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Shoup AM, Porwal N, Fakharian MA, Hage P, Orozco SP, Shadmehr R. Rejuvenating silicon probes for acute neurophysiology. J Neurophysiol 2024; 132:308-315. [PMID: 38865216 PMCID: PMC11383388 DOI: 10.1152/jn.00121.2024] [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: 03/25/2024] [Revised: 06/11/2024] [Accepted: 06/11/2024] [Indexed: 06/14/2024] Open
Abstract
Neurophysiological recording with a new probe often yields better signal quality than with a used probe. Why does the signal quality degrade after only a few experiments? Here, we considered silicon probes in which the contacts are densely packed, and each contact is coated with a conductive polymer that increases its surface area. We tested 12 Cambridge Neurotech silicon probes during 61 recording sessions from the brain of three marmosets. Out of the box, each probe arrived with an electrodeposited polymer coating on 64 gold contacts and an impedance of around 50 kΩ. With repeated use, the impedance increased and there was a corresponding decrease in the number of well-isolated neurons. Imaging of the probes suggested that the reduction in signal quality was due to a gradual loss of the polymer coating. To rejuvenate the probes, we first stripped the contacts, completely removing their polymer coating, and then recoated them in a solution of 10 mM 3,4-Ethylenedioxythiophene (EDOT) monomer with 11 mM Poly(sodium 4-styrenesulfonate) (PSS) using a current density of about 3 mA/cm2 for 30 s. This recoating process not only returned probe impedance to around 50 kΩ but also yielded significantly improved signal quality during neurophysiological recordings. Thus, insertion into the brain promoted the loss of the polymer that coated the contacts of the silicon probes. This led to degradation of signal quality, but recoating rejuvenated the probes.NEW & NOTEWORTHY With repeated use, a silicon probe's ability to isolate neurons degrades. As a result, the probe is often discarded after only a handful of uses. Here, we demonstrate a major source of this problem and then produce a solution to rejuvenate the probes.
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Affiliation(s)
- Alden M Shoup
- Laboratory for Computational Motor Control, Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Natasha Porwal
- Laboratory for Computational Motor Control, Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Mohammad Amin Fakharian
- Laboratory for Computational Motor Control, Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Paul Hage
- Laboratory for Computational Motor Control, Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Simon P Orozco
- Laboratory for Computational Motor Control, Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Reza Shadmehr
- Laboratory for Computational Motor Control, Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
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2
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Duan W, Robles UA, Poole‐Warren L, Esrafilzadeh D. Bioelectronic Neural Interfaces: Improving Neuromodulation Through Organic Conductive Coatings. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306275. [PMID: 38115740 PMCID: PMC11251570 DOI: 10.1002/advs.202306275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/07/2023] [Indexed: 12/21/2023]
Abstract
Integration of bioelectronic devices in clinical practice is expanding rapidly, focusing on conditions ranging from sensory to neurological and mental health disorders. While platinum (Pt) electrodes in neuromodulation devices such as cochlear implants and deep brain stimulators have shown promising results, challenges still affect their long-term performance. Key among these are electrode and device longevity in vivo, and formation of encapsulating fibrous tissue. To overcome these challenges, organic conductors with unique chemical and physical properties are being explored. They hold great promise as coatings for neural interfaces, offering more rapid regulatory pathways and clinical implementation than standalone bioelectronics. This study provides a comprehensive review of the potential benefits of organic coatings in neuromodulation electrodes and the challenges that limit their effective integration into existing devices. It discusses issues related to metallic electrode use and introduces physical, electrical, and biological properties of organic coatings applied in neuromodulation. Furthermore, previously reported challenges related to organic coating stability, durability, manufacturing, and biocompatibility are thoroughly reviewed and proposed coating adhesion mechanisms are summarized. Understanding organic coating properties, modifications, and current challenges of organic coatings in clinical and industrial settings is expected to provide valuable insights for their future development and integration into organic bioelectronics.
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Affiliation(s)
- Wenlu Duan
- The Graduate School of Biomedical EngineeringUNSWSydneyNSW2052Australia
| | | | - Laura Poole‐Warren
- The Graduate School of Biomedical EngineeringUNSWSydneyNSW2052Australia
- Tyree Foundation Institute of Health EngineeringUNSWSydneyNSW2052Australia
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3
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Han J, Choi J, Jeong H, Park D, Cheong E, Sung J, Choi HJ. Impact of Impedance Levels on Recording Quality in Flexible Neural Probes. SENSORS (BASEL, SWITZERLAND) 2024; 24:2300. [PMID: 38610511 PMCID: PMC11014004 DOI: 10.3390/s24072300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/01/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024]
Abstract
Flexible neural probes are attractive emerging technologies for brain recording because they can effectively record signals with minimal risk of brain damage. Reducing the electrode impedance of the probe before recording is a common practice of many researchers. However, studies investigating the impact of low impedance levels on high-quality recordings using flexible neural probes are lacking. In this study, we electrodeposited Pt onto a commercial flexible polyimide neural probe and investigated the relationship between the impedance level and the recording quality. The probe was inserted into the brains of anesthetized mice. The electrical signals of neurons in the brain, specifically the ventral posteromedial nucleus of the thalamus, were recorded at impedance levels of 50, 250, 500 and 1000 kΩ at 1 kHz. The study results demonstrated that as the impedance decreased, the quality of the signal recordings did not consistently improve. This suggests that extreme lowering of the impedance may not always be advantageous in the context of flexible neural probes.
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Affiliation(s)
- Juyeon Han
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
| | - Jungsik Choi
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
- Nformare Inc., Seodamun-gu, Seoul 03722, Republic of Korea
| | - Hyeonyeong Jeong
- Department of Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Daerl Park
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
| | - Eunji Cheong
- Department of Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Jaesuk Sung
- Nformare Inc., Seodamun-gu, Seoul 03722, Republic of Korea
| | - Heon-Jin Choi
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
- Nformare Inc., Seodamun-gu, Seoul 03722, Republic of Korea
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4
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Weiss DA, Borsa AM, Pala A, Sederberg AJ, Stanley GB. A machine learning approach for real-time cortical state estimation. J Neural Eng 2024; 21:016016. [PMID: 38232377 PMCID: PMC10868597 DOI: 10.1088/1741-2552/ad1f7b] [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: 06/20/2023] [Accepted: 01/17/2024] [Indexed: 01/19/2024]
Abstract
Objective.Cortical function is under constant modulation by internally-driven, latent variables that regulate excitability, collectively known as 'cortical state'. Despite a vast literature in this area, the estimation of cortical state remains relatively ad hoc, and not amenable to real-time implementation. Here, we implement robust, data-driven, and fast algorithms that address several technical challenges for online cortical state estimation.Approach. We use unsupervised Gaussian mixture models to identify discrete, emergent clusters in spontaneous local field potential signals in cortex. We then extend our approach to a temporally-informed hidden semi-Markov model (HSMM) with Gaussian observations to better model and infer cortical state transitions. Finally, we implement our HSMM cortical state inference algorithms in a real-time system, evaluating their performance in emulation experiments.Main results. Unsupervised clustering approaches reveal emergent state-like structure in spontaneous electrophysiological data that recapitulate arousal-related cortical states as indexed by behavioral indicators. HSMMs enable cortical state inferences in a real-time context by modeling the temporal dynamics of cortical state switching. Using HSMMs provides robustness to state estimates arising from noisy, sequential electrophysiological data.Significance. To our knowledge, this work represents the first implementation of a real-time software tool for continuously decoding cortical states with high temporal resolution (40 ms). The software tools that we provide can facilitate our understanding of how cortical states dynamically modulate cortical function on a moment-by-moment basis and provide a basis for state-aware brain machine interfaces across health and disease.
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Affiliation(s)
- David A Weiss
- Program in Bioengineering, Georgia Institute of Technology, Atlanta, GA, United States of America
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States of America
| | - Adriano Mf Borsa
- Program in Bioengineering, Georgia Institute of Technology, Atlanta, GA, United States of America
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Aurélie Pala
- Department of Biology, Emory University, Atlanta, GA, United States of America
| | - Audrey J Sederberg
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN, United States of America
- Medical Discovery Team in Optical Imaging and Brain Science, University of Minnesota, Minneapolis, MN, United States of America
| | - Garrett B Stanley
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States of America
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5
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Coop SH, Yates JL, Mitchell JF. Pre-saccadic Neural Enhancements in Marmoset Area MT. J Neurosci 2024; 44:e2034222023. [PMID: 38050176 PMCID: PMC10860570 DOI: 10.1523/jneurosci.2034-22.2023] [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: 10/31/2022] [Revised: 09/15/2023] [Accepted: 11/20/2023] [Indexed: 12/06/2023] Open
Abstract
Each time we make an eye movement, attention moves before the eyes, resulting in a perceptual enhancement at the target. Recent psychophysical studies suggest that this pre-saccadic attention enhances the visual features at the saccade target, whereas covert attention causes only spatially selective enhancements. While previous nonhuman primate studies have found that pre-saccadic attention does enhance neural responses spatially, no studies have tested whether changes in neural tuning reflect an automatic feature enhancement. Here we examined pre-saccadic attention using a saccade foraging task developed for marmoset monkeys (one male and one female). We recorded from neurons in the middle temporal area with peripheral receptive fields that contained a motion stimulus, which would either be the target of a saccade or a distracter as a saccade was made to another location. We established that marmosets, like macaques, show enhanced pre-saccadic neural responses for saccades toward the receptive field, including increases in firing rate and motion information. We then examined if the specific changes in neural tuning might support feature enhancements for the target. Neurons exhibited diverse changes in tuning but predominantly showed additive and multiplicative increases that were uniformly applied across motion directions. These findings confirm that marmoset monkeys, like macaques, exhibit pre-saccadic neural enhancements during saccade foraging tasks with minimal training requirements. However, at the level of individual neurons, the lack of feature-tuned enhancements is similar to neural effects reported during covert spatial attention.
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Affiliation(s)
- Shanna H Coop
- Brain and Cognitive Sciences, University of Rochester, Rochester 14627-0268, New York
- Center for Visual Science, University of Rochester, Rochester 14627-0268, New York
| | - Jacob L Yates
- Brain and Cognitive Sciences, University of Rochester, Rochester 14627-0268, New York
- Center for Visual Science, University of Rochester, Rochester 14627-0268, New York
- Department of Biology, University of Maryland College Park, College Park, Maryland, 20742-5025
| | - Jude F Mitchell
- Brain and Cognitive Sciences, University of Rochester, Rochester 14627-0268, New York
- Center for Visual Science, University of Rochester, Rochester 14627-0268, New York
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6
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Chung B, Zia M, Thomas KA, Michaels JA, Jacob A, Pack A, Williams MJ, Nagapudi K, Teng LH, Arrambide E, Ouellette L, Oey N, Gibbs R, Anschutz P, Lu J, Wu Y, Kashefi M, Oya T, Kersten R, Mosberger AC, O'Connell S, Wang R, Marques H, Mendes AR, Lenschow C, Kondakath G, Kim JJ, Olson W, Quinn KN, Perkins P, Gatto G, Thanawalla A, Coltman S, Kim T, Smith T, Binder-Markey B, Zaback M, Thompson CK, Giszter S, Person A, Goulding M, Azim E, Thakor N, O'Connor D, Trimmer B, Lima SQ, Carey MR, Pandarinath C, Costa RM, Pruszynski JA, Bakir M, Sober SJ. Myomatrix arrays for high-definition muscle recording. eLife 2023; 12:RP88551. [PMID: 38113081 PMCID: PMC10730117 DOI: 10.7554/elife.88551] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023] Open
Abstract
Neurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups. Here we present a novel class of electrode devices ('Myomatrix arrays') that record muscle activity at unprecedented resolution across muscles and behaviors. High-density, flexible electrode arrays allow for stable recordings from the muscle fibers activated by a single motor neuron, called a 'motor unit,' during natural behaviors in many species, including mice, rats, primates, songbirds, frogs, and insects. This technology therefore allows the nervous system's motor output to be monitored in unprecedented detail during complex behaviors across species and muscle morphologies. We anticipate that this technology will allow rapid advances in understanding the neural control of behavior and identifying pathologies of the motor system.
