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Videhult Pierre P, Fransson A, Kisiel MA, Laurell G. Hydrogen Gas Inhalation Attenuates Acute Impulse Noise Trauma: A Preclinical In Vivo Study. Ann Otol Rhinol Laryngol 2022:34894221118764. [PMID: 35962590 DOI: 10.1177/00034894221118764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Molecular hydrogen (H2) has shown therapeutic potential in several oxidative stress-related conditions in humans, is well-tolerated, and is easily administered via inhalation.The aim of this preclinical in vivo study was to investigate whether impulse noise trauma can be prevented by H2 when inhaled immediately after impulse noise exposure. METHODS Guinea pigs (n = 26) were subjected to impulse noise (n = 400; 156 dB SPL; 0.33/s; n = 11; the Noise group), to impulse noise immediately followed by H2 inhalation (2 mol%; 500 ml/min; 1 hour; n = 10; the Noise + H2 group), or to H2 inhalation (n = 5; the H2 group). The acoustically evoked ABR threshold at 3.15, 6.30, 12.5, 20.0, and 30.0 kHz was assessed before and 4 days after impulse noise and/or H2 exposure. The cochleae were harvested after the final ABR assessment for quantification of hair cells. RESULTS Noise exposure caused ABR threshold elevations at all frequencies (median 35, 35, 30, 35, and 35 dB SPL, the Noise group; 20, 25, 10, 13, and 20 dB SPL, the Noise + H2 group; P < .05) but significantly less so in the Noise + H2 group (P < .05). Outer hair cell (OHC) loss was in the apical, mid, and basal regions 8.8%, 53%, and 14% in the Noise group and 3.5%, 22%, and 1.2% in the Noise + H2 group. The corresponding inner hair cell (IHC) loss was 0.1%, 14%, and 3.5% in the Noise group and 0%, 2.8%, and 0% in the Noise + H2 group. The difference between the groups was significant in the basal region for OHCs (P = .003) and apical (P = .033) and basal (P = .048) regions for IHCs. CONCLUSIONS Acute acoustic trauma can be reduced by H2 when inhaled immediately after impulse noise exposure.
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Affiliation(s)
- Pernilla Videhult Pierre
- Division of Audiology, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Huddinge, Sweden
| | - Anette Fransson
- Department of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden.,Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Marta A Kisiel
- Department of Medical Sciences, Occupational and Environmental Medicine, Uppsala University Hospital, Uppsala, Sweden
| | - Göran Laurell
- Department of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden
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2
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Occelli F, Hasselmann F, Bourien J, Puel JL, Desvignes N, Wiszniowski B, Edeline JM, Gourévitch B. Temporal Alterations to Central Auditory Processing without Synaptopathy after Lifetime Exposure to Environmental Noise. Cereb Cortex 2021; 32:1737-1754. [PMID: 34494109 DOI: 10.1093/cercor/bhab310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 11/13/2022] Open
Abstract
People are increasingly exposed to environmental noise through the cumulation of occupational and recreational activities, which is considered harmless to the auditory system, if the sound intensity remains <80 dB. However, recent evidence of noise-induced peripheral synaptic damage and central reorganizations in the auditory cortex, despite normal audiometry results, has cast doubt on the innocuousness of lifetime exposure to environmental noise. We addressed this issue by exposing adult rats to realistic and nontraumatic environmental noise, within the daily permissible noise exposure limit for humans (80 dB sound pressure level, 8 h/day) for between 3 and 18 months. We found that temporary hearing loss could be detected after 6 months of daily exposure, without leading to permanent hearing loss or to missing synaptic ribbons in cochlear hair cells. The degraded temporal representation of sounds in the auditory cortex after 18 months of exposure was very different from the effects observed after only 3 months of exposure, suggesting that modifications to the neural code continue throughout a lifetime of exposure to noise.
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Affiliation(s)
- Florian Occelli
- NeuroScience Paris-Saclay Institute (NeuroPSI), CNRS, University of Paris-Saclay, Orsay F-91405, France
| | - Florian Hasselmann
- Institute for Neurosciences of Montpellier (INM), INSERM, University of Montpellier, Montpellier F-34091, France
| | - Jérôme Bourien
- Institute for Neurosciences of Montpellier (INM), INSERM, University of Montpellier, Montpellier F-34091, France
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), INSERM, University of Montpellier, Montpellier F-34091, France
| | - Nathalie Desvignes
- NeuroScience Paris-Saclay Institute (NeuroPSI), CNRS, University of Paris-Saclay, Orsay F-91405, France
| | - Bernadette Wiszniowski
- NeuroScience Paris-Saclay Institute (NeuroPSI), CNRS, University of Paris-Saclay, Orsay F-91405, France
| | - Jean-Marc Edeline
- NeuroScience Paris-Saclay Institute (NeuroPSI), CNRS, University of Paris-Saclay, Orsay F-91405, France
| | - Boris Gourévitch
- NeuroScience Paris-Saclay Institute (NeuroPSI), CNRS, University of Paris-Saclay, Orsay F-91405, France.,Institut de l'Audition, Institut Pasteur, INSERM, Paris F-75012, France.,CNRS, France
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3
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Fransson AE, Videhult Pierre P, Risling M, Laurell GFE. Inhalation of Molecular Hydrogen, a Rescue Treatment for Noise-Induced Hearing Loss. Front Cell Neurosci 2021; 15:658662. [PMID: 34140880 PMCID: PMC8205059 DOI: 10.3389/fncel.2021.658662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/30/2021] [Indexed: 11/17/2022] Open
Abstract
Noise exposure is the most important external factor causing acquired hearing loss in humans, and it is strongly associated with the production of reactive oxygen species (ROS) in the cochlea. Several studies reported that the administration of various compounds with antioxidant effects can treat oxidative stress-induced hearing loss. However, traditional systemic drug administration to the human inner ear is problematic and has not been successful in a clinical setting. Thus, there is an urgent need to develop rescue treatment for patients with acute acoustic injuries. Hydrogen gas has antioxidant effects, rapid distribution, and distributes systemically after inhalation.The purpose of this study was to determine the protective efficacy of a single dose of molecular hydrogen (H2) on cochlear structures. Guinea pigs were divided into six groups and sacrificed immediately after or at 1 or 2 weeks. The animals were exposed to broadband noise for 2 h directly followed by 1-h inhalation of 2% H2 or room air. Electrophysiological hearing thresholds using frequency-specific auditory brainstem response (ABR) were measured prior to noise exposure and before sacrifice. ABR thresholds were significantly lower in H2-treated animals at 2 weeks after exposure, with significant preservation of outer hair cells in the entire cochlea. Quantification of synaptophysin immunoreactivity revealed that H2 inhalation protected the cochlear inner hair cell synaptic structures containing synaptophysin. The inflammatory response was greater in the stria vascularis, showing increased Iba1 due to H2 inhalation.Repeated administration of H2 inhalation may further improve the therapeutic effect. This animal model does not reproduce conditions in humans, highlighting the need for additional real-life studies in humans.
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Affiliation(s)
- Anette Elisabeth Fransson
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.,Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Pernilla Videhult Pierre
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Mårten Risling
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Hsp70/Bmi1-FoxO1-SOD Signaling Pathway Contributes to the Protective Effect of Sound Conditioning against Acute Acoustic Trauma in a Rat Model. Neural Plast 2020; 2020:8823785. [PMID: 33082778 PMCID: PMC7556106 DOI: 10.1155/2020/8823785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/27/2020] [Accepted: 08/05/2020] [Indexed: 02/06/2023] Open
Abstract
Sound conditioning (SC) is defined as “toughening” to lower levels of sound over time, which reduces a subsequent noise-induced threshold shift. Although the protective effect of SC in mammals is generally understood, the exact mechanisms involved have not yet been elucidated. To confirm the protective effect of SC against noise exposure (NE) and the stress-related signaling pathway of its rescue, we observed target molecule changes caused by SC of low frequency prior to NE as well as histology analysis in vivo and verified the suggested mechanisms in SGNs in vitro. Further, we investigated the potential role of Hsp70 and Bmi1 in SC by targeting SOD1 and SOD2 which are regulated by the FoxO1 signaling pathway based on mitochondrial function and reactive oxygen species (ROS) levels. Finally, we sought to identify the possible molecular mechanisms associated with the beneficial effects of SC against noise-induced trauma. Data from the rat model were evaluated by western blot, immunofluorescence, and RT-PCR. The results revealed that SC upregulated Hsp70, Bmi1, FoxO1, SOD1, and SOD2 expression in spiral ganglion neurons (SGNs). Moreover, the auditory brainstem responses (ABRs) and electron microscopy revealed that SC could protect against acute acoustic trauma (AAT) based on a significant reduction of hearing impairment and visible reduction in outer hair cell loss as well as ultrastructural changes in OHCs and SGNs. Collectively, these results suggested that the contribution of Bmi1 toward decreased sensitivity to noise-induced trauma following SC was triggered by Hsp70 induction and associated with enhancement of the antioxidant system and decreased mitochondrial superoxide accumulation. This contribution of Bmi1 was achieved by direct targeting of SOD1 and SOD2, which was regulated by FoxO1. Therefore, the Hsp70/Bmi1-FoxO1-SOD signaling pathway might contribute to the protective effect of SC against AAT in a rat model.
