Hydrogel-Based Transparent Subdural Electrode with Salt Bridge As Interface to Brain Surface

Abstract A totally soft organic subdural electrode has been developed by embedding an array of poly(3,4-ethylenedioxythiophene)-modified carbon fabric (PEDOT-CF) into the polyvinyl alcohol (PVA) hydrogel substrate. The mesh structure of the stretchable PEDOT-CF allowed stable structural integration with the PVA substrate. The electrode performance for monitoring electrocorticography (ECoG) was evaluated in saline solution, on ex vivo brains, and in vivo animal experiments using rats and porcines. It was demonstrated that the large double-layer capacitance of the PEDOT-CF brings low impedance at the frequency of brain wave including epileptic seizures, and PVA hydrogel substrate minimized the contact impedance on the brain. The most important unique feature of the hydrogel-based ECoG electrode was its shape conformability to enable tight adhesion even to curved, grooved surface of brains by just being placed. In addition, since the hydrogel-based electrode is totally organic, the simultaneous ECoG-fMRI measurements could be conducted without image artifacts, avoiding problems induced by conventional metallic electrodes.

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Totally transparent hydrogel-based subdural electrode with patterned salt bridge

Biomedical Microdevices ◽

10.1007/s10544-020-00517-0 ◽

2020 ◽

Vol 22 (3) ◽

Author(s):

Ayaka Nishimura ◽

Ryota Suwabe ◽

Yuka Ogihara ◽

Shotaro Yoshida ◽

Hiroya Abe ◽

...

Keyword(s):

Salt Bridge ◽

Subdural Electrode

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Analytical Electron Microscopy (AEM) of Meningeal Cells Exposed to Particulate Cobalt During Studies of Experimental Epilepsy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053590 ◽

1982 ◽

Vol 40 ◽

pp. 186-187

Author(s):

R.G. Frederickson ◽

R.G. Ulrich ◽

J.L. Culberson

Keyword(s):

Electron Microscopy ◽

Analytical Electron Microscopy ◽

Experimental Epilepsy ◽

Metallic Cobalt ◽

Experimental Animals ◽

X Ray ◽

Brain Surface ◽

Meningeal Cells ◽

Analytical Electron ◽

The Brain

Metallic cobalt acts as an epileptogenic agent when placed on the brain surface of some experimental animals. The mechanism by which this substance produces abnormal neuronal discharge is unknown. One potentially useful approach to this problem is to study the cellular and extracellular distribution of elemental cobalt in the meninges and adjacent cerebral cortex. Since it is possible to demonstrate the morphological localization and distribution of heavy metals, such as cobalt, by correlative x-ray analysis and electron microscopy (i.e., by AEM), we are using AEM to locate and identify elemental cobalt in phagocytic meningeal cells of young 80-day postnatal opossums following a subdural injection of cobalt particles.

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Brain surface ependymoma

Neuropathology ◽

10.1046/j.1440-1789.2000.00355.x ◽

2000 ◽

Vol 20 (4) ◽

pp. 315-318 ◽

Cited By ~ 16

Author(s):

Yuichiro Sato ◽

Hidenobu Ochiai ◽

Yuzo Yamakawa ◽

Kazuki Nabeshima ◽

Yujiro Asada ◽

...

Keyword(s):

Brain Surface

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A new technique for the mapping of oxygen tension on the brain surface

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/sj.jcbfm.9591524.0543 ◽

2005 ◽

Vol 25 (1_suppl) ◽

pp. S543-S543

Author(s):

Satoshi Kimura ◽

Keigo Matsumoto ◽

Yoshio Imahori ◽

Katsuyoshi Mineura ◽

Toshiyuki Itoh

Keyword(s):

Oxygen Tension ◽

New Technique ◽

Brain Surface ◽

A New Technique ◽

The Brain

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Frontier concept of rabi chip for intelligent humanoid

Journal of Analytical Chromatography and Spectroscopy ◽

10.24294/jacs.v1i2.908 ◽

2018 ◽

Vol 1 (2) ◽

Author(s):

Preecha Yupapin ◽

Amiri I. S. ◽

Ali J. ◽

Ponsuwancharoen N. ◽

Youplao P.

