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The Effect of Noise Trauma and Deep Brain Stimulation of the Medial Geniculate Body on Tissue Activity in the Auditory Pathway. Brain Sci 2022; 12:brainsci12081099. [PMID: 36009162 PMCID: PMC9405782 DOI: 10.3390/brainsci12081099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/08/2022] [Accepted: 08/15/2022] [Indexed: 11/17/2022] Open
Abstract
Tinnitus is defined as the phantom perception of sound. To date, there is no curative treatment, and contemporary treatments have failed to show beneficial outcomes. Deep brain stimulation has been suggested as a potential therapy for refractory tinnitus. However, the optimal target and stimulation regimens remain to be defined. Herein, we investigated metabolic and neuronal activity changes using cytochrome C oxidase histochemistry and c-Fos immunohistochemistry in a noise trauma-induced rat model of tinnitus. We also assessed changes in neuronal activity following medial geniculate body (MGB) high-frequency stimulation (HFS). Metabolic activity was reduced in the primary auditory cortex, MGB and CA1 region of the hippocampus in noise-exposed rats. Additionally, c-Fos expression was increased in the primary auditory cortex of those animals. Furthermore, MGB-HFS enhanced c-Fos expression in the thalamic reticular nucleus. We concluded that noise trauma alters tissue activity in multiple brain areas including the auditory and limbic regions. MGB-HFS resulted in higher neuronal activity in the thalamic reticular nucleus. Given the prominent role of the auditory thalamus in tinnitus, these data provide more rationales towards targeting the MGB with HFS as a symptom management tool in tinnitus.
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2
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郭 晓, 王 斌, 曹 克, 高 志, 魏 朝. [Analysis of intraoperative EABR characteristics and postoperative efficacy of cochlear implant in patients with tinnitus]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2022; 36:423-428. [PMID: 35822359 PMCID: PMC10128491 DOI: 10.13201/j.issn.2096-7993.2022.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Objective:To investigate the characteristics of intraoperative electrically stimulated auditory brainstem responses(EABR) in patients with neural deafness and tinnitus, and to analyze the inhibitory effect of cochlear implantation on tinnitus and its correlation with auditory evoked potential. Methods:Twenty-eight adult patients with neuronal deafness accompanied by tinnitus who underwent cochlear implant surgery in the Peking Union Medical College Hospital from 2014 to 2015 were selected, and 10 age-matched patients without tinnitus with the same age were selected as the control group. Preoperative audiology, imaging and tinnitus history of the patients were retrospectively analyzed. During the operation, EABR were used to detect the auditory central functions at all levels, and the electrophysiological characteristics of the two groups were analyzed. The tinnitus handicap inventory(THI) was used to evaluate the severity of tinnitus before and after surgery, and the correlation between EABR results and THI score was analyzed. Results:There were no postoperative complications such as facial paralysis, cerebrospinal fluid leakage, meningitis, etc. , and electroacoustic reactions were observed in all 38 patients. The results of intraoperative EABR showed that there were significant differences in Ⅲ wave amplitude, Ⅴ wave amplitude and Ⅴ wave latency between tinnitus group and control group(P<0.05). The mean C value of (162.78± 24.57)CL and the mean intraoperative EABR threshold of (158.62± 10.31) CL were collected in the two groups 12 months after starting the machine, and there was a significant correlation according to linear correlation analysis(r=0.903, P<0.01). The total THI scores of 28 tinnitus patients were 65.00±14.93, 55.00±15.93 and 36.00±21.02 at three time points before, 1 day after and 1 year after cochlear implantation, respectively. The scores of 1 year after cochlear implantation were significantly different by ANOVA(P<0.05), but there was no statistically significant difference 1 day after operation(P>0.05). There was significant correlation between the intraoperative EABR wave Ⅲ amplitude and the linear correlation analysis of THI changes 1 year after operation(r=0.873, P<0.05). Conclusion:There is significant difference in intraoperative EABR between patients with neural deafness accompanied with tinnitus and patients without tinnitus. Cochlear electrical stimulation has a good inhibitory effect on tinnitus, and intraoperative EABR can be used as a objective assessment tool for cochlear implant to inhibit tinnitus.
