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Offutt SJ, Rose JE, Crawford KJ, Harris ML, Lim HH. Gradients of response latencies and temporal precision of auditory neurons extend across the whole inferior colliculus. J Neurophysiol 2023; 130:719-735. [PMID: 37609690 PMCID: PMC10650646 DOI: 10.1152/jn.00461.2022] [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: 11/07/2022] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/24/2023] Open
Abstract
Neural responses to acoustic stimulation have long been studied throughout the auditory system to understand how sound information is coded for perception. Within the inferior colliculus (IC), a majority of the studies have focused predominantly on characterizing neural responses within the central region (ICC), as it is viewed as part of the lemniscal system mainly responsible for auditory perception. In contrast, the responses of outer cortices (ICO) have largely been unexplored, though they also function in auditory perception tasks. Therefore, we sought to expand on previous work by completing a three-dimensional (3-D) functional mapping study of the whole IC. We analyzed responses to different pure tone and broadband noise stimuli across all IC subregions and correlated those responses with over 2,000 recording locations across the IC. Our study revealed there are well-organized trends for temporal response parameters across the full IC that do not show a clear distinction at the ICC and ICO border. These gradients span from slow, imprecise responses in the caudal-medial IC to fast, precise responses in the rostral-lateral IC, regardless of subregion, including the fastest responses located in the ICO. These trends were consistent at various acoustic stimulation levels. Weaker spatial trends could be found for response duration and spontaneous activity. Apart from tonotopic organization, spatial trends were not apparent for spectral response properties. Overall, these detailed acoustic response maps across the whole IC provide new insights into the organization and function of the IC.NEW & NOTEWORTHY Study of the inferior colliculus (IC) has largely focused on the central nucleus, with little exploration of the outer cortices. Here, we systematically assessed the acoustic response properties from over 2,000 locations in different subregions of the IC. The results revealed spatial trends in temporal response patterns that span all subregions. Furthermore, two populations of temporal response types emerged for neurons in the outer cortices that may contribute to their functional roles in auditory tasks.
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Affiliation(s)
- Sarah J Offutt
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Jessica E Rose
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Kellie J Crawford
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Megan L Harris
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States
- Department of Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, Minnesota, United States
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota, United States
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Gloeckner CD, Nocon JC, Lim HH. Topographic and widespread auditory modulation of the somatosensory cortex: potential for bimodal sound and body stimulation for pain treatment. J Neural Eng 2022; 19. [PMID: 35671702 DOI: 10.1088/1741-2552/ac7665] [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: 01/11/2022] [Accepted: 06/07/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE There has been growing interest in understanding multisensory integration in the cortex through activation of multiple sensory and motor pathways to treat brain disorders, such as tinnitus or essential tremors. For tinnitus, previous studies show that combined sound and body stimulation can modulate the auditory pathway and lead to significant improvements in tinnitus symptoms. Considering that tinnitus is a type of chronic auditory pain, bimodal stimulation could potentially alter activity in the somatosensory pathway relevant for treating chronic pain. As an initial step towards that goal, we mapped and characterized neuromodulation effects in the somatosensory cortex (SC) in response to sound and/or electrical stimulation of the body. APPROACH We first mapped the topographic organization of activity across the SC of ketamine-anesthetized guinea pigs through electrical stimulation of different body locations using subcutaneous needle electrodes or with broadband acoustic stimulation. We then characterized how neural activity in different parts of the SC could be facilitated or suppressed with bimodal stimulation. MAIN RESULTS The topography in the SC of guinea pigs in response to electrical stimulation of the body aligns consistently to that shown in previous rodent studies. Interestingly, auditory broadband noise stimulation primarily excited SC areas that typically respond to stimulation of lower body locations. Although there was only a small subset of SC locations that were excited by acoustic stimulation alone, all SC recording sites could be altered (facilitated or suppressed) with bimodal stimulation. Furthermore, specific regions of the SC could be modulated by stimulating an appropriate body region combined with broadband noise. SIGNIFICANCE These findings show that bimodal stimulation can excite or modulate firing across a widespread yet targeted population of SC neurons. This approach may provide a non-invasive method for altering or disrupting abnormal firing patterns within certain parts of the SC for chronic pain treatment.
