The authors thank Ofer Feinerman, Fred Wolf, Menahem Segal, Andreas Neef and Eitan Reuveny for very helpful discussions. The authors thank Ilan Breskin and Jordi Soriano for developing early versions of the technology. The authors thank Tsvi Tlusty and Jean-Pierre Eckmann for help with the theoretical concepts. This research was supported by the Minerva Foundation, the Ministry of Science and Technology, Israel, and by Israel Science Foundation grant 1320/09 and the Bi-National Science Foundation grant 2008331.

<ol>
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The authors declare that they have no competing financial interests.

1D patterning is an important tool that can be used for a variety of applications. For example, we have used 1D patterning for creating logic gates from neuronal cultures 29 and more recently to measure the Chronaxie and Rheobase of rat hippocampal neurons 5, and the slowing down of signal propagation velocity of firing activity in Down syndrome hippocampal neurons compared to the wild type (WT) hippocampal neurons 27. The suggested protocol for 1D p...

The interaction between neurons and external electric fields has fundamental implications as well as practical ones. While it is known since the times of Volta that an externally applied electric field can excite tissue, the mechanisms responsible for the production of a resultant action potential in neurons are only recently starting to be unraveled 1,2,3,4. This includes finding answers to questions regarding the mechanism that causes depolarization of membrane potential, the role of membrane properties and of ion channels, and even the region in the neuron that responds to the electric field 2,5. Therapeutic neurostimulation 6,7,8,9,10 methodologies are particularly dependent on this information, which can be crucial for targeting the afflicted areas and for understanding the outcome of the therapy. Such understanding can also help in developing treatment protocols and new approaches for stimulation of different areas in the brain.
Measuring the interaction within the in vivo brain adds an important component to this understanding, but is hampered by the imprecision and low controllability of measurements within the skull. In contrast, measurements in cultures can easily be performed in high volume with high precision, excellent signal to noise performance and a high degree of reproducibility and of control. Using cultures a large variety of neuronal properties of collective network behavior can be elucidated 11,12,13,14,15,16. Similarly, this well controlled system is expected be highly efficient in elucidating the mechanism by which other stimulation methods work, for example how channel opening during optical stimulation in optogenetically active neurons 17,18,19 is responsible for creating action potential.
Here the focus is on describing the development and understanding of tools that can efficiently excite the neuron via an external electric field. In this paper we describe the preparation of two-dimensional and one-dimensional patterned hippocampal cultures, stimulation using different configurations and orientation of a directly applied electric field by bath electrodes, and finally stimulation of two-dimensional and patterned one-dimensional cultures by a time-varying magnetic field, which induces an electric field 5,20,21.

