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Shi S, Guo P, Li W, Wang W. 3D Real IR MR Findings in Acoustic Neuromas: Altered Perilymph Metabolism. EAR, NOSE & THROAT JOURNAL 2024; 103:NP173-NP178. [PMID: 34560831 DOI: 10.1177/01455613211047124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES This study aimed to investigate the perilymph metabolism by analyzing the 3D real IR MR findings in acoustic neuroma (AN) after intravenous administration of gadolinium (Gd). METHODS Eleven patients (6 men and 5 women) diagnosed with AN were included, and 3D real IR MRI was performed 4 hours after intravenous Gd injection. The signal intensity and details of inner ear, tumor, and internal auditory canal (IAC) by MRI were analyzed. RESULTS Four patients had tumors confined to the IAC, and 5 had tumors that extended to the cerebellopontine angle cistern. The signal intensity of the cochlea, vestibule, and IAC fundus was conspicuously enhanced in 3D real IR images than the control side. One patient had a tumor in the cochlea, in which the signal intensity of the semicircular canal and vestibule was increased. One patient had an intravestibular tumor in which the signal intensity of the semicircular canal was increased and the cochlea had endolymphatic hydrops in the affected ear. CONCLUSIONS The synchronously increased signal intensity in the inner ear and IAC may indicate that IAC may serve as a channel for removal of the perilymph in the inner ear; the blockage by the tumor may have changed the hydrodynamics of the perilymph to cause a longer retention of Gd in the inner ear.
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Affiliation(s)
- Suming Shi
- ENT Institute and Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Hearing Medicine of National Health and Family Planning Commission (NHFPC), Fudan University, Shanghai, China
| | - Ping Guo
- ENT Institute and Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Hearing Medicine of National Health and Family Planning Commission (NHFPC), Fudan University, Shanghai, China
| | - Wenquan Li
- Department of Otolaryngology, The Second Affiliated Hospital of Soochow University, Soochow, China
| | - Wuqing Wang
- ENT Institute and Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, China
- Key Laboratory of Hearing Medicine of National Health and Family Planning Commission (NHFPC), Fudan University, Shanghai, China
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2
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Bridging the electrode-neuron gap: finite element modeling of in vitro neurotrophin gradients to optimize neuroelectronic interfaces in the inner ear. Acta Biomater 2022; 151:360-378. [PMID: 36007779 DOI: 10.1016/j.actbio.2022.08.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/13/2022] [Accepted: 08/16/2022] [Indexed: 11/23/2022]
Abstract
Although cochlear implant (CI) technology has allowed for the partial restoration of hearing over the last few decades, persistent challenges (e.g., poor performance in noisy environments and limited ability to decode intonation and music) remain. The "electrode-neuron gap" is inherent to these challenges and poses the most significant obstacle to advancing past the current plateau in CI performance. We propose the development of a "neuro-regenerative nexus"-a biological interface that doubly preserves native spiral ganglion neurons (SGNs) while precisely directing the growth of neurites arising from transplanted human pluripotent stem cell (hPSC)-derived otic neuronal progenitors (ONPs) toward the native SGN population. We hypothesized that the Polyhedrin Delivery System (PODS®-recombinant human brain-derived neurotrophic factor [rhBDNF]) could stably provide the adequate BDNF concentration gradient to hPSC-derived late-stage ONPs to facilitate otic neuronal differentiation and directional neurite outgrowth. To test this hypothesis, a finite element model (FEM) was constructed to simulate BDNF concentration profiles generated by PODS®-rhBDNF based on initial concentration and culture device geometry. For biological validation of the FEM, cell culture experiments assessing survival, differentiation, neurite growth direction, and synaptic connections were conducted using a multi-chamber microfluidic device. We were able to successfully generate the optimal BDNF concentration gradient to enable survival, neuronal differentiation toward SGNs, directed neurite extension of hPSC-derived SGNs, and synaptogenesis between two hPSC-derived SGN populations. This proof-of-concept study provides a step toward the next generation of CI technology. STATEMENT OF SIGNIFICANCE: Our study demonstrates that the generation of in vitro neurotrophin concentration gradients facilitates survival, neuronal differentiation toward auditory neurons, and directed neurite extension of human pluripotent stem cell-derived auditory neurons. These findings are indispensable to designing a bioactive cochlear implant, in which stem cell-derived neurons are integrated into a cochlear implant electrode strip, as the strategy will confer directional neurite growth from the transplanted cells in the inner ear. This study is the first to present the concept of a "neuro-regenerative nexus" congruent with a bioactive cochlear implant to eliminate the electrode-neuron gapthe most significant barrier to next-generation cochlear implant technology.
