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Sander MY, Zhu X. Infrared neuromodulation-a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:066701. [PMID: 38701769 DOI: 10.1088/1361-6633/ad4729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 05/03/2024] [Indexed: 05/05/2024]
Abstract
Infrared (IR) neuromodulation (INM) is an emerging light-based neuromodulation approach that can reversibly control neuronal and muscular activities through the transient and localized deposition of pulsed IR light without requiring any chemical or genetic pre-treatment of the target cells. Though the efficacy and short-term safety of INM have been widely demonstrated in both peripheral and central nervous systems, the investigations of the detailed cellular and biological processes and the underlying biophysical mechanisms are still ongoing. In this review, we discuss the current research progress in the INM field with a focus on the more recently discovered IR nerve inhibition. Major biophysical mechanisms associated with IR nerve stimulation are summarized. As the INM effects are primarily attributed to the spatiotemporal thermal transients induced by water and tissue absorption of pulsed IR light, temperature monitoring techniques and simulation models adopted in INM studies are discussed. Potential translational applications, current limitations, and challenges of the field are elucidated to provide guidance for future INM research and advancement.
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Affiliation(s)
- Michelle Y Sander
- Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary's Street, Boston, MA 02215, United States of America
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, United States of America
- Division of Materials Science and Engineering, Boston University, 15 Saint Mary's Street, Brookline, MA 02446, United States of America
- Photonics Center, Boston University, 8 Saint Mary's Street, Boston, MA 02215, United States of America
- Neurophotonics Center, Boston University, 24 Cummington Mall, Boston, MA 02215, United States of America
| | - Xuedong Zhu
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, United States of America
- Photonics Center, Boston University, 8 Saint Mary's Street, Boston, MA 02215, United States of America
- Neurophotonics Center, Boston University, 24 Cummington Mall, Boston, MA 02215, United States of America
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2
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Garrido-Peña A, Sanchez-Martin P, Reyes-Sanchez M, Levi R, Rodriguez FB, Castilla J, Tornero J, Varona P. Modulation of neuronal dynamics by sustained and activity-dependent continuous-wave near-infrared laser stimulation. NEUROPHOTONICS 2024; 11:024308. [PMID: 38764942 PMCID: PMC11100521 DOI: 10.1117/1.nph.11.2.024308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/21/2024]
Abstract
Significance Near-infrared laser illumination is a non-invasive alternative/complement to classical stimulation methods in neuroscience but the mechanisms underlying its action on neuronal dynamics remain unclear. Most studies deal with high-frequency pulsed protocols and stationary characterizations disregarding the dynamic modulatory effect of sustained and activity-dependent stimulation. The understanding of such modulation and its widespread dissemination can help to develop specific interventions for research applications and treatments for neural disorders. Aim We quantified the effect of continuous-wave near-infrared (CW-NIR) laser illumination on single neuron dynamics using sustained stimulation and an open-source activity-dependent protocol to identify the biophysical mechanisms underlying this modulation and its time course. Approach We characterized the effect by simultaneously performing long intracellular recordings of membrane potential while delivering sustained and closed-loop CW-NIR laser stimulation. We used waveform metrics and conductance-based models to assess the role of specific biophysical candidates on the modulation. Results We show that CW-NIR sustained illumination asymmetrically accelerates action potential dynamics and the spiking rate on single neurons, while closed-loop stimulation unveils its action at different phases of the neuron dynamics. Our model study points out the action of CW-NIR on specific ionic-channels and the key role of temperature on channel properties to explain the modulatory effect. Conclusions Both sustained and activity-dependent CW-NIR stimulation effectively modulate neuronal dynamics by a combination of biophysical mechanisms. Our open-source protocols can help to disseminate this non-invasive optical stimulation in novel research and clinical applications.
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Affiliation(s)
- Alicia Garrido-Peña
- Grupo de Neurocomputación Biológica, Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Madrid, Spain
| | - Pablo Sanchez-Martin
- Grupo de Neurocomputación Biológica, Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Madrid, Spain
| | - Manuel Reyes-Sanchez
- Grupo de Neurocomputación Biológica, Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rafael Levi
- Grupo de Neurocomputación Biológica, Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Madrid, Spain
| | - Francisco B. Rodriguez
- Grupo de Neurocomputación Biológica, Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Madrid, Spain
| | - Javier Castilla
- Hospital los Madroños, Center for Clinical Neuroscience, Brunete, Spain
| | - Jesus Tornero
- Hospital los Madroños, Center for Clinical Neuroscience, Brunete, Spain
| | - Pablo Varona
- Grupo de Neurocomputación Biológica, Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Madrid, Spain
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3
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Coventry BS, Lawlor GL, Bagnati CB, Krogmeier C, Bartlett EL. Characterization and closed-loop control of infrared thalamocortical stimulation produces spatially constrained single-unit responses. PNAS NEXUS 2024; 3:pgae082. [PMID: 38725532 PMCID: PMC11079674 DOI: 10.1093/pnasnexus/pgae082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/07/2024] [Indexed: 05/12/2024]
Abstract
Deep brain stimulation (DBS) is a powerful tool for the treatment of circuitopathy-related neurological and psychiatric diseases and disorders such as Parkinson's disease and obsessive-compulsive disorder, as well as a critical research tool for perturbing neural circuits and exploring neuroprostheses. Electrically mediated DBS, however, is limited by the spread of stimulus currents into tissue unrelated to disease course and treatment, potentially causing undesirable patient side effects. In this work, we utilize infrared neural stimulation (INS), an optical neuromodulation technique that uses near to midinfrared light to drive graded excitatory and inhibitory responses in nerves and neurons, to facilitate an optical and spatially constrained DBS paradigm. INS has been shown to provide spatially constrained responses in cortical neurons and, unlike other optical techniques, does not require genetic modification of the neural target. We show that INS produces graded, biophysically relevant single-unit responses with robust information transfer in rat thalamocortical circuits. Importantly, we show that cortical spread of activation from thalamic INS produces more spatially constrained response profiles than conventional electrical stimulation. Owing to observed spatial precision of INS, we used deep reinforcement learning (RL) for closed-loop control of thalamocortical circuits, creating real-time representations of stimulus-response dynamics while driving cortical neurons to precise firing patterns. Our data suggest that INS can serve as a targeted and dynamic stimulation paradigm for both open and closed-loop DBS.
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Affiliation(s)
- Brandon S Coventry
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
- Center for Implantable Devices and the Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Georgia L Lawlor
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
- Center for Implantable Devices and the Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
| | - Christina B Bagnati
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Claudia Krogmeier
- Department of Computer Graphics Technology, Purdue University, West Lafayette, IN 47907, USA
| | - Edward L Bartlett
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
- Center for Implantable Devices and the Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN 47907, USA
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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4
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Mohseni-Dargah M, Falahati Z, Pastras C, Khajeh K, Mukherjee P, Razmjou A, Stefani S, Asadnia M. Meniere's disease: Pathogenesis, treatments, and emerging approaches for an idiopathic bioenvironmental disorder. ENVIRONMENTAL RESEARCH 2023; 238:116972. [PMID: 37648189 DOI: 10.1016/j.envres.2023.116972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/10/2023] [Accepted: 08/22/2023] [Indexed: 09/01/2023]
Abstract
Meniere's disease (MD) is a severe inner ear condition known by debilitating symptoms, including spontaneous vertigo, fluctuating and progressive hearing loss, tinnitus, and aural fullness or pressure within the affected ear. Prosper Meniere first described the origins of MD in the 1860s, but its underlying mechanisms remain largely elusive today. Nevertheless, researchers have identified a key histopathological feature called Endolymphatic Hydrops (ELH), which refers to the excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. The exact root of ELH is not fully understood. Still, it is believed to involve several biological and bioenvironmental etiological factors such as genetics, autoimmunity, infection, trauma, allergy, and new theories, such as saccular otoconia blocking the endolymphatic duct and sac. Regarding treatment, there are no reliable and definitive cures for MD. Most therapies focus on managing symptoms and improving the overall quality of patients' life. To make significant advancements in addressing MD, it is crucial to gain a fundamental understanding of the disease process, laying the groundwork for more effective therapeutic approaches. This paper provides a comprehensive review of the pathophysiology of MD with a focus on old and recent theories. Current treatment strategies and future translational approaches (with low-level evidence but promising results) related to MD are also discussed, including patents, drug delivery, and nanotechnology, that may provide future benefits to patients suffering from MD.