<table><tbody><tr><td>APV</td><td>Sigma-Aldrich</td><td>A8054</td><td>Disconnect the network. Mentioned in Section 2.4.2</td></tr><tr><td>B27 supp</td><td>Gibco</td><td>17504-044</td><td>Plating medium. Mentioned in Section 1.1.1</td></tr><tr><td>bicuculline</td><td>Sigma-Aldrich</td><td>14343</td><td>Disconnect the network. Mentioned in Section 2.4.2</td></tr><tr><td>Borax (sodium tetraborate decahydrate)</td><td>Sigma-Aldrich</td><td>S9640</td><td>Borate buffer. Mentioned in Section 1.1.2</td></tr><tr><td>Boric acid</td><td>Frutarom LTD</td><td>5550710</td><td>Borate buffer. Mentioned in Section 1.1.2</td></tr><tr><td>CaCl&lt;sub&gt;2&lt;/sub&gt; , 1 M</td><td>Fluka&amp;nbsp;</td><td>21098</td><td>Extracellular recording solution. Mentioned in Section 1.5.2</td></tr><tr><td>CNQX</td><td>Sigma-Aldrich</td><td>C239</td><td>Disconnect the network. Mentioned in Section 2.4.2</td></tr><tr><td>COMSOL</td><td>COMSOL Inc</td><td>Multiphysics 3.5</td><td>Numerical simulation. Mentioned in Section 3.5.2</td></tr><tr><td>D-(+)-Glucose, 1 M</td><td>Sigma-Aldrich</td><td>65146</td><td>Plating medium, Extracellular recording solution. Mentioned in Sections 1.1.1 and 1.5.2</td></tr><tr><td>D-PBS</td><td>Sigma-Aldrich</td><td>D8537</td><td>Cell Cultures. Mentioned in Sections 1.2.4 and 1.2.6</td></tr><tr><td>FCS (FBS)</td><td>Gibco</td><td>12657-029</td><td>Plating medium. Mentioned in Section 1.1.1</td></tr><tr><td>Fibronectin</td><td>Sigma-Aldrich</td><td>F1141</td><td>Bio Coating. Mentioned in Section 1.2.6</td></tr><tr><td>Fluo4AM</td><td>Life technologies</td><td>F14201</td><td>Imaging of spontaneous or evoked activity. Mentioned in Sections 1.5.1, 1.5.3, and 1.5.5</td></tr><tr><td>FUDR</td><td>Sigma-Aldrich</td><td>F0503</td><td>Changing medium. Mentioned in Section 1.4.1</td></tr><tr><td>Gentamycin</td><td>Sigma-Aldrich</td><td>G1272</td><td>Plating medium, Changing medium, Final medium. Mentioned in Section 1.1.1</td></tr><tr><td>GlutaMAX 100x</td><td>Gibco</td><td>35050-038</td><td>Plating medium, Changing medium, Final medium. Mentioned in Section 1.1.1</td></tr><tr><td>Hepes, 1 M</td><td>Sigma-Aldrich</td><td>H0887</td><td>Extracellular recording solution. Mentioned in Section 1.5.2</td></tr><tr><td>HI HS</td><td>BI</td><td>04-124-1A</td><td>Plating medium, Changing medium, Final medium. Mentioned in Sections 1.1.1, 1.4.1, and 1.4.2</td></tr><tr><td>KCl,&amp;nbsp; 3 M</td><td>Merck</td><td>1049361000</td><td>Extracellular recording solution. Mentioned in Section 1.5.2</td></tr><tr><td>Laminin&amp;nbsp;</td><td>Sigma-Aldrich</td><td>L2020</td><td>Bio Coating. Mentioned in Section 1.2.6</td></tr><tr><td>MEM x 1</td><td>Gibco</td><td>21090-022</td><td>Plating medium, Changing medium, Final medium. Mentioned in Section 1.4.1&amp;nbsp;&amp;nbsp;&amp;nbsp; 1.4.2</td></tr><tr><td>MgCl&lt;sub&gt;2&lt;/sub&gt; , 1 M</td><td>Sigma-Aldrich</td><td>M1028</td><td>Extracellular recording solution. Mentioned in Section 1.5.2</td></tr><tr><td>NaCl, 4 