Name: one-channel cell-attached patch-clamp recording
Uploaded: 2014-06-09T14:45:00
Description: Watch this Scientific Journal Video about One-channel Cell-attached Patch-clamp Recording at JoVE.com

Ce travail a été soutenu par F31NS086765 (KAC), F31NS076235 (MAP), et R01 NS052669 (GKP) et EIA9100012. Les auteurs remercient Eileen Kasperek d&#39;expertise et d&#39;aide à la biologie moléculaire et de la culture de tissus; et Jason Myers pour partager les données obtenues à partir de début neurones corticaux préfrontaux.

1. Culture cellulaire et l&#39;expression des protéines <ol><li> Maintenir des cellules HEK293 (numéro ATCC CRL-1573) entre les passages 22 et 40, qui comprend des passages effectués par l&#39;ATCC, en culture monocouche dans du milieu DMEM supplémenté avec 10% de sérum bovin fœtal (FBS) et 1% de pénicilline / mélange streptomycine à 5% de CO 2 et 37 ° C. Entre expériences, les cellules de passage dans des flacons T25 à 5-20 dilutions dans un volume final de 10 ml. Remarque: En utilisant des ce...

<ol>
	<li>Neher, E., Sakmann, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-channel+currents+recorded+from+membrane+of+denervated+frog+muscle+fibres.">Single-channel currents recorded from membrane of denervated frog muscle fibres.</a> Nature. 260, 799-802 (1976).</li><li>Hamill, O. P., Marty, A., Neher, E., Sakmann, B., Sigworth, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+patch-clamp+techniques+for+high-resolution+current+recording+from+cells+and+cell-free+membrane+patches.">Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.</a> Pflugers Arch. 391, 85-100 (1981).</li><li>Piccolino, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+electricity+and+the+birth+of+electrophysiology:+the+legacy+of+Luigi+Galvani.">Animal electricity and the birth of electrophysiology: the legacy of Luigi Galvani.</a> Brain Research Bulletin. 46, 381-407 (1998).</li><li>Albright, T. D., Jessell, T. M., Kandel, E. R., Posner, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+Science:+A+Century+of+Progress+and+the+Mysteries+that+Remain.">Neural Science: A Century of Progress and the Mysteries that Remain.</a> Neuron. 25, (2000).</li><li>Popescu, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modes+of+glutamate+receptor+gating.">Modes of glutamate receptor gating.</a> The Journal of Physiology. 590, 73-91 (2012).</li><li>Morimoto-Tomita, M., 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=Autoinactivation+of+Neuronal+AMPA+Receptors+via+Glutamate-Regulated+TARP+Interaction.">Autoinactivation of Neuronal AMPA Receptors via Glutamate-Regulated TARP Interaction.</a> Neuron. 61, 101-112 (2009).</li><li>Thomas, P., Smart, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HEK293+cell+line:+A+vehicle+for+the+expression+of+recombinant+proteins.">HEK293 cell line: A vehicle for the expression of recombinant proteins.</a> Journal of Pharmacological and Toxicological Methods. 51, 187-200 (2005).</li><li>Huang, Z., Li, G., Pei, W., Sosa, L. A., Niu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancing+protein+expression+in+single+HEK+293+cells.">Enhancing protein expression in single HEK 293 cells.</a> Journal of Neuroscience Methods. 142, 159-166 (2005).</li><li>Raymond, L. A., Moshaver, A., Tingley, W. G., Huganir, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glutamate+receptor+ion+channel+properties+predict+vulnerability+to+cytotoxicity+in+a+transfected+nonneuronal+cell+line.">Glutamate receptor ion channel properties predict vulnerability to cytotoxicity in a transfected nonneuronal cell line.</a> Mol Cell Neurosci. 7, 102-115 (1996).</li><li>Suchyna, T. M., Markin, V. S., Sachs, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biophysics+and+Structure+of+the+Patch+and+the+Gigaseal.">Biophysics and Structure of the Patch and the Gigaseal.</a> Biophysical Journal. 97, 738-747 (2009).</li><li>Qin, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Restoration+of+single-channel+currents+using+the+segmental+k-means+method+based+on+hidden+Markov+modeling.">Restoration of single-channel currents using the segmental k-means method based on hidden Markov modeling.</a> Biophys J. 86, 1488-1501 (2004).</li><li>Colquhoun, D., Sigworth, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> chapter in Single-channel recording. 