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Affiliation(s)
- Bryce Chung
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Muneeb Zia
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Kyle A Thomas
- Graduate Program in Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | | | - Amanda Jacob
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Andrea Pack
- Neuroscience Graduate Program, Emory UniversityAtlantaUnited States
| | - Matthew J Williams
- Graduate Program in Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | | | - Lay Heng Teng
- Department of Biology, Emory UniversityAtlantaUnited States
| | | | | | - Nicole Oey
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Rhuna Gibbs
- Department of Biology, Emory UniversityAtlantaUnited States
| | - Philip Anschutz
- Graduate Program in BioEngineering, Georgia TechAtlantaUnited States
| | - Jiaao Lu
- Graduate Program in Electrical and Computer Engineering, Georgia TechAtlantaUnited States
| | - Yu Wu
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Mehrdad Kashefi
- Department of Physiology and Pharmacology, Western UniversityLondonCanada
| | - Tomomichi Oya
- Department of Physiology and Pharmacology, Western UniversityLondonCanada
| | - Rhonda Kersten
- Department of Physiology and Pharmacology, Western UniversityLondonCanada
| | - Alice C Mosberger
- Zuckerman Mind Brain Behavior Institute at Columbia UniversityNew YorkUnited States
| | - Sean O'Connell
- Graduate Program in Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | - Runming Wang
- Department of Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | - Hugo Marques
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Ana Rita Mendes
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Constanze Lenschow
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | | | - Jeong Jun Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - William Olson
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Kiara N Quinn
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Pierce Perkins
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Graziana Gatto
- Salk Institute for Biological StudiesLa JollaUnited States
| | | | - Susan Coltman
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Taegyo Kim
- Department of Neurobiology & Anatomy, Drexel University, College of MedicinePhiladelphiaUnited States
| | - Trevor Smith
- Department of Neurobiology & Anatomy, Drexel University, College of MedicinePhiladelphiaUnited States
| | - Ben Binder-Markey
- Department of Physical Therapy and Rehabilitation Sciences, Drexel University College of Nursing and Health ProfessionsPhiladelphiaUnited States
| | - Martin Zaback
- Department of Health and Rehabilitation Sciences, Temple UniversityPhiladelphiaUnited States
| | - Christopher K Thompson
- Department of Health and Rehabilitation Sciences, Temple UniversityPhiladelphiaUnited States
| | - Simon Giszter
- Department of Neurobiology & Anatomy, Drexel University, College of MedicinePhiladelphiaUnited States
| | - Abigail Person
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical CampusAuroraUnited States
- Allen InstituteSeattleUnited States
| | | | - Eiman Azim
- Salk Institute for Biological StudiesLa JollaUnited States
| | - Nitish Thakor
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Daniel O'Connor
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Barry Trimmer
- Department of Biology, Tufts UniversityMedfordUnited States
| | - Susana Q Lima
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Megan R Carey
- Champalimaud Neuroscience Programme, Champalimaud FoundationLisbonPortugal
| | - Chethan Pandarinath
- Department of Biomedical Engineering at Emory University and Georgia TechAtlantaUnited States
| | - Rui M Costa
- Zuckerman Mind Brain Behavior Institute at Columbia UniversityNew YorkUnited States
| | | | - Muhannad Bakir
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Samuel J Sober
- Department of Biology, Emory UniversityAtlantaUnited States
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7
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Lee CH, Park YK, Lee K. Recent strategies for neural dynamics observation at a larger scale and wider scope. Biosens Bioelectron 2023; 240:115638. [PMID: 37647685 DOI: 10.1016/j.bios.2023.115638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 08/15/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023]
Abstract
The tremendous technical progress in neuroscience offers opportunities to observe a more minor or/and broader dynamic picture of the brain. Moreover, the large-scale neural activity of individual neurons enables the dissection of detailed mechanistic links between neural populations and behaviors. To measure neural activity in-vivo, multi-neuron recording, and neuroimaging techniques are employed and developed to acquire more neurons. The tools introduced concurrently recorded dozens to hundreds of neurons in the coordinated brain regions and elucidated the neuronal ensembles from a massive population perspective of diverse neurons at cellular resolution. In particular, the increasing spatiotemporal resolution of neuronal monitoring across the whole brain dramatically facilitates our understanding of additional nervous system functions in health and disease. Here, we will introduce state-of-the-art neuroscience tools involving large-scale neural population recording and the long-range connections spanning multiple brain regions. Their synergic effects provide to clarify the controversial circuitry underlying neuroscience. These challenging neural tools present a promising outlook for the fundamental dynamic interplay across levels of synaptic cellular, circuit organization, and brain-wide. Hence, more observations of neural dynamics will provide more clues to elucidate brain functions and push forward innovative technology at the intersection of neural engineering disciplines. We hope this review will provide insight into the use or development of recent neural techniques considering spatiotemporal scales of brain observation.
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Affiliation(s)
- Chang Hak Lee
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, South Korea
| | - Young Kwon Park
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, South Korea
| | - Kwang Lee
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, South Korea.
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8
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Zhu Y, Yang Y, Ni G, Li S, Liu W, Gao Z, Zhang X, Zhang Q, Wang C, Zhou J. On-demand electrically controlled melatonin release from PEDOT/SNP composite improves quality of chronic neural recording. Front Bioeng Biotechnol 2023; 11:1284927. [PMID: 38033812 PMCID: PMC10684936 DOI: 10.3389/fbioe.2023.1284927] [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: 08/30/2023] [Accepted: 11/06/2023] [Indexed: 12/02/2023] Open
Abstract
Long-time and high-quality signal acquisition performance from implantable electrodes is the key to establish stable and efficient brain-computer interface (BCI) connections. The chronic performance of implantable electrodes is hindered by the inflammatory response of brain tissue. In order to solve the material limitation of biological interface electrodes, we designed sulfonated silica nanoparticles (SNPs) as the dopant of Poly (3,4-ethylenedioxythiophene) (PEDOT) to modify the implantable electrodes. In this work, melatonin (MT) loaded SNPs were incorporated in PEDOT via electrochemical deposition on nickel-chromium (Ni-Cr) alloy electrode and carbon nanotube (CNT) fiber electrodes, without affecting the acute neural signal recording capacity. After coating with PEDOT/SNP-MT, the charge storage capacity of both electrodes was significantly increased, and the electrochemical impedance at 1 kHz of the Ni-Cr alloy electrodes was significantly reduced, while that of the CNT electrodes was significantly increased. In addition, this study inspected the effect of electrically triggered MT release every other day on the quality and longevity of neural recording from implanted neural electrodes in rat hippocampus for 1 month. Both MT modified Ni-Cr alloy electrodes and CNT electrodes showed significantly higher spike amplitude after 26-day recording. Significantly, the histological studies showed that the number of astrocytes around the implanted Ni-Cr alloy electrodes was significantly reduced after MT release. These results demonstrate the potent outcome of PEDOT/SNP-MT treatment in improving the chronic neural recording quality possibly through its anti-inflammatory property.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Changyong Wang
- Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Jin Zhou
- Beijing Institute of Basic Medical Sciences, Beijing, China
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9
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Chung B, Zia M, Thomas KA, Michaels JA, Jacob A, Pack A, Williams MJ, Nagapudi K, Teng LH, Arrambide E, Ouellette L, Oey N, Gibbs R, Anschutz P, Lu J, Wu Y, Kashefi M, Oya T, Kersten R, Mosberger AC, O'Connell S, Wang R, Marques H, Mendes AR, Lenschow C, Kondakath G, Kim JJ, Olson W, Quinn KN, Perkins P, Gatto G, Thanawalla A, Coltman S, Kim T, Smith T, Binder-Markey B, Zaback M, Thompson CK, Giszter S, Person A, Goulding M, Azim E, Thakor N, O'Connor D, Trimmer B, Lima SQ, Carey MR, Pandarinath C, Costa RM, Pruszynski JA, Bakir M, Sober SJ. Myomatrix arrays for high-definition muscle recording. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.21.529200. [PMID: 36865176 PMCID: PMC9980060 DOI: 10.1101/2023.02.21.529200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Neurons coordinate their activity to produce an astonishing variety of motor behaviors. Our present understanding of motor control has grown rapidly thanks to new methods for recording and analyzing populations of many individual neurons over time. In contrast, current methods for recording the nervous system's actual motor output - the activation of muscle fibers by motor neurons - typically cannot detect the individual electrical events produced by muscle fibers during natural behaviors and scale poorly across species and muscle groups. Here we present a novel class of electrode devices ("Myomatrix arrays") that record muscle activity at unprecedented resolution across muscles and behaviors. High-density, flexible electrode arrays allow for stable recordings from the muscle fibers activated by a single motor neuron, called a "motor unit", during natural behaviors in many species, including mice, rats, primates, songbirds, frogs, and insects. This technology therefore allows the nervous system's motor output to be monitored in unprecedented detail during complex behaviors across species and muscle morphologies. We anticipate that this technology will allow rapid advances in understanding the neural control of behavior and in identifying pathologies of the motor system.
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Affiliation(s)
- Bryce Chung
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Muneeb Zia
- School of Electrical and Computer Engineering, Georgia Institute of Technology (Atlanta, GA, USA)
| | - Kyle A Thomas
- Graduate Program in Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Jonathan A Michaels
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Amanda Jacob
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Andrea Pack
- Neuroscience Graduate Program, Emory University (Atlanta, GA, USA)
| | - Matthew J Williams
- Graduate Program in Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | | | - Lay Heng Teng
- Department of Biology, Emory University (Atlanta, GA, USA)
| | | | | | - Nicole Oey
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Rhuna Gibbs
- Department of Biology, Emory University (Atlanta, GA, USA)
| | - Philip Anschutz
- Graduate Program in BioEngineering, Georgia Tech (Atlanta, GA, USA)
| | - Jiaao Lu
- Graduate Program in Electrical and Computer Engineering, Georgia Tech (Atlanta, GA, USA)
| | - Yu Wu
- School of Electrical and Computer Engineering, Georgia Institute of Technology (Atlanta, GA, USA)
| | - Mehrdad Kashefi
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Tomomichi Oya
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Rhonda Kersten
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Alice C Mosberger
- Zuckerman Mind Brain Behavior Institute at Columbia University (New York, NY, USA)
| | - Sean O'Connell
- Graduate Program in Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Runming Wang
- Department of Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Hugo Marques
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Ana Rita Mendes
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Constanze Lenschow
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
- current address: Institute of Biology, Otto-von-Guericke University, (Magdeburg, Germany)
| | | | - Jeong Jun Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - William Olson
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Kiara N Quinn
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Pierce Perkins
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Graziana Gatto
- Salk Institute for Biological Studies (La Jolla, CA, USA)
- current address: Department of Neurology, University Hospital of Cologne (Cologne, Germany)
| | | | - Susan Coltman
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus (Aurora, CO, USA)
| | - Taegyo Kim
- Department of Neurobiology & Anatomy, Drexel University, College of Medicine (Philadelphia, PA, USA)
| | - Trevor Smith
- Department of Neurobiology & Anatomy, Drexel University, College of Medicine (Philadelphia, PA, USA)
| | - Ben Binder-Markey
- Department of Physical Therapy and Rehabilitation Sciences, Drexel University College of Nursing and Health Professions (Philadelphia, PA)
| | - Martin Zaback
- Department of Health and Rehabilitation Sciences, Temple University (Philadelphia, PA, USA)
| | - Christopher K Thompson
- Department of Health and Rehabilitation Sciences, Temple University (Philadelphia, PA, USA)
| | - Simon Giszter
- Department of Neurobiology & Anatomy, Drexel University, College of Medicine (Philadelphia, PA, USA)
| | - Abigail Person
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus (Aurora, CO, USA)
| | | | - Eiman Azim
- Salk Institute for Biological Studies (La Jolla, CA, USA)
| | - Nitish Thakor
- Departments of Biomedical Engineering and Neurology, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Daniel O'Connor
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins School of Medicine (Baltimore, MD, USA)
| | - Barry Trimmer
- Department of Biology, Tufts University (Medford, MA, USA)
| | - Susana Q Lima
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Megan R Carey
- Champalimaud Neuroscience Programme, Champalimaud Foundation (Lisbon, Portugal)
| | - Chethan Pandarinath
- Department of Biomedical Engineering at Emory University and Georgia Tech (Atlanta, GA, USA)
| | - Rui M Costa
- Zuckerman Mind Brain Behavior Institute at Columbia University (New York, NY, USA)
- Allen Institute (Seattle, WA, USA)
| | - J Andrew Pruszynski
- Department of Physiology and Pharmacology, Western University (London, ON, Canada)
| | - Muhannad Bakir
- School of Electrical and Computer Engineering, Georgia Institute of Technology (Atlanta, GA, USA)
| | - Samuel J Sober
- Department of Biology, Emory University (Atlanta, GA, USA)
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10
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Muguet I, Maziz A, Mathieu F, Mazenq L, Larrieu G. Combining PEDOT:PSS Polymer Coating with Metallic 3D Nanowires Electrodes to Achieve High Electrochemical Performances for Neuronal Interfacing Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302472. [PMID: 37385261 DOI: 10.1002/adma.202302472] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/18/2023] [Accepted: 05/26/2023] [Indexed: 07/01/2023]
Abstract
This study presents a novel approach to improve the performance of microelectrode arrays (MEAs) used for electrophysiological studies of neuronal networks. The integration of 3D nanowires (NWs) with MEAs increases the surface-to-volume ratio, which enables subcellular interactions and high-resolution neuronal signal recording. However, these devices suffer from high initial interface impedance and limited charge transfer capacity due to their small effective area. To overcome these limitations, the integration of conductive polymer coatings, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is investigated as a mean of improving the charge transfer capacity and biocompatibility of MEAs. The study combines platinum silicide-based metallic 3D nanowires electrodes with electrodeposited PEDOT:PSS coatings to deposit ultra-thin (<50 nm) layers of conductive polymer onto metallic electrodes with very high selectivity. The polymer-coated electrodes were fully characterized electrochemically and morphologically to establish a direct relationship between synthesis conditions, morphology, and conductive features. Results show that PEDOT-coated electrodes exhibit thickness-dependent improved stimulation and recording performances, offering new perspectives for neuronal interfacing with optimal cell engulfment to enable the study of neuronal activity with acute spatial and signal resolution at the sub-cellular level.