M</td><td>Bio-Lab</td><td>19030591</td><td>Extracellular recording solution. Mentioned in Section 1.5.2</td></tr><tr><td>Octadecanethiol</td><td>Sigma-Aldrich</td><td>01858</td><td>Cleaning Cr-Au coated coverslips (1D cultures). Mentioned in Section 1.2.3</td></tr><tr><td>Pluracare F108 NF Prill</td><td>BASF Corparation&amp;nbsp;</td><td>50475278</td><td>Bio-Rejection Coating, Bio Coating. Mentioned in Sections 1.2.4 and 1.2.6</td></tr><tr><td>Poly-L-lysine 0.01% solution&amp;nbsp;</td><td>Sigma-Aldrich</td><td>&amp;nbsp;P47075</td><td>Promote cell division. Mentioned in Section 1.1.4</td></tr><tr><td>Sucrose, 1 M</td><td>Sigma-Aldrich</td><td>S1888</td><td>Extracellular recording solution. Mentioned in Section 1.5.2</td></tr><tr><td>Thiol&amp;nbsp;</td><td>Sigma-Aldrich</td><td>1858</td><td>Bio-Rejection Coating. Mentioned in Section 1.2.3</td></tr><tr><td>URIDINE</td><td>Sigma-Aldrich</td><td>U3750</td><td>Changing medium. Mentioned in Section 1.4.1</td></tr><tr><td>Sputtering machine</td><td>AJA International, Inc</td><td>ATC Orion-5Series&amp;nbsp;</td><td>coating glass with thin layers of metal. Mentioned in Section 1.2.2</td></tr><tr><td>Pen plotter&amp;nbsp;</td><td>Hewlett Packard&amp;nbsp;</td><td>HP 7475A</td><td>Etching of pattern to the coated coverslip. Mentioned in Section 1.2.5</td></tr><tr><td>Electrodes wires&amp;nbsp;</td><td>A-M Systems, Carlsborg WA</td><td>767000</td><td>Electric stimulation of neuronal cultures. Mentioned in Sections 2.1, 2.2, 2.3, and 2.4.5</td></tr><tr><td>Signal generator</td><td>BKPrecision</td><td>4079</td><td>Shaping of the electric signal. Mentioned in Section 2.3</td></tr><tr><td>Amplifier</td><td>Homemade</td><td></td><td>Voltage amplification of the signal from the signal generator to the electrodes. Mentioned in Section 2.3</td></tr><tr><td>Power supply</td><td>Matrix&amp;nbsp;</td><td>MPS-3005 LK-3&amp;nbsp;</td><td>Power supply to the sputtering machine. Mentioned in Section 1.2.2.3</td></tr><tr><td>Transcranial magnetic stimulation</td><td>Magstim, Spring Gardens, UK</td><td>Rapid 2</td><td>Magnetic stimulation of neuronal culture. Mentioned in Sections 3.1, 3.3, and 3.4</td></tr><tr><td>Epoxy</td><td>Cognis</td><td>Versamid 140</td><td>Casting of homemade coils. Mentioned in Section 3.4</td></tr><tr><td>Epoxy</td><td>Shell</td><td>EPON 815&amp;nbsp;</td><td>Casting of homemade coils. Mentioned in Section 3.4</td></tr><tr><td>Platinum wires 0.005&#039;&#039; thick; A-M Systems,&amp;nbsp;</td><td>&amp;nbsp;Carlsborg WA</td><td>&amp;nbsp;767000</td><td>Electric stimulation of neuronal cultures. Mentioned in Section 2.1</td></tr><tr><td>Circular magnetic coil</td><td>Homemade</td><td></td><td>Magnetic stimulation of neuronal culture. Mentioned in Section 3.3</td></tr><tr><td>WaveXpress SW</td><td>B&amp;amp;K Precision&amp;nbsp;</td><td></td><td>Waveform editing software. Mentioned in Section 2.1.32</td></tr><tr><td>Xion Ultra 897</td><td>Andor</td><td></td><td>Sensitive EMCCD camera. Mentioned in Section 2.4.4</td></tr></tbody></table>

