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Ratzan EM, Lee J, Madison MA, Zhu H, Zhou W, Géléoc GSG, Holt JR. TMC function, dysfunction, and restoration in mouse vestibular organs. Front Neurol 2024; 15:1356614. [PMID: 38638308 PMCID: PMC11024474 DOI: 10.3389/fneur.2024.1356614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/18/2024] [Indexed: 04/20/2024] Open
Abstract
Tmc1 and Tmc2 are essential pore-forming subunits of mechanosensory transduction channels localized to the tips of stereovilli in auditory and vestibular hair cells of the inner ear. To investigate expression and function of Tmc1 and Tmc2 in vestibular organs, we used quantitative polymerase chain reaction (qPCR), fluorescence in situ hybridization - hairpin chain reaction (FISH-HCR), immunostaining, FM1-43 uptake and we measured vestibular evoked potentials (VsEPs) and vestibular ocular reflexes (VORs). We found that Tmc1 and Tmc2 showed dynamic developmental changes, differences in regional expression patterns, and overall expression levels which differed between the utricle and saccule. These underlying changes contributed to unanticipated phenotypic loss of VsEPs and VORs in Tmc1 KO mice. In contrast, Tmc2 KO mice retained VsEPs despite the loss of the calcium buffering protein calretinin, a characteristic biomarker of mature striolar calyx-only afferents. Lastly, we found that neonatal Tmc1 gene replacement therapy is sufficient to restore VsEP in Tmc1 KO mice for up to six months post-injection.
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Affiliation(s)
- Evan M. Ratzan
- Department of Otolaryngology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
| | - John Lee
- Department of Otolaryngology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Margot A. Madison
- Department of Otolaryngology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Hong Zhu
- Department of Otolaryngology - Head and Neck Surgery, University of Mississippi Medical Center, Jackson, MS, United States
| | - Wu Zhou
- Department of Otolaryngology - Head and Neck Surgery, University of Mississippi Medical Center, Jackson, MS, United States
| | - Gwenaëlle S. G. Géléoc
- Department of Otolaryngology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Jeffrey R. Holt
- Department of Otolaryngology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
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2
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Herb M. NADPH Oxidase 3: Beyond the Inner Ear. Antioxidants (Basel) 2024; 13:219. [PMID: 38397817 PMCID: PMC10886416 DOI: 10.3390/antiox13020219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.
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Affiliation(s)
- Marc Herb
- Institute for Medical Microbiology, Immunology and Hygiene, Faculty of Medicine, University Hospital Cologne, University of Cologne, 50935 Cologne, Germany;
- German Centre for Infection Research, Partner Site Bonn-Cologne, 50931 Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
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3
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Lee JH, Park S, Perez-Flores MC, Chen Y, Kang M, Choi J, Levine L, Gratton MA, Zhao J, Notterpek L, Yamoah EN. Demyelination and Na + Channel Redistribution Underlie Auditory and Vestibular Dysfunction in PMP22-Null Mice. eNeuro 2024; 11:ENEURO.0462-23.2023. [PMID: 38378628 PMCID: PMC11059428 DOI: 10.1523/eneuro.0462-23.2023] [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: 11/05/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 02/22/2024] Open
Abstract
Altered expression of peripheral myelin protein 22 (PMP22) results in demyelinating peripheral neuropathy. PMP22 exhibits a highly restricted tissue distribution with marked expression in the myelinating Schwann cells of peripheral nerves. Auditory and vestibular Schwann cells and the afferent neurons also express PMP22, suggesting a unique role in hearing and balancing. Indeed, neuropathic patients diagnosed with PMP22-linked hereditary neuropathies often present with auditory and balance deficits, an understudied clinical complication. To investigate the mechanism by which abnormal expression of PMP22 may cause auditory and vestibular deficits, we studied gene-targeted PMP22-null mice. PMP22-null mice exhibit an unsteady gait, have difficulty maintaining balance, and live for only ∼3-5 weeks relative to unaffected littermates. Histological analysis of the inner ear revealed reduced auditory and vestibular afferent nerve myelination and profound Na+ channel redistribution without PMP22. Yet, Na+ current density was unaltered, in stark contrast to increased K+ current density. Atypical postsynaptic densities and a range of neuronal abnormalities in the organ of Corti were also identified. Analyses of auditory brainstem responses (ABRs) and vestibular sensory-evoked potential (VsEP) revealed that PMP22-null mice had auditory and vestibular hypofunction. These results demonstrate that PMP22 is required for hearing and balance, and the protein is indispensable for the formation and maintenance of myelin in the peripheral arm of the eighth nerve. Our findings indicate that myelin abnormalities and altered signal propagation in the peripheral arm of the auditory nerve are likely causes of auditory deficits in patients with PMP22-linked neuropathies.
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Affiliation(s)
- Jeong Han Lee
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Seojin Park
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
- Prestige BioPharma, Busan 67264, South Korea
| | - Maria C Perez-Flores
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Yingying Chen
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Mincheol Kang
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
- Prestige BioPharma, Busan 67264, South Korea
| | - Jinsil Choi
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Lauren Levine
- Program in Audiology and Communication Sciences, Washington University, St. Louis 63110, Missouri
| | | | - Jie Zhao
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Lucia Notterpek
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Reno 89557, Nevada
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Pastras CJ, Curthoys IS. Vestibular Testing-New Physiological Results for the Optimization of Clinical VEMP Stimuli. Audiol Res 2023; 13:910-928. [PMID: 37987337 PMCID: PMC10660708 DOI: 10.3390/audiolres13060079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/05/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
Both auditory and vestibular primary afferent neurons can be activated by sound and vibration. This review relates the differences between them to the different receptor/synaptic mechanisms of the two systems, as shown by indicators of peripheral function-cochlear and vestibular compound action potentials (cCAPs and vCAPs)-to click stimulation as recorded in animal studies. Sound- and vibration-sensitive type 1 receptors at the striola of the utricular macula are enveloped by the unique calyx afferent ending, which has three modes of synaptic transmission. Glutamate is the transmitter for both cochlear and vestibular primary afferents; however, blocking glutamate transmission has very little effect on vCAPs but greatly reduces cCAPs. We suggest that the ultrafast non-quantal synaptic mechanism called resistive coupling is the cause of the short latency vestibular afferent responses and related results-failure of transmitter blockade, masking, and temporal precision. This "ultrafast" non-quantal transmission is effectively electrical coupling that is dependent on the membrane potentials of the calyx and the type 1 receptor. The major clinical implication is that decreasing stimulus rise time increases vCAP response, corresponding to the increased VEMP response in human subjects. Short rise times are optimal in human clinical VEMP testing, whereas long rise times are mandatory for audiometric threshold testing.
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Affiliation(s)
- Christopher J. Pastras
- Faculty of Science and Engineering, School of Engineering, Macquarie University, Sydney, NSW 2109, Australia;
| | - Ian S. Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
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5
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Fritzsch B, Elliott KL. Fish hearing revealed: Do we understand hearing in critical fishes and marine tetrapods. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:3019-3026. [PMID: 37955566 PMCID: PMC10769566 DOI: 10.1121/10.0022355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 11/14/2023]
Abstract
Hearing evolved in lampreys with a frequency range of 50-200 Hz. This hearing range is comparable to that of elasmobranchs, most non-teleosts, and lungfish. Elasmobranchs most likely use the saccule and the papilla neglecta (PN) for hearing. In non-teleosts and teleosts, lungfish, and certain tetrapods the saccule is the likely sensor for sound reception while the lagena and the PN are important for gravistatic sensing. Coelacanth and most tetrapods have a basilar papilla (BP) for hearing. In coelacanth and tetrapods, the hair cells of the BP are in contact with a basilar and a tectorial membrane. These membranes transmit mechanical vibrations. A cochlear aqueduct (CA) provides a connection between the cerebrospinal fluid that has a sodium rich space in coelacanth and tetrapods while the potassium rich endolymph is known in vertebrates. A unique feature is known in basic sarcopterygians, the intracranial joint, that never developed in actinopterygians and has been lost in lungfish and tetrapods. The BP in coelacanths is thought to generate pressure with the intracranial joint that will be transmitted to the CA. Lungs or a swim bladder are not forming in Chondrichthyes, structures that have a major impact on hearing in teleosts and tetrapods.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology & Department of Otolaryngology, The University of Iowa, Iowa City, Iowa 52242, USA
| | - Karen L Elliott
- Department of Biology & Department of Otolaryngology, The University of Iowa, Iowa City, Iowa 52242, USA
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Pastras CJ, Curthoys IS, Asadnia M, McAlpine D, Rabbitt RD, Brown DJ. Evidence That Ultrafast Nonquantal Transmission Underlies Synchronized Vestibular Action Potential Generation. J Neurosci 2023; 43:7149-7157. [PMID: 37775302 PMCID: PMC10601366 DOI: 10.1523/jneurosci.1417-23.2023] [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: 07/27/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 10/01/2023] Open
Abstract
Amniotes evolved a unique postsynaptic terminal in the inner ear vestibular organs called the calyx that receives both quantal and nonquantal (NQ) synaptic inputs from Type I sensory hair cells. The nonquantal synaptic current includes an ultrafast component that has been hypothesized to underlie the exceptionally high synchronization index (vector strength) of vestibular afferent neurons in response to sound and vibration. Here, we present three lines of evidence supporting the hypothesis that nonquantal transmission is responsible for synchronized vestibular action potentials of short latency in the guinea pig utricle of either sex. First, synchronized vestibular nerve responses are unchanged after administration of the AMPA receptor antagonist CNQX, while auditory nerve responses are completely abolished. Second, stimulus evoked vestibular nerve compound action potentials (vCAP) are shown to occur without measurable synaptic delay and three times shorter than the latency of auditory nerve compound action potentials (cCAP), relative to the generation of extracellular receptor potentials. Third, paired-pulse stimuli designed to deplete the readily releasable pool (RRP) of synaptic vesicles in hair cells reveal forward masking in guinea pig auditory cCAPs, but a complete lack of forward masking in vestibular vCAPs. Results support the conclusion that the fast component of nonquantal transmission at calyceal synapses is indefatigable and responsible for ultrafast responses of vestibular organs evoked by transient stimuli.SIGNIFICANCE STATEMENT The mammalian vestibular system drives some of the fastest reflex pathways in the nervous system, ensuring stable gaze and postural control for locomotion on land. To achieve this, terrestrial amniotes evolved a large, unique calyx afferent terminal which completely envelopes one or more presynaptic vestibular hair cells, which transmits mechanosensory signals mediated by quantal and nonquantal (NQ) synaptic transmission. We present several lines of evidence in the guinea pig which reveals the most sensitive vestibular afferents are remarkably fast, much faster than their auditory nerve counterparts. Here, we present neurophysiological and pharmacological evidence that demonstrates this vestibular speed advantage arises from ultrafast NQ electrical synaptic transmission from Type I hair cells to their calyx partners.
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Affiliation(s)
- Christopher J Pastras
- Faculty of Science and Engineering, School of Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Ian S Curthoys
- School of Psychology, Vestibular Research Laboratory, The University of Sydney, Sydney, New South Wales 2050, Australia
- Department of Linguistics, The Australian Hearing Hub, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Mohsen Asadnia
- Faculty of Science and Engineering, School of Engineering, Macquarie University, Sydney, New South Wales 2109, Australia
| | - David McAlpine
- Department of Linguistics, The Australian Hearing Hub, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Richard D Rabbitt
- Departments of Biomedical Engineering, Otolaryngology, and Neuroscience Program, University of Utah, Salt Lake City, Utah 84112
| | - Daniel J Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Western Australia 6102, Australia
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Sinha AK, Lee C, Holt JC. Elucidating the role of muscarinic acetylcholine receptor (mAChR) signaling in efferent mediated responses of vestibular afferents in mammals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.31.549902. [PMID: 37577578 PMCID: PMC10418111 DOI: 10.1101/2023.07.31.549902] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The peripheral vestibular system detects head position and movement through activation of vestibular hair cells (HCs) in vestibular end organs. HCs transmit this information to the CNS by way of primary vestibular afferent neurons. The CNS, in turn, modulates HCs and afferents via the efferent vestibular system (EVS) through activation of cholinergic signaling mechanisms. In mice, we previously demonstrated that activation of muscarinic acetylcholine receptors (mAChRs), during EVS stimulation, gives rise to a slow excitation that takes seconds to peak and tens of seconds to decay back to baseline. This slow excitation is mimicked by muscarine and ablated by the non-selective mAChR blockers scopolamine, atropine, and glycopyrrolate. While five distinct mAChRs (M1-M5) exist, the subtype(s) driving EVS-mediated slow excitation remain unidentified and details on how these mAChRs alter vestibular function is not well understood. The objective of this study is to characterize which mAChR subtypes drive the EVS-mediated slow excitation, and how their activation impacts vestibular physiology and behavior. In C57Bl/6J mice, M3mAChR antagonists were more potent at blocking slow excitation than M1mAChR antagonists, while M2/M4 blockers were ineffective. While unchanged in M2/M4mAChR double KO mice, EVS-mediated slow excitation in M3 mAChR-KO animals were reduced or absent in irregular afferents but appeared unchanged in regular afferents. In agreement, vestibular sensory-evoked potentials (VsEP), known to be predominantly generated from irregular afferents, were significantly less enhanced by mAChR activation in M3mAChR-KO mice compared to controls. Finally, M3mAChR-KO mice display distinct behavioral phenotypes in open field activity, and thermal profiles, and balance beam and forced swim test. M3mAChRs mediate efferent-mediated slow excitation in irregular afferents, while M1mAChRs may drive the same process in regular afferents.
