1
|
Fabrizio-Stover EM, Oliver DL, Burghard AL. Tinnitus mechanisms and the need for an objective electrophysiological tinnitus test. Hear Res 2024; 449:109046. [PMID: 38810373 DOI: 10.1016/j.heares.2024.109046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/16/2024] [Accepted: 05/22/2024] [Indexed: 05/31/2024]
Abstract
Tinnitus, the perception of sound with no external auditory stimulus, is a complex, multifaceted, and potentially devastating disorder. Despite recent advances in our understanding of tinnitus, there are limited options for effective treatment. Tinnitus treatments are made more complicated by the lack of a test for tinnitus based on objectively measured physiological characteristics. Such an objective test would enable a greater understanding of tinnitus mechanisms and may lead to faster treatment development in both animal and human research. This review makes the argument that an objective tinnitus test, such as a non-invasive electrophysiological measure, is desperately needed. We review the current tinnitus assessment methods, the underlying neural correlates of tinnitus, the multiple tinnitus generation theories, and the previously investigated electrophysiological measurements of tinnitus. Finally, we propose an alternate objective test for tinnitus that may be valid in both animal and human subjects.
Collapse
Affiliation(s)
- Emily M Fabrizio-Stover
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA; Department of Otolaryngology-Head and Neck Surgery, Medical University South Carolina, Charleston, SC, USA
| | - Douglas L Oliver
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Alice L Burghard
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA.
| |
Collapse
|
2
|
Singh A, Smith PF, Zheng Y. Targeting the Limbic System: Insights into Its Involvement in Tinnitus. Int J Mol Sci 2023; 24:9889. [PMID: 37373034 DOI: 10.3390/ijms24129889] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Tinnitus is originally derived from the Latin verb tinnire, which means "to ring". Tinnitus, a complex disorder, is a result of sentient cognizance of a sound in the absence of an external auditory stimulus. It is reported in children, adults, and older populations. Patients suffering from tinnitus often present with hearing loss, anxiety, depression, and sleep disruption in addition to a hissing and ringing in the ear. Surgical interventions and many other forms of treatment have been only partially effective due to heterogeneity in tinnitus patients and a lack of understanding of the mechanisms of tinnitus. Although researchers across the globe have made significant progress in understanding the underlying mechanisms of tinnitus over the past few decades, tinnitus is still deemed to be a scientific enigma. This review summarises the role of the limbic system in tinnitus development and provides insight into the development of potential target-specific tinnitus therapies.
Collapse
Affiliation(s)
- Anurag Singh
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
- The Eisdell Moore Centre for Research in Hearing and Balance Disorders, University of Auckland, Auckland 1023, New Zealand
| | - Paul F Smith
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
- The Eisdell Moore Centre for Research in Hearing and Balance Disorders, University of Auckland, Auckland 1023, New Zealand
| | - Yiwen Zheng
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
- The Eisdell Moore Centre for Research in Hearing and Balance Disorders, University of Auckland, Auckland 1023, New Zealand
| |
Collapse
|
3
|
De Vis C, Barry KM, Mulders WHAM. Hearing Loss Increases Inhibitory Effects of Prefrontal Cortex Stimulation on Sound Evoked Activity in Medial Geniculate Nucleus. Front Synaptic Neurosci 2022; 14:840368. [PMID: 35300310 PMCID: PMC8921694 DOI: 10.3389/fnsyn.2022.840368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/08/2022] [Indexed: 11/21/2022] Open
Abstract
Sensory gating is the process whereby irrelevant sensory stimuli are inhibited on their way to higher cortical areas, allowing for focus on salient information. Sensory gating circuitry includes the thalamus as well as several cortical regions including the prefrontal cortex (PFC). Defective sensory gating has been implicated in a range of neurological disorders, including tinnitus, a phantom auditory perception strongly associated with cochlear trauma. Recently, we have shown in rats that functional connectivity between PFC and auditory thalamus, i.e., the medial geniculate nucleus (MGN), changes following cochlear trauma, showing an increased inhibitory effect from PFC activation on the spontaneous firing rate of MGN neurons. In this study, we further investigated this phenomenon using a guinea pig model, in order to demonstrate the validity of our finding beyond a single species and extend data to include data on sound evoked responses. Effects of PFC electrical stimulation on spontaneous and sound-evoked activity of single neurons in MGN were recorded in anaesthetised guinea pigs with normal hearing or hearing loss 2 weeks after acoustic trauma. No effect, inhibition and excitation were observed following PFC stimulation. The proportions of these effects were not different in animals with normal hearing and hearing loss but the magnitude of effect was. Indeed, hearing loss significantly increased the magnitude of inhibition for sound evoked responses, but not for spontaneous activity. The findings support previous observations that PFC can modulate MGN activity and that functional changes occur within this pathway after cochlear trauma. These data suggest hearing loss can alter sensory gating which may be a contributing factor toward tinnitus development.
Collapse
|
4
|
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]
|
5
|
Zhou GP, Chen YC, Li WW, Wei HL, Yu YS, Zhou QQ, Yin X, Tao YJ, Zhang H. Aberrant functional and effective connectivity of the frontostriatal network in unilateral acute tinnitus patients with hearing loss. Brain Imaging Behav 2021; 16:151-160. [PMID: 34296381 DOI: 10.1007/s11682-021-00486-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2021] [Indexed: 12/25/2022]
Abstract
PURPOSE The present study combined resting-state functional connectivity (FC) and Granger causality analysis (GCA) to explore frontostriatal network dysfunction in unilateral acute tinnitus (AT) patients with hearing loss. METHODS The participants included 42 AT patients and 43 healthy control (HC) subjects who underwent resting-state functional magnetic resonance imaging (fMRI) scans. Based on the seed regions in the frontostriatal network, FC and GCA were conducted between the AT patients and HC subjects. Correlation analyses were used to examine correlations among altered FC values, GCA values, and clinical features in AT patients. RESULTS Compared with HCs, AT patients showed a general reduction in FC between the seed regions in the frontostriatal network and nonauditory areas, including the frontal cortices, midcingulate cortex (MCC), supramarginal gyrus, and postcentral gyrus (PoCG). Using the GCA algorithm, we detected abnormal effective connectivity (EC) in the inferior occipital gyrus, MCC, Cerebelum_Crus1, and PoCG. Furthermore, correlations between disrupted FC/EC and clinical characteristics, especially tinnitus distress-related characteristics, were found in AT patients. CONCLUSIONS Our work demonstrated abnormal FC and EC between the frontostriatal network and several nonauditory regions in AT patients with hearing loss, suggesting that multiple large-scale network dysfunctions and interactions are involved in the perception of tinnitus. These findings not only enhance the current understanding of the frontostriatal network in tinnitus but also serve as a reminder of the importance of focusing on tinnitus at an early stage.
Collapse
Affiliation(s)
- Gang-Ping Zhou
- Department of Radiology, The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China
| | - Yu-Chen Chen
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu Province, China
| | - Wang-Wei Li
- Department of E.N.T., The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China
| | - Heng-Le Wei
- Department of Radiology, The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China
| | - Yu-Sheng Yu
- Department of Radiology, The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China
| | - Qing-Qing Zhou
- Department of Radiology, The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China
| | - Xindao Yin
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu Province, China
| | - Yue-Jin Tao
- Department of E.N.T., The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China.
| | - Hong Zhang
- Department of Radiology, The Affiliated Jiangning Hospital of Nanjing Medical University, No. 168, Gushan Road, Nanjing, 211100, Jiangsu Province, China.
| |
Collapse
|
6
|
Zimdahl JW, Thomas H, Bolland SJ, Leggett K, Barry KM, Rodger J, Mulders WHAM. Excitatory Repetitive Transcranial Magnetic Stimulation Over Prefrontal Cortex in a Guinea Pig Model Ameliorates Tinnitus. Front Neurosci 2021; 15:693935. [PMID: 34366777 PMCID: PMC8339289 DOI: 10.3389/fnins.2021.693935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/01/2021] [Indexed: 11/13/2022] Open
Abstract
Tinnitus, a phantom auditory perception that can seriously affect quality of life, is generally triggered by cochlear trauma and associated with aberrant activity throughout the auditory pathways, often referred to as hyperactivity. Studies suggest that non-auditory structures, such as prefrontal cortex (PFC), may be involved in tinnitus generation, by affecting sensory gating in auditory thalamus, allowing hyperactivity to reach the cortex and lead to perception. Indeed, human studies have shown that repetitive transcranial magnetic stimulation (rTMS) of PFC can alleviate tinnitus. The current study investigated whether this therapeutic effect is achieved through inhibition of thalamic hyperactivity, comparing effects of two common clinical rTMS protocols with sham treatment, in a guinea pig tinnitus model. Animals underwent acoustic trauma and once tinnitus developed were treated with either intermittent theta burst stimulation (iTBS), 20 Hz rTMS, or sham rTMS (10 days, 10 min/day; weekdays only). Tinnitus was reassessed and extracellular recordings of spontaneous tonic and burst firing rates in auditory thalamus made. To verify effects in PFC, densities of neurons positive for calcium-binding proteins, calbindin and parvalbumin, were investigated using immunohistochemistry. Both rTMS protocols significantly reduced tinnitus compared to sham. However, spontaneous tonic firing decreased following 20 Hz stimulation and increased following iTBS in auditory thalamus. Burst rate was significantly different between 20 Hz and iTBS stimulation, and burst duration was increased only after 20 Hz treatment. Density of calbindin, but not parvalbumin positive neurons, was significantly increased in the most dorsal region of PFC indicating that rTMS directly affected PFC. Our results support the involvement of PFC in tinnitus modulation, and the therapeutic benefit of rTMS on PFC in treating tinnitus, but indicate this is not achieved solely by suppression of thalamic hyperactivity.
Collapse
Affiliation(s)
- Jack W Zimdahl
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Harrison Thomas
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Samuel J Bolland
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Research, Crawley, WA, Australia
| | - Kerry Leggett
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Kristin M Barry
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Jennifer Rodger
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Research, Crawley, WA, Australia
| | | |
Collapse
|
7
|
Cook JA, Barry KM, Zimdahl JW, Leggett K, Mulders WHAM. Spontaneous firing patterns in the medial geniculate nucleus in a guinea pig model of tinnitus. Hear Res 2021; 403:108190. [PMID: 33556774 DOI: 10.1016/j.heares.2021.108190] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 01/21/2021] [Accepted: 01/27/2021] [Indexed: 12/14/2022]
Abstract
The mechanism of tinnitus, the perception of sound in the absence of acoustic stimulation, remains as yet unknown. It has been proposed that tinnitus is caused by altered spontaneous activity in the auditory pathway following cochlear damage in combination with inadequate gating at the level of the auditory thalamus, the medial geniculate nucleus (MGN). To investigate this further we made electrophysiological recordings in MGN of guinea pigs (n = 9) with and without tinnitus after acoustic trauma (continuous loud tone at 10 kHz, 124 dB SPL for 2 h). Parameters of interest were spontaneous tonic and burst firing. After acoustic trauma, 5 out of 9 guinea pigs developed signs of tinnitus as determined by the gap prepulse inhibition of acoustic startle. Spontaneous firing rates were significantly increased in the tinnitus animals as compared to the non-tinnitus animals and this change was specific to pure-tone responsive MGN neurons. However, burst firing parameters, including number of bursts per minute, burst duration, number of spikes in each burst, and percentage of spikes occurring in a burst, were not different between tinnitus and non-tinnitus animals. In addition, our data showed a strong dependence of spontaneous firing rates with heart rate, which implies that monitoring physiological status in animals is pertinent to obtaining reliable data when recording at higher levels of the auditory pathway. Our results suggest that increases in the tonic spontaneous fining rate of pure-tone responsive MGN neurons but not changes in burst firing parameters, are a robust neural signature of tinnitus in anaesthetised animals.
Collapse
Affiliation(s)
- J A Cook
- The Auditory laboratory, School of Human Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - K M Barry
- The Auditory laboratory, School of Human Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - J W Zimdahl
- The Auditory laboratory, School of Human Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - K Leggett
- The Auditory laboratory, School of Human Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - W H A M Mulders
- The Auditory laboratory, School of Human Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
| |
Collapse
|
8
|
Cai Y, Yu JG, Chen Y, Liu C, Xiao L, M Grais E, Zhao F, Lan L, Zeng S, Zeng J, Wu M, Su Y, Li Y, Zheng Y. Investigating the use of a two-stage attention-aware convolutional neural network for the automated diagnosis of otitis media from tympanic membrane images: a prediction model development and validation study. BMJ Open 2021; 11:e041139. [PMID: 33478963 PMCID: PMC7825258 DOI: 10.1136/bmjopen-2020-041139] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 12/18/2020] [Accepted: 12/28/2020] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES This study investigated the usefulness and performance of a two-stage attention-aware convolutional neural network (CNN) for the automated diagnosis of otitis media from tympanic membrane (TM) images. DESIGN A classification model development and validation study in ears with otitis media based on otoscopic TM images. Two commonly used CNNs were trained and evaluated on the dataset. On the basis of a Class Activation Map (CAM), a two-stage classification pipeline was developed to improve accuracy and reliability, and simulate an expert reading the TM images. SETTING AND PARTICIPANTS This is a retrospective study using otoendoscopic images obtained from the Department of Otorhinolaryngology in China. A dataset was generated with 6066 otoscopic images from 2022 participants comprising four kinds of TM images, that is, normal eardrum, otitis media with effusion (OME) and two stages of chronic suppurative otitis media (CSOM). RESULTS The proposed method achieved an overall accuracy of 93.4% using ResNet50 as the backbone network in a threefold cross-validation. The F1 Score of classification for normal images was 94.3%, and 96.8% for OME. There was a small difference between the active and inactive status of CSOM, achieving 91.7% and 82.4% F1 scores, respectively. The results demonstrate a classification performance equivalent to the diagnosis level of an associate professor in otolaryngology. CONCLUSIONS CNNs provide a useful and effective tool for the automated classification of TM images. In addition, having a weakly supervised method such as CAM can help the network focus on discriminative parts of the image and improve performance with a relatively small database. This two-stage method is beneficial to improve the accuracy of diagnosis of otitis media for junior otolaryngologists and physicians in other disciplines.
Collapse
Affiliation(s)
- Yuexin Cai
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Jin-Gang Yu
- Department of Automation Science and Engineering, South China University of Technology School, Guangzhou, Guangdong, China
| | - Yuebo Chen
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Chu Liu
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Lichao Xiao
- Department of Automation Science and Engineering, South China University of Technology School, Guangzhou, Guangdong, China
| | - Emad M Grais
- Centre for Speech and Language Therapy and Hearing Science, Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Fei Zhao
- Centre for Speech and Language Therapy and Hearing Science, Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - Liping Lan
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Shengxin Zeng
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Junbo Zeng
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Minjian Wu
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Yuejia Su
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Yuanqing Li
- Department of Automation Science and Engineering, South China University of Technology School, Guangzhou, Guangdong, China
| | - Yiqing Zheng
- Department of Otolaryngology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Institute of Hearing and Speech-Language Science, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| |
Collapse
|
9
|
Barry KM, Robertson D, Mulders WHAM. Changes in Prefrontal Cortex-Thalamic Circuitry after Acoustic Trauma. Biomedicines 2021; 9:biomedicines9010077. [PMID: 33466899 PMCID: PMC7829915 DOI: 10.3390/biomedicines9010077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 11/16/2022] Open
Abstract
In the adult auditory system, loss of input resulting from peripheral deafferentation is well known to lead to plasticity in the central nervous system, manifested as reorganization of cortical maps and altered activity throughout the central auditory pathways. The auditory system also has strong afferent and efferent connections with cortico-limbic circuitry including the prefrontal cortex and the question arises whether this circuitry is also affected by loss of peripheral input. Recent studies in our laboratory showed that PFC activation can modulate activity of the auditory thalamus or medial geniculate nucleus (MGN) in normal hearing rats. In addition, we have shown in rats that cochlear trauma resulted in altered spontaneous burst firing in MGN. However, whether the PFC influence on MGN is changed after cochlear trauma is unknown. We investigated the effects of electrical stimulation of PFC on single neuron activity in the MGN in anaesthetized Wistar rats 2 weeks after acoustic trauma or sham surgery. Electrical stimulation of PFC showed a variety of effects in MGN neurons both in sham and acoustic trauma groups but inhibitory responses were significantly larger in the acoustic trauma animals. These results suggest an alteration in functional connectivity between PFC and MGN after cochlear trauma. This change may be a compensatory mechanism increasing sensory gating after the development of altered spontaneous activity in MGN, to prevent altered activity reaching the cortex and conscious perception.
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Auditory fear conditioning alters neural gain in the cochlear nucleus: a wireless neural recording study in freely behaving rats. Neuronal Signal 2020; 4:NS20200009. [PMID: 33274069 PMCID: PMC7681204 DOI: 10.1042/ns20200009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022] Open
Abstract
Anxiety disorders involve distorted perception of the world including increased saliency of stress-associated cues. However, plasticity in the initial sensory regions of the brain following a fearful experience has never been examined. The cochlear nucleus (CN) is the first station in the central auditory system, with heterogeneous collections of neurons that not only project to but also receive projections from cortico-limbic regions, suggesting a potential for experience-dependent plasticity. Using wireless neural recordings in freely behaving rats, we demonstrate for the first time that neural gain in the CN is significantly altered by fear conditioning to auditory sequences. Specifically, the ventral subnuclei significantly increased firing rate to the conditioned tone sequence, while the dorsal subnuclei significantly decreased firing rate during the conditioning session overall. These findings suggest subregion-specific changes in the balance of inhibition and excitation in the CN as a result of conditioning experience. Heart rate was measured as the conditioned response (CR), which showed that while pre-conditioned stimulus (CS) responding did not change across baseline and conditioning sessions, significant changes in heart rate were observed to the tone sequence followed by shock. Heart-rate findings support acquisition of conditioned fear. Taken together, the present study presents first evidence for potential experience-dependent changes in auditory perception that involve novel plasticity within the first site of processing auditory information in the brain.
Collapse
|
12
|
Liu Y, Alkharabsheh A, Sun W. Hyperexcitability of the Nucleus Accumbens Is Involved in Noise-Induced Hyperacusis. Neural Plast 2020; 2020:8814858. [PMID: 33293947 PMCID: PMC7714561 DOI: 10.1155/2020/8814858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 10/18/2020] [Accepted: 11/12/2020] [Indexed: 11/18/2022] Open
Abstract
Reduced tolerance to sound stimuli (hyperacusis) is commonly seen in tinnitus patients. Dysfunction of limbic systems, such as the nucleus accumbens (NAc), may be involved in emotional reactions to the sound stimuli in tinnitus patients. To study the functional changes in the NAc in hyperacusis, we have examined the neural activity changes of the NAc using c-Fos staining in an animal model of hyperacusis. The c-Fos staining was also examined in the medial geniculate nucleus (MGN), a central auditory pathway which has neural projections to the NAc. Postnatal rats (14 days) were exposed to loud noise (115 dB SPL, 4 hours for two consecutive days) to induce hyperacusis (n = 4). Rats without noise exposure were used as the controls (n = 4). After P35, rats in both groups were put in a behavioral training for sound detection. After they were trained to detect sound stimuli, their reaction time to noise bursts centered at 2 kHz (40-110 dB SPL) was measured. Rats in the noise group showed a significantly shorter reaction time than those in the control group to the noise bursts at high intensities, suggesting the noise exposure induced hyperacusis behavior. The c-Fos expressions in the NAc and the MGNs of the noise group were significantly higher than those of the control group. Our results suggested that early-age noise exposure caused hyperactivity in the NAc and the MGNs which may induce the loudness increase in these rats.
Collapse
Affiliation(s)
- Yuying Liu
- Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 100 Haining Road, Shanghai, China 200080
| | - Ana''am Alkharabsheh
- Department of Hearing and Speech Sciences, University of Jordan, Queen Rania Al Abdallah St., Amman, Jordan 11942
| | - Wei Sun
- Department of Communicative Disorders and Sciences, Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| |
Collapse
|
13
|
Xu JJ, Cui J, Feng Y, Yong W, Chen H, Chen YC, Yin X, Wu Y. Chronic Tinnitus Exhibits Bidirectional Functional Dysconnectivity in Frontostriatal Circuit. Front Neurosci 2019; 13:1299. [PMID: 31866810 PMCID: PMC6909243 DOI: 10.3389/fnins.2019.01299] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/20/2019] [Indexed: 12/28/2022] Open
Abstract
Purpose The phantom sound of tinnitus is considered to be associated with abnormal functional coupling between the nucleus accumbens (NAc) and the prefrontal cortex, which may form a frontostriatal top-down gating system to evaluate and modulate sensory signals. Resting-state functional magnetic resonance imaging (fMRI) was used to recognize the aberrant directional connectivity of the NAc in chronic tinnitus and to ascertain the relationship between this connectivity and tinnitus characteristics. Methods Participants included chronic tinnitus patients (n = 50) and healthy controls (n = 55), matched for age, sex, education, and hearing thresholds. The hearing status of both groups was comparable. On the basis of the NAc as a seed region, a Granger causality analysis (GCA) study was conducted to investigate the directional connectivity and the relationship with tinnitus duration or distress. Results Compared with healthy controls, tinnitus patients exhibited abnormal directional connectivity between the NAc and the prefrontal cortex, principally the middle frontal gyrus (MFG), orbitofrontal cortex (OFC), and inferior frontal gyrus (IFG). Additionally, positive correlations between tinnitus handicap questionnaire (THQ) scores and increased directional connectivity from the right NAc to the left MFG (r = 0.357, p = 0.015) and from the right MFG to the left NAc (r = 0.626, p < 0.001) were observed. Furthermore, the enhanced directional connectivity from the right NAc to the right OFC was positively associated with the duration of tinnitus (r = 0.599, p < 0.001). Conclusion In concurrence with expectations, tinnitus distress was correlated with enhanced directional connectivity between the NAc and the prefrontal cortex. The current study not only helps illuminate the neural basis of the frontostriatal gating control of tinnitus sensation but also contributes to deciphering the neuropathological features of tinnitus.
Collapse
Affiliation(s)
- Jin-Jing Xu
- Department of Otolaryngology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Jinluan Cui
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yuan Feng
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Wei Yong
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Huiyou Chen
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yu-Chen Chen
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Xindao Yin
- Department of Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yuanqing Wu
- Department of Otolaryngology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| |
Collapse
|
14
|
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: 74] [Impact Index Per Article: 14.8] [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.
Collapse
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
| |
Collapse
|
15
|
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]
|
16
|
van Zwieten G, Janssen MLF, Smit JV, Janssen AML, Roet M, Jahanshahi A, Stokroos RJ, Temel Y. Inhibition of Experimental Tinnitus With High Frequency Stimulation of the Rat Medial Geniculate Body. Neuromodulation 2018; 22:416-424. [PMID: 30102446 PMCID: PMC6618158 DOI: 10.1111/ner.12795] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/28/2018] [Accepted: 05/02/2018] [Indexed: 12/24/2022]
Abstract
BACKGROUND Neuromodulation is a promising treatment modality for tinnitus, especially in chronic and severe cases. The auditory thalamus plays a key role in the pathophysiology of tinnitus, as it integrates and processes auditory and limbic information. OBJECTIVE The effect of high frequency stimulation and low frequency stimulation of the medial geniculate bodies on tinnitus in a noise-induced tinnitus rat model is assessed. MATERIALS AND METHODS Presence of tinnitus was verified using the gap-induced prepulse inhibition of the acoustic startle response paradigm. Hearing thresholds were determined before and after noise trauma with auditory brainstem responses. Anxiety-related side-effects were evaluated in the elevated zero maze and open field. RESULTS Results show tinnitus development after noise exposure and preserved hearing thresholds of the ear that was protected from noise trauma. We found that high frequency stimulation of the medial geniculate bodies suppressed tinnitus. This effect maintained directly after stimulation when the stimulator was turned off. Low frequency stimulation did not have any effects on the gap:no-gap ratio of the acoustic startle response. CONCLUSION High frequency stimulation of the MGB has a direct and residual suppressing effect on tinnitus in this animal model. Low frequency stimulation of the MGB did not inhibit tinnitus.
Collapse
Affiliation(s)
- Gusta van Zwieten
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Marcus L F Janssen
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurology and Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jasper V Smit
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A Miranda L Janssen
- Department of Ear Nose and Throat/Head and Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Methodology and Statistics, School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands
| | - Milaine Roet
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ali Jahanshahi
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Robert J Stokroos
- Department of Ear Nose and Throat/Head and Neck Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Yasin Temel
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| |
Collapse
|
17
|
Barry K, Robertson D, Mulders W. Medial geniculate neurons show diverse effects in response to electrical stimulation of prefrontal cortex. Hear Res 2017; 353:204-212. [DOI: 10.1016/j.heares.2017.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/07/2017] [Accepted: 07/06/2017] [Indexed: 01/04/2023]
|