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Affiliation(s)
- 晓会 郭
- 解放军总医院第三医学中心眼科医学部(北京,100853)Senior Department of Ophthalmology, the Third Medical Center of PLA General Hospital, Beijing, 100853, China
| | - 斌 王
- 中国医学科学院北京协和医院耳鼻喉科Department of Otolaryngology, the Peking Union Medical College Hospital
| | - 克利 曹
- 中国医学科学院北京协和医院耳鼻喉科Department of Otolaryngology, the Peking Union Medical College Hospital
| | - 志强 高
- 中国医学科学院北京协和医院耳鼻喉科Department of Otolaryngology, the Peking Union Medical College Hospital
| | - 朝刚 魏
- 北京大学第一医院耳鼻咽喉头颈外科Department of Otolaryngology Head and Neck Surgery, Peking University First Hospital
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Malfatti T, Ciralli B, Hilscher MM, Leao RN, Leao KE. Decreasing dorsal cochlear nucleus activity ameliorates noise-induced tinnitus perception in mice. BMC Biol 2022; 20:102. [PMID: 35550106 PMCID: PMC9097071 DOI: 10.1186/s12915-022-01288-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 03/30/2022] [Indexed: 01/05/2023] Open
Abstract
Background The dorsal cochlear nucleus (DCN) is a region known to integrate somatosensory and auditory inputs and is identified as a potential key structure in the generation of phantom sound perception, especially noise-induced tinnitus. Yet, how altered homeostatic plasticity of the DCN induces and maintains the sensation of tinnitus is not clear. Here, we chemogenetically decrease activity of a subgroup of DCN neurons, Ca2+/Calmodulin kinase 2 α (CaMKII α)-positive DCN neurons, using Gi-coupled human M4 Designer Receptors Exclusively Activated by Designer Drugs (hM4Di DREADDs), to investigate their role in noise-induced tinnitus. Results Mice were exposed to loud noise (9–11kHz, 90dBSPL, 1h, followed by 2h of silence), and auditory brainstem responses (ABRs) and gap prepulse inhibition of acoustic startle (GPIAS) were recorded 2 days before and 2 weeks after noise exposure to identify animals with a significantly decreased inhibition of startle, indicating tinnitus but without permanent hearing loss. Neuronal activity of CaMKII α+ neurons expressing hM4Di in the DCN was lowered by administration of clozapine-N-oxide (CNO). We found that acutely decreasing firing rate of CaMKII α+ DCN units decrease tinnitus-like responses (p = 3e −3, n = 11 mice), compared to the control group that showed no improvement in GPIAS (control virus; CaMKII α-YFP + CNO, p = 0.696, n = 7 mice). Extracellular recordings confirmed CNO to decrease unit firing frequency of CaMKII α-hM4Di+ mice and alter best frequency and tuning width of response to sound. However, these effects were not seen if CNO had been previously administered during the noise exposure (n = 6 experimental and 6 control mice). Conclusion We found that lowering DCN activity in mice displaying tinnitus-related behavior reduces tinnitus, but lowering DCN activity during noise exposure does not prevent noise-induced tinnitus. Our results suggest that CaMKII α-positive cells in the DCN are not crucial for tinnitus induction but play a significant role in maintaining tinnitus perception in mice. Supplementary Information The online version contains supplementary material available at (10.1186/s12915-022-01288-1).
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Affiliation(s)
- Thawann Malfatti
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Barbara Ciralli
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Markus M Hilscher
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Richardson N Leao
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Katarina E Leao
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil.
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4
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Devos JVP, Temel Y, Ackermans L, Visser-Vandewalle V, Onur OA, Schruers K, Smit J, Janssen MLF. Methodological Considerations for Setting Up Deep Brain Stimulation Studies for New Indications. J Clin Med 2022; 11:jcm11030696. [PMID: 35160153 PMCID: PMC8836606 DOI: 10.3390/jcm11030696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 11/29/2022] Open
Abstract
Deep brain stimulation (DBS) is a neurosurgical treatment with a growing range of indications. The number of clinical studies is expanding because of DBS for new indications and efforts to improve DBS for existing indications. To date, various methods have been used to perform DBS studies. Designing a clinical intervention study with active implantable medical devices has specific challenges while expanding patient treatment. This paper provides an overview of the key aspects that are essential for setting up a DBS study.
