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Cunha AB, Schuelke C, Mesri A, Ruud SK, Aizenshtadt A, Ferrari G, Heiskanen A, Asif A, Keller SS, Ramos-Moreno T, Kalvøy H, Martínez-Serrano A, Krauss S, Emnéus J, Sampietro M, Martinsen ØG. Development of a Smart Wireless Multisensor Platform for an Optogenetic Brain Implant. SENSORS (BASEL, SWITZERLAND) 2024; 24:575. [PMID: 38257668 PMCID: PMC11154348 DOI: 10.3390/s24020575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024]
Abstract
Implantable cell replacement therapies promise to completely restore the function of neural structures, possibly changing how we currently perceive the onset of neurodegenerative diseases. One of the major clinical hurdles for the routine implementation of stem cell therapies is poor cell retention and survival, demanding the need to better understand these mechanisms while providing precise and scalable approaches to monitor these cell-based therapies in both pre-clinical and clinical scenarios. This poses significant multidisciplinary challenges regarding planning, defining the methodology and requirements, prototyping and different stages of testing. Aiming toward an optogenetic neural stem cell implant controlled by a smart wireless electronic frontend, we show how an iterative development methodology coupled with a modular design philosophy can mitigate some of these challenges. In this study, we present a miniaturized, wireless-controlled, modular multisensor platform with fully interfaced electronics featuring three different modules: an impedance analyzer, a potentiostat and an optical stimulator. We show the application of the platform for electrical impedance spectroscopy-based cell monitoring, optical stimulation to induce dopamine release from optogenetically modified neurons and a potentiostat for cyclic voltammetry and amperometric detection of dopamine release. The multisensor platform is designed to be used as an opto-electric headstage for future in vivo animal experiments.
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Affiliation(s)
- André B. Cunha
- Department of Physics, University of Oslo, Sem Sælands vei 24, 0371 Oslo, Norway; (A.B.C.); (C.S.); (S.K.R.)
| | - Christin Schuelke
- Department of Physics, University of Oslo, Sem Sælands vei 24, 0371 Oslo, Norway; (A.B.C.); (C.S.); (S.K.R.)
- Hybrid Technology Hub—Centre of Excellence, Institute of Basic Medical Sciences, P.O. Box 1110 Blindern, 0317 Oslo, Norway; (A.A.); (S.K.)
| | - Alireza Mesri
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy; (A.M.); (G.F.); (M.S.)
| | - Simen K. Ruud
- Department of Physics, University of Oslo, Sem Sælands vei 24, 0371 Oslo, Norway; (A.B.C.); (C.S.); (S.K.R.)
| | - Aleksandra Aizenshtadt
- Hybrid Technology Hub—Centre of Excellence, Institute of Basic Medical Sciences, P.O. Box 1110 Blindern, 0317 Oslo, Norway; (A.A.); (S.K.)
| | - Giorgio Ferrari
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy; (A.M.); (G.F.); (M.S.)
| | - Arto Heiskanen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.H.); (A.A.); (J.E.)
| | - Afia Asif
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.H.); (A.A.); (J.E.)
| | - Stephan S. Keller
- National Centre for Nano Fabrication and Characterization, Technical University of Denmark, 2800 Kongens Lyngby, Denmark;
| | - Tania Ramos-Moreno
- Lund Stem Cell Center, Division of Neurosurgery, Department of Clinical Sciences, Faculty of Medicine, Lund University, 22184 Lund, Sweden;
| | - Håvard Kalvøy
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway;
| | - Alberto Martínez-Serrano
- Department of Molecular Neurobiology, Center of Molecular Biology ‘Severo Ochoa’, Universidad Autónoma de Madrid, Calle Nicolás Cabrera 1, 28049 Madrid, Spain;
| | - Stefan Krauss
- Hybrid Technology Hub—Centre of Excellence, Institute of Basic Medical Sciences, P.O. Box 1110 Blindern, 0317 Oslo, Norway; (A.A.); (S.K.)
- Department of Immunology and Transfusion Medicine, Oslo University Hospital, P.O. Box 4950, 0424 Oslo, Norway
| | - Jenny Emnéus
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.H.); (A.A.); (J.E.)
| | - Marco Sampietro
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy; (A.M.); (G.F.); (M.S.)
| | - Ørjan G. Martinsen
- Department of Physics, University of Oslo, Sem Sælands vei 24, 0371 Oslo, Norway; (A.B.C.); (C.S.); (S.K.R.)