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Vartanian V, Krey JF, Chatterjee P, Curtis A, Six M, Rice SPM, Jones SM, Sampath H, Allen CN, Ryals RC, Lloyd RS, Barr‐Gillespie PG. Spontaneous allelic variant in deafness-blindness gene Ush1g resulting in an expanded phenotype. GENES, BRAIN, AND BEHAVIOR 2023; 22:e12849. [PMID: 37328946 PMCID: PMC10393423 DOI: 10.1111/gbb.12849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/05/2023] [Accepted: 05/07/2023] [Indexed: 06/18/2023]
Abstract
Relationships between novel phenotypic behaviors and specific genetic alterations are often discovered using target-specific, directed mutagenesis or phenotypic selection following chemical mutagenesis. An alternative approach is to exploit deficiencies in DNA repair pathways that maintain genetic integrity in response to spontaneously induced damage. Mice deficient in the DNA glycosylase NEIL1 show elevated spontaneous mutations, which arise from translesion DNA synthesis past oxidatively induced base damage. Several litters of Neil1 knockout mice included animals that were distinguished by their backwards-walking behavior in open-field environments, while maintaining frantic forward movements in their home cage environment. Other phenotypic manifestations included swim test failures, head tilting and circling. Mapping of the mutation that conferred these behaviors showed the introduction of a stop codon at amino acid 4 of the Ush1g gene. Ush1gbw/bw null mice displayed auditory and vestibular defects that are commonly seen with mutations affecting inner-ear hair-cell function, including a complete lack of auditory brainstem responses and vestibular-evoked potentials. As in other Usher syndrome type I mutant mouse lines, hair cell phenotypes included disorganized and split hair bundles, as well as altered distribution of proteins for stereocilia that localize to the tips of row 1 or row 2. Disruption to the bundle and kinocilium displacement suggested that USH1G is essential for forming the hair cell's kinocilial links. Consistent with other Usher type 1 models, Ush1gbw/bw mice had no substantial retinal degeneration compared with Ush1gbw /+ controls. In contrast to previously described Ush1g alleles, this new allele provides the first knockout model for this gene.
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Affiliation(s)
- Vladimir Vartanian
- Oregon Institute of Occupational Health SciencesOregon Health & Science UniversityPortlandOregonUSA
| | - Jocelyn F. Krey
- Oregon Hearing Research Center and Vollum InstituteOregon Health & Science UniversityPortlandOregonUSA
| | - Paroma Chatterjee
- Oregon Hearing Research Center and Vollum InstituteOregon Health & Science UniversityPortlandOregonUSA
| | - Allison Curtis
- Department of Ophthalmology, Casey Eye InstituteOregon Health & Science UniversityPortlandOregonUSA
| | - Makayla Six
- Department of Ophthalmology, Casey Eye InstituteOregon Health & Science UniversityPortlandOregonUSA
| | - Sean P. M. Rice
- Oregon Institute of Occupational Health Sciences and School of Public HealthOregon Health & Science University‐Portland State UniversityPortlandOregonUSA
| | - Sherri M. Jones
- Department of Special Education and Communication DisordersUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| | - Harini Sampath
- Department of Nutritional Sciences and New Jersey Institute for Food, Nutrition, and HealthRutgers UniversityNew BrunswickNew JerseyUSA
| | - Charles N. Allen
- Oregon Institute of Occupational Health Sciences and Department of Behavioral NeuroscienceOregon Health & Science UniversityPortlandOregonUSA
| | - Renee C. Ryals
- Department of Ophthalmology, Casey Eye InstituteOregon Health & Science UniversityPortlandOregonUSA
| | - R. Stephen Lloyd
- Oregon Institute of Occupational Health SciencesOregon Health & Science UniversityPortlandOregonUSA
- Department of Molecular and Medical GeneticsOregon Health & Science UniversityPortlandOregonUSA
| | - Peter G. Barr‐Gillespie
- Oregon Hearing Research Center and Vollum InstituteOregon Health & Science UniversityPortlandOregonUSA
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Pastras CJ, Curthoys IS, Rabbitt RD, Brown DJ. Using macular velocity measurements to relate parameters of bone conduction to vestibular compound action potential responses. Sci Rep 2023; 13:10204. [PMID: 37353559 PMCID: PMC10290084 DOI: 10.1038/s41598-023-37102-3] [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: 11/29/2022] [Accepted: 06/15/2023] [Indexed: 06/25/2023] Open
Abstract
To examine mechanisms responsible for vestibular afferent sensitivity to transient bone conducted vibration, we performed simultaneous measurements of stimulus-evoked vestibular compound action potentials (vCAPs), utricular macula velocity, and vestibular microphonics (VMs) in anaesthetized guinea pigs. Results provide new insights into the kinematic variables of transient motion responsible for triggering mammalian vCAPs, revealing synchronized vestibular afferent responses are not universally sensitive to linear jerk as previously thought. For short duration stimuli (< 1 ms), the vCAP increases magnitude in close proportion to macular velocity and temporal bone (linear) acceleration, rather than other kinematic elements. For longer duration stimuli, the vCAP magnitude switches from temporal bone acceleration sensitive to linear jerk sensitive while maintaining macular velocity sensitivity. Frequency tuning curves evoked by tone-burst stimuli show vCAPs increase in proportion to onset macular velocity, while VMs increase in proportion to macular displacement across the entire frequency bandwidth tested between 0.1 and 2 kHz. The subset of vestibular afferent neurons responsible for synchronized firing and vCAPs have been shown previously to make calyceal synaptic contacts with type I hair cells in the striolar region of the epithelium and have irregularly spaced inter-spike intervals at rest. Present results provide new insight into mechanical and neural mechanisms underlying synchronized action potentials in these sensitive afferents, with clinical relevance for understanding the activation and tuning of neurons responsible for driving rapid compensatory reflex responses.
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Affiliation(s)
- Christopher J Pastras
- Faculty of Science and Engineering, School of Engineering, Macquarie University, Sydney, NSW, 2109, Australia.
- School of Medical Sciences, The University of Sydney, Sydney, NSW, 2050, Australia.
| | - Ian S Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW, 2050, Australia
| | - Richard D Rabbitt
- Departments of Biomedical Engineering, Otolaryngology and Neuroscience Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Daniel J Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, WA, 6102, Australia
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10
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Pastras CJ, Gholami N, Jennings S, Zhu H, Zhou W, Brown DJ, Curthoys IS, Rabbitt RD. A mathematical model for mechanical activation and compound action potential generation by the utricle in response to sound and vibration. Front Neurol 2023; 14:1109506. [PMID: 37051057 PMCID: PMC10083375 DOI: 10.3389/fneur.2023.1109506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 03/01/2023] [Indexed: 03/28/2023] Open
Abstract
IntroductionCalyx bearing vestibular afferent neurons innervating type I hair cells in the striolar region of the utricle are exquisitely sensitive to auditory-frequency air conducted sound (ACS) and bone conducted vibration (BCV). Here, we present experimental data and a mathematical model of utricular mechanics and vestibular compound action potential generation (vCAP) in response to clinically relevant levels of ACS and BCV. Vibration of the otoconial layer relative to the sensory epithelium was simulated using a Newtonian two-degree-of-freedom spring-mass-damper system, action potential timing was simulated using an empirical model, and vCAPs were simulated by convolving responses of the population of sensitive neurons with an empirical extracellular voltage kernel. The model was validated by comparison to macular vibration and vCAPs recorded in the guinea pig, in vivo.ResultsTransient stimuli evoked short-latency vCAPs that scaled in magnitude and timing with hair bundle mechanical shear rate for both ACS and BCV. For pulse BCV stimuli with durations <0.8 ms, the vCAP magnitude increased in proportion to temporal bone acceleration, but for pulse durations >0.9 ms the magnitude increased in proportion to temporal bone jerk. Once validated using ACS and BCV data, the model was applied to predict blast-induced hair bundle shear, with results predicting acute mechanical damage to bundles immediately upon exposure.DiscussionResults demonstrate the switch from linear acceleration to linear jerk as the adequate stimulus arises entirely from mechanical factors controlling the dynamics of sensory hair bundle deflection. The model describes the switch in terms of the mechanical natural frequencies of vibration, which vary between species based on morphology and mechanical factors.
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Affiliation(s)
- Christopher J. Pastras
- Faculty of Science and Engineering, School of Engineering, Macquarie University, Sydney, NSW, Australia
| | - Nastaran Gholami
- Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Skyler Jennings
- Communication Sciences and Neuroscience Program, University of Utah, Salt Lake City, UT, United States
| | - Hong Zhu
- University of Mississippi Medical Center, Jackson, MS, United States
| | - Wu Zhou
- University of Mississippi Medical Center, Jackson, MS, United States
| | - Daniel J. Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, WA, Australia
| | - Ian S. Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Richard D. Rabbitt
- Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
- Otolaryngology and Neuroscience Program, University of Utah, Salt Lake City, UT, United States
- *Correspondence: Richard D. Rabbitt,
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11
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Ji YR, Tona Y, Wafa T, Christman ME, Tourney ED, Jiang T, Ohta S, Cheng H, Fitzgerald T, Fritzsch B, Jones SM, Cullen KE, Wu DK. Function of bidirectional sensitivity in the otolith organs established by transcription factor Emx2. Nat Commun 2022; 13:6330. [PMID: 36280667 PMCID: PMC9592604 DOI: 10.1038/s41467-022-33819-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 10/04/2022] [Indexed: 12/25/2022] Open
Abstract
Otolith organs of the inner ear are innervated by two parallel afferent projections to the brainstem and cerebellum. These innervations were proposed to segregate across the line of polarity reversal (LPR) within each otolith organ, which divides the organ into two regions of hair cells (HC) with opposite stereociliary orientation. The relationship and functional significance of these anatomical features are not known. Here, we show regional expression of Emx2 in otolith organs, which establishes LPR, mediates the neuronal segregation across LPR and constitutes the bidirectional sensitivity function. Conditional knockout (cKO) of Emx2 in HCs lacks LPR. Tmie cKO, in which mechanotransduction was abolished selectively in HCs within the Emx2 expression domain also lacks bidirectional sensitivity. Analyses of both mutants indicate that LPR is specifically required for mice to swim comfortably and to traverse a balance beam efficiently, but LPR is not required for mice to stay on a rotating rod.
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Affiliation(s)
- Young Rae Ji
- Section on Sensory Cell Regeneration and Development, Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
- Sensory & Motor Systems Research Group, Korea Brain Research Institute (KBRI), 61 Cheomdan-ro, Dong-gu, Daegu, 41062, Republic of Korea
| | - Yosuke Tona
- Section on Sensory Cell Regeneration and Development, Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
- Otolaryngology/Head and Neck Surgery, Kyoto University Hospital, 54 Shogoin-kawahara-cho, Sakyo-ku, Kyoto City, Kyoto, 606-8507, Japan
| | - Talah Wafa
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Matthew E Christman
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Edward D Tourney
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Tao Jiang
- Section on Sensory Cell Regeneration and Development, Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Sho Ohta
- Section on Sensory Cell Regeneration and Development, Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Hui Cheng
- Bioinformatics and Biostatistics Collaboration Core, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Tracy Fitzgerald
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Bernd Fritzsch
- Department of Biology & Department of Otolaryngology, University of Iowa, Iowa City, IA, 52242, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, 301 Barkley Memorial Center, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Kathleen E Cullen
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Doris K Wu
- Section on Sensory Cell Regeneration and Development, Laboratory of Molecular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA.
