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Ding D, Manohar S, Kador PF, Salvi R. Multifunctional redox modulator prevents blast-induced loss of cochlear and vestibular hair cells and auditory spiral ganglion neurons. Sci Rep 2024; 14:15296. [PMID: 38961203 PMCID: PMC11222375 DOI: 10.1038/s41598-024-66406-1] [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: 04/29/2024] [Accepted: 07/01/2024] [Indexed: 07/05/2024] Open
Abstract
Blast wave exposure, a leading cause of hearing loss and balance dysfunction among military personnel, arises primarily from direct mechanical damage to the mechanosensory hair cells and supporting structures or indirectly through excessive oxidative stress. We previously reported that HK-2, an orally active, multifunctional redox modulator (MFRM), was highly effective in reducing both hearing loss and hair cells loss in rats exposed to a moderate intensity workday noise that likely damages the cochlea primarily from oxidative stress versus direct mechanical trauma. To determine if HK-2 could also protect cochlear and vestibular cells from damage caused primarily from direct blast-induced mechanical trauma versus oxidative stress, we exposed rats to six blasts of 186 dB peak SPL. The rats were divided into four groups: (B) blast alone, (BEP) blast plus earplugs, (BHK-2) blast plus HK-2 and (BEPHK-2) blast plus earplugs plus HK-2. HK-2 was orally administered at 50 mg/kg/d from 7-days before to 30-day after the blast exposure. Cochlear and vestibular tissues were harvested 60-d post-exposure and evaluated for loss of outer hair cells (OHC), inner hair cells (IHC), auditory nerve fibers (ANF), spiral ganglion neurons (SGN) and vestibular hair cells in the saccule, utricle and semicircular canals. In the untreated blast-exposed group (B), massive losses occurred to OHC, IHC, ANF, SGN and only the vestibular hair cells in the striola region of the saccule. In contrast, rats treated with HK-2 (BHK-2) sustained significantly less OHC (67%) and IHC (57%) loss compared to the B group. OHC and IHC losses were smallest in the BEPHK-2 group, but not significantly different from the BEP group indicating lack of protective synergy between EP and HK-2. There was no loss of ANF, SGN or saccular hair cells in the BHK-2, BEP and BEPHK-2 groups. Thus, HK-2 not only significantly reduced OHC and IHC damage, but completely prevented loss of ANF, SGN and saccule hair cells. The powerful protective effects of this oral MFRM make HK-2 an extremely promising candidate for human clinical trials.
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Affiliation(s)
- Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA
| | | | | | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA.
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2
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Wei H, Jiang H, Zhou Y, Liu L, Ma W, Ni S, Zhou C, Ji X. Cerebral venous congestion alters CNS homeostatic plasticity, evoking tinnitus-like behavior. Cell Biosci 2024; 14:47. [PMID: 38594782 PMCID: PMC11003147 DOI: 10.1186/s13578-024-01221-9] [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: 07/11/2023] [Accepted: 03/19/2024] [Indexed: 04/11/2024] Open
Abstract
BACKGROUND Brain function and neuronal activity depend on a constant supply of blood from the cerebral circulation. The cerebral venous system (CVS) contains approximately 70% of the total cerebral blood volume; similar to the cerebral arterial system, the CVS plays a prominent role in the maintenance of central nervous system (CNS) homeostasis. Impaired venous autoregulation, which can appear in forms such as cerebral venous congestion, may lead to metabolic abnormalities in the brain, causing severe cerebral functional defects and even chronic tinnitus. However, the role of cerebral venous congestion in the progression of tinnitus is underrecognized, and its pathophysiology is still incompletely understood. This study elucidated the specific pathogenetic role of cerebral venous congestion in the onset and persistence of tinnitus and the possible neurophysiological mechanisms. RESULTS We found that a rat model of cerebral venous congestion exhibited tinnitus-like behavioral manifestations at 14 days postoperatively; from that point onward, they showed signs of persistent tinnitus without significant hearing impairment. Subsequent neuroimaging and neurochemical findings showed CNS homeostatic plasticity disturbance in rats with cerebral venous congestion, reflected in increased neural metabolic activity, ultrastructural synaptic changes, upregulated synaptic efficacy, reduced inhibitory synaptic transmission (due to GABA deficiency), and elevated expression of neuroplasticity-related proteins in central auditory and extra-auditory pathways. CONCLUSION Collectively, our data suggest that alternations in CNS homeostatic plasticity may play a vital role in tinnitus pathology caused by cerebral venous congestion. These findings provide a new perspective on tinnitus related to cerebral venous congestion and may facilitate the development of precise interventions to interrupt its pathogenesis.
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Affiliation(s)
- Huimin Wei
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, School of Biological Science and Medical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, China
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Huimin Jiang
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Yifan Zhou
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Lu Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Wei Ma
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Shanshan Ni
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China.
- Department of Neurology, Wuqing Hospital of Traditional Chinese Medicine Affiliated to Tianjin University of Traditional Chinese Medicine, Tianjin, 301700, China.
| | - Chen Zhou
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China.
| | - Xunming Ji
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, School of Biological Science and Medical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, China.
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China.
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China.
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3
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Husain FT, Khan RA. Review and Perspective on Brain Bases of Tinnitus. J Assoc Res Otolaryngol 2023; 24:549-562. [PMID: 37919556 PMCID: PMC10752862 DOI: 10.1007/s10162-023-00914-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/18/2023] [Indexed: 11/04/2023] Open
Abstract
In advancing our understanding of tinnitus, some of the more impactful contributions in the past two decades have come from human brain imaging studies, specifically the idea of both auditory and extra-auditory neural networks that mediate tinnitus. These networks subserve both the perception of tinnitus and the psychological reaction to chronic, continuous tinnitus. In this article, we review particular studies that report on the nodes and links of such neural networks and their inter-network connections. Innovative neuroimaging tools have contributed significantly to the increased understanding of anatomical and functional connections of attention, emotion-processing, and default mode networks in adults with tinnitus. We differentiate between the neural correlates of tinnitus and those of comorbid hearing loss; surprisingly, tinnitus and hearing loss when they co-occur are not necessarily additive in their impact and, in rare cases, additional tinnitus may act to mitigate the consequences of hearing loss alone on the brain. The scale of tinnitus severity also appears to have an impact on brain networks, with some of the alterations typically attributed to tinnitus reaching significance only in the case of bothersome tinnitus. As we learn more about comorbid conditions of tinnitus, such as depression, anxiety, hyperacusis, or even aging, their contributions to the network-level changes observed in tinnitus will need to be parsed out in a manner similar to what is currently being done for hearing loss or severity. Together, such studies advance our understanding of the heterogeneity of tinnitus and will lead to individualized treatment plans.
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Affiliation(s)
- Fatima T Husain
- Department of Speech and Hearing Science, University of Illinois Urbana-Champaign, 901 S. Sixth Street, Champaign, IL, 61820, USA.
- Neuroscience Program, University of Illinois Urbana-Champaign, 2355/57 Beckman Institute, 405 North Mathews Avenue, Urbana, IL, 61801, USA.
- The Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL, 61801, USA.
| | - Rafay A Khan
- Neuroscience Program, University of Illinois Urbana-Champaign, 2355/57 Beckman Institute, 405 North Mathews Avenue, Urbana, IL, 61801, USA
- The Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL, 61801, USA
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4
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Manohar S, Chen GD, Li L, Liu X, Salvi R. Chronic stress induced loudness hyperacusis, sound avoidance and auditory cortex hyperactivity. Hear Res 2023; 431:108726. [PMID: 36905854 DOI: 10.1016/j.heares.2023.108726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 02/22/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Hyperacusis, a debilitating loudness intolerance disorder, has been linked to chronic stress and adrenal insufficiency. To investigate the role of chronic stress, rats were chronically treated with corticosterone (CORT) stress hormone. Chronic CORT produced behavioral evidence of loudness hyperacusis, sound avoidance hyperacusis, and abnormal temporal integration of loudness. CORT treatment did not disrupt cochlear or brainstem function as reflected by normal distortion product otoacoustic emissions, compound action potentials, acoustic startle reflexex, and auditory brainstem responses. In contrast, the evoked response from the auditory cortex was enhanced up to three fold after CORT treatment. This hyperactivity was associated with a significant increase in glucocorticoid receptors in auditory cortex layers II/III and VI. Basal serum CORT levels remained normal after chronic CORT stress whereas reactive serum CORT levels evoked by acute restraint stress were blunted (reduced) after chronic CORT stress; similar changes were observed after chronic, intense noise stress. Taken together, our results show for the first time that chronic stress can induce hyperacusis and sound avoidance. A model is proposed in which chronic stress creates a subclinical state of adrenal insufficiency that establishes the necessary conditions for inducing hyperacusis.
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Affiliation(s)
- Senthilvelan Manohar
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Li Li
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Xiaopeng Liu
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA.
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5
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Hayes SH, Beh K, Typlt M, Schormans AL, Stolzberg D, Allman BL. Using an appetitive operant conditioning paradigm to screen rats for tinnitus induced by intense sound exposure: Experimental considerations and interpretation. Front Neurosci 2023; 17:1001619. [PMID: 36845432 PMCID: PMC9950262 DOI: 10.3389/fnins.2023.1001619] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 01/25/2023] [Indexed: 02/12/2023] Open
Abstract
In an effort to help elucidate the neural mechanisms underlying tinnitus in humans, researchers have often relied on animal models; a preclinical approach which ultimately required that behavioral paradigms be designed to reliably screen animals for tinnitus. Previously, we developed a two-alternative forced-choice (2AFC) paradigm for rats that allowed for the simultaneous recording of neural activity at the very moments when they were reporting the presence/absence of tinnitus. Because we first validated our paradigm in rats experiencing transient tinnitus following a high-dose of sodium salicylate, the present study now sought to evaluate its utility to screen for tinnitus caused by intense sound exposure; a common tinnitus-inducer in humans. More specifically, through a series of experimental protocols, we aimed to (1) conduct sham experiments to ensure that the paradigm was able to correctly classify control rats as not having tinnitus, (2) confirm the time course over which the behavioral testing could reliably be performed post-exposure to assess chronic tinnitus, and (3) determine if the paradigm was sensitive to the variable outcomes often observed after intense sound exposure (e.g., hearing loss with our without tinnitus). Ultimately, in accordance with our predictions, the 2AFC paradigm was indeed resistant to false-positive screening of rats for intense sound-induced tinnitus, and it was able to reveal variable tinnitus and hearing loss profiles in individual rats following intense sound exposure. Taken together, the present study documents the utility of our appetitive operant conditioning paradigm to assess acute and chronic sound-induced tinnitus in rats. Finally, based on our findings, we discuss important experimental considerations that will help ensure that our paradigm is able to provide a suitable platform for future investigations into the neural basis of tinnitus.
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Affiliation(s)
- Sarah H. Hayes
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada,*Correspondence: Sarah H. Hayes,
| | - Krystal Beh
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada,National Centre for Audiology, Elborn College, The University of Western Ontario, London, ON, Canada
| | - Marei Typlt
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada,Audifon GmbH & Co. KG, Kölleda, Germany
| | - Ashley L. Schormans
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Daniel Stolzberg
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Brian L. Allman
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada,National Centre for Audiology, Elborn College, The University of Western Ontario, London, ON, Canada
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6
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Fawcett TJ, Longenecker RJ, Brunelle DL, Berger JI, Wallace MN, Galazyuk AV, Rosen MJ, Salvi RJ, Walton JP. Universal automated classification of the acoustic startle reflex using machine learning. Hear Res 2023; 428:108667. [PMID: 36566642 PMCID: PMC10734095 DOI: 10.1016/j.heares.2022.108667] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 12/06/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
The startle reflex (SR), a robust, motor response elicited by an intense auditory, visual, or somatosensory stimulus has been widely used as a tool to assess psychophysiology in humans and animals for almost a century in diverse fields such as schizophrenia, bipolar disorder, hearing loss, and tinnitus. Previously, SR waveforms have been ignored, or assessed with basic statistical techniques and/or simple template matching paradigms. This has led to considerable variability in SR studies from different laboratories, and species. In an effort to standardize SR assessment methods, we developed a machine learning algorithm and workflow to automatically classify SR waveforms in virtually any animal model including mice, rats, guinea pigs, and gerbils obtained with various paradigms and modalities from several laboratories. The universal features common to SR waveforms of various species and paradigms are examined and discussed in the context of each animal model. The procedure describes common results using the SR across species and how to fully implement the open-source R implementation. Since SR is widely used to investigate toxicological or pharmaceutical efficacy, a detailed and universal SR waveform classification protocol should be developed to aid in standardizing SR assessment procedures across different laboratories and species. This machine learning-based method will improve data reliability and translatability between labs that use the startle reflex paradigm.