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway;
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Wu Y, Li BZ, Wang L, Fan S, Chen C, Li A, Lin Q, Wang P. An unsupervised real-time spike sorting system based on optimized OSort. J Neural Eng 2023; 20:066015. [PMID: 37972395 DOI: 10.1088/1741-2552/ad0d15] [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: 05/29/2023] [Accepted: 11/15/2023] [Indexed: 11/19/2023]
Abstract
Objective. The OSort algorithm, a pivotal unsupervised spike sorting method, has been implemented in dedicated hardware devices for real-time spike sorting. However, due to the inherent complexity of neural recording environments, OSort still grapples with numerous transient cluster occurrences during the practical sorting process. This leads to substantial memory usage, heavy computational load, and complex hardware architectures, especially in noisy recordings and multi-channel systems.Approach. This study introduces an optimized OSort algorithm (opt-OSort) which utilizes correlation coefficient (CC), instead of Euclidean distance as classification criterion. TheCCmethod not only bolsters the robustness of spike classification amidst the diverse and ever-changing conditions of physiological and recording noise environments, but also can finish the entire sorting procedure within a fixed number of cluster slots, thus preventing a large number of transient clusters. Moreover, the opt-OSort incorporates two configurable validation loops to efficiently reject cluster outliers and track recording variations caused by electrode drifting in real-time.Main results. The opt-OSort significantly reduces transient cluster occurrences by two orders of magnitude and decreases memory usage by 2.5-80 times in the number of pre-allocated transient clusters compared with other hardware implementations of OSort. The opt-OSort maintains an accuracy comparable to offline OSort and other commonly-used algorithms, with a sorting time of 0.68µs as measured by the hardware-implemented system in both simulated datasets and experimental data. The opt-OSort's ability to handle variations in neural activity caused by electrode drifting is also demonstrated.Significance. These results present a rapid, precise, and robust spike sorting solution suitable for integration into low-power, portable, closed-loop neural control systems and brain-computer interfaces.
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Affiliation(s)
- Yingjiang Wu
- School of Biomedical Engineering, Guangdong Medical University, Dongguan, People's Republic of China
- Songshan Lake Innovation Center of Medicine and Engineering, Guangdong Medical University, Dongguan, People's Republic of China
- Dongguan Key Laboratory of Medical Electronics and Medical Imaging Equipment, Dongguan, People's Republic of China
| | - Ben-Zheng Li
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
- Department of Electrical Engineering, University of Colorado Denver, Denver, CO, United States of America
| | - Liyang Wang
- State Key Laboratory of Analog and Mixed Signal VLSI, University of Macau, Macau, People's Republic of China
- Department of Electrical and Computer Engineering, University of Macau, Macau, People's Republic of China
| | - Shaocan Fan
- School of Electronics and Communication Engineering, Sun Yat-sen University-Shenzhen Campus, Shenzhen, People's Republic of China
| | - Changhao Chen
- Zhuhai Hokai Medical Instruments Co., Ltd, Zhuhai, People's Republic of China
| | - Anan Li
- Jiangsu Key Laboratory of Brain Disease and Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou, People's Republic of China
| | - Qin Lin
- School of Biomedical Engineering, Guangdong Medical University, Dongguan, People's Republic of China
- Songshan Lake Innovation Center of Medicine and Engineering, Guangdong Medical University, Dongguan, People's Republic of China
- Dongguan Key Laboratory of Medical Electronics and Medical Imaging Equipment, Dongguan, People's Republic of China
| | - Panke Wang
- School of Biomedical Engineering, Guangdong Medical University, Dongguan, People's Republic of China
- Songshan Lake Innovation Center of Medicine and Engineering, Guangdong Medical University, Dongguan, People's Republic of China
- Dongguan Key Laboratory of Medical Electronics and Medical Imaging Equipment, Dongguan, People's Republic of China
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DAS D, Xu Z, Nasrollahpour M, Martos-Repath I, Zaeimbashi M, Khalifa A, Mittal A, Cash SS, Sun NX, Shrivastava A, Onabajo M. Circuit-Level Modeling and Simulation of Wireless Sensing and Energy Harvesting With Hybrid Magnetoelectric Antennas for Implantable Neural Devices. IEEE OPEN JOURNAL OF CIRCUITS AND SYSTEMS 2023; 4:139-155. [PMID: 37829556 PMCID: PMC10569408 DOI: 10.1109/ojcas.2023.3259233] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
A magnetoelectric antenna (ME) can exhibit the dual capabilities of wireless energy harvesting and sensing at different frequencies. In this article, a behavioral circuit model for hybrid ME antennas is described to emulate the radio frequency (RF) energy harvesting and sensing operations during circuit simulations. The ME antenna of this work is interfaced with a CMOS energy harvester chip towards the goal of developing a wireless communication link for fully integrated implantable devices. One role of the integrated system is to receive pulse-modulated power from a nearby transmitter, and another role is to sense and transmit low-magnitude neural signals. The measurements reported in this paper are the first results that demonstrate simultaneous low-frequency wireless magnetic sensing and high-frequency wireless energy harvesting at two different frequencies with one dual-mode ME antenna. The proposed behavioral ME antenna model can be utilized during design optimizations of energy harvesting circuits. Measurements were performed to validate the wireless power transfer link with an ME antenna having a 2.57 GHz resonance frequency connected to an energy harvester chip designed in 65nm CMOS technology. Furthermore, this dual-mode ME antenna enables concurrent sensing using a carrier signal with a frequency that matches the second 63.63 MHz resonance mode. A wireless test platform has been developed for evaluation of ME antennas as a tool for neural implant design, and this prototype system was utilized to provide first experimental results with the transmission of magnetically modulated action potential waveforms.