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12
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Effects of pyrroloquinoline quinone on noise-induced and age-related hearing loss in mice. Sci Rep 2022; 12:15911. [PMID: 36151123 PMCID: PMC9508078 DOI: 10.1038/s41598-022-19842-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/05/2022] [Indexed: 11/10/2022] Open
Abstract
We investigated whether the oxidoreductase cofactor pyrroloquinoline quinone (PQQ) prevents noise-induced and age-related hearing loss (NIHL and ARHL) in mice. To assess NIHL, 8 week-old mice with and without PQQ administration were exposed to noise for 4 h. PQQ was orally administered for one week before and after noise exposure and subcutaneously once before noise exposure. For ARHL evaluation, mice were given drinking water with or without PQQ starting at 2 months of age. In the NIHL model, PQQ-treated mice had auditory brainstem response (ABR) thresholds of significantly reduced elevation at 8 kHz, a significantly increased number of hair cells at the basal turn, and significantly better maintained synapses beneath the inner hair cells compared to controls. In the ARHL model, PQQ significantly attenuated the age-related increase in ABR thresholds at 8 and 32 kHz at 10 months of age compared to controls. In addition, the hair cells, spiral ganglion cells, ribbon synapses, stria vascularis and nerve fibers were all significantly better maintained in PQQ-treated animals compared to controls at 10 months of age. These physiological and histological results demonstrate that PQQ protects the auditory system from NIHL and ARHL in mice.
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13
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Kim GS, Wang T, Sayyid ZN, Fuhriman J, Jones SM, Cheng AG. Repair of surviving hair cells in the damaged mouse utricle. Proc Natl Acad Sci U S A 2022; 119:e2116973119. [PMID: 35380897 PMCID: PMC9169652 DOI: 10.1073/pnas.2116973119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/21/2022] [Indexed: 11/18/2022] Open
Abstract
Sensory hair cells (HCs) in the utricle are mechanoreceptors required to detect linear acceleration. After damage, the mammalian utricle partially restores the HC population and organ function, although regenerated HCs are primarily type II and immature. Whether native, surviving HCs can repair and contribute to this recovery is unclear. Here, we generated the Pou4f3DTR/+; Atoh1CreERTM/+; Rosa26RtdTomato/+ mouse to fate map HCs prior to ablation. After HC ablation, vestibular evoked potentials were abolished in all animals, with ∼57% later recovering responses. Relative to nonrecovery mice, recovery animals harbored more Atoh1-tdTomato+ surviving HCs. In both groups, surviving HCs displayed markers of both type I and type II subtypes and afferent synapses, despite distorted lamination and morphology. Surviving type II HCs remained innervated in both groups, whereas surviving type I HCs first lacked and later regained calyces in the recovery, but not the nonrecovery, group. Finally, surviving HCs initially displayed immature and subsequently mature-appearing bundles in the recovery group. These results demonstrate that surviving HCs are capable of self-repair and may contribute to the recovery of vestibular function.
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Affiliation(s)
- Grace S. Kim
- Department of Otolaryngology–Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305
| | - Tian Wang
- Department of Otolaryngology–Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305
| | - Zahra N. Sayyid
- Department of Otolaryngology–Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305
| | - Jessica Fuhriman
- Department of Otolaryngology–Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305
| | - Sherri M. Jones
- Department of Special Education and Communication Disorders, College of Education and Human Sciences, University of Nebraska, Lincoln, NE 68583
| | - Alan G. Cheng
- Department of Otolaryngology–Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305
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14
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Krey JF, Liu C, Belyantseva IA, Bateschell M, Dumont RA, Goldsmith J, Chatterjee P, Morrill RS, Fedorov LM, Foster S, Kim J, Nuttall AL, Jones SM, Choi D, Friedman TB, Ricci AJ, Zhao B, Barr-Gillespie PG. ANKRD24 organizes TRIOBP to reinforce stereocilia insertion points. J Cell Biol 2022; 221:e202109134. [PMID: 35175278 PMCID: PMC8859912 DOI: 10.1083/jcb.202109134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/07/2022] [Accepted: 01/21/2022] [Indexed: 01/04/2023] Open
Abstract
The stereocilia rootlet is a key structure in vertebrate hair cells, anchoring stereocilia firmly into the cell's cuticular plate and protecting them from overstimulation. Using superresolution microscopy, we show that the ankyrin-repeat protein ANKRD24 concentrates at the stereocilia insertion point, forming a ring at the junction between the lower and upper rootlets. Annular ANKRD24 continues into the lower rootlet, where it surrounds and binds TRIOBP-5, which itself bundles rootlet F-actin. TRIOBP-5 is mislocalized in Ankrd24KO/KO hair cells, and ANKRD24 no longer localizes with rootlets in mice lacking TRIOBP-5; exogenous DsRed-TRIOBP-5 restores endogenous ANKRD24 to rootlets in these mice. Ankrd24KO/KO mice show progressive hearing loss and diminished recovery of auditory function after noise damage, as well as increased susceptibility to overstimulation of the hair bundle. We propose that ANKRD24 bridges the apical plasma membrane with the lower rootlet, maintaining a normal distribution of TRIOBP-5. Together with TRIOBP-5, ANKRD24 organizes rootlets to enable hearing with long-term resilience.
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Affiliation(s)
- Jocelyn F. Krey
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Chang Liu
- Department of Otolaryngology—Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Inna A. Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD
| | - Michael Bateschell
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Rachel A. Dumont
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Jennifer Goldsmith
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Paroma Chatterjee
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Rachel S. Morrill
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Lev M. Fedorov
- Transgenic Mouse Models, University Shared Resources Program, Oregon Health & Science University, Portland, OR
| | - Sarah Foster
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
| | - Jinkyung Kim
- Department of Otolaryngology—Head & Neck Surgery, Stanford University, Stanford, CA
| | - Alfred L. Nuttall
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
| | - Sherri M. Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE
| | - Dongseok Choi
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR
| | - Thomas B. Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD
| | - Anthony J. Ricci
- Department of Otolaryngology—Head & Neck Surgery, Stanford University, Stanford, CA
| | - Bo Zhao
- Department of Otolaryngology—Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Peter G. Barr-Gillespie
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
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15
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Gao Y, Kamogashira T, Fujimoto C, Iwasaki S, Yamasoba T. Beneficial effects of time‐restricted feeding on gentamicin cytotoxicity in mouse cochlea and vestibular organs. Laryngoscope Investig Otolaryngol 2022; 7:530-539. [PMID: 35434314 PMCID: PMC9008174 DOI: 10.1002/lio2.748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/07/2022] [Accepted: 01/17/2022] [Indexed: 12/28/2022] Open
Affiliation(s)
- Ying Gao
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine University of Tokyo Tokyo Japan
- Department of Otolaryngology and Head and Neck Surgery The Second Affiliated Hospital of Xi'an Jiaotong University Xi'an China
| | - Teru Kamogashira
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine University of Tokyo Tokyo Japan
| | - Chisato Fujimoto
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine University of Tokyo Tokyo Japan
| | - Shinichi Iwasaki
- Department of Otolaryngology & Head and Neck Surgery Nagoya City University Graduate School of Medicine Nagoya Japan
| | - Tatsuya Yamasoba
- Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine University of Tokyo Tokyo Japan
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16
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Jiang W, Wang Z, Xiao S, Zeng D, Wu Z, Peng C, Chen F. Pulsed infrared stimulation evoked electrical potential in mouse vestibular system. Neurosci Lett 2022; 775:136510. [DOI: 10.1016/j.neulet.2022.136510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 01/17/2022] [Accepted: 02/01/2022] [Indexed: 10/19/2022]
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17
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An unbiased algorithm for objective separation of Alzheimer's, Alzheimer's mixed with cerebrovascular symptomology, and healthy controls from one another using electrovestibulography (EVestG). Med Biol Eng Comput 2022; 60:797-810. [PMID: 35102489 DOI: 10.1007/s11517-022-02507-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 01/18/2022] [Indexed: 10/19/2022]
Abstract
Diagnosis of Alzheimer's disease (AD) from AD with cerebrovascular disease pathology (AD-CVD) is a rising challenge. Using electrovestibulography (EVestG) measured signals, we develop an automated feature extraction and selection algorithm for an unbiased identification of AD and AD-CVD from healthy controls as well as their separation from each other. EVestG signals of 24 healthy controls, 16 individuals with AD, and 13 with AD-CVD were analyzed within two separate groupings: One-versus-One and One-versus-All. A multistage feature selection process was conducted over the training dataset using linear support vector machine (SVM) classification with 10-fold cross-validation, k nearest neighbors/averaging imputation, and exhaustive search. The most frequently selected features that achieved highest classification performance were selected. 10-fold cross-validation was applied via a linear SVM classification on the entire dataset. Multivariate analysis was run to test the between population differences while controlling for the covariates. Classification accuracies of ≥ 80% and 78% were achieved for the One-versus-All classification approach and AD versus AD-CVD separation, respectively. The results also held true after controlling for the effect of covariates. AD/AD-CVD participants showed smaller/larger EVestG averaged field potential signals compared to healthy controls and AD-CVD/AD participants. These characteristics are in line with our previous study results.
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18
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Stewart CE, Bauer DS, Altschuler RA, King WM. Transient peripheral vestibular hypofunction measured with vestibular short-latency evoked potentials following noise exposure in rats. J Neurophysiol 2021; 126:1547-1554. [PMID: 34550030 PMCID: PMC8782663 DOI: 10.1152/jn.00131.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Exposure to 120 dB sound pressure level (SPL) band-limited noise results in delayed onset latency and reduced vestibular short-latency evoked potential (VsEP) responses. These changes are still present 4 wk after noise overstimulation. Noise-induced hearing loss (NIHL) has been shown to vary in extent and duration based on the noise intensity. This study investigated whether noise-induced peripheral vestibular hypofunction (NPVH) would also decrease in extent and/or duration with less intense noise exposure. In the present study, rats were exposed to a less intense noise (110 dB SPL) but for the same duration (6 h) and frequency range (500–4,000 Hz) as used in previous studies. The VsEP was assessed 1, 3, 7, 14, 21, and 28 days after noise exposure. In contrast to 120 dB SPL noise exposure, the 110 dB SPL noise exposures produced smaller deficits in VsEP responses that fully recovered in 62% (13/21) of animals within 1 wk. These findings suggest that NPVH, a loss or attenuation of VsEP responses with a requirement for elevated stimulus intensity to elicit measurable responses, is similar to NIHL, that is, lower sound levels produce a smaller or transient deficit. These results show that it will be important to determine the extent and duration of vestibular hypofunction for different noise exposure conditions and their impact on balance. NEW & NOTEWORTHY This is the first study to show a temporary noise-induced peripheral vestibular hypofunction that recovers following exposure to continuous noise.
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Affiliation(s)
- Courtney E Stewart
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan.,Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
| | - David S Bauer
- Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
| | - Richard A Altschuler
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan.,Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
| | - William Michael King
- Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
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19
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Curthoys IS, Grant JW, Pastras CJ, Fröhlich L, Brown DJ. Similarities and Differences Between Vestibular and Cochlear Systems - A Review of Clinical and Physiological Evidence. Front Neurosci 2021; 15:695179. [PMID: 34456671 PMCID: PMC8397526 DOI: 10.3389/fnins.2021.695179] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/12/2021] [Indexed: 12/04/2022] Open
Abstract
The evoked response to repeated brief stimuli, such as clicks or short tone bursts, is used for clinical evaluation of the function of both the auditory and vestibular systems. One auditory response is a neural potential - the Auditory Brainstem Response (ABR) - recorded by surface electrodes on the head. The clinical analogue for testing the otolithic response to abrupt sounds and vibration is the myogenic potential recorded from tensed muscles - the vestibular evoked myogenic potential (VEMP). VEMPs have provided clinicians with a long sought-after tool - a simple, clinically realistic indicator of the function of each of the 4 otolithic sensory regions. We review the basic neural evidence for VEMPs and discuss the similarities and differences between otolithic and cochlear receptors and afferents. VEMPs are probably initiated by sound or vibration selectively activating afferent neurons with irregular resting discharge originating from the unique type I receptors at a specialized region of the otolithic maculae (the striola). We review how changes in VEMP responses indicate the functional state of peripheral vestibular function and the likely transduction mechanisms allowing otolithic receptors and afferents to trigger such very short latency responses. In section "ELECTROPHYSIOLOGY" we show how cochlear and vestibular receptors and afferents have many similar electrophysiological characteristics [e.g., both generate microphonics, summating potentials, and compound action potentials (the vestibular evoked potential, VsEP)]. Recent electrophysiological evidence shows that the hydrodynamic changes in the labyrinth caused by increased fluid volume (endolymphatic hydrops), change the responses of utricular receptors and afferents in a way which mimics the changes in vestibular function attributed to endolymphatic hydrops in human patients. In section "MECHANICS OF OTOLITHS IN VEMPS TESTING" we show how the major VEMP results (latency and frequency response) follow from modeling the physical characteristics of the macula (dimensions, stiffness etc.). In particular, the structure and mechanical operation of the utricular macula explains the very fast response of the type I receptors and irregular afferents which is the very basis of VEMPs and these structural changes of the macula in Menière's Disease (MD) predict the upward shift of VEMP tuning in these patients.
