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Schilling A, Sedley W, Gerum R, Metzner C, Tziridis K, Maier A, Schulze H, Zeng FG, Friston KJ, Krauss P. Predictive coding and stochastic resonance as fundamental principles of auditory phantom perception. Brain 2023; 146:4809-4825. [PMID: 37503725 PMCID: PMC10690027 DOI: 10.1093/brain/awad255] [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: 10/26/2022] [Revised: 06/27/2023] [Accepted: 07/15/2023] [Indexed: 07/29/2023] Open
Abstract
Mechanistic insight is achieved only when experiments are employed to test formal or computational models. Furthermore, in analogy to lesion studies, phantom perception may serve as a vehicle to understand the fundamental processing principles underlying healthy auditory perception. With a special focus on tinnitus-as the prime example of auditory phantom perception-we review recent work at the intersection of artificial intelligence, psychology and neuroscience. In particular, we discuss why everyone with tinnitus suffers from (at least hidden) hearing loss, but not everyone with hearing loss suffers from tinnitus. We argue that intrinsic neural noise is generated and amplified along the auditory pathway as a compensatory mechanism to restore normal hearing based on adaptive stochastic resonance. The neural noise increase can then be misinterpreted as auditory input and perceived as tinnitus. This mechanism can be formalized in the Bayesian brain framework, where the percept (posterior) assimilates a prior prediction (brain's expectations) and likelihood (bottom-up neural signal). A higher mean and lower variance (i.e. enhanced precision) of the likelihood shifts the posterior, evincing a misinterpretation of sensory evidence, which may be further confounded by plastic changes in the brain that underwrite prior predictions. Hence, two fundamental processing principles provide the most explanatory power for the emergence of auditory phantom perceptions: predictive coding as a top-down and adaptive stochastic resonance as a complementary bottom-up mechanism. We conclude that both principles also play a crucial role in healthy auditory perception. Finally, in the context of neuroscience-inspired artificial intelligence, both processing principles may serve to improve contemporary machine learning techniques.
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Affiliation(s)
- Achim Schilling
- Neuroscience Lab, University Hospital Erlangen, 91054 Erlangen, Germany
- Cognitive Computational Neuroscience Group, University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - William Sedley
- Translational and Clinical Research Institute, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Richard Gerum
- Cognitive Computational Neuroscience Group, University Erlangen-Nürnberg, 91058 Erlangen, Germany
- Department of Physics and Astronomy and Center for Vision Research, York University, Toronto, ON M3J 1P3, Canada
| | - Claus Metzner
- Neuroscience Lab, University Hospital Erlangen, 91054 Erlangen, Germany
| | | | - Andreas Maier
- Pattern Recognition Lab, University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Holger Schulze
- Neuroscience Lab, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Fan-Gang Zeng
- Center for Hearing Research, Departments of Anatomy and Neurobiology, Biomedical Engineering, Cognitive Sciences, Otolaryngology–Head and Neck Surgery, University of California Irvine, Irvine, CA 92697, USA
| | - Karl J Friston
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London WC1N 3AR, UK
| | - Patrick Krauss
- Neuroscience Lab, University Hospital Erlangen, 91054 Erlangen, Germany
- Cognitive Computational Neuroscience Group, University Erlangen-Nürnberg, 91058 Erlangen, Germany
- Pattern Recognition Lab, University Erlangen-Nürnberg, 91058 Erlangen, Germany
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2
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Pham MD, D’Angiulli A, Dehnavi MM, Chhabra R. From Brain Models to Robotic Embodied Cognition: How Does Biological Plausibility Inform Neuromorphic Systems? Brain Sci 2023; 13:1316. [PMID: 37759917 PMCID: PMC10526461 DOI: 10.3390/brainsci13091316] [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: 07/05/2023] [Revised: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
We examine the challenging "marriage" between computational efficiency and biological plausibility-A crucial node in the domain of spiking neural networks at the intersection of neuroscience, artificial intelligence, and robotics. Through a transdisciplinary review, we retrace the historical and most recent constraining influences that these parallel fields have exerted on descriptive analysis of the brain, construction of predictive brain models, and ultimately, the embodiment of neural networks in an enacted robotic agent. We study models of Spiking Neural Networks (SNN) as the central means enabling autonomous and intelligent behaviors in biological systems. We then provide a critical comparison of the available hardware and software to emulate SNNs for investigating biological entities and their application on artificial systems. Neuromorphics is identified as a promising tool to embody SNNs in real physical systems and different neuromorphic chips are compared. The concepts required for describing SNNs are dissected and contextualized in the new no man's land between cognitive neuroscience and artificial intelligence. Although there are recent reviews on the application of neuromorphic computing in various modules of the guidance, navigation, and control of robotic systems, the focus of this paper is more on closing the cognition loop in SNN-embodied robotics. We argue that biologically viable spiking neuronal models used for electroencephalogram signals are excellent candidates for furthering our knowledge of the explainability of SNNs. We complete our survey by reviewing different robotic modules that can benefit from neuromorphic hardware, e.g., perception (with a focus on vision), localization, and cognition. We conclude that the tradeoff between symbolic computational power and biological plausibility of hardware can be best addressed by neuromorphics, whose presence in neurorobotics provides an accountable empirical testbench for investigating synthetic and natural embodied cognition. We argue this is where both theoretical and empirical future work should converge in multidisciplinary efforts involving neuroscience, artificial intelligence, and robotics.
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Affiliation(s)
- Martin Do Pham
- Department of Computer Science, University of Toronto, Toronto, ON M5S 1A1, Canada; (M.D.P.); (M.M.D.)
| | - Amedeo D’Angiulli
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada;
| | - Maryam Mehri Dehnavi
- Department of Computer Science, University of Toronto, Toronto, ON M5S 1A1, Canada; (M.D.P.); (M.M.D.)
| | - Robin Chhabra
- Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, ON K1S 5B6, Canada
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3
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Schultheiβ H, Zulfiqar I, Verardo C, Jolivet RB, Moerel M. Modelling homeostatic plasticity in the auditory cortex results in neural signatures of tinnitus. Neuroimage 2023; 271:119987. [PMID: 36940510 DOI: 10.1016/j.neuroimage.2023.119987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/23/2022] [Accepted: 02/25/2023] [Indexed: 03/22/2023] Open
Abstract
Tinnitus is a clinical condition where a sound is perceived without an external sound source. Homeostatic plasticity (HSP), serving to increase neural activity as compensation for the reduced input to the auditory pathway after hearing loss, has been proposed as a mechanism underlying tinnitus. In support, animal models of tinnitus show evidence of increased neural activity after hearing loss, including increased spontaneous and sound-driven firing rate, as well as increased neural noise throughout the auditory processing pathway. Bridging these findings to human tinnitus, however, has proven to be challenging. Here we implement hearing loss-induced HSP in a Wilson-Cowan Cortical Model of the auditory cortex to predict how homeostatic principles operating at the microscale translate to the meso- to macroscale accessible through human neuroimaging. We observed HSP-induced response changes in the model that were previously proposed as neural signatures of tinnitus, but that have also been reported as correlates of hearing loss and hyperacusis. As expected, HSP increased spontaneous and sound-driven responsiveness in hearing-loss affected frequency channels of the model. We furthermore observed evidence of increased neural noise and the appearance of spatiotemporal modulations in neural activity, which we discuss in light of recent human neuroimaging findings. Our computational model makes quantitative predictions that require experimental validation, and may thereby serve as the basis of future human studies of hearing loss, tinnitus, and hyperacusis.
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Affiliation(s)
- Hannah Schultheiβ
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands; Master Systems Biology, Faculty of Science and Engineering, Maastricht University, Maastricht, the Netherlands
| | - Isma Zulfiqar
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Claudio Verardo
- Maastricht Centre for Systems Biology, Maastricht University, Maastricht, the Netherlands; The BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Renaud B Jolivet
- Maastricht Centre for Systems Biology, Maastricht University, Maastricht, the Netherlands
| | - Michelle Moerel
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands; Maastricht Brain Imaging Center (MBIC), Maastricht, the Netherlands; Maastricht Centre for Systems Biology, Maastricht University, Maastricht, the Netherlands.
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Dotan A, Shriki O. Tinnitus-like "hallucinations" elicited by sensory deprivation in an entropy maximization recurrent neural network. PLoS Comput Biol 2021; 17:e1008664. [PMID: 34879061 PMCID: PMC8687580 DOI: 10.1371/journal.pcbi.1008664] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 12/20/2021] [Accepted: 11/24/2021] [Indexed: 11/19/2022] Open
Abstract
Sensory deprivation has long been known to cause hallucinations or "phantom" sensations, the most common of which is tinnitus induced by hearing loss, affecting 10-20% of the population. An observable hearing loss, causing auditory sensory deprivation over a band of frequencies, is present in over 90% of people with tinnitus. Existing plasticity-based computational models for tinnitus are usually driven by homeostatic mechanisms, modeled to fit phenomenological findings. Here, we use an objective-driven learning algorithm to model an early auditory processing neuronal network, e.g., in the dorsal cochlear nucleus. The learning algorithm maximizes the network's output entropy by learning the feed-forward and recurrent interactions in the model. We show that the connectivity patterns and responses learned by the model display several hallmarks of early auditory neuronal networks. We further demonstrate that attenuation of peripheral inputs drives the recurrent network towards its critical point and transition into a tinnitus-like state. In this state, the network activity resembles responses to genuine inputs even in the absence of external stimulation, namely, it "hallucinates" auditory responses. These findings demonstrate how objective-driven plasticity mechanisms that normally act to optimize the network's input representation can also elicit pathologies such as tinnitus as a result of sensory deprivation.