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Le Prell CG, Hammill TL, Murphy WJ. Noise-induced hearing loss and its prevention: Integration of data from animal models and human clinical trials. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:4051. [PMID: 31795668 PMCID: PMC7195863 DOI: 10.1121/1.5132951] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Animal models have been used to gain insight into the risk of noise-induced hearing loss (NIHL) and its potential prevention using investigational new drug agents. A number of compounds have yielded benefit in pre-clinical (animal) models. However, the acute traumatic injury models commonly used in pre-clinical testing are fundamentally different from the chronic and repeated exposures experienced by many human populations. Diverse populations that are potentially at risk and could be considered for enrollment in clinical studies include service members, workers exposed to occupational noise, musicians and other performing artists, and children and young adults exposed to non-occupational (including recreational) noise. Both animal models and clinical populations were discussed in this special issue, followed by discussion of individual variation in vulnerability to NIHL. In this final contribution, study design considerations for NIHL otoprotection in pre-clinical and clinical testing are integrated and broadly discussed with evidence-based guidance offered where possible, drawing on the contributions to this special issue as well as other existing literature. The overarching goals of this final paper are to (1) review and summarize key information across contributions and (2) synthesize information to facilitate successful translation of otoprotective drugs from animal models into human application.
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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
| | - Tanisha L Hammill
- Department of Defense, Defense Health Agency, Falls Church, Virginia 22042, USA
| | - William J Murphy
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Cincinanati, Ohio 45226-1998, USA
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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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7
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Xia C, Yin M, Pan P, Fang F, Zhou Y, Ji Y. Long-term exposure to moderate noise induces neural plasticity in the infant rat primary auditory cortex. Anim Cells Syst (Seoul) 2019; 23:260-269. [PMID: 31489247 PMCID: PMC6711034 DOI: 10.1080/19768354.2019.1643782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 11/17/2022] Open
Abstract
Previous studies have reported that rearing infant rat pups in continuous moderate-level noise delayed the formation of topographic representational order and the refinement of response selectivity in the primary auditory (A1) cortex. The present study further verified that exposure to long-term moderate-intensity white noise (70 dB sound pressure level) from postnatal day (P) 12 to P30 elevated the hearing thresholds of infant rats. Compared with age-matched control rats, noise exposure (NE) rats had elevated hearing thresholds ranging from low to high frequencies, accompanied by decreased amplitudes and increased latencies of the two initial auditory brainstem response waves. The power of raw local field potential oscillations and high-frequency β oscillation in the A1 cortex of NE rats were larger, whereas the power of high-frequency γ oscillation was smaller than that of control rats. In addition, the expression levels of five glutamate receptor (GluR) subunits in the A1 cortex of NE rats were decreased with laminar specificity. These results suggest that the altered neural excitability and decreased GluR expression may underlie the delay of functional maturation in the A1 cortex, and may have implications for the treatment of hearing impairment induced by environmental noise.
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Affiliation(s)
- Chenchen Xia
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, People's Republic of China
| | - Manli Yin
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, People's Republic of China
| | - Ping Pan
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, People's Republic of China
| | - Fanghao Fang
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, People's Republic of China
| | - You Zhou
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, People's Republic of China.,Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China.,Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, People's Republic of China
| | - Yonghua Ji
- Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai, People's Republic of China
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Capsaicin Protects Against Cisplatin Ototoxicity by Changing the STAT3/STAT1 Ratio and Activating Cannabinoid (CB2) Receptors in the Cochlea. Sci Rep 2019; 9:4131. [PMID: 30858408 PMCID: PMC6411993 DOI: 10.1038/s41598-019-40425-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 07/26/2018] [Indexed: 12/20/2022] Open
Abstract
Capsaicin, the spicy component of hot chili peppers activates the TRPV1 pain receptors, and causes rapid desensitization. Capsaicin also ameliorates cisplatin-induced nephrotoxicity. Cisplatin, a commonly used anti-neoplastic agent for solid tumors causes significant hearing loss, nephrotoxicity and peripheral neuropathy. Upregulation of cochlear TRPV1 expression is related to cisplatin-mediated ototoxicity. Here we report that direct TRPV1 activation by localized trans-tympanic (TT) or oral administration of capsaicin (TRPV1 agonist) prevents cisplatin ototoxicity by sustained increased activation of pro-survival transcription factor signal transducer and activator of transcription (STAT3) in the Wistar rat. Cisplatin treatment produced prolonged activation of pro-apoptotic Ser727 p-STAT1 and suppressed Tyr705-p-STAT3 for up to 72 h in the rat cochlea. Our data indicate that capsaicin causes a transient STAT1 activation via TRPV1 activation, responsible for the previously reported temporary threshold shift. Additionally, we found that capsaicin increased cannabinoid receptor (CB2) in the cochlea, which leads to pro-survival Tyr705-p-STAT3 activation. This tilts the delicate balance of p-STAT3/p-STAT1 towards survival. Furthermore, capsaicin mediated protection is lost when CB2 antagonist AM630 is administered prior to capsaicin treatment. In conclusion, capsaicin otoprotection appears to be mediated by activation of CB2 receptors in the cochlea which are coupled to both STAT1 and STAT3 activation.
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9
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Effects of Acoustic Environment on Tinnitus Behavior in Sound-Exposed Rats. J Assoc Res Otolaryngol 2018; 19:133-146. [PMID: 29294193 DOI: 10.1007/s10162-017-0651-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 12/18/2017] [Indexed: 01/08/2023] Open
Abstract
Laboratory studies often rely on a damaging sound exposure to induce tinnitus in animal models. Because the time course and ultimate success of the induction process is not known in advance, it is not unusual to maintain sound-exposed animals for months while they are periodically assessed for behavioral indications of the disorder. To demonstrate the importance of acoustic environment during this period of behavioral screening, sound-exposed rats were tested for tinnitus while housed under quiet or constant noise conditions. More than half of the quiet-housed rats developed behavioral indications of the disorder. None of the noise-housed rats exhibited tinnitus behavior during 2 months of behavioral screening. It is widely assumed that the "phantom sound" of tinnitus reflects abnormal levels of spontaneous activity in the central auditory pathways that are triggered by cochlear injury. Our results suggest that sustained patterns of noise-driven activity may prevent the injury-induced changes in central auditory processing that lead to this hyperactive state. From the perspective of laboratory studies of tinnitus, housing sound-exposed animals in uncontrolled noise levels may significantly reduce the success of induction procedures. From a broader clinical perspective, an early intervention with sound therapy may reduce the risk of tinnitus in individuals who have experienced an acute cochlear injury.
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Fransson AE, Kisiel M, Pirttilä K, Pettersson C, Videhult Pierre P, Laurell GFE. Hydrogen Inhalation Protects against Ototoxicity Induced by Intravenous Cisplatin in the Guinea Pig. Front Cell Neurosci 2017; 11:280. [PMID: 28955207 PMCID: PMC5601388 DOI: 10.3389/fncel.2017.00280] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/29/2017] [Indexed: 11/13/2022] Open
Abstract
Introduction: Permanent hearing loss and tinnitus as side-effects from treatment with the anticancer drug cisplatin is a clinical problem. Ototoxicity may be reduced by co-administration of an otoprotective agent, but the results in humans have so far been modest. Aim: The present preclinical in vivo study aimed to explore the protective efficacy of hydrogen (H2) inhalation on ototoxicity induced by intravenous cisplatin. Materials and Methods: Albino guinea pigs were divided into four groups. The Cispt (n = 11) and Cispt+H2 (n = 11) groups were given intravenous cisplatin (8 mg/kg b.w., injection rate 0.2 ml/min). Immediately after, the Cispt+H2 group also received gaseous H2 (2% in air, 60 min). The H2 group (n = 5) received only H2 and the Control group (n = 7) received neither cisplatin nor H2. Ototoxicity was assessed by measuring frequency specific ABR thresholds before and 96 h after treatment, loss of inner (IHCs) and outer (OHCs) hair cells, and by performing densitometry-based immunohistochemistry analysis of cochlear synaptophysin, organic transporter 2 (OCT2), and copper transporter 1 (CTR1) at 12 and 7 mm from the round window. By utilizing metabolomics analysis of perilymph the change of metabolites in the perilymph was assessed. Results: Cisplatin induced electrophysiological threshold shifts, hair cell loss, and reduced synaptophysin immunoreactivity in the synapse area around the IHCs and OHCs. H2 inhalation mitigated all these effects. Cisplatin also reduced the OCT2 intensity in the inner and outer pillar cells and in the stria vascularis as well as the CTR1 intensity in the synapse area around the IHCs, the Deiters' cells, and the stria vascularis. H2 prevented the majority of these effects. Conclusion: H2 inhalation can reduce cisplatin-induced ototoxicity on functional, cellular, and subcellular levels. It is proposed that synaptopathy may serve as a marker for cisplatin ototoxicity. The effect of H2 on the antineoplastic activity of cisplatin needs to be further explored.