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Affiliation(s)
- Ines Muguet
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Ali Maziz
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Fabrice Mathieu
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Laurent Mazenq
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
| | - Guilhem Larrieu
- LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, Toulouse, F-31400, France
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11
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Hsiao YS, Quiñones ED, Yen SC, Yu J, Fang JT, Chen P, Juang RS. PEDOT:PSS-Based Bioelectrodes for Multifunctional Drug Release and Electric Cell-Substrate Impedance Sensing. ACS APPLIED MATERIALS & INTERFACES 2023; 15:21953-21964. [PMID: 37129106 DOI: 10.1021/acsami.3c02769] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Electric cell-substrate impedance sensing (ECIS) is an innovative approach for the label-free and real-time detection of cell morphology, growth, and apoptosis, thereby playing an essential role as both a viable alternative and valuable complement to conventional biochemical/pharmaceutical analysis in the field of diagnostics. Constant improvements are naturally sought to further improve the effective range and reliability of this technology. In this study, we developed poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conducting polymer (CP)-based bioelectrodes integrated into homemade ECIS cell-culture chamber slides for the simultaneous drug release and real-time biosensing of cancer cell viability under drug treatment. The CP comprised tailored PEDOT:PSS, poly(ethylene oxide) (PEO), and (3-glycidyloxypropyl)trimethoxysilane (GOPS) capable of encapsulating antitumor chemotherapeutic agents such as doxorubicin (DOX), docetaxel (DTX), and a DOX/DTX combination. This device can reliably monitor impedance signal changes correlated with cell viability on chips generated by cell adhesion onto a predetermined CP-based working electrode while simultaneously exhibiting excellent properties for both drug encapsulation and on-demand release from another CP-based counter electrode under electrical stimulation (ES) operation. Cyclic voltammetry curves and surface profile data of different CP-based coatings (without or with drugs) were used to analyze the changes in charge capacity and thickness, respectively, thereby further revealing the correlation between their drug-releasing performance under ES operation (determined using ultraviolet-visible (UV-vis) spectroscopy). Finally, antitumor drug screening tests (DOX, DTX, and DOX/DTX combination) were performed on MCF-7 and HeLa cells using our developed CP-based ECIS chip system to monitor the impedance signal changes and their related cell viability results.
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Affiliation(s)
- Yu-Sheng Hsiao
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Edgar Daniel Quiñones
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Shih-Chieh Yen
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Jiashing Yu
- Department of Chemical Engineering, National Taiwan University, Taipei 10607, Taiwan
| | - Ji-Tseng Fang
- Department of Nephrology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan
| | - Peilin Chen
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Ruey-Shin Juang
- Department of Chemical and Materials Engineering, Chang Gung University, Guishan, Taoyuan, 33302, Taiwan
- Division of Nephrology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan
- Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, Taishan, New Taipei City, 24301, Taiwan
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12
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Shen K, Chen O, Edmunds JL, Piech DK, Maharbiz MM. Translational opportunities and challenges of invasive electrodes for neural interfaces. Nat Biomed Eng 2023; 7:424-442. [PMID: 37081142 DOI: 10.1038/s41551-023-01021-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 02/15/2023] [Indexed: 04/22/2023]
Abstract
Invasive brain-machine interfaces can restore motor, sensory and cognitive functions. However, their clinical adoption has been hindered by the surgical risk of implantation and by suboptimal long-term reliability. In this Review, we highlight the opportunities and challenges of invasive technology for clinically relevant electrophysiology. Specifically, we discuss the characteristics of neural probes that are most likely to facilitate the clinical translation of invasive neural interfaces, describe the neural signals that can be acquired or produced by intracranial electrodes, the abiotic and biotic factors that contribute to their failure, and emerging neural-interface architectures.
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Affiliation(s)
- Konlin Shen
- University of California, Berkeley - University of California, San Francisco Graduate Program in Bioengineering, Berkeley, CA, USA.
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.
| | - Oliver Chen
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, CA, USA
| | - Jordan L Edmunds
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, CA, USA
| | - David K Piech
- University of California, Berkeley - University of California, San Francisco Graduate Program in Bioengineering, Berkeley, CA, USA
| | - Michel M Maharbiz
- Department of Electrical Engineering and Computer Science, University of California, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
- Chan-Zuckerberg Biohub, San Francisco, CA, USA
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13
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Niederhoffer T, Vanhoestenberghe A, Lancashire HT. Methods of poly(3,4)-ethylenedioxithiophene (PEDOT) electrodeposition on metal electrodes for neural stimulation and recording. J Neural Eng 2023; 20. [PMID: 36603213 DOI: 10.1088/1741-2552/acb084] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 01/05/2023] [Indexed: 01/06/2023]
Abstract
Conductive polymers are of great interest in the field of neural electrodes because of their potential to improve the interfacial properties of electrodes. In particular, the conductive polymer poly (3,4)-ethylenedioxithiophene (PEDOT) has been widely studied for neural applications.Objective:This review compares methods for electrodeposition of PEDOT on metal neural electrodes, and analyses the effects of deposition methods on morphology and electrochemical performance.Approach:Electrochemical performances were analysed against several deposition method choices, including deposition charge density and co-ion, and correlations were explained to morphological and structural arguments as well as characterisation methods choices.Main results:Coating thickness and charge storage capacity are positively correlated with PEDOT electrodeposition charge density. We also show that PEDOT coated electrode impedance at 1 kHz, the only consistently reported impedance quantity, is strongly dependent upon electrode radius across a wide range of studies, because PEDOT coatings reduces the reactance of the complex impedance, conferring a more resistive behaviour to electrodes (at 1 kHz) dominated by the solution resistance and electrode geometry. This review also summarises how PEDOT co-ion choice affects coating structure and morphology and shows that co-ions notably influence the charge injection limit but have a limited influence on charge storage capacity and impedance. Finally we discuss the possible influence of characterisation methods to assess the robustness of comparisons between published results using different methods of characterisation.Significance:This review aims to serve as a common basis for researchers working with PEDOT by showing the effects of deposition methods on electrochemical performance, and aims to set a standard for accurate and uniform reporting of methods.
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Affiliation(s)
- Thomas Niederhoffer
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Anne Vanhoestenberghe
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Henry T Lancashire
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
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14
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Erofeev A, Antifeev I, Bolshakova A, Bezprozvanny I, Vlasova O. In Vivo Penetrating Microelectrodes for Brain Electrophysiology. SENSORS (BASEL, SWITZERLAND) 2022; 22:s22239085. [PMID: 36501805 PMCID: PMC9735502 DOI: 10.3390/s22239085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/14/2022] [Accepted: 11/22/2022] [Indexed: 05/13/2023]
Abstract
In recent decades, microelectrodes have been widely used in neuroscience to understand the mechanisms behind brain functions, as well as the relationship between neural activity and behavior, perception and cognition. However, the recording of neuronal activity over a long period of time is limited for various reasons. In this review, we briefly consider the types of penetrating chronic microelectrodes, as well as the conductive and insulating materials for microelectrode manufacturing. Additionally, we consider the effects of penetrating microelectrode implantation on brain tissue. In conclusion, we review recent advances in the field of in vivo microelectrodes.
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Affiliation(s)
- Alexander Erofeev
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Correspondence: (A.E.); (O.V.)
| | - Ivan Antifeev
- Laboratory of Methods and Instruments for Genetic and Immunoassay Analysis, Institute for Analytical Instrumentation of the Russian Academy of Sciences, 198095 Saint Petersburg, Russia
| | - Anastasia Bolshakova
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Olga Vlasova
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Correspondence: (A.E.); (O.V.)
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15
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Chen PC, Young CG, Schaffer CB, Lal A. Ultrasonically actuated neural probes for reduced trauma and inflammation in mouse brain. MICROSYSTEMS & NANOENGINEERING 2022; 8:117. [PMID: 36341081 PMCID: PMC9626596 DOI: 10.1038/s41378-022-00438-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/13/2022] [Accepted: 07/08/2022] [Indexed: 06/16/2023]
Abstract
Electrical neural recordings measured using direct electrical interfaces with neural tissue suffer from a short lifespan because the signal strength decreases over time. The inflammatory response to the inserted microprobe can create insulating tissue over the electrical interfaces, reducing the recorded signal below noise levels. One of the factors contributing to this inflammatory response is the tissue damage caused during probe insertion. Here, we explore the use of ultrasonic actuation of the neural probe during insertion to minimize tissue damage in mice. Silicon neural microprobes were designed and fabricated with integrated electrical recording sites and piezoelectric transducers. The microprobes were actuated at ultrasonic frequencies using integrated piezoelectric transducers. The microprobes were inserted into mouse brains under a glass window over the brain surface to image the tissue surrounding the probe using two-photon microscopy. The mechanical force required to penetrate the tissue was reduced by a factor of 2-3 when the microprobe was driven at ultrasonic frequencies. Tissue histology at the probe insertion site showed a reduced area of damage and decreased microglia counts with increasing ultrasonic actuation of the probes. Two-photon imaging of the microprobe over weeks demonstrated stabilization of the inflammatory response. Recording of electrical signals from neurons over time suggests that microprobes inserted using ultrasound have a higher signal-to-noise ratio over an extended time period.
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Affiliation(s)
- Po-Cheng Chen
- SonicMEMS Laboratory, School of Electrical and Computer Engineering, Cornell University, Ithaca, NY USA
| | - Catharine G. Young
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY USA
| | - Chris B. Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY USA
| | - Amit Lal
- SonicMEMS Laboratory, School of Electrical and Computer Engineering, Cornell University, Ithaca, NY USA
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16
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Sadeghi A, Afshari E, Hashemi M, Kaplan D, Mozafari M. Brainy Biomaterials: Latest Advances in Smart Biomaterials to Develop the Next Generation of Neural Interfaces. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2022. [DOI: 10.1016/j.cobme.2022.100420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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17
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Towards an artificial peripheral nerve: Liquid metal-based fluidic cuff electrodes for long-term nerve stimulation and recording. Biosens Bioelectron 2022; 216:114600. [DOI: 10.1016/j.bios.2022.114600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/21/2022] [Accepted: 07/24/2022] [Indexed: 12/29/2022]
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18
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Maddah M, Unsworth CP, Gouws GJ, Plank NOV. Synthesis of encapsulated ZnO nanowires provide low impedance alternatives for microelectrodes. PLoS One 2022; 17:e0270164. [PMID: 35709181 PMCID: PMC9202946 DOI: 10.1371/journal.pone.0270164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 06/03/2022] [Indexed: 11/19/2022] Open
Abstract
Microelectrodes are commonly used in electrochemical analysis and biological sensing applications owing to their miniaturised dimensions. It is often desirable to improve the performance of microelectrodes by reducing their electrochemical impedance for increasing the signal-to-noise of the recorded signals. One successful route is to incorporate nanomaterials directly onto microelectrodes; however, it is essential that these fabrication routes are simple and repeatable. In this article, we demonstrate how to synthesise metal encapsulated ZnO nanowires (Cr/Au-ZnO NWs, Ti-ZnO NWs and Pt-ZnO NWs) to reduce the impedance of the microelectrodes. Electrochemical impedance modelling and characterisation of Cr/Au-ZnO NWs, Ti-ZnO NWs and Pt-ZnO NWs are carried out in conjunction with controls of planar Cr/Au and pristine ZnO NWs. It was found that the ZnO NW microelectrodes that were encapsulated with a 10 nm thin layer of Ti or Pt demonstrated the lowest electrochemical impedance of 400 ± 25 kΩ at 1 kHz. The Ti and Pt encapsulated ZnO NWs have the potential to offer an alternative microelectrode modality that could be attractive to electrochemical and biological sensing applications.
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Affiliation(s)
- Mohsen Maddah
- School of Chemical and Physical Science, Victoria University of Wellington, Wellington, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
- * E-mail:
| | - Charles P. Unsworth
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Gideon J. Gouws
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
- School of Engineering and Computer Science, Victoria University of Wellington, Wellington, New Zealand
| | - Natalie O. V. Plank
- School of Chemical and Physical Science, Victoria University of Wellington, Wellington, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
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19
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Murphy BB, Apollo NV, Unegbu P, Posey T, Rodriguez-Perez N, Hendricks Q, Cimino F, Richardson AG, Vitale F. Vitamin C-reduced graphene oxide improves the performance and stability of multimodal neural microelectrodes. iScience 2022; 25:104652. [PMID: 35811842 PMCID: PMC9263525 DOI: 10.1016/j.isci.2022.104652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/28/2022] [Accepted: 06/16/2022] [Indexed: 11/28/2022] Open
Abstract
Nanocarbons are often employed as coatings for neural electrodes to enhance surface area. However, processing and integrating them into microfabrication flows requires complex and harmful chemical and heating conditions. This article presents a safe, scalable, cost-effective method to produce reduced graphene oxide (rGO) coatings using vitamin C (VC) as the reducing agent. We spray coat GO + VC mixtures onto target substrates, and then heat samples for 15 min at 150°C. The resulting rGO films have conductivities of ∼44 S cm−1, and are easily integrated into an ad hoc microfabrication flow. The rGO/Au microelectrodes show ∼8x lower impedance and ∼400x higher capacitance than bare Au, resulting in significantly enhanced charge storage and injection capacity. We subsequently use rGO/Au arrays to detect dopamine in vitro, and to map cortical activity intraoperatively over rat whisker barrel cortex, demonstrating that conductive VC-rGO coatings improve the performance and stability of multimodal microelectrodes for different applications. Easy, scalable, and safe reduction method to create rGO films with vitamin C VC-rGO coatings improve the performance of bare gold microelectrodes in vitro VC-rGO coatings enable the voltammetric detection of dopamine on the microscale rGO/Au electrode arrays enable high-resolution microscale recording in vivo
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Affiliation(s)
- Brendan B. Murphy
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Nicholas V. Apollo
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Placid Unegbu
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Tessa Posey
- Department of Biomedical Engineering, University of South Carolina, Columbia, SC 29206, USA
| | - Nancy Rodriguez-Perez
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85281, USA
| | - Quincy Hendricks
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Francesca Cimino
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew G. Richardson
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Flavia Vitale
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Neurotrauma, Neurodegeneration and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
- Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Philadelphia, PA 19146, USA
- Corresponding author
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20
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Bianchi M, De Salvo A, Asplund M, Carli S, Di Lauro M, Schulze‐Bonhage A, Stieglitz T, Fadiga L, Biscarini F. Poly(3,4-ethylenedioxythiophene)-Based Neural Interfaces for Recording and Stimulation: Fundamental Aspects and In Vivo Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104701. [PMID: 35191224 PMCID: PMC9036021 DOI: 10.1002/advs.202104701] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Indexed: 05/29/2023]
Abstract
Next-generation neural interfaces for bidirectional communication with the central nervous system aim to achieve the intimate integration with the neural tissue with minimal neuroinflammatory response, high spatio-temporal resolution, very high sensitivity, and readout stability. The design and manufacturing of devices for low power/low noise neural recording and safe and energy-efficient stimulation that are, at the same time, conformable to the brain, with matched mechanical properties and biocompatibility, is a convergence area of research where neuroscientists, materials scientists, and nanotechnologists operate synergically. The biotic-abiotic neural interface, however, remains a formidable challenge that prompts for new materials platforms and innovation in device layouts. Conductive polymers (CP) are attractive materials to be interfaced with the neural tissue and to be used as sensing/stimulating electrodes because of their mixed ionic-electronic conductivity, their low contact impedance, high charge storage capacitance, chemical versatility, and biocompatibility. This manuscript reviews the state-of-the-art of poly(3,4-ethylenedioxythiophene)-based neural interfaces for extracellular recording and stimulation, focusing on those technological approaches that are successfully demonstrated in vivo. The aim is to highlight the most reliable and ready-for-clinical-use solutions, in terms of materials technology and recording performance, other than spot major limitations and identify future trends in this field.
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Affiliation(s)
- Michele Bianchi
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
| | - Anna De Salvo
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Sezione di FisiologiaUniversità di Ferraravia Fossato di Mortara 17Ferrara44121Italy
| | - Maria Asplund
- Division of Nursing and Medical TechnologyLuleå University of TechnologyLuleå971 87Sweden
- Department of Microsystems Engineering‐IMTEKUniversity of FreiburgFreiburg79110Germany
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
| | - Stefano Carli
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Present address:
Department of Environmental and Prevention SciencesUniversità di FerraraFerrara44121Italy
| | - Michele Di Lauro
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
| | - Andreas Schulze‐Bonhage
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
- Epilepsy CenterFaculty of MedicineUniversity of FreiburgFreiburg79110Germany
| | - Thomas Stieglitz
- Department of Microsystems Engineering‐IMTEKUniversity of FreiburgFreiburg79110Germany
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
| | - Luciano Fadiga
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Sezione di FisiologiaUniversità di Ferraravia Fossato di Mortara 17Ferrara44121Italy
| | - Fabio Biscarini
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Life Science DepartmentUniversità di Modena e Reggio EmiliaVia Campi 103Modena41125Italy
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21
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Pala A, Stanley GB. Ipsilateral Stimulus Encoding in Primary and Secondary Somatosensory Cortex of Awake Mice. J Neurosci 2022; 42:2701-2715. [PMID: 35135855 PMCID: PMC8973421 DOI: 10.1523/jneurosci.1417-21.2022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 01/28/2022] [Accepted: 01/31/2022] [Indexed: 11/21/2022] Open
Abstract
Lateralization is a hallmark of somatosensory processing in the mammalian brain. However, in addition to their contralateral representation, unilateral tactile stimuli also modulate neuronal activity in somatosensory cortices of the ipsilateral hemisphere. The cellular organization and functional role of these ipsilateral stimulus responses in awake somatosensory cortices, especially regarding stimulus coding, are unknown. Here, we targeted silicon probe recordings to the vibrissa region of primary (S1) and secondary (S2) somatosensory cortex of awake head-fixed mice of either sex while delivering ipsilateral and contralateral whisker stimuli. Ipsilateral stimuli drove larger and more reliable responses in S2 than in S1, and activated a larger fraction of stimulus-responsive neurons. Ipsilateral stimulus-responsive neurons were rare in layer 4 of S1, but were located in equal proportion across all layers in S2. Linear classifier analyses further revealed that decoding of the ipsilateral stimulus was more accurate in S2 than S1, whereas S1 decoded contralateral stimuli most accurately. These results reveal substantial encoding of ipsilateral stimuli in S1 and especially S2, consistent with the hypothesis that higher cortical areas may integrate tactile inputs across larger portions of space, spanning both sides of the body.SIGNIFICANCE STATEMENT Tactile information obtained by one side of the body is represented in the activity of neurons of the opposite brain hemisphere. However, unilateral tactile stimulation also modulates neuronal activity in the other, or ipsilateral, brain hemisphere. This ipsilateral activity may play an important role in the representation and processing of tactile information, in particular when the sense of touch involves both sides of the body. Our work in the whisker system of awake mice reveals that neocortical ipsilateral activity, in particular that of deep layer excitatory neurons of secondary somatosensory cortex (S2), contains information about the presence and the velocity of unilateral tactile stimuli, which supports a key role for S2 in integrating tactile information across both body sides.
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Affiliation(s)
- Aurélie Pala
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332
| | - Garrett B Stanley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332
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22
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Weaver IA, Li A, Shields BC, Tadross MR. An Open-Source Transparent Microelectrode Array. J Neural Eng 2022; 19. [PMID: 35349992 PMCID: PMC9176384 DOI: 10.1088/1741-2552/ac620d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/28/2022] [Indexed: 11/12/2022]
Abstract
Abstract
The micro-electrode array (MEA) is a cell-culture surface with integrated electrodes used for assays of electrically excitable cells and tissues. MEAs have been a workhorse in the study of neurons and myocytes, owing to the scalability and millisecond temporal resolution of the technology. However, traditional MEAs are opaque, precluding inverted microscope access to modern genetically encoded optical sensors and effectors. To address this gap, transparent MEAs have been developed. However, for many labs, transparent MEAs remain out of reach due to the cost of commercially available products, and the complexity of custom fabrication. Here, we describe an open-source transparent MEA based on the OpenEphys platform. This resource is designed to be accessible, requiring minimal microelectrode fabrication or circuit design experience. We include low-noise connectors for seamless integration with the Intan Technologies headstage, and a mechanically stable adaptor conforming to the 24-well plate footprint for compatibility with most inverted microscopes. We demonstrate the performance of this transparent MEA in a multiplexed electrical and optogenetic assay of primary rat hippocampal neurons.
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23
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Flexible Neural Probes with Optical Artifact-Suppressing Modification and Biofriendly Polypeptide Coating. MICROMACHINES 2022; 13:mi13020199. [PMID: 35208323 PMCID: PMC8877708 DOI: 10.3390/mi13020199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/23/2022] [Accepted: 01/23/2022] [Indexed: 11/24/2022]
Abstract
The advent of optogenetics provides a well-targeted tool to manipulate neurons because of its high time resolution and cell-type specificity. Recently, closed-loop neural manipulation techniques consisting of optical stimulation and electrical recording have been widely used. However, metal microelectrodes exposed to light radiation could generate photoelectric noise, thus causing loss or distortion of neural signal in recording channels. Meanwhile, the biocompatibility of neural probes remains to be improved. Here, five kinds of neural interface materials are deposited on flexible polyimide-based neural probes and illuminated with a series of blue laser pulses to study their electrochemical performance and photoelectric noises for single-unit recording. The results show that the modifications can not only improve the electrochemical performance, but can also reduce the photoelectric artifacts. In particular, the double-layer composite consisting of platinum-black and conductive polymer has the best comprehensive performance. Thus, a layer of polypeptide is deposited on the entire surface of the double-layer modified neural probes to further improve their biocompatibility. The results show that the biocompatible polypeptide coating has little effect on the electrochemical performance of the neural probe, and it may serve as a drug carrier due to its special micromorphology.
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24
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Karalis N, Sirota A. Breathing coordinates cortico-hippocampal dynamics in mice during offline states. Nat Commun 2022; 13:467. [PMID: 35075139 PMCID: PMC8786964 DOI: 10.1038/s41467-022-28090-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 12/13/2021] [Indexed: 12/18/2022] Open
Abstract
Network dynamics have been proposed as a mechanistic substrate for the information transfer across cortical and hippocampal circuits. However, little is known about the mechanisms that synchronize and coordinate these processes across widespread brain regions during offline states. Here we address the hypothesis that breathing acts as an oscillatory pacemaker, persistently coupling distributed brain circuit dynamics. Using large-scale recordings from a number of cortical and subcortical brain regions in behaving mice, we uncover the presence of an intracerebral respiratory corollary discharge, that modulates neural activity across these circuits. During offline states, the respiratory modulation underlies the coupling of hippocampal sharp-wave ripples and cortical DOWN/UP state transitions, which mediates systems memory consolidation. These results highlight breathing, a perennial brain rhythm, as an oscillatory scaffold for the functional coordination of the limbic circuit that supports the segregation and integration of information flow across neuronal networks during offline states.
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Affiliation(s)
- Nikolaos Karalis
- Faculty of Medicine, Ludwig-Maximilian University, Munich, 82152, Martinsried, Germany.
- Friedrich Miescher Institute for Biomedical Research, 4058, Basel, Switzerland.
| | - Anton Sirota
- Faculty of Medicine, Ludwig-Maximilian University, Munich, 82152, Martinsried, Germany.
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25
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Seaton BT, Heien ML. Biocompatible reference electrodes to enhance chronic electrochemical signal fidelity in vivo. Anal Bioanal Chem 2021; 413:6689-6701. [PMID: 34595560 DOI: 10.1007/s00216-021-03640-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/17/2022]
Abstract
In vivo electrochemistry is a vital tool of neuroscience that allows for the detection, identification, and quantification of neurotransmitters, their metabolites, and other important analytes. One important goal of in vivo electrochemistry is a better understanding of progressive neurological disorders (e.g., Parkinson's disease). A complete understanding of such disorders can only be achieved through a combination of acute (i.e., minutes to hours) and chronic (i.e., days or longer) experimentation. Chronic studies are more challenging because they require prolonged implantation of electrodes, which elicits an immune response, leading to glial encapsulation of the electrodes and altered electrode performance (i.e., biofouling). Biofouling leads to increased electrode impedance and reference electrode polarization, both of which diminish the selectivity and sensitivity of in vivo electrochemical measurements. The increased impedance factor has been successfully mitigated previously with the use of a counter electrode, but the challenge of reference electrode polarization remains. The commonly used Ag/AgCl reference electrode lacks the long-term potential stability in vivo required for chronic measurements. In addition, the cytotoxicity of Ag/AgCl adversely affects animal experimentation and prohibits implantation in humans, hindering translational research progress. Thus, a move toward biocompatible reference electrodes with superior chronic potential stability is necessary. Two qualifying materials, iridium oxide and boron-doped diamond, are introduced and discussed in terms of their electrochemical properties, biocompatibilities, fabrication methods, and applications. In vivo electrochemistry continues to advance toward more chronic experimentation in both animal models and humans, necessitating the utilization of biocompatible reference electrodes that should provide superior potential stability and allow for unprecedented chronic signal fidelity when used with a counter electrode for impedance mitigation.
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Affiliation(s)
- Blake T Seaton
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Michael L Heien
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA.
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26
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Fan B, Wolfrum B, Robinson JT. Impedance scaling for gold and platinum microelectrodes. J Neural Eng 2021; 18. [PMID: 34433150 DOI: 10.1088/1741-2552/ac20e5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/25/2021] [Indexed: 11/11/2022]
Abstract
Objective.Electrical measurement of the activity of individual neurons is a primary goal for many invasive neural electrodes. Making these 'single unit' measurements requires that we fabricate electrodes small enough so that only a few neurons contribute to the signal, but not so small that the impedance of the electrode creates overwhelming noise or signal attenuation. Thus, neuroelectrode design often must strike a balance between electrode size and electrode impedance, where the impedance is often assumed to scale linearly with electrode area.Approach and main results. Here we study how impedance scales with neural electrode area and find that the 1 kHz impedance of Pt electrodes (but not Au electrodes) transitions from scaling with area (r-2) to scaling with perimeter (r-1) when the electrode radius falls below 10µm. This effect can be explained by the transition from planar to spherical diffusion behavior previously reported for electrochemical microelectrodes.Significance.These results provide important intuition for designing small, single unit recording electrodes. Specifically, for materials where the impedance is dominated by a pseudo-capacitance that is associated with a diffusion limited process, the total impedance will scale with perimeter rather than area when the electrode size becomes comparable with the diffusion layer thickness. For Pt electrodes this transition occurs around 10µm radius electrodes. At even lower frequencies (1 Hz) impedance approaches a constant. This transition tor-1scaling implies that electrodes with a pseudo-capacitance can be made smaller than one might expect before thermal noise or voltage division limits the ability to acquire high-quality single-unit recordings.
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Affiliation(s)
- Bo Fan
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America
| | - Bernhard Wolfrum
- Department of Electrical and Computer Engineering, Technical University of Munich, Garching, 85748, Germany
| | - Jacob T Robinson
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, United States of America.,Department of Bioengineering, Rice University, Houston, TX 77005, United States of America.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, United States of America
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27
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Lu HY, Lorenc ES, Zhu H, Kilmarx J, Sulzer J, Xie C, Tobler PN, Watrous AJ, Orsborn AL, Lewis-Peacock J, Santacruz SR. Multi-scale neural decoding and analysis. J Neural Eng 2021; 18. [PMID: 34284369 PMCID: PMC8840800 DOI: 10.1088/1741-2552/ac160f] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 07/20/2021] [Indexed: 12/15/2022]
Abstract
Objective. Complex spatiotemporal neural activity encodes rich information related to behavior and cognition. Conventional research has focused on neural activity acquired using one of many different measurement modalities, each of which provides useful but incomplete assessment of the neural code. Multi-modal techniques can overcome tradeoffs in the spatial and temporal resolution of a single modality to reveal deeper and more comprehensive understanding of system-level neural mechanisms. Uncovering multi-scale dynamics is essential for a mechanistic understanding of brain function and for harnessing neuroscientific insights to develop more effective clinical treatment. Approach. We discuss conventional methodologies used for characterizing neural activity at different scales and review contemporary examples of how these approaches have been combined. Then we present our case for integrating activity across multiple scales to benefit from the combined strengths of each approach and elucidate a more holistic understanding of neural processes. Main results. We examine various combinations of neural activity at different scales and analytical techniques that can be used to integrate or illuminate information across scales, as well the technologies that enable such exciting studies. We conclude with challenges facing future multi-scale studies, and a discussion of the power and potential of these approaches. Significance. This roadmap will lead the readers toward a broad range of multi-scale neural decoding techniques and their benefits over single-modality analyses. This Review article highlights the importance of multi-scale analyses for systematically interrogating complex spatiotemporal mechanisms underlying cognition and behavior.
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Affiliation(s)
- Hung-Yun Lu
- The University of Texas at Austin, Biomedical Engineering, Austin, TX, United States of America
| | - Elizabeth S Lorenc
- The University of Texas at Austin, Psychology, Austin, TX, United States of America.,The University of Texas at Austin, Institute for Neuroscience, Austin, TX, United States of America
| | - Hanlin Zhu
- Rice University, Electrical and Computer Engineering, Houston, TX, United States of America
| | - Justin Kilmarx
- The University of Texas at Austin, Mechanical Engineering, Austin, TX, United States of America
| | - James Sulzer
- The University of Texas at Austin, Mechanical Engineering, Austin, TX, United States of America.,The University of Texas at Austin, Institute for Neuroscience, Austin, TX, United States of America
| | - Chong Xie
- Rice University, Electrical and Computer Engineering, Houston, TX, United States of America
| | - Philippe N Tobler
- University of Zurich, Neuroeconomics and Social Neuroscience, Zurich, Switzerland
| | - Andrew J Watrous
- The University of Texas at Austin, Neurology, Austin, TX, United States of America
| | - Amy L Orsborn
- University of Washington, Electrical and Computer Engineering, Seattle, WA, United States of America.,University of Washington, Bioengineering, Seattle, WA, United States of America.,Washington National Primate Research Center, Seattle, WA, United States of America
| | - Jarrod Lewis-Peacock
- The University of Texas at Austin, Psychology, Austin, TX, United States of America.,The University of Texas at Austin, Institute for Neuroscience, Austin, TX, United States of America
| | - Samantha R Santacruz
- The University of Texas at Austin, Biomedical Engineering, Austin, TX, United States of America.,The University of Texas at Austin, Institute for Neuroscience, Austin, TX, United States of America
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28
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Functionalization Strategies of PEDOT and PEDOT:PSS Films for Organic Bioelectronics Applications. CHEMOSENSORS 2021. [DOI: 10.3390/chemosensors9080212] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Organic bioelectronics involves the connection of organic semiconductors with living organisms, organs, tissues, cells, membranes, proteins, and even small molecules. In recent years, this field has received great interest due to the development of all kinds of devices architectures, enabling the detection of several relevant biomarkers, the stimulation and sensing of cells and tissues, and the recording of electrophysiological signals, among others. In this review, we discuss recent functionalization approaches for PEDOT and PEDOT:PSS films with the aim of integrating biomolecules for the fabrication of bioelectronics platforms. As the choice of the strategy is determined by the conducting polymer synthesis method, initially PEDOT and PEDOT:PSS films preparation methods are presented. Later, a wide variety of PEDOT functionalization approaches are discussed, together with bioconjugation techniques to develop efficient organic-biological interfaces. Finally, and by making use of these approaches, the fabrication of different platforms towards organic bioelectronics devices is reviewed.
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29
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Lee Y, Shin H, Lee D, Choi S, Cho I, Seo J. A Lubricated Nonimmunogenic Neural Probe for Acute Insertion Trauma Minimization and Long-Term Signal Recording. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100231. [PMID: 34085402 PMCID: PMC8336494 DOI: 10.1002/advs.202100231] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/29/2021] [Indexed: 05/06/2023]
Abstract
Brain-machine interfaces (BMIs) that link the brain to a machine are promising for the treatment of neurological disorders through the bi-directional translation of neural information over extended periods. However, the longevity of such implanted devices remains limited by the deterioration of their signal sensitivity over time due to acute inflammation from insertion trauma and chronic inflammation caused by the foreign body reaction. To address this challenge, a lubricated surface is fabricated to minimize friction during insertion and avoid immunogenicity during neural signal recording. Reduced friction force leads to 86% less impulse on the brain tissue, and thus immediately increases the number of measured signal electrodes by 102% upon insertion. Furthermore, the signal measurable period increases from 8 to 16 weeks due to the prevention of gliosis. By significantly reducing insertion damage and the foreign body reaction, the lubricated immune-stealthy probe surface (LIPS) can maximize the longevity of implantable BMIs.
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Affiliation(s)
- Yeontaek Lee
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Hyogeun Shin
- Center for BioMicrosystemsBrain Science InstituteKorea Institute of Science and Technology (KIST)Seoul02792Republic of Korea
- Division of Bio‐Medical Science & Technology, KIST SchoolKorea University of Science and Technology (UST)Seoul02792Republic of Korea
| | - Dongwon Lee
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Sungah Choi
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Il‐Joo Cho
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
- Center for BioMicrosystemsBrain Science InstituteKorea Institute of Science and Technology (KIST)Seoul02792Republic of Korea
- Division of Bio‐Medical Science & Technology, KIST SchoolKorea University of Science and Technology (UST)Seoul02792Republic of Korea
- Yonsei‐KIST Convergence Research InstituteYonsei UniversitySeoul03722Republic of Korea
| | - Jungmok Seo
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
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30
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Zheng XS, Yang Q, Vazquez AL, Tracy Cui X. Imaging the Efficiency of Poly(3,4-ethylenedioxythiophene) Doped with Acid-Functionalized Carbon Nanotube and Iridium Oxide Electrode Coatings for Microstimulation. ADVANCED NANOBIOMED RESEARCH 2021; 1:2000092. [PMID: 34746928 PMCID: PMC8552016 DOI: 10.1002/anbr.202000092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/18/2021] [Indexed: 12/02/2022] Open
Abstract
Electrical microstimulation has shown promise in restoring neural deficits in humans. Electrodes coated with materials like the conducting polymer poly(3,4-ethylenedioxythiophene) doped with acid-functionalized carbon nanotubes (PEDOT/CNTs, or PC) exhibit superior charge injection than traditional metals like platinum. However, the stimulation performance of PC remains to be fully characterized. Advanced imaging techniques and transgenic tools allow for real-time observations of neural activity in vivo. Herein, microelectrodes coated with PC and iridium oxide (IrOx) (a commonly used high-charge-injection material) are implanted in GCaMP6s mice and electrical stimulation is applied while imaging neuronal calcium responses. Results show that PC-coated electrodes stimulate more intense and broader GCaMP responses than IrOx. Two-photon microscopy reveals that PC-coated electrodes activate significantly more neuronal soma and neuropil than IrOx-coated electrodes in constant-voltage stimulation and significantly more neuronal soma in constant-current stimulation. Furthermore, with the same injected charge, both materials activate more spatially confined neural elements with shorter pulses than longer pulses, providing a means to tune stimulation selectivity. Finite element analyses reveal that the PC coating creates a denser and nonuniform electric field, increasing the likelihood of activating nearby neural elements. PC coating can significantly improve energy efficiency for electrical stimulation applications.
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Affiliation(s)
- Xin S. Zheng
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Qianru Yang
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Alberto L. Vazquez
- Departments of Radiology and BioengineeringUniversity of Pittsburgh3025 E. Carson St.PittsburghPA15203USA
| | - Xinyan Tracy Cui
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
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31
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Middya S, Curto VF, Fernández‐Villegas A, Robbins M, Gurke J, Moonen EJM, Kaminski Schierle GS, Malliaras GG. Microelectrode Arrays for Simultaneous Electrophysiology and Advanced Optical Microscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004434. [PMID: 36246164 PMCID: PMC9539726 DOI: 10.1002/advs.202004434] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/01/2021] [Indexed: 05/09/2023]
Abstract
Advanced optical imaging techniques address important biological questions in neuroscience, where structures such as synapses are below the resolution limit of a conventional microscope. At the same time, microelectrode arrays (MEAs) are indispensable in understanding the language of neurons. Here, the authors show transparent MEAs capable of recording action potentials from neurons and compatible with advanced microscopy. The electrodes are made of the conducting polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) and are patterned by optical lithography, ensuring scalable fabrication with good control over device parameters. A thickness of 380 nm ensures low enough impedance and >75% transparency throughout the visible part of the spectrum making them suitable for artefact-free recording in the presence of laser illumination. Using primary neuronal cells, the arrays record single units from multiple nearby sources with a signal-to-noise ratio of 7.7 (17.7 dB). Additionally, it is possible to perform calcium (Ca2+) imaging, a measure of neuronal activity, using the novel transparent electrodes. Different biomarkers are imaged through the electrodes using conventional and super-resolution microscopy (SRM), showing no qualitative differences compared to glass substrates. These transparent MEAs pave the way for harnessing the synergy between the superior temporal resolution of electrophysiology and the selectivity and high spatial resolution of optical imaging.