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Affiliation(s)
- Cory D Gloeckner
- University of Minnesota Duluth, 1305 Ordean Court, Duluth, Minnesota, 55812, UNITED STATES
| | - Jian C Nocon
- Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts, 02215, UNITED STATES
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, 7-105 Hasselmo Hall, 312 Church Street SE, Minneapolis, MN 55455, USA, Minneapolis, Minnesota, 55455, UNITED STATES
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3
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Ultrasound does not activate but can inhibit in vivo mammalian nerves across a wide range of parameters. Sci Rep 2022; 12:2182. [PMID: 35140238 PMCID: PMC8828880 DOI: 10.1038/s41598-022-05226-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 12/24/2021] [Indexed: 11/21/2022] Open
Abstract
Ultrasound (US) has been shown to stimulate brain circuits, however, the ability to excite peripheral nerves with US remains controversial. To the best of our knowledge, there is still no in vivo neural recording study that has applied US stimulation to a nerve isolated from surrounding tissue to confirm direct activation effects. Here, we show that US cannot excite an isolated mammalian sciatic nerve in an in vivo preparation, even at high pressures (relative to levels recommended in the FDA guidance for diagnostic ultrasound) and for a wide range of parameters, including different pulse patterns and center frequencies. US can, however, reliably inhibit nerve activity whereby greater suppression is correlated with increases in nerve temperature. By prohibiting the nerve temperature from increasing during US application, we did not observe suppressive effects. Overall, these findings demonstrate that US can reliably inhibit nerve activity through a thermal mechanism that has potential for various health disorders, though future studies are needed to evaluate the long-term safety of therapeutic ultrasound applications.
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Hosseini M, Rodriguez G, Guo H, Lim HH, Plourde E. The effect of input noises on the activity of auditory neurons using GLM-based metrics. J Neural Eng 2021; 18. [PMID: 33626516 DOI: 10.1088/1741-2552/abe979] [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: 07/09/2020] [Accepted: 02/24/2021] [Indexed: 11/11/2022]
Abstract
CONTEXT The auditory system is extremely efficient in extracting auditory information in the presence of background noise. However, people with auditory implants have a hard time understanding speech in noisy conditions. Understanding the mechanisms of perception in noise could lead to better stimulation or preprocessing strategies for such implants. OBJECTIVE The neural mechanisms related to the processing of background noise, especially in the inferior colliculus (IC) where the auditory midbrain implant is located, are still not well understood. We thus wish to investigate if there is a difference in the activity of neurons in the IC when presenting noisy vocalizations with different types of noise (stationary vs. non-stationary), input signal-to-noise ratios (SNR) and signal levels. APPROACH We developed novel metrics based on a generalized linear model (GLM) to investigate the effect of a given input noise on neural activity. We used these metrics to analyze neural data recorded from the IC in ketamine-anesthetized female Hartley guinea pigs while presenting noisy vocalizations. MAIN RESULTS We found that non-stationary noise clearly contributes to the multi-unit neural activity in the IC by causing excitation, regardless of the SNR, input level or vocalization type. However, when presenting white or natural stationary noises, a great diversity of responses was observed for the different conditions, where the multi-unit activity of some sites was affected by the presence of noise and the activity of others was not. SIGNIFICANCE The GLM-based metrics allowed the identification of a clear distinction between the effect of white or natural stationary noises and that of non-stationary noise on the multi-unit activity in the IC. This had not been observed before and indicates that the so-called noise invariance in the IC is dependent on the input noisy conditions. This could suggest different preprocessing or stimulation approaches for auditory midbrain implants depending on the noisy conditions.