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Affiliation(s)
- Ian S. Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - John Wally Grant
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States
| | - Christopher J. Pastras
- The Menière’s Research Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Laura Fröhlich
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Daniel J. Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, WA, Australia
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20
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Stimulus duration and vestibular sensory evoked potentials (VsEPs). Hear Res 2021; 408:108293. [PMID: 34175587 DOI: 10.1016/j.heares.2021.108293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/10/2021] [Accepted: 06/07/2021] [Indexed: 11/20/2022]
Abstract
Recording the linear vestibular sensory evoked potential (VsEP) relies on moving the head in a prescribed manner to synchronously activate neurons of the gravity receptor organs. One problematic issue in accomplishing this is the potential coactivation of cochlear neurons. Although the major stimulus parameters required to elicit the vestibular response have been characterized, some of the determinants of auditory coactivation have not been clearly addressed. In the present study, we show that the duration of the linear cranial jerk stimulus plays a critical role in avoiding coactivation of auditory responses during VsEP recordings. Acoustic masking procedures are essential when recording the VsEP, particularly when using stimulus durations of less than 1 ms.
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21
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Effects of Several Therapeutic Agents on Mammalian Vestibular Function: Meclizine, Diazepam, and JNJ7777120. J Assoc Res Otolaryngol 2021; 22:527-549. [PMID: 34009490 DOI: 10.1007/s10162-021-00803-5] [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: 10/10/2020] [Accepted: 04/27/2021] [Indexed: 10/21/2022] Open
Abstract
Management of vestibular dysfunction may include treatment with medications that are thought to act to suppress vestibular function and reduce or eliminate abnormal sensitivity to head motions. The extent to which vestibular medications act centrally or peripherally is still debated. In this study, two commonly prescribed medications, meclizine and diazepam, and a candidate for future clinical use, JNJ7777120, were evaluated for their effects on short latency compound action potentials generated by the peripheral vestibular system and corresponding central neural relays (i.e., vestibular sensory-evoked potentials, VsEPs). The effects of the selected drugs developed slowly over the course of two hours in the mouse. Findings indicate that meclizine (600 mg/kg) and diazepam (> 60 mg/kg) can act on peripheral elements of the vestibular maculae whereas diazepam also acts most effectively on central gravity receptor circuits to exert its suppressive effects. The novel pharmacological agent JNJ7777120 (160 mg/kg) acts in the vestibular periphery to enhance macular responses to transient stimuli (VsEPs) while, hypothetically, suppressing macular responses to sustained or slowly changing stimuli.
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22
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Xu Y, Yang L, Zhao X, Zhang Y, Jones TA, Jones SM, Lundberg YW. Functional cooperation between two otoconial proteins Oc90 and Nox3. J Vestib Res 2021; 31:441-449. [PMID: 33554930 DOI: 10.3233/ves-201591] [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] [Indexed: 11/15/2022]
Abstract
BACKGROUND Otoconia-related vertigo and balance deficits are common in humans, but the molecular etiology is unknown at present. OBJECTIVE In order to study mechanisms of otoconia formation and maintenance, we have investigated whether otoconin-90 (Oc90), the predominant otoconial constituent protein, and the NADPH oxidase Nox3, an essential regulatory protein for otoconia formation, are functionally interlinked. METHODS We performed balance behavioral, electrophysiological, morphological and molecular cellular analyses. RESULTS Double heterozygous mutant mice for Oc90 and Nox3 show severe imbalance, albeit less profound than double null mutants. In contrast, single heterozygous mutant mice have normal balance. Double heterozygous mice have otoconia defects and double null mice have no otoconia. In addition, some hair bundles in the latter mice go through accelerated degeneration. In vitro calcification analysis in cells stably expressing these proteins singly and doubly shows much more intense calcification in the double transfectants. CONCLUSIONS Oc90 and Nox3 augment each other's function, which is not only critical for otoconia formation but also for hair bundle maintenance.
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Affiliation(s)
- Yinfang Xu
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, Omaha, NE, USA
| | - Liping Yang
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, Omaha, NE, USA.,Current address: Changsha Environmental Protection College, 10 Jinggui Rd, Yuhua Qu, Changsha, Hunan, China
| | - Xing Zhao
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, Omaha, NE, USA
| | - Yan Zhang
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, Omaha, NE, USA
| | - Timothy A Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Yunxia Wang Lundberg
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, Omaha, NE, USA
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23
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Qian ZJ, Ricci AJ. Effects of cochlear hair cell ablation on spatial learning/memory. Sci Rep 2020; 10:20687. [PMID: 33244175 PMCID: PMC7692547 DOI: 10.1038/s41598-020-77803-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 11/12/2020] [Indexed: 12/12/2022] Open
Abstract
Current clinical interest lies in the relationship between hearing loss and cognitive impairment. Previous work demonstrated that noise exposure, a common cause of sensorineural hearing loss (SNHL), leads to cognitive impairments in mice. However, in noise-induced models, it is difficult to distinguish the effects of noise trauma from subsequent SNHL on central processes. Here, we use cochlear hair cell ablation to isolate the effects of SNHL. Cochlear hair cells were conditionally and selectively ablated in mature, transgenic mice where the human diphtheria toxin (DT) receptor was expressed behind the hair-cell specific Pou4f3 promoter. Due to higher Pou4f3 expression in cochlear hair cells than vestibular hair cells, administration of a low dose of DT caused profound SNHL without vestibular dysfunction and had no effect on wild-type (WT) littermates. Spatial learning/memory was assayed using an automated radial 8-arm maze (RAM), where mice were trained to find food rewards over a 14-day period. The number of working memory errors (WME) and reference memory errors (RME) per training day were recorded. All animals were injected with DT during P30-60 and underwent the RAM assay during P90-120. SNHL animals committed more WME and RME than WT animals, demonstrating that isolated SNHL affected cognitive function. Duration of SNHL (60 versus 90 days post DT injection) had no effect on RAM performance. However, younger age of acquired SNHL (DT on P30 versus P60) was associated with fewer WME. This describes the previously undocumented effect of isolated SNHL on cognitive processes that do not directly rely on auditory sensory input.
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MESH Headings
- Animals
- Cognition/physiology
- Deafness/metabolism
- Deafness/physiopathology
- Evoked Potentials, Auditory, Brain Stem/physiology
- Hair Cells, Auditory/metabolism
- Hair Cells, Auditory/physiology
- Hair Cells, Vestibular/metabolism
- Hair Cells, Vestibular/physiology
- Hearing/physiology
- Hearing Loss, Sensorineural/metabolism
- Hearing Loss, Sensorineural/physiopathology
- Heparin-binding EGF-like Growth Factor/metabolism
- Memory/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Noise
- Spatial Learning/physiology
- Transcription Factor Brn-3C/metabolism
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Affiliation(s)
- Z Jason Qian
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, 240 Pasteur Drive, Biomedical Innovations Building, R0551, Palo Alto, CA, 94304, USA
| | - Anthony J Ricci
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, 240 Pasteur Drive, Biomedical Innovations Building, R0551, Palo Alto, CA, 94304, USA.
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24
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Stewart CE, Holt AG, Altschuler RA, Cacace AT, Hall CD, Murnane OD, King WM, Akin FW. Effects of Noise Exposure on the Vestibular System: A Systematic Review. Front Neurol 2020; 11:593919. [PMID: 33324332 PMCID: PMC7723874 DOI: 10.3389/fneur.2020.593919] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/28/2020] [Indexed: 11/13/2022] Open
Abstract
Despite our understanding of the impact of noise-induced damage to the auditory system, much less is known about the impact of noise exposure on the vestibular system. In this article, we review the anatomical, physiological, and functional evidence for noise-induced damage to peripheral and central vestibular structures. Morphological studies in several animal models have demonstrated cellular damage throughout the peripheral vestibular system and particularly in the otolith organs; however, there is a paucity of data on the effect of noise exposure on human vestibular end organs. Physiological studies have corroborated morphological studies by demonstrating disruption across vestibular pathways with otolith-mediated pathways impacted more than semicircular canal-mediated pathways. Similar to the temporary threshold shifts observed in the auditory system, physiological studies in animals have suggested a capacity for recovery following noise-induced vestibular damage. Human studies have demonstrated that diminished sacculo-collic responses are related to the severity of noise-induced hearing loss, and dose-dependent vestibular deficits following noise exposure have been corroborated in animal models. Further work is needed to better understand the physiological and functional consequences of noise-induced vestibular impairment in animals and humans.
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Affiliation(s)
- Courtney Elaine Stewart
- University of Michigan Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, Ann Arbor, MI, United States.,VA Ann Arbor Healthcare System, Research Service, Ann Arbor, MI, United States
| | - Avril Genene Holt
- Department of Ophthalmology Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States.,John D. Dingell VA Medical Center, Molecular Anatomy of Central Sensory Systems Laboratory, Research Service, Detroit, MI, United States
| | - Richard A Altschuler
- University of Michigan Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, Ann Arbor, MI, United States.,VA Ann Arbor Healthcare System, Research Service, Ann Arbor, MI, United States
| | - Anthony Thomas Cacace
- Department of Communication Sciences and Disorders, Wayne State University, Detroit, MI, United States
| | - Courtney D Hall
- Department of Rehabilitative Sciences, Doctor of Physical Therapy Program, East Tennessee State University, Johnson City, TN, United States.,Gait and Balance Research Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN, United States
| | - Owen D Murnane
- Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN, United States.,Vestibular Research Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN, United States
| | - W Michael King
- University of Michigan Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, Ann Arbor, MI, United States
| | - Faith W Akin
- Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN, United States.,Vestibular Research Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN, United States
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25
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Sayyid ZN, Wang T, Chen L, Jones SM, Cheng AG. Atoh1 Directs Regeneration and Functional Recovery of the Mature Mouse Vestibular System. Cell Rep 2020; 28:312-324.e4. [PMID: 31291569 PMCID: PMC6659123 DOI: 10.1016/j.celrep.2019.06.028] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 02/13/2019] [Accepted: 06/06/2019] [Indexed: 12/02/2022] Open
Abstract
Utricular hair cells (HCs) are mechanoreceptors required for vestibular function. After damage, regeneration of mammalian utricular HCs is limited and regenerated HCs appear immature. Thus, loss of vestibular function is presumed irreversible. Here, we found partial HC replacement and functional recovery in the mature mouse utricle, both enhanced by overexpressing the transcription factor Atoh1. Following damage, long-term fate mapping revealed that support cells non-mitotically and modestly regenerated HCs displaying no or immature bundles. By contrast, Atoh1 overexpression stimulated proliferation and widespread regeneration of HCs exhibiting elongated bundles, patent mechanotransduction channels, and synaptic connections. Finally, although damage without Atoh1 overexpression failed to initiate or sustain a spontaneous functional recovery, Atoh1 overexpression significantly enhanced both the degree and percentage of animals exhibiting sustained functional recovery. Therefore, the mature, damaged utricle has an Atoh1-responsive regenerative program leading to functional recovery, underscoring the potential of a reprogramming approach to sensory regeneration. The mature mouse utricle, which detects linear acceleration, displays limited regeneration, but whether function returns is unknown. Sayyid et al. show that regenerated hair cells appear and mature over months, resulting in a limited, unsustained functional recovery. Atoh1 overexpression enhances regeneration and leads to a sustained recovery of vestibular function.
