The Experts below are selected from a list of 5160 Experts worldwide ranked by ideXlab platform
Xinxia Cai - One of the best experts on this subject based on the ideXlab platform.
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mwcnts pedot pss nanocomposites modified Microelectrode Array for spatial dynamics recording of epileptic discharges in multi subregion of hippocampal slice
Sensors and Actuators B-chemical, 2021Co-Authors: Guihua Xiao, Yilin Song, Yuchuan Dai, Fei Gao, Yu Zhang, Xinxia CaiAbstract:Abstract The acute hippocampal slice is useful for understanding how epilepsy spatially initiates, propagates, and terminates in the hippocampus, which is vital to study the epileptic mechanism in it. However, it is challenging to detect the electrical signals of the main cell layer (the granular cell layer in the dentate gyrus (DG) and the pyramidal cell layer in CA1 and CA3a–c), which play an important role in epilepsy, because it is difficult to be accurately located by electrodes and typically show low throughput. In this study, a special in vitro Microelectrode Array (MEA) for rat hippocampal slices was fabricated. The recording sites of the MEA were designed along the main cell layer to record accurately the electrical signals of this layer in each hippocampal sub-region. A special “less-hydrophilic-MWCNTs/PEDOT:PSS modification method” for in vitro MEA was applied to deposit electrochemically the MWCNTs/PEDOT:PSS nanocomposites onto the surface of the Microelectrodes, which significantly improved their performance with low impedance (36.41 ± 3.07 kΩ), small phase delay (−41.2 ± 4.90°), high signal-to-noise ratio (S/N = 5.4) and good biocompatibility. The application of high-K+-ACSF and D-AP5 (NMDA receptor antagonist) showed a neural signal projection pathway of the epileptic discharges in the hippocampal slice. The epileptic discharges originated in CA3b, where the neurons acted as a pacemaker, and spread to CA1 and DG bi-directionally along the main cell layer. Moreover, the epileptic discharges spread backward (CA3b to DG) faster than forward (CA3b to CA1). The MEA provides a reliable and sensitive dedicated biosensor for hippocampal slices.
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implanted multichannel Microelectrode Array for simultaneous electrophysiological signal detection of hippocampal ca1 and dg neurons of simulated microgravity rats
Biochemical and Biophysical Research Communications, 2020Co-Authors: Hao Wang, Guihua Xiao, Yilin Song, Juntao Liu, Yuchuan Dai, Jingyu Xie, Fei Gao, Xinxia CaiAbstract:Abstract Microgravity can cause body fluids to accumulate in the brain, resulting in brain damage. There are few studies that focus on the detection of electrophysiological signals in simulated microgravity rats, and the precise mechanisms are unknown. In this study, a new device was established to investigate the influence of microgravity on hippocampal neurons. A 16-channel Microelectrode Array was fabricated for in vivo multichannel electrophysiological recordings. In these experiments, Microelectrode Array was inserted into normal, 28-day tail suspension model, and 3-day recovered after modulation rats to record electrophysiological signals in the CA1 and DG regions of the hippocampus. Through analysis of electrophysiological signals, we obtained the following results: (1) spike signals of model rats sporadically showed brief periods of suspension involving most of the recorded neurons, which corresponded to slow and smooth peaks in local field potentials. For model rats, the firing rate was reduced, and the power in the frequency spectrum was concentrated in the slow frequency band (0–1 Hz); (2) after the detected hippocampal cells divided into pyramidal cells and interneurons, the spike duration of pyramidal cells showed remarkable latency, and their average firing rates showed a more significant decrease compared to interneurons. These results demonstrate that the hippocampal neurons were impaired after modulation in the cellular dimension, and pyramidal cells were more susceptible than interneurons.
