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Wu J, Xu X, Zhang S, Li M, Qiu Y, Lu G, Zheng Z, Huang H. Plastic Events of the Vestibular Nucleus: the Initiation of Central Vestibular Compensation. Mol Neurobiol 2024:10.1007/s12035-024-04208-2. [PMID: 38689145 DOI: 10.1007/s12035-024-04208-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
Vestibular compensation is a physiological response of the vestibular organs within the inner ear. This adaptation manifests during consistent exposure to acceleration or deceleration, with the vestibular organs incrementally adjusting to such changes. The molecular underpinnings of vestibular compensation remain to be fully elucidated, yet emerging studies implicate associations with neuroplasticity and signal transduction pathways. Throughout the compensation process, the vestibular sensory neurons maintain signal transmission to the central equilibrium system, facilitating adaptability through alterations in synaptic transmission and neuronal excitability. Notable molecular candidates implicated in this process include variations in ion channels and neurotransmitter profiles, as well as neuronal and synaptic plasticity, metabolic processes, and electrophysiological modifications. This study consolidates the current understanding of the molecular events in vestibular compensation, augments the existing research landscape, and evaluates contemporary therapeutic strategies. Furthermore, this review posits potential avenues for future research that could enhance our comprehension of vestibular compensation mechanisms.
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Affiliation(s)
- Junyu Wu
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Xue Xu
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Shifeng Zhang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Minping Li
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Yuemin Qiu
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Gengxin Lu
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Zhihui Zheng
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China
| | - Haiwei Huang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, No.58 Zhongshan Road 2, Guangzhou, 510080, China.
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Tian C, Yang Y, Li Y, Sun F, Qu J, Zha D. Expression and localization of α 2A-adrenergic receptor in the rat post-natal developing cochlea. Eur J Histochem 2023; 67:3748. [PMID: 37548252 PMCID: PMC10476538 DOI: 10.4081/ejh.2023.3748] [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: 04/11/2023] [Accepted: 07/22/2023] [Indexed: 08/08/2023] Open
Abstract
Lots of adrenergic receptors (ARs) are widely present across the auditory pathways and are positioned to affect auditory and vestibular functions. However, noradrenergic regulation in the cochlea has not been well characterized. In this study, a rat model of noise-induced hearing loss was developed to investigate the expression of α2A-adrenergic receptor (AR) after acoustic trauma, then, we investigated the expression of α2A-AR in the developing rat cochlea using immunofluorescence, qRT-PCR, and Western blotting. We found that the expression of α2A-AR significantly increased in rats exposed to noise compared with controls. Immunofluorescence analysis demonstrated that α2A-AR is localized on hair cells (HCs), spiral ganglion neurons (SGNs), and the stria vascularis (SV) in the postnatal developing cochlea from post-natal day (P) 0 to P28. Furthermore, we observed α2A-AR mRNA reached a maximum level at P14 and P28 when compared with P0, while no significant differences in α2A-AR protein levels at the various stages when compared with P0. This study provides direct evidence for the expression of α2A-AR in HCs, SGNs, and the SV of the cochlea, indicating that norepinephrine might play a vital role in hearing function within the cochlea through α2A-AR.
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Affiliation(s)
- Chaoyong Tian
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shannxi Province.
| | - Yang Yang
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shannxi Province.
| | - Yao Li
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shannxi Province.
| | - Fei Sun
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shannxi Province.
| | - Juan Qu
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shannxi Province.
| | - Dingjun Zha
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Air Force Medical University, Xi'an, Shannxi Province.
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Tian C, Zha D. Sympathetic Nervous System Regulation of Auditory Function. Audiol Neurootol 2021; 27:93-103. [PMID: 34407531 DOI: 10.1159/000517452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 05/26/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The auditory system processes how we hear and understand sounds within the environment. It comprises both peripheral and central structures. Sympathetic nervous system projections are present throughout the auditory system. The function of sympathetic fibers in the cochlea has not been studied extensively due to the limited number of direct projections in the auditory system. Nevertheless, research on adrenergic and noradrenergic regulation of the cochlea and central auditory system is growing. With the rapid development of neuroscience, auditory central regulation is an extant topic of focus in research on hearing. SUMMARY As such, understanding sympathetic nervous system regulation of auditory function is a growing topic of interest. Herein, we review the distribution and putative physiological and pathological roles of sympathetic nervous system projections in hearing. Key Messages: In the peripheral auditory system, the sympathetic nervous system regulates cochlear blood flow, modulates cochlear efferent fibers, affects hair cells, and influences the habenula region. In central auditory pathways, norepinephrine is essential for plasticity in the auditory cortex and affects auditory cortex activity. In pathological states, the sympathetic nervous system is associated with many hearing disorders. The mechanisms and pathways of sympathetic nervous system modulation of auditory function is still valuable for us to research and discuss.