2nd edn eds B. Sakmann and E Neher. , (1995).</li><li>Popescu, G., Auerbach, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modal+gating+of+NMDA+receptors+and+the+shape+of+their+synaptic+response.">Modal gating of NMDA receptors and the shape of their synaptic response.</a> Nat Neurosci. 6, 476-483 (2003).</li><li>Colquhoun, D., Hawkes, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stochastic+properties+of+ion+channel+openings+and+bursts+in+a+membrane+patch+that+contains+two+channels:+evidence+concerning+the+number+of+channels+present+when+a+record+containing+only+single+openings+is+observed.">Stochastic properties of ion channel openings and bursts in a membrane patch that contains two channels: evidence concerning the number of channels present when a record containing only single openings is observed.</a> Proc R Soc Lond B Biol Sci. 240, 453-477 (1990).</li><li>Kussius, C. L., Kaur, N., Popescu, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pregnanolone+Sulfate+Promotes+Desensitization+of+Activated+NMDA+Receptors.">Pregnanolone Sulfate Promotes Desensitization of Activated NMDA Receptors.</a> J. Neurosci. 29, 6819-6827 (2009).</li><li>Amico-Ruvio, S., Popescu, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stationary+gating+of+GluN1/GluN2B+receptors+in+intact+membrane+patches.">Stationary gating of GluN1/GluN2B receptors in intact membrane patches.</a> Biophysical Journal. 98, 1160-1169 (2010).</li><li>Borschel, W. F., 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=Gating+reaction+mechanism+of+neuronal+NMDA+receptors.">Gating reaction mechanism of neuronal NMDA receptors.</a> J Neurophysiol. 108, 3105-3115 (2012).</li><li>Colquhoun, D., Hatton, C. J., Hawkes, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+quality+of+maximum+likelihood+estimates+of+ion+channel+rate+constants.">The quality of maximum likelihood estimates of ion channel rate constants.</a> The Journal of Physiology. 547, 699-728 (2003).</li><li>Kussius, C. L., Kaur, N., Popescu, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pregnanolone+Sulfate+Promotes+Desensitization+of+Activated+NMDA+Receptors.">Pregnanolone Sulfate Promotes Desensitization of Activated NMDA Receptors.</a> The Journal of Neuroscience. 29, 6819-6827 (2009).</li><li>Popescu, G., Auerbach, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modal+gating+of+NMDA+receptors+and+the+shape+of+their+synaptic+response.">Modal gating of NMDA receptors and the shape of their synaptic response.</a> Nat Neurosci. 6, 476-483 (2003).</li><li>Popescu, G., Robert, A., Howe, J. R., Auerbach, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reaction+mechanism+determines+NMDA+receptor+response+to+repetitive+stimulation.">Reaction mechanism determines NMDA receptor response to repetitive stimulation.</a> Nature. 430, 790-793 (2004).</li><li>Prieto, M. L., Wollmuth, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gating+Modes+in+AMPA+Receptors.">Gating Modes in AMPA Receptors.</a> The Journal of Neuroscience. 30, 4449-4459 (2010).</li><li>Poon, K., Nowak, L. M., Oswald, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterizing+Single-Channel+Behavior+of+GluA3+Receptors.">Characterizing Single-Channel Behavior of GluA3 Receptors.</a> Biophysical Journal. 99, 1437-1446 (2010).</li><li>Smith, T. C., Wang, L. -. Y., Howe, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterogeneous+Conductance+Levels+of+Native+AMPA+Receptors.">Heterogeneous Conductance Levels of Native AMPA Receptors.</a> The Journal of Neuroscience. 20, 2073-2085 (2000).</li><li>Coste, B., 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=Piezo1+and+Piezo2+Are+Essential+Components+of+Distinct+Mechanically+Activated+Cation+Channels.">Piezo1 and Piezo2 Are Essential Components of Distinct Mechanically Activated Cation Channels.</a> Science. 330, 55-60 (2010).</li><li>Coste, B., 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=Piezo+proteins+are+pore-forming+subunits+of+mechanically+activated+channels.">Piezo proteins are pore-forming subunits of mechanically activated channels.</a> Nature. 483, 176-181 (2012).</li><li>Benndorf, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> chapter in Single-channel recording. 2nd edn eds B. Sakmann and E Neher. , (1995).</li></ol>