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in vivo optogenetic modulation with simultaneous neural detection using Microelectrode Array integrated with optical fiber
Sensors, 2020Co-Authors: Penghui Fan, Yilin Song, Hao Wang, Yuchuan Dai, Jingyu Xie, Yiding Wang, Xinxia CaiAbstract:The detection of neuroelectrophysiology while performing optogenetic modulation can provide more reliable and useful information for neural research. In this study, an optical fiber and a Microelectrode Array were integrated through hot-melt adhesive bonding, which combined optogenetics and electrophysiological detection technology to achieve neuromodulation and neuronal activity recording. We carried out the experiments on the activation and electrophysiological detection of infected neurons at the depth range of 900-1250 μm in the brain which covers hippocampal CA1 and a part of the upper cortical area, analyzed a possible local inhibition circuit by combining opotogenetic modulation and electrophysiological characteristics and explored the effects of different optical patterns and light powers on the neuromodulation. It was found that optogenetics, combined with neural recording technology, could provide more information and ideas for neural circuit recognition. In this study, the optical stimulation with low frequency and large duty cycle induces more intense neuronal activity and larger light power induced more action potentials of neurons within a certain power range (1.032 mW-1.584 mW). The present study provided an efficient method for the detection and modulation of neurons in vivo and an effective tool to study neural circuit in the brain.
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in situ detection of neurotransmitters and epileptiform electrophysiology activity in awake mice brains using a nanocomposites modified Microelectrode Array
Sensors and Actuators B-chemical, 2019Co-Authors: Guihua Xiao, Yilin Song, Jingyu Xie, Fei Gao, Yu Zhang, Longze Sha, Yan Shen, Xinxia CaiAbstract:Abstract A novel nanocomposites modified Microelectrode Array (MEA) was designed and fabricated for in situ detection of neurotransmitters (glutamate and dopamine) and electrophysiology activity. The MEAs were implanted into the hippocampus of four epileptic mice to detect the neuron activity along with their behaviours. Six spontaneous seizures were recorded, with each seizure having 5 periods. From the normal to the pre-seizure period, both the concentrations of neurotransmitters and the intensities of electrophysiology activities increased by 20%–70%. During the seizure period, the glutamate level dramatically increased to approximately 10 times its normal, while the dopamine level sharply decreased to approximately one third of the normal; the spike firing rate and the power of the local field potential significantly increased more than three-fold. During the inhibitory period, neurotransmitters and electrophysiology activities were significantly inhibited, and then they gradually returned to normal. These results revealed that seizures were highly correlated with glutamate, dopamine and electrophysiology activity and abnormalities in the neuron activity appeared earlier than any abnormal behaviour. Moreover, synchronized changes of these multiple signals in the pre-seizure period could be used to predict seizures. This novel MEA provides an effective technology and a new perspective for understanding the epileptic mechanism.
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a silicon based implantable Microelectrode Array for electrophysiological and dopamine recording from cortex to striatum in the non human primate brain
Biosensors and Bioelectronics, 2016Co-Authors: Song Zhang, Yilin Song, Mixia Wang, Zhiming Zhang, Xinyi Fan, Xianteng Song, Ping Zhuang, Feng Yue, Piu Chan, Xinxia CaiAbstract:Dual-mode, multielectrode recordings have become routine in rodent neuroscience research and have recently been adapted to the non-human primate. However, robust and reliable application of acute, multielectrode recording methods in monkeys especially for deep brain nucleus research remains a challenge. In this paper, We described a low cost silicon based 16-site implantable Microelectrode Array (MEA) chip fabricated by standard lithography technology for in vivo test. The Array was 25mm long and designed to use in non-human primate models, for electrophysiological and electrochemical recording. We presented a detailed protocol for Array fabrication, then showed that the device can record Spikes, LFPs and dopamine (DA) variation continuously from cortex to striatum in an esthetized monkey. Though our experiment, high-quality electrophysiological signals were obtained from the animal. Across any given Microelectrode, spike amplitudes ranged from 70 to 300μV peak to peak, with a mean signal-to-noise ratio of better than 5:1. Calibration results showed the MEA probe had high sensitivity and good selectivity for DA. The DA concentration changed from 42.8 to 481.6μM when the MEA probe inserted from cortex into deep brain nucleus of striatum, which reflected the inhomogeneous distribution of DA in brains. Compared with existing methods allowing single mode (electrophysiology or electrochemistry) recording. This system is designed explicitly for dual-mode recording to meet the challenges of recording in non-human primates.