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Affiliation(s)
- Sagnik Middya
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
| | - Vincenzo F. Curto
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
| | - Ana Fernández‐Villegas
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Miranda Robbins
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB3 0ASUK
| | - Johannes Gurke
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
| | - Emma J. M. Moonen
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
- Department of Mechanical EngineeringMicrosystemsEindhoven University of TechnologyEindhoven5600 MBthe Netherlands
| | | | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FFUK
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32
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Lee EK, Baruah RK, Bhamra H, Kim YJ, Yoo H. Recent advances in electrode development for biomedical applications. Biomed Eng Lett 2021; 11:107-115. [PMID: 34150347 DOI: 10.1007/s13534-021-00189-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/27/2021] [Accepted: 04/10/2021] [Indexed: 11/24/2022] Open
Abstract
Elaborate electrodes that enable adhesion to the skin surface and effectively collect vital signs are necessitated. In recent years, various electrode materials and novel structures have been developed, and they have garnered scientific attention due to their higher sensing performances compared with those of conventional electrode-based sensors. This paper provides an overview of recent advances in biomedical sensors, focusing on the development of novel electrodes. We comprehensively review the different types of electrode materials in the context of efficient biosignal detection, with respect to material composition for flexible and wearable electrodes and novel electrode structures. Finally, we discuss recent packaging technologies in biomedical applications using flexible and wearable electrodes.
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Affiliation(s)
- Eun Kwang Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 USA.,MLCC Development, 1 team, Samsung Electro-Mechanics, 150, Maeyeong-ro, Yeongtong-gu, Suwon, Gyeonggi-do Republic of Korea
| | - Ratul Kumar Baruah
- Department of Electronics and Communication Engineering, Tezpur University, Assam, 784028 India
| | - Hansraj Bhamra
- Department of Electrical and Computer Engineering, Center for implantable devices, Purdue University, West Lafayette, IN 47907 USA
| | - Young-Joon Kim
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam, 13120 Republic of Korea
| | - Hocheon Yoo
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam, 13120 Republic of Korea
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33
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Liang Y, Offenhäusser A, Ingebrandt S, Mayer D. PEDOT:PSS-Based Bioelectronic Devices for Recording and Modulation of Electrophysiological and Biochemical Cell Signals. Adv Healthc Mater 2021; 10:e2100061. [PMID: 33970552 PMCID: PMC11468774 DOI: 10.1002/adhm.202100061] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/31/2021] [Indexed: 12/16/2022]
Abstract
To understand the physiology and pathology of electrogenic cells and the corresponding tissue in their full complexity, the quantitative investigation of the transmission of ions as well as the release of chemical signals is important. Organic (semi-) conducting materials and in particular organic electrochemical transistor are gaining in importance for the investigation of electrophysiological and recently biochemical signals due to their synthetic nature and thus chemical diversity and modifiability, their biocompatible and compliant properties, as well as their mixed electronic and ionic conductivity featuring ion-to-electron conversion. Here, the aim is to summarize recent progress on the development of bioelectronic devices utilizing polymer polyethylenedioxythiophene: poly(styrene sulfonate) (PEDOT:PSS) to interface electronics and biological matter including microelectrode arrays, neural cuff electrodes, organic electrochemical transistors, PEDOT:PSS-based biosensors, and organic electronic ion pumps. Finally, progress in the material development is summarized for the improvement of polymer conductivity, stretchability, higher transistor transconductance, or to extend their field of application such as cation sensing or metabolite recognition. This survey of recent trends in PEDOT:PSS electrophysiological sensors highlights the potential of this multifunctional material to revolve current technology and to enable long-lasting, multichannel polymer probes for simultaneous recordings of electrophysiological and biochemical signals from electrogenic cells.
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Affiliation(s)
- Yuanying Liang
- Institute of Polymer Optoelectronic Materials and DevicesState Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhouGuangdong510640China
| | - Andreas Offenhäusser
- Institute of Biological Information ProcessingBioelectronics IBI‐3Forschungszentrum JülichJülich52425Germany
| | - Sven Ingebrandt
- Faculty of Electrical Engineering and Information TechnologyInstitute of Materials in Electrical Engineering 1RWTH Aachen UniversityAachen52074Germany
| | - Dirk Mayer
- Institute of Biological Information ProcessingBioelectronics IBI‐3Forschungszentrum JülichJülich52425Germany
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34
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Schoonover CE, Ohashi SN, Axel R, Fink AJP. Representational drift in primary olfactory cortex. Nature 2021; 594:541-546. [PMID: 34108681 DOI: 10.1038/s41586-021-03628-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 05/11/2021] [Indexed: 02/05/2023]
Abstract
Perceptual constancy requires the brain to maintain a stable representation of sensory input. In the olfactory system, activity in primary olfactory cortex (piriform cortex) is thought to determine odour identity1-5. Here we present the results of electrophysiological recordings of single units maintained over weeks to examine the stability of odour-evoked responses in mouse piriform cortex. Although activity in piriform cortex could be used to discriminate between odorants at any moment in time, odour-evoked responses drifted over periods of days to weeks. The performance of a linear classifier trained on the first recording day approached chance levels after 32 days. Fear conditioning did not stabilize odour-evoked responses. Daily exposure to the same odorant slowed the rate of drift, but when exposure was halted the rate increased again. This demonstration of continuous drift poses the question of the role of piriform cortex in odour perception. This instability might reflect the unstructured connectivity of piriform cortex6-12, and may be a property of other unstructured cortices.
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Affiliation(s)
- Carl E Schoonover
- Howard Hughes Medical Institute, Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA.
| | - Sarah N Ohashi
- Howard Hughes Medical Institute, Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA.,Immunobiology Graduate Program, Yale School of Medicine, New Haven, CT, USA
| | - Richard Axel
- Howard Hughes Medical Institute, Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA.
| | - Andrew J P Fink
- Howard Hughes Medical Institute, Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, NY, USA.
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Kolaya E, Firestein BL. Deep brain stimulation: Challenges at the tissue-electrode interface and current solutions. Biotechnol Prog 2021; 37:e3179. [PMID: 34056871 DOI: 10.1002/btpr.3179] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/19/2021] [Accepted: 05/27/2021] [Indexed: 11/08/2022]
Abstract
Deep brain stimulation (DBS) is used to treat the motor symptoms of Parkinson's disease patients by stimulating the subthalamic nucleus. However, optimization of DBS is still needed since the performance of the neural electrodes is limited by the body's response to the implant. This review discusses the issues with DBS, such as placement of electrodes, foreign body response, and electrode degradation. The current solutions to these technical issues include modifications to electrode material, coatings, and geometry.
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Affiliation(s)
- Emily Kolaya
- Biomedical Engineering Graduate Program, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
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Olvera D, Monaghan MG. Electroactive material-based biosensors for detection and drug delivery. Adv Drug Deliv Rev 2021; 170:396-424. [PMID: 32987096 DOI: 10.1016/j.addr.2020.09.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/22/2020] [Accepted: 09/23/2020] [Indexed: 12/20/2022]
Abstract
Electroactive materials are employed at the interface of biology and electronics due to their advantageous intrinsic properties as soft organic electronics. We examine the most recent literature of electroactive material-based biosensors and their emerging role as theranostic devices for the delivery of therapeutic agents. We consider electroactive materials through the lens of smart drug delivery systems as materials that enable the release of therapeutic cargo in response to specific physiological and external stimuli and discuss the way these mechanisms are integrated into medical devices with examples of the latest advances. Studies that harness features unique to conductive polymers are emphasized; lastly, we highlight new perspectives and future research direction for this emerging technology and the challenges that remain to overcome.
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Sahasrabuddhe K, Khan AA, Singh AP, Stern TM, Ng Y, Tadić A, Orel P, LaReau C, Pouzzner D, Nishimura K, Boergens KM, Shivakumar S, Hopper MS, Kerr B, Hanna MES, Edgington RJ, McNamara I, Fell D, Gao P, Babaie-Fishani A, Veijalainen S, Klekachev AV, Stuckey AM, Luyssaert B, Kozai TDY, Xie C, Gilja V, Dierickx B, Kong Y, Straka M, Sohal HS, Angle MR. The Argo: a high channel count recording system for neural recording in vivo. J Neural Eng 2021; 18:015002. [PMID: 33624614 PMCID: PMC8607496 DOI: 10.1088/1741-2552/abd0ce] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Decoding neural activity has been limited by the lack of tools available to record from large numbers of neurons across multiple cortical regions simultaneously with high temporal fidelity. To this end, we developed the Argo system to record cortical neural activity at high data rates. APPROACH Here we demonstrate a massively parallel neural recording system based on platinum-iridium microwire electrode arrays bonded to a CMOS voltage amplifier array. The Argo system is the highest channel count in vivo neural recording system, supporting simultaneous recording from 65 536 channels, sampled at 32 kHz and 12-bit resolution. This system was designed for cortical recordings, compatible with both penetrating and surface microelectrodes. MAIN RESULTS We validated this system through initial bench testing to determine specific gain and noise characteristics of bonded microwires, followed by in-vivo experiments in both rat and sheep cortex. We recorded spiking activity from 791 neurons in rats and surface local field potential activity from over 30 000 channels in sheep. SIGNIFICANCE These are the largest channel count microwire-based recordings in both rat and sheep. While currently adapted for head-fixed recording, the microwire-CMOS architecture is well suited for clinical translation. Thus, this demonstration helps pave the way for a future high data rate intracortical implant.
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Affiliation(s)
| | - Aamir A Khan
- Paradromics, Inc, Austin, TX, United States of America
| | | | - Tyler M Stern
- Paradromics, Inc, Austin, TX, United States of America
| | - Yeena Ng
- Paradromics, Inc, Austin, TX, United States of America
| | | | - Peter Orel
- Paradromics, Inc, Austin, TX, United States of America
| | - Chris LaReau
- Paradromics, Inc, Austin, TX, United States of America
| | | | | | | | | | | | - Bryan Kerr
- Paradromics, Inc, Austin, TX, United States of America
| | | | | | | | - Devin Fell
- Paradromics, Inc, Austin, TX, United States of America
| | - Peng Gao
- Caeleste CVBA, Mechelen, Belgium
| | | | | | | | | | | | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States of America
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States of America
- NeuroTech Center, University of Pittsburgh Brain Institute, Pittsburgh, PA, United States of America
| | - Chong Xie
- Department of Electrical and Computer Engineering, Rice University, Houston, TX, United States of America
- Department of Bioengineering, Rice University, Houston, TX, United States of America
- NeuroEngineering Initiative, Rice University, Houston, TX, United States of America
| | - Vikash Gilja
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, United States of America
| | | | - Yifan Kong
- Paradromics, Inc, Austin, TX, United States of America
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Forro C, Caron D, Angotzi GN, Gallo V, Berdondini L, Santoro F, Palazzolo G, Panuccio G. Electrophysiology Read-Out Tools for Brain-on-Chip Biotechnology. MICROMACHINES 2021; 12:124. [PMID: 33498905 PMCID: PMC7912435 DOI: 10.3390/mi12020124] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
Brain-on-Chip (BoC) biotechnology is emerging as a promising tool for biomedical and pharmaceutical research applied to the neurosciences. At the convergence between lab-on-chip and cell biology, BoC couples in vitro three-dimensional brain-like systems to an engineered microfluidics platform designed to provide an in vivo-like extrinsic microenvironment with the aim of replicating tissue- or organ-level physiological functions. BoC therefore offers the advantage of an in vitro reproduction of brain structures that is more faithful to the native correlate than what is obtained with conventional cell culture techniques. As brain function ultimately results in the generation of electrical signals, electrophysiology techniques are paramount for studying brain activity in health and disease. However, as BoC is still in its infancy, the availability of combined BoC-electrophysiology platforms is still limited. Here, we summarize the available biological substrates for BoC, starting with a historical perspective. We then describe the available tools enabling BoC electrophysiology studies, detailing their fabrication process and technical features, along with their advantages and limitations. We discuss the current and future applications of BoC electrophysiology, also expanding to complementary approaches. We conclude with an evaluation of the potential translational applications and prospective technology developments.
