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Merlin S, Vidyasagar T. Optogenetics in primate cortical networks. Front Neuroanat 2023; 17:1193949. [PMID: 37284061 PMCID: PMC10239886 DOI: 10.3389/fnana.2023.1193949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 05/08/2023] [Indexed: 06/08/2023] Open
Abstract
The implementation of optogenetics in studies on non-human primates has generally proven quite difficult, but recent successes have paved the way for its rapid increase. Limitations in the genetic tractability in primates, have been somewhat overcome by implementing tailored vectors and promoters to maximize expression and specificity in primates. More recently, implantable devices, including microLED arrays, have made it possible to deliver light deeper into brain tissue, allowing targeting of deeper structures. However, the greatest limitation in applying optogenetics to the primate brain is the complex connections that exist within many neural circuits. In the past, relatively cruder methods such as cooling or pharmacological blockade have been used to examine neural circuit functions, though their limitations were well recognized. In some ways, similar shortcomings remain for optogenetics, with the ability to target a single component of complex neural circuits being the greatest challenge in applying optogenetics to systems neuroscience in primate brains. Despite this, some recent approaches combining Cre-expressing and Cre-dependent vectors have overcome some of these limitations. Here we suggest that optogenetics provides its greatest advantage to systems neuroscientists when applied as a specific tool to complement the techniques of the past, rather than necessarily replacing them.
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Affiliation(s)
- Sam Merlin
- Medical Science, School of Science, Western Sydney University, Campbelltown, NSW, Australia
| | - Trichur Vidyasagar
- Department of Optometry and Vision Sciences, School of Health Science, The University of Melbourne, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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Mitra E, Guo R, Nelson S, Nagarajan N, Menon R. Computational microscopy for fast widefield deep-tissue fluorescence imaging using a commercial dual-cannula probe. OPTICS CONTINUUM 2022; 1:2091-2099. [PMID: 37378086 PMCID: PMC10299805 DOI: 10.1364/optcon.469219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/25/2022] [Indexed: 06/29/2023]
Abstract
A solid-glass cannula serves as a micro-endoscope that can deliver excitation light deep inside tissue while also collecting emitted fluorescence. Then, we utilize deep neural networks to reconstruct images from the collected intensity distributions. By using a commercially available dual-cannula probe, and training a separate deep neural network for each cannula, we effectively double the field of view compared to prior work. We demonstrated ex vivo imaging of fluorescent beads and brain slices and in vivo imaging from whole brains. We clearly resolved 4 μm beads, with FOV from each cannula of 0.2 mm (diameter), and produced images from a depth of ~1.2 mm in the whole brain, currently limited primarily by the labeling. Since no scanning is required, fast widefield fluorescence imaging limited primarily by the brightness of the fluorophores, collection efficiency of our system, and the frame rate of the camera becomes possible.
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Affiliation(s)
- Ekata Mitra
- Department of Electrical & Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Ruipeng Guo
- Department of Electrical & Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Soren Nelson
- Department of Computer Science, Boston University, Boston, MA 02215, USA
| | - Naveen Nagarajan
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Rajesh Menon
- Department of Electrical & Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA
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McAlinden N, Cheng Y, Scharf R, Xie E, Gu E, Reiche CF, Sharma R, Tathireddy P, Dawson MD, Rieth L, Blair S, Mathieson K. Multisite microLED optrode array for neural interfacing. NEUROPHOTONICS 2019; 6:035010. [PMID: 31528655 PMCID: PMC6732520 DOI: 10.1117/1.nph.6.3.035010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 08/05/2019] [Indexed: 05/23/2023]
Abstract
We present an electrically addressable optrode array capable of delivering light to 181 sites in the brain, each providing sufficient light to optogenetically excite thousands of neurons in vivo, developed with the aim to allow behavioral studies in large mammals. The device is a glass microneedle array directly integrated with a custom fabricated microLED device, which delivers light to 100 needle tips and 81 interstitial surface sites, giving two-level optogenetic excitation of neurons in vivo. Light delivery and thermal properties are evaluated, with the device capable of peak irradiances > 80 mW / mm 2 per needle site. The device consists of an array of 181 80 μ m × 80 μ m 2 microLEDs, fabricated on a 150 - μ m -thick GaN-on-sapphire wafer, coupled to a glass needle array on a 150 - μ m thick backplane. A pinhole layer is patterned on the sapphire side of the microLED array to reduce stray light. Future designs are explored through optical and thermal modeling and benchmarked against the current device.
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Affiliation(s)
- Niall McAlinden
- University of Strathclyde, SUPA, Institute of Photonics, Department of Physics, Glasgow, United Kingdom
| | - Yunzhou Cheng
- University of Strathclyde, SUPA, Institute of Photonics, Department of Physics, Glasgow, United Kingdom
| | - Robert Scharf
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
| | - Enyuan Xie
- University of Strathclyde, SUPA, Institute of Photonics, Department of Physics, Glasgow, United Kingdom
| | - Erdan Gu
- University of Strathclyde, SUPA, Institute of Photonics, Department of Physics, Glasgow, United Kingdom
| | - Christopher F. Reiche
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
| | - Rohit Sharma
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
| | - Prashant Tathireddy
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
| | - Martin D. Dawson
- University of Strathclyde, SUPA, Institute of Photonics, Department of Physics, Glasgow, United Kingdom
| | - Loren Rieth
- Feinstein Institute for Medical Research, Manhasset, New York, United States
| | - Steve Blair
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
| | - Keith Mathieson
- University of Strathclyde, SUPA, Institute of Photonics, Department of Physics, Glasgow, United Kingdom
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Xi Y, Ji B, Guo Z, Li W, Liu J. Fabrication and Characterization of Micro-Nano Electrodes for Implantable BCI. MICROMACHINES 2019; 10:mi10040242. [PMID: 30979081 PMCID: PMC6523908 DOI: 10.3390/mi10040242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 03/29/2019] [Accepted: 04/08/2019] [Indexed: 02/07/2023]
Abstract
Signal recording and stimulation with high spatial and temporal resolution are of increasing interest with the development of implantable brain-computer interfaces (BCIs). However, implantable BCI technology still faces challenges in the biocompatibility and long-term stability of devices after implantation. Due to the cone structure, needle electrodes have advantages in the biocompatibility and stability as nerve recording electrodes. This paper develops the fabrication of Ag needle micro/nano electrodes with a laser-assisted pulling method and modifies the electrode surface by electrochemical oxidation. A significant impedance reduction of the modified Ag/AgCl electrodes compared to the Ag electrodes is demonstrated by the electrochemical impedance spectrum (EIS). Furthermore, the stability of modified Ag/AgCl electrodes is confirmed by cyclic voltammogram (CV) scanning. These findings suggest that these micro/nano electrodes have a great application prospect in neural interfaces.
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Affiliation(s)
- Ye Xi
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory, Department of Micro/Nano-electronics, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Bowen Ji
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory, Department of Micro/Nano-electronics, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Zhejun Guo
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory, Department of Micro/Nano-electronics, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Wen Li
- Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48823, USA.
| | - Jingquan Liu
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory, Department of Micro/Nano-electronics, Shanghai Jiao Tong University, Shanghai 200240, China.
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Choi JR, Kim SM, Ryu RH, Kim SP, Sohn JW. Implantable Neural Probes for Brain-Machine Interfaces - Current Developments and Future Prospects. Exp Neurobiol 2018; 27:453-471. [PMID: 30636899 PMCID: PMC6318554 DOI: 10.5607/en.2018.27.6.453] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 12/14/2022] Open
Abstract
A Brain-Machine interface (BMI) allows for direct communication between the brain and machines. Neural probes for recording neural signals are among the essential components of a BMI system. In this report, we review research regarding implantable neural probes and their applications to BMIs. We first discuss conventional neural probes such as the tetrode, Utah array, Michigan probe, and electroencephalography (ECoG), following which we cover advancements in next-generation neural probes. These next-generation probes are associated with improvements in electrical properties, mechanical durability, biocompatibility, and offer a high degree of freedom in practical settings. Specifically, we focus on three key topics: (1) novel implantable neural probes that decrease the level of invasiveness without sacrificing performance, (2) multi-modal neural probes that measure both electrical and optical signals, (3) and neural probes developed using advanced materials. Because safety and precision are critical for practical applications of BMI systems, future studies should aim to enhance these properties when developing next-generation neural probes.
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Affiliation(s)
- Jong-Ryul Choi
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation (DGMIF), Daegu 41061, Korea
| | - Seong-Min Kim
- Department of Medical Science, College of Medicine, Catholic Kwandong University, Gangneung 25601, Korea.,Biomedical Research Institute, Catholic Kwandong University International St. Mary's Hospital, Incheon 21711, Korea
| | - Rae-Hyung Ryu
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation (DGMIF), Daegu 41061, Korea
| | - Sung-Phil Kim
- Department of Human Factors Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Jeong-Woo Sohn
- Department of Medical Science, College of Medicine, Catholic Kwandong University, Gangneung 25601, Korea.,Biomedical Research Institute, Catholic Kwandong University International St. Mary's Hospital, Incheon 21711, Korea
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Wang H, Su K, Su L, Liang P, Ji P, Wang C. The effect of 3D-printed Ti6Al4V scaffolds with various macropore structures on osteointegration and osteogenesis: A biomechanical evaluation. J Mech Behav Biomed Mater 2018; 88:488-496. [DOI: 10.1016/j.jmbbm.2018.08.049] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/05/2018] [Accepted: 08/29/2018] [Indexed: 12/25/2022]
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