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Affiliation(s)
| | - Marta Kisiel
- Department of Surgical Science, Uppsala UniversityUppsala, Sweden
| | - Kristian Pirttilä
- Division of Analytical Pharmaceutical Chemistry, Department of Medical Chemistry, Uppsala UniversityUppsala, Sweden
| | - Curt Pettersson
- Division of Analytical Pharmaceutical Chemistry, Department of Medical Chemistry, Uppsala UniversityUppsala, Sweden
| | - Pernilla Videhult Pierre
- Division of Audiology, Department of Clinical Science, Intervention and Technology, Karolinska InstitutetStockholm, Sweden
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Eggermont JJ. Effects of long-term non-traumatic noise exposure on the adult central auditory system. Hearing problems without hearing loss. Hear Res 2017; 352:12-22. [DOI: 10.1016/j.heares.2016.10.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/18/2016] [Accepted: 10/21/2016] [Indexed: 11/27/2022]
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12
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Sheppard AM, Chen GD, Manohar S, Ding D, Hu BH, Sun W, Zhao J, Salvi R. Prolonged low-level noise-induced plasticity in the peripheral and central auditory system of rats. Neuroscience 2017; 359:159-171. [PMID: 28711622 DOI: 10.1016/j.neuroscience.2017.07.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 06/28/2017] [Accepted: 07/04/2017] [Indexed: 02/06/2023]
Abstract
Prolonged low-level noise exposure alters loudness perception in humans, presumably by decreasing the gain of the central auditory system. Here we test the central gain hypothesis by measuring the acute and chronic physiologic changes at the level of the cochlea and inferior colliculus (IC) after a 75-dB SPL, 10-20-kHz noise exposure for 5weeks. The compound action potential (CAP) and summating potential (SP) were used to assess the functional status of the cochlea and 16 channel electrodes were used to measure the local field potentials (LFP) and multi-unit spike discharge rates (SDR) from the IC immediately after and one-week post-exposure. Measurements obtained immediately post-exposure demonstrated a significant reduction in supra-threshold CAP amplitudes. In contrast to the periphery, sound-evoked activity in the IC was enhanced in a frequency-dependent manner consistent with models of enhanced central gain. Surprisingly, one-week post-exposure supra-threshold responses from the cochlea had not only recovered, but were significantly larger than normal, and thresholds were significantly better than controls. Moreover, sound-evoked hyperactivity in the IC was sustained within the noise exposure frequency band but suppressed at higher frequencies. When response amplitudes representing the neural output of the cochlea and IC activity at one-week post exposure were compared with control animal responses, a central attenuation phenomenon becomes evident, which may play a key role in understanding why low-level noise can sometimes ameliorate tinnitus and hyperacusis percepts.
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Affiliation(s)
- Adam M Sheppard
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | - Guang-Di Chen
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Dalian Ding
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Bo-Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Wei Sun
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| | - Jiwei Zhao
- Department of Biostatistics, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
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Fuente A. The olivocochlear system and protection from acoustic trauma: a mini literature review. Front Syst Neurosci 2015; 9:94. [PMID: 26157366 PMCID: PMC4475794 DOI: 10.3389/fnsys.2015.00094] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/02/2015] [Indexed: 11/29/2022] Open
Abstract
Large intersubject variability in the susceptibility to noise-induced hearing loss (NIHL) is known to occur in both humans and animals. It has been suggested that the olivocochlear system (OCS) plays a significant role in protecting the cochlea from exposure to high levels of noise. A mini literature review about the scientific evidence from animal and human studies about the association between the function of the OCS and susceptibility to NIHL was carried out. Animal data consistently show that de-efferented ears exhibit larger temporary threshold shift (TTS) and permanent threshold shift (PTS) than efferented ears. Data from human studies do not consistently show a correlation between the strength of the OCS function and amount of TTS. Further research on human subjects is required to determine how the OCS function could be used to predict susceptibility to NIHL in individual subjects.
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Affiliation(s)
- Adrian Fuente
- Faculté de médecine, École d'orthophonie et d'audiologie, Université de Montréal Montréal, QC, Canada
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14
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Strose A, Hyppolito MÂ, Colombari GC, Rossato M, Oliveira JAAD. [Lack of protection against gentamicin ototoxicity by auditory conditioning with noise]. Braz J Otorhinolaryngol 2014; 80:390-6. [PMID: 25303813 PMCID: PMC9444619 DOI: 10.1016/j.bjorl.2014.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 06/05/2014] [Indexed: 11/16/2022] Open
Abstract
Introduction Auditory conditioning consists of the pre-exposure to low levels of a potential harmful agent to protect against a subsequent harmful exposure. Objective To confirm if conditioning with an agent different from that used to cause the trauma can also be effective. Methods This was an experimental study with 17 guinea pigs, divided into three groups: an ototoxic control group (Cont) that received intramuscular administration of gentamicin 160 mg/kg/day for ten consecutive days, but no sound exposure; a sound control group (Sound) that was exposed to 85 dB broadband noise centered at 4 kHz, 30 min each day for ten consecutive days, but received no ototoxic medications; and an experimental group (Expt) that received sound exposure identical to the Sound group and after each noise presentation, received gentamicin similarly to Cont group. The animals were evaluated by distortion product otoacoustic emissions (DPOAEs), brainstem auditory evoked potentials (BAEPs), and scanning electron microscopy. Results The animals that were conditioned with noise did not show any protective effect compared with the ones that received only the ototoxic gentamicin administration. This lack of protection was observed functionally and morphologically. Conclusion Conditioning with 85 dB broadband noises, 30 min a day for ten consecutive days does not protect against an ototoxic gentamicin administration of 160 mg/kg/day for ten consecutive days in the guinea pig.
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Affiliation(s)
- Alex Strose
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil.
| | - Miguel Ângelo Hyppolito
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Gleice Cristina Colombari
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Maria Rossato
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Jose Antônio Aparecido de Oliveira
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil
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15
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Harrison RT, DeBacker JR, Bielefeld EC. A low-dose regimen of cisplatin before high-dose cisplatin potentiates ototoxicity. Laryngoscope 2014; 125:E78-83. [DOI: 10.1002/lary.24948] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 08/30/2014] [Accepted: 09/04/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Ryan T. Harrison
- Department of Speech and Hearing Science; The Ohio State University; Columbus Ohio U.S.A
| | - J. Riley DeBacker
- Department of Speech and Hearing Science; The Ohio State University; Columbus Ohio U.S.A
| | - Eric C. Bielefeld
- Department of Speech and Hearing Science; The Ohio State University; Columbus Ohio U.S.A
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16
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Fournier P, Schönwiesner M, Hébert S. Loudness modulation after transient and permanent hearing loss: implications for tinnitus and hyperacusis. Neuroscience 2014; 283:64-77. [PMID: 25135356 DOI: 10.1016/j.neuroscience.2014.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 11/19/2022]
Abstract
Loudness is the primary perceptual correlate of sound intensity. The relationship between sound intensity and loudness is not fixed, and can be modified by short-term sound deprivation or stimulation. Deprivation increases sound sensitivity, whereas stimulation decreases it. We review the effects of short-term auditory deprivation and stimulation on the auditory central nervous system of humans and animals, and we extend the discussion to permanent auditory deprivation (hearing loss) and auditory pathologies of loudness perception. Although there is sufficient evidence to conclude that loudness can be modulated in normal hearing listeners by temporary sound deprivation and stimulation, evidence is scanter for the hearing-impaired listeners. In addition, cortical effects of sound deprivation and stimulation in humans, which may correlate with loudness coding, are still largely unknown and should be the target of future research.
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Affiliation(s)
- P Fournier
- School of Speech Pathology and Audiology, Université de Montréal, Montréal, Québec, Canada; International Laboratory for Research on Brain, Music, and Sound (BRAMS), Université de Montréal, Montréal, Québec, Canada; Centre de recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, Québec, Canada
| | - M Schönwiesner
- International Laboratory for Research on Brain, Music, and Sound (BRAMS), Université de Montréal, Montréal, Québec, Canada; Department of Psychology, Université de Montréal, Montréal, Québec, Canada
| | - S Hébert
- School of Speech Pathology and Audiology, Université de Montréal, Montréal, Québec, Canada; International Laboratory for Research on Brain, Music, and Sound (BRAMS), Université de Montréal, Montréal, Québec, Canada; Centre de recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, Québec, Canada.
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17
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Gourévitch B, Edeline JM, Occelli F, Eggermont JJ. Is the din really harmless? Long-term effects of non-traumatic noise on the adult auditory system. Nat Rev Neurosci 2014; 15:483-91. [DOI: 10.1038/nrn3744] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Roy S, Ryals MM, Van den Bruele AB, Fitzgerald TS, Cunningham LL. Sound preconditioning therapy inhibits ototoxic hearing loss in mice. J Clin Invest 2014; 123:4945-9. [PMID: 24216513 DOI: 10.1172/jci71353] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/12/2013] [Indexed: 01/28/2023] Open
Abstract
Therapeutic drugs with ototoxic side effects cause significant hearing loss for thousands of patients annually. Two major classes of ototoxic drugs are cisplatin and the aminoglycoside antibiotics, both of which are toxic to mechanosensory hair cells, the receptor cells of the inner ear. A critical need exists for therapies that protect the inner ear without inhibiting the therapeutic efficacy of these drugs. The induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death and hearing loss. We hypothesized that exposure to sound that is titrated to stress the inner ear without causing permanent damage would induce HSPs in the cochlea and inhibit ototoxic drug–induced hearing loss. We developed a sound exposure protocol that induces HSPs without causing permanent hearing loss. We used this protocol in conjunction with a newly developed mouse model of cisplatin ototoxicity and found that preconditioning mouse inner ears with sound has a robust protective effect against cisplatin-induced hearing loss and hair cell death. Sound therapy also provided protection against aminoglycoside-induced hearing loss. These data indicate that sound preconditioning protects against both classes of ototoxic drugs, and they suggest that sound therapy holds promise for preventing hearing loss in patients receiving these drugs.
