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Yang Y, Murtha K, Climer LK, Ceriani F, Thompson P, Hornak AJ, Marcotti W, Simmons DD. Oncomodulin regulates spontaneous calcium signalling and maturation of afferent innervation in cochlear outer hair cells. J Physiol 2023; 601:4291-4308. [PMID: 37642186 PMCID: PMC10621907 DOI: 10.1113/jp284690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 08/08/2023] [Indexed: 08/31/2023] Open
Abstract
Cochlear outer hair cells (OHCs) are responsible for the exquisite frequency selectivity and sensitivity of mammalian hearing. During development, the maturation of OHC afferent connectivity is refined by coordinated spontaneous Ca2+ activity in both sensory and non-sensory cells. Calcium signalling in neonatal OHCs can be modulated by oncomodulin (OCM, β-parvalbumin), an EF-hand calcium-binding protein. Here, we investigated whether OCM regulates OHC spontaneous Ca2+ activity and afferent connectivity during development. Using a genetically encoded Ca2+ sensor (GCaMP6s) expressed in OHCs in wild-type (Ocm+/+ ) and Ocm knockout (Ocm-/- ) littermates, we found increased spontaneous Ca2+ activity and upregulation of purinergic receptors in OHCs from Ocm-/- cochlea immediately following birth. The afferent synaptic maturation of OHCs was delayed in the absence of OCM, leading to an increased number of ribbon synapses and afferent fibres on Ocm-/- OHCs before hearing onset. We propose that OCM regulates the spontaneous Ca2+ signalling in the developing cochlea and the maturation of OHC afferent innervation. KEY POINTS: Cochlear outer hair cells (OHCs) exhibit spontaneous Ca2+ activity during a narrow period of neonatal development. OHC afferent maturation and connectivity requires spontaneous Ca2+ activity. Oncomodulin (OCM, β-parvalbumin), an EF-hand calcium-binding protein, modulates Ca2+ signals in immature OHCs. Using transgenic mice that endogenously expressed a Ca2+ sensor, GCaMP6s, we found increased spontaneous Ca2+ activity and upregulated purinergic receptors in Ocm-/- OHCs. The maturation of afferent synapses in Ocm-/- OHCs was also delayed, leading to an upregulation of ribbon synapses and afferent fibres in Ocm-/- OHCs before hearing onset. We propose that OCM plays an important role in modulating Ca2+ activity, expression of Ca2+ channels and afferent innervation in developing OHCs.
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Affiliation(s)
- Yang Yang
- Department of Biology, Baylor University, 101 Bagby Ave, Waco, TX
| | - Kaitlin Murtha
- Department of Biology, Baylor University, 101 Bagby Ave, Waco, TX
| | - Leslie K. Climer
- Department of Biology, Baylor University, 101 Bagby Ave, Waco, TX
| | - Federico Ceriani
- School of Biosciences, University of Sheffield, S10 2TN Sheffield, United Kingdom
| | - Pierce Thompson
- Department of Biology, Baylor University, 101 Bagby Ave, Waco, TX
| | - Aubrey J. Hornak
- Department of Biology, Baylor University, 101 Bagby Ave, Waco, TX
| | - Walter Marcotti
- School of Biosciences, University of Sheffield, S10 2TN Sheffield, United Kingdom
- Sheffield Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
| | - Dwayne D. Simmons
- Department of Biology, Baylor University, 101 Bagby Ave, Waco, TX
- School of Biosciences, University of Sheffield, S10 2TN Sheffield, United Kingdom
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA
- Department of Psychology and Neuroscience, Baylor University, Waco, TX
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Pan J, Zhao Y, Sang R, Yang R, Bao J, Wu Y, Fei Y, Wu J, Chen G. Huntington-associated protein 1 inhibition contributes to neuropathic pain by suppressing Cav1.2 activity and attenuating inflammation. Pain 2023; 164:e286-e302. [PMID: 36508175 DOI: 10.1097/j.pain.0000000000002837] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 11/21/2022] [Indexed: 12/14/2022]
Abstract
ABSTRACT Although pain dysfunction is increasingly observed in Huntington disease, the underlying mechanisms still unknown. As a crucial Huntington-associated protein, Huntington-associated protein 1 (HAP1) is enriched in normal spinal dorsal horn and dorsal root ganglia (DRG) which are regarded as "primary sensory center," indicating its potential functions in pain process. Here, we discovered that HAP1 level was greatly increased in the dorsal horn and DRG under acute and chronic pain conditions. Lack of HAP1 obviously suppressed mechanical allodynia and hyperalgesia in spared nerve injury (SNI)-induced and chronic constriction injury-induced pain. Its deficiency also greatly inhibited the excitability of nociceptive neurons. Interestingly, we found that suppressing HAP1 level diminished the membrane expression of the L-type calcium channel (Cav1.2), which can regulate Ca 2+ influx and then influence brain-derived neurotrophic factor (BDNF) synthesis and release. Furthermore, SNI-induced activation of astrocytes and microglia notably decreased in HAP1-deficient mice. These results indicate that HAP1 deficiency might attenuate pain responses. Collectively, our results suggest that HAP1 in dorsal horn and DRG neurons regulates Cav1.2 surface expression, which in turn reduces neuronal excitability, BDNF secretion, and inflammatory responses and ultimately influences neuropathic pain progression.
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Affiliation(s)
- JingYing Pan
- Department of Histology and Embryology, Medical School of Nantong University, Nantong, China
| | - YaYu Zhao
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Rui Sang
- Department of Physiology, Medical School of Nantong University, Nantong, China
| | - RiYun Yang
- Department of Histology and Embryology, Medical School of Nantong University, Nantong, China
| | - JingYin Bao
- Center for Basic Medical Research, Medical School of Nantong University, Nantong, China
| | - YongJiang Wu
- Center for Basic Medical Research, Medical School of Nantong University, Nantong, China
| | - Ying Fei
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jian Wu
- Department of Histology and Embryology, Medical School of Nantong University, Nantong, China
| | - Gang Chen
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Center for Basic Medical Research, Medical School of Nantong University, Nantong, China
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong, China
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3
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Yang Y, Murtha K, Climer LK, Ceriani F, Thompson P, Hornak AJ, Marcotti W, Simmons DD. Oncomodulin Regulates Spontaneous Calcium Signaling and Maturation of Afferent Innervation in Cochlear Outer Hair Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.529895. [PMID: 36909575 PMCID: PMC10002690 DOI: 10.1101/2023.03.01.529895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Cochlear outer hair cells (OHCs) are responsible for the exquisite frequency selectivity and sensitivity of mammalian hearing. During development, the maturation of OHC afferent connectivity is refined by coordinated spontaneous Ca 2+ activity in both sensory and non-sensory cells. Calcium signaling in neonatal OHCs can be modulated by Oncomodulin (OCM, β-parvalbumin), an EF-hand calcium-binding protein. Here, we investigated whether OCM regulates OHC spontaneous Ca 2+ activity and afferent connectivity during development. Using a genetically encoded Ca 2+ sensor (GCaMP6s) expressed in OHCs in wild-type (Ocm +/+ ) and Ocm knockout (Ocm -/- ) littermates, we found increased spontaneous Ca 2+ activity and upregulation of purinergic receptors in OHCs from GCaMP6s Ocm -/- cochlea immediately following birth. The afferent synaptic maturation of OHCs was delayed in the absence of OCM, leading to an increased number of ribbon synapses and afferent fibers on GCaMP6s Ocm -/- OHCs before hearing onset. We propose that OCM regulates the spontaneous Ca 2+ signaling in the developing cochlea and the maturation of OHC afferent innervation.
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Sorg K, Heimann L, Lana GM, Langenbucher A, Schick B, Arzt E, Wenzel GI. Optoacoustically induced auditory brainstem responses in the mouse model enhanced through an absorbing film. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210173R. [PMID: 34480448 PMCID: PMC8414560 DOI: 10.1117/1.jbo.26.9.098001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE Optoacoustic stimulation offers an alternative stimulation strategy for the hearing organ. To serve as the base for a novel auditory prosthesis, the optoacoustic stimulation must be biocompatible and energy-saving. AIM Enhancing the efficiency of optoacoustic stimulation while reducing the energy input in a suited animal model. APPROACH Optoacoustically induced auditory brainstem responses (oABRs) were recorded after the pulsed laser irradiation of the tympanic membrane (TM) in mice. The results were compared with the ABRs induced through acoustic click stimulation. In addition, self-adhesive absorbing films were applied on the TM before the optoacoustic stimulation to investigate their effect on the resulting ABRs. RESULTS Using an absorbing film on the TM during optical stimulation led to considerably enhanced oABR wave I amplitude values compared with the stimulation of the bare TM. When using our stimulation strategy, we induced oABR waves in the 50% to 60% range of the acoustical stimulation reached with 80-dB SPL click stimuli. CONCLUSIONS The mouse model can be used for certain developmental work for an optoacoustic auditory prosthesis. Using absorbing films on the TM during optical stimulation considerably enhances oABR wave I amplitude. Optimization of the stimulation strategy could further enhance the efficiency within biocompatibility margins.
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Affiliation(s)
- Katharina Sorg
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Larissa Heimann
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Gabriela Moreira Lana
- INM Leibniz Institute for New Materials, Saarbrücken, Germany
- Saarland University, Department of Materials Science and Engineering, Saarbrücken, Germany
| | - Achim Langenbucher
- Saarland University, Department of Experimental Ophthalmology, Homburg, Germany
| | - Bernhard Schick
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Eduard Arzt
- INM Leibniz Institute for New Materials, Saarbrücken, Germany
- Saarland University, Department of Materials Science and Engineering, Saarbrücken, Germany
| | - Gentiana Ioana Wenzel
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
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Yu Y, Yang J, Luan F, Gu G, Zhao R, Wang Q, Dong Z, Tang J, Wang W, Sun J, Lv P, Zhang H, Wang C. Sensorineural Hearing Loss and Mitochondrial Apoptosis of Cochlear Spiral Ganglion Neurons in Fibroblast Growth Factor 13 Knockout Mice. Front Cell Neurosci 2021; 15:658586. [PMID: 34220452 PMCID: PMC8242186 DOI: 10.3389/fncel.2021.658586] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
Deafness is known to occur in more than 400 syndromes and accounts for almost 30% of hereditary hearing loss. The molecular mechanisms underlying such syndromic deafness remain unclear. Furthermore, deafness has been a common feature in patients with three main syndromes, the BÖrjeson-Forssman-Lehmann syndrome, Wildervanck syndrome, and Congenital Generalized Hirsutism, all of which are characterized by loss-of-function mutations in the Fgf13 gene. Whether the pathogenesis of deafness in these syndromes is associated with the Fgf13 mutation is not known. To elucidate its role in auditory function, we generated a mouse line with conditional knockout of the Fgf13 gene in the inner ear (Fgf13 cKO). FGF13 is expressed predominantly in the organ of Corti, spiral ganglion neurons (SGNs), stria vascularis, and the supporting cells. Conditional knockout of the gene in the inner ear led to sensorineural deafness with low amplitude and increased latency of wave I in the auditory brainstem response test but had a normal distortion product otoacoustic emission threshold. Fgf13 deficiency resulted in decreased SGN density from the apical to the basal region without significant morphological changes and those in the number of hair cells. TUNEL and caspase-3 immunocytochemistry assays showed that apoptotic cell death mediated the loss of SGNs. Further detection of apoptotic factors through qRT-PCR suggested the activation of the mitochondrial apoptotic pathway in SGNs. Together, this study reveals a novel role for Fgf13 in auditory function, and indicates that the gene could be a potential candidate for understanding deafness. These findings may provide new perspectives on the molecular mechanisms and novel therapeutic targets for treatment deafness.