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Tani T, Koike-Tani M, Tran MT, Shribak M, Levic S. Postnatal structural development of mammalian Basilar Membrane provides anatomical basis for the maturation of tonotopic maps and frequency tuning. Sci Rep 2021; 11:7581. [PMID: 33828185 PMCID: PMC8027603 DOI: 10.1038/s41598-021-87150-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/16/2021] [Indexed: 02/01/2023] Open
Abstract
The basilar membrane (BM) of the mammalian cochlea constitutes a spiraling acellular ribbon that is intimately attached to the organ of Corti. Its graded stiffness, increasing from apex to the base of the cochlea provides the mechanical basis for sound frequency analysis. Despite its central role in auditory signal transduction, virtually nothing is known about the BM's structural development. Using polarized light microscopy, the present study characterized the architectural transformations of freshly dissected BM at time points during postnatal development and maturation. The results indicate that the BM structural elements increase progressively in size, becoming radially aligned and more tightly packed with maturation and reach the adult structural signature by postnatal day 20 (P20). The findings provide insight into structural details and developmental changes of the mammalian BM, suggesting that BM is a dynamic structure that changes throughout the life of an animal.
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Affiliation(s)
- Tomomi Tani
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, MA, USA
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka, Japan
| | - Maki Koike-Tani
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, MA, USA
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka, Japan
| | - Mai Thi Tran
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, MA, USA
- College of Engineering and Computer Science, VinUniversity, Gia Lam District, Hanoi, Vietnam
| | - Michael Shribak
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, MA, USA
| | - Snezana Levic
- Marine Biological Laboratory, Eugene Bell Center, Woods Hole, MA, USA.
- Sensory Neuroscience Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Brighton, BN2 4GJ, UK.
- Brighton and Sussex Medical School, University of Sussex, Brighton, BN1 9PX, UK.
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4
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Li D, Sun J, Zhao L, Guo W, Sun W, Yang S. Aminoglycoside Increases Permeability of Osseous Spiral Laminae of Cochlea by Interrupting MMP-2 and MMP-9 Balance. Neurotox Res 2016; 31:348-357. [PMID: 28005182 DOI: 10.1007/s12640-016-9689-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/10/2016] [Accepted: 12/12/2016] [Indexed: 12/20/2022]
Abstract
The spiral ganglion neurons (SGNs) located in the Rosenthal's canal of cochlea are essential target for cochlear implant. Previous studies found that the canaliculi perforantes, small pores on the surface of the osseous spiral lamina (OSL) of the scala tympanic (ST) of cochlea, may provide communication between the cochlear perilymph and SGNs. In this study, we found that chronic treatment of aminoglycosides antibiotics, which is well known to cause sensory cell damage in the cochlea, induced significant damage of bone lining cells on the OSLs and increased the permeability of the Rosenthal's canal. The pores among the bone lining cells became significantly wider after chronic treatment of amikacin (100 mg/kg/day for 3-7 days). Injection of Evans Blue in the ST resulted in significant increase in its migration in the modulus in the amikacin-treated cochlea compared to the control ears, suggesting increased permeability of these passages. Treatment of amikacin with oxytetracycline, an inhibitor of matrix metalloproteases (MMPs), significantly reduced the amount of dye migrated from the ST to the modiolus. These results suggest that amikacin enhanced the permeability between the ST and SGNs by increasing MMPs. Aggregating the permeability of the bone lining cells on the OSLs may benefit gene and stem cell delivery to the SGNs in the cochlea.
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Affiliation(s)
- Dengke Li
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing, 100853, People's Republic of China
| | - Jianhe Sun
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing, 100853, People's Republic of China
| | - Lidong Zhao
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing, 100853, People's Republic of China
| | - Weiwei Guo
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing, 100853, People's Republic of China
| | - Wei Sun
- Department of Communicative Disorders and Sciences, Center for Hearing and Deafness, the State University of New York at Buffalo, Buffalo, New York, 14214, USA
| | - Shiming Yang
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, Beijing, 100853, People's Republic of China.