external excitation of neurons using electric and magnetic fields in one- and two-dimensional cultures

A neuron will fire an action potential when its membrane potential exceeds a certain threshold. In typical activity of the brain, this occurs as a result of chemical inputs to its synapses. However, neurons can also be excited by an imposed electric field. In particular, recent clinical applications activate neurons by creating an electric field externally. It is therefore of interest to investigate how the neuron responds to the external field and what causes the action potential. Fortunately, precise and controlled application of an external electric field is possible for embryonic neuronal cells that are excised, dissociated and grown in cultures. This allows the investigation of these questions in a highly reproducible system.
In this paper some of the techniques used for controlled application of external electric field on neuronal cultures are reviewed. The networks can be either one dimensional, i.e. patterned in linear forms or allowed to grow on the whole plane of the substrate, and thus two dimensional. Furthermore, the excitation can be created by the direct application of electric field via electrodes immersed in the fluid (bath electrodes) or by inducing the electric field using the remote creation of magnetic pulses.

The protocol presented allows for easy patterning of neuronal cultures. When it is combined with several methods we developed for stimulation, it enables to make measurements of some intrinsic neuron properties such as Chronaxie and Rheobase5, to compare properties of healthy and diseased neurons27, to find optimal ways to stimulate cultures as a function of their structure and many more novel approaches. Some examples are presented in the n...

Watch this Scientific Journal Video about External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures at JoVE.com

External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures

Neuronal cultures are a good model for studying emerging brain stimulation techniques via their effect on single neurons or a population of neurons. Presented here are different methods for stimulation of patterned neuronal cultures by an electric field produced directly by bath electrodes or induced by a time-varying magnetic field.

A neuron will fire an action potential when its membrane potential exceeds a certain threshold. In typical activity of the brain, this occurs as a result ...

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13.2K Views.  The Salk Institute for Biological Studies.  Neuronale kweken zijn een goed model voor het bestuderen van de opkomende hersenstimulatie technieken via hun effect op enkele neuronen of een populatie van neuronen. Hier voorgesteld zijn verschillende methoden voor het stimuleren van neuronale kweken patroon door een elektrisch veld rechtstreeks bad elektroden geproduceerd of geïnduceerd door een in de tijd variërend magnetisch veld. 

Video: External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures

Electric Field-controlled Directed Migration of Neural Progenitor Cells in 2D and 3D Environments

Endogenous electric fields (EFs) occur naturally in vivo and play a critical role during tissue/organ development and regeneration, including that of the central nervous system1,2. These endogenous EFs are generated by cellular regulation of ionic transport combined with the electrical resistance of cells and tissues. It has been reported that applied EF treatment can promote functional repair of spinal cord injuries in animals and humans3,4. In particular, EF-directed cell migration has been demonstrated in a wide variety of cell types5,6, including neural progenitor cells (NPCs)7,8. Application of direct current (DC) EFs is not a commonly available technique in most laboratories. We have described detailed protocols for the application of DC EFs to cell and tissue cultures previously5,11. Here we present a video demonstration of standard methods based on a calculated field strength to set up 2D and 3D environments for NPCs, and to investigate cellular responses to EF stimulation in both single cell growth conditions in 2D, and the organotypic spinal cord slice in 3D. The spinal cordslice is an ideal recipient tissue for studying NPC ex vivo behaviours, post-transplantation, because the cytoarchitectonic tissue organization is well preserved within these cultures9,10. Additionally, this ex vivo model also allows procedures that are not technically feasible to track cells in vivo using time-lapse recording at the single cell level. It is critically essential to evaluate cell behaviours in not only a 2D environment, but also in a 3D organotypic condition which mimicks the in vivo environment. This system will allow high-resolution imaging using cover glass-based dishes in tissue or organ culture with 3D tracking of single cell migration in vitro and ex vivo and can be an intermediate step before moving onto in vivo paradigms.

This protocol demonstrates methods used to establish 2D and 3D environments in custom-designed electrotactic chambers, which can track cells in vivo/ex vivo using time-lapse recording at the single cell level, in order to investigate galvanotaxis/electrotaxis and other cellular responses to direct current (DC) electric fields (EFs).

Endogenous electric fields (EFs) occur naturally in vivo and play a critical role during tissue/organ development and regeneration, including that of the ...

