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Multielectrode array

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https://www.readbyqxmd.com/read/28819130/a-multielectrode-array-microchannel-platform-reveals-both-transient-and-slow-changes-in-axonal-conduction-velocity
#1
Rouhollah Habibey, Shahrzad Latifi, Hossein Mousavi, Mattia Pesce, Elmira Arab-Tehrany, Axel Blau
Due to their small dimensions, electrophysiology on thin and intricate axonal branches in support of understanding their role in normal and diseased brain function poses experimental challenges. To reduce experimental complexity, we coupled microelectrode arrays (MEAs) to bi-level microchannel devices for the long-term in vitro tracking of axonal morphology and activity with high spatiotemporal resolution. Our model allowed the long-term multisite recording from pure axonal branches in a microscopy-compatible environment...
August 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28795515/multiplexed-optogenetic-stimulation-of-neurons-with-spectrum-selective-upconversion-nanoparticles
#2
Xudong Lin, Ying Wang, Xian Chen, Runhuai Yang, Zixun Wang, Jingyu Feng, Haitao Wang, King W C Lai, Jufang He, Feng Wang, Peng Shi
Optical modulation of nervous system becomes increasingly popular as the wide adoption of optogenetics. For these applications, upconversion materials hold great promise as novel photonic elements. This study describes an upconversion based strategy for combinatorial neural stimulation both in vitro and in vivo by using spectrum-selective upconversion nanoparticles (UCNPs). NaYF4 based UCNPs are used to absorb near-infrared (NIR) energy and to emit visible light for stimulating neurons expressing different channelrhodopsin (ChR) proteins...
August 10, 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28749937/recurrently-connected-and-localized-neuronal-communities-initiate-coordinated-spontaneous-activity-in-neuronal-networks
#3
Davide Lonardoni, Hayder Amin, Stefano Di Marco, Alessandro Maccione, Luca Berdondini, Thierry Nieus
Developing neuronal systems intrinsically generate coordinated spontaneous activity that propagates by involving a large number of synchronously firing neurons. In vivo, waves of spikes transiently characterize the activity of developing brain circuits and are fundamental for activity-dependent circuit formation. In vitro, coordinated spontaneous spiking activity, or network bursts (NBs), interleaved within periods of asynchronous spikes emerge during the development of 2D and 3D neuronal cultures. Several studies have investigated this type of activity and its dynamics, but how a neuronal system generates these coordinated events remains unclear...
July 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28744551/neural-responses-to-multielectrode-stimulation-of-healthy-and-degenerate-retina
#4
Kerry J Halupka, Carla J Abbott, Yan T Wong, Shaun L Cloherty, David B Grayden, Anthony N Burkitt, Evgeni N Sergeev, Chi D Luu, Alice Brandli, Penelope J Allen, Hamish Meffin, Mohit N Shivdasani
Purpose: Simultaneous stimulation of multiple retinal electrodes in normally sighted animals shows promise in improving the resolution of retinal prostheses. However, the effects of simultaneous stimulation on degenerate retinae remain unknown. Therefore, we investigated the characteristics of cortical responses to multielectrode stimulation of the degenerate retina. Methods: Four adult cats were bilaterally implanted with retinal electrode arrays in the suprachoroidal space after unilateral adenosine triphosphate (ATP)-induced retinal photoreceptor degeneration...
July 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28742044/multipolar-field-shaping-in-a-suprachoroidal-visual-prosthesis
#5
Calvin D Eiber, Socrates Dokos, Nigel H Lovell, Gregg J Suaning
Visual prostheses are now an available mobility aid for patients blinded by degenerative retinal diseases. However, the spatial resolution of existing devices is still insufficient to deliver normal levels of mobility vision without stimulation strategies which enable existing devices to deliver several different percepts per stimulation site. A stimulation strategy in which field shaping is achieved by incorporating multipolar (bipolar and tripolar) stimulation could convey additional information to a user of a visual prosthesis, as compared to monopolar stimulation, is investigated...
