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Suraj U, Nisha KV, Prabhu P. Normal linear and non-linear cochlear mechanisms and efferent system functioning in individuals with misophonia. Eur Arch Otorhinolaryngol 2024; 281:1709-1716. [PMID: 37837477 DOI: 10.1007/s00405-023-08273-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 10/02/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Misophonia, a condition characterized by heightened sensitivity and strong emotional reactions to specific sounds, has sparked considerable interest and debate regarding its underlying auditory mechanisms. The study aimed to understand the auditory underpinnings of two such potential inner ear systems, non-linear and linear outer hair cell functioning along with auditory efferent functioning in individuals with misophonia. METHODS 40 ears with misophonia (20 participants) and 37 ears without misophonia (20 participants), both having normal hearing sensitivity were included in this study. Transient evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) were obtained in two conditions (with and without contralateral noise). RESULTS Results of independent-samples t-test showed no statistically significant difference (p > 0.05) in the absolute amplitudes of both TEOAEs and DPOAEs between the individuals with and without misophonia. There was no statistically significant difference (p > 0.05) observed in the magnitude of suppression amplitude between the two groups for in both TEOAEs and DPOAEs between individuals with and without misophonia. CONCLUSION These results suggest that the cochlear and efferent auditory underpinnings examined in this study may not be major contributors to the development or manifestation of misophonia.
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Affiliation(s)
- Urs Suraj
- Department of Audiology, All India Institute of Speech and Hearing, Manasagangothri, Mysuru, 570 006, Karnataka, India.
| | - Kavassery Venkateswaran Nisha
- Department of Audiology, All India Institute of Speech and Hearing, Manasagangothri, Mysuru, 570 006, Karnataka, India
| | - Prashanth Prabhu
- Department of Audiology, All India Institute of Speech and Hearing, Manasagangothri, Mysuru, 570 006, Karnataka, India
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Munoz F, Vicencio-Jimenez S, Jorratt P, Delano PH, Terreros G. Corticofugal and Brainstem Functions Associated With Medial Olivocochlear Cholinergic Transmission. Front Neurosci 2022; 16:866161. [PMID: 35573302 PMCID: PMC9094045 DOI: 10.3389/fnins.2022.866161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/24/2022] [Indexed: 11/29/2022] Open
Abstract
Cholinergic transmission is essential for survival and reproduction, as it is involved in several physiological responses. In the auditory system, both ascending and descending auditory pathways are modulated by cholinergic transmission, affecting the perception of sounds. The auditory efferent system is a neuronal network comprised of several feedback loops, including corticofugal and brainstem pathways to the cochlear receptor. The auditory efferent system's -final and mandatory synapses that connect the brain with the cochlear receptor- involve medial olivocochlear neurons and outer hair cells. A unique cholinergic transmission mediates these synapses through α9/α10 nicotinic receptors. To study this receptor, it was generated a strain of mice carrying a null mutation of the Chrna9 gene (α9-KO mice), lacking cholinergic transmission between medial olivocochlear neurons and outer hair cells, providing a unique opportunity to study the role of medial olivocochlear cholinergic transmission in auditory and cognitive functions. In this article, we review behavioral and physiological studies carried out to research auditory efferent function in the context of audition, cognition, and hearing impairments. Auditory studies have shown that hearing thresholds in the α9-KO mice are normal, while more complex auditory functions, such as frequency selectivity and sound localization, are altered. The corticofugal pathways have been studied in α9-KO mice using behavioral tasks, evidencing a reduced capacity to suppress auditory distractors during visual selective attention. Finally, we discuss the evolutionary role of the auditory efferent system detecting vocalizations in noise and its role in auditory disorders, such as the prevention of age-related hearing loss.