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Affiliation(s)
- Masoud Mohseni-Dargah
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia; Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Zahra Falahati
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran
| | - Christopher Pastras
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia; The Meniere's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Khosro Khajeh
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Payal Mukherjee
- RPA Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Amir Razmjou
- Centre for Technology in Water and Wastewater, University of Technology Sydney, New South Wales 2007, Australia
| | - Sebastian Stefani
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia
| | - Mohsen Asadnia
- School of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
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5
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Coventry BS, Lawlor GL, Bagnati CB, Krogmeier C, Bartlett EL. Spatially specific, closed-loop infrared thalamocortical deep brain stimulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.04.560859. [PMID: 37904955 PMCID: PMC10614743 DOI: 10.1101/2023.10.04.560859] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Deep brain stimulation (DBS) is a powerful tool for the treatment of circuitopathy-related neurological and psychiatric diseases and disorders such as Parkinson's disease and obsessive-compulsive disorder, as well as a critical research tool for perturbing neural circuits and exploring neuroprostheses. Electrically-mediated DBS, however, is limited by the spread of stimulus currents into tissue unrelated to disease course and treatment, potentially causing undesirable patient side effects. In this work, we utilize infrared neural stimulation (INS), an optical neuromodulation technique that uses near to mid-infrared light to drive graded excitatory and inhibitory responses in nerves and neurons, to facilitate an optical and spatially constrained DBS paradigm. INS has been shown to provide spatially constrained responses in cortical neurons and, unlike other optical techniques, does not require genetic modification of the neural target. We show that INS produces graded, biophysically relevant single-unit responses with robust information transfer in thalamocortical circuits. Importantly, we show that cortical spread of activation from thalamic INS produces more spatially constrained response profiles than conventional electrical stimulation. Owing to observed spatial precision of INS, we used deep reinforcement learning for closed-loop control of thalamocortical circuits, creating real-time representations of stimulus-response dynamics while driving cortical neurons to precise firing patterns. Our data suggest that INS can serve as a targeted and dynamic stimulation paradigm for both open and closed-loop DBS.
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Affiliation(s)
- Brandon S Coventry
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN USA
- Center for Implantable Devices and the Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
| | - Georgia L Lawlor
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN USA
- Center for Implantable Devices and the Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
| | - Christina B Bagnati
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN USA
| | - Claudia Krogmeier
- Department of Computer Graphics Technology, Purdue University, West Lafayette, IN USA
| | - Edward L Bartlett
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN USA
- Center for Implantable Devices and the Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
- Department of Biological Sciences, Purdue University, West Lafayette, IN USA
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6
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Almasri RM, Ladouceur F, Mawad D, Esrafilzadeh D, Firth J, Lehmann T, Poole-Warren LA, Lovell NH, Al Abed A. Emerging trends in the development of flexible optrode arrays for electrophysiology. APL Bioeng 2023; 7:031503. [PMID: 37692375 PMCID: PMC10491464 DOI: 10.1063/5.0153753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/08/2023] [Indexed: 09/12/2023] Open
Abstract
Optical-electrode (optrode) arrays use light to modulate excitable biological tissues and/or transduce bioelectrical signals into the optical domain. Light offers several advantages over electrical wiring, including the ability to encode multiple data channels within a single beam. This approach is at the forefront of innovation aimed at increasing spatial resolution and channel count in multichannel electrophysiology systems. This review presents an overview of devices and material systems that utilize light for electrophysiology recording and stimulation. The work focuses on the current and emerging methods and their applications, and provides a detailed discussion of the design and fabrication of flexible arrayed devices. Optrode arrays feature components non-existent in conventional multi-electrode arrays, such as waveguides, optical circuitry, light-emitting diodes, and optoelectronic and light-sensitive functional materials, packaged in planar, penetrating, or endoscopic forms. Often these are combined with dielectric and conductive structures and, less frequently, with multi-functional sensors. While creating flexible optrode arrays is feasible and necessary to minimize tissue-device mechanical mismatch, key factors must be considered for regulatory approval and clinical use. These include the biocompatibility of optical and photonic components. Additionally, material selection should match the operating wavelength of the specific electrophysiology application, minimizing light scattering and optical losses under physiologically induced stresses and strains. Flexible and soft variants of traditionally rigid photonic circuitry for passive optical multiplexing should be developed to advance the field. We evaluate fabrication techniques against these requirements. We foresee a future whereby established telecommunications techniques are engineered into flexible optrode arrays to enable unprecedented large-scale high-resolution electrophysiology systems.
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Affiliation(s)
- Reem M. Almasri
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | | | - Damia Mawad
- School of Materials Science and Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
| | - Josiah Firth
- Australian National Fabrication Facility, UNSW, Sydney, NSW 2052, Australia
| | - Torsten Lehmann
- School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052, Australia
| | | | | | - Amr Al Abed
- Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia
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7
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Whalen AJ, Fried SI. Thermal safety considerations for implantable micro-coil design. J Neural Eng 2023; 20:10.1088/1741-2552/ace79a. [PMID: 37451256 PMCID: PMC10467159 DOI: 10.1088/1741-2552/ace79a] [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: 03/03/2023] [Accepted: 07/14/2023] [Indexed: 07/18/2023]
Abstract
Micro magnetic stimulation of the brain via implantable micro-coils is a promising novel technology for neuromodulation. Careful consideration of the thermodynamic profile of such devices is necessary for effective and safe designs.Objective.We seek to quantify the thermal profile of bent wire micro-coils in order to understand and mitigate thermal impacts of micro-coil stimulation.Approach. In this study, we use fine wire thermocouples and COMSOL finite element modeling to examine the profile of the thermal gradients generated near bent wire micro-coils submerged in a water bath during stimulation. We tested a range of stimulation parameters previously reported in the literature such as voltage amplitude, stimulus frequency, stimulus repetition rate and coil wire materials.Main results. We found temperature increases ranging from <1 °C to 8.4 °C depending upon the stimulation parameters tested and coil wire materials used. Numerical modeling of the thermodynamics identified hot spots of the highest temperatures along the micro-coil contributing to the thermal gradients and demonstrated that these thermal gradients can be mitigated by the choice of wire conductor material and construction geometry.Significance. ISO standard 14708-1 designates a thermal safety limit of 2 °C temperature increase for active implantable medical devices. By switching the coil wire material from platinum/iridium to gold, our study achieved a 5-6-fold decrease in the thermal impact of coil stimulation. The thermal gradients generated from the gold wire coil were measured below the 2 °C safety limit for all stimulation parameters tested.
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Affiliation(s)
- Andrew J. Whalen
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Shelley I. Fried
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, USA
- Boston VA Medical Center, Boston, USA
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8
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Bassetto CAZ, Pinto BI, Latorre R, Bezanilla F. Ion channel thermodynamics studied with temperature jumps measured at the cell membrane. Biophys J 2023; 122:661-671. [PMID: 36654507 PMCID: PMC9989882 DOI: 10.1016/j.bpj.2023.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/29/2022] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
Perturbing the temperature of a system modifies its energy landscape, thus providing a ubiquitous tool to understand biological processes. Here, we developed a framework to generate sudden temperature jumps (Tjumps) and sustained temperature steps (Tsteps) to study the temperature dependence of membrane proteins under voltage clamp while measuring the membrane temperature. Utilizing the melanin under the Xenopus laevis oocytes membrane as a photothermal transducer, we achieved short Tjumps up to 9°C in less than 1.5 ms and constant Tsteps for durations up to 150 ms. We followed the temperature at the membrane with sub-ms time resolution by measuring the time course of membrane capacitance, which is linearly related to temperature. We applied Tjumps in Kir1.1 isoform b, which reveals a highly temperature-sensitive blockage relief, and characterized the effects of Tsteps on the temperature-sensitive channels TRPM8 and TRPV1. These newly developed approaches provide a general tool to study membrane protein thermodynamics.
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Affiliation(s)
- Carlos A Z Bassetto
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois
| | - Bernardo I Pinto
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencias de Valparaiso, Universidad de Valparaiso, Valparaiso, Chile.
| | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois; Centro Interdisciplinario de Neurociencias de Valparaiso, Universidad de Valparaiso, Valparaiso, Chile.
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9
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Kim T, Kadji H, Whalen AJ, Ashourvan A, Freeman E, Fried SI, Tadigadapa S, Schiff SJ. Thermal effects on neurons during stimulation of the brain. J Neural Eng 2022; 19:056029. [PMID: 36126646 PMCID: PMC9855718 DOI: 10.1088/1741-2552/ac9339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 09/13/2022] [Accepted: 09/20/2022] [Indexed: 01/25/2023]
Abstract
All electric and magnetic stimulation of the brain deposits thermal energy in the brain. This occurs through either Joule heating of the conductors carrying current through electrodes and magnetic coils, or through dissipation of energy in the conductive brain.Objective.Although electrical interaction with brain tissue is inseparable from thermal effects when electrodes are used, magnetic induction enables us to separate Joule heating from induction effects by contrasting AC and DC driving of magnetic coils using the same energy deposition within the conductors. Since mammalian cortical neurons have no known sensitivity to static magnetic fields, and if there is no evidence of effect on spike timing to oscillating magnetic fields, we can presume that the induced electrical currents within the brain are below the molecular shot noise where any interaction with tissue is purely thermal.Approach.In this study, we examined a range of frequencies produced from micromagnetic coils operating below the molecular shot noise threshold for electrical interaction with single neurons.Main results.We found that small temperature increases and decreases of 1∘C caused consistent transient suppression and excitation of neurons during temperature change. Numerical modeling of the biophysics demonstrated that the Na-K pump, and to a lesser extent the Nernst potential, could account for these transient effects. Such effects are dependent upon compartmental ion fluxes and the rate of temperature change.Significance.A new bifurcation is described in the model dynamics that accounts for the transient suppression and excitation; in addition, we note the remarkable similarity of this bifurcation's rate dependency with other thermal rate-dependent tipping points in planetary warming dynamics. These experimental and theoretical findings demonstrate that stimulation of the brain must take into account small thermal effects that are ubiquitously present in electrical and magnetic stimulation. More sophisticated models of electrical current interaction with neurons combined with thermal effects will lead to more accurate modulation of neuronal activity.
