IL-1β, IL-6 and TNF-α as well as their receptors were significantly increased in the spiral ganglion of ototoxic rats as compared with sham control animals (P<0.05, ototoxic rats vs. control rats). Cisplatin-ototoxicity also induced upregulation of the protein levels of GAT-1 and GAT-3 in the spiral ganglion (P<0.05 vs. controls). In addition, administration of inhibitors to IL-1β, IL-6 and TNF-α attenuated amplification of GAT-1 and GAT-3 and improved hearing impairment induced by cisplatin. Conclusion: Our data indicate that PIC signals are activated in the spiral ganglion during cisplatin-ototoxicity which thereby leads to upregulation of GABA transporters. As a result, it is likely that de-inhibition of GABA system is enhanced in the cochlear spiral ganglion. This supports a role for PICs in engagement of the signal mechanisms associated with cisplatin-ototoxicity, and has pharmacological implications to target specific PICs for GABAergic dysfunction and vulnerability related to cisplatin-ototoxicity.

APA, Harvard, Vancouver, ISO, and other styles

33

Rask-Andersen, Helge, Sven Tylstedt, Anders Kinnefors, and Anneliese Schrott-Fischer. "Nerve fibre interaction with large ganglion cells in the human spiral ganglion." Auris Nasus Larynx 24, no. 1 (January 1997): 1–11. http://dx.doi.org/10.1016/s0385-8146(96)00039-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Xu, Linjing, Alison E. Seline, Braden Leigh, Mark Ramirez, C. Allan Guymon, and Marlan R. Hansen. "Photopolymerized Microfeatures Guide Adult Spiral Ganglion and Dorsal Root Ganglion Neurite Growth." Otology & Neurotology 39, no. 1 (January 2018): 119–26. http://dx.doi.org/10.1097/mao.0000000000001622.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Sun, Gaoying, Wenwen Liu, Zhaomin Fan, Daogong Zhang, Yuechen Han, Lei Xu, Jieyu Qi, et al. "The Three-Dimensional Culture System with Matrigel and Neurotrophic Factors Preserves the Structure and Function of Spiral Ganglion NeuronIn Vitro." Neural Plasticity 2016 (2016): 1–15. http://dx.doi.org/10.1155/2016/4280407.

Full text

Abstract:

Whole organ culture of the spiral ganglion region is a resourceful model system facilitating manipulation and analysis of live sprial ganglion neurons (SGNs). Three-dimensional (3D) cultures have been demonstrated to have many biomedical applications, but the effect of 3D culture in maintaining the SGNs structure and function in explant culture remains uninvestigated. In this study, we used the matrigel to encapsulate the spiral ganglion region isolated from neonatal mice. First, we optimized the matrigel concentration for the 3D culture system and found the 3D culture system protected the SGNs against apoptosis, preserved the structure of spiral ganglion region, and promoted the sprouting and outgrowth of SGNs neurites. Next, we found the 3D culture system promoted growth cone growth as evidenced by a higher average number and a longer average length of filopodia and a larger growth cone area. 3D culture system also significantly elevated the synapse density of SGNs. Last, we found that the 3D culture system combined with neurotrophic factors had accumulated effects in promoting the neurites outgrowth compared with 3D culture or NFs treatment only groups. Together, we conclude that the 3D culture system preserves the structure and function of SGN in explant culture.

APA, Harvard, Vancouver, ISO, and other styles

36

Nadol, Joseph B., and Aaron R. Thornton. "Ultrastructural Findings in a Case of Meniere's Disease." Annals of Otology, Rhinology & Laryngology 96, no. 4 (July 1987): 449–54. http://dx.doi.org/10.1177/000348948709600420.

