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Li G, Jang D, Shin Y, Qiang Y, Qi Y, Wang S, Fang H. Cracking modes and force dynamics in the insertion of neural probes into hydrogel brain phantom. J Neural Eng 2024; 21:046009. [PMID: 38885673 PMCID: PMC11225066 DOI: 10.1088/1741-2552/ad5937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 04/23/2024] [Accepted: 06/17/2024] [Indexed: 06/20/2024]
Abstract
Objective. The insertion of penetrating neural probes into the brain is crucial for advancing neuroscience, yet it involves various inherent risks. Prototype probes are typically inserted into hydrogel-based brain phantoms and the mechanical responses are analyzed in order to inform the insertion mechanics duringin vivoimplantation. However, the underlying mechanism of the insertion dynamics of neural probes in hydrogel brain phantoms, particularly the phenomenon of cracking, remains insufficiently understood. This knowledge gap leads to misinterpretations and discrepancies when comparing results obtained from phantom studies to those observed under thein vivoconditions. This study aims to elucidate the impact of probe sharpness and dimensions on the cracking mechanisms and insertion dynamics characterized during the insertion of probes in hydrogel phantoms.Approach. The insertion of dummy probes with different shank shapes defined by the tip angle, width, and thickness is systematically studied. The insertion-induced cracks in the transparent hydrogel were accentuated by an immiscible dye, tracked byin situimaging, and the corresponding insertion force was recorded. Three-dimensional finite element analysis models were developed to obtain the contact stress between the probe tip and the phantom.Main results. The findings reveal a dual pattern: for sharp, slender probes, the insertion forces remain consistently low during the insertion process, owing to continuously propagating straight cracks that align with the insertion direction. In contrast, blunt, thick probes induce large forces that increase rapidly with escalating insertion depth, mainly due to the formation of branched crack with a conical cracking surface, and the subsequent internal compression. This interpretation challenges the traditional understanding that neglects the difference in the cracking modes and regards increased frictional force as the sole factor contributing to higher insertion forces. The critical probe sharpness factors separating straight and branched cracking is identified experimentally, and a preliminary explanation of the transition between the two cracking modes is derived from three-dimensional finite element analysis.Significance. This study presents, for the first time, the mechanism underlying two distinct cracking modes during the insertion of neural probes into hydrogel brain phantoms. The correlations between the cracking modes and the insertion force dynamics, as well as the effects of the probe sharpness were established, offering insights into the design of neural probes via phantom studies and informing future investigations into cracking phenomena in brain tissue during probe implantations.
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Affiliation(s)
- Gen Li
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Dongyeol Jang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Yieljae Shin
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Yi Qiang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Yongli Qi
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
| | - Shuodao Wang
- School of Mechanical & Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, United States of America
| | - Hui Fang
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States of America
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2
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Bhatia A, Hanna J, Stuart T, Kasper KA, Clausen DM, Gutruf P. Wireless Battery-free and Fully Implantable Organ Interfaces. Chem Rev 2024; 124:2205-2280. [PMID: 38382030 DOI: 10.1021/acs.chemrev.3c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Advances in soft materials, miniaturized electronics, sensors, stimulators, radios, and battery-free power supplies are resulting in a new generation of fully implantable organ interfaces that leverage volumetric reduction and soft mechanics by eliminating electrochemical power storage. This device class offers the ability to provide high-fidelity readouts of physiological processes, enables stimulation, and allows control over organs to realize new therapeutic and diagnostic paradigms. Driven by seamless integration with connected infrastructure, these devices enable personalized digital medicine. Key to advances are carefully designed material, electrophysical, electrochemical, and electromagnetic systems that form implantables with mechanical properties closely matched to the target organ to deliver functionality that supports high-fidelity sensors and stimulators. The elimination of electrochemical power supplies enables control over device operation, anywhere from acute, to lifetimes matching the target subject with physical dimensions that supports imperceptible operation. This review provides a comprehensive overview of the basic building blocks of battery-free organ interfaces and related topics such as implantation, delivery, sterilization, and user acceptance. State of the art examples categorized by organ system and an outlook of interconnection and advanced strategies for computation leveraging the consistent power influx to elevate functionality of this device class over current battery-powered strategies is highlighted.
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Affiliation(s)
- Aman Bhatia
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Jessica Hanna
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Tucker Stuart
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Kevin Albert Kasper
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - David Marshall Clausen
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Philipp Gutruf
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Department of Electrical and Computer Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Bio5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
- Neuroscience Graduate Interdisciplinary Program (GIDP), The University of Arizona, Tucson, Arizona 85721, United States
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3
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Wei S, Jiang A, Sun H, Zhu J, Jia S, Liu X, Xu Z, Zhang J, Shang Y, Fu X, Li G, Wang P, Xia Z, Jiang T, Cao A, Duan X. Shape-changing electrode array for minimally invasive large-scale intracranial brain activity mapping. Nat Commun 2024; 15:715. [PMID: 38267440 PMCID: PMC10808108 DOI: 10.1038/s41467-024-44805-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 01/03/2024] [Indexed: 01/26/2024] Open
Abstract
Large-scale brain activity mapping is important for understanding the neural basis of behaviour. Electrocorticograms (ECoGs) have high spatiotemporal resolution, bandwidth, and signal quality. However, the invasiveness and surgical risks of electrode array implantation limit its application scope. We developed an ultrathin, flexible shape-changing electrode array (SCEA) for large-scale ECoG mapping with minimal invasiveness. SCEAs were inserted into cortical surfaces in compressed states through small openings in the skull or dura and fully expanded to cover large cortical areas. MRI and histological studies on rats proved the minimal invasiveness of the implantation process and the high chronic biocompatibility of the SCEAs. High-quality micro-ECoG activities mapped with SCEAs from male rodent brains during seizures and canine brains during the emergence period revealed the spatiotemporal organization of different brain states with resolution and bandwidth that cannot be achieved using existing noninvasive techniques. The biocompatibility and ability to map large-scale physiological and pathological cortical activities with high spatiotemporal resolution, bandwidth, and signal quality in a minimally invasive manner offer SCEAs as a superior tool for applications ranging from fundamental brain research to brain-machine interfaces.
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Affiliation(s)
- Shiyuan Wei
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Anqi Jiang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Hongji Sun
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Jingjun Zhu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
- National Biomedical Imaging Centre, Peking University, Beijing, 100871, China
| | - Shengyi Jia
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Xiaojun Liu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Zheng Xu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Jing Zhang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Yuanyuan Shang
- Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450052, China
| | - Xuefeng Fu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Gen Li
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
| | - Puxin Wang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Zhiyuan Xia
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Tianzi Jiang
- Brainnetome Centre, Institute of Automation, Chinese Academy of Sciences (CAS), Beijing, 100190, China
| | - Anyuan Cao
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Xiaojie Duan
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, 100871, China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
- National Biomedical Imaging Centre, Peking University, Beijing, 100871, China.