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Affiliation(s)
- TaeKen Kim
- Department of Physics, The Pennsylvania State University, University Park, PA, United States of America
| | - Herve Kadji
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States of America
- Department of Radiation Oncology, Hackensack Meridian Health Mountainside Medical Center, Montclair, NJ, United States of America
| | - Andrew J Whalen
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, United States of America
- Department of Neurosurgery, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States of America
| | - Arian Ashourvan
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States of America
| | - Eugene Freeman
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, United States of America
- Honeywell International Aerospace Advanced Technology, Plymouth, MN, United States of America
| | - Shelley I Fried
- Department of Neurosurgery, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States of America
- Boston VA Healthcare System, Boston 02130, United States of America
| | - Srinivas Tadigadapa
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, United States of America
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, United States of America
| | - Steven J Schiff
- Department of Physics, The Pennsylvania State University, University Park, PA, United States of America
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, United States of America
- Department of Neurosurgery, Penn State College of Medicine, Hershey, PA 17033, United States of America
- Department of Neurosurgery, Yale University, 333 Cedar Street, TMP 410, New Haven, CT 06510, United States of America
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10
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Zhu X, Lin JW, Sander MY. Bidirectional modulation of evoked synaptic transmission by pulsed infrared light. Sci Rep 2022; 12:14196. [PMID: 35987765 PMCID: PMC9392733 DOI: 10.1038/s41598-022-18139-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/05/2022] [Indexed: 12/05/2022] Open
Abstract
Infrared (IR) neuromodulation (INM) has been demonstrated as a novel modulation modality of neuronal excitability. However, the effects of pulsed IR light on synaptic transmission have not been investigated systematically. In this report, the IR light (2 μm) is used to directly modulate evoked synaptic transmission at the crayfish opener neuromuscular junction. The extracellularly recorded terminal action potentials (tAPs) and evoked excitatory postsynaptic currents (EPSCs) modulated by localized IR light illumination (500 ms, 3–13 mW) aimed at the synapses are analyzed. The impact of a single IR light pulse on the presynaptic Ca2+ influx is monitored with Ca2+ indicators. The EPSC amplitude is enhanced, and its rising phase is accelerated under relatively low IR light power levels and localized temperature rises. Increasing the IR light power reversibly suppresses and eventually blocks the EPSCs. Meanwhile, the synaptic delay, tAP amplitude, and presynaptic Ca2+ influx decrease monotonously with higher IR light power. It is demonstrated for the first time that IR light illumination has bidirectional effects on evoked synaptic transmission. These results highlight the efficacy and flexibility of using pulsed IR light to directly control synaptic transmission and advance our understanding of INM of neural networks.
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11
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Bian Y, Lu S, Wang Z, Qin Y, Li J, Guo G, Gong J, Jiang Y. Study the biomechanical performance of the membranous semicircular canal based on bionic models. Heliyon 2022; 8:e09480. [PMID: 35647361 PMCID: PMC9136265 DOI: 10.1016/j.heliyon.2022.e09480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/13/2022] [Accepted: 05/13/2022] [Indexed: 11/16/2022] Open
Abstract
A BA (bionic ampulla) was designed and fabricated using an SMPF (Symmetric electrodes Metal core PVDF Fiber) sensor, which could imitate the sensory hair cells to sense the deformation of the cupula of the BA. Based on the BA, a bionic semicircular canal with membrane semicircular canal (MBSC) and a bionic semicircular canal without membrane semicircular canal (NBSC) were designed and fabricated. The biomechanical models of the MBSC and NBSC were established. The biomechanical models were verified through the perception experiments of the MBSC and the NBSC. The results showed that the SMPF could sense the deformation of the cupula. The MBSC and NBSC could sense the angular velocity and accelerations. What's more, it was speculated that in a human body, the endolymph probably had a function of liquid mass while the membranous semicircular canal and the cupula had a function similar to a spring in the human semicircular canal.
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Affiliation(s)
- Yixiang Bian
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Shien Lu
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Zhi Wang
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Yongbin Qin
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Jialing Li
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Guangming Guo
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Junjie Gong
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
| | - Yani Jiang
- School of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China
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12
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Development of Bionic Semicircular Canals and the Sensation of Angular Acceleration. Bioengineering (Basel) 2022; 9:bioengineering9050180. [PMID: 35621458 PMCID: PMC9138073 DOI: 10.3390/bioengineering9050180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022] Open
Abstract
To study the sensing process of the human semicircular canals (HSCs) during head rotation, which is difficult to directly measure due to physiological reasons. A 1-BSC (one-dimensional bionic semicircular canal) and 3-BSC were prepared with soft SMPFs (symmetric electrode metal core polyvinylidene difluoride fibers), which could sense deformations similar to human sensory cells. Based on these models, experiments were carried out to study the principle of the HSCs. Deformations of the bionic ampulla (BA) depended on the angular acceleration. Gravity had a strong influence on the deformation of the BA in the vertical plane. When the 3-BSC was subjected to angular acceleration around one of its centerlines, the three BAs all deformed. The deformation of the BAs was linearly related to the angular acceleration. The deformation of the BA in the main semicircular canal was exactly three times that of the other two BAs.
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13
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Huang J, Tang X, Xu Y, Zhang C, Chen T, Yu Y, Mustain W, Allison J, Iversen MM, Rabbitt RD, Zhou W, Zhu H. Differential Activation of Canal and Otolith Afferents by Acoustic Tone Bursts in Rats. J Assoc Res Otolaryngol 2022; 23:435-453. [DOI: 10.1007/s10162-022-00839-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 01/31/2022] [Indexed: 01/08/2023] Open
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14
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Jiang W, Wang Z, Xiao S, Zeng D, Wu Z, Peng C, Chen F. Pulsed infrared stimulation evoked electrical potential in mouse vestibular system. Neurosci Lett 2022; 775:136510. [DOI: 10.1016/j.neulet.2022.136510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 01/17/2022] [Accepted: 02/01/2022] [Indexed: 10/19/2022]
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15
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Zhu X, Lin JW, Turnali A, Sander MY. Single infrared light pulses induce excitatory and inhibitory neuromodulation. BIOMEDICAL OPTICS EXPRESS 2022; 13:374-388. [PMID: 35154878 PMCID: PMC8803021 DOI: 10.1364/boe.444577] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
The excitatory and inhibitory effects of single and brief infrared (IR) light pulses (2 µm) with millisecond durations and various power levels are investigated with a custom-built fiber amplification system. Intracellular recordings from motor axons of the crayfish opener neuromuscular junction are performed ex vivo. Single IR light pulses induce a membrane depolarization during the light pulses, which is followed by a hyperpolarization that can last up to 100 ms. The depolarization amplitude is dependent on the optical pulse duration, total energy deposition and membrane potential, but is insensitive to tetrodotoxin. The hyperpolarization reverses its polarity near the potassium equilibrium potential and is barium-sensitive. The membrane depolarization activates an action potential (AP) when the axon is near firing threshold, while the hyperpolarization reversibly inhibits rhythmically firing APs. In summary, we demonstrate for the first time that single and brief IR light pulses can evoke initial depolarization followed by hyperpolarization on individual motor axons. The corresponding mechanisms and functional outcomes of the dual effects are investigated.