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19
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Gentamicin conditioning confers auditory protection against noise trauma. Eur Arch Otorhinolaryngol 2013; 271:2641-8. [PMID: 24114061 DOI: 10.1007/s00405-013-2707-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 09/13/2013] [Indexed: 10/26/2022]
Abstract
Auditory conditioning consists of the pre-exposure to low levels of a potential harmful agent to protect against a subsequent harmful presentation. The agent that was first tested was noise. This paradigm was more recently successfully tested with other agents. Nonetheless, the vast majority of the studies utilize the same agent to condition and to cause the trauma. The aim of this study was to verify whether conditioning with an agent different from the agent used to cause the trauma can also be effective. Thus, the following groups were organized: group Cont, which is the noise trauma control group, was exposed to 110-dB broadband noise centered at 4 kHz for 72 h; group Gent, which is the gentamicin conditioning control group, was administered 30 mg/kg of gentamicin daily for 30 consecutive days; and group Expt was conditioned with gentamicin similarly to group Gent and then subjected to a noise trauma similarly to group Cont. The animals were functionally and morphologically evaluated through the measurement of the auditory brainstem response and scanning electron microscopy, respectively. The following variables were investigated: outer hair cell injury and auditory threshold shift. The group that was conditioned with the drug exhibited significantly less outer hair cell damage, 10.8 and 22.9%, respectively (p = 0.0146), although did not maintain the proper functioning of the auditory system. We, therefore, conclude that conditioning with a different agent from that used to cause the trauma is effective, which suggests that both agents that were used promote similar mechanisms of self-protection.
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20
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Eggermont JJ. Hearing loss, hyperacusis, or tinnitus: What is modeled in animal research? Hear Res 2013; 295:140-9. [DOI: 10.1016/j.heares.2012.01.005] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/09/2012] [Accepted: 01/16/2012] [Indexed: 11/29/2022]
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21
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Basappa J, Graham CE, Turcan S, Vetter DE. The cochlea as an independent neuroendocrine organ: expression and possible roles of a local hypothalamic-pituitary-adrenal axis-equivalent signaling system. Hear Res 2012; 288:3-18. [PMID: 22484018 DOI: 10.1016/j.heares.2012.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Revised: 03/19/2012] [Accepted: 03/20/2012] [Indexed: 02/07/2023]
Abstract
A key property possessed by the mammalian cochlea is its ability to dynamically alter its own sensitivity. Because hair cells and ganglion cells are prone to damage following exposure to loud sound, extant mechanisms limiting cochlear damage include modulation involving both the mechanical (via outer hair cell motility) and neural signaling (via inner hair cell-ganglion cell synapses) steps of peripheral auditory processing. Feedback systems such as that embodied by the olivocochlear system can alter sensitivity, but respond only after stimulus encoding, allowing potentially damaging sounds to impact the inner ear before sensitivity is adjusted. Less well characterized are potential cellular signaling systems involved in protection against metabolic stress and resultant damage. Although pharmacological manipulation of the olivocochlear system may hold some promise for attenuating cochlear damage, targeting this system may still allow damage to occur that does not depend on a fully functional feedback loop for its mitigation. Thus, understanding endogenous cell signaling systems involved in cochlear protection may lead to new strategies and therapies for prevention of cochlear damage and consequent hearing loss. We have recently discovered a novel cochlear signaling system that is molecularly equivalent to the classic hypothalamic-pituitary-adrenal (HPA) axis. This cochlear HPA-equivalent system functions to balance auditory sensitivity and susceptibility to noise-induced hearing loss, and also protects against cellular metabolic insults resulting from exposures to ototoxic drugs. This system may represent a local cellular response system designed to mitigate damage arising from various types of insult.
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22
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Graham CE, Basappa J, Turcan S, Vetter DE. The cochlear CRF signaling systems and their mechanisms of action in modulating cochlear sensitivity and protection against trauma. Mol Neurobiol 2011; 44:383-406. [PMID: 21909974 DOI: 10.1007/s12035-011-8203-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 08/31/2011] [Indexed: 12/19/2022]
Abstract
A key requirement for encoding the auditory environment is the ability to dynamically alter cochlear sensitivity. However, merely attaining a steady state of maximal sensitivity is not a viable solution since the sensory cells and ganglion cells of the cochlea are prone to damage following exposure to loud sound. Most often, such damage is via initial metabolic insult that can lead to cellular death. Thus, establishing the highest sensitivity must be balanced with protection against cellular metabolic damage that can lead to loss of hair cells and ganglion cells, resulting in loss of frequency representation. While feedback mechanisms are known to exist in the cochlea that alter sensitivity, they respond only after stimulus encoding, allowing potentially damaging sounds to impact the inner ear at times coincident with increased sensitivity. Thus, questions remain concerning the endogenous signaling systems involved in dynamic modulation of cochlear sensitivity and protection against metabolic stress. Understanding endogenous signaling systems involved in cochlear protection may lead to new strategies and therapies for prevention of cochlear damage and consequent hearing loss. We have recently discovered a novel cochlear signaling system that is molecularly equivalent to the classic hypothalamic-pituitary-adrenal (HPA) axis. This cochlear HPA-equivalent system functions to balance auditory sensitivity and susceptibility to noise-induced hearing loss, and also protects against cellular metabolic insults resulting from exposures to ototoxic drugs. We review the anatomy, physiology, and cellular signaling of this system, and compare it to similar signaling in other organs/tissues of the body.
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Affiliation(s)
- Christine E Graham
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
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23
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Le Prell CG, Hensley BN, Campbell KCM, Hall JW, Guire K. Evidence of hearing loss in a 'normally-hearing' college-student population. Int J Audiol 2011; 50 Suppl 1:S21-31. [PMID: 21288064 DOI: 10.3109/14992027.2010.540722] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We report pure-tone hearing threshold findings in 56 college students. All subjects reported normal hearing during telephone interviews, yet not all subjects had normal sensitivity as defined by well-accepted criteria. At one or more test frequencies (0.25-8 kHz), 7% of ears had thresholds ≥25 dB HL and 12% had thresholds ≥20 dB HL. The proportion of ears with abnormal findings decreased when three-frequency pure-tone-averages were used. Low-frequency PTA hearing loss was detected in 2.7% of ears and high-frequency PTA hearing loss was detected in 7.1% of ears; however, there was little evidence for 'notched' audiograms. There was a statistically reliable relationship in which personal music player use was correlated with decreased hearing status in male subjects. Routine screening and education regarding hearing loss risk factors are critical as college students do not always self-identify early changes in hearing. Large-scale systematic investigations of college students' hearing status appear to be warranted; the current sample size was not adequate to precisely measure potential contributions of different sound sources to the elevated thresholds measured in some subjects.
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Affiliation(s)
- C G Le Prell
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL 32610, USA.
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24
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Berglin CE, Pierre PV, Bramer T, Edsman K, Ehrsson H, Eksborg S, Laurell G. Prevention of cisplatin-induced hearing loss by administration of a thiosulfate-containing gel to the middle ear in a guinea pig model. Cancer Chemother Pharmacol 2011; 68:1547-56. [PMID: 21533919 DOI: 10.1007/s00280-011-1656-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/14/2011] [Indexed: 12/20/2022]
Abstract
PURPOSE Thiosulfate may reduce cisplatin-induced ototoxicity, most likely by relieving oxidative stress and by forming inactive platinum complexes. This study aimed to determine the concentration and protective effect of thiosulfate in the cochlea after application of a thiosulfate-containing high viscosity formulation of sodium hyaluronan (HYA gel) to the middle ear prior to i.v. injection of cisplatin in a guinea pig model. METHODS The release of thiosulfate (0.1 M) from HYA gel (0.5% w/w) was explored in vitro. Thiosulfate in the scala tympani perilymph of the cochlea 1 and 3 h after application of thiosulfate in HYA gel to the middle ear was quantified with HPLC and fluorescence detection. Thiosulfate in blood and CSF was also explored. The potential otoprotective effect was evaluated by hair cell count after treatment with thiosulfate in HYA gel applied to the middle ear 3 h prior to cisplatin injection (8 mg/kg b.w.). RESULTS HYA did not impede the release of thiosulfate. Middle ear administration of thiosulfate in HYA gel gave high concentrations in the scala tympani perilymph while maintaining low levels in blood, and it protected against cisplatin-induced hair cell loss. CONCLUSION HYA gel is an effective vehicle for administration of thiosulfate to the middle ear. Local application of a thiosulfate-containing HYA gel reduces the ototoxicity of cisplatin most likely without compromising its antineoplastic effect. This provides a minimally invasive protective treatment that can easily be repeated if necessary.
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Affiliation(s)
- Cecilia Engmér Berglin
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
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25
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Le Prell CG, Hensley BN, Campbell KCM, Hall JW, Guire K. Evidence of hearing loss in a 'normally-hearing' college-student population. Int J Audiol 2011. [PMID: 21288064 DOI: 10.3109/14992027.2010.540722.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We report pure-tone hearing threshold findings in 56 college students. All subjects reported normal hearing during telephone interviews, yet not all subjects had normal sensitivity as defined by well-accepted criteria. At one or more test frequencies (0.25-8 kHz), 7% of ears had thresholds ≥25 dB HL and 12% had thresholds ≥20 dB HL. The proportion of ears with abnormal findings decreased when three-frequency pure-tone-averages were used. Low-frequency PTA hearing loss was detected in 2.7% of ears and high-frequency PTA hearing loss was detected in 7.1% of ears; however, there was little evidence for 'notched' audiograms. There was a statistically reliable relationship in which personal music player use was correlated with decreased hearing status in male subjects. Routine screening and education regarding hearing loss risk factors are critical as college students do not always self-identify early changes in hearing. Large-scale systematic investigations of college students' hearing status appear to be warranted; the current sample size was not adequate to precisely measure potential contributions of different sound sources to the elevated thresholds measured in some subjects.
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Affiliation(s)
- C G Le Prell
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL 32610, USA.
