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Multi-electrode array

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https://www.readbyqxmd.com/read/29029261/selective-enhancement-of-domoic-acid-toxicity-in-primary-cultures-of-cerebellar-granule-cells-by-lowering-extracellular-na-concentration
#1
Anabel Pérez-Gómez, David Cabrera-García, Davide Warm, Ann M Marini, Javier Salas Puig, Maria Teresa Fernández-Sánchez, Antonello Novelli
Domoic acid (DOM) is an excitatory amino acid analog of kainic acid (KA) that acts through glutamic acid (GLU) receptors, inducing a fast and potent neurotoxic response. Here we present evidence for an enhancement of excitotoxicity following exposure of cultured cerebellar granule cells to DOM in the presence of lower than physiological Na+ concentrations. The concentration of DOM that reduced by 50% neuronal survival was ̴ 3 µM in Na+-free conditions and 16 µM in presence of a physiological concentration of extracellular Na+...
September 25, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
https://www.readbyqxmd.com/read/29024712/brief-activation-of-gabaergic-interneurons-initiates-the-transition-to-ictal-events-through-post-inhibitory-rebound-excitation
#2
Michael Chang, Joshua A Dian, Suzie Dufour, Lihua Wang, Homeira Moradi-Chameh, Meera Ramani, Liang Zhang, Peter L Carlen, Thilo Womelsdorf, Taufik A Valiante
Activation of γ-aminobutyric acid (GABAA) receptors have been associated with the onset of epileptiform events. To investigate if a causal relationship exists between GABAA receptor activation and ictal event onset, we activated inhibitory GABAergic networks in the superficial layer (2/3) of the somatosensory cortex during hyperexcitable conditions using optogenetic techniques in mice expressing channelrhodopsin-2 in all GABAergic interneurons. We found that a brief 30ms light pulse reliably triggered either an interictal-like event (IIE) or ictal-like ("ictal") event in the in vitro cortical 4-Aminopyridine (4-AP) slice model...
October 9, 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/29020304/identification-of-a-targeted-and-testable-antiarrhythmic-therapy-for-long-qt-syndrome-type-2-using-a-patient-specific-cellular-model
#3
Ashish Mehta, Chrishan J A Ramachandra, Pritpal Singh, Anuja Chitre, Chong Hui Lua, Manuela Mura, Lia Crotti, Philip Wong, Peter J Schwartz, Massimiliano Gnecchi, Winston Shim
Aims: Loss-of-function mutations in the hERG gene causes long-QT syndrome type 2 (LQT2), a condition associated with reduced IKr current. Four different mutation classes define the molecular mechanisms impairing hERG. Among them, Class 2 mutations determine hERG trafficking defects. Lumacaftor (LUM) is a drug acting on channel trafficking already successfully tested for cystic fibrosis and its safety profile is well known. We hypothesize that LUM might rescue also hERG trafficking defects in LQT2 and exert anti-arrhythmic effects...
July 21, 2017: European Heart Journal
https://www.readbyqxmd.com/read/29016848/mdm2-mediates-fmrp-and-gp1-mglur-dependent-protein-translation-and-neural-network-activity
#4
Dai-Chi Liu, Joseph Seimetz, Kwan Young Lee, Auinash Kalsotra, Hee Jung Chung, Hua Lu, Nien-Pei Tsai
Activating Group 1 (Gp1) metabotropic glutamate receptors (mGluRs), including mGluR1 and mGluR5, elicits translation-dependent neural plasticity mechanisms that are crucial to animal behavior and circuit development. Dysregulated Gp1 mGluR signaling has been observed in numerous neurological and psychiatric disorders. However, the molecular pathways underlying Gp1 mGluR-dependent plasticity mechanisms are complex and have been elusive. In this study, we identified a novel mechanism through which Gp1 mGluR mediates protein translation and neural plasticity...
October 15, 2017: Human Molecular Genetics
https://www.readbyqxmd.com/read/28988388/spicodyn-a-toolbox-for-the-analysis-of-neuronal-network-dynamics-and-connectivity-from-multi-site-spike-signal-recordings
#5
Vito Paolo Pastore, Aleksandar Godjoski, Sergio Martinoia, Paolo Massobrio
We implemented an automated and efficient open-source software for the analysis of multi-site neuronal spike signals. The software package, named SPICODYN, has been developed as a standalone windows GUI application, using C# programming language with Microsoft Visual Studio based on .NET framework 4.5 development environment. Accepted input data formats are HDF5, level 5 MAT and text files, containing recorded or generated time series spike signals data. SPICODYN processes such electrophysiological signals focusing on: spiking and bursting dynamics and functional-effective connectivity analysis...