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Landry TG, Fallon JB, Wise AK, Shepherd RK. Chronic neurotrophin delivery promotes ectopic neurite growth from the spiral ganglion of deafened cochleae without compromising the spatial selectivity of cochlear implants. J Comp Neurol 2014; 521:2818-32. [PMID: 23436344 DOI: 10.1002/cne.23318] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 02/05/2013] [Indexed: 12/25/2022]
Abstract
Cochlear implants restore hearing cues in the severe-profoundly deaf by electrically stimulating spiral ganglion neurons (SGNs). However, SGNs degenerate following loss of cochlear hair cells, due at least in part to a reduction in the endogenous neurotrophin (NT) supply, normally provided by hair cells and supporting cells of the organ of Corti. Delivering exogenous NTs to the cochlea can rescue SGNs from degeneration and can also promote the ectopic growth of SGN neurites. This resprouting may disrupt the cochleotopic organization upon which cochlear implants rely to impart pitch cues. Using retrograde labeling and confocal imaging of SGNs, we determined the extent of neurite growth following 28 days of exogenous NT treatment in deafened guinea pigs with and without chronic electrical stimulation (ES). On completion of this treatment, we measured the spread of neural activation to intracochlear ES by recording neural responses across the cochleotopically organized inferior colliculus using multichannel recording techniques. Although NT treatment significantly increased both the length and the lateral extent of growth of neurites along the cochlea compared with deafened controls, these anatomical changes did not affect the spread of neural activation when examined immediately after 28 days of NT treatment. NT treatment did, however, result in lower excitation thresholds compared with deafened controls. These data support the application of NTs for improved clinical outcomes for cochlear implant patients.
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Affiliation(s)
- Thomas G Landry
- The Bionics Institute, East Melbourne, Victoria 3002, Australia
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6
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Surgical access to the mammalian cochlea for cell-based therapies. Exp Neurol 2008; 214:193-200. [PMID: 18773894 DOI: 10.1016/j.expneurol.2008.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 08/04/2008] [Accepted: 08/05/2008] [Indexed: 12/17/2022]
Abstract
Cochlear implants are dependent on functionally viable spiral ganglion neurons (SGNs) - the primary auditory neurons of the inner ear. Cell-based therapies are being used experimentally in an attempt to rescue SGNs from deafness-induced degeneration or to generate new neurons. The success of these therapies will be dependent on the development of surgical techniques designed to ensure precise cell placement while minimizing surgical trauma, adverse tissue reaction and cell dispersal. Using 24 normal adult guinea pigs we assessed three surgical procedures for cell delivery into the cochlea: (i) a cochleostomy into the scala tympani (ST); (ii) direct access to Rosenthal's canal - the site of the SGN soma - via a localized fracture of the osseous spiral lamina (RC); and (iii) direct access to the auditory nerve via a translabyrinthine surgical approach (TL). Half the cohort had surgery alone while the other half had surgery combined with the delivery of biocompatible microspheres designed to model implanted cells. Following a four week survival period the inflammatory response and SGN survival were measured for each cohort and the location of microspheres were determined. We observed a wide variability across the three surgical approaches examined, including the extent of the inflammatory tissue response (TL>>RC> or =ST) and the survival of SGNs (ST>RC>>TL). Importantly, microspheres were effectively retained at the implant site after all three surgical approaches. Direct access to Rosenthal's canal offered the most promising surgical approach to the SGNs, although the technique must be further refined to reduce the localized trauma associated with the procedure.