Yilin Song - One of the best experts on this subject based on the ideXlab platform.
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mwcnts pedot pss nanocomposites modified Microelectrode Array for spatial dynamics recording of epileptic discharges in multi subregion of hippocampal slice
Sensors and Actuators B-chemical, 2021Co-Authors: Guihua Xiao, Yilin Song, Yuchuan Dai, Fei Gao, Yu Zhang, Xinxia CaiAbstract:Abstract The acute hippocampal slice is useful for understanding how epilepsy spatially initiates, propagates, and terminates in the hippocampus, which is vital to study the epileptic mechanism in it. However, it is challenging to detect the electrical signals of the main cell layer (the granular cell layer in the dentate gyrus (DG) and the pyramidal cell layer in CA1 and CA3a–c), which play an important role in epilepsy, because it is difficult to be accurately located by electrodes and typically show low throughput. In this study, a special in vitro Microelectrode Array (MEA) for rat hippocampal slices was fabricated. The recording sites of the MEA were designed along the main cell layer to record accurately the electrical signals of this layer in each hippocampal sub-region. A special “less-hydrophilic-MWCNTs/PEDOT:PSS modification method” for in vitro MEA was applied to deposit electrochemically the MWCNTs/PEDOT:PSS nanocomposites onto the surface of the Microelectrodes, which significantly improved their performance with low impedance (36.41 ± 3.07 kΩ), small phase delay (−41.2 ± 4.90°), high signal-to-noise ratio (S/N = 5.4) and good biocompatibility. The application of high-K+-ACSF and D-AP5 (NMDA receptor antagonist) showed a neural signal projection pathway of the epileptic discharges in the hippocampal slice. The epileptic discharges originated in CA3b, where the neurons acted as a pacemaker, and spread to CA1 and DG bi-directionally along the main cell layer. Moreover, the epileptic discharges spread backward (CA3b to DG) faster than forward (CA3b to CA1). The MEA provides a reliable and sensitive dedicated biosensor for hippocampal slices.
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implanted multichannel Microelectrode Array for simultaneous electrophysiological signal detection of hippocampal ca1 and dg neurons of simulated microgravity rats
Biochemical and Biophysical Research Communications, 2020Co-Authors: Hao Wang, Guihua Xiao, Yilin Song, Juntao Liu, Yuchuan Dai, Jingyu Xie, Fei Gao, Xinxia CaiAbstract:Abstract Microgravity can cause body fluids to accumulate in the brain, resulting in brain damage. There are few studies that focus on the detection of electrophysiological signals in simulated microgravity rats, and the precise mechanisms are unknown. In this study, a new device was established to investigate the influence of microgravity on hippocampal neurons. A 16-channel Microelectrode Array was fabricated for in vivo multichannel electrophysiological recordings. In these experiments, Microelectrode Array was inserted into normal, 28-day tail suspension model, and 3-day recovered after modulation rats to record electrophysiological signals in the CA1 and DG regions of the hippocampus. Through analysis of electrophysiological signals, we obtained the following results: (1) spike signals of model rats sporadically showed brief periods of suspension involving most of the recorded neurons, which corresponded to slow and smooth peaks in local field potentials. For model rats, the firing rate was reduced, and the power in the frequency spectrum was concentrated in the slow frequency band (0–1 Hz); (2) after the detected hippocampal cells divided into pyramidal cells and interneurons, the spike duration of pyramidal cells showed remarkable latency, and their average firing rates showed a more significant decrease compared to interneurons. These results demonstrate that the hippocampal neurons were impaired after modulation in the cellular dimension, and pyramidal cells were more susceptible than interneurons.