July 24, 2017: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/28659709/meclofenamic-acid-improves-the-signal-to-noise-ratio-for-visual-responses-produced-by-ectopic-expression-of-human-rod-opsin
#6
Cyril G Eleftheriou, Jasmina Cehajic-Kapetanovic, Franck P Martial, Nina Milosavljevic, Robert A Bedford, Robert J Lucas
PURPOSE: Retinal dystrophy through outer photoreceptor cell death affects 1 in 2,500 people worldwide with severe impairment of vision in advanced stages of the disease. Optogenetic strategies to restore visual function to animal models of retinal degeneration by introducing photopigments to neurons spared degeneration in the inner retina have been explored, with variable degrees of success. It has recently been shown that the non-steroidal anti-inflammatory and non-selective gap-junction blocker meclofenamic acid (MFA) can enhance the visual responses produced by an optogenetic actuator (channelrhodopsin) expressed in retinal ganglion cells (RGCs) in the degenerate retina...
2017: Molecular Vision
https://www.readbyqxmd.com/read/28634436/dual-coding-theory-explains-biphasic-collective-computation-in-neural-decision-making
#7
Bryan C Daniels, Jessica C Flack, David C Krakauer
A central question in cognitive neuroscience is how unitary, coherent decisions at the whole organism level can arise from the distributed behavior of a large population of neurons with only partially overlapping information. We address this issue by studying neural spiking behavior recorded from a multielectrode array with 169 channels during a visual motion direction discrimination task. It is well known that in this task there are two distinct phases in neural spiking behavior. Here we show Phase I is a distributed or incompressible phase in which uncertainty about the decision is substantially reduced by pooling information from many cells...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28619993/low-extracellular-potassium-prolongs-repolarization-and-evokes-early-afterdepolarization-in-human-induced-pluripotent-stem-cell-derived-cardiomyocytes
#8
Jukka Kuusela, Kim Larsson, Disheet Shah, Chandra Prajapati, Katriina Aalto-Setälä
Long QT syndrome (LQTS) is characterized by a prolonged QT-interval on electrocardiogram and by increased risk of sudden death. One of the most common and potentially life-threatening electrolyte disturbances is hypokalemia, characterized by low concentrations of K(+) Using a multielectrode array platform and current clamp technique, we investigated the effect of low extracellular K(+) concentration ([K(+)]Ex) on the electrophysiological properties of hiPSC-derived cardiomyocytes (CMs) generated from a healthy control subject (WT) and from two symptomatic patients with type 1 of LQTS carrying G589D (LQT1A) or IVS7-2A>G mutation (LQT1B) in KCNQ1 The baseline prolongations of field potential durations (FPDs) and action potential durations (APDs) were longer in LQT1-CMs than in WT-CMs...
June 15, 2017: Biology Open
https://www.readbyqxmd.com/read/28534411/intracellular-and-extracellular-recording-of-spontaneous-action-potentials-in-mammalian-neurons-and-cardiac-cells-with-3d-plasmonic-nanoelectrodes
#9
Michele Dipalo, Hayder Amin, Laura Lovato, Fabio Moia, Valeria Caprettini, Gabriele C Messina, Francesco Tantussi, Luca Berdondini, Francesco De Angelis
Three-dimensional vertical micro- and nanostructures can enhance the signal quality of multielectrode arrays and promise to become the prime methodology for the investigation of large networks of electrogenic cells. So far, access to the intracellular environment has been obtained via spontaneous poration, electroporation, or by surface functionalization of the micro/nanostructures; however, these methods still suffer from some limitations due to their intrinsic characteristics that limit their widespread use...