Full text

Abstract:

The temporal bones of an individual with documented unilateral Meniere's disease were prepared for light and electron microscopy. a morphometric analysis was performed on hair cells, spiral ganglion cells, dendritic fibers in the osseous spiral lamina, afferent and efferent endings, and afferent synaptic contacts. In the ear with Meniere's disease, we found hair cell damage, including disruption of the cuticular bodies and basalward displacement of some outer hair cells. There was no significant difference in the number of hair cells or spiral ganglion cells on the two sides. There was a significant decrease, however, in the number of afferent nerve endings and afferent synapses at the base of both inner and outer hair cells in the ear with Meniere's disease as compared to the contralateral ear.

APA, Harvard, Vancouver, ISO, and other styles

37

Mo, Zun-Li, and Robin L. Davis. "Endogenous Firing Patterns of Murine Spiral Ganglion Neurons." Journal of Neurophysiology 77, no. 3 (March 1, 1997): 1294–305. http://dx.doi.org/10.1152/jn.1997.77.3.1294.

Full text

Abstract:

Mo, Zun-Li and Robin L. Davis. Endogenous firing patterns of murine spiral ganglion neurons. J. Neurophysiol. 77: 1294–1305, 1997. Current-clamp recordings with the use of the whole cell configuration of the patch-clamp technique were made from postnatal mouse spiral ganglion neurons in vitro. Cultures contained neurons that displayed monopolar, bipolar, and pseudomonopolar morphologies. Additionally, a class of neurons having exceptionally large somata was observed. Frequency histograms of the maximum number of action potentials fired from 240-ms step depolarizations showed that neurons could be classified as either slowly adapting or rapidly adapting. Most neurons (85%) were in the rapidly adapting category (58 of 68 recordings). Measurements of elementary properties were used to define the endogenous firing characteristics of both neuron classes. Action potential number varied with step and holding potential, spike amplitude decayed during prolonged depolarizations, and spike frequency adaptation was observed in both rapidly and slowly adapting neurons. The apparent input resistance, spike amplitude decrement, and instantaneous firing frequency differed significantly between rapidly and slowly adapting neurons. Inward rectification was evaluated in response to hyperpolarizing constant current injections. Present in both electrophysiological classes, its magnitude was graded from neuron to neuron, reflecting differences in number, type, and/or voltage dependence of the underlying channels. These data suggest that spiral ganglion neurons possess intrinsic firing properties that regulate action potential number and timing, features that may be crucial to signal coding in the auditory periphery.

APA, Harvard, Vancouver, ISO, and other styles

38

Euteneuer, Sara, Amaretta Evans, Stefan Hansen, Stefan Dazert, and Allen F. Ryan. "R205: ECM Proteins Guide Adult Spiral Ganglion Neurites." Otolaryngology–Head and Neck Surgery 135, no. 2_suppl (August 2006): P177. http://dx.doi.org/10.1016/j.otohns.2006.06.961.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Lv, Ping, Dongguang Wei, and Ebenezer N. Yamoah. "Kv7-type Channel Currents in Spiral Ganglion Neurons." Journal of Biological Chemistry 285, no. 45 (August 25, 2010): 34699–707. http://dx.doi.org/10.1074/jbc.m110.136192.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Lu, Sumei, Zhaomin Fan, and Haibo Wang. "L-cysteine Arrests Apoptosis of Spiral Ganglion Neuron." Otolaryngology–Head and Neck Surgery 143, no. 2_suppl (August 2010): P97. http://dx.doi.org/10.1016/j.otohns.2010.06.164.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Diensthuber, Marc, Veronika Zecha, Jens Wagenblast, Stefan Arnhold, and Timo Stöver. "Clonal colony formation from spiral ganglion stem cells." NeuroReport 25, no. 14 (October 2014): 1129–35. http://dx.doi.org/10.1097/wnr.0000000000000240.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Brown, M. C., A. M. Berglund, N. Y. S. Kiang, and D. K. Ryugo. "Central trajectories of type II spiral ganglion neurons." Journal of Comparative Neurology 278, no. 4 (December 22, 1988): 581–90. http://dx.doi.org/10.1002/cne.902780409.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Roehm, Pamela C., and Marlan R. Hansen. "Strategies to preserve or regenerate spiral ganglion neurons." Current Opinion in Otolaryngology & Head and Neck Surgery 13, no. 5 (October 2005): 294–300. http://dx.doi.org/10.1097/01.moo.0000180919.68812.b9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Nadol, Joseph B., Barbara J. Burgess, and Christoph Reisser. "Morphometric Analysis of Normal Human Spiral Ganglion Cells." Annals of Otology, Rhinology & Laryngology 99, no. 5 (May 1990): 340–48. http://dx.doi.org/10.1177/000348949009900505.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Steinbach, Silke, and Jens Lutz. "Glutamate induces apoptosis in cultured spiral ganglion explants." Biochemical and Biophysical Research Communications 357, no. 1 (May 2007): 14–19. http://dx.doi.org/10.1016/j.bbrc.2007.03.098.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Romand, M. R., and R. Romand. "Development of spiral ganglion cells in mammalian cochlea." Journal of Electron Microscopy Technique 15, no. 2 (June 1990): 144–54. http://dx.doi.org/10.1002/jemt.1060150206.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Liu, Qing, and Robin L. Davis. "Regional Specification of Threshold Sensitivity and Response Time in CBA/CaJ Mouse Spiral Ganglion Neurons." Journal of Neurophysiology 98, no. 4 (October 2007): 2215–22. http://dx.doi.org/10.1152/jn.00284.2007.

