scholarly journals A modular high-density 294-channel μECoG system on macaque vlPFC for auditory cognitive decoding

2019 ◽  
Author(s):  
Chia-Han Chiang ◽  
Jaejin Lee ◽  
Charles Wang ◽  
Ashley J. Williams ◽  
Timothy H. Lucas ◽  
...  
Keyword(s):  
High Resolution ◽  
Auditory Perception ◽  
Large Scale ◽  
Electrode Array ◽  
Auditory Pathway ◽  
Sound Level ◽  
High Density ◽  
Electrode Arrays ◽  
Spatiotemporal Resolution

AbstractOBJECTIVEA fundamental goal of the auditory system is to parse the auditory environment into distinct perceptual representations. Auditory perception is mediated by the ventral auditory pathway, which includes the ventrolateral prefrontal cortex (vlPFC) late. Because large-scale recordings of auditory signals are quite rare, the spatiotemporal resolution of the neuronal code that underlies vlPFC’s contribution to auditory perception has not been fully elucidated. Therefore, we developed a modular, chronic, high-resolution, multi-electrode array system with long-term viability.APPROACHWe molded three separate μECoG arrays into one and implanted this system in a non-human primate. A custom 3D-printed titanium chamber was mounted on left hemisphere. The molded 294-contact μECoG array was implanted subdurally over vlPFC. μECoG activity was recorded while the monkey participated in a “hearing-in-noise” task in which they reported hearing a “target” vocalization from a background “chorus” of vocalizations. We titrated task difficulty by varying the sound level of the target vocalization, relative to the chorus (target-to-chorus ratio, TCr).MAIN RESULTSWe decoded the TCr and the monkey’s behavioral choices from the μECoG signal. We analyzed decoding capacity as a function of neuronal frequency band, spatial resolution, and time from implantation. Over a one-year period, we were successfully able to record μECoG signals. Although we found significant decoding with as few as two electrodes, we found near-perfect decoding with ∼16 electrodes. Decoding further improved when we included more electrodes. Finally, because the decoding capacity of individual electrodes varied on a day-by-day basis, high-density electrode arrays ensure robust decoding in the long term.SIGNIFICANCEOur results demonstrate the utility and robustness of high-resolution chronic µECoG recording. We developed a new high-resolution surface electrode array that can be scaled to cover larger cortical areas without increasing the chamber footprint.

scholarly journals A Gel‐Free Ti 3 C 2 T x ‐Based Electrode Array for High‐Density, High‐Resolution Surface Electromyography

2020 ◽  
Vol 5 (8) ◽  
pp. 2000325 ◽  
Author(s):  
Brendan B. Murphy ◽  
Patrick J. Mulcahey ◽  
Nicolette Driscoll ◽  
Andrew G. Richardson ◽  
Gregory T. Robbins ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Electromyography ◽  
Electrode Array ◽  
High Density

scholarly journals Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Dong-Wook Park ◽  
Amelia A. Schendel ◽  
Solomon Mikael ◽  
Sarah K. Brodnick ◽  
Thomas J. Richner ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Electrode Array ◽  
Electrode Arrays ◽  
Neural Imaging ◽  
Brain Surface ◽  
Array Technology ◽  
Micro Electrode Arrays ◽  
The Brain

Abstract Neural micro-electrode arrays that are transparent over a broad wavelength spectrum from ultraviolet to infrared could allow for simultaneous electrophysiology and optical imaging, as well as optogenetic modulation of the underlying brain tissue. The long-term biocompatibility and reliability of neural micro-electrodes also require their mechanical flexibility and compliance with soft tissues. Here we present a graphene-based, carbon-layered electrode array (CLEAR) device, which can be implanted on the brain surface in rodents for high-resolution neurophysiological recording. We characterize optical transparency of the device at >90% transmission over the ultraviolet to infrared spectrum and demonstrate its utility through optical interface experiments that use this broad spectrum transparency. These include optogenetic activation of focal cortical areas directly beneath electrodes, in vivo imaging of the cortical vasculature via fluorescence microscopy and 3D optical coherence tomography. This study demonstrates an array of interfacing abilities of the CLEAR device and its utility for neural applications.