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Affiliation(s)
- Aviv Dotan
- Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Oren Shriki
- Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Department of Computer Science, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Durai M, Sanders P, Doborjeh Z, Doborjeh M, Wendt A, Kasabov N, Searchfield GD. Prediction of tinnitus masking benefit within a case series using a spiking neural network model. PROGRESS IN BRAIN RESEARCH 2020; 260:129-165. [PMID: 33637215 DOI: 10.1016/bs.pbr.2020.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Masking has been widely used as a tinnitus therapy, with large individual differences in its effectiveness. The basis of this variation is unknown. We examined individual tinnitus and psychological responses to three masking types, energetic masking (bilateral broadband static or rain noise [BBN]), informational masking (BBN with a notch at tinnitus pitch and 3-dimensional cues) and a masker combining both effects (BBN with spatial cues). Eleven participants with chronic tinnitus were followed for 12 months, each person used each masking approach for 3 months with a 1 month washout-baseline. The Tinnitus Functional Index (TFI), Tinnitus Rating Scales, Positive and Negative Affect Scale and Depression Anxiety Stress Scales, were measured every month of treatment. Electroencephalography (EEG) and psychoacoustic assessment was undertaken at baseline and following 3 months of each masking sound. The computational modeling of EEG data was based on the framework of brain-inspired Spiking Neural Network (SNN) architecture called NeuCube, designed for this study for mapping, learning, visualizing and classifying of brain activity patterns. EEG was related to clinically significant change in the TFI using the SNN model. The SNN framework was able to predict sound therapy responders (93% accuracy) from non-responders (100% accuracy) using baseline EEG recordings. The combination of energetic and informational masking was an effective treatment sound in more individuals than the other sounds used. Although the findings are promising, they are preliminary and require confirmation in independent and larger samples.
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Affiliation(s)
- Mithila Durai
- Section of Audiology, The University of Auckland, Auckland, New Zealand; Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand; Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Brain Research New Zealand-Rangahau Roro Aotearoa, Auckland, New Zealand
| | - Philip Sanders
- Section of Audiology, The University of Auckland, Auckland, New Zealand; Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand; Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Brain Research New Zealand-Rangahau Roro Aotearoa, Auckland, New Zealand
| | - Zohreh Doborjeh
- Section of Audiology, The University of Auckland, Auckland, New Zealand; Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand; Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Brain Research New Zealand-Rangahau Roro Aotearoa, Auckland, New Zealand
| | - Maryam Doborjeh
- Information Technology and Software Engineering department, Auckland University of Technology, Auckland, New Zealand
| | - Anne Wendt
- School of Engineering, Computing and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Nikola Kasabov
- School of Engineering, Computing and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand; Intelligent Systems Research Centre, Ulster University, Newtownabbey, United Kingdom
| | - Grant D Searchfield
- Section of Audiology, The University of Auckland, Auckland, New Zealand; Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand; Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Brain Research New Zealand-Rangahau Roro Aotearoa, Auckland, New Zealand.
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Hayes SH, Schormans AL, Sigel G, Beh K, Herrmann B, Allman BL. Uncovering the contribution of enhanced central gain and altered cortical oscillations to tinnitus generation. Prog Neurobiol 2020; 196:101893. [PMID: 32783988 DOI: 10.1016/j.pneurobio.2020.101893] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/20/2020] [Accepted: 08/02/2020] [Indexed: 12/22/2022]
Abstract
Various theories and their associated mechanisms have been proposed as the neural basis of phantom sound perception (tinnitus), including central gain enhancement and altered cortical oscillations. However, it remains unknown whether these cortical changes directly cause tinnitus, or simply coexist with the phantom percept. Using chronically-implanted electrodes and drug delivery cannulae in rats, we examined whether enhanced central gain and cortical oscillations are consistent across different tinnitus induction methods (noise exposure; salicylate), and if directly-inducing enhanced central gain or altered cortical oscillations via pharmacologic manipulation of inhibition along the auditory pathway would cause behavioral evidence of tinnitus. We show that, while there appeared to be no clear link between tinnitus and the presence of enhanced sound-evoked cortical activity or altered spontaneous cortical oscillations, pharmacologic impairment of GABAergic neurotransmission in the auditory cortex was sufficient to cause tinnitus; collective findings which further advance our understanding of the neural basis of tinnitus.
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Affiliation(s)
- Sarah H Hayes
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada.
| | - Ashley L Schormans
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Gregory Sigel
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Krystal Beh
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Björn Herrmann
- Department of Psychology, Brain and Mind Institute, The University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Brian L Allman
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, N6A 3K7, Canada
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7
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Abstract
Tinnitus is a common symptom of unclear origin that can be multifactorially caused and maintained. It is frequently, but not inevitably, associated with hearing loss. Emotional distress and maladaptive coping strategies - that are associated with or amplified by the tinnitus percept - pose key targets for psychological interventions. Once somatic contributors are identified and treated as applicable, psychological approaches comprise normalizing psychoeducational and psychotherapeutic interventions. Measures to improve hearing perception (e. g., hearing aids or cochlear implants) can also contribute to tinnitus habituation through direct (improvement of hearing perception) or indirect (improvement of emotional wellbeing or quality of life) effects.
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Affiliation(s)
- B Boecking
- Tinnituszentrum, Charité - Universitätsmedizin Berlin, Karlplatz 7, 10117, Berlin, Deutschland.
| | - P Brueggemann
- Tinnituszentrum, Charité - Universitätsmedizin Berlin, Karlplatz 7, 10117, Berlin, Deutschland
| | - B Mazurek
- Tinnituszentrum, Charité - Universitätsmedizin Berlin, Karlplatz 7, 10117, Berlin, Deutschland
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Phillips JS, Erskine S, Moore T, Nunney I, Wright C. Eye movement desensitization and reprocessing as a treatment for tinnitus. Laryngoscope 2019; 129:2384-2390. [PMID: 30693546 DOI: 10.1002/lary.27841] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/15/2018] [Accepted: 01/07/2019] [Indexed: 12/20/2022]
Abstract
OBJECTIVES/HYPOTHESIS To determine the effectiveness of eye movement desensitization and reprocessing (EMDR) as a treatment for tinnitus. STUDY DESIGN Single-site prospective interventional clinical trial at a university hospital in the United Kingdom. METHODS Participants were provided with tEMDR. This is a bespoke EMDR protocol that was developed specifically to treat individuals with tinnitus. Participants received a maximum of 10 sessions of tEMDR. Outcome measures including tinnitus questionnaires and mood questionnaires were recorded at baseline, discharge, and at 6 months postdischarge. RESULTS Tinnitus Handicap Inventory and Beck Depression Inventory scores demonstrated a statistically significant improvement at discharge after EMDR intervention (P = .0005 and P = .0098, respectively); this improvement was maintained at 6 months postdischarge. There was also a moderate but not significant (P = .0625) improvement in Beck Anxiety Inventory scores. CONCLUSIONS This study has demonstrated that the provision of tEMDR has resulted in a clinically and statistically significant improvement in tinnitus symptoms in the majority of those participants who took part. Furthermore, the treatment effect was maintained at 6 months after treatment ceased. This study is of particular interest, as the study protocol was designed to be purposefully inclusive of a diverse range of tinnitus patients. However, as a small uncontrolled study, these results do not consider the significant effects of placebo and therapist interaction. Larger high-quality studies are essential for the verification of these preliminary results. LEVEL OF EVIDENCE 4 Laryngoscope, 129:2384-2390, 2019.
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Affiliation(s)
- John S Phillips
- Norfolk and Norwich University Hospital National Health Service Foundation Trust, Norwich, United Kingdom
| | - Sally Erskine
- Norfolk and Norwich University Hospital National Health Service Foundation Trust, Norwich, United Kingdom
| | - Tal Moore
- Norfolk and Norwich University Hospital National Health Service Foundation Trust, Norwich, United Kingdom
| | - Ian Nunney
- Norwich Clinical Trials Unit, Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Catherine Wright
- Norfolk and Norwich University Hospital National Health Service Foundation Trust, Norwich, United Kingdom
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Gault R, Mcginnity TM, Coleman S. A Computational Model of Thalamocortical Dysrhythmia in People With Tinnitus. IEEE Trans Neural Syst Rehabil Eng 2018; 26:1845-1857. [PMID: 30106678 DOI: 10.1109/tnsre.2018.2863740] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Tinnitus is a problem that affects a diverse range of people. One common trait amongst people with tinnitus is the presence of hearing loss, which is apparent in over 90% of the cohort. It is postulated that the remainder of people with tinnitus have hidden hearing loss in the form of cochlear synaptopathy. The loss of hearing sensation is thought to cause a reduction in the bottom-up excitatory signals of the auditory pathway leading to a change in the frequency of thalamocortical oscillations known as thalamocortical dysrhythmia (TCD). The downward shift in oscillatory behavior, characteristic of TCD, has been recorded experimentally but the underlying mechanisms responsible for TCD in tinnitus subjects cannot be directly observed. This paper investigates these underlying mechanisms by creating a biologically faithful model of the auditory periphery and thalamocortical network, called the central auditory processing (CAP) model. The proposed model replicates tinnitus related activity in the presence of hearing loss and hidden hearing loss in the form of cochlear synaptopathy. The results of this paper show that, both the bottom-up and top-down changes are required in the auditory system for tinnitus related hyperactivity to coexist with TCD, contrary to the theoretical model for TCD. The CAP model provides a novel modeling approach to account for tinnitus related activity with and without hearing loss. Moreover, the results provide additional clarity to the understanding of TCD and tinnitus and provide direction for future approaches to treating tinnitus.