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in vivo optogenetic modulation with simultaneous neural detection using Microelectrode Array integrated with optical fiber
Sensors, 2020Co-Authors: Penghui Fan, Yilin Song, Hao Wang, Yuchuan Dai, Jingyu Xie, Yiding Wang, Xinxia CaiAbstract:The detection of neuroelectrophysiology while performing optogenetic modulation can provide more reliable and useful information for neural research. In this study, an optical fiber and a Microelectrode Array were integrated through hot-melt adhesive bonding, which combined optogenetics and electrophysiological detection technology to achieve neuromodulation and neuronal activity recording. We carried out the experiments on the activation and electrophysiological detection of infected neurons at the depth range of 900-1250 μm in the brain which covers hippocampal CA1 and a part of the upper cortical area, analyzed a possible local inhibition circuit by combining opotogenetic modulation and electrophysiological characteristics and explored the effects of different optical patterns and light powers on the neuromodulation. It was found that optogenetics, combined with neural recording technology, could provide more information and ideas for neural circuit recognition. In this study, the optical stimulation with low frequency and large duty cycle induces more intense neuronal activity and larger light power induced more action potentials of neurons within a certain power range (1.032 mW-1.584 mW). The present study provided an efficient method for the detection and modulation of neurons in vivo and an effective tool to study neural circuit in the brain.
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in situ detection of neurotransmitters and epileptiform electrophysiology activity in awake mice brains using a nanocomposites modified Microelectrode Array
Sensors and Actuators B-chemical, 2019Co-Authors: Guihua Xiao, Yilin Song, Jingyu Xie, Fei Gao, Yu Zhang, Longze Sha, Yan Shen, Xinxia CaiAbstract:Abstract A novel nanocomposites modified Microelectrode Array (MEA) was designed and fabricated for in situ detection of neurotransmitters (glutamate and dopamine) and electrophysiology activity. The MEAs were implanted into the hippocampus of four epileptic mice to detect the neuron activity along with their behaviours. Six spontaneous seizures were recorded, with each seizure having 5 periods. From the normal to the pre-seizure period, both the concentrations of neurotransmitters and the intensities of electrophysiology activities increased by 20%–70%. During the seizure period, the glutamate level dramatically increased to approximately 10 times its normal, while the dopamine level sharply decreased to approximately one third of the normal; the spike firing rate and the power of the local field potential significantly increased more than three-fold. During the inhibitory period, neurotransmitters and electrophysiology activities were significantly inhibited, and then they gradually returned to normal. These results revealed that seizures were highly correlated with glutamate, dopamine and electrophysiology activity and abnormalities in the neuron activity appeared earlier than any abnormal behaviour. Moreover, synchronized changes of these multiple signals in the pre-seizure period could be used to predict seizures. This novel MEA provides an effective technology and a new perspective for understanding the epileptic mechanism.
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a silicon based implantable Microelectrode Array for electrophysiological and dopamine recording from cortex to striatum in the non human primate brain
Biosensors and Bioelectronics, 2016Co-Authors: Song Zhang, Yilin Song, Mixia Wang, Zhiming Zhang, Xinyi Fan, Xianteng Song, Ping Zhuang, Feng Yue, Piu Chan, Xinxia CaiAbstract:Dual-mode, multielectrode recordings have become routine in rodent neuroscience research and have recently been adapted to the non-human primate. However, robust and reliable application of acute, multielectrode recording methods in monkeys especially for deep brain nucleus research remains a challenge. In this paper, We described a low cost silicon based 16-site implantable Microelectrode Array (MEA) chip fabricated by standard lithography technology for in vivo test. The Array was 25mm long and designed to use in non-human primate models, for electrophysiological and electrochemical recording. We presented a detailed protocol for Array fabrication, then showed that the device can record Spikes, LFPs and dopamine (DA) variation continuously from cortex to striatum in an esthetized monkey. Though our experiment, high-quality electrophysiological signals were obtained from the animal. Across any given Microelectrode, spike amplitudes ranged from 70 to 300μV peak to peak, with a mean signal-to-noise ratio of better than 5:1. Calibration results showed the MEA probe had high sensitivity and good selectivity for DA. The DA concentration changed from 42.8 to 481.6μM when the MEA probe inserted from cortex into deep brain nucleus of striatum, which reflected the inhomogeneous distribution of DA in brains. Compared with existing methods allowing single mode (electrophysiology or electrochemistry) recording. This system is designed explicitly for dual-mode recording to meet the challenges of recording in non-human primates.