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Affiliation(s)
- Timothy J Fawcett
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, USA; Research Computing, University of South Florida, Tampa, FL, USA.
| | - Ryan J Longenecker
- Sound Pharmaceuticals Inc, 4010 Stone Way N., Suite 120, Seattle, WA 98103, USA
| | - Dimitri L Brunelle
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, USA
| | - Joel I Berger
- Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Mark N Wallace
- Hearing Sciences, School of Medicine, University of Nottingham, Nottingham, UK
| | - Alex V Galazyuk
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Merri J Rosen
- Hearing Research Group, Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Richard J Salvi
- Center for Hearing and Deafness, University at Buffalo, University of Buffalo, USA
| | - Joseph P Walton
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, USA; Department of Medical Engineering, University of South Florida, Tampa, FL, USA; Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, USA.
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7
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Protective Effect of Resveratrol in an Experimental Model of Salicylate-Induced Tinnitus. Int J Mol Sci 2022; 23:ijms232214183. [PMID: 36430660 PMCID: PMC9692321 DOI: 10.3390/ijms232214183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 11/05/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
To date, the effect of resveratrol on tinnitus has not been reported. The attenuative effects of resveratrol (RSV) on a salicylate-induced tinnitus model were evaluated by in vitro and in vivo experiments. The gene expression of the activity-regulated cytoskeleton-associated protein (ARC), tumor necrosis factor-alpha (TNFα), and NMDA receptor subunit 2B (NR2B) in SH-SY5Y cells was examined using qPCR. Phosphorylated cAMP response element-binding protein (p-CREB), apoptosis markers, and reactive oxygen species (ROS) were evaluated by in vitro experiments. The in vivo experiment evaluated the gap-prepulse inhibition of the acoustic startle reflex (GPIAS) and auditory brainstem response (ABR) level. The NR2B expression in the auditory cortex (AC) was determined by immunohistochemistry. RSV significantly reduced the salicylate-induced expression of NR2B, ARC, and TNFα in neuronal cells; the GPIAS and ABR thresholds altered by salicylate in rats were recovered close to their normal range. RSV also reduced the salicylate-induced NR2B overexpression of the AC. These results confirmed that resveratrol exerted an attenuative effect on salicylate-induced tinnitus and may have a therapeutic potential.
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8
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Scott LL, Lowe AS, Brecht EJ, Franco-Waite L, Walton JP. Small molecule modulation of the large-conductance calcium-activated potassium channel suppresses salicylate-induced tinnitus in mice. Front Neurosci 2022; 16:763855. [PMID: 36090293 PMCID: PMC9453485 DOI: 10.3389/fnins.2022.763855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 08/04/2022] [Indexed: 11/22/2022] Open
Abstract
Tinnitus is the phantom perception of sound that has no external source. A neurological signature of tinnitus, and the frequently associated hyperacusis, is an imbalance between excitatory and inhibitory activity in the central auditory system (CAS), leading to dysregulated network excitability. The large conductance, calcium-activated potassium (BK) channel is a key player in pre- and post-synaptic excitability through its mediation of K+ currents. Changes in BK channel activity are associated with aberrant network activity in sensory regions of the CNS, raising the possibility that BK channel modulation could regulate activity associated with tinnitus and hyperacusis. To test whether BK channel openers are able to suppress biomarkers of drug-induced tinnitus and hyperacusis, the 1,3,4 oxadiazole BMS-191011 was given to young adult CBA mice that had been administered 250 mg/kg sodium salicylate (SS). Systemic treatment with BMS-191011 reduced behavioral manifestations of SS-induced tinnitus, but not hyperacusis, probed via the gap-in-noise startle response method. Systemic BMS-191011 treatment did not influence SS-induced increases in auditory brainstem response functions, but local application at the inferior colliculus did reverse SS-suppressed spontaneous activity, particularly in the frequency region of the tinnitus percept. Thus, action of BMS-191011 in the inferior colliculus may contribute to the reduction in behaviorally measured tinnitus. Together, these findings support the utility of BK channel openers in reducing central auditory processing changes associated with the formation of the tinnitus percept.
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Affiliation(s)
| | - Andrea S. Lowe
- Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL, United States
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States
| | - Elliott J. Brecht
- Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL, United States
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States
| | - Luis Franco-Waite
- Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL, United States
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States
| | - Joseph P. Walton
- Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL, United States
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL, United States
- Department of Communication Sciences and Disorders, University of South Florida, Tampa, FL, United States
- *Correspondence: Joseph P. Walton,
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9
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Tziridis K, Schulze H. Preventive Effects of Ginkgo-Extract EGb 761 ® on Noise Trauma-Induced Cochlear Synaptopathy. Nutrients 2022; 14:3015. [PMID: 35893868 PMCID: PMC9330013 DOI: 10.3390/nu14153015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 07/18/2022] [Indexed: 11/26/2022] Open
Abstract
Noise trauma-induced loss of ribbon synapses at the inner hair cells (IHC) of the cochlea may lead to hearing loss (HL), resulting in tinnitus. We are convinced that a successful and sustainable therapy of tinnitus has to treat both symptom and cause. One of these causes may be the mentioned loss of ribbon synapses at the IHC of the cochlea. In this study, we investigated the possible preventive and curative effects of the Ginkgo biloba extract EGb 761® on noise-induced synaptopathy, HL, and tinnitus development in Mongolian gerbils (Meriones unguiculatus). To this end, 37 male animals received EGb 761® or placebo orally 3 weeks before (16 animals) or after (21 animals) a monaural acoustic noise trauma (2 kHz, 115 dB SPL, 75 min). Animals' hearing thresholds were determined by auditory brainstem response (ABR) audiometry. A possible tinnitus percept was assessed by the gap prepulse inhibition acoustic startle reflex (GPIAS) response paradigm. Synaptopathy was quantified by cochlear immunofluorescence histology, counting the ribbon synapses of 15 IHCs at 11 different cochlear frequency locations per ear. We found a clear preventive effect of EGb 761® on ribbon synapse numbers with the surprising result of a significant increase in synaptic innervation on the trauma side relative to placebo-treated animals. Consequently, animals treated with EGb 761® before noise trauma did not develop a significant HL and were also less affected by tinnitus compared to placebo-treated animals. On the other hand, we did not see a curative effect (EGb 761® treatment after noise trauma) of the extract on ribbon synapse numbers and, consequently, a significant HL and no difference in tinnitus development compared to the placebo-treated animals. Taken together, EGb 761® prevented noise-induced HL and tinnitus by protecting from noise trauma-induced cochlear ribbon synapse loss; however, in our model, it did not restore lost ribbon synapses.
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Affiliation(s)
| | - Holger Schulze
- Experimental Otolaryngology, ENT Clinic Head and Neck Surgery, University Hospital Erlangen, 91054 Erlangen, Germany;
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10
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The blinking eye as a window into tinnitus: A new animal model of tinnitus in the macaque. Hear Res 2022; 420:108517. [DOI: 10.1016/j.heares.2022.108517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/16/2022] [Accepted: 05/10/2022] [Indexed: 11/22/2022]
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11
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Zhang C, Ding D, Sun W, Hu BH, Manohar S, Salvi R. Time- and frequency-dependent changes in acoustic startle reflex amplitude following cyclodextrin-induced outer and inner cell loss. Hear Res 2022; 415:108441. [DOI: 10.1016/j.heares.2022.108441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 01/04/2022] [Accepted: 01/13/2022] [Indexed: 11/27/2022]
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12
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Brinkmann P, Kotz SA, Smit JV, Janssen MLF, Schwartze M. Auditory thalamus dysfunction and pathophysiology in tinnitus: a predictive network hypothesis. Brain Struct Funct 2021; 226:1659-1676. [PMID: 33934235 PMCID: PMC8203542 DOI: 10.1007/s00429-021-02284-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 04/21/2021] [Indexed: 01/12/2023]
Abstract
Tinnitus is the perception of a 'ringing' sound without an acoustic source. It is generally accepted that tinnitus develops after peripheral hearing loss and is associated with altered auditory processing. The thalamus is a crucial relay in the underlying pathways that actively shapes processing of auditory signals before the respective information reaches the cerebral cortex. Here, we review animal and human evidence to define thalamic function in tinnitus. Overall increased spontaneous firing patterns and altered coherence between the thalamic medial geniculate body (MGB) and auditory cortices is observed in animal models of tinnitus. It is likely that the functional connectivity between the MGB and primary and secondary auditory cortices is reduced in humans. Conversely, there are indications for increased connectivity between the MGB and several areas in the cingulate cortex and posterior cerebellar regions, as well as variability in connectivity between the MGB and frontal areas regarding laterality and orientation in the inferior, medial and superior frontal gyrus. We suggest that these changes affect adaptive sensory gating of temporal and spectral sound features along the auditory pathway, reflecting dysfunction in an extensive thalamo-cortical network implicated in predictive temporal adaptation to the auditory environment. Modulation of temporal characteristics of input signals might hence factor into a thalamo-cortical dysrhythmia profile of tinnitus, but could ultimately also establish new directions for treatment options for persons with tinnitus.
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Affiliation(s)
- Pia Brinkmann
- Department of Neuropsychology and Psychopharmacology, University of Maastricht, Universiteitssingel 40, 6229, Maastricht, The Netherlands.
| | - Sonja A Kotz
- Department of Neuropsychology and Psychopharmacology, University of Maastricht, Universiteitssingel 40, 6229, Maastricht, The Netherlands
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Jasper V Smit
- Department of Ear Nose and Throat/Head and Neck Surgery, Zuyderland Medical Center, Sittard/Heerlen, the Netherlands
| | - Marcus L F Janssen
- Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Michael Schwartze
- Department of Neuropsychology and Psychopharmacology, University of Maastricht, Universiteitssingel 40, 6229, Maastricht, The Netherlands
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13
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The Neural Bases of Tinnitus: Lessons from Deafness and Cochlear Implants. J Neurosci 2021; 40:7190-7202. [PMID: 32938634 DOI: 10.1523/jneurosci.1314-19.2020] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/05/2020] [Accepted: 08/08/2020] [Indexed: 02/06/2023] Open
Abstract
Subjective tinnitus is the conscious perception of sound in the absence of any acoustic source. The literature suggests various tinnitus mechanisms, most of which invoke changes in spontaneous firing rates of central auditory neurons resulting from modification of neural gain. Here, we present an alternative model based on evidence that tinnitus is: (1) rare in people who are congenitally deaf, (2) common in people with acquired deafness, and (3) potentially suppressed by active cochlear implants used for hearing restoration. We propose that tinnitus can only develop after fast auditory fiber activity has stimulated the synapse formation between fast-spiking parvalbumin positive (PV+) interneurons and projecting neurons in the ascending auditory path and coactivated frontostriatal networks after hearing onset. Thereafter, fast auditory fiber activity promotes feedforward and feedback inhibition mediated by PV+ interneuron activity in auditory-specific circuits. This inhibitory network enables enhanced stimulus resolution, attention-driven contrast improvement, and augmentation of auditory responses in central auditory pathways (neural gain) after damage of slow auditory fibers. When fast auditory fiber activity is lost, tonic PV+ interneuron activity is diminished, resulting in the prolonged response latencies, sudden hyperexcitability, enhanced cortical synchrony, elevated spontaneous γ oscillations, and impaired attention/stress-control that have been described in previous tinnitus models. Moreover, because fast processing is gained through sensory experience, tinnitus would not exist in congenital deafness. Electrical cochlear stimulation may have the potential to reestablish tonic inhibitory networks and thus suppress tinnitus. The proposed framework unites many ideas of tinnitus pathophysiology and may catalyze cooperative efforts to develop tinnitus therapies.
