1
|
Kang YJ, Zheng Y. Current understanding of subjective tinnitus in adults. Eur Arch Otorhinolaryngol 2024; 281:4507-4517. [PMID: 38632112 DOI: 10.1007/s00405-024-08633-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 03/14/2024] [Indexed: 04/19/2024]
Abstract
PURPOSE An up-to-date overview of epidemiology, etiology and pathophysiological mechanisms, diagnostic and evaluation methods, current treatment status and future directions of subjective tinnitus in adults. METHODS Review of current evidence-based literature on subjective tinnitus in adults. RESULTS The prevalence of subjective tinnitus in the adult population is estimated to be around 14%, and it tends to increase with age. Subjective tinnitus is a complex condition with multiple factors contributing to its origin. However, the exact causes and underlying mechanisms remain unknown. Potential causes may include hearing loss, dysfunction in the somatosensory system, and auditory cortical dysfunction, although severe underlying pathology is rare. Currently, diagnosis primarily relies on patient self-reported medical history and physician-based clinical assessment due to the lack of objective testing. Various treatment and management options have been proposed, but their effectiveness varies, and there is no universally agreed-upon treatment option. CONCLUSIONS Tinnitus is a complex and heterogeneous disease with a high incidence rate and a tendency to increase with age. A holistic perspective is needed to understand the generation, perception, and emotional responses to tinnitus. Diagnosis requires a comprehensive assessment based on medical history and relevant examinations, identification of concurrent psychosomatic comorbidities, and active pursuit of objective diagnostic methods. At the same time, on the basis of existing treatment plans and combining emerging technologies, we will develop new personalized, precise, and combined treatment plans.
Collapse
Affiliation(s)
- Yao-Jie Kang
- Hearing Center, Department of Otolaryngology-Head and Neck Surgery, West China Hospital of Sichuan University, Chengdu, China
- Department of Otolaryngology-Head and Neck Surgery, The Central Hospital of Enshi Tujia and Miao Autonomous Prefecture, Enshi Tujia and Miao Autonomous Prefecture, China
| | - Yun Zheng
- Hearing Center, Department of Otolaryngology-Head and Neck Surgery, West China Hospital of Sichuan University, Chengdu, China.
| |
Collapse
|
2
|
Ono M, Ito T. Hearing loss-related altered neuronal activity in the inferior colliculus. Hear Res 2024; 449:109033. [PMID: 38797036 DOI: 10.1016/j.heares.2024.109033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/01/2024] [Accepted: 05/13/2024] [Indexed: 05/29/2024]
Abstract
Hearing loss is well known to cause plastic changes in the central auditory system and pathological changes such as tinnitus and hyperacusis. Impairment of inner ear functions is the main cause of hearing loss. In aged individuals, not only inner ear dysfunction but also senescence of the central nervous system is the cause of malfunction of the auditory system. In most cases of hearing loss, the activity of the auditory nerve is reduced, but that of the successive auditory centers is increased in a compensatory way. It has been reported that activity changes occur in the inferior colliculus (IC), a critical nexus of the auditory pathway. The IC integrates the inputs from the brainstem and drives the higher auditory centers. Since abnormal activity in the IC is likely to affect auditory perception, it is crucial to elucidate the neuronal mechanism to induce the activity changes of IC neurons with hearing loss. This review outlines recent findings on hearing-loss-induced plastic changes in the IC and brainstem auditory neuronal circuits and discusses what neuronal mechanisms underlie hearing-loss-induced changes in the activity of IC neurons. Considering the different causes of hearing loss, we discuss age-related hearing loss separately from other forms of hearing loss (non-age-related hearing loss). In general, the main plastic change of IC neurons caused by both age-related and non-age-related hearing loss is increased central gain. However, plastic changes in the IC caused by age-related hearing loss seem to be more complex than those caused by non-age-related hearing loss.
Collapse
Affiliation(s)
- Munenori Ono
- Department of Physiology, School of Medicine, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.
| | - Tetsufumi Ito
- Systems Function and Morphology, University of Toyama, Toyama 930-0194, Japan.
| |
Collapse
|
3
|
Mellott JG, Duncan S, Busby J, Almassri LS, Wawrzyniak A, Iafrate MC, Ohl AP, Slabinski EA, Beaver AM, Albaba D, Vega B, Mafi AM, Buerke M, Tokar NJ, Young JW. Age-related upregulation of dense core vesicles in the central inferior colliculus. Front Cell Neurosci 2024; 18:1396387. [PMID: 38774486 PMCID: PMC11107844 DOI: 10.3389/fncel.2024.1396387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 04/11/2024] [Indexed: 05/24/2024] Open
Abstract
Presbycusis is one of the most prevalent disabilities in aged populations of industrialized countries. As we age less excitation reaches the central auditory system from the periphery. To compensate, the central auditory system [e.g., the inferior colliculus (IC)], downregulates GABAergic inhibition to maintain homeostatic balance. However, the continued downregulation of GABA in the IC causes a disruption in temporal precision related to presbycusis. Many studies of age-related changes to neurotransmission in the IC have therefore focused on GABAergic systems. However, we have discovered that dense core vesicles (DCVs) are significantly upregulated with age in the IC. DCVs can carry neuropeptides, co-transmitters, neurotrophic factors, and proteins destined for the presynaptic zone to participate in synaptogenesis. We used immuno transmission electron microscopy across four age groups (3-month; 19-month; 24-month; and 28-month) of Fisher Brown Norway rats to examine the ultrastructure of DCVs in the IC. Tissue was stained post-embedding for GABA immunoreactivity. DCVs were characterized by diameter and by the neurochemical profile (GABAergic/non-GABAergic) of their location (bouton, axon, soma, and dendrite). Our data was collected across the dorsolateral to ventromedial axis of the central IC. After quantification, we had three primary findings. First, the age-related increase of DCVs occurred most robustly in non-GABAergic dendrites in the middle and low frequency regions of the central IC during middle age. Second, the likelihood of a bouton having more than one DCV increased with age. Lastly, although there was an age-related loss of terminals throughout the IC, the proportion of terminals that contained at least one DCV did not decline. We interpret this finding to mean that terminals carrying proteins packaged in DCVs are spared with age. Several recent studies have demonstrated a role for neuropeptides in the IC in defining cell types and regulating inhibitory and excitatory neurotransmission. Given the age-related increase of DCVs in the IC, it will be critical that future studies determine whether (1) specific neuropeptides are altered with age in the IC and (2) if these neuropeptides contribute to the loss of inhibition and/or increase of excitability that occurs during presbycusis and tinnitus.
Collapse
Affiliation(s)
- Jeffrey G. Mellott
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
- University Hospitals Hearing Research Center, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Syllissa Duncan
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Justine Busby
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Laila S. Almassri
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
- University Hospitals Hearing Research Center, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Alexa Wawrzyniak
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Milena C. Iafrate
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Andrew P. Ohl
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Elizabeth A. Slabinski
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Abigail M. Beaver
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Diana Albaba
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Brenda Vega
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Amir M. Mafi
- The Ohio State University College of Medicine, Columbus, OH, United States
| | - Morgan Buerke
- Department of Psychology, Louisiana State University, Baton Rouge, LA, United States
| | - Nick J. Tokar
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Jesse W. Young
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States
| |
Collapse
|
4
|
Dai Q, Qu T, Shen G, Wang H. Characterization of the neural circuitry of the auditory thalamic reticular nucleus and its potential role in salicylate-induced tinnitus. Front Neurosci 2024; 18:1368816. [PMID: 38629053 PMCID: PMC11019010 DOI: 10.3389/fnins.2024.1368816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
Introduction Subjective tinnitus, the perception of sound without an external acoustic source, is often subsequent to noise-induced hearing loss or ototoxic medications. The condition is believed to result from neuroplastic alterations in the auditory centers, characterized by heightened spontaneous neural activities and increased synchrony due to an imbalance between excitation and inhibition. However, the role of the thalamic reticular nucleus (TRN), a structure composed exclusively of GABAergic neurons involved in thalamocortical oscillations, in the pathogenesis of tinnitus remains largely unexplored. Methods We induced tinnitus in mice using sodium salicylate and assessed tinnitus-like behaviors using the Gap Pre-Pulse Inhibition of the Acoustic Startle (GPIAS) paradigm. We utilized combined viral tracing techniques to identify the neural circuitry involved and employed immunofluorescence and confocal imaging to determine cell types and activated neurons. Results Salicylate-treated mice exhibited tinnitus-like behaviors. Our tracing clearly delineated the inputs and outputs of the auditory-specific TRN. We discovered that chemogenetic activation of the auditory TRN significantly reduced the salicylate-evoked rise in c-Fos expression in the auditory cortex. Discussion This finding posits the TRN as a potential modulatory target for tinnitus treatment. Furthermore, the mapped sensory inputs to the auditory TRN suggest possibilities for employing optogenetic or sensory stimulations to manipulate thalamocortical activities. The precise mapping of the auditory TRN-mediated neural pathways offers a promising avenue for designing targeted interventions to alleviate tinnitus symptoms.
Collapse
Affiliation(s)
| | | | - Guoming Shen
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Haitao Wang
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| |
Collapse
|
5
|
Liu P, Xue X, Zhang C, Zhou H, Ding Z, Wang L, Jiang Y, Shen WD, Yang S, Wang F. Transcriptional-profile changes in the medial geniculate body after noise-induced tinnitus. Exp Biol Med (Maywood) 2024; 249:10057. [PMID: 38562529 PMCID: PMC10984379 DOI: 10.3389/ebm.2024.10057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
Tinnitus is a disturbing condition defined as the occurrence of acoustic hallucinations with no actual sound. Although the mechanisms underlying tinnitus have been explored extensively, the pathophysiology of the disease is not completely understood. Moreover, genes and potential treatment targets related to auditory hallucinations remain unknown. In this study, we examined transcriptional-profile changes in the medial geniculate body after noise-induced tinnitus in rats by performing RNA sequencing and validated differentially expressed genes via quantitative polymerase chain reaction analysis. The rat model of tinnitus was established by analyzing startle behavior based on gap-pre-pulse inhibition of acoustic startles. We identified 87 differently expressed genes, of which 40 were upregulated and 47 were downregulated. Pathway-enrichment analysis revealed that the differentially enriched genes in the tinnitus group were associated with pathway terms, such as coronavirus disease COVID-19, neuroactive ligand-receptor interaction. Protein-protein-interaction networks were established, and two hub genes (Rpl7a and AC136661.1) were identified among the selected genes. Further studies focusing on targeting and modulating these genes are required for developing potential treatments for noise-induced tinnitus in patients.