Dans le domaine de canal ionique, un domaine important de la recherche est consacrée à la compréhension de la séquence d&#39;événements qui conduit à la voie d&#39;ouverture ou le mécanisme de déclenchement de la voie. Pour la plupart des canaux, ce processus est complexe et implique plusieurs étapes cinétiques qui ne peuvent être déduites à partir d&#39;un signal multicanal macroscopique. En revanche, les expériences peuvent être conçus où l&#39;observation de la séquence des événements ouverts / f...

Communication rapide à travers les membranes biologiques repose presque exclusivement sur les oligomères pores formant les protéines membranaires, communément appelées canaux. Ces protéines sont très différentes dans les signaux d&#39;activation, les mécanismes de déclenchement et les propriétés de conductance. protéines de la Manche dont les pores sont sélectifs pour les ions sont classés comme des canaux ioniques; leur activation produit des courants ioniques à travers la membrane, et leurs réponses peuvent être enregistrées avec une haute résolution en temps réel en utilisant des techniques électrophysiologiques. Les signaux d&#39;activation couvrent un large éventail de produits chimiques et physiques, y compris des gradients de concentration, les forces mécaniques et électriques, et de la température; ainsi, une classification supplémentaire des canaux ioniques dans ligand fermée, mécano, tension fermée, ou types sensibles à la chaleur. Dans cet article, les protocoles sont décrits pour enregistrer l&#39;activité d&#39;un canal à partir d&#39;un canal de ligand fermée, le récepteur de NMDA, et d&#39;un canal mécanosensible, PIEZO1, en utilisant la technique de patch-clamp.0; Patch-clamp électrophysiologie est le premier et le plus largement utilisé la méthode expérimentale suffisamment sensible pour permettre l&#39;observation de molécules simples 1, 2. En plus de cette sensibilité exquise, il a considérablement élargi les préparations biologiques qui se prêtent à l&#39;enregistrement électrophysiologique et a également permis l&#39;observation des canaux ioniques dans les membranes intactes. Tout d&#39;abord, parce que les deux serrage de tension et l&#39;enregistrement de courant sont réalisées avec la même électrode, il peut être utilisé pour enregistrer des signaux à travers les petites membranes des cellules ou des patchs. La technique a révélé que les canaux ioniques sont pas limités à membranes excitables des muscles de la grenouille, electroplaques d&#39;anguilles, ou axones géants de calmar 3, 4, mais plutôt qu&#39;ils représentent appareils omniprésents de mécanismes de signalisation transmembranaires et sont intrinsèques à tous les types de membranes cellulaires des uni-ou organismes multicellulaires, et aussi à des membranes intracellulaires. Importerantly, la capacité d&#39;enregistrer des courants transmembranaires en attachant simplement une pipette en verre à une cellule intacte l&#39;occasion sans précédent pour enregistrer l&#39;activité de canaux ioniques dans leurs membranes natives sans perturbation. Ainsi, l&#39;attaché technique de patch-clamp cellule, qui est décrite dans ce protocole, permet le suivi de l&#39;activité des canaux ioniques en continu pendant des dizaines de minutes ou plus dans leur environnement naturel. Sous fluctuations thermiques normales, toutes les protéines, y compris les protéines de canaux ioniques, subissent des changements structuraux sur une échelle de temps grande, avec les réarrangements les plus rapides et les plus fréquemment représentés le plus probable par les mouvements de la chaîne latérale et beaucoup plus lentes modifications et moins fréquentes représentés par le repositionnement de l&#39;ensemble de des domaines ou des sous-unités, ou dans certains cas par des modifications post-traductionnelles ou des interactions protéine-protéine 5, 6. Observant de longues périodes d&#39;activité générés par une molécule peut aider à comprendre la fonctiondynamique internationales des canaux ioniques dans les membranes intactes physiologiques et fournit des informations précieuses sur le mécanisme de fonctionnement de la molécule observée. Contrairement à la compréhension croissante de la diversité des canaux ioniques dans des types de cellules et les stades de développement, les connaissances sur la composition moléculaire des canaux ioniques dans les membranes natives est encore limitée. Tous les canaux ioniques sont des protéines multimériques et la majorité des canaux ioniques natifs assembler à partir de plusieurs types de sous-unités produisant des protéines de grande diversité moléculaire, qui est souvent accompagnée par des propriétés de conductance et de déclenchement divers. Pour cette raison, les canaux ioniques de la composition moléculaire définie sont étudiés lors de l&#39;expression dans des systèmes hétérologues. En particulier, les cellules HEK293, qui sont une lignée clonale de cellules embryonnaires de rein humaines immortalisées 7, acquis une large acceptation en tant que le système préféré pour l&#39;expression hétérologue des canaux ioniques recombinants. Parmi l&#39;hommeavantages y qui a élevé les cellules HEK293 que le système de choix pour les canaux ioniques électrophysiologie sont la facilité et l&#39;accessibilité de la culture et le maintien de cultures à long terme stables, leur capacité à mener à bien pliage post-traductionnelle, la transformation et le trafic de protéines de mammifères, et dans de nombreux cas , leur faible niveau voire l&#39;absence d&#39;expression endogène pour le canal d&#39;intérêt 7, 8. Exprimant canaux ioniques recombinantes et d&#39;étudier leurs propriétés fonctionnelles dans les cellules HEK293 continue d&#39;être une approche intéressante pour obtenir des informations sur les propriétés de structure-fonction des canaux ioniques ainsi que les propriétés spécifiques des isoformes de canaux ioniques et leurs rôles dans le tissu natif. Les protocoles décrits dans cet article peuvent être appliquées aussi bien aux canaux ioniques recombinants exprimés dans des cellules HEK293 et ​​de canaux ioniques natifs. En résumé, la technique de patch-clamp, grâce à sa capacité sans précédent pour résoudre le signals d&#39;une molécule demeure, à ce jour, la méthode la plus directe pour observer le comportement des molécules simples. Dans son mode cellule attachée, l&#39;enregistrement de patch-clamp permet longues périodes d&#39;observation qui, après l&#39;avoir fait pour une molécule, peuvent fournir des renseignements de qualité exceptionnelle dans le fonctionnement des canaux ioniques. Ci-dessous est présenté un protocole permettant d&#39;obtenir des enregistrements de courant à haute résolution à partir de patchs attachés de cellules contenant une protéine de canal ionique.