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Affiliation(s)
- Csaba Forro
- Tissue Electronics, Fondazione Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci, 53-80125 Naples, Italy; (C.F.); (F.S.)
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Davide Caron
- Enhanced Regenerative Medicine, Fondazione Istituto Italiano di Tecnologia, Via Morego, 30-16163 Genova, Italy; (D.C.); (V.G.)
| | - Gian Nicola Angotzi
- Microtechnology for Neuroelectronics, Fondazione Istituto Italiano di Tecnologia, Via Morego, 30-16163 Genova, Italy; (G.N.A.); (L.B.)
| | - Vincenzo Gallo
- Enhanced Regenerative Medicine, Fondazione Istituto Italiano di Tecnologia, Via Morego, 30-16163 Genova, Italy; (D.C.); (V.G.)
| | - Luca Berdondini
- Microtechnology for Neuroelectronics, Fondazione Istituto Italiano di Tecnologia, Via Morego, 30-16163 Genova, Italy; (G.N.A.); (L.B.)
| | - Francesca Santoro
- Tissue Electronics, Fondazione Istituto Italiano di Tecnologia, Largo Barsanti e Matteucci, 53-80125 Naples, Italy; (C.F.); (F.S.)
| | - Gemma Palazzolo
- Enhanced Regenerative Medicine, Fondazione Istituto Italiano di Tecnologia, Via Morego, 30-16163 Genova, Italy; (D.C.); (V.G.)
| | - Gabriella Panuccio
- Enhanced Regenerative Medicine, Fondazione Istituto Italiano di Tecnologia, Via Morego, 30-16163 Genova, Italy; (D.C.); (V.G.)
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Krukiewicz K, Britton J, Więcławska D, Skorupa M, Fernandez J, Sarasua JR, Biggs MJP. Electrical percolation in extrinsically conducting, poly(ε-decalactone) composite neural interface materials. Sci Rep 2021; 11:1295. [PMID: 33446813 PMCID: PMC7809477 DOI: 10.1038/s41598-020-80361-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/18/2020] [Indexed: 11/08/2022] Open
Abstract
By providing a bidirectional communication channel between neural tissues and a biomedical device, it is envisaged that neural interfaces will be fundamental in the future diagnosis and treatment of neurological disorders. Due to the mechanical mismatch between neural tissue and metallic neural electrodes, soft electrically conducting materials are of great benefit in promoting chronic device functionality. In this study, carbon nanotubes (CNT), silver nanowires (AgNW) and poly(hydroxymethyl 3,4-ethylenedioxythiophene) microspheres (MSP) were employed as conducting fillers within a poly(ε-decalactone) (EDL) matrix, to form a soft and electrically conducting composite. The effect of a filler type on the electrical percolation threshold, and composite biocompatibility was investigated in vitro. EDL-based composites exhibited favourable electrochemical characteristics: EDL/CNT-the lowest film resistance (1.2 ± 0.3 kΩ), EDL/AgNW-the highest charge storage capacity (10.7 ± 0.3 mC cm- 2), and EDL/MSP-the highest interphase capacitance (1478.4 ± 92.4 µF cm-2). All investigated composite surfaces were found to be biocompatible, and to reduce the presence of reactive astrocytes relative to control electrodes. The results of this work clearly demonstrated the ability of high aspect ratio structures to form an extended percolation network within a polyester matrix, resulting in the formulation of composites with advantageous mechanical, electrochemical and biocompatibility properties.
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Affiliation(s)
- Katarzyna Krukiewicz
- Centre for Research in Medical Devices, National University of Ireland, Newcastle Road, Galway, H91 W2TY, Ireland.
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, M.Strzody 9, 44-100, Gliwice, Poland.
| | - James Britton
- Centre for Research in Medical Devices, National University of Ireland, Newcastle Road, Galway, H91 W2TY, Ireland
| | - Daria Więcławska
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, M.Strzody 9, 44-100, Gliwice, Poland
| | - Małgorzata Skorupa
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, M.Strzody 9, 44-100, Gliwice, Poland
| | - Jorge Fernandez
- Department of Mining-Metallurgy Engineering and Materials Science, School of Engineering, POLYMAT, University of the Basque Country (UPV/EHU), Alameda de Urquijo s/n, 48013, Bilbao, Spain
- Polimerbio, S.L, Paseo Mikeletegi 83, 20009, Donostia-San Sebastian, Spain
| | - Jose-Ramon Sarasua
- Department of Mining-Metallurgy Engineering and Materials Science, School of Engineering, POLYMAT, University of the Basque Country (UPV/EHU), Alameda de Urquijo s/n, 48013, Bilbao, Spain
| | - Manus J P Biggs
- Centre for Research in Medical Devices, National University of Ireland, Newcastle Road, Galway, H91 W2TY, Ireland
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Baker C, Wagner K, Wagner P, Officer DL, Mawad D. Biofunctional conducting polymers: synthetic advances, challenges, and perspectives towards their use in implantable bioelectronic devices. ADVANCES IN PHYSICS: X 2021. [DOI: 10.1080/23746149.2021.1899850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Carly Baker
- ARC Centre of Excellence for Electromaterials Science and Intelligent Polymer Research Institute, AIIM Faculty, Innovation Campus, University of Wollongong, North Wollongong, Australia
| | - Klaudia Wagner
- ARC Centre of Excellence for Electromaterials Science and Intelligent Polymer Research Institute, AIIM Faculty, Innovation Campus, University of Wollongong, North Wollongong, Australia
| | - Pawel Wagner
- ARC Centre of Excellence for Electromaterials Science and Intelligent Polymer Research Institute, AIIM Faculty, Innovation Campus, University of Wollongong, North Wollongong, Australia
| | - David L. Officer
- ARC Centre of Excellence for Electromaterials Science and Intelligent Polymer Research Institute, AIIM Faculty, Innovation Campus, University of Wollongong, North Wollongong, Australia
| | - Damia Mawad
- School of Materials Science and Engineering, UNSW Science, University of New South Wales, Sydney, Australia
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Patel PR, Popov P, Caldwell CM, Welle EJ, Egert D, Pettibone JR, Roossien DH, Becker JB, Berke JD, Chestek CA, Cai D. High density carbon fiber arrays for chronic electrophysiology, fast scan cyclic voltammetry, and correlative anatomy. J Neural Eng 2020; 17:056029. [PMID: 33055366 DOI: 10.1088/1741-2552/abb1f6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Multimodal measurements at the neuronal level allow for detailed insight into local circuit function. However, most behavioral studies focus on one or two modalities and are generally limited by the available technology. APPROACH Here, we show a combined approach of electrophysiology recordings, chemical sensing, and histological localization of the electrode tips within tissue. The key enabling technology is the underlying use of carbon fiber electrodes, which are small, electrically conductive, and sensitive to dopamine. The carbon fibers were functionalized by coating with Parylene C, a thin insulator with a high dielectric constant, coupled with selective re-exposure of the carbon surface using laser ablation. MAIN RESULTS We demonstrate the use of this technology by implanting 16 channel arrays in the rat nucleus accumbens. Chronic electrophysiology and dopamine signals were detected 1 month post implant. Additionally, electrodes were left in the tissue, sliced in place during histology, and showed minimal tissue damage. SIGNIFICANCE Our results validate our new technology and methods, which will enable a more comprehensive circuit level understanding of the brain.
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Affiliation(s)
- Paras R Patel
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
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Moreaux LC, Yatsenko D, Sacher WD, Choi J, Lee C, Kubat NJ, Cotton RJ, Boyden ES, Lin MZ, Tian L, Tolias AS, Poon JKS, Shepard KL, Roukes ML. Integrated Neurophotonics: Toward Dense Volumetric Interrogation of Brain Circuit Activity-at Depth and in Real Time. Neuron 2020; 108:66-92. [PMID: 33058767 PMCID: PMC8061790 DOI: 10.1016/j.neuron.2020.09.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/18/2020] [Accepted: 09/28/2020] [Indexed: 12/17/2022]
Abstract
We propose a new paradigm for dense functional imaging of brain activity to surmount the limitations of present methodologies. We term this approach "integrated neurophotonics"; it combines recent advances in microchip-based integrated photonic and electronic circuitry with those from optogenetics. This approach has the potential to enable lens-less functional imaging from within the brain itself to achieve dense, large-scale stimulation and recording of brain activity with cellular resolution at arbitrary depths. We perform a computational study of several prototype 3D architectures for implantable probe-array modules that are designed to provide fast and dense single-cell resolution (e.g., within a 1-mm3 volume of mouse cortex comprising ∼100,000 neurons). We describe progress toward realizing integrated neurophotonic imaging modules, which can be produced en masse with current semiconductor foundry protocols for chip manufacturing. Implantation of multiple modules can cover extended brain regions.
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Affiliation(s)
- Laurent C Moreaux
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Dimitri Yatsenko
- Vathes LLC, Houston, TX 77030, USA; Center for Neuroscience and Artificial Intelligence and Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Wesley D Sacher
- Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA 91125, USA; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA; Max Planck Institute for Microstructure Physics, Halle, Germany
| | - Jaebin Choi
- Departments of Electrical Engineering and Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Changhyuk Lee
- Departments of Electrical Engineering and Biomedical Engineering, Columbia University, New York, NY 10027, USA; Center for BioMicrosystems, Brain Science Institute, Korea Institute of Science and Technology, Korea
| | - Nicole J Kubat
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA
| | - R James Cotton
- Shirley Ryan AbilityLab, Northwestern University, Chicago, IL 60611, USA; Center for Neuroscience and Artificial Intelligence and Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Edward S Boyden
- Howard Hughes Medical Institute, Cambridge, MA, USA; McGovern Institute, MIT, Cambridge, USA; Koch Institute, MIT, Cambridge, USA; Departments of Brain and Cognitive Sciences, Media Arts and Sciences, and Biological Engineering, MIT, Cambridge, USA
| | - Michael Z Lin
- Departments of Neurobiology and Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95616, USA
| | - Andreas S Tolias
- Vathes LLC, Houston, TX 77030, USA; Center for Neuroscience and Artificial Intelligence and Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA
| | - Joyce K S Poon
- Max Planck Institute for Microstructure Physics, Halle, Germany; Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Rd., Toronto, ON M5S 3G4, Canada
| | - Kenneth L Shepard
- Departments of Electrical Engineering and Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Michael L Roukes
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA; Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA 91125, USA; Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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A simultaneous optical and electrical in-vitro neuronal recording system to evaluate microelectrode performance. PLoS One 2020; 15:e0237709. [PMID: 32817653 PMCID: PMC7440637 DOI: 10.1371/journal.pone.0237709] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 07/31/2020] [Indexed: 11/24/2022] Open
Abstract
Objectives In this paper, we aim to detail the setup of a high spatio-temporal resolution, electrical recording system utilising planar microelectrode arrays with simultaneous optical imaging suitable for evaluating microelectrode performance with a proposed ′performance factor′ metric. Methods Techniques that would facilitate low noise electrical recordings were coupled with voltage sensitive dyes and neuronal activity was recorded both electrically via a customised amplification system and optically via a high speed CMOS camera. This technique was applied to characterise microelectrode recording performance of gold and poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) coated electrodes through traditional signal to noise (SNR) calculations as well as the proposed performance factor. Results Neuronal activity was simultaneously recorded using both electrical and optical techniques and this activity was confirmed via tetrodotoxin application to inhibit action potential firing. PEDOT/PSS outperformed gold using both measurements, however, the performance factor metric estimated a 3 fold improvement in signal transduction when compared to gold, whereas SNR estimated an 8 fold improvement when compared to gold. Conclusion The design and functionality of a system to record from neurons both electrically, through microelectrode arrays, and optically via voltage sensitive dyes was successfully achieved. Significance The high spatiotemporal resolution of both electrical and optical methods will allow for an array of applications such as improved detection of subthreshold synaptic events, validation of spike sorting algorithms and a provides a robust evaluation of extracellular microelectrode performance.
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Cho W, Liu F, Hendrix A, McCray B, Asrat T, Connaughton V, Zestos AG. Timed Electrodeposition of PEDOT:Nafion onto Carbon Fiber-Microelectrodes Enhances Dopamine Detection in Zebrafish Retina. JOURNAL OF THE ELECTROCHEMICAL SOCIETY 2020; 167:115501. [PMID: 33927449 PMCID: PMC8081298 DOI: 10.1149/1945-7111/aba33d] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Carbon fiber-microelectrodes (CFMEs) are one of the standards for the detection of neurotransmitters such as dopamine (DA). In this study, we demonstrate that CFMEs electrodeposited with poly (3,4-ethylenedioxythiophene) (PEDOT) in the presence of Nafion exhibit enhanced sensitivity for DA detection. Scanning electron microscopy (SEM) revealed the smooth outer surface morphologies of polymer coatings, which filled in the ridges and grooves of the bare unmodified carbon electrode and energy-dispersive X-ray spectroscopy (EDX) confirmed PEDOT:Nafion incorporation. PEDOT:Nafion coated CMFEs exhibited a statistically enhanced two-fold increase in DA sensitivity compared to unmodified microelectrodes, with stability and integrity of the coated microelectrodes maintained for at least 4 h. A scan rate test revealed a linear relationship with peak DA oxidative current (5 μM), indicating adsorption control of DA to the surface of the PEDOT:Nafion electrode. As proof of principle, PEDOT:Nafion coated electrodes were used to detect potassium chloride (KCl)-induced DA release in zebrafish (Danio rerio) retinal tissue ex vivo, thus illustrating their applicability as biosensors.