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Longenecker RJ, Gu R, Homan J, Kil J. A Novel Mouse Model of Aminoglycoside-Induced Hyperacusis and Tinnitus. Front Neurosci 2020; 14:561185. [PMID: 33041759 PMCID: PMC7530258 DOI: 10.3389/fnins.2020.561185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/20/2020] [Indexed: 11/13/2022] Open
Abstract
Aminoglycosides (AG) such as amikacin are commonly used in cystic fibrosis patients with opportunistic pulmonary infections including multi-drug resistant mycobacterium tuberculous and non-tuberculous mycobacterium. Unfortunately, this class of drugs is known to cause peripheral damage to the cochlea leading to hearing loss that can fluctuate and become permanent over time or multiple exposures. However, whether amikacin can lead to central auditory dysfunction like hyperacusis (increased sensitivity to sound) or tinnitus (perception of sound in the absence of acoustic stimulation) is not well-described in the literature. Thus, an animal model needs to be developed that documents these side effects in order to develop therapeutic solutions to reduce AG-induced auditory dysfunction. Here we present pioneer work in mice which demonstrates that amikacin can lead to fluctuating behavioral evidence of hyperacusis and tinnitus as assessed by the acoustic startle reflex. Additionally, electrophysiological assessments of hearing via auditory brainstem response demonstrate increased central activity in the auditory brainstem. These data together suggest that peripheral AG-induced dysfunction can lead to central hyperactivity and possible behavioral manifestations of hyperacusis and tinnitus. Importantly, we demonstrate that ebselen, a novel investigational drug that acts as both an antioxidant and anti-inflammatory, can mitigate AG-induced hyperacusis.
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Affiliation(s)
| | - Rende Gu
- Sound Pharmaceuticals, Inc., Seattle, WA, United States
| | | | - Jonathan Kil
- Sound Pharmaceuticals, Inc., Seattle, WA, United States
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15
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Lee JH, Jung JY, Park I. A Gap Prepulse with a Principal Stimulus Yields a Combined Auditory Late Response. J Audiol Otol 2020; 24:149-156. [PMID: 32397012 PMCID: PMC7364191 DOI: 10.7874/jao.2019.00374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/23/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The gap prepulse inhibition of the acoustic startle response has been used to screen tinnitus in an animal model. Here, we examined changes in the auditory late response under various conditions of gap prepulse inhibition. SUBJECTS AND METHODS We recruited 19 healthy adults (5 males, 14 females) and their auditory late responses were recorded after various stimuli with or without gap prepulsing. The N1 and P2 responses were selected for analysis. The gap prepulse inhibition was estimated to determine the optimal auditory late response in the gap prepulse paradigm. RESULTS We found that the gap per se generated a response that was very similar to the response elicited by sound stimuli. This critically affected the gap associated with the maximal inhibition of the stimulus response. Among the various gap-stimulus intervals (GSIs) between the gap and principal stimulus, the GSI of 150 ms maximally inhibited the response. However, after zero padding was used to minimize artifacts after a P2 response to a gap stimulus, the differences among the GSIs disappeared. CONCLUSIONS Overall, the data suggest that both the prepulse inhibition and the gap per se should be considered when using the gap prepulse paradigm to assess tinnitus in humans.
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Affiliation(s)
- Jae-Hun Lee
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Korea
| | - Jae Yun Jung
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Korea.,Department of Otolaryngology Head and Neck Surgery, Dankook University Hospital, Cheonan, Korea
| | - Ilyong Park
- Beckman Laser Institute Korea, College of Medicine, Dankook University, Cheonan, Korea.,Department of Biomedical Engineering, College of Medicine, Dankook University, Cheonan, Korea
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16
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Zhang W, Peng Z, Yu S, Song QL, Qu TF, Liu K, Gong SS. Exposure to sodium salicylate disrupts VGLUT3 expression in cochlear inner hair cells and contributes to tinnitus. Physiol Res 2019; 69:181-190. [PMID: 31852197 DOI: 10.33549/physiolres.934180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
To examine whether exposure to sodium salicylate disrupts expression of vesicular glutamate transporter 3 (VGLUT3) and whether the alteration in expression corresponds to increased risk for tinnitus. Rats were treated with saline (control) or sodium salicylate (treated) Rats were examined for tinnitus by monitoring gap-pre-pulse inhibition of the acoustic startle reflex (GPIAS). Auditory brainstem response (ABR) was applied to evaluate hearing function after treatment. Rats were sacrificed after injection to obtain the cochlea, cochlear nucleus (CN), and inferior colliculus (IC) for examination of VGLUT3 expression. No significant differences in hearing thresholds between groups were identified (p>0.05). Tinnitus in sodium salicylate-treated rats was confirmed by GPIAS. VGLUT3 encoded by solute carrier family 17 members 8 (SLC17a8) expression was significantly increased in inner hair cells (IHCs) of the cochlea in treated animals, compared with controls (p<0.01). No significant differences in VGLUT3 expression between groups were found for the cochlear nucleus (CN) or IC (p>0.05). Exposure to sodium salicylate may disrupt SLC17a8 expression in IHCs, leading to alterations that correspond to tinnitus in rats. However, the CN and IC are unaffected by exposure to sodium salicylate, suggesting that enhancement of VGLUT3 expression in IHCs may contribute to the pathogenesis of tinnitus.
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Affiliation(s)
- W Zhang
- Department of Otolaryngology - Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China, Z. Peng or K. Liu or S.-S. Gong
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17
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Tinnitus Correlates with Downregulation of Cortical Glutamate Decarboxylase 65 Expression But Not Auditory Cortical Map Reorganization. J Neurosci 2019; 39:9989-10001. [PMID: 31704784 DOI: 10.1523/jneurosci.1117-19.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/23/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022] Open
Abstract
Hearing loss is the biggest risk factor for tinnitus, and hearing-loss-related pathological changes in the auditory pathway have been hypothesized as the mechanism underlying tinnitus. However, due to the comorbidity of tinnitus and hearing loss, it has been difficult to differentiate between neural correlates of tinnitus and consequences of hearing loss. In this study, we dissociated tinnitus and hearing loss in FVB mice, which exhibit robust resistance to tinnitus following monaural noise-induced hearing loss. Furthermore, knock-down of glutamate decarboxylase 65 (GAD65) expression in auditory cortex (AI) by RNA interference gave rise to tinnitus in normal-hearing FVB mice. We found that tinnitus was significantly correlated with downregulation of GAD65 in the AI. By contrast, cortical map distortions, which have been hypothesized as a mechanism underlying tinnitus, were correlated with hearing loss but not tinnitus. Our findings suggest new strategies for the rehabilitation of tinnitus and other phantom sensation, such as phantom pain.SIGNIFICANCE STATEMENT Hearing loss is the biggest risk factor for tinnitus in humans. Most animal models of tinnitus also exhibit comorbid hearing loss, making it difficult to dissociate the mechanisms underlying tinnitus from mere consequences of hearing loss. Here we show that, although both C57BL/6 and FVB mice exhibited similar noise-induced hearing threshold increase, only C57BL/6, but not FVB, mice developed tinnitus following noise exposure. Although both strains showed frequency map reorganization following noise-induced hearing loss, only C57BL/6 mice had reduced glutamate decarboxylase 65 (GAD65) expression in the auditory cortex (AI). Knocking down GAD65 expression in the AI resulted in tinnitus in normal-hearing FVB mice. Our results suggest that reduced inhibitory neuronal function, but not sensory map reorganization, underlies noise-induced tinnitus.
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18
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Exposing Pathological Sensory Predictions in Tinnitus Using Auditory Intensity Deviant Evoked Responses. J Neurosci 2019; 39:10096-10103. [PMID: 31699888 PMCID: PMC6978936 DOI: 10.1523/jneurosci.1308-19.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/08/2019] [Accepted: 10/04/2019] [Indexed: 12/19/2022] Open
Abstract
We tested the popular, unproven theory that tinnitus is caused by resetting of auditory predictions toward a persistent low-intensity sound. Electroencephalographic mismatch negativity responses, which quantify the violation of sensory predictions, to unattended tinnitus-like sounds were greater in response to upward than downward intensity deviants in 26 unselected chronic tinnitus subjects with normal to severely impaired hearing, and in 15 acute tinnitus subjects, but not in 26 hearing and age-matched controls (p < 0.001, receiver operator characteristic, area under the curve, 0.77), or in 20 healthy and hearing-impaired controls presented with simulated tinnitus. The findings support a prediction resetting model of tinnitus generation, and may form the basis of a convenient tinnitus biomarker, which we name Intensity Mismatch Asymmetry, which is usable across species, is quick and tolerable, and requires no training.SIGNIFICANCE STATEMENT In current models, perception is based around the generation of internal predictions of the environment, which are tested and updated using evidence from the senses. Here, we test the theory that auditory phantom perception (tinnitus) occurs when a default auditory prediction is formed to explain spontaneous activity in the subcortical pathway, rather than ignoring it as noise. We find that chronic tinnitus patients show an abnormal pattern of evoked responses to unexpectedly loud and quiet sounds that both supports this hypothesis and provides fairly accurate classification of tinnitus status at the individual subject level. This approach to objectively demonstrating the predictions underlying pathological perceptual states may also have a much wider utility, for instance, in chronic pain.
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19
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Escabi CD, Frye MD, Trevino M, Lobarinas E. The rat animal model for noise-induced hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3692. [PMID: 31795685 PMCID: PMC7480078 DOI: 10.1121/1.5132553] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Rats make excellent models for the study of medical, biological, genetic, and behavioral phenomena given their adaptability, robustness, survivability, and intelligence. The rat's general anatomy and physiology of the auditory system is similar to that observed in humans, and this has led to their use for investigating the effect of noise overexposure on the mammalian auditory system. The current paper provides a review of the rat model for studying noise-induced hearing loss and highlights advancements that have been made using the rat, particularly as these pertain to noise dose and the hazardous effects of different experimental noise types. In addition to the traditional loss of auditory function following acoustic trauma, recent findings have indicated the rat as a useful model in observing alterations in neuronal processing within the central nervous system following noise injury. Furthermore, the rat provides a second animal model when investigating noise-induced cochlear synaptopathy, as studies examining this in the rat model resemble the general patterns observed in mice. Together, these findings demonstrate the relevance of this animal model for furthering the authors' understanding of the effects of noise on structural, anatomical, physiological, and perceptual aspects of hearing.