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How stimulation frequency and intensity impact on the long-lasting effects of coordinated reset stimulation. PLoS Comput Biol 2018; 14:e1006113. [PMID: 29746458 PMCID: PMC5963814 DOI: 10.1371/journal.pcbi.1006113] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 05/22/2018] [Accepted: 04/03/2018] [Indexed: 12/31/2022] Open
Abstract
Several brain diseases are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR) stimulation was computationally designed to specifically counteract abnormal neuronal synchronization processes by desynchronization. In the presence of spike-timing-dependent plasticity (STDP) this may lead to a decrease of synaptic excitatory weights and ultimately to an anti-kindling, i.e. unlearning of abnormal synaptic connectivity and abnormal neuronal synchrony. The long-lasting desynchronizing impact of CR stimulation has been verified in pre-clinical and clinical proof of concept studies. However, as yet it is unclear how to optimally choose the CR stimulation frequency, i.e. the repetition rate at which the CR stimuli are delivered. This work presents the first computational study on the dependence of the acute and long-term outcome on the CR stimulation frequency in neuronal networks with STDP. For this purpose, CR stimulation was applied with Rapidly Varying Sequences (RVS) as well as with Slowly Varying Sequences (SVS) in a wide range of stimulation frequencies and intensities. Our findings demonstrate that acute desynchronization, achieved during stimulation, does not necessarily lead to long-term desynchronization after cessation of stimulation. By comparing the long-term effects of the two different CR protocols, the RVS CR stimulation turned out to be more robust against variations of the stimulation frequency. However, SVS CR stimulation can obtain stronger anti-kindling effects. We revealed specific parameter ranges that are favorable for long-term desynchronization. For instance, RVS CR stimulation at weak intensities and with stimulation frequencies in the range of the neuronal firing rates turned out to be effective and robust, in particular, if no closed loop adaptation of stimulation parameters is (technically) available. From a clinical standpoint, this may be relevant in the context of both invasive as well as non-invasive CR stimulation.
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Zeitler M, Tass PA. Computationally Developed Sham Stimulation Protocol for Multichannel Desynchronizing Stimulation. Front Physiol 2018; 9:512. [PMID: 29867556 PMCID: PMC5952302 DOI: 10.3389/fphys.2018.00512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/20/2018] [Indexed: 12/12/2022] Open
Abstract
A characteristic pattern of abnormal brain activity is abnormally strong neuronal synchronization, as found in several brain disorders, such as tinnitus, Parkinson's disease, and epilepsy. As observed in several diseases, different therapeutic interventions may induce a placebo effect that may be strong and hinder reliable clinical evaluations. Hence, to distinguish between specific, neuromodulation-induced effects and unspecific, placebo effects, it is important to mimic the therapeutic procedure as precisely as possibly, thereby providing controls that actually lack specific effects. Coordinated Reset (CR) stimulation has been developed to specifically counteract abnormally strong synchronization by desynchronization. CR is a spatio-temporally patterned multichannel stimulation which reduces the extent of coincident neuronal activity and aims at an anti-kindling, i.e., an unlearning of both synaptic connectivity and neuronal synchrony. Apart from acute desynchronizing effects, CR may cause sustained, long-lasting desynchronizing effects, as already demonstrated in pre-clinical and clinical proof of concept studies. In this computational study, we set out to computationally develop a sham stimulation protocol for multichannel desynchronizing stimulation. To this end, we compare acute effects and long-lasting effects of six different spatio-temporally patterned stimulation protocols, including three variants of CR, using a no-stimulation condition as additional control. This is to provide an inventory of different stimulation algorithms with similar fundamental stimulation parameters (e.g., mean stimulation rates) but qualitatively different acute and/or long-lasting effects. Stimulation protocols sharing basic parameters, but inducing nevertheless completely different or even no acute effects and/or after-effects, might serve as controls to validate the specific effects of particular desynchronizing protocols such as CR. In particular, based on our computational findings we propose a multichannel sham (i.e., inactive) stimulation protocol as control condition for phase 2 and phase 3 studies with desynchronizing multichannel stimulation techniques.
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Affiliation(s)
- Magteld Zeitler
- Research Center Jülich, Institute for Neuroscience and Medicine, Brain and Behaviour (INM-7), Jülich, Germany
| | - Peter A Tass
- Department of Neurosurgery, Stanford University, Stanford, CA, United States
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Manos T, Zeitler M, Tass PA. Short-Term Dosage Regimen for Stimulation-Induced Long-Lasting Desynchronization. Front Physiol 2018; 9:376. [PMID: 29706900 PMCID: PMC5906576 DOI: 10.3389/fphys.2018.00376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 03/27/2018] [Indexed: 11/23/2022] Open
Abstract
In this paper, we computationally generate hypotheses for dose-finding studies in the context of desynchronizing neuromodulation techniques. Abnormally strong neuronal synchronization is a hallmark of several brain disorders. Coordinated Reset (CR) stimulation is a spatio-temporally patterned stimulation technique that specifically aims at disrupting abnormal neuronal synchrony. In networks with spike-timing-dependent plasticity CR stimulation may ultimately cause an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and neuronal synchrony. This long-lasting desynchronization was theoretically predicted and verified in several pre-clinical and clinical studies. We have shown that CR stimulation with rapidly varying sequences (RVS) robustly induces an anti-kindling at low intensities e.g., if the CR stimulation frequency (i.e., stimulus pattern repetition rate) is in the range of the frequency of the neuronal oscillation. In contrast, CR stimulation with slowly varying sequences (SVS) turned out to induce an anti-kindling more strongly, but less robustly with respect to variations of the CR stimulation frequency. Motivated by clinical constraints and inspired by the spacing principle of learning theory, in this computational study we propose a short-term dosage regimen that enables a robust anti-kindling effect of both RVS and SVS CR stimulation, also for those parameter values where RVS and SVS CR stimulation previously turned out to be ineffective. Intriguingly, for the vast majority of parameter values tested, spaced multishot CR stimulation with demand-controlled variation of stimulation frequency and intensity caused a robust and pronounced anti-kindling. In contrast, spaced CR stimulation with fixed stimulation parameters as well as singleshot CR stimulation of equal integral duration failed to improve the stimulation outcome. In the model network under consideration, our short-term dosage regimen enables to robustly induce long-term desynchronization at comparably short stimulation duration and low integral stimulation duration. Currently, clinical proof of concept is available for deep brain CR stimulation for Parkinson's therapy and acoustic CR stimulation for tinnitus therapy. Promising first in human data is available for vibrotactile CR stimulation for Parkinson's treatment. For the clinical development of these treatments it is mandatory to perform dose-finding studies to reveal optimal stimulation parameters and dosage regimens. Our findings can straightforwardly be tested in human dose-finding studies.
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Affiliation(s)
- Thanos Manos
- Institute of Neuroscience and Medicine (INM-7), Research Centre Jülich, Jülich, Germany
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Magteld Zeitler
- Institute of Neuroscience and Medicine (INM-7), Research Centre Jülich, Jülich, Germany
| | - Peter A. Tass
- Department of Neurosurgery, Stanford University, Stanford, CA, United States
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Paul A, Prasad C, Kamath SS, Dalwai S, C Nair MK, Pagarkar W. Consensus Statement of the Indian Academy of Pediatrics on Newborn Hearing Screening. Indian Pediatr 2017; 54:647-651. [PMID: 28607211 DOI: 10.1007/s13312-017-1128-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
JUSTIFICATION Hearing impairment is one of the most critical sensory impairments with significant social and psychological consequences. Evidence-based, standardized national guidelines are needed for professionals to screen for hearing impairment during the neonatal period. PROCESS The meeting on formulation of national consensus guidelines on developmental disorders was organized by Indian Academy of Pediatrics in Mumbai, on 18th and 19th December, 2015. The invited experts included Pediatricians, Developmental Pediatricians, Pediatric Neurologists and Clinical Psychologists. The participants framed guidelines after extensive discussions. OBJECTIVE To provide guidelines on newborn hearing screening in India. RECOMMENDATIONS The first screening should be conducted before the neonate's discharge from the hospital - if it 'fails', then it should be repeated after four weeks, or at first immunization visit. If it 'fails' again, then Auditory Brainstem Response (ABR) audiometry should be conducted. All babies admitted to intensive care unit should be screened via ABR. All babies with abnormal ABR should undergo detailed evaluation, hearing aid fitting and auditory rehabilitation, before six months of age. The goal is to screen newborn babies before one month of age, diagnose hearing loss before three months of age and start intervention before six months of age.
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Affiliation(s)
| | - Abraham Paul
- From Child Care Centre, Cochin Hospital; #Max Super Speciality Hospital, Chandigarh; $Welcare Hospital, Vytilla; *New Horizons Group, Mumbai; ‡Kerala University, Thrissur; India, and @Audiovestibular Medicine, Hackney ARK and Royal National Throat Nose and Ear Hospital, London. Correspondence to: Dr Samir Dalwai, Director, New Horizons Child Development Centre, Mumbai.