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Affiliation(s)
- Felipe Munoz
- Instituto de Ciencias de la Salud, Universidad de O’Higgins, Rancagua, Chile
- Universidad de Valparaíso, Valparaíso, Chile
| | - Sergio Vicencio-Jimenez
- Department of Otolaryngology-Head and Neck Surgery, The Center for Hearing and Balance, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Pascal Jorratt
- National Institute of Mental Health, Klecany, Czechia
- Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Paul H. Delano
- Facultad de Medicina, Neuroscience Department, Universidad de Chile, Santiago, Chile
- Department of Otolaryngology, Hospital Clínico de la Universidad de Chile, Santiago, Chile
- Centro Avanzado de Ingeniería Eléctrica y Electrónica, AC3E, Universidad Técnica Federico Santa María, Valparaíso, Chile
- Facultad de Medicina, Biomedical Neuroscience Institute, Universidad de Chile, Santiago, Chile
| | - Gonzalo Terreros
- Instituto de Ciencias de la Salud, Universidad de O’Higgins, Rancagua, Chile
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Lorincz D, Poppi LA, Holt JC, Drury HR, Lim R, Brichta AM. The Long and Winding Road-Vestibular Efferent Anatomy in Mice. Front Neural Circuits 2022; 15:751850. [PMID: 35153679 PMCID: PMC8832101 DOI: 10.3389/fncir.2021.751850] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 12/23/2021] [Indexed: 11/20/2022] Open
Abstract
The precise functional role of the Efferent Vestibular System (EVS) is still unclear, but the auditory olivocochlear efferent system has served as a reasonable model on the effects of a cholinergic and peptidergic input on inner ear organs. However, it is important to appreciate the similarities and differences in the structure of the two efferent systems, especially within the same animal model. Here, we examine the anatomy of the mouse EVS, from its central origin in the Efferent Vestibular Nucleus (EVN) of the brainstem, to its peripheral terminations in the vestibular organs, and we compare these findings to known mouse olivocochlear anatomy. Using transgenic mouse lines and two different tracing strategies, we examine central and peripheral anatomical patterning, as well as the anatomical pathway of EVS axons as they leave the mouse brainstem. We separately tag the left and right efferent vestibular nuclei (EVN) using Cre-dependent, adeno-associated virus (AAV)-mediated expression of fluorescent reporters to map their central trajectory and their peripheral terminal fields. We couple this with Fluro-Gold retrograde labeling to quantify the proportion of ipsi- and contralaterally projecting cholinergic efferent neurons. As in some other mammals, the mouse EVN comprises one group of neurons located dorsal to the facial genu, close to the vestibular nuclei complex (VNC). There is an average of just 53 EVN neurons with rich dendritic arborizations towards the VNC. The majority of EVN neurons, 55%, project to the contralateral eighth nerve, crossing the midline rostral to the EVN, and 32% project to the ipsilateral eighth nerve. The vestibular organs, therefore, receive bilateral EVN innervation, but without the distinctive zonal innervation patterns suggested in gerbil. Similar to gerbil, however, our data also suggest that individual EVN neurons do not project bilaterally in mice. Taken together, these data provide a detailed map of EVN neurons from the brainstem to the periphery and strong anatomical support for a dominant contralateral efferent innervation in mammals.
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Affiliation(s)
- David Lorincz
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia
| | - Lauren A. Poppi
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia
| | - Joseph C. Holt
- Department of Otolaryngology, University of Rochester, Rochester, NY, United States
| | - Hannah R. Drury
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia
| | - Rebecca Lim
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia
| | - Alan M. Brichta
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, Australia
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Abstract
The efferent auditory nervous system may be a potent force in shaping how the brain responds to behaviorally significant sounds. Previous human experiments using the frequency following response (FFR) have shown efferent-induced modulation of subcortical auditory function online and over short- and long-term time scales; however, a contemporary understanding of FFR generation presents new questions about whether previous effects were constrained solely to the auditory subcortex. The present experiment used sine-wave speech (SWS), an acoustically-sparse stimulus in which dynamic pure tones represent speech formant contours, to evoke FFRSWS. Due to the higher stimulus frequencies used in SWS, this approach biased neural responses toward brainstem generators and allowed for three stimuli (/bɔ/, /bu/, and /bo/) to be used to evoke FFRSWSbefore and after listeners in a training group were made aware that they were hearing a degraded speech stimulus. All SWS stimuli were rapidly perceived as speech when presented with a SWS carrier phrase, and average token identification reached ceiling performance during a perceptual training phase. Compared to a control group which remained naïve throughout the experiment, training group FFRSWS amplitudes were enhanced post-training for each stimulus. Further, linear support vector machine classification of training group FFRSWS significantly improved post-training compared to the control group, indicating that training-induced neural enhancements were sufficient to bolster machine learning classification accuracy. These results suggest that the efferent auditory system may rapidly modulate auditory brainstem representation of sounds depending on their context and perception as non-speech or speech.
