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Wei H, Jiang H, Zhou Y, Liu L, Ma W, Ni S, Zhou C, Ji X. Cerebral venous congestion alters CNS homeostatic plasticity, evoking tinnitus-like behavior. Cell Biosci 2024; 14:47. [PMID: 38594782 PMCID: PMC11003147 DOI: 10.1186/s13578-024-01221-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 03/19/2024] [Indexed: 04/11/2024] Open
Abstract
BACKGROUND Brain function and neuronal activity depend on a constant supply of blood from the cerebral circulation. The cerebral venous system (CVS) contains approximately 70% of the total cerebral blood volume; similar to the cerebral arterial system, the CVS plays a prominent role in the maintenance of central nervous system (CNS) homeostasis. Impaired venous autoregulation, which can appear in forms such as cerebral venous congestion, may lead to metabolic abnormalities in the brain, causing severe cerebral functional defects and even chronic tinnitus. However, the role of cerebral venous congestion in the progression of tinnitus is underrecognized, and its pathophysiology is still incompletely understood. This study elucidated the specific pathogenetic role of cerebral venous congestion in the onset and persistence of tinnitus and the possible neurophysiological mechanisms. RESULTS We found that a rat model of cerebral venous congestion exhibited tinnitus-like behavioral manifestations at 14 days postoperatively; from that point onward, they showed signs of persistent tinnitus without significant hearing impairment. Subsequent neuroimaging and neurochemical findings showed CNS homeostatic plasticity disturbance in rats with cerebral venous congestion, reflected in increased neural metabolic activity, ultrastructural synaptic changes, upregulated synaptic efficacy, reduced inhibitory synaptic transmission (due to GABA deficiency), and elevated expression of neuroplasticity-related proteins in central auditory and extra-auditory pathways. CONCLUSION Collectively, our data suggest that alternations in CNS homeostatic plasticity may play a vital role in tinnitus pathology caused by cerebral venous congestion. These findings provide a new perspective on tinnitus related to cerebral venous congestion and may facilitate the development of precise interventions to interrupt its pathogenesis.
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Affiliation(s)
- Huimin Wei
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, School of Biological Science and Medical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, China
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Huimin Jiang
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Yifan Zhou
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Lu Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Wei Ma
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China
| | - Shanshan Ni
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China.
- Department of Neurology, Wuqing Hospital of Traditional Chinese Medicine Affiliated to Tianjin University of Traditional Chinese Medicine, Tianjin, 301700, China.
| | - Chen Zhou
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China.
| | - Xunming Ji
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, School of Biological Science and Medical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing, 100191, China.
- Laboratory of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Beijing Advanced Innovation Center for Big Data-based Precision Medicine, Ministry of Science and Technology, Capital Medical University, No.10 Xitoutiao, You An Men, Beijing, 100069, China.
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China.
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Cai R, Ling L, Ghimire M, Brownell KA, Caspary DM. Tinnitus-related increases in single-unit activity in awake rat auditory cortex correlate with tinnitus behavior. Hear Res 2024; 445:108993. [PMID: 38518392 DOI: 10.1016/j.heares.2024.108993] [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: 01/25/2024] [Revised: 03/04/2024] [Accepted: 03/10/2024] [Indexed: 03/24/2024]
Abstract
Tinnitus is known to affect 10-15 % of the population, severely impacting 1-2 % of those afflicted. Canonically, tinnitus is generally a consequence of peripheral auditory damage resulting in maladaptive plastic changes in excitatory/inhibitory homeostasis at multiple levels of the central auditory pathway as well as changes in diverse nonauditory structures. Animal studies of primary auditory cortex (A1) generally find tinnitus-related changes in excitability across A1 layers and differences between inhibitory neuronal subtypes. Changes due to sound-exposure include changes in spontaneous activity, cross-columnar synchrony, bursting and tonotopic organization. Few studies in A1 directly correlate tinnitus-related changes in neural activity to an individual animal's behavioral evidence of tinnitus. The present study used an established condition-suppression sound-exposure model of chronic tinnitus and recorded spontaneous and driven single-unit responses from A1 layers 5 and 6 of awake Long-Evans rats. A1 units recorded from animals with behavioral evidence of tinnitus showed significant increases in spontaneous and sound-evoked activity which directly correlated to the animal's tinnitus score. Significant increases in the number of bursting units, the number of bursts/minute and burst duration were seen for A1 units recorded from animals with behavioral evidence of tinnitus. The present A1 findings support prior unit recording studies in auditory thalamus and recent in vitro findings in this same animal model. The present findings are consistent with sensory cortical studies showing tinnitus- and neuropathic pain-related down-regulation of inhibition and increased excitation based on plastic neurotransmitter and potassium channel changes. Reducing A1 deep-layer tinnitus-related hyperactivity is a potential target for tinnitus pharmacotherapy.
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Affiliation(s)
- Rui Cai
- Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, United States
| | - Lynne Ling
- Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, United States
| | - Madan Ghimire
- Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, United States
| | - Kevin A Brownell
- Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, United States
| | - Donald M Caspary
- Department of Pharmacology, Southern Illinois University School of Medicine, PO Box 19629, Springfield, IL 62794-9629, United States.
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Colak H, Sendesen E, Turkyilmaz MD. Subcortical auditory system in tinnitus with normal hearing: insights from electrophysiological perspective. Eur Arch Otorhinolaryngol 2024:10.1007/s00405-024-08583-3. [PMID: 38555317 DOI: 10.1007/s00405-024-08583-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/26/2024] [Indexed: 04/02/2024]
Abstract
PURPOSE The mechanism of tinnitus remains poorly understood; however, studies have underscored the significance of the subcortical auditory system in tinnitus perception. In this study, our aim was to investigate the subcortical auditory system using electrophysiological measurements in individuals with tinnitus and normal hearing. Additionally, we aimed to assess speech-in-noise (SiN) perception to determine whether individuals with tinnitus exhibit SiN deficits despite having normal-hearing thresholds. METHODS A total 42 normal-hearing participants, including 22 individuals with chronic subjective tinnitus and 20 normal individuals, participated in the study. We recorded auditory brainstem response (ABR) and speech-evoked frequency following response (sFFR) from the participants. SiN perception was also assessed using the Matrix test. RESULTS Our results revealed a significant prolongation of the O peak, which encodes sound offset in sFFR, for the tinnitus group (p < 0.01). The greater non-stimulus-evoked activity was also found in individuals with tinnitus (p < 0.01). In ABR, the tinnitus group showed reduced wave I amplitude and prolonged absolute wave I, III, and V latencies (p ≤ 0.02). Our findings suggested that individuals with tinnitus had poorer SiN perception compared to normal participants (p < 0.05). CONCLUSION The deficit in encoding sound offset may indicate an impaired inhibitory mechanism in tinnitus. The greater non-stimulus-evoked activity observed in the tinnitus group suggests increased neural noise at the subcortical level. Additionally, individuals with tinnitus may experience speech-in-noise deficits despite having a normal audiogram. Taken together, these findings suggest that the lack of inhibition and increased neural noise may be associated with tinnitus perception.
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Affiliation(s)
- Hasan Colak
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK.
| | - Eser Sendesen
- Department of Audiology, Hacettepe University, Ankara, Turkey
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4
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Wójcik J, Kochański B, Cieśla K, Lewandowska M, Karpiesz L, Niedziałek I, Raj-Koziak D, Skarżyński PH, Wolak T. An MR spectroscopy study of temporal areas excluding primary auditory cortex and frontal regions in subjective bilateral and unilateral tinnitus. Sci Rep 2023; 13:18417. [PMID: 37891242 PMCID: PMC10611771 DOI: 10.1038/s41598-023-45024-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 10/14/2023] [Indexed: 10/29/2023] Open
Abstract
Previous studies indicate changes in neurotransmission along the auditory pathway in subjective tinnitus. Most authors, however, investigated brain regions including the primary auditory cortex, whose physiology can be affected by concurrent hearing deficits. In the present MR spectroscopy study we assumed increased levels of glutamate and glutamine (Glx), and other Central Nervous System metabolites in the temporal lobe outside the primary auditory cortex, in a region involved in conscious auditory perception and memory. We studied 52 participants with unilateral (n = 24) and bilateral (n = 28) tinnitus, and a control group without tinnitus (n = 25), all with no severe hearing losses and a similar hearing profile. None of the metabolite levels in the temporal regions of interest were found related to tinnitus status or laterality. Unexpectedly, we found a tendency of increased concentration of Glx in the control left medial frontal region in bilateral vs unilateral tinnitus. Slightly elevated depressive and anxiety symptoms were also shown in participants with tinnitus, as compared to healthy individuals, with the bilateral tinnitus group marginally more affected. We discuss no apparent effect in the temporal lobes, as well as the role of frontal brain areas, with respect to hearing loss, attention and psychological well-being in chronic tinnitus. We furthermore elaborate on the design-related and technical obstacles of MR spectroscopy.