Urs Frey - One of the best experts on this subject based on the ideXlab platform.
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Combination of High-density Microelectrode Array and Patch Clamp Recordings to Enable Studies of Multisynaptic Integration.
Scientific reports, 2017Co-Authors: David Jackel, Urs Frey, Felix Franke, Douglas J Bakkum, Jan Muller, Milos Radivojevic, Thomas L. Russell, Andreas HierlemannAbstract:We present a novel, all-electric approach to record and to precisely control the activity of tens of individual presynaptic neurons. The method allows for parallel mapping of the efficacy of multiple synapses and of the resulting dynamics of postsynaptic neurons in a cortical culture. For the measurements, we combine an extracellular high-density Microelectrode Array, featuring 11’000 electrodes for extracellular recording and stimulation, with intracellular patch-clamp recording. We are able to identify the contributions of individual presynaptic neurons - including inhibitory and excitatory synaptic inputs - to postsynaptic potentials, which enables us to study dendritic integration. Since the electrical stimuli can be controlled at microsecond resolution, our method enables to evoke action potentials at tens of presynaptic cells in precisely orchestrated sequences of high reliability and minimum jitter. We demonstrate the potential of this method by evoking short- and long-term synaptic plasticity through manipulation of multiple synaptic inputs to a specific neuron.
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a Microelectrode Array with 8 640 electrodes enabling simultaneous full frame readout at 6 5 kfps and 112 channel switch matrix readout at 20 ks s
Symposium on VLSI Circuits, 2016Co-Authors: X Yuan, Andreas Hierlemann, Torsten Bullmann, Yihui Chen, J Juyon, M Durbino, Alexander Stettler, Urs FreyAbstract:CMOS Microelectrode Arrays allow for recording from neurons at thousands of sites. Here, we introduce the concept of a ‘dual-mode operation’ Microelectrode Array, leveraging the advantages of full-frame scanning and switch-matrix Array architectures into a single device. The chip was fabricated in 0.18 µm CMOS technology. Measured noise levels were 11.1 µV rms for full-frame scanning and 1.6 µV rms for switch-matrix mode at 3.3 µW and 38.1 µW per channel power consumption. Recordings of electrical activity from cultured neurons have been successfully conducted.
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revealing neuronal function through Microelectrode Array recordings
Frontiers in Neuroscience, 2015Co-Authors: Marie Engelene J Obien, Urs Frey, Kosmas Deligkaris, Torsten Bullmann, Douglas J BakkumAbstract:Microelectrode Arrays and microprobes have been widely utilized to measure neuronal activity, both in vitro and in vivo. The key advantage is the capability to record and stimulate neurons at multiple sites simultaneously. However, unlike the single-cell or single-channel resolution of intracellular recording, Microelectrodes detect signals from all possible sources around the sensor. Here, we review the current understanding of Microelectrode signals and the techniques for analyzing them. We introduce the ongoing advancements in Microelectrode technology, with focus on achieving higher resolution and quality of recordings by means of monolithic integration with on-chip circuitry. We show how recent advanced Microelectrode Array measurement methods facilitate the understanding of single neurons as well as network function.
