This work was supported by the National Institute of Health (RO1 NS120945, R37NS119012 to JK) and the UVA Brain Institute.

The present work is approved by the University of Virginia Animal Care and Use Committee. C57Bl/6 mice of both sexes (7-12 weeks) were used for the experiments. The animals were maintained on a 12 h light/12 h dark cycle and had ad libitum access to food and water.
1. Microelectrode construction
<ol>
	<li>To construct the microelectrodes, use 50 &#181;m (diameter) diamel-coated nickel-chromium wire (see Table of Materials). Tape one end of the wire ...

<ol>
	<li>Buzs&#225;ki, G., Anastassiou, C. A., Koch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+origin+of+extracellular+fields+and+currents-EEG,+ECoG,+LFP+and+spikes.">The origin of extracellular fields and currents-EEG, ECoG, LFP and spikes.</a> Nature Reviews Neuroscience. 13, 407-420 (2012).</li><li>Hubel, D. H., Wiesel, T. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Receptive+fields+of+single+neurones+in+the+cat's+striate+cortex.">Receptive fields of single neurones in the cat's striate cortex.</a> The Journal of Physiology. 148 (3), 574-591 (1959).</li><li>O'Keefe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Place+units+in+the+hippocampus+of+the+freely+moving+rat.">Place units in the hippocampus of the freely moving rat.</a> Experimental Neurology. 51 (1), 78-109 (1976).</li><li>Fyhn, M., Molden, S., Witter, M. P., Moser, E. I., Moser, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+representation+in+the+entorhinal+cortex.">Spatial representation in the entorhinal cortex.</a> Science. 305 (5688), 1258-1264 (2004).</li><li>Buzs&#225;ki, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+recording+of+neuronal+ensembles.">Large-scale recording of neuronal ensembles.</a> Nature Neuroscience. 7, 446-451 (2004).</li><li>Buckmaster, P. S., Edward Dudek, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+intracellular+analysis+of+granule+cell+axon+reorganization+in+epileptic+rats.">In vivo intracellular analysis of granule cell axon reorganization in epileptic rats.</a> Journal of Neurophysiology. 81 (2), 712-721 (1999).</li><li>Driscoll, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multimodal+in+vivo+recording+using+transparent+graphene+microelectrodes+illuminates+spatiotemporal+seizure+dynamics+at+the+microscale.">Multimodal in vivo recording using transparent graphene microelectrodes illuminates spatiotemporal seizure dynamics at the microscale.</a> Communications Biology. 4, 1-14 (2021).</li><li>Roy, D. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Memory+retrieval+by+activating+engram+cells+in+mouse+models+of+early+Alzheimer's+disease.">Memory retrieval by activating engram cells in mouse models of early Alzheimer's disease.</a> Nature. 531, 508-512 (2016).</li><li>Igarashi, K. M., Lu, L., Colgin, L. L., Moser, M. B., Moser, E. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coordination+of+entorhinal-hippocampal+ensemble+activity+during+associative+learning.">Coordination of entorhinal-hippocampal ensemble activity during associative learning.</a> Nature. 510, 143-147 (2014).</li><li>Gage, G. J., Kipke, D. R., Shain, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+animal+perfusion+fixation+for+rodents.">Whole animal perfusion fixation for rodents.</a> Journal of Visualized Experiments. (65), e3564 (2012).</li><li>Brodovskaya, A., Shiono, S., Kapur, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+the+basal+ganglia+and+indirect+pathway+neurons+during+frontal+lobe+seizures.">Activation of the basal ganglia and indirect pathway neurons during frontal lobe seizures.</a> Brain. 144 (7), 2074-2091 (2021).</li><li>Ren, X., Brodovskaya, A., Hudson, J. L., Kapur, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Connectivity+and+neuronal+synchrony+during+seizures.">Connectivity and neuronal synchrony during seizures.</a> The Journal of Neuroscience. 41 (36), 7623-7635 (2021).</li><li>Chang, E. H., Frattini, S. A., Robbiati, S., Huerta, P. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Construction+of+microdrive+arrays+for+chronic+neural+recordings+in+awake+behaving+mice.">Construction of microdrive arrays for chronic neural recordings in awake behaving mice.</a> Journal of Visualized Experiments. (77), e50470 (2013).</li></ol>

Historically, microelectrode arrays have been extensively used to record neuronal activity from a specific brain region of interest2,3,4,5,6,7,8,9,13. However, our easy microelectrode design allows recording from multiple ...