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Affiliation(s)
- Joanna Wójcik
- Bioimaging Research Center, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
| | - Bartosz Kochański
- Bioimaging Research Center, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
| | - Katarzyna Cieśla
- Bioimaging Research Center, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland.
| | - Monika Lewandowska
- Faculty of Philosophy and Social Sciences, Institute of Psychology, Nicolaus Copernicus University, Fosa Staromiejska 1a Street, 87-100, Toruń, Poland
| | - Lucyna Karpiesz
- Tinnitus Department, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
| | - Iwona Niedziałek
- Tinnitus Department, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
| | - Danuta Raj-Koziak
- Tinnitus Department, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
| | - Piotr Henryk Skarżyński
- Department of Teleaudiology and Screening, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
- Institute of Sensory Organs, Mokra 1 Street, Kajetany, 05-830, Nadarzyn, Poland
- Heart Failure and Cardiac Rehabilitation Department, Faculty of Medicine, Medical University of Warsaw, Kondratowicza 8 Street, 03-242, Warsaw, Poland
| | - Tomasz Wolak
- Bioimaging Research Center, World Hearing Center, Institute of Physiology and Pathology of Hearing, Mokra 17 Street, Kajetany, 05-830, Nadarzyn, Poland
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Vanneste S, De Ridder D. BurstDR spinal cord stimulation rebalances pain input and pain suppression in the brain in chronic neuropathic pain. Brain Stimul 2023; 16:1186-1195. [PMID: 37541579 DOI: 10.1016/j.brs.2023.07.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 07/06/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023] Open
Abstract
OBJECTIVE Chronic pain is processed by at least three well-known pathways, two pain provoking pathways including a medial 'suffering' and lateral 'painfulness' pathway. A third descending pain pathway modulates pain but is predominantly inhibitory. Chronic pain can be seen as an imbalance between the two pain-provoking and the pain inhibitory pathways. If this assumption is correct, then the imbalance between pain input and pain suppression should reverse and normalize in response to successful, i.e., pain reducing burstDR spinal cord stimulation, one of the current treatment options for neuropathic pain. MATERIALS AND METHODS Fifteen patients, who received spinal cord stimulation for failed back surgery were included in this study, using source localized electrical brain activity and connectivity recording via EEG to identify the purported imbalance. RESULTS BurstDR spinal cord stimulation induces a significant change in EEG activity in both the left and right somatosensory cortex (SSC) for both θ and γ oscillations. In the dorsal anterior cingulate cortex (dACC), we observed a significant drop in both α and β oscillations. This reduction is accompanied by a change in pain intensity and suffering. BurstDR spinal cord stimulation is also associated with a reduction in θ at the pregenual anterior cingulate cortex (pgACC). Analyzing effective connectivity indicates that for the θ band, more information is sent from the pgACC to the left and right SSC. For α, increased information is sent from the pgACC to the dACC and both the left and right SSC. This is associated with a reduced θ-γ coupling in the SSC and reduced α-β coupling in dACC. CONCLUSION This study suggests that chronic pain is indeed an imbalance between the ascending and descending pathways in the brain and that burst spinal cord stimulation can normalize this imbalance in the brain.
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Affiliation(s)
- Sven Vanneste
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
| | - Dirk De Ridder
- Department of Surgical Sciences, Section of Neurosurgery, Dunedin School of Medicine, University of Otago, New Zealand
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6
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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.
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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
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Ruan J, Hu X, Liu Y, Han Z, Ruan Q. Vulnerability to chronic stress and the phenotypic heterogeneity of presbycusis with subjective tinnitus. Front Neurosci 2022; 16:1046095. [PMID: 36620444 PMCID: PMC9812577 DOI: 10.3389/fnins.2022.1046095] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Age-related functional reserve decline and vulnerability of multiple physiological systems and organs, as well as at the cellular and molecular levels, result in different frailty phenotypes, such as physical, cognitive, and psychosocial frailty, and multiple comorbidities, including age-related hearing loss (ARHL) and/or tinnitus due to the decline in auditory reserve. However, the contributions of chronic non-audiogenic cumulative exposure, and chronic audiogenic stress to phenotypic heterogeneity of presbycusis and/or tinnitus remain elusive. Because of the cumulative environmental stressors throughout life, allostasis systems, the hypothalamus-pituitary-adrenal (HPA) and the sympathetic adrenal-medullary (SAM) axes become dysregulated and less able to maintain homeostasis, which leads to allostatic load and maladaptation. Brain-body communication via the neuroendocrine system promotes systemic chronic inflammation, overmobilization of energetic substances (glucose and lipids), and neuroplastic changes via the non-genomic and genomic actions of glucocorticoids, catecholamines, and their receptors. These systemic maladaptive alterations might lead to different frailty phenotypes and physical, cognitive, and psychological comorbidities, which, in turn, cause and exacerbate ARHL and/or tinnitus with phenotypic heterogeneity. Chronic audiogenic stressors, including aging accompanying ontological diseases, cumulative noise exposure, and ototoxic drugs as well as tinnitus, activate the HPA axis and SAM directly and indirectly by the amygdala, promoting allostatic load and maladaptive neuroplasticity in the auditory system and other vulnerable brain regions, such as the hippocampus, amygdala, and medial prefrontal cortex (mPFC). In the auditory system, peripheral deafferentation, central disinhibition, and tonotopic map reorganization may trigger tinnitus. Cross-modal maladaptive neuroplasticity between the auditory and other sensory systems is involved in tinnitus modulation. Persistent dendritic growth and formation, reduction in GABAergic inhibitory synaptic inputs induced by chronic audiogenic stresses in the amygdala, and increased dendritic atrophy in the hippocampus and mPFC, might involve the enhancement of attentional processing and long-term memory storage of chronic subjective tinnitus, accompanied by cognitive impairments and emotional comorbidities. Therefore, presbycusis and tinnitus are multisystem disorders with phenotypic heterogeneity. Stressors play a critical role in the phenotypic heterogeneity of presbycusis. Differential diagnosis based on biomarkers of metabonomics study, and interventions tailored to different ARHL phenotypes and/or tinnitus will contribute to healthy aging and improvement in the quality of life.
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Affiliation(s)
- Jian Ruan
- Department of Otolaryngology, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiuhua Hu
- Laboratory of Aging, Anti-aging & Cognitive Performance, Shanghai Institute of Geriatrics and Gerontology, Huadong Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Clinical Geriatrics, Research Center of Aging and Medicine, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yuehong Liu
- Department of Otolaryngology, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhao Han
- Department of Otolaryngology, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Qingwei Ruan
- Laboratory of Aging, Anti-aging & Cognitive Performance, Shanghai Institute of Geriatrics and Gerontology, Huadong Hospital, Fudan University, Shanghai, China,Shanghai Key Laboratory of Clinical Geriatrics, Research Center of Aging and Medicine, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, China,*Correspondence: Qingwei Ruan,
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8
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Smeele SJ, Adhia DB, De Ridder D. Feasibility and Safety of High-Definition Infraslow Pink Noise Stimulation for Treating Chronic Tinnitus—A Randomized Placebo-Controlled Trial. Neuromodulation 2022:S1094-7159(22)01339-3. [DOI: 10.1016/j.neurom.2022.10.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 12/03/2022]
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9
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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]
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10
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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.
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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
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11
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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]
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12
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Li ZC, Fang BX, Yuan LX, Zheng K, Wu SX, Zhong N, Zeng XL. Analysis of Studies in Tinnitus-Related Gene Research. Noise Health 2021; 23:95-107. [PMID: 34975125 PMCID: PMC8772442 DOI: 10.4103/nah.nah_57_21] [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] [Indexed: 11/04/2022] Open
Abstract
Objective Summarize and analyze the current research results of tinnitus-related genes, explore the potential links between the results of each study, and provide reference for subsequent studies. Methods Collect and sort out the research literature related to tinnitus genes included in PubMed, Web of Science, China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform before December 31, 2019. Then the relevant contents of the literature were sorted out and summarized. Results Fifty-one articles were finally selected for analysis: 31 articles (60.8%) were classified as researches on animal models of tinnitus, and 20 (39.2%) as researches on tinnitus patients. Existing studies have shown that genes related to oxidative stress, inflammatory response, nerve excitation/inhibition, and nerve growth are differentially expressed in tinnitus patients or animal models, and have presented the potential links between genes or proteins in the occurrence and development of tinnitus. Conclusion The research on tinnitus-related genes is still in the exploratory stage, and further high-quality research evidence is needed.