Collapse
Affiliation(s)
- Peng Liu
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Xinmiao Xue
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Chi Zhang
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Hanwen Zhou
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Zhiwei Ding
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Li Wang
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Yuke Jiang
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Wei-Dong Shen
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Shiming Yang
- Medical School of Chinese PLA, Beijing, China
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, China
| | - Fangyuan Wang
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| |
Collapse
|
6
|
Ghimire M, Cai R, Ling L, Brownell KA, Hackett TA, Llano DA, Caspary DM. Increased pyramidal and VIP neuronal excitability in rat primary auditory cortex directly correlates with tinnitus behaviour. J Physiol 2023; 601:2493-2511. [PMID: 37119035 PMCID: PMC10330441 DOI: 10.1113/jp284675] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 04/25/2023] [Indexed: 04/30/2023] Open
Abstract
Tinnitus affects roughly 15%-20% of the population while severely impacting 10% of those afflicted. Tinnitus pathology is multifactorial, generally initiated by damage to the auditory periphery, resulting in a cascade of maladaptive plastic changes at multiple levels of the central auditory neuraxis as well as limbic and non-auditory cortical centres. Using a well-established condition-suppression model of tinnitus, we measured tinnitus-related changes in the microcircuits of excitatory/inhibitory neurons onto layer 5 pyramidal neurons (PNs), as well as changes in the excitability of vasoactive intestinal peptide (VIP) neurons in primary auditory cortex (A1). Patch-clamp recordings from PNs in A1 slices showed tinnitus-related increases in spontaneous excitatory postsynaptic currents (sEPSCs) and decreases in spontaneous inhibitory postsynaptic currents (sIPSCs). Both measures could be correlated to the rat's behavioural evidence of tinnitus. Tinnitus-related changes in PN excitability were independent of changes in A1 excitatory or inhibitory cell numbers. VIP neurons, part of an A1 local circuit that can control the excitation of layer 5 PNs via disinhibitory mechanisms, showed significant tinnitus-related increases in excitability that directly correlated with the rat's behavioural tinnitus score. That PN and VIP changes directly correlated to tinnitus behaviour suggests an important role in A1 tinnitus pathology. Tinnitus-related A1 changes were similar to findings in studies of neuropathic pain in somatosensory cortex suggesting a common pathology of these troublesome perceptual impairments. Improved understanding between excitatory, inhibitory and disinhibitory sensory cortical circuits can serve as a model for testing therapeutic approaches to the treatment of tinnitus and chronic pain. KEY POINTS: We identified tinnitus-related changes in synaptic function of specific neuronal subtypes in a reliable animal model of tinnitus. The findings show direct and indirect tinnitus-related losses of normal inhibitory function at A1 layer 5 pyramidal cells, and increased VIP excitability. The findings are similar to what has been shown for neuropathic pain suggesting that restoring normal inhibitory function at synaptic inputs onto A1 pyramidal neurons (PNs) could conceptually reduce tinnitus discomfort.
Collapse
Affiliation(s)
- Madan Ghimire
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702
| | - Rui Cai
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702
| | - Lynne Ling
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702
| | - Kevin A. Brownell
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702
| | - Troy A. Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Daniel A. Llano
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Donald M. Caspary
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702
| |
Collapse
|
7
|
Pisani A, Paciello F, Del Vecchio V, Malesci R, De Corso E, Cantone E, Fetoni AR. The Role of BDNF as a Biomarker in Cognitive and Sensory Neurodegeneration. J Pers Med 2023; 13:jpm13040652. [PMID: 37109038 PMCID: PMC10140880 DOI: 10.3390/jpm13040652] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/04/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) has a crucial function in the central nervous system and in sensory structures including olfactory and auditory systems. Many studies have highlighted the protective effects of BDNF in the brain, showing how it can promote neuronal growth and survival and modulate synaptic plasticity. On the other hand, conflicting data about BDNF expression and functions in the cochlear and in olfactory structures have been reported. Several clinical and experimental research studies showed alterations in BDNF levels in neurodegenerative diseases affecting the central and peripheral nervous system, suggesting that BDNF can be a promising biomarker in most neurodegenerative conditions, including Alzheimer's disease, shearing loss, or olfactory impairment. Here, we summarize current research concerning BDNF functions in brain and in sensory domains (olfaction and hearing), focusing on the effects of the BDNF/TrkB signalling pathway activation in both physiological and pathological conditions. Finally, we review significant studies highlighting the possibility to target BDNF as a biomarker in early diagnosis of sensory and cognitive neurodegeneration, opening new opportunities to develop effective therapeutic strategies aimed to counteract neurodegeneration.
Collapse
Affiliation(s)
- Anna Pisani
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Valeria Del Vecchio
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| | - Rita Malesci
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| | - Eugenio De Corso
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Elena Cantone
- Department of Neuroscience, Reproductive Sciences and Dentistry-ENT Section, University of Naples Federico II, 80131 Naples, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
| |
Collapse
|
8
|
Paciello F, Ripoli C, Fetoni AR, Grassi C. Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline. Antioxidants (Basel) 2023; 12:antiox12020332. [PMID: 36829891 PMCID: PMC9952092 DOI: 10.3390/antiox12020332] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.
Collapse
Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Correspondence: ; Tel.: +39-0630154966
| | - Anna Rita Fetoni
- Unit of Audiology, Department of Neuroscience, Università degli Studi di Napoli Federico II, 80138 Naples, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| |
Collapse
|
9
|
Owoc MS, Rubio ME, Brockway B, Sadagopan S, Kandler K. Embryonic medial ganglionic eminence cells survive and integrate into the inferior colliculus of adult mice. Hear Res 2022; 420:108520. [PMID: 35617926 DOI: 10.1016/j.heares.2022.108520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/29/2022] [Accepted: 05/14/2022] [Indexed: 11/20/2022]
Abstract
Acoustic overexposure can lead to decreased inhibition in auditory centers, including the inferior colliculus (IC), and has been implicated in the development of central auditory pathologies. While systemic drugs that increase GABAergic transmission have been shown to provide symptomatic relief, their side effect profiles impose an upper-limit on the dose and duration of use. A treatment that locally increases inhibition in auditory nuclei could mitigate these side effects. One such approach could be transplantation of inhibitory precursor neurons derived from the medial ganglionic eminence (MGE). The present study investigated whether transplanted MGE cells can survive and integrate into the IC of non-noise exposed and noise exposed mice. MGE cells were harvested on embryonic days 12-14 and injected bilaterally into the IC of adult mice, with or without previous noise exposure. At one-week post transplantation, MGE cells possessed small, elongated soma and bipolar processes, characteristic of migrating cells. By 5 weeks, MGE cells exhibited a more mature morphology, with multiple branching processes and axons with boutons that stain positive for the vesicular GABA transporter (VGAT). The MGE survival rate after 14 weeks post transplantation was 1.7% in non-noise exposed subjects. MGE survival rate was not significantly affected by noise exposure (1.2%). In both groups the vast majority of transplanted MGE cells (>97%) expressed the vesicular GABA transporter. Furthermore, electronmicroscopic analysis indicated that transplanted MGE cells formed synapses with and received synaptic endings from host IC neurons. Acoustic stimulation lead to a significant increase in the percentage of endogenous inhibitory cells that express c-fos but had no effect on the percentage of c-fos expressing transplanted MGE cells. MGE cells were observed in the IC up to 22 weeks post transplantation, the longest time point investigated, suggesting long term survival and integration. These data provide the first evidence that transplantation of MGE cells is viable in the IC and provides a new strategy to explore treatment options for central hearing dysfunction following noise exposure.
Collapse
Affiliation(s)
- Maryanna S Owoc
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Medical Scientist Training Program, University of Pittsburgh - Carnegie Mellon University, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States.
| | - María E Rubio
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States; Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Brian Brockway
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Srivatsun Sadagopan
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Medical Scientist Training Program, University of Pittsburgh - Carnegie Mellon University, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, United States
| | - Karl Kandler
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Medical Scientist Training Program, University of Pittsburgh - Carnegie Mellon University, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, United States
| |
Collapse
|
10
|
Malfatti T, Ciralli B, Hilscher MM, Leao RN, Leao KE. Decreasing dorsal cochlear nucleus activity ameliorates noise-induced tinnitus perception in mice. BMC Biol 2022; 20:102. [PMID: 35550106 PMCID: PMC9097071 DOI: 10.1186/s12915-022-01288-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 03/30/2022] [Indexed: 01/05/2023] Open
Abstract
Background The dorsal cochlear nucleus (DCN) is a region known to integrate somatosensory and auditory inputs and is identified as a potential key structure in the generation of phantom sound perception, especially noise-induced tinnitus. Yet, how altered homeostatic plasticity of the DCN induces and maintains the sensation of tinnitus is not clear. Here, we chemogenetically decrease activity of a subgroup of DCN neurons, Ca2+/Calmodulin kinase 2 α (CaMKII α)-positive DCN neurons, using Gi-coupled human M4 Designer Receptors Exclusively Activated by Designer Drugs (hM4Di DREADDs), to investigate their role in noise-induced tinnitus. Results Mice were exposed to loud noise (9–11kHz, 90dBSPL, 1h, followed by 2h of silence), and auditory brainstem responses (ABRs) and gap prepulse inhibition of acoustic startle (GPIAS) were recorded 2 days before and 2 weeks after noise exposure to identify animals with a significantly decreased inhibition of startle, indicating tinnitus but without permanent hearing loss. Neuronal activity of CaMKII α+ neurons expressing hM4Di in the DCN was lowered by administration of clozapine-N-oxide (CNO). We found that acutely decreasing firing rate of CaMKII α+ DCN units decrease tinnitus-like responses (p = 3e −3, n = 11 mice), compared to the control group that showed no improvement in GPIAS (control virus; CaMKII α-YFP + CNO, p = 0.696, n = 7 mice). Extracellular recordings confirmed CNO to decrease unit firing frequency of CaMKII α-hM4Di+ mice and alter best frequency and tuning width of response to sound. However, these effects were not seen if CNO had been previously administered during the noise exposure (n = 6 experimental and 6 control mice). Conclusion We found that lowering DCN activity in mice displaying tinnitus-related behavior reduces tinnitus, but lowering DCN activity during noise exposure does not prevent noise-induced tinnitus. Our results suggest that CaMKII α-positive cells in the DCN are not crucial for tinnitus induction but play a significant role in maintaining tinnitus perception in mice. Supplementary Information The online version contains supplementary material available at (10.1186/s12915-022-01288-1).
Collapse
Affiliation(s)
- Thawann Malfatti
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Barbara Ciralli
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Markus M Hilscher
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Richardson N Leao
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Katarina E Leao
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil.
| |
Collapse
|
11
|
Can GABAkines Quiet the Noise? The GABAA Receptor Neurobiology and Pharmacology of Tinnitus. Biochem Pharmacol 2022; 201:115067. [DOI: 10.1016/j.bcp.2022.115067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 11/20/2022]
|
12
|
Isler B, von Burg N, Kleinjung T, Meyer M, Stämpfli P, Zölch N, Neff P. Lower glutamate and GABA levels in auditory cortex of tinnitus patients: a 2D-JPRESS MR spectroscopy study. Sci Rep 2022; 12:4068. [PMID: 35260698 PMCID: PMC8904839 DOI: 10.1038/s41598-022-07835-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/25/2022] [Indexed: 12/14/2022] Open
Abstract
We performed magnetic resonance spectroscopy (MRS) on healthy individuals with tinnitus and no hearing loss (n = 16) vs. a matched control group (n = 17) to further elucidate the role of excitatory and inhibitory neurotransmitters in tinnitus. Two-dimensional J-resolved spectroscopy (2D-JPRESS) was applied to disentangle Glutamate (Glu) from Glutamine and to estimate GABA levels in two bilateral voxels in the primary auditory cortex. Results indicated a lower Glu concentration (large effect) in right auditory cortex and lower GABA concentration (medium effect) in the left auditory cortex of the tinnitus group. Within the tinnitus group, Glu levels positively correlated with tinnitus loudness measures. While the GABA difference between groups is in line with former findings and theories about a dysfunctional auditory inhibition system in tinnitus, the novel finding of reduced Glu levels came as a surprise and is discussed in the context of a putative framework of inhibitory mechanisms related to Glu throughout the auditory pathway. Longitudinal or interventional studies could shed more light on interactions and causality of Glu and GABA in tinnitus neurochemistry.