Polytrodes: High-Density Silicon Electrode Arrays for Large-Scale Multiunit Recording

2005 ◽  
Vol 93 (5) ◽  
pp. 2987-3000 ◽  
Author(s):  
Timothy J. Blanche ◽  
Martin A. Spacek ◽  
Jamille F. Hetke ◽  
Nicholas V. Swindale
Keyword(s):  
Large Scale ◽  
High Density ◽  
Clustering Methods ◽  
Electrode Arrays ◽  
Large Numbers ◽  
High Bandwidth ◽  
Electrode Positioning ◽  
Multiunit Recording ◽  
Silicon Based

We developed a variety of 54-channel high-density silicon electrode arrays (polytrodes) designed to record from large numbers of neurons spanning millimeters of brain. In cat visual cortex, it was possible to make simultaneous recordings from >100 well-isolated neurons. Using standard clustering methods, polytrodes provide a quality of single-unit isolation that surpasses that attainable with tetrodes. Guidelines for successful in vivo recording and precise electrode positioning are described. We also describe a high-bandwidth continuous data-acquisition system designed specifically for polytrodes and an automated impedance meter for testing polytrode site integrity. Despite having smaller interconnect pitches than earlier silicon-based electrodes of this type, these polytrodes have negligible channel crosstalk, comparable reliability, and low site impedances and are capable of making high-fidelity multiunit recordings with minimal tissue damage. The relatively benign nature of planar electrode arrays is evident both histologically and in experiments where the polytrode was repeatedly advanced and retracted hundreds of microns over periods of many hours. It was possible to maintain stable recordings from active neurons adjacent to the polytrode without change in their absolute positions, neurophysiological or receptive field properties.

scholarly journals A High-Resolution Flood Inundation Archive (2016–the Present) from Sentinel-1 SAR Imagery over CONUS

2021 ◽  
pp. 1-40
Author(s):  
Qing Yang ◽  
Xinyi Shen ◽  
Emmanouil N. Anagnostou ◽  
Chongxun Mo ◽  
Jack R. Eggleston ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Weather Conditions ◽  
Automated System ◽  
Flood Inundation ◽  
Spatiotemporal Resolution ◽  
Dynamic Surface ◽  
Critical Success ◽  
Sar Imagery ◽  
Mapping Techniques

AbstractMost existing inundation inventories are based on surveys, news, or passive remote sensing imagery. Affected by spatiotemporal resolution or weather conditions, these inventories are limited in spatial details or coverage. Satellite Synthetic Aperture Radar (SAR) data has recently enabled flood mapping at unprecedented spatiotemporal resolution. However, the bottleneck in producing SAR-based flood maps is the requirement of expert manual processing to maintain acceptable accuracy by most SAR-driven mapping techniques. To fill the vacancy, we generate a high-resolution (10 m) flood inundation dataset over the contiguous United States (CONUS) from nearly the entire Sentinel-1 SAR archive (from January 2016 to the present), using a recently developed automated Radar Produced Inundation Diary (RAPID) system. RAPID uses U.S. Geological Survey (USGS) water watch system and accumulated precipitation to identify SAR images that potentially overlap a flood event. The dataset includes inundation events with the temporal scale from several days to months. Concluded from all 559 overlapping images in the period from 2016 to the first half of 2019, the comparison of the proposed dataset against the USGS Dynamic Surface Water Extent (DSWE) product yields an overall, user, producer agreements, and critical success index of 99.06%, 87.63%, 91.76%, and 81.23%, respectively, demonstrating the high accuracy of the proposed dataset and the robustness of the automated system. We anticipate this archive to facilitate many applications, including large-scale flood loss and risk assessment, and inundation model calibration and validation.

scholarly journals Intraoperative microseizure detection using a high-density micro-electrocorticography electrode array

2021 ◽  
Author(s):  
James Sun ◽  
Katrina Barth ◽  
Shaoyu Qiao ◽  
Chia-Han Chiang ◽  
Charles Wang ◽  
...  
Keyword(s):  
Permutation Test ◽  
Epileptiform Activity ◽  
Electrode Array ◽  
High Density ◽  
Electrode Arrays ◽  
Contact Density ◽  
Accurate Localization ◽  
Spatially Distributed ◽  
Subdural Electrode ◽  
Patients With Epilepsy