<table border="0" cellpadding="0" cellspacing="0" width="695">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:189px;">Chemicals</td>
			<td style="width:173px;">Sigma</td>
			<td style="width:128px;">Various</td>
			<td style="width:205px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Borosillicate Glass</td>
			<td>Sutter</td>
			<td>BF-150-86-10</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Bright field inverted microscope</td>
			<td>Olympus</td>
			<td>1x51</td>
			<td>Nikon also has similar microscopes</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fluroescent box</td>
			<td>X-cite</td>
			<td>Series 120</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Liquid Light Guide</td>
			<td>X-cite</td>
			<td>OEX-LG15</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Micromanipulator</td>
			<td>Sutter Instruments</td>
			<td>MP-225</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Oscilloscope</td>
			<td>Tektronix</td>
			<td>TDS1001</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Amplifier</td>
			<td>Molecular Devices</td>
			<td colspan="2">Axon Axopatch 200B&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Table</td>
			<td>TMC</td>
			<td align="right">63561</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NIDAQ card</td>
			<td>National Instruments</td>
			<td>776844-01</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Puller</td>
			<td>Narishige</td>
			<td>PC-10</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Polisher</td>
			<td>Narishige</td>
			<td>Microforge MF-830</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Faraday Cage</td>
			<td>TMC</td>
			<td align="right">8133306</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">High Speed Pressure Clamp</td>
			<td>ALA Scientific Instruments</td>
			<td>ALA HSPC</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Pressue/Vaccuum Pump</td>
			<td>ALA Scientific Instruments</td>
			<td>ALA PV-PUMP</td>
			<td>For HSPC-1</td>
		</tr>
	</tbody>
</table>

