Patterned Live Neural Networks by Induced Electrical Fields for Bio-Sensing

It is estimated that about 18 million people worldwide suffer from dementia and it is projected to increase to about 35 million by the year 2025. All types of dementia occur due to an aberration in memory retention and development, caused by malfunctioning neurons. Experimental investigation of the dynamics of biological networks is a fundamental step towards understanding how the nervous system works. Activity-dependant modification of synaptic strength is widely recognized as cellular basis of learning, memory and developmental plasticity. Understanding memory formation and development, thus translates to changes in the electrical activity of the neurons. It is not possible to achieve this understanding at a cellular level by in vivo studies. To map the changes in the electrical activity it is essential to conduct in-vitro studies on individual neurons. Hence there is an enormous need to develop novel ways for assembly of highly controlled neuronal networks. To this end, we used a 5 × 5 multiple microelectrode array system to spatially arrange neurons, by combination of applied DC and AC fields We characterized electric field distribution inside our test platform by using two dimensional finite element modeling (FEM). As the first stage in the formation of a neural network dielectrophoretic AC fields were used to position the neurons over the electrodes. We used DC electric field to control axon growth direction within the network. Applied electric field direction is found to be an important parameter for axon growth. Electrical impulses were recorded from the individual neurons in the network during positioning and network formation.

Download Full-text

Electric Field-Assisted Positioning of Neurons on Pt Microelectrode Arrays

MRS Proceedings ◽

10.1557/proc-773-n4.6 ◽

2003 ◽

Vol 773 ◽

Author(s):

Shalini Prasad ◽

Mo Yang ◽

Xuan Zhang ◽

Yingchun Ni ◽

Vladimir Parpura ◽

...

Keyword(s):

Electric Field ◽

Electrical Activity ◽

Electric Fields ◽

Microelectrode Array ◽

Electrode Array ◽

Sprague Dawley ◽

A Cell ◽

Neuron Patterning

AbstractCharacterization of electrical activity of individual neurons is the fundamental step in understanding the functioning of the nervous system. Single cell electrical activity at various stages of cell development is essential to accurately determine in in-vivo conditions the position of a cell based on the procured electrical activity. Understanding memory formation and development translates to changes in the electrical activity of individual neurons. Hence, there is an enormous need to develop novel ways for isolating and positioning individual neurons over single recording sites. To this end, we used a 3x3 multiple microelectrode array system to spatially arrange neurons by applying a gradient AC field. We characterized the electric field distribution inside our test platform by using two dimensiona l finite element modeling (FEM) and determined the location of neurons over the electrode array. Dielectrophoretic AC fields were utilized to separate the neurons from the glial cells and to position the neurons over the electrodes. The neurons were obtained from 0-2-day-old rat (Sprague-Dawley) pups. The technique of using electric fields to achieve single neuron patterning has implications in neural engineering, elucidating a new and simpler method to develop and study neuronal activity as compared to conventional microelectrode array techniques.

Download Full-text

Single Cell Based Microelectrode Array Biosensors

MRS Proceedings ◽

10.1557/proc-773-n11.6 ◽

2003 ◽

Vol 773 ◽

Author(s):

Mo Yang ◽

Shalini Prasad ◽

Xuan Zhang ◽

Mihrimah Ozkan ◽

Cengiz S. Ozkan

Keyword(s):

Electrical Activity ◽

Single Cell ◽

Cellular Response ◽

Microelectrode Array ◽

Fast Fourier Transformation ◽

Chemical Agent ◽

Extracellular Potential ◽

Membrane Excitability ◽

Specific Chemical ◽

Chemical Agents

AbstractExtracellular potential is an important parameter which indicates the electrical activity of live cells. Membrane excitability in osteoblasts plays a key role in modulating the electrical activity in the presence of chemical agents. The complexity of cell signal makes interpretation of the cellular response to a chemical agent very difficult. By analyzing shifts in the signal power spectrum, it is possible to determine a frequency spectrum also known as Signature Pattern Vectors (SPV) specific to a chemical. It is also essential to characterize single cell sensitivity and response time for specific chemical agents for developing detect-to-warn biosensors. We used a 4x4 multiple Pt microelectrode array to spatially position single osteoblast cells, by using a gradient AC field. Fast Fourier Transformation (FFT) and Wavelet Transformation (WT) analyses were used to extract information pertaining to the frequency of firing from the extracellular potential.