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Ghodratitoostani I, Zana Y, Delbem ACB, Sani SS, Ekhtiari H, Sanchez TG. Theoretical Tinnitus Framework: A Neurofunctional Model. Front Neurosci 2016; 10:370. [PMID: 27594822 PMCID: PMC4990547 DOI: 10.3389/fnins.2016.00370] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 07/29/2016] [Indexed: 01/01/2023] Open
Abstract
Subjective tinnitus is the conscious (attended) awareness perception of sound in the absence of an external source and can be classified as an auditory phantom perception. Earlier literature establishes three distinct states of conscious perception as unattended, attended, and attended awareness conscious perception. The current tinnitus development models depend on the role of external events congruently paired with the causal physical events that precipitate the phantom perception. We propose a novel Neurofunctional Tinnitus Model to indicate that the conscious (attended) awareness perception of phantom sound is essential in activating the cognitive-emotional value. The cognitive-emotional value plays a crucial role in governing attention allocation as well as developing annoyance within tinnitus clinical distress. Structurally, the Neurofunctional Tinnitus Model includes the peripheral auditory system, the thalamus, the limbic system, brainstem, basal ganglia, striatum, and the auditory along with prefrontal cortices. Functionally, we assume the model includes presence of continuous or intermittent abnormal signals at the peripheral auditory system or midbrain auditory paths. Depending on the availability of attentional resources, the signals may or may not be perceived. The cognitive valuation process strengthens the lateral-inhibition and noise canceling mechanisms in the mid-brain, which leads to the cessation of sound perception and renders the signal evaluation irrelevant. However, the “sourceless” sound is eventually perceived and can be cognitively interpreted as suspicious or an indication of a disease in which the cortical top-down processes weaken the noise canceling effects. This results in an increase in cognitive and emotional negative reactions such as depression and anxiety. The negative or positive cognitive-emotional feedbacks within the top-down approach may have no relation to the previous experience of the patients. They can also be associated with aversive stimuli similar to abnormal neural activity in generating the phantom sound. Cognitive and emotional reactions depend on general personality biases toward evaluative conditioning combined with a cognitive-emotional negative appraisal of stimuli such as the case of people with present hypochondria. We acknowledge that the projected Neurofunctional Tinnitus Model does not cover all tinnitus variations and patients. To support our model, we present evidence from several studies using neuroimaging, electrophysiology, brain lesion, and behavioral techniques.
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Affiliation(s)
- Iman Ghodratitoostani
- Neurocognitive Engineering Laboratory, Institute of Mathematics and Computer Sciences, University of São Paulo São Carlos, Brazil
| | - Yossi Zana
- Center of Mathematics, Computation and Cognition, Federal University of ABC São Bernardo do Campo, Brazil
| | - Alexandre C B Delbem
- Neurocognitive Engineering Laboratory, Institute of Mathematics and Computer Sciences, University of São PauloSão Carlos, Brazil; Institute of Mathematics and Computer Sciences, University of São PauloSão Carlos, Brazil
| | - Siamak S Sani
- WHO Research- World Hearing Organization San Jose, CA, USA
| | - Hamed Ekhtiari
- Iranian National Center for Addiction Studies, Tehran University of Medical Sciences Tehran, Iran
| | - Tanit G Sanchez
- ENT Department, Faculty of Medicine, University of São PauloSão Carlos, Brazil; Instituto Ganz SanchezSão Paulo, Brazil
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Manohar S, Dahar K, Adler HJ, Dalian D, Salvi R. Noise-induced hearing loss: Neuropathic pain via Ntrk1 signaling. Mol Cell Neurosci 2016; 75:101-12. [PMID: 27473923 DOI: 10.1016/j.mcn.2016.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 06/30/2016] [Accepted: 07/25/2016] [Indexed: 12/18/2022] Open
Abstract
Severe noise-induced damage to the inner ear leads to auditory nerve fiber degeneration thereby reducing the neural input to the cochlear nucleus (CN). Paradoxically, this leads to a significant increase in spontaneous activity in the CN which has been linked to tinnitus, hyperacusis and ear pain. The biological mechanisms that lead to an increased spontaneous activity are largely unknown, but could arise from changes in glutamatergic or GABAergic neurotransmission or neuroinflammation. To test this hypothesis, we unilaterally exposed rats for 2h to a 126dB SPL narrow band noise centered at 12kHz. Hearing loss measured by auditory brainstem responses exceeded 55dB from 6 to 32kHz. The mRNA from the exposed CN was harvested at 14 or 28days post-exposure and qRT-PCR analysis was performed on 168 genes involved in neural inflammation, neuropathic pain and glutamatergic or GABAergic neurotransmission. Expression levels of mRNA of Slc17a6 and Gabrg3, involved in excitation and inhibition respectively, were significantly increased at 28days post-exposure, suggesting a possible role in the CN spontaneous hyperactivity associated with tinnitus and hyperacusis. In the pain and inflammatory array, noise exposure upregulated mRNA expression levels of four pain/inflammatory genes, Tlr2, Oprd1, Kcnq3 and Ntrk1 and decreased mRNA expression levels of two more genes, Ccl12 and Il1β. Pain/inflammatory gene expression changes via Ntrk1 signaling may induce sterile inflammation, neuropathic pain, microglial activation and migration of nerve fibers from the trigeminal, cuneate and vestibular nuclei into the CN. These changes could contribute to somatic tinnitus, hyperacusis and otalgia.
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Affiliation(s)
- Senthilvelan Manohar
- Center for Hearing & Deafness, State University of New York at Buffalo, Buffalo, NY 14214, United States.
| | - Kimberly Dahar
- Center for Hearing & Deafness, State University of New York at Buffalo, Buffalo, NY 14214, United States
| | - Henry J Adler
- Center for Hearing & Deafness, State University of New York at Buffalo, Buffalo, NY 14214, United States
| | - Ding Dalian
- Center for Hearing & Deafness, State University of New York at Buffalo, Buffalo, NY 14214, United States
| | - Richard Salvi
- Center for Hearing & Deafness, State University of New York at Buffalo, Buffalo, NY 14214, United States
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Hamilton C, D'Arcy S, Pearlmutter BA, Crispino G, Lalor EC, Conlon BJ. An Investigation of Feasibility and Safety of Bi-Modal Stimulation for the Treatment of Tinnitus: An Open-Label Pilot Study. Neuromodulation 2016; 19:832-837. [PMID: 27310062 PMCID: PMC5157761 DOI: 10.1111/ner.12452] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/31/2016] [Accepted: 04/22/2016] [Indexed: 01/23/2023]
Abstract
Objectives Tinnitus is the perception of sound in the absence of an external auditory stimulus. It is widely believed that tinnitus, in patients with associated hearing loss, is a neurological phenomenon primarily affecting the central auditory structures. However, there is growing evidence for the involvement of the somatosensory system in this form of tinnitus. For this reason it has been suggested that the condition may be amenable to bi‐modal stimulation of the auditory and somatosensory systems. We conducted a pilot study to investigate the feasibility and safety of a device that delivers simultaneous auditory and somatosensory stimulation to treat the symptoms of chronic tinnitus. Methods A cohort of 54 patients used the stimulation device for 10 weeks. Auditory stimulation was delivered via headphones and somatosensory stimulation was delivered via electrical stimulation of the tongue. Patient usage, logged by the device, was used to classify patients as compliant or noncompliant. Safety was assessed by reported adverse events and changes in tinnitus outcome measures. Response to treatment was assessed using tinnitus outcome measures: Minimum Masking Level (MML), Tinnitus Loudness Matching (TLM), and Tinnitus Handicap Inventory (THI). Results The device was well tolerated by patients and no adverse events or serious difficulties using the device were reported. Overall, 68% of patients met the defined compliance threshold. Compliant patients (N = 30) demonstrated statistically significant improvements in mean outcome measures after 10 weeks of treatment: THI (−11.7 pts, p < 0.001), TLM (−7.5dB, p < 0.001), and MML (−9.7dB, p < 0.001). The noncompliant group (N = 14) demonstrated no statistical improvements. Conclusion This study demonstrates the feasibility and safety of a new bi‐modal stimulation device and supports the potential efficacy of this new treatment for tinnitus.
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Affiliation(s)
- Caroline Hamilton
- Brain and Computation Lab, National University of Ireland Maynooth, Co. Kildare, Ireland.,ENT Department, Hermitage Medical Centre, Dublin, Ireland
| | | | - Barak A Pearlmutter
- Brain and Computation Lab, National University of Ireland Maynooth, Co. Kildare, Ireland
| | | | - Edmund C Lalor
- Neural-Engineering, School of Engineering, Trinity College Institute of Neuroscience and Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
| | - Brendan J Conlon
- ENT Department, Hermitage Medical Centre, Dublin, Ireland.,Department of Otolaryngology, St. James's Hospital, Dublin, Ireland
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Zeitler M, Tass PA. Anti-kindling Induced by Two-Stage Coordinated Reset Stimulation with Weak Onset Intensity. Front Comput Neurosci 2016; 10:44. [PMID: 27242500 PMCID: PMC4868855 DOI: 10.3389/fncom.2016.00044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/18/2016] [Indexed: 11/16/2022] Open
Abstract
Abnormal neuronal synchrony plays an important role in a number of brain diseases. To specifically counteract abnormal neuronal synchrony by desynchronization, Coordinated Reset (CR) stimulation, a spatiotemporally patterned stimulation technique, was designed with computational means. In neuronal networks with spike timing–dependent plasticity CR stimulation causes a decrease of synaptic weights and finally anti-kindling, i.e., unlearning of abnormally strong synaptic connectivity and abnormal neuronal synchrony. Long-lasting desynchronizing aftereffects of CR stimulation have been verified in pre-clinical and clinical proof of concept studies. In general, for different neuromodulation approaches, both invasive and non-invasive, it is desirable to enable effective stimulation at reduced stimulation intensities, thereby avoiding side effects. For the first time, we here present a two-stage CR stimulation protocol, where two qualitatively different types of CR stimulation are delivered one after another, and the first stage comes at a particularly weak stimulation intensity. Numerical simulations show that a two-stage CR stimulation can induce the same degree of anti-kindling as a single-stage CR stimulation with intermediate stimulation intensity. This stimulation approach might be clinically beneficial in patients suffering from brain diseases characterized by abnormal neuronal synchrony where a first treatment stage should be performed at particularly weak stimulation intensities in order to avoid side effects. This might, e.g., be relevant in the context of acoustic CR stimulation in tinnitus patients with hyperacusis or in the case of electrical deep brain CR stimulation with sub-optimally positioned leads or side effects caused by stimulation of the target itself. We discuss how to apply our method in first in man and proof of concept studies.