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Affiliation(s)
- Chaoyong Tian
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Dingjun Zha
- Department of Otolaryngology Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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Kitcher SR, Pederson AM, Weisz CJC. Diverse identities and sites of action of cochlear neurotransmitters. Hear Res 2021; 419:108278. [PMID: 34108087 DOI: 10.1016/j.heares.2021.108278] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 04/30/2021] [Accepted: 05/18/2021] [Indexed: 11/18/2022]
Abstract
Accurate encoding of acoustic stimuli requires temporally precise responses to sound integrated with cellular mechanisms that encode the complexity of stimuli over varying timescales and orders of magnitude of intensity. Sound in mammals is initially encoded in the cochlea, the peripheral hearing organ, which contains functionally specialized cells (including hair cells, afferent and efferent neurons, and a multitude of supporting cells) to allow faithful acoustic perception. To accomplish the demanding physiological requirements of hearing, the cochlea has developed synaptic arrangements that operate over different timescales, with varied strengths, and with the ability to adjust function in dynamic hearing conditions. Multiple neurotransmitters interact to support the precision and complexity of hearing. Here, we review the location of release, action, and function of neurotransmitters in the mammalian cochlea with an emphasis on recent work describing the complexity of signaling.
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Affiliation(s)
- Siân R Kitcher
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, United States
| | - Alia M Pederson
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, United States
| | - Catherine J C Weisz
- Section on Neuronal Circuitry, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD 20892, United States.
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Abstract
Emotional stress has accompanied humans since the dawn of time and has played an essential role not only in positive selection and adaptation to an ever-changing environment, but also in the acceleration or even initiation of many illnesses. The three main somatic mechanisms induced by stress are the hypothalamus-pituitary-adrenal axis (HPA axis), the sympathetic-adreno-medullar (SAM) axis, and the immune axis. In this chapter, the stress-induced mechanisms that can affect cochlear physiology are presented and discussed in the context of tinnitus generation and auditory neurobiology. It is concluded that all of the presented mechanisms need to be further investigated. It is advised that clinical practitioners ask patients about stressful events or chronic stress preceding the tinnitus onset and measure the vital signs. Finally, taking into account that tinnitus itself acts as a stressor, the implementation of anti-stress therapies for tinnitus treatment is recommended.
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Al-Ghamdi BS, Rohra DK, Abuharb GAI, Alkofide HA, AlRuwaili NS, Shoukri MM, Cahusac PMB. Use of beta blockers is associated with hearing loss. Int J Audiol 2017; 57:213-220. [DOI: 10.1080/14992027.2017.1405162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Bandar Saeed Al-Ghamdi
- Department of Cardiology, Heart Centre, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia,
- Department of Medicine, Alfaisal University, Riyadh, Saudi Arabia,
| | - Dileep Kumar Rohra
- Department of Pharmacology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia,
| | - Gheid Ali Ibrahim Abuharb
- Clinical Audiology, Department of Otolaryngology, Head & Neck Surgery and Communication Sciences, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia,
| | - Hala Abdulrahman Alkofide
- Clinical Audiology, Department of Otolaryngology, Head & Neck Surgery and Communication Sciences, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia,
| | - Nadiah Salem AlRuwaili
- Department of Cardiology, Heart Centre, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia,
| | - Mohamed M. Shoukri
- Department of Cell Biology and the National Biotechnology Centre, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia, and
| | - Peter M. B. Cahusac
- Department of Pharmacology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia,
- Department of Comparative Medicine, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
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Cortada M, Levano S, Bodmer D. Brimonidine Protects Auditory Hair Cells from in vitro-Induced Toxicity of Gentamicin. Audiol Neurootol 2017; 22:125-134. [PMID: 28889125 DOI: 10.1159/000479218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 07/05/2017] [Indexed: 12/11/2022] Open
Abstract
Brimonidine, an alpha-2 adrenergic receptor (α2-AR) agonist, has neuroprotective effects in the visual system and in spiral ganglion neurons. Auditory hair cells (HCs) express all 3 α2-AR subtypes, but their roles in HCs remain unknown. This study investigated the effects of brimonidine on auditory HCs that were also exposed to gentamicin, which is toxic to HCs. Organ of Corti explants were exposed to gentamicin in the presence or absence of brimonidine, and the α2-AR protein expression levels and Erk1/2 and Akt phosphorylation levels were determined. Brimonidine had a protective effect on auditory HCs against gentamicin-induced toxicity that was blocked by yohimbine. This suggested that the protective effect of brimonidine on HCs was mediated by the α2-AR. None of the treatments altered α2-AR protein expression levels, and brimonidine did not significantly change the activation levels of the Erk1/2 and Akt proteins. These observations indicated that brimonidine, acting directly via α2-AR, protects HCs from gentamicin-induced toxicity. Therefore, brimonidine shows potential for preventing or treating sensorineural hearing loss.