Bioengineering

A Galvanotaxis Assay for Analysis of Neural Precursor Cell Migration Kinetics in an Externally Applied Direct Current Electric Field

The discovery of neural stem and progenitor cells (collectively termed neural precursor cells) (NPCs) in the adult mammalian brain has led to a body of research aimed at utilizing the multipotent and proliferative properties of these cells for the development of neuroregenerative strategies. A critical step for the success of such strategies is the mobilization of NPCs toward a lesion site following exogenous transplantation or to enhance the response of the endogenous precursors that are found in the periventricular region of the CNS. Accordingly, it is essential to understand the mechanisms that promote, guide, and enhance NPC migration. Our work focuses on the utilization of direct current electric fields (dcEFs) to promote and direct NPC migration - a phenomenon known as galvanotaxis. Endogenous physiological electric fields function as critical cues for cell migration during normal development and wound repair. Pharmacological disruption of the trans-neural tube potential in axolotl embryos causes severe developmental malformations1. In the context of wound healing, the rate of repair of wounded cornea is directly correlated with the magnitude of the epithelial wound potential that arises after injury, as shown by pharmacological enhancement or disruption of this dcEF2-3. We have demonstrated that adult subependymal NPCs undergo rapid and directed cathodal migration in vitro when exposed to an externally applied dcEF. In this protocol we describe our lab's techniques for creating a simple and effective galvanotaxis assay for high-resolution, long-term observation of directed cell body translocation (migration) on a single-cell level. This assay would be suitable for investigating the mechanisms that regulate dcEF transduction into cellular motility through the use of transgenic or knockout mice, short interfering RNA, or specific receptor agonists/antagonists.

In this protocol we demonstrate how to construct custom chambers that permit the application of a direct current electric field to enable time-lapse imaging of adult brain derived neural precursor cell translocation during galvanotaxis.

The discovery of neural stem and progenitor  cells (collectively termed neural precursor cells) (NPCs) in the adult  mammalian brain has led to a body of ...

Spiral Ganglion Neuron Explant Culture and Electrophysiology on Multi Electrode Arrays

Spiral ganglion neurons (SGNs) participate in the physiological process of hearing by relaying signals from sensory hair cells to the cochlear nucleus in the brain stem. Loss of hair cells is a major cause of sensory hearing loss. Prosthetic devices such as cochlear implants function by bypassing lost hair cells and directly stimulating SGNs electrically, allowing for restoration of hearing in deaf patients. The performance of these devices depends on the functionality of SGNs, the implantation procedure and on the distance between the electrodes and the auditory neurons. 
We hypothesized, that reducing the distance between the SGNs and the electrode array of the implant would allow for improved stimulation and frequency resolution, with the best results in a gapless position. Currently we lack in vitro culture systems to study, modify and optimize the interaction between auditory neurons and electrode arrays and characterize their electrophysiological response. To address these issues, we developed an in vitro bioassay using SGN cultures on a planar multi electrode array (MEA). With this method we were able to perform extracellular recording of the basal and electrically induced activity of a population of spiral ganglion neurons. We were also able to optimize stimulation protocols and analyze the response to electrical stimuli as a function of the electrode distance. This platform could also be used to optimize electrode features such as surface coatings.

We present a protocol to culture primary murine spiral ganglion neuron explants on multi electrode arrays to study neuronal response profiles and optimize stimulation parameters. Such studies aim to improve the neuron-electrode interface of cochlear implants to benefit hearing in patients as well as the energy consumption of the device.

Spiral ganglion neurons (SGNs) participate in the physiological process of hearing by relaying signals from sensory hair cells to the cochlear nucleus in ...

Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays

Micro-electrode arrays (MEAs) can be used to investigate drug toxicity, design paradigms for next-generation personalized medicine, and study network dynamics in neuronal cultures. In contrast with more traditional methods, such as patch-clamping, which can only record activity from a single cell, MEAs can record simultaneously from multiple sites in a network, without requiring the arduous task of placing each electrode individually. Moreover, numerous control and stimulation configurations can be easily applied within the same experimental setup, allowing for a broad range of dynamics to be explored. One of the key dynamics of interest in these in vitro studies has been the extent to which cultured networks display properties indicative of learning. Mouse neuronal cells cultured on MEAs display an increase in response following training induced by electrical stimulation. This protocol demonstrates how to culture neuronal cells on MEAs; successfully record from over 95% of the plated dishes; establish a protocol to train the networks to respond to patterns of stimulation; and sort, plot, and interpret the results from such experiments. The use of a proprietary system for stimulating and recording neuronal cultures is demonstrated. Software packages are also used to sort neuronal units. A custom-designed graphical user interface is used to visualize post-stimulus time histograms, inter-burst intervals, and burst duration, as well as to compare the cellular response to stimulation before and after a training protocol. Finally, representative results and future directions of this research effort are discussed.

