1
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Smith KE, Lezmy J, Arancibia-Cárcamo IL, Bullen A, Jagger DJ, Attwell D. Developmental shaping of node of Ranvier geometry contributes to spike timing maturation in primary auditory afferents. Cell Rep 2024; 43:114651. [PMID: 39178117 DOI: 10.1016/j.celrep.2024.114651] [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] [Received: 11/01/2023] [Revised: 06/06/2024] [Accepted: 08/01/2024] [Indexed: 08/25/2024] Open
Abstract
Sound is encoded by action potentials in spiral ganglion neurons (SGNs), the auditory afferents from the cochlea. Rapid action potential transmission along SGNs is crucial for quick reactions to sounds, and binaural differences in action potential arrival time at the SGN output synapses enable sound localization based on interaural time or phase differences. SGN myelination increases conduction speed but other cellular changes may contribute. We show that nodes of Ranvier along peripherally and centrally directed SGN neurites form around hearing onset, but peri-somatic nodes mature later. There follows an adjustment of nodal geometry, notably a decrease in length and increase in diameter. Computational modeling predicts this increases conduction speed by >4%, and that four additional myelin wraps would be required on internodes to achieve the same conduction speed increase. We propose that nodal geometry changes optimize signal conduction for mature sound coding and decrease the energy needed for myelination.
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Affiliation(s)
- Katie E Smith
- UCL Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, UK.
| | - Jonathan Lezmy
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower St., London WC1E 6BT, UK
| | - I Lorena Arancibia-Cárcamo
- UK Dementia Research Institute, Institute of Neurology, London WC1N 3BG, UK; Francis Crick Institute, London NW1 1AT, UK
| | - Anwen Bullen
- UCL Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, UK
| | - Daniel J Jagger
- UCL Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, UK
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower St., London WC1E 6BT, UK.
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2
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Cassinotti LR, Ji L, Yuk MC, Desai AS, Cass ND, Amir ZA, Corfas G. Hidden hearing loss in a Charcot-Marie-Tooth type 1A mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.14.571732. [PMID: 38168255 PMCID: PMC10760174 DOI: 10.1101/2023.12.14.571732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Hidden hearing loss (HHL), a recently described auditory neuropathy characterized by normal audiometric thresholds but reduced sound-evoked cochlear compound action potentials, has been proposed to contribute to hearing difficulty in noisy environments in people with normal hearing thresholds, a widespread complaint. While most studies on HHL pathogenesis have focused on inner hair cell (IHC) synaptopathy, we recently showed that transient auditory nerve (AN) demyelination also causes HHL in mice. To test the impact of myelinopathy on hearing in a clinically relevant model, we studied a mouse model of Charcot-Marie-Tooth type 1A (CMT1A), the most prevalent hereditary peripheral neuropathy in humans. CMT1A mice exhibited the functional hallmarks of HHL together with disorganization of AN heminodes near the IHCs with minor loss of AN fibers. These results support the hypothesis that mild disruptions of AN myelination can cause HHL, and that heminodal defects contribute to the alterations in the sound-evoked cochlear compound action potentials seen in this mouse model. Also, these findings suggest that patients with CMT1A or other mild peripheral neuropathies are likely to suffer from HHL. Furthermore, these results suggest that studies of hearing in CMT1A patients might help develop robust clinical tests for HHL, which are currently lacking.
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3
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Affortit C, Blanc F, Nasr J, Ceccato JC, Markossian S, Guyot R, Puel JL, Flamant F, Wang J. A disease-associated mutation in thyroid hormone receptor α1 causes hearing loss and sensory hair cell patterning defects in mice. Sci Signal 2022; 15:eabj4583. [PMID: 35700264 DOI: 10.1126/scisignal.abj4583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Resistance to thyroid hormone due to mutations in THRA, which encodes the thyroid hormone receptor α (TRα1), shows variable clinical presentation. Mutations affecting TRβ1 and TRβ2 cause deafness in mice and have been associated with deafness in humans. To test whether TRα1 also affects hearing function, we used mice heterozygous for a frameshift mutation in Thra that is similar to human THRA mutations (ThraS1/+ mice) and reduces tissue sensitivity to thyroid hormone. Compared to wild-type littermates, ThraS1/+ mice showed moderate high-frequency sensorineural hearing loss as juveniles and increased age-related hearing loss. Ultrastructural examination revealed aberrant orientation of ~20% of sensory outer hair cells (OHCs), as well as increased numbers of mitochondria with fragmented morphology and autophagic vacuoles in both OHCs and auditory nerve fibers. Molecular dissection of the OHC lateral wall components revealed that the potassium ion channel Kcnq4 was aberrantly targeted to the cytoplasm of mutant OHCs. In addition, mutant cochleae showed increased oxidative stress, autophagy, and mitophagy associated with greater age-related cochlear cell damage, demonstrating that TRα1 is required for proper development of OHCs and for maintenance of OHC function. These findings suggest that patients with THRA mutations may present underdiagnosed, mild hearing loss and may be more susceptible to age-related hearing loss.
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Affiliation(s)
- Corentin Affortit
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Fabian Blanc
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France.,Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, Montpellier, France
| | - Jamal Nasr
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Jean-Charles Ceccato
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Suzy Markossian
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS, Lyon, France
| | - Romain Guyot
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS, Lyon, France
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France
| | - Frédéric Flamant
- Institut de Génomique Fonctionnelle de Lyon (IGFL), INRAE USC1370, CNRS (UMR5242), ENS, Lyon, France
| | - Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, Montpellier, France.,Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, Montpellier, France
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4
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Hosoya M, Fujioka M, Murayama AY, Ozawa H, Okano H, Ogawa K. Neuronal development in the cochlea of a nonhuman primate model, the common marmoset. Dev Neurobiol 2021; 81:905-938. [PMID: 34545999 PMCID: PMC9298346 DOI: 10.1002/dneu.22850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/25/2021] [Accepted: 09/13/2021] [Indexed: 01/02/2023]
Abstract
Precise cochlear neuronal development is vital to hearing ability. Understanding the developmental process of the spiral ganglion is useful for studying hearing loss aimed at aging or regenerative therapy. Although interspecies differences have been reported between rodents and humans, to date, most of our knowledge about the development of cochlear neuronal development has been obtained from rodent models because of the difficulty in using human fetal samples in this field. In this study, we investigated cochlear neuronal development in a small New World monkey species, the common marmoset (Callithrix jacchus). We examined more than 25 genes involved in the neuronal development of the cochlea and described the critical developmental steps of these neurons. We also revealed similarities and differences between previously reported rodent models and this primate animal model. Our results clarified that this animal model of cochlear neuronal development is more similar to humans than rodents and is suitable as an alternative for the analysis of human cochlear development. The time course established in this report will be a useful tool for studying primate‐specific neuronal biology of the inner ear, which could eventually lead to new treatment strategies for human hearing loss.
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Affiliation(s)
- Makoto Hosoya
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masato Fujioka
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Ayako Y Murayama
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan.,Laboratory for Marmoset Neural Architecture, Center for Brain Science, RIKEN, Wako, Japan
| | - Hiroyuki Ozawa
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan.,Laboratory for Marmoset Neural Architecture, Center for Brain Science, RIKEN, Wako, Japan
| | - Kaoru Ogawa
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
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5
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Kohrman D, Borges BC, Cassinotti L, Ji L, Corfas G. Axon-glia interactions in the ascending auditory system. Dev Neurobiol 2021; 81:546-567. [PMID: 33561889 PMCID: PMC9004231 DOI: 10.1002/dneu.22813] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/25/2020] [Accepted: 02/05/2021] [Indexed: 11/09/2022]
Abstract
The auditory system detects and encodes sound information with high precision to provide a high-fidelity representation of the environment and communication. In mammals, detection occurs in the peripheral sensory organ (the cochlea) containing specialized mechanosensory cells (hair cells) that initiate the conversion of sound-generated vibrations into action potentials in the auditory nerve. Neural activity in the auditory nerve encodes information regarding the intensity and frequency of sound stimuli, which is transmitted to the auditory cortex through the ascending neural pathways. Glial cells are critical for precise control of neural conduction and synaptic transmission throughout the pathway, allowing for the precise detection of the timing, frequency, and intensity of sound signals, including the sub-millisecond temporal fidelity is necessary for tasks such as sound localization, and in humans, for processing complex sounds including speech and music. In this review, we focus on glia and glia-like cells that interact with hair cells and neurons in the ascending auditory pathway and contribute to the development, maintenance, and modulation of neural circuits and transmission in the auditory system. We also discuss the molecular mechanisms of these interactions, their impact on hearing and on auditory dysfunction associated with pathologies of each cell type.
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Affiliation(s)
- David Kohrman
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Beatriz C. Borges
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Luis Cassinotti
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Lingchao Ji
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Gabriel Corfas
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
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6
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Wang S, Lee MP, Jones S, Liu J, Waldhaus J. Mapping the regulatory landscape of auditory hair cells from single-cell multi-omics data. Genome Res 2021; 31:1885-1899. [PMID: 33837132 DOI: 10.1101/gr.271080.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 03/23/2021] [Indexed: 11/25/2022]
Abstract
Auditory hair cells transduce sound to the brain and in mammals these cells reside together with supporting cells in the sensory epithelium of the cochlea, called the organ of Corti. To establish the organ's delicate function during development and differentiation, spatiotemporal gene expression is strictly controlled by chromatin accessibility and cell type-specific transcription factors, jointly representing the regulatory landscape. Bulk-sequencing technology and cellular heterogeneity obscured investigations on the interplay between transcription factors and chromatin accessibility in inner ear development. To study the formation of the regulatory landscape in hair cells, we collected single-cell chromatin accessibility profiles accompanied by single-cell RNA data from genetically labeled murine hair cells and supporting cells after birth. Using an integrative approach, we predicted cell type-specific activating and repressing functions of developmental transcription factors. Furthermore, by integrating gene expression and chromatin accessibility datasets, we reconstructed gene regulatory networks. Then, using a comparative approach, 20 hair cell-specific activators and repressors, including putative downstream target genes, were identified. Clustering of target genes resolved groups of related transcription factors and was utilized to infer their developmental functions. Finally, the heterogeneity in the single-cell data allowed us to spatially reconstruct transcriptional as well as chromatin accessibility trajectories, indicating that gradual changes in the chromatin accessibility landscape were lagging behind the transcriptional identity of hair cells along the organ's longitudinal axis. Overall, this study provides a strategy to spatially reconstruct the formation of a lineage specific regulatory landscape using a single-cell multi-omics approach.
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Affiliation(s)
- Shuze Wang
- University of Michigan, Kresge Hearing Research Institute
| | - Mary P Lee
- University of Michigan, Kresge Hearing Research Institute
| | - Scott Jones
- University of Michigan, Kresge Hearing Research Institute
| | | | - Joerg Waldhaus
- University of Michigan, Kresge Hearing Research Institute;
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7
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Affortit C, Casas F, Ladrech S, Ceccato JC, Bourien J, Coyat C, Puel JL, Lenoir M, Wang J. Exacerbated age-related hearing loss in mice lacking the p43 mitochondrial T3 receptor. BMC Biol 2021; 19:18. [PMID: 33526032 PMCID: PMC7852282 DOI: 10.1186/s12915-021-00953-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 01/08/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Age-related hearing loss (ARHL), also known as presbycusis, is the most common sensory impairment seen in elderly people. However, the cochlear aging process does not affect people uniformly, suggesting that both genetic and environmental (e.g., noise, ototoxic drugs) factors and their interaction may influence the onset and severity of ARHL. Considering the potential links between thyroid hormone, mitochondrial activity, and hearing, here, we probed the role of p43, a N-terminally truncated and ligand-binding form of the nuclear receptor TRα1, in hearing function and in the maintenance of hearing during aging in p43-/- mice through complementary approaches, including in vivo electrophysiological recording, ultrastructural assessments, biochemistry, and molecular biology. RESULTS We found that the p43-/- mice exhibit no obvious hearing loss in juvenile stages, but that these mice developed a premature, and more severe, ARHL resulting from the loss of cochlear sensory outer and inner hair cells and degeneration of spiral ganglion neurons. Exacerbated ARHL in p43-/- mice was associated with the early occurrence of a drastic fall of SIRT1 expression, together with an imbalance between pro-apoptotic Bax, p53 expression, and anti-apoptotic Bcl2 expression, as well as an increase in mitochondrial dysfunction, oxidative stress, and inflammatory process. Finally, p43-/- mice were also more vulnerable to noise-induced hearing loss. CONCLUSIONS These results demonstrate for the first time a requirement for p43 in the maintenance of hearing during aging and highlight the need to probe the potential link between human THRA gene polymorphisms and/or mutations and accelerated age-related deafness or some adult-onset syndromic deafness.
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Affiliation(s)
- Corentin Affortit
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - François Casas
- INRA, UMR 866 Dynamique Musculaire et Métabolisme,, 34060, Montpellier, France
| | - Sabine Ladrech
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - Jean-Charles Ceccato
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - Jérôme Bourien
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - Carolanne Coyat
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - Jean-Luc Puel
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - Marc Lenoir
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France
- Université de Montpellier, 34000, Montpellier, France
| | - Jing Wang
- INSERM - UMR 1051, Institut des Neurosciences de Montpellier, 80 rue Augustin Fliche, 34295, Montpellier, France.
- Université de Montpellier, 34000, Montpellier, France.
- ENT Department, CHU Montpellier, 34295, Montpellier, France.
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8
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Moore S, Meschkat M, Ruhwedel T, Trevisiol A, Tzvetanova ID, Battefeld A, Kusch K, Kole MHP, Strenzke N, Möbius W, de Hoz L, Nave KA. A role of oligodendrocytes in information processing. Nat Commun 2020; 11:5497. [PMID: 33127910 PMCID: PMC7599337 DOI: 10.1038/s41467-020-19152-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Myelinating oligodendrocytes enable fast propagation of action potentials along the ensheathed axons. In addition, oligodendrocytes play diverse non-canonical roles including axonal metabolic support and activity-dependent myelination. An open question remains whether myelination also contributes to information processing in addition to speeding up conduction velocity. Here, we analyze the role of myelin in auditory information processing using paradigms that are also good predictors of speech understanding in humans. We compare mice with different degrees of dysmyelination using acute multiunit recordings in the auditory cortex, in combination with behavioral readouts. We find complex alterations of neuronal responses that reflect fatigue and temporal acuity deficits. We observe partially discriminable but similar deficits in well myelinated mice in which glial cells cannot fully support axons metabolically. We suggest a model in which myelination contributes to sustained stimulus perception in temporally complex paradigms, with a role of metabolically active oligodendrocytes in cortical information processing.
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Affiliation(s)
- Sharlen Moore
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- International Max Planck Research School for Neurosciences, Göttingen, Germany
- Göttingen Graduate Center for Neurosciences, Biophysics and Molecular Biosciences, Georg-August-Universität Göttingen, Göttingen, Germany
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, USA
| | - Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Andrea Trevisiol
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Iva D Tzvetanova
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Section of Pharmacology, School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - Arne Battefeld
- Department of Axonal Signaling, Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Maarten H P Kole
- Department of Axonal Signaling, Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, University of Utrecht, Utrecht, The Netherlands
| | - Nicola Strenzke
- Institute for Auditory Neuroscience, University Medical Center, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Livia de Hoz
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
- Charité Medical University, Neuroscience Research Center, Berlin, Germany.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
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9
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Fischl MJ, Weisz CJC. In Vitro Wedge Slice Preparation for Mimicking In Vivo Neuronal Circuit Connectivity. J Vis Exp 2020. [PMID: 32894269 DOI: 10.3791/61664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
In vitro slice electrophysiology techniques measure single-cell activity with precise electrical and temporal resolution. Brain slices must be relatively thin to properly visualize and access neurons for patch-clamping or imaging, and in vitro examination of brain circuitry is limited to only what is physically present in the acute slice. To maintain the benefits of in vitro slice experimentation while preserving a larger portion of presynaptic nuclei, we developed a novel slice preparation. This "wedge slice" was designed for patch-clamp electrophysiology recordings to characterize the diverse monaural, sound-driven inputs to medial olivocochlear (MOC) neurons in the brainstem. These neurons receive their primary afferent excitatory and inhibitory inputs from neurons activated by stimuli in the contralateral ear and corresponding cochlear nucleus (CN). An asymmetrical brain slice was designed which is thickest in the rostro-caudal domain at the lateral edge of one hemisphere and then thins towards the lateral edge of the opposite hemisphere. This slice contains, on the thick side, the auditory nerve root conveying information about auditory stimuli to the brain, the intrinsic CN circuitry, and both the disynaptic excitatory and trisynaptic inhibitory afferent pathways that converge on contralateral MOC neurons. Recording is performed from MOC neurons on the thin side of the slice, where they are visualized using DIC optics for typical patch-clamp experiments. Direct stimulation of the auditory nerve is performed as it enters the auditory brainstem, allowing for intrinsic CN circuit activity and synaptic plasticity to occur at synapses upstream of MOC neurons. With this technique, one can mimic in vivo circuit activation as closely as possible within the slice. This wedge slice preparation is applicable to other brain circuits where circuit analyses would benefit from preservation of upstream connectivity and long-range inputs, in combination with the technical advantages of in vitro slice physiology.
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Affiliation(s)
- Matthew J Fischl
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH
| | - Catherine J C Weisz
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH;
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10
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Congenital hearing impairment associated with peripheral cochlear nerve dysmyelination in glycosylation-deficient muscular dystrophy. PLoS Genet 2020; 16:e1008826. [PMID: 32453729 PMCID: PMC7274486 DOI: 10.1371/journal.pgen.1008826] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 06/05/2020] [Accepted: 05/04/2020] [Indexed: 02/06/2023] Open
Abstract
Hearing loss (HL) is one of the most common sensory impairments and etiologically and genetically heterogeneous disorders in humans. Muscular dystrophies (MDs) are neuromuscular disorders characterized by progressive degeneration of skeletal muscle accompanied by non-muscular symptoms. Aberrant glycosylation of α-dystroglycan causes at least eighteen subtypes of MD, now categorized as MD-dystroglycanopathy (MD-DG), with a wide spectrum of non-muscular symptoms. Despite a growing number of MD-DG subtypes and increasing evidence regarding their molecular pathogeneses, no comprehensive study has investigated sensorineural HL (SNHL) in MD-DG. Here, we found that two mouse models of MD-DG, Largemyd/myd and POMGnT1-KO mice, exhibited congenital, non-progressive, and mild-to-moderate SNHL in auditory brainstem response (ABR) accompanied by extended latency of wave I. Profoundly abnormal myelination was found at the peripheral segment of the cochlear nerve, which is rich in the glycosylated α-dystroglycan–laminin complex and demarcated by “the glial dome.” In addition, patients with Fukuyama congenital MD, a type of MD-DG, also had latent SNHL with extended latency of wave I in ABR. Collectively, these findings indicate that hearing impairment associated with impaired Schwann cell-mediated myelination at the peripheral segment of the cochlear nerve is a notable symptom of MD-DG. Hearing loss (HL) is one of the most common sensory impairments and heterogeneous disorders in humans. Up to 60% of HL cases are caused by genetic factors, and approximately 30% of genetic HL cases are syndromic. Although 400–700 genetic syndromes are associated with sensorineural HL (SNHL), caused due to problems in the nerve pathways from the cochlea to the brain, only about 45 genes are known to be associated with syndromic HL. Muscular dystrophies (MDs) are neuromuscular disorders characterized by progressive degeneration of skeletal muscle accompanied by non-muscular symptoms. MD-dystroglycanopathy (MD-DG), caused by aberrant glycosylation of α-dystroglycan, is an MD subtype with a wide spectrum of non-muscular symptoms. Despite a growing number of MD-DG subtypes (at least 18), no comprehensive study has investigated SNHL in MD-DG. Here, we found that hearing impairment was associated with abnormal myelination of the peripheral segment of the cochlear nerve caused by impaired dystrophin–dystroglycan complex in two mouse models (type 3 and 6) of MD-DG and in patients (type 4) with MD-DG. This is the first comprehensive study investigating SNHL in MD-DG. Our findings may provide new insights into understanding the pathogenic characteristics and mechanisms underlying inherited syndromic hearing impairment.
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11
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Schwarzer S, Asokan N, Bludau O, Chae J, Kuscha V, Kaslin J, Hans S. Neurogenesis in the inner ear: the zebrafish statoacoustic ganglion provides new neurons from a Neurod/Nestin-positive progenitor pool well into adulthood. Development 2020; 147:dev.176750. [PMID: 32165493 DOI: 10.1242/dev.176750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 02/25/2020] [Indexed: 01/13/2023]
Abstract
The vertebrate inner ear employs sensory hair cells and neurons to mediate hearing and balance. In mammals, damaged hair cells and neurons are not regenerated. In contrast, hair cells in the inner ear of zebrafish are produced throughout life and regenerate after trauma. However, it is unknown whether new sensory neurons are also formed in the adult zebrafish statoacoustic ganglion (SAG), the sensory ganglion connecting the inner ear to the brain. Using transgenic lines and marker analysis, we identify distinct cell populations and anatomical landmarks in the juvenile and adult SAG. In particular, we analyze a Neurod/Nestin-positive progenitor pool that produces large amounts of new neurons at juvenile stages, which transitions to a quiescent state in the adult SAG. Moreover, BrdU pulse chase experiments reveal the existence of a proliferative but otherwise marker-negative cell population that replenishes the Neurod/Nestin-positive progenitor pool at adult stages. Taken together, our study represents the first comprehensive characterization of the adult zebrafish SAG showing that zebrafish, in sharp contrast to mammals, display continued neurogenesis in the SAG well beyond embryonic and larval stages.
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Affiliation(s)
- Simone Schwarzer
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Nandini Asokan
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Oliver Bludau
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Jeongeun Chae
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Veronika Kuscha
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Jan Kaslin
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
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12
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Stephani F, Scheuer V, Eckrich T, Blum K, Wang W, Obermair GJ, Engel J. Deletion of the Ca 2+ Channel Subunit α 2δ3 Differentially Affects Ca v2.1 and Ca v2.2 Currents in Cultured Spiral Ganglion Neurons Before and After the Onset of Hearing. Front Cell Neurosci 2019; 13:278. [PMID: 31293392 PMCID: PMC6606706 DOI: 10.3389/fncel.2019.00278] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 06/07/2019] [Indexed: 12/14/2022] Open
Abstract
Voltage-gated Ca2+ channels are composed of a pore-forming α1 subunit and auxiliary β and α2δ subunits, which modulate Ca2+ current properties and channel trafficking. So far, the partial redundancy and specificity of α1 for α2δ subunits in the CNS have remained largely elusive. Mature spiral ganglion (SG) neurons express α2δ subunit isoforms 1, 2, and 3 and multiple Ca2+ channel subtypes. Differentiation and in vivo functions of their endbulb of Held synapses, which rely on presynaptic P/Q channels (Lin et al., 2011), require the α2δ3 subunit (Pirone et al., 2014). This led us to hypothesize that P/Q channels may preferentially co-assemble with α2δ3. Using a dissociated primary culture, we analyzed the effects of α2δ3 deletion on somatic Ca2+ currents (ICa) of SG neurons isolated at postnatal day 20 (P20), when the cochlea is regarded to be mature. P/Q currents were the dominating steady-state Ca2+ currents (54% of total) followed by T-type, L-type, N-type, and R-type currents. Deletion of α2δ3 reduced P/Q- and R-type currents by 60 and 38%, respectively, whereas L-type, N-type, and T-type currents were not altered. A subset of ICa types was also analyzed in SG neurons isolated at P5, i.e., before the onset of hearing (P12). Both L-type and N-type current amplitudes of wildtype SG neurons were larger at P5 compared with P20. Deletion of α2δ3 reduced L-type and N-type currents by 23 and 44%, respectively. In contrast, small P/Q currents, which were just being up-regulated at P5, were unaffected by the lack of α2δ3. In summary, α2δ3 regulates amplitudes of L- and N-type currents of immature cultured SG neurons, whereas it regulates P/Q- and R-type currents at P20. Our data indicate a developmental switch from dominating somatic N- to P/Q-type currents in cultured SG neurons. A switch from N- to P/Q-type channels, which has been observed at several central synapses, may also occur at developing endbulbs of Held. In this case, reduction of both neonatal N- (P5) and more mature P/Q-type currents (around/after hearing onset) may contribute to the impaired morphology and function of endbulb synapses in α2δ3-deficient mice.
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Affiliation(s)
- Friederike Stephani
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Veronika Scheuer
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Tobias Eckrich
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Kerstin Blum
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Wenying Wang
- Department of Physiology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Gerald J Obermair
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria.,Division Physiology, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Jutta Engel
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
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13
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Partearroyo T, Murillo-Cuesta S, Vallecillo N, Bermúdez-Muñoz JM, Rodríguez-de la Rosa L, Mandruzzato G, Celaya AM, Zeisel SH, Pajares MA, Varela-Moreiras G, Varela-Nieto I. Betaine-homocysteine S-methyltransferase deficiency causes increased susceptibility to noise-induced hearing loss associated with plasma hyperhomocysteinemia. FASEB J 2019; 33:5942-5956. [PMID: 30753104 PMCID: PMC6463923 DOI: 10.1096/fj.201801533r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/15/2019] [Indexed: 12/16/2022]
Abstract
Betaine-homocysteine S-methyltransferases (BHMTs) are methionine cycle enzymes that remethylate homocysteine; hence, their malfunction leads to hyperhomocysteinemia. Epidemiologic and experimental studies have revealed a correlation between hyperhomocysteinemia and hearing loss. Here, we have studied the expression of methionine cycle genes in the mouse cochlea and the impact of knocking out the Bhmt gene in the auditory receptor. We evaluated age-related changes in mouse hearing by recording auditory brainstem responses before and following exposure to noise. Also, we measured cochlear cytoarchitecture, gene expression by RNA-arrays and quantitative RT-PCR, and metabolite levels in liver and plasma by HPLC. Our results indicate that there is an age-dependent strain-specific expression of methionine cycle genes in the mouse cochlea and a further regulation during the response to noise damage. Loss of Bhmt did not cause an evident impact in the hearing acuity of young mice, but it produced higher threshold shifts and poorer recovery following noise challenge. Hearing loss was associated with increased cochlear injury, outer hair cell loss, altered expression of cochlear methionine cycle genes, and hyperhomocysteinemia. Our results suggest that BHMT plays a central role in the homeostasis of cochlear methionine metabolism and that Bhmt2 up-regulation could carry out a compensatory role in cochlear protection against noise injury in the absence of BHMT.-Partearroyo, T., Murillo-Cuesta, S., Vallecillo, N., Bermúdez-Muñoz, J. M., Rodríguez-de la Rosa, L., Mandruzzato, G., Celaya, A. M., Zeisel, S. H., Pajares, M. A., Varela-Moreiras, G., Varela-Nieto, I. Betaine-homocysteine S-methyltransferase deficiency causes increased susceptibility to noise-induced hearing loss associated with plasma hyperhomocysteinemia.
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Affiliation(s)
- Teresa Partearroyo
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad Centro de Estudios Universitarios CEU San Pablo, Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Silvia Murillo-Cuesta
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Madrid, Spain
| | - Néstor Vallecillo
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Jose M. Bermúdez-Muñoz
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Lourdes Rodríguez-de la Rosa
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Madrid, Spain
| | | | - Adelaida M. Celaya
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Steven H. Zeisel
- Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, North Carolina, USA; and
| | - María A. Pajares
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Madrid, Spain
- Centro de Investigaciones Biológicas, (CSIC) Madrid, Spain
| | - Gregorio Varela-Moreiras
- Departamento de Ciencias Farmacéuticas y de la Salud, Facultad de Farmacia, Universidad Centro de Estudios Universitarios CEU San Pablo, Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
| | - Isabel Varela-Nieto
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas–Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras, (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Madrid, Spain
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14
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Celaya AM, Sánchez-Pérez I, Bermúdez-Muñoz JM, Rodríguez-de la Rosa L, Pintado-Berninches L, Perona R, Murillo-Cuesta S, Varela-Nieto I. Deficit of mitogen-activated protein kinase phosphatase 1 (DUSP1) accelerates progressive hearing loss. eLife 2019; 8:39159. [PMID: 30938680 PMCID: PMC6464786 DOI: 10.7554/elife.39159] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 04/01/2019] [Indexed: 12/12/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) such as p38 and the c-Jun N-terminal kinases (JNKs) are activated during the cellular response to stress signals. Their activity is regulated by the MAPK-phosphatase 1 (DUSP1), a key component of the anti-inflammatory response. Stress kinases are well-described elements of the response to otic injury and the otoprotective potential of JNK inhibitors is being tested in clinical trials. By contrast, there are no studies exploring the role of DUSP1 in hearing and hearing loss. Here we show that Dusp1 expression is age-regulated in the mouse cochlea. Dusp1 gene knock-out caused premature progressive hearing loss, as confirmed by auditory evoked responses in Dusp1-/- mice. Hearing loss correlated with cell death in hair cells, degeneration of spiral neurons and increased macrophage infiltration. Dusp1-/- mouse cochleae showed imbalanced redox status and dysregulated expression of cytokines. These data suggest that DUSP1 is essential for cochlear homeostasis in the response to stress during ageing.
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Affiliation(s)
- Adelaida M Celaya
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
| | - Isabel Sánchez-Pérez
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain.,Biochemistry Department, Faculty of Medicine, Autonomous University of Madrid, Madrid, Spain.,Biomedicine Unit UCLM-CSIC, Madrid, Spain
| | - Jose M Bermúdez-Muñoz
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
| | - Lourdes Rodríguez-de la Rosa
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Laura Pintado-Berninches
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Rosario Perona
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Silvia Murillo-Cuesta
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
| | - Isabel Varela-Nieto
- Institute for Biomedical Research "Alberto Sols" (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), CIBER, ISCIII, Madrid, Spain
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15
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Brown LN, Xing Y, Noble KV, Barth JL, Panganiban CH, Smythe NM, Bridges MC, Zhu J, Lang H. Macrophage-Mediated Glial Cell Elimination in the Postnatal Mouse Cochlea. Front Mol Neurosci 2017; 10:407. [PMID: 29375297 PMCID: PMC5770652 DOI: 10.3389/fnmol.2017.00407] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/23/2017] [Indexed: 12/20/2022] Open
Abstract
Hearing relies on the transmission of auditory information from sensory hair cells (HCs) to the brain through the auditory nerve. This relay of information requires HCs to be innervated by spiral ganglion neurons (SGNs) in an exclusive manner and SGNs to be ensheathed by myelinating and non-myelinating glial cells. In the developing auditory nerve, mistargeted SGN axons are retracted or pruned and excessive cells are cleared in a process referred to as nerve refinement. Whether auditory glial cells are eliminated during auditory nerve refinement is unknown. Using early postnatal mice of either sex, we show that glial cell numbers decrease after the first postnatal week, corresponding temporally with nerve refinement in the developing auditory nerve. Additionally, expression of immune-related genes was upregulated and macrophage numbers increase in a manner coinciding with the reduction of glial cell numbers. Transient depletion of macrophages during early auditory nerve development, using transgenic CD11bDTR/EGFP mice, resulted in the appearance of excessive glial cells. Macrophage depletion caused abnormalities in myelin formation and transient edema of the stria vascularis. Macrophage-depleted mice also showed auditory function impairment that partially recovered in adulthood. These findings demonstrate that macrophages contribute to the regulation of glial cell number during postnatal development of the cochlea and that glial cells play a critical role in hearing onset and auditory nerve maturation.
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Affiliation(s)
- LaShardai N. Brown
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Yazhi Xing
- Department of Otorhinolaryngology, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China
| | - Kenyaria V. Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Jeremy L. Barth
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Clarisse H. Panganiban
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Nancy M. Smythe
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Mary C. Bridges
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Juhong Zhu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States
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16
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Long P, Wan G, Roberts MT, Corfas G. Myelin development, plasticity, and pathology in the auditory system. Dev Neurobiol 2017; 78:80-92. [PMID: 28925106 DOI: 10.1002/dneu.22538] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/23/2017] [Accepted: 09/14/2017] [Indexed: 11/11/2022]
Abstract
Myelin allows for the rapid and precise timing of action potential propagation along neuronal circuits and is essential for healthy auditory system function. In this article, we discuss what is currently known about myelin in the auditory system with a focus on the timing of myelination during auditory system development, the role of myelin in supporting peripheral and central auditory circuit function, and how various myelin pathologies compromise auditory information processing. Additionally, in keeping with the increasing recognition that myelin is dynamic and is influenced by experience throughout life, we review the growing evidence that auditory sensory deprivation alters myelin along specific segments of the brain's auditory circuit. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 80-92, 2018.
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Affiliation(s)
- Patrick Long
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, 48109
| | - Guoqiang Wan
- MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center of Nanjing University, Nanjing, Jiangsu Province, China
| | - Michael T Roberts
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, 48109
| | - Gabriel Corfas
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, 48109
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17
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Bojrab D, Zhang B, Jiang H, Zhang L, Cohen DS, Luo X, Hu Z. Expression of Oligodendrocyte Marker during Peripheral-Central Transitional Zone Formation of the Postnatal Mouse Cochlear Nerve. Otolaryngol Head Neck Surg 2017; 157:488-492. [PMID: 28695768 DOI: 10.1177/0194599817718806] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Objective To better understand oligodendrocyte protein expression along the mouse cochlear nerve in postnatal mice. Study Design In vivo murine study. Setting Research laboratory. Subjects and Methods Swiss Webster mice used at multiple postnatal days (0, 1, 3, 5, 7, 8, 10, 14, 30, and 60). There were 5 replicates at each postnatal day. Cryosection was done to produce sections that included the cochlear nucleus, cochlear nerve, and cochlea in a single sample. Differential interference contrast (DIC) microscopy and immunofluorescence with antibodies specific to the oligodendrocyte protein Olig2 were used to study the cochlear nerve of Swiss Webster mice at postnatal days. Results The myelination of central nervous system projections initiates in close proximity to the peripheral nervous system-central nervous system transitional zone (PCTZ), and oligodendrocytes in neonatal mice are seen with immunohistochemistry peripheral to the DIC-PCTZ interface. Conclusions As the PCTZ migrates from the brain to the cochlea, oligodendrocytes are a part of peripheral extension of central nervous system tissue along the cochlear nerve. Expression of oligodendrocyte marker Oligo2 was observed peripherally to the formation of PCTZ, as determined by DIC microscopy.
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Affiliation(s)
- Dennis Bojrab
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA
| | - Baofu Zhang
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA
| | - Hui Jiang
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA.,2 Department of Otolaryngology-Head and Neck Surgery, Fudan University Jinshan Hospital, Shanghai, China
| | - Lei Zhang
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA
| | - David S Cohen
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA
| | - Xuemei Luo
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA.,3 Department of Otolaryngology-Head and Neck Surgery, Fudan University Zhongshan Hospital, Shanghai, China
| | - Zhengqing Hu
- 1 Department of Otolaryngology-Head and Neck Surgery, Wayne State University, Detroit, Michigan, USA
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18
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Ca 2+-Permeable AMPARs Mediate Glutamatergic Transmission and Excitotoxic Damage at the Hair Cell Ribbon Synapse. J Neurosci 2017; 37:6162-6175. [PMID: 28539424 DOI: 10.1523/jneurosci.3644-16.2017] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/20/2017] [Accepted: 04/24/2017] [Indexed: 01/21/2023] Open
Abstract
We report functional and structural evidence for GluA2-lacking Ca2+-permeable AMPARs (CP-AMPARs) at the mature hair cell ribbon synapse. By using the methodological advantages of three species (of either sex), we demonstrate that CP-AMPARs are present at the hair cell synapse in an evolutionarily conserved manner. Via a combination of in vivo electrophysiological and Ca2+ imaging approaches in the larval zebrafish, we show that hair cell stimulation leads to robust Ca2+ influx into afferent terminals. Prolonged application of AMPA caused loss of afferent terminal responsiveness, whereas blocking CP-AMPARs protects terminals from excitotoxic swelling. Immunohistochemical analysis of AMPAR subunits in mature rat cochlea show regions within synapses lacking the GluA2 subunit. Paired recordings from adult bullfrog auditory synapses demonstrate that CP-AMPARs mediate a major component of glutamatergic transmission. Together, our results support the importance of CP-AMPARs in mediating transmission at the hair cell ribbon synapse. Further, excess Ca2+ entry via CP-AMPARs may underlie afferent terminal damage following excitotoxic challenge, suggesting that limiting Ca2+ levels in the afferent terminal may protect against cochlear synaptopathy associated with hearing loss.SIGNIFICANCE STATEMENT A single incidence of noise overexposure causes damage at the hair cell synapse that later leads to neurodegeneration and exacerbates age-related hearing loss. A first step toward understanding cochlear neurodegeneration is to identify the cause of initial excitotoxic damage to the postsynaptic neuron. Using a combination of immunohistochemical, electrophysiological, and Ca2+ imaging approaches in evolutionarily divergent species, we demonstrate that Ca2+-permeable AMPARs (CP-AMPARs) mediate glutamatergic transmission at the adult auditory hair cell synapse. Overexcitation of the terminal causes Ca2+ accumulation and swelling that can be prevented by blocking CP-AMPARs. We demonstrate that CP-AMPARs mediate transmission at this first-order sensory synapse and that limiting Ca2+ accumulation in the terminal may protect against hearing loss.
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19
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Neuhaus C, Lang-Roth R, Zimmermann U, Heller R, Eisenberger T, Weikert M, Markus S, Knipper M, Bolz H. Extension of the clinical and molecular phenotype of DIAPH1
-associated autosomal dominant hearing loss (DFNA1
). Clin Genet 2016; 91:892-901. [DOI: 10.1111/cge.12915] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/27/2016] [Indexed: 12/11/2022]
Affiliation(s)
- C. Neuhaus
- Bioscientia Center for Human Genetics; Ingelheim Germany
| | - R. Lang-Roth
- Department of Otorhinolaryngology, Head and Neck Surgery; University of Cologne; Cologne Germany
| | - U. Zimmermann
- Molecular Physiology of Hearing, Hearing Research Centre Tübingen (THRC), Department of Otolaryngology; University of Tübingen; Tübingen Germany
| | - R. Heller
- Institute of Human Genetics; University Hospital of Cologne; Cologne Germany
| | - T. Eisenberger
- Bioscientia Center for Human Genetics; Ingelheim Germany
| | - M. Weikert
- Gemeinschaftspraxis für Phoniatrie; Pädaudiologie und Hals-Nasen-Ohrenheilkunde; Regensburg Germany
| | - S. Markus
- Kompetenzzentrum für Humangenetik; Gynäkologie und Laboratoriumsmedizin; Regensburg Germany
| | - M. Knipper
- Department of Otorhinolaryngology, Head and Neck Surgery; University of Cologne; Cologne Germany
| | - H.J. Bolz
- Bioscientia Center for Human Genetics; Ingelheim Germany
- Institute of Human Genetics; University Hospital of Cologne; Cologne Germany
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