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.

scholarly journals Sea of Electrodes Array (SEA): Extremely Dense and High-Count Silicon-Based Electrode Array Technology for High-Resolution High-Bandwidth Interfacing with 3D Neural Structures

2021 ◽  
Author(s):  
Amin Sandoughsaz Zardini ◽  
Behnoush Rostami ◽  
Khalil Najafi ◽  
Vaughn L. Hetrick ◽  
Omar J. Ahmed
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Electrode Array ◽  
High Count ◽  
Array Technology ◽  
High Bandwidth ◽  
Length Width ◽  
Silicon Based ◽  
The Brain

AbstractIn this work, we propose a new silicon-based micro-fabrication technology to fabricate 3D high-density high-electrode-count neural micro-probe arrays scalable to thousands and even millions of individual electrodes with user-defined length, width, shape, and tip profile. This unique technology utilizes DRIE of ultra-high aspect-ratio holes in silicon and refilling them with multiple films to form thousands of individual needles with metal tips making up the “sea-of-electrodes” array (SEA). World-record density of 400 electrodes/mm2 in a 5184-needle array is achieved. The needles are ~0.5-1.2mm long, <20μm wide at the base, and <1μm at the tip. The silicon-based structure of these 3D array probes with sharp tips, makes them stiff enough and easily implantable in the brain to reach a targeted region without failing. Moreover, the high aspect ratio of these extremely fine needles reduces the tissue damage and improves the chronic stability. Functionality of the electrodes is investigated using acute in vivo recording in a rat barrel field cortex under isoflurane anesthesia.

Bistability of somatic pattern memories: stochastic outcomes in bioelectric circuits underlying regeneration

2021 ◽  
Vol 376 (1821) ◽  
pp. 20190765 ◽  
Author(s):  
Giovanni Pezzulo ◽  
Joshua LaPalme ◽  
Fallon Durant ◽  
Michael Levin
Keyword(s):  
Large Scale ◽  
Computational Models ◽  
State Of The Art ◽  
Memory Representation ◽  
Theme Issue ◽  
Evolutionary Innovation ◽  
New Interpretation ◽  
The Brain

Nervous systems’ computational abilities are an evolutionary innovation, specializing and speed-optimizing ancient biophysical dynamics. Bioelectric signalling originated in cells' communication with the outside world and with each other, enabling cooperation towards adaptive construction and repair of multicellular bodies. Here, we review the emerging field of developmental bioelectricity, which links the field of basal cognition to state-of-the-art questions in regenerative medicine, synthetic bioengineering and even artificial intelligence. One of the predictions of this view is that regeneration and regulative development can restore correct large-scale anatomies from diverse starting states because, like the brain, they exploit bioelectric encoding of distributed goal states—in this case, pattern memories. We propose a new interpretation of recent stochastic regenerative phenotypes in planaria, by appealing to computational models of memory representation and processing in the brain. Moreover, we discuss novel findings showing that bioelectric changes induced in planaria can be stored in tissue for over a week, thus revealing that somatic bioelectric circuits in vivo can implement a long-term, re-writable memory medium. A consideration of the mechanisms, evolution and functionality of basal cognition makes novel predictions and provides an integrative perspective on the evolution, physiology and biomedicine of information processing in vivo . This article is part of the theme issue ‘Basal cognition: multicellularity, neurons and the cognitive lens’.

scholarly journals Development of Optically-Controlled “Living Electrodes” with Long-Projecting Axon Tracts for a Synaptic Brain-Machine Interface

2018 ◽  
Author(s):  
Dayo O. Adewole ◽  
Laura A. Struzyna ◽  
James P. Harris ◽  
Ashley D. Nemes ◽  
Justin C. Burrell ◽  
...  
Keyword(s):  
Brain Activity ◽  
Optical Recording ◽  
Neural Interfaces ◽  
New Class ◽  
Brain Surface ◽  
Long Term Performance ◽  
Term Performance ◽  
The Brain

AbstractAchievements in intracortical neural interfaces are compromised by limitations in specificity and long-term performance. A biological intermediary between devices and the brain may offer improved specificity and longevity through natural synaptic integration with deep neural circuitry, while being accessible on the brain surface for optical read-out/control. Accordingly, we have developed the first “living electrodes” comprised of implantable axonal tracts protected within soft hydrogel cylinders for the biologically-mediated monitoring/modulation of brain activity. Here we demonstrate the controlled fabrication, rapid axonal outgrowth, reproducible cytoarchitecture, and simultaneous optical stimulation and recording of neuronal activity within these engineered constructs in vitro. We also present their transplantation, survival, integration, and optical recording in rat cortex in vivo as a proof-of-concept for this neural interface paradigm. The creation and functional validation of these preformed, axon-based “living electrodes” is a critical step towards developing a new class of biohybrid neural interfaces to probe and modulate native circuitry.