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Affiliation(s)
- Zahra N Sayyid
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tian Wang
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Leon Chen
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, College of Education and Human Sciences, University of Nebraska, Lincoln, NE 68583, USA
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
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26
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Raghu V, Ramakrishna Y, Burkard RF, Sadeghi SG. A novel intracochlear injection method for rapid drug delivery to vestibular end organs. J Neurosci Methods 2020; 341:108689. [PMID: 32380226 DOI: 10.1016/j.jneumeth.2020.108689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 03/15/2020] [Accepted: 03/15/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Injection into the inner ear through the round window (RW) or a cochleostomy is a reliable method for delivering drugs or viruses to the cochlea. This method has been less effective for fast deliveries to vestibular end organs. NEW METHOD We describe a novel approach for rapid delivery of drugs to the vestibular end organ via the oval window (OW) and scala vestibuli in 1-3 month old C57BL/6 mice. The OW was directly accessed through the external ear canal after ablating the tympanic membrane and middle ear ossicles. A canalostomy in the superior canal provided a low pressure point for faster transit of injected solution from the OW to the vestibular neuroepithelia, allowing for higher rates of injection. RESULTS The efficacy of this technique was shown by fast transit times of a colored artificial perilymph from the OW to the utricle and the ampullae of the horizontal and superior canals in ∼2 min. Following injection, the response of the vestibular nerve was preserved, as measured by the vestibular sensory evoked potentials (VsEP). COMPARISON WITH EXISTING METHODS Previous studies have used posterior semicircular canals or the RW with canalostomy to gain access to vestibular end organs in mice. The OW with canalostomy, provides the means for high injection rates and fast and reliable delivery of drugs to vestibular hair cells and afferent terminals. CONCLUSIONS The presented method for injections through the OW provides rapid delivery of solutions to vestibular end organs without adversely affecting vestibular nerve responses measured by VsEP.
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Affiliation(s)
- Vishal Raghu
- Center for Hearing and Deafness, Dept. of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, NY, United States; Neuroscience Program, State University of New York at Buffalo, Buffalo, NY, United States
| | - Yugandhar Ramakrishna
- Center for Hearing and Deafness, Dept. of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, NY, United States; Dept. of Communication Disorders and Sciences, California State University - Northridge, Northridge, CA, United States
| | - Robert F Burkard
- Dept. of Rehabilitation Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Soroush G Sadeghi
- Center for Hearing and Deafness, Dept. of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, NY, United States; Neuroscience Program, State University of New York at Buffalo, Buffalo, NY, United States.
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27
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Yang X, Sun P, Wu JP, Jiang W, Vai MI, Pun SH, Peng C, Chen F. Nondestructive and objective assessment of the vestibular function in rodent models: A review. Neurosci Lett 2020; 717:134608. [PMID: 31743751 DOI: 10.1016/j.neulet.2019.134608] [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: 06/11/2019] [Revised: 10/28/2019] [Accepted: 10/31/2019] [Indexed: 11/25/2022]
Abstract
The normal function of the vestibular system is crucial for the sense of balance. The techniques used to assess the vestibular function plays a vital role in the research of the vestibular system. In this article, we have systematically reviewed some popular methods employing vestibular reflexes and vestibular evoked potentials for assessing the vestibular function in rodent models. These vestibular reflexes and vestibular evoked potentials to effective stimuli have been used as nondestructive and objective functional measures. The main types of vestibular reflexes include the vestibulo-ocular reflex (VOR), vestibulocollic reflex (VCR), and vestibulo-sympathetic reflex (VSR). They are all capable of indicating the functions of the semicircular canals and otoliths. However, the VOR assessment is much more prevalently used because of the relatively stereotypical inputoutput relationship and simple motion pattern of the ocular response. In contrast, the complicated motion pattern and small gain of the VCR response, as well as the undesired component possibly contributed from the acceleration receptors outside the labyrinths in the VSR response, restrict the widespread applications of VCR and VSR in the assessment of the vestibular system. The vestibular evoked myogenic potentials (VEMPs) and vestibular sensory evoked potentials (VsEPs) are the two typical evoked potentials that have been also employed for evaluating the vestibular function. Through exploiting different types of the VEMPs, the saccular and utricular functions can be evaluated separately. The sound-induced VEMPs, moreover, are capable of noninvasively assessing the unilateral vestibular function. The VsEPs, via the morphology of their signal waveforms, enable the access to the location-specific information that indicates the functional statuses of different components within the vestibular neural pathway.
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Affiliation(s)
- Xiaojie Yang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Peng Sun
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau, China
| | - Jian-Ping Wu
- Academy of Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Weitao Jiang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Mang I Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau, China.
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau, Macau, China.
| | - Cheng Peng
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
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28
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Stewart CE, Bauer DS, Kanicki AC, Altschuler RA, King WM. Intense noise exposure alters peripheral vestibular structures and physiology. J Neurophysiol 2019; 123:658-669. [PMID: 31875485 DOI: 10.1152/jn.00642.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The otolith organs play a critical role in detecting linear acceleration and gravity to control posture and balance. Some afferents that innervate these structures can be activated by sound and are at risk for noise overstimulation. A previous report demonstrated that noise exposure can abolish vestibular short-latency evoked potential (VsEP) responses and damage calyceal terminals. However, the stimuli that were used to elicit responses were weaker than those established in previous studies and may have been insufficient to elicit VsEP responses in noise-exposed animals. The goal of this study was to determine the effect of an established noise exposure paradigm on VsEP responses using large head-jerk stimuli to determine if noise induces a stimulus threshold shift and/or if large head-jerks are capable of evoking VsEP responses in noise-exposed rats. An additional goal is to relate these measurements to the number of calyceal terminals and hair cells present in noise-exposed vs. non-noise-exposed tissue. Exposure to intense continuous noise significantly reduced VsEP responses to large stimuli and abolished VsEP responses to small stimuli. This finding confirms that while measurable VsEP responses can be elicited from noise-lesioned rat sacculi, larger head-jerk stimuli are required, suggesting a shift in the minimum stimulus necessary to evoke the VsEP. Additionally, a reduction in labeled calyx-only afferent terminals was observed without a concomitant reduction in the overall number of calyces or hair cells. This finding supports a critical role of calretinin-expressing calyceal-only afferents in the generation of a VsEP response.NEW & NOTEWORTHY This study identifies a change in the minimum stimulus necessary to evoke vestibular short-latency evoked potential (VsEP) responses after noise-induced damage to the vestibular periphery and reduced numbers of calretinin-labeled calyx-only afferent terminals in the striolar region of the sacculus. These data suggest that a single intense noise exposure may impact synaptic function in calyx-only terminals in the striolar region of the sacculus. Reduced calretinin immunolabeling may provide insight into the mechanism underlying noise-induced changes in VsEP responses.
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Affiliation(s)
- C E Stewart
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - D S Bauer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - A C Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - R A Altschuler
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
| | - W M King
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan
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29
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Suthakar K, Liberman MC. A simple algorithm for objective threshold determination of auditory brainstem responses. Hear Res 2019; 381:107782. [PMID: 31437652 DOI: 10.1016/j.heares.2019.107782] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/05/2019] [Accepted: 08/06/2019] [Indexed: 10/26/2022]
Abstract
The auditory brainstem response (ABR) is a sound-evoked neural response commonly used to assess auditory function in humans and laboratory animals. ABR thresholds are typically chosen by visual inspection, leaving the procedure susceptible to user bias. We sought to develop an algorithm to automate determination of ABR thresholds to eliminate such biases and to standardize approaches across investigators and laboratories. Two datasets of mouse ABR waveforms obtained from previously published studies of normal ears as well as ears with varying degrees of cochlear-based threshold elevations (Maison et al., 2013; Sergeyenko et al., 2013) were reanalyzed using an algorithm based on normalized cross-covariation of adjacent level presentations. Correlation-coefficient vs. level data for each ABR level series were fit with both a sigmoidal and two-term power function. From these fits, threshold was interpolated at different criterion values of correlation-coefficient ranging from 0 to 0.5. The criterion value of 0.35 was selected by comparing visual thresholds to computed thresholds across all frequencies tested. With such a criterion, the mean algorithm-computed thresholds were comparable to the visual thresholds noted by two independent observers for each data set. The success of the algorithm was also qualitatively assessed by comparing averaged waveforms at the thresholds determined by the two methods, and quantitatively assessed by comparing peak 1 amplitude growth functions expressed as dB re each of the two threshold measures. Application of a cross-covariance analysis to ABR waveforms can emulate visual thresholding decisions made by highly trained observers. Unlike previous applications of similar methodologies using template matching, our algorithm performs only intrinsic comparisons within ABR sets, and therefore is more robust to equipment and investigator differences in assessing waveforms, as evidenced by similar results across the two datasets.
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Affiliation(s)
- Kirupa Suthakar
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Otolaryngology, Harvard Medical School, Boston, MA, 02115, USA.
| | - M Charles Liberman
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, 02114, USA; Department of Otolaryngology, Harvard Medical School, Boston, MA, 02115, USA
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30
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Vijayakumar S, Jones SM, Jones TA, Tian C, Johnson KR. Spontaneous mutations of the Zpld1 gene in mice cause semicircular canal dysfunction but do not impair gravity receptor or hearing functions. Sci Rep 2019; 9:12430. [PMID: 31455802 PMCID: PMC6711997 DOI: 10.1038/s41598-019-48835-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/13/2019] [Indexed: 11/23/2022] Open
Abstract
The cupula is a gelatinous membrane overlying the crista ampullaris of the semicircular canal, important for sensing rotation of the head and critical for normal balance. Recently the zona pellucida like domain containing 1 protein (ZPLD1, also known as cupulin) was identified in the cupula of fish. Here, we describe two new spontaneous mutations in the mouse Zpld1 gene, which were discovered by the circling behavior of mutant mice, an indicator of balance dysfunction. The Zpld1 mutant mice exhibited normal hearing function as assessed by auditory brainstem response (ABR) measurements, and their otolithic organs appeared normal. In the inner ear, Zpld1 mRNA expression was detected only in the hair cells and supporting cells of the crista ampullaris. Normal vestibular sensory evoked potential (VsEP) responses and abnormal vestibulo-ocular reflex (VOR) responses demonstrated that the vestibular dysfunction of the Zpld1 mutant mice is caused by loss of sensory input for rotary head movements (detected by cristae ampullaris) and not by loss of input for linear head translations (detected by maculae of the utricle and saccule). Taken together, these results are consistent with ZPLD1 being an important functional component of the cupula, but not tectorial or otoconial membranes.
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Affiliation(s)
- Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska, Lincoln, NE, USA.,Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska, Lincoln, NE, USA
| | - Timothy A Jones
- Department of Special Education and Communication Disorders, University of Nebraska, Lincoln, NE, USA.
| | - Cong Tian
- The Jackson Laboratory, Bar Harbor, ME, USA
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31
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Wan G, Ji L, Schrepfer T, Gong S, Wang GP, Corfas G. Synaptopathy as a Mechanism for Age-Related Vestibular Dysfunction in Mice. Front Aging Neurosci 2019; 11:156. [PMID: 31293415 PMCID: PMC6606700 DOI: 10.3389/fnagi.2019.00156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/11/2019] [Indexed: 12/27/2022] Open
Abstract
Age-related decline of inner ear function contributes to both hearing loss and balance disorders, which lead to impaired quality of life and falls that can result in injury and even death. The cellular mechanisms responsible for the ear's functional decline have been controversial, but hair cell loss has been considered the key cause for a long time. However, recent studies showed that in the cochlea, loss of inner hair cell (IHC) synapses precedes hair cell or neuronal loss, and this synaptopathy is an early step in the functional decline. Whether a similar process occurs in the vestibular organ, its timing and its relationship to organ dysfunction remained unknown. We compared the time course of age-related deterioration in vestibular and cochlear functions in mice as well as characterized the age-associated changes in their utricles at the histological level. We found that in the mouse, as in humans, age-related decline in vestibular evoked potentials (VsEPs) occurs later than hearing loss. As in the cochlea, deterioration of VsEPs correlates with the loss of utricular ribbon synapses but not hair cells or neuronal cell bodies. Furthermore, the age-related synaptic loss is restricted to calyceal innervations in the utricular extrastriolar region. Hence, our findings suggest that loss of extrastriolar calyceal synapses has a key role in age-related vestibular dysfunction (ARVD).