Download Full-text

Faculty Opinions recommendation of Nanoparticles induce changes of the electrical activity of neuronal networks on microelectrode array neurochips.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.3225956.2911054 ◽

2010 ◽

Author(s):

Philip Burcham

Keyword(s):

Electrical Activity ◽

Neuronal Networks ◽

Microelectrode Array

Download Full-text

Faculty Opinions recommendation of Electrical activity suppresses axon growth through Ca(v)1.2 channels in adult primary sensory neurons.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.4568976.7023054 ◽

2010 ◽

Author(s):

Andrew Chisholm

Keyword(s):

Electrical Activity ◽

Sensory Neurons ◽

Axon Growth ◽

Primary Sensory Neurons

Download Full-text

Universal converse flexoelectricity in dielectric materials via varying electric field direction

International Journal of Smart and Nano Materials ◽

10.1080/19475411.2021.1880491 ◽

2021 ◽

pp. 1-22

Author(s):

Saurav Sharma ◽

Rajeev Kumar ◽

Rahul Vaish

Keyword(s):

Electric Field ◽

Dielectric Materials ◽

Field Direction ◽

Electric Field Direction

Download Full-text

BRIDGING OF CARBON FIBERS IN CF/EPOXY COMPOSITES USING ELECTROSTATICALLY INDUCED CNT ALIGNMENT

10.12783/asc36/35765 ◽

2021 ◽

Author(s):

DANDAN ZHANG ◽

XINGKANG SHE ◽

YIPENG HE ◽

WESLEY A. CHAPKIN, ◽

VI T. BREGMAN ◽

...

Keyword(s):

Carbon Fiber ◽

Electric Field ◽

Carbon Fibers ◽

Hybrid Composites ◽

Tensile Modulus ◽

Tensile Tests ◽

Polymer Mixture ◽

Ac Electric Field ◽

Reinforced Polymer ◽

Electric Field Direction

Carbon fiber reinforced polymer (CFRP) composites are lightweight materials with superior strength but are expensive due to the increased cost of carbon fibers (CFs). The addition of carbon nanotubes (CNTs) to polymer nanocomposites are becoming an excellent alternative to CF due to their unique combination of electrical, thermal, and mechanical properties. With the application of an electric field across the CNT/polymer mixture before curing, CNTs will not only be aligned along the electric field direction, but also form networks after reaching to a certain degree of alignment. In this study, an alternating current (AC) electric field was applied continuously to CNT/CF/Epoxy hybrid composites before curing. By cutting off the applied voltage when the monitored electric current increased, the degree of networking of CNTs between two CF tows was controlled. The relative electric field strength around the end of conductive carbon fiber tows in the epoxy matrix was modeled using COMSOL Multiphysics. It increased after applying AC electric field parallel to the CF tows, thereby increasing the alignment degree of CNTs and building a network to bridge the CF tows. The preliminary results indicate that the microhardness and tensile modulus between two CF tows are increased due to the networking of CNTs in this area. The fracture surface of the specimens after tensile tests were characterized to reveal more details of the microstructure.

Download Full-text

Effect of green density and electric field direction on densification of YAG nano-powders by spark plasma sintering

Journal of Materials Science ◽

10.1007/s10853-009-3300-7 ◽

2009 ◽

Vol 44 (8) ◽

pp. 2063-2068 ◽

Cited By ~ 11

Author(s):

O. Tobi Even-Zur ◽

R. Chaim

Keyword(s):

Electric Field ◽

Spark Plasma Sintering ◽

Field Direction ◽

Green Density ◽

Plasma Sintering ◽

Electric Field Direction ◽

Spark Plasma

Download Full-text

Spiral wave unpinning facilitated by wave emitting sites in cardiac monolayers

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2019.0420 ◽

2019 ◽

Vol 475 (2230) ◽

pp. 20190420

Author(s):

Shreyas Punacha ◽

Sebastian Berg ◽

Anupama Sebastian ◽

Valentin I. Krinski ◽

Stefan Luther ◽

...

Keyword(s):

Electric Field ◽

Electrical Activity ◽

Spiral Wave ◽

Electrical Stimulus ◽

Spiral Waves ◽

Time Interval ◽

Field Pulse ◽

The Core ◽

Rotating Wave ◽

Multiple Obstacles

Rotating spiral waves of electrical activity in the heart can anchor to unexcitable tissue (an obstacle) and become stable pinned waves. A pinned rotating wave can be unpinned either by a local electrical stimulus applied close to the spiral core, or by an electric field pulse that excites the core of a pinned wave independently of its localization. The wave will be unpinned only when the pulse is delivered inside a narrow time interval called the unpinning window (UW) of the spiral. In experiments with cardiac monolayers, we found that other obstacles situated near the pinning centre of the spiral can facilitate unpinning. In numerical simulations, we found increasing or decreasing of the UW depending on the location, orientation and distance between the pinning centre and an obstacle. Our study indicates that multiple obstacles could contribute to unpinning in experiments with intact hearts.

Download Full-text