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4
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Yu A, Zhu M, Chen C, Li Y, Cui H, Liu S, Zhao Q. Implantable Flexible Sensors for Health Monitoring. Adv Healthc Mater 2024; 13:e2302460. [PMID: 37816513 DOI: 10.1002/adhm.202302460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/05/2023] [Indexed: 10/12/2023]
Abstract
Flexible sensors, as a significant component of flexible electronics, have attracted great interest the realms of human-computer interaction and health monitoring due to their high conformability, adjustable sensitivity, and excellent durability. In comparison to wearable sensor-based in vitro health monitoring, the use of implantable flexible sensors (IFSs) for in vivo health monitoring offers more accurate and reliable vital sign information due to their ability to adapt and directly integrate with human tissue. IFSs show tremendous promise in the field of health monitoring, with unique advantages such as robust signal reading capabilities, lightweight design, flexibility, and biocompatibility. Herein, a review of IFSs for vital signs monitoring is detailly provided, highlighting the essential conditions for in vivo applications. As the prerequisites of IFSs, the stretchability and wireless self-powered properties of the sensor are discussed, with a special attention paid to the sensing materials which can maintain prominent biosafety (i.e., biocompatibility, biodegradability, bioresorbability). Furthermore, the applications of IFSs monitoring various parts of the body are described in detail, with a summary in brain monitoring, eye monitoring, and blood monitoring. Finally, the challenges as well as opportunities in the development of next-generation IFSs are presented.
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Affiliation(s)
- Aoxi Yu
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
| | - Mingye Zhu
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Congkai Chen
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Yang Li
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
| | - Haixia Cui
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Shujuan Liu
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
| | - Qiang Zhao
- College of Electronic and Optical Engineering, and College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, 9 Wenyuan, Nanjing, 210023, P. R. China
- State Key Laboratory of Organic Electronics and Information Displays, and Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, P. R. China
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5
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Zhou Y, Yang H, Wang X, Yang H, Sun K, Zhou Z, Sun L, Zhao J, Tao TH, Wei X. A mosquito mouthpart-like bionic neural probe. MICROSYSTEMS & NANOENGINEERING 2023; 9:88. [PMID: 37448967 PMCID: PMC10336119 DOI: 10.1038/s41378-023-00565-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/05/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
Advancements in microscale electrode technology have revolutionized the field of neuroscience and clinical applications by offering high temporal and spatial resolution of recording and stimulation. Flexible neural probes, with their mechanical compliance to brain tissue, have been shown to be superior to rigid devices in terms of stability and longevity in chronic recordings. Shuttle devices are commonly used to assist flexible probe implantation; however, the protective membrane of the brain still makes penetration difficult. Hidden damage to brain vessels during implantation is a significant risk. Inspired by the anatomy of the mosquito mouthparts, we present a biomimetic neuroprobe system that integrates high-sensitivity sensors with a high-fidelity multichannel flexible electrode array. This customizable system achieves distributed and minimally invasive implantation across brain regions. Most importantly, the system's nonvisual monitoring capability provides an early warning detection for intracranial soft tissues, such as vessels, reducing the potential for injury during implantation. The neural probe system demonstrates exceptional sensitivity and adaptability to environmental stimuli, as well as outstanding performance in postoperative and chronic recordings. These findings suggest that our biomimetic neural-probe device offers promising potential for future applications in neuroscience and brain-machine interfaces. A mosquito mouthpart-like bionic neural probe consisting of a highly sensitive tactile sensor module, a flexible microelectrode array, and implanted modules that mimic the structure of mosquito mouthparts. The system enables distributed implantation of electrode arrays across multiple brain regions while making the implantation minimally invasive and avoiding additional dural removal. The tactile sensor array can monitor the implantation process to achieve early warning of vascular damage. The excellent postoperative short-term recording performance and long-term neural activity tracking ability demonstrate that the system is a promising tool in the field of brain-computer interfaces.
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Affiliation(s)
- Yu Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Huiran Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xueying Wang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Heng Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Ke Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Zhitao Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Liuyang Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
| | - Jianlong Zhao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Tiger H. Tao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 200031 Shanghai, China
- Neuroxess Co., Ltd. (Jiangxi), 330029 Nanchang, Jiangxi China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, 519031 Zhuhai, Guangdong China
- Tianqiao and Chrissy Chen Institute for Translational Research, Shanghai, China
| | - Xiaoling Wei
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
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6
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Böhler C, Vomero M, Soula M, Vöröslakos M, Porto Cruz M, Liljemalm R, Buzsaki G, Stieglitz T, Asplund M. Multilayer Arrays for Neurotechnology Applications (MANTA): Chronically Stable Thin-Film Intracortical Implants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207576. [PMID: 36935361 DOI: 10.1002/advs.202207576] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/07/2023] [Indexed: 05/18/2023]
Abstract
Flexible implantable neurointerfaces show great promise in addressing one of the major challenges of implantable neurotechnology, namely the loss of signal connected to unfavorable probe tissue interaction. The authors here show how multilayer polyimide probes allow high-density intracortical recordings to be combined with a reliable long-term stable tissue interface, thereby progressing toward chronic stability of implantable neurotechnology. The probes could record 10-60 single units over 5 months with a consistent peak-to-peak voltage at dimensions that ensure robust handling and insulation longevity. Probes that remain in intimate contact with the signaling tissue over months to years are a game changer for neuroscience and, importantly, open up for broader clinical translation of systems relying on neurotechnology to interface the human brain.