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Affiliation(s)
- Fan-Yin Cheng
- Department of Speech, Language, and Hearing Sciences, University of Texas at Austin, Austin, TX, United States
| | - Can Xu
- Department of Speech, Language, and Hearing Sciences, University of Texas at Austin, Austin, TX, United States
| | - Lisa Gold
- Department of Speech, Language, and Hearing Sciences, University of Texas at Austin, Austin, TX, United States
| | - Spencer Smith
- Department of Speech, Language, and Hearing Sciences, University of Texas at Austin, Austin, TX, United States
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Köhler MHA, Demarchi G, Weisz N. Cochlear activity in silent cue-target intervals shows a theta-rhythmic pattern and is correlated to attentional alpha and theta modulations. BMC Biol 2021; 19:48. [PMID: 33726746 PMCID: PMC7968255 DOI: 10.1186/s12915-021-00992-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 02/24/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND A long-standing debate concerns where in the processing hierarchy of the central nervous system (CNS) selective attention takes effect. In the auditory system, cochlear processes can be influenced via direct and mediated (by the inferior colliculus) projections from the auditory cortex to the superior olivary complex (SOC). Studies illustrating attentional modulations of cochlear responses have so far been limited to sound-evoked responses. The aim of the present study is to investigate intermodal (audiovisual) selective attention in humans simultaneously at the cortical and cochlear level during a stimulus-free cue-target interval. RESULTS We found that cochlear activity in the silent cue-target intervals was modulated by a theta-rhythmic pattern (~ 6 Hz). While this pattern was present independently of attentional focus, cochlear theta activity was clearly enhanced when attending to the upcoming auditory input. On a cortical level, classical posterior alpha and beta power enhancements were found during auditory selective attention. Interestingly, participants with a stronger release of inhibition in auditory brain regions show a stronger attentional modulation of cochlear theta activity. CONCLUSIONS These results hint at a putative theta-rhythmic sampling of auditory input at the cochlear level. Furthermore, our results point to an interindividual variable engagement of efferent pathways in an attentional context that are linked to processes within and beyond processes in auditory cortical regions.
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Affiliation(s)
- Moritz Herbert Albrecht Köhler
- Centre for Cognitive Neuroscience, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.
- Department of Psychology, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria.
| | - Gianpaolo Demarchi
- Centre for Cognitive Neuroscience, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
- Department of Psychology, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
| | - Nathan Weisz
- Centre for Cognitive Neuroscience, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
- Department of Psychology, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
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Sisto R, Viziano A, Stefani A, Moleti A, Cerroni R, Liguori C, Garasto E, Pierantozzi M. Lateralization of cochlear dysfunction as a specific biomarker of Parkinson's disease. Brain Commun 2020; 2:fcaa144. [PMID: 33376982 PMCID: PMC7751021 DOI: 10.1093/braincomms/fcaa144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/21/2020] [Accepted: 08/03/2020] [Indexed: 11/18/2022] Open
Abstract
In the last decade, animal studies highlighted the sensitivity of hearing function to lack of specific cochlear dopamine receptors, while several studies on humans reported association between hearing loss and Parkinson's disease, partially recovered after levodopa administration in de novo patients. Taken together, these observations suggest investigating the possible use of cochlear function outcome variables, particularly, otoacoustic emissions, as sensitive biomarkers of Parkinson's disease. Any lateralization of hearing dysfunction correlated with Parkinson's disease lateralization would (i) further confirm their association and (ii) provide a disease-specific differential outcome variable. Differential indicators are particularly useful for diagnostic purposes, because their effectiveness is not limited by physiological inter-subject fluctuations of the outcome variable. Recent advances in the acquisition and analysis techniques of otoacoustic emissions suggest using them for evaluating differential cochlear damage in the two ears. In this study, we quantitatively evaluated hearing function in a population of subjects with Parkinson's disease, to investigate the occurrence of hearing loss, and, particularly, whether hearing dysfunction shows lateralization correlated with motor symptoms. Pure tone audiometry and distortion product otoacoustic emissions were used as outcome variables in 80 patients (mean age 65 ± 9 years) and 41 controls (mean age 64 ± 10 years). An advanced customized acquisition and analysis system was developed and used for otoacoustic testing, which guarantees response stability independent of probe insertion depth, and has the sensitivity necessary to accurately assess the low levels of otoacoustic response typical of elderly subjects. To our knowledge, this is the first study introducing the distinction between ipsilateral and contralateral ear, with respect to the body side more affected by Parkinson's disease motor symptoms. Significant asymmetry was found in the auditory function, as both otoacoustic responses and audiometric hearing levels were worse in the ipsilateral ear. Significantly worse hearing function was also observed in patients with Parkinson's disease compared to controls, confirming previous studies. Several pathophysiological mechanisms may be hypothesized to explain asymmetric cochlear damage in Parkinson's disease, including the impairment of dopamine release and the involvement of extra-dopaminergic circuits, with the cholinergic pathway as a likely candidate. The observed asymmetry in the audiological response of patients with Parkinson's disease suggests that lateralization of hearing dysfunction could represent a specific non-motor signature of the disease. The possible diagnostic use of cochlear dysfunction asymmetry as a specific biomarker of Parkinson's disease deserves further investigation, needing a more precise quantitative assessment, which would require a larger sample size.