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26
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Kopke RD. Pharmacological approaches to the prevention and treatment of cochlear injury due to noise. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/16513860601181046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Suo-qiang Z, Wei-wei G, Ning Y. The protective effects against noise trauma by sound conditioning in rats. J Otol 2009. [DOI: 10.1016/s1672-2930(09)50010-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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28
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Niu X, Tahera Y, Canlon B. Environmental enrichment to sound activates dopaminergic pathways in the auditory system. Physiol Behav 2007; 92:34-9. [PMID: 17631367 DOI: 10.1016/j.physbeh.2007.05.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Environmental enrichment to sound stimulation, in the adult, can promote physiological changes and protection against trauma in the auditory peripheral and central nervous system. Sound enrichment, or sound conditioning is a method that utilizes a low-level, non-damaging acoustic stimulus as a protective agent. Pre-treating subjects to a moderate or low-level acoustic stimulus reduces the damaging effects of a subsequent traumatic stimulus. The intention of this review is to describe how environmental enrichment to sound affords protection against a subsequent trauma, and the role that the dopaminergic pathways in the cochlea and the auditory brainstem play in this protection. Dopamine is released from the lateral efferents and exerts a tonic inhibition of auditory nerve activity thus preserving auditory sensitivity and protecting against excitotoxicity. Sound conditioning up-regulated tyrosine hydroxylase in the lateral efferents under the inner hair cells and acoustic trauma reduced these levels. Thus, sound conditioning triggers an up-regulation of tyrosine hydroxylase both in the lateral efferent of cochlea and in the lateral superior olivary complex. These findings expand our understanding of the neurochemical balance and regulation between the lateral olivocochlear neurons and the lateral efferent terminals in the cochlea during sound stimulation.
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Affiliation(s)
- Xianzhi Niu
- Karolinska Institutet, Department of Physiology and Pharmacology, Stockholm, Sweden
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29
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Szucs A, Szappanos H, Batta TJ, Tóth A, Szigeti GP, Panyi G, Csernoch L, Sziklai I. Changes in purinoceptor distribution and intracellular calcium levels following noise exposure in the outer hair cells of the guinea pig. J Membr Biol 2007; 213:135-41. [PMID: 17468959 DOI: 10.1007/s00232-006-0045-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2006] [Revised: 10/05/2006] [Indexed: 11/29/2022]
Abstract
Among the cells of the inner ear, the outer hair cells (OHCs) are the most important targets of noise-induced effects, being the most sensitive cell types. The aim of this study was to examine the effects of noise (50 Hz-20 kHz, 80 dB sound pressure level, 14 days) on intracellular calcium levels and on the expression pattern of purinoceptors in the membrane of the OHCs of the guinea pig and to measure the stiffness changes of the lateral membrane of these cells. In noise-exposed animals, the resting intracellular calcium concentration increased compared to nontreated animals and was slightly higher in the cells of the basal (219 +/- 29 nM: ) than in the apical (181 +/- 24 nM: ) turns of the cochlea. After application of 180 muM: adenosine triphosphate, the intracellular calcium level rose by 60 +/- 22 nM: in cells from the apical and by 44 +/- 10 nM: in cells from the basal turns, significantly less than in nontreated animals. Expression of the P(2X1), P(2X2), P(2X4), P(2X7), P(2Y1) and P(2Y4) receptor subtypes was suppressed, while expression of the P(2Y2) subtype did not decrease in either of the two preparations. In parallel with the increase in intracellular calcium concentration, the stiffness of the lateral wall of the OHCs was increased. Noise-induced changes in intracellular calcium homeostasis and subsequently in the calcium-dependent regulatory mechanisms may modify OHC lateral wall stiffness and may lead to reduction of the efficacy of the cochlear amplifier.
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Affiliation(s)
- Attila Szucs
- Department of Otolaryngology and Head and Neck Surgery, Medical and Health Science Center, Medical School, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary.
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30
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Arnold W, Senn P, Hennig M, Michaelis C, Deingruber K, Scheler R, Steinhoff HJ, Riphagen F, Lamm K. Novel slow- and fast-type drug release round-window microimplants for local drug application to the cochlea: an experimental study in guinea pigs. Audiol Neurootol 2004; 10:53-63. [PMID: 15591792 DOI: 10.1159/000082575] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2003] [Accepted: 06/07/2004] [Indexed: 11/19/2022] Open
Abstract
Novel drug release microimplants (0.8 x 1.14 mm; custom-made by Leiras, now Schering OY, Finland) of slow- and fast-release types containing either 0.9 mg beclomethasone or no drug at all were placed unilaterally onto the round-window membrane (RWM) of 45 guinea pigs for a maximum duration of 28 days. The following parameters were tested on days 1, 14 and 28 after implantation: threshold levels of beclomethasone in the perilymph of the scala tympani, auditory brain stem responses (ABR thresholds and ABR threshold shifts), RWM morphology and hair cell loss (cytocochleograms). None of the animals in the non-implanted control group (n = 5) or placebo implant group (n = 15), but all animals in the slow-release-type implant group (n = 15) and fast-release-type implant group (n = 15) revealed the presence of beclomethasone on day 1 (34.9 and 64.3 pg/microl, respectively), day 14 (43.8 and 46.9 pg/microl, respectively) and day 28 after implantation (4.7 and 60.5 pg/microl, respectively). Histology of the RWMs appeared normal, and cytocochleograms revealed no inner hair cell loss and outer hair cell loss within normal ranges (from 0.5 +/- 0.4 to 0.8 +/- 0.2% per cochlea) in both ears in all experimental groups at any time during examination (days 1, 14 and 28). Initial values of ABR thresholds at 3, 6, 9 and 12 kHz did not differ significantly in any of the experimental groups. In non-implanted controls, no significant differences of ABR thresholds were observed in all frequencies tested in either ear on days 1, 14 and 28 compared to initial values, and ABR threshold shifts ranged from -3 +/- 5 dB (min.) to +5 +/- 7 dB (max.). On day 28 after implantation, there were no significant differences of ABR threshold shifts between this and the implant groups, except for 6 kHz of the slow-release device. Therefore, the placebo implants, the slow-release and the fast-release beclomethasone implants appear suitable for further experiments.
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Affiliation(s)
- Wolfgang Arnold
- Clinic for Otorhinolaryngology, Head and Neck Surgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Strasse 22, DE-81675 Munich, Germany.
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31
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Harding GW, Bohne BA. Temporary DPOAE level shifts, ABR threshold shifts and histopathological damage following below-critical-level noise exposures. Hear Res 2004; 196:94-108. [PMID: 15464306 DOI: 10.1016/j.heares.2004.03.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Accepted: 03/08/2004] [Indexed: 11/18/2022]
Abstract
DPOAE temporary level shift (TLS) at 2f(1)-f(2) and f(2)-f(1), ABR temporary threshold shift (TTS), and detailed histopathological findings were compared in three groups of chinchillas that were exposed for 24 h to an octave band of noise (OBN) centered at 4 kHz with a sound pressure level (SPL) of 80, 86 or 92 dB (n=3,4,6). DPOAE levels at 39 frequencies from f(1)=0.3 to 16 kHz (f(2)/f(1)=1.23; L(2) and L(1)=55, 65 and 75 dB, equal and differing by 10 dB) and ABR thresholds at 13 frequencies from 0.5 to 20 kHz were collected pre- and immediately post-exposure. The functional data were converted to pre- minus post-exposure shift and overlaid upon the cytocochleogram of cochlear damage using the frequency-place map for the chinchilla. The magnitude and frequency place of components in the 2f(1)-f(2) TLS patterns were determined and group averages for each OBN SPL and L(1), L(2) combination were calculated. The f(2)-f(1) TLS was also examined in ears with focal lesions equal to or greater than 0.4 mm. The 2f(1)-f(2) TLS (plotted at f(1)) and TTS aligned with the extent and location of damaged supporting cells. The TLS patterns over frequency had two features which were unexpected: (1) a peak at about a half octave above the center of the OBN with a valley just above and below it and (2) a peak (often showing enhancement) at the apical boundary of the supporting-cell damage. The magnitudes of the TLS and TTS generally increased with increasing SPL of the exposure. The peaks of the TLS and TTS, as well as the peaks and valleys of the TLS pattern moved apically as the SPL of the OBN was increased. However, there was little consistency in the pattern relations with differing L(1), L(2) combinations. In addition, neither the 2f(1)-f(2) nor f(2)-f(1) TLS for any L(1), L(2) combination reliably detected focal lesions (100% OHC loss) from 0.4 to 1.2 mm in size. Often, the TLS went in the opposite direction from what would be expected at focal lesions. Recovery from TLS and TTS was also examined in seven animals. Both TLS and TTS recovered partially or completely, the magnitude depending upon exposure SPL.
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Affiliation(s)
- Gary W Harding
- Department of Otolaryngology, Washington University School of Medicine, P.O. Box 8115, 660 South Euclid, St. Louis, MO 63110, USA.