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Affiliation(s)
- Magteld Zeitler
- Research Center Jülich, Institute of Neuroscience and Medicine, Neuromodulation (INM-7) Jülich, Germany
| | - Peter A Tass
- Research Center Jülich, Institute of Neuroscience and Medicine, Neuromodulation (INM-7)Jülich, Germany; Department of Neurosurgery, Stanford UniversityStanford, CA, USA; Department of Neuromodulation, University of CologneCologne, Germany
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Zeitler M, Tass PA. Augmented brain function by coordinated reset stimulation with slowly varying sequences. Front Syst Neurosci 2015; 9:49. [PMID: 25873867 PMCID: PMC4379899 DOI: 10.3389/fnsys.2015.00049] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/10/2015] [Indexed: 12/15/2022] Open
Abstract
Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR) stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS). In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e., CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.
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Affiliation(s)
- Magteld Zeitler
- Research Center Jülich, Institute of Neuroscience and Medicine, Neuromodulation (INM-7) Jülich, Germany
| | - Peter A Tass
- Research Center Jülich, Institute of Neuroscience and Medicine, Neuromodulation (INM-7) Jülich, Germany ; Department of Neurosurgery, Stanford University Stanford, CA, USA ; Department of Neuromodulation, University of Cologne Cologne, Germany
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Eggermont JJ, Tass PA. Maladaptive neural synchrony in tinnitus: origin and restoration. Front Neurol 2015; 6:29. [PMID: 25741316 PMCID: PMC4330892 DOI: 10.3389/fneur.2015.00029] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/03/2015] [Indexed: 11/14/2022] Open
Abstract
Tinnitus is the conscious perception of sound heard in the absence of physical sound sources external or internal to the body, reflected in aberrant neural synchrony of spontaneous or resting-state brain activity. Neural synchrony is generated by the nearly simultaneous firing of individual neurons, of the synchronization of membrane-potential changes in local neural groups as reflected in the local field potentials, resulting in the presence of oscillatory brain waves in the EEG. Noise-induced hearing loss, often resulting in tinnitus, causes a reorganization of the tonotopic map in auditory cortex and increased spontaneous firing rates and neural synchrony. Spontaneous brain rhythms rely on neural synchrony. Abnormal neural synchrony in tinnitus appears to be confined to specific frequency bands of brain rhythms. Increases in delta-band activity are generated by deafferented/deprived neuronal networks resulting from hearing loss. Coordinated reset (CR) stimulation was developed in order to specifically counteract such abnormal neuronal synchrony by desynchronization. The goal of acoustic CR neuromodulation is to desynchronize tinnitus-related abnormal delta-band oscillations. CR neuromodulation does not require permanent stimulus delivery in order to achieve long-lasting desynchronization or even a full-blown anti-kindling but may have cumulative effects, i.e., the effect of different CR epochs separated by pauses may accumulate. Unlike other approaches, acoustic CR neuromodulation does not intend to reduce tinnitus-related neuronal activity by employing lateral inhibition. The potential efficacy of acoustic CR modulation was shown in a clinical proof of concept trial, where effects achieved in 12 weeks of treatment delivered 4–6 h/day persisted through a preplanned 4-week therapy pause and showed sustained long-term effects after 10 months of therapy, leading to 75% responders.
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Affiliation(s)
- Jos J Eggermont
- Department of Physiology and Pharmacology, University of Calgary , Calgary, AB , Canada ; Department of Psychology, University of Calgary , Calgary, AB , Canada
| | - Peter A Tass
- Institute of Neuroscience and Medicine - Neuromodulation (INM-7), Research Center Jülich , Jülich , Germany ; Department of Neurosurgery, Stanford University , Stanford, CA , USA ; Department of Neuromodulation, University of Cologne , Cologne , Germany
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Lanting CP, de Kleine E, Langers DRM, van Dijk P. Unilateral tinnitus: changes in connectivity and response lateralization measured with FMRI. PLoS One 2014; 9:e110704. [PMID: 25329557 PMCID: PMC4203817 DOI: 10.1371/journal.pone.0110704] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 09/25/2014] [Indexed: 12/26/2022] Open
Abstract
Tinnitus is a percept of sound that is not related to an acoustic source outside the body. For many forms of tinnitus, mechanisms in the central nervous system are believed to play a role in the pathology. In this work we specifically assessed possible neural correlates of unilateral tinnitus. Functional magnetic resonance imaging (fMRI) was used to investigate differences in sound-evoked neural activity between controls, subjects with left-sided tinnitus, and subjects with right-sided tinnitus. We assessed connectivity patterns between auditory nuclei and the lateralization of the sound-evoked responses. Interestingly, these response characteristics did not relate to the laterality of tinnitus. The lateralization for left- or right ear stimuli, as expressed in a lateralization index, was considerably smaller in subjects with tinnitus compared to that in controls, reaching significance in the right primary auditory cortex (PAC) and the right inferior colliculus (IC). Reduced functional connectivity between the brainstem and the cortex was observed in subjects with tinnitus. These differences are consistent with two existing models that relate tinnitus to i) changes in the corticothalamic feedback loops or ii) reduced inhibitory effectiveness between the limbic system and the thalamus. The vermis of the cerebellum also responded to monaural sound in subjects with unilateral tinnitus. In contrast, no cerebellar response was observed in control subjects. This suggests the involvement of the vermis of the cerebellum in unilateral tinnitus.
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Affiliation(s)
- Cornelis P. Lanting
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, Netherlands
- * E-mail:
| | - Emile de Kleine
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, Netherlands
| | - Dave R. M. Langers
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- National Institute for Health Research, Nottingham Hearing Biomedical Research Unit, School of Clinical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Pim van Dijk
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, Netherlands
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Gold JR, Bajo VM. Insult-induced adaptive plasticity of the auditory system. Front Neurosci 2014; 8:110. [PMID: 24904256 PMCID: PMC4033160 DOI: 10.3389/fnins.2014.00110] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 04/28/2014] [Indexed: 01/10/2023] Open
Abstract
The brain displays a remarkable capacity for both widespread and region-specific modifications in response to environmental challenges, with adaptive processes bringing about the reweighing of connections in neural networks putatively required for optimizing performance and behavior. As an avenue for investigation, studies centered around changes in the mammalian auditory system, extending from the brainstem to the cortex, have revealed a plethora of mechanisms that operate in the context of sensory disruption after insult, be it lesion-, noise trauma, drug-, or age-related. Of particular interest in recent work are those aspects of auditory processing which, after sensory disruption, change at multiple—if not all—levels of the auditory hierarchy. These include changes in excitatory, inhibitory and neuromodulatory networks, consistent with theories of homeostatic plasticity; functional alterations in gene expression and in protein levels; as well as broader network processing effects with cognitive and behavioral implications. Nevertheless, there abounds substantial debate regarding which of these processes may only be sequelae of the original insult, and which may, in fact, be maladaptively compelling further degradation of the organism's competence to cope with its disrupted sensory context. In this review, we aim to examine how the mammalian auditory system responds in the wake of particular insults, and to disambiguate how the changes that develop might underlie a correlated class of phantom disorders, including tinnitus and hyperacusis, which putatively are brought about through maladaptive neuroplastic disruptions to auditory networks governing the spatial and temporal processing of acoustic sensory information.
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Affiliation(s)
- Joshua R Gold
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
| | - Victoria M Bajo
- Department of Physiology, Anatomy and Genetics, University of Oxford Oxford, UK
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Tinnitus in men, mice (as well as other rodents), and machines. Hear Res 2013; 311:63-71. [PMID: 24374091 DOI: 10.1016/j.heares.2013.12.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 12/13/2013] [Accepted: 12/17/2013] [Indexed: 11/20/2022]
Abstract
The phantom auditory sensation of tinnitus is now studied in humans, animals, and computer models, and our understanding of how tinnitus is triggered and which neural mechanisms give rise to the phantom sensation in the brain has increased considerably. In most cases, tinnitus is associated with hearing loss, and even tinnitus patients with normal hearing thresholds might have cochlear damage that is not detected through conventional audiometry, as has been recently shown through auditory brainstem response measurements. Animals show behavioural signs of tinnitus after induction of hearing loss, indicating a causal relation. Moreover, surgical reduction of hearing loss in otosclerosis can reduce or even abolish tinnitus. However, hearing loss does not always lead to tinnitus. Psychophysical measurements have indicated that certain types of cochlear damage might be more closely linked to tinnitus than others. Recent animal studies have used behavioural testing to distinguish between animals with and without tinnitus after noise exposure. Comparisons between these groups of animals have helped identify neural correlates of tinnitus as well as factors that could represent a predisposition for tinnitus. Human neuroimaging studies have also begun to separate the neural signature of tinnitus from other consequences of hearing loss. The functional mechanisms that could underlie tinnitus development tinnitus have been analysed in computational modelling studies, which indicate that tinnitus could be a side-effect of the brain's attempt to compensate for hearing loss. Even though causal treatments for tinnitus are currently not available, hearing aids can provide considerable benefit when used in conjunction with counselling, tinnitus retraining therapy or cognitive behavioural therapy. Finally, animal studies demonstrate that the development of chronic noise-induced tinnitus might be prevented through timely interventions after noise exposure. This article is part of a Special Issue entitled <Annual Reviews 2014>.