October 7, 2017: Neuroinformatics
https://www.readbyqxmd.com/read/28979189/uncorrelated-neural-firing-in-mouse-visual-cortex-during-spontaneous-retinal-waves
#6
Matthew T Colonnese, Jing Shen, Yasunobu Murata
Synchronous firing among the elements of forming circuits is critical for stabilization of synapses. Understanding the nature of these local network interactions during development can inform models of circuit formation. Within cortex, spontaneous activity changes throughout development. Unlike the adult, early spontaneous activity occurs in discontinuous population bursts separated by long silent periods, suggesting a high degree of local synchrony. However, whether the micro-patterning of activity within early bursts is unique to this early age and specifically tuned for early development is poorly understood, particularly within the column...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/28975276/design-and-fabrication-of-a-three-dimensional-multi-electrode-array-for-neuron-electrophysiology
#7
Lei Zuo, Shifeng Yu, Clark A Briggs, Stanislaw Kantor, Jeffery Y Pan
Neural recording and stimulation with high spatial and temporal resolution are highly desirable in the study of neurocommunication and diseases. Planar multiple microelectrode arrays (MEA) or quasi-three-dimensional (3D) MEA with fixed height have been proposed by many researchers and become commercially available. In this paper, we present the design, fabrication, and test of a novel true 3D multiple electrode array for brain slice stimulation and recording. This MEA is composed of 105 microelectrodes with 50 μm diameter and 125 μm center-to-center spacing integrated in a 1...
December 1, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/28971674/3d-printed-molds-encompassing-carbon-composite-electrodes-to-conduct-multisite-monitoring-in-the-entire-colon
#8
Nirav Patel, Aidan Fagan-Murphy, Derek Covill, Bhavik Anil Patel
The activity of the colon is regulated by chemical signaling, of which serotonin (5-HT) is a key transmitter. Monitoring of mucosal 5-HT overflow has been achieved to date using microelectrodes on a small segment of colonic tissue; however, little is known if such measurements are reflective with regards to 5-HT signaling from the entire colon. This study focused on developing an electrochemical array device that could be utilized to conduct multisite measurements of 5-HT overflow from the entire colon. A 3D printed mold was fabricated that could house 6 multiwall carbon nanotube composite electrodes and provide a fixed distance between the electrodes and the tissue along the entire length of the colon...
October 10, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28956012/flecainide-ameliorates-arrhythmogenicity-through-ncx-flux-in-andersen-tawil-syndrome-ips-cell-derived-cardiomyocytes
#9
Yusuke Kuroda, Shinsuke Yuasa, Yasuhide Watanabe, Shogo Ito, Toru Egashira, Tomohisa Seki, Tetsuhisa Hattori, Seiko Ohno, Masaki Kodaira, Tomoyuki Suzuki, Hisayuki Hashimoto, Shinichiro Okata, Atsushi Tanaka, Yoshiyasu Aizawa, Mitsushige Murata, Takeshi Aiba, Naomasa Makita, Tetsushi Furukawa, Wataru Shimizu, Itsuo Kodama, Satoshi Ogawa, Norito Kokubun, Hitoshi Horigome, Minoru Horie, Kaichiro Kamiya, Keiichi Fukuda
Andersen-Tawil syndrome (ATS) is a rare inherited channelopathy. The cardiac phenotype in ATS is typified by a prominent U wave and ventricular arrhythmia. An effective treatment for this disease remains to be established. We reprogrammed somatic cells from three ATS patients to generate induced pluripotent stem cells (iPSCs). Multi-electrode arrays (MEAs) were used to record extracellular electrograms of iPSC-derived cardiomyocytes, revealing strong arrhythmic events in the ATS-iPSC-derived cardiomyocytes...