Collapse
Affiliation(s)
- B Isler
- Department of Otorhinolaryngology, University Hospital Zurich, (USZ), University of Zurich (UZH), Zurich, Switzerland. .,Faculty of Medicine, University of Zurich (UZH), Zurich, Switzerland.
| | - N von Burg
- Faculty of Medicine, University of Zurich (UZH), Zurich, Switzerland
| | - T Kleinjung
- Department of Otorhinolaryngology, University Hospital Zurich, (USZ), University of Zurich (UZH), Zurich, Switzerland.,Faculty of Medicine, University of Zurich (UZH), Zurich, Switzerland
| | - M Meyer
- Division of Neuropsychology, University of Zurich (UZH), Zurich, Switzerland.,University Research Priority Program 'Dynamics of Healthy Aging', University of Zurich (UZH), Zurich, Switzerland
| | - P Stämpfli
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich (UZH), Zurich, Switzerland
| | - N Zölch
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital Zurich, University of Zurich (UZH), Zurich, Switzerland.,Institute of Forensic Medicine, University of Zurich (UZH), Zurich, Switzerland
| | - P Neff
- Department of Psychology, Center for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria.,Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany.,Institute of Bioengineering, Center for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland.,Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland
| |
Collapse
|
13
|
The role of the medial geniculate body of the thalamus in the pathophysiology of tinnitus and implications for treatment. Brain Res 2022; 1779:147797. [DOI: 10.1016/j.brainres.2022.147797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 11/25/2021] [Accepted: 01/13/2022] [Indexed: 01/12/2023]
|
14
|
Paciello F, Rinaudo M, Longo V, Cocco S, Conforto G, Pisani A, Podda MV, Fetoni AR, Paludetti G, Grassi C. Auditory sensory deprivation induced by noise exposure exacerbates cognitive decline in a mouse model of Alzheimer's disease. eLife 2021; 10:70908. [PMID: 34699347 PMCID: PMC8547960 DOI: 10.7554/elife.70908] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/15/2021] [Indexed: 12/18/2022] Open
Abstract
Although association between hearing impairment and dementia has been widely documented by epidemiological studies, the role of auditory sensory deprivation in cognitive decline remains to be fully understood. To address this issue we investigated the impact of hearing loss on the onset and time-course of cognitive decline in an animal model of Alzheimer's disease (AD), that is the 3×Tg-AD mice and the underlying mechanisms. We found that hearing loss induced by noise exposure in the 3×Tg-AD mice before the phenotype is manifested caused persistent synaptic and morphological alterations in the auditory cortex. This was associated with earlier hippocampal dysfunction, increased tau phosphorylation, neuroinflammation, and redox imbalance, along with anticipated memory deficits compared to the expected time-course of the neurodegenerative phenotype. Our data suggest that a mouse model of AD is more vulnerable to central damage induced by hearing loss and shows reduced ability to counteract noise-induced detrimental effects, which accelerates the neurodegenerative disease onset.
Collapse
Affiliation(s)
- Fabiola Paciello
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Marco Rinaudo
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Valentina Longo
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Sara Cocco
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Giulia Conforto
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Anna Pisani
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Maria Vittoria Podda
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Anna Rita Fetoni
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Gaetano Paludetti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Claudio Grassi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| |
Collapse
|
15
|
Zhang Q, Zhao L, Shen W, Yang S. Subjective tinnitus: lesion-induced pathological central homeostasis remodeling. J Otol 2021; 16:266-272. [PMID: 34548874 PMCID: PMC8438635 DOI: 10.1016/j.joto.2021.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 11/25/2022] Open
Abstract
Subjective tinnitus is the most common type of tinnitus, which is the manifestation of pathological activities in the brain. It happens in a substantial portion of the general population and brings significant burden to the society. Severe subjective tinnitus can lead to depression and insomnia and severely affects patients' quality of life. However, due to poor understanding of its etiology and pathogenesis, treatment of subjective tinnitus remains challenging. In recent decades, a growing number of studies have shown that subjective tinnitus is related to lesion-induced neural plasticity of auditory and non-auditory central systems. This article reviews cellular mechanisms of neural plasticity in subjective tinnitus to provide further understanding of its pathogenesis.
Collapse
Affiliation(s)
- Qi Zhang
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Fuxing Street NO.28, Haidian District, Beijing, 100039, China
| | - Lidong Zhao
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Fuxing Street NO.28, Haidian District, Beijing, 100039, China
| | - Weidong Shen
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Fuxing Street NO.28, Haidian District, Beijing, 100039, China
| | - Shiming Yang
- Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Fuxing Street NO.28, Haidian District, Beijing, 100039, China
| |
Collapse
|
16
|
Hill M, Třískala Z, Honců P, Krejčí M, Kajzar J, Bičíková M, Ondřejíková L, Jandová D, Sterzl I. Aging, hormones and receptors. Physiol Res 2021; 69:S255-S272. [PMID: 33094624 DOI: 10.33549/physiolres.934523] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Ageing is accompanied by deterioration in physical condition and a number of physiological processes and thus a higher risk of a range of diseases and disorders. In particular, we focused on the changes associated with aging, especially the role of small molecules, their role in physiological and pathophysiological processes and potential treatment options. Our previously published results and data from other authors lead to the conclusion that these unwanted changes are mainly linked to the hypothalamic-pituitary-adrenal axis can be slowed down, stopped, or in some cases even reversed by an appropriate treatment, but especially by a life-management adjustment.
Collapse
Affiliation(s)
- M Hill
- Department of Steroids and Proteohormones, Institute of Endocrinology, Prague, Czech Republic.
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Saeed S, Khan QU. The Pathological Mechanisms and Treatments of Tinnitus. Discoveries (Craiova) 2021; 9:e137. [PMID: 35350720 PMCID: PMC8956333 DOI: 10.15190/d.2021.16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/21/2021] [Accepted: 09/30/2021] [Indexed: 11/22/2022] Open
Abstract
Tinnitus is defined as the ringing, hissing, clicking or roaring sounds an individual consciously perceives in the absence of an external auditory stimulus. Currently, the literature on the mechanism of tinnitus pathology is multifaceted, ranging from tinnitus generation at the cellular level to its perception at the system level. Cellular level mechanisms include increased neuronal synchrony, neurotransmission changes and maladaptive plasticity. At the system level, the role of auditory structures, non-auditory structures, changes in the functional connectivities in higher regions and tinnitus networks have been investigated. The exploration of all these mechanisms creates a holistic view on understanding the changes the pathophysiology of tinnitus undertakes. Although tinnitus percept may start at the level of cochlear nerve deafferentation, the neuronal changes in the central auditory system to the neuronal and connectivity changes in non-auditory regions, such as the limbic system, become cardinal in chronic tinnitus generation. At the present moment, some tinnitus generation mechanisms are well established (e.g., increased neuronal synchrony) whereas other mechanisms have gained more traction recently (e.g., tinnitus networks, tinnitus-distress networks) and therefore, require additional investigation to solidify their role in tinnitus pathology.
The treatments and therapeutics designed for tinnitus are numerous, with varied levels of success. They are generally two-fold: some treatments focus on tinnitus cessation (including cochlear implants, deep brain stimulation, transcranial direct current stimulation and transcranial magnetic stimulation) whereas the other set focuses on tinnitus reduction or masking (including hearing aids, sound therapy, cognitive behavioral therapy, tinnitus retraining therapy, and tailor made notched musical training). Tinnitus management has focused on implementing tinnitus masking/reducing therapies more than tinnitus cessation, since cessation treatments are still lacking in streamlined treatment protocols and long-term sustainability and efficacy of the treatment.
This review will focus on concisely exploring the current and most relevant tinnitus pathophysiology mechanisms, treatments and therapeutics.
Collapse
Affiliation(s)
- Sana Saeed
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | | |
Collapse
|
18
|
Paraouty N, Mowery TM. Early Sensory Deprivation Leads to Differential Inhibitory Changes in the Striatum During Learning. Front Neural Circuits 2021; 15:670858. [PMID: 34122017 PMCID: PMC8194259 DOI: 10.3389/fncir.2021.670858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/29/2021] [Indexed: 11/13/2022] Open
Abstract
The corticostriatal circuit has been identified as a vital pathway for associative learning. However, how learning is implemented when the sensory striatum is permanently impaired remains unclear. Using chemogenetic techniques to suppress layer five auditory cortex (AC) input to the auditory striatum, learning of a sound discrimination task was significantly impacted in freely moving Mongolian gerbils, in particular when this suppression occurs early on during learning. Whole-cell recordings sampled throughout learning revealed a transient reduction in postsynaptic (GABAA) inhibition in both striatal D1 and D2 cells in normal-hearing gerbils during task acquisition. In contrast, when the baseline striatal inhibitory strengths and firing rates were permanently reduced by a transient period of developmental sensory deprivation, learning was accompanied by augmented inhibition and increased firing rates. Direct manipulation of striatal inhibition in vivo and in vitro revealed a key role of the transient inhibitory changes in task acquisition. Together, these results reveal a flexible corticostriatal inhibitory synaptic plasticity mechanism that accompanies associative auditory learning.
Collapse
Affiliation(s)
- Nihaad Paraouty
- Center for Neural Science, New York University, New York, NY, United States
| | - Todd M Mowery
- Department of Otolaryngology, Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States.,Rutgers Brain Health Institute, Rutgers University, New Brunswick, NJ, United States
| |
Collapse
|
19
|
Shao N, Jiang S, Younger D, Chen T, Brown M, Rao KVR, Skotak M, Gan RZ, Chandra N. Central and peripheral auditory abnormalities in chinchilla animal model of blast-injury. Hear Res 2021; 407:108273. [PMID: 34139381 DOI: 10.1016/j.heares.2021.108273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 11/25/2022]
Abstract
Exposure to blast overpressure or high-intensity sound can cause injuries to the auditory system, which leads to hearing loss or tinnitus. In this study, we examined the involvement of peripheral auditory system (PAS), and central auditory system (CAS) changes after exposure to blast overpressure (15-25 psi) on Day 1 and additionally during 7 days of post blast time period in chinchillas. Auditory brainstem response (ABR), distortion product otoacoustic emission (DPOAE), and cochlear hair cell changes were measured or identified in post-blast period within 7 days to detect injuries in the PAS. In the CAS, changes in NMDAR1 (excitatory receptor) and GABAA (inhibitory receptor) as well as changes in serotonin (5-HT2A) and acetylcholine (AChR) receptors were examined in different brain regions: auditory cortex (AC), geniculate body (GB), inferior colliculus (IC) and amygdala by immunofluorescence staining. We observed the PAS abnormalities of increased ABR threshold and decreased DPOAE response in animals after blast exposure with hearing protection devices (e.g., earplug). Blast exposure also caused a reduction in both NMDAR1 and GABAA receptor levels in acute condition (post-blast or Day 1) in AC and IC, while serotonin and acetylcholine receptor levels displayed a biphasic response at Day 1 and Day 7 post-exposure. Results demonstrate that the earplug can protect the tympanic membrane and middle ear against structural damage, but the hearing level, cochlear outer hair cell, and the central auditory system (levels of excitatory and inhibitory neurotransmitter receptors) were only partially protected at the tested blast overpressure level. The findings in this study indicate that blast exposure can cause both peripheral and central auditory dysfunctions, and the central auditory response is independent of peripheral auditory damage. The CAS dysfunction is likely mediated by direct transmission of shockwaves in all the regions of central nervous system (CNS), including nerves and surrounding tissues along the auditory pathways. Hence, targeting central auditory neurotransmitter abnormalities may have a therapeutic benefit to attenuate blast-induced hearing loss and tinnitus.