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Affiliation(s)
- Celia D Escabi
- Callier Center for Communication Disorders, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
| | - Mitchell D Frye
- Callier Center for Communication Disorders, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
| | - Monica Trevino
- Callier Center for Communication Disorders, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
| | - Edward Lobarinas
- Callier Center for Communication Disorders, School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
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20
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Naert G, Pasdelou MP, Le Prell CG. Use of the guinea pig in studies on the development and prevention of acquired sensorineural hearing loss, with an emphasis on noise. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3743. [PMID: 31795705 PMCID: PMC7195866 DOI: 10.1121/1.5132711] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/30/2019] [Accepted: 08/12/2019] [Indexed: 05/10/2023]
Abstract
Guinea pigs have been used in diverse studies to better understand acquired hearing loss induced by noise and ototoxic drugs. The guinea pig has its best hearing at slightly higher frequencies relative to humans, but its hearing is more similar to humans than the rat or mouse. Like other rodents, it is more vulnerable to noise injury than the human or nonhuman primate models. There is a wealth of information on auditory function and vulnerability of the inner ear to diverse insults in the guinea pig. With respect to the assessment of potential otoprotective agents, guinea pigs are also docile animals that are relatively easy to dose via systemic injections or gavage. Of interest, the cochlea and the round window are easily accessible, notably for direct cochlear therapy, as in the chinchilla, making the guinea pig a most relevant and suitable model for hearing. This article reviews the use of the guinea pig in basic auditory research, provides detailed discussion of its use in studies on noise injury and other injuries leading to acquired sensorineural hearing loss, and lists some therapeutics assessed in these laboratory animal models to prevent acquired sensorineural hearing loss.
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Affiliation(s)
| | | | - Colleen G Le Prell
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
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21
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Holt AG, Kühl A, Braun RD, Altschuler R. The rat as a model for studying noise injury and otoprotection. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3681. [PMID: 31795688 DOI: 10.1121/1.5131344] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A major challenge for those studying noise-induced injury pre-clinically is the selection of an animal model. Noise injury models are particularly relevant in an age when people are constantly bombarded by loud noise due to occupation and/or recreation. The rat has been widely used for noise-related morphological, physiological, biochemical, and molecular assessment. Noise exposure resulting in a temporary (TTS) or permanent threshold shift (PTS) yields trauma in peripheral and central auditory related pathways. While the precise nature of noise-related injuries continues to be delineated, both PTS and TTS (with or without hidden hearing loss) result in homeostatic changes implicated in conditions such as tinnitus and hyperacusis. Compared to mice, rats generally tolerate exposure to loud sounds reasonably well, often without exhibiting other physical non-inner ear related symptoms such as death, loss of consciousness, or seizures [Skradski, Clark, Jiang, White, Fu, and Ptacek (2001). Neuron 31, 537-544; Faingold (2002). Hear. Res. 168, 223-237; Firstova, Abaimov, Surina, Poletaeva, Fedotova, and Kovalev (2012). Bull Exp. Biol. Med. 154, 196-198; De Sarro, Russo, Citraro, and Meldrum (2017). Epilepsy Behav. 71, 165-173]. This ability of the rat to thrive following noise exposure permits study of long-term effects. Like the mouse, the rat also offers a well-characterized genome allowing genetic manipulations (i.e., knock-out, viral-based gene expression modulation, and optogenetics). Rat models of noise-related injury also provide valuable information for understanding mechanistic changes to identify therapeutic targets for treatment. This article provides a framework for selection of the rat as a model for noise injury studies.
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Affiliation(s)
- Avril Genene Holt
- Department of Ophthalmology, Visual, and Anatomical Sciences (OVAS), School of Medicine, Wayne State University, 550 East Canfield Avenue, 454 Lande Building, Detroit, Michigan 48201, USA
| | - André Kühl
- Department of Ophthalmology, Visual, and Anatomical Sciences (OVAS), School of Medicine, Wayne State University, 550 East Canfield Avenue, 454 Lande Building, Detroit, Michigan 48201, USA
| | - Rod D Braun
- Department of Ophthalmology, Visual, and Anatomical Sciences (OVAS), School of Medicine, Wayne State University, 550 East Canfield Avenue, 454 Lande Building, Detroit, Michigan 48201, USA
| | - Richard Altschuler
- Department of Otolaryngology; Cell and Developmental Biology, Kresge Hearing Research Institute, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, Michigan 48109, USA
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22
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Rybalko N, Mitrovic D, Šuta D, Bureš Z, Popelář J, Syka J. Behavioral evaluation of auditory function abnormalities in adult rats with normal hearing thresholds that were exposed to noise during early development. Physiol Behav 2019; 210:112620. [DOI: 10.1016/j.physbeh.2019.112620] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 06/07/2019] [Accepted: 07/15/2019] [Indexed: 11/25/2022]
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23
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Morse K, Vander Werff KR. Comparison of Silent Gap in Noise Cortical Auditory Evoked Potentials in Matched Tinnitus and No-Tinnitus Control Subjects. Am J Audiol 2019; 28:260-273. [PMID: 31184965 DOI: 10.1044/2018_aja-18-0074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purpose Previous research suggests the existence of gap detection impairments because of tinnitus. The current study aimed to determine whether there was objective evidence of gap impairment in individuals with tinnitus by recording silent gap in white noise cortical auditory evoked potentials (CAEPs) in a chronic tinnitus group and a no-tinnitus group. The results were compared to previous gap-evoked potential and behavioral gap detection studies. Method Chronic tinnitus and no-tinnitus groups were formed by matching pairs of subjects ( n = 26) based on age, gender, and hearing thresholds. Behaviorally determined gap detection thresholds were used to define the electrophysiological gap duration conditions of subthreshold, threshold, and suprathreshold gaps in white noise. Amplitude, latency, and area of the CAEP were analyzed by group and condition using mixed-model analyses of variance. Results Across all participants, as the duration of the gap increased, amplitude and area of the CAEP increased. There were no significant differences by tinnitus status between groups for any outcome measures, except for a significant interaction between group and gap duration for P1 latency. Conclusions Silent gap-evoked CAEPs can be recorded in adults with and without tinnitus. Amplitude and area were sensitive to gap duration across groups; latency was not. Contrary to hypotheses, there was little evidence supporting differences in gap-evoked CAEPs between the tinnitus and control groups. Stimulus and other factors that may have contributed to the lack of a group difference in the current study are discussed, as well as implications for future studies of objective measures of tinnitus perception. Supplemental Material https://doi.org/10.23641/asha.7822601.
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Affiliation(s)
- Kenneth Morse
- Department of Communication Sciences and Disorders, Syracuse University, New York
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24
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Hayes SH, Manohar S, Majumdar A, Allman BL, Salvi R. Noise-induced hearing loss alters hippocampal glucocorticoid receptor expression in rats. Hear Res 2019; 379:43-51. [PMID: 31071644 DOI: 10.1016/j.heares.2019.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/25/2019] [Accepted: 04/24/2019] [Indexed: 12/11/2022]
Abstract
Although the effects of intense noise exposure on the peripheral and central auditory pathway have been well characterized, its effects on non-classical auditory structures in the brain, such as the hippocampus, are less well understood. Previously, we demonstrated that noise-induced hearing loss causes a significant long-term reduction in hippocampal neurogenesis and cell proliferation. Given the known suppressive effects of stress hormones on neurogenesis, the goal of the present study was to determine if activation of the stress response is an underlying mechanism for the long-term reduction in hippocampal neurogenesis observed following noise trauma. To accomplish this, we monitored basal and reactive blood plasma levels of the stress hormone corticosterone in rats for ten weeks following acoustic trauma, and quantified changes in hippocampal glucocorticoid and mineralocorticoid receptors. Our results indicate that long-term auditory deprivation does not cause a persistent increase in basal or reactive stress hormone levels in the weeks following noise exposure. Instead, we observed a greater decline in reactive corticosterone release in noise-exposed rats between the first and tenth week of sampling compared to control rats. We also observed a significant increase in hippocampal glucocorticoid receptor expression which may cause greater hippocampal sensitivity to circulating glucocorticoid levels and result in glucocorticoid-induced suppression of neurogenesis, as well as increased feedback inhibition on the HPA axis. No change in mineralocorticoid receptor expression was observed between control and noise exposed rats. These results highlight the adverse effect of intense noise exposure and auditory deprivation on the hippocampus.
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Affiliation(s)
- Sarah H Hayes
- Center for Hearing and Deafness, The State University of New York at Buffalo, Buffalo, NY, USA; Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, Ontario, N6A 5C1, Canada.
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, The State University of New York at Buffalo, Buffalo, NY, USA
| | - Antara Majumdar
- Center for Hearing and Deafness, The State University of New York at Buffalo, Buffalo, NY, USA
| | - Brian L Allman
- Center for Hearing and Deafness, The State University of New York at Buffalo, Buffalo, NY, USA; Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, Ontario, N6A 5C1, Canada
| | - Richard Salvi
- Center for Hearing and Deafness, The State University of New York at Buffalo, Buffalo, NY, USA
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25
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Pienkowski M. Prolonged Exposure of CBA/Ca Mice to Moderately Loud Noise Can Cause Cochlear Synaptopathy but Not Tinnitus or Hyperacusis as Assessed With the Acoustic Startle Reflex. Trends Hear 2019. [PMID: 29532738 PMCID: PMC5858683 DOI: 10.1177/2331216518758109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hearing loss changes the auditory brain, sometimes maladaptively. When deprived of cochlear input, central auditory neurons become more active spontaneously and begin to respond more strongly and synchronously to better preserved sound frequencies. This spontaneous and sound-evoked central hyperactivity has been postulated to trigger tinnitus and hyperacusis, respectively. Localized hyperactivity has also been observed after long-term exposure to noise levels that do not damage the cochlea. Adult animals exposed to bands of nondamaging noise exhibited suppressed spontaneous and sound-evoked activity in the area of primary auditory cortex (A1) stimulated by the exposure band but had increased spontaneous and evoked activity in neighboring A1 areas. We hypothesized that the cortically suppressed frequencies should for some time after exposure be perceived as less loud than before (hypoacusis), whereas the hyperactivity outside of the exposure band might lead to frequency-specific hyperacusis or tinnitus. To investigate this, adult CBA/Ca mice were exposed for >2 months to 8 to 16 kHz noise at 70 or 75 dB sound pressure level and tested for hypo-/hyperacusis and tinnitus using tone and gap prepulse inhibition of the acoustic startle reflex. Auditory brainstem responses and distortion product otoacoustic emissions showed evidence of cochlear synaptopathy after exposure at 75 but not 70 dB, putting a lower bound on damaging noise levels for CBA/Ca mice. Contrary to hypothesis, neither exposure significantly shifted startle results from baseline. These negative findings nevertheless have implications for startle test methodology and for the putative role of central hyperactivity in hyperacusis and tinnitus.
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Affiliation(s)
- Martin Pienkowski
- 1 Osborne College of Audiology, Salus University, Elkins Park, PA, USA
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26
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Wu C, Bao W, Yi B, Wang Q, Wu X, Qian M, Zuo C, Huang Z. Increased metabolic activity and hysteretic enhanced GABA A receptor binding in a rat model of salicylate-induced tinnitus. Behav Brain Res 2019; 364:348-355. [PMID: 30797852 DOI: 10.1016/j.bbr.2019.02.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 11/16/2022]
Abstract
Tinnitus is relevant to neural hyperactivity in the central nervous system (CNS). Normal quantity and functioning of the γ-aminobutyric acid (GABA) receptor are crucial for maintaining the balance between excitation and inhibition in the brain. In this study, we applied a rat model of tinnitus via long-term salicylate administration. The combination of the gap pre-pulse inhibition of acoustic startle (GPIAS) and pre-pulse inhibition (PPI) tests were used to detect tinnitus-like behavior, and rats receiving 7 or 14 consecutive days of salicylate administration showed evidence of tinnitus. After positron emission tomography (PET) scan, we found that the metabolic activity was increased after salicylate treatment followed by enhanced GABAA receptor binding with cessation of salicylate administration in the auditory cortex (AC), medial prefrontal cortex (mPFC), hippocampus (HP), cingulate cortex (CiC) and insular (InC). The inferior colliculus (IC) showed an elevated metabolic activity with no change in the GABAA receptor binding. All the alterations returned to baseline several days after cessation of salicylate treatment despite a mismatch between the time-course of them. By contrast, we found alterations in neither the metabolic activity nor the GABAA receptor binding in the amygdala (AMY) and cerebellum (CRB). These findings indicate that enhanced neural activity in the auditory and limbic system may contribute to the development of tinnitus, while the hysteretic increase of GABAA receptor binding in specific areas of the CNS may be a compensation for hyperactivity, which may be involved in tinnitus relieving.