Mouse neuronal cells cultured on multi-electrode arrays display an increase in response following electrical stimulation. This protocol demonstrates how to culture neurons, how to record activity, and how to establish a protocol to train the networks to respond to patterns of stimulation.

Micro-electrode arrays (MEAs) can be used to investigate drug toxicity, design paradigms for next-generation personalized medicine, and study network ...

Silicon Nanowires and Optical Stimulation for Investigations of Intra- and Intercellular Electrical Coupling

Myofibroblasts can spontaneously internalize silicon nanowires (SiNWs), making them an attractive target for bioelectronic applications. These cell-silicon hybrids offer leadless optical modulation capabilities with minimal perturbation to normal cell behavior. The optical capabilities are obtained by the photothermal and photoelectric properties of SiNWs. These hybrids can be harvested using standard tissue culture techniques and then applied to different biological scenarios. We demonstrate here how these hybrids can be used to study the electrical coupling of cardiac cells and compare how myofibroblasts couple to one another or to cardiomyocytes. This process can be accomplished without special equipment beyond a fluorescent microscope with coupled laser line. Also shown is the use of a custom-built MATLAB routine that allows the quantification of calcium propagation within and between the different cells in the culture. Myofibroblasts are shown to have a slower electrical response than that of cardiomyocytes. Moreover, the myofibroblast intercellular propagation shows slightly slower, though comparable velocities to their intracellular velocities, suggesting passive propagation through gap junctions or nanotubes. This technique is highly adaptable and can be easily applied to other cellular arenas, for in vitro as well as in vivo or ex vivo investigations.

This protocol describes the use of silicon nanowires for intracellular optical bio-modulation of cell in a simple and easy to perform method. The technique is highly adaptable to diverse cell types and can be used for in vitro as well as in vivo applications.

Myofibroblasts can spontaneously internalize silicon nanowires (SiNWs), making them an attractive target for bioelectronic applications. These ...

Electric-Field-Induced Neural Precursor Cell Differentiation in Microfluidic Devices

Physiological electric fields (EF) play vital roles in cell migration, differentiation, division, and death. This paper describes a microfluidic cell culture system that was used for a long-term cell differentiation study using microscopy. The microfluidic system consists of the following major components: an optically transparent electrotactic chip, a transparent indium-tin-oxide (ITO) heater, a culture media-filling pump, an electrical power supply, a high-frequency power amplifier, an EF multiplexer, a programmable X-Y-Z motorized stage, and an inverted phase-contrast microscope equipped with a digital camera. The microfluidic system is beneficial in simplifying the overall experimental setup and, in turn, the reagent and sample consumption. This work involves the differentiation of neural stem and progenitor cells (NPCs) induced by direct current (DC) pulse stimulation. In the stem cell maintenance medium, the mouse NPCs (mNPCs) differentiated into neurons, astrocytes, and oligodendrocytes after the DC pulse stimulation. The results suggest that simple DC pulse treatment could control the fate of mNPCs and could be used to develop therapeutic strategies for nervous system disorders. The system can be used for cell culture in multiple channels, for long-term EF stimulation, for cell morphological observation, and for automatic time-lapse image acquisition. This microfluidic system not only shortens the required experimental time, but also increases the accuracy of control on the microenvironment.

