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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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Stoddart PR, Begeng JM, Tong W, Ibbotson MR, Kameneva T. Nanoparticle-based optical interfaces for retinal neuromodulation: a review. Front Cell Neurosci 2024; 18:1360870. [PMID: 38572073 PMCID: PMC10987880 DOI: 10.3389/fncel.2024.1360870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 03/04/2024] [Indexed: 04/05/2024] Open
Abstract
Degeneration of photoreceptors in the retina is a leading cause of blindness, but commonly leaves the retinal ganglion cells (RGCs) and/or bipolar cells extant. Consequently, these cells are an attractive target for the invasive electrical implants colloquially known as "bionic eyes." However, after more than two decades of concerted effort, interfaces based on conventional electrical stimulation approaches have delivered limited efficacy, primarily due to the current spread in retinal tissue, which precludes high-acuity vision. The ideal prosthetic solution would be less invasive, provide single-cell resolution and an ability to differentiate between different cell types. Nanoparticle-mediated approaches can address some of these requirements, with particular attention being directed at light-sensitive nanoparticles that can be accessed via the intrinsic optics of the eye. Here we survey the available known nanoparticle-based optical transduction mechanisms that can be exploited for neuromodulation. We review the rapid progress in the field, together with outstanding challenges that must be addressed to translate these techniques to clinical practice. In particular, successful translation will likely require efficient delivery of nanoparticles to stable and precisely defined locations in the retinal tissues. Therefore, we also emphasize the current literature relating to the pharmacokinetics of nanoparticles in the eye. While considerable challenges remain to be overcome, progress to date shows great potential for nanoparticle-based interfaces to revolutionize the field of visual prostheses.
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Affiliation(s)
- Paul R. Stoddart
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC, Australia
| | - James M. Begeng
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC, Australia
- Department of Biomedical Engineering, Faculty of Engineering & Information Technology, The University of Melbourne, Melbourne, VIC, Australia
| | - Wei Tong
- Department of Biomedical Engineering, Faculty of Engineering & Information Technology, The University of Melbourne, Melbourne, VIC, Australia
- School of Physics, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael R. Ibbotson
- Department of Biomedical Engineering, Faculty of Engineering & Information Technology, The University of Melbourne, Melbourne, VIC, Australia
| | - Tatiana Kameneva
- School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC, Australia
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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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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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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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Ping A, Pan L, Zhang J, Xu K, Schriver KE, Zhu J, Roe AW. Targeted Optical Neural Stimulation: A New Era for Personalized Medicine. Neuroscientist 2023; 29:202-220. [PMID: 34865559 DOI: 10.1177/10738584211057047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Targeted optical neural stimulation comprises infrared neural stimulation and optogenetics, which affect the nervous system through induced thermal transients and activation of light-sensitive proteins, respectively. The main advantage of this pair of optical tools is high functional selectivity, which conventional electrical stimulation lacks. Over the past 15 years, the mechanism, safety, and feasibility of optical stimulation techniques have undergone continuous investigation and development. When combined with other methods like optical imaging and high-field functional magnetic resonance imaging, the translation of optical stimulation to clinical practice adds high value. We review the theoretical foundations and current state of optical stimulation, with a particular focus on infrared neural stimulation as a potential bridge linking optical stimulation to personalized medicine.
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Affiliation(s)
- An Ping
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Li Pan
- Qiushi Academy for Advanced Studies (QAAS), Key Laboratory of Biomedical Engineering of Education Ministry & Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianmin Zhang
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Kedi Xu
- Qiushi Academy for Advanced Studies (QAAS), Key Laboratory of Biomedical Engineering of Education Ministry & Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, Zhejiang, China.,Zhejiang Lab, Hangzhou, Zhejiang, China
| | - Kenneth E Schriver
- Zhejiang University Interdisciplinary Institute of Neuroscience and Technology (ZIINT), School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Junming Zhu
- Department of Neurosurgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Anna Wang Roe
- Zhejiang University Interdisciplinary Institute of Neuroscience and Technology (ZIINT), School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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Uenaka M, Nagamura H, Okamoto A, Hiryu S, Kobayasi KI, Tamai Y. Feasibility evaluation of transtympanic laser stimulation of the cochlea from the outer ear. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 152:1850. [PMID: 36182303 DOI: 10.1121/10.0014241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 09/06/2022] [Indexed: 06/16/2023]
Abstract
Infrared laser stimulation has been studied as an alternative approach to auditory prostheses. This study evaluated the feasibility of infrared laser stimulation of the cochlea from the outer ear, bypassing the middle ear function. An optic fiber was inserted into the ear canal, and a laser was used to irradiate the cochlea through the tympanic membrane in Mongolian gerbils. A pulsed infrared laser (6.9 mJ/cm2) and clicking sound (70 peak-to-peak equivalent sound pressure level) were presented to the animals. The amplitude of the laser-evoked cochlear response was systematically decreased following insertion of a filter between the tympanic membrane and cochlea; however, the auditory-evoked cochlear response did not decrease. The filter was removed, and the laser-evoked response returned to around the original level. The amplitude ratio and the relative change in response amplitude before and during filter insertion significantly decreased as the absorbance of the infrared filter increased. These results indicate that laser irradiation could bypass the function of the middle ear and directly activate the cochlea. Therefore, laser irradiation from the outer ear is a possible alternative for stimulating the cochlea, circumventing the middle ear.
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Affiliation(s)
- Miku Uenaka
- Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Hidekazu Nagamura
- Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Aya Okamoto
- Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Shizuko Hiryu
- Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Kohta I Kobayasi
- Graduate School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Yuta Tamai
- Organization for Research Initiatives and Development, Doshisha University, Kyotanabe, Kyoto, Japan
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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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Current Review of Optical Neural Interfaces for Clinical Applications. MICROMACHINES 2021; 12:mi12080925. [PMID: 34442547 PMCID: PMC8400671 DOI: 10.3390/mi12080925] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/20/2021] [Accepted: 07/29/2021] [Indexed: 11/16/2022]
Abstract
Neural interfaces, which enable the recording and stimulation of living neurons, have emerged as valuable tools in understanding the brain in health and disease, as well as serving as neural prostheses. While neural interfaces are typically based on electrical transduction, alternative energy modalities have been explored to create safe and effective approaches. Among these approaches, optical methods of linking neurons to the outside world have gained attention because light offers high spatial selectivity and decreased invasiveness. Here, we review the current state-of-art of optical neural interfaces and their clinical applications. Optical neural interfaces can be categorized into optical control and optical readout, each of which can be divided into intrinsic and extrinsic approaches. We discuss the advantages and disadvantages of each of these methods and offer a comparison of relative performance. Future directions, including their clinical opportunities, are discussed with regard to the optical properties of biological tissue.
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Kaszas A, Szalay G, Slézia A, Bojdán A, Vanzetta I, Hangya B, Rózsa B, O'Connor R, Moreau D. Two-photon GCaMP6f imaging of infrared neural stimulation evoked calcium signals in mouse cortical neurons in vivo. Sci Rep 2021; 11:9775. [PMID: 33963220 PMCID: PMC8105372 DOI: 10.1038/s41598-021-89163-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/22/2021] [Indexed: 02/07/2023] Open
Abstract
Infrared neural stimulation is a promising tool for stimulating the brain because it can be used to excite with high spatial precision without the need of delivering or inserting any exogenous agent into the tissue. Very few studies have explored its use in the brain, as most investigations have focused on sensory or motor nerve stimulation. Using intravital calcium imaging with the genetically encoded calcium indicator GCaMP6f, here we show that the application of infrared neural stimulation induces intracellular calcium signals in Layer 2/3 neurons in mouse cortex in vivo. The number of neurons exhibiting infrared-induced calcium response as well as the amplitude of those signals are shown to be both increasing with the energy density applied. By studying as well the spatial extent of the stimulation, we show that reproducibility of the stimulation is achieved mainly in the central part of the infrared beam path. Stimulating in vivo at such a degree of precision and without any exogenous chromophores enables multiple applications, from mapping the brain's connectome to applications in systems neuroscience and the development of new therapeutic tools for investigating the pathological brain.
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Affiliation(s)
- Attila Kaszas
- Mines Saint-Etienne, Centre CMP, Département BEL, F - 13541, Gardanne, France
- Institut de Neurosciences de la Timone, CNRS UMR 7289 & Aix-Marseille Université, 13005, Marseille, France
| | - Gergely Szalay
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Andrea Slézia
- Mines Saint-Etienne, Centre CMP, Département BEL, F - 13541, Gardanne, France
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Alexandra Bojdán
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Ivo Vanzetta
- Institut de Neurosciences de la Timone, CNRS UMR 7289 & Aix-Marseille Université, 13005, Marseille, France
| | - Balázs Hangya
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Balázs Rózsa
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Budapest, 1083, Hungary
- Two-Photon Laboratory, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, 1083, Hungary
| | - Rodney O'Connor
- Mines Saint-Etienne, Centre CMP, Département BEL, F - 13541, Gardanne, France
- Institut de Neurosciences de la Timone, CNRS UMR 7289 & Aix-Marseille Université, 13005, Marseille, France
| | - David Moreau
- Mines Saint-Etienne, Centre CMP, Département BEL, F - 13541, Gardanne, France.
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Littlefield PD, Richter C. Near-infrared stimulation of the auditory nerve: A decade of progress toward an optical cochlear implant. Laryngoscope Investig Otolaryngol 2021; 6:310-319. [PMID: 33869763 PMCID: PMC8035937 DOI: 10.1002/lio2.541] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 12/14/2020] [Accepted: 02/12/2021] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES We provide an appraisal of recent research on stimulation of the auditory system with light. In particular, we discuss direct infrared stimulation and ongoing controversies regarding the feasibility of this modality. We also discuss advancements and barriers to the development of an optical cochlear implant. METHODS This is a review article that covers relevant animal studies. RESULTS The auditory system has been stimulated with infrared light, and in a much more spatially selective manner than with electrical stimulation. However, there are experiments from other labs that have not been able to reproduce these results. This has resulted in an ongoing controversy regarding the feasibility of infrared stimulation, and the reasons for these experimental differences still require explanation. The neural response characteristics also appear to be much different than with electrical stimulation. The electrical stimulation paradigms used for modern cochlear implants do not apply well to optical stimulation and new coding strategies are under development. Stimulation with infrared light brings the risk of heat accumulation in the tissue at high pulse repetition rates, so optimal pulse shapes and combined optical/electrical stimulation are being investigated to mitigate this. Optogenetics is another promising technique, which makes neurons more sensitive to light stimulation by inserting light sensitive ion channels via viral vectors. Challenges of optogenetics include the expression of light sensitive channels in sufficient density in the target neurons, and the risk of damaging neurons by the expression of a foreign protein. CONCLUSION Optical stimulation of the nervous system is a promising new field, and there has been progress toward the development of a cochlear implant that takes advantage of the benefits of optical stimulation. There are barriers, and controversies, but so far none that seem intractable. LEVEL OF EVIDENCE NA (animal studies and basic research).
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Affiliation(s)
| | - Claus‐Peter Richter
- Department of OtolaryngologyNorthwestern UniversityChicagoIllinoisUSA
- Department of Communication Sciences and DisordersNorthwestern UniversityEvanstonIllinoisUSA
- Department of Biomedical EngineeringNorthwestern UniversityEvanstonIllinoisUSA
- The Hugh Knowles Center, Department of Communication Sciences and DisordersNorthwestern UniversityEvanstonIllinoisUSA
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Throckmorton G, Cayce J, Ricks Z, Adams WR, Jansen ED, Mahadevan-Jansen A. Identifying optimal parameters for infrared neural stimulation in the peripheral nervous system. NEUROPHOTONICS 2021; 8:015012. [PMID: 33816649 PMCID: PMC8010905 DOI: 10.1117/1.nph.8.1.015012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/17/2021] [Indexed: 05/19/2023]
Abstract
Significance: Infrared neural stimulation (INS) utilizes pulsed infrared light to selectively elicit neural activity without exogenous compounds. Despite its versatility in a broad range of biomedical applications, no comprehensive comparison of factors pertaining to the efficacy and safety of INS such as wavelength, radiant exposure, and optical spot size exists in the literature. Aim: Here, we evaluate these parameters using three of the wavelengths commonly used for INS, 1450 nm, 1875 nm, and 2120 nm. Approach: In an in vivo rat sciatic nerve preparation, the stimulation threshold and transition rate to 100% activation probability were used to compare the effects of each parameter. Results: The pulsed diode lasers at 1450 nm and 1875 nm had a consistently higher ( ∼ 1.0 J / cm 2 ) stimulation threshold than that of the Ho:YAG laser at 2120 nm ( ∼ 0.7 J / cm 2 ). In addition, the Ho:YAG produced a faster transition rate to 100% activation probability compared to the diode lasers. Our data suggest that the superior performance of the Ho:YAG is a result of the high-intensity microsecond spike at the onset of the pulse. Acute histological evaluation of diode irradiated nerves revealed a safe range of radiant exposures for stimulation. Conclusion: Together, our results identify measures to improve the safety, efficacy, and accessibility of INS technology for research and clinical applications.
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Affiliation(s)
- Graham Throckmorton
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Jonathan Cayce
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Zane Ricks
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Wilson R. Adams
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Eric Duco Jansen
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Neurological Surgery, Nashville, Tennessee, United States
| | - Anita Mahadevan-Jansen
- Vanderbilt Biophotonics Center, Keck FEL Center, Nashville, Tennessee, United States
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Vanderbilt University Medical Center, Department of Neurological Surgery, Nashville, Tennessee, United States
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Tamai Y, Ito Y, Furuyama T, Horinouchi K, Murashima N, Michimoto I, Hishida R, Shibuki K, Hiryu S, Kobayasi KI. Auditory cortical activity elicited by infrared laser irradiation from the outer ear in Mongolian gerbils. PLoS One 2020; 15:e0240227. [PMID: 33057339 PMCID: PMC7561108 DOI: 10.1371/journal.pone.0240227] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/22/2020] [Indexed: 12/16/2022] Open
Abstract
Infrared neural stimulation has been studied for its potential to replace an electrical stimulation of a cochlear implant. No studies, however, revealed how the technic reliably evoke auditory cortical activities. This research investigated the effects of cochlear laser stimulation from the outer ear on auditory cortex using brain imaging of activity-dependent changes in mitochondrial flavoprotein fluorescence signal. An optic fiber was inserted into the gerbil’s ear canal to stimulate the lateral side of the cochlea with an infrared laser. Laser stimulation was found to activate the identified primary auditory cortex. In addition, the temporal profile of the laser-evoked responses was comparable to that of the auditory responses. Our results indicate that infrared laser irradiation from the outer ear has the capacity to evoke, and possibly manipulate, the neural activities of the auditory cortex and may substitute for the present cochlear implants in future.
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Affiliation(s)
- Yuta Tamai
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Yuki Ito
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Takafumi Furuyama
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
- Department of Physiology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
| | - Kensuke Horinouchi
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Nagomi Murashima
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Itsuki Michimoto
- Faculty of Science and Engineering, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Ryuichi Hishida
- Department of Neurophysiology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Katsuei Shibuki
- Department of Neurophysiology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Shizuko Hiryu
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
| | - Kohta I. Kobayasi
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto, Japan
- * E-mail:
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14
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Kozin ED, Brown MC, Lee DJ, Stankovic KM. Light-Based Neuronal Activation: The Future of Cranial Nerve Stimulation. Otolaryngol Clin North Am 2020; 53:171-183. [PMID: 31739905 DOI: 10.1016/j.otc.2019.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Despite advances in implant hardware, neuroprosthetic devices in otolaryngology have sustained evolutionary rather than revolutionary changes over the past half century. Although electrical stimulation has the capacity for facile activation of neurons and high temporal resolution, it has limited spatial selectivity. Alternative strategies for neuronal stimulation are being investigated to improve spatial resolution. In particular, light-based neuronal stimulation is a viable alternative and complement to electrical stimulation. This article provides a broad overview of light-based neuronal stimulation technologies. Specific examples of active research on light-based prostheses, including cochlear implants, auditory brainstem implants, retinal implants, and facial nerve implants, are reviewed.
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Affiliation(s)
- Elliott D Kozin
- Massachusetts Eye and Ear Infirmary and Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA.
| | - M Christian Brown
- Massachusetts Eye and Ear Infirmary and Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
| | - Daniel J Lee
- Massachusetts Eye and Ear Infirmary and Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
| | - Konstantina M Stankovic
- Massachusetts Eye and Ear Infirmary and Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA
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15
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Brown WGA, Needham K, Begeng JM, Thompson AC, Nayagam BA, Kameneva T, Stoddart PR. Thermal damage threshold of neurons during infrared stimulation. BIOMEDICAL OPTICS EXPRESS 2020; 11:2224-2234. [PMID: 32341879 PMCID: PMC7173919 DOI: 10.1364/boe.383165] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/11/2020] [Accepted: 03/23/2020] [Indexed: 05/25/2023]
Abstract
In infrared neural stimulation (INS), laser-evoked thermal transients are used to generate small depolarising currents in neurons. The laser exposure poses a moderate risk of thermal damage to the target neuron. Indeed, exogenous methods of neural stimulation often place the target neurons under stressful non-physiological conditions, which can hinder ordinary neuronal function and hasten cell death. Therefore, quantifying the exposure-dependent probability of neuronal damage is essential for identifying safe operating limits of INS and other interventions for therapeutic and prosthetic use. Using patch-clamp recordings in isolated spiral ganglion neurons, we describe a method for determining the dose-dependent damage probabilities of individual neurons in response to both acute and cumulative infrared exposure parameters based on changes in injection current. The results identify a local thermal damage threshold at approximately 60 °C, which is in keeping with previous literature and supports the claim that damage during INS is a purely thermal phenomenon. In principle this method can be applied to any potentially injurious stimuli, allowing for the calculation of a wide range of dose-dependent neural damage probabilities. Unlike histological analyses, the technique is well-suited to quantifying gradual neuronal damage, and critical threshold behaviour is not required.