March 2017: Biochemistry and Biophysics Reports
https://www.readbyqxmd.com/read/28932183/plant-polyphenols-and-exendin-4-prevent-hyperactivity-and-tnf-%C3%AE-release-in-lps-treated-in-vitro-neuron-astrocyte-microglial-networks
#10
Francesca Gullo, Michela Ceriani, Alessia D'Aloia, Enzo Wanke, Andrew Constanti, Barbara Costa, Marzia Lecchi
Increasing evidence supports a decisive role for neuroinflammation in the neurodegenerative process of several central nervous system (CNS) disorders. Microglia are essential mediators of neuroinflammation and can regulate a broad spectrum of cellular responses by releasing reactive oxygen intermediates, nitric oxide, proteases, excitatory amino acids, and cytokines. We have recently shown that also in ex-vivo cortical networks of neurons, astrocytes and microglia, an increased level of tumor necrosis factor-alpha (TNF-α) was detected a few hours after exposure to the bacterial endotoxin lipopolysaccharide (LPS)...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28916033/ca-2-detection-utilising-algan-gan-transistors-with-ion-selective-polymer-membranes
#11
Mohsen Asadnia, Matthew Myers, Gilberto A Umana-Membreno, Tarun M Sanders, Umesh K Mishra, Brett D Nener, Murray V Baker, Giacinta Parish
We demonstrate highly selective and sensitive potentiometric ion sensors for calcium ion detection, operated without the use of a reference electrode. The sensors consist of AlGaN/GaN heterostructure-based transistor devices with chemical functionalisation of the gate area using poly (vinylchloride)-based (PVC) membranes having high selectivity towards calcium ions, Ca(2+). The sensors exhibited stable and rapid responses when introduced to various concentrations of Ca(2+). In both 0.01 M KCl and 0.01 M NaCl ionic strength buffer solutions, the sensors exhibited near Nernstian responses with detection limits of less than 10(-7) M, and a linear response range between 10(-7)-10(-2) M...
September 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28900397/the-comparative-efficiency-of-intraperitoneal-and-intravitreous-injection-of-hydrogen-rich-saline-against-n-methyl-n-nitrosourea-induced-retinal-degeneration-a-topographic-study
#12
Ye Tao, Tao Chen, Wei Fang, Zhongjun Yan, Qinghua Yang, Yifei Huang, Linjun Yu, Lingling Fan
Retinitis pigmentosa (RP) comprises a heterogeneous group of inherited retinal diseases leading to blindness. The present study explored the protective effects of hydrogen rich saline (HRS) against the photoreceptor degeneration in the N-Methyl-N-nitrosourea (MNU) administrated rat, a pharmacologically induced RP model. The therapeutic effects of intraperitoneal (IP) and intravitreous (IV) injections of HRS on regional retina was quantified via topographic measurements. The MNU administrated rats received IV or IP injections of HRS, and then they were subjected to electroretinography, multi electrode array, histological and immunohistochemistry examinations...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28888021/simultaneous-monitoring-of-single-cell-and-of-micro-organ-activity-by-pedot-pss-covered-multi-electrode-arrays
#13
Dimitrios A Koutsouras, Romain Perrier, Ariana Villarroel Marquez, Antoine Pirog, Eileen Pedraza, Eric Cloutet, Sylvie Renaud, Matthieu Raoux, George G Malliaras, Jochen Lang
Continuous and long-term monitoring of cellular and micro-organ activity is required for new insights into physiology and novel technologies such as Organs-on-Chip. Moreover, recent advances in stem cell technology and especially in the field of diabetes call for non-invasive approaches in quality testing of the large quantities of surrogate pancreatic islets to be generated. Electrical activity of such a micro-organ results in single cell action potentials (APs) of high frequency and in low frequency changes in local field potentials (slow potentials or SPs), reflecting coupled cell activity and overall organ physiology...
December 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28880155/identification-of-ion-currents-components-generating-field-potential-recorded-in-mea-from-hipsc-cm
#14
Fabien Raphel, Muriel Boulakia, Nejib Zemzemi, Yves Coudiere, Jean-Michel Guillon, Philippe Zitoun, Jean-Frederic Gerbeau
Multi Electrodes Arrays (MEAs) combined with cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) can enable high- or medium-throughput drug screening in safety pharmacology. This technology has recently attracted a lot of attention, in particular from an international initiative named CiPA. But it is currently limited by the difficulty to analyze the measured signals. We propose a strategy to analyze the signals acquired by the MEA and to automatically deduce the channels affected by the drug...
September 4, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28868212/high-density-mapping-of-brain-slices-using-a-large-multi-functional-high-density-cmos-microelectrode-array-system
#15
Vijay Viswam, Raziyeh Bounik, Amir Shadmani, Jelena Dragas, Marie Obien, Jan Müller, Yihui Chen, Andreas Hierlemann
We present a CMOS-based high-density microelectrode array (HD-MEA) system that enables high-density mapping of brain slices in-vitro with multiple readout modalities. The 4.48×2.43 mm(2) array consists of 59,760 micro-electrodes at 13.5 µm pitch (5487 electrodes/mm(2)). The overall system features 2048 action-potential, 32 local-field-potential and 32 current recording channels, 32 impedance-measurement and 28 neurotransmitter-detection channels and 16 voltage/current stimulation channels. The system enables real-time and label-free monitoring of position, size, morphology and electrical activity of brain slices...