one-channel cell-attached patch-clamp recording

Protéines de canaux ioniques sont des dispositifs universels de communication rapide à travers les membranes biologiques. La signature temporelle du flux ionique qu&#39;ils génèrent dépend des propriétés intrinsèques de chaque protéine de canal ainsi que le mécanisme par lequel il est généré et contrôlé et représente un domaine important de la recherche actuelle. D&#39;informations sur la dynamique de fonctionnement des protéines de canal ionique peut être obtenue par l&#39;observation de longues étendues de courant produites par une seule molécule. Décrit ici est un protocole permettant d&#39;obtenir un canal de patch-clamp enregistrements actuels attachés cellulaires pour un canal ionique ligand fermée, le récepteur de NMDA, exprimé de manière hétérologue dans des cellules HEK293 ou nativement dans les neurones corticaux. Également des instructions sur la façon d&#39;adapter la méthode à d&#39;autres canaux ioniques d&#39;intérêt en présentant l&#39;exemple du canal PIEZO1 mécano-sensible. Cette méthode peut fournir des données concernant les propriétés de conductance de la chaîne et la séquence temporelle de l&#39;OPEconformations n-fermées qui constituent le mécanisme d&#39;activation de la chaîne, aidant ainsi à comprendre leurs fonctions en matière de santé et de la maladie.

Recombinant récepteurs NMDA Récepteurs NMDA se lient et de répondre à l&#39;action concomitante des deux co-agonistes: glutamate et la glycine. Ils assemblent comme hétérotétramères de deux sous-unités glycine GluN1 et sous-unités GluN2 liaison deux glutamate de liaison. Sous-unités GluN2 sont codés par quatre gènes (AD) et de ces formes les plus largement transcrites dans le cerveau sont GluN2A chez les adultes et chez les animaux jeunes GluN2B. En raison de la...

Watch this Scientific Journal Video about One-channel Cell-attached Patch-clamp Recording at JoVE.com

One-channel Cell-attached Patch-clamp Recording

Décrit ici est un procédé d&#39;obtention de longues étendues de l&#39;enregistrement en cours d&#39;un canal ionique avec la technique de patch-clamp cellule attachée. Cette méthode permet d&#39;observer, en temps réel, le modèle de conformations ouverture-fermeture de canal qui sous-tendent le signal biologique. Ces données renseignent sur les propriétés du canal dans les membranes biologiques intactes.

Un canal cellulaire attaché patch-clamp enregistrement

Ion channel proteins are universal devices for fast communication across biological membranes. The temporal signature of the ionic flux they generate ...

one-channel-cell-attached-patch-clamp-recording

Research

JoVE Journal

Biology

Methods for Patch Clamp Capacitance Recordings from the Calyx

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. Electrical recordings from the presynaptic terminal allow the measurement of action potentials, calcium channel currents, vesicle fusion (exocytosis) and subsequent membrane uptake (endocytosis). The fusion of vesicles containing neurotransmitter causes the vesicle membrane to be added to the cell membrane of the calyx. This increase in the amount of cell membrane is measured as an increase in capacitance. The subsequent reduction in capacitance indicates endocytosis, the process of membrane uptake or removal from the calyx membrane. Endocytosis, is necessary to maintain the structure of the calyx and it is also necessary to form vesicles that will be filled with neurotransmitter for future exocytosis events. Capacitance recordings at the calyx of Held have made it possible to directly and rapidly measure vesicular release and subsequent endocytosis in a mammalian CNS nerve terminal. In addition, the corresponding postsynaptic activity can be simultaneously measured by using paired recordings. Thus a complete picture of the presynaptic and postsynaptic electrical activity at a central nervous system synapse is achievable using this preparation. Here, the methods for slice preparation, morphological features for identification of calyces of Held, basic patch clamping techniques, and examples of capacitance recordings to measure exocytosis and endocytosis are presented.

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal.

Méthodes pour les enregistrements patch clamp Capacité du calice

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. ...