Collapse
Affiliation(s)
- Ningning Shao
- Center for Injury Biomechanics, Materials, and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
| | - Shangyuan Jiang
- School of Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, United States.
| | - Daniel Younger
- Center for Injury Biomechanics, Materials, and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
| | - Tao Chen
- School of Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, United States.
| | - Marcus Brown
- School of Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, United States.
| | - Kakulavarapu V Rama Rao
- Center for Injury Biomechanics, Materials, and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
| | - Maciej Skotak
- Center for Injury Biomechanics, Materials, and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
| | - Rong Z Gan
- School of Aerospace & Mechanical Engineering, University of Oklahoma, Norman, OK, United States.
| | - Namas Chandra
- Center for Injury Biomechanics, Materials, and Medicine, Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States; Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience (CMPN), Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, United States.
| |
Collapse
|
20
|
Ahmed S, Mohan A, Yoo HB, To WT, Kovacs S, Sunaert S, De Ridder D, Vanneste S. Structural correlates of the audiological and emotional components of chronic tinnitus. PROGRESS IN BRAIN RESEARCH 2021; 262:487-509. [PMID: 33931193 DOI: 10.1016/bs.pbr.2021.01.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The objective is to investigate white matter tracts, more specifically the arcuate fasciculus and acoustic radiation, in tinnitus and assess their relationship with distress, loudness and hearing loss. DTI images were acquired for 58 tinnitus patients and 65 control subjects. Deterministic tractography was first performed to visualize the arcuate fasciculus and acoustic radiation tracts bilaterally and to calculate tract density, fractional anisotropy, radial diffusivity, and axial diffusivity for tinnitus and control subjects. Tinnitus patients had a significantly reduced tract density compared to controls in both tracts of interest. They also exhibited increased axial diffusivity in the left acoustic radiation, as well as increased radial diffusivity in the left arcuate fasciculus, and both the left and right acoustic radiation. Furthermore, they exhibited decreased fractional anisotropy in the left arcuate fasciculus, as well as the left and right acoustic radiation tracts. Partial correlation analysis showed: (1) a negative correlation between arcuate fasciculus tract density and tinnitus distress, (2) a negative correlation between acoustic radiation tract density and hearing loss, (3) a negative correlation between acoustic radiation tract density and loudness, (4) a positive correlation between left arcuate fasciculus and tinnitus distress for radial diffusivity, (5) a negative correlation between left arcuate fasciculus and tinnitus distress for fractional anisotropy, (6) a positive correlation between left and right acoustic radiation and hearing loss for radial diffusivity, (7) No correlation between any of the white matter characteristics and tinnitus loudness. Structural alterations in the acoustic radiation and arcuate fasciculus correlate with hearing loss and distress in tinnitus but not tinnitus loudness showing that loudness is a more functional correlate of the disorder which does not manifest structurally.
Collapse
Affiliation(s)
- Shaheen Ahmed
- Lab for Clinical and Integrative Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Anusha Mohan
- Global Brain Health Institute & Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Hye Bin Yoo
- Lab for Clinical and Integrative Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States
| | - Wing Ting To
- School of Nursing & Midwifery, Trinity College Dublin, Dublin, Ireland
| | - Silvia Kovacs
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Stefan Sunaert
- Translational MRI, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Dirk De Ridder
- School of Nursing & Midwifery, Trinity College Dublin, Dublin, Ireland
| | - Sven Vanneste
- Lab for Clinical and Integrative Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States; Global Brain Health Institute & Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
| |
Collapse
|
21
|
Hayes SH, Schormans AL, Sigel G, Beh K, Herrmann B, Allman BL. Uncovering the contribution of enhanced central gain and altered cortical oscillations to tinnitus generation. Prog Neurobiol 2020; 196:101893. [PMID: 32783988 DOI: 10.1016/j.pneurobio.2020.101893] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/20/2020] [Accepted: 08/02/2020] [Indexed: 12/22/2022]
Abstract
Various theories and their associated mechanisms have been proposed as the neural basis of phantom sound perception (tinnitus), including central gain enhancement and altered cortical oscillations. However, it remains unknown whether these cortical changes directly cause tinnitus, or simply coexist with the phantom percept. Using chronically-implanted electrodes and drug delivery cannulae in rats, we examined whether enhanced central gain and cortical oscillations are consistent across different tinnitus induction methods (noise exposure; salicylate), and if directly-inducing enhanced central gain or altered cortical oscillations via pharmacologic manipulation of inhibition along the auditory pathway would cause behavioral evidence of tinnitus. We show that, while there appeared to be no clear link between tinnitus and the presence of enhanced sound-evoked cortical activity or altered spontaneous cortical oscillations, pharmacologic impairment of GABAergic neurotransmission in the auditory cortex was sufficient to cause tinnitus; collective findings which further advance our understanding of the neural basis of tinnitus.
Collapse
Affiliation(s)
- Sarah H Hayes
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada.
| | - Ashley L Schormans
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Gregory Sigel
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Krystal Beh
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Björn Herrmann
- Department of Psychology, Brain and Mind Institute, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Brian L Allman
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| |
Collapse
|
22
|
Keesom SM, Hurley LM. Silence, Solitude, and Serotonin: Neural Mechanisms Linking Hearing Loss and Social Isolation. Brain Sci 2020; 10:brainsci10060367. [PMID: 32545607 PMCID: PMC7349698 DOI: 10.3390/brainsci10060367] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/06/2020] [Accepted: 06/09/2020] [Indexed: 12/11/2022] Open
Abstract
For social animals that communicate acoustically, hearing loss and social isolation are factors that independently influence social behavior. In human subjects, hearing loss may also contribute to objective and subjective measures of social isolation. Although the behavioral relationship between hearing loss and social isolation is evident, there is little understanding of their interdependence at the level of neural systems. Separate lines of research have shown that social isolation and hearing loss independently target the serotonergic system in the rodent brain. These two factors affect both presynaptic and postsynaptic measures of serotonergic anatomy and function, highlighting the sensitivity of serotonergic pathways to both types of insult. The effects of deficits in both acoustic and social inputs are seen not only within the auditory system, but also in other brain regions, suggesting relatively extensive effects of these deficits on serotonergic regulatory systems. Serotonin plays a much-studied role in depression and anxiety, and may also influence several aspects of auditory cognition, including auditory attention and understanding speech in challenging listening conditions. These commonalities suggest that serotonergic pathways are worthy of further exploration as potential intervening mechanisms between the related conditions of hearing loss and social isolation, and the affective and cognitive dysfunctions that follow.
Collapse
Affiliation(s)
- Sarah M. Keesom
- Department of Biology, Utica College, Utica, NY 13502, USA
- Correspondence:
| | - Laura M. Hurley
- Center for the Integrative Study of Animal Behavior, Department of Biology, Indiana University, Bloomington, IN 47405, USA;
| |
Collapse
|
23
|
Richardson BD, Sottile SY, Caspary DM. Mechanisms of GABAergic and cholinergic neurotransmission in auditory thalamus: Impact of aging. Hear Res 2020; 402:108003. [PMID: 32703637 DOI: 10.1016/j.heares.2020.108003] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/15/2020] [Accepted: 05/23/2020] [Indexed: 12/18/2022]
Abstract
Age-related hearing loss is a complex disorder affecting a majority of the elderly population. As people age, speech understanding becomes a challenge especially in complex acoustic settings and negatively impacts the ability to accurately analyze the auditory scene. This is in part due to an inability to focus auditory attention on a particular stimulus source while simultaneously filtering out other sound stimuli. The present review examines the impact of aging on two neurotransmitter systems involved in accurate temporal processing and auditory gating in auditory thalamus (medial geniculate body; MGB), a critical brain region involved in the coding and filtering of auditory information. The inhibitory neurotransmitter GABA and its synaptic receptors (GABAARs) are key to maintaining accurate temporal coding of complex sounds, such as speech, throughout the central auditory system. In the MGB, synaptic and extrasynaptic GABAARs mediate fast phasic and slow tonic inhibition respectively, which in turn regulate MGB neuron excitability, firing modes, and engage thalamocortical oscillations that shape coding and gating of acoustic content. Acoustic coding properties of MGB neurons are further modulated through activation of tegmental cholinergic afferents that project to MGB to potentially modulate attention and help to disambiguate difficult to understand or novel sounds. Acetylcholine is released onto MGB neurons and presynaptic terminals in MGB activating neuronal nicotinic and muscarinic acetylcholine receptors (nAChRs, mAChRs) at a subset of MGB afferents to optimize top-down and bottom-up information flow. Both GABAergic and cholinergic neurotransmission is significantly altered with aging and this review will detail how age-related changes in these circuits within the MGB may impact coding of acoustic stimuli.
Collapse
Affiliation(s)
- B D Richardson
- WWAMI Medical Education, University of Idaho, Moscow, ID, 83844, USA; Biological Engineering, University of Idaho, Moscow, ID, 83844, USA
| | - S Y Sottile
- Center for Clinical Research Southern Illinois University - School of Medicine, Springfield, IL, 62702, USA
| | - D M Caspary
- Department of Pharmacology Southern Illinois University - School of Medicine, Springfield, IL, 62702, USA.
| |
Collapse
|
24
|
Zhang Z, Jia X, Guan X, Zhang Y, Lyu Y, Yang J, Jiang T. White Matter Abnormalities of Auditory Neural Pathway in Sudden Sensorineural Hearing Loss Using Diffusion Spectrum Imaging: Different Findings From Tinnitus. Front Neurosci 2020; 14:200. [PMID: 32269506 PMCID: PMC7109467 DOI: 10.3389/fnins.2020.00200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/24/2020] [Indexed: 01/06/2023] Open
Abstract
Sudden sensorineural hearing loss (SSNHL) is a complex and challenging emergency which requires evidence regarding its pathophysiological changes to guide the treatment. The aim of this study was to evaluate the white matter integrity of the auditory neural pathway in patients with unilateral SSNHL in acute stage by using diffusion spectrum imaging tractography. In the present study, 60 individuals with acute SSNHL (29 males, 50.7 ± 11.8 years) and 25 healthy controls (13 males, 45.2 ± 13.2 years) underwent diffusion spectrum imaging tractography and high resolution T1 structural examinations using a 3T magnetic resonance imaging system. The areas of the auditory neural pathway were defined as regions of interest (ROIs). The quantitative anisotropy (QA) and the generalized fractional anisotropy (GFA) were compared between the patients with unilateral SSNHL and controls in these ROIs. We further evaluated the correlation between the parameter values and hearing loss level. The mean pure tone audiometry of patients at the onset presentation was 63.2 ± 26.2 dB. The right-sided SSNHL was involved in 25 (41.7%) cases and the left-sided in 35 (58.3%) cases. The QA values in the contralateral medial geniculate body, the bilateral anterior corona radiata and the anterior limb of internal capsule were significantly reduced in SSNHL patients compared to controls. In addition, the decrease QA value of the contralateral medial geniculate body was related to the increase severity of disease, even after controlling potential confounding factors. The present study demonstrated that patients with SSNHL exhibited altered integrity of white matter in the auditory neural pathway. Furthermore, the decreased QA values in the contralateral medial geniculate body might predict the severity of this disease. In the present study, tinnitus has not been found to effect in brain area obviously.