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Affiliation(s)
- Whirang Cho
- Department of Chemistry, American University, Washington, D.C. 20016, United States of America
| | - Favian Liu
- Department of Chemistry, American University, Washington, D.C. 20016, United States of America
| | - Aaron Hendrix
- Department of Biology, American University, Washington, D.C. 20016, United States of America
| | - Brazil McCray
- Department of Biology, American University, Washington, D.C. 20016, United States of America
| | - Thomas Asrat
- Department of Chemistry, American University, Washington, D.C. 20016, United States of America
| | - Victoria Connaughton
- Department of Biology, American University, Washington, D.C. 20016, United States of America
- Center for Behavioral Neuroscience, American University, Washington, D.C. 20016, United States of America
| | - Alexander G. Zestos
- Department of Chemistry, American University, Washington, D.C. 20016, United States of America
- Center for Behavioral Neuroscience, American University, Washington, D.C. 20016, United States of America
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Zha F, Chen W, Hao L, Wu C, Lu M, Zhang L, Yu D. Electrospun cellulose-based conductive polymer nanofibrous mats: composite scaffolds and their influence on cell behavior with electrical stimulation for nerve tissue engineering. SOFT MATTER 2020; 16:6591-6598. [PMID: 32597437 DOI: 10.1039/d0sm00593b] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The fabrication of scaffolds with suitable chemical, physical, and electrical properties is critical for nerve cell adhesion and proliferation. Recently, electrical stimulation on conductive polymers has been applied to construct functional nerve cell scaffolds. Herein, we prepared natural polymer (cellulose)/conductive polymer nanofibrous mats, i.e., electrospun cellulose (EC)/poly N-vinylpyrrole (PNVPY) and EC/poly(3-hexylthiophene) (P3HT) through an efficient in situ polymerization method. The surface immobilization was characterized by optical microscopy (OM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, hydrophilicity, porosity, and cyclic voltammetry. The OM and SEM images showed that PNVPY formed polymer coatings and aggregated nanoparticles on the EC nanofibers, while P3HT only produced polymer coatings. Compared with pure EC mats, both the composite mats had increased thickness, higher porosity, and higher conductivity. Also, an increase in hydrophilicity was found for EC/P3HT. In vivo cytocompatibility of the undifferentiated PC12 cells showed that the EC/PNVPY and EC/P3HT scaffolds exhibited favorable cell activity, adhesion, and proliferation. Furthermore, the results of electrical stimulation experiments indicated that the EC/P3HT mats could effectively promote the proliferation of the PC12 cells more than the EC and EC/PNVPY mats. The findings suggest a positive outcome regarding the conductive polymer-modified EC/PNVPY and EC/P3HT nanofibrous mats in neural tissue engineering.
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Affiliation(s)
- Fangwen Zha
- School of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipments, MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
| | - Wei Chen
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P. R. China
| | - Lu Hao
- School of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipments, MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
| | - Chunsheng Wu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P. R. China
| | - Meng Lu
- Institute of Medical Engineering, Department of Biophysics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P. R. China
| | - Lifeng Zhang
- Department of Nanoengineering, Joint School of Nanoscience and Nanoengineering, NC A&T State University, Greensboro, NC, USA
| | - Demei Yu
- School of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipments, MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an, Shaanxi, P. R. China.
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Fan B, Rodriguez AV, Vercosa DG, Kemere C, Robinson JT. Sputtered porous Pt for wafer-scale manufacture of low-impedance flexible microelectrodes. J Neural Eng 2020; 17:036029. [PMID: 32454468 DOI: 10.1088/1741-2552/ab965c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Recording electrical activity from individual cells in vivo is a key technology for basic neuroscience and has growing clinical applications. To maximize the number of independent recording channels as well as the longevity, and quality of these recordings, researchers often turn to small and flexible electrodes that minimize tissue damage and can isolate signals from individual neurons. One challenge when creating these small electrodes, however, is to maintain a low interfacial impedance by applying a surface coating that is stable in tissue and does not significantly complicate the fabrication process. APPROACH Here we use a high-pressure Pt sputtering process to create low-impedance electrodes at the wafer scale using standard microfabrication equipment. MAIN RESULTS We find that direct-sputtered Pt provides a reliable and well-controlled porous coating that reduces the electrode impedance by 5-9 fold compared to flat Pt and is compatible with the microfabrication technologies used to create flexible electrodes. These porous Pt electrodes show reduced thermal noise that matches theoretical predictions. In addition, we show that these electrodes can be implanted into rat cortex, record single unit activity, and be removed all without disrupting the integrity of the coating. We also demonstrate that the shape of the electrode (in addition to the surface area) has a significant effect on the electrode impedance when the feature sizes are on the order of tens of microns. SIGNIFICANCE Overall, porous Pt represents a promising method for manufacturing low-impedance electrodes that can be seamlessly integrated into existing processes for producing flexible neural probes.
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Affiliation(s)
- Bo Fan
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States of America. Co-first authors
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Colachis M, Shqau K, Colachis S, Annetta N, Heintz AM. Soft mixed ionic–electronic conductive electrodes for noninvasive stimulation. J Appl Polym Sci 2020. [DOI: 10.1002/app.48998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Matthew Colachis
- Department of Advanced Materials and MicrofabricationBattelle Memorial Institute Columbus Ohio
| | - Krenar Shqau
- Department of Advanced Materials and MicrofabricationBattelle Memorial Institute Columbus Ohio
| | - Samuel Colachis
- Department of Medical Devices and Health AnalyticsBattelle Memorial Institute Columbus Ohio
| | - Nicholas Annetta
- Department of Medical Devices and Health AnalyticsBattelle Memorial Institute Columbus Ohio
| | - Amy M. Heintz
- Department of Advanced Materials and MicrofabricationBattelle Memorial Institute Columbus Ohio
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48
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Jones PD, Moskalyuk A, Barthold C, Gutöhrlein K, Heusel G, Schröppel B, Samba R, Giugliano M. Low-Impedance 3D PEDOT:PSS Ultramicroelectrodes. Front Neurosci 2020; 14:405. [PMID: 32508562 PMCID: PMC7248397 DOI: 10.3389/fnins.2020.00405] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/02/2020] [Indexed: 12/02/2022] Open
Abstract
The technology for producing microelectrode arrays (MEAs) has been developing since the 1970s and extracellular electrophysiological recordings have become well established in neuroscience, drug screening and cardiology. MEAs allow monitoring of long-term spiking activity of large ensembles of excitable cells noninvasively with high temporal resolution and mapping its spatial features. However, their inability to register subthreshold potentials, such as intrinsic membrane oscillations and synaptic potentials, has inspired a number of laboratories to search for alternatives to bypass the restrictions and/or increase the sensitivity of microelectrodes. In this study, we present the fabrication and in vitro experimental validation of arrays of PEDOT:PSS-coated 3D ultramicroelectrodes, with the best-reported combination of small size and low electrochemical impedance. We observed that this type of microelectrode does not alter neuronal network biological properties, improves the signal quality of extracellular recordings and exhibits higher selectivity toward single unit recordings. With fabrication processes simpler than those reported in the literature for similar electrodes, our technology is a promising tool for study of neuronal networks.
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Affiliation(s)
- Peter D. Jones
- Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Anastasiya Moskalyuk
- Theoretical Neurobiology & Neuroengineering, University of Antwerp, Antwerp, Belgium
| | - Clemens Barthold
- Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
- joimax GmbH, Karlsruhe, Germany
| | - Katja Gutöhrlein
- Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
- Bosch Sensortec GmbH, Reutlingen, Germany
| | - Gerhard Heusel
- Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Birgit Schröppel
- Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Ramona Samba
- NMI Technologietransfer GmbH, Reutlingen, Germany
| | - Michele Giugliano
- Theoretical Neurobiology & Neuroengineering, University of Antwerp, Antwerp, Belgium
- Neuroscience Sector, International School for Advanced Studies (SISSA), Trieste, Italy
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Wu X, Surendran A, Moser M, Chen S, Muhammad BT, Maria IP, McCulloch I, Leong WL. Universal Spray-Deposition Process for Scalable, High-Performance, and Stable Organic Electrochemical Transistors. ACS APPLIED MATERIALS & INTERFACES 2020; 12:20757-20764. [PMID: 32281363 DOI: 10.1021/acsami.0c04776] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Organic electrochemical transistors (OECTs) with high transconductance and good operating stability in an aqueous environment are receiving substantial attention as promising ion-to-electron transducers for bioelectronics. However, to date, in most of the reported OECTs, the fabrication procedures have been devoted to spin-coating processes that may nullify the advantages of large-area and scalable manufacturing. In addition, conventional microfabrication and photolithography techniques are complicated or incompatible with various nonplanar flexible and curved substrates. Herein, we demonstrate a facile patterning method via spray deposition to fabricate ionic-liquid-doped poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based OECTs, with a high peak transconductance of 12.9 mS and high device stability over 4000 switching cycles. More importantly, this facile technique makes it possible to fabricate high-performance OECTs on versatile substrates with different textures and form factors such as thin permeable membranes, flexible plastic sheets, hydrophobic elastomers, and rough textiles. Overall, the results highlight the spray-deposition technique as a convenient route to prepare high-performing OECTs and will contribute to the translation of OECTs into real-world applications.
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Affiliation(s)
- Xihu Wu
- School of Electrical Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Abhijith Surendran
- School of Electrical Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Maximilian Moser
- Department of Chemistry, Imperial College London, London SW7 2AX, U.K
| | - Shuai Chen
- School of Electrical Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Bening Tirta Muhammad
- School of Electrical Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | | | - Iain McCulloch
- Department of Chemistry, Imperial College London, London SW7 2AX, U.K
- Physical Sciences and Engineering Division, KAUST Solar Center (KSC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Wei Lin Leong
- School of Electrical Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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He F, Sullender CT, Zhu H, Williamson MR, Li X, Zhao Z, Jones TA, Xie C, Dunn AK, Luan L. Multimodal mapping of neural activity and cerebral blood flow reveals long-lasting neurovascular dissociations after small-scale strokes. SCIENCE ADVANCES 2020; 6:eaba1933. [PMID: 32494746 PMCID: PMC7244270 DOI: 10.1126/sciadv.aba1933] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/10/2020] [Indexed: 06/02/2023]
Abstract
Neurovascular coupling, the close spatial and temporal relationship between neural activity and hemodynamics, is disrupted in pathological brain states. To understand the altered neurovascular relationship in brain disorders, longitudinal, simultaneous mapping of neural activity and hemodynamics is critical yet challenging to achieve. Here, we use a multimodal neural platform in a mouse model of stroke and realize long-term, spatially resolved tracking of intracortical neural activity and cerebral blood flow in the same brain regions. We observe a pronounced neurovascular dissociation that occurs immediately after small-scale strokes, becomes the most severe a few days after, lasts into chronic periods, and varies with the level of ischemia. Neuronal deficits extend spatiotemporally, whereas restoration of cerebral blood flow occurs sooner and reaches a higher relative value. Our findings reveal the neurovascular impact of ministrokes and inform the limitation of neuroimaging techniques that infer neural activity from hemodynamic responses.
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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
| | - Colin T. Sullender
- Department of Biomedical Engineering, The University of Texas at Austin, 107 E. Dean Keeton Street, 1 University Station, C0800, Austin, TX 78712, USA
| | - Hanlin Zhu
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Michael R. Williamson
- Institute for Neuroscience, The University of Texas at Austin, 1 University Station, Stop C7000, Austin, TX 78712, USA
| | - Xue Li
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Zhengtuo Zhao
- 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
| | - Theresa A. Jones
- Department of Psychology, The University of Texas at Austin, 108 E. Dean Keeton Street, Stop A8000, SEA 6.106, 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
| | - Andrew K. Dunn
- Department of Biomedical Engineering, The University of Texas at Austin, 107 E. Dean Keeton Street, 1 University Station, C0800, Austin, TX 78712, 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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