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Affiliation(s)
- Zhi-Cheng Li
- Department of Otolaryngology, Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Bi-Xing Fang
- Department of Otolaryngology, Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou; Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Sun Yat-sen University, China
| | - Lian-Xiong Yuan
- Department of Science and Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ke Zheng
- Department of Otolaryngology, Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Shi-Xin Wu
- Department of Otolaryngology, Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Nanbert Zhong
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, New York, USA
| | - Xiang-Li Zeng
- Department of Otolaryngology, Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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13
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Chen M, Min S, Zhang C, Hu X, Li S. Using Extracochlear Multichannel Electrical Stimulation to Relieve Tinnitus and Reverse Tinnitus-Related Auditory-Somatosensory Plasticity in the Cochlear Nucleus. Neuromodulation 2021; 25:1338-1350. [PMID: 34346133 DOI: 10.1111/ner.13506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/15/2021] [Accepted: 06/29/2021] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Tinnitus has no reliable cure but may be significantly relieved by the usage of cochlear implants. However, not all tinnitus patients necessitate cochlear implantation that can impair hearing. This study was to investigate whether a novel extracochlear electrical stimulation (EES) strategy could relieve tinnitus of guinea pigs without hearing impairment, and the roles of auditory-somatosensory plasticity in the cochlear nucleus in the tinnitus relief. MATERIALS AND METHODS We used a novel four-electrode extracochlear implant to electrically stimulate the cochlea of tinnitus guinea pigs. Tinnitus was assessed by the gap-prepulse inhibition of the acoustic startle reflex (GPIAS) ratios and the tinnitus index. The plasticity of auditory and somatosensory innervation in the different subdivisions of cochlear nucleus was evaluated by immunostaining of vesicular glutamate transporter 1 (VGLUT1) and VGLUT2, respectively. RESULTS The EES induced significant decreases of GPIAS ratios and the tinnitus index of tinnitus guinea pigs, indicating reductions of tinnitus behavioral manifestations. Meanwhile, the EES reversed the abnormal auditory-somatosensory innervation in the cochlear nucleus of tinnitus animals but did not change the hearing and the numbers of inner hair cell synapses. CONCLUSIONS This study demonstrated that the novel EES strategy could effectively relieve tinnitus without impairment to hearing and cochlear structure of tinnitus animals. The reversal of tinnitus-related auditory-somatosensory plasticity in the cochlear nucleus was correlated with the tinnitus relief induced by the EES.
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Affiliation(s)
- Min Chen
- ENT Institute and Department of Otolaryngology & Head-Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031, China
| | - Shiyao Min
- ENT Institute and Department of Otolaryngology & Head-Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031, China
| | - Chen Zhang
- ENT Institute and Department of Otolaryngology & Head-Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031, China
| | - Xuerui Hu
- ENT Institute and Department of Otolaryngology & Head-Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031, China
| | - Shufeng Li
- ENT Institute and Department of Otolaryngology & Head-Neck Surgery, Eye & ENT Hospital of Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, 200031, China
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14
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Brinkmann P, Kotz SA, Smit JV, Janssen MLF, Schwartze M. Auditory thalamus dysfunction and pathophysiology in tinnitus: a predictive network hypothesis. Brain Struct Funct 2021; 226:1659-1676. [PMID: 33934235 PMCID: PMC8203542 DOI: 10.1007/s00429-021-02284-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 04/21/2021] [Indexed: 01/12/2023]
Abstract
Tinnitus is the perception of a 'ringing' sound without an acoustic source. It is generally accepted that tinnitus develops after peripheral hearing loss and is associated with altered auditory processing. The thalamus is a crucial relay in the underlying pathways that actively shapes processing of auditory signals before the respective information reaches the cerebral cortex. Here, we review animal and human evidence to define thalamic function in tinnitus. Overall increased spontaneous firing patterns and altered coherence between the thalamic medial geniculate body (MGB) and auditory cortices is observed in animal models of tinnitus. It is likely that the functional connectivity between the MGB and primary and secondary auditory cortices is reduced in humans. Conversely, there are indications for increased connectivity between the MGB and several areas in the cingulate cortex and posterior cerebellar regions, as well as variability in connectivity between the MGB and frontal areas regarding laterality and orientation in the inferior, medial and superior frontal gyrus. We suggest that these changes affect adaptive sensory gating of temporal and spectral sound features along the auditory pathway, reflecting dysfunction in an extensive thalamo-cortical network implicated in predictive temporal adaptation to the auditory environment. Modulation of temporal characteristics of input signals might hence factor into a thalamo-cortical dysrhythmia profile of tinnitus, but could ultimately also establish new directions for treatment options for persons with tinnitus.
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Affiliation(s)
- Pia Brinkmann
- Department of Neuropsychology and Psychopharmacology, University of Maastricht, Universiteitssingel 40, 6229, Maastricht, The Netherlands.
| | - Sonja A Kotz
- Department of Neuropsychology and Psychopharmacology, University of Maastricht, Universiteitssingel 40, 6229, Maastricht, The Netherlands
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Jasper V Smit
- Department of Ear Nose and Throat/Head and Neck Surgery, Zuyderland Medical Center, Sittard/Heerlen, the Netherlands
| | - Marcus L F Janssen
- Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands
- School for Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Michael Schwartze
- Department of Neuropsychology and Psychopharmacology, University of Maastricht, Universiteitssingel 40, 6229, Maastricht, The Netherlands
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15
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Koops EA, Eggermont JJ. The thalamus and tinnitus: Bridging the gap between animal data and findings in humans. Hear Res 2021; 407:108280. [PMID: 34175683 DOI: 10.1016/j.heares.2021.108280] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/26/2021] [Accepted: 05/27/2021] [Indexed: 12/16/2022]
Abstract
The neuronal mechanisms underlying tinnitus are yet to be revealed. Tinnitus, an auditory phantom sensation, used to be approached as a purely auditory domain symptom. More recently, the modulatory impact of non-auditory brain regions on the percept and burden of tinnitus are explored. The thalamus is uniquely situated to facilitate the communication between auditory and non-auditory subcortical and cortical structures. Traditionally, animal models of tinnitus have focussed on subcortical auditory structures, and research with human participants has been concerned with cortical activity in auditory and non-auditory areas. Recently, both research fields have investigated the connectivity between subcortical and cortical regions and between auditory and non-auditory areas. We show that even though the different fields employ different methods to investigate the activity and connectivity of brain areas, there is consistency in the results on tinnitus between these different approaches. This consistency between human and animals research is observed for tinnitus with peripherally instigated hearing damage, and for results obtained with salicylate and noise-induced tinnitus. The thalamus integrates input from limbic and prefrontal areas and modulates auditory activity via its connections to both subcortical and cortical auditory areas. Reported altered activity and connectivity of the auditory, prefrontal, and limbic regions suggest a more systemic approach is necessary to understand the origins and impact of tinnitus.
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Affiliation(s)
- Elouise A Koops
- Department of Otorhinolaryngology/Head and Neck Surgery, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
| | - Jos J Eggermont
- Departments of Physiology and Pharmacology, and Psychology, University of Calgary, Calgary, Alberta, Canada
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16
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Henton A, Tzounopoulos T. What's the buzz? The neuroscience and the treatment of tinnitus. Physiol Rev 2021; 101:1609-1632. [PMID: 33769102 DOI: 10.1152/physrev.00029.2020] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Tinnitus is a pervasive public health issue that affects ∼15% of the United States population. Similar estimates have also been shown on a global scale, with similar prevalence found in Europe, Asia, and Africa. The severity of tinnitus is heterogeneous, ranging from mildly bothersome to extremely disruptive. In the United States, ∼10-20% of individuals who experience tinnitus report symptoms that severely reduce their quality of life. Due to the huge personal and societal burden, in the last 20 yr a concerted effort on basic and clinical research has significantly advanced our understanding and treatment of this disorder. Yet, neither full understanding, nor cure exists. We know that tinnitus is the persistent involuntary phantom percept of internally generated nonverbal indistinct noises and tones, which in most cases is initiated by acquired hearing loss and maintained only when this loss is coupled with distinct neuronal changes in auditory and extra-auditory brain networks. Yet, the exact mechanisms and patterns of neural activity that are necessary and sufficient for the perceptual generation and maintenance of tinnitus remain incompletely understood. Combinations of animal model and human research will be essential in filling these gaps. Nevertheless, the existing progress in investigating the neurophysiological mechanisms has improved current treatment and highlighted novel targets for drug development and clinical trials. The aim of this review is to thoroughly discuss the current state of human and animal tinnitus research, outline current challenges, and highlight new and exciting research opportunities.
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Affiliation(s)
- A Henton
- Pittsburgh Hearing Research Center and Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - T Tzounopoulos
- Pittsburgh Hearing Research Center and Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
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17
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Resnik J, Polley DB. Cochlear neural degeneration disrupts hearing in background noise by increasing auditory cortex internal noise. Neuron 2021; 109:984-996.e4. [PMID: 33561398 PMCID: PMC7979519 DOI: 10.1016/j.neuron.2021.01.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 12/09/2020] [Accepted: 01/14/2021] [Indexed: 12/29/2022]
Abstract
Correlational evidence in humans suggests that selective difficulties hearing in noisy, social settings may reflect premature auditory nerve degeneration. Here, we induced primary cochlear neural degeneration (CND) in adult mice and found direct behavioral evidence for selective detection deficits in background noise. To identify central determinants for this perceptual disorder, we tracked daily changes in ensembles of layer 2/3 auditory cortex parvalbumin-expressing inhibitory neurons and excitatory pyramidal neurons with chronic two-photon calcium imaging. CND induced distinct forms of plasticity in cortical excitatory and inhibitory neurons that culminated in net hyperactivity, increased neural gain, and reduced adaptation to background noise. Ensemble activity measured while mice detected targets in noise could accurately decode whether individual behavioral trials were hits or misses. After CND, random surges of hypercorrelated cortical activity occurring just before target onset reliably predicted impending detection failures, revealing a source of internal cortical noise underlying perceptual difficulties in external noise.