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Affiliation(s)
- Cong Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Weiqi Bao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Bin Yi
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Qixuan Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Xu Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Minfei Qian
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Chuantao Zuo
- PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Zhiwu Huang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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27
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Shimoji M, Ramaswamy B, Shukoor MI, Benhal P, Broda A, Kulkarni S, Malik P, McCaffrey B, Lafond JF, Nacev A, Weinberg IN, Shapiro B, Depireux DA. Toxicology study for magnetic injection of prednisolone into the rat cochlea. Eur J Pharm Sci 2019; 126:33-48. [PMID: 29933075 PMCID: PMC6235712 DOI: 10.1016/j.ejps.2018.06.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/31/2018] [Accepted: 06/12/2018] [Indexed: 01/28/2023]
Abstract
This paper investigates the safety of a novel 'magnetic injection' method of delivering therapy to the cochlea, in a rodent model. In this method of administration, a magnetic field is employed to actively transport drug-eluting superparamagnetic iron-oxide core nanoparticles into the cochlea, where they then release their drug payload (we delivered the steroid prednisolone). Our study design and selection of control groups was based on published regulatory guidance for safety studies that involve local drug delivery. We tested for both single and multiple delivery doses to the cochlea, and found that magnetic delivery did not harm hearing. There was no statistical difference in hearing between magnetically treated ears versus ears that received intra-tympanic steroid (a mimic of a standard-of-care for sudden sensorineural hearing loss), both 2 and 30 days after treatment. Since our treatment is local to the ear, the levels of steroid and iron circulating systemically after our treatment were low, below mass-spectrometry detection limits for the steroid and no different from normal for iron. No adverse findings were observed in ear tissue histopathology or in animal gross behavior. At 2 and 30 days after treatment, inflammatory changes examined in the ear were limited to the middle ear, were very mild in severity, and by day 90 there was ongoing and almost complete reversibility of these changes. There were no ear tissue scarring or hemorrhage trends associated with magnetic delivery. In summary, after conducting a pre-clinical safety study, no adverse safety issues were observed.
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Affiliation(s)
- M Shimoji
- Otomagnetics, Inc., Rockville, MD 20852, United States of America.
| | - B Ramaswamy
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | - M I Shukoor
- Otomagnetics, Inc., Rockville, MD 20852, United States of America
| | - P Benhal
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | - A Broda
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | - S Kulkarni
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | - P Malik
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | - B McCaffrey
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | | | - A Nacev
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| | - I N Weinberg
- Otomagnetics, Inc., Rockville, MD 20852, United States of America
| | - B Shapiro
- Otomagnetics, Inc., Rockville, MD 20852, United States of America; Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America; Institute for Systems Research (ISR), University of Maryland, College Park, MD 20742, United States of America
| | - D A Depireux
- Otomagnetics, Inc., Rockville, MD 20852, United States of America; Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America; Institute for Systems Research (ISR), University of Maryland, College Park, MD 20742, United States of America
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Möhrle D, Hofmeier B, Amend M, Wolpert S, Ni K, Bing D, Klose U, Pichler B, Knipper M, Rüttiger L. Enhanced Central Neural Gain Compensates Acoustic Trauma-induced Cochlear Impairment, but Unlikely Correlates with Tinnitus and Hyperacusis. Neuroscience 2018; 407:146-169. [PMID: 30599268 DOI: 10.1016/j.neuroscience.2018.12.038] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 01/09/2023]
Abstract
For successful future therapeutic strategies for tinnitus and hyperacusis, a subcategorization of both conditions on the basis of differentiated neural correlates would be of invaluable advantage. In the present study, we used our refined operant conditioning animal model to divide equally noise-exposed rats into groups with either tinnitus or hyperacusis, with neither condition, or with both conditions co-occurring simultaneously. Using click stimulus and noise burst-evoked Auditory Brainstem Responses (ABR) and Distortion Product Otoacoustic Emissions, no hearing threshold difference was observed between any of the groups. However, animals with neither tinnitus nor hyperacusis responded to noise trauma with shortened ABR wave I and IV latencies and elevated central neuronal gain (increased ABR wave IV/I amplitude ratio), which was previously assumed in most of the literature to be a neural correlate for tinnitus. In contrast, animals with tinnitus had reduced neural response gain and delayed ABR wave I and IV latencies, while animals with hyperacusis showed none of these changes. Preliminary studies, aimed at establishing comparable non-invasive objective tools for identifying tinnitus in humans and animals, confirmed reduced central gain and delayed response latency in human and animals. Moreover, the first ever resting state functional Magnetic Resonance Imaging (rs-fMRI) analyses comparing humans and rats with and without tinnitus showed reduced rs-fMRI activities in the auditory cortex in both patients and animals with tinnitus. These findings encourage further efforts to establish non-invasive diagnostic tools that can be used in humans and animals alike and give hope for differentiated classification of tinnitus and hyperacusis.
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Affiliation(s)
- Dorit Möhrle
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
| | - Benedikt Hofmeier
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
| | - Mario Amend
- University of Tübingen, Department of Preclinical Imaging and Radiopharmacy, University Hospital Tübingen, Röntgenweg 13, 72076 Tübingen, Germany.
| | - Stephan Wolpert
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
| | - Kun Ni
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany; Shanghai Jiao Tong University, Department of Otolaryngology, Head & Neck Surgery, Shanghai Children's Hospital, Shanghai Luding Road, NO. 355. Putuo District, 200062 Shanghai, China.
| | - Dan Bing
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
| | - Uwe Klose
- University Hospital Tübingen, Department of Diagnostic and Interventional Neuroradiology, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany.
| | - Bernd Pichler
- University of Tübingen, Department of Preclinical Imaging and Radiopharmacy, University Hospital Tübingen, Röntgenweg 13, 72076 Tübingen, Germany.
| | - Marlies Knipper
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
| | - Lukas Rüttiger
- University of Tübingen, Department of Otolaryngology, Head & Neck Surgery, Tübingen Hearing Research Centre (THRC), Molecular Physiology of Hearing, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
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Wu C, Wu X, Yi B, Cui M, Wang X, Wang Q, Wu H, Huang Z. Changes in GABA and glutamate receptors on auditory cortical excitatory neurons in a rat model of salicylate-induced tinnitus. Am J Transl Res 2018; 10:3941-3955. [PMID: 30662641 PMCID: PMC6325520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/18/2018] [Indexed: 06/09/2023]
Abstract
Tinnitus is associated with neural hyperactivity, which is regulated by neuronal plasticity in the auditory central system, especially the auditory cortex (AC). Excitatory neurons constitute approximately 70-85% of the total populations of neuronal cells. However, few reports have focused on the AMPA receptor (AMPAR) and the GABAA receptor (GABAAR) on the excitatory neuron in animal model of tinnitus. In this study, we gave rats a single or long-term of salicylate administrations. The tinnitus-like behavior was assessed by combination of the gap prepulse inhibition of acoustic startle (GPIAS) and the pre-pulse inhibition (PPI) tests. Using immunofluorescent staining, we examined whether the AMPAR and the GABAAR on the calcium/calmodulin-dependent protein kinase IIα (CaMKIIα) -labeled excitatory neurons in the auditory cortex underwent changes following salicylate treatment. The rats with 14 days of salicylate administration showed evidence of experiencing tinnitus, while the rats receiving a single dose of salicylate manifested no tinnitus-like behavior. Furthermore, the AMPAR and GABAAR responded in a homeostatic manner after a single dose of salicylate while those showing in a Hebbian way after long-term salicylate administration. Thus, the different patterns of plasticity change in cortical excitatory neurons might affect the generating of salicylate-induced tinnitus.
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Affiliation(s)
- Cong Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Xu Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Bin Yi
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Mengchen Cui
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Xueling Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Qixuan Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Hao Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
| | - Zhiwu Huang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Laboratory of Auditory Neuroscience, Ear Institute, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai, China
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Haider HF, Bojić T, Ribeiro SF, Paço J, Hall DA, Szczepek AJ. Pathophysiology of Subjective Tinnitus: Triggers and Maintenance. Front Neurosci 2018; 12:866. [PMID: 30538616 PMCID: PMC6277522 DOI: 10.3389/fnins.2018.00866] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 11/06/2018] [Indexed: 01/07/2023] Open
Abstract
Tinnitus is the conscious perception of a sound without a corresponding external acoustic stimulus, usually described as a phantom perception. One of the major challenges for tinnitus research is to understand the pathophysiological mechanisms triggering and maintaining the symptoms, especially for subjective chronic tinnitus. Our objective was to synthesize the published literature in order to provide a comprehensive update on theoretical and experimental advances and to identify further research and clinical directions. We performed literature searches in three electronic databases, complemented by scanning reference lists from relevant reviews in our included records, citation searching of the included articles using Web of Science, and manual searching of the last 6 months of principal otology journals. One-hundred and thirty-two records were included in the review and the information related to peripheral and central mechanisms of tinnitus pathophysiology was collected in order to update on theories and models. A narrative synthesis examined the main themes arising from this information. Tinnitus pathophysiology is complex and multifactorial, involving the auditory and non-auditory systems. Recent theories assume the necessary involvement of extra-auditory brain regions for tinnitus to reach consciousness. Tinnitus engages multiple active dynamic and overlapping networks. We conclude that advancing knowledge concerning the origin and maintenance of specific tinnitus subtypes origin and maintenance mechanisms is of paramount importance for identifying adequate treatment.
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Affiliation(s)
- Haúla Faruk Haider
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - Tijana Bojić
- Laboratory of Radiobiology and Molecular Genetics, Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
| | - Sara F Ribeiro
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - João Paço
- ENT Department, Hospital Cuf Infante Santo - NOVA Medical School, Lisbon, Portugal
| | - Deborah A Hall
- NIHR Nottingham Biomedical Research Centre, Nottingham, United Kingdom.,Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom.,Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom.,University of Nottingham Malaysia, Semeniyh, Malaysia
| | - Agnieszka J Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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31
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van Zwieten G, Janssen MLF, Smit JV, Janssen AML, Roet M, Jahanshahi A, Stokroos RJ, Temel Y. Inhibition of Experimental Tinnitus With High Frequency Stimulation of the Rat Medial Geniculate Body. Neuromodulation 2018; 22:416-424. [PMID: 30102446 PMCID: PMC6618158 DOI: 10.1111/ner.12795] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/28/2018] [Accepted: 05/02/2018] [Indexed: 12/24/2022]
Abstract
BACKGROUND Neuromodulation is a promising treatment modality for tinnitus, especially in chronic and severe cases. The auditory thalamus plays a key role in the pathophysiology of tinnitus, as it integrates and processes auditory and limbic information. OBJECTIVE The effect of high frequency stimulation and low frequency stimulation of the medial geniculate bodies on tinnitus in a noise-induced tinnitus rat model is assessed. MATERIALS AND METHODS Presence of tinnitus was verified using the gap-induced prepulse inhibition of the acoustic startle response paradigm. Hearing thresholds were determined before and after noise trauma with auditory brainstem responses. Anxiety-related side-effects were evaluated in the elevated zero maze and open field. RESULTS Results show tinnitus development after noise exposure and preserved hearing thresholds of the ear that was protected from noise trauma. We found that high frequency stimulation of the medial geniculate bodies suppressed tinnitus. This effect maintained directly after stimulation when the stimulator was turned off. Low frequency stimulation did not have any effects on the gap:no-gap ratio of the acoustic startle response. CONCLUSION High frequency stimulation of the MGB has a direct and residual suppressing effect on tinnitus in this animal model. Low frequency stimulation of the MGB did not inhibit tinnitus.