June 2017: Int Solid State Sens Actuators Microsyst Conf
https://www.readbyqxmd.com/read/28863695/a-multi-frequency-electrical-impedance-tomography-system-for-real-time-2d-and-3d-imaging
#16
Yunjie Yang, Jiabin Jia
This paper presents the design and evaluation of a configurable, fast multi-frequency Electrical Impedance Tomography (mfEIT) system for real-time 2D and 3D imaging, particularly for biomedical imaging. The system integrates 32 electrode interfaces and the current frequency ranges from 10 kHz to 1 MHz. The system incorporates the following novel features. First, a fully adjustable multi-frequency current source with current monitoring function is designed. Second, a flexible switching scheme is developed for arbitrary sensing configuration and a semi-parallel data acquisition architecture is implemented for high-frame-rate data acquisition...
August 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28831071/stimulation-triggers-endogenous-activity-patterns-in-cultured-cortical-networks
#17
Valentina Pasquale, Sergio Martinoia, Michela Chiappalone
Cultures of dissociated cortical neurons represent a powerful trade-off between more realistic experimental models and abstract modeling approaches, allowing to investigate mechanisms of synchronized activity generation. These networks spontaneously alternate periods of high activity (i.e. network bursts) with periods of quiescence in a dynamic state which recalls the fluctuation of in vivo UP and DOWN states. Network bursts can also be elicited by external stimulation and their spatial propagation patterns tracked by means of multi-channel micro-electrode arrays...
August 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28813427/electromagneto-squeezing-rotational-flow-of-carbon-c-water-h2o-kerosene-oil-nanofluid-past-a-riga-plate-a-numerical-study
#18
Tasawar Hayat, Mumtaz Khan, Muhammad Ijaz Khan, Ahmed Alsaedi, Muhammad Ayub
This article predicts the electromagneto squeezing rotational flow of carbon-water nanofluid between two stretchable Riga plates. Riga plate is known as electromagnetic actuator which is the combination of permanent magnets and a span wise aligned array of alternating electrodes mounted on a plane surface. Mathematical model is developed for the flow problem with the phenomena of melting heat transfer, viscous dissipation and heat generation/absorption. Water and kerosene oil are utilized as the base fluids whereas single and multi-wall carbon nanotubes as the nanomaterials...
2017: PloS One
https://www.readbyqxmd.com/read/28806330/nanoci-nanotechnology-based-cochlear-implant-with-gapless-interface-to-auditory-neurons
#19
Pascal Senn, Marta Roccio, Stefan Hahnewald, Claudia Frick, Monika Kwiatkowska, Masaaki Ishikawa, Peter Bako, Hao Li, Fredrik Edin, Wei Liu, Helge Rask-Andersen, Ilmari Pyykkö, Jing Zou, Marika Mannerström, Herbert Keppner, Alexandra Homsy, Edith Laux, Miguel Llera, Jean-Paul Lellouche, Stella Ostrovsky, Ehud Banin, Aharon Gedanken, Nina Perkas, Ute Wank, Karl-Heinz Wiesmüller, Pavel Mistrík, Heval Benav, Carolyn Garnham, Claude Jolly, Filippo Gander, Peter Ulrich, Marcus Müller, Hubert Löwenheim
: Cochlear implants (CI) restore functional hearing in the majority of deaf patients. Despite the tremendous success of these devices, some limitations remain. The bottleneck for optimal electrical stimulation with CI is caused by the anatomical gap between the electrode array and the auditory neurons in the inner ear. As a consequence, current devices are limited through 1) low frequency resolution, hence sub-optimal sound quality and 2), large stimulation currents, hence high energy consumption (responsible for significant battery costs and for impeding the development of fully implantable systems)...
September 2017: Otology & Neurotology
https://www.readbyqxmd.com/read/28800169/global-multielectrode-contact-mapping-plus-ablation-with-a-single-catheter-preclinical-and-preliminary-experience-in-humans-with-atrial-fibrillation
#20
Hans Kottkamp, Fabian Moser, Andreas Rieger, Doreen Schreiber, Christian Pönisch, Monica Trofin
INTRODUCTION: One question for the technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the diagnostic mapping options of single-tip and basket catheters with the simplicity of the use of balloon catheters for ablation. Herein, we describe the first in-human experience with a single catheter offering such a complete solution. METHODS AND RESULTS: A new catheter (Globe(®) ) with a distal multielectrode array consisting of 16 ribs with 122 gold-plated electrodes was used...
August 11, 2017: Journal of Cardiovascular Electrophysiology
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