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Affiliation(s)
- Diptashree DAS
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
| | - Ziyue Xu
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
| | - Mehdi Nasrollahpour
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
- MediaTek Inc., Woburn, MA 01801, USA
| | - Isabel Martos-Repath
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
| | - Mohsen Zaeimbashi
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Adam Khalifa
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Ankit Mittal
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nian X Sun
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
| | - Aatmesh Shrivastava
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
| | - Marvin Onabajo
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA
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Shen J, Xu Y, Xiao Z, Liu Y, Liu H, Wang F, Yan C, Wang L, Chen C, Wu Z, Liu Y, Mak PU, Vai MI, Pun SH, Lei TC, Zhang B. Double-Sided Sapphire Optrodes with Conductive Shielding Layers to Reduce Optogenetic Stimulation Artifacts. MICROMACHINES 2022; 13:1836. [PMID: 36363857 PMCID: PMC9695949 DOI: 10.3390/mi13111836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/15/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Optrodes, which are single shaft neural probes integrated with microelectrodes and optical light sources, offer a remarkable opportunity to simultaneously record and modulate neural activities using light within an animal's brain; however, a common problem with optrodes is that stimulation artifacts can be observed in the neural recordings of microelectrodes when the light source on the optrode is activated. These stimulation artifacts are undesirable contaminants, and they cause interpretation complexity when analyzing the recorded neural activities. In this paper, we tried to mitigate the effects of the stimulation artifacts by developing a low-noise, double-sided optrode integrated with multiple Electromagnetic Shielding (EMS) layers. The LED and microelectrodes were constructed separately on the top epitaxial and bottom substrate layers, and EMS layers were used to separate the microelectrodes and LED to reduce signal cross-talks. Compared with conventional single-sided designs, in which the LED and microelectrodes are constructed on the same side, our results indicate that double-sided optrodes can significantly reduce the presence of stimulation artifacts. In addition, the presence of stimulation artifacts can further be reduced by decreasing the voltage difference and increasing the rise/fall time of the driving LED pulsed voltage. With all these strategies, the presence of stimulation artifacts was significantly reduced by ~76%. As well as stimulation suppression, the sapphire substrate also provided strong mechanical stiffness and support to the optrodes, as well as improved electronic stability, thus making the double-sided sapphire optrodes highly suitable for optogenetic neuroscience research on animal models.
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Affiliation(s)
- Junyu Shen
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Yanyan Xu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhengwen Xiao
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Yuebo Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Honghui Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Fengge Wang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Chaokun Yan
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Liyang Wang
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China
| | - Changhao Chen
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China
| | - Zhisheng Wu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Yang Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Peng Un Mak
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau 999078, China
| | - Mang I. Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau 999078, China
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China
| | - Tim C. Lei
- Department of Electrical Engineering, University of Colorado, Denver, CO 80204, USA
| | - Baijun Zhang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
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5
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Sui K, Meneghetti M, Kaur J, Sørensen JF, Berg RW, Markos C. Adaptive polymer fiber neural device for drug delivery and enlarged illumination angle for neuromodulation. J Neural Eng 2022; 19. [PMID: 35130533 DOI: 10.1088/1741-2552/ac5267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/07/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Optical fiber devices constitute significant tools for the modulation and interrogation of neuronal circuitry in the mid and deep brain regions. The illuminated brain area during neuromodulation has a direct impact on the spatio-temporal properties of the brain activity and depends solely on the material and geometrical characteristics of the optical fibers. In the present work, we developed two different flexible polymer optical fibers (POFs) with integrated microfluidic channels (MFCs) and an ultra-high numerical aperture (UHNA) for enlarging the illumination angle to achieve efficient neuromodulation. APPROACH Three distinct thermoplastic polymers: polysulfone (PSU), polycarbonate (PC), and fluorinated ethylene propylene (FEP) were used to fabricate two step-index UHNA POF neural devices using a scalable thermal drawing process. The POFs were characterized in terms of their illumination map as well as their fluid delivery capability in phantom and adult rat brain slices. MAIN RESULTS A 100-fold reduced bending stiffness of the proposed fiber devices compared to their commercially available counterparts has been found. The integrated MFCs can controllably deliver dye (trypan blue) on-demand over a wide range of injection rates spanning from 10 nL/min to 1000 nL/min. Compared with commercial silica fibers, the proposed UHNA POFs exhibited an increased illumination area by 17% and 21% under 470 and 650 nm wavelength, respectively. In addition, a fluorescent light recording experiment has been conducted to demonstrate the ability of our UHNA POFs to be used as optical waveguides in fiber photometry. SIGNIFICANCE Our results overcome the current technological limitations of fiber implants that have limited illumination area and we suggest that soft neural fiber devices can be developed using different custom designs for illumination, collection, and photometry applications. We anticipate our work to pave the way towards the development of next-generation functional optical fibers for neuroscience.