Keyword(s):

Human Brain ◽

Brain Function ◽

Rabi Oscillation ◽

Liquid Core ◽

Brain Surface ◽

Dipole Oscillation ◽

On Chip ◽

The Brain ◽

Robotic Applications ◽

Atom System

The sequence of the human brain can be configured by the originated strongly coupling fields to a pair of the ionic substances(bio-cells) within the microtubules. From which the dipole oscillation begins and transports by the strong trapped force, which is known as a tweezer. The tweezers are the trapped polaritons, which are the electrical charges with information. They will be collected on the brain surface and transport via the liquid core guide wave, which is the mixture of blood content and water. The oscillation frequency is called the Rabi frequency, is formed by the two-level atom system. Our aim will manipulate the Rabi oscillation by an on-chip device, where the quantum outputs may help to form the realistic human brain function for humanoid robotic applications.

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Ion Pairing and Dielectric Decrement in Glycosaminoglycan Brushes

10.26434/chemrxiv.13501698.v1 ◽

2020 ◽

Author(s):

James Sterling ◽

Wenjuan Jiang ◽

Wesley M. Botello-Smith ◽

Yun L. Luo

Keyword(s):

Molecular Dynamics ◽

Ion Pairs ◽

Mean Field ◽

Salt Bridge ◽

Ion Pairing ◽

Donnan Potential ◽

Mean Field Models ◽

Ion Exclusion ◽

Dynamics Simulations ◽

Contact Ion Pairs

Molecular dynamics simulations of hyaluronic acid and heparin brushes are presented that show important effects of ion-pairing, water dielectric decrease, and co-ion exclusion. Results show equilibria with electroneutrality attained through screening and pairing of brush anionic charges by cations. Most surprising is the reversal of the Donnan potential that would be expected based on electrostatic Boltzmann partitioning alone. Water dielectric decrement within the brush domain is also associated with Born hydration-driven cation exclusion from the brush. We observe that the primary partition energy attracting cations to attain brush electroneutrality is the ion-pairing or salt-bridge energy associated with cation-sulfate and cation-carboxylate solvent-separated and contact ion pairs. Potassium and sodium pairing to glycosaminoglycan carboxylates and sulfates consistently show similar abundance of contact-pairing and solvent-separated pairing. In these crowded macromolecular brushes, ion-pairing, Born-hydration, and electrostatic potential energies all contribute to attain electroneutrality and should therefore contribute in mean-field models to accurately represent brush electrostatics.

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Coaction of Electrostatic and Hydrophobic Interactions: Dynamic Constraints on Disordered TrkA Juxtamembrane Domain

10.26434/chemrxiv.9847190 ◽

2019 ◽

Author(s):

Zichen Wang ◽

Huaxun Fan ◽

Xiao Hu ◽

John Khamo ◽

Jiajie Diao ◽

...

Keyword(s):

Single Molecule ◽

Protein Function ◽

Hydrophobic Interactions ◽

Transmembrane Helix ◽

Point Mutations ◽

Salt Bridge ◽

Receptor Activation ◽

Membrane Dynamics ◽

Juxtamembrane Domain ◽

Joint Work

<p>The receptor tyrosine kinase family transmits signals into cell via a single transmembrane helix and a flexible juxtamembrane domain (JMD). Membrane dynamics makes it challenging to study the structural mechanism of receptor activation experimentally. In this study, we employ all-atom molecular dynamics with Highly Mobile Membrane-Mimetic to capture membrane interactions with the JMD of tropomyosin receptor kinase A (TrkA). We find that PIP<sub>2 </sub>lipids engage in lasting binding to multiple basic residues and compete with salt bridge within the peptide. We discover three residues insertion into the membrane, and perturb it through computationally designed point mutations. Single-molecule experiments indicate the contribution from hydrophobic insertion is comparable to electrostatic binding, and in-cell experiments show that enhanced TrkA-JMD insertion promotes receptor ubiquitination. Our joint work points to a scenario where basic and hydrophobic residues on disordered domains interact with lipid headgroups and tails, respectively, to restrain flexibility and potentially modulate protein function.</p>

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