Collapse
Affiliation(s)
- Zihao Zhang
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Xiuqin Jia
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Xiaojiao Guan
- Department of Radiology, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Yi Zhang
- Department of Hyperbaric Oxygen, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Yuelei Lyu
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Jing Yang
- Department of Hyperbaric Oxygen, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Tao Jiang
- Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
25
|
Kapolowicz MR, Thompson LT. Plasticity in Limbic Regions at Early Time Points in Experimental Models of Tinnitus. Front Syst Neurosci 2020; 13:88. [PMID: 32038184 PMCID: PMC6992603 DOI: 10.3389/fnsys.2019.00088] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/23/2019] [Indexed: 01/09/2023] Open
Abstract
Tinnitus is one of the most prevalent auditory disorders worldwide, manifesting in both chronic and acute forms. The pathology of tinnitus has been mechanistically linked to induction of harmful neural plasticity stemming from traumatic noise exposure, exposure to ototoxic medications, input deprivation from age-related hearing loss, and in response to injuries or disorders damaging the conductive apparatus of the ears, the cochlear hair cells, the ganglionic cells of the VIIIth cranial nerve, or neurons of the classical auditory pathway which link the cochlear nuclei through the inferior colliculi and medial geniculate nuclei to auditory cortices. Research attempting to more specifically characterize the neural plasticity occurring in tinnitus have used a wide range of techniques, experimental paradigms, and sampled at different windows of time to reach different conclusions about why and which specific brain regions are crucial in the induction or ongoing maintenance of tinnitus-related plasticity. Despite differences in experimental methodologies, evidence reveals similar findings that strongly suggest that immediate and prolonged activation of non-classical auditory structures (i.e., amygdala, hippocampus, and cingulate cortex) may contribute to the initiation and development of tinnitus in addition to the ongoing maintenance of this devastating condition. The overarching focus of this review, therefore, is to highlight findings from the field supporting the hypothesis that abnormal early activation of non-classical sensory limbic regions are involved in tinnitus induction, with activation of these regions continuing to occur at different temporal stages. Since initial/early stages of tinnitus are difficult to control and to quantify in human clinical populations, a number of different animal paradigms have been developed and assessed in experimental investigations. Reviews of traumatic noise exposure and ototoxic doses of sodium salicylate, the most prevalently used animal models to induce experimental tinnitus, indicate early limbic system plasticity (within hours, minutes, or days after initial insult), supports subsequent plasticity in other auditory regions, and contributes to the pathophysiology of tinnitus. Understanding this early plasticity presents additional opportunities for intervention to reduce or eliminate tinnitus from the human condition.
Collapse
Affiliation(s)
- Michelle R. Kapolowicz
- Center for Hearing Research, University of California, Irvine, Irvine, CA, United States
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Lucien T. Thompson
- Department of Neurobiology, School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, United States
| |
Collapse
|
26
|
Zhang W, Peng Z, Yu S, Song QL, Qu TF, Liu K, Gong SS. Exposure to sodium salicylate disrupts VGLUT3 expression in cochlear inner hair cells and contributes to tinnitus. Physiol Res 2019; 69:181-190. [PMID: 31852197 DOI: 10.33549/physiolres.934180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
To examine whether exposure to sodium salicylate disrupts expression of vesicular glutamate transporter 3 (VGLUT3) and whether the alteration in expression corresponds to increased risk for tinnitus. Rats were treated with saline (control) or sodium salicylate (treated) Rats were examined for tinnitus by monitoring gap-pre-pulse inhibition of the acoustic startle reflex (GPIAS). Auditory brainstem response (ABR) was applied to evaluate hearing function after treatment. Rats were sacrificed after injection to obtain the cochlea, cochlear nucleus (CN), and inferior colliculus (IC) for examination of VGLUT3 expression. No significant differences in hearing thresholds between groups were identified (p>0.05). Tinnitus in sodium salicylate-treated rats was confirmed by GPIAS. VGLUT3 encoded by solute carrier family 17 members 8 (SLC17a8) expression was significantly increased in inner hair cells (IHCs) of the cochlea in treated animals, compared with controls (p<0.01). No significant differences in VGLUT3 expression between groups were found for the cochlear nucleus (CN) or IC (p>0.05). Exposure to sodium salicylate may disrupt SLC17a8 expression in IHCs, leading to alterations that correspond to tinnitus in rats. However, the CN and IC are unaffected by exposure to sodium salicylate, suggesting that enhancement of VGLUT3 expression in IHCs may contribute to the pathogenesis of tinnitus.
Collapse
Affiliation(s)
- W Zhang
- Department of Otolaryngology - Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China, Z. Peng or K. Liu or S.-S. Gong
| | | | | | | | | | | | | |
Collapse
|
27
|
Zhang J. Blast-induced tinnitus: Animal models. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3811. [PMID: 31795642 DOI: 10.1121/1.5132551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Blast-induced tinnitus is a prevalent problem among military personnel and veterans, as blast-related trauma damages the vulnerable microstructures within the cochlea, impacts auditory and non-auditory brain structures, and causes tinnitus and other disorders. Thus far, there is no effective treatment of blast-induced tinnitus due to an incomplete understanding of its underlying mechanisms, necessitating development of reliable animal models. This article focuses on recent animal studies using behavioral, electrophysiological, imaging, and pharmacological tools. The mechanisms underlying blast-induced tinnitus are largely similar to those underlying noise-induced tinnitus: increased spontaneous firing rates, bursting, and neurosynchrony, Mn++ accumulation, and elevated excitatory synaptic transmission. The differences mainly lie in the data variability and time course. Noise trauma-induced tinnitus mainly originates from direct peripheral deafferentation at the cochlea, and its etiology subsequently develops along the ascending auditory pathways. Blast trauma-induced tinnitus, on the other hand, results from simultaneous impact on both the peripheral and central auditory systems, and the resultant maladaptive neuroplasticity may also be related to the additional traumatic brain injury. Consequently, the neural correlates of blast-induced tinnitus have different time courses and less uniform manifestations of its neural correlates.
Collapse
Affiliation(s)
- Jinsheng Zhang
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 4201 Saint Antoine, Detroit, Michigan 48201, USA
| |
Collapse
|
28
|
Preserving Inhibition during Developmental Hearing Loss Rescues Auditory Learning and Perception. J Neurosci 2019; 39:8347-8361. [PMID: 31451577 DOI: 10.1523/jneurosci.0749-19.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 12/15/2022] Open
Abstract
Transient periods of childhood hearing loss can induce deficits in aural communication that persist long after auditory thresholds have returned to normal, reflecting long-lasting impairments to the auditory CNS. Here, we asked whether these behavioral deficits could be reversed by treating one of the central impairments: reduction of inhibitory strength. Male and female gerbils received bilateral earplugs to induce a mild, reversible hearing loss during the critical period of auditory cortex development. After earplug removal and the return of normal auditory thresholds, we trained and tested animals on an amplitude modulation detection task. Transient developmental hearing loss induced both learning and perceptual deficits, which were entirely corrected by treatment with a selective GABA reuptake inhibitor (SGRI). To explore the mechanistic basis for these behavioral findings, we recorded the amplitudes of GABAA and GABAB receptor-mediated IPSPs in auditory cortical and thalamic brain slices. In hearing loss-reared animals, cortical IPSP amplitudes were significantly reduced within a few days of hearing loss onset, and this reduction persisted into adulthood. SGRI treatment during the critical period prevented the hearing loss-induced reduction of IPSP amplitudes; but when administered after the critical period, it only restored GABAB receptor-mediated IPSP amplitudes. These effects were driven, in part, by the ability of SGRI to upregulate α1 subunit-dependent GABAA responses. Similarly, SGRI prevented the hearing loss-induced reduction of GABAA and GABAB IPSPs in the ventral nucleus of the medial geniculate body. Thus, by maintaining, or subsequently rescuing, GABAergic transmission in the central auditory thalamocortical pathway, some perceptual and cognitive deficits induced by developmental hearing loss can be prevented.SIGNIFICANCE STATEMENT Even a temporary period of childhood hearing loss can induce communication deficits that persist long after auditory thresholds return to normal. These deficits may arise from long-lasting central impairments, including the loss of synaptic inhibition. Here, we asked whether hearing loss-induced behavioral deficits could be reversed by reinstating normal inhibitory strength. Gerbils reared with transient hearing loss displayed both learning and perceptual deficits. However, when animals were treated with a selective GABA reuptake inhibitor during or after hearing loss, behavioral deficits were entirely corrected. This behavioral recovery was correlated with the return of normal thalamic and cortical inhibitory function. Thus, some perceptual and cognitive deficits induced by developmental hearing loss were prevented with a treatment that rescues a central synaptic property.
Collapse
|
29
|
Castañeda R, Natarajan S, Jeong SY, Hong BN, Kang TH. Electrophysiological changes in auditory evoked potentials in rats with salicylate-induced tinnitus. Brain Res 2019; 1715:235-244. [PMID: 30958992 DOI: 10.1016/j.brainres.2019.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 04/01/2019] [Accepted: 04/04/2019] [Indexed: 11/19/2022]
Abstract
Early-response auditory evoked potentials (AEPs) in humans are significantly altered in tinnitus. These changes are closely related to that seen in animals, leading to new approaches to study tinnitus based on objective parameters. The purpose of this study was to characterize the AEPs in animals with tinnitus, by assessing early to late latency responses. For behavioral evaluation, rats were trained using positive reinforcement to press a lever in the presence of an auditory stimulus and to not press during silence. The auditory brainstem response (ABR), middle latency response (MLR) and auditory late latency response (LLR) were correlated to the false-positive responses (pressing the lever during silence), after oral administrations of Sodium Salicylate (SS, 350 mg/kg). In the present study, SS significantly increased the hearing thresholds and reduced ABR peak I amplitudes across the frequency range (4-32 kHz). In contrast, increased amplitudes were observed for several peaks in ABR, MLR, and LLR. Moreover, reduced ABR latencies in response to 8, 16 and 24 kHz tone bursts were observed after SS administration. Similarly, the central evaluation also revealed significantly reduced latencies in MLR and LLR during SS administration. In contrast, increased latencies were observed for ABR latencies in response to 32 kHz tone bursts, and at the P1-N1 component of LLR. Correlational analysis revealed that latencies and amplitudes of peaks II and IV (8 and 16 kHz) of ABR, and N2 latency and P2-N2 amplitude of LLR were associated with behavioral tinnitus. We suggest that AEPs can be used in the rat to evaluate the reduced sensory input and the increased central gain in SS-induced tinnitus, as well as reduced latencies (8-16 kHz) to distinguish between hearing loss and tinnitus.