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Niu X, Tahera Y, Canlon B. Protection against Acoustic Trauma by Forward and Backward Sound Conditioning. Audiol Neurootol 2004; 9:265-73. [PMID: 15316199 DOI: 10.1159/000080226] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2003] [Accepted: 01/12/2004] [Indexed: 11/19/2022] Open
Abstract
The purpose of the present study was to determine if short-term sound conditioning provides protection when delivered either before (forward sound conditioning) or after (backward sound conditioning) a traumatic exposure in the guinea pig. Two different sound conditioning paradigms were studied (1 kHz, 81 dB SPL, 24 h; 6.3 kHz, 78 dB SPL, 24 h). The 1-kHz forward sound conditioning paradigm (81 dB SPL, 24 h) protected distortion product otoacoustic emissions (DPOAEs) against a short-duration acoustic trauma (2.7 kHz, 103 dB SPL, 5 min) compared to the group exposed to the acoustic trauma alone. The 1-kHz forward sound conditioning paradigm (81 dB SPL, 24 h) also protected both the auditory brainstem response (ABR) thresholds and DPOAEs against a longer-duration acoustic trauma (2.7 kHz, 103 dB SPL, 30 min). The group exposed to the acoustic trauma alone showed ABR threshold shifts between 15 and 24 dB, and DPOAE amplitude shifts between 11 and 24 dB, while the group with 1-kHz forward sound conditioning showed statistically significant protection at all ABR frequencies and at all DPOAE frequencies. The 1-kHz backward sound conditioning paradigm protected against acoustic trauma (2.7 kHz, 103 dB SPL, 30 min). The ABR thresholds were protected at 1, 2 and 4 kHz, and DPOAEs at all frequencies (except 8 kHz) when compared to the group exposed only to the acoustic trauma. The 6.3-kHz forward sound conditioning paradigm protected against acoustic trauma (5.5 kHz, 109 dB SPL, 30 min) at 6.3, 8 and 10 kHz. The 6.3-kHz backward sound conditioning paradigm showed no protection against acoustic trauma at any DPOAE frequency. Taken together, these findings are important for understanding how the auditory system can be modulated by acoustic stimulation and highlights the importance of the acoustic environment during the recovery process of the auditory system.
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Affiliation(s)
- Xianzhi Niu
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Le Prell CG, Yagi M, Kawamoto K, Beyer LA, Atkin G, Raphael Y, Dolan DF, Bledsoe SC, Moody DB. Chronic excitotoxicity in the guinea pig cochlea induces temporary functional deficits without disrupting otoacoustic emissions. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2004; 116:1044-56. [PMID: 15376671 DOI: 10.1121/1.1772395] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Brief cochlear excitotoxicity produces temporary neural swelling and transient deficits in auditory sensitivity; however, the consequences of long-lasting excitotoxic insult have not been tested. Chronic intra-cochlear infusion of the glutamate agonist AMPA (a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) resulted in functional deficits in the sound-evoked auditory brainstem response, as well as in behavioral measures of hearing. The electrophysiological deficits were similar to those observed following acute infusion of AMPA into the cochlea; however, the concentration-response curve was significantly shifted as a consequence of the slower infusion rate used with chronic cochlear administration. As observed following acute excitotoxic insult, complete functional recovery was evident within 7 days of discontinuing the AMPA infusion. Distortion product otoacoustic emissions were not affected by chronic AMPA infusion, suggesting that trauma to outer hair cells did not contribute to AMPA-induced deficits in acoustic sensitivity. Results from the current experiment address the permanence of deficits induced by chronic (14 day) excitotoxic insult as well as deficits in psychophysical detection of longer duration acoustic signals.
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Affiliation(s)
- Colleen G Le Prell
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0506, USA.
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Lamm K, Michaelis C, Deingruber K, Scheler R, Steinhoff HJ, Gröber I, Huth M, Kutscher C, Arnold W. [Inner ear damage due to leisure and broadband noise. An experimental study on initial and permanent functional and morphological damage]. HNO 2004; 52:301-10. [PMID: 15007514 DOI: 10.1007/s00106-003-1042-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The initial and permanent effects of leisure noise (toy pistols, rock music) compared to broadband noise were examined in 68 guinea pigs. Auditory threshold shifts at 1.5, 2, 3, 4, 6, 8, 12 und 16 kHz were registered before and immediately after exposure as well as on days 1, 2, 3, 5,7 and 21 post-exposure using the auditory brain stem response (ABR) technique. In order to examine cilia and hair cell damage in eight cochlear frequency regions (<0,4 kHz, 0,4-0,8 kHz, 0,8-1.5 kHz, 1.5-3 kHz, 3-5 kHz, 5-11.5 kHz, 11.5-26 kHz und >26 kHz), cytocochleograms were performed immediately after exposure and on days 1, 7 and 21.Frequency dependent functional or morphological damage was found which depended on the type of trauma tested. All results were highly significant ( P<0.001). The results show that partial recovery of hearing occurred within 3 days of acute acoustic trauma induced by toy pistols and within 1 day after exposure to rock music or broadband noise. There was no further recovery of hearing within the following 18 and 20 days, respectively. Furthermore, permanent threshold shifts after exposure to rock music or broadband noise were not associated with cilia and/or hair cell damage.
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Affiliation(s)
- K Lamm
- Hals-Nasen-Ohren-Klinik des Klinikum rechts der Isar, Technische Universität München.
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Harding GW, Bohne BA, Ahmad M. DPOAE level shifts and ABR threshold shifts compared to detailed analysis of histopathological damage from noise. Hear Res 2002; 174:158-71. [PMID: 12433407 DOI: 10.1016/s0378-5955(02)00653-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A detailed comparison of 2f(1)-f(2) distortion product otoacoustic emission (DPOAE) level shifts (LS) and auditory brainstem response (ABR) threshold shifts with noise-induced histopathology was conducted in chinchillas. DPOAE levels (i.e., L(1) and L(2)) at f(1) and f(2), respectively, ranged from 55-75 dB sound pressure level (SPL), with f(2)/f(1)=1.23, 6 points/octave, f(2)=0.41-20 kHz, and ABR thresholds at 0.5-20 kHz, 2 points/octave, were determined pre-exposure. The exposure was a 108 dB SPL octave band of noise centered at 4 kHz (1-1.75 h, n=6) or 80-86 dB SPL (24 h, n=5). DPOAE LSs (magnitude pre- minus post-exposure) and ABR threshold shifts (TS) were determined at 0 days and up to 28 days post-exposure. The cochleae were fixed, embedded in plastic and dissected into flat preparations. The length of the organ of Corti (OC) was measured; missing inner (IHC) and outer (OHC) hair cells counted; stereocilia damage rated; and regions of OC and nerve-fiber loss determined. Cytocochleograms were made showing functional loss and structural damage with the LS and TS overlaid. Some unexpected results were obtained. First, the best correlation of LS with histopathology required plotting the DPOAE data at f(1) with respect to the chinchilla-place map. The best correlation of TS was with IHC and nerve-fiber loss. Second, wide regions of up to 10% scattered OHC loss in the apical half of the OC showed little or no LS. Third, with the 108 dB SPL noise, there was 20-40 dB of recovery for DPOAEs at mid-high frequencies (3-10 kHz) in eight of 12 cochleae where there was 70-100% OHC loss in the basal half of the OC. The largest recovery at mid-high frequencies occurred in regions where the OC was entirely missing. Fourth, with the 80-86 dB SPL noise, there was no LS at small focal lesions (100% loss of OHCs over 0.4 mm) when the frequency place of either f(1) or f(2) was within the lesion but not both. There was no correlation of LS with OHC stereocilia loss, fusion or disarray. These results suggest that, after noise exposure, DPOAEs at mid-high frequencies can originate from or be augmented by generators located at someplace other than the frequency place of f(2), possibly the basal 20% of the OC when this region is intact. Also, noise-induced DPOAE LSs seemed to reflect differing mechanisms for temporary and permanent hearing loss.
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Affiliation(s)
- Gary W Harding
- Department of Otolaryngology, Box 8115, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Ekborn A, Laurell G, Johnström P, Wallin I, Eksborg S, Ehrsson H. D-Methionine and cisplatin ototoxicity in the guinea pig: D-methionine influences cisplatin pharmacokinetics. Hear Res 2002; 165:53-61. [PMID: 12031515 DOI: 10.1016/s0378-5955(02)00277-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
D-Methionine has recently been advocated as a protectant against cisplatin toxicity. The use of systemic D-methionine as a protector was studied in 58 guinea pigs. Kinetics and distribution of [11CH(3)]D-methionine was analysed by positron emission tomography. Cisplatin and the monohydrated complex of cisplatin was quantified in blood ultrafiltrate using reversed-phase liquid chromatography with post-column derivatisation. Administration of 300 mg/kg of D-methionine caused a 30% decrease in the area under the concentration-time curve (AUC) of cisplatin. The toxic effect of cisplatin was studied after dose adjustment of cisplatin, i.e. with similar cisplatin AUC in the group receiving D-methionine and the saline control group. A significant ototoxic effect, measured as difference in pre- and 96 h post-treatment electrophysiological hearing threshold (auditory brainstem response), was observed at stimulus frequencies of 30 and 20 kHz. There was no difference between the groups in the extent of threshold shift. Quantitative outer hair cell counts showed a similar loss of cells in the two groups. All animals had a significant increase in plasma-creatinine but there was no difference between the groups. The results indicate that protection from cisplatin ototoxicity by systemic D-methionine can be explained by a lowered systemic exposure to the drug.
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Affiliation(s)
- Andreas Ekborn
- Department of Otorhinolaryngology, Head and Neck Surgery, Karolinska Hospital, SE-171 76, Stockholm, Sweden.