Full text

Abstract:

Previous studies of spiral ganglion neuron electrophysiology have shown that specific parameters differ according to cochlear location, with apical neurons being distinctly different from basal neurons. To align these features more precisely along the tonotopic axis of the cochlea, we developed a novel spiral ganglion culture system in which positional information is retained. Patch-clamp recordings made from neurons of known gangliotopic location revealed two basic firing pattern distributions. Membrane characteristics related to spike timing, such as accommodation, latency and onset tau, were distinctly heterogeneous, yet when averaged, they were distributed in a graded manner along the length of the cochlea. Action potential threshold levels also displayed a wide range, the averages of which were distributed nonmonotonically such that neurons with the greatest sensitivity were localized to the mid-regions of the ganglion. These studies shed new light on the complexity and sophistication of the intrinsic firing features of spiral ganglion neurons. Because timing-related elements are organized in an overall tonotopic manner, it is hypothesized that they contribute to aspects of frequency-dependent acoustic processing. On the other hand, the different distribution of threshold levels, with the greatest sensitivity in the middle region of the tonotopic map, suggests that this neuronal parameter is regulated differently and thus may contribute a distinct realm of auditory sensory processing.

APA, Harvard, Vancouver, ISO, and other styles

48

Gawthrop, Charles Stroud, Kavitha Challagulla, Annette Vu, Lynne Bianchi, Kate F. Barald, and John A. Germiller. "R440 – Generation of Neuron-Like Cells in Spiral Ganglion Cultures." Otolaryngology–Head and Neck Surgery 139, no. 2_suppl (August 2008): P191—P192. http://dx.doi.org/10.1016/j.otohns.2008.05.596.

Full text

Abstract:

Problem Development of the auditory nerve is dependent on neurotrophic factors. Neurotrophins BDNF and NT-3 are critical in the later stages of development. More recently, a substance secreted by the early inner ear, otocyst-derived factor (ODF), was shown to stimulate development of primitive auditory neurons at the earliest stages. We hypothesized that this powerful neurotrophic substance might be capable of regenerating auditory neurons in the mature animal. Methods Cultured neurons and whole explants from neonatal mouse spiral ganglia were incubated with either BDNF or supernatant from an ODF-secreting cell line. Results Exposure to ODF resulted in large numbers of cells which stained with neuronal markers, and had neuronal morphology. Though they appeared somewhat different from the native spiral ganglion neurons seen in BDNF-treated cultures, they were present in vastly greater numbers, and appeared to arise from within the proliferating, migrating glial cell populations growing along with the neurons. These cells were not seen in cultures containing either control serum or BDNF. Addition of beta-bungarotoxin, a neurotoxin, to spiral ganglia just after harvest destroyed the native neurons, which did not regenerate upon addition of BDNF. However, many of the new neuron-like cells were observed after rescue with ODF, suggesting they represented a newly regenerated population of cells. Conclusion These data suggest that the components of ODF have the potential to regenerate neuronal cells, possibly from precursors or stem cells existing within the supporting cell populations of the auditory nerve. Significance The ability to regenerate auditory neurons would have exciting implications on the design and function of cochlear implants. Work continues in our lab to better define the properties of these new cells, and to isolate ODF's active component growth factors. Support Commonwealth of Pennsylvania's Tobacco Formula Fund.