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Affiliation(s)
- Christian Böhler
- Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110, Freiburg, Germany
- BrainLinks-BrainTools Center, University of Freiburg, 79110, Freiburg, Germany
| | - Maria Vomero
- Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110, Freiburg, Germany
- BrainLinks-BrainTools Center, University of Freiburg, 79110, Freiburg, Germany
| | - Marisol Soula
- Neuroscience Institute, Langone Medical Center, New York University, New York, 10016, USA
| | - Mihály Vöröslakos
- Neuroscience Institute, Langone Medical Center, New York University, New York, 10016, USA
| | - Maria Porto Cruz
- Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110, Freiburg, Germany
- BrainLinks-BrainTools Center, University of Freiburg, 79110, Freiburg, Germany
| | - Rickard Liljemalm
- Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110, Freiburg, Germany
| | - György Buzsaki
- Neuroscience Institute, Langone Medical Center, New York University, New York, 10016, USA
- Department of Physiology and Neuroscience, Langone Medical Center, New York University, New York, 10016, USA
- Department of Neurology, Langone Medical Center, New York University, New York, 10016, USA
| | - Thomas Stieglitz
- Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110, Freiburg, Germany
- BrainLinks-BrainTools Center, University of Freiburg, 79110, Freiburg, Germany
- Bernstein Center Freiburg, University of Freiburg, 79110, Freiburg, Germany
| | - Maria Asplund
- Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110, Freiburg, Germany
- BrainLinks-BrainTools Center, University of Freiburg, 79110, Freiburg, Germany
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, SE-41296, Sweden
- Division of Nursing and Medical Technology, Luleå University of Technology, Luleå, 97187, Sweden
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79110, Freiburg, Germany
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7
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Duan Y, Wang S, Yuan Q, Shi Y, Jiang N, Jiang D, Song J, Wang P, Zhuang L. Long-Term Flexible Neural Interface for Synchronous Recording of Cross-Regional Sensory Processing along the Olfactory Pathway. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2205768. [PMID: 37035943 DOI: 10.1002/smll.202205768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 02/04/2023] [Indexed: 06/19/2023]
Abstract
Humans perceive the world through five senses, of which olfaction is the oldest evolutionary sense that enables the detection of chemicals in the external environment. Recent progress in bioinspired electronics has boosted the development of artificial sensory systems. Here, a biohybrid olfactory system is proposed by integrating living mammals with implantable flexible neural electrodes, to employ the outstanding properties of mammalian olfactory system. In olfactory perception, the peripheral organ-olfactory epithelium (OE) projects axons into the olfactory relay station-olfactory bulb (OB). The olfactory information encoded in the neural activity is recorded from both OE and OB simultaneously using flexible neural electrodes. Results reveal that spontaneous slow oscillations (<12 Hz) in both OE and OB closely follow respiration. This respiration-locked rhythm modulates the amplitude of fast oscillations (>20 Hz), which are associated with odor perception. Further, by extracting the characteristics of odor-evoked oscillatory signals, responses of different odors are identified and classified with 80% accuracy. This study demonstrates for the first time that the flexible electrode enables chronic stable electrophysiological recordings of the peripheral and central olfactory system in vivo. Overall, the method provides a novel neural interface for olfactory biosensing and cognitive processing.
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Affiliation(s)
- Yan Duan
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
- The MOE Frontier Science Center for Brain Science and Brain-Machine Integration, Zhejiang University, Hangzhou, 310027, China
| | - Suhao Wang
- Department of Engineering Mechanics, Soft Matter Research Center, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou, 310027, China
| | - Qunchen Yuan
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
- Innovation Center for Smart Medical Technologies & Devices, Binjiang Institute of Zhejiang University, Hangzhou, 310027, China
| | - Yingqian Shi
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Nan Jiang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Deming Jiang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
- Innovation Center for Smart Medical Technologies & Devices, Binjiang Institute of Zhejiang University, Hangzhou, 310027, China
| | - Jizhou Song
- Department of Engineering Mechanics, Soft Matter Research Center, Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou, 310027, China
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027, China
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310012, China
| | - Ping Wang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
- The MOE Frontier Science Center for Brain Science and Brain-Machine Integration, Zhejiang University, Hangzhou, 310027, China
- Innovation Center for Smart Medical Technologies & Devices, Binjiang Institute of Zhejiang University, Hangzhou, 310027, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai, 200050, China
| | - Liujing Zhuang
- Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China
- The MOE Frontier Science Center for Brain Science and Brain-Machine Integration, Zhejiang University, Hangzhou, 310027, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Shanghai, 200050, China
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8
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Wang Y, Yang X, Zhang X, Wang Y, Pei W. Implantable intracortical microelectrodes: reviewing the present with a focus on the future. MICROSYSTEMS & NANOENGINEERING 2023; 9:7. [PMID: 36620394 PMCID: PMC9814492 DOI: 10.1038/s41378-022-00451-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 08/08/2022] [Accepted: 08/22/2022] [Indexed: 06/17/2023]
Abstract
Implantable intracortical microelectrodes can record a neuron's rapidly changing action potentials (spikes). In vivo neural activity recording methods often have either high temporal or spatial resolution, but not both. There is an increasing need to record more neurons over a longer duration in vivo. However, there remain many challenges to overcome before achieving long-term, stable, high-quality recordings and realizing comprehensive, accurate brain activity analysis. Based on the vision of an idealized implantable microelectrode device, the performance requirements for microelectrodes are divided into four aspects, including recording quality, recording stability, recording throughput, and multifunctionality, which are presented in order of importance. The challenges and current possible solutions for implantable microelectrodes are given from the perspective of each aspect. The current developments in microelectrode technology are analyzed and summarized.
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Affiliation(s)
- Yang Wang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xinze Yang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xiwen Zhang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yijun Wang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
- Chinese Institute for Brain Research, 102206 Beijing, China
| | - Weihua Pei
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083 Beijing, China
- University of Chinese Academy of Sciences, 100049 Beijing, China
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9
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He F, Sun Y, Jin Y, Yin R, Zhu H, Rathore H, Xie C, Luan L. Longitudinal neural and vascular recovery following ultraflexible neural electrode implantation in aged mice. Biomaterials 2022; 291:121905. [PMID: 36403326 PMCID: PMC9701172 DOI: 10.1016/j.biomaterials.2022.121905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/24/2022] [Accepted: 11/04/2022] [Indexed: 11/16/2022]
Abstract
Flexible neural electrodes improve the recording longevity and quality of individual neurons by promoting tissue-electrode integration. However, the intracortical implantation of flexible electrodes inevitably induces tissue damage. Understanding the longitudinal neural and vascular recovery following the intracortical implantation is critical for the ever-growing applications of flexible electrodes in both healthy and disordered brains. Aged animals are of particular interest because they play a key role in modeling neurological disorders, but their tissue-electrode interface remains mostly unstudied. Here we integrate in-vivo two-photon imaging and electrophysiological recording to determine the time-dependent neural and vascular dynamics after the implantation of ultraflexible neural electrodes in aged mice. We find heightened angiogenesis and vascular remodeling in the first two weeks after implantation, which coincides with the rapid increase in local field potentials and unit activities detected by electrophysiological recordings. Vascular remodeling in shallow cortical layers preceded that in deeper layers, which often lasted longer than the recovery of neural signals. By six weeks post-implantation vascular abnormalities had subsided, resulting in normal vasculature and microcirculation. Putative cell classification based on firing pattern and waveform shows similar recovery time courses in fast-spiking interneurons and pyramidal neurons. These results elucidate how structural damages and remodeling near implants affecting recording efficacy, and support the application of ultraflexible electrodes in aged animals at minimal perturbations to endogenous neurophysiology.