AbstractOne-third of epilepsy patients suffer from medication-resistant seizures. While surgery to remove epileptogenic tissue helps some patients, 30–70% of patients continue to experience seizures following resection. Surgical outcomes may be improved with more accurate localization of epileptogenic tissue. We have previously developed novel thin-film, subdural electrode arrays with hundreds of microelectrodes over a 100–1,000 mm2 area to enable high-resolution mapping of neural activity. Here we used these high-density arrays to study microscale properties of human epileptiform activity. We performed intraoperative micro-electrocorticographic recordings within epileptic cortex (the site of seizure onset and early spread) in nine patients with epilepsy. In two of these patients, we obtained recordings from cortical areas distal to the epileptic cortex. Additionally, we recorded from two non-epileptic patients with movement disorders undergoing deep brain stimulator implantation as non-epileptic tissue controls. A board-certified epileptologist identified microseizures, which resembled electrographic seizures normally observed with clinical macroelectrodes. Epileptic cortex exhibited a significantly higher microseizure rate (2.01 events/min) than non-epileptic cortex (0.01 events/min; permutation test, P=0.0068). Using spatial averaging to simulate recordings from larger electrode contacts, we found that the number of detected microseizures decreased rapidly with increasing contact diameter and decreasing contact density. In cases in which microseizures were spatially distributed across multiple channels, the approximate onset region was identified. Our results suggest that micro-electrocorticographic electrode arrays with a high density of contacts and large coverage are essential for capturing microseizures in epilepsy patients and may be beneficial for localizing epileptogenic tissue to plan surgery or target brain stimulation.

scholarly journals Modeling large-scale neural network culture interface on very-high density multi-electrode arrays

2007 ◽  
Vol 8 (S2) ◽  
Author(s):  
André Garenne ◽  
Luca Berdondini ◽  
Milena Koudelka ◽  
Sergio Martinoia ◽  
Frédéric Nagy ◽  
...  
Keyword(s):  
Neural Network ◽  
Large Scale ◽  
High Density ◽  
Electrode Arrays ◽  
Network Culture ◽  
Very High

scholarly journals How many fish could be vocal? An estimation from a coral reef (Moorea Island)

2021 ◽  
Vol 151 ◽  
Author(s):  
Eric Parmentier ◽  
Frédéric Bertucci ◽  
Marta Bolgan ◽  
David Lecchini
Keyword(s):  
Coral Reef ◽  
High Resolution ◽  
Coral Reefs ◽  
Large Scale ◽  
Fish Populations ◽  
Successful Management ◽  
Acoustic Behaviour ◽  
Management Plans ◽  
Moorea Island

A recurrent question arising in fish bioacoustics research concerns the number of vocal fish species that may exist. Although it is not possible to provide a precise globally valid number, an estimation based on recordings already collected at coral reefs (Moorea) and on morphological approaches indicates that approximately half of the fish families of this particular environment has at least one known sound-producing species. In light of this, acoustic behaviour should be fully considered in biology, ecology and management plans as it may provide information on a consistent portion of fish biodiversity. Fish bioacoustics has switched from anecdotal reports to long-term, large-scale monitoring studies, capable of providing high resolution information on fish populations’ composition and dynamics. This information is vital for successful management plans in our quickly changing seas.

scholarly journals Engineered biological neural networks on high density CMOS micro electrode arrays

2021 ◽  
Author(s):  
Jens Duru ◽  
Joel Kuechler ◽  
Stephan Johannes Ihle ◽  
Csaba Forro ◽  
Aeneas Bernardi ◽  
...  
Keyword(s):  
Neural Networks ◽  
Network Topology ◽  
Complementary Metal Oxide Semiconductor ◽  
High Density ◽  
Oxide Semiconductor ◽  
Electrode Arrays ◽  
Spatiotemporal Resolution ◽  
Biological Neural Networks ◽  
Micro Electrode Arrays