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Affiliation(s)
- Gusta van Zwieten
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Marcus L F Janssen
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurology and Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jasper V Smit
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A Miranda L Janssen
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Methodology and Statistics, School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands
| | - Milaine Roet
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ali Jahanshahi
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Robert J Stokroos
- Department of Ear Nose and Throat/Head and Neck Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Yasin Temel
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
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32
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Baizer JS, Wong KM, Salvi RJ, Manohar S, Sherwood CC, Hof PR, Baker JF, Witelson SF. Species Differences in the Organization of the Ventral Cochlear Nucleus. Anat Rec (Hoboken) 2018; 301:862-886. [PMID: 29236365 PMCID: PMC5902649 DOI: 10.1002/ar.23751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 08/18/2017] [Accepted: 09/17/2017] [Indexed: 01/18/2023]
Abstract
The mammalian cochlear nuclei (CN) consist of two major subdivisions, the dorsal (DCN) and ventral (VCN) nuclei. We previously reported differences in the structural and neurochemical organization of the human DCN from that in several other species. Here we extend this analysis to the VCN, considering both the organization of subdivisions and the types and distributions of neurons. Classically, the VCN in mammals is composed of two subdivisions, the anteroventral (VCA) and posteroventral cochlear nuclei (VCP). Anatomical and electrophysiological data in several species have defined distinct neuronal types with different distributions in the VCA and VCP. We asked if VCN subdivisions and anatomically defined neuronal types might be distinguished by patterns of protein expression in humans. We also asked if the neurochemical characteristics of the VCN are the same in humans as in other mammalian species, analyzing data from chimpanzees, macaque monkeys, cats, rats and chinchillas. We examined Nissl- and immunostained sections, using antibodies that had labeled neurons in other brainstem nuclei in humans. Nissl-stained sections supported the presence of both VCP and VCA in humans and chimpanzees. However, patterns of protein expression did not differentiate classes of neurons in humans; neurons of different soma shapes and dendritic configurations all expressed the same proteins. The patterns of immunostaining in macaque monkey, cat, rat, and chinchilla were different from those in humans and chimpanzees and from each other. The results may correlate with species differences in auditory function and plasticity. Anat Rec, 301:862-886, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Joan S Baizer
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York
| | - Keit Men Wong
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York
| | - Richard J Salvi
- Department of Communicative Disorders and Sciences, Center for Hearing and Deafness, University at Buffalo, Buffalo, New York
| | - Senthilvelan Manohar
- Department of Communicative Disorders and Sciences, Center for Hearing and Deafness, University at Buffalo, Buffalo, New York
| | - Chet C Sherwood
- Department of Anthropology, The George Washington University, Washington, DC
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - James F Baker
- Department of Physiology, Northwestern University Medical School, Chicago, Illinois
| | - Sandra F Witelson
- Department of Psychiatry and Behavioural Neurosciences, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, L8S 4K1, Canada
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33
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Longenecker RJ, Kristaponyte I, Nelson GL, Young JW, Galazyuk AV. Addressing variability in the acoustic startle reflex for accurate gap detection assessment. Hear Res 2018; 363:119-135. [PMID: 29602592 DOI: 10.1016/j.heares.2018.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/06/2018] [Accepted: 03/09/2018] [Indexed: 11/18/2022]
Abstract
The acoustic startle reflex (ASR) is subject to substantial variability. This inherent variability consequently shapes the conclusions drawn from gap-induced prepulse inhibition of the acoustic startle reflex (GPIAS) assessments. Recent studies have cast doubt as to the efficacy of this methodology as it pertains to tinnitus assessment, partially, due to variability in and between data sets. The goal of this study was to examine the variance associated with several common data collection variables and data analyses with the aim to improve GPIAS reliability. To study this the GPIAS tests were conducted in adult male and female CBA/CaJ mice. Factors such as inter-trial interval, circadian rhythm, sex differences, and sensory adaptation were each evaluated. We then examined various data analysis factors which influence GPIAS assessment. Gap-induced facilitation, data processing options, and assessments of tinnitus were studied. We found that the startle reflex is highly variable in CBA/CaJ mice, but this can be minimized by certain data collection factors. We also found that careful consideration of temporal fluctuations of the ASR and controlling for facilitation can lead to more accurate GPIAS results. This study provides a guide for reducing variance in the GPIAS methodology - thereby improving the diagnostic power of the test.
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Affiliation(s)
- Ryan J Longenecker
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA
| | - Inga Kristaponyte
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA; Biomedical Sciences Program, Kent State University, Kent, OH, USA
| | - Gregg L Nelson
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA
| | - Jesse W Young
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA
| | - Alexander V Galazyuk
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA.
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34
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Berger JI, Owen W, Wilson CA, Hockley A, Coomber B, Palmer AR, Wallace MN. Gap-induced reductions of evoked potentials in the auditory cortex: A possible objective marker for the presence of tinnitus in animals. Brain Res 2017; 1679:101-108. [PMID: 29191772 PMCID: PMC5780299 DOI: 10.1016/j.brainres.2017.11.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/09/2017] [Accepted: 11/23/2017] [Indexed: 01/03/2023]
Abstract
Gap-suppression of startle responses is regularly used as a measure for tinnitus. We studied this phenomenon in auditory cortical evoked potentials in awake animals. Gap-suppression of evoked potentials was also examined following noise exposure. 120 dB SPL noise exposure, but not 105 dB, resulted in deficits in gap-suppression. Results are discussed in the context of a potential correlate of tinnitus.
Animal models of tinnitus are essential for determining the underlying mechanisms and testing pharmacotherapies. However, there is doubt over the validity of current behavioural methods for detecting tinnitus. Here, we applied a stimulus paradigm widely used in a behavioural test (gap-induced inhibition of the acoustic startle reflex GPIAS) whilst recording from the auditory cortex, and showed neural response changes that mirror those found in the behavioural tests. We implanted guinea pigs (GPs) with electrocorticographic (ECoG) arrays and recorded baseline auditory cortical responses to a startling stimulus. When a gap was inserted in otherwise continuous background noise prior to the startling stimulus, there was a clear reduction in the subsequent evoked response (termed gap-induced reductions in evoked potentials; GIREP), suggestive of a neural analogue of the GPIAS test. We then unilaterally exposed guinea pigs to narrowband noise (left ear; 8–10 kHz; 1 h) at one of two different sound levels – either 105 dB SPL or 120 dB SPL – and recorded the same responses seven-to-ten weeks following the noise exposure. Significant deficits in GIREP were observed for all areas of the auditory cortex (AC) in the 120 dB-exposed GPs, but not in the 105 dB-exposed GPs. These deficits could not simply be accounted for by changes in response amplitudes. Furthermore, in the contralateral (right) caudal AC we observed a significant increase in evoked potential amplitudes across narrowband background frequencies in both 105 dB and 120 dB-exposed GPs. Taken in the context of the large body of literature that has used the behavioural test as a demonstration of the presence of tinnitus, these results are suggestive of objective neural correlates of the presence of noise-induced tinnitus and hyperacusis.
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Affiliation(s)
- Joel I Berger
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - William Owen
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Caroline A Wilson
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Adam Hockley
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ben Coomber
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Alan R Palmer
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Mark N Wallace
- Medical Research Council Institute of Hearing Research, School of Medicine, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
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Han JH, Won JY, Hong SK, Kim JH, Kim ES, Kim HJ, Lee HJ. Objective measurement of subjective tinnitus using the acoustic change complex. PLoS One 2017; 12:e0188268. [PMID: 29176873 PMCID: PMC5703484 DOI: 10.1371/journal.pone.0188268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/05/2017] [Indexed: 11/18/2022] Open
Abstract
At present, there is no objective method for diagnosing subjective sensorineural tinnitus. Recently, the acoustic change complex (ACC) has been used to evaluate neural detection of sounds. Thus, the present study aimed to examine whether the ACC can reflect cortical detection and discrimination of sounds matched with tinnitus frequencies. We hypothesized that the ACC to change stimuli matched with tinnitus frequencies would be decreased in tinnitus patients because the tinnitus interferes with the perception of acoustic changes. To test the hypothesis, 96 ears of normal-hearing (NH) tinnitus patients and controls were tested. Among the tinnitus patients, 33 ears with a tinnitus frequency of 8 kHz constituted the tinnitus group, and the remaining 63 ears with no experience of tinnitus were allocated to the control group. For the 4 kHz non-tinnitus matched frequency, a subset of tinnitus (n = 17) and NH (n = 47) subjects was tested. The acoustic stimuli were pure tones with a total duration of 500 ms consisting of a 1 kHz tone in the first 250 ms and a second tone of either 8 kHz or 4 kHz in the latter 250 ms. The normalized amplitude of the ACC (naACC) was calculated separately for the amplitude of the N1'-P2' complex evoked by an 8 kHz or 4 kHz change stimulus and for the amplitude of the N1-P2 complex elicited by the initial 1 kHz background stimulus. Our results showed that the naACC to an 8 kHz stimulus in the tinnitus group was significantly smaller than those to 4 kHz and 8 kHz in normal controls. Additionally, in the tinnitus group, the naACC to 4 kHz was greater compared to 8 kHz. The receiver operating characteristic (ROC) curve analysis conducted for naACC to 8 kHz at UCL revealed a fair degree of diagnostic efficacy. Overall, our results indicated that the ACC to a change stimulus matched with the tinnitus frequency can provide an objective measure of frequency-specific tinnitus.
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Affiliation(s)
- Ji-Hye Han
- Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Joong Yeon Won
- Department of Otolaryngology, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Sung Kwang Hong
- Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea
- Department of Otolaryngology, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Ja Hee Kim
- Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Eun Soo Kim
- Department of Neuroradiology, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Hyung-Jong Kim
- Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea
- Department of Otolaryngology, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - Hyo-Jeong Lee
- Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea
- Department of Otolaryngology, Hallym University College of Medicine, Chuncheon, Republic of Korea
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36
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Allen PD, Luebke AE. Reflex Modification Audiometry Reveals Dual Roles for Olivocochlear Neurotransmission. Front Cell Neurosci 2017; 11:361. [PMID: 29213229 PMCID: PMC5702649 DOI: 10.3389/fncel.2017.00361] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 11/03/2017] [Indexed: 11/23/2022] Open
Abstract
Approximately 15% of American adults report some degree of difficulty hearing in a noisy environment or have auditory filtering difficulties. There are objective clinical tests of auditory filtering, yet few tests exist for mouse models that do not rely on extensive training. We have used reflex modification audiometry (RMA) and developed exclusion criteria for the mouse model. This RMA based test makes use of the acoustic startle response (ASR) and the ability of prepulses to inhibit the ASR [i.e., prepulse inhibition (PPI)] to assess the mouse's ability to detect prepulse signals presented in quiet or embedded in masking noise. We have studied PPI behavior across four inbred mouse strains with normal cochlear function and developed pre-testing exclusion criteria and test/retest reliability measures. Moreover, because both the medial (MOC) and the lateral (LOC) olivocochlear efferent feedback systems have been proposed to improve auditory behavior performance, especially in noisy backgrounds, we have examined PPI abilities in mice (with their littermate controls) either lacking the MOC receptor subunit α9 nicotinic acetylcholine receptor [α9 nAChR (–/–)] or expressing an overactive receptor [Ld'T mutation in α9 nAChR KI], or lacking an LOC efferent neuropeptide, alpha calcitonin gene-related peptide [αCGRP (–/–)] only in the CNS. Because CGRP receptor formation has been shown to mature from juvenile to adult ages, we also studied if this maturation would be reflected in PPI behavioral responses in juvenile and adult (+/+) controls and in adult αCGRP (–/–) animals. We show that 50% PPI response thresholds (sound level with 50% correct responses) in quiet are decreased in the (–/–) α9 nAChR animals, and 50% PPI responses are increased for mice with an overactive receptor (α9 nAChR KI) and are increased in adult mice lacking αCGRP (–/–). However, in background noise, only mice lacking αCGRP exhibited increased 50% PPI response thresholds, as there were no significant differences between α9 nAChR adult mouse lines and their littermate controls. These findings suggest that MOC and LOC olivocochlear neurotransmission work in tandem to improve behavioral responses to sound. These experiments further pave the way for rapid behavioral hearing assessments in other mouse models.