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Affiliation(s)
- Fei He
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA
| | - Yingchu Sun
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA
| | - Yifu Jin
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA
| | - Rongkang Yin
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA
| | - Hanlin Zhu
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA
| | - Haad Rathore
- Rice Neuroengineering Initiative, Rice University, Houston, USA; Applied Physics Graduate Program, Rice University, Houston, USA
| | - Chong Xie
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA; Department of Bioengineering, Rice University, Houston, USA
| | - Lan Luan
- Department of Electrical and Computer Engineering, Rice University, Houston, USA; Rice Neuroengineering Initiative, Rice University, Houston, USA; Department of Bioengineering, Rice University, Houston, USA.
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10
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Zhou Y, Gu C, Liang J, Zhang B, Yang H, Zhou Z, Li M, Sun L, Tao TH, Wei X. A silk-based self-adaptive flexible opto-electro neural probe. MICROSYSTEMS & NANOENGINEERING 2022; 8:118. [PMID: 36389054 PMCID: PMC9643444 DOI: 10.1038/s41378-022-00461-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 09/15/2022] [Accepted: 10/09/2022] [Indexed: 06/16/2023]
Abstract
The combination of optogenetics and electrophysiological recording enables high-precision bidirectional interactions between neural interfaces and neural circuits, which provides a promising approach for the study of progressive neurophysiological phenomena. Opto-electrophysiological neural probes with sufficient flexibility and biocompatibility are desirable to match the low mechanical stiffness of brain tissue for chronic reliable performance. However, lack of rigidity poses challenges for the accurate implantation of flexible neural probes with less invasiveness. Herein, we report a hybrid probe (Silk-Optrode) consisting of a silk protein optical fiber and multiple flexible microelectrode arrays. The Silk-Optrode can be accurately inserted into the brain and perform synchronized optogenetic stimulation and multichannel recording in freely behaving animals. Silk plays an important role due to its high transparency, excellent biocompatibility, and mechanical controllability. Through the hydration of the silk optical fiber, the Silk-Optrode probe enables itself to actively adapt to the environment after implantation and reduce its own mechanical stiffness to implant into the brain with high fidelity while maintaining mechanical compliance with the surrounding tissue. The probes with 128 recording channels can detect high-yield well-isolated single units while performing intracranial light stimulation with low optical losses, surpassing previous work of a similar type. Two months of post-surgery results suggested that as-reported Silk-Optrode probes exhibit better implant-neural interfaces with less immunoreactive glial responses and tissue lesions. A silk optical fiber-based Silk-Optrode probe consisting of a natural silk optical fiber and a flexible micro/nano electrode array is reported. The multifunctional soft probe can modify its own Young's modulus through hydration to achieve accurate implantation into the brain. The low optical loss and single-unit recording abilities allow simultaneous optogenetic stimulation and multichannel readout, which expands the applications in the operation and parsing of neural circuits in behavioral animals.
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Affiliation(s)
- Yu Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Chi Gu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Jizhi Liang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Bohan Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Physical Science and Technology, ShanghaiTech University, 200031 Shanghai, China
| | - Huiran Yang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
| | - Zhitao Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Meng Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Liuyang Sun
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
| | - Tiger H. Tao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
- School of Physical Science and Technology, ShanghaiTech University, 200031 Shanghai, China
- 2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 200031 Shanghai, China
- Neuroxess Co., Ltd. (Jiangxi), 330029 Nanchang, Jiangxi China
- Guangdong Institute of Intelligence Science and Technology, Hengqin, 519031 Zhuhai, Guangdong China
- Tianqiao and Chrissy Chen Institute for Translational Research, Shanghai, China
| | - Xiaoling Wei
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050 Shanghai, China
- School of Graduate Study, University of Chinese Academy of Sciences, 100049 Beijing, China
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11
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Yin R, Noble BC, He F, Zolotavin P, Rathore H, Jin Y, Sevilla N, Xie C, Luan L. Chronic co-implantation of ultraflexible neural electrodes and a cranial window. NEUROPHOTONICS 2022; 9:032204. [PMID: 35036472 PMCID: PMC8756486 DOI: 10.1117/1.nph.9.3.032204] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/04/2021] [Indexed: 06/01/2023]
Abstract
Significance: Electrophysiological recording and optical imaging are two prevalent neurotechnologies with complementary strengths, the combined application of which can significantly improve our capacity in deciphering neural circuits. Flexible electrode arrays can support longitudinal optical imaging in the same brain region, but their mechanical flexibility makes surgical preparation challenging. Here, we provide a step-by-step protocol by which an ultraflexible nanoelectronic thread is co-implanted with a cranial window in a single surgery to enable chronic, dual-modal measurements. Aim: The method uses 1 - μ m -thick polymer neural electrodes which conform to the site of implantation. The mechanical flexibility of the probe allows bending without breaking and enables long-lasting electrophysiological recordings of single-unit activities and concurrent, high-resolution optical imaging through the cranial window. Approach: The protocol describes methods and procedures to co-implant an ultraflexible electrode array and a glass cranial window in the mouse neocortex. The implantation strategy includes temporary attachment of flexible electrodes to a retractable tungsten-microwire insertion shuttle, craniotomy, stereotaxic insertion of the electrode array, skull fixation of the cranial window and electrode, and installation of a head plate. Results: The resultant implant allows simultaneous interrogation of brain activity both electrophysiologically and optically for several months. Importantly, a variety of optical imaging modalities, including wide-field fluorescent imaging, two-photon microscopy, and functional optical imaging, can be readily applied to the specific brain region where ultraflexible electrodes record from. Conclusions: The protocol describes a method for co-implantation of ultraflexible neural electrodes and a cranial window for chronic, multimodal measurements of brain activity in mice. Device preparation and surgical implantation are described in detail to guide the adaptation of these methods for other flexible neural implants and cranial windows.