APA, Harvard, Vancouver, ISO, and other styles

49

Topcuoglu, Turgay, Murat Kocyıgıt, Erdogan Bulut, Safiye Ortekın, Mehmet Kanter, and Recep Yagız. "The Effects of Experimental Intratympanic Steroid Administration on Organ of Corti Type 1 Spiral Ganglion." International Archives of Otorhinolaryngology 22, no. 02 (July 14, 2017): 171–76. http://dx.doi.org/10.1055/s-0037-1604067.

Full text

Abstract:

Introduction It is unclear how effective is the intratympanic (IT) steroid treatment on organ of Corti type 1 spiral ganglion, its optimal dosage and frequency of administration. The effect of dexamethasone on cochlear functions in individuals with a normal hearing ability is also unknown. Objective The aim of this study was to evaluate, at the electrophysiological and ultrastructural levels, the effect of IT dexamethasone administration in guinea pigs with normal hearing on organ of Corti type 1 spiral ganglion. Methods A total of 20 guinea pigs (n = 40 ears) whose hearing was detected to be normal by electrophysiological tests were included in the study and randomly divided into 6 groups. Four groups were considered study groups, while 2 groups were considered control groups. Dexamethasone was administered intratympanically in doses of 2 mg/mL and 4 mg/mL in the guinea pigs in the study groups. The animals in the control groups received physiological saline in equal doses as the study groups. All interventions were performed under general anesthesia, and the electrophysiological tests were repeated following the IT injections. Results No statistically significant differences were found among the groups when the IT injections were evaluated in terms of the electrophysiological measurements (p > 0.05). The ultrastructural evaluation showed a cellular mitochondrial increase in the spiral ganglions of the cochlea in the groups in which dexamethasone was administered in a dose of 4 mg/mL. Conclusion According to the findings of this study, it can be suggested that the IT injection of dexamethasone is safe, and when applied in a dose of 4 mg/mL, it increases metabolic activity at the cellular level.

APA, Harvard, Vancouver, ISO, and other styles

50

Kuhweide, R., V. Van de Steene, S. Vlaminck, and J. W. Casselman. "Ramsay Hunt syndrome: pathophysiology of cochleovestibular symptoms." Journal of Laryngology & Otology 116, no. 10 (October 2002): 844–48. http://dx.doi.org/10.1258/00222150260293691.

Full text

Abstract:

Ramsay Hunt’s hypothesis that herpes zoster oticus results from reactivation of the varicella zoster virus (VZV) in the geniculate ganglion is supported by the detection of viral genome in archival temporal bones of normals and Ramsay Hunt patients by the polymerase chain reaction. Ramsay Hunt syndrome is characterized by the presence of cochleovestibular symptoms in association with facial paralysis. VZV has also been demonstrated in the spiral and/or vestibular ganglion. Two cases are reported in which cochleovestibular symptoms outweighed the facial nerve symptoms, presumably representing VZV reactivation in the spiral and/or vestibular ganglion. From these observations and the known dormancy of VZV in non-neuronal satellite cells, it is argued that the cochleovestibular symptoms in Ramsay Hunt syndrome may result from VZV transmission across the nerves inside the internal auditory canal and that prompt treatment with an antiviral-corticosteroid combination might be justified in the management of any acute non-hydropic cochleovestibular syndrome.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Ganglion spiral'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles