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Dai Q, Qu T, Shen G, Wang H. Characterization of the neural circuitry of the auditory thalamic reticular nucleus and its potential role in salicylate-induced tinnitus. Front Neurosci 2024; 18:1368816. [PMID: 38629053 PMCID: PMC11019010 DOI: 10.3389/fnins.2024.1368816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
Introduction Subjective tinnitus, the perception of sound without an external acoustic source, is often subsequent to noise-induced hearing loss or ototoxic medications. The condition is believed to result from neuroplastic alterations in the auditory centers, characterized by heightened spontaneous neural activities and increased synchrony due to an imbalance between excitation and inhibition. However, the role of the thalamic reticular nucleus (TRN), a structure composed exclusively of GABAergic neurons involved in thalamocortical oscillations, in the pathogenesis of tinnitus remains largely unexplored. Methods We induced tinnitus in mice using sodium salicylate and assessed tinnitus-like behaviors using the Gap Pre-Pulse Inhibition of the Acoustic Startle (GPIAS) paradigm. We utilized combined viral tracing techniques to identify the neural circuitry involved and employed immunofluorescence and confocal imaging to determine cell types and activated neurons. Results Salicylate-treated mice exhibited tinnitus-like behaviors. Our tracing clearly delineated the inputs and outputs of the auditory-specific TRN. We discovered that chemogenetic activation of the auditory TRN significantly reduced the salicylate-evoked rise in c-Fos expression in the auditory cortex. Discussion This finding posits the TRN as a potential modulatory target for tinnitus treatment. Furthermore, the mapped sensory inputs to the auditory TRN suggest possibilities for employing optogenetic or sensory stimulations to manipulate thalamocortical activities. The precise mapping of the auditory TRN-mediated neural pathways offers a promising avenue for designing targeted interventions to alleviate tinnitus symptoms.
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Affiliation(s)
| | | | - Guoming Shen
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Haitao Wang
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
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Peng X, Mao Y, Liu Y, Dai Q, Tai Y, Luo B, Liang Y, Guan R, Zhou W, Chen L, Zhang Z, Shen G, Wang H. Microglial activation in the lateral amygdala promotes anxiety-like behaviors in mice with chronic moderate noise exposure. CNS Neurosci Ther 2024; 30:e14674. [PMID: 38468130 PMCID: PMC10927919 DOI: 10.1111/cns.14674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 01/26/2024] [Accepted: 02/24/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Long-term non-traumatic noise exposure, such as heavy traffic noise, can elicit emotional disorders in humans. However, the underlying neural substrate is still poorly understood. METHODS We exposed mice to moderate white noise for 28 days to induce anxiety-like behaviors, measured by open-field, elevated plus maze, and light-dark box tests. In vivo multi-electrode recordings in awake mice were used to examine neuronal activity. Chemogenetics were used to silence specific brain regions. Viral tracing, immunofluorescence, and confocal imaging were applied to define the neural circuit and characterize the morphology of microglia. RESULTS Exposure to moderate noise for 28 days at an 85-dB sound pressure level resulted in anxiety-like behaviors in open-field, elevated plus maze, and light-dark box tests. Viral tracing revealed that fibers projecting from the auditory cortex and auditory thalamus terminate in the lateral amygdala (LA). A noise-induced increase in spontaneous firing rates of the LA and blockade of noise-evoked anxiety-like behaviors by chemogenetic inhibition of LA glutamatergic neurons together confirmed that the LA plays a critical role in noise-induced anxiety. Noise-exposed animals were more vulnerable to anxiety induced by acute noise stressors than control mice. In addition to these behavioral abnormalities, ionized calcium-binding adaptor molecule 1 (Iba-1)-positive microglia in the LA underwent corresponding morphological modifications, including reduced process length and branching and increased soma size following noise exposure. Treatment with minocycline to suppress microglia inhibited noise-associated changes in microglial morphology, neuronal electrophysiological activity, and behavioral changes. Furthermore, microglia-mediated synaptic phagocytosis favored inhibitory synapses, which can cause an imbalance between excitation and inhibition, leading to anxiety-like behaviors. CONCLUSIONS Our study identifies LA microglial activation as a critical mediator of noise-induced anxiety-like behaviors, leading to neuronal and behavioral changes through selective synapse phagocytosis. Our results highlight the pivotal but previously unrecognized roles of LA microglia in chronic moderate noise-induced behavioral changes.
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Affiliation(s)
- Xiaoqi Peng
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Yunfeng Mao
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Yehao Liu
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
| | - Qian Dai
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
| | - Yingju Tai
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Bin Luo
- Auditory Research Laboratory, Department of Neurobiology and Biophysics, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
- Department of PsychiatryThe First Affiliated Hospital of USTCHefeiChina
| | - Yue Liang
- Department of OtolaryngologyThe First Affiliated Hospital of USTCHefeiChina
| | - Ruirui Guan
- Department of OtolaryngologyThe First Affiliated Hospital of USTCHefeiChina
| | - Wenjie Zhou
- Songjiang Research InstituteShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Lin Chen
- Auditory Research Laboratory, Department of Neurobiology and Biophysics, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Zhi Zhang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Guoming Shen
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
| | - Haitao Wang
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
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Jelinek J, Johne M, Alam M, Krauss JK, Kral A, Schwabe K. Hearing loss in juvenile rats leads to excessive play fighting and hyperactivity, mild cognitive deficits and altered neuronal activity in the prefrontal cortex. CURRENT RESEARCH IN NEUROBIOLOGY 2024; 6:100124. [PMID: 38616957 PMCID: PMC11015060 DOI: 10.1016/j.crneur.2024.100124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/23/2023] [Accepted: 12/29/2023] [Indexed: 04/16/2024] Open
Abstract
Background In children, hearing loss has been associated with hyperactivity, disturbed social interaction, and risk of cognitive disturbances. Mechanistic explanations of these relations sometimes involve language. To investigate the effect of hearing loss on behavioral deficits in the absence of language, we tested the impact of hearing loss in juvenile rats on motor, social, and cognitive behavior and on physiology of prefrontal cortex. Methods Hearing loss was induced in juvenile (postnatal day 14) male Sprague-Dawley rats by intracochlear injection of neomycin under general anesthesia. Sham-operated and non-operated hearing rats served as controls. One week after surgery auditory brainstem response (ABR) measurements verified hearing loss or intact hearing in sham-operated and non-operated controls. All rats were then tested for locomotor activity (open field), coordination (Rotarod), and for social interaction during development in weeks 1, 2, 4, 8, 16, and 24 after surgery. From week 8 on, rats were trained and tested for spatial learning and memory (4-arm baited 8-arm radial maze test). In a final setting, neuronal activity was recorded in the medial prefrontal cortex (mPFC). Results In the open field deafened rats moved faster and covered more distance than sham-operated and non-operated controls from week 8 on (both p < 0.05). Deafened rats showed significantly more play fighting during development (p < 0.05), whereas other aspects of social interaction, such as following, were not affected. Learning of the radial maze test was not impaired in deafened rats (p > 0.05), but rats used less next-arm entries than other groups indicating impaired concept learning (p < 0.05). In the mPFC neuronal firing rate was reduced and enhanced irregular firing was observed. Moreover, oscillatory activity was altered, both within the mPFC and in coherence of mPFC with the somatosensory cortex (p < 0.05). Conclusions Hearing loss in juvenile rats leads to hyperactive behavior and pronounced play-fighting during development, suggesting a causal relationship between hearing loss and cognitive development. Altered neuronal activities in the mPFC after hearing loss support such effects on neuronal networks outside the central auditory system. This animal model provides evidence of developmental consequences of juvenile hearing loss on prefrontal cortex in absence of language as potential confounding factor.
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Affiliation(s)
- Jonas Jelinek
- Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Marie Johne
- Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Cluster of Excellence Hearing4all, German Research Foundation, Hannover, Germany
| | - Mesbah Alam
- Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Joachim K. Krauss
- Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Andrej Kral
- Cluster of Excellence Hearing4all, German Research Foundation, Hannover, Germany
- Institute of AudioNeuroTechnology, Hannover Medical School, Stadtfelddamm 34, 30625, Hanover, Germany
- Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Stadtfelddamm 34, 30625, Hannover, Germany
| | - Kerstin Schwabe
- Department of Neurosurgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Cluster of Excellence Hearing4all, German Research Foundation, Hannover, Germany
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Peng X, Mao Y, Tai Y, Luo B, Dai Q, Wang X, Wang H, Liang Y, Guan R, Liu C, Guo Y, Chen L, Zhang Z, Wang H. Characterization of Anxiety-Like Behaviors and Neural Circuitry following Chronic Moderate Noise Exposure in Mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2023; 131:107004. [PMID: 37796530 PMCID: PMC10552915 DOI: 10.1289/ehp12532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 08/13/2023] [Accepted: 09/06/2023] [Indexed: 10/06/2023]
Abstract
BACKGROUND Commonly encountered nontraumatic, moderate noise is increasingly implicated in anxiety; however, the neural substrates underlying this process remain unclear. OBJECTIVES We investigated the neural circuit mechanism through which chronic exposure to moderate-level noise causes anxiety-like behaviors. METHODS Mice were exposed to chronic, moderate white noise [85 decibel (dB) sound pressure level (SPL)], 4 h/d for 4 wk to induce anxiety-like behaviors, which were assessed by open field, elevated plus maze, light-dark box, and social interaction tests. Viral tracing, immunofluorescence confocal imaging, and brain slice patch-clamp recordings were used to characterize projections from auditory brain regions to the lateral amygdala. Neuronal activities were characterized by in vivo multielectrode and fiber photometry recordings in awake mice. Optogenetics and chemogenetics were used to manipulate specific neural circuitry. RESULTS Mice chronically (4 wk) exposed to moderate noise (85 dB SPL, 4 h/d) demonstrated greater neuronal activity in the lateral amygdala (LA), and the LA played a critical role in noise-induced anxiety-like behavior in these model mice. Viral tracing showed that the LA received monosynaptic projections from the medial geniculate body (MG) and auditory cortex (ACx). Optogenetic excitation of the MG → LA or ACx → LA circuits acutely evoked anxiety-like behaviors, whereas their chemogenetic inactivation abolished noise-induced anxiety-like behavior. Moreover, mice chronically exposed to moderate noise were more susceptible to acute stress, with more neuronal firing in the LA, even after noise withdrawal. DISCUSSION Mice exposed to 4 wk of moderate noise (85 dB SPL, 4 h/d) demonstrated behavioral and physiological differences compared to controls. The neural circuit mechanisms involved greater excitation from glutamatergic neurons of the MG and ACx to LA neurons under chronic, moderate noise exposure, which ultimately promoted anxiety-like behaviors. Our findings support the hypothesis that nontraumatic noise pollution is a potentially serious but unrecognized public health concern. https://doi.org/10.1289/EHP12532.
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Affiliation(s)
- Xiaoqi Peng
- Department of Anesthesiology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yunfeng Mao
- Department of Anesthesiology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yingju Tai
- Department of Anesthesiology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Bin Luo
- Auditory Research Laboratory, Department of Neurobiology and Biophysics, Division of Life Sciences and Medicine, USTC, Hefei, China
- Department of Psychiatry, The First Affiliated Hospital of USTC, Hefei, China
| | - Qian Dai
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Xiyang Wang
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Hao Wang
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Yue Liang
- Department of Otolaryngology, The First Affiliated Hospital of USTC, Hefei, China
| | - Ruirui Guan
- Department of Otolaryngology, The First Affiliated Hospital of USTC, Hefei, China
| | - Chunhua Liu
- Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Yiping Guo
- Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Lin Chen
- Auditory Research Laboratory, Department of Neurobiology and Biophysics, Division of Life Sciences and Medicine, USTC, Hefei, China
| | - Zhi Zhang
- Department of Anesthesiology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Haitao Wang
- Department of Anesthesiology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
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Self-Directed Neurofeedback Treatment for Subjective Tinnitus Patients Evaluated by Multimodal Functional Imaging. Neural Plast 2022; 2022:5114721. [PMID: 36304208 PMCID: PMC9596274 DOI: 10.1155/2022/5114721] [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: 01/17/2022] [Revised: 09/13/2022] [Accepted: 09/24/2022] [Indexed: 11/17/2022] Open
Abstract
Neurofeedback (NFB) is a relatively novel approach to the treatment of tinnitus, and prior studies have demonstrated that the increases in alpha activity rather than reduced delta power seem to drive these NFB-related improvements in tinnitus symptoms. The present study was therefore designed to explore whether the implementation of an alpha training protocol with a portable neurofeedback apparatus would achieve improvements in tinnitus patient symptoms. In this study, 38 tinnitus patients underwent NFB training while 18 were enrolled in a control group. The study was single-blinded such that only participants were not aware of their group assignments. Those in the NFB group underwent 15 NFB training sessions over 5 weeks, in addition to pre- and posttraining tests including the Tinnitus Handicap Inventory (THI), Tinnitus Handicap Questionnaire (THQ), visual analog scales (VAS), electroencephalography (EEG), and functional magnetic resonance imaging (fMRI). Our result find that when the THI, THQ, and VAS scores of patients in the two groups were assessed after a 5-week training period, these scores were unchanged in control patients whereas they had significantly improved in the NFB group patients. EEG analyses revealed that the alpha band was increased in the occipital lobe following NFB treatment, while fMRI indicated an increase in regional homogeneity (ReHo) in the right frontal lobe of patients in the NFB group after treatment that was negatively correlated with THI and VAS scores. The results of this analysis indicate that alpha NFB training can be effectively used to reduce tinnitus-related distress and sound perception in patients.
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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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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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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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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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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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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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