June 14, 2017: Nano Letters
https://www.readbyqxmd.com/read/28507435/mesoporous-silica-nanoparticles-trigger-mitophagy-in-endothelial-cells-and-perturb-neuronal-network-activity-in-a-size-and-time-dependent-manner
#10
Antonina Orlando, Emanuela Cazzaniga, Maria Tringali, Francesca Gullo, Andrea Becchetti, Stefania Minniti, Francesca Taraballi, Ennio Tasciotti, Francesca Re
PURPOSE: Mesoporous silica nanoparticles (MSNPs) are excellent candidates for biomedical applications and drug delivery to different human body areas, the brain included. Although toxicity at cellular level has been investigated, we are still far from using MSNPs in the clinic, because the mechanisms involved in the cellular responses activated by MSNPs have not yet been elucidated. MATERIALS AND METHODS: This study used an in vitro multiparametric approach to clarify relationships among size, dose, and time of exposure of MSNPs (0...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28483438/construction-of-vascularized-pacemaker-tissues-by-seeding-cardiac-progenitor-cells-and-endothelial-progenitor-cells-into-matrigel
#11
Luping Zhang, Xiaotong Li, Xiaolong Yu, Yuquan Li, Aijun Sun, Chao Huang, Feng Xu, Jinping Guo, Yao Sun, Xi Zhang, Xiangqun Yang, Chuansen Zhang
AIMS: Transplantation of a tissue engineered cardiac pacemaker (TECP) may represent a novel therapy for cardiac sinus node dysfunction. We previously reported that cardiac progenitor cells (CPCs) derived from embryonic heart tubes could differentiate into cardiac pacemaking cells after endothelin-1 treatment. We aimed to examine the feasibility of TECP fabricated from CPCs-derived pacemaking cells and vascularization of TECP fabricated from CPCs-derived pacemaking cells and endothelial progenitor cells (EPCs) in vitro and in vivo implantation...
June 15, 2017: Life Sciences
https://www.readbyqxmd.com/read/28461461/high-spatial-correspondence-at-a-columnar-level-between-activation-and-resting-state-fmri-signals-and-local-field-potentials
#12
Zhaoyue Shi, Ruiqi Wu, Pai-Feng Yang, Feng Wang, Tung-Lin Wu, Arabinda Mishra, Li Min Chen, John C Gore
Although blood oxygenation level-dependent (BOLD) fMRI has been widely used to map brain responses to external stimuli and to delineate functional circuits at rest, the extent to which BOLD signals correlate spatially with underlying neuronal activity, the spatial relationships between stimulus-evoked BOLD activations and local correlations of BOLD signals in a resting state, and whether these spatial relationships vary across functionally distinct cortical areas are not known. To address these critical questions, we directly compared the spatial extents of stimulated activations and the local profiles of intervoxel resting state correlations for both high-resolution BOLD at 9...
May 16, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28432013/design-of-multielectrode-arrays-for-uniform-sampling-of-different-orientations-of-tuned-unit-populations-in-the-cat-visual-cortex
#13
Yoshiko Maruyama, Hiroyuki Ito
For better reconstruction of stimulus orientation from a single trial activity of the neuron population in the visual cortex, we need uniform samplings of differently oriented tuned neurons. We recorded multiple neurons simultaneously by using either a four-tetrode array or an eight-microelectrode array, and examined what kinds of electrodes and layouts provided a more homogeneous distribution of the units' optimal orientations. The unit population sampled by a four-tetrode array showed more homogeneous distribution than those sampled by an eight-microelectrode array...
April 18, 2017: Neuroscience Research
https://www.readbyqxmd.com/read/28416676/dissociation-of-per1-and-bmal1-circadian-rhythms-in-the-suprachiasmatic-nucleus-in-parallel-with-behavioral-outputs
#14
Daisuke Ono, Sato Honma, Yoshihiro Nakajima, Shigeru Kuroda, Ryosuke Enoki, Ken-Ichi Honma
The temporal order of physiology and behavior in mammals is primarily regulated by the circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). Taking advantage of bioluminescence reporters, we monitored the circadian rhythms of the expression of clock genes Per1 and Bmal1 in the SCN of freely moving mice and found that the rate of phase shifts induced by a single light pulse was different in the two rhythms. The Per1-luc rhythm was phase-delayed instantaneously by the light presented at the subjective evening in parallel with the activity onset of behavioral rhythm, whereas the Bmal1-ELuc rhythm was phase-delayed gradually, similar to the activity offset...
May 2, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28371490/graphene-multielectrode-arrays-as-a-versatile-tool-for-extracellular-measurements
#15
Dmitry Kireev, Silke Seyock, Johannes Lewen, Vanessa Maybeck, Bernhard Wolfrum, Andreas Offenhäusser
Graphene multielectrode arrays (GMEAs) presented in this work are used for cardio and neuronal extracellular recordings. The advantages of the graphene as a part of the multielectrode arrays are numerous: from a general flexibility and biocompatibility to the unique electronic properties of graphene. The devices used for extensive in vitro studies of a cardiac-like cell line and cortical neuronal networks show excellent ability to extracellularly detect action potentials with signal to noise ratios in the range of 45 ± 22 for HL-1 cells and 48 ± 26 for spontaneous bursting/spiking neuronal activity...