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Affiliation(s)
- Maryam Hosseini
- Electrical engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec, J1K 2R1, CANADA
| | - Gerardo Rodriguez
- Biomedical engineering, University of Minnesota, 312 Church St SE, Minneapolis, Minnesota, 55455, UNITED STATES
| | - Hongsun Guo
- Biomedical engineering, University of Minnesota, 312 Church St SE, Minneapolis, Minnesota, 55455, UNITED STATES
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, 7-105 Hasselmo Hall, 312 Church Street SE, Minneapolis, MN 55455, USA, Minneapolis, Minnesota, 55455, UNITED STATES
| | - Eric Plourde
- Electrical engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec, J1K 2R1, CANADA
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Zhang J, Firestone E, Elattma A. Animal Models of Tinnitus Treatment: Cochlear and Brain Stimulation. Curr Top Behav Neurosci 2021; 51:83-129. [PMID: 34282563 DOI: 10.1007/7854_2021_227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neuromodulation, via stimulation of a variety of peripheral and central structures, is used to suppress tinnitus. However, investigative limitations in humans due to ethical reasons have made it difficult to decipher the mechanisms underlying treatment-induced tinnitus relief, so a number of animal models have arisen to address these unknowns. This chapter reviews animal models of cochlear and brain stimulation and assesses their modulatory effects on behavioral evidence of tinnitus and its related neural correlates. When a structure is stimulated, localized modulation, often presenting as downregulation of spontaneous neuronal spike firing rate, bursting and neurosynchrony, occurs within the brain area. Through anatomical projections and transmitter pathways, the interventions activate both auditory- and non-auditory structures by taking bottom-up ascending and top-down descending modes to influence their target brain structures. Furthermore, it is the brain oscillations that cochlear or brain stimulation evoke and connect the prefrontal cortex, striatal systems, and other limbic structures to refresh neural networks and relieve auditory, attentive, conscious, as well as emotional reactive aspects of tinnitus. This oscillatory neural network connectivity is achieved via the thalamocorticothalamic circuitry including the lemniscal and non-lemniscal auditory brain structures. Beyond existing technologies, the review also reveals opportunities for developing advanced animal models using new modalities to achieve precision neuromodulation and tinnitus abatement, such as optogenetic cochlear and/or brain stimulation.
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Affiliation(s)
- Jinsheng Zhang
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, USA. .,Department of Communication Sciences and Disorders, Wayne State University College of Liberal Arts and Sciences, Detroit, MI, USA.
| | - Ethan Firestone
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ahmed Elattma
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit, MI, USA
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Abstract
Tinnitus is a common symptom. Standard therapies aim at improving the quality of life and reducing the psychological stress associated with tinnitus. Most interventions have little or no effect on the main symptom. Those affected subjects, however, want such a change and prefer a specific solution, such as pharmacologic therapy to other modalities. Scientific efforts have not yet led to significant improvement in the range of therapies. This article outlines existing efforts and develops ideas on how research for improved tinnitus therapy might look in the future.
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Affiliation(s)
- Tobias Kleinjung
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 24, Zurich CH 8091, Switzerland.