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Biologie

Patch Clamp Recording of Ion Channels Expressed in  Xenopus Oocytes

Since its development by Sakmann and Neher 1, 2, the patch clamp has become established as an extremely useful technique for electrophysiological measurement of single or multiple ion channels in cells. This technique can be applied to ion channels in both their native environment and expressed in heterologous cells, such as oocytes harvested from the African clawed frog, Xenopus laevis. Here, we describe the well-established technique of patch clamp recording from Xenopus oocytes. This technique is used to measure the properties of expressed ion channels either in populations (macropatch) or individually (single-channel recording). We focus on techniques to maximize the quality of oocyte preparation and seal generation. With all factors optimized, this technique gives a probability of successful seal generation over 90 percent. The process may be optimized differently by every researcher based on the factors he or she finds most important, and we present the approach that have lead to the greatest success in our hands.

This is intended as an introduction to patch clamp recording from Xenopus laevis oocytes. It covers vitelline membrane removal, formation of a gigaohm seal (gigaseal), and the optional conversion of the patch to the outside-out topology.

Enregistrement Patch Clamp des canaux ioniques exprimés dans les oocytes de Xenopus

Since its development by Sakmann and Neher 1, 2, the patch clamp has become established as an extremely useful technique for electrophysiological ...

Pressure-polishing Pipettes for Improved Patch-clamp Recording

Pressure-polishing is a method for shaping glass pipettes for patch-clamp recording. We first developed this method for fabricating pipettes suitable for recording from small (&lt;3 m) neuronal cell bodies. The basic principal is similar to glass-blowing and combines air pressure and heat to modify the shape of patch pipettes prepared by a conventional micropipette puller. It can be applied to so-called soft (soda lime) and hard (borosilicate) glasses. Generally speaking, pressure polishing can reduce pipette resistance by 25% without decreasing the diameter of the tip opening (Goodman and Lockery, 2000). It can be applied to virtually any type of glass and requires only the addition of a high-pressure valve and fitting to a microforge. This technique is essential for recording from ultrasmall cells (&lt;5 m) and can also improve single-channel recording by minimizing pipette resistance. The blunt shape is also useful for perforated-patch clamp recording since this tip shape results in a larger membrane bleb available for perforation.

This is a guide to modifying the shape of glass micropipettes. Specifically, by using heat and air pressure the taper is widened without increasing the tip opening, leading to lower pipette resistance. This is critical to obtain low noise recordings of small cells but is useful in many applications.

Pression de polissage Pipettes Amélioration patch-clamp

Pressure-polishing is a method for shaping glass pipettes for patch-clamp recording.  We first developed this method for fabricating pipettes suitable for ...

Dissecting and Recording from The C. Elegans Neuromuscular Junction

Neurotransmission is the process by which neurons transfer information via chemical signals to their post-synaptic targets, on a rapid time scale. This complex process requires the coordinated activity of many pre- and post-synaptic proteins to ensure appropriate synaptic connectivity, conduction of electrical signals, targeting and priming of secretory vesicles, calcium sensing, vesicle fusion, localization and function of postsynaptic receptors and finally, recycling mechanisms. As neuroscientists it is our goal to elucidate which proteins function in each of these steps and understand their mechanisms of action. Electrophysiological recordings from synapses provide a quantifiable read out of the underlying electrical events that occur during synaptic transmission. By combining this technique with the powerful array of molecular and genetic tools available to manipulate synaptic proteins in C. elegans, we can analyze the resulting functional changes in synaptic transmission. 
The C. elegans NMJs formed between motor neurons and body wall muscles control locomotion, therefore, mutants with uncoordinated locomotory phenotypes (known as unc s) often perturb synaptic transmission at these synapses 1. Since unc mutants are maintained on a rich supply of a bacterial food source, they remain viable as long as they retain some pharyngeal pumping ability to ingest food. This, together with the fact that C. elegans exist as hermaphrodites, allows them to pass on mutant progeny without the need for elaborate mating behaviors. These attributes, coupled with our recent ability to record from the worms NMJs 2,3,7 make this an excellent model organism in which to address precisely how unc mutants impact neurotransmission. 
The dissection method involves immobilizing adult worms using a cyanoacrylic glue in order to make an incision in the worm cuticle exposing the NMJs. Since C. elegans adults are only 1 mm in length the dissection is performed with the use of a dissecting microscope and requires excellent hand-eye coordination. NMJ recordings are made by whole-cell voltage clamping individual body wall muscle cells and neurotransmitter release can be evoