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Unal S, Musicki B, Burnett AL. Cavernous nerve mapping methods for radical prostatectomy. Sex Med Rev 2023; 11:421-430. [PMID: 37500541 DOI: 10.1093/sxmrev/qead030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION Preserving the cavernous nerves, the main autonomic nerve supply of the penis, is a major challenge of radical prostatectomy. Cavernous nerve injury during radical prostatectomy predominantly accounts for post-radical prostatectomy erectile dysfunction. The cavernous nerve is a bilateral structure that branches in a weblike distribution over the prostate surface and varies anatomically in individuals, such that standard nerve-sparing methods do not sufficiently sustain penile erection ability. As a consequence, researchers have focused on developing personalized cavernous nerve mapping methods applied to the surgical procedure aiming to improve postoperative sexual function outcomes. OBJECTIVES We provide an updated overview of preclinical and clinical data of cavernous nerve mapping methods, emphasizing their strengths, limitations, and future directions. METHODS A literature review was performed via Scopus, PubMed, and Google Scholar for studies that describe cavernous nerve mapping/localization. RESULTS Several cavernous nerve mapping methods have been investigated based on various properties of the nerve structures including stimulation techniques, spectroscopy/imaging techniques, and assorted combinations of these methods. More recent methods have portrayed the course of the main cavernous nerve as well as its branches based on real-time mapping, high-resolution imaging, and functional imaging. However, each of these methods has distinctive limitations, including low spatial accuracy, lack of standardization for stimulation and response measurement, superficial imaging depth, toxicity risk, and lack of suitability for intraoperative use. CONCLUSION While various cavernous nerve mapping methods have provided improvements in identification and preservation of the cavernous nerve during radical prostatectomy, no method has been implemented in clinical practice due to their distinctive limitations. To overcome the limitations of existing cavernous nerve mapping methods, the development of new imaging techniques and mapping methods is in progress. There is a need for further research in this area to improve sexual function outcomes and quality of life after radical prostatectomy.
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Affiliation(s)
- Selman Unal
- The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
- Department of Urology, Ankara Yildirim Beyazit University School of Medicine, Ankara 06800, Turkey
| | - Biljana Musicki
- The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
| | - Arthur L Burnett
- The James Buchanan Brady Urological Institute and Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
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2
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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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Cury J, Vande Perre L, Smets H, Stumpp L, Vespa S, Vanhoestenberghe A, Doguet P, Delbeke J, El Tahry R, Gorza SP, Nonclercq A. Infrared neurostimulation in ex-vivorat sciatic nerve using 1470 nm wavelength. J Neural Eng 2021; 18. [PMID: 33770780 DOI: 10.1088/1741-2552/abf28f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 03/26/2021] [Indexed: 12/22/2022]
Abstract
Objective.To design and implement a setup forex-vivooptical stimulation for exploring the effect of several key parameters (optical power and pulse duration), activation features (threshold, spatial selectivity) and recovery characteristics (repeated stimuli) in peripheral nerves.Approach.A nerve chamber allowing ex-vivo electrical and optical stimulation was designed and built. A 1470 nm light source was chosen to stimulate the nerve. A photodiode module was implemented for synchronization of the electrical and optical channels.Main results. Compound neural action potentials (CNAPs) were successfully generated with infrared light pulses of 200-2000µs duration and power in the range of 3-10 W. These parameters determine a radiant exposure for stimulation in the range 1.59-4.78 J cm-2. Recruitment curves were obtained by increasing durations at a constant power level. Neural activation threshold is reached at a mean radiant exposure of 3.16 ± 0.68 J cm-2and mean pulse energy of 3.79 ± 0.72 mJ. Repetition rates of 2-10 Hz have been explored. In eight out of ten sciatic nerves (SNs), repeated light stimuli induced a sensitization effect in that the CNAP amplitude progressively grows, representing an increasing number of recruited fibres. In two out of ten SNs, CNAPs were composed of a succession of peaks corresponding to different conduction velocities.Significance.The reported sensitization effect could shed light on the mechanism underlying infrared neurostimulation. Our results suggest that, in sharp contrast with electrical stimuli, optical pulses could recruit slow fibres early on. This more physiological order of recruitment opens the perspective for specific neuromodulation of fibre population who remained poorly accessible until now. Short high-power light pulses at wavelengths below 1.5µm offer interesting perspectives for neurostimulation.
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Affiliation(s)
- Joaquin Cury
- Bio, Electro and Mechanical Systems (BEAMS), Université libre de Bruxelles, Brussels, Belgium.,Opera Photonics, Université libre de Bruxelles, Brussels, Belgium
| | - Louis Vande Perre
- Bio, Electro and Mechanical Systems (BEAMS), Université libre de Bruxelles, Brussels, Belgium
| | - Hugo Smets
- Bio, Electro and Mechanical Systems (BEAMS), Université libre de Bruxelles, Brussels, Belgium
| | - Lars Stumpp
- Institute of Neurosciences (IONS), Université Catholique de Louvain, Belgium-Cliniques Universitaires Saint Luc, Department of Neurology, Brussels, Belgium
| | - Simone Vespa
- Institute of Neurosciences (IONS), Université Catholique de Louvain, Belgium-Cliniques Universitaires Saint Luc, Department of Neurology, Brussels, Belgium
| | - Anne Vanhoestenberghe
- Aspire Centre for Rehabilitation Engineering and Assistive Technology, University College London, London, United Kingdom
| | | | - Jean Delbeke
- Institute of Neurosciences (IONS), Université Catholique de Louvain, Belgium-Cliniques Universitaires Saint Luc, Department of Neurology, Brussels, Belgium
| | - Riëm El Tahry
- Institute of Neurosciences (IONS), Université Catholique de Louvain, Belgium-Cliniques Universitaires Saint Luc, Department of Neurology, Brussels, Belgium
| | | | - Antoine Nonclercq
- Bio, Electro and Mechanical Systems (BEAMS), Université libre de Bruxelles, Brussels, Belgium
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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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5
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Richardson RT, Ibbotson MR, Thompson AC, Wise AK, Fallon JB. Optical stimulation of neural tissue. Healthc Technol Lett 2020; 7:58-65. [PMID: 32754339 PMCID: PMC7353819 DOI: 10.1049/htl.2019.0114] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/08/2020] [Accepted: 05/15/2020] [Indexed: 12/23/2022] Open
Abstract
Electrical stimulation has been used for decades in devices such as pacemakers, cochlear implants and more recently for deep brain and retinal stimulation and electroceutical treatment of disease. However, current spread from the electrodes limits the precision of neural activation, leading to a low quality therapeutic outcome or undesired side-effects. Alternative methods of neural stimulation such as optical stimulation offer the potential to deliver higher spatial resolution of neural activation. Direct optical stimulation is possible with infrared light, while visible light can be used to activate neurons if the neural tissue is genetically modified with a light sensitive ion channel. Experimentally, both methods have resulted in highly precise stimulation with little spread of activation at least in the cochlea, each with advantages and disadvantages. Infrared neural stimulation does not require modification of the neural tissue, but has very high power requirements. Optogenetics can achieve precision of activation with lower power, but only in conjunction with targeted insertion of a light sensitive ion channel into the nervous system via gene therapy. This review will examine the advantages and limitations of optical stimulation of neural tissue, using the cochlea as an exemplary model and recent developments for retinal and deep brain stimulation.
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Affiliation(s)
- Rachael Theresa Richardson
- Bionics Institute, Melbourne 3002, Australia.,University of Melbourne, Medical Bionics Department, Melbourne, 3002, Australia.,University of Melbourne, Department of Surgery (Otolaryngology), Melbourne, 3002, Australia
| | - Michael R Ibbotson
- National Vision Research Institute, Australian College of Optometry, and Department of Optometry and Vision Science, University of Melbourne, Melbourne, Australia
| | | | - Andrew K Wise
- Bionics Institute, Melbourne 3002, Australia.,University of Melbourne, Medical Bionics Department, Melbourne, 3002, Australia.,University of Melbourne, Department of Surgery (Otolaryngology), Melbourne, 3002, Australia
| | - James B Fallon
- Bionics Institute, Melbourne 3002, Australia.,University of Melbourne, Medical Bionics Department, Melbourne, 3002, Australia.,University of Melbourne, Department of Surgery (Otolaryngology), Melbourne, 3002, Australia
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6
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Selective stimulation of bullfrog sciatic nerve by gold nanorod assisted combined electrical and near-infrared stimulation. Biomed Microdevices 2019; 21:76. [DOI: 10.1007/s10544-019-0428-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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7
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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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8
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Ibarra-Escamilla B, Hernández-Arriaga MV, Durán-Sánchez M, Santiago-Hernández H, Bello-Jiménez M, Pérez ER, Rodríguez-Morales LA, Kuzin EA. Abrupt-tapered fiber filter arrangement for a switchable multi-wavelength and tunable Tm-doped fiber laser. OPTICS EXPRESS 2018; 26:14894-14904. [PMID: 30114794 DOI: 10.1364/oe.26.014894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/12/2018] [Indexed: 06/08/2023]
Abstract
A switchable and tunable multi-wavelength Tm-doped fiber laser is successfully demonstrated using a filter constructed with two tapered fiber elements in the cavity. The proposed system design uses a low-cost simple filter that allows stable dual, triple, quadruple, and quintuple-wavelength emission operation in the region around 1.9 μm. In the dual wavelength regime, the laser is capable of independently tuning each wavelength. For switching and tuning, a curvature is applied to the tapered fibers.
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9
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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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10
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Moreau D, Lefort C, Pas J, Bardet SM, Leveque P, O'Connor RP. Infrared neural stimulation induces intracellular Ca 2+ release mediated by phospholipase C. JOURNAL OF BIOPHOTONICS 2018; 11:e201700020. [PMID: 28700117 DOI: 10.1002/jbio.201700020] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/29/2017] [Accepted: 07/01/2017] [Indexed: 05/18/2023]
Abstract
The influence of infrared laser pulses on intracellular Ca2+ signaling was investigated in neural cell lines with fluorescent live cell imaging. The probe Fluo-4 was used to measure Ca2+ in HT22 mouse hippocampal neurons and nonelectrically excitable U87 human glioblastoma cells exposed to 50 to 500 ms infrared pulses at 1470 nm. Fluorescence recordings of Fluo-4 demonstrated that infrared stimulation induced an instantaneous intracellular Ca2+ transient with similar dose-response characteristics in hippocampal neurons and glioblastoma cells (half-maximal effective energy density EC50 of around 58 J.cm-2 ). For both type of cells, the source of the infrared-induced Ca2+ transients was found to originate from intracellular stores and to be mediated by phospholipase C and IP3 -induced Ca2+ release from the endoplasmic reticulum. The activation of phosphoinositide signaling by IR light is a new mechanism of interaction relevant to infrared neural stimulation that will also be widely applicable to nonexcitable cell types. The prospect of infrared optostimulation of the PLC/IP3 cell signaling cascade has many potential applications including the development of optoceutical therapeutics.
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Affiliation(s)
- David Moreau
- CNRS, XLIM, University of Limoges, UMR 7252, Limoges, France
| | - Claire Lefort
- CNRS, XLIM, University of Limoges, UMR 7252, Limoges, France
| | - Jolien Pas
- Bioelectronics Department, École Nationale Supérieure des Mines de Saint-Étienne, Centre Microélectronique de Provence - Georges Charpak Campus, 880 route de Mimet, 13541 Gardanne, France
| | - Sylvia M Bardet
- CNRS, XLIM, University of Limoges, UMR 7252, Limoges, France
| | | | - Rodney P O'Connor
- Bioelectronics Department, École Nationale Supérieure des Mines de Saint-Étienne, Centre Microélectronique de Provence - Georges Charpak Campus, 880 route de Mimet, 13541 Gardanne, France
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11
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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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Effect of shorter pulse duration in cochlear neural activation with an 810-nm near-infrared laser. Lasers Med Sci 2016; 32:389-396. [PMID: 27995385 DOI: 10.1007/s10103-016-2129-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 12/08/2016] [Indexed: 10/20/2022]
Abstract
Optical neural stimulation in the cochlea has been presented as an alternative technique to the electrical stimulation due to its potential in spatially selectivity enhancement. So far, few studies have selected the near-infrared (NIR) laser in cochlear neural stimulation and limited optical parameter space has been examined. This paper focused on investigating the optical parameter effect on NIR stimulation of auditory neurons, especially under shorter pulse durations. The spiral ganglion neurons in the cochlea of deafened guinea pigs were stimulated with a pulsed 810-nm NIR laser in vivo. The laser radiation was delivered by an optical fiber and irradiated towards the modiolus. Optically evoked auditory brainstem responses (OABRs) with various optical parameters were recorded and investigated. The OABRs could be elicited with the cochlear deafened animals by using the 810-nm laser in a wide pulse duration ranged from 20 to 1000 μs. Results showed that the OABR intensity increased along with the increasing laser radiant exposure of limited range at each specific pulse duration. In addition, for the pulse durations from 20 to 300 μs, the OABR intensity increased monotonically along with the pulse duration broadening. While for pulse durations above 300 μs, the OABR intensity basically kept stable with the increasing pulse duration. The 810-nm NIR laser could be an effective stimulus in evoking the cochlear neuron response. Our experimental data provided evidence to optimize the pulse duration range, and the results suggested that the pulse durations from 20 to 300 μs could be the optimized range in cochlear neural activation with the 810-nm-wavelength laser.