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Kiani F, Yoganantha U, Tan CM, Meddis R, Schaette R. Off-frequency listening in subjects with chronic tinnitus. Hear Res 2013; 306:1-10. [DOI: 10.1016/j.heares.2013.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 08/21/2013] [Accepted: 08/26/2013] [Indexed: 11/15/2022]
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Hendrickson PJ, Yu GJ, Robinson BS, Song D, Berger TW. The contribution of relative activation levels between populations of cells to network activity in a large-scale biologically realistic model of the hippocampus. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:5962-5. [PMID: 24111097 DOI: 10.1109/embc.2013.6610910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In previously published work, we showed the progress we've made towards creating a large-scale, biologically realistic model of the rat hippocampus, starting with the projection from entorhinal cortex (EC) to the dentate gyrus (DG). We created the model to help us study how the common components of neurobiological systems in mammals - large numbers of neurons with intricate, branching morphologies; active, non-linear membrane properties; nonuniform distributions throughout membrane surface of these non-linear conductances; non-uniform and topographic connectivity between pre- and post-synaptic neurons; and activity-dependent changes in synaptic function - combine and contribute to give a particular brain region its "neural processing" properties. In this work, we report on the results of a series of simulations we ran to test the role of feed-forward and feedback inhibition in the dentate gyrus. We find that a) the system shows rhythmic bands of activity only in the presence of feedback inhibition, b) that the frequency of rhythmicity increases with increasing amounts of feed-forward inhibition, c) that it decreases with increasing amounts of feedback inhibition, and d) that strong excitatory inputs appear to enhance and prolong the amount of rhythmicity in the system.
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Nagashino H, Kinouchi Y, Danesh AA, Pandya AS. A neuronal network model with simplified tonotopicity for tinnitus generation and its relief by sound therapy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:5966-9. [PMID: 24111098 DOI: 10.1109/embc.2013.6610911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Tinnitus is the perception of sound in the ears or in the head where no external source is present. Sound therapy is one of the most effective techniques for tinnitus treatment that have been proposed. In order to investigate mechanisms of tinnitus generation and the clinical effects of sound therapy, we have proposed conceptual and computational models with plasticity using a neural oscillator or a neuronal network model. In the present paper, we propose a neuronal network model with simplified tonotopicity of the auditory system as more detailed structure. In this model an integrate-and-fire neuron model is employed and homeostatic plasticity is incorporated. The computer simulation results show that the present model can show the generation of oscillation and its cessation by external input. It suggests that the present framework is promising as a modeling for the tinnitus generation and the effects of sound therapy.
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The reduced cochlear output and the failure to adapt the central auditory response causes tinnitus in noise exposed rats. PLoS One 2013; 8:e57247. [PMID: 23516401 PMCID: PMC3596376 DOI: 10.1371/journal.pone.0057247] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 01/18/2013] [Indexed: 01/15/2023] Open
Abstract
Tinnitus is proposed to be caused by decreased central input from the cochlea, followed by increased spontaneous and evoked subcortical activity that is interpreted as compensation for increased responsiveness of central auditory circuits. We compared equally noise exposed rats separated into groups with and without tinnitus for differences in brain responsiveness relative to the degree of deafferentation in the periphery. We analyzed (1) the number of CtBP2/RIBEYE-positive particles in ribbon synapses of the inner hair cell (IHC) as a measure for deafferentation; (2) the fine structure of the amplitudes of auditory brainstem responses (ABR) reflecting differences in sound responses following decreased auditory nerve activity and (3) the expression of the activity-regulated gene Arc in the auditory cortex (AC) to identify long-lasting central activity following sensory deprivation. Following moderate trauma, 30% of animals exhibited tinnitus, similar to the tinnitus prevalence among hearing impaired humans. Although both tinnitus and no-tinnitus animals exhibited a reduced ABR wave I amplitude (generated by primary auditory nerve fibers), IHCs ribbon loss and high-frequency hearing impairment was more severe in tinnitus animals, associated with significantly reduced amplitudes of the more centrally generated wave IV and V and less intense staining of Arc mRNA and protein in the AC. The observed severe IHCs ribbon loss, the minimal restoration of ABR wave size, and reduced cortical Arc expression suggest that tinnitus is linked to a failure to adapt central circuits to reduced cochlear input.
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Abstract
PURPOSE OF REVIEW Tinnitus is the sensation of hearing a sound when no external auditory stimulus is present. Most individuals experience tinnitus for brief, unobtrusive periods. However, chronic sensation of tinnitus affects approximately 17% (44 million people) of the general US population. Tinnitus, usually a benign symptom, can be constant, loud and annoying to the point that it causes significant emotional distress, poor sleep, less efficient activities of daily living, anxiety, depression and suicidal ideation/attempts. Tinnitus remains a major challenge to physicians because its pathophysiology is poorly understood and there are few management options to offer to patients. The purpose of this article is to describe the current understanding of central neural mechanisms in tinnitus and to summarize recent developments in clinical approaches to tinnitus patients. RECENT FINDINGS Recently developed animal models of tinnitus provide the possibility to determine neuronal mechanisms of tinnitus generation and to test the effects of various treatments. The latest research using animal models has identified a number of abnormal changes, in both auditory and nonauditory brain regions, that underlie tinnitus. Furthermore this research sheds light on cellular mechanisms that are responsible for development of these abnormal changes. SUMMARY Tinnitus remains a challenging disorder for patients, physicians, audiologists and scientists studying tinnitus-related brain changes. This article reviews recent findings of brain changes in animal models associated with tinnitus and a brief review of clinical approach to tinnitus patients.
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Eggermont JJ. Hearing loss, hyperacusis, or tinnitus: What is modeled in animal research? Hear Res 2013; 295:140-9. [DOI: 10.1016/j.heares.2012.01.005] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/09/2012] [Accepted: 01/16/2012] [Indexed: 11/29/2022]
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Schaette R, Kempter R. Computational models of neurophysiological correlates of tinnitus. Front Syst Neurosci 2012; 6:34. [PMID: 22586377 PMCID: PMC3347476 DOI: 10.3389/fnsys.2012.00034] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 04/17/2012] [Indexed: 11/13/2022] Open
Abstract
The understanding of tinnitus has progressed considerably in the past decade, but the details of the mechanisms that give rise to this phantom perception of sound without a corresponding acoustic stimulus have not yet been pinpointed. It is now clear that tinnitus is generated in the brain, not in the ear, and that it is correlated with pathologically altered spontaneous activity of neurons in the central auditory system. Both increased spontaneous firing rates and increased neuronal synchrony have been identified as putative neuronal correlates of phantom sounds in animal models, and both phenomena can be triggered by damage to the cochlea. Various mechanisms could underlie the generation of such aberrant activity. At the cellular level, decreased synaptic inhibition and increased neuronal excitability, which may be related to homeostatic plasticity, could lead to an over-amplification of natural spontaneous activity. At the network level, lateral inhibition could amplify differences in spontaneous activity, and structural changes such as reorganization of tonotopic maps could lead to self-sustained activity in recurrently connected neurons. However, it is difficult to disentangle the contributions of different mechanisms in experiments, especially since not all changes observed in animal models of tinnitus are necessarily related to tinnitus. Computational modeling presents an opportunity of evaluating these mechanisms and their relation to tinnitus. Here we review the computational models for the generation of neurophysiological correlates of tinnitus that have been proposed so far, and evaluate predictions and compare them to available data. We also assess the limits of their explanatory power, thus demonstrating where an understanding is still lacking and where further research may be needed. Identifying appropriate models is important for finding therapies, and we therefore, also summarize the implications of the models for approaches to treat tinnitus.
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Popovych OV, Tass PA. Desynchronizing electrical and sensory coordinated reset neuromodulation. Front Hum Neurosci 2012; 6:58. [PMID: 22454622 PMCID: PMC3308339 DOI: 10.3389/fnhum.2012.00058] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 03/03/2012] [Indexed: 11/13/2022] Open
Abstract
Coordinated reset (CR) stimulation is a desynchronizing stimulation technique based on timely coordinated phase resets of sub-populations of a synchronized neuronal ensemble. It has initially been computationally developed for electrical deep brain stimulation (DBS), to enable an effective desynchronization and unlearning of pathological synchrony and connectivity (anti-kindling). Here we computationally show for ensembles of spiking and bursting model neurons interacting via excitatory and inhibitory adaptive synapses that a phase reset of neuronal populations as well as a desynchronization and an anti-kindling can robustly be achieved by direct electrical stimulation or indirect (synaptically-mediated) excitatory and inhibitory stimulation. Our findings are relevant for DBS as well as for sensory stimulation in neurological disorders characterized by pathological neuronal synchrony. Based on the obtained results, we may expect that the local effects in the vicinity of a depth electrode (realized by direct stimulation of the neurons' somata or stimulation of axon terminals) and the non-local CR effects (realized by stimulation of excitatory or inhibitory efferent fibers) of deep brain CR neuromodulation may be similar or even identical. Furthermore, our results indicate that an effective desynchronization and anti-kindling can even be achieved by non-invasive, sensory CR neuromodulation. We discuss the concept of sensory CR neuromodulation in the context of neurological disorders.