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Affiliation(s)
- Maurizio Cortada
- Department of Biomedicine, University of Basel, Basel, Switzerland
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Kim BG, Kim JY, Jung J, Moon IS, Yoon JH, Choi JY, Kim SH. β 1- and β 2-adrenergic stimulation-induced electrogenic transport by human endolymphatic sac epithelium and its clinical implications. Sci Rep 2017; 7:42217. [PMID: 28165045 PMCID: PMC5292703 DOI: 10.1038/srep42217] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/03/2017] [Indexed: 01/02/2023] Open
Abstract
The endolymphatic sac (ES) is a cystic structure of the inner ear connected to the cochlea and vestibule, which plays a role in regulating ion homeostasis in inner ear fluid. Disruption of ion homeostasis can cause inner ear disorders with hearing loss and dizziness, such as Meniere's disease. Herein, we found, for the first time, functional evidence for the involvement of β1- and β2-adrenergic receptors in apical electrogenic ion transport by human ES epithelium by using electrophysiological/pharmacological and molecular biological methods, which were dependent on K+ and Cl- ion transport. The apical electrogenic transport was absent or very weak in ES epithelia of patients with Meniere's disease. These results suggested that adrenergic stimulation via β1- and β2-adrenergic receptors in the human ES was involved in regulation of inner ear fluid ion homeostasis and impairment of this response could be a pathological mechanism of Meniere's disease.
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Affiliation(s)
- Bo Gyung Kim
- Department of Otorhinolaryngology, Soonchunhyang University College of Medicine, Bucheon, 420-767, Republic of Korea
| | - Jin Young Kim
- Research Center for Natural Human Defense System, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Republic of Korea
| | - JinSei Jung
- Department of Otorhinolaryngology, Yonsei University College of Medicine
| | - In Seok Moon
- Department of Otorhinolaryngology, Yonsei University College of Medicine
| | - Joo-Heon Yoon
- Research Center for Natural Human Defense System, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Republic of Korea.,Department of Otorhinolaryngology, Yonsei University College of Medicine.,The Airway Mucus Institute, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Jae Young Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine.,The Airway Mucus Institute, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Sung Huhn Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine.,The Airway Mucus Institute, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
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Martín-Sierra C, Requena T, Frejo L, Price SD, Gallego-Martinez A, Batuecas-Caletrio A, Santos-Pérez S, Soto-Varela A, Lysakowski A, Lopez-Escamez JA. A novel missense variant in PRKCB segregates low-frequency hearing loss in an autosomal dominant family with Meniere's disease. Hum Mol Genet 2016; 25:3407-3415. [PMID: 27329761 DOI: 10.1093/hmg/ddw183] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/13/2022] Open
Abstract
Meniere's Disease (MD) is a complex disorder associated with an accumulation of endolymph in the membranous labyrinth in the inner ear. It is characterized by recurrent attacks of spontaneous vertigo associated with sensorineural hearing loss (SNHL) and tinnitus. The SNHL usually starts at low and medium frequencies with a variable progression to high frequencies. We identified a novel missense variant in the PRKCB gene in a Spanish family with MD segregating low-to-middle frequency SNHL. Confocal imaging showed strong PKCB II protein labelling in non-sensory cells, the tectal cells and inner border cells of the rat organ of Corti with a tonotopic expression gradient. The PKCB II signal was more pronounced in the apical turn of the cochlea when compared with the middle and basal turns. It was also much higher in cochlear tissue than in vestibular tissue. Taken together, our findings identify PRKCB gene as a novel candidate gene for familial MD and its expression gradient in supporting cells of the organ of Corti deserves attention, given the role of supporting cells in K+ recycling within the endolymph, and its apical turn location may explain the onset of hearing loss at low frequencies in MD.