Cannabinoid effects on adenylate cyclase and phosphodiesterase activities of mouse brain

1977 ◽  
Vol 55 (4) ◽  
pp. 934-942 ◽  
Author(s):  
Thomas W. Dolby ◽  
Lewis J. Kleinsmith
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Mouse Brain ◽  
Biogenic Amine ◽  
Specific Activity ◽  
Intraperitoneal Administration ◽  
The Brain

The experiments presented in this paper examine the mechanisms underlying the ability of cannabinoids to alter the in vivo levels of cyclic adenosine 3′,5′-monophosphate (cyclic AMP) in mouse brain. It was found that changes in cyclic AMP levels are a composite result of direct actions of cannabinoids on adenylate cyclase (EC 4.6.1.1) activity and indirect actions involving the potentiation or inhibition of biogenic amine induced activity of adenylate cyclase. Furthermore, the long-term intraperitoneal administration of 1-(−)-Δ-tetrahydrocannabinol to mice produced a form of phosphodiesterase (EC 3.1.4.17) in the brain whose activity is not stimulated by Ca2+, although its basal specific activity is similar to that of control animals. In vitro, the presence of the cannabinoids caused no significant changes in activity of brain PDE at the concentrations tested. Some correlations are presented which imply that many of the observed behavioral and physiological actions of the cannabinoids in mammalian organisms may be mediated via cyclic AMP mechanisms.

scholarly journals Improving electrocorticograms of awake and anaesthetized mice using wavelet denoising

2018 ◽  
Vol 4 (1) ◽  
pp. 469-472 ◽  
Author(s):  
Michael Schweigmann ◽  
Klaus Peter Koch ◽  
Fabian Auler ◽  
Frank Kirchhoff
Keyword(s):  
Signal To Noise Ratio ◽  
Wavelet Denoising ◽  
Functional Evaluation ◽  
Electrode Impedance ◽  
Electrode Arrays ◽  
Brain Surface ◽  
Micro Electrode Arrays ◽  
Cellular Circuits ◽  
Noise Models

AbstractThe quality of bioelectrical signals is essential for functional evaluation of cellular circuits. The electrical activity recorded from the cortical brain surface represents the average of many individual synaptic processes. By downsizing micro-electrode arrays, the spatial resolution of electrocortico-grams (ECoGs) can be increased. But, upon increasing electrode impedance, recorded noise from the electrode-tissue interface and the surroundings will become more prominent. Frequently, signal interpretation is improved by post-processing using filtering or pattern recognition. For a variety of applications, wavelet denoising has become an accepted tool. Here, we present how wavelet denoising affects the signal-to-noise ratio of ECoGs. The recording qualities from awake and anesthetized mice was artificially reduced by adding two noise models prior to filtering. Raw and filtered signals were compared by calculating the linear correlation coefficient.

scholarly journals Non-invasive long-term and real-time analysis of endocrine cells on micro-electrode arrays

2012 ◽  
Vol 590 (5) ◽  
pp. 1085-1091 ◽  
Author(s):  
Matthieu Raoux ◽  
Yannick Bornat ◽  
Adam Quotb ◽  
Bogdan Catargi ◽  
Sylvie Renaud ◽  
...  
Keyword(s):  
Real Time ◽  
Endocrine Cells ◽  
Electrode Arrays ◽  
Time Analysis ◽  
Non Invasive ◽  
Real Time Analysis ◽  
Micro Electrode Arrays

scholarly journals Neural plate targeting by in utero nanoinjection (NEPTUNE) reveals a role for Sptbn2 in neurulation and abdominal wall closure

2020 ◽  
Author(s):  
Katrin Mangold ◽  
Jan Mašek ◽  
Jingyan He ◽  
Urban Lendahl ◽  
Elaine Fuchs ◽  
...  
Keyword(s):  
Cost Effective ◽  
Cell Types ◽  
Neural Plate ◽  
Spinocerebellar Ataxia Type ◽  
Loss Of Function ◽  
Conditional Expression ◽  
Cost Effective Technique ◽  
The Brain

ABSTRACTGene variants associated with disease are efficiently identified with whole genome sequencing or GWAS, but validation in vivo lags behind. We developed NEPTUNE (neural plate targeting by in utero nanoinjection), to rapidly and flexibly introduce gene expression-modifying viruses to the embryonic murine neural plate prior to neurulation, to target the future adult nervous system. Stable integration in >95% of cells in the brain enabled long-term gain- or loss-of-function, and conditional expression was achieved using mini-promotors for cell types of interest. Using NEPTUNE, we silenced Sptbn2, a gene associated with Spinocerebellar ataxia type 5 (SCA5) in humans. Silencing of Sptbn2 induced severe neural tube defects and embryo resorption, suggesting that SPTBN2 in-frame and missense deletions in SCA5 reflect hypomorphic or neomorphic functions, not loss of function. In conclusion, NEPTUNE offers a novel, rapid and cost-effective technique to test gene function in brain development, and can reveal loss of function phenotypes incompatible with life.

scholarly journals Injection with Toxoplasma gondii protein affects neuron health and survival

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Oscar A Mendez ◽  
Emiliano Flores Machado ◽  
Jing Lu ◽  
Anita Koshy
Keyword(s):  
Toxoplasma Gondii ◽  
Single Neuron ◽  
Latent Infection ◽  
Medium Spiny Neurons ◽  
Patch Clamping ◽  
Spiny Neurons ◽  
The Brain ◽  
Mapping Program

Toxoplasma gondii is an intracellular parasite that causes a long-term latent infection of neurons. Using a custom MATLAB-based mapping program in combination with a mouse model that allows us to permanently mark neurons injected with parasite proteins, we found that Toxoplasma-injected neurons (TINs) are heterogeneously distributed in the brain, primarily localizing to the cortex followed by the striatum. In addition, we determined that cortical TINs are commonly (>50%) excitatory neurons (FoxP2+) and that striatal TINs are often (>65%) medium spiny neurons (MSNs) (FoxP2+). By performing single neuron patch-clamping on striatal TINs and neighboring uninfected MSNs, we discovered that TINs have highly aberrant electrophysiology. As approximately 90% of TINs will die by 8 weeks post-infection, this abnormal physiology suggests that injection with Toxoplasma protein— either directly or indirectly— affects neuronal health and survival. Collectively, these data offer the first insights into which neurons interact with Toxoplasma and how these interactions alter neuron physiology in vivo.

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.

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