In bottom-up neuroscience, questions on neural information processing are addressed by engineering small but reproducible biological neural networks of defined network topology \textit{in vitro}. The network topology can be controlled by culturing neurons within polydimethylsiloxane (PDMS) microstructures that are combined with microelectrode arrays (MEAs) for electric access to the network. However, currently used glass MEAs are limited to 256 electrodes and pose a limitation to the spatial resolution as well as the design of more complex microstructures. The use of high density complementary metal-oxide-semiconductor (CMOS) MEAs greatly increases the spatiotemporal resolution, enabling sub-cellular readout and stimulation of neurons in defined neural networks. Unfortunately, the non-planar surface of CMOS MEAs complicates the attachment of PDMS microstructures. To overcome the problem of axons escaping the microstructures through the ridges of the CMOS MEA, we stamp-transferred a thin film of hexane-diluted PDMS onto the array such that the PDMS filled the ridges at the contact surface of the microstructures without clogging the axon guidance channels. Moreover, we provide an impedance-based method to visualize the exact location of the microstructures on the MEA and show that our method can confine axonal growth within the PDMS microstructures. Finally, the high spatiotemporal resolution of the CMOS MEA enabled us to show that we can guide action potentials using the unidirectional topology of our circular multi-node microstructure.

scholarly journals Large-scale neural recordings with single-cell resolution in human cortex using high-density Neuropixels probes

2021 ◽  
Author(s):  
Angelique C Paulk ◽  
Yoav Kfir ◽  
Arjun Khanna ◽  
Martina Mustroph ◽  
Eric M Trautmann ◽  
...  
Keyword(s):  
Large Scale ◽  
Field Potential ◽  
Electrode Array ◽  
Simultaneous Recording ◽  
Neurosurgical Procedures ◽  
Spatiotemporal Resolution ◽  
Spatial Spread ◽  
Neural Recordings ◽  
Neuronal Ensembles ◽  
Human Participants

Recent advances in multi-electrode array technology have made it possible to monitor large neuronal ensembles at high resolution. In humans, however, current approaches either restrict recordings to only a few neurons per penetrating electrode or combine the signals of thousands of neurons in local field potential (LFP) recordings. Here, we describe a set of techniques which enable simultaneous recording from over 200 well-isolated cortical single units in human participants during intraoperative neurosurgical procedures using Neuropixels silicon probes. We characterized a diversity of extracellular waveforms with eight separable single unit classes, with differing firing rates, positions along the length of the linear electrode array, spatial spread of the waveform, and modulation by LFP events such as inter-ictal discharges and burst suppression. While some additional challenges remain in creating a turn-key system capable of recording, Neuropixels technology could pave the way to studying human-specific cognitive processes and their dysfunction at unprecedented spatiotemporal resolution.

scholarly journals Potassium Carbonate (K2CO3) – A cheap, non-toxic and high-density floating solution for microplastic isolation from beach sediments

2020 ◽  
Author(s):  
Jan Gohla ◽  
Sandra Bračun ◽  
Gerwin Gretschel ◽  
Stephan Koblmüller ◽  
Wagner Maximilian ◽  
...  
Keyword(s):  
Potassium Carbonate ◽  
Recovery Rate ◽  
Large Scale ◽  
Public Awareness ◽  
High Density ◽  
Multiple Methods ◽  
Density Separation ◽  
Beach Sediments

ABSTRACTBeaches are good indicators for microplastic distribution and local microplastic pollution. Multiple methods have been developed for extracting microplastics from sediment, mainly through density separation. However, the chemicals applied are often expensive and harmful for the user or to the environment. We briefly review the problems associated with the use of these chemicals and present a new floatation solution, potassium carbonate (K2CO3) that has many advantages over available media. It is non-toxic and cheap, and with a density of 1.54 g/cm3 the K2CO3 solution yielded a mean recovery rate of around 92% for PVC, one of the densest polymers, that cannot be easily extracted with alternative floatation agents. We propose that the use of K2CO3 is particularly promising for long term and large-scale monitoring studies, not least because it allows an increasing involvement of citizen scientists, hopefully leading to an increased public awareness of the plastic problem in the seas.

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