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Affiliation(s)
- Paul D Allen
- Department of Otolaryngology, University of Rochester Medical Center, Rochester, NY, United States
| | - Anne E Luebke
- Department of Neuroscience and the Ernst J. Del Monte Institute for Neuroscience, University of Rochester Medical Center, Rochester, NY, United States.,Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States
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37
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Zuo H, Lei D, Sivaramakrishnan S, Howie B, Mulvany J, Bao J. An operant-based detection method for inferring tinnitus in mice. J Neurosci Methods 2017; 291:227-237. [DOI: 10.1016/j.jneumeth.2017.08.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 07/25/2017] [Accepted: 08/24/2017] [Indexed: 01/04/2023]
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38
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Chen XH, Zheng LL. Expression of pro-inflammatory cytokines in the auditory cortex of rats with salicylate-induced tinnitus. Mol Med Rep 2017; 16:5643-5648. [PMID: 28849125 DOI: 10.3892/mmr.2017.7235] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 06/06/2017] [Indexed: 11/06/2022] Open
Abstract
Tinnitus often results in severe psychological distress. The present study hypothesized that tinnitus acts as a chronic stressor and induces dysregulation of the production of cytokines. The gap pre‑pulse inhibition of acoustic startle paradigm was applied to test tinnitus‑like behavior in rats. Following this, the mRNA and protein expression levels of interferon (IFN)‑γ, tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and N‑methyl D‑aspartate receptor subunit 2A (NR2A) were measured in rats subjected to acute and chronic salicylate treatment, using reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. The gap prepulse inhibition of acoustic startle paradigm detected the tinnitus‑like behavior of rats. The expression of TNF‑α and NR2A genes were increased in the auditory cortex (AC) following long‑term administration of salicylate, whereas the expression of IFN‑γ genes decreased; however, the mRNA levels reversed back to normal baseline 14 days following the cease of salicylate administration. IL‑6 gene expression, however, was not fundamentally altered by salicylate treatment. The data demonstrated that chronic salicylate administration induces tinnitus, in part, via dysregulation of cytokines and specific membrane receptors in the AC.
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Affiliation(s)
- Xiang-Hong Chen
- Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Li-Li Zheng
- Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
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39
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Ouyang J, Pace E, Lepczyk L, Kaufman M, Zhang J, Perrine SA, Zhang J. Blast-Induced Tinnitus and Elevated Central Auditory and Limbic Activity in Rats: A Manganese-Enhanced MRI and Behavioral Study. Sci Rep 2017; 7:4852. [PMID: 28687812 PMCID: PMC5501813 DOI: 10.1038/s41598-017-04941-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 04/27/2017] [Indexed: 02/06/2023] Open
Abstract
Blast-induced tinitus is the number one service-connected disability that currently affects military personnel and veterans. To elucidate its underlying mechanisms, we subjected 13 Sprague Dawley adult rats to unilateral 14 psi blast exposure to induce tinnitus and measured auditory and limbic brain activity using manganese-enhanced MRI (MEMRI). Tinnitus was evaluated with a gap detection acoustic startle reflex paradigm, while hearing status was assessed with prepulse inhibition (PPI) and auditory brainstem responses (ABRs). Both anxiety and cognitive functioning were assessed using elevated plus maze and Morris water maze, respectively. Five weeks after blast exposure, 8 of the 13 blasted rats exhibited chronic tinnitus. While acoustic PPI remained intact and ABR thresholds recovered, the ABR wave P1-N1 amplitude reduction persisted in all blast-exposed rats. No differences in spatial cognition were observed, but blasted rats as a whole exhibited increased anxiety. MEMRI data revealed a bilateral increase in activity along the auditory pathway and in certain limbic regions of rats with tinnitus compared to age-matched controls. Taken together, our data suggest that while blast-induced tinnitus may play a role in auditory and limbic hyperactivity, the non-auditory effects of blast and potential traumatic brain injury may also exert an effect.
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Affiliation(s)
- Jessica Ouyang
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Edward Pace
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Laura Lepczyk
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Michael Kaufman
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Jessica Zhang
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Jinsheng Zhang
- Department of Otolaryngology and Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
- Department of Communication Sciences & Disorders, Wayne State University College of Liberal Arts and Sciences, Detroit, MI, 48201, USA.
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40
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Lauer AM, Behrens D, Klump G. Acoustic startle modification as a tool for evaluating auditory function of the mouse: Progress, pitfalls, and potential. Neurosci Biobehav Rev 2017; 77:194-208. [PMID: 28327385 PMCID: PMC5446932 DOI: 10.1016/j.neubiorev.2017.03.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/23/2017] [Accepted: 03/13/2017] [Indexed: 12/16/2022]
Abstract
Acoustic startle response (ASR) modification procedures, especially prepulse inhibition (PPI), are increasingly used as behavioral measures of auditory processing and sensorimotor gating in rodents due to their perceived ease of implementation and short testing times. In practice, ASR and PPI procedures are extremely variable across animals, experimental setups, and studies, and the interpretation of results is subject to numerous caveats and confounding influences. We review considerations for modification of the ASR using acoustic stimuli, and we compare the sensitivity of PPI procedures to more traditional operant psychoacoustic techniques. We also discuss non-auditory variables that must be considered. We conclude that ASR and PPI measures cannot substitute for traditional operant techniques due to their low sensitivity. Additionally, a substantial amount of pilot testing must be performed to properly optimize an ASR modification experiment, negating any time benefit over operant conditioning. Nevertheless, there are some circumstances where ASR measures may be the only option for assessing auditory behavior, such as when testing mouse strains with early-onset hearing loss or learning impairments.
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Affiliation(s)
- Amanda M Lauer
- Department of Otolaryngology-Head and Neck Surgery and Center for Hearing and Balance, Johns Hopkins University, 515 Traylor Building, 720 Rutland Ave., Baltimore, MD 21205, USA.
| | - Derik Behrens
- Cluster of Excellence Hearing4all, Animal Physiology & Behavior Group, Department for Neuroscience, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, Carl Von Ossietzky Str. 9-11, 26111 Oldenburg, Germany
| | - Georg Klump
- Cluster of Excellence Hearing4all, Animal Physiology & Behavior Group, Department for Neuroscience, School of Medicine and Health Sciences, Carl Von Ossietzky University Oldenburg, Carl Von Ossietzky Str. 9-11, 26111 Oldenburg, Germany
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41
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Radziwon K, Holfoth D, Lindner J, Kaier-Green Z, Bowler R, Urban M, Salvi R. Salicylate-induced hyperacusis in rats: Dose- and frequency-dependent effects. Hear Res 2017; 350:133-138. [PMID: 28463806 DOI: 10.1016/j.heares.2017.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/10/2017] [Accepted: 04/07/2017] [Indexed: 12/29/2022]
Abstract
The use of auditory reaction time is a reliable measure of loudness perception in both animals and humans with reaction times (RT) decreasing with increasing stimulus intensity. Since abnormal loudness perception is a common feature of hyperacusis, a potentially debilitating auditory disorder in which moderate-intensity sounds are perceived as uncomfortable or painfully loud, we used RT measures to assess rats for salicylate-induced hyperacusis. A previous study using an operant conditioning RT procedure found that high-dose sodium salicylate (SS) induced hyperacusis-like behavior, i.e., faster than normal RTs to moderate and high level sounds, when rats were tested with broadband noise stimuli. However, it was not clear from that study if salicylate induces hyperacusis-like behavior in a dose- or frequency-dependent manner. Therefore, the goals of the current study were to determine how RT-intensity functions were altered by different doses of salicylate, and, using tone bursts, to determine if salicylate induces hyperacusis-like behavior across the entire frequency spectrum or only at certain frequencies. Similar to previous physiological studies, we began to see faster than normal RTs for sounds 60 dB SPL and greater with salicylate doses of 150 mg/kg and higher; indicating the rats were experiencing hyperacusis at high salicylate doses. In addition, high-dose salicylate significantly reduced RTs across all stimulus frequencies tested which suggests that a central neural excitability mechanism may be a potential driver of salicylate-induced changes in loudness perception and hyperacusis.
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Affiliation(s)
- Kelly Radziwon
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA.
| | - David Holfoth
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA
| | - Julia Lindner
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA
| | - Zoe Kaier-Green
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA
| | - Rachael Bowler
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA
| | - Maxwell Urban
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA
| | - Richard Salvi
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, SUNY at Buffalo, 137 Cary Hall, Buffalo, NY, 14214, USA
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42
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Lobarinas E, Spankovich C, Le Prell CG. Evidence of "hidden hearing loss" following noise exposures that produce robust TTS and ABR wave-I amplitude reductions. Hear Res 2016; 349:155-163. [PMID: 28003148 DOI: 10.1016/j.heares.2016.12.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 11/21/2016] [Accepted: 12/12/2016] [Indexed: 11/30/2022]
Abstract
In animals, noise exposures that produce robust temporary threshold shifts (TTS) can produce immediate damage to afferent synapses and long-term degeneration of low spontaneous rate auditory nerve fibers. This synaptopathic damage has been shown to correlate with reduced auditory brainstem response (ABR) wave-I amplitudes at suprathreshold levels. The perceptual consequences of this "synaptopathy" remain unknown but have been suggested to include compromised hearing performance in competing background noise. Here, we used a modified startle inhibition paradigm to evaluate whether noise exposures that produce robust TTS and ABR wave-I reduction but not permanent threshold shift (PTS) reduced hearing-in-noise performance. Animals exposed to 109 dB SPL octave band noise showed TTS >30 dB 24-h post noise and modest but persistent ABR wave-I reduction 2 weeks post noise despite full recovery of ABR thresholds. Hearing-in-noise performance was negatively affected by the noise exposure. However, the effect was observed only at the poorest signal to noise ratio and was frequency specific. Although TTS >30 dB 24-h post noise was a predictor of functional deficits, there was no relationship between the degree of ABR wave-I reduction and degree of functional impairment.
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Affiliation(s)
- Edward Lobarinas
- The University of Texas at Dallas, School of Behavioral and Brain Sciences, USA.
| | - Christopher Spankovich
- University of Mississippi Medical Center, Department of Otolaryngology and Communicative Sciences, USA
| | - Colleen G Le Prell
- The University of Texas at Dallas, School of Behavioral and Brain Sciences, USA
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43
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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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44
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Mulders WHAM, Vooys V, Makowiecki K, Tang AD, Rodger J. The effects of repetitive transcranial magnetic stimulation in an animal model of tinnitus. Sci Rep 2016; 6:38234. [PMID: 27905540 PMCID: PMC5131273 DOI: 10.1038/srep38234] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/07/2016] [Indexed: 02/04/2023] Open
Abstract
Tinnitus (phantom auditory perception associated with hearing loss) can seriously affect wellbeing. Its neural substrate is unknown however it has been linked with abnormal activity in auditory pathways. Though no cure currently exists, repetitive transcranial magnetic stimulation (rTMS) has been shown to reduce tinnitus in some patients, possibly via induction of cortical plasticity involving brain derived neurotrophic factor (BDNF). We examined whether low intensity rTMS (LI-rTMS) alleviates signs of tinnitus in a guinea pig model and whether this involves changes in BDNF expression and hyperactivity in inferior colliculus. Acoustic trauma was used to evoke hearing loss, central hyperactivity and tinnitus. When animals developed tinnitus, treatment commenced (10 sessions of 10 minutes 1 Hz LI-rTMS or sham over auditory cortex over 14 days). After treatment ceased animals were tested for tinnitus, underwent single-neuron recordings in inferior colliculus to assess hyperactivity and samples from cortex and inferior colliculus were taken for BDNF ELISA. Analysis revealed a significant reduction of tinnitus after LI-rTMS compared to sham, without a statistical significant effect on BDNF levels or hyperactivity. This suggests that LI-rTMS alleviates behavioural signs of tinnitus by a mechanism independent of inferior colliculus hyperactivity and BDNF levels and opens novel therapeutic avenues for tinnitus treatment.