| | - Berthold Langguth
- Department of Psychiatry and Psychotherapy, Interdisciplinary Tinnitus Center, University of Regensburg, Universitätsstrasse 84, Regensburg D 93053, Germany
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Kleinlogel S, Vogl C, Jeschke M, Neef J, Moser T. Emerging approaches for restoration of hearing and vision. Physiol Rev 2020; 100:1467-1525. [DOI: 10.1152/physrev.00035.2019] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Impairments of vision and hearing are highly prevalent conditions limiting the quality of life and presenting a major socioeconomic burden. For long, retinal and cochlear disorders have remained intractable for causal therapies, with sensory rehabilitation limited to glasses, hearing aids, and electrical cochlear or retinal implants. Recently, the application of gene therapy and optogenetics to eye and ear has generated hope for a fundamental improvement of vision and hearing restoration. To date, one gene therapy for the restoration of vision has been approved and undergoing clinical trials will broaden its application including gene replacement, genome editing, and regenerative approaches. Moreover, optogenetics, i.e. controlling the activity of cells by light, offers a more general alternative strategy. Over little more than a decade, optogenetic approaches have been developed and applied to better understand the function of biological systems, while protein engineers have identified and designed new opsin variants with desired physiological features. Considering potential clinical applications of optogenetics, the spotlight is on the sensory systems. Multiple efforts have been undertaken to restore lost or hampered function in eye and ear. Optogenetic stimulation promises to overcome fundamental shortcomings of electrical stimulation, namely poor spatial resolution and cellular specificity, and accordingly to deliver more detailed sensory information. This review aims at providing a comprehensive reference on current gene therapeutic and optogenetic research relevant to the restoration of hearing and vision. We will introduce gene-therapeutic approaches and discuss the biotechnological and optoelectronic aspects of optogenetic hearing and vision restoration.
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Affiliation(s)
| | | | | | | | - Tobias Moser
- Institute for Auditory Neuroscience, University Medical Center Goettingen, Germany
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Conlon B, Hamilton C, Hughes S, Meade E, Hall DA, Vanneste S, Langguth B, Lim HH. Noninvasive Bimodal Neuromodulation for the Treatment of Tinnitus: Protocol for a Second Large-Scale Double-Blind Randomized Clinical Trial to Optimize Stimulation Parameters. JMIR Res Protoc 2019; 8:e13176. [PMID: 31573942 PMCID: PMC6789422 DOI: 10.2196/13176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 01/13/2023] Open
Abstract
Background There is increasing evidence from animal and human studies that bimodal neuromodulation combining sound and electrical somatosensory stimulation of the tongue can induce extensive brain changes and treat tinnitus. Objective The main objectives of the proposed clinical study are to confirm the efficacy, safety, and tolerability of treatment demonstrated in a previous large-scale study of bimodal auditory and trigeminal nerve (tongue) stimulation (Treatment Evaluation of Neuromodulation for Tinnitus - Stage A1); evaluate the therapeutic effects of adjusting stimulation parameters over time; and determine the contribution of different features of bimodal stimulation in improving tinnitus outcomes. Methods This study will be a prospective, randomized, double-blind, parallel-arm, comparative clinical trial of a 12-week treatment for tinnitus using a Conformité Européenne (CE)–marked device with a pre-post and 12-month follow-up design. Four treatment arms will be investigated, in which each arm consists of two different stimulation settings, with the first setting presented during the first 6 weeks and the second setting presented during the next 6 weeks of treatment. The study will enroll 192 participants, split in a ratio of 80:80:16:16 across the four arms. Participants will be randomized to one of four arms and stratified to minimize baseline variability in four categories: two separate strata for sound level tolerance (using loudness discomfort level as indicators for hyperacusis severity), high tinnitus symptom severity based on the Tinnitus Handicap Inventory (THI), and tinnitus laterality. The primary efficacy endpoints are within-arm changes in THI and Tinnitus Functional Index as well as between-arm changes in THI after 6 weeks of treatment for the full cohort and two subgroups of tinnitus participants (ie, one hyperacusis subgroup and a high tinnitus symptom