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Affiliation(s)
- Oleksandr V Popovych
- Research Center Jülich, Institute of Neuroscience and Medicine - Neuromodulation (INM-7) Jülich, Germany
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31
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Langers DRM, de Kleine E, van Dijk P. Tinnitus does not require macroscopic tonotopic map reorganization. Front Syst Neurosci 2012; 6:2. [PMID: 22347171 PMCID: PMC3269775 DOI: 10.3389/fnsys.2012.00002] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 01/16/2012] [Indexed: 01/12/2023] Open
Abstract
The pathophysiology underlying tinnitus, a hearing disorder characterized by the chronic perception of phantom sound, has been related to aberrant plastic reorganization of the central auditory system. More specifically, tinnitus is thought to involve changes in the tonotopic representation of sound. In the present study we used high-resolution functional magnetic resonance imaging to determine tonotopic maps in the auditory cortex of 20 patients with tinnitus but otherwise near-normal hearing, and compared these to equivalent outcomes from 20 healthy controls with matched hearing thresholds. Using a dedicated experimental paradigm and data-driven analysis techniques, multiple tonotopic gradients could be robustly distinguished in both hemispheres, arranged in a pattern consistent with previous findings. Yet, maps were not found to significantly differ between the two groups in any way. In particular, we found no evidence for an overrepresentation of high sound frequencies, matching the tinnitus pitch. A significant difference in evoked response magnitude was found near the low-frequency tonotopic endpoint on the lateral extreme of left Heschl's gyrus. Our results suggest that macroscopic tonotopic reorganization in the auditory cortex is not required for the emergence of tinnitus, and is not typical for tinnitus that accompanies normal hearing to mild hearing loss.
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Affiliation(s)
- Dave R M Langers
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen Groningen, Netherlands
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32
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Tass PA, Popovych OV. Unlearning tinnitus-related cerebral synchrony with acoustic coordinated reset stimulation: theoretical concept and modelling. BIOLOGICAL CYBERNETICS 2012; 106:27-36. [PMID: 22350536 DOI: 10.1007/s00422-012-0479-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 01/26/2012] [Indexed: 05/31/2023]
Abstract
Tinnitus is a deafferentation-induced phantom phenomenon characterized by abnormal cerebral synchrony and connectivity. Computationally, we show that desynchronizing acoustic coordinated reset (CR) stimulation can effectively counteract both up-regulated synchrony and connectivity. CR stimulation has initially been developed for the application to electrical deep brain stimulation. We here adapt this approach to non-invasive, acoustic CR stimulation. For this, we use the tonotopic organization of the central auditory system and replace electrical stimulation bursts applied to different brain sites by acoustically delivered tones of different pitch. Based on our simulations, we propose non-invasive acoustic CR stimulation as a possible novel therapy for tinnitus.
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Affiliation(s)
- Peter A Tass
- Institute of Neuroscience and Medicine-Neuromodulation-INM-7, Research Center Jülich, 52425 Jülich, Germany.
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33
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Tinnitus with a normal audiogram: physiological evidence for hidden hearing loss and computational model. J Neurosci 2011; 31:13452-7. [PMID: 21940438 DOI: 10.1523/jneurosci.2156-11.2011] [Citation(s) in RCA: 656] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ever since Pliny the Elder coined the term tinnitus, the perception of sound in the absence of an external sound source has remained enigmatic. Traditional theories assume that tinnitus is triggered by cochlear damage, but many tinnitus patients present with a normal audiogram, i.e., with no direct signs of cochlear damage. Here, we report that in human subjects with tinnitus and a normal audiogram, auditory brainstem responses show a significantly reduced amplitude of the wave I potential (generated by primary auditory nerve fibers) but normal amplitudes of the more centrally generated wave V. This provides direct physiological evidence of "hidden hearing loss" that manifests as reduced neural output from the cochlea, and consequent renormalization of neuronal response magnitude within the brainstem. Employing an established computational model, we demonstrate how tinnitus could arise from a homeostatic response of neurons in the central auditory system to reduced auditory nerve input in the absence of elevated hearing thresholds.
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Homeostatic plasticity drives tinnitus perception in an animal model. Proc Natl Acad Sci U S A 2011; 108:14974-9. [PMID: 21896771 DOI: 10.1073/pnas.1107998108] [Citation(s) in RCA: 207] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hearing loss often results in tinnitus and auditory cortical map changes, leading to the prevailing view that the phantom perception is associated with cortical reorganization. However, we show here that tinnitus is mediated by a cortical area lacking map reorganization. High-frequency hearing loss results in two distinct cortical regions: a sensory-deprived region characterized by a decrease in inhibitory synaptic transmission and a normal hearing region showing increases in inhibitory and excitatory transmission and map reorganization. Hearing-lesioned animals displayed tinnitus with a pitch in the hearing loss range. Furthermore, drugs that enhance inhibition, but not those that reduce excitation, reversibly eliminated the tinnitus behavior. These results suggest that sensory deprivation-induced homeostatic down-regulation of inhibitory synapses may contribute to tinnitus perception. Enhancing sensory input through map reorganization may plausibly alleviate phantom sensation.
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Noreña AJ. An integrative model of tinnitus based on a central gain controlling neural sensitivity. Neurosci Biobehav Rev 2011; 35:1089-109. [PMID: 21094182 DOI: 10.1016/j.neubiorev.2010.11.003] [Citation(s) in RCA: 285] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/20/2010] [Accepted: 11/12/2010] [Indexed: 02/03/2023]
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Zhou X, Henin S, Long GR, Parra LC. Impaired cochlear function correlates with the presence of tinnitus and its estimated spectral profile. Hear Res 2011; 277:107-16. [PMID: 21376109 DOI: 10.1016/j.heares.2011.02.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 02/17/2011] [Accepted: 02/21/2011] [Indexed: 11/18/2022]
Abstract
The presence of tinnitus often coincides with hearing loss. It has been argued that reduced peripheral input leads to frequency-specific increase in neuronal gains resulting in tinnitus-related hyper-activity. Following this gain-adaptation hypothesis, impaired cochlear function should be predictive of the presence and spectral characteristics of tinnitus. To assess cochlear function, perceptual thresholds and distortion product otoacoustic emissions (DPOAEs) were measured with high frequency resolution for subjects with tinnitus and non-tinnitus control subjects (N = 29 and N = 18) with and without hearing loss. Subjects with tinnitus also provided a 'tinnitus likeness spectrum' by rating the similarity of their tinnitus to tones at various frequencies. On average, subjects with tinnitus had elevated thresholds, reduced DPOAE, and increased slope of the DPOAE input-output function in the range from 4 to 10 kHz. These measures were strongly correlated and were equally predictive of the presence of tinnitus. Subjects with a pronounced edge to their hearing loss profile were very likely to have tinnitus. In the group average, the tinnitus likeness spectrum was correlated with perceptual thresholds (r = 0.98, p < 0.01), confirming previous reports. For 19 of 29 of subjects, perceptual thresholds were correlated with the tinnitus likeness ratings across frequencies and this correlation was significantly improved when low input-level DPOAE were included as an additional variable (r = 0.83 ± 0.09, N = 19). Thus, cochlear function is strongly associated with the tinnitus percept and measures of cochlear function using DPOAEs provide additional diagnostic information over perceptual thresholds alone.
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Affiliation(s)
- Xiang Zhou
- Department of Biomedical Engineering, The City College of The City University of New York, New York, NY 10031, USA.
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37
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Acoustic stimulation treatments against tinnitus could be most effective when tinnitus pitch is within the stimulated frequency range. Hear Res 2010; 269:95-101. [DOI: 10.1016/j.heares.2010.06.022] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 06/22/2010] [Accepted: 06/28/2010] [Indexed: 11/24/2022]
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Chrostowski M, Yang L, Wilson HR, Bruce IC, Becker S. Can homeostatic plasticity in deafferented primary auditory cortex lead to travelling waves of excitation? J Comput Neurosci 2010; 30:279-99. [PMID: 20623168 DOI: 10.1007/s10827-010-0256-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/06/2010] [Accepted: 06/18/2010] [Indexed: 12/19/2022]
Abstract
Travelling waves of activity in neural circuits have been proposed as a mechanism underlying a variety of neurological disorders, including epileptic seizures, migraine auras and brain injury. The highly influential Wilson-Cowan cortical model describes the dynamics of a network of excitatory and inhibitory neurons. The Wilson-Cowan equations predict travelling waves of activity in rate-based models that have sufficiently reduced levels of lateral inhibition. Travelling waves of excitation may play a role in functional changes in the auditory cortex after hearing loss. We propose that down-regulation of lateral inhibition may be induced in deafferented cortex via homeostatic plasticity mechanisms. We use the Wilson-Cowan equations to construct a spiking model of the primary auditory cortex that includes a novel, mathematically formalized description of homeostatic plasticity. In our model, the homeostatic mechanisms respond to hearing loss by reducing inhibition and increasing excitation, producing conditions under which travelling waves of excitation can emerge. However, our model predicts that the presence of spontaneous activity prevents the development of long-range travelling waves of excitation. Rather, our simulations show short-duration excitatory waves that cancel each other out. We also describe changes in spontaneous firing, synchrony and tuning after simulated hearing loss. With the exception of shifts in characteristic frequency, changes after hearing loss were qualitatively the same as empirical findings. Finally, we discuss possible applications to tinnitus, the perception of sound without an external stimulus.
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Affiliation(s)
- Michael Chrostowski
- McMaster Integrative Neuroscience Discovery & Study, McMaster University, 1280 Main Street West, Hamilton, ON, Canada.
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39
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Balanced tone-evoked synaptic excitation and inhibition in mouse auditory cortex. Neuroscience 2009; 163:1302-15. [PMID: 19628023 DOI: 10.1016/j.neuroscience.2009.07.032] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 07/14/2009] [Accepted: 07/15/2009] [Indexed: 11/20/2022]
Abstract
The recent characterization of excitatory and inhibitory synaptic receptive fields in rat auditory cortex laid the basis for further investigation of the roles of synaptic excitation and inhibition in cortical computation and plasticity. The mouse is an increasingly important model system because of the wide range of genetic tools available for it. Here we present the first in vivo whole-cell voltage-clamp measurements of synaptic excitation and inhibition in the mouse cortex. We find that a substantial population of auditory cortical neurons receives balanced synaptic excitation and inhibition, whose amplitude ratios and relative time courses remain approximately constant across tone frequency. We conclude that the synaptic mechanisms underlying tone-evoked auditory cortical responses in mice closely resemble those in rats, supporting the mouse as a suitable model for synaptic processing in auditory cortex.