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Affiliation(s)
- Rongkang Yin
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
| | - Brian C. Noble
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
- Rice University, Applied Physics Graduate Program, Houston, Texas, United States
| | - Fei He
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
| | - Pavlo Zolotavin
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
| | - Haad Rathore
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
- Rice University, Applied Physics Graduate Program, Houston, Texas, United States
| | - Yifu Jin
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
| | - Nicole Sevilla
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
- Rice University, Department of Bioengineering, Houston, Texas, United States
| | - Chong Xie
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
- Rice University, Department of Bioengineering, Houston, Texas, United States
| | - Lan Luan
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Rice University, Rice Neuroengineering Initiative, Houston, Texas, United States
- Rice University, Department of Bioengineering, Houston, Texas, United States
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12
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Geramifard N, Dousti B, Nguyen CK, Abbott JR, Cogan S, Varner V. Insertion mechanics of amorphous SiC ultra-micro scale neural probes. J Neural Eng 2022; 19. [PMID: 35263724 PMCID: PMC9339220 DOI: 10.1088/1741-2552/ac5bf4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 03/09/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Trauma induced by the insertion of microelectrodes into cortical neural tissue is a significant problem. Further, micromotion and mechanical mismatch between microelectrode probes and neural tissue is implicated in an adverse foreign body response (FBR). Hence, intracortical ultra-microelectrode probes have been proposed as alternatives that minimize this FBR. However, significant challenges in implanting these flexible probes remain. We investigated the insertion mechanics of amorphous silicon carbide (a-SiC) probes with a view to defining probe geometries that can be inserted into cortex without buckling. APPROACH We determined the critical buckling force of a-SiC probes as a function of probe geometry and then characterized the buckling behavior of these probes by measuring force-displacement responses during insertion into agarose gel and rat cortex. MAIN RESULTS Insertion forces for a range of probe geometries were determined and compared with critical buckling forces to establish geometries that should avoid buckling during implantation into brain. The studies show that slower insertion speeds reduce the maximum insertion force for single-shank probes but increase cortical dimpling during insertion of multi-shank probes. SIGNIFICANCE Our results provide a guide for selecting probe geometries and insertion speeds that allow unaided implantation of probes into rat cortex. The design approach is applicable to other animal models where insertion of intracortical probes to a depth of 2 mm is required.
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Affiliation(s)
- Negar Geramifard
- Department of Bioeengineering, The University of Texas at Dallas Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Rd., BSB 13.601, Richardson, Texas, 75080-3021, UNITED STATES
| | - Behnoush Dousti
- The University of Texas at Dallas, Department of Bioengineering, Richardson, Texas, 75080-3021, UNITED STATES
| | - Christopher Khanhtuan Nguyen
- Department of Bioengineering, The University of Texas at Dallas, 800 W Campbell Rd, Richardson, Texas, 75080-3021, UNITED STATES
| | - Justin Robert Abbott
- Department of Bioengineering, The University of Texas at Dallas, 800 West Campbell Rd, Richardson, Texas, 75080, UNITED STATES
| | - Stuart Cogan
- Department of Bioengineering, The University of Texas at Dallas Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Road, Richardson, Texas, 75080-3021, UNITED STATES
| | - Victor Varner
- Department of Bioengineering, The University of Texas at Dallas Erik Jonsson School of Engineering and Computer Science, 800 West Campbell Rd, Richardson, Texas, 75080, UNITED STATES
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13
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Research Progress on the Flexibility of an Implantable Neural Microelectrode. MICROMACHINES 2022; 13:mi13030386. [PMID: 35334680 PMCID: PMC8954487 DOI: 10.3390/mi13030386] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/25/2021] [Accepted: 01/16/2022] [Indexed: 12/22/2022]
Abstract
Neural microelectrode is the important bridge of information exchange between the human body and machines. By recording and transmitting nerve signals with electrodes, people can control the external machines. At the same time, using electrodes to electrically stimulate nerve tissue, people with long-term brain diseases will be safely and reliably treated. Young’s modulus of the traditional rigid electrode probe is not matched well with that of biological tissue, and tissue immune rejection is easy to generate, resulting in the electrode not being able to achieve long-term safety and reliable working. In recent years, the choice of flexible materials and design of electrode structures can achieve modulus matching between electrode and biological tissue, and tissue damage is decreased. This review discusses nerve microelectrodes based on flexible electrode materials and substrate materials. Simultaneously, different structural designs of neural microelectrodes are reviewed. However, flexible electrode probes are difficult to implant into the brain. Only with the aid of certain auxiliary devices, can the implant be safe and reliable. The implantation method of the nerve microelectrode is also reviewed.
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14
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Vėbraitė I, Hanein Y. Soft Devices for High-Resolution Neuro-Stimulation: The Interplay Between Low-Rigidity and Resolution. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 3:675744. [PMID: 35047928 PMCID: PMC8757739 DOI: 10.3389/fmedt.2021.675744] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/14/2021] [Indexed: 12/27/2022] Open
Abstract
The field of neurostimulation has evolved over the last few decades from a crude, low-resolution approach to a highly sophisticated methodology entailing the use of state-of-the-art technologies. Neurostimulation has been tested for a growing number of neurological applications, demonstrating great promise and attracting growing attention in both academia and industry. Despite tremendous progress, long-term stability of the implants, their large dimensions, their rigidity and the methods of their introduction and anchoring to sensitive neural tissue remain challenging. The purpose of this review is to provide a concise introduction to the field of high-resolution neurostimulation from a technological perspective and to focus on opportunities stemming from developments in materials sciences and engineering to reduce device rigidity while optimizing electrode small dimensions. We discuss how these factors may contribute to smaller, lighter, softer and higher electrode density devices.
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Affiliation(s)
- Ieva Vėbraitė
- School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Yael Hanein
- School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel
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15
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Sharafkhani N, Kouzani AZ, Adams SD, Long JM, Lissorgues G, Rousseau L, Orwa JO. Neural tissue-microelectrode interaction: Brain micromotion, electrical impedance, and flexible microelectrode insertion. J Neurosci Methods 2022; 365:109388. [PMID: 34678387 DOI: 10.1016/j.jneumeth.2021.109388] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/17/2021] [Accepted: 10/17/2021] [Indexed: 10/20/2022]
Abstract
Insertion of a microelectrode into the brain to record/stimulate neurons damages neural tissue and blood vessels and initiates the brain's wound healing response. Due to the large difference between the stiffness of neural tissue and microelectrode, brain micromotion also leads to neural tissue damage and associated local immune response. Over time, following implantation, the brain's response to the tissue damage can result in microelectrode failure. Reducing the microelectrode's cross-sectional dimensions to single-digit microns or using soft materials with elastic modulus close to that of the neural tissue are effective methods to alleviate the neural tissue damage and enhance microelectrode longevity. However, the increase in electrical impedance of the microelectrode caused by reducing the microelectrode contact site's dimensions can decrease the signal-to-noise ratio. Most importantly, the reduced dimensions also lead to a reduction in the critical buckling force, which increases the microelectrode's propensity to buckling during insertion. After discussing brain micromotion, the main source of neural tissue damage, surface modification of the microelectrode contact site is reviewed as a key method for addressing the increase in electrical impedance issue. The review then focuses on recent approaches to aiding insertion of flexible microelectrodes into the brain, including bending stiffness modification, effective length reduction, and application of a magnetic field to pull the electrode. An understanding of the advantages and drawbacks of the developed strategies offers a guide for dealing with the buckling phenomenon during implantation.