In this study, we present a protocol for the differentiation of neural stem and progenitor cells (NPCs) solely induced by direct current (DC) pulse stimulation in a microfluidic system.

Physiological electric fields (EF) play vital roles in cell migration, differentiation, division, and death. This paper describes a microfluidic cell ...

Electric and Magnetic Field Devices for Stimulation of Biological Tissues

Electric fields (EFs) and magnetic fields (MFs) have been widely used by tissue engineering to improve cell dynamics such as proliferation, migration, differentiation, morphology, and molecular synthesis. However, variables such stimuli strength and stimulation times need to be considered when stimulating either cells, tissues or scaffolds. Given that EFs and MFs vary according to cellular response, it remains unclear how to build devices that generate adequate biophysical stimuli to stimulate biological samples. In fact, there is a lack of evidence regarding the calculation and distribution when biophysical stimuli are applied. This protocol is focused on the design and manufacture of devices to generate EFs and MFs and implementation of a computational methodology to predict biophysical stimuli distribution inside and outside of biological samples. The EF device was composed of two parallel stainless-steel electrodes located at the top and bottom of biological cultures. Electrodes were connected to an oscillator to generate voltages (50, 100, 150 and 200 Vp-p) at 60 kHz. The MF device was composed of a coil, which was energized with a transformer to generate a current (1 A) and voltage (6 V) at 60 Hz. A polymethyl methacrylate support was built to locate the biological cultures in the middle of the coil. The computational simulation elucidated the homogeneous distribution of EFs and MFs inside and outside of biological tissues. This computational model is a promising tool that can modify parameters such as voltages, frequencies, tissue morphologies, well plate types, electrodes and coil size to estimate the EFs and MFs to achieve a cellular response.

This protocol describes the step-by-step process to build both electrical and magnetic stimulators used to stimulate biological tissues. The protocol includes a guideline to simulate computationally electric and magnetic fields and manufacture of stimulator devices.

Electric fields (EFs) and magnetic fields (MFs) have been widely used by tissue engineering to improve cell dynamics such as proliferation, migration, ...

External Excitation of One-Dimensional Patterned Neuronal Cultures

Source:Stern, S., et al. <a href="https://app.jove.com/v/54357">External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures.</a> J. Vis. Exp. (2017)
This video demonstrates a technique for stimulating line-patterned neuronal cultures with a uniform, unidirectional electric field.

1. Imaging of spontaneous or evoked activity in neuronal cultures with fluorescent dyes.

	Prepare a solution of 50 &#181;g calcium sensitive fluorescent ...

JoVE Encyclopedia of Experiments

Neurophysiology

Stimulation and Modulation Techniques

Stimulation of Patterned Neuronal Cultures by a Magnetic Field

Source: Stern, S., et al., <a href="https://app.jove.com/v/54357">External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures.</a> J. Vis. Exp. (2017)
This video demonstrates a method for stimulating neuronal cultures grown in a patterned circular ring on a coverslip, using a time-varying magnetic field.

1. Preparation of coverslips for 1D cultures.

	Clean glass coverslips by immersion in a base piranha solution consisting of 75 mL DDW, 25 mL 25% ammonia ...

Building Three-Dimensional Neuronal Networks Coupled to Micro-Electrode Arrays

Source: Tedesco, M., et al., <a href="https://app.jove.com/v/53080">Interfacing 3D Engineered Neuronal Cultures to Micro-Electrode Arrays: An Innovative In Vitro Experimental Model.</a> J. Vis. Exp. (2015)
This video demonstrates the development of a 3D neuronal culture coupled to a planar microelectrode array with hippocampal neurons. The isolated neurons form a 2D network on the microelectrode array&#39;s active area and adhere to glass microbeads in a multi-well plate with a membrane insert. Upon transferring these neuron-coated microbeads to the electrode, they organize into an interconnected 3D neural network.

External Excitation of Neurons Using Electric and Magnetic Fields in One- and Two-dimensional Cultures

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