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Affiliation(s)
- Jennifer Resnik
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA
| | - Daniel B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA; Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02114, USA.
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18
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Vanneste S, De Ridder D. Chronic pain as a brain imbalance between pain input and pain suppression. Brain Commun 2021; 3:fcab014. [PMID: 33758824 PMCID: PMC7966784 DOI: 10.1093/braincomms/fcab014] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 12/20/2022] Open
Abstract
Chronic pain is pain that persists beyond the expected period of healing. The subjective experience of chronic pain results from pathological brain network interactions, rather than from persisting physiological sensory input of nociceptors. We hypothesize that pain is an imbalance between pain evoking dorsal anterior cingulate cortex and somatosensory cortex and pain suppression (i.e. pregenual anterior cingulate cortex). This imbalance can be measured objectively by current density ratios between pain input and pain inhibition. A balance between areas involved in pain input and pain suppression requires communication, which can be objectively identified by connectivity measures, both functional and effective connectivity. In patients with chronic neuropathic pain, electroencephalography is performed with source localization demonstrating that pain is reflected by an abnormal ratio between the dorsal anterior cingulate cortex, somatosensory cortex and pregenual anterior cingulate cortex. Functional connectivity demonstrates decreased communication between these areas, and effective connectivity puts the culprit at the dorsal anterior cingulate cortex, suggesting that the problem is related to abnormal behavioral relevance attached to the pain. In conclusion, chronic pain can be considered as an imbalance between pain input and pain suppression.
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Affiliation(s)
- Sven Vanneste
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Dirk De Ridder
- Department of Surgical Sciences, Section of Neurosurgery, Dunedin School of Medicine, University of Otago, 9016 Dunedin, New Zealand
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19
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Lu J, West MB, Du X, Cai Q, Ewert DL, Cheng W, Nakmali D, Li W, Huang X, Kopke RD. Electrophysiological assessment and pharmacological treatment of blast-induced tinnitus. PLoS One 2021; 16:e0243903. [PMID: 33411811 PMCID: PMC7790300 DOI: 10.1371/journal.pone.0243903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 12/01/2020] [Indexed: 11/19/2022] Open
Abstract
Tinnitus, the phantom perception of sound, often occurs as a clinical sequela of auditory traumas. In an effort to develop an objective test and therapeutic approach for tinnitus, the present study was performed in blast-exposed rats and focused on measurements of auditory brainstem responses (ABRs), prepulse inhibition of the acoustic startle response, and presynaptic ribbon densities on cochlear inner hair cells (IHCs). Although the exact mechanism is unknown, the “central gain theory” posits that tinnitus is a perceptual indicator of abnormal increases in the gain (or neural amplification) of the central auditory system to compensate for peripheral loss of sensory input from the cochlea. Our data from vehicle-treated rats supports this rationale; namely, blast-induced cochlear synaptopathy correlated with imbalanced elevations in the ratio of centrally-derived ABR wave V amplitudes to peripherally-derived wave I amplitudes, resulting in behavioral evidence of tinnitus. Logistic regression modeling demonstrated that the ABR wave V/I amplitude ratio served as a reliable metric for objectively identifying tinnitus. Furthermore, histopathological examinations in blast-exposed rats revealed tinnitus-related changes in the expression patterns of key plasticity factors in the central auditory pathway, including chronic loss of Arc/Arg3.1 mobilization. Using a formulation of N-acetylcysteine (NAC) and disodium 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07) as a therapeutic for addressing blast-induced neurodegeneration, we measured a significant treatment effect on preservation or restoration of IHC ribbon synapses, normalization of ABR wave V/I amplitude ratios, and reduced behavioral evidence of tinnitus in blast-exposed rats, all of which accorded with mitigated histopathological evidence of tinnitus-related neuropathy and maladaptive neuroplasticity.
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Affiliation(s)
- Jianzhong Lu
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Matthew B. West
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Xiaoping Du
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Qunfeng Cai
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Donald L. Ewert
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Weihua Cheng
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Don Nakmali
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Wei Li
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Xiangping Huang
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
| | - Richard D. Kopke
- Hough Ear Institute, Oklahoma City, Oklahoma, United States of America
- Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
- Departments of Physiology and Otolaryngology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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20
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van Zwieten G, Roberts MJ, Schaper FLVW, Smit JV, Temel Y, Janssen MLF. Noise-induced neurophysiological alterations in the rat medial geniculate body and thalamocortical desynchronization by deep brain stimulation. J Neurophysiol 2021; 125:661-671. [PMID: 33405997 DOI: 10.1152/jn.00752.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The thalamic medial geniculate body (MGB) is uniquely positioned within the neural tinnitus networks. Deep brain stimulation (DBS) of the MGB has been proposed as a possible novel treatment for tinnitus, yet mechanisms remain elusive. The aim of this study was to characterize neurophysiologic hallmarks in the MGB after noise exposure and to assess the neurophysiological effects of electrical stimulation of the MGB. Fourteen male Sprague-Dawley rats were included. Nine subjects were unilaterally exposed to a 16-kHz octave-band noise at 115 dB for 90 min, five received sham exposure. Single units were recorded from the contralateral MGB where spontaneous firing, coefficient of variation, response type, rate-level functions, and thresholds were determined. Local field potentials and electroencephalographical (EEG) recordings were performed before and after high-frequency DBS of the MGB. Thalamocortical synchronization and power were analyzed. In total, 214 single units were identified (n = 145 in noise-exposed group, n = 69 in control group). After noise exposure, fast-responding neurons become less responsive or nonresponsive without change to their spontaneous rate, whereas sustained- and suppressed-type neurons exhibit enhanced spontaneous activity without change to their stimulus-driven activity. MGB DBS suppressed thalamocortical synchronization in the β and γ bands, supporting suppression of thalamocortical synchronization as an underlying mechanism of tinnitus suppression by high frequency DBS. These findings contribute to our understanding of the neurophysiologic consequences of noise exposure and the mechanism of potential DBS therapy for tinnitus.NEW & NOTEWORTHY Separate functional classes of MGB neurons might have distinct roles in tinnitus pathophysiology. After noise exposure, fast-responding neurons become less responsive or nonresponsive without change to their spontaneous firing, whereas sustained and suppressed neurons exhibit enhanced spontaneous activity without change to their stimulus-driven activity. Furthermore, results suggest desynchronization of thalamocortical β and γ oscillations as a mechanism of tinnitus suppression by MGB DBS.
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Affiliation(s)
- Gusta van Zwieten
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Mark J Roberts
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Frédéric L V W Schaper
- School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jasper V Smit
- School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Ear Nose and Throat/Head and Neck Surgery, Zuyderland Hospital, Heerlen, The Netherlands
| | - Yasin Temel
- School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marcus L F Janssen
- School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands
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21
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Riffle TL, Martel DT, Jones GR, Shore SE. Bimodal Auditory Electrical Stimulation for the Treatment of Tinnitus: Preclinical and Clinical Studies. Curr Top Behav Neurosci 2021; 51:295-323. [PMID: 33083999 PMCID: PMC8058117 DOI: 10.1007/7854_2020_180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tinnitus, or the phantom perception of sound, arises from pathological neural activity. Neurophysiological research has shown increased spontaneous firing rates and synchronization along the auditory pathway correlate strongly with behavioral measures of tinnitus. Auditory neurons are plastic, enabling external stimuli to be utilized to elicit long-term changes to spontaneous firing and synchrony. Pathological plasticity can thus be reversed using bimodal auditory plus nonauditory stimulation to reduce tinnitus. This chapter discusses preclinical and clinical evidence for efficacy of bimodal stimulation treatments of tinnitus, with highlights on sham-controlled, double-blinded clinical trials. The results from these studies have shown some efficacy in reducing the severity of tinnitus, based on subjective and objective outcome measures including tinnitus questionnaires and psychophysical tinnitus measurements. While results of some studies have been positive, the degree of benefit and the populations that respond to treatment vary across the studies. Directions and implications of future studies are discussed.
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Affiliation(s)
- Travis L Riffle
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | - David T Martel
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | - Gerilyn R Jones
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA
| | - Susan E Shore
- Department of Otolaryngology, University of Michigan, Ann Arbor, MI, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
- Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
- Kresge Hearing Research Institute, Ann Arbor, MI, USA.
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22
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Zhang J, Firestone E, Elattma A. Animal Models of Tinnitus Treatment: Cochlear and Brain Stimulation. Curr Top Behav Neurosci 2021; 51:83-129. [PMID: 34282563 DOI: 10.1007/7854_2021_227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neuromodulation, via stimulation of a variety of peripheral and central structures, is used to suppress tinnitus. However, investigative limitations in humans due to ethical reasons have made it difficult to decipher the mechanisms underlying treatment-induced tinnitus relief, so a number of animal models have arisen to address these unknowns. This chapter reviews animal models of cochlear and brain stimulation and assesses their modulatory effects on behavioral evidence of tinnitus and its related neural correlates. When a structure is stimulated, localized modulation, often presenting as downregulation of spontaneous neuronal spike firing rate, bursting and neurosynchrony, occurs within the brain area. Through anatomical projections and transmitter pathways, the interventions activate both auditory- and non-auditory structures by taking bottom-up ascending and top-down descending modes to influence their target brain structures. Furthermore, it is the brain oscillations that cochlear or brain stimulation evoke and connect the prefrontal cortex, striatal systems, and other limbic structures to refresh neural networks and relieve auditory, attentive, conscious, as well as emotional reactive aspects of tinnitus. This oscillatory neural network connectivity is achieved via the thalamocorticothalamic circuitry including the lemniscal and non-lemniscal auditory brain structures. Beyond existing technologies, the review also reveals opportunities for developing advanced animal models using new modalities to achieve precision neuromodulation and tinnitus abatement, such as optogenetic cochlear and/or brain stimulation.
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Affiliation(s)
- Jinsheng Zhang
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, USA. .,Department of Communication Sciences and Disorders, Wayne State University College of Liberal Arts and Sciences, Detroit, MI, USA.
| | - Ethan Firestone
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ahmed Elattma
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, USA
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23
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Zhang J, Huang S, Nan W, Zhou H, Wang J, Wang H, Salvi R, Yin S. Switching Tinnitus-On: Maps and source localization of spontaneous EEG. Clin Neurophysiol 2020; 132:345-357. [PMID: 33450557 DOI: 10.1016/j.clinph.2020.10.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/05/2020] [Accepted: 10/11/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To identify the spectrotemporal changes and sources in patients that could "turn on" tinnitus with multichannel electroencephalography (EEG) system. METHODS Multichannel EEG was recorded from six patients during the Tinnitus-On and Tinnitus-Off states. The EEG power spectrum and eLORETA-based sources were measured. RESULTS There was a global increase in delta and theta during Tinnitus-On plus large changes in alpha 1 and alpha 2. During the Tinnitus-On state, many new sources in delta, theta, alpha 1 and gamma bands emerged in the opposite hemisphere in the inferior temporal gyrus (Brodmann area, BA 20), middle temporal gyrus (BA 21), lateral perirhinal cortex (BA 36), ventral entorhinal cortex (BA 28) and anterior pole of the temporal gyrus (BA 38). CONCLUSIONS The emergence of new delta, theta and gamma band sources in the inferior temporal gyrus (BA 20), middle temporal gyrus (BA 21) and lateral perirhinal cortex (BA 36) plus the appearance of new delta and theta sources in the ventral entorhinal cortex (BA28) and anterior pole of the temporal lobe (BA 38) may comprise a network capable of evoking the phantom sound of tinnitus by simultaneously engaging brain regions involved in memory, sound recognition, and distress which together contribute to tinnitus severity. SIGNIFICANCE The sudden appearance of new sources of activity in the opposite hemisphere within the inferior temporal gyrus, middle temporal gyrus and perirhinal cortex may initiate the perception of tinnitus perception.
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Affiliation(s)
- Jiajia Zhang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China
| | - Shujian Huang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China
| | - Wenya Nan
- Department of Psychology, Shanghai Normal University, Shanghai 200234, China
| | - Huiqun Zhou
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China.
| | - Jian Wang
- School of Communication Science and Disorders, Dalhousie University, Halifax, Canada
| | - Hui Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China.
| | - Richard Salvi
- SUNY Distinguished Professor Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY, USA
| | - Shankai Yin
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China; Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai 200233, China; Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai 200233, China
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Xia C, Yin M, Wu C, Ji Y, Zhou Y. Neuroglial activation in the auditory cortex and medial geniculate body of salicylate-induced tinnitus rats. Am J Transl Res 2020; 12:6043-6059. [PMID: 33194013 PMCID: PMC7653558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Neuroglial activation has been recognized as a pathological hallmark of a variety of neurological diseases, yet the role of neuroglia in tinnitus hasn't been well established so far. To explore the potential roles of two types of glia cells (astrocyte and microglia) in the development of tinnitus, we examined markers associated with them in the primary auditory (A1) cortex and medial geniculate body (MGB) of rats with salicylate-induced tinnitus. The results demonstrated that acute and chronic administrations of salicylate could cause reversible tinnitus-like behavior in rats. The expression level of GFAP markedly increased in the A1 cortex of rats following acute and chronic treatments of salicylate, accompanied by increased endpoint and process length of astrocyte. The expression level of GFAP and the morphology of astrocyte in the rat MGB remained almost constant following salicylate treatment. On the other hand, the expression level of Iba1 markedly increased in the rat A1 cortex and MGB following acute and chronic treatments of salicylate, together with increased endpoint and process length of microglia in the MGB. Additionally, interleukin 1β (IL-1β), a pro-inflammatory cytokine released by activated glia was significantly up-regulated in the A1 cortex and MGB of rats after salicylate treatments. These findings highlight astrocyte activation and microglia proliferation in the central auditory system of rats experiencing tinnitus, which potently implicate an indispensable glial regulation in tinnitus development.
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Affiliation(s)
- Chenchen Xia
- Institute of Biomembrane and Biopharmaceutics, Shanghai UniversityShanghai 200444, China
| | - Manli Yin
- Institute of Biomembrane and Biopharmaceutics, Shanghai UniversityShanghai 200444, China
| | - Cong Wu
- Department of Otolaryngology-Head and Neck Surgery, Ninth People’s Hospital, Shanghai Jiaotong University School of MedicineShanghai 200011, China
- Ear Institute, Shanghai Jiaotong University School of MedicineShanghai 200125, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai 200125, China
| | - Yonghua Ji
- Institute of Biomembrane and Biopharmaceutics, Shanghai UniversityShanghai 200444, China
- Translational Institute for Cancer Pain, Xinhua Hospital Chongming BranchShanghai 202150, China
| | - You Zhou
- Department of Otolaryngology-Head and Neck Surgery, Ninth People’s Hospital, Shanghai Jiaotong University School of MedicineShanghai 200011, China
- Ear Institute, Shanghai Jiaotong University School of MedicineShanghai 200125, China
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose DiseasesShanghai 200125, China
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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: 13] [Impact Index Per Article: 3.3] [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.
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Affiliation(s)
- Sarah H Hayes
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, 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
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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: 13] [Impact Index Per Article: 3.3] [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.
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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.
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Nagumo Y, Ueta Y, Nakayama H, Osaki H, Takeuchi Y, Uesaka N, Kano M, Miyata M. Tonic GABAergic Inhibition Is Essential for Nerve Injury-Induced Afferent Remodeling in the Somatosensory Thalamus and Ectopic Sensations. Cell Rep 2020; 31:107797. [DOI: 10.1016/j.celrep.2020.107797] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 03/10/2020] [Accepted: 06/01/2020] [Indexed: 11/16/2022] Open
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Acoustic trauma induced the alteration of the activity balance of excitatory and inhibitory neurons in the inferior colliculus of mice. Hear Res 2020; 391:107957. [DOI: 10.1016/j.heares.2020.107957] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 12/16/2022]
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Gault R, McGinnity TM, Coleman S. Perceptual Modeling of Tinnitus Pitch and Loudness. IEEE Trans Cogn Dev Syst 2020. [DOI: 10.1109/tcds.2020.2964841] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Eggermont JJ. Separate auditory pathways for the induction and maintenance of tinnitus and hyperacusis? PROGRESS IN BRAIN RESEARCH 2020; 260:101-127. [PMID: 33637214 DOI: 10.1016/bs.pbr.2020.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tinnitus and hyperacusis often occur together, however tinnitus may occur without hyperacusis or hyperacusis without tinnitus. Based on animal research one could argue that hyperacusis results from noise exposures that increase central gain in the lemniscal, tonotopically organized, pathways, whereas tinnitus requires increased burst firing and neural synchrony in the extra-lemniscal pathway. However, these substrates are not sufficient and require involvement of the central nervous system. The dominant factors in changing cortical networks in tinnitus patients are foremost the degree and type of hearing loss, and comorbidities such as distress and mood. So far, no definite changes have been established for tinnitus proper, albeit that changes in connectivity between the dorsal attention network and the parahippocampal area, as well as the default-mode network-precuneus decoupling, appear to be strong candidates. I conclude that there is still a strong need for further integrating animal and human research into tinnitus and hyperacusis.
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Affiliation(s)
- Jos J Eggermont
- Department of Psychology, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.
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31
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Zheng Y, McTavish J, Smith PF. Pharmacological Evaluation of Drugs in Animal Models of Tinnitus. Curr Top Behav Neurosci 2020; 51:51-82. [PMID: 33590458 DOI: 10.1007/7854_2020_212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Despite the pressing need for effective drug treatments for tinnitus, currently, there is no single drug that is approved by the FDA for this purpose. Instead, a wide range of unproven over-the-counter tinnitus remedies are available on the market with little or no benefit for tinnitus but with potential harm and adverse effects. Animal models of tinnitus have played a critical role in exploring the pathophysiology of tinnitus, identifying therapeutic targets and evaluating novel and existing drugs for tinnitus treatment. This review summarises and compares the studies on pharmacological evaluation of tinnitus treatment in different animal models based on the pharmacological properties of the drug and provides insights into future directions for tinnitus drug discovery.
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Affiliation(s)
- Yiwen Zheng
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand. .,Brain Research New Zealand, Auckland, New Zealand. .,Brain Health Research Centre, University of Otago, Dunedin, New Zealand. .,Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand.
| | - Jessica McTavish
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
| | - Paul F Smith
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,Brain Research New Zealand, Auckland, New Zealand.,Brain Health Research Centre, University of Otago, Dunedin, New Zealand.,Eisdell Moore Centre for Hearing and Balance Research, University of Auckland, Auckland, New Zealand
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Shore SE, Wu C. Mechanisms of Noise-Induced Tinnitus: Insights from Cellular Studies. Neuron 2019; 103:8-20. [PMID: 31271756 DOI: 10.1016/j.neuron.2019.05.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/25/2019] [Accepted: 05/03/2019] [Indexed: 01/21/2023]
Abstract
Tinnitus, sound perception in the absence of physical stimuli, occurs in 15% of the population and is the top-reported disability for soldiers after combat. Noise overexposure is a major factor associated with tinnitus but does not always lead to tinnitus. Furthermore, people with normal audiograms can get tinnitus. In animal models, equivalent cochlear damage occurs in animals with and without behavioral evidence of tinnitus. But cochlear-nerve-recipient neurons in the brainstem demonstrate distinct, synchronized spontaneous firing patterns only in animals that develop tinnitus, driving activity in central brain regions and ultimately giving rise to phantom perception. Examining tinnitus-specific changes in single-cell populations enables us to begin to distinguish neural changes due to tinnitus from those that are due to hearing loss.
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Affiliation(s)
- Susan E Shore
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109, USA; Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Calvin Wu
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109, USA
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Zhang L, Wu C, Martel DT, West M, Sutton MA, Shore SE. Remodeling of cholinergic input to the hippocampus after noise exposure and tinnitus induction in Guinea pigs. Hippocampus 2019; 29:669-682. [PMID: 30471164 PMCID: PMC7357289 DOI: 10.1002/hipo.23058] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 10/23/2018] [Accepted: 11/03/2018] [Indexed: 01/12/2023]
Abstract
Here, we investigate remodeling of hippocampal cholinergic inputs after noise exposure and determine the relevance of these changes to tinnitus. To assess the effects of noise exposure on the hippocampus, guinea pigs were exposed to unilateral noise for 2 hr and 2 weeks later, immunohistochemistry was performed on hippocampal sections to examine vesicular acetylcholine transporter (VAChT) expression. To evaluate whether the changes in VAChT were relevant to tinnitus, another group of animals was exposed to the same noise band twice to induce tinnitus, which was assessed using gap-prepulse Inhibition of the acoustic startle (GPIAS) 12 weeks after the first noise exposure, followed by immunohistochemistry. Acoustic Brainstem Response (ABR) thresholds were elevated immediately after noise exposure for all experimental animals but returned to baseline levels several days after noise exposure. ABR wave I amplitude-intensity functions did not show any changes after 2 or 12 weeks of recovery compared to baseline levels. In animals assessed 2-weeks following noise-exposure, hippocampal VAChT puncta density decreased on both sides of the brain by 20-60% in exposed animals. By 12 weeks following the initial noise exposure, changes in VAChT puncta density largely recovered to baseline levels in exposed animals that did not develop tinnitus, but remained diminished in animals that developed tinnitus. These tinnitus-specific changes were particularly prominent in hippocampal synapse-rich layers of the dentate gyrus and areas CA3 and CA1, and VAChT density in these regions negatively correlated with tinnitus severity. The robust changes in VAChT labeling in the hippocampus 2 weeks after noise exposure suggest involvement of this circuitry in auditory processing. After chronic tinnitus induction, tinnitus-specific changes occurred in synapse-rich layers of the hippocampus, suggesting that synaptic processing in the hippocampus may play an important role in the pathophysiology of tinnitus.
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Affiliation(s)
- Liqin Zhang
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
- Xiangya Medical School, Central South University, Changsha, Hunan, China
| | - Calvin Wu
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
| | - David T. Martel
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael West
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael A. Sutton
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
- Correspondence to: Michael A. Sutton, Molecular and Behavioral Neuroscience Institute, 5067, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA. Tel: 734-615-2445; ; Susan E. Shore, Kresge Hearing Research Institute, 5434, Medical Science Building, 1100 W. Medical Center Drive, Ann Arbor, MI 48109, USA. Tel: 734-647-2116;
| | - Susan E. Shore
- Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
- Correspondence to: Michael A. Sutton, Molecular and Behavioral Neuroscience Institute, 5067, BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA. Tel: 734-615-2445; ; Susan E. Shore, Kresge Hearing Research Institute, 5434, Medical Science Building, 1100 W. Medical Center Drive, Ann Arbor, MI 48109, USA. Tel: 734-647-2116;
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34
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Barry K, Robertson D, Mulders W. Changes in auditory thalamus neural firing patterns after acoustic trauma in rats. Hear Res 2019; 379:89-97. [DOI: 10.1016/j.heares.2019.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 12/28/2022]
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Abstract
BACKGROUND AND OBJECTIVE Deafferentation caused by cochlear pathology (which can be hidden from the audiogram) activates forms of neural plasticity in auditory pathways, generating tinnitus and its associated conditions including hyperacusis. This article discusses tinnitus mechanisms and suggests how these mechanisms may relate to those involved in normal auditory information processing. MATERIALS AND METHODS Research findings from animal models of tinnitus and from electromagnetic imaging of tinnitus patients are reviewed which pertain to the role of deafferentation and neural plasticity in tinnitus and hyperacusis. RESULTS Auditory neurons compensate for deafferentation by increasing their input/output functions (gain) at multiple levels of the auditory system. Forms of homeostatic plasticity are believed to be responsible for this neural change, which increases the spontaneous and driven activity of neurons in central auditory structures in animals expressing behavioral evidence of tinnitus. Another tinnitus correlate, increased neural synchrony among the affected neurons, is forged by spike-timing-dependent neural plasticity in auditory pathways. Slow oscillations generated by bursting thalamic neurons verified in tinnitus animals appear to modulate neural plasticity in the cortex, integrating tinnitus neural activity with information in brain regions supporting memory, emotion, and consciousness which exhibit increased metabolic activity in tinnitus patients. DISCUSSION AND CONCLUSION The latter process may be induced by transient auditory events in normal processing but it persists in tinnitus, driven by phantom signals from the auditory pathway. Several tinnitus therapies attempt to suppress tinnitus through plasticity, but repeated sessions will likely be needed to prevent tinnitus activity from returning owing to deafferentation as its initiating condition.
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Esmaeeli S, Murphy K, Swords GM, Ibrahim BA, Brown JW, Llano DA. Visual hallucinations, thalamocortical physiology and Lewy body disease: A review. Neurosci Biobehav Rev 2019; 103:337-351. [PMID: 31195000 DOI: 10.1016/j.neubiorev.2019.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 06/03/2019] [Accepted: 06/08/2019] [Indexed: 12/22/2022]
Abstract
One of the core diagnostic criteria for Dementia with Lewy Bodies (DLB) is the presence of visual hallucinations. The presence of hallucinations, along with fluctuations in the level of arousal and sleep disturbance, point to potential pathological mechanisms at the level of the thalamus. However, the potential role of thalamic dysfunction in DLB, particularly as it relates to the presence of formed visual hallucinations is not known. Here, we review the literature on the pathophysiology of DLB with respect to modern theories of thalamocortical function and attempt to derive an understanding of how such hallucinations arise. Based on the available literature, we propose that combined thalamic-thalamic reticular nucleus and thalamocortical pathology may explain the phenomenology of visual hallucinations in DLB. In particular, diminished α7 cholinergic activity in the thalamic reticular nucleus may critically disinhibit thalamocortical activity. Further, concentrated pathological changes within the posterior regions of the thalamus may explain the predilection for the hallucinations to be visual in nature.
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Affiliation(s)
- Shooka Esmaeeli
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Kathleen Murphy
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Gabriel M Swords
- University of Illinois at Chicago College of Medicine, Chicago, IL, United States
| | - Baher A Ibrahim
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jeffrey W Brown
- University of Illinois at Chicago College of Medicine, Chicago, IL, United States
| | - Daniel A Llano
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Carle Neuroscience Institute, Urbana, IL, United States.
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37
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Sedley W. Tinnitus: Does Gain Explain? Neuroscience 2019; 407:213-228. [DOI: 10.1016/j.neuroscience.2019.01.027] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 02/01/2023]
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38
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Wu C, Bao W, Yi B, Wang Q, Wu X, Qian M, Zuo C, Huang Z. Increased metabolic activity and hysteretic enhanced GABA A receptor binding in a rat model of salicylate-induced tinnitus. Behav Brain Res 2019; 364:348-355. [PMID: 30797852 DOI: 10.1016/j.bbr.2019.02.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 11/16/2022]
Abstract
Tinnitus is relevant to neural hyperactivity in the central nervous system (CNS). Normal quantity and functioning of the γ-aminobutyric acid (GABA) receptor are crucial for maintaining the balance between excitation and inhibition in the brain. In this study, we applied a rat model of tinnitus via long-term salicylate administration. The combination of the gap pre-pulse inhibition of acoustic startle (GPIAS) and pre-pulse inhibition (PPI) tests were used to detect tinnitus-like behavior, and rats receiving 7 or 14 consecutive days of salicylate administration showed evidence of tinnitus. After positron emission tomography (PET) scan, we found that the metabolic activity was increased after salicylate treatment followed by enhanced GABAA receptor binding with cessation of salicylate administration in the auditory cortex (AC), medial prefrontal cortex (mPFC), hippocampus (HP), cingulate cortex (CiC) and insular (InC). The inferior colliculus (IC) showed an elevated metabolic activity with no change in the GABAA receptor binding. All the alterations returned to baseline several days after cessation of salicylate treatment despite a mismatch between the time-course of them. By contrast, we found alterations in neither the metabolic activity nor the GABAA receptor binding in the amygdala (AMY) and cerebellum (CRB). These findings indicate that enhanced neural activity in the auditory and limbic system may contribute to the development of tinnitus, while the hysteretic increase of GABAA receptor binding in specific areas of the CNS may be a compensation for hyperactivity, which may be involved in tinnitus relieving.
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Affiliation(s)
- Cong Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Weiqi Bao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Bin Yi
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Qixuan Wang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Xu Wu
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Minfei Qian
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
| | - Chuantao Zuo
- PET Center, Huashan Hospital, Fudan University, Shanghai, China.
| | - Zhiwu Huang
- Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Laboratoryof Auditory Neuroscience, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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Mucke HA. Drug Repurposing Patent Applications July–September 2018. Assay Drug Dev Technol 2018; 16:472-477. [DOI: 10.1089/adt.2018.29083.pq3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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40
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Gault R, Mcginnity TM, Coleman S. A Computational Model of Thalamocortical Dysrhythmia in People With Tinnitus. IEEE Trans Neural Syst Rehabil Eng 2018; 26:1845-1857. [PMID: 30106678 DOI: 10.1109/tnsre.2018.2863740] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Tinnitus is a problem that affects a diverse range of people. One common trait amongst people with tinnitus is the presence of hearing loss, which is apparent in over 90% of the cohort. It is postulated that the remainder of people with tinnitus have hidden hearing loss in the form of cochlear synaptopathy. The loss of hearing sensation is thought to cause a reduction in the bottom-up excitatory signals of the auditory pathway leading to a change in the frequency of thalamocortical oscillations known as thalamocortical dysrhythmia (TCD). The downward shift in oscillatory behavior, characteristic of TCD, has been recorded experimentally but the underlying mechanisms responsible for TCD in tinnitus subjects cannot be directly observed. This paper investigates these underlying mechanisms by creating a biologically faithful model of the auditory periphery and thalamocortical network, called the central auditory processing (CAP) model. The proposed model replicates tinnitus related activity in the presence of hearing loss and hidden hearing loss in the form of cochlear synaptopathy. The results of this paper show that, both the bottom-up and top-down changes are required in the auditory system for tinnitus related hyperactivity to coexist with TCD, contrary to the theoretical model for TCD. The CAP model provides a novel modeling approach to account for tinnitus related activity with and without hearing loss. Moreover, the results provide additional clarity to the understanding of TCD and tinnitus and provide direction for future approaches to treating tinnitus.
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Asokan MM, Williamson RS, Hancock KE, Polley DB. Sensory overamplification in layer 5 auditory corticofugal projection neurons following cochlear nerve synaptic damage. Nat Commun 2018; 9:2468. [PMID: 29941910 PMCID: PMC6018400 DOI: 10.1038/s41467-018-04852-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 05/24/2018] [Indexed: 11/09/2022] Open
Abstract
Layer 5 (L5) cortical projection neurons innervate far-ranging brain areas to coordinate integrative sensory processing and adaptive behaviors. Here, we characterize a plasticity in L5 auditory cortex (ACtx) neurons that innervate the inferior colliculus (IC), thalamus, lateral amygdala and striatum. We track daily changes in sound processing using chronic widefield calcium imaging of L5 axon terminals on the dorsal cap of the IC in awake, adult mice. Sound level growth functions at the level of the auditory nerve and corticocollicular axon terminals are both strongly depressed hours after noise-induced damage of cochlear afferent synapses. Corticocollicular response gain rebounded above baseline levels by the following day and remained elevated for several weeks despite a persistent reduction in auditory nerve input. Sustained potentiation of excitatory ACtx projection neurons that innervate multiple limbic and subcortical auditory centers may underlie hyperexcitability and aberrant functional coupling of distributed brain networks in tinnitus and hyperacusis.
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Affiliation(s)
- Meenakshi M Asokan
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, 02114, USA.
- Division of Medical Sciences, Harvard University, Boston, MA, 02114, USA.
| | - Ross S Williamson
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, 02114, USA
- Department of Otolaryngology, Harvard Medical School, Boston, MA, 02114, USA
| | - Kenneth E Hancock
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, 02114, USA
- Department of Otolaryngology, Harvard Medical School, Boston, MA, 02114, USA
| | - Daniel B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, MA, 02114, USA
- Division of Medical Sciences, Harvard University, Boston, MA, 02114, USA
- Department of Otolaryngology, Harvard Medical School, Boston, MA, 02114, USA
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Tetteh H, Lee M, Lau CG, Yang S, Yang S. Tinnitus: Prospects for Pharmacological Interventions With a Seesaw Model. Neuroscientist 2017; 24:353-367. [PMID: 29283017 DOI: 10.1177/1073858417733415] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Chronic tinnitus, the perception of lifelong constant ringing in ear, is one capital cause of disability in modern society. It is often present with various comorbid factors that severely affect quality of life, including insomnia, deficits in attention, anxiety, and depression. Currently, there are limited therapeutic treatments for alleviation of tinnitus. Tinnitus can involve a shift in neuronal excitation/inhibition (E/I) balance, which is largely modulated by ion channels and receptors. Thus, ongoing research is geared toward pharmaceutical approaches that modulate the function of ion channels and receptors. Here, we propose a seesaw model that delineates how tinnitus-related ion channels and receptors are involved in homeostatic E/I balance of neurons. This review provides a thorough account of our current mechanistic understanding of tinnitus and insight into future direction of drug development.
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Affiliation(s)
- Hannah Tetteh
- 1 Department of Biomedical Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Minseok Lee
- 2 Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| | - C Geoffrey Lau
- 1 Department of Biomedical Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Sunggu Yang
- 2 Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| | - Sungchil Yang
- 1 Department of Biomedical Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
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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: 58] [Impact Index Per Article: 8.3] [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.
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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.
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Brozoski T, Brozoski D, Wisner K, Bauer C. Chronic tinnitus and unipolar brush cell alterations in the cerebellum and dorsal cochlear nucleus. Hear Res 2017; 350:139-151. [PMID: 28478300 DOI: 10.1016/j.heares.2017.04.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/18/2017] [Accepted: 04/28/2017] [Indexed: 12/19/2022]
Abstract
Animal model research has shown that the central features of tinnitus, the perception of sound without an acoustic correlate, include elevated spontaneous and stimulus-driven activity, enhanced burst-mode firing, decreased variance of inter-spike intervals, and distortion of tonotopic frequency representation. Less well documented are cell-specific correlates of tinnitus. Unipolar brush cell (UBC) alterations in animals with psychophysical evidence of tinnitus has recently been reported. UBCs are glutamatergic interneurons that appear to function as local-circuit signal amplifiers. UBCs are abundant in the dorsal cochlear nucleus (DCN) and very abundant in the flocculus (FL) and paraflocculus (PFL) of the cerebellum. In the present research, two indicators of UBC structure and function were examined: Doublecortin (DCX) and epidermal growth factor receptor substrate 8 (Eps8). DCX is a protein that binds to microtubules where it can modify their assembly and growth. Eps8 is a cell-surface tyrosine kinase receptor mediating the response to epidermal growth factor; it appears to have a role in actin polymerization as well as cytoskeletal protein interactions. Both functions could contribute to synaptic remodeling. In the present research UBC Eps8 and DCX immunoreactivity (IR) were determined in 4 groups of rats distinguished by their exposure to high-level sound and psychophysical performance: Unexposed, exposed to high-level sound with behavioral evidence of tinnitus, and two exposed groups without behavioral evidence of tinnitus. Compared to unexposed controls, exposed animals with tinnitus had Eps8 IR elevated in their PFL; other structures were not affected, nor was DCX IR affected. This was interpreted as UBC upregulation in animals with tinnitus. Exposure that failed to produce tinnitus did not increase either Eps8 or DCX IR. Rather Eps8 IR was decreased in the FL and DCN of one subgroup (Least-Tinnitus), while DCX IR decreased in the FL of the other subgroup (No-Tinnitus). Neuron degeneration was also documented in the cochlear nucleus and PFL of exposed animals, both with and without tinnitus. Degeneration was not found in unexposed animals. Implications for tinnitus neuropathy are discussed in the context of synaptic remodeling and cerebellar sensory modulation.
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Affiliation(s)
- Thomas Brozoski
- Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL 62794, United States.
| | - Daniel Brozoski
- Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL 62794, United States
| | - Kurt Wisner
- Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL 62794, United States
| | - Carol Bauer
- Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL 62794, United States
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Resnik J, Polley DB. Fast-spiking GABA circuit dynamics in the auditory cortex predict recovery of sensory processing following peripheral nerve damage. eLife 2017; 6. [PMID: 28323619 PMCID: PMC5378474 DOI: 10.7554/elife.21452] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/20/2017] [Indexed: 12/20/2022] Open
Abstract
Cortical neurons remap their receptive fields and rescale sensitivity to spared peripheral inputs following sensory nerve damage. To address how these plasticity processes are coordinated over the course of functional recovery, we tracked receptive field reorganization, spontaneous activity, and response gain from individual principal neurons in the adult mouse auditory cortex over a 50-day period surrounding either moderate or massive auditory nerve damage. We related the day-by-day recovery of sound processing to dynamic changes in the strength of intracortical inhibition from parvalbumin-expressing (PV) inhibitory neurons. Whereas the status of brainstem-evoked potentials did not predict the recovery of sensory responses to surviving nerve fibers, homeostatic adjustments in PV-mediated inhibition during the first days following injury could predict the eventual recovery of cortical sound processing weeks later. These findings underscore the potential importance of self-regulated inhibitory dynamics for the restoration of sensory processing in excitatory neurons following peripheral nerve injuries. DOI:http://dx.doi.org/10.7554/eLife.21452.001
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Affiliation(s)
- Jennifer Resnik
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, United States.,Department of Otolaryngology, Harvard Medical School, Boston, United States
| | - Daniel B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, United States.,Department of Otolaryngology, Harvard Medical School, Boston, United States
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Zhang C, Chen RX, Zhang Y, Wang J, Liu FY, Cai J, Liao FF, Xu FQ, Yi M, Wan Y. Reduced GABAergic transmission in the ventrobasal thalamus contributes to thermal hyperalgesia in chronic inflammatory pain. Sci Rep 2017; 7:41439. [PMID: 28150719 PMCID: PMC5288727 DOI: 10.1038/srep41439] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/20/2016] [Indexed: 12/26/2022] Open
Abstract
The ventrobasal (VB) thalamus is innervated by GABAergic afferents from the thalamic reticular nucleus (TRN) and participates in nociception. But how the TRN-VB pathway regulates pain is not fully understood. In the present study, we reported decreased extracellular GABA levels in the VB of rats with CFA-induced chronic inflammatory pain, measured by microdialysis with HPLC analysis. In vitro whole-cell patch-clamp recording showed decreased amplitudes of tonic currents, increased frequencies of mIPSCs, and increased paired-pulse ratios in thalamic slices from chronic inflammatory rats (7 days). Microinjection of the GABAAR agonist muscimol and optogenetic activation of the TRN-VB pathway relieved thermal hyperalgesia in chronic inflammatory pain. By contrast, microinjecting the extrasynaptic GABAAR agonist THIP or selective knockout of synaptic GABAAR γ2 subunits aggravated thermal hyperalgesia in the chronic stage of inflammatory pain. Our findings indicate that reduced GABAergic transmission in the VB contributes to thermal hyperalgesia in chronic inflammatory pain, which could be a synaptic target for pharmacotherapy.
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Affiliation(s)
- Chan Zhang
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China.,Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, P.R. China
| | - Rong-Xiang Chen
- Research Center for Medicine and Biology, Zunyi Medical University, Zunyi, 563000, P.R. China
| | - Yu Zhang
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Jie Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P.R. China
| | - Feng-Yu Liu
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Jie Cai
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Fei-Fei Liao
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China
| | - Fu-Qiang Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P.R. China
| | - Ming Yi
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China.
| | - You Wan
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University, Beijing, 100191, P.R. China. .,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Beijing, 100191, P.R. China.
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Chambers AR, Salazar JJ, Polley DB. Persistent Thalamic Sound Processing Despite Profound Cochlear Denervation. Front Neural Circuits 2016; 10:72. [PMID: 27630546 PMCID: PMC5005347 DOI: 10.3389/fncir.2016.00072] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 08/19/2016] [Indexed: 11/13/2022] Open
Abstract
Neurons at higher stages of sensory processing can partially compensate for a sudden drop in peripheral input through a homeostatic plasticity process that increases the gain on weak afferent inputs. Even after a profound unilateral auditory neuropathy where >95% of afferent synapses between auditory nerve fibers and inner hair cells have been eliminated with ouabain, central gain can restore cortical processing and perceptual detection of basic sounds delivered to the denervated ear. In this model of profound auditory neuropathy, auditory cortex (ACtx) processing and perception recover despite the absence of an auditory brainstem response (ABR) or brainstem acoustic reflexes, and only a partial recovery of sound processing at the level of the inferior colliculus (IC), an auditory midbrain nucleus. In this study, we induced a profound cochlear neuropathy with ouabain and asked whether central gain enabled a compensatory plasticity in the auditory thalamus comparable to the full recovery of function previously observed in the ACtx, the partial recovery observed in the IC, or something different entirely. Unilateral ouabain treatment in adult mice effectively eliminated the ABR, yet robust sound-evoked activity persisted in a minority of units recorded from the contralateral medial geniculate body (MGB) of awake mice. Sound driven MGB units could decode moderate and high-intensity sounds with accuracies comparable to sham-treated control mice, but low-intensity classification was near chance. Pure tone receptive fields and synchronization to broadband pulse trains also persisted, albeit with significantly reduced quality and precision, respectively. MGB decoding of temporally modulated pulse trains and speech tokens were both greatly impaired in ouabain-treated mice. Taken together, the absence of an ABR belied a persistent auditory processing at the level of the MGB that was likely enabled through increased central gain. Compensatory plasticity at the level of the auditory thalamus was less robust overall than previous observations in cortex or midbrain. Hierarchical differences in compensatory plasticity following sensorineural hearing loss may reflect differences in GABA circuit organization within the MGB, as compared to the ACtx or IC.
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Affiliation(s)
- Anna R Chambers
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary Boston, MA, USA
| | - Juan J Salazar
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear InfirmaryBoston, MA, USA; Department of Biology, École Normale Supérieure, PSL Research UniversityParis, France
| | - Daniel B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear InfirmaryBoston, MA, USA; Department of Otolaryngology, Harvard Medical SchoolBoston, MA, USA
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Brozoski TJ, Bauer CA. Animal models of tinnitus. Hear Res 2016; 338:88-97. [DOI: 10.1016/j.heares.2015.10.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 12/18/2022]
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Additive effect of BLA GABAA receptor mechanism and (+)-MK-801 on memory retention deficit, an isobologram analysis. Pharmacol Biochem Behav 2016; 143:57-64. [DOI: 10.1016/j.pbb.2016.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/02/2016] [Accepted: 02/03/2016] [Indexed: 11/21/2022]
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Abstract
UNLABELLED It is not known why tinnitus occurs in some cases of hearing damage but not others. Abnormalities of excitation-inhibition balance could influence whether tinnitus develops and its severity if it does. Animal models of hearing damage, which also produce tinnitus based on behavioral evidence, have identified abnormalities of GABAergic inhibition, both cortically and subcortically. However, the precise relationships of GABA inhibitory changes to tinnitus itself, as opposed to other consequences of hearing damage, remain uncertain. Here, we used magnetic resonance spectroscopy to non-invasively quantify GABA in the left (LAC) and right (RAC) auditory cortices of a group of 14 patients with lateralized tinnitus (eight left ear) and 14 controls matched for age, sex, and hearing. We also explored the potential relationships with other brain metabolites (i.e., choline, N-acetylaspartate, and creatine). The presence of tinnitus was associated with a reduction in auditory cortex GABA concentration. Regardless of tinnitus laterality, post hoc testing indicated reductions that were significant in RAC and nonsignificant in LAC. Tinnitus severity and hearing loss were correlated positively with RAC choline but not GABA. We discuss the results in the context of current models of tinnitus and methodological constraints. SIGNIFICANCE STATEMENT Permanently affecting one in seven adults, tinnitus lacks both widely effective treatments and adequate understanding of its brain mechanisms. Existing animal models represent tinnitus that may not be distinguishable from homeostatic responses to the auditory insults used to induce it. Human studies can be well controlled in this regard but are usually not (with few even matching control subjects for hearing loss) and are limited in scope as a result of relying solely on non-invasive recording techniques. Here, we exploit recent advances in non-invasive spectroscopic techniques to establish, in a human study tightly controlled for hearing loss and hyperacusis, that tinnitus is associated with a significant reduction in auditory cortex GABA concentration, which has implications for understanding and treatment of the condition.
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