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Affiliation(s)
- Kunyang Sui
- DTU Fotonik, DTU - Lyngby Campus, Ørsteds Plads, 343, Lyngby, 2800, DENMARK
| | - Marcello Meneghetti
- DTU Fotonik, DTU - Lyngby Campus, Ørsteds Plads, 343,, Lyngby, 2800, DENMARK
| | - Jaspreet Kaur
- Department of Neuroscience, University of Copenhagen Faculty of Health and Medical Sciences, Building: 62, Copenhagen, 2200, DENMARK
| | - Jakob Fleng Sørensen
- Department of Neuroscience, University of Copenhagen Faculty of Health and Medical Sciences, Building: 62, Copenhagen, 2200, DENMARK
| | - Rune W Berg
- Department of Neuroscience, University of Copenhagen Faculty of Health and Medical Sciences, Building: 62, Copenhagen, 2200, DENMARK
| | - Christos Markos
- DTU Fotonik, Technical University of Denmark, DTU Fotonik, Ørsteds Plads Building 343, room 022, Kgs.Lyngby, Lyngby, 2800, DENMARK
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Shen J, Xu Y, Xiao Z, Liu Y, Liu H, Wang F, Yao W, Yan Z, Zhang M, Wu Z, Liu Y, Pun SH, Lei TC, Vai MI, Mak PU, Chen C, Zhang B. Influence of the Surface Material and Illumination upon the Performance of a Microelectrode/Electrolyte Interface in Optogenetics. MICROMACHINES 2021; 12:1061. [PMID: 34577704 PMCID: PMC8471589 DOI: 10.3390/mi12091061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 11/17/2022]
Abstract
Integrated optrodes for optogenetics have been becoming a significant tool in neuroscience through the combination of offering accurate stimulation to target cells and recording biological signals simultaneously. This makes it not just be widely used in neuroscience researches, but also have a great potential to be employed in future treatments in clinical neurological diseases. To optimize the integrated optrodes, this paper aimed to investigate the influence of surface material and illumination upon the performance of the microelectrode/electrolyte interface and build a corresponding evaluation system. In this work, an integrated planar optrode with a blue LED and microelectrodes was designed and fabricated. The charge transfer mechanism on the interface was theoretically modeled and experimentally verified. An evaluation system for assessing microelectrodes was also built up. Using this system, the proposed model of various biocompatible surface materials on microelectrodes was further investigated under different illumination conditions. The influence of illumination on the microelectrode/electrolyte interface was the cause of optical artifacts, which interfere the biological signal recording. It was found that surface materials had a great effect on the charge transfer capacity, electrical stability and recoverability, photostability, and especially optical artifacts. The metal with better charge transfer capacity and electrical stability is highly possible to have a better performance on the optical artifacts, regardless of its electrical recoverability and photostability under the illumination conditions of optogenetics. Among the five metals used in our investigation, iridium served as the best surface material for the proposed integrated optrodes. Thus, optimizing the surface material for optrodes could reduce optical interference, enhance the quality of the neural signal recording for optogenetics, and thus help to advance the research in neuroscience.
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Grants
- 62061160368 & 0022/2020/AFJ This research was funded by the joint funding of the Nature Science Foundation of China (NSFC) & the Macao Science and Technology Development Fund (FDCT) of China
- 2019B010132003, 2019B010132001 Science & Technology Plan of Guangdong Province, China
- 2016YFB0400105, 2017YFB0403001 the National Key Research and Development Program
- 20167612042080001 the Zhuhai Key Technology Laboratory of Wide Bandgap Semiconductor Power Electronics, Sun Yat-sen University, China
- 088/2016/A2, 0144/2019/A3, 0022/2020/AFJ, SKL-AMSV (FDCT-funded), SKL-AMSV-ADDITIONAL FUND, SKL-AMSV(UM)-2020-2022 the Science and Technology Development Fund, Macau SAR
- MYRG2018-00146-AMSV, MYRG2019-00056-AMSV the University of Macau
- 2020YFB1313502 the National Key R&D Program of China
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Affiliation(s)
- Junyu Shen
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Yanyan Xu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Zhengwen Xiao
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Yuebo Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Honghui Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Fengge Wang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Wanqing Yao
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Zhaokun Yan
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Minjie Zhang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
| | - Zhisheng Wu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Yang Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China; (S.H.P.); (M.I.V.); (C.C.)
| | - Tim C. Lei
- Department of Electrical Engineering, University of Colorado Denver, Denver, CO 80204, USA;
| | - Mang I Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China; (S.H.P.); (M.I.V.); (C.C.)
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau 999078, China;
| | - Peng Un Mak
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau 999078, China;
| | - Changhao Chen
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau 999078, China; (S.H.P.); (M.I.V.); (C.C.)
| | - Baijun Zhang
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China; (J.S.); (Y.X.); (Z.X.); (Y.L.); (H.L.); (F.W.); (W.Y.); (Z.Y.); (M.Z.); (Z.W.); (Y.L.)
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
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7
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Jeon S, Lee Y, Ryu D, Cho YK, Lee Y, Jun SB, Ji CH. Implantable Optrode Array for Optogenetic Modulation and Electrical Neural Recording. MICROMACHINES 2021; 12:mi12060725. [PMID: 34205473 PMCID: PMC8234104 DOI: 10.3390/mi12060725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023]
Abstract
During the last decade, optogenetics has become an essential tool for neuroscience research due to its unrivaled feature of cell-type-specific neuromodulation. There have been several technological advances in light delivery devices. Among them, the combination of optogenetics and electrophysiology provides an opportunity for facilitating optogenetic approaches. In this study, a novel design of an optrode array was proposed for realizing optical modulation and electrophysiological recording. A 4 × 4 optrode array and five-channel recording electrodes were assembled as a disposable part, while a reusable part comprised an LED (light-emitting diode) source and a power line. After the characterization of the intensity of the light delivered at the fiber tips, in vivo animal experiment was performed with transgenic mice expressing channelrhodopsin, showing the effectiveness of optical activation and neural recording.
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Affiliation(s)
- Saeyeong Jeon
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea; (S.J.); (D.R.)
| | - Youjin Lee
- Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea; (Y.L.); (Y.K.C.); (Y.L.); (S.B.J.)
- Graduate Program in Smart Factory, Ewha Womans University, Seoul 03760, Korea
| | - Daeho Ryu
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Korea; (S.J.); (D.R.)
| | - Yoon Kyung Cho
- Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea; (Y.L.); (Y.K.C.); (Y.L.); (S.B.J.)
| | - Yena Lee
- Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea; (Y.L.); (Y.K.C.); (Y.L.); (S.B.J.)
| | - Sang Beom Jun
- Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea; (Y.L.); (Y.K.C.); (Y.L.); (S.B.J.)
- Graduate Program in Smart Factory, Ewha Womans University, Seoul 03760, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University, Seoul 03760, Korea
| | - Chang-Hyeon Ji
- Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea; (Y.L.); (Y.K.C.); (Y.L.); (S.B.J.)
- Graduate Program in Smart Factory, Ewha Womans University, Seoul 03760, Korea
- Correspondence: ; Tel.: +82-2-3277-3895
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8
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Li X, Liu C, Wang R. Light Modulation of Brain and Development of Relevant Equipment. J Alzheimers Dis 2021; 74:29-41. [PMID: 32039856 DOI: 10.3233/jad-191240] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Light modulation plays an important role in understanding the pathology of brain disorders and improving brain function. Optogenetic techniques can activate or silence targeted neurons with high temporal and spatial accuracy and provide precise control, and have recently become a method for quick manipulation of genetically identified types of neurons. Photobiomodulation (PBM) is light therapy that utilizes non-ionizing light sources, including lasers, light emitting diodes, or broadband light. It provides a safe means of modulating brain activity without any irreversible damage and has established optimal treatment parameters in clinical practice. This manuscript reviews 1) how optogenetic approaches have been used to dissect neural circuits in animal models of Alzheimer's disease, Parkinson's disease, and depression, and 2) how low level transcranial lasers and LED stimulation in humans improves brain activity patterns in these diseases. State-of-the-art brain machine interfaces that can record neural activity and stimulate neurons with light have good prospects in the future.
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Affiliation(s)
- Xiaoran Li
- School of Information and Electronics, Beijing Institute of Technology, Beijing, China
| | - Chunyan Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Rong Wang
- Central Laboratory, Xuanwu Hospital, Capital Medical University, Beijing Geriatric Medical Research Center, Beijing, China.,Beijing Institute for Brain Disorders, Beijing, China
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9
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A Lead Field Two-Domain Model for Longitudinal Neural Tracts-Analytical Framework and Implications for Signal Bandwidth. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:5436807. [PMID: 32565881 PMCID: PMC7275970 DOI: 10.1155/2020/5436807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 11/18/2022]
Abstract
Somatosensory evoked potentials are a well-established tool for assessing volley conduction in afferent neural pathways. However, from a clinical perspective, recording of spinal signals is still a demanding task due to the low amplitudes compared to relevant noise sources. Computer modeling is a powerful tool for gaining insight into signal genesis and, thus, for promoting future innovations in signal extraction. However, due to the complex structure of neural pathways, modeling is computationally demanding. We present a theoretical framework which allows computing the electric potential generated by a single axon in a body surface lead by the convolution of the neural lead field function with a propagating action potential term. The signal generated by a large cohort of axons was obtained by convoluting a single axonal signal with the statistical distribution of temporal dispersion of individual axonal signals. For establishing the framework, analysis was based on an analytical model. Our approach was further adopted for a numerical computation of body surface neuropotentials employing the lead field theory. Double convolution allowed straightforward analysis in the frequency domain. The highest frequency components occurred at the cellular membrane. A bandpass type spectral shape and a peak frequency of 1800 Hz was observed. The volume conductor transmitting the signal to the recording lead acted as an additional bandpass reducing the axonal peak frequency from 200 Hz to 500 Hz. The superposition of temporally dispersed axonal signals acted as an additional low-pass filter further reducing the compound action potential peak frequency from 90 Hz to 170 Hz. Our results suggest that the bandwidth of spinal evoked potentials might be narrower than the bandwidth requested by current clinical guidelines. The present findings will allow the optimization of noise suppression. Furthermore, our theoretical framework allows the adaptation in numerical methods and application in anatomically realistic geometries in future studies.
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10
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Jia Y, Lee B, Kong F, Zeng Z, Connolly M, Mahmoudi B, Ghovanloo M. A Software-Defined Radio Receiver for Wireless Recording From Freely Behaving Animals. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:1645-1654. [PMID: 31647447 PMCID: PMC6990704 DOI: 10.1109/tbcas.2019.2949233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
To eliminate tethering effects on the small animals' behavior during electrophysiology experiments, such as neural interfacing, a robust and wideband wireless data link is needed for communicating with the implanted sensing elements without blind spots. We present a software-defined radio (SDR) based scalable data acquisition system, which can be programmed to provide coverage over standard-sized or customized experimental arenas. The incoming RF signal with the highest power among SDRs is selected in real-time to prevent data loss in the presence of spatial and angular misalignments between the transmitter (Tx) and receiver (Rx) antennas. A 32-channel wireless neural recording system-on-a-chip (SoC), known as WINeRS-8, is embedded in a headstage and transmits digitalized raw neural signals, which are sampled at 25 kHz/ch, at 9 Mbps via on-off keying (OOK) of a 434 MHz RF carrier. Measurement results show that the dual-SDR Rx system reduces the packet loss down to 0.12%, on average, by eliminating the blind spots caused by the moving Tx directionality. The system operation is verified in vivo on a freely behaving rat and compared with a commercial hardwired system.
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11
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Kuenzel T. Modulatory influences on time-coding neurons in the ventral cochlear nucleus. Hear Res 2019; 384:107824. [DOI: 10.1016/j.heares.2019.107824] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 09/10/2019] [Accepted: 10/14/2019] [Indexed: 02/07/2023]
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12
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Wang PK, Pun SH, Chen CH, McCullagh EA, Klug A, Li A, Vai MI, Mak PU, Lei TC. Low-latency single channel real-time neural spike sorting system based on template matching. PLoS One 2019; 14:e0225138. [PMID: 31756211 PMCID: PMC6874356 DOI: 10.1371/journal.pone.0225138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 10/29/2019] [Indexed: 11/26/2022] Open
Abstract
Recent technical advancements in neural engineering allow for precise recording and control of neural circuits simultaneously, opening up new opportunities for closed-loop neural control. In this work, a rapid spike sorting system was developed based on template matching to rapidly calculate instantaneous firing rates for each neuron in a multi-unit extracellular recording setting. Cluster templates were first generated by a desktop computer using a non-parameter spike sorting algorithm (Super-paramagnetic clustering) and then transferred to a field-programmable gate array digital circuit for rapid sorting through template matching. Two different matching techniques–Euclidean distance (ED) and correlational matching (CM)–were compared for the accuracy of sorting and the performance of calculating firing rates. The performance of the system was first verified using publicly available artificial data and was further confirmed with pre-recorded neural spikes from an anesthetized Mongolian gerbil. Real-time recording and sorting from an awake mouse were also conducted to confirm the system performance in a typical behavioral neuroscience experimental setting. Experimental results indicated that high sorting accuracies were achieved for both template-matching methods, but CM can better handle spikes with non-Gaussian spike distributions, making it more robust for in vivo recording. The technique was also compared to several other off-line spike sorting algorithms and the results indicated that the sorting accuracy is comparable but sorting time is significantly shorter than these other techniques. A low sorting latency of under 2 ms and a maximum spike sorting rate of 941 spikes/second have been achieved with our hybrid hardware/software system. The low sorting latency and fast sorting rate allow future system developments of neural circuit modulation through analyzing neural activities in real-time.
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Affiliation(s)
- Pan Ke Wang
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau, China
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Sio Hang Pun
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau, China
- * E-mail:
| | - Chang Hao Chen
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau, China
| | - Elizabeth A. McCullagh
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
| | - Achim Klug
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
| | - Anan Li
- Jiangsu Key Laboratory of Brain Disease and Bioinformation, Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Xuzhou, China
| | - Mang I. Vai
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau, China
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Peng Un Mak
- Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Tim C. Lei
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macau, China
- Department of Electrical Engineering, University of Colorado, Denver, CO, United States of America
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13
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Gagnon-Turcotte G, Keramidis I, Ethier C, De Koninck Y, Gosselin B. A Wireless Electro-Optic Headstage With a 0.13- μm CMOS Custom Integrated DWT Neural Signal Decoder for Closed-Loop Optogenetics. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2019; 13:1036-1051. [PMID: 31352352 DOI: 10.1109/tbcas.2019.2930498] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present a wireless electro-optic headstage that uses a 0.13- μm CMOS custom integrated circuit (IC) implementing a digital neural decoder (ND-IC) for enabling real-time closed-loop (CL) optogenetics. The ND-IC processes the neural activity data using three digital cores: 1) the detector core detects and extracts the action potential (AP) of individual neurons by using an adaptive threshold; 2) the data compression core compresses the detected AP by using an efficient Symmlet-2 discrete wavelet transform (DWT) processor for decreasing the amount of data to be transmitted by the low-power wireless link; and 3) the classification core sorts the compressed AP into separated clusters on the fly according to their wave shapes. The ND-IC encompasses several innovations: 1) the compression core decreases the complexity from O(n 2) to O(n · log(n)) compared to the previous solutions, while using two times less memory, thanks to the use of a new coefficient sorting tree; and 2) the AP classification core reuses both the compressed DWT coefficients to perform implicit dimensionality reduction, which allows for performing intensive signal processing on-chip, while increasing power and hardware efficiency. This core also reuses the signal standard deviation already computed by the AP detector core as threshold for performing automatic AP sorting. The headstage also introduces innovations by enabling a new wireless CL scheme between the neural data acquisition module and the optical stimulator. Our CL scheme uses the AP sorting and timing information produced by the ND-IC for detecting complex firing patterns within the brain. The headstage is also smaller (1.13 cm 3), lighter (3.0 g with a 40 mAh battery) and less invasive than the previous solutions, while providing a measured autonomy of 2h40, with the ND-IC. The whole system and the ND-IC are first validated in vivo in the LD thalamus of a Long-Evans rat, and then in freely-moving CL experiments involving a mouse virally expressing ChR2-mCherry in inhibitory neurons of the prelimbic cortex, and the results show that our system works well within an in vivo experimental setting with a freely moving mouse.
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14
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Mohammadi Z, Kincaid JM, Pun SH, Klug A, Liu C, Lei TC. Computationally inexpensive enhanced growing neural gas algorithm for real-time adaptive neural spike clustering. J Neural Eng 2019; 16:056007. [DOI: 10.1088/1741-2552/ab208c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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15
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Sharma K, Sharma R. Design considerations for effective neural signal sensing and amplification: a review. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab1674] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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16
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Massey TL, Santacruz SR, Hou JF, Pister KSJ, Carmena JM, Maharbiz MM. A high-density carbon fiber neural recording array technology. J Neural Eng 2019; 16:016024. [DOI: 10.1088/1741-2552/aae8d9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Ramezani R, Liu Y, Dehkhoda F, Soltan A, Haci D, Zhao H, Firfilionis D, Hazra A, Cunningham MO, Jackson A, Constandinou TG, Degenaar P. On-Probe Neural Interface ASIC for Combined Electrical Recording and Optogenetic Stimulation. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2018; 12:576-588. [PMID: 29877821 DOI: 10.1109/tbcas.2018.2818818] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Neuromodulation technologies are progressing from pacemaking and sensory operations to full closed-loop control. In particular, optogenetics-the genetic modification of light sensitivity into neural tissue allows for simultaneous optical stimulation and electronic recording. This paper presents a neural interface application-specified integrated circuit (ASIC) for intelligent optoelectronic probes. The architecture is designed to enable simultaneous optical neural stimulation and electronic recording. It provides four low noise (2.08 μV) recording channels optimized for recording local field potentials (LFPs) (0.1-300 Hz bandwidth, 5 mV range, sampled 10-bit@4 kHz), which are more stable for chronic applications. For stimulation, it provides six independently addressable optical driver circuits, which can provide both intensity (8-bit resolution across a 1.1 mA range) and pulse-width modulation for high-radiance light emitting diodes (LEDs). The system includes a fully digital interface using a serial peripheral interface (SPI) protocol to allow for use with embedded controllers. The SPI interface is embedded within a finite state machine (FSM), which implements a command interpreter that can send out LFP data whilst receiving instructions to control LED emission. The circuit has been implemented in a commercially available 0.35 μm CMOS technology occupying a 1.95 mm 1.10 mm footprint for mounting onto the head of a silicon probe. Measured results are given for a variety of bench-top, in vitro and in vivo experiments, quantifying system performance and also demonstrating concurrent recording and stimulation within relevant experimental models.
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18
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Keplinger S, Beiderbeck B, Michalakis S, Biel M, Grothe B, Kunz L. Optogenetic Control of Neural Circuits in the Mongolian Gerbil. Front Cell Neurosci 2018; 12:111. [PMID: 29740286 PMCID: PMC5928259 DOI: 10.3389/fncel.2018.00111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 04/05/2018] [Indexed: 12/17/2022] Open
Abstract
The Mongolian gerbil (Meriones unguiculatus) is widely used as a model organism for the human auditory system. Its hearing range is very similar to ours and it uses the same mechanisms for sound localization. The auditory circuits underlying these functions have been characterized. However, important mechanistic details are still under debate. To elucidate these issues, precise and reversible optogenetic manipulation of neuronal activity in this complex circuitry is required. However, genetic and genomic resources for the Mongolian gerbil are poorly developed. Here, we demonstrate a reliable gene delivery system using an AAV8(Y337F)-pseudotyped recombinant adeno-associated virus (AAV) 2-based vector in which the pan-neural human synapsin (hSyn) promoter drives neuron-specific expression of CatCH (Ca2+-permeable channelrhodopsin) or NpHR3.0 (Natronomonas pharaonis halorhodopsin). After stereotactic injection into the gerbil’s auditory brainstem (medial nucleus of the trapezoid body, dorsal nucleus of the lateral lemniscus) and midbrain [inferior colliculus (IC)], we characterized CatCH- and/or NpHR3.0-transduced neurons in acute brain slices by means of whole-cell patch-clamp recordings. As the response properties of optogenetic tools strongly depend on neuronal biophysics, this parameterization is crucial for their in vivo application. In a proof-of-principle experiment in anesthetized gerbils, we observed strong suppression of sound-evoked neural responses in the dorsal nucleus of the lateral lemniscus (DNLL) and IC upon light activation of NpHR3.0. The successful validation of gene delivery and optogenetic tools in the Mongolian gerbil paves the way for future studies of the auditory circuits in this model system.
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Affiliation(s)
- Stefan Keplinger
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany
| | - Barbara Beiderbeck
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, GSN-LMU, Ludwig Maximilian University of Munich, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CiPSM), Department of Pharmacy, Center for Drug Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CiPSM), Department of Pharmacy, Center for Drug Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany
| | - Lars Kunz
- Division of Neurobiology, Department Biology II, Biocenter, Ludwig Maximilian University of Munich, Munich, Germany
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19
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Saran S, Gupta N, Roy S. Theoretical analysis of low-power fast optogenetic control of firing of Chronos-expressing neurons. NEUROPHOTONICS 2018; 5:025009. [PMID: 29845088 PMCID: PMC5966744 DOI: 10.1117/1.nph.5.2.025009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/11/2018] [Indexed: 05/15/2023]
Abstract
A detailed theoretical analysis of low-power, fast optogenetic control of firing of Chronos-expressing neurons has been presented. A three-state model for the Chronos photocycle has been formulated and incorporated in a fast-spiking interneuron circuit model. The effect of excitation wavelength, pulse irradiance, pulse width, and pulse frequency has been studied in detail and compared with ChR2. Theoretical simulations are in excellent agreement with recently reported experimental results and bring out additional interesting features. At very low irradiances ([Formula: see text]), the plateau current in Chronos exhibits a maximum. At [Formula: see text], the plateau current is 2 orders of magnitude smaller and saturates at longer pulse widths ([Formula: see text]) compared to ChR2 ([Formula: see text]). [Formula: see text] in Chronos saturates at much shorter pulse widths (1775 pA at 1.5 ms and [Formula: see text]) than in ChR2. Spiking fidelity is also higher at lower irradiances and longer pulse widths compared to ChR2. Chronos exhibits an average maximal driven rate of over [Formula: see text] in response to [Formula: see text] stimuli, each of 1-ms pulse-width, in the intensity range 0 to [Formula: see text]. The analysis is important to not only understand the photodynamics of Chronos and Chronos-expressing neurons but also to design opsins with optimized properties and perform precision experiments with required spatiotemporal resolution.
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Affiliation(s)
- Sant Saran
- Dayalbagh Educational Institute, Department of Electrical Engineering, Agra, Uttar Pradesh, India
| | - Neha Gupta
- Dayalbagh Educational Institute, Department of Physics and Computer Science, Agra, Uttar Pradesh, India
| | - Sukhdev Roy
- Dayalbagh Educational Institute, Department of Physics and Computer Science, Agra, Uttar Pradesh, India
- Address all correspondence to: Sukhdev Roy, E-mail:
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20
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Delbeke J, Hoffman L, Mols K, Braeken D, Prodanov D. And Then There Was Light: Perspectives of Optogenetics for Deep Brain Stimulation and Neuromodulation. Front Neurosci 2017; 11:663. [PMID: 29311765 PMCID: PMC5732983 DOI: 10.3389/fnins.2017.00663] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 11/14/2017] [Indexed: 12/12/2022] Open
Abstract
Deep Brain Stimulation (DBS) has evolved into a well-accepted add-on treatment for patients with severe Parkinsons disease as well as for other chronic neurological conditions. The focal action of electrical stimulation can yield better responses and it exposes the patient to fewer side effects compared to pharmaceuticals distributed throughout the body toward the brain. On the other hand, the current practice of DBS is hampered by the relatively coarse level of neuromodulation achieved. Optogenetics, in contrast, offers the perspective of much more selective actions on the various physiological structures, provided that the stimulated cells are rendered sensitive to the action of light. Optogenetics has experienced tremendous progress since its first in vivo applications about 10 years ago. Recent advancements of viral vector technology for gene transfer substantially reduce vector-associated cytotoxicity and immune responses. This brings about the possibility to transfer this technology into the clinic as a possible alternative to DBS and neuromodulation. New paths could be opened toward a rich panel of clinical applications. Some technical issues still limit the long term use in humans but realistic perspectives quickly emerge. Despite a rapid accumulation of observations about patho-physiological mechanisms, it is still mostly serendipity and empiric adjustments that dictate clinical practice while more efficient logically designed interventions remain rather exceptional. Interestingly, it is also very much the neuro technology developed around optogenetics that offers the most promising tools to fill in the existing knowledge gaps about brain function in health and disease. The present review examines Parkinson's disease and refractory epilepsy as use cases for possible optogenetic stimulation therapies.
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Affiliation(s)
- Jean Delbeke
- LCEN3, Department of Neurology, Institute of Neuroscience, Ghent University, Ghent, Belgium
| | | | - Katrien Mols
- Neuroscience Research Flanders, Leuven, Belgium.,Life Science and Imaging, Imec, Leuven, Belgium
| | | | - Dimiter Prodanov
- Neuroscience Research Flanders, Leuven, Belgium.,Environment, Health and Safety, Imec, Leuven, Belgium
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