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Affiliation(s)
- Guoqiang Wan
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States.,MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Lingchao Ji
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States.,Department of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Thomas Schrepfer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Sihao Gong
- MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Guo-Peng Wang
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
| | - Gabriel Corfas
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, MI, United States
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32
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Eatock RA. Specializations for Fast Signaling in the Amniote Vestibular Inner Ear. Integr Comp Biol 2019; 58:341-350. [PMID: 29920589 DOI: 10.1093/icb/icy069] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
During rapid locomotion, the vestibular inner ear provides head-motion signals that stabilize posture, gaze, and heading. Afferent nerve fibers from central and peripheral zones of vestibular sensory epithelia use temporal and rate encoding, respectively, to emphasize different aspects of head motion: central afferents adapt faster to sustained head position and favor higher stimulus frequencies, reflecting specializations at each stage from motion of the accessory structure to spike propagation to the brain. One specialization in amniotes is an unusual nonquantal synaptic mechanism by which type I hair cells transmit to large calyceal terminals of afferent neurons. The reduced synaptic delay of this mechanism may have evolved to serve reliable and fast input to reflex pathways that ensure stable locomotion on land.
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Affiliation(s)
- Ruth Anne Eatock
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
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33
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Investigating the validity and reliability of Electrovestibulography (EVestG) for detecting post-concussion syndrome (PCS) with and without comorbid depression. Sci Rep 2018; 8:14495. [PMID: 30262840 PMCID: PMC6160464 DOI: 10.1038/s41598-018-32808-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/10/2018] [Indexed: 11/08/2022] Open
Abstract
Features from Electrovestibulography (EVestG) recordings have been used to classify and measure the severity of both persistent post-concussion syndrome (PCS) and major depressive disorder. Herein, we examined the effect of comorbid depression on the detection of persistent PCS using EVestG. To validate our previously developed EVestG classifier for PCS detection, the classifier was tested with a new blind dataset (N = 21). The unbiased accuracy for identifying the new PCS from controls was found to be >90%. Next, the PCS group (N = 59) was divided into three subgroups: PCS with no-depression (n = 18), PCS with mild-depression (n = 27) and PCS with moderate/severe-depression (n = 14). When moderate/severe depression was present, PCS classification accuracy dropped to 83%. By adding an EVestG depression feature from a previous study, separation accuracy of each PCS subgroup from controls was >90%. A four and three-group (excluding mild-depression subgroup) classification, achieved an accuracy of 74% and 81%, respectively. Correlation analysis indicated a significant correlation (R = 0.67) between the depression feature and the MADRS depression score as well as between the PCS-specific feature and Rivermead Post-Concussion Questionnaire (RPQ) (R = −0.48). No significant correlation was found between the PCS-specific feature and the MADRS score (R = 0.20) or between RPQ and the depression feature (R = 0.12). The (PCS-specific and depression-specific) EVestG features used herein have the potential to robustly detect and monitor changes, relatively independently, in both persistent PCS and its depression comorbidity. Clinically, this can be particularly advantageous.
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34
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Avenarius MR, Jung JY, Askew C, Jones SM, Hunker KL, Azaiez H, Rehman AU, Schraders M, Najmabadi H, Kremer H, Smith RJH, Géléoc GSG, Dolan DF, Raphael Y, Kohrman DC. Grxcr2 is required for stereocilia morphogenesis in the cochlea. PLoS One 2018; 13:e0201713. [PMID: 30157177 PMCID: PMC6114524 DOI: 10.1371/journal.pone.0201713] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/22/2018] [Indexed: 11/18/2022] Open
Abstract
Hearing and balance depend upon the precise morphogenesis and mechanosensory function of stereocilia, the specialized structures on the apical surface of sensory hair cells in the inner ear. Previous studies of Grxcr1 mutant mice indicated a critical role for this gene in control of stereocilia dimensions during development. In this study, we analyzed expression of the paralog Grxcr2 in the mouse and evaluated auditory and vestibular function of strains carrying targeted mutations of the gene. Peak expression of Grxcr2 occurs during early postnatal development of the inner ear and GRXCR2 is localized to stereocilia in both the cochlea and in vestibular organs. Homozygous Grxcr2 deletion mutants exhibit significant hearing loss by 3 weeks of age that is associated with developmental defects in stereocilia bundle orientation and organization. Despite these bundle defects, the mechanotransduction apparatus assembles in relatively normal fashion as determined by whole cell electrophysiological evaluation and FM1-43 uptake. Although Grxcr2 mutants do not exhibit overt vestibular dysfunction, evaluation of vestibular evoked potentials revealed subtle defects of the mutants in response to linear accelerations. In addition, reduced Grxcr2 expression in a hypomorphic mutant strain is associated with progressive hearing loss and bundle defects. The stereocilia localization of GRXCR2, together with the bundle pathologies observed in the mutants, indicate that GRXCR2 plays an intrinsic role in bundle orientation, organization, and sensory function in the inner ear during development and at maturity.
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Affiliation(s)
- Matthew R. Avenarius
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jae-Yun Jung
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Charles Askew
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, United States of America
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sherri M. Jones
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, North Carolina, United States of America
| | - Kristina L. Hunker
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Hela Azaiez
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Atteeq U. Rehman
- Section on Human Genetics, Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, United States of America
| | - Margit Schraders
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hannie Kremer
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Richard J. H. Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Gwenaëlle S. G. Géléoc
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David F. Dolan
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Yehoash Raphael
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - David C. Kohrman
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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35
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Jones SM, Vijayakumar S, Dow SA, Holt JC, Jordan PM, Luebke AE. Loss of α-Calcitonin Gene-Related Peptide (αCGRP) Reduces Otolith Activation Timing Dynamics and Impairs Balance. Front Mol Neurosci 2018; 11:289. [PMID: 30197585 PMCID: PMC6117397 DOI: 10.3389/fnmol.2018.00289] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/31/2018] [Indexed: 12/03/2022] Open
Abstract
Calcitonin gene-related peptide (CGRP) is a neuroactive peptide that is thought to play a role at efferent synapses in hair cell organs including the cochlea, lateral line, and semicircular canal. The deletion of CGRP in transgenic mice is associated with a significant reduction in suprathreshold cochlear nerve activity and vestibulo–ocular reflex (VOR) gain efficacy when compared to littermate controls. Here we asked whether the loss of CGRP also influences otolithic end organ function and contributes to balance impairments. Immunostaining for CGRP was absent in the otolithic end organs of αCGRP null (-/-) mice while choline acetyltransferase (ChAT) immunolabeling appeared unchanged suggesting the overall gross development of efferent innervation in otolithic organs was unaltered. Otolithic function was assessed by quantifying the thresholds, suprathreshold amplitudes, and latencies of vestibular sensory-evoked potentials (VsEPs) while general balance function was assessed using a modified rotarod assay. The loss of αCGRP in null (-/-) mice was associated with: (1) shorter VsEP latencies without a concomitant change in amplitude or thresholds, and (2) deficits in the rotarod balance assay. Our findings show that CGRP loss results in faster otolith afferent activation timing, suggesting that the CGRP component of the efferent vestibular system (EVS) also plays a role in otolithic organ dynamics, which when coupled with reduced VOR gain efficacy, impairs balance.
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Affiliation(s)
- Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska, Lincoln, NE, United States
| | - Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska, Lincoln, NE, United States
| | - Samantha A Dow
- Department of Neuroscience and Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, United States
| | - Joseph C Holt
- Department of Neuroscience and Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, United States.,Department of Otolaryngology, University of Rochester Medical Center, Rochester, NY, United States
| | - Paivi M Jordan
- Department of Otolaryngology, University of Rochester Medical Center, Rochester, NY, United States
| | - Anne E Luebke
- Department of Neuroscience and Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, United States.,Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States
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36
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Lee C, Jones TA. Effects of Ketamine Compared with Urethane Anesthesia on Vestibular Sensory Evoked Potentials and Systemic Physiology in Mice. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2018; 57:268-277. [PMID: 29784077 PMCID: PMC5966234 DOI: 10.30802/aalas-jaalas-17-000131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 10/19/2017] [Accepted: 01/05/2018] [Indexed: 06/08/2023]
Abstract
The injectable anesthetic mixture ketamine-xylazine is commonly used for electrophysiologic experiments in laboratory animals, especially rodents. General anesthesia can induce significant changes in systemic physiology, including those that compromise neural function, thus introducing research confounds. The extent of such concerns varies by agent. Here in mice, we compared the effects of ketamine-xylazine and urethane-xylazine anesthesia on systemic physiologic parameters and the vestibular sensory evoked potential (VsEP), a tool used commonly to assess peripheral vestibular function. Urethane-xylazine anesthesia provided longer anesthesia, prolonged survival times, and less compromised respiratory and cardiovascular function, compared with ketamine-xylazine. In the absence of countermeasures, mice anesthetized with either ketamine-xylazine or urethane-xylazine showed evidence of hypoxemia and fluctuations in brain temperature, heart rate, respiration rate, and VsEP response latency. The levels of hypoxemia had no effect on VsEP response parameters over the period of study (2 to 5 h). Hypoxemia was effectively countered with O2 supplementation, which stabilized respiratory rates and improved mean survival times by 160% in mice anesthetized with ketamine-xylazine. Monitoring and controlling brain temperature reduced variation in VsEP latency. VsEP thresholds, latencies, and amplitudes did not differ between mice under ketamine-xylazine compared with urethane-xylazine when the brain temperature was held at the same set point. These findings demonstrate that urethane-xylazine provides improved systemic physiologic conditions during anesthesia in mice and may be substituted for ketamine-xylazine in studies using the VsEP to evaluate peripheral vestibular function. Such advantages may prove useful to research in other neuroscience areas and might reduce the number of animals used to achieve adequate sample sizes.
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Affiliation(s)
- Choongheon Lee
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska, Department of Otolaryngology, Washington University School of Medicine, St Louis, Missouri
| | - Timothy A Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska;,
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Yang L, Xu Y, Zhang Y, Vijayakumar S, Jones SM, Lundberg YYW. Mechanism Underlying the Effects of Estrogen Deficiency on Otoconia. J Assoc Res Otolaryngol 2018; 19:353-362. [PMID: 29687165 DOI: 10.1007/s10162-018-0666-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/03/2018] [Indexed: 12/19/2022] Open
Abstract
Otoconia-related vertigo and balance deficits, particularly benign paroxysmal positional vertigo (BPPV), are common. Our recent studies in humans show that, while BPPV prevalence greatly increases with age in both genders, peri-menopausal women are especially susceptible. In the present study, we show that bilateral ovariectomized (OVX) mice have significant balance behavioral deficits, and that estrogen deficiency compromises otoconia maintenance and anchoring by reducing the expression of otoconial component and anchoring proteins. There is ectopic debris formation in the ampulla under estrogen deficiency due to aberrant matrix protein expression. Furthermore, phytoestrogen is effective in rescuing the otoconia abnormalities. By comparing the expression levels of known estrogen receptor (Esr) subtypes, and by examining the otoconia phenotypes of null mice for selected receptors, we postulate that Esr2 may be critical in mediating the effects of estrogen in otoconia maintenance.
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Affiliation(s)
- Liping Yang
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, 555 N. 30th St, Omaha, NE, 68131, USA.,Changsha Environmental Protection College, 10 Jinggui Rd, Yuhua Qu, Changsha, Hunan, China
| | - Yinfang Xu
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, 555 N. 30th St, Omaha, NE, 68131, USA
| | - Yan Zhang
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, 555 N. 30th St, Omaha, NE, 68131, USA
| | - Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Yunxia Yesha Wang Lundberg
- Vestibular Genetics Laboratory, Boys Town National Research Hospital, 555 N. 30th St, Omaha, NE, 68131, USA.
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38
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Llorens J, Callejo A, Greguske EA, Maroto AF, Cutillas B, Martins-Lopes V. Physiological assesment of vestibular function and toxicity in humans and animals. Neurotoxicology 2018; 66:204-212. [PMID: 29428870 DOI: 10.1016/j.neuro.2018.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/29/2018] [Accepted: 02/04/2018] [Indexed: 01/15/2023]
Abstract
Physiological methods that can be similarly recorded in humans and animals have a major role in sensory toxicology, as they provide a bridge between human sensory perception data and the molecular and cellular data obtained in animal studies. Vestibular toxicity research lags well behind other sensory systems in many aspects, including the availability of methods for functional assessment in animals that could be robustly translated to human significance. Here we review the methods available for the assessment of vestibular function in both humans and laboratory animals, with an emphasis on their similarity or divergence, to highlight their potential utility for the predictive assessment of vestibular toxicity.