June 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28334377/lrit3-differentially-affects-connectivity-and-synaptic-transmission-of-cones-to-on-and-off-bipolar-cells
#16
Marion Neuillé, Yan Cao, Romain Caplette, Debbie Guerrero-Given, Connon Thomas, Naomi Kamasawa, José-Alain Sahel, Christian P Hamel, Isabelle Audo, Serge Picaud, Kirill A Martemyanov, Christina Zeitz
Purpose: Mutations in LRIT3 lead to complete congenital stationary night blindness (cCSNB). Using a cCSNB mouse model lacking Lrit3 (nob6), we recently have shown that LRIT3 has a role in the correct localization of TRPM1 (transient receptor potential melastatin 1) to the dendritic tips of ON-bipolar cells (BCs), contacting both rod and cone photoreceptors. Furthermore, postsynaptic clustering of other mGluR6 cascade components is selectively eliminated at the dendritic tips of cone ON-BCs...
March 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28273464/unsupervised-spike-sorting-for-large-scale-high-density-multielectrode-arrays
#17
Gerrit Hilgen, Martino Sorbaro, Sahar Pirmoradian, Jens-Oliver Muthmann, Ibolya Edit Kepiro, Simona Ullo, Cesar Juarez Ramirez, Albert Puente Encinas, Alessandro Maccione, Luca Berdondini, Vittorio Murino, Diego Sona, Francesca Cella Zanacchi, Evelyne Sernagor, Matthias Helge Hennig
We present a method for automated spike sorting for recordings with high-density, large-scale multielectrode arrays. Exploiting the dense sampling of single neurons by multiple electrodes, an efficient, low-dimensional representation of detected spikes consisting of estimated spatial spike locations and dominant spike shape features is exploited for fast and reliable clustering into single units. Millions of events can be sorted in minutes, and the method is parallelized and scales better than quadratically with the number of detected spikes...
March 7, 2017: Cell Reports
https://www.readbyqxmd.com/read/28272020/a-stationary-wavelet-transform-and-a-time-frequency-based-spike-detection-algorithm-for-extracellular-recorded-data
#18
Florian Lieb, Hans-Georg Stark, Christiane Thielemann
OBJECTIVE: Spike detection from extracellular recordings is a crucial preprocessing step when analyzing neuronal activity. The decision whether a specific part of the signal is a spike or not is important for any kind of other subsequent preprocessing steps, like spike sorting or burst detection in order to reduce the classification of erroneously identified spikes. Many spike detection algorithms have already been suggested, all working reasonably well whenever the signal-to-noise ratio is large enough...
June 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28270025/a-scalable-weight-free-learning-algorithm-for-regulatory-control-of-cell-activity-in-spiking-neuronal-networks
#19
Xu Zhang, Greg Foderaro, Craig Henriquez, Silvia Ferrari
Recent developments in neural stimulation and recording technologies are providing scientists with the ability of recording and controlling the activity of individual neurons in vitro or in vivo, with very high spatial and temporal resolution. Tools such as optogenetics, for example, are having a significant impact in the neuroscience field by delivering optical firing control with the precision and spatiotemporal resolution required for investigating information processing and plasticity in biological brains...
December 22, 2016: International Journal of Neural Systems
https://www.readbyqxmd.com/read/28269358/modeling-the-debye-dielectric-response-in-the-time-domain-for-a-liquid-crystal-based-biopotential-optrode
#20
Hrishikesh Srinivas, Amr Al Abed, Francois Ladouceur, Nigel H Lovell, Leonardo Silvestri
Multielectrode arrays (MEAs) are widely used for recording biopotentials, with an ongoing research effort to improve their characteristics and performance. In this spirit, we are currently investigating a novel concept for a liquid crystal-based optical electrode (optrode) that has the potential to overcome some of the limitations of MEAs, including that of wiring complexity. In this paper we present a model to fully describe the electrical response of the proposed optrode to biopotentials, taking into account dielectric relaxation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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