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a 1024 channel cmos Microelectrode Array with 26 400 electrodes for recording and stimulation of electrogenic cells in vitro
IEEE Journal of Solid-state Circuits, 2014Co-Authors: Matilde Ballini, Urs Frey, Jan Muller, Paolo Livi, Yihui Chen, Amir Shadmani, Ian L Jones, Alexander Stettler, Vijay Viswam, David JackelAbstract:To advance our understanding of the functioning of neuronal ensembles, systems are needed to enable simultaneous recording from a large number of individual neurons at high spatiotemporal resolution and good signal-to-noise ratio. Moreover, stimulation capability is highly desirable for investigating, for example, plasticity and learning processes. Here, we present a Microelectrode Array (MEA) system on a single CMOS die for in vitro recording and stimulation. The system incorporates 26,400 platinum electrodes, fabricated by in-house post-processing, over a large sensing area (3.85 × 2.10 mm2) with sub-cellular spatial resolution (pitch of 17.5 μm). Owing to an area and power efficient implementation, we were able to integrate 1024 readout channels on chip to record extracellular signals from a user-specified selection of electrodes. These channels feature noise values of 2.4 μVrms in the action-potential band (300 Hz-10 kHz) and 5.4 μVrms in the local-field-potential band (1 Hz-300 Hz), and provide programmable gain (up to 78 dB) to accommodate various biological preparations. Amplified and filtered signals are digitized by 10 bit parallel single-slope ADCs at 20 kSamples/s. The system also includes 32 stimulation units, which can elicit neural spikes through either current or voltage pulses. The chip consumes only 75 mW in total, which obviates the need of active cooling even for sensitive cell cultures.
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a 1024 channel cmos Microelectrode Array system with 26 400 electrodes for recording and stimulation of electro active cells in vitro
Symposium on VLSI Circuits, 2013Co-Authors: Matilde Ballini, Urs Frey, Michele Fiscella, Jan Muller, Paolo Livi, Yihui Chen, Amir Shadmani, Ian L Jones, Wei Gong, Milos RadivojevicAbstract:We report on a CMOS Microelectrode Array system chip for recording and stimulation of electrogenic cell cultures and tissues, featuring a sensing area of 8.09 mm2, composed of 26'400 electrodes at 17.5 μm pitch. A user-configurable selection of the electrodes can be routed to 32 stimulation units and to 1024 recording channels with 2.4 μVrms input-referred noise and 10-bit 20-kS/s A/D conversion. The system offers a versatile platform with excellent signal characteristics for a wide range of electrophysiological recordings.
Andreas Hierlemann - One of the best experts on this subject based on the ideXlab platform.
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Combination of High-density Microelectrode Array and Patch Clamp Recordings to Enable Studies of Multisynaptic Integration.
Scientific reports, 2017Co-Authors: David Jackel, Urs Frey, Felix Franke, Douglas J Bakkum, Jan Muller, Milos Radivojevic, Thomas L. Russell, Andreas HierlemannAbstract:We present a novel, all-electric approach to record and to precisely control the activity of tens of individual presynaptic neurons. The method allows for parallel mapping of the efficacy of multiple synapses and of the resulting dynamics of postsynaptic neurons in a cortical culture. For the measurements, we combine an extracellular high-density Microelectrode Array, featuring 11’000 electrodes for extracellular recording and stimulation, with intracellular patch-clamp recording. We are able to identify the contributions of individual presynaptic neurons - including inhibitory and excitatory synaptic inputs - to postsynaptic potentials, which enables us to study dendritic integration. Since the electrical stimuli can be controlled at microsecond resolution, our method enables to evoke action potentials at tens of presynaptic cells in precisely orchestrated sequences of high reliability and minimum jitter. We demonstrate the potential of this method by evoking short- and long-term synaptic plasticity through manipulation of multiple synaptic inputs to a specific neuron.