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Affiliation(s)
- Renata Sisto
- INAIL Research, Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, 00078 Monte Porzio Catone (Rome), Italy
| | - Andrea Viziano
- Department of Physics, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
- Department of Clinical Sciences and Translational Medicine, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
| | - Alessandro Stefani
- Department of Systems Medicine, Parkinson’s Disease Center, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
| | - Arturo Moleti
- Department of Physics, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
| | - Rocco Cerroni
- Department of Systems Medicine, Parkinson’s Disease Center, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
| | - Claudio Liguori
- Department of Systems Medicine, Parkinson’s Disease Center, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
| | - Elena Garasto
- Department of Systems Medicine, Parkinson’s Disease Center, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
| | - Mariangela Pierantozzi
- Department of Systems Medicine, Parkinson’s Disease Center, University of Rome ‘Tor Vergata’, 00133 Rome, Italy
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Guinan JJ Jr. Olivocochlear efferents: Their action, effects, measurement and uses, and the impact of the new conception of cochlear mechanical responses. Hear Res 2018; 362:38-47. [PMID: 29291948 DOI: 10.1016/j.heares.2017.12.012] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 11/08/2017] [Accepted: 12/12/2017] [Indexed: 12/27/2022]
Abstract
The anatomy and physiology of olivocochlear (OC) efferents are reviewed. To help interpret these, recent advances in cochlear mechanics are also reviewed. Lateral OC (LOC) efferents innervate primary auditory-nerve (AN) fiber dendrites. The most important LOC function may be to reduce auditory neuropathy. Medial OC (MOC) efferents innervate the outer hair cells (OHCs) and act to turn down the gain of cochlear amplification. Cochlear amplification had been thought to act only through basilar membrane (BM) motion, but recent reports show that motion near the reticular lamina (RL) is amplified more than BM motion, and that RL-motion amplification extends to several octaves below the local characteristic frequency. Data on efferent effects on AN-fiber responses, otoacoustic emissions (OAEs) and human psychophysics are reviewed and reinterpreted in the light of the new cochlear-mechanical data. The possible origin of OAEs in RL motion is considered. MOC-effect measuring methods and MOC-induced changes in human responses are also reviewed, including that ipsilateral and contralateral sound can produce MOC effects with different patterns across frequency. MOC efferents help to reduce damage due to acoustic trauma. Many, but not all, reports show that subjects with stronger contralaterally-evoked MOC effects have better ability to detect signals (e.g. speech) in noise, and that MOC effects can be modulated by attention.
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Lamas V, Estévez S, Pernía M, Plaza I, Merchán MA. Stereotactically-guided Ablation of the Rat Auditory Cortex, and Localization of the Lesion in the Brain. J Vis Exp 2017. [PMID: 29053697 PMCID: PMC5752406 DOI: 10.3791/56429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The rat auditory cortex (AC) is becoming popular among auditory neuroscience investigators who are interested in experience-dependence plasticity, auditory perceptual processes, and cortical control of sound processing in the subcortical auditory nuclei. To address new challenges, a procedure to accurately locate and surgically expose the auditory cortex would expedite this research effort. Stereotactic neurosurgery is routinely used in pre-clinical research in animal models to engraft a needle or electrode at a pre-defined location within the auditory cortex. In the following protocol, we use stereotactic methods in a novel way. We identify four coordinate points over the surface of the temporal bone of the rat to define a window that, once opened, accurately exposes both the primary (A1) and secondary (Dorsal and Ventral) cortices of the AC. Using this method, we then perform a surgical ablation of the AC. After such a manipulation is performed, it is necessary to assess the localization, size, and extension of the lesions made in the cortex. Thus, we also describe a method to easily locate the AC ablation postmortem using a coordinate map constructed by transferring the cytoarchitectural limits of the AC to the surface of the brain.The combination of the stereotactically-guided location and ablation of the AC with the localization of the injured area in a coordinate map postmortem facilitates the validation of information obtained from the animal, and leads to a better analysis and comprehension of the data.
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Affiliation(s)
- Verónica Lamas
- Institute of Neuroscience of Castilla y León, University of Salamanca; Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Department of Otolaryngology, Harvard Medical School;
| | - Sheila Estévez
- Institute of Neuroscience of Castilla y León, University of Salamanca
| | - Marianni Pernía
- Institute of Neuroscience of Castilla y León, University of Salamanca
| | - Ignacio Plaza
- Institute of Neuroscience of Castilla y León, University of Salamanca
| | - Miguel A Merchán
- Institute of Neuroscience of Castilla y León, University of Salamanca
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