Collapse
Affiliation(s)
- Rodrigo Castañeda
- Graduate School of Biotechnology, Kyung Hee University, Republic of Korea; Department of Oriental Medicine Biotechnology, College of Life Sciences, Kyung Hee University, Global Campus, Gyeonggi, Republic of Korea; Department of Pharmacology and Physiology, School of Pharmacy, San Carlos University, Guatemala
| | - Sathishkumar Natarajan
- Graduate School of Biotechnology, Kyung Hee University, Republic of Korea; Department of Oriental Medicine Biotechnology, College of Life Sciences, Kyung Hee University, Global Campus, Gyeonggi, Republic of Korea
| | - Seo Yule Jeong
- Graduate School of Biotechnology, Kyung Hee University, Republic of Korea; Department of Oriental Medicine Biotechnology, College of Life Sciences, Kyung Hee University, Global Campus, Gyeonggi, Republic of Korea
| | - Bin Na Hong
- Graduate School of Biotechnology, Kyung Hee University, Republic of Korea
| | - Tong Ho Kang
- Graduate School of Biotechnology, Kyung Hee University, Republic of Korea; Department of Oriental Medicine Biotechnology, College of Life Sciences, Kyung Hee University, Global Campus, Gyeonggi, Republic of Korea.
| |
Collapse
|
30
|
Lauer AM, Dent ML, Sun W, Xu-Friedman MA. Effects of Non-traumatic Noise and Conductive Hearing Loss on Auditory System Function. Neuroscience 2019; 407:182-191. [PMID: 30685543 DOI: 10.1016/j.neuroscience.2019.01.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 01/25/2023]
Abstract
The effects of traumatic noise-exposure and deafening on auditory system function have received a great deal of attention. However, lower levels of noise as well as temporary conductive hearing loss also have consequences on auditory physiology and hearing. Here we review how abnormal acoustic experience at early ages affects the ascending and descending auditory pathways, as well as hearing behavior.
Collapse
Affiliation(s)
- Amanda M Lauer
- Dept of Otolaryngology-HNS, Center for Hearing and Balance, Johns Hopkins University School of Medicine, United States
| | - Micheal L Dent
- Dept. Psychology, University at Buffalo, SUNY, United States
| | - Wei Sun
- Dept. Communicative Disorders and Sciences, University at Buffalo, SUNY, United States
| | | |
Collapse
|
31
|
Changes in the regional shape and volume of subcortical nuclei in patients with tinnitus comorbid with mild hearing loss. Neuroradiology 2018; 60:1203-1211. [DOI: 10.1007/s00234-018-2093-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/29/2018] [Indexed: 12/26/2022]
|
32
|
Altschuler RA, Halsey K, Kanicki A, Martin C, Prieskorn D, DeRemer S, Dolan DF. Small Arms Fire-like noise: Effects on Hearing Loss, Gap Detection and the Influence of Preventive Treatment. Neuroscience 2018; 407:32-40. [PMID: 30053484 DOI: 10.1016/j.neuroscience.2018.07.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/09/2018] [Accepted: 07/13/2018] [Indexed: 10/28/2022]
Abstract
A noise-induced loss of inner hair cell (IHC) - auditory nerve synaptic connections has been suggested as a factor that can trigger the progression of maladaptive plastic changes leading to noise-induced tinnitus. The present study used a military relevant small arms fire (SAF)-like noise (50 biphasic impulses over 2.5 min at 152 dB SPL given unilaterally to the right ear) to induce loss (∼1/3) of IHC synaptic ribbons (associated with synapse loss) in rat cochleae with only minor (less than 10%) loss of outer hair cells. Approximately half of the noise-exposed rats showed poorer Gap Detection post-noise, a behavioral indication suggesting the presence of tinnitus. There was significantly greater loss of IHC ribbons in noise-exposed rats with reduced Gap Detection compared to noise-exposed rats retaining normal Gap Detection. We have previously shown systemic administration of piribedil, memantine, and/or ACEMg significantly reduced loss of IHC ribbons induced by a 3 h 4 kHz octave band 117 dB (SPL) noise. The present study examined if this treatment would also reduce ribbon loss from the SAF-like noise exposure and if this would prevent the reduced Gap Detection. As in the previous study, piribedil, memantine, and ACEMg treatment significantly reduced the noise-induced loss of ribbons, such that it was no longer significantly different from normal. However, it did not prevent development of the reduced Gap Detection indication of tinnitus in all treated noise-exposed rats, reducing the incidence but not reaching significance.
Collapse
Affiliation(s)
- Richard A Altschuler
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States; Department of Cell & Developmental Biology, University of Michigan, United States; VA Ann Arbor Health System, United States.
| | - Karin Halsey
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States
| | - Ariane Kanicki
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States
| | - Cathy Martin
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States
| | - Diane Prieskorn
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States
| | - Susan DeRemer
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States
| | - David F Dolan
- Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States
| |
Collapse
|
33
|
Gauvin DV, Yoder J, Zimmermann ZJ, Tapp R. Ototoxicity: The Radical Drum Beat and Rhythm of Cochlear Hair Cell Life and Death. Int J Toxicol 2018; 37:195-206. [PMID: 29575954 DOI: 10.1177/1091581818761128] [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] [Indexed: 01/15/2023]
Abstract
The function and structure of the auditory information processing system establishes a unique sensory environment for the "perfect storm." The battle between life and death pits the cascade of an apoptotic storm, programmed cell death cascades, against simple cell death (necrosis) pathways. Live or die, the free radical biology of oxygen and hydroxylation, and the destruction of transition metal migration through the mechanical gate sensory processes of the hair cell lead to direct access to the cytoplasm, cytoplasmic reticulum, and mitochondria of the inner workings of the hair cells. These lead to subsequent interactions with nuclear DNA resulting in permanent hearing loss. The yin and yang of pharmaceutical product development is to document what kills, why it kills, and how do we mitigate it. This review highlights the processes of cell death within the cochlea.
Collapse
Affiliation(s)
- David V Gauvin
- 1 Neurobehavioral Sciences Department, MPI Research, Inc., Mattawan, MI, USA
| | - Joshua Yoder
- 1 Neurobehavioral Sciences Department, MPI Research, Inc., Mattawan, MI, USA
| | | | - Rachel Tapp
- 1 Neurobehavioral Sciences Department, MPI Research, Inc., Mattawan, MI, USA
| |
Collapse
|
34
|
Carroll BJ, Bertram R, Hyson RL. Intrinsic physiology of inhibitory neurons changes over auditory development. J Neurophysiol 2017; 119:290-304. [PMID: 29046423 DOI: 10.1152/jn.00447.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
During auditory development, changes in membrane properties promote the ability of excitatory neurons in the brain stem to code aspects of sound, including the level and timing of a stimulus. Some of these changes coincide with hearing onset, suggesting that sound-driven neural activity produces developmental plasticity of ion channel expression. While it is known that the coding properties of excitatory neurons are modulated by inhibition in the mature system, it is unknown whether there are also developmental changes in the membrane properties of brain stem inhibitory neurons. We investigated the primary source of inhibition in the avian auditory brain stem, the superior olivary nucleus (SON). The present studies test the hypothesis that, as in excitatory neurons, the membrane properties of these inhibitory neurons change after hearing onset. We examined SON neurons at different stages of auditory development: embryonic days 14-16 (E14-E16), a time at which cochlear ganglion neurons are just beginning to respond to sound; later embryonic stages (E18-E19); and after hatching (P0-P2). We used in vitro whole cell patch electrophysiology to explore physiological changes in SON. Age-related changes were observed at the level of a single spike and in multispiking behavior. In particular, tonic behavior, measured as a neuron's ability to sustain tonic firing over a range of current steps, became more common later in development. Voltage-clamp recordings and biophysical models were employed to examine how age-related increases in ion currents enhance excitability in SON. Our findings suggest that concurrent increases in sodium and potassium currents underlie the emergence of tonic behavior. NEW & NOTEWORTHY This article is the first to examine heterogeneity of neuronal physiology in the inhibitory nucleus of the avian auditory system and demonstrate that tonic firing here emerges over development. By pairing computer simulations with physiological data, we show that increases in both sodium and potassium channels over development are necessary for the emergence of tonic firing.
Collapse
Affiliation(s)
- Briana J Carroll
- Department of Psychology, Florida State University , Tallahassee, Florida.,Program in Neuroscience, Florida State University , Tallahassee, Florida
| | - Richard Bertram
- Deparment of Mathematics, Florida State University , Tallahassee, Florida.,Program in Molecular Biophysics, Florida State University , Tallahassee, Florida.,Program in Neuroscience, Florida State University , Tallahassee, Florida
| | - Richard L Hyson
- Department of Psychology, Florida State University , Tallahassee, Florida.,Program in Neuroscience, Florida State University , Tallahassee, Florida
| |
Collapse
|
35
|
Caspary DM, Llano DA. Auditory thalamic circuits and GABA A receptor function: Putative mechanisms in tinnitus pathology. Hear Res 2017; 349:197-207. [PMID: 27553899 PMCID: PMC5319923 DOI: 10.1016/j.heares.2016.08.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/28/2016] [Accepted: 08/17/2016] [Indexed: 01/02/2023]
Abstract
Tinnitus is defined as a phantom sound (ringing in the ears), and can significantly reduce the quality of life for those who suffer its effects. Ten to fifteen percent of the general adult population report symptoms of tinnitus with 1-2% reporting that tinnitus negatively impacts their quality of life. Noise exposure is the most common cause of tinnitus and the military environment presents many challenging high-noise situations. Military noise levels can be so intense that standard hearing protection is not adequate. Recent studies suggest a role for inhibitory neurotransmitter dysfunction in response to noise-induced peripheral deafferentation as a key element in the pathology of tinnitus. The auditory thalamus, or medial geniculate body (MGB), is an obligate auditory brain center in a unique position to gate the percept of sound as it projects to auditory cortex and to limbic structures. Both areas are thought to be involved in those individuals most impacted by tinnitus. For MGB, opposing hypotheses have posited either a tinnitus-related pathologic decrease or pathologic increase in GABAergic inhibition. In sensory thalamus, GABA mediates fast synaptic inhibition via synaptic GABAA receptors (GABAARs) as well as a persistent tonic inhibition via high-affinity extrasynaptic GABAARs and slow synaptic inhibition via GABABRs. Down-regulation of inhibitory neurotransmission, related to partial peripheral deafferentation, is consistently presented as partially underpinning neuronal hyperactivity seen in animal models of tinnitus. This maladaptive plasticity/Gain Control Theory of tinnitus pathology (see Auerbach et al., 2014; Richardson et al., 2012) is characterized by reduced inhibition associated with increased spontaneous and abnormal neuronal activity, including bursting and increased synchrony throughout much of the central auditory pathway. A competing hypothesis suggests that maladaptive oscillations between the MGB and auditory cortex, thalamocortical dysrhythmia, predict tinnitus pathology (De Ridder et al., 2015). These unusual oscillations/rhythms reflect net increased tonic inhibition in a subset of thalamocortical projection neurons resulting in abnormal bursting. Hyperpolarizing de-inactivation of T-type Ca2+ channels switches thalamocortical projection neurons into burst mode. Thalamocortical dysrhythmia originating in sensory thalamus has been postulated to underpin neuropathies including tinnitus and chronic pain. Here we review the relationship between noise-induced tinnitus and altered inhibition in the MGB.