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7
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Wenzel GI, Anvari B, Mazhar A, Pikkula B, Oghalai JS. Laser-induced collagen remodeling and deposition within the basilar membrane of the mouse cochlea. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:021007. [PMID: 17477714 PMCID: PMC3651902 DOI: 10.1117/1.2714286] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The cochlea is the mammalian organ of hearing. Its predominant vibratory element, the basilar membrane, is tonotopically tuned, based on the spatial variation of its mass and stiffness. The constituent collagen fibers of the basilar membrane affect its stiffness. Laser irradiation can induce collagen remodeling and deposition in various tissues. We tested whether similar effects could be induced within the basilar membrane. Trypan blue was perfused into the scala tympani of anesthetized mice to stain the basilar membrane. We then irradiated the cochleas with a 694-nm pulsed ruby laser at 15 or 180 Jcm(2). The mice were sacrificed 14 to 16 days later and collagen organization was studied. Polarization microscopy revealed that laser irradiation increased the birefringence within the basilar membrane in a dose-dependent manner. Electron microscopy demonstrated an increase in the density of collagen fibers and the deposition of new fibrils between collagen fibers after laser irradiation. As an assessment of hearing, auditory brainstem response (ABR) thresholds were found to increase moderately after 15 Jcm(2) and substantially after 180 Jcm(2). Our results demonstrate that collagen remodeling and new collagen deposition occurs within the basilar membrane after laser irradiation in a similar fashion to that found in other tissues.
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Affiliation(s)
- Gentiana I. Wenzel
- Baylor College of Medicine, Bobby R. Alford Department of Otolaryngology, Head and Neck Surgery, One Baylor Plaza, NA102, Houston, Texas 77030
| | - Bahman Anvari
- Rice University, Department of Bioengineering, Houston, Texas 77005-1892
| | - Amaan Mazhar
- Rice University, Department of Bioengineering, Houston, Texas 77005-1892
| | - Brian Pikkula
- Rice University, Department of Bioengineering, Houston, Texas 77005-1892
| | - John S. Oghalai
- Baylor College of Medicine, Bobby R. Alford Department of Otolaryngology, Head and Neck Surgery, One Baylor Plaza, NA102, Houston, Texas 77030, and Rice University, Department of Bioengineering, Houston, Texas 77005-1892,
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8
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Maruyama J, Yamagata T, Ulfendahl M, Bredberg G, Altschuler RA, Miller JM. Effects of antioxidants on auditory nerve function and survival in deafened guinea pigs. Neurobiol Dis 2006; 25:309-18. [PMID: 17112730 PMCID: PMC2048572 DOI: 10.1016/j.nbd.2006.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 09/19/2006] [Accepted: 09/21/2006] [Indexed: 10/23/2022] Open
Abstract
Based on in vitro studies, it is hypothesized that neurotrophic factor deprivation following deafferentation elicits an oxidative state change in the deafferented neuron and the formation of free radicals that then signal cell death pathways. This pathway to cell death was tested in vivo by assessing the efficacy of antioxidants (AOs) to prevent degeneration of deafferented CNVIII spiral ganglion cells (SGCs) in deafened guinea pigs. Following destruction of sensory cells, guinea pigs were treated immediately with Trolox (a water soluble vitamin E analogue)+ascorbic acid (vitamin C) administered either locally, directly in the inner ear, or systemically. Electrical auditory brainstem response (EABR) thresholds were recorded to assess nerve function and showed a large increase following deafness. In treated animals EABR thresholds decreased and surviving SGCs were increased significantly compared to untreated animals. These results indicate that a change in oxidative state following deafferentation plays a role in nerve cell death and antioxidant therapy may rescue SGCs from deafferentation-induced degeneration.