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Affiliation(s)
- Xuedong Zhu
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
- Neurophotonics Center, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
- Photonics Center, Boston University, 8 Saint Mary’s Street, Boston, MA 02215, USA
| | - Jen-Wei Lin
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Ahmet Turnali
- Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary’s Street, Boston, MA 02215, USA
- Photonics Center, Boston University, 8 Saint Mary’s Street, Boston, MA 02215, USA
| | - Michelle Y. Sander
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
- Neurophotonics Center, Boston University, 24 Cummington Mall, Boston, MA 02215, USA
- Department of Electrical and Computer Engineering, Boston University, 8 Saint Mary’s Street, Boston, MA 02215, USA
- Photonics Center, Boston University, 8 Saint Mary’s Street, Boston, MA 02215, USA
- Division of Materials Science and Engineering, Boston University, 15 Saint Mary’s Street, Brookline, MA 02446, USA
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16
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Rice D, Martinelli GP, Jiang W, Holstein GR, Rajguru SM. Pulsed Infrared Stimulation of Vertical Semicircular Canals Evokes Cardiovascular Changes in the Rat. Front Neurol 2021; 12:680044. [PMID: 34122320 PMCID: PMC8193737 DOI: 10.3389/fneur.2021.680044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 04/20/2021] [Indexed: 11/28/2022] Open
Abstract
A variety of stimuli activating vestibular end organs, including sinusoidal galvanic vestibular stimulation, whole body rotation and tilt, and head flexion have been shown to evoke significant changes in blood pressure (BP) and heart rate (HR). While a role for the vertical semicircular canals in altering autonomic activity has been hypothesized, studies to-date attribute the evoked BP and HR responses to the otolith organs. The present study determined whether unilateral activation of the posterior (PC) or anterior (AC) semicircular canal is sufficient to elicit changes in BP and/or HR. The study employed frequency-modulated pulsed infrared radiation (IR: 1,863 nm) directed via optical fibers to PC or AC of adult male Long-Evans rats. BP and HR changes were detected using a small-animal single pressure telemetry device implanted in the femoral artery. Eye movements evoked during IR of the vestibular endorgans were used to confirm the stimulation site. We found that sinusoidal IR delivered to either PC or AC elicited a rapid decrease in BP and HR followed by a stimulation frequency-matched modulation. The magnitude of the initial decrements in HR and BP did not correlate with the energy of the suprathreshold stimulus. This response pattern was consistent across multiple trials within an experimental session, replicable, and in most animals showed no evidence of habituation or an additive effect. Frequency modulated electrical current delivered to the PC and IR stimulation of the AC, caused decrements in HR and BP that resembled those evoked by IR of the PC. Frequency domain heart rate variability assessment revealed that, in most subjects, IR stimulation increased the low frequency (LF) component and decreased the high frequency (HF) component, resulting in an increase in the LF/HF ratio. This ratio estimates the relative contributions of sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activities. An injection of atropine, a muscarinic cholinergic receptor antagonist, diminished the IR evoked changes in HR, while the non-selective beta blocker propranolol eliminated changes in both HR and BP. This study provides direct evidence that activation of a single vertical semicircular canal is sufficient to activate and modulate central pathways that control HR and BP.
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Affiliation(s)
- Darrian Rice
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Giorgio P Martinelli
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Weitao Jiang
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Gay R Holstein
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States.,Department of Otolaryngology, University of Miami, Miami, FL, United States
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17
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Brown WGA, Needham K, Begeng JM, Thompson AC, Nayagam BA, Kameneva T, Stoddart PR. Response of primary auditory neurons to stimulation with infrared light in vitro. J Neural Eng 2021; 18:046003. [PMID: 33724234 DOI: 10.1088/1741-2552/abe7b8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Infrared light can be used to modulate the activity of neuronal cells through thermally-evoked capacitive currents and thermosensitive ion channel modulation. The infrared power threshold for action potentials has previously been found to be far lower in the in vivo cochlea when compared with other neuronal targets, implicating spiral ganglion neurons (SGNs) as a potential target for infrared auditory prostheses. However, conflicting experimental evidence suggests that this low threshold may arise from an intermediary mechanism other than direct SGN stimulation, potentially involving residual hair cell activity. APPROACH Patch-clamp recordings from cultured SGNs were used to explicitly quantify the capacitive and ion channel currents in an environment devoid of hair cells. Neurons were irradiated by a 1870 nm laser with pulse durations of 0.2-5.0 ms and powers up to 1.5 W. A Hodgkin-Huxley-type model was established by first characterising the voltage dependent currents, and then incorporating laser-evoked currents separated into temperature-dependent and temperature-gradient-dependent components. This model was found to accurately simulate neuronal responses and allowed the results to be extrapolated to stimulation parameter spaces not accessible during this study. MAIN RESULTS The previously-reported low in vivo SGN stimulation threshold was not observed, and only subthreshold depolarisation was achieved, even at high light exposures. Extrapolating these results with our Hodgkin-Huxley-type model predicts an action potential threshold which does not deviate significantly from other neuronal types. SIGNIFICANCE This suggests that the low-threshold response that is commonly reported in vivo may arise from an alternative mechanism, and calls into question the potential usefulness of the effect for auditory prostheses. The step-wise approach to modelling optically-evoked currents described here may prove useful for analysing a wider range of cell types where capacitive currents and conductance modulation are dominant.
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Affiliation(s)
- William G A Brown
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, John Street, Hawthorn VIC 3122, Australia
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18
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Yu Z, McIntosh JM, Sadeghi SG, Glowatzki E. Efferent synaptic transmission at the vestibular type II hair cell synapse. J Neurophysiol 2020; 124:360-374. [PMID: 32609559 DOI: 10.1152/jn.00143.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the vestibular peripheral organs, type I and type II hair cells (HCs) transmit incoming signals via glutamatergic quantal transmission onto afferent nerve fibers. Additionally, type I HCs transmit via "non-quantal" transmission to calyx afferent fibers, by accumulation of glutamate and potassium in the synaptic cleft. Vestibular efferent inputs originating in the brainstem contact type II HCs and vestibular afferents. Here, synaptic inputs to type II HCs were characterized by using electrical and optogenetic stimulation of efferent fibers combined with in vitro whole cell patch-clamp recording from type II HCs in the rodent vestibular crista. Properties of efferent synaptic currents in type II HCs were similar to those found in cochlear HCs and mediated by activation of α9-containing nicotinic acetylcholine receptors (nAChRs) and small-conductance calcium-activated potassium (SK) channels. While efferents showed a low probability of release at low frequencies of stimulation, repetitive stimulation resulted in facilitation and increased probability of release. Notably, the membrane potential of type II HCs during optogenetic stimulation of efferents showed a strong hyperpolarization in response to single pulses and was further enhanced by repetitive stimulation. Such efferent-mediated inhibition of type II HCs can provide a mechanism to adjust the contribution of signals from type I and type II HCs to vestibular nerve fibers, with a shift of the response to be more like that of calyx-only afferents with faster non-quantal responses.NEW & NOTEWORTHY Type II vestibular hair cells (HCs) receive inputs from efferent neurons in the brain stem. We used in vitro optogenetic and electrical stimulation of vestibular efferent fibers to study their synaptic inputs to type II HCs. Stimulation of efferents inhibited type II HCs, similar to efferent effects on cochlear HCs. We propose that efferent inputs adjust the contribution of signals from type I and II HCs to vestibular nerve fibers.
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Affiliation(s)
- Zhou Yu
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Otolaryngology-Head and Neck Surgery, The Center for Hearing and Balance, and The Center for Sensory Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Soroush G Sadeghi
- Department of Communicative Disorders and Sciences, and Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, New York.,Neuroscience Program, State University of New York at Buffalo, Buffalo, New York
| | - Elisabeth Glowatzki
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Otolaryngology-Head and Neck Surgery, The Center for Hearing and Balance, and The Center for Sensory Biology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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19
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Perez-Flores MC, Lee JH, Park S, Zhang XD, Sihn CR, Ledford HA, Wang W, Kim HJ, Timofeyev V, Yarov-Yarovoy V, Chiamvimonvat N, Rabbitt RD, Yamoah EN. Cooperativity of K v7.4 channels confers ultrafast electromechanical sensitivity and emergent properties in cochlear outer hair cells. SCIENCE ADVANCES 2020; 6:eaba1104. [PMID: 32285007 PMCID: PMC7141818 DOI: 10.1126/sciadv.aba1104] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/14/2020] [Indexed: 05/22/2023]
Abstract
The mammalian cochlea relies on active electromotility of outer hair cells (OHCs) to resolve sound frequencies. OHCs use ionic channels and somatic electromotility to achieve the process. It is unclear, though, how the kinetics of voltage-gated ionic channels operate to overcome extrinsic viscous drag on OHCs at high frequency. Here, we report ultrafast electromechanical gating of clustered Kv7.4 in OHCs. Increases in kinetics and sensitivity resulting from cooperativity among clustered-Kv7.4 were revealed, using optogenetics strategies. Upon clustering, the half-activation voltage shifted negative, and the speed of activation increased relative to solitary channels. Clustering also rendered Kv7.4 channels mechanically sensitive, confirmed in consolidated Kv7.4 channels at the base of OHCs. Kv7.4 clusters provide OHCs with ultrafast electromechanical channel gating, varying in magnitude and speed along the cochlea axis. Ultrafast Kv7.4 gating provides OHCs with a feedback mechanism that enables the cochlea to overcome viscous drag and resolve sounds at auditory frequencies.
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Affiliation(s)
- Maria C. Perez-Flores
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Jeong H. Lee
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Seojin Park
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Xiao-Dong Zhang
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655, USA
| | - Choong-Ryoul Sihn
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Hannah A. Ledford
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
| | - Wenying Wang
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Hyo Jeong Kim
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
| | - Valeriy Timofeyev
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655, USA
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | - Nipavan Chiamvimonvat
- Department of Internal Medicine, Division of Cardiology, University of California, Davis, Davis, CA 95616, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655, USA
| | - Richard D. Rabbitt
- Departments of Biomedical Engineering, Otolaryngology, and Neuroscience Program, University of Utah, Salt Lake City, UT 84112, USA
- Corresponding author. (E.N.Y.); (R.D.R.)
| | - Ebenezer N. Yamoah
- Department of Physiology, School of Medicine, University of Nevada, Reno, Reno, NV 89557, USA
- Corresponding author. (E.N.Y.); (R.D.R.)
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20
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Raphan T. Vestibular, locomotor, and vestibulo-autonomic research: 50 years of collaboration with Bernard Cohen. J Neurophysiol 2019; 123:329-345. [PMID: 31747361 DOI: 10.1152/jn.00485.2019] [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] [Indexed: 01/27/2023] Open
Abstract
My collaboration on the vestibulo-ocular reflex with Bernard Cohen began in 1972. Until 2017, this collaboration included studies of saccades, quick phases of nystagmus, the introduction of the concept of velocity storage, the relationship of velocity storage to motion sickness, primate and human locomotion, and studies of vasovagal syncope. These studies have elucidated the functioning of the vestibuloocular reflex, the locomotor system, the functioning of the vestibulo-sympathetic reflex, and how blood pressure and heart rate are controlled by the vestibular system. Although it is virtually impossible to review all the contributions in detail in a single paper, this article traces a thread of modeling that I brought to the collaboration, which, coupled with Bernie Cohen's expertise in vestibular and sensory-motor physiology and clinical insights, has broadened our understanding of the role of the vestibular system in a wide range of sensory-motor systems. Specifically, the paper traces how the concept of a relaxation oscillator was used to model the slow and rapid phases of ocular nystagmus. Velocity information that drives the slow compensatory eye movements was used to activate the saccadic system that resets the eyes, giving rise to the relaxation oscillator properties and simulated nystagmus as well as predicting the types of unit activity that generated saccades and nystagmic beats. The slow compensatory component of ocular nystagmus was studied in depth and gave rise to the idea that there was a velocity storage mechanism or integrator that not only is a focus for visual-vestibular interaction but also codes spatial orientation relative to gravity as referenced by the otoliths. Velocity storage also contributes to motion sickness when there are visual-vestibular as well as orientation mismatches in velocity storage. The relaxation oscillator concept was subsequently used to model the stance and swing phases of locomotion, how this impacted head and eye movements to maintain gaze in the direction of body motion, and how these were affected by Parkinson's disease. Finally, the relaxation oscillator was used to elucidate the functional form of the systolic and diastolic beats during blood pressure and how vasovagal syncope might be initiated by cerebellar-vestibular malfunction.
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Affiliation(s)
- Theodore Raphan
- Institute of Neural and Intelligent Systems and Department of Computer and Information Science, Brooklyn College and Graduate Center, City University of New York, Brooklyn, New York
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21
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Efferent Inputs Are Required for Normal Function of Vestibular Nerve Afferents. J Neurosci 2019; 39:6922-6935. [PMID: 31285300 DOI: 10.1523/jneurosci.0237-19.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/28/2019] [Accepted: 07/01/2019] [Indexed: 01/09/2023] Open
Abstract
A group of vestibular afferent nerve fibers with irregular-firing resting discharges are thought to play a prominent role in responses to fast head movements and vestibular plasticity. We show that, in C57BL/6 mice (either sex, 4-5 weeks old), normal activity in the efferent vestibular pathway is required for function of these irregular afferents. Thermal inhibition of efferent fibers results in a profound inhibition of irregular afferents' resting discharges, rendering them inadequate for signaling head movements. In this way, efferent inputs adjust the contribution of the peripheral irregular afferent pathway that plays a critical role in peripheral vestibular signaling and plasticity.SIGNIFICANCE STATEMENT Vestibular end organs in the inner ear receive efferent inputs from the brainstem. Previously, electrical stimulation of efferents was linked to an increase in resting discharges of afferents and a decrease in their sensitivities. Here, we show that localized thermal inhibition of unmyelinated efferents results in a significant decrease in the activity of afferent nerve fibers, particularly those with irregular resting discharges implicated in responses to fast head movements and vestibular compensation. Thus, by upregulating and downregulating of afferent firing, particularly irregular afferents, efferents adjust neural activity sensitive to rapid head movements. These findings support the notion that peripheral vestibular end organs are not passive transducers of head movements and their sensory signal transmission is modulated by efferent inputs.
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22
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Holman HA, Poppi LA, Frerck M, Rabbitt RD. Spontaneous and Acetylcholine Evoked Calcium Transients in the Developing Mouse Utricle. Front Cell Neurosci 2019; 13:186. [PMID: 31133810 PMCID: PMC6514437 DOI: 10.3389/fncel.2019.00186] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 04/12/2019] [Indexed: 11/13/2022] Open
Abstract
Spontaneous calcium transients are present during early postnatal development in the mouse retina and cochlea, and play an important role in maturation of the sensory organs and neural circuits in the central nervous system (CNS). It is not known whether similar calcium transients occur during postnatal development in the vestibular sensory organs. Here we demonstrate spontaneous intracellular calcium transients in sensory hair cells (HCs) and supporting cells (SCs) in the murine utricular macula during the first two postnatal weeks. Calcium transients were monitored using a genetically encoded calcium indicator, GCaMP5G (G5), at 100 ms-frame−1 in excised utricle sensory epithelia, including HCs, SCs, and neurons. The reporter line expressed G5 and tdTomato (tdT) in a Gad2-Cre dependent manner within a subset of utricular HCs, SCs and neurons. Kinetics of the G5 reporter limited temporal resolution to calcium events lasting longer than 200 ms. Spontaneous calcium transients lasting 1-2 s were observed in the expressing population of HCs at birth and slower spontaneous transients lasting 10-30 s appeared in SCs by P3. Beginning at P5, calcium transients could be modulated by application of the efferent neurotransmitter acetylcholine (ACh). In mature mice, calcium transients in the utricular macula occurred spontaneously, had a duration 1-2 s, and could be modulated by the exogenous application of acetylcholine (ACh) or muscarine. Long-lasting calcium transients evoked by ACh in mature mice were blocked by atropine, consistent with previous reports describing the role of muscarinic receptors expressed in calyx bearing afferents in efferent control of vestibular sensation. Large spontaneous and ACh evoked transients were reversibly blocked by the inositol trisphosphate receptor (IP3R) antagonist aminoethoxydiphenyl borate (2-APB). Results demonstrate long-lasting calcium transients are present in the utricular macula during the first postnatal week, and that responses to ACh mature over this same time period.
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Affiliation(s)
- Holly A Holman
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Lauren A Poppi
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States.,School of Biomedical Science and Pharmacy, Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
| | - Micah Frerck
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Richard D Rabbitt
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States.,Neuroscience Program, University of Utah, Salt Lake City, UT, United States.,Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, UT, United States
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23
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Rabbitt RD. Semicircular canal biomechanics in health and disease. J Neurophysiol 2019; 121:732-755. [PMID: 30565972 PMCID: PMC6520623 DOI: 10.1152/jn.00708.2018] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/11/2018] [Accepted: 12/11/2018] [Indexed: 12/12/2022] Open
Abstract
The semicircular canals are responsible for sensing angular head motion in three-dimensional space and for providing neural inputs to the central nervous system (CNS) essential for agile mobility, stable vision, and autonomic control of the cardiovascular and other gravity-sensitive systems. Sensation relies on fluid mechanics within the labyrinth to selectively convert angular head acceleration into sensory hair bundle displacements in each of three inner ear sensory organs. Canal afferent neurons encode the direction and time course of head movements over a broad range of movement frequencies and amplitudes. Disorders altering canal mechanics result in pathological inputs to the CNS, often leading to debilitating symptoms. Vestibular disorders and conditions with mechanical substrates include benign paroxysmal positional nystagmus, direction-changing positional nystagmus, alcohol positional nystagmus, caloric nystagmus, Tullio phenomena, and others. Here, the mechanics of angular motion transduction and how it contributes to neural encoding by the semicircular canals is reviewed in both health and disease.
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Affiliation(s)
- R. D. Rabbitt
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah
- Otolaryngology-Head Neck Surgery, University of Utah, Salt Lake City, Utah
- Neuroscience Program, University of Utah, Salt Lake City, Utah
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24
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Xu Y, Xia N, Lim M, Tan X, Tran MH, Boulger E, Peng F, Young H, Rau C, Rack A, Richter CP. Multichannel optrodes for photonic stimulation. NEUROPHOTONICS 2018; 5:045002. [PMID: 30397630 PMCID: PMC6197865 DOI: 10.1117/1.nph.5.4.045002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 09/24/2018] [Indexed: 05/27/2023]
Abstract
An emerging method in the field of neural stimulation is the use of photons to activate neurons. The possible advantage of optical stimulation over electrical is attributable to its spatially selective activation of small neuron populations, which is promising in generating superior spatial resolution in neural interfaces. Two principal methods are explored for cochlear prostheses: direct stimulation of nerves with infrared light and optogenetics. This paper discusses basic requirements for developing a light delivery system (LDS) for the cochlea and provides examples for building such devices. The proposed device relies on small optical sources, which are assembled in an array to be inserted into the cochlea. The mechanical properties, the biocompatibility, and the efficacy of optrodes have been tested in animal models. The force required to insert optrodes into a model of the human scala tympani was comparable to insertion forces obtained for contemporary cochlear implant electrodes. Side-emitting diodes are powerful enough to evoke auditory responses in guinea pigs. Chronic implantation of the LDS did not elevate auditory brainstem responses over 26 weeks.
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Affiliation(s)
- Yingyue Xu
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
- Northwestern University, Department of Communication Sciences and Disorders, Evanston, Illinois, United States
| | - Nan Xia
- Qingdao University, Institute for Digital Medicine and Computer-assisted Surgery, Qingdao, China
| | - Michelle Lim
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
| | - Xiaodong Tan
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
| | - Minh Ha Tran
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
| | - Erin Boulger
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
| | - Fei Peng
- Chongqing University, Bioengineering College, Chongqing, China
| | - Hunter Young
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
| | - Christoph Rau
- Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Alexander Rack
- Structure of Materials Group-ID19, European Synchrotron Radiation Facility, Cedex 9, France
| | - Claus-Peter Richter
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois, United States
- Northwestern University, Department of Communication Sciences and Disorders, Evanston, Illinois, United States
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Northwestern University, Hugh Knowles Center for Clinical and Basic Sciences in Hearing, Evanston, Illinois, United States
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Jiang W, Rajguru SM. Eye Movements Evoked by Pulsed Infrared Radiation of the Rat Vestibular System. Ann Biomed Eng 2018; 46:1406-1418. [PMID: 29845411 PMCID: PMC6095805 DOI: 10.1007/s10439-018-2059-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/24/2018] [Indexed: 10/16/2022]
Abstract
Light at infrared wavelengths has been demonstrated to modulate the pattern of neural signals transmitted from the angular motion sensing semicircular canals of the vestibular system to the brain. In the present study, we have characterized physiological eye movements evoked by focused, pulsed infrared radiation (IR) stimuli directed at an individual semicircular canal in a mammalian model. Pulsed IR (1863 nm) trains were directed at the posterior semicircular canal in a rat using 200-400 µm optical fibers. Evoked bilateral eye movements were measured using a custom-modified video-oculography system. The activation of vestibulo-ocular motor pathways by frequency modulated pulsed IR directed at single posterior semicircular canals evoked significant, characteristic bilateral eye movements. In this case, the resulting eye movements were disconjugate with ipsilateral eye moving upwards with a rotation towards the stimulated ear and the contralateral eye moving downwards. The eye movements were stable through several hours of repeated stimulation and could be maintained with 30 + minutes of continuous, frequency-modulated IR stimulation. Following the measurements, the distance of the fiber from target structures and orientation of the beam relative to vestibular structures were determined using micro-computed tomography. Results highlight the spatial selectivity of optical stimulation. Our results demonstrate a novel strategy for direct optical stimulation of the vestibular pathway in rodents and lays the groundwork for future applications of optical neural stimulation in inner ear research and therapeutic applications.
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Affiliation(s)
- Weitao Jiang
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive, MEA 204, Coral Gables, FL, 33146, USA
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive, MEA 204, Coral Gables, FL, 33146, USA.
- Department of Otolaryngology, University of Miami, 1600 NW 10th Ave, RMSB 3160, Miami, FL, 33136, USA.
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Barrett JN, Rincon S, Singh J, Matthewman C, Pasos J, Barrett EF, Rajguru SM. Pulsed infrared releases Ca 2+ from the endoplasmic reticulum of cultured spiral ganglion neurons. J Neurophysiol 2018; 120:509-524. [PMID: 29668377 DOI: 10.1152/jn.00740.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Inner ear spiral ganglion neurons were cultured from day 4 postnatal mice and loaded with a fluorescent Ca2+ indicator (fluo-4, -5F, or -5N). Pulses of infrared radiation (IR; 1,863 nm, 200 µs, 200-250 Hz for 2-5 s, delivered via an optical fiber) produced a rapid, transient temperature increase of 6-12°C (above a baseline of 24-30°C). These IR pulse trains evoked transient increases in both nuclear and cytosolic Ca2+ concentration ([Ca2+]) of 0.20-1.4 µM, with a simultaneous reduction of [Ca2+] in regions containing endoplasmic reticulum (ER). IR-induced increases in cytosolic [Ca2+] continued in medium containing no added Ca2+ (±Ca2+ buffers) and low [Na+], indicating that the [Ca2+] increase was mediated by release from intracellular stores. Consistent with this hypothesis, the IR-induced [Ca2+] response was prolonged and eventually blocked by inhibition of ER Ca2+-ATPase with cyclopiazonic acid, and was also inhibited by a high concentration of ryanodine and by inhibitors of inositol (1,4,5)-trisphosphate (IP3)-mediated Ca2+ release (xestospongin C and 2-aminoethoxydiphenyl borate). The thermal sensitivity of the response suggested involvement of warmth-sensitive transient receptor potential (TRP) channels. The IR-induced [Ca2+] increase was inhibited by TRPV4 inhibitors (HC-067047 and GSK-2193874), and immunostaining of spiral ganglion cultures demonstrated the presence of TRPV4 and TRPM2 that colocalized with ER marker GRP78. These results suggest that the temperature sensitivity of IR-induced [Ca2+] elevations is conferred by TRP channels on ER membranes, which facilitate Ca2+ efflux into the cytosol and thereby contribute to Ca2+-induced Ca2+-release via IP3 and ryanodine receptors. NEW & NOTEWORTHY Infrared radiation-induced photothermal effects release Ca2+ from the endoplasmic reticulum of primary spiral ganglion neurons. This Ca2+ release is mediated by activation of transient receptor potential (TRPV4) channels and involves amplification by Ca2+-induced Ca2+-release. The neurons immunostained for warmth-sensitive channels, TRPV4 and TRPM2, which colocalize with endoplasmic reticulum. Pulsed infrared radiation provides a novel experimental tool for releasing intracellular Ca2+, studying Ca2+ regulatory mechanisms, and influencing neuronal excitability.
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Affiliation(s)
- John N Barrett
- Department of Physiology and Biophysics, University of Miami , Miami, Florida.,Neuroscience Program, University of Miami , Miami, Florida
| | - Samantha Rincon
- Department of Biomedical Engineering, University of Miami , Miami, Florida
| | - Jayanti Singh
- Department of Otolaryngology, University of Miami , Miami, Florida
| | | | - Julio Pasos
- Department of Otolaryngology, University of Miami , Miami, Florida
| | - Ellen F Barrett
- Department of Physiology and Biophysics, University of Miami , Miami, Florida.,Neuroscience Program, University of Miami , Miami, Florida
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami , Miami, Florida.,Department of Otolaryngology, University of Miami , Miami, Florida
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Ultrasound Elicits Behavioral Responses through Mechanical Effects on Neurons and Ion Channels in a Simple Nervous System. J Neurosci 2018; 38:3081-3091. [PMID: 29463641 DOI: 10.1523/jneurosci.1458-17.2018] [Citation(s) in RCA: 155] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 01/11/2018] [Accepted: 01/27/2018] [Indexed: 01/07/2023] Open
Abstract
Focused ultrasound has been shown to stimulate excitable cells, but the biophysical mechanisms behind this phenomenon remain poorly understood. To provide additional insight, we devised a behavioral-genetic assay applied to the well-characterized nervous system of Caenorhabditis elegans nematodes. We found that pulsed ultrasound elicits robust reversal behavior in wild-type animals in a pressure-, duration-, and pulse protocol-dependent manner. Responses were preserved in mutants unable to sense thermal fluctuations and absent in mutants lacking neurons required for mechanosensation. Additionally, we found that the worm's response to ultrasound pulses rests on the expression of MEC-4, a DEG/ENaC/ASIC ion channel required for touch sensation. Consistent with prior studies of MEC-4-dependent currents in vivo, the worm's response was optimal for pulses repeated 300-1000 times per second. Based on these findings, we conclude that mechanical, rather than thermal, stimulation accounts for behavioral responses. Further, we propose that acoustic radiation force governs the response to ultrasound in a manner that depends on the touch receptor neurons and MEC-4-dependent ion channels. Our findings illuminate a complete pathway of ultrasound action, from the forces generated by propagating ultrasound to an activation of a specific ion channel. The findings further highlight the importance of optimizing ultrasound pulsing protocols when stimulating neurons via ion channels with mechanosensitive properties.SIGNIFICANCE STATEMENT How ultrasound influences neurons and other excitable cells has remained a mystery for decades. Although it is widely understood that ultrasound can heat tissues and induce mechanical strain, whether or not neuronal activation depends on heat, mechanical force, or both physical factors is not known. We harnessed Caenorhabditis elegans nematodes and their extraordinary sensitivity to thermal and mechanical stimuli to address this question. Whereas thermosensory mutants respond to ultrasound similar to wild-type animals, mechanosensory mutants were insensitive to ultrasound stimulation. Additionally, stimulus parameters that accentuate mechanical effects were more effective than those producing more heat. These findings highlight a mechanical nature of the effect of ultrasound on neurons and suggest specific ways to optimize stimulation protocols in specific tissues.
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Azimzadeh JB, Fabella BA, Kastan NR, Hudspeth AJ. Thermal Excitation of the Mechanotransduction Apparatus of Hair Cells. Neuron 2018; 97:586-595.e4. [PMID: 29395911 PMCID: PMC5805653 DOI: 10.1016/j.neuron.2018.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/13/2017] [Accepted: 01/03/2018] [Indexed: 12/21/2022]
Abstract
Although a hair bundle is normally deflected by mechanical stimuli, we found that irradiation of a hair cell from the bullfrog's sacculus with ultraviolet light causes rapid motion of the hair bundle toward its tall edge. This movement is associated with opening of mechanotransduction channels and disappears when tip links are disrupted. We localized the absorptive element responsible for the motion to the region directly below the hair bundle and measured an action spectrum similar to the absorption spectra of mitochondrial constituents. Temperature measurements revealed heating around the site of absorption; direct heating of the hair bundle confirmed that the response to light is mediated through heat. Although mechanical offsets of the hair bundle revealed that heat softens gating springs, it also acts directly to open transduction channels. This study identifies an unconventional method of hair-cell stimulation and clarifies the previously unexplained sensitivity of auditory organs to thermal stimulation.
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Affiliation(s)
- Julien B Azimzadeh
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Brian A Fabella
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Nathaniel R Kastan
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - A J Hudspeth
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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29
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Tan X, Jahan I, Xu Y, Stock S, Kwan CC, Soriano C, Xiao X, García-Añoveros J, Fritzsch B, Richter CP. Auditory Neural Activity in Congenitally Deaf Mice Induced by Infrared Neural Stimulation. Sci Rep 2018; 8:388. [PMID: 29321651 PMCID: PMC5762820 DOI: 10.1038/s41598-017-18814-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/11/2017] [Indexed: 11/16/2022] Open
Abstract
To determine whether responses during infrared neural stimulation (INS) result from the direct interaction with spiral ganglion neurons (SGNs), we tested three genetically modified deaf mouse models: Atoh1-cre; Atoh1f/f (Atoh1 conditional knockout, CKO), Atoh1-cre; Atoh1f/kiNeurog1 (Neurog1 knockin, KI), and the Vglut3 knockout (Vglut3−/−) mice. All animals were exposed to tone bursts and clicks up to 107 dB (re 20 µPa) and to INS, delivered with a 200 µm optical fiber. The wavelength (λ) was 1860 nm, the radiant energy (Q) 0-800 µJ/pulse, and the pulse width (PW) 100–500 µs. No auditory responses to acoustic stimuli could be evoked in any of these animals. INS could not evoke auditory brainstem responses in Atoh1 CKO mice but could in Neurog1 KI and Vglut3−/− mice. X-ray micro-computed tomography of the cochleae showed that responses correlated with the presence of SGNs and hair cells. Results in Neurog1 KI mice do not support a mechanical stimulation through the vibration of the basilar membrane, but cannot rule out the direct activation of the inner hair cells. Results in Vglut3−/− mice, which have no synaptic transmission between inner hair cells and SGNs, suggested that hair cells are not required.
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Affiliation(s)
- Xiaodong Tan
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, 320 E. Chicago Avenue, Searle 12-561, Chicago, IL, 60611, USA
| | - Israt Jahan
- Department of Biology, University of Iowa, 129 E. Jefferson Street, Iowa City, IA, 52242, USA
| | - Yingyue Xu
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, 320 E. Chicago Avenue, Searle 12-561, Chicago, IL, 60611, USA
| | - Stuart Stock
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Chicago, IL, 60611, USA
| | - Changyow Claire Kwan
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, 320 E. Chicago Avenue, Searle 12-561, Chicago, IL, 60611, USA
| | - Carmen Soriano
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Xianghui Xiao
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Jaime García-Añoveros
- Departments of Anesthesiology, Physiology, and Neurology, Northwestern University Institute for Neuroscience, Ward 10-070, 303 East Chicago Avenue, Chicago, IL, 60611, USA
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, 129 E. Jefferson Street, Iowa City, IA, 52242, USA
| | - Claus-Peter Richter
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, 320 E. Chicago Avenue, Searle 12-561, Chicago, IL, 60611, USA. .,Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Tech E310, Evanston, IL, 60208, USA. .,The Hugh Knowles Center, Department of Communication Sciences and Disorders, Northwestern University, Frances Searle Building, 2240 Campus Drive, Evanston, IL, 60208, USA.
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30
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Correspondence: Revisiting the theoretical cell membrane thermal capacitance response. Nat Commun 2017; 8:1431. [PMID: 29127422 PMCID: PMC5820289 DOI: 10.1038/s41467-017-00435-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 06/28/2017] [Indexed: 12/14/2022] Open
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31
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Poppi LA, Tabatabaee H, Drury HR, Jobling P, Callister RJ, Migliaccio AA, Jordan PM, Holt JC, Rabbitt RD, Lim R, Brichta AM. ACh-induced hyperpolarization and decreased resistance in mammalian type II vestibular hair cells. J Neurophysiol 2017; 119:312-325. [PMID: 28978760 DOI: 10.1152/jn.00030.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In the mammalian vestibular periphery, electrical activation of the efferent vestibular system (EVS) has two effects on afferent activity: 1) it increases background afferent discharge and 2) decreases afferent sensitivity to rotational stimuli. Although the cellular mechanisms underlying these two contrasting afferent responses remain obscure, we postulated that the reduction in afferent sensitivity was attributed, in part, to the activation of α9- containing nicotinic acetylcholine (ACh) receptors (α9*nAChRs) and small-conductance potassium channels (SK) in vestibular type II hair cells, as demonstrated in the peripheral vestibular system of other vertebrates. To test this hypothesis, we examined the effects of the predominant EVS neurotransmitter ACh on vestibular type II hair cells from wild-type (wt) and α9-subunit nAChR knockout (α9-/-) mice. Immunostaining for choline acetyltransferase revealed there were no obvious gross morphological differences in the peripheral EVS innervation among any of these strains. ACh application onto wt type II hair cells, at resting potentials, produced a fast inward current followed by a slower outward current, resulting in membrane hyperpolarization and decreased membrane resistance. Hyperpolarization and decreased resistance were due to gating of SK channels. Consistent with activation of α9*nAChRs and SK channels, these ACh-sensitive currents were antagonized by the α9*nAChR blocker strychnine and SK blockers apamin and tamapin. Type II hair cells from α9-/- mice, however, failed to respond to ACh at all. These results confirm the critical importance of α9nAChRs in efferent modulation of mammalian type II vestibular hair cells. Application of exogenous ACh reduces electrical impedance, thereby decreasing type II hair cell sensitivity. NEW & NOTEWORTHY Expression of α9 nicotinic subunit was crucial for fast cholinergic modulation of mammalian vestibular type II hair cells. These findings show a multifaceted efferent mechanism for altering hair cell membrane potential and decreasing membrane resistance that should reduce sensitivity to hair bundle displacements.
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Affiliation(s)
- Lauren A Poppi
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
| | - Hessam Tabatabaee
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
| | - Hannah R Drury
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
| | - Phillip Jobling
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
| | - Robert J Callister
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
| | | | - Paivi M Jordan
- Department of Otolaryngology, University of Rochester , Rochester, New York
| | - Joseph C Holt
- Department of Otolaryngology, University of Rochester , Rochester, New York
| | - Richard D Rabbitt
- Department of Bioengineering, University of Utah , Salt Lake City, Utah
| | - Rebecca Lim
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
| | - Alan M Brichta
- School of Biomedical Sciences and Pharmacy, The University of Newcastle and Hunter Medical Research Institute , Newcastle, New South Wales , Australia
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32
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Paris L, Marc I, Charlot B, Dumas M, Valmier J, Bardin F. Millisecond infrared laser pulses depolarize and elicit action potentials on in-vitro dorsal root ganglion neurons. BIOMEDICAL OPTICS EXPRESS 2017; 8:4568-4578. [PMID: 29082085 PMCID: PMC5654800 DOI: 10.1364/boe.8.004568] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 05/27/2023]
Abstract
This work focuses on the optical stimulation of dorsal root ganglion (DRG) neurons through infrared laser light stimulation. We show that a few millisecond laser pulse at 1875 nm induces a membrane depolarization, which was observed by the patch-clamp technique. This stimulation led to action potentials firing on a minority of neurons beyond an energy threshold. A depolarization without action potential was observed for the majority of DRG neurons, even beyond the action potential energy threshold. The use of ruthenium red, a thermal channel blocker, stops the action potential generation, but has no effects on membrane depolarization. Local temperature measurements reveal that the depolarization amplitude is sensitive to the amplitude of the temperature rise as well as to the time rate of change of temperature, but in a way which may not fully follow a photothermal capacitive mechanism, suggesting that more complex mechanisms are involved.
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Affiliation(s)
- Lambert Paris
- Institut d’Electronique et des Systèmes, CNRS UMR5214, Université de Montpellier, Montpellier, France
- Institut des Neurosciences de Montpellier, INSERM U1051, Montpellier, France
| | | | - Benoit Charlot
- Institut d’Electronique et des Systèmes, CNRS UMR5214, Université de Montpellier, Montpellier, France
| | | | - Jean Valmier
- Institut des Neurosciences de Montpellier, INSERM U1051, Montpellier, France
| | - Fabrice Bardin
- Institut d’Electronique et des Systèmes, CNRS UMR5214, Université de Montpellier, Montpellier, France
- MIPA, Université de Nîmes, Place Gabriel Péri, 30000, Nîmes, France
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33
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Favre-Bulle IA, Stilgoe AB, Rubinsztein-Dunlop H, Scott EK. Optical trapping of otoliths drives vestibular behaviours in larval zebrafish. Nat Commun 2017; 8:630. [PMID: 28931814 PMCID: PMC5606998 DOI: 10.1038/s41467-017-00713-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/18/2017] [Indexed: 11/22/2022] Open
Abstract
The vestibular system, which detects gravity and motion, is crucial to survival, but the neural circuits processing vestibular information remain incompletely characterised. In part, this is because the movement needed to stimulate the vestibular system hampers traditional neuroscientific methods. Optical trapping uses focussed light to apply forces to targeted objects, typically ranging from nanometres to a few microns across. In principle, optical trapping of the otoliths (ear stones) could produce fictive vestibular stimuli in a stationary animal. Here we use optical trapping in vivo to manipulate 55-micron otoliths in larval zebrafish. Medial and lateral forces on the otoliths result in complementary corrective tail movements, and lateral forces on either otolith are sufficient to cause a rolling correction in both eyes. This confirms that optical trapping is sufficiently powerful and precise to move large objects in vivo, and sets the stage for the functional mapping of the resulting vestibular processing.The neural circuits of the vestibular system, which detects gravity and motion, remain incompletely characterised. Here the authors use an optical trap to manipulate otoliths (ear stones) in zebrafish larvae, and elicit corrective tail movements and eye rolling, thus establishing a method for mapping vestibular processing.
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Affiliation(s)
- Itia A Favre-Bulle
- School of Mathematics and Physics, The University of Queensland, St. Lucia, QLD, 4072, Australia
- School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Alexander B Stilgoe
- School of Mathematics and Physics, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | | | - Ethan K Scott
- School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia.
- Queensland Brain Institute, The University of Queensland, St. Lucia, QLD, 4072, Australia.
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34
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Weissler Y, Farah N, Shoham S. Simulation of morphologically structured photo-thermal neural stimulation. J Neural Eng 2017; 14:055001. [PMID: 28820744 DOI: 10.1088/1741-2552/aa7805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Rational design of next-generation techniques for photo-thermal excitation requires the development of tools capable of modeling the effects of spatially- and temporally-dependent temperature distribution on cellular neuronal structures. APPROACH We present a new computer simulation tool for predicting the effects of arbitrary spatiotemporally-structured photo-thermal stimulation on 3D, morphologically realistic neurons. The new simulation tool is based on interfacing two generic platforms, NEURON and MATLAB and is therefore suited for capturing different kinds of stimuli and neural models. MAIN RESULTS Simulation results are validated using photo-absorber induced neuro-thermal stimulation (PAINTS) empirical results, and advanced features are explored. SIGNIFICANCE The new simulation tool could have an important role in understanding and investigating complex optical stimulation at the single-cell and network levels.
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Affiliation(s)
- Y Weissler
- The Faculty of Biomedical Engineering and Russel-Berrie Nanoscience and Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa, Israel
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35
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Bazard P, Frisina RD, Walton JP, Bhethanabotla VR. Nanoparticle-based Plasmonic Transduction for Modulation of Electrically Excitable Cells. Sci Rep 2017; 7:7803. [PMID: 28798342 PMCID: PMC5552804 DOI: 10.1038/s41598-017-08141-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 07/05/2017] [Indexed: 11/11/2022] Open
Abstract
There is a compelling need for the development of new sensory and neural prosthetic devices which are capable of more precise point stimulation. Current prosthetic devices suffer from the limitation of low spatial resolution due to the non-specific stimulation characteristics of electrical stimulation, i.e., the spread of electric fields generated. We present a visible light stimulation method for modulating the firing patterns of electrically-excitable cells using surface plasmon resonance phenomena. In in-vitro studies using gold (Au) nanoparticle-coated nanoelectrodes, we show that this method (substrate coated with nanoparticles) has the potential for incorporating this new technology into neural stimulation prosthetics, such as cochlear implants for the deaf, with very high spatial resolution. Au nanoparticles (NPs) were coated on micropipettes using aminosilane linkers; and these micropipettes were used for stimulating and inhibiting the action potential firing patterns of SH-SY5Y human neuroblastoma cells and neonatal cardiomyocytes. Our findings pave the way for development of biomedical implants and neural testing devices using nanoelectrodes capable of temporally and spatially precise excitation and inhibition of electrically-excitable cellular activity.
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Affiliation(s)
- Parveen Bazard
- Department of Chemical and Biomedical Engineering, College of Engineering, University of South Florida, Tampa, FL-33620, USA.,Global Center of Hearing and Speech Research, University of South Florida, Tampa, FL-33612, USA
| | - Robert D Frisina
- Department of Chemical and Biomedical Engineering, College of Engineering, University of South Florida, Tampa, FL-33620, USA.,Department of Communication Sciences and Disorders, College of Behavioral & Community Sciences, University of South Florida, Tampa, FL-33620, USA.,Global Center of Hearing and Speech Research, University of South Florida, Tampa, FL-33612, USA
| | - Joseph P Walton
- Department of Chemical and Biomedical Engineering, College of Engineering, University of South Florida, Tampa, FL-33620, USA.,Department of Communication Sciences and Disorders, College of Behavioral & Community Sciences, University of South Florida, Tampa, FL-33620, USA.,Global Center of Hearing and Speech Research, University of South Florida, Tampa, FL-33612, USA
| | - Venkat R Bhethanabotla
- Department of Chemical and Biomedical Engineering, College of Engineering, University of South Florida, Tampa, FL-33620, USA. .,Global Center of Hearing and Speech Research, University of South Florida, Tampa, FL-33612, USA.
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36
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Iversen MM, Christensen DA, Parker DL, Holman HA, Chen J, Frerck MJ, Rabbitt RD. Low-intensity ultrasound activates vestibular otolith organs through acoustic radiation force. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:4209. [PMID: 28618821 PMCID: PMC5552392 DOI: 10.1121/1.4984287] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 06/03/2023]
Abstract
The present study examined the efficacy of 5 MHz low-intensity focused ultrasound (LiFU) as a stimulus to remotely activate inner ear vestibular otolith organs. The otolith organs are the primary sensory apparati responsible for detecting orientation of the head relative to gravity and linear acceleration in three-dimensional space. These organs also respond to loud sounds and vibration of the temporal bone. The oyster toadfish, Opsanus tau, was used to facilitate unobstructed acoustic access to the otolith organs in vivo. Single-unit responses to amplitude-modulated LiFU were recorded in afferent neurons identified as innervating the utricle or the saccule. Neural responses were equivalent to direct mechanical stimulation, and arose from the nonlinear acoustic radiation force acting on the otolithic mass. The magnitude of the acoustic radiation force acting on the otolith was measured ex vivo. Results demonstrate that LiFU stimuli can be tuned to mimic directional forces occurring naturally during physiological movements of the head, loud air conducted sound, or bone conducted vibration.
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Affiliation(s)
- M M Iversen
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - D A Christensen
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - D L Parker
- Department of Radiology, University of Utah, 30 North 1900 East, Salt Lake City, Utah 84132, USA
| | - H A Holman
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - J Chen
- Communication Sciences and Disorders, University of Utah, 390 South 1530 East, Salt Lake City, Utah 84112, USA
| | - M J Frerck
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
| | - R D Rabbitt
- Department of Bioengineering, University of Utah, 36 South Wasatch Drive, Salt Lake City, Utah 84112, USA
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BODIPY-Conjugated Xyloside Primes Fluorescent Glycosaminoglycans in the Inner Ear of Opsanus tau. J Assoc Res Otolaryngol 2016; 17:525-540. [PMID: 27619213 DOI: 10.1007/s10162-016-0585-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 08/23/2016] [Indexed: 12/22/2022] Open
Abstract
We report on a new xyloside conjugated to BODIPY, BX and its utility to prime fluorescent glycosaminoglycans (BX-GAGs) within the inner ear in vivo. When BX is administered directly into the endolymphatic space of the oyster toadfish (Opsanus tau) inner ear, fluorescent BX-GAGs are primed and become visible in the sensory epithelia of the semicircular canals, utricle, and saccule. Confocal and 2-photon microscopy of vestibular organs fixed 4 h following BX treatment, reveal BX-GAGs constituting glycocalyces that envelop hair cell kinocilium, nerve fibers, and capillaries. In the presence of GAG-specific enzymes, the BX-GAG signals are diminished, suggesting that chondroitin sulfates are the primary GAGs primed by BX. Results are consistent with similar click-xylosides in CHO cell lines, where the xyloside enters the Golgi and preferentially initiates chondroitin sulfate B production. Introduction of BX produces a temporary block of hair cell mechanoelectrical transduction (MET) currents in the crista, reduction in background discharge rate of afferent neurons, and a reduction in sensitivity to physiological stimulation. A six-degree-of-freedom pharmacokinetic mathematical model has been applied to interpret the time course and spatial distribution of BX and BX-GAGs. Results demonstrate a new optical approach to study GAG biology in the inner ear, for tracking synthesis and localization in real time.
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