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a Microelectrode Array with 8 640 electrodes enabling simultaneous full frame readout at 6 5 kfps and 112 channel switch matrix readout at 20 ks s
Symposium on VLSI Circuits, 2016Co-Authors: X Yuan, Andreas Hierlemann, Torsten Bullmann, Yihui Chen, J Juyon, M Durbino, Alexander Stettler, Urs FreyAbstract:CMOS Microelectrode Arrays allow for recording from neurons at thousands of sites. Here, we introduce the concept of a ‘dual-mode operation’ Microelectrode Array, leveraging the advantages of full-frame scanning and switch-matrix Array architectures into a single device. The chip was fabricated in 0.18 µm CMOS technology. Measured noise levels were 11.1 µV rms for full-frame scanning and 1.6 µV rms for switch-matrix mode at 3.3 µW and 38.1 µW per channel power consumption. Recordings of electrical activity from cultured neurons have been successfully conducted.
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recording from defined populations of retinal ganglion cells using a high density cmos integrated Microelectrode Array with real time switchable electrode selection
Journal of Neuroscience Methods, 2012Co-Authors: Michele Fiscella, Urs Frey, David Jackel, Douglas J Bakkum, Jan Muller, Ian L Jones, Karl Farrow, Peter Hantz, Botond Roska, Andreas HierlemannAbstract:Abstract In order to understand how retinal circuits encode visual scenes, the neural activity of defined populations of retinal ganglion cells (RGCs) has to be investigated. Here we report on a method for stimulating, detecting, and subsequently targeting defined populations of RGCs. The possibility to select a distinct population of RGCs for extracellular recording enables the design of experiments that can increase our understanding of how these neurons extract precise spatio-temporal features from the visual scene, and how the brain interprets retinal signals. We used light stimulation to elicit a response from physiologically distinct types of RGCs and then utilized the dynamic-configurability capabilities of a microelectronics-based high-density Microelectrode Array (MEA) to record their synchronous action potentials. The layout characteristics of the MEA made it possible to stimulate and record from multiple, highly overlapping RGCs simultaneously without light-induced artifacts. The high-density of electrodes and the high signal-to-noise ratio of the MEA circuitry allowed for recording of the activity of each RGC on 14 ± 7 electrodes. The spatial features of the electrical activity of each RGC greatly facilitated spike sorting. We were thus able to localize, identify and record from defined RGCs within a region of mouse retina. In addition, we stimulated and recorded from genetically modified RGCs to demonstrate the applicability of optogenetic methods, which introduces an additional feature to target a defined cell type. The developed methodologies can likewise be applied to other neuronal preparations including brain slices or cultured neurons.
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applicability of independent component analysis on high density Microelectrode Array recordings
Journal of Neurophysiology, 2012Co-Authors: David Jackel, Urs Frey, Michele Fiscella, Felix Franke, Andreas HierlemannAbstract:Emerging complementary metal oxide semiconductor (CMOS)-based, high-density Microelectrode Array (HD-MEA) devices provide high spatial resolution at subcellular level and a large number of readout ...
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an 11k electrode 126 channel high density Microelectrode Array to interact with electrogenic cells
International Solid-State Circuits Conference, 2007Co-Authors: Urs Frey, Sadik Hafizovic, F Heer, R Pedron, F Greve, J Sedivy, K U Kirstein, Andreas HierlemannAbstract:A Microelectrode Array allows an arbitrary group of 126 electrodes to be selected from a total of 11,016 in order to do cell or neural recordings from areas of interest with 18 mum spatial resolution and 2.4 muv input-referred noise. Signals are amplified by 0 to 80dB, bandpass filtered (0.3 to 4kHz), and finally digitized (20kS/s, 8b). Example recordings from acute brain slices are shown
Richard A Normann - One of the best experts on this subject based on the ideXlab platform.