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MESH Headings
- Animals
- Antioxidants/pharmacology
- Antioxidants/therapeutic use
- Ascorbic Acid/pharmacology
- Auditory Threshold/drug effects
- Auditory Threshold/physiology
- Cell Survival/drug effects
- Cell Survival/physiology
- Chromans/pharmacology
- Cochlear Nerve/drug effects
- Cochlear Nerve/metabolism
- Cochlear Nerve/physiopathology
- Deafness/drug therapy
- Deafness/metabolism
- Deafness/physiopathology
- Denervation
- Evoked Potentials, Auditory, Brain Stem/drug effects
- Evoked Potentials, Auditory, Brain Stem/physiology
- Guinea Pigs
- Hair Cells, Auditory/injuries
- Hair Cells, Auditory/physiopathology
- Hearing Loss, Sensorineural/drug therapy
- Hearing Loss, Sensorineural/metabolism
- Hearing Loss, Sensorineural/physiopathology
- Male
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Neurons, Afferent/pathology
- Neuroprotective Agents/pharmacology
- Neuroprotective Agents/therapeutic use
- Oxidative Stress/drug effects
- Oxidative Stress/physiology
- Spiral Ganglion/drug effects
- Spiral Ganglion/metabolism
- Spiral Ganglion/physiopathology
- Treatment Outcome
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Affiliation(s)
- Jun Maruyama
- Center for Hearing and Communication Research, Karolinska Institutet, and Department of Otolaryngology, Karolinska University Hospital, Solna, Stockholm, Sweden
- Department of Otolaryngology, Ehime University School of Medicine, Matsuyama, Japan
| | - Takahiko Yamagata
- Center for Hearing and Communication Research, Karolinska Institutet, and Department of Otolaryngology, Karolinska University Hospital, Solna, Stockholm, Sweden
- Department of Otolaryngology, Ehime University School of Medicine, Matsuyama, Japan
| | - Mats Ulfendahl
- Center for Hearing and Communication Research, Karolinska Institutet, and Department of Otolaryngology, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Göran Bredberg
- Department of Cochlear Implant, Karolinska Hospital, Huddinge, Sweden
| | | | - Josef M. Miller
- Center for Hearing and Communication Research, Karolinska Institutet, and Department of Otolaryngology, Karolinska University Hospital, Solna, Stockholm, Sweden
- Kresge Hearing Research Institute, University of Michigan, Ann Arbor, USA
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9
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Hu Z, Ulfendahl M, Olivius NP. NGF stimulates extensive neurite outgrowth from implanted dorsal root ganglion neurons following transplantation into the adult rat inner ear. Neurobiol Dis 2005; 18:184-92. [PMID: 15649709 DOI: 10.1016/j.nbd.2004.09.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Revised: 08/31/2004] [Accepted: 09/13/2004] [Indexed: 11/19/2022] Open
Abstract
Neuronal tissue transplantation is a potential way to replace degenerated spiral ganglion neurons (SGNs) since these cells cannot regenerate in adult mammals. To investigate whether nerve growth factor (NGF) can stimulate neurite outgrowth from implanted neurons, mouse embryonic dorsal root ganglion (DRG) cells expressing enhanced green fluorescent protein (EGFP) were transplanted into the scala tympani of adult rats with a supplement of NGF or artificial perilymph. DRG neurons were observed in the cochlea for up to 6 weeks postoperatively. A significant difference was identified in the number of DRG neurons between the NGF and non-NGF groups. In the NGF group, extensive neurite projections from DRGs were found penetrating the osseous modiolus towards the spiral ganglion. These results suggest the possibility that embryonic neuronal implants may become integrated within the adult auditory nervous system. In combination with a cochlear prosthesis, a neuronal implantation strategy may provide a possibility for further treatment of profoundly deaf patients.
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MESH Headings
- Animals
- Cell Count
- Cell Differentiation/drug effects
- Cell Differentiation/physiology
- Cell Proliferation/drug effects
- Ear, Inner/pathology
- Ear, Inner/physiopathology
- Ear, Inner/surgery
- Female
- Ganglia, Spinal/cytology
- Ganglia, Spinal/transplantation
- Graft Survival/drug effects
- Graft Survival/physiology
- Green Fluorescent Proteins
- Growth Cones/drug effects
- Growth Cones/ultrastructure
- Hearing Loss, Sensorineural/pathology
- Hearing Loss, Sensorineural/therapy
- Male
- Nerve Growth Factor/pharmacology
- Nerve Regeneration/drug effects
- Nerve Regeneration/physiology
- Neurites/drug effects
- Neurites/physiology
- Neurons/cytology
- Neurons/drug effects
- Neurons/transplantation
- Neurons, Afferent/drug effects
- Neurons, Afferent/physiology
- Rats
- Rats, Sprague-Dawley
- Scala Tympani/pathology
- Scala Tympani/surgery
- Spiral Ganglion/pathology
- Spiral Ganglion/surgery
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Affiliation(s)
- Zhengqing Hu
- Center for Hearing and Communication Research, Karolinska Institute, SE-171 76 Stockholm, Sweden.