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Adjamian P, Sereda M, Hall DA. The mechanisms of tinnitus: perspectives from human functional neuroimaging. Hear Res 2009; 253:15-31. [PMID: 19364527 DOI: 10.1016/j.heares.2009.04.001] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/02/2009] [Accepted: 04/05/2009] [Indexed: 10/20/2022]
Abstract
In this review, we highlight the contribution of advances in human neuroimaging to the current understanding of central mechanisms underpinning tinnitus and explain how interpretations of neuroimaging data have been guided by animal models. The primary motivation for studying the neural substrates of tinnitus in humans has been to demonstrate objectively its representation in the central auditory system and to develop a better understanding of its diverse pathophysiology and of the functional interplay between sensory, cognitive and affective systems. The ultimate goal of neuroimaging is to identify subtypes of tinnitus in order to better inform treatment strategies. The three neural mechanisms considered in this review may provide a basis for TI classification. While human neuroimaging evidence strongly implicates the central auditory system and emotional centres in TI, evidence for the precise contribution from the three mechanisms is unclear because the data are somewhat inconsistent. We consider a number of methodological issues limiting the field of human neuroimaging and recommend approaches to overcome potential inconsistency in results arising from poorly matched participants, lack of appropriate controls and low statistical power.
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Affiliation(s)
- Peyman Adjamian
- MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD, United Kingdom.
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41
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Schaette R, Kempter R. Predicting tinnitus pitch from patients' audiograms with a computational model for the development of neuronal hyperactivity. J Neurophysiol 2009; 101:3042-52. [PMID: 19357344 DOI: 10.1152/jn.91256.2008] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Tinnitus is often related to hearing loss, but how hearing loss could lead to tinnitus has remained unclear. Animal studies show that the occurrence of tinnitus is correlated to increased spontaneous firing rates of central auditory neurons, but mechanisms that give rise to such hyperactivity have not been identified yet. Here we present a computational model that reproduces tinnitus-related hyperactivity and predicts tinnitus pitch from the audiograms of tinnitus patients with noise-induced hearing loss and tone-like tinnitus. Our key assumption is that the mean firing rates of central auditory neurons are controlled by homeostatic plasticity. Decreased auditory nerve activity after hearing loss is counteracted through an increase of the neuronal response gain, which restores the mean rate but can also lead to hyperactivity. Hyperactivity patterns calculated from patients' audiograms exhibit distinct peaks at frequencies close to the perceived tinnitus pitch, corroborating hyperactivity through homeostatic plasticity as a mechanism for the development of tinnitus after hearing loss. The model suggests that such hyperactivity, and thus also tinnitus caused by cochlear damage, could be alleviated through additional stimulation.
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Affiliation(s)
- Roland Schaette
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, Berlin.
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42
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Linking the response properties of cells in auditory cortex with network architecture: cotuning versus lateral inhibition. J Neurosci 2008; 28:9151-63. [PMID: 18784296 DOI: 10.1523/jneurosci.1789-08.2008] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The frequency-intensity receptive fields (RF) of neurons in primary auditory cortex (AI) are heterogeneous. Some neurons have V-shaped RFs, whereas others have enclosed ovoid RFs. Moreover, there is a wide range of temporal response profiles ranging from phasic to tonic firing. The mechanisms underlying this diversity of receptive field properties are yet unknown. Here we study the characteristics of thalamocortical (TC) and intracortical connectivity that give rise to the individual cell responses. Using a mouse auditory TC slice preparation, we found that the amplitude of synaptic responses in AI varies non-monotonically with the intensity of the stimulation in the medial geniculate nucleus (MGv). We constructed a network model of MGv and AI that was simulated using either rate model cells or in vitro neurons through an iterative procedure that used the recorded neural responses to reconstruct network activity. We compared the receptive fields and firing profiles obtained with networks configured to have either cotuned excitatory and inhibitory inputs or relatively broad, lateral inhibitory inputs. Each of these networks yielded distinct response properties consistent with those documented in vivo with natural stimuli. The cotuned network produced V-shaped RFs, phasic-tonic firing profiles, and predominantly monotonic rate-level functions. The lateral inhibitory network produced enclosed RFs with narrow frequency tuning, a variety of firing profiles, and robust non-monotonic rate-level functions. We conclude that both types of circuits must be present to account for the wide variety of responses observed in vivo.
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Bauer CA, Turner JG, Caspary DM, Myers KS, Brozoski TJ. Tinnitus and inferior colliculus activity in chinchillas related to three distinct patterns of cochlear trauma. J Neurosci Res 2008; 86:2564-78. [PMID: 18438941 DOI: 10.1002/jnr.21699] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A longstanding hypothesis is that tinnitus, the perception of sound without an external acoustic source, is triggered by a distinctive pattern of cochlear hair cell (HC) damage and that this subsequently leads to altered neural activity in the central auditory pathway. This hypothesis was tested by assessing behavioral evidence of tinnitus and spontaneous neural activity in the inferior colliculus (IC) after unilateral cochlear trauma. Chinchillas were assigned to four cochlear treatment groups. Each treatment produced a distinctive pattern of HC damage, as follows: acoustic exposure (AEx): sparse low-frequency inner hair cell (IHC) and outer hair cell (OHC) loss; round window cisplatin (CisEx): pronounced OHC loss mixed with some IHC loss; round window carboplatin (CarbEx): pronounced IHC loss without OHC loss; control: no loss. Compared with controls, all experimental groups displayed significant and similar psychophysical evidence of tinnitus with features resembling a 1-kHz tone. Contralateral IC spontaneous activity was elevated in the AEx and CisEx groups, which showed increased spiking and increased cross-fiber synchrony. A multidimensional analysis identified a subpopulation of neurons more prevalent in animals with tinnitus. These units were characterized by high bursting, low ISI variance, and within-burst peak spiking of approximately 1,000/sec. It was concluded that cochlear trauma in general, rather than its specific features, leads to multiple changes in central activity that underpin tinnitus. Particularly affected was a subpopulation ensemble of IC neurons with the described unique triad of features.
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Affiliation(s)
- Carol A Bauer
- Division of Otolaryngology-Head and Neck Surgery, Southern Illinois University School of Medicine, Springfield, Illinois 62794-9629, USA
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44
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Pathological effect of homeostatic synaptic scaling on network dynamics in diseases of the cortex. J Neurosci 2008; 28:1709-20. [PMID: 18272691 PMCID: PMC2882860 DOI: 10.1523/jneurosci.4263-07.2008] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Slow periodic EEG discharges are common in CNS disorders. The pathophysiology of this aberrant rhythmic activity is poorly understood. We used a computational model of a neocortical network with a dynamic homeostatic scaling rule to show that loss of input (partial deafferentation) can trigger network reorganization that results in pathological periodic discharges. The decrease in average firing rate in the network by deafferentation was compensated by homeostatic synaptic scaling of recurrent excitation among pyramidal cells. Synaptic scaling succeeded in recovering the network target firing rate for all degrees of deafferentation (fraction of deafferented cells), but there was a critical degree of deafferentation for pathological network reorganization. For deafferentation degrees below this value, homeostatic upregulation of recurrent excitation had minimal effect on the macroscopic network dynamics. For deafferentation above this threshold, however, a slow periodic oscillation appeared, patterns of activity were less sparse, and bursting occurred in individual neurons. Also, comparison of spike-triggered afferent and recurrent excitatory conductances revealed that information transmission was strongly impaired. These results suggest that homeostatic plasticity can lead to secondary functional impairment in case of cortical disorders associated with cell loss.
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Saunders JC. The role of central nervous system plasticity in tinnitus. JOURNAL OF COMMUNICATION DISORDERS 2007; 40:313-34. [PMID: 17418230 PMCID: PMC2083119 DOI: 10.1016/j.jcomdis.2007.03.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Accepted: 03/01/2007] [Indexed: 05/14/2023]
Abstract
UNLABELLED Tinnitus is a vexing disorder of hearing characterized by sound sensations originating in the head without any external stimulation. The specific etiology of these sensations is uncertain but frequently associated with hearing loss. The "neurophysiogical" model of tinnitus has enhanced appreciation of central nervous system (CNS) contributions. The model assumes that plastic changes in the primary and non-primary auditory pathways contribute to tinnitus with the former perhaps sustaining them, and the latter contributing to perceived severity and emotionality. These plastic changes are triggered by peripheral injury, which results in new patterns of brain activity due to anatomic alterations in the connectivity of CNS neurons. These alterations may change the balance between excitatory and inhibitory brain processes, perhaps producing cascades of new neural activity flowing between brainstem and cortex in a self-sustaining manner that produces persistent perceptions of tinnitus. The bases of this model are explored with an attempt to distinguish phenomenological from mechanistic explanations. LEARNING OUTCOMES (1) Readers will learn that the variables associated with the behavioral experience of tinnitus are as complex as the biological variables. (2) Readers will understand what the concept of neuroplastic brain change means, and how it is associated with tinnitus. (3) Readers will learn that there may be no one brain location associated with tinnitus, and it may result from interactions between multiple brain areas. (4) Readers will learn how disinhibition, spontaneous activity, neural synchronization, and tonotopic reorganization may contribute to tinnitus.
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Affiliation(s)
- James C Saunders
- Department of Otorhinolaryngololgy, Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
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46
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Husain FT. Neural network models of tinnitus. TINNITUS: PATHOPHYSIOLOGY AND TREATMENT 2007; 166:125-40. [DOI: 10.1016/s0079-6123(07)66011-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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