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Affiliation(s)
- Jana V. P. Devos
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Ear, Nose, Throat, Head and Neck Surgery, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
- Correspondence: (J.V.P.D.); (Y.T.)
| | - Yasin Temel
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
- Correspondence: (J.V.P.D.); (Y.T.)
| | - Linda Ackermans
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
| | - Veerle Visser-Vandewalle
- Department of Stereotactic and Functional Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany;
| | - Oezguer A. Onur
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany;
| | - Koen Schruers
- Department of Psychiatry and Neuropsychology, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands;
| | - Jasper Smit
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Ear, Nose, Throat, Head and Neck Surgery, Zuyderland Medical Center, 6419 PC Heerlen, The Netherlands
| | - Marcus L. F. Janssen
- School for Mental Health and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands; (L.A.); (J.S.); (M.L.F.J.)
- Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht University, 6229 HX Maastricht, The Netherlands
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5
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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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6
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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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7
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Saeed S, Khan QU. The Pathological Mechanisms and Treatments of Tinnitus. Discoveries (Craiova) 2021; 9:e137. [PMID: 35350720 PMCID: PMC8956333 DOI: 10.15190/d.2021.16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/21/2021] [Accepted: 09/30/2021] [Indexed: 11/22/2022] Open
Abstract
Tinnitus is defined as the ringing, hissing, clicking or roaring sounds an individual consciously perceives in the absence of an external auditory stimulus. Currently, the literature on the mechanism of tinnitus pathology is multifaceted, ranging from tinnitus generation at the cellular level to its perception at the system level. Cellular level mechanisms include increased neuronal synchrony, neurotransmission changes and maladaptive plasticity. At the system level, the role of auditory structures, non-auditory structures, changes in the functional connectivities in higher regions and tinnitus networks have been investigated. The exploration of all these mechanisms creates a holistic view on understanding the changes the pathophysiology of tinnitus undertakes. Although tinnitus percept may start at the level of cochlear nerve deafferentation, the neuronal changes in the central auditory system to the neuronal and connectivity changes in non-auditory regions, such as the limbic system, become cardinal in chronic tinnitus generation. At the present moment, some tinnitus generation mechanisms are well established (e.g., increased neuronal synchrony) whereas other mechanisms have gained more traction recently (e.g., tinnitus networks, tinnitus-distress networks) and therefore, require additional investigation to solidify their role in tinnitus pathology.
The treatments and therapeutics designed for tinnitus are numerous, with varied levels of success. They are generally two-fold: some treatments focus on tinnitus cessation (including cochlear implants, deep brain stimulation, transcranial direct current stimulation and transcranial magnetic stimulation) whereas the other set focuses on tinnitus reduction or masking (including hearing aids, sound therapy, cognitive behavioral therapy, tinnitus retraining therapy, and tailor made notched musical training). Tinnitus management has focused on implementing tinnitus masking/reducing therapies more than tinnitus cessation, since cessation treatments are still lacking in streamlined treatment protocols and long-term sustainability and efficacy of the treatment.
This review will focus on concisely exploring the current and most relevant tinnitus pathophysiology mechanisms, treatments and therapeutics.
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Affiliation(s)
- Sana Saeed
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
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Different Neurogenic Potential in the Subnuclei of the Postnatal Rat Cochlear Nucleus. Stem Cells Int 2021; 2021:8871308. [PMID: 33880121 PMCID: PMC8046557 DOI: 10.1155/2021/8871308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 02/03/2021] [Accepted: 03/12/2021] [Indexed: 11/17/2022] Open
Abstract
In patients suffering from hearing loss, the reduced or absent neural input induces morphological changes in the cochlear nucleus (CN). Neural stem cells have recently been identified in this first auditory relay. Afferent nerve signals and their impact on the immanent neural stem and progenitor cells already impinge upon the survival of early postnatal cells within the CN. This auditory brainstem nucleus consists of three different subnuclei: the anteroventral cochlear nucleus (AVCN), the posteroventral cochlear nucleus (PVCN), and the dorsal cochlear nucleus (DCN). Since these subdivisions differ ontogenetically and physiologically, the question arose whether regional differences exist in the neurogenic niche. CN from postnatal day nine Sprague-Dawley rats were microscopically dissected into their subnuclei and cultivated in vitro as free-floating cell cultures and as whole-mount organ cultures. In addition to cell quantifications, immunocytological and immunohistological studies of the propagated cells and organ preparations were performed. The PVCN part showed the highest mitotic potential, while the AVCN and DCN had comparable activity. Specific stem cell markers and the ability to differentiate into cells of the neural lineage were detected in all three compartments. The present study shows that in all subnuclei of rat CN, there is a postnatal neural stem cell niche, which, however, differs significantly in its potential. The results can be explained by the origin from different regions in the rhombic lip, the species, and the various analysis techniques applied. In conclusion, the presented results provide further insight into the neurogenic potential of the CN, which may prove beneficial for the development of new regenerative strategies for hearing loss.