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Affiliation(s)
- Naser Sharafkhani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
| | - Abbas Z Kouzani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - Scott D Adams
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - John M Long
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | | | | | - Julius O Orwa
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
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16
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McGlynn E, Nabaei V, Ren E, Galeote‐Checa G, Das R, Curia G, Heidari H. The Future of Neuroscience: Flexible and Wireless Implantable Neural Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002693. [PMID: 34026431 PMCID: PMC8132070 DOI: 10.1002/advs.202002693] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/15/2021] [Indexed: 05/04/2023]
Abstract
Neurological diseases are a prevalent cause of global mortality and are of growing concern when considering an ageing global population. Traditional treatments are accompanied by serious side effects including repeated treatment sessions, invasive surgeries, or infections. For example, in the case of deep brain stimulation, large, stiff, and battery powered neural probes recruit thousands of neurons with each pulse, and can invoke a vigorous immune response. This paper presents challenges in engineering and neuroscience in developing miniaturized and biointegrated alternatives, in the form of microelectrode probes. Progress in design and topology of neural implants has shifted the goal post toward highly specific recording and stimulation, targeting small groups of neurons and reducing the foreign body response with biomimetic design principles. Implantable device design recommendations, fabrication techniques, and clinical evaluation of the impact flexible, integrated probes will have on the treatment of neurological disorders are provided in this report. The choice of biocompatible material dictates fabrication techniques as novel methods reduce the complexity of manufacture. Wireless power, the final hurdle to truly implantable neural interfaces, is discussed. These aspects are the driving force behind continued research: significant breakthroughs in any one of these areas will revolutionize the treatment of neurological disorders.
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Affiliation(s)
- Eve McGlynn
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Vahid Nabaei
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Elisa Ren
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Gabriel Galeote‐Checa
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Rupam Das
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
| | - Giulia Curia
- Laboratory of Experimental Electroencephalography and NeurophysiologyDepartment of BiomedicalMetabolic and Neural SciencesUniversity of Modena and Reggio EmiliaModena41125Italy
| | - Hadi Heidari
- Microelectronics LabJames Watt School of EngineeringUniversity of GlasgowGlasgowG12 8QQUnited Kingdom
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17
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Thielen B, Meng E. A comparison of insertion methods for surgical placement of penetrating neural interfaces. J Neural Eng 2021; 18:10.1088/1741-2552/abf6f2. [PMID: 33845469 PMCID: PMC8600966 DOI: 10.1088/1741-2552/abf6f2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/12/2021] [Indexed: 02/07/2023]
Abstract
Many implantable electrode arrays exist for the purpose of stimulating or recording electrical activity in brain, spinal, or peripheral nerve tissue, however most of these devices are constructed from materials that are mechanically rigid. A growing body of evidence suggests that the chronic presence of these rigid probes in the neural tissue causes a significant immune response and glial encapsulation of the probes, which in turn leads to gradual increase in distance between the electrodes and surrounding neurons. In recording electrodes, the consequence is the loss of signal quality and, therefore, the inability to collect electrophysiological recordings long term. In stimulation electrodes, higher current injection is required to achieve a comparable response which can lead to tissue and electrode damage. To minimize the impact of the immune response, flexible neural probes constructed with softer materials have been developed. These flexible probes, however, are often not strong enough to be inserted on their own into the tissue, and instead fail via mechanical buckling of the shank under the force of insertion. Several strategies have been developed to allow the insertion of flexible probes while minimizing tissue damage. It is critical to keep these strategies in mind during probe design in order to ensure successful surgical placement. In this review, existing insertion strategies will be presented and evaluated with respect to surgical difficulty, immune response, ability to reach the target tissue, and overall limitations of the technique. Overall, the majority of these insertion techniques have only been evaluated for the insertion of a single probe and do not quantify the accuracy of probe placement. More work needs to be performed to evaluate and optimize insertion methods for accurate placement of devices and for devices with multiple probes.
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Affiliation(s)
- Brianna Thielen
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
| | - Ellis Meng
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
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18
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Vandekerckhove B, Missinne J, Vonck K, Bauwens P, Verplancke R, Boon P, Raedt R, Vanfleteren J. Technological Challenges in the Development of Optogenetic Closed-Loop Therapy Approaches in Epilepsy and Related Network Disorders of the Brain. MICROMACHINES 2020; 12:38. [PMID: 33396287 PMCID: PMC7824489 DOI: 10.3390/mi12010038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 12/25/2022]
Abstract
Epilepsy is a chronic, neurological disorder affecting millions of people every year. The current available pharmacological and surgical treatments are lacking in overall efficacy and cause side-effects like cognitive impairment, depression, tremor, abnormal liver and kidney function. In recent years, the application of optogenetic implants have shown promise to target aberrant neuronal circuits in epilepsy with the advantage of both high spatial and temporal resolution and high cell-specificity, a feature that could tackle both the efficacy and side-effect problems in epilepsy treatment. Optrodes consist of electrodes to record local field potentials and an optical component to modulate neurons via activation of opsin expressed by these neurons. The goal of optogenetics in epilepsy is to interrupt seizure activity in its earliest state, providing a so-called closed-loop therapeutic intervention. The chronic implantation in vivo poses specific demands for the engineering of therapeutic optrodes. Enzymatic degradation and glial encapsulation of implants may compromise long-term recording and sufficient illumination of the opsin-expressing neural tissue. Engineering efforts for optimal optrode design have to be directed towards limitation of the foreign body reaction by reducing the implant's elastic modulus and overall size, while still providing stable long-term recording and large-area illumination, and guaranteeing successful intracerebral implantation. This paper presents an overview of the challenges and recent advances in the field of electrode design, neural-tissue illumination, and neural-probe implantation, with the goal of identifying a suitable candidate to be incorporated in a therapeutic approach for long-term treatment of epilepsy patients.
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Affiliation(s)
- Bram Vandekerckhove
- Center for Microsystems Technology, Imec and Ghent University, 9000 Ghent, Belgium; (B.V.); (J.M.); (P.B.); (R.V.)
| | - Jeroen Missinne
- Center for Microsystems Technology, Imec and Ghent University, 9000 Ghent, Belgium; (B.V.); (J.M.); (P.B.); (R.V.)
| | - Kristl Vonck
- 4Brain Team, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (K.V.); (P.B.); (R.R.)
| | - Pieter Bauwens
- Center for Microsystems Technology, Imec and Ghent University, 9000 Ghent, Belgium; (B.V.); (J.M.); (P.B.); (R.V.)
| | - Rik Verplancke
- Center for Microsystems Technology, Imec and Ghent University, 9000 Ghent, Belgium; (B.V.); (J.M.); (P.B.); (R.V.)
| | - Paul Boon
- 4Brain Team, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (K.V.); (P.B.); (R.R.)
| | - Robrecht Raedt
- 4Brain Team, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (K.V.); (P.B.); (R.R.)
| | - Jan Vanfleteren
- Center for Microsystems Technology, Imec and Ghent University, 9000 Ghent, Belgium; (B.V.); (J.M.); (P.B.); (R.V.)