severity subgroup). Additional efficacy endpoints include within-arm or between-arm changes in THI after 6 or 12 weeks of treatment and in different subgroups of tinnitus participants as well as at posttreatment assessments at 6 weeks, 6 months, and 12 months. Treatment safety, attrition rates, and compliance rates will also be assessed and reported. Results This study protocol was approved by the Tallaght University Hospital/St. James’s Hospital Joint Research Ethics Committee in Dublin, Ireland. The first participant was enrolled on March 20, 2018. The data collection and database lock are expected to be completed by February 2020, and the data analysis and manuscript submission are expected to be conducted in autumn of 2020. Conclusions The findings of this study will be disseminated to relevant research, clinical, and health services and patient communities through publications in peer-reviewed journals and presentations at scientific and clinical conferences. Trial Registration ClinicalTrials.gov NCT03530306; https://clinicaltrials.gov/ct2/show/NCT03530306 International Registered Report Identifier (IRRID) DERR1-10.2196/13176
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Affiliation(s)
- Brendan Conlon
- Department of Otolaryngology, St James Hospital Dublin and Tallaght University Hospital Dublin, Dublin, Ireland.,Neuromod Devices Limited, Dublin, Ireland.,Trinity College Dublin, Dublin, Ireland
| | | | | | - Emma Meade
- Neuromod Devices Limited, Dublin, Ireland
| | - Deborah A Hall
- Hearing Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom.,National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham, United Kingdom.,University of Nottingham Malaysia, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Sven Vanneste
- Trinity College Dublin, Dublin, Ireland.,University of Texas at Dallas, Richardson, TX, United States
| | - Berthold Langguth
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Hubert H Lim
- Neuromod Devices Limited, Dublin, Ireland.,University of Minnesota, Minneapolis, MN, United States
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Stahn P, Lim HH, Hinsberger MP, Sorg K, Pillong L, Kannengießer M, Schreiter C, Foth HJ, Langenbucher A, Schick B, Wenzel GI. Frequency-specific activation of the peripheral auditory system using optoacoustic laser stimulation. Sci Rep 2019; 9:4171. [PMID: 30862850 PMCID: PMC6414650 DOI: 10.1038/s41598-019-40860-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 02/22/2019] [Indexed: 11/09/2022] Open
Abstract
Hearing impairment is one of the most common sensory deficits in humans. Hearing aids are helpful to patients but can have poor sound quality or transmission due to insufficient output or acoustic feedback, such as for high frequencies. Implantable devices partially overcome these issues but require surgery with limited locations for device attachment. Here, we investigate a new optoacoustic approach to vibrate the hearing organ with laser stimulation to improve frequency bandwidth, not requiring attachment to specific vibratory structures, and potentially reduce acoustic feedback. We developed a laser pulse modulation strategy and simulated its response at the umbo (1-10 kHz) based on a convolution-based model. We achieved frequency-specific activation in which non-contact laser stimulation of the umbo, as well as within the middle ear at the round window and otic capsule, induced precise shifts in the maximal vibratory response of the umbo and neural activation within the inferior colliculus of guinea pigs, corresponding to the targeted, modelled and then stimulated frequency. There was also no acoustic feedback detected from laser stimulation with our experimental setup. These findings open up the potential for using a convolution-based optoacoustic approach as a new type of laser hearing aid or middle ear implant.
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Affiliation(s)
- Patricia Stahn
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany.
| | - Hubert H Lim
- University of Minnesota, Department of Biomedical Engineering, Department of Otolaryngology, Minnesota, USA
| | - Marius P Hinsberger
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Katharina Sorg
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Lukas Pillong
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Marc Kannengießer
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
- Saarland University, Experimental Ophthalmology, Homburg, Germany
| | - Cathleen Schreiter
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Hans-Jochen Foth
- Technische Universität Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | | | - Bernhard Schick
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Gentiana I Wenzel
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany.