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9
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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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10
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Domarecka E, Olze H, Szczepek AJ. Auditory Brainstem Responses (ABR) of Rats during Experimentally Induced Tinnitus: Literature Review. Brain Sci 2020; 10:brainsci10120901. [PMID: 33255266 PMCID: PMC7760291 DOI: 10.3390/brainsci10120901] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/16/2020] [Accepted: 11/21/2020] [Indexed: 12/31/2022] Open
Abstract
Tinnitus is a subjective phantom sound perceived only by the affected person and a symptom of various auditory and non-auditory conditions. The majority of methods used in clinical and basic research for tinnitus diagnosis are subjective. To better understand tinnitus-associated changes in the auditory system, an objective technique measuring auditory sensitivity-the auditory brainstem responses (ABR)-has been suggested. Therefore, the present review aimed to summarize ABR's features in a rat model during experimentally induced tinnitus. PubMed, Web of Science, Science Direct, and Scopus databanks were searched using Medical Subject Heading (MeSH) terms: auditory brainstem response, tinnitus, rat. The search identified 344 articles, and 36 of them were selected for the full-text analyses. The experimental protocols and results were evaluated, and the gained knowledge was synthesized. A high level of heterogeneity between the studies was found regarding all assessed areas. The most consistent finding of all studies was a reduction in the ABR wave I amplitude following exposure to noise and salicylate. Simultaneously, animals with salicylate-induced but not noise-induced tinnitus had an increased amplitude of wave IV. Furthermore, the present study identified a need to develop a consensus experimental ABR protocol applied in future tinnitus studies using the rat model.
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Affiliation(s)
- Ewa Domarecka
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany; (E.D.); (H.O.)
| | - Heidi Olze
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany; (E.D.); (H.O.)
| | - Agnieszka J. Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany; (E.D.); (H.O.)
- Faculty of Medicine and Health Sciences, University of Zielona Gora, 65-046 Zielona Gora, Poland
- Correspondence:
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Pol S, Temel Y, Jahanshahi A. A Custom Made Electrode Construct and Reliable Implantation Method That Allows for Long-Term Bilateral Deep Brain Stimulation in Mice. Neuromodulation 2020; 24:212-219. [PMID: 32385967 PMCID: PMC7984026 DOI: 10.1111/ner.13165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 03/20/2020] [Accepted: 04/06/2020] [Indexed: 12/11/2022]
Abstract
Objectives The underlying mechanisms behind the therapeutic and side effects of deep brain stimulation (DBS) need further investigation. The utilization of transgenic mouse lines is a suitable approach to better understand the cellular and network effects of DBS. However, not many bilateral DBS studies have been conducted in mice. This might be due to a lack of commercially available bilateral DBS constructs. Materials and Methods We developed an approach to perform repetitive long‐term DBS in freely moving mice. In this study, we implanted an in‐house custom‐made DBS construct containing two bipolar concentric electrodes to target the subthalamic nucleus (STN) bilaterally. Subsequently, we stimulated half of the animals with clinically relevant parameters three to five times a week with a duration of 20 min for ten weeks. Several behavioral tests were conducted of which the open field test (OFT) is shown to validate the reliability of this electrode construct and implantation method. Furthermore, we performed fiber photometry measurements to show the acute effect of STN‐DBS on serotonin network activity in the dorsal raphe nucleus. Results Repetitive DBS and long‐term behavioral testing were performed without complications. STN‐DBS resulted in an increase of the distance traveled in the OFT and a reduction of calcium levels in serotonergic neurons of the dorsal raphe nucleus. None of the mice had lost their electrodes and postmortem evaluation of the tissue showed accurate targeting of the STN without excessive gliosis. Conclusion The DBS electrode construct and implantation method described can be used for long‐term DBS studies to further investigate the mechanisms underlying DBS.
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Affiliation(s)
- Sylvana Pol
- Department of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Neurosurgery, Maastricht University Medical Center, Maastricht, 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
| | - 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
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