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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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14
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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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Abstract
The cavernous nerves, which course along the surface of the prostate gland, are responsible for erectile function. During radical prostatectomy, urologists are challenged in preserving these nerves and their function. Cavernous nerves are microscopic and show variable location in different patients; therefore, postoperative sexual potency rates are widely variable following radical prostatectomy. A variety of technologies, including electrical and optical nerve stimulation, dye-based optical fluorescence and microscopy, spectroscopy, ultrasound and magnetic resonance imaging have all been used to study cavernous nerve anatomy and physiology, and some of these methods are also potential intraoperative methods for identifying and preserving cavernous nerves. However, all of these technologies have inherent limitations, including slow or inconsistent nerve responses, poor image resolution, shallow image depth, slow image acquisition times and/or safety concerns. New and emerging technologies, as well as multimodal approaches combining existing methods, hold promise for improved postoperative sexual outcomes and patient quality of life following radical prostatectomy.
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Wang J, Lu J, Li C, Xu L, Li X, Tian L. Pulsed 980 nm short wavelength infrared neural stimulation in cochlea and laser parameter effects on auditory response characteristics. Biomed Eng Online 2015; 14:89. [PMID: 26445884 PMCID: PMC4597400 DOI: 10.1186/s12938-015-0084-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/22/2015] [Indexed: 11/10/2022] Open
Abstract
Background Auditory neural stimulation with pulsed infrared radiation has been proposed as an alternative method to activate the auditory nerves in vivo. Infrared wavelengths from 1800–2150 nm with high water absorption were mainly selected in previous studies. However, few researchers have used the short-wavelength infrared (SWIR) for auditory nerve stimulation and limited pulse parameters variability has been investigated so far. Methods In this paper, we pioneered to use the 980 nm SWIR laser with adjustable pulse parameter as a stimulus to act on the deafened guinea pigs’ cochlea in vivo. Pulsed laser light was guided through the cochlear round window to irradiate the spiral ganglion cells via a 105 μm optical fiber, and then the laser pulse parameters variability and its influence to auditory response characteristics were studied. Results The results showed that the optically evoked auditory brainstem response (OABR) had a similar waveform to the acoustically induced ABR with click sound stimulus. And the evoked OABR amplitude had a positive correlation, while the OABR latency period showed a negative correlation, with the laser pulse energy increase. However, when holding the laser peak power constant, the pulse width variability ranged from 100 to 800 μs showed little influence on the evoked OABR amplitude and its latency period. Conclusions Our study suggests that 980 nm SWIR laser is an effective stimulus for auditory neurons activation in vivo. The evoked OABR amplitude and latency are highly affected by the laser pulse energy, while not sensitive to the pulse width variability in 100–800 μs range.
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Affiliation(s)
- Jingxuan Wang
- School of Information Science and Engineering, Shandong University, 250100, Jinan, Shandong, China.
| | - Jianren Lu
- School of Information Science and Engineering, Shandong University, 250100, Jinan, Shandong, China.
| | - Chen Li
- School of Information Science and Engineering, Shandong University, 250100, Jinan, Shandong, China.
| | - Lei Xu
- Shandong Artificial Auditory Engineering Centre, 250022, Jinan, Shandong, China.
| | - Xiaofei Li
- Shandong Artificial Auditory Engineering Centre, 250022, Jinan, Shandong, China.
| | - Lan Tian
- School of Information Science and Engineering, Shandong University, 250100, Jinan, Shandong, China.
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17
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Radiant energy required for infrared neural stimulation. Sci Rep 2015; 5:13273. [PMID: 26305106 PMCID: PMC4548241 DOI: 10.1038/srep13273] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 07/06/2015] [Indexed: 12/15/2022] Open
Abstract
Infrared neural stimulation (INS) has been proposed as an alternative method to electrical stimulation because of its spatial selective stimulation. Independent of the mechanism for INS, to translate the method into a device it is important to determine the energy for stimulation required at the target structure. Custom-designed, flat and angle polished fibers, were used to deliver the photons. By rotating the angle polished fibers, the orientation of the radiation beam in the cochlea could be changed. INS-evoked compound action potentials and single unit responses in the central nucleus of the inferior colliculus (ICC) were recorded. X-ray computed tomography was used to determine the orientation of the optical fiber. Maximum responses were observed when the radiation beam was directed towards the spiral ganglion neurons (SGNs), whereas little responses were seen when the beam was directed towards the basilar membrane. The radiant exposure required at the SGNs to evoke compound action potentials (CAPs) or ICC responses was on average 18.9 ± 12.2 or 10.3 ± 4.9 mJ/cm(2), respectively. For cochlear INS it has been debated whether the radiation directly stimulates the SGNs or evokes a photoacoustic effect. The results support the view that a direct interaction between neurons and radiation dominates the response to INS.
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18
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Wang J, Xia M, Lu J, Li C, Tian X, Tian L. Performance analysis of the beam shaping method on optical auditory neural stimulation in vivo. Lasers Med Sci 2015; 30:1533-40. [PMID: 25947304 DOI: 10.1007/s10103-015-1763-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 04/28/2015] [Indexed: 11/28/2022]
Abstract
Previous research has shown that infrared neural stimulation (INS) could be an alternative approach to evoke auditory neural activities. The laser beam property of the fiber output is a considerable aspect of INS, and the corresponding effects on auditory responses in vivo deserve further discussions. The paper presents a beam-shaped infrared laser stimulation method of auditory nerves. Pulsed 980-nm fiber-coupled laser systems were used as the radiant sources. The gradient reflective index (GRIN) lens was added at the port of the optical fiber as a beam shaping structure. The laser spot sizes and properties between the beam-shaped output and the bare fiber output were preliminarily analyzed by a laser beam profiler. And further experiments in vivo with four deafened adult guinea pigs were conducted. Optically evoked auditory brainstem responses (OABRs) of the animal samples were recorded and compared under the two output configurations. The results show a decrease of the beam divergence compared to a bare output fiber, and the INS with a beam shaping design evokes above 13 % increase on OABR amplitudes than the bare fiber output, especially when enlarging the distance between the optical fiber and the nerve tissue. The beam shaping design can enhance the effect of INS for evoking auditory nerves, and it could be an optimized design in the future implementation of optical cochlear implants.
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Affiliation(s)
- Jingxuan Wang
- School of Information Science and Engineering, Shandong University, Jinan, Shandong, 250100, China
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19
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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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20
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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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21
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Pisipati S, Ali A, Mandalapu RS, Haines Iii GK, Singhal P, Reddy BN, Leung R, Tewari AK. Newer concepts in neural anatomy and neurovascular preservation in robotic radical prostatectomy. Indian J Urol 2014; 30:399-409. [PMID: 25378822 PMCID: PMC4220380 DOI: 10.4103/0970-1591.142064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
With more than 60% of radical prostatectomies being performed robotically, robotic-assisted laparoscopic prostatectomy (RALP) has largely replaced the open and laparoscopic approaches and has become the standard of care surgical treatment option for localized prostate cancer in the United States. Accomplishing negative surgical margins while preserving functional outcomes of sexual function and continence play a significant role in determining the success of surgical intervention, particularly since the advent of nerve-sparing (NS) robotic prostatectomy. Recent evidence suggests that NS surgery improves continence in addition to sexual function. In this review, we describe the neuroanatomical concepts and recent developments in the NS technique of RALP with a view to improving the “trifecta” outcomes.
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Affiliation(s)
- Sailaja Pisipati
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - Adnan Ali
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - Rao S Mandalapu
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - George K Haines Iii
- Department of Pathology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - Paras Singhal
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - Balaji N Reddy
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - Robert Leung
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
| | - Ashutosh K Tewari
- Department of Urology, Icahn School of Medicine, Mount Sinai Hospital, New York, NY 10029, USA
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22
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Bareket-Keren L, Hanein Y. Novel interfaces for light directed neuronal stimulation: advances and challenges. Int J Nanomedicine 2014; 9 Suppl 1:65-83. [PMID: 24872704 PMCID: PMC4024977 DOI: 10.2147/ijn.s51193] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Light activation of neurons is a growing field with applications ranging from basic investigation of neuronal systems to the development of new therapeutic methods such as artificial retina. Many recent studies currently explore novel methods for optical stimulation with temporal and spatial precision. Novel materials in particular provide an opportunity to enhance contemporary approaches. Here we review recent advances towards light directed interfaces for neuronal stimulation, focusing on state-of-the-art nanoengineered devices. In particular, we highlight challenges and prospects towards improved retinal prostheses.
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Affiliation(s)
- Lilach Bareket-Keren
- School of Electrical Engineering, Tel-Aviv University, Tel-Aviv University, Tel-Aviv, Israel ; Tel-Aviv University Center for Nanoscience and Nanotechnology, Tel-Aviv University, Tel-Aviv, Israel
| | - Yael Hanein
- School of Electrical Engineering, Tel-Aviv University, Tel-Aviv University, Tel-Aviv, Israel ; Tel-Aviv University Center for Nanoscience and Nanotechnology, Tel-Aviv University, Tel-Aviv, Israel
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23
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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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24
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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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25
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Duke AR, Jenkins MW, Lu H, McManus JM, Chiel HJ, Jansen ED. Transient and selective suppression of neural activity with infrared light. Sci Rep 2014; 3:2600. [PMID: 24009039 PMCID: PMC3764437 DOI: 10.1038/srep02600] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 08/19/2013] [Indexed: 11/09/2022] Open
Abstract
Analysis and control of neural circuitry requires the ability to selectively activate or inhibit neurons. Previous work showed that infrared laser light selectively excited neural activity in endogenous unmyelinated and myelinated axons. However, inhibition of neuronal firing with infrared light was only observed in limited cases, is not well understood and was not precisely controlled. Using an experimentally tractable unmyelinated preparation for detailed investigation and a myelinated preparation for validation, we report that it is possible to selectively and transiently inhibit electrically-initiated axonal activation, as well as to both block or enhance the propagation of action potentials of specific motor neurons. Thus, in addition to previously shown excitation, we demonstrate an optical method of suppressing components of the nervous system with functional spatiotemporal precision. We believe this technique is well-suited for non-invasive investigations of diverse excitable tissues and may ultimately be applied for treating neurological disorders.
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Affiliation(s)
- Austin R Duke
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
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26
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Verma RU, Guex AA, Hancock KE, Durakovic N, McKay CM, Slama MCC, Brown MC, Lee DJ. Auditory responses to electric and infrared neural stimulation of the rat cochlear nucleus. Hear Res 2014; 310:69-75. [PMID: 24508368 DOI: 10.1016/j.heares.2014.01.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/11/2014] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported "optophonic" effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach.
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Affiliation(s)
- Rohit U Verma
- School of Medicine, University of Manchester, UK; Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, USA; Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02114, USA
| | - Amélie A Guex
- Ecole Polytechnique Fédérale de Lausanne, Switzerland
| | - Kenneth E Hancock
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, USA
| | - Nedim Durakovic
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, USA
| | - Colette M McKay
- School of Psychological Sciences, University of Manchester, UK; The Bionics Institute of Australia, Melbourne, Australia
| | - Michaël C C Slama
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, USA; Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02114, USA
| | - M Christian Brown
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, USA; Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02114, USA.
| | - Daniel J Lee
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, USA; Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02114, USA
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27
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Calcium imaging of infrared-stimulated activity in rodent brain. Cell Calcium 2014; 55:183-90. [PMID: 24674600 DOI: 10.1016/j.ceca.2014.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/16/2014] [Accepted: 01/21/2014] [Indexed: 11/20/2022]
Abstract
Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain.
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28
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Tozburun S, Stahl CD, Hutchens TC, Lagoda GA, Burnett AL, Fried NM. Continuous-wave infrared subsurface optical stimulation of the rat prostate cavernous nerves using a 1490-nm diode laser. Urology 2013; 82:969-73. [PMID: 23953608 DOI: 10.1016/j.urology.2013.06.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 06/08/2013] [Accepted: 06/21/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To optimize the infrared laser wavelength and optical nerve stimulation (ONS) parameters for both deep and rapid subsurface cavernous nerve (CN) stimulation in a rat model, in vivo. MATERIALS AND METHODS A 150-mW, 1490-nm diode laser providing an optical penetration depth (OPD) of 518 μm in water was operated in continuous-wave mode during stimulation of the CNs in 8 rats for 15 seconds irradiation time through a custom-built, single-mode fiber optic probe capable of producing a collimated, 1-mm diameter laser beam. Successful ONS was judged by an intracavernous pressure response in the rat penis. Subsurface ONS at 1490 nm was also compared with previous studies using 1455 nm and 1550 nm near-infrared diode laser wavelengths. RESULTS Subsurface ONS of the rat CN was successful through fascia layers with a thickness up to 380 μm using an incident laser power of ∼50 mW. Intracavernous pressure response times as short as 4.6 ± 0.2 seconds were recorded using higher laser powers below the nerve damage threshold. CONCLUSION The 1490-nm diode laser represents a compact, low cost, high power, and high quality infrared light source for use in ONS. This wavelength provides deeper penetration than 1455-nm diode laser and more rapid and efficient nerve stimulation than 1550-nm diode laser.
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Affiliation(s)
- Serhat Tozburun
- Department of Physics and Optical Science, University of North Carolina at Charlotte, Charlotte, NC; Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA.
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29
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Richter CP, Rajguru S, Stafford R, Stock SR. Radiant energy during infrared neural stimulation at the target structure. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2013; 8565:85655P. [PMID: 25075261 DOI: 10.1117/12.2013849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Infrared neural stimulation (INS) describes a method, by which an infrared laser is used to stimulate neurons. The major benefit of INS over stimulating neurons with electrical current is its spatial selectivity. To translate the technique into a clinical application it is important to know the energy required to stimulate the neural structure. With this study we provide measurements of the radiant exposure, at the target structure that is required to stimulate the auditory neurons. Flat polished fibers were inserted into scala tympani so that the spiral ganglion was in front of the optical fiber. Angle polished fibers were inserted along scala tympani, and rotating the beveled surface of the fiber allowed the radiation beam to be directed perpendicular to the spiral ganglion. The radiant exposure for stimulation at the modiolus for flat and angle polished fibers averaged 6.78±2.15 mJ/cm2. With the angle polished fibers, a 90° change in the orientation of the optical beam from an orientation that resulted in an INS-evoked maximum response, resulted in a 50% drop in the response amplitude. When the orientation of the beam was changed by 180°, such that it was directed opposite to the orientation with the maxima, minimum response amplitude was observed.
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Affiliation(s)
- Claus-Peter Richter
- Department of Otolaryngology, Northwestern University, 303 E. Chicago Ave, 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, Evanston, IL 60208, USA
| | - Suhrud Rajguru
- Department of Biomedical Engineering, University of Miami, Miami FL 33146, USA ; Department of Otolaryngology, University of Miami, Miami FL 33136, USA
| | - Ryan Stafford
- Lockheed Martin Aculight, 22121 20th Ave SE, Bothell WA, USA
| | - Stuart R Stock
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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30
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Richter CP, Rajguru S, Bendett M. Infrared neural stimulation in the cochlea. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2013; 8565:85651Y. [PMID: 25075260 DOI: 10.1117/12.2010337] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The application of photonics to manipulate and stimulate neurons and to study neural networks has gained momentum over the last decade. Two general methods have been used: the genetic expression of light or temperature sensitive ion channels in the plasma membrane of neurons (Optogenetics and Thermogenetics) and the direct stimulation of neurons using infrared radiation (Infrared Neural Stimulation, INS). Both approaches have their strengths and challenges, which are well understood with a profound understanding of the light tissue interaction(s). This paper compares the opportunities of the methods for the use in cochlear prostheses. Ample data are already available on the stimulation of the cochlea with INS. The data show that the stimulation is selective, feasible at rates that would be sufficient to encode acoustic information and may be beneficial over conventional pulsed electrical stimulation. A third approach, using lasers in stress confinement to generate pressure waves and to stimulate the functional cochlea mechanically will also be discussed.
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Affiliation(s)
- Claus-Peter Richter
- Department of Otolaryngology, Northwestern University, 303 E. Chicago Ave, 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, Evanston, IL 60208, USA
| | - Suhrud Rajguru
- Department of Biomedical Engineering, University of Miami, Miami FL 33146, USA ; Department of Otolaryngology, University of Miami, Miami FL 33136, USA
| | - Mark Bendett
- Lockheed Martin Aculight, 22121 20th Ave SE, Bothell WA, USA
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31
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Duke AR, Peterson E, Mackanos MA, Atkinson J, Tyler D, Jansen ED. Hybrid electro-optical stimulation of the rat sciatic nerve induces force generation in the plantarflexor muscles. J Neural Eng 2012. [PMID: 23186608 DOI: 10.1088/1741-2560/9/6/066006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Objective. Optical methods of neural activation are becoming important tools for the study and treatment of neurological disorders. Infrared nerve stimulation (INS) is an optical technique exhibiting spatially precise activation in the native neural system. While this technique shows great promise, the risk of thermal damage may limit some applications. Combining INS with traditional electrical stimulation, a method known as hybrid electro-optical stimulation, reduces the laser power requirements and mitigates the risk of thermal damage while maintaining spatial selectivity. Here we investigate the capability of inducing force generation in the rat hind limb through hybrid stimulation of the sciatic nerve. Approach. Hybrid stimulation was achieved by combining an optically transparent nerve cuff for electrical stimulation and a diode laser coupled to an optical fiber for infrared stimulation. Force generation in the rat plantarflexor muscles was measured in response to hybrid stimulation with 1 s bursts of pulses at 15 and 20 Hz and with a burst frequency of 0.5 Hz. Main results. Forces were found to increase with successive stimulus trains, ultimately reaching a plateau by the 20th train. Hybrid evoked forces decayed at a rate similar to the rate of thermal diffusion in tissue. Preconditioning the nerve with an optical stimulus resulted in an increase in the force response to both electrical and hybrid stimulation. Histological evaluation showed no signs of thermally induced morphological changes following hybrid stimulation. Our results indicate that an increase in baseline temperature is a likely contributor to hybrid force generation. Significance. Extraneural INS of peripheral nerves at physiologically relevant repetition rates is possible using hybrid electro-optical stimulation.
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Affiliation(s)
- Austin R Duke
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
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Goyal V, Rajguru S, Matic AI, Stock SR, Richter CP. Acute damage threshold for infrared neural stimulation of the cochlea: functional and histological evaluation. Anat Rec (Hoboken) 2012; 295:1987-99. [PMID: 23044730 DOI: 10.1002/ar.22583] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 11/09/2022]
Abstract
This article provides a mini review of the current state of infrared neural stimulation (INS), and new experimental results concerning INS damage thresholds. INS promises to be an attractive alternative for neural interfaces. With this method, one can attain spatially selective neural stimulation that is not possible with electrical stimulation. INS is based on the delivery of short laser pulses that result in a transient temperature increase in the tissue and depolarize the neurons. At a high stimulation rate and/or high pulse energy, the method bears the risk of thermal damage to the tissue from the instantaneous temperature increase or from potential accumulation of thermal energy. With the present study, we determined the injury thresholds in guinea pig cochleae for acute INS using functional measurements (compound action potentials) and histological evaluation. The selected laser parameters for INS were the wavelength (λ = 1,869 nm), the pulse duration (100 μs), the pulse repetition rate (250 Hz), and the radiant energy (0-127 μJ/pulse). For up to 5 hr of continuous irradiation at 250 Hz and at radiant energies up to 25 μJ/pulse, we did not observe any functional or histological damage in the cochlea. Functional loss was observed for energies above 25 μJ/pulse and the probability of injury to the target tissue resulting in functional loss increased with increasing radiant energy. Corresponding cochlear histology from control animals and animals exposed to 98 or 127 μJ/pulse at 250 Hz pulse repetition rate did not show a loss of spiral ganglion cells, hair cells, or other soft tissue structures of the organ of Corti. Light microscopy did not reveal any structural changes in the soft tissue either. Additionally, microcomputed tomography was used to visualize the placement of the optical fiber within the cochlea.
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Affiliation(s)
- Vinay Goyal
- Department of Otolaryngology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611-3008, USA
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33
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Tozburun S, Lagoda GA, Burnett AL, Fried NM. Subsurface near-infrared laser stimulation of the periprostatic cavernous nerves. JOURNAL OF BIOPHOTONICS 2012; 5:793-800. [PMID: 22345079 DOI: 10.1002/jbio.201100134] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/04/2012] [Accepted: 01/17/2012] [Indexed: 05/13/2023]
Abstract
Successful identification and preservation of the cavernous nerves (CN), which are responsible for sexual function and vulnerable to damage during prostate cancer surgery, will require subsurface detection of the CN's beneath a thin fascia layer. This study explores the feasibility of optical nerve stimulation (ONS) in the rat with a fascia layer placed over the CN. Two near-infrared diode lasers with wavelengths of 1455 and 1550 nm were operated in continuous-wave mode for stimulation of the CN in 8 rats, in vivo. Successful ONS was confirmed by an intracavernous pressure (ICP) response in the rat penis at 1455 nm through fascia with a thickness up to 110 μm and at 1550 nm through fascia with a thickness up to 450 μm. Higher incident laser power was required to produce an ICP response as fascia thickness was increased. Also, weaker and slower ICP responses were observed as fascia thickness was increased. Subsurface ONS of the rat CN at a depth of 450 μm using a 1550 nm laser is feasible as an intermediate step towards developing ONS as an intra-operative diagnostic tool for identification and preservation of the cavernous nerves during prostate cancer surgery.
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Affiliation(s)
- Serhat Tozburun
- Dept. of Physics and Optical Science, University of North Carolina at Charlotte, NC, USA
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34
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Wu XY, Mou ZX, Hou WS, Zheng XL, Yao JP, Shang GB, Yin ZQ. Irradiation of 850-nm laser light changes the neural activities in rat primary visual cortex. Lasers Med Sci 2012; 28:791-8. [PMID: 22814897 DOI: 10.1007/s10103-012-1160-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 07/05/2012] [Indexed: 12/11/2022]
Abstract
Although infrared laser was proven to be an alternative approach for neural stimulation, there is very little known about the neural response to infrared laser irradiation in visual cortex. This study is to investigate the effect of near-infrared laser irradiation on neural activities at the cortex level. A 850-nm pigtailed diode laser was applied to stimulate the rat primary visual cortex while the horizontal black and white stripe pattern was used as standard visual stimulation to evoke visual-evoked potential (VEP). Both amplitude and latency of VEP P100 was measured with or without infrared pulse stimulation applied in rat primary visual cortex. Paired t test and one-way analysis of variance were used to evaluate the impact of infrared irradiation and its pulse width on the amplitudes and latencies of P100, respectively. The results from our preliminary study revealed that, the pulsed near-infrared laser depressed the VEP amplitude and shortened the latency of P100; with the increment of pulse width of infrared irradiation, further decline of VEP amplitude and much shortened latency of P100 were observed. The present work suggests that near-infrared laser irradiation can alter the neural activities in primary visual cortex transiently, and could provide a novel contactless artificial neural stimulus to brain cortex with high spatial selectivity.
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Affiliation(s)
- Xiao Y Wu
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, China
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35
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Ponnusamy K, Sorger JM, Mohr C. Nerve mapping for prostatectomies: novel technologies under development. J Endourol 2012; 26:769-77. [PMID: 22142311 DOI: 10.1089/end.2011.0355] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Prostatic neuroanatomy is difficult to visualize intraoperatively and can be extremely variable. Damage to these nerves during prostatectomies may lead to postoperative complications such as erectile dysfunction and incontinence. This review aims to discuss the prostatic neuroanatomy, sites of potential nerve damage during a prostatectomy, and nerve-mapping technologies being developed to prevent neural injury. These technologies include stimulation, dyes, and direct visualization. Nerve stimulation works by testing an area and observing a physiologic response but is limited by the long half-life for an erectile response; examples include CaverMap, ProPep, and optical nerve stimulation. Few nerve dyes have been approved by the Food and Drug Administration (FDA) because of the extensive testing required; examples of nerve dyes include compounds from Avelas and General Electric, fluorescent cholera toxin subunit B, indocyanine green, fluorescent inactivated herpes simplex 2, and Fluoro-Gold. Direct visualization techniques have a simpler FDA approval process; examples include optical coherence tomography, multiphoton microscopy, ultrasound, coherent anti-Stokes Raman scattering. Many researchers are developing several novel technologies that can be categorized as stimulation based, dye-based, or direct visualization. As of yet, none has shown clear evidence to improve surgical outcomes and consequently lack wide adoption. Further development of these technologies may lead to improved complication rates after prostatectomies. Clinically, some technologies have demonstrated utility in predicting the development of complications. By using that information, more aggressive rehabilitation programs may lead to improved long-term function. These technologies can also be applied for research to improve our knowledge of the neuroanatomy and physiology of erection and incontinence.
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36
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Tozburun S, Lagoda GA, Burnett AL, Fried NM. Continuous-wave laser stimulation of the rat prostate cavernous nerves using a compact and inexpensive all single mode optical fiber system. J Endourol 2011; 25:1727-31. [PMID: 21883012 DOI: 10.1089/end.2011.0172] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Laser stimulation of the rat cavernous nerve (CN) recently has been demonstrated as an alternative to electrical stimulation for potential application in nerve mapping during nerve-sparing radical prostatectomy. Advantages include noncontact stimulation and improved spatial selectivity. Previous studies, however, have used large and/or expensive laser sources for stimulation. This study demonstrates the feasibility of optical stimulation of the rat CN, in vivo, using a compact, inexpensive all-single-mode fiberoptic system. MATERIALS AND METHODS A 1455-nm wavelength infrared diode laser beam was coupled into a 9-μm-core single-mode fiber for delivery through a 10F laparoscopic probe and used for laser stimulation of the CN in a total of eight rats, in vivo. RESULTS Laser stimulation of the CN was observed at threshold temperatures of 41°C, with intracavernous pressure response times as short as 4 s, and magnitudes up to 50 mm Hg, compared with baselines of 10 mm Hg. CONCLUSION This novel, all-single-mode-fiber laser nerve stimulation system introduces several advantages including: (1) lower cost laser; (2) more robust fiberoptic design, eliminating alignment and cleaning of bulk optical components; and (3) improved Gaussian spatial beam profile for simplified alignment of the laser beam with the nerve. With further development, laser nerve stimulation may be useful for identification and preservation of the CN during prostate cancer surgery.
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Affiliation(s)
- Serhat Tozburun
- Department of Physics and Optical Science, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA
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37
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Cayce JM, Friedman RM, Jansen ED, Mahavaden-Jansen A, Roe AW. Pulsed infrared light alters neural activity in rat somatosensory cortex in vivo. Neuroimage 2011; 57:155-166. [PMID: 21513806 DOI: 10.1016/j.neuroimage.2011.03.084] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 03/25/2011] [Accepted: 03/29/2011] [Indexed: 11/26/2022] Open
Abstract
Pulsed infrared light has shown promise as an alternative to electrical stimulation in applications where contact free or high spatial precision stimulation is desired. Infrared neural stimulation (INS) is well characterized in the peripheral nervous system; however, to date, research has been limited in the central nervous system. In this study, pulsed infrared light (λ=1.875 μm, pulse width=250 μs, radiant exposure=0.01-0.55 J/cm(2), fiber size=400 μm, repetition rate=50-200 Hz) was used to stimulate the somatosensory cortex of anesthetized rats, and its efficacy was assessed using intrinsic optical imaging and electrophysiology techniques. INS was found to evoke an intrinsic response of similar magnitude to that evoked by tactile stimulation (0.3-0.4% change in intrinsic signal magnitude). A maximum deflection in the intrinsic signal was measured to range from 0.05% to 0.4% in response to INS, and the activated region of cortex measured approximately 2mm in diameter. The intrinsic signal magnitude increased with faster laser repetition rates and increasing radiant exposures. Single unit recordings indicated a statistically significant decrease in neuronal firing that was observed at the onset of INS stimulation (0.5s stimulus) and continued up to 1s after stimulation onset. The pattern of neuronal firing differed from that observed during tactile stimulation, potentially due to a different spatial integration field of the pulsed infrared light compared to tactile stimulation. The results demonstrate that INS can be used safely and effectively to manipulate neuronal firing.
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Affiliation(s)
- Jonathan M Cayce
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | | | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | | | - Anna W Roe
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Department of Psychology, Vanderbilt University, Nashville, TN, USA.
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38
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Richter CP, Matic AI, Wells JD, Jansen ED, Walsh JT. Neural stimulation with optical radiation. LASER & PHOTONICS REVIEWS 2011; 5:68-80. [PMID: 23082105 PMCID: PMC3472451 DOI: 10.1002/lpor.200900044] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Accepted: 04/08/2010] [Indexed: 05/18/2023]
Abstract
This paper reviews the existing research on infrared neural stimulation, a means of artificially stimulating neurons that has been proposed as an alternative to electrical stimulation. Infrared neural stimulation (INS) is defined as the direct induction of an evoked potential in response to a transient targeted deposition of optical energy. The foremost advantage of using optical radiation for neural stimulation is its spatial resolution. Exogenously applied or trans-genetically synthesized fluorophores are not used to achieve stimulation. Here, current work on INS is presented for motor nerves, sensory nerves, central nervous system, and in vitro preparations. A discussion follows addressing the mechanism of INS and its potential use in neuroprostheses. A brief review of neural depolarization involving other optical methods is also presented. Topics covered include optical stimulation concurrent with electrical stimulation, optical stimulation using exogenous fluorophores, and optical stimulation by transgenic induction of light-gated ion channels.
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Affiliation(s)
- Claus-Peter Richter
- Department of Otolaryngology, Feinberg Medical School, Northwestern University, Searle Building 12-470, 303 E. Chicago Avenue, Chicago, IL 60611-3008, USA
- The Hugh Knowles Center, Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, USA
| | - Agnella Izzo Matic
- Department of Otolaryngology, Feinberg Medical School, Northwestern University, Searle Building 12-470, 303 E. Chicago Avenue, Chicago, IL 60611-3008, USA
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | | | - E. Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Joseph T. Walsh
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
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39
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Abstract
Near-infrared light therapy is an emerging neurostimulation technology, but its cellular mechanism of action remains unresolved. Using standard intracellular recording techniques, we observed that 5-10 ms pulses of 1889 nm light depolarized the membrane potential for hundreds of milliseconds in more than 85% of dorsal root ganglion and nodose ganglion neurons tested. The laser-evoked depolarizations (LEDs) exhibited complex, multiphasic kinetics comprising fast and slow components. There was no discernable difference in the LEDs in intact ganglion neurons and in acutely isolated neurons. Thus, the LED sensor seems to reside within the neuronal membrane. The near-uniform distribution of responsive neurons increased membrane conductance, and the negative reversal potential value (-41+/-2.9 mV) suggests that LED is unrelated to the activation of heat-sensitive transient receptor potential cation channel subfamily V member 1 channels. The long duration of LEDs favors an involvement of second messengers.
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40
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Tozburun S, Cilip CM, Lagoda GA, Burnett AL, Fried NM. Continuous-wave infrared optical nerve stimulation for potential diagnostic applications. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:055012. [PMID: 21054094 DOI: 10.1117/1.3500656] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Optical nerve stimulation using infrared laser radiation has recently been developed as a potential alternative to electrical nerve stimulation. However, recent studies have focused primarily on pulsed delivery of the laser radiation and at relatively low pulse rates. The objective of this study is to demonstrate faster optical stimulation of the prostate cavernous nerves using continuous-wave (cw) infrared laser radiation for potential diagnostic applications. A thulium fiber laser (λ=1870 nm) is used for noncontact optical stimulation of the rat prostate cavernous nerves in vivo. Optical nerve stimulation, as measured by an intracavernous pressure (ICP) response in the penis, is achieved with the laser operating in either cw mode, or with a 5-ms pulse duration at 10, 20, 30, 40, 50, and 100 Hz. Successful optical stimulation is observed to be primarily dependent on a threshold nerve temperature (42 to 45 °C), rather than an incident fluence, as previously reported. cw optical nerve stimulation provides a significantly faster ICP response time using a lower power (and also less expensive) laser than pulsed stimulation. cw optical nerve stimulation may therefore represent an alternative mode of stimulation for intraoperative diagnostic applications where a rapid response is critical, such as identification of the cavernous nerves during prostate cancer surgery.
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Affiliation(s)
- Serhat Tozburun
- University of North Carolina at Charlotte, Department of Physics and Optical Science, Charlotte, North Carolina 28223-0001, USA
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41
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McCaughey RG, Chlebicki C, Wong BJF. Novel wavelengths for laser nerve stimulation. Lasers Surg Med 2010; 42:69-75. [PMID: 19802885 DOI: 10.1002/lsm.20856] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Laser light is known to stimulate nerves. This study investigated alternative wavelengths for nerve stimulation. MATERIALS AND METHODS The sciatic nerves of rats were irradiated with four different lasers-a Ho:YAG (2100 nm), a Yb:glass fiber laser (1495 nm) and diode lasers (1450 nm and 1540 nm). RESULTS All lasers evoked a visible leg twitch response, and electromyography confirmed muscle activation. The Yb:glass laser at 1495 nm delivered through a single mode fiber was found to be the most effective stimulus. The stimulation threshold for a 2 millisecond pulse from the Yb:glass laser was determined to be 3.7+/-2.8 mJ/cm(2). CONCLUSIONS The Yb:glass laser has the potential for use in neurostimulation, as an alternative to electrical stimulation.
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Affiliation(s)
- Ryan G McCaughey
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92612, USA.
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42
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Duke AR, Cayce JM, Malphrus JD, Konrad P, Mahadevan-Jansen A, Jansen ED. Combined optical and electrical stimulation of neural tissue in vivo. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:060501. [PMID: 20059232 PMCID: PMC2789115 DOI: 10.1117/1.3257230] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 08/13/2009] [Accepted: 09/08/2009] [Indexed: 05/25/2023]
Abstract
Low-intensity, pulsed infrared light provides a novel nerve stimulation modality that avoids the limitations of traditional electrical methods such as necessity of contact, presence of a stimulation artifact, and relatively poor spatial precision. Infrared neural stimulation (INS) is, however, limited by a 2:1 ratio of threshold radiant exposures for damage to that for stimulation. We have shown that this ratio is increased to nearly 6:1 by combining the infrared pulse with a subthreshold electrical stimulus. Our results indicate a nonlinear relationship between the subthreshold depolarizing electrical stimulus and additional optical energy required to reach stimulation threshold. The change in optical threshold decreases linearly as the delay between the electrical and optical pulses is increased. We have shown that the high spatial precision of INS is maintained for this combined stimulation modality. Results of this study will facilitate the development of applications for infrared neural stimulation, as well as target the efforts to uncover the mechanism by which infrared light activates neural tissue.
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43
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Fried NM, Lagoda GA, Scott NJ, Su LM, Burnett AL. Laser stimulation of the cavernous nerves in the rat prostate, in vivo: optimization of wavelength, pulse energy, and pulse repetition rate. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:2777-80. [PMID: 19163281 DOI: 10.1109/iembs.2008.4649778] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The cavernous nerves on the prostate surface are responsible for erectile function. Improved diagnostic techniques are necessary for identification of the nerves during prostate cancer surgery and preservation of sexual function after surgery. Electrical mapping of the nerves has been used as an intra-operative tool during prostate surgery, but it has proven inconsistent and unreliable. Non-contact optical stimulation of the cavernous nerves in the rat prostate has recently been demonstrated as a potential alternative to electrical nerve stimulation. The purpose of this study is to optimize the laser parameters to provide the maximum intracavernosal pressure response after optical nerve stimulation in the rat prostate. Optimal laser nerve stimulation parameters provided comparable response to electrical nerve stimulation. Optical nerve stimulation may represent a potential intra-operative diagnostic technique for use in laparoscopic and robotic nerve-sparing prostate cancer surgery.
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Affiliation(s)
- Nathaniel M Fried
- Department of Physics and Optical Science at the University of North Carolina at Charlotte, NC 28223, USA.
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