Collapse
Affiliation(s)
- Donald M Caspary
- Department of Pharmacology and Neuroscience, Southern Illinois University School of Medicine, Springfield, IL, USA.
| | - Daniel A Llano
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| |
Collapse
|
36
|
He J, Zhu Y, Aa J, Smith PF, De Ridder D, Wang G, Zheng Y. Brain Metabolic Changes in Rats following Acoustic Trauma. Front Neurosci 2017; 11:148. [PMID: 28392756 PMCID: PMC5364180 DOI: 10.3389/fnins.2017.00148] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/09/2017] [Indexed: 12/14/2022] Open
Abstract
Acoustic trauma is the most common cause of hearing loss and tinnitus in humans. However, the impact of acoustic trauma on system biology is not fully understood. It has been increasingly recognized that tinnitus caused by acoustic trauma is unlikely to be generated by a single pathological source, but rather a complex network of changes involving not only the auditory system but also systems related to memory, emotion and stress. One obvious and significant gap in tinnitus research is a lack of biomarkers that reflect the consequences of this interactive "tinnitus-causing" network. In this study, we made the first attempt to analyse brain metabolic changes in rats following acoustic trauma using metabolomics, as a pilot study prior to directly linking metabolic changes to tinnitus. Metabolites in 12 different brain regions collected from either sham or acoustic trauma animals were profiled using a gas chromatography mass spectrometry (GC/MS)-based metabolomics platform. After deconvolution of mass spectra and identification of the molecules, the metabolomic data were processed using multivariate statistical analysis. Principal component analysis showed that metabolic patterns varied among different brain regions; however, brain regions with similar functions had a similar metabolite composition. Acoustic trauma did not change the metabolite clusters in these regions. When analyzed within each brain region using the orthogonal projection to latent structures discriminant analysis sub-model, 17 molecules showed distinct separation between control and acoustic trauma groups in the auditory cortex, inferior colliculus, superior colliculus, vestibular nucleus complex (VNC), and cerebellum. Further metabolic pathway impact analysis and the enrichment overview with network analysis suggested the primary involvement of amino acid metabolism, including the alanine, aspartate and glutamate metabolic pathways, the arginine and proline metabolic pathways and the purine metabolic pathway. Our results provide the first metabolomics evidence that acoustic trauma can induce changes in multiple metabolic pathways. This pilot study also suggests that the metabolomic approach has the potential to identify acoustic trauma-specific metabolic shifts in future studies where metabolic changes are correlated with the animal's tinnitus status.
Collapse
Affiliation(s)
- Jun He
- Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, Jiangsu, China
| | - Yejin Zhu
- Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, Jiangsu, China
| | - Jiye Aa
- Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, Jiangsu, China
| | - Paul F Smith
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of OtagoDunedin, New Zealand; Brain Health Research Centre, University of OtagoDunedin, New Zealand; Brain Research New ZealandDunedin, New Zealand; Eisdell Moore Centre for Hearing and Balance Research, University of AucklandAuckland, New Zealand
| | - Dirk De Ridder
- Brain Health Research Centre, University of OtagoDunedin, New Zealand; Brain Research New ZealandDunedin, New Zealand; Eisdell Moore Centre for Hearing and Balance Research, University of AucklandAuckland, New Zealand; Department of Neurosurgery, Dunedin Medical School, University of OtagoOtago, New Zealand
| | - Guangji Wang
- Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University Nanjing, Jiangsu, China
| | - Yiwen Zheng
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of OtagoDunedin, New Zealand; Brain Health Research Centre, University of OtagoDunedin, New Zealand; Brain Research New ZealandDunedin, New Zealand; Eisdell Moore Centre for Hearing and Balance Research, University of AucklandAuckland, New Zealand
| |
Collapse
|
37
|
High-Resolution fMRI of Auditory Cortical Map Changes in Unilateral Hearing Loss and Tinnitus. Brain Topogr 2017; 30:685-697. [DOI: 10.1007/s10548-017-0547-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 01/18/2017] [Indexed: 12/19/2022]
|
38
|
Chen YC, Wang F, Wang J, Bo F, Xia W, Gu JP, Yin X. Resting-State Brain Abnormalities in Chronic Subjective Tinnitus: A Meta-Analysis. Front Hum Neurosci 2017; 11:22. [PMID: 28174532 PMCID: PMC5258692 DOI: 10.3389/fnhum.2017.00022] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 01/11/2017] [Indexed: 11/13/2022] Open
Abstract
Purpose: The neural mechanisms that give rise to the phantom sound of tinnitus have not been fully elucidated. Neuroimaging studies have revealed abnormalities in resting-state activity that could represent the neural signature of tinnitus, but there is considerable heterogeneity in the data. To address this issue, we conducted a meta-analysis of published neuroimaging studies aimed at identifying a common core of resting-state brain abnormalities in tinnitus patients. Methods: A systematic search was conducted for whole-brain resting-state neuroimaging studies with SPECT, PET and functional MRI that compared chronic tinnitus patients with healthy controls. The authors searched PubMed, Science Direct, Web of Knowledge and Embase databases for neuroimaging studies on tinnitus published up to September 2016. From each study, coordinates were extracted from clusters with significant differences between tinnitus subjects and controls. Meta-analysis was performed using the activation likelihood estimation (ALE) method. Results: Data were included from nine resting-state neuroimaging studies that reported a total of 51 distinct foci. The meta-analysis identified consistent regions of increased resting-state brain activity in tinnitus patients relative to controls that included, bilaterally, the insula, middle temporal gyrus (MTG), inferior frontal gyrus (IFG), parahippocampal gyrus, cerebellum posterior lobe and right superior frontal gyrus. Moreover, decreased brain activity was only observed in the left cuneus and right thalamus. Conclusions: The current meta-analysis is, to our knowledge, the first to demonstrate a characteristic pattern of resting-state brain abnormalities that may serve as neuroimaging markers and contribute to the understanding of neuropathophysiological mechanisms for chronic tinnitus.
Collapse
Affiliation(s)
- Yu-Chen Chen
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| | - Fang Wang
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| | - Jie Wang
- Department of Otolaryngology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| | - Fan Bo
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| | - Wenqing Xia
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| | - Jian-Ping Gu
- Department of Vascular and Interventional Radiology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| | - Xindao Yin
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University Nanjing, China
| |
Collapse
|
39
|
Luo H, Pace E, Zhang J. Blast-induced tinnitus and hyperactivity in the auditory cortex of rats. Neuroscience 2017; 340:515-520. [DOI: 10.1016/j.neuroscience.2016.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/07/2016] [Accepted: 11/09/2016] [Indexed: 11/26/2022]
|
40
|
Kapolowicz MR, Thompson LT. Acute high-intensity noise induces rapid Arc protein expression but fails to rapidly change GAD expression in amygdala and hippocampus of rats: Effects of treatment with D-cycloserine. Hear Res 2016; 342:69-79. [PMID: 27702572 DOI: 10.1016/j.heares.2016.09.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 08/26/2016] [Accepted: 09/30/2016] [Indexed: 10/20/2022]
Abstract
Tinnitus is a devastating auditory disorder impacting a growing number of people each year. The aims of the current experiment were to assess neuronal mechanisms involved in the initial plasticity after traumatic noise exposure that could contribute to the emergence of tinnitus and to test a potential pharmacological treatment to alter this early neural plasticity. Specifically, this study addressed rapid effects of acute noise trauma on amygdalo-hippocampal circuitry, characterizing biomarkers of both excitation and inhibition in these limbic regions, and compared them to expression of these same markers in primary auditory cortex shortly after acute noise trauma. To assess excitatory plasticity, activity-regulated cytoskeleton-associated (Arc) protein expression was evaluated in male rats 45 min after bilateral exposure to acute high-intensity noise (16 kHz, 115 dB SPL, for 1 h), sufficient to cause acute cochlear trauma, a common cause of tinnitus in humans and previously shown sufficient to induce tinnitus in rat models of this auditory neuropathology. Western blot analyses confirmed that up-regulation of amygdalo-hippocampal Arc expression occurred rapidly post-noise trauma, corroborating several lines of evidence from our own and other laboratories indicating that limbic brain structures, i.e. outside of the classical auditory pathways, exhibit plasticity early in the initiation of tinnitus. Western blot analyses revealed no noise-induced changes in amygdalo-hippocampal expression of glutamate decarboxylase (GAD), the biosynthetic enzyme required for GABAergic inhibition. No changes in either Arc or GAD protein expression were observed in primary auditory cortex in this immediate post-noise exposure period, confirming other reports that auditory cortical plasticity may not occur until later in the development of tinnitus. As a further control, our experiments compared Arc protein expression between groups exposed to the quiet background of a sound-proof chamber to those exposed not only to the traumatic noise described above, but also to an intermediate, non-traumatic noise level (70 dB SPL) for the same duration in each of these three brain regions. We found that non-traumatic noise did not up-regulate Arc protein expression in these brain regions. To see if changes in Arc expression due to acute traumatic noise exposure were stress-related, we compared circulating serum corticosterone in controls and rats exposed to traumatic noise at the time when changes in Arc were observed, and found no significant differences in this stress hormone in our experimental conditions. Finally, the ability of D-cycloserine (DCS; an NMDA-receptor NR1 partial agonist) to reduce or prevent the noise trauma-related plastic changes in the biomarker, Arc, was tested. D-cycloserine prevented traumatic noise-induced up-regulation of Arc protein expression in amygdala but not in hippocampus, suggesting that DCS alone is not fully effective in eliminating regionally-specific early plastic changes after traumatic noise exposure.
Collapse
Affiliation(s)
- M R Kapolowicz
- Behavioral & Brain Sciences, Neuroscience, The University of Texas at Dallas, 800W. Campbell Rd., BSB 14, Richardson, TX, 75080, USA
| | - L T Thompson
- Behavioral & Brain Sciences, Neuroscience, The University of Texas at Dallas, 800W. Campbell Rd., BSB 14, Richardson, TX, 75080, USA.
| |
Collapse
|
41
|
Abstract
PURPOSE OF REVIEW Tinnitus, the perception of sound in the absence of a corresponding external acoustic stimulus, is a highly prevalent and frequently severely impairing disorder with worldwide impact. In this article after a short overview about epidemiology and pathophysiology the currently available treatment options will be discussed with specific consideration of the available evidence, their mechanisms of action and their limitations. RECENT FINDINGS During the last decades, advances in neuroimaging methods and the development of animal models have contributed to an increasing understanding of the neuronal correlates of tinnitus and have motivated the development of innovative brain-based treatment approaches for directly targeting the neuronal correlates of tinnitus. A further important development has been the insight that there exist different forms of tinnitus that differ in their pathophysiology and their response to specific treatments. SUMMARY Treatment of tinnitus should be based on a comprehensive diagnosis of etiologic and concomitant aspects of an individual's tinnitus. Already today a large variety of therapeutic interventions are available, which can efficiently reduce tinnitus severity. Several innovative treatment approaches are currently under development.
Collapse
|
42
|
Rauschecker JP, May ES, Maudoux A, Ploner M. Frontostriatal Gating of Tinnitus and Chronic Pain. Trends Cogn Sci 2016; 19:567-578. [PMID: 26412095 DOI: 10.1016/j.tics.2015.08.002] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/04/2015] [Accepted: 08/07/2015] [Indexed: 12/18/2022]
Abstract
Tinnitus and chronic pain are sensory-perceptual disorders associated with negative affect and high impact on well-being and behavior. It is now becoming increasingly clear that higher cognitive and affective brain systems are centrally involved in the pathology of both disorders. We propose that the ventromedial prefrontal cortex and the nucleus accumbens are part of a central 'gatekeeping' system in both sensory modalities, a system which evaluates the relevance and affective value of sensory stimuli and controls information flow via descending pathways. If this frontostriatal system is compromised, long-lasting disturbances are the result. Parallels in both systems are striking and mutually informative, and progress in understanding central gating mechanisms might provide a new impetus to the therapy of tinnitus and chronic pain.
Collapse
Affiliation(s)
- Josef P Rauschecker
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, USA; Department of Neurology and TUM-Neuroimaging Center, Technische Universität München, Munich, Germany; Institute for Advanced Study, Technische Universität München, Munich, Germany.
| | - Elisabeth S May
- Department of Neurology and TUM-Neuroimaging Center, Technische Universität München, Munich, Germany
| | - Audrey Maudoux
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, USA
| | - Markus Ploner
- Department of Neurology and TUM-Neuroimaging Center, Technische Universität München, Munich, Germany
| |
Collapse
|
43
|
Neural Hyperactivity of the Central Auditory System in Response to Peripheral Damage. Neural Plast 2016; 2016:2162105. [PMID: 26881094 PMCID: PMC4736999 DOI: 10.1155/2016/2162105] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/12/2015] [Accepted: 11/15/2015] [Indexed: 11/19/2022] Open
Abstract
It is increasingly appreciated that cochlear pathology is accompanied by adaptive responses in the central auditory system. The cause of cochlear pathology varies widely, and it seems that few commonalities can be drawn. In fact, despite intricate internal neuroplasticity and diverse external symptoms, several classical injury models provide a feasible path to locate responses to different peripheral cochlear lesions. In these cases, hair cell damage may lead to considerable hyperactivity in the central auditory pathways, mediated by a reduction in inhibition, which may underlie some clinical symptoms associated with hearing loss, such as tinnitus. Homeostatic plasticity, the most discussed and acknowledged mechanism in recent years, is most likely responsible for excited central activity following cochlear damage.
Collapse
|
44
|
Enhanced GABAA-Mediated Tonic Inhibition in Auditory Thalamus of Rats with Behavioral Evidence of Tinnitus. J Neurosci 2015; 35:9369-80. [PMID: 26109660 DOI: 10.1523/jneurosci.5054-14.2015] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Accumulating evidence suggests a role for inhibitory neurotransmitter dysfunction in the pathology of tinnitus. Opposing hypotheses proposed either a pathologic decrease or increase of GABAergic inhibition in medial geniculate body (MGB). In thalamus, GABA mediates fast synaptic inhibition via synaptic GABAA receptors (GABAARs) and persistent tonic inhibition via high-affinity extrasynaptic GABAARs. Given that extrasynaptic GABAARs control the firing mode of thalamocortical neurons, we examined tonic GABAAR currents in MGB neurons in vitro, using the following three groups of adult rats: unexposed control (Ctrl); sound exposed with behavioral evidence of tinnitus (Tin); and sound exposed with no behavioral evidence of tinnitus (Non-T). Tonic GABAAR currents were evoked using the selective agonist gaboxadol. Months after a tinnitus-inducing sound exposure, gaboxadol-evoked tonic GABAAR currents showed significant tinnitus-related increases contralateral to the sound exposure. In situ hybridization studies found increased mRNA levels for GABAAR δ-subunits contralateral to the sound exposure. Tin rats showed significant increases in the number of spikes per burst evoked using suprathreshold-injected current steps. In summary, we found little evidence of tinnitus-related decreases in GABAergic neurotransmission. Tinnitus and chronic pain may reflect thalamocortical dysrhythmia, which results from abnormal theta-range resonant interactions between thalamus and cortex, due to neuronal hyperpolarization and the initiation of low-threshold calcium spike bursts (Walton and Llinás, 2010). In agreement with this hypothesis, we found tinnitus-related increases in tonic extrasynaptic GABAAR currents, in action potentials/evoked bursts, and in GABAAR δ-subunit gene expression. These tinnitus-related changes in GABAergic function may be markers for tinnitus pathology in the MGB.
Collapse
|
45
|
Pattyn T, Van Den Eede F, Vanneste S, Cassiers L, Veltman DJ, Van De Heyning P, Sabbe BCG. Tinnitus and anxiety disorders: A review. Hear Res 2015; 333:255-265. [PMID: 26342399 DOI: 10.1016/j.heares.2015.08.014] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 05/06/2015] [Accepted: 08/27/2015] [Indexed: 12/28/2022]
Abstract
BACKGROUND The most common form of tinnitus is a subjective, auditory, and distressing phantom phenomenon. Comorbidity with depression is high but other important psychiatric disorders such as anxiety disorders have received less attention. The current paper reviews the literature on the associations between tinnitus and anxiety disorders and the underlying pathophysiology, and discusses the clinical implications. METHODOLOGY PubMed and Web of Science were searched for all articles published up until October 2014 using combinations of the following search strings "Tinnitus", "Anxiety disorder", "Panic Disorder", "Generalized Anxiety Disorder", "Post traumatic stress disorder", "PTSD" "Social Phobia", "Phobia Disorder", "Obsessive Compulsive Disorder", "Agoraphobia". RESULTS A total of 117 relevant papers were included. A 45% lifetime prevalence of anxiety disorders is reported in tinnitus populations, while an important overlap in associated (sub)cortical brain areas and cortico-subcortical networks involved in attention, distress, and memory functions is suggested. A disturbed hypothalamic-pituitary-adrenal axis function can be found in tinnitus and in anxiety disorders but, in comorbidity, the direction of the dysfunction is unclear. CONCLUSION Comorbidity is high and screening for and treatment of anxiety disorders is recommended in moderate to severe tinnitus, as, given the overlap in the structural and functional brain circuitries involved, theoretically, their management could improve (subjective) levels of tinnitus although further empirical research on this topic is required.
Collapse
Affiliation(s)
- T Pattyn
- University of Antwerp, Collaborative Antwerp Psychiatric Research Institute (CAPRI), Antwerp, Belgium; University Department of Psychiatry, Campus Antwerp University Hospital, Antwerp, Belgium.
| | - F Van Den Eede
- University Department of Psychiatry, Campus Antwerp University Hospital, Antwerp, Belgium; University of Antwerp, Collaborative Antwerp Psychiatric Research Institute (CAPRI), Antwerp, Belgium
| | - S Vanneste
- University of Antwerp, Department of Translational Neuroscience, Faculty of Medicine, Antwerp, Belgium; University of Texas, School of Behavioral and Brain Sciences, Dallas, Richardson, TX, United States
| | - L Cassiers
- University of Antwerp, Collaborative Antwerp Psychiatric Research Institute (CAPRI), Antwerp, Belgium; University Department of Psychiatry, Campus Antwerp University Hospital, Antwerp, Belgium
| | - D J Veltman
- VU University Medical Centre, Department of Psychiatry and EMGO Institute of Health and Care Research and Neuroscience Campus Amsterdam, Amsterdam, The Netherlands
| | - P Van De Heyning
- University of Antwerp, Department of Translational Neuroscience, Faculty of Medicine, Antwerp, Belgium; Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, Antwerp, Belgium
| | - B C G Sabbe
- University of Antwerp, Collaborative Antwerp Psychiatric Research Institute (CAPRI), Antwerp, Belgium; University Department of Psychiatry, Campus Psychiatric Hospital Duffel, Duffel, Belgium
| |
Collapse
|
46
|
Impairments of thalamic resting-state functional connectivity in patients with chronic tinnitus. Eur J Radiol 2015; 84:1277-84. [DOI: 10.1016/j.ejrad.2015.04.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 03/23/2015] [Accepted: 04/04/2015] [Indexed: 11/15/2022]
|
47
|
|
48
|
Fetoni AR, Troiani D, Petrosini L, Paludetti G. Cochlear injury and adaptive plasticity of the auditory cortex. Front Aging Neurosci 2015; 7:8. [PMID: 25698966 PMCID: PMC4318425 DOI: 10.3389/fnagi.2015.00008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/21/2015] [Indexed: 12/20/2022] Open
Abstract
Growing evidence suggests that cochlear stressors as noise exposure and aging can induce homeostatic/maladaptive changes in the central auditory system from the brainstem to the cortex. Studies centered on such changes have revealed several mechanisms that operate in the context of sensory disruption after insult (noise trauma, drug-, or age-related injury). The oxidative stress is central to current theories of induced sensory-neural hearing loss and aging, and interventions to attenuate the hearing loss are based on antioxidant agent. The present review addresses the recent literature on the alterations in hair cells and spiral ganglion neurons due to noise-induced oxidative stress in the cochlea, as well on the impact of cochlear damage on the auditory cortex neurons. The emerging image emphasizes that noise-induced deafferentation and upward spread of cochlear damage is associated with the altered dendritic architecture of auditory pyramidal neurons. The cortical modifications may be reversed by treatment with antioxidants counteracting the cochlear redox imbalance. These findings open new therapeutic approaches to treat the functional consequences of the cortical reorganization following cochlear damage.
Collapse
Affiliation(s)
- Anna Rita Fetoni
- Department of Head and Neck Surgery, Medical School, Catholic University of the Sacred Heart, Rome, Italy
| | - Diana Troiani
- Institute of Human Physiology, Medical School, Catholic University of the Sacred Heart, Rome, Italy
| | - Laura Petrosini
- Department of Psychology, Sapienza University of Rome and IRCCS Santa Lucia Foundation, Rome, Italy
| | - Gaetano Paludetti
- Department of Head and Neck Surgery, Medical School, Catholic University of the Sacred Heart, Rome, Italy
| |
Collapse
|
49
|
Altered intra- and interregional synchronization in resting-state cerebral networks associated with chronic tinnitus. Neural Plast 2015; 2015:475382. [PMID: 25734018 PMCID: PMC4334979 DOI: 10.1155/2015/475382] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 12/20/2014] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE Subjective tinnitus is hypothesized to arise from aberrant neural activity; however, its neural bases are poorly understood. To identify aberrant neural networks involved in chronic tinnitus, we compared the resting-state functional magnetic resonance imaging (fMRI) patterns of tinnitus patients and healthy controls. MATERIALS AND METHODS Resting-state fMRI measurements were obtained from a group of chronic tinnitus patients (n = 29) with normal hearing and well-matched healthy controls (n = 30). Regional homogeneity (ReHo) analysis and functional connectivity analysis were used to identify abnormal brain activity; these abnormalities were compared to tinnitus distress. RESULTS Relative to healthy controls, tinnitus patients had significant greater ReHo values in several brain regions including the bilateral anterior insula (AI), left inferior frontal gyrus, and right supramarginal gyrus. Furthermore, the left AI showed enhanced functional connectivity with the left middle frontal gyrus (MFG), while the right AI had enhanced functional connectivity with the right MFG; these measures were positively correlated with Tinnitus Handicap Questionnaires (r = 0.459, P = 0.012 and r = 0.479, P = 0.009, resp.). CONCLUSIONS Chronic tinnitus patients showed abnormal intra- and interregional synchronization in several resting-state cerebral networks; these abnormalities were correlated with clinical tinnitus distress. These results suggest that tinnitus distress is exacerbated by attention networks that focus on internally generated phantom sounds.
Collapse
|
50
|
Zheng Y, Dixon S, MacPherson K, Smith PF. Glutamic acid decarboxylase levels in the cochlear nucleus of rats with acoustic trauma-induced chronic tinnitus. Neurosci Lett 2015; 586:60-4. [DOI: 10.1016/j.neulet.2014.11.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/26/2014] [Accepted: 11/28/2014] [Indexed: 11/30/2022]
|