Local field potentials (LFPs) are the electric potentials recorded from the extracellular space in the brain. They are generated by ion concentration imbalances outside of neurons and represent the activity of a small, localized population of neurons, allowing to precisely monitor the activity of a specific brain region compared to the macroscale EEG recordings1. As an estimate, the LFP microelectrodes separated by 1 mm correspond to two completely different populations of neurons. While EEG signal is filtered by brain tissue, cerebrospinal fluid, skull, muscle, and skin, LFP signal is a reliable marker of local neuronal activity1.
Researchers often need to simultaneously record LFPs from several brain structures, but commercially available microelectrode arrays often do not offer such flexibility. Here, the present protocol describes fully customizable, easily constructed microelectrodes to simultaneously record LFPs from any desired brain region at different depths. Although LFPs have extensively been used to record the neuronal activity of a specific brain region2,3,4,5,6,7,8,9, the current easy customizable design allows recording LFPs from any multiple superficial or deep brain regions11,12. The protocol can also be modified to construct any desired microelectrode array by determining stereotaxic coordinates of the brain regions and assembling the array accordingly. These microelectrodes with a 10 kHz sampling rate and 60-70 k&#8486; resistance (2 cm length) allow us to record LFPs with millisecond precision. The data can then be amplified by a 16-channel amplifier, filtered (low pass 1 Hz, high pass 5 kHz), and digitized.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Amplifier 16-Channel</td>
			<td>A-M Systems</td>
			<td>Model 3600</td>
			<td>Amplifier</td>
		</tr>
		<tr>
			<td>Cranioplasty cement</td>
			<td>Coltene</td>
			<td>Perm Reeline/Repair Resin Type II Class I Shade - Clear</td>
			<td>Cement to hold microelectrodes</td>
		</tr>
		<tr>
			<td>Cryostat Microtome</td>
			<td>Precisionary</td>
			<td>CF-6100</td>
			<td>To slice brain</td>
		</tr>
		<tr>
			<td>Diamel-coatednickel-chromium wire</td>
			<td>Johnson Matthey Inc.</td>
			<td>50 &#181;m</td>
			<td>Microelectrode wire</td>
		</tr>
		<tr>
			<td>Dremel</td>
			<td>Dremel</td>
			<td>300 Series</td>
			<td>To drill holes in mouse skull</td>
		</tr>
		<tr>
			<td>Epoxy</td>
			<td>CEC Corp</td>
			<td>C-POXY 5</td>
			<td>Fast setting adhesive</td>
		</tr>
		<tr>
			<td>Hemostat</td>
			<td>Any</td>
			<td></td>
			<td>To hold the headset</td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>Any</td>
			<td></td>
			<td>To hold microelectrodes</td>
		</tr>
		<tr>
			<td>Light microscope</td>
			<td>Nikon</td>
			<td>SMZ-10</td>
			<td>To see alignment</td>
		</tr>
		<tr>
			<td>Ohmmeter</td>
			<td>Any</td>
			<td></td>
			<td>To measurre resistance</td>
		</tr>
		<tr>
			<td>Pins (Headers and matching Sockets)</td>
			<td>Mill-Max</td>
			<td>Interconnects, 833 series, 2 mm grid gull wing surface mount headers and sockets</td>
			<td>To attach microelectrodes to</td>
		</tr>
		<tr>
			<td>Polymicro Tubing Kit</td>
			<td>Neuralynx</td>
			<td>ID 100 &#177; 04 &#181;m, OD 164 &#177; 06 &#181;m, coating thickness 12 &#181;m</td>
			<td>Glass tubes</td>
		</tr>
		<tr>
			<td>Pulse Stimulator</td>
			<td>A-M Systems</td>
			<td>Model 2100</td>
			<td>To mark the microelectrode location at the end of the recordings</td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td>Any</td>
			<td></td>
			<td>To cut microelectrodes</td>
		</tr>
		<tr>
			<td>Superglue</td>
			<td>Gorilla</td>
			<td></td>
			<td>Adhesive</td>
		</tr>
		<tr>
			<td>Thick wire 0.008 in. &#8211; 0.011 in.</td>
			<td>A-M Systems</td>
			<td>791900</td>
			<td>Tick wire to hold the microelectrode array</td>
		</tr>
		<tr>
			<td>Thin wire 0.005 in. - 0.008 in.</td>
			<td>A-M Systems</td>
			<td>791400</td>
			<td>Thin wire for reference and ground</td>
		</tr>
	</tbody>
</table>

construction of local field potential microelectrodes for in vivo recordings from multiple brain structures simultaneously

Researchers often need to record local field potentials (LFPs) simultaneously from several brain structures. Recording from multiple desired brain regions requires different microelectrode designs, but commercially available microelectrode arrays often do not offer such flexibility. Here, the present protocol outlines the straightforward design of custom-made microelectrode arrays to record LFPs from multiple brain structures simultaneously at different depths. This work describes the construction of the bilateral cortical, striatal, ventrolateral thalamic, and nigral microelectrodes as an example. The outlined design principle offers flexibility, and the microelectrodes can be modified and customized to record LFPs from any structure by calculating stereotaxic coordinates and quickly changing the construction accordingly to target different brain regions in either freely moving or anesthetized mice. The microelectrode assembly requires standard tools and supplies. These custom microelectrode arrays allow investigators to easily design microelectrode arrays in any configuration to track neuronal activity, providing LFP recordings with millisecond resolution.