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Affiliation(s)
- Yulou Yu
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Jing Yang
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Feng Luan
- Department of Otolaryngology, The Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Guoqiang Gu
- Department of Cardiology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Ran Zhao
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Qiong Wang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Zishan Dong
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Junming Tang
- Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan, China
| | - Wei Wang
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Jinpeng Sun
- Key Laboratory Experimental Teratology of the Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Ping Lv
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Hailin Zhang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Chuan Wang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
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Milon B, Mitra S, Song Y, Margulies Z, Casserly R, Drake V, Mong JA, Depireux DA, Hertzano R. The impact of biological sex on the response to noise and otoprotective therapies against acoustic injury in mice. Biol Sex Differ 2018; 9:12. [PMID: 29530094 PMCID: PMC5848513 DOI: 10.1186/s13293-018-0171-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 02/27/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Noise-induced hearing loss (NIHL) is the most prevalent form of acquired hearing loss and affects about 40 million US adults. Among the suggested therapeutics tested in rodents, suberoylanilide hydroxamic acid (SAHA) has been shown to be otoprotective from NIHL; however, these results were limited to male mice. METHODS Here we tested the effect of SAHA on the hearing of 10-week-old B6CBAF1/J mice of both sexes, which were exposed to 2 h of octave-band noise (101 dB SPL centered at 11.3 kHz). Hearing was assessed by measuring auditory brainstem responses (ABR) at 8, 16, 24, and 32 kHz, 1 week before, as well as at 24 h and 15-21 days following exposure (baseline, compound threshold shift (CTS) and permanent threshold shift (PTS), respectively), followed by histologic analyses. RESULTS We found significant differences in the CTS and PTS of the control (vehicle injected) mice to noise, where females had a significantly smaller CTS at 16 and 24 kHz (p < 0.0001) and PTS at 16, 24, and 32 kHz (16 and 24 kHz p < 0.001, 32 kHz p < 0.01). This sexual dimorphic effect could not be explained by a differential loss of sensory cells or synapses but was reflected in the amplitude and amplitude progression of wave I of the ABR, which correlates with outer hair cell (OHC) function. Finally, the frequency of the protective effect of SAHA differed significantly between males (PTS, 24 kHz, p = 0.002) and females (PTS, 16 kHz, p = 0.003), and the magnitude of the protection was smaller in females than in males. Importantly, the magnitude of the protection by SAHA was smaller than the effect of sex as a biological factor in the vehicle-injected mice. CONCLUSIONS These results indicate that female mice are significantly protected from NIHL in comparison to males and that therapeutics for NIHL may have a different effect in males and females. The data highlight the importance of analyzing NIHL experiments from males and females, separately. Finally, these data also raise the possibility of effectors in the estrogen signaling pathway as novel therapeutics for NIHL.
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Affiliation(s)
- Béatrice Milon
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Sunayana Mitra
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Yang Song
- 0000 0001 2175 4264grid.411024.2Institute for Genome Science, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Zachary Margulies
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Ryan Casserly
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Virginia Drake
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA
| | - Jessica A. Mong
- 0000 0001 2175 4264grid.411024.2Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Didier A. Depireux
- 0000 0001 2175 4264grid.411024.2Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD 21201 USA ,0000 0001 0941 7177grid.164295.dInstitute for Systems Research, University of Maryland, College Park, MD 20742 USA
| | - Ronna Hertzano
- Department of Otorhinolaryngology - Head and Neck Surgery, University of Maryland, 16 South Eutaw Street, Suite 500, Baltimore, MD, 21201, USA. .,Institute for Genome Science, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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Möhrle D, Ni K, Varakina K, Bing D, Lee SC, Zimmermann U, Knipper M, Rüttiger L. Loss of auditory sensitivity from inner hair cell synaptopathy can be centrally compensated in the young but not old brain. Neurobiol Aging 2016; 44:173-184. [DOI: 10.1016/j.neurobiolaging.2016.05.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/28/2016] [Accepted: 05/01/2016] [Indexed: 11/30/2022]
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8
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Dlugaiczyk J, Hecker D, Neubert C, Buerbank S, Campanelli D, Becker CM, Betz H, Knipper M, Rüttiger L, Schick B. Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function. Hear Res 2016; 337:25-34. [DOI: 10.1016/j.heares.2016.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/25/2016] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
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9
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Reijntjes DO, Pyott SJ. The afferent signaling complex: Regulation of type I spiral ganglion neuron responses in the auditory periphery. Hear Res 2016; 336:1-16. [DOI: 10.1016/j.heares.2016.03.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 02/12/2016] [Accepted: 03/07/2016] [Indexed: 12/19/2022]
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Ebbers L, Satheesh SV, Janz K, Rüttiger L, Blosa M, Hofmann F, Morawski M, Griesemer D, Knipper M, Friauf E, Nothwang HG. L-type Calcium Channel Cav1.2 Is Required for Maintenance of Auditory Brainstem Nuclei. J Biol Chem 2015; 290:23692-710. [PMID: 26242732 DOI: 10.1074/jbc.m115.672675] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 12/13/2022] Open
Abstract
Cav1.2 and Cav1.3 are the major L-type voltage-gated Ca(2+) channels in the CNS. Yet, their individual in vivo functions are largely unknown. Both channel subunits are expressed in the auditory brainstem, where Cav1.3 is essential for proper maturation. Here, we investigated the role of Cav1.2 by targeted deletion in the mouse embryonic auditory brainstem. Similar to Cav1.3, loss of Cav1.2 resulted in a significant decrease in the volume and cell number of auditory nuclei. Contrary to the deletion of Cav1.3, the action potentials of lateral superior olive (LSO) neurons were narrower compared with controls, whereas the firing behavior and neurotransmission appeared unchanged. Furthermore, auditory brainstem responses were nearly normal in mice lacking Cav1.2. Perineuronal nets were also unaffected. The medial nucleus of the trapezoid body underwent a rapid cell loss between postnatal days P0 and P4, shortly after circuit formation. Phosphorylated cAMP response element-binding protein (CREB), nuclear NFATc4, and the expression levels of p75NTR, Fas, and FasL did not correlate with cell death. These data demonstrate for the first time that both Cav1.2 and Cav1.3 are necessary for neuronal survival but are differentially required for the biophysical properties of neurons. Thus, they perform common as well as distinct functions in the same tissue.