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Affiliation(s)
- Jordi Llorens
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Catalonia, Spain; Institute of Neuroscience, Universitat de Barcelona, Catalonia, Spain; Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, 08907 Hospitalet de Llobregat, Catalonia, Spain.
| | - Angela Callejo
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Catalonia, Spain
| | - Erin A Greguske
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Catalonia, Spain; Institute of Neuroscience, Universitat de Barcelona, Catalonia, Spain; Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, 08907 Hospitalet de Llobregat, Catalonia, Spain
| | - Alberto F Maroto
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Catalonia, Spain
| | - Blanca Cutillas
- Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, 08907 Hospitalet de Llobregat, Catalonia, Spain; Department d'Infermeria Fonamental i Medicoquirúrgica, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Catalonia, Spain
| | - Vanessa Martins-Lopes
- Department de Ciències Fisiològiques, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08907 Hospitalet de Llobregat, Catalonia, Spain
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Vijayakumar S, Depreux FF, Jodelka FM, Lentz JJ, Rigo F, Jones TA, Hastings ML. Rescue of peripheral vestibular function in Usher syndrome mice using a splice-switching antisense oligonucleotide. Hum Mol Genet 2018. [PMID: 28633508 DOI: 10.1093/hmg/ddx234] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Usher syndrome type 1C (USH1C/harmonin) is associated with profound retinal, auditory and vestibular dysfunction. We have previously reported on an antisense oligonucleotide (ASO-29) that dramatically improves auditory function and balance behavior in mice homozygous for the harmonin mutation Ush1c c.216G > A following a single systemic administration. The findings were suggestive of improved vestibular function; however, no direct vestibular assessment was made. Here, we measured vestibular sensory evoked potentials (VsEPs) to directly assess vestibular function in Usher mice. We report that VsEPs are absent or abnormal in Usher mice, indicating profound loss of vestibular function. Strikingly, Usher mice receiving ASO-29 treatment have normal or elevated vestibular response thresholds when treated during a critical period between postnatal day 1 and 5, respectively. In contrast, treatment of mice with ASO-29 treatment at P15 was minimally effective at rescuing vestibular function. Interestingly, ASO-29 treatment at P1, P5 or P15 resulted in sufficient vestibular recovery to support normal balance behaviors, suggesting a therapeutic benefit to balance with ASO-29 treatment at P15 despite the profound vestibular functional deficits that persist with treatment at this later time. These findings provide the first direct evidence of an effective treatment of peripheral vestibular function in a mouse model of USH1C and reveal the potential for using antisense technology to treat vestibular dysfunction.
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Affiliation(s)
- Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, 304 Barkley Memorial Center, Lincoln, NE 68583, USA
| | - Frederic F Depreux
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Francine M Jodelka
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Jennifer J Lentz
- Department of Otorhinolaryngology, Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Timothy A Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, 304 Barkley Memorial Center, Lincoln, NE 68583, USA
| | - Michelle L Hastings
- Department of Cell Biology and Anatomy, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
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40
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Suleiman A, Lithgow B, Dastgheib Z, Mansouri B, Moussavi Z. Quantitative measurement of post-concussion syndrome Using Electrovestibulography. Sci Rep 2017; 7:16371. [PMID: 29180620 PMCID: PMC5703984 DOI: 10.1038/s41598-017-15487-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 10/27/2017] [Indexed: 12/27/2022] Open
Abstract
In this study, a noninvasive quantitative measure was used to identify short and long term post-concussion syndrome (PCS) both from each other and from healthy control populations. We used Electrovestibulography (EVestG) for detecting neurophysiological PCS consequent to a mild traumatic brain injury (mTBI) in both short-term (N = 8) and long-term (N = 30) (beyond the normal recovery period) symptomatic individuals. Peripheral, spontaneously evoked vestibuloacoustic signals incorporating - and modulated by - brainstem responses were recorded using EVestG, while individuals were stationary (no movement stimulus). Tested were 38 individuals with PCS in comparison to those of 33 age-and-gender-matched healthy controls. The extracted features were based on the shape of the averaged extracted field potentials (FPs) and their detected firing pattern. Linear discriminant analysis classification, incorporating a leave-one-out routine, resulted in (A) an unbiased 84% classification accuracy for separating healthy controls from a mix of long and short-term symptomatology PCS sufferers and (B) a 79% classification accuracy for separating between long and short-term symptomatology PCS sufferers. Comparatively, short-term symptomatology PCS was generally detected as more distal from controls. Based on the results, the EVestG recording shows promise as an assistive objective tool for detecting and monitoring individuals with PCS after normal recovery periods.
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Affiliation(s)
- Abdelbaset Suleiman
- Biomedical Engineering Program, University of Manitoba, Winnipeg, MB, Canada
| | - Brian Lithgow
- Biomedical Engineering Program, University of Manitoba, Winnipeg, MB, Canada.,Monash Alfred Psychiatry Research Center, Monash University, Melbourne, Australia
| | - Zeinab Dastgheib
- Biomedical Engineering Program, University of Manitoba, Winnipeg, MB, Canada
| | - Behzad Mansouri
- Biomedical Engineering Program, University of Manitoba, Winnipeg, MB, Canada.,Department of Internal Medicine (Neurology), University of Manitoba, Winnipeg, MB, Canada
| | - Zahra Moussavi
- Biomedical Engineering Program, University of Manitoba, Winnipeg, MB, Canada.
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41
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Stewart CE, Kanicki AC, Altschuler RA, King WM. Vestibular short-latency evoked potential abolished by low-frequency noise exposure in rats. J Neurophysiol 2017; 119:662-667. [PMID: 29118200 DOI: 10.1152/jn.00668.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The vestibular system plays a critical role in detection of head movements and is essential for normal postural control. Because of their anatomical proximity to the cochlea, the otolith organs are selectively exposed to sound pressure and are at risk for noise overstimulation. Clinical reports suggest a link between noise exposure and balance problems, but the structural and physiological basis for this linkage is not well understood. The goal of this study was to determine the effects of low-frequency noise (LFN) on the otolith organs by correlating changes in vestibular short-latency evoked potentials (VsEPs) with changes in saccular afferent endings following noise exposure. LFN exposure transiently abolished the VsEP and reduced the number of stained calyces within the sacculus. Although some recovery of the VsEP waveform could be observed within 3 days after noise, at 3 wk recovery was only partial in most animals, consistent with a reduced number of afferents with calyceal endings. These data show that a single intense noise exposure is capable of causing a vestibular deficit that appears to mirror the synaptic deficit associated with hidden hearing loss after noise-induced cochlear injury. NEW & NOTEWORTHY This is the first study to explore the effects of low-frequency high-intensity noise on vestibular short-latency evoked potential (VsEP) responses, which shows a linkage between attenuated noise-induced VsEPs and pathological changes to otolith organ afferents. This finding suggests a potential limitation of the VsEP for evaluation of vestibular dysfunction, since the VsEP measurement may assess the activity of a specific class rather than all afferents.
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Affiliation(s)
- Courtney E Stewart
- Department of Otolaryngology, University of Michigan , Ann Arbor, Michigan
| | - Ariane C Kanicki
- Department of Otolaryngology, University of Michigan , Ann Arbor, Michigan
| | - Richard A Altschuler
- Department of Otolaryngology, University of Michigan , Ann Arbor, Michigan.,Ann Arbor Department of Veterans Affairs Medical Center , Ann Arbor, Michigan
| | - W M King
- Department of Otolaryngology, University of Michigan , Ann Arbor, Michigan
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42
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Lee C, Holt JC, Jones TA. Effect of M-current modulation on mammalian vestibular responses to transient head motion. J Neurophysiol 2017; 118:2991-3006. [PMID: 28855291 DOI: 10.1152/jn.00384.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/25/2017] [Accepted: 08/25/2017] [Indexed: 12/26/2022] Open
Abstract
The precise role and mechanisms underlying efferent modulation of peripheral vestibular afferent function are not well understood in mammals. Clarifying the details of efferent action may lead to new strategies for clinical management of debilitating disturbances in vestibular and balance function. Recent evidence in turtle indicates that efferent modulation of M-currents is likely one mechanism for modifying afferent discharge. M-currents depend in part on KCNQ potassium conductances (Kv7), which can be adjusted through efferent activation of M1, M3, and/or M5 muscarinic acetylcholine receptors (mAChRs). How KCNQ channels and altered M-currents affect vestibular afferent function in vivo is unclear, and whether such a mechanism operates in mammals is unknown. In this study we used the KCNQ antagonist XE991 and the KCNQ activator retigabine in anesthetized mice to evaluate the effects of M-current modulation on peripheral vestibular responses to transient head motion. At low doses of XE991, responses were modestly enhanced, becoming larger in amplitude and shorter in latency. Higher doses of XE991 produced transient response enhancement, followed by steady-state suppression where latencies and thresholds increased and amplitudes decreased. Retigabine produced opposite effects. Auditory function was also impacted, based on results of companion auditory brain stem response testing. We propose that closure of KCNQ channels transforms vestibular afferent behavior by suppressing responses to transient high-frequency stimuli while simultaneously enhancing responses to sustained low-frequency stimulation. Our results clearly demonstrate that KCNQ channels are critical for normal mammalian vestibular function and suggest that efferent action may utilize these mechanisms to modulate the dynamic characteristics and gain of vestibular afferent responses.NEW & NOTEWORTHY The role of calyceal KCNQ channels and associated M-current in normal mammalian vestibular function is unknown. Our results show that calyceal KCNQ channels are critical for normal vestibular function in the intact mammal. The findings provide evidence that efferent modulation of M-currents may act normally to differentially adjust the sensitivity of vestibular neurons to transient and tonic stimulation and that such mechanisms may be targeted to achieve effective clinical management of vestibular disorders.
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Affiliation(s)
- Choongheon Lee
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska; and
| | - J Chris Holt
- Department of Otolaryngology, Department of Neuroscience, and Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York
| | - Timothy A Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska; and
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Iversen MM, Christensen DA, Parker DL, Holman HA, Chen J, Frerck MJ, Rabbitt RD. Low-intensity ultrasound activates vestibular otolith organs through acoustic radiation force. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:4209. [PMID: 28618821 PMCID: PMC5552392 DOI: 10.1121/1.4984287] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 06/03/2023]
Abstract
The present study examined the efficacy of 5 MHz low-intensity focused ultrasound (LiFU) as a stimulus to remotely activate inner ear vestibular otolith organs. The otolith organs are the primary sensory apparati responsible for detecting orientation of the head relative to gravity and linear acceleration in three-dimensional space. These organs also respond to loud sounds and vibration of the temporal bone. The oyster toadfish, Opsanus tau, was used to facilitate unobstructed acoustic access to the otolith organs in vivo. Single-unit responses to amplitude-modulated LiFU were recorded in afferent neurons identified as innervating the utricle or the saccule. Neural responses were equivalent to direct mechanical stimulation, and arose from the nonlinear acoustic radiation force acting on the otolithic mass. The magnitude of the acoustic radiation force acting on the otolith was measured ex vivo. Results demonstrate that LiFU stimuli can be tuned to mimic directional forces occurring naturally during physiological movements of the head, loud air conducted sound, or bone conducted vibration.
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Affiliation(s)
- M M Iversen
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - D A Christensen
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - D L Parker
- Department of Radiology, University of Utah, 30 North 1900 East, Salt Lake City, Utah 84132, USA
| | - H A Holman
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - J Chen
- Communication Sciences and Disorders, University of Utah, 390 South 1530 East, Salt Lake City, Utah 84112, USA
| | - M J Frerck
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - R D Rabbitt
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
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44
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Brown DJ, Pastras CJ, Curthoys IS. Electrophysiological Measurements of Peripheral Vestibular Function-A Review of Electrovestibulography. Front Syst Neurosci 2017; 11:34. [PMID: 28620284 PMCID: PMC5450778 DOI: 10.3389/fnsys.2017.00034] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/05/2017] [Indexed: 12/19/2022] Open
Abstract
Electrocochleography (EcochG), incorporating the Cochlear Microphonic (CM), the Summating Potential (SP), and the cochlear Compound Action Potential (CAP), has been used to study cochlear function in humans and experimental animals since the 1930s, providing a simple objective tool to assess both hair cell (HC) and nerve sensitivity. The vestibular equivalent of ECochG, termed here Electrovestibulography (EVestG), incorporates responses of the vestibular HCs and nerve. Few research groups have utilized EVestG to study vestibular function. Arguably, this is because stimulating the cochlea in isolation with sound is a trivial matter, whereas stimulating the vestibular system in isolation requires significantly more technical effort. That is, the vestibular system is sensitive to both high-level sound and bone-conducted vibrations, but so is the cochlea, and gross electrical responses of the inner ear to such stimuli can be difficult to interpret. Fortunately, several simple techniques can be employed to isolate vestibular electrical responses. Here, we review the literature underpinning gross vestibular nerve and HC responses, and we discuss the nomenclature used in this field. We also discuss techniques for recording EVestG in experimental animals and humans and highlight how EVestG is furthering our understanding of the vestibular system.
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Affiliation(s)
- Daniel J Brown
- Neurotology Laboratory, Sydney Medical School, The University of SydneySydney, NSW, Australia
| | - Christopher J Pastras
- Neurotology Laboratory, Sydney Medical School, The University of SydneySydney, NSW, Australia
| | - Ian S Curthoys
- Department of Psychology, The University of SydneySydney, NSW, Australia
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45
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The Severity of Vestibular Dysfunction in Deafness as a Determinant of Comorbid Hyperactivity or Anxiety. J Neurosci 2017; 37:5144-5154. [PMID: 28438970 DOI: 10.1523/jneurosci.3545-16.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/29/2017] [Accepted: 04/02/2017] [Indexed: 12/11/2022] Open
Abstract
Attention-deficit/hyperactivity disorder (ADHD) and anxiety-related disorders occur at rates 2-3 times higher in deaf compared with hearing children. Potential explanations for these elevated rates and the heterogeneity of behavioral disorders associated with deafness have usually focused on socio-environmental rather than biological effects. Children with the 22q11.2 deletion or duplication syndromes often display hearing loss and behavioral disorders, including ADHD and anxiety-related disorders. Here, we show that mouse mutants with either a gain or loss of function of the T-Box transcription factor gene, Tbx1, which lies within the 22q11.2 region and is responsible for most of the syndromic defects, exhibit inner ear defects and hyperactivity. Furthermore, we show that (1) inner ear dysfunction due to the tissue-specific loss of Tbx1 or Slc12a2, which encodes a sodium-potassium-chloride cotransporter and is also necessary for inner ear function, causes hyperactivity; (2) vestibular rather than auditory failure causes hyperactivity; and (3) the severity rather than the age of onset of vestibular dysfunction differentiates whether hyperactivity or anxiety co-occurs with inner ear dysfunction. Together, these findings highlight a biological link between inner ear dysfunction and behavioral disorders and how sensory abnormalities can contribute to the etiology of disorders traditionally considered of cerebral origin.SIGNIFICANCE STATEMENT This study examines the biological rather than socio-environmental reasons why hyperactivity and anxiety disorders occur at higher rates in deaf individuals. Using conditional genetic approaches in mice, the authors show that (1) inner ear dysfunction due to either Tbx1 or Slc12a2 mutations cause hyperactivity; (2) it is vestibular dysfunction, which frequently co-occurs with deafness but often remains undiagnosed, rather than auditory dysfunction that causes hyperactivity and anxiety-related symptoms; and (3) the severity of vestibular dysfunction can predict whether hyperactivity or anxiety coexist with inner ear dysfunction. These findings suggest a need to evaluate vestibular function in hearing impaired individuals, especially those who exhibit hyperactive and anxiety-related symptoms.
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46
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Suzuki J, Hashimoto K, Xiao R, Vandenberghe LH, Liberman MC. Cochlear gene therapy with ancestral AAV in adult mice: complete transduction of inner hair cells without cochlear dysfunction. Sci Rep 2017; 7:45524. [PMID: 28367981 PMCID: PMC5377419 DOI: 10.1038/srep45524] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/01/2017] [Indexed: 12/23/2022] Open
Abstract
The use of viral vectors for inner ear gene therapy is receiving increased attention for treatment of genetic hearing disorders. Most animal studies to date have injected viral suspensions into neonatal ears, via the round window membrane. Achieving transduction of hair cells, or sensory neurons, throughout the cochlea has proven difficult, and no studies have been able to efficiently transduce sensory cells in adult ears while maintaining normal cochlear function. Here, we show, for the first time, successful transduction of all inner hair cells and the majority of outer hair cells in an adult cochlea via virus injection into the posterior semicircular canal. We used a “designer” AAV, AAV2/Anc80L65, in which the main capsid proteins approximate the ancestral sequence state of AAV1, 2, 8, and 9. Our injections also transduced ~10% of spiral ganglion cells and a much larger fraction of their satellite cells. In the vestibular sensory epithelia, the virus transduced large numbers of hair cells and virtually all the supporting cells, along with close to half of the vestibular ganglion cells. We conclude that this viral vector and this delivery route hold great promise for gene therapy applications in both cochlear and vestibular sense organs.
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Affiliation(s)
- Jun Suzuki
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye &Ear Infirmary, Boston, MA 02114, USA.,Department of Otorhinolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8574, Japan
| | - Ken Hashimoto
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye &Ear Infirmary, Boston, MA 02114, USA.,Department of Otorhinolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8574, Japan
| | - Ru Xiao
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye &Ear Infirmary, Boston, MA 02114, USA.,Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Luk H Vandenberghe
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye &Ear Infirmary, Boston, MA 02114, USA.,Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.,Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - M Charles Liberman
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02115, USA.,Eaton-Peabody Laboratories, Massachusetts Eye &Ear Infirmary, Boston, MA 02114, USA
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47
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Curthoys IS, MacDougall HG, Vidal PP, de Waele C. Sustained and Transient Vestibular Systems: A Physiological Basis for Interpreting Vestibular Function. Front Neurol 2017; 8:117. [PMID: 28424655 PMCID: PMC5371610 DOI: 10.3389/fneur.2017.00117] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 03/14/2017] [Indexed: 01/17/2023] Open
Abstract
Otolithic afferents with regular resting discharge respond to gravity or low-frequency linear accelerations, and we term these the static or sustained otolithic system. However, in the otolithic sense organs, there is anatomical differentiation across the maculae and corresponding physiological differentiation. A specialized band of receptors called the striola consists of mainly type I receptors whose hair bundles are weakly tethered to the overlying otolithic membrane. The afferent neurons, which form calyx synapses on type I striolar receptors, have irregular resting discharge and have low thresholds to high frequency (e.g., 500 Hz) bone-conducted vibration and air-conducted sound. High-frequency sound and vibration likely causes fluid displacement which deflects the weakly tethered hair bundles of the very fast type I receptors. Irregular vestibular afferents show phase locking, similar to cochlear afferents, up to stimulus frequencies of kilohertz. We term these irregular afferents the transient system signaling dynamic otolithic stimulation. A 500-Hz vibration preferentially activates the otolith irregular afferents, since regular afferents are not activated at intensities used in clinical testing, whereas irregular afferents have low thresholds. We show how this sustained and transient distinction applies at the vestibular nuclei. The two systems have differential responses to vibration and sound, to ototoxic antibiotics, to galvanic stimulation, and to natural linear acceleration, and such differential sensitivity allows probing of the two systems. A 500-Hz vibration that selectively activates irregular otolithic afferents results in stimulus-locked eye movements in animals and humans. The preparatory myogenic potentials for these eye movements are measured in the new clinical test of otolith function—ocular vestibular-evoked myogenic potentials. We suggest 500-Hz vibration may identify the contribution of the transient system to vestibular controlled responses, such as vestibulo-ocular, vestibulo-spinal, and vestibulo-sympathetic responses. The prospect of particular treatments targeting one or the other of the transient or sustained systems is now being realized in the clinic by the use of intratympanic gentamicin which preferentially attacks type I receptors. We suggest that it is valuable to view vestibular responses by this sustained-transient distinction.
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Affiliation(s)
- Ian S Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Hamish G MacDougall
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Pierre-Paul Vidal
- Cognition and Action Group, CNRS UMR8257, Centre Universitaire des Saints-Pères, University Paris Descartes, Paris, France
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Gfi1 Cre mice have early onset progressive hearing loss and induce recombination in numerous inner ear non-hair cells. Sci Rep 2017; 7:42079. [PMID: 28181545 PMCID: PMC5299610 DOI: 10.1038/srep42079] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 01/05/2017] [Indexed: 12/20/2022] Open
Abstract
Studies of developmental and functional biology largely rely on conditional expression of genes in a cell type-specific manner. Therefore, the importance of specificity and lack of inherent phenotypes for Cre-driver animals cannot be overemphasized. The Gfi1Cre mouse is commonly used for conditional hair cell-specific gene deletion/reporter gene activation in the inner ear. Here, using immunofluorescence and flow cytometry, we show that the Gfi1Cre mice produce a pattern of recombination that is not strictly limited to hair cells within the inner ear. We observe a broad expression of Cre recombinase in the Gfi1Cre mouse neonatal inner ear, primarily in inner ear resident macrophages, which outnumber the hair cells. We further show that heterozygous Gfi1Cre mice exhibit an early onset progressive hearing loss as compared with their wild-type littermates. Importantly, vestibular function remains intact in heterozygotes up to 10 months, the latest time point tested. Finally, we detect minor, but statistically significant, changes in expression of hair cell-enriched transcripts in the Gfi1Cre heterozygous mice cochleae compared with their wild-type littermate controls. Given the broad use of the Gfi1Cre mice, both for gene deletion and reporter gene activation, these data are significant and necessary for proper planning and interpretation of experiments.
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Ohlemiller KK, Jones SM, Johnson KR. Application of Mouse Models to Research in Hearing and Balance. J Assoc Res Otolaryngol 2016; 17:493-523. [PMID: 27752925 PMCID: PMC5112220 DOI: 10.1007/s10162-016-0589-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/15/2016] [Indexed: 01/10/2023] Open
Abstract
Laboratory mice (Mus musculus) have become the major model species for inner ear research. The major uses of mice include gene discovery, characterization, and confirmation. Every application of mice is founded on assumptions about what mice represent and how the information gained may be generalized. A host of successes support the continued use of mice to understand hearing and balance. Depending on the research question, however, some mouse models and research designs will be more appropriate than others. Here, we recount some of the history and successes of the use of mice in hearing and vestibular studies and offer guidelines to those considering how to apply mouse models.
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Affiliation(s)
- Kevin K Ohlemiller
- Department of Otolaryngology, Central Institute for the Deaf, Fay and Carl Simons Center for Hearing and Deafness, Washington University School of Medicine, 660 S. Euclid, Saint Louis, MO, 63110, USA.
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
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50
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Krey JF, Krystofiak ES, Dumont RA, Vijayakumar S, Choi D, Rivero F, Kachar B, Jones SM, Barr-Gillespie PG. Plastin 1 widens stereocilia by transforming actin filament packing from hexagonal to liquid. J Cell Biol 2016; 215:467-482. [PMID: 27811163 PMCID: PMC5119939 DOI: 10.1083/jcb.201606036] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/29/2016] [Accepted: 10/11/2016] [Indexed: 11/24/2022] Open
Abstract
With their essential role in inner ear function, stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. Actin packing in stereocilia is mediated by cross-linkers of the plastin, fascin, and espin families. Although mice lacking espin (ESPN) have no vestibular or auditory function, we found that mice that either lacked plastin 1 (PLS1) or had nonfunctional fascin 2 (FSCN2) had reduced inner ear function, with double-mutant mice most strongly affected. Targeted mass spectrometry indicated that PLS1 was the most abundant cross-linker in vestibular stereocilia and the second most abundant protein overall; ESPN only accounted for ∼15% of the total cross-linkers in bundles. Mouse utricle stereocilia lacking PLS1 were shorter and thinner than wild-type stereocilia. Surprisingly, although wild-type stereocilia had random liquid packing of their actin filaments, stereocilia lacking PLS1 had orderly hexagonal packing. Although all three cross-linkers are required for stereocilia structure and function, PLS1 biases actin toward liquid packing, which allows stereocilia to grow to a greater diameter.
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Affiliation(s)
- Jocelyn F Krey
- Oregon Hearing Research Center, Oregon Health and Science University, Portland, OR 97239
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | - Evan S Krystofiak
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892
| | - Rachel A Dumont
- Oregon Hearing Research Center, Oregon Health and Science University, Portland, OR 97239
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | - Sarath Vijayakumar
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE 68583
| | - Dongseok Choi
- Oregon Health and Science University-Portland State University School of Public Health, Oregon Health and Science University, Portland, OR 97239
- Graduate School of Dentistry, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Francisco Rivero
- Centre for Cardiovascular and Metabolic Research, The Hull York Medical School, University of Hull, Hull HU6 7RX, England, UK
| | - Bechara Kachar
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE 68583
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center, Oregon Health and Science University, Portland, OR 97239
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
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