In this work, the LFP microelectrodes were used to map the seizure spread through the basal ganglia11. Simultaneous LFP recordings were performed from the right premotor cortex (where the seizure focus was) and the left VL, striatum, and SNR (Figure 4). Seizure start was identified as deflection of the voltage trace at least twice the baseline (Figure 4A, red arrow). The power spectrum plot11&#160;shows frequency d...

Watch this Scientific Journal Video about Construction of Local Field Potential Microelectrodes for in vivo Recordings from Multiple Brain Structures Simultaneously at JoVE.com

Construction of Local Field Potential Microelectrodes for in vivo Recordings from Multiple Brain Structures Simultaneously

The present protocol describes the construction of custom-made microelectrode arrays to record local field potentials in vivo from multiple brain structures simultaneously.

Construction of Local Field Potential Microelectrodes for in vivo Recordings from Multiple Brain Structures Simultaneously

Researchers often need to record local field potentials (LFPs) simultaneously from several brain structures. Recording from multiple desired brain regions ...

Researchers often need to record local field potentials from multiple structures at the same time. Our easy microelectrode design allows us to record LFPs from several brain structures at different depths simultaneously. Commercially available microelectrodes often lack flexibility and do not allow to record from multiple brain structures.Our microelectrode design allows to easily modify the construction to fit any desired structure. Start by taking a dianal-coated nickel chromium wire 50 micrometers in diameter. Tape one end of the wire to the back of the platform and wrap the wire three times around the nearest knob on the platform.Stretch the wire around the farthest second knob to make two loops between the knobs. Wrap the wire three more times around the first knob to fix the wire in place and tape the end at the back of the platform. Place the tension bars under the wires with the tape wrapped around them.Using a microscope and fine forceps, make either a three-millimeter gap between the wires to make cortical, ventral-lateral, thalamic nucleus microelectrodes or a 4.5-millimeter gap to make striatal-nidral microelectrodes. If magnification is used on the microscope, ensure to calculate and adjust for the difference in magnification and the actual distance between the wires. Cut four small pieces of 0.5-millimeter-thick plastic approximately six millimeters in width and three millimeters in height.Apply glue on the plastic. Place the plastic pieces approximately one centimeter away from the middle of the wire, which is one centimeter away from the tension bar. Remove excess glue with a cotton swab.After the glue dries, cut the wire using fine scissors. Cut four seven-millimeter glass tubes using a commercially available kit and insert the electrode wire into the glass tubes. Put the glue at the base of the glass tubes to connect them to the plastic.Wait until the glue dries, then cut the glass tubes and wires using a scalpel. Use super glue to attach plastics in the desired order of target regions. Apply epoxy resin around the plastic to bind the electrodes together.Take a thick wire and make a loop on one end, dip the loop in the epoxy solution, and place it on the plastic, ensuring the thick wire is lying flat so that this wire could be used as a handle. Cut the wire to two centimeters. Group the wires and scrape away one millimeter of the isolated ends with a scalpel.Bend the cortical electrodes and separate the wires. Using fine forceps, make a loop at the end of each wire. Hold a 10-pin headset with a hemostat and use the wooden end of a cotton swab to apply minimal amounts of flux on the pins.Using the wooden end of the cotton swab, apply flux to the wire loops. Solder the wire loops to the 10-pin headset. Dry the headset to prevent short circuit among the pins.Take a thin wire of about 0.05 to 0.008 inches for reference and ground wires and strip off the plastic from one end. Make a loop on the other end of the wire. Solder the stripped side of the reference and ground wires to their respective pins.Holding the thick wire, apply cranioplasty cement around the microelectrodes, especially where the wires connect to the pins. Avoid touching the actual electrode ends with the cement. After the cement dries, put epoxy resin at the base of the glass tubes, striatal microelectrode wires, and around the whole electrode.Avoid touching the electrode ends with epoxy resin. Local field potential recordings were performed from the right pre-motor cortex, the left VL, striatum, and SNR. Seizure start was identified as a deflection of the voltage trace at least twice the baseline.The power spectrum plot shows the frequency distribution for the recorded local potential recordings. Seizure onset latencies could be compared between each structure with millisecond precision. A current pulse was applied at the end of the recordings to mark and confirm the location of the electrodes tips forming the lesion.If the microelectrodes are constructed for different brain structures, remember to modify the gaps between the wires according to the stereotactic coordinates of your desired structure. Place the deep structure electrodes into the glass tubes and adjust the lengths of the microelectrodes. Then, attach the plastics in the required order.

construction-local-field-potential-microelectrodes-for-vivo

Research

JoVE Journal

Neuroscience

2.7K visualizações.  University of Virginia. Os pesquisadores muitas vezes precisam registrar potenciais de campo locais a partir de múltiplas estruturas ao mesmo tempo. Nosso design fácil de microeletrodes nos permite gravar LFPs de várias estruturas cerebrais em diferentes profundidades simultaneamente. Microeletros disponíveis comercialmente muitas vezes carecem de flexibilidade e não permitem gravar a partir de múltiplas estruturas cerebrais.Nosso projeto de microeletrodo permite modificar facilmente a construção para...