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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
| | - Karina Needham
- Department of Surgery (Otolaryngology), University of Melbourne, Royal Victoria Eye & Ear Hospital, 32 Gisborne St, East Melbourne, VIC 3002, Australia
| | - James M. Begeng
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, John Street, Hawthorn, VIC 3122, Australia
| | | | - Bryony A. Nayagam
- Department of Audiology and Speech Pathology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Tatiana Kameneva
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, John Street, Hawthorn, VIC 3122, Australia
| | - Paul R. Stoddart
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, John Street, Hawthorn, VIC 3122, Australia
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16
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Ganguly M, Jenkins MW, Jansen ED, Chiel HJ. Thermal block of action potentials is primarily due to voltage-dependent potassium currents: a modeling study. J Neural Eng 2019; 16:036020. [PMID: 30909171 PMCID: PMC11190670 DOI: 10.1088/1741-2552/ab131b] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Thermal block of action potential conduction using infrared lasers is a new modality for manipulating neural activity. It could be used for analysis of the nervous system and for therapeutic applications. We sought to understand the mechanisms of thermal block. APPROACH To analyze the mechanisms of thermal block, we studied both the original Hodgkin/Huxley model, and a version modified to more accurately match experimental data on thermal responses in the squid giant axon. MAIN RESULTS Both the original and modified models suggested that thermal block, especially at higher temperatures, is primarily due to a depolarization-activated hyperpolarization as increased temperature leads to faster activation of voltage-gated potassium ion channels. The minimum length needed to block an axon scaled with the square root of the axon's diameter. SIGNIFICANCE The results suggest that voltage-dependent potassium ion channels play a major role in thermal block, and that relatively short lengths of axon could be thermally manipulated to selectively block fine, unmyelinated axons, such as C fibers, that carry pain and other sensory information.
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Affiliation(s)
- Mohit Ganguly
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America
- Biophotonics Center, Vanderbilt University, Nashville, TN, United States of America
| | - Michael W Jenkins
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States of America
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America
- Biophotonics Center, Vanderbilt University, Nashville, TN, United States of America
| | - Hillel J Chiel
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Department of Biology, Case Western Reserve University, Cleveland, OH, United States of America
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, United States of America
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17
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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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18
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Abstract
Optical pacing (OP) uses pulsed infrared light to initiate heartbeats in electrically excitable cardiac tissues without employing exogenous agents. OP is an alternative approach to electrical pacing that may overcome some its disadvantages for some applications. In this review, we discuss the initial demonstrations, mechanisms, safety, advantages and applications of OP.
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Affiliation(s)
- S M Ford
- Rainbow Babies and Children's Hospital Divisions of Neonatology and Pediatric Cardiology, 11100 Euclid Ave, MS 6010, Cleveland, OH 44106, United States of America
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19
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Lothet EH, Shaw KM, Lu H, Zhuo J, Wang YT, Gu S, Stolz DB, Jansen ED, Horn CC, Chiel HJ, Jenkins MW. Selective inhibition of small-diameter axons using infrared light. Sci Rep 2017; 7:3275. [PMID: 28607402 PMCID: PMC5468240 DOI: 10.1038/s41598-017-03374-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 04/27/2017] [Indexed: 12/25/2022] Open
Abstract
Novel clinical treatments to target peripheral nerves are being developed which primarily use electrical current. Recently, infrared (IR) light was shown to inhibit peripheral nerves with high spatial and temporal specificity. Here, for the first time, we demonstrate that IR can selectively and reversibly inhibit small-diameter axons at lower radiant exposures than large-diameter axons. We provide a mathematical rationale, and then demonstrate it experimentally in individual axons of identified neurons in the marine mollusk Aplysia californica, and in axons within the vagus nerve of a mammal, the musk shrew Suncus murinus. The ability to selectively, rapidly, and reversibly control small-diameter sensory fibers may have many applications, both for the analysis of physiology, and for treating diseases of the peripheral nervous system, such as chronic nausea, vomiting, pain, and hypertension. Moreover, the mathematical analysis of how IR affects the nerve could apply to other techniques for controlling peripheral nerve signaling.
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Affiliation(s)
- Emilie H Lothet
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA.,Department of Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Kendrick M Shaw
- Department of Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Hui Lu
- Department of Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Junqi Zhuo
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Yves T Wang
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Shi Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Donna B Stolz
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Charles C Horn
- Biobehavioral Program in Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.,Department of Medicine: Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hillel J Chiel
- Department of Biology, Case Western Reserve University, Cleveland, OH, USA.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Michael W Jenkins
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA. .,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
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20
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Tolstykh GP, Olsovsky CA, Ibey BL, Beier HT. Ryanodine and IP 3 receptor-mediated calcium signaling play a pivotal role in neurological infrared laser modulation. NEUROPHOTONICS 2017; 4:025001. [PMID: 28413806 PMCID: PMC5381754 DOI: 10.1117/1.nph.4.2.025001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/20/2017] [Indexed: 05/13/2023]
Abstract
Pulsed infrared (IR) laser energy has been shown to modulate neurological activity through both stimulation and inhibition of action potentials. While the mechanism(s) behind this phenomenon is (are) not completely understood, certain hypotheses suggest that the rise in temperature from IR exposure could activate temperature- or pressure-sensitive ion channels or create pores in the cellular outer membrane, allowing an influx of typically plasma-membrane-impermeant ions. Studies using fluorescent intensity-based calcium ion ([Formula: see text]) sensitive dyes show changes in [Formula: see text] levels after various IR stimulation parameters, which suggests that [Formula: see text] may originate from the external solution. However, activation of intracellular signaling pathways has also been demonstrated, indicating a more complex mechanism of increasing intracellular [Formula: see text] concentration. We quantified the [Formula: see text] mobilization in terms of influx from the external solution and efflux from intracellular organelles using Fura-2 and a high-speed ratiometric imaging system that rapidly alternates the dye excitation wavelengths. Using nonexcitable Chinese hamster ovarian ([Formula: see text]) cells and neuroblastoma-glioma (NG108) cells, we demonstrate that intracellular [Formula: see text] receptors play an important role in the IR-induced [Formula: see text], with the [Formula: see text] response augmented by ryanodine receptors in excitable cells.
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Affiliation(s)
- Gleb P. Tolstykh
- General Dynamics Information Technology, JBSA Fort Sam Houston, San Antonio, Texas, United States
- Address all correspondence to: Gleb P. Tolstykh, E-mail:
| | - Cory A. Olsovsky
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
| | - Bennett L. Ibey
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Radio Frequency Bioeffects Branch, JBSA Fort Sam Houston, San Antonio, Texas, United States
| | - Hope T. Beier
- Air Force Research Laboratory, 711th Human Performance Wing, Airman System Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, San Antonio, Texas, United States
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21
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Richardson RT, Thompson AC, Wise AK, Needham K. Challenges for the application of optical stimulation in the cochlea for the study and treatment of hearing loss. Expert Opin Biol Ther 2016; 17:213-223. [PMID: 27960585 DOI: 10.1080/14712598.2017.1271870] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Electrical stimulation has long been the most effective strategy for evoking neural activity from bionic devices and has been used with great success in the cochlear implant to allow deaf people to hear speech and sound. Despite its success, the spread of electrical current stimulates a broad region of neural tissue meaning that contemporary devices have limited precision. Optical stimulation as an alternative has attracted much recent interest for its capacity to provide highly focused stimuli, and therefore, potentially improved sensory perception. Given its specificity of activation, optical stimulation may also provide a useful tool in the study of fundamental neuroanatomy and neurophysiological processes. Areas covered: This review examines the advances in optical stimulation - infrared, nanoparticle-enhanced, and optogenetic-based - and its application in the inner ear for the restoration of auditory function following hearing loss. Expert opinion: Initial outcomes suggest that optogenetic-based approaches hold the greatest potential and viability amongst optical techniques for application in the cochlea. The future success of this approach will be governed by advances in the targeted delivery of opsins to auditory neurons, improvements in channel kinetics, development of optical arrays, and innovation of opsins that activate within the optimal near-infrared therapeutic window.
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Affiliation(s)
- Rachael T Richardson
- a Bionics Institute , East Melbourne , Australia.,b Department of Medical Bionics , University of Melbourne , East Melbourne , Australia
| | | | - Andrew K Wise
- a Bionics Institute , East Melbourne , Australia.,b Department of Medical Bionics , University of Melbourne , East Melbourne , Australia
| | - Karina Needham
- d Department of Surgery (Otolaryngology) , University of Melbourne, Royal Victorian Eye & Ear Hospital , East Melbourne , Australia
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22
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Tian L, Wang J, Wei Y, Lu J, Xu A, Xia M. Short-wavelength infrared laser activates the auditory neurons: comparing the effect of 980 vs. 810 nm wavelength. Lasers Med Sci 2016; 32:357-362. [DOI: 10.1007/s10103-016-2123-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 11/30/2016] [Indexed: 11/25/2022]
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23
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Wang YT, Rollins AM, Jenkins MW. Infrared inhibition of embryonic hearts. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:60505. [PMID: 27367249 PMCID: PMC5994995 DOI: 10.1117/1.jbo.21.6.060505] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 06/13/2016] [Indexed: 05/18/2023]
Abstract
Infrared control is a new technique that uses pulsed infrared lasers to thermally alter electrical activity. Originally developed for nerves, we have applied this technology to embryonic hearts using a quail model, previously demonstrating infrared stimulation and, here, infrared inhibition. Infrared inhibition enables repeatable and reversible block, stopping cardiac contractions for several seconds. Normal beating resumes after the laser is turned off. The block can be spatially specific, affecting propagation on the ventricle or initiation on the atrium. Optical mapping showed that the block affects action potentials and not just calcium or contraction. Increased resting intracellular calcium was observed after a 30-s exposure to the inhibition laser, which likely resulted in reduced mechanical function. Further optimization of the laser illumination should reduce potential damage. Stopping cardiac contractions by disrupting electrical activity with infrared inhibition has the potential to be a powerful tool for studying the developing heart.
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Affiliation(s)
- Yves T. Wang
- Case Western Reserve University, Department of Pediatrics, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
- Case Western Reserve University, Department of Biomedical Engineering, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Andrew M. Rollins
- Case Western Reserve University, Department of Biomedical Engineering, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Michael W. Jenkins
- Case Western Reserve University, Department of Pediatrics, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
- Case Western Reserve University, Department of Biomedical Engineering, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
- Address all correspondence to: Michael W. Jenkins, E-mail:
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24
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Tan X, Young H, Matic AI, Zirkle W, Rajguru S, Richter CP. Temporal properties of inferior colliculus neurons to photonic stimulation in the cochlea. Physiol Rep 2015; 3:3/8/e12491. [PMID: 26311831 PMCID: PMC4562577 DOI: 10.14814/phy2.12491] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Infrared neural stimulation (INS) may be beneficial in auditory prostheses because of its spatially selective activation of spiral ganglion neurons. However, the response properties of single auditory neurons to INS and the possible contributions of its optoacoustic effects are yet to be examined. In this study, the temporal properties of auditory neurons in the central nucleus of the inferior colliculus (ICC) of guinea pigs in response to INS were characterized. Spatial selectivity of INS was observed along the tonotopically organized ICC. Trains of laser pulses and trains of acoustic clicks were used to evoke single unit responses in ICC of normal hearing animals. In response to INS, ICC neurons showed lower limiting rates, longer latencies, and lower firing efficiencies. In deaf animals, ICC neurons could still be stimulated by INS while unresponsive to acoustic stimulation. The site and spatial selectivity of INS both likely shaped the temporal properties of ICC neurons.
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Affiliation(s)
- Xiaodong Tan
- Department of Otolaryngology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Hunter Young
- Department of Otolaryngology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Agnella Izzo Matic
- Department of Otolaryngology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Whitney Zirkle
- Department of Otolaryngology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Suhrud Rajguru
- Department of Biomedical Engineering, University of Miami, Miami, Florida, USA Department of Otolaryngology, University of Miami, Miami, Florida, USA
| | - Claus-Peter Richter
- Department of Otolaryngology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA The Hugh Knowles Center, Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, USA
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25
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Xie B, Dai C, Li H. Attenuated infrared neuron stimulation response in cochlea of deaf animals may associate with the degeneration of spiral ganglion neurons. BIOMEDICAL OPTICS EXPRESS 2015; 6:1990-2005. [PMID: 26114024 PMCID: PMC4473739 DOI: 10.1364/boe.6.001990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 05/13/2023]
Abstract
HYPOTHESIS We hypothesize that degenerated spiral ganglion neurons (SGNs) in guinea pigs reduces auditory brainstem responses evoked by pulsed infrared stimulation. BACKGROUND Pulsed infrared laser excitation can directly evoke physiological responses in neuronal and other excitable cells in vivo and in vitro. Laser pulses could benefit patients with cochlear implants to stimulate the auditory system. METHODS Pulsed infrared lasers were used to study evoked optical auditory brainstem responses (oABRs) in normal hearing and deafened animals. Aslo, the morphology and anatomy of SGNs in normal hearing and deafened guinea pigs were compared. RESULTS By recording oABRs evoked by varying infrared laser pulse durations, it is suggested that degeneration of SGNs in deafened guinea pigs was associated with an elevated oABR threshold and with lower amplitudes. Moreover, oABR threshold decreased while amplitudes increased in both normal hearing and deafened animals as the pulse duration prolonged. Electron microscopy revealed that SGNs in deafened guinea pigs had swollen and vacuolar mitochondria, as well as demyelinated soma and axons. CONCLUSION Infrared laser pulses can stimulate SGNs to evoke oABRs in guinea pigs. Deafened guinea pigs have elevated thresholds and smaller amplitude responses, likely a result of degenerated SGNs. Short pulse durations are more suitable to evoke responses in both normal hearing and deafened animals.
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Affiliation(s)
- Bingbin Xie
- Department of Otology and Skull Base Surgery, Hearing Research Key Lab of Health Ministry of China, Eye and ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Chunfu Dai
- Department of Otology and Skull Base Surgery, Hearing Research Key Lab of Health Ministry of China, Eye and ENT Hospital, Fudan University, Shanghai, 200031, China ;
| | - Huawei Li
- Department of Otology and Skull Base Surgery, Hearing Research Key Lab of Health Ministry of China, Eye and ENT Hospital, Fudan University, Shanghai, 200031, China ;
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26
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Infrared neural stimulation fails to evoke neural activity in the deaf guinea pig cochlea. Hear Res 2015; 324:46-53. [PMID: 25796297 DOI: 10.1016/j.heares.2015.03.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 03/02/2015] [Accepted: 03/09/2015] [Indexed: 11/23/2022]
Abstract
At present there is some debate as to the processes by which infrared neural stimulation (INS) activates neurons in the cochlea, as the lasers used for INS can potentially generate a range of secondary stimuli e.g. an acoustic stimulus is produced when the light is absorbed by water. To clarify whether INS in the cochlea requires functioning hair cells and to explore the potential relevance to cochlear implants, experiments using INS were performed in the cochleae of both normal hearing and profoundly deaf guinea pigs. A response to laser stimulation was readily evoked in normal hearing cochlea. However, no response was evoked in any profoundly deaf cochleae, for either acute or chronic deafening, contrary to previous work where a response was observed after acute deafening with ototoxic drugs. A neural response to electrical stimulation was readily evoked in all cochleae after deafening. The absence of a response from optical stimuli in profoundly deaf cochleae suggests that the response from INS in the cochlea is hair cell mediated.
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27
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Zhang K, Ma Y, Zhou Y, Wang Q. Effects of heat conduction on the spatial selectivity of infrared stimulation in the cochlea. Biomed Eng Online 2015; 14:23. [PMID: 25889277 PMCID: PMC4369098 DOI: 10.1186/s12938-015-0017-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 02/25/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It has been reported that one of the main mechanisms that induces the activation of the cochlea through infrared laser light is the photothermal effect. The temperature in the spiral ganglion cells increases as a result of photon absorption. However, heat conduction can induce an increase in the temperature within the cochlea and change the spatial selectivity of activation. METHODS We analyzed the effects of heat conduction on the increase in temperature within the cochlea using a 3D model that simplifies the spiraled cochlea as a rotational symmetric structure . The model is solved using the finite element method. RESULTS Taken as an example, the cochlea is stimulated by laser pulses at eight sites in its first turn. The temperature rise in time domain and spatial domain is simulated for different laser pulse energies and repetition rates. The results demonstrate that the temperature in the cochlea increases as the laser pulse energy and repetition rate increase. Additionally, the zone affected by the laser is enlarged because of the heat conduction in the surrounding structures. As a result, more auditory neurons can be stimulated than the expected. CONCLUSIONS The heat conduction affects the laser spatial selectivity however, by adjusting the stimulation schemes of the laser pulse-trains, such as laser repetition rate and laser power, the laser selectivity can be optimized.
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Affiliation(s)
- Kaiyin Zhang
- School of Physics and Electronics, Fuyang Normal College, Fuyang, 236037, Anhui, China.
| | - Yue Ma
- School of Physics and Electronics, Fuyang Normal College, Fuyang, 236037, Anhui, China.
| | - Yunfei Zhou
- School of Physics and Electronics, Fuyang Normal College, Fuyang, 236037, Anhui, China.
| | - Qiuling Wang
- School of Physics and Electronics, Fuyang Normal College, Fuyang, 236037, Anhui, China.
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Thompson AC, Stoddart PR, Jansen ED. Optical Stimulation of Neurons. ACTA ACUST UNITED AC 2015; 3:162-177. [PMID: 26322269 PMCID: PMC4541079 DOI: 10.2174/2211555203666141117220611] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/26/2014] [Accepted: 10/20/2014] [Indexed: 01/01/2023]
Abstract
Our capacity to interface with the nervous system remains overwhelmingly reliant on electrical stimulation devices, such as electrode arrays and cuff electrodes that can stimulate both central and peripheral nervous systems. However, electrical stimulation has to deal with multiple challenges, including selectivity, spatial resolution, mechanical stability, implant-induced injury and the subsequent inflammatory response. Optical stimulation techniques may avoid some of these challenges by providing more selective stimulation, higher spatial resolution and reduced invasiveness of the device, while also avoiding the electrical artefacts that complicate recordings of electrically stimulated neuronal activity. This review explores the current status of optical stimulation techniques, including optogenetic methods, photoactive molecule approaches and infrared neural stimulation, together with emerging techniques such as hybrid optical-electrical stimulation, nanoparticle enhanced stimulation and optoelectric methods. Infrared neural stimulation is particularly emphasised, due to the potential for direct activation of neural tissue by infrared light, as opposed to techniques that rely on the introduction of exogenous light responsive materials. However, infrared neural stimulation remains imperfectly understood, and techniques for accurately delivering light are still under development. While the various techniques reviewed here confirm the overall feasibility of optical stimulation, a number of challenges remain to be overcome before they can deliver their full potential.
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Affiliation(s)
- Alexander C Thompson
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Australia
| | - Paul R Stoddart
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Australia
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
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Cayce JM, Wells JD, Malphrus JD, Kao C, Thomsen S, Tulipan NB, Konrad PE, Jansen ED, Mahadevan-Jansen A. Infrared neural stimulation of human spinal nerve roots in vivo. NEUROPHOTONICS 2015; 2:015007. [PMID: 26157986 PMCID: PMC4478764 DOI: 10.1117/1.nph.2.1.015007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/12/2015] [Indexed: 05/13/2023]
Abstract
Infrared neural stimulation (INS) is a neurostimulation modality that uses pulsed infrared light to evoke artifact-free, spatially precise neural activity with a noncontact interface; however, the technique has not been demonstrated in humans. The objective of this study is to demonstrate the safety and efficacy of INS in humans in vivo. The feasibility of INS in humans was assessed in patients ([Formula: see text]) undergoing selective dorsal root rhizotomy, where hyperactive dorsal roots, identified for transection, were stimulated in vivo with INS on two to three sites per nerve with electromyogram recordings acquired throughout the stimulation. The stimulated dorsal root was removed and histology was performed to determine thermal damage thresholds of INS. Threshold activation of human dorsal rootlets occurred in 63% of nerves for radiant exposures between 0.53 and [Formula: see text]. In all cases, only one or two monitored muscle groups were activated from INS stimulation of a hyperactive spinal root identified by electrical stimulation. Thermal damage was first noted at [Formula: see text] and a [Formula: see text] safety ratio was identified. These findings demonstrate the success of INS as a fresh approach for activating human nerves in vivo and providing the necessary safety data needed to pursue clinically driven therapeutic and diagnostic applications of INS in humans.
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Affiliation(s)
- Jonathan M. Cayce
- Vanderbilt University, Department of Biomedical Engineering, 5824 Stevenson Center, Station B, Box 351631 Nashville, Tennessee 37235-1631, United States
| | - Jonathon D. Wells
- Lockheed Martin, 22121 20th Avenue SE, Bothell, Washington 98021, United States
| | - Jonathan D. Malphrus
- Vanderbilt University, Department of Biomedical Engineering, 5824 Stevenson Center, Station B, Box 351631 Nashville, Tennessee 37235-1631, United States
| | - Chris Kao
- Vanderbilt University, Department of Neurological Surgery, 1161 21st Avenue, Nashville, Tennessee 37232-2380, United States
| | - Sharon Thomsen
- University of Texas, Department of Biomedical Engineering, Austin, Texas, and 500 Discovery View Drive, Sequim, Washington 98382, United States
| | - Noel B. Tulipan
- Vanderbilt University, Department of Neurological Surgery, 1161 21st Avenue, Nashville, Tennessee 37232-2380, United States
| | - Peter E. Konrad
- Vanderbilt University, Department of Biomedical Engineering, 5824 Stevenson Center, Station B, Box 351631 Nashville, Tennessee 37235-1631, United States
- Vanderbilt University, Department of Neurological Surgery, 1161 21st Avenue, Nashville, Tennessee 37232-2380, United States
| | - E. Duco Jansen
- Vanderbilt University, Department of Biomedical Engineering, 5824 Stevenson Center, Station B, Box 351631 Nashville, Tennessee 37235-1631, United States
- Vanderbilt University, Department of Neurological Surgery, 1161 21st Avenue, Nashville, Tennessee 37232-2380, United States
| | - Anita Mahadevan-Jansen
- Vanderbilt University, Department of Biomedical Engineering, 5824 Stevenson Center, Station B, Box 351631 Nashville, Tennessee 37235-1631, United States
- Vanderbilt University, Department of Neurological Surgery, 1161 21st Avenue, Nashville, Tennessee 37232-2380, United States
- Address all correspondence to: Anita Mahadevan-Jansen, E-mail:
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Abstract
The success of conventional hearing aids and electrical auditory prostheses for hearing impaired patients is still limited in noisy environments and for sounds more complex than speech (e. g. music). This is partially due to the difficulty of frequency-specific activation of the auditory system using these devices. Stimulation of the auditory system using light pulses represents an alternative to mechanical and electrical stimulation. Light is a source of energy that can be very exactly focused and applied with little scattering, thus offering perspectives for optimal activation of the auditory system. Studies investigating light stimulation of sectors along the auditory pathway have shown stimulation of the auditory system is possible using light pulses. However, further studies and developments are needed before a new generation of light stimulation-based auditory prostheses can be made available for clinical application.
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Lumbreras V, Bas E, Gupta C, Rajguru SM. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling. J Neurophysiol 2014; 112:1246-55. [PMID: 24920028 DOI: 10.1152/jn.00253.2014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses.
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Affiliation(s)
- Vicente Lumbreras
- Department of Biomedical Engineering, University of Miami, Miami, Florida; and
| | - Esperanza Bas
- Department of Otolaryngology, University of Miami, Miami, Florida
| | - Chhavi Gupta
- Department of Otolaryngology, University of Miami, Miami, Florida
| | - Suhrud M Rajguru
- Department of Biomedical Engineering, University of Miami, Miami, Florida; and Department of Otolaryngology, University of Miami, Miami, Florida
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Abstract
Methods to control neural activity by light have been introduced to the field of neuroscience. During the last decade, several techniques have been established, including optogenetics, thermogenetics, and infrared neural stimulation. The techniques allow investigators to turn-on or turn-off neural activity. This review is an attempt to show the importance of the techniques for the auditory field and provide insight in the similarities, overlap, and differences of the techniques. Discussing the mechanism of each of the techniques will shed light on the abilities and challenges for each of the techniques. The field has been grown tremendously and a review cannot be complete. However, efforts are made to summarize the important points and to refer the reader to excellent papers and reviews to specific topics. This article is part of a Special Issue entitled .
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Affiliation(s)
- Claus-Peter Richter
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, 303 E. Chicago Ave, Searle 12-561, Chicago, IL 60611, USA; Dept. 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, Evanston, IL 60208, USA.
| | - Xiaodong Tan
- Northwestern University Feinberg School of Medicine, Department of Otolaryngology, 303 E. Chicago Ave, Searle 12-561, Chicago, IL 60611, USA
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Wang YT, Gu S, Ma P, Watanabe M, Rollins AM, Jenkins MW. Optical stimulation enables paced electrophysiological studies in embryonic hearts. BIOMEDICAL OPTICS EXPRESS 2014; 5:1000-13. [PMID: 24761284 PMCID: PMC3985989 DOI: 10.1364/boe.5.001000] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/13/2014] [Accepted: 02/21/2014] [Indexed: 05/11/2023]
Abstract
Cardiac electrophysiology plays a critical role in the development and function of the heart. Studies of early embryonic electrical activity have lacked a viable point stimulation technique to pace in vitro samples. Here, optical pacing by high-precision infrared stimulation is used to pace excised embryonic hearts, allowing electrophysiological parameters to be quantified during pacing at varying rates with optical mapping. Combined optical pacing and optical mapping enables electrophysiological studies in embryos under more physiological conditions and at varying heart rates, allowing detection of abnormal conduction and comparisons between normal and pathological electrical activity during development in various models.
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Affiliation(s)
- Yves T. Wang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Shi Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Pei Ma
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Michiko Watanabe
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Andrew M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
| | - Michael W. Jenkins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44120, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, 44120, USA
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Jenkins MW, Wang YT, Doughman YQ, Watanabe M, Cheng Y, Rollins AM. Optical pacing of the adult rabbit heart. BIOMEDICAL OPTICS EXPRESS 2013; 4:1626-35. [PMID: 24049683 PMCID: PMC3771833 DOI: 10.1364/boe.4.001626] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/21/2013] [Accepted: 07/30/2013] [Indexed: 05/03/2023]
Abstract
Optical pacing has been demonstrated to be a viable alternative to electrical pacing in embryonic hearts. In this study, the feasibility of optically pacing an adult rabbit heart was explored. Hearts from adult New Zealand White rabbits (n = 9) were excised, cannulated and perfused on a modified Langendorff apparatus. Pulsed laser light (λ = 1851 nm) was directed to either the left or right atrium through a multimode optical fiber. An ECG signal from the left ventricle and a trigger pulse from the laser were recorded simultaneously to determine when capture was achieved. Successful optical pacing was demonstrated by obtaining pacing capture, stopping, then recapturing as well as by varying the pacing frequency. Stimulation thresholds measured at various pulse durations suggested that longer pulses (8 ms) had a lower energy capture threshold. To determine whether optical pacing caused damage, two hearts were perfused with 30 µM of propidium iodide and analyzed histologically. A small number of cells near the stimulation site had compromised cell membranes, which probably limited the time duration over which pacing was maintained. Here, short-term optical pacing (few minutes duration) is demonstrated in the adult rabbit heart for the first time. Future studies will be directed to optimize optical pacing parameters to decrease stimulation thresholds and may enable longer-term pacing.
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Affiliation(s)
- Michael W. Jenkins
- Department of Biomedical Engineering, Case Western Reserve University, 11000 Euclid Ave., Cleveland, Oh. 44106 USA
| | - Y. T. Wang
- Department of Biomedical Engineering, Case Western Reserve University, 11000 Euclid Ave., Cleveland, Oh. 44106 USA
- Department of Molecular Cardiology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Oh. 44195 USA
| | - Y. Q. Doughman
- Department of Pediatrics, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Oh. 44106 USA
| | - M. Watanabe
- Department of Pediatrics, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Oh. 44106 USA
| | - Y. Cheng
- Department of Biomedical Engineering, Case Western Reserve University, 11000 Euclid Ave., Cleveland, Oh. 44106 USA
- Department of Molecular Cardiology, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Oh. 44195 USA
- Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Ave., Cleveland, Oh. 44195 USA
| | - A. M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University, 11000 Euclid Ave., Cleveland, Oh. 44106 USA
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