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10
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Hu Z, Wei D, Johansson CB, Holmström N, Duan M, Frisén J, Ulfendahl M. Survival and neural differentiation of adult neural stem cells transplanted into the mature inner ear. Exp Cell Res 2005; 302:40-7. [PMID: 15541724 DOI: 10.1016/j.yexcr.2004.08.023] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 08/11/2004] [Indexed: 01/27/2023]
Abstract
The cochlear sensory epithelium and spiral ganglion neurons (SGNs) in the adult mammalian inner ear do not regenerate following severe injury. To replace the degenerated SGNs, neural stem cell (NSC) is an attractive alternative for substitution cell therapy. In this study, adult mouse NSCs were transplanted into normal and deafened inner ears of guinea pigs. To more efficiently drive the implanted cells into a neuronal fate, NSCs were also transduced with neurogenin 2 (ngn2) before transplantation. In deafened inner ears and in animals transplanted with ngn2-transduced NSCs, surviving cells expressed the neuronal marker neural class III beta-tubulin. Transplanted cells were found close to the sensory epithelium and adjacent to the SGNs and their peripheral processes. The results illustrate that adult NSCs can survive and differentiate in the injured inner ear. It also demonstrates the feasibility of gene transfer to generate specific progeny for cell replacement therapy in the inner ear.
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Affiliation(s)
- Zhengqing Hu
- Center for Hearing and Communication Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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11
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Hu Z, Ulfendahl M, Olivius NP. Survival of neuronal tissue following xenograft implantation into the adult rat inner ear. Exp Neurol 2004; 185:7-14. [PMID: 14697314 DOI: 10.1016/j.expneurol.2003.09.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The poor regenerative capacity of the spiral ganglion neurons of the mammalian inner ear has initiated research on how to assist the functional recovery of the injured auditory system. A possible treatment is to use a biological implant with a potential to establish central or peripheral synaptic contacts to develop into a functional auditory unit. The feasibility of this approach was tested by xenograft implantation of dorsal root ganglion (DRG) neurons from embryonic days 13 to 14, mouse expressing either LacZ or enhanced green fluorescent protein (EGFP) into the scala tympani of the adult rat inner ear. Transplanted DRG neurons survived in the scala tympani for a postoperative period ranging from 3 to 10 weeks, as verified by histochemical detection of LacZ, EGFP fluorescence and immunohistochemical labeling of the neuronal markers neurofilament and Thy 1.2. DRG neurons were found close to structures near the sensory epithelium (the organ of Corti) as well as adjacent to the spiral ganglion neurons with their peripheral dendrites. These results illustrate not only the survival of xenografted DRG neurons in the adult inner ear but also the feasibility of a neuronal transplantation strategy in the degenerated auditory system, thereby creating possibilities to replace spiral ganglion neurons.
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MESH Headings
- Animals
- Cell Survival/physiology
- Ear, Inner/cytology
- Ear, Inner/physiology
- Ear, Inner/surgery
- Feasibility Studies
- Fetal Tissue Transplantation
- Ganglia, Spinal/cytology
- Ganglia, Spinal/embryology
- Ganglia, Spinal/transplantation
- Graft Survival/physiology
- Green Fluorescent Proteins
- Luminescent Proteins/biosynthesis
- Luminescent Proteins/genetics
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Nerve Tissue/cytology
- Nerve Tissue/embryology
- Nerve Tissue/transplantation
- Neurons/cytology
- Neurons/metabolism
- Neurons/transplantation
- Rats
- Rats, Sprague-Dawley
- Scala Tympani/cytology
- Scala Tympani/physiology
- Scala Tympani/surgery
- Transplantation, Heterologous/methods
- beta-Galactosidase/biosynthesis
- beta-Galactosidase/genetics
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Affiliation(s)
- Zhengqing Hu
- Center for Hearing and Communication Research, and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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12
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Lotz P, Posse D, Haberland EJ, Kuhl KD, Ernst A. The metabolic reaction of the cochlea to unphysiological noise exposure. Acta Otolaryngol 1986; 102:20-6. [PMID: 3739689 DOI: 10.3109/00016488609108641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Guinea pigs were exposed to continuous white noise of 120 dB SPL. The performance included a recording of CM, pO2, and metabolites in the perfusate of the perilymphatic spaces. The metabolic reactions observed following the exposure are limited. No evidence of an overstimulation or of an insufficiency of the energy metabolism in the cochlea could be found. The results suggest the metabolic processes to be secondary to the sound-dependent damage of the organ of Corti after irreversible mechanical destructions in the hair cells.
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