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19
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Luan L, Robinson JT, Aazhang B, Chi T, Yang K, Li X, Rathore H, Singer A, Yellapantula S, Fan Y, Yu Z, Xie C. Recent Advances in Electrical Neural Interface Engineering: Minimal Invasiveness, Longevity, and Scalability. Neuron 2020; 108:302-321. [PMID: 33120025 PMCID: PMC7646678 DOI: 10.1016/j.neuron.2020.10.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 10/03/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022]
Abstract
Electrical neural interfaces serve as direct communication pathways that connect the nervous system with the external world. Technological advances in this domain are providing increasingly more powerful tools to study, restore, and augment neural functions. Yet, the complexities of the nervous system give rise to substantial challenges in the design, fabrication, and system-level integration of these functional devices. In this review, we present snapshots of the latest progresses in electrical neural interfaces, with an emphasis on advances that expand the spatiotemporal resolution and extent of mapping and manipulating brain circuits. We include discussions of large-scale, long-lasting neural recording; wireless, miniaturized implants; signal transmission, amplification, and processing; as well as the integration of interfaces with optical modalities. We outline the background and rationale of these developments and share insights into the future directions and new opportunities they enable.
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Affiliation(s)
- Lan Luan
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; NeuroEngineering Initiative, Rice University, Houston, TX, USA
| | - Jacob T Robinson
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; NeuroEngineering Initiative, Rice University, Houston, TX, USA
| | - Behnaam Aazhang
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA; NeuroEngineering Initiative, Rice University, Houston, TX, USA
| | - Taiyun Chi
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Kaiyuan Yang
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Xue Li
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA; NeuroEngineering Initiative, Rice University, Houston, TX, USA
| | - Haad Rathore
- NeuroEngineering Initiative, Rice University, Houston, TX, USA; Applied Physics Graduate Program, Rice University, Houston, TX, USA
| | - Amanda Singer
- NeuroEngineering Initiative, Rice University, Houston, TX, USA; Applied Physics Graduate Program, Rice University, Houston, TX, USA
| | - Sudha Yellapantula
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA; NeuroEngineering Initiative, Rice University, Houston, TX, USA
| | - Yingying Fan
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Zhanghao Yu
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Chong Xie
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; NeuroEngineering Initiative, Rice University, Houston, TX, USA.
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Kampasi K, Alameda J, Sahota S, Hernandez J, Patra S, Haque R. Design and microfabrication strategies for thin-film, flexible optical neural implant .. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:4314-4317. [PMID: 33018950 DOI: 10.1109/embc44109.2020.9175440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Advanced polymer science and design technologies are constantly evolving to meet ever-growing expectations for flexible optical MEMS. In this work, we present design and microfabrication considerations for designed flexible Polymeric Opto-Electro-Mechanical Systems (POEMS). The presented methods integrate waveguide fabrication and laser diode (LD) chip assembly with Lawrence Livermore National Laboratory's (LLNL's) flexible thin-film technology to enable LLNL's first neural optoelectrode that can deliver guided light for neural activation. We support our findings with electrical and optical bench verification tests, present thermal simulation models to analyze heat dissipation of laser light sources on polymer substrates and discuss potential modifications for next generation prototypes. This fully integrated approach will allow spatial precision, scalability and more particularly, longer lifetime, needed to enable chronic studies of brain activities.
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21
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He F, Lycke R, Ganji M, Xie C, Luan L. Ultraflexible Neural Electrodes for Long-Lasting Intracortical Recording. iScience 2020; 23:101387. [PMID: 32745989 PMCID: PMC7398974 DOI: 10.1016/j.isci.2020.101387] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/22/2020] [Accepted: 07/16/2020] [Indexed: 11/16/2022] Open
Abstract
Implanted electrodes provide one of the most important neurotechniques for fundamental and translational neurosciences by permitting time-resolved electrical detection of individual neurons in vivo. However, conventional rigid electrodes typically cannot provide stable, long-lasting recordings. Numerous interwoven biotic and abiotic factors at the tissue-electrode interface lead to short- and long-term instability of the recording performance. Making neural electrodes flexible provides a promising approach to mitigate these challenges on the implants and at the tissue-electrode interface. Here we review the recent progress of ultraflexible neural electrodes and discuss the engineering principles, the material properties, and the implantation strategies to achieve stable tissue-electrode interface and reliable unit recordings in living brains.
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Affiliation(s)
- Fei He
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA; NeuroEngineering Initiative, Rice University, 6500 Main Street, Houston, TX 77005, USA
| | - Roy Lycke
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA; NeuroEngineering Initiative, Rice University, 6500 Main Street, Houston, TX 77005, USA; Department of Biomedical Engineering, University of Texas at Austin, 107 Dean Keeton, Austin, TX 78712, USA
| | - Mehran Ganji
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA; NeuroEngineering Initiative, Rice University, 6500 Main Street, Houston, TX 77005, USA; Department of Biomedical Engineering, University of Texas at Austin, 107 Dean Keeton, Austin, TX 78712, USA
| | - Chong Xie
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA; NeuroEngineering Initiative, Rice University, 6500 Main Street, Houston, TX 77005, USA; Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Lan Luan
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA; NeuroEngineering Initiative, Rice University, 6500 Main Street, Houston, TX 77005, USA; Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA.
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22
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Wang X, Weltman Hirschberg A, Xu H, Slingsby-Smith Z, Lecomte A, Scholten K, Song D, Meng E. A Parylene Neural Probe Array for Multi-Region Deep Brain Recordings. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS : A JOINT IEEE AND ASME PUBLICATION ON MICROSTRUCTURES, MICROACTUATORS, MICROSENSORS, AND MICROSYSTEMS 2020; 29:499-513. [PMID: 35663261 PMCID: PMC9164222 DOI: 10.1109/jmems.2020.3000235] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A Parylene C polymer neural probe array with 64 electrodes purposefully positioned across 8 individual shanks to anatomically match specific regions of the hippocampus was designed, fabricated, characterized, and implemented in vivo for enabling recording in deep brain regions in freely moving rats. Thin film polymer arrays were fabricated using surface micromachining techniques and mechanically braced to prevent buckling during surgical implantation. Importantly, the mechanical bracing technique developed in this work involves a novel biodegradable polymer brace that temporarily reduces shank length and consequently, increases its stiffness during implantation, therefore enabling access to deeper brain regions while preserving a low original cross-sectional area of the shanks. The resulting mechanical properties of braced shanks were evaluated at the benchtop. Arrays were then implemented in vivo in freely moving rats, achieving both acute and chronic recordings from the pyramidal cells in the cornu ammonis (CA) 1 and CA3 regions of the hippocampus which are responsible for memory encoding. This work demonstrated the potential for minimally invasive polymer-based neural probe arrays for multi-region recording in deep brain structures.
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Affiliation(s)
- Xuechun Wang
- Biomedical Engineering Department, University of Southern California, Los Angeles, CA 90089 USA
| | | | - Huijing Xu
- Biomedical Engineering Department, University of Southern California, Los Angeles, CA 90089 USA
| | | | - Aziliz Lecomte
- Fondazione Istituto Italiano di Technologia, 16163 Genova, Italy
| | - Kee Scholten
- Biomedical Engineering Department, University of Southern California, Los Angeles, CA 90089 USA
| | - Dong Song
- Biomedical Engineering Department, University of Southern California, Los Angeles, CA 90089 USA
| | - Ellis Meng
- Biomedical Engineering and Electrical and Computer Engineering Department, University of Southern California, Los Angeles, CA 90089 USA
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23
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BRAIN Initiative: Cutting-Edge Tools and Resources for the Community. J Neurosci 2020; 39:8275-8284. [PMID: 31619497 DOI: 10.1523/jneurosci.1169-19.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/09/2019] [Accepted: 08/14/2019] [Indexed: 12/16/2022] Open
Abstract
The overarching goal of the NIH BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative is to advance the understanding of healthy and diseased brain circuit function through technological innovation. Core principles for this goal include the validation and dissemination of the myriad innovative technologies, tools, methods, and resources emerging from BRAIN-funded research. Innovators, BRAIN funding agencies, and non-Federal partners are working together to develop strategies for making these products usable, available, and accessible to the scientific community. Here, we describe several early strategies for supporting the dissemination of BRAIN technologies. We aim to invigorate a dialogue with the neuroscience research and funding community, interdisciplinary collaborators, and trainees about the existing and future opportunities for cultivating groundbreaking research products into mature, integrated, and adaptable research systems. Along with the accompanying Society for Neuroscience 2019 Mini-Symposium, "BRAIN Initiative: Cutting-Edge Tools and Resources for the Community," we spotlight the work of several BRAIN investigator teams who are making progress toward providing tools, technologies, and services for the neuroscience community. These tools access neural circuits at multiple levels of analysis, from subcellular composition to brain-wide network connectivity, including the following: integrated systems for EM- and florescence-based connectomics, advances in immunolabeling capabilities, and resources for recording and analyzing functional connectivity. Investigators describe how the resources they provide to the community will contribute to achieving the goals of the NIH BRAIN Initiative. Finally, in addition to celebrating the contributions of these BRAIN-funded investigators, the Mini-Symposium will illustrate the broader diversity of BRAIN Initiative investments in cutting-edge technologies and resources.
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Voigts J, Harnett MT. Somatic and Dendritic Encoding of Spatial Variables in Retrosplenial Cortex Differs during 2D Navigation. Neuron 2020; 105:237-245.e4. [PMID: 31759808 PMCID: PMC6981016 DOI: 10.1016/j.neuron.2019.10.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/14/2019] [Accepted: 10/09/2019] [Indexed: 12/21/2022]
Abstract
Active amplification of organized synaptic inputs in dendrites can endow individual neurons with the ability to perform complex computations. However, whether dendrites in behaving animals perform independent local computations is not known. Such activity may be particularly important for complex behavior, where neurons integrate multiple streams of information. Head-restrained imaging has yielded important insights into cellular and circuit function, but this approach limits behavior and the underlying computations. We describe a method for full-featured 2-photon imaging in awake mice during free locomotion with volitional head rotation. We examine head direction and position encoding in simultaneously imaged apical tuft dendrites and their respective cell bodies in retrosplenial cortex, an area that encodes multi-modal navigational information. Activity in dendrites was not determined solely by somatic activity but reflected distinct navigational variables, fulfilling the requirements for dendritic computation. Our approach provides a foundation for studying sub-cellular processes during complex behaviors.
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Affiliation(s)
- Jakob Voigts
- Department of Brain & Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mark T Harnett
- Department of Brain & Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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25
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Kleinfeld D, Luan L, Mitra PP, Robinson JT, Sarpeshkar R, Shepard K, Xie C, Harris TD. Can One Concurrently Record Electrical Spikes from Every Neuron in a Mammalian Brain? Neuron 2019; 103:1005-1015. [PMID: 31495645 PMCID: PMC6763354 DOI: 10.1016/j.neuron.2019.08.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/30/2019] [Accepted: 08/03/2019] [Indexed: 12/26/2022]
Abstract
The classic approach to measure the spiking response of neurons involves the use of metal electrodes to record extracellular potentials. Starting over 60 years ago with a single recording site, this technology now extends to ever larger numbers and densities of sites. We argue, based on the mechanical and electrical properties of existing materials, estimates of signal-to-noise ratios, assumptions regarding extracellular space in the brain, and estimates of heat generation by the electronic interface, that it should be possible to fabricate rigid electrodes to concurrently record from essentially every neuron in the cortical mantle. This will involve fabrication with existing yet nontraditional materials and procedures. We further emphasize the need to advance materials for improved flexible electrodes as an essential advance to record from neurons in brainstem and spinal cord in moving animals.
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Affiliation(s)
- David Kleinfeld
- Section of Neurobiology, University of California, San Diego, CA, USA; Department of Physics, University of California, San Diego, CA, USA.
| | - Lan Luan
- Department of Biomedical Engineering, University of Texas, Austin, TX, USA
| | - Partha P Mitra
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Jacob T Robinson
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Rahul Sarpeshkar
- Department of Engineering, Dartmouth, Hanover, NH, USA; Department of Microbiology and Immunology, Dartmouth, Hanover, NH, USA; Department of Molecular and Systems Biology, Dartmouth, Hanover, NH, USA; Department of Physics, Dartmouth, Hanover, NH, USA
| | - Kenneth Shepard
- Department of Electrical Engineering, Columbia University, New York, NY, USA
| | - Chong Xie
- Department of Biomedical Engineering, University of Texas, Austin, TX, USA
| | - Timothy D Harris
- Howard Hughes Medical Institutes, Janelia Research Campus, Ashburn, VA, USA; Department of Bioengineering, Johns Hopkins University, Baltimore, MD, USA.
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