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a new high density 25 electrodes mm2 penetrating Microelectrode Array for recording and stimulating sub millimeter neuroanatomical structures
Journal of Neural Engineering, 2013Co-Authors: Heather A C Wark, Eduardo Fernandez, Patrick A Tresco, Rohit Sharma, Kiran S Mathews, Je Min Yoo, B Christensen, Loren Rieth, Florian Solzbacher, Richard A NormannAbstract:Objective. Among the currently available neural interface devices, there has been a need for a penetrating electrode Array with a high electrode-count and high electrode-density (the number of electrodes/mm 2 ) that can be used for electrophysiological studies of sub-millimeter neuroanatomical structures. We have developed such a penetrating Microelectrode Array with both a high electrode-density (25 electrodes/mm 2 ) and high electrode-count (up to 96 electrodes) for small nervous system structures, based on the existing Utah Slanted Electrode Array (USEA). Such high electrode-density Arrays are expected to provide greater access to nerve fibers than the conventionally spaced USEA especially in small diameter nerves. Approach. One concern for such high density Microelectrode Arrays is that they may cause a nerve crush-type injury upon implantation. We evaluated this possibility during acute (<10 h) in vivo experiments with electrode Arrays implanted into small diameter peripheral nerves of anesthetized rats (sciatic nerve) and cats (pudendal nerve). Main results. Successful intrafascicular implantation and viable nerve function was demonstrated via microstimulation, single-unit recordings and histological analysis. Measurements of the electrode impedances and quantified electrode dimensions demonstrated fabrication quality. The results of these experiments show that such high density neural interfaces can be implanted acutely into neural tissue without causing a complete nerve crush injury, while mediating intrafascicular access to fibers in small diameter peripheral nerves. Significance. This new penetrating Microelectrode Array has characteristics un-matched by other neural interface devices currently available for peripheral nervous system neurophysiological research.
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acute Microelectrode Array implantation into human neocortex preliminary technique and histological considerations
Neurosurgical Focus, 2006Co-Authors: Paul A House, Joel D Macdonald, Patrick A Tresco, Richard A NormannAbstract:Object Researchers at The Center for Neural Interfaces at the University of Utah have designed and produced a silicon-based high-density Microelectrode Array that has been used successfully in mammalian models. The authors investigate the ability to transfer Array insertion techniques to humans and examine the acute response of human cortical tissue to Array implantation. Methods Six patients who were scheduled to undergo temporal lobectomy surgery were enrolled in an Institutional Review Board–approved protocol. Before the patients underwent lateral temporal cortical resection, one or two high-density Microelectrode Arrays were implanted in each individual by using a pneumatic insertion device. Cortical tissue was then excised and preserved in formalin. The specimens were sectioned and stained for histological examination. Pneumatic insertion of a Microelectrode Array into human cortex in the operating room was feasible. There were no clinical complications associated with implantation and no evidence of...
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long term stimulation and recording with a penetrating Microelectrode Array in cat sciatic nerve
IEEE Transactions on Biomedical Engineering, 2004Co-Authors: Almut Branner, Eduardo Fernandez, R B Stein, Yoichiro Aoyagi, Richard A NormannAbstract:We studied the consequences of long-term implantation of a penetrating Microelectrode Array in peripheral nerve over the time course of 4-6 mo. Electrode Arrays without lead wires were implanted to test the ability of different containment systems to protect the Array and nerve during contractions of surrounding muscles. Treadmill walking was monitored and the animals showed no functional deficits as a result of implantation. In a different set of experiments, electrodes with lead wires were implanted for up to 7 mo and the animals were tested at 2-4 week intervals at which time stimulation thresholds and recorded sensory activity were monitored for every electrode. It was shown that surgical technique highly affected the long-term stimulation results. Results between measurement sessions were compared, and in the best case, the stimulation properties stabilized in 80% of the electrodes over the course of the experiment (162 days). The recorded sensory signals, however, were not stable over time. A histological analysis performed on all implanted tissues indicated that the morphology and fiber density of the nerve around the electrodes were normal.