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Affiliation(s)
- Wilhelmina H A M Mulders
- The Auditory Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Vanessa Vooys
- The Auditory Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Kalina Makowiecki
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Alex D Tang
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
| | - Jennifer Rodger
- School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia
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45
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Berger JI, Coomber B, Wallace MN, Palmer AR. Reductions in cortical alpha activity, enhancements in neural responses and impaired gap detection caused by sodium salicylate in awake guinea pigs. Eur J Neurosci 2016; 45:398-409. [PMID: 27862478 PMCID: PMC5763375 DOI: 10.1111/ejn.13474] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/07/2016] [Indexed: 11/30/2022]
Abstract
Tinnitus chronically affects between 10-15% of the population but, despite its prevalence, the underlying mechanisms are still not properly understood. One experimental model involves administration of high doses of sodium salicylate, as this is known to reliably induce tinnitus in both humans and animals. Guinea pigs were implanted with chronic electrocorticography (ECoG) electrode arrays, with silver-ball electrodes placed on the dura over left and right auditory cortex. Two more electrodes were positioned over the cerebellum to monitor auditory brainstem responses (ABRs). We recorded resting-state and auditory evoked neural activity from awake animals before and 2 h following salicylate administration (350 mg/kg; i.p.). Large increases in click-evoked responses (> 100%) were evident across the whole auditory cortex, despite significant reductions in wave I ABR amplitudes (in response to 20 kHz tones), which are indicative of auditory nerve activity. In the same animals, significant decreases in 6-10 Hz spontaneous oscillations (alpha waves) were evident over dorsocaudal auditory cortex. We were also able to demonstrate for the first time that cortical evoked potentials can be inhibited by a preceding gap in background noise [gap-induced pre-pulse inhibition (PPI)], in a similar fashion to the gap-induced inhibition of the acoustic startle reflex that is used as a behavioural test for tinnitus. Furthermore, 2 h following salicylate administration, we observed significant deficits in PPI of cortical responses that were closely aligned with significant deficits in behavioural responses to the same stimuli. Together, these data are suggestive of neural correlates of tinnitus and oversensitivity to sound (hyperacusis).
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Affiliation(s)
- Joel I Berger
- MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, UK.,School of Medicine, University of Nottingham, Nottingham, UK
| | - Ben Coomber
- MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, UK.,School of Medicine, University of Nottingham, Nottingham, UK
| | - Mark N Wallace
- MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, UK.,School of Medicine, University of Nottingham, Nottingham, UK
| | - Alan R Palmer
- MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, UK.,School of Medicine, University of Nottingham, Nottingham, UK
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46
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Eggermont JJ. Can Animal Models Contribute to Understanding Tinnitus Heterogeneity in Humans? Front Aging Neurosci 2016; 8:265. [PMID: 27895575 PMCID: PMC5107573 DOI: 10.3389/fnagi.2016.00265] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/24/2016] [Indexed: 12/30/2022] Open
Abstract
The brain activity of humans with tinnitus of various etiologies is typically studied with electro- and magneto-encephalography and functional magnetic resonance imaging-based imaging techniques. Consequently, they measure population responses and mostly from the neocortex. The latter also underlies changes in neural networks that may be attributed to tinnitus. However, factors not strictly related to tinnitus such as hearing loss and hyperacusis, as well as other co-occurring disorders play a prominent role in these changes. Different types of tinnitus can often not be resolved with these brain-imaging techniques. In animal models of putative behavioral signs of tinnitus, neural activity ranging from auditory nerve to auditory cortex, is studied largely by single unit recordings, augmented by local field potentials (LFPs), and the neural correlates of tinnitus are mainly based on spontaneous neural activity, such as spontaneous firing rates and pair-wise spontaneous spike-firing correlations. Neural correlates of hyperacusis rely on measurement of stimulus-evoked activity and are measured as increased driven firing rates and LFP amplitudes. Connectivity studies would rely on correlated neural activity between pairs of neurons or LFP amplitudes, but are only recently explored. In animal models of tinnitus, only two etiologies are extensively studied; tinnitus evoked by salicylate application and by noise exposure. It appears that they have quite different neural biomarkers. The unanswered question then is: does this different etiology also result in different tinnitus?
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Affiliation(s)
- Jos J Eggermont
- Department of Physiology and Pharmacology, University of Calgary, CalgaryAB, Canada; Department of Psychology, University of Calgary, CalgaryAB, Canada
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47
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Pace E, Luo H, Bobian M, Panekkad A, Zhang X, Zhang H, Zhang J. A Conditioned Behavioral Paradigm for Assessing Onset and Lasting Tinnitus in Rats. PLoS One 2016; 11:e0166346. [PMID: 27835697 PMCID: PMC5105995 DOI: 10.1371/journal.pone.0166346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/27/2016] [Indexed: 01/19/2023] Open
Abstract
Numerous behavioral paradigms have been developed to assess tinnitus-like behavior in animals. Nevertheless, they are often limited by prolonged training requirements, as well as an inability to simultaneously assess onset and lasting tinnitus behavior, tinnitus pitch or duration, or tinnitus presence without grouping data from multiple animals or testing sessions. To enhance behavioral testing of tinnitus, we developed a conditioned licking suppression paradigm to determine the pitch(s) of both onset and lasting tinnitus-like behavior within individual animals. Rats learned to lick water during broadband or narrowband noises, and to suppress licking to avoid footshocks during silence. After noise exposure, rats significantly increased licking during silent trials, suggesting onset tinnitus-like behavior. Lasting tinnitus-behavior, however, was exhibited in about half of noise-exposed rats through 7 weeks post-exposure tested. Licking activity during narrowband sound trials remained unchanged following noise exposure, while ABR hearing thresholds fully recovered and were comparable between tinnitus(+) and tinnitus(-) rats. To assess another tinnitus inducer, rats were injected with sodium salicylate. They demonstrated high pitch tinnitus-like behavior, but later recovered by 5 days post-injection. Further control studies showed that 1): sham noise-exposed rats tested with footshock did not exhibit tinnitus-like behavior, and 2): noise-exposed or sham rats tested without footshocks showed no fundamental changes in behavior compared to those tested with shocks. Together, these results demonstrate that this paradigm can efficiently test the development of noise- and salicylate-induced tinnitus behavior. The ability to assess tinnitus individually, over time, and without averaging data enables us to realistically address tinnitus in a clinically relevant way. Thus, we believe that this optimized behavioral paradigm will facilitate investigations into the mechanisms of tinnitus and development of effective treatments.
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Affiliation(s)
- Edward Pace
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 4201 Saint Antoine, Detroit, Michigan 48201, United States of America
| | - Hao Luo
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 4201 Saint Antoine, Detroit, Michigan 48201, United States of America
| | - Michael Bobian
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 4201 Saint Antoine, Detroit, Michigan 48201, United States of America
| | - Ajay Panekkad
- Department of Electrical Engineering, Wayne State College of Engineering, 5050 Anthony Wayne Drive, Detroit, Michigan 48202, United States of America
| | - Xueguo Zhang
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 4201 Saint Antoine, Detroit, Michigan 48201, United States of America
| | - Huiming Zhang
- Department of Biological Sciences, University of Windsor, 401 Sunset Avenue, Windsor, Ontario, Canada
| | - Jinsheng Zhang
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 4201 Saint Antoine, Detroit, Michigan 48201, United States of America
- Department of Communication Sciences & Disorders, Wayne State University College of Liberal Arts & Sciences, 60 Farnsworth St., Detroit, Michigan 48202, United States of America
- * E-mail:
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Jones A, May BJ. Improving the Reliability of Tinnitus Screening in Laboratory Animals. J Assoc Res Otolaryngol 2016; 18:183-195. [PMID: 27807642 DOI: 10.1007/s10162-016-0597-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/17/2016] [Indexed: 12/21/2022] Open
Abstract
Behavioral screening remains a contentious issue for animal studies of tinnitus. Most paradigms base a positive tinnitus test on an animal's natural tendency to respond to the "sound" of tinnitus as if it were an actual sound. As a result, animals with tinnitus are expected to display sound-conditioned behaviors when no sound is present or to miss gaps in background sounds because tinnitus "fills in the gap." Reliable confirmation of the behavioral indications of tinnitus can be problematic because the reinforcement contingencies of conventional discrimination tasks break down an animal's tendency to group tinnitus with sound. When responses in silence are rewarded, animals respond in silence regardless of their tinnitus status. When responses in silence are punished, animals stop responding. This study introduces stimulus classification as an alternative approach to tinnitus screening. Classification procedures train animals to respond to the common perceptual features that define a group of sounds (e.g., high pitch or narrow bandwidth). Our procedure trains animals to drink when they hear tinnitus and to suppress drinking when they hear other sounds. Animals with tinnitus are revealed by their tendency to drink in the presence of unreinforced probe sounds that share the perceptual features of the tinnitus classification. The advantages of this approach are illustrated by taking laboratory rats through a testing sequence that includes classification training, the experimental induction of tinnitus, and postinduction screening. Behavioral indications of tinnitus are interpreted and then verified by simulating a known tinnitus percept with objective sounds.
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Affiliation(s)
- Aikeen Jones
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Traylor Research Building, Room 521, 720 Rutland Avenue, Baltimore, MD, 21205, USA
| | - Bradford J May
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Traylor Research Building, Room 521, 720 Rutland Avenue, Baltimore, MD, 21205, USA.
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Brozoski TJ, Bauer CA. Animal models of tinnitus. Hear Res 2016; 338:88-97. [DOI: 10.1016/j.heares.2015.10.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 12/18/2022]
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Longenecker RJ, Alghamdi F, Rosen MJ, Galazyuk AV. Prepulse inhibition of the acoustic startle reflex vs. auditory brainstem response for hearing assessment. Hear Res 2016; 339:80-93. [PMID: 27349914 DOI: 10.1016/j.heares.2016.06.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/18/2016] [Accepted: 06/13/2016] [Indexed: 02/08/2023]
Abstract
The high prevalence of noise-induced and age-related hearing loss in the general population has warranted the use of animal models to study the etiology of these pathologies. Quick and accurate auditory threshold determination is a prerequisite for experimental manipulations targeting hearing loss in animal models. The standard auditory brainstem response (ABR) measurement is fairly quick and translational across species, but is limited by the need for anesthesia and a lack of perceptual assessment. The goal of this study was to develop a new method of hearing assessment utilizing prepulse inhibition (PPI) of the acoustic startle reflex, a commonly used tool that measures detection thresholds in awake animals, and can be performed on multiple animals simultaneously. We found that in control mice PPI audiometric functions are similar to both ABR and traditional operant conditioning audiograms. The hearing thresholds assessed with PPI audiometry in sound exposed mice were also similar to those detected by ABR thresholds one day after exposure. However, three months after exposure PPI threshold shifts were still evident at and near the frequency of exposure whereas ABR thresholds recovered to the pre-exposed level. In contrast, PPI audiometry and ABR wave one amplitudes detected similar losses. PPI audiometry provides a high throughput automated behavioral screening tool of hearing in awake animals. Overall, PPI audiometry and ABR assessments of the auditory system are robust techniques with distinct advantages and limitations, which when combined, can provide ample information about the functionality of the auditory system.
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Affiliation(s)
- R J Longenecker
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA.
| | - F Alghamdi
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA
| | - M J Rosen
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA
| | - A V Galazyuk
- Northeast Ohio Medical University, Department of Anatomy and Neurobiology, Rootstown, OH, USA
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