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Affiliation(s)
- Lena Ebbers
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Somisetty V Satheesh
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Katrin Janz
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Lukas Rüttiger
- the Department of Otolaryngology, Hearing Research Centre Tübingen (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede Aulhorn Strasse 5, 72076 Tübingen, Germany
| | - Maren Blosa
- the Paul Flechsig Institute of Brain Research, Faculty of Medicine, University Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Franz Hofmann
- the Institut für Pharmakologie und Toxikologie, Technische Universität, Biedersteiner Strasse 29, D-80802 München, and
| | - Markus Morawski
- the Paul Flechsig Institute of Brain Research, Faculty of Medicine, University Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Désirée Griesemer
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Marlies Knipper
- the Department of Otolaryngology, Hearing Research Centre Tübingen (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede Aulhorn Strasse 5, 72076 Tübingen, Germany
| | - Eckhard Friauf
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Hans Gerd Nothwang
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany, the Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
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11
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Shi L, Liu K, Wang H, Zhang Y, Hong Z, Wang M, Wang X, Jiang X, Yang S. Noise induced reversible changes of cochlear ribbon synapses contribute to temporary hearing loss in mice. Acta Otolaryngol 2015; 135:1093-102. [PMID: 26139555 DOI: 10.3109/00016489.2015.1061699] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSION Noise exposure can cause a decline in cochlear ribbon synapses and result in consequent hearing loss. The reduction of synaptic puncta appears reversible and may contribute to hearing restoration in mice after noise exposure. OBJECTIVE To detect whether noise induced reversible changes of cochlear ribbon synapses contribute to temporary hearing loss in C57BL/6J mice. METHODS The mice were assigned randomly to five groups and exposed to white noise at 110 dB SPL for 2 h except the control group. ABR thresholds were acquired before noise exposure (control), immediately following exposure (Day 0), or on Days 4, 7, or 14 after noise exposure. Light microscopy, scanning emission microscopy, and whole mounts examination was utilized to study whether there is morphology change of outer hair cells (OHC), inner hair cells (IHC), or spiral ganglion cells (SGN) due to the 110 dB white noise. Moreover, experimental approaches, including immunostaining and confocal microcopy, were used to detect whether ribbon synapses were the primary targets of noise-induced temporary hearing loss. RESULT Exposure to 110 dB white noise for 2 h induced TTS in mice, with the maximal ABR threshold elevations seen on the 4(th) day after noise exposure. There were no significant morphological changes in the cochlea. Paralleled changes of pre-synaptic ribbons in both the number and post-synaptic density (PSDs) during this noise exposure were detected. The number of pre-synaptic ribbon, post-synaptic density (PSDs), and co-localized puncta correlated with the shifts of ABR thresholds. Moreover, a complete recovery of ABR thresholds and synaptic puncta was seen on the 14(th) day after the noise stimulations.
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MESH Headings
- Acoustic Stimulation/adverse effects
- Animals
- Auditory Threshold/physiology
- Cochlea/metabolism
- Cochlea/physiopathology
- Cochlea/ultrastructure
- Disease Models, Animal
- Evoked Potentials, Auditory, Brain Stem/physiology
- Hair Cells, Auditory, Inner/metabolism
- Hair Cells, Auditory, Inner/ultrastructure
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/ultrastructure
- Hearing Loss, Noise-Induced/metabolism
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Mice
- Mice, Inbred C57BL
- Microscopy, Confocal
- Microscopy, Electron, Scanning
- Neuronal Plasticity
- Spiral Ganglion/metabolism
- Spiral Ganglion/ultrastructure
- Synapses
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Affiliation(s)
- Lin Shi
- a 1 Department of Otorhinolaryngology, The First Affiliated Hospital, China Medical University , Shenyang 110001, PR China
- c 3 Department of Otorhinolaryngology, The First Affiliated Hospital, Dalian Medical University , Dalian 116013, PR China
| | - Ke Liu
- b 2 Department of Otolaryngology, Head & Neck Surgery, The Institute of Otolaryngology, Chinese PLA General Hospital , 28 Fuxing Road, Beijing, 100853, PR China
| | - Haolin Wang
- c 3 Department of Otorhinolaryngology, The First Affiliated Hospital, Dalian Medical University , Dalian 116013, PR China
| | - Yue Zhang
- b 2 Department of Otolaryngology, Head & Neck Surgery, The Institute of Otolaryngology, Chinese PLA General Hospital , 28 Fuxing Road, Beijing, 100853, PR China
| | - Zhijun Hong
- c 3 Department of Otorhinolaryngology, The First Affiliated Hospital, Dalian Medical University , Dalian 116013, PR China
| | - Mingyu Wang
- c 3 Department of Otorhinolaryngology, The First Affiliated Hospital, Dalian Medical University , Dalian 116013, PR China
| | - Xiaoyu Wang
- b 2 Department of Otolaryngology, Head & Neck Surgery, The Institute of Otolaryngology, Chinese PLA General Hospital , 28 Fuxing Road, Beijing, 100853, PR China
| | - Xuejun Jiang
- a 1 Department of Otorhinolaryngology, The First Affiliated Hospital, China Medical University , Shenyang 110001, PR China
| | - Shiming Yang
- b 2 Department of Otolaryngology, Head & Neck Surgery, The Institute of Otolaryngology, Chinese PLA General Hospital , 28 Fuxing Road, Beijing, 100853, PR China
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12
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Davis RL, Crozier RA. Dynamic firing properties of type I spiral ganglion neurons. Cell Tissue Res 2015; 361:115-27. [PMID: 25567109 DOI: 10.1007/s00441-014-2071-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/17/2014] [Indexed: 10/24/2022]
Abstract
Spiral ganglion neurons, the first neural element in the auditory system, possess complex intrinsic properties, possibly required to process frequency-specific sensory input that is integrated with extensive efferent regulation. Together with their tonotopically-graded sizes, the somata of these neurons reveal a sophisticated electrophysiological profile. Type I neurons, which make up ~95 % of the ganglion, have myriad voltage-gated ion channels that not only vary along the frequency contour of the cochlea, but also can be modulated by regulators such as voltage, calcium, and second messengers. The resultant developmentally- and tonotopically-regulated neuronal firing patterns conform to three distinct response modes (unitary, rapid, and slow) based on threshold and accommodation. This phenotype, however, is not static for any individual type I neuron. Recent observations have shown that, as neurons become less excitable with age, they demonstrate enhanced plasticity enabling them to change from one response mode to another depending upon resting membrane potential and the presence of neurotrophin-3. Thus, the primary auditory afferents utilized to encode dynamic acoustic stimuli possess the intrinsic specializations that allow them dynamically to alter their firing pattern.
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Affiliation(s)
- Robin L Davis
- Department of Cell Biology and Neuroscience, Nelson Laboratories, Rutgers University, 604 Allison Road, Piscataway, NJ 08854, USA,
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Liu W, Edin F, Atturo F, Rieger G, Löwenheim H, Senn P, Blumer M, Schrott-Fischer A, Rask-Andersen H, Glueckert R. The pre- and post-somatic segments of the human type I spiral ganglion neurons--structural and functional considerations related to cochlear implantation. Neuroscience 2014; 284:470-482. [PMID: 25316409 PMCID: PMC4300406 DOI: 10.1016/j.neuroscience.2014.09.059] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/21/2022]
Abstract
Human auditory nerve afferents consist of two separate systems; one is represented by the large type I cells innervating the inner hair cells and the other one by the small type II cells innervating the outer hair cells. Type I spiral ganglion neurons (SGNs) constitute 96% of the afferent nerve population and, in contrast to other mammals, their soma and pre- and post-somatic segments are unmyelinated. Type II nerve soma and fibers are unmyelinated. Histopathology and clinical experience imply that human SGNs can persist electrically excitable without dendrites, thus lacking connection to the organ of Corti. The biological background to this phenomenon remains elusive. We analyzed the pre- and post-somatic segments of the type I human SGNs using immunohistochemistry and transmission electron microscopy (TEM) in normal and pathological conditions. These segments were found surrounded by non-myelinated Schwann cells (NMSCs) showing strong intracellular expression of laminin-β2/collagen IV. These cells also bordered the perikaryal entry zone and disclosed surface rugosities outlined by a folded basement membrane (BM) expressing laminin-β2 and collagen IV. It is presumed that human large SGNs are demarcated by three cell categories: (a) myelinated Schwann cells, (b) NMSCs and (c) satellite glial cells (SGCs). Their BMs express laminin-β2/collagen IV and reaches the BM of the sensory epithelium at the habenula perforata. We speculate that the NMSCs protect SGNs from further degeneration following dendrite loss. It may give further explanation why SGNs can persist as electrically excitable monopolar cells even after long-time deafness, a blessing for the deaf treated with cochlear implantation.
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Affiliation(s)
- W Liu
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
| | - F Edin
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
| | - F Atturo
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Neurology, Mental Health and Sensory Organs, Otorhinolaryngologic Unit, Medicine and Psychology, Sapienza, Rome, Italy.
| | - G Rieger
- Department of Otolaryngology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria.
| | - H Löwenheim
- Department of Otorhinolaryngology-Head & Neck Surgery, European Medical School, University of Oldenburg, Steinweg 13-17, 26122 Oldenburg, Germany.
| | - P Senn
- University Department of ORL, Head & Neck Surgery, Inselspital and Department of Clinical Research, University of Bern, Switzerland; University Department of ORL, Head & Neck Surgery, HUG, Geneva, Switzerland.
| | - M Blumer
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria.
| | - A Schrott-Fischer
- Department of Otolaryngology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria.
| | - H Rask-Andersen
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden; Department of Otolaryngology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
| | - R Glueckert
- Department of Otolaryngology, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria.
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Genetic, cellular, and functional evidence for Ca2+ inflow through Cav1.2 and Cav1.3 channels in murine spiral ganglion neurons. J Neurosci 2014; 34:7383-93. [PMID: 24849370 DOI: 10.1523/jneurosci.5416-13.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Spiral ganglion neurons (SGNs) of the eighth nerve serve as the bridge between hair cells and the cochlear nucleus. Hair cells use Cav1.3 as the primary channel for Ca(2+) inflow to mediate transmitter release. In contrast, SGNs are equipped with multiple Ca(2+) channels to mediate Ca(2+)-dependent functions. We examined directly the role of Cav1.3 channels in SGNs using Cav1.3-deficient mice (Cav1.3(-/-)). We revealed a surprising finding that SGNs functionally express the cardiac-specific Cav1.2, as well as neuronal Cav1.3 channels. We show that evoked action potentials recorded from SGNs show a significant decrease in the frequency of firing in Cav1.3(-/-) mice compared with wild-type (Cav1.3(+/+)) littermates. Although Cav1.3 is the designated L-type channel in neurons, whole-cell currents recorded in isolated SGNs from Cav1.3(-/-) mice showed a surprising remnant current with sensitivity toward the dihydropyridine (DHP) agonist and antagonist, and a depolarization shift in the voltage-dependent activation compared with that in the Cav1.3(+/+) mice. Indeed, direct measurement of the elementary properties of Ca(2+) channels, in Cav1.3(+/+) neurons, confirmed the existence of two DHP-sensitive single-channel currents, with distinct open probabilities and conductances. We demonstrate that the DHP-sensitive current in Cav1.3(-/-) mice is derived from Cav1.2 channel activity, providing for the first time, to our knowledge, functional data for the expression of Cav1.2 currents in neurons. Finally, using shRNA gene knockdown methodology, and histological analyses of SGNs from Cav1.2(+/-) and Cav1.3(+/-) mice, we were able to establish the differential roles of Cav1.2 and Cav1.3 in SGNs.
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