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Abstract
Noise and aminoglycosides initially attack cochlear outer hair cells (OHCs). Distortion product otoacoustic emissions (DPOAEs) are used for the early diagnosis of damage to OHCs. The effects of sub-damaging doses of amikacin, an aminoglycoside antibiotic agent, on noise-induced hearing loss (NIHL) were examined in guinea pigs. Animals were grouped by gender and exposed to broadband noise at 105 dB SPL for 12 h and/or injected i.m. with either amikacin (100 mg/kg/day) or saline for 10 days. Auditory brainstem response (ABR) thresholds, along with DPOAE amplitudes, were measured serially before and after noise exposure. DPOAE amplitudes decreased and ABR thresholds elevated immediately after noise exposure and then gradually recovered. At all frequencies, the emission amplitudes recovered completely to pre-exposure baseline values by 4 days after noise exposure. There was no effect of amikacin on either the ABR threshold or DPOAE amplitudes, in animals treated with amikacin only. However, amikacin significantly prolonged the effect of noise exposure on DPOAE amplitude but not on the noise-induced temporary threshold shift (TTS) of the ABR. In animals treated with a combination of noise and amikacin, significant changes in DPOAE amplitudes were still observed at 4 weeks after cessation of noise exposure. No gender difference in the responses to noise and/or amikacin could be demonstrated. The present findings indicate that even sub-damaging dosages of amikacin might impair recovery from NIHL in guinea pigs.
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Affiliation(s)
- C T Tan
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
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Kossowski M, Mom T, Guitton M, Poncet JL, Bonfils P, Avan P. Fine Alterations of Distortion-product Otoacoustic Emissions after Moderate Acoustic Overexposure in Guinea Pigs: Alteraciones moderadas de los productos de distorsion de las emisiones otoacusticas después de sobrexposición acústica moderada en cobayos. Int J Audiol 2001. [DOI: 10.3109/00206090109073106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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McFadden SL, Zheng XY, Ding DL. Conditioning-induced protection from impulse noise in female and male chinchillas. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2000; 107:2162-8. [PMID: 10790042 DOI: 10.1121/1.428497] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Sound conditioning (pre-exposure to a moderate-level acoustic stimulus) can induce resistance to hearing loss from a subsequent traumatic exposure. Most sound conditioning experiments have utilized long-duration tones and noise at levels below 110 dB SPL as traumatic stimuli. It is important to know if sound conditioning can also provide protection from brief, high-level stimuli such as impulses produced by gunfire, and whether there are differences between females and males in the response of the ear to noise. In the present study, chinchillas were exposed to 95 dB SPL octave band noise centered at 0.5 kHz for 6 h/day for 5 days. After 5 days of recovery, they were exposed to simulated M16 rifle fire at a level of 150 dB peak SPL. Animals that were sound conditioned showed less hearing loss and smaller hair cell lesions than controls. Females showed significantly less hearing loss than males at low frequencies, but more hearing loss at 16 kHz. Cochleograms showed slightly less hair cell loss in females than in males. The results show that significant protection from impulse noise can be achieved with a 5-day conditioning regimen, and that there are consistent differences between female and male chinchillas in the response of the cochlea to impulse noise.
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Affiliation(s)
- S L McFadden
- Center for Hearing and Deafness, University of Buffalo, New York 14214, USA
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41
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Canlon B, Fransson A, Viberg A. Medial olivocochlear efferent terminals are protected by sound conditioning. Brain Res 1999; 850:253-60. [PMID: 10629772 DOI: 10.1016/s0006-8993(99)02091-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synaptophysin immunoreactivity was used as a marker for the olivocochlear efferent system that innervates the outer hair cells of the cochlea. An intense noise exposure at either 6.3 kHz or 1.0 kHz caused a significant reduction in anti-synaptophysin immunoreactivity within the 8-6 mm or 14-11 mm distance from the round window, respectively. In the region of the main lesion, the reduction in synaptophysin immunoreactivity for both the 6.3 and 1.0 kHz exposures correlated well with outer hair cell loss. In regions peripheral to the main lesion, some remnants of efferent nerve endings could remain even when their associated outer hair cells were missing. Pre-treatment with a low level sound conditioner (either at 6.3 tone or 1.0 kHz) effectively reduced the efferent and outer hair cell pathology induced by the 6.3 and 1.0 kHz intense noise exposures, respectively. The results demonstrate the feasibility of using anti-synaptophysin immunoreactivity as an effective means of quantifying pathological alterations to the medial cochlear efferent terminals throughout the cochlea. Furthermore, the results show that sound conditioning significantly reduces damage to the efferent terminals.
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MESH Headings
- Acoustic Stimulation
- Animals
- Cochlea/cytology
- Cochlea/physiology
- Conditioning, Psychological/physiology
- Guinea Pigs
- Hair Cells, Auditory, Inner/pathology
- Hair Cells, Auditory, Inner/ultrastructure
- Hair Cells, Auditory, Outer/pathology
- Hair Cells, Auditory, Outer/ultrastructure
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/prevention & control
- Image Processing, Computer-Assisted
- Immunohistochemistry
- Microscopy, Confocal
- Neurons, Efferent/physiology
- Olivary Nucleus/cytology
- Olivary Nucleus/physiology
- Presynaptic Terminals/physiology
- Synaptophysin/immunology
- Synaptophysin/metabolism
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Affiliation(s)
- B Canlon
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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Abstract
Exposure of the auditory system to either continuous or interrupted nontraumatic noises, often collectively referred to as priming exposures, has been shown, in a number of experimental paradigms, to reduce the susceptibility of the auditory system to noise-induced hearing and sensory cell loss from a subsequent traumatic exposure. Using auditory evoked potentials to obtain pure-tone thresholds and cochleograms to quantify sensory cell losses, the issue of priming-induced protective effects was examined in the chinchilla. Priming was accomplished with either a continuous noise or with a continuous noise followed by an interrupted noise. Trauma was induced by exposure to high-level impacts over a 5-day period that resulted in an asymptotic threshold shift. A comparison of the two groups of primed subjects with an unprimed control group showed that there were some statistically significant reductions in the asymptotic response of the primed groups to the traumatic exposure but no differences in permanent changes in thresholds among the three groups 30 days following the traumatic exposure. There were, however, some statistically significant, frequency-specific, reductions in outer hair cell loss in the primed groups. When conditioning was followed by the interrupted exposure that produced a threshold shift toughening effect, the conditioning protocol had no effect on the response of subjects to the interrupted exposure. There were also no differences in thresholds or sensory cell loss between the two primed groups 30 days post-trauma. Priming protocols may have different effects on the development of noise-induced trauma that are dependent on the nature of the traumatic stimulus, that is, long-term high-level impact noise exposure versus acute continuous noise exposure.
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MESH Headings
- Animals
- Auditory Threshold
- Chinchilla/physiology
- Disease Models, Animal
- Ear, Inner/pathology
- Ear, Inner/physiology
- Ear, Inner/physiopathology
- Evoked Potentials, Auditory, Brain Stem
- Guinea Pigs
- Hair Cells, Auditory, Outer/injuries
- Hair Cells, Auditory, Outer/pathology
- Hair Cells, Auditory, Outer/physiopathology
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Hearing Loss, Noise-Induced/prevention & control
- Noise/adverse effects
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Affiliation(s)
- R P Hamernik
- Auditory Research Laboratory, Plattsburgh State University of New York, 107 Beaumont Hall, Plattsburgh, NY 12901-2681, USA.
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Abstract
Sound conditioning, by chronic exposure to moderate-level sound, can protect the inner ear (reduce threshold shifts and hair cell damage) from subsequent high-level sound exposure. To investigate the mechanisms underlying this protective effect, the present study focuses on the physiological changes brought on by the conditioning exposure itself. In our guinea-pig model, 6-h daily conditioning exposure to an octave-band noise at 85 dB SPL reduces the permanent threshold shifts (PTSs) from a subsequent 4-h traumatic exposure to the same noise band at 109 dB SPL, as assessed by both compound action potentials (CAPs) and distortion product otoacoustic emissions (DPOAEs). The frequency region of maximum threshold protection is approximately one-half octave above the upper frequency cutoff of the exposure band. Protection is also evident in the magnitude of suprathreshold CAPs and DPOAEs, where effects are more robust and extend to higher frequencies than those evident at or near threshold. The conditioning exposure also enhanced cochlear sensitivity, when evaluated at the same postconditioning time at which the traumatic exposure would be delivered in a protection study. Response enhancements were seen in both threshold and suprathreshold CAPs and DPOAEs. The frequency dependence of the enhancement effects differed, however, by these two metrics. For CAPs, effects were maximum in the same frequency region as those most protected by the conditioning. For DPOAEs, enhancements were shifted to lower frequencies. The conditioning exposure also enhanced both ipsilaterally and contralaterally evoked olivocochlear (OC) reflex strength, as assessed using DPOAEs. The frequency and level dependence of the reflex enhancements were consistent with changes seen in sound-evoked discharge rates in OC fibers after conditioning. However, comparison with the frequency range and magnitude of conditioning-related protection suggests that the protection cannot be completely explained by amplification of the OC reflex and the known protective effects of OC feedback. Rather, the present results suggest that sound conditioning leads to changes in the physiology of the outer hair cells themselves, the peripheral targets of the OC reflex.
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Affiliation(s)
- S G Kujawa
- Department of Otology and Laryngology, Harvard Medical School; and Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114, USA
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Abstract
This experimental study was undertaken to investigate the dose-related effect of cisplatin exposure in young gerbils (2 weeks of age) and explore the relationship between different methods used to monitor auditory function after exposure to cisplatin. Four groups of animals, including a control group, were used. The treatment groups, D1 (n = 6), D2 (n = 7) and D3 (n = 6), received one, two, and three doses of cisplatin (5 mg/kg/dose), respectively, at weekly intervals. Treated animals were first exposed to cisplatin at 2 weeks of age. Distortion product otoacoustic emissions (DPOAE) and auditory brainstem responses (ABR) were measured in treated and control animals at 6 weeks of age. The effects of dose and frequency on the DPOAE amplitude, as well as the relationship between the DPOAE and the ABR thresholds were analyzed. Animals in the D1 and D3 groups demonstrated significant elevation of DPOAE and ABR thresholds. Interestingly, animals in the D2 group demonstrated a bimodal distribution of DPOAE and ABR responses, with four animals severely affected and three not showing an effect. A tendency for a bimodal distribution of DPOAE and ABR responses was also observed in the D1 group, at frequencies below 8 kHz.
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Affiliation(s)
- D A Tampakopoulou
- Department of Surgery, Children's Hospital and Regional Medical Center, University of Washington School of Medicine, Seattle 98105, USA
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Abstract
The auditory system, toughened by an interrupted noise exposure, has been shown in several reports to be less affected by (or protected from) a subsequent high-level noise exposure. Exposure to 115 dB peak SPL, 1 kHz narrow band (400 Hz) transients presented l/s, 6 h/day, to four groups of chinchillas produced a 10-28 dB toughening effect across the 0.5-8.0 kHz test frequency range. Following either a 30 day or an 18 h recovery period the animals were exposed to the same impulses but presented at 121 or 127 dB peak SPL for five uninterrupted days, thus producing an asymptotic threshold shift (ATS) condition. Comparisons between toughened and untoughened control subjects showed: (1) During the 121 dB exposure there was a statistically significant reduction of 10-25 dB in ATS across the entire test frequency range. Thirty days following the 121 dB exposure there were no significant differences in the postexposure permanent effects on thresholds and sensory cell loss. (2) During the 127 dB exposure only the group with the 30 day interval between the toughening and traumatic exposures showed a small (approximately 10 dB), statistically significant, frequency-specific (8 kHz), reduction in ATS. Thirty days following the 127 dB exposure a statistically significant protective effect on threshold was measured only at 16.0 kHz. However, both toughened groups showed less inner hair cell loss at and above 1.0 kHz, while only the group with the 18 h interval between the toughening and traumatic exposures showed less outer hair cell loss at and above 1.0 kHz. There were no systematic differences in the response of the toughened animals that could be attributed to the 30 day or 18 h post-toughening interval.
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Affiliation(s)
- W A Ahroon
- Auditory Research Laboratory, Plattsburgh State University of New York, 12901-2681, USA.
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Ochi A, Yasuhara A, Kobayashi Y. Comparison of distortion product otoacoustic emissions with auditory brain-stem response for clinical use in neonatal intensive care unit. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1998; 108:577-83. [PMID: 9872429 DOI: 10.1016/s0168-5597(98)00038-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES This study compares the clinical usefulness of distortion product otoacoustic emissions (DPOAEs) with the auditory brain-stem response (ABR) for neonates in the neonatal intensive care unit for the evaluation of hearing impairment. METHODS Both DPOAEs and ABR were performed on 36 neonates (67 ears) on the same day. We defined neonates as having normal hearing when the thresholds of wave V of ABR were < or =45 dB hearing level. RESULTS (1) We could not obtain DPOAEs at f2 = 977 Hz in neonates with normal hearing because of high noise floors. DPOAE recording time was 36 min shorter than that of ABR. (2) We defined as normal DPOAEs, the number of frequencies which showed the DPgram-noise floor > or =4 dB was > or =4 at 6 f2 frequencies, from 1416 Hz to 7959 Hz. (3) Normal thresholds of ABR and normal DPOAEs showed the same percentages, i.e. 68.7%, but the percentage of different results between ABR and DPOAEs was 6.0%. CONCLUSIONS Our study indicates that DPOAEs represent a simple procedure, which can be easily performed in the NICU to obtain reliable results in high-risk neonates. Results obtained by DPOAEs were comparable to those obtained by the more complex procedure of ABR.
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Affiliation(s)
- A Ochi
- Department of Pediatrics, Kansai Medical University, Osaka, Japan
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Yamasoba T, Dolan DF. The medial cochlear efferent system does not appear to contribute to the development of acquired resistance to acoustic trauma. Hear Res 1998; 120:143-51. [PMID: 9667438 DOI: 10.1016/s0378-5955(98)00054-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Noise-induced hearing loss (NIHL) was compared between sound conditioned and unconditioned guinea pigs, in which the left ear in both groups had been perfused with strychnine. Animals in the conditioned group were subjected to moderate sound (85 dB SPL broadband, 5 h/day, 10 days) and then exposed to intense sound (110 dB SPL broadband, 5 h). Unconditioned animals were exposed only to the intense sound. Following intense sound exposure, strychnine-treated ears showed greater NIHL than untreated ears in both unconditioned and conditioned animals, demonstrating the role of the medial efferents to reduce NIHL. Conditioned animals, however, showed smaller hearing loss and cochlear damage in both strychnine-treated and untreated ears compared to unconditioned animals; the protective effects given by conditioning were equivalent between the strychnine-treated and untreated ears. These results suggest that, although the medial efferent system acts to attenuate NIHL, it may not be necessary for the acquired resistance to NIHL provided by conditioning.
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Affiliation(s)
- T Yamasoba
- Kresge Hearing Research Institute, The University of Michigan, Ann Arbor 48109-0506, USA
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Skellett RA, Cullen JK, Fallon M, Bobbin RP. Conditioning the auditory system with continuous vs. interrupted noise of equal acoustic energy: is either exposure more protective? Hear Res 1998; 116:21-32. [PMID: 9508025 DOI: 10.1016/s0378-5955(97)00199-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The purpose of this study was to test the hypothesis that differences exist in the amount of protection provided by prior sound conditioning with continuous vs. interrupted, moderate-level noise. Differences were determined by monitoring the changes that occurred in cubic (2f1-f2) distortion product otoacoustic emission (DPOAE) amplitude growth functions subsequent to a traumatizing noise exposure (105 dB SPL, 1.0-2.0 kHz octave band noise presented 24 h per day for 3 days) in guinea pigs which had been conditioned with either continuous (89 dB SPL, 1.0-2.0 kHz octave band noise presented 24 h per day for 11 days) or interrupted noise (95 dB SPL, 1.0-2.0 kHz octave band noise presented on a 6-h 'on'/18-h 'off' schedule for 11 days) of equal acoustic energy. Results suggest that there are significant differences in the degree of protection provided by prior sound conditioning with the continuous and interrupted schedules of moderate-level noise used in this study. Specifically, the interrupted conditioning protocol afforded some degree of protection against the damaging effects of the traumatizing noise exposure, limited to frequencies above the noise exposure band. Conversely, there was a lack of any consistent and sizable protective effect found across the entire test frequency range for the continuous sound conditioning protocol.
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Affiliation(s)
- R A Skellett
- Department of Otorhinolaryngology and Biocommunication, Louisiana State University Medical Center, New Orleans, USA.
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Abstract
Sound conditioning guinea pigs to a 6.3 kHz tone at 78 dB SPL for either 13 or 24 days provides significant physiological (auditory brain stem responses, ABR; and distortion product otoacoustic emissions, DPOAE) and morphological (cochleograms) protection against a subsequent traumatic exposure (6.3 kHz, 100 dB SPL for 24 h) delivered 2 h after sound conditioning. Threshold shifts (ABR, DPOAE) were significantly reduced and the degree of hair cell loss was minimal. When a 1 week pause was given between the end of the sound conditioning and the traumatic exposure, protection was still observed, but to a lesser degree. These findings demonstrate that mid-frequency sound conditioning protects against noise trauma and that the protective effect is maintained for at least 1 week.
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Affiliation(s)
- B Canlon
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Kujawa SG, Liberman MC. Conditioning-related protection from acoustic injury: effects of chronic deefferentation and sham surgery. J Neurophysiol 1997; 78:3095-106. [PMID: 9405529 DOI: 10.1152/jn.1997.78.6.3095] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The inner ear can be made less vulnerable to acoustic injury by a "conditioning" treatment involving exposure to a moderate-level acoustic stimulus before the acoustic overexposure. The present study was designed to explore the role of the olivocochlear (OC) system in this "protection." Guinea pigs were divided into a number of groups: some (trauma-only) were exposed to a traumatic noise for 4 h at 109 dB SPL; others (condition/trauma) were conditioned by daily exposure to the same noise at 85 dB SPL before the traumatic exposure. In OC-intact animals, the condition/trauma group showed significantly less permanent threshold shift (PTS) than the trauma-only group as measured via compound action potentials and distortion-product otoacoustic emissions (DPOAEs). Other animals with identical noise-exposure regimens underwent deefferentation surgery before the start of conditioning: the OC bundle (OCB) was cut in the brain stem, either at the midline (cutting the crossed OCB to both ears) or at the sulcus limitans (cutting all OC fibers to 1 side). Lesion success was quantified by measuring OC fascicles to the outer hair cell region in each ear. The results from the surgical groups showed that total loss of the OCB significantly increased the noise-induced PTS, whereas loss of the COCB only did not; that the conditioning exposure in deefferented animals increased, rather than decreased, the PTS from the traumatic exposure; and that animals undergoing sham surgery (brain stem cuts that failed to transect the OCB) appeared protected whether or not they received the conditioning noise exposure. The latter result suggests that conditioning-related protection may arise from a generalized stress response, which can be elicited by noise exposure, brain surgery, or a variety of other means. The former results make an OC role in the conditioning process, per se, difficult to assess, given the large effects of OC activity on general acoustic vulnerability.
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Affiliation(s)
- S G Kujawa
- Department of Otology and Laryngology, Harvard Medical School, Boston 02115, USA
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