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Guo H, Hamilton M, Offutt SJ, Gloeckner CD, Li T, Kim Y, Legon W, Alford JK, Lim HH. Ultrasound Produces Extensive Brain Activation via a Cochlear Pathway. Neuron 2018; 98:1020-1030.e4. [PMID: 29804919 DOI: 10.1016/j.neuron.2018.04.036] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/21/2018] [Accepted: 04/27/2018] [Indexed: 12/25/2022]
Abstract
Ultrasound (US) can noninvasively activate intact brain circuits, making it a promising neuromodulation technique. However, little is known about the underlying mechanism. Here, we apply transcranial US and perform brain mapping studies in guinea pigs using extracellular electrophysiology. We find that US elicits extensive activation across cortical and subcortical brain regions. However, transection of the auditory nerves or removal of cochlear fluids eliminates the US-induced activity, revealing an indirect auditory mechanism for US neural activation. Our findings indicate that US activates the ascending auditory system through a cochlear pathway, which can activate other non-auditory regions through cross-modal projections. This cochlear pathway mechanism challenges the idea that US can directly activate neurons in the intact brain, suggesting that future US stimulation studies will need to control for this effect to reach reliable conclusions.
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Affiliation(s)
- Hongsun Guo
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Mark Hamilton
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sarah J Offutt
- Restorative Therapies Group, Medtronic, Inc., Minneapolis, MN 55432, USA
| | - Cory D Gloeckner
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tianqi Li
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yohan Kim
- Restorative Therapies Group, Medtronic, Inc., Minneapolis, MN 55432, USA
| | - Wynn Legon
- Department of Rehabilitation Medicine, Medical School, University of Minnesota, Minneapolis, MN 55455, USA; Department of Neurological Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Jamu K Alford
- Restorative Therapies Group, Medtronic, Inc., Minneapolis, MN 55432, USA
| | - Hubert H Lim
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; Department of Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, MN 55455, USA
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11
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Normann RA, Fernandez E. Clinical applications of penetrating neural interfaces and Utah Electrode Array technologies. J Neural Eng 2016; 13:061003. [PMID: 27762237 DOI: 10.1088/1741-2560/13/6/061003] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper briefly describes some of the recent progress in the development of penetrating microelectrode arrays and highlights the use of two of these devices, Utah electrode arrays and Utah slanted electrode arrays, in two therapeutic interventions: recording volitional skeletal motor commands from the central nervous system, and recording motor commands and evoking somatosensory percepts in the peripheral nervous system (PNS). The paper also briefly explores other potential sites for microelectrode array interventions that could be profitably pursued and that could have important consequences in enhancing the quality of life of patients that has been compromised by disorders of the central and PNSs.
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Affiliation(s)
- Richard A Normann
- Departments of Bioengineering and Ophthalmology, University of Utah, Salt Lake City, UT 84112, USA
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12
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Deep brain stimulation of the inferior colliculus in the rodent suppresses tinnitus. Brain Res 2016; 1650:118-124. [PMID: 27592136 DOI: 10.1016/j.brainres.2016.08.046] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/12/2016] [Accepted: 08/30/2016] [Indexed: 11/24/2022]
Abstract
In animal models of tinnitus pathological neuronal activity has been demonstrated. Deep brain stimulation disrupts pathological neuronal activity and might therefore be a potential treatment for patients who suffer severely from tinnitus. In this study, the effect of DBS in the inferior colliculi is investigated in an animal model of tinnitus. The external cortex of the inferior colliculus was targeted because of the key position of the inferior colliculus within the auditory network and the relation of the external cortex with the limbic system. In this study we show the effect of DBS in the inferior colliculus on tinnitus using a within-subject experimental design. After noise trauma, rats showed a significant increase in gap:no gap ratio of the gap-induced prepulse inhibition at 16 and 20kHz (p<0.05), indicating the presence of tinnitus in these frequency bands. During DBS the gap:no gap ratio returned back to baseline (p<0.05). Hearing thresholds before and during DBS did not differ, indicating that hearing function is probably not impaired by electrical stimulation. In summary, this study shows that DBS of the inferior colliculi is effective in reducing behavioral signs of tinnitus in an animal model. Impaired hearing function could not be objectified as a side effect of stimulation.