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Affiliation(s)
- Carmen Martín-Sierra
- Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer/University of Granada/Junta de Andalucía, PTS, Granada 18016, Spain
| | - Teresa Requena
- Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer/University of Granada/Junta de Andalucía, PTS, Granada 18016, Spain
| | - Lidia Frejo
- Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer/University of Granada/Junta de Andalucía, PTS, Granada 18016, Spain
| | - Steven D Price
- Dept. of Anatomy and Cell Biology, Univ. of Illinois at Chicago, Chicago, IL 60612, USA
| | - Alvaro Gallego-Martinez
- Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer/University of Granada/Junta de Andalucía, PTS, Granada 18016, Spain
| | | | - Sofía Santos-Pérez
- Division of Otoneurology, Department of Otorhinolaryngology, Complexo Hospitalario Universitario, Santiago de Compostela 15706, Spain
| | - Andrés Soto-Varela
- Division of Otoneurology, Department of Otorhinolaryngology, Complexo Hospitalario Universitario, Santiago de Compostela 15706, Spain
| | - Anna Lysakowski
- Dept. of Anatomy and Cell Biology, Univ. of Illinois at Chicago, Chicago, IL 60612, USA.,Dept. of Otolaryngology-Head and Neck Surgery, Univ. of Illinois at Chicago, Chicago IL 60612, USA
| | - Jose A Lopez-Escamez
- Otology & Neurotology Group CTS495, Department of Genomic Medicine, GENYO - Centre for Genomics and Oncological Research - Pfizer/University of Granada/Junta de Andalucía, PTS, Granada 18016, Spain .,Department of Otolaryngology, Instituto de Investigación Biosanitaria ibs.GRANADA, Complejo Hospitalario Universidad de Granada (CHUGRA) Granada 18016, Spain
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Hormigo S, Gómez-Nieto R, Castellano O, Herrero-Turrión MJ, López DE, de Anchieta de Castro E Horta-Júnior J. The noradrenergic projection from the locus coeruleus to the cochlear root neurons in rats. Brain Struct Funct 2014; 220:1477-96. [PMID: 24623157 DOI: 10.1007/s00429-014-0739-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/17/2014] [Indexed: 12/18/2022]
Abstract
The cochlear root neurons (CRNs) are key components of the primary acoustic startle circuit; mediating auditory alert and escape behaviors in rats. They receive a great variety of inputs which serve to elicit and modulate the acoustic startle reflex (ASR). Recently, our group has suggested that CRNs receive inputs from the locus coeruleus (LC), a noradrenergic nucleus which participates in attention and alertness. Here, we map the efferent projection patterns of LC neurons and confirm the existence of the LC-CRN projection using both anterograde and retrograde tract tracers. Our results show that each LC projects to the CRNs of both sides with a clear ipsilateral predominance. The LC axons terminate as small endings distributed preferentially on the cell body and primary dendrites of CRNs. Using light and confocal microscopy, we show a strong immunoreactivity for tyrosine hydroxylase and dopamine β-hydroxylase in these terminals, indicating noradrenaline release. We further studied the noradrenergic system using gene expression analysis (RT-qPCR) and immunohistochemistry to detect specific noradrenergic receptor subunits in the cochlear nerve root. Our results indicate that CRNs contain a noradrenergic receptor profile sufficient to modulate the ASR, and also show important gender-specific differences in their gene expression. 3D reconstruction analysis confirms the presence of sexual dimorphism in the density and distribution of LC neurons. Our study describes a coerulean noradrenergic projection to the CRNs that might contribute to neural processes underlying sensory gating of the ASR, and also provides an explanation for the gender differences observed in the behavioral paradigm.
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Affiliation(s)
- Sebastián Hormigo
- Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain
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