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Electrical Stimulation of the Ear, Head, Cranial Nerve, or Cortex for the Treatment of Tinnitus: A Scoping Review. Neural Plast 2016; 2016:5130503. [PMID: 27403346 PMCID: PMC4925995 DOI: 10.1155/2016/5130503] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 04/22/2016] [Accepted: 05/18/2016] [Indexed: 11/18/2022] Open
Abstract
Tinnitus is defined as the perception of sound in the absence of an external source. It is often associated with hearing loss and is thought to result from abnormal neural activity at some point or points in the auditory pathway, which is incorrectly interpreted by the brain as an actual sound. Neurostimulation therapies therefore, which interfere on some level with that abnormal activity, are a logical approach to treatment. For tinnitus, where the pathological neuronal activity might be associated with auditory and other areas of the brain, interventions using electromagnetic, electrical, or acoustic stimuli separately, or paired electrical and acoustic stimuli, have been proposed as treatments. Neurostimulation therapies should modulate neural activity to deliver a permanent reduction in tinnitus percept by driving the neuroplastic changes necessary to interrupt abnormal levels of oscillatory cortical activity and restore typical levels of activity. This change in activity should alter or interrupt the tinnitus percept (reduction or extinction) making it less bothersome. Here we review developments in therapies involving electrical stimulation of the ear, head, cranial nerve, or cortex in the treatment of tinnitus which demonstrably, or are hypothesised to, interrupt pathological neuronal activity in the cortex associated with tinnitus.
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14
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Two Laskers and Counting: Learning From the Past Enables Future Innovations With Central Neural Prostheses. Brain Stimul 2015; 8:439-41. [DOI: 10.1016/j.brs.2014.10.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 10/23/2014] [Accepted: 10/23/2014] [Indexed: 12/20/2022] Open
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Markovitz CD, Hogan PS, Wesen KA, Lim HH. Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity. J Neural Eng 2015; 12:026006. [PMID: 25686163 PMCID: PMC4359690 DOI: 10.1088/1741-2560/12/2/026006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. APPROACH We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. MAIN RESULTS All eight stimulated AC subregions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. SIGNIFICANCE We propose that the corticofugal system is designed to decrease the brain's input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders.
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Affiliation(s)
- Craig D. Markovitz
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
| | - Patrick S. Hogan
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
| | - Kyle A. Wesen
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
| | - Hubert H. Lim
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, MN USA
- University of Minnesota, Department of Otolaryngology-Head and Neck Surgery, Minneapolis, MN USA
- University of Minnesota, Institute for Translational Neuroscience, Minneapolis, MN USA
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Berger JI, Coomber B. Tinnitus-related changes in the inferior colliculus. Front Neurol 2015; 6:61. [PMID: 25870582 PMCID: PMC4378364 DOI: 10.3389/fneur.2015.00061] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/09/2015] [Indexed: 12/21/2022] Open
Abstract
Tinnitus is highly complex, diverse, and difficult to treat, in part due to the fact that the underlying causes and mechanisms remain elusive. Tinnitus is generated within the auditory brain; however, consolidating our understanding of tinnitus pathophysiology is difficult due to the diversity of reported effects and the variety of implicated brain nuclei. Here, we focus on the inferior colliculus (IC), a midbrain structure that integrates the vast majority of ascending auditory information and projects via the thalamus to the auditory cortex. The IC is also a point of convergence for corticofugal input and input originating outside the auditory pathway. We review the evidence, from both studies with human subjects and from animal models, for the contribution the IC makes to tinnitus. Changes in the IC, caused by either noise exposure or drug administration, involve fundamental, heterogeneous alterations in the balance of excitation and inhibition. However, differences between hearing loss-induced pathology and tinnitus-related pathology are not well understood. Moreover, variability in tinnitus induction methodology has a significant impact on subsequent neural and behavioral changes, which could explain some of the seemingly contradictory data. Nonetheless, the IC is likely involved in the generation and persistence of tinnitus perception.
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Affiliation(s)
- Joel I Berger
- Medical Research Council Institute of Hearing Research, University of Nottingham , Nottingham , UK
| | - Ben Coomber
- Medical Research Council Institute of Hearing Research, University of Nottingham , Nottingham , UK
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Markovitz CD, Smith BT, Gloeckner CD, Lim HH. Investigating a new neuromodulation treatment for brain disorders using synchronized activation of multimodal pathways. Sci Rep 2015; 5:9462. [PMID: 25804410 PMCID: PMC4372796 DOI: 10.1038/srep09462] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 03/06/2015] [Indexed: 11/21/2022] Open
Abstract
Neuromodulation is an increasingly accepted treatment for neurological and psychiatric disorders but is limited by its invasiveness or its inability to target deep brain structures using noninvasive techniques. We propose a new concept called Multimodal Synchronization Therapy (mSync) for achieving targeted activation of the brain via noninvasive and precisely timed activation of auditory, visual, somatosensory, motor, cognitive, and limbic pathways. In this initial study in guinea pigs, we investigated mSync using combined activation of just the auditory and somatosensory pathways, which induced differential and timing dependent plasticity in neural firing within deep brain and cortical regions of the auditory system. Furthermore, by varying the location of somatosensory stimulation across the body, we increased or decreased spiking activity across different neurons. These encouraging results demonstrate the feasibility of systematically modulating the brain using mSync. Considering that hearing disorders such as tinnitus and hyperacusis have been linked to abnormal and hyperactive firing patterns within the auditory system, these results open up the possibility for using mSync to decrease this pathological activity by varying stimulation parameters. Incorporating multiple types of pathways beyond just auditory and somatosensory inputs and using other activation patterns may enable treatment of various brain disorders.
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Affiliation(s)
- Craig D Markovitz
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA
| | - Benjamin T Smith
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA
| | - Cory D Gloeckner
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA
| | - Hubert H Lim
- 1] Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN USA [2] Department of Otolaryngology-Head and Neck Surgery, University of Minnesota, Minneapolis, MN USA [3] Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN USA
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Lim HH, Lenarz T. Auditory midbrain implant: research and development towards a second clinical trial. Hear Res 2015; 322:212-23. [PMID: 25613994 DOI: 10.1016/j.heares.2015.01.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 12/04/2014] [Accepted: 01/08/2015] [Indexed: 11/30/2022]
Abstract
The cochlear implant is considered one of the most successful neural prostheses to date, which was made possible by visionaries who continued to develop the cochlear implant through multiple technological and clinical challenges. However, patients without a functional auditory nerve or implantable cochlea cannot benefit from a cochlear implant. The focus of the paper is to review the development and translation of a new type of central auditory prosthesis for this group of patients that is known as the auditory midbrain implant (AMI) and is designed for electrical stimulation within the inferior colliculus. The rationale and results for the first AMI clinical study using a multi-site single-shank array will be presented initially. Although the AMI has achieved encouraging results in terms of safety and improvements in lip-reading capabilities and environmental awareness, it has not yet provided sufficient speech perception. Animal and human data will then be presented to show that a two-shank AMI array can potentially improve hearing performance by targeting specific neurons of the inferior colliculus. A new two-shank array, stimulation strategy, and surgical approach are planned for the AMI that are expected to improve hearing performance in the patients who will be implanted in an upcoming clinical trial funded by the National Institutes of Health. Positive outcomes from this clinical trial will motivate new efforts and developments toward improving central auditory prostheses for those who cannot sufficiently benefit from cochlear implants. This article is part of a Special Issue entitled <Lasker Award>.
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Affiliation(s)
- Hubert H Lim
- Department of Biomedical Engineering, Department of Otolaryngology, and Institute for Translational Neuroscience, University of Minnesota, 312 Church Street S.E., Minneapolis, MN, 55455, USA.
| | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School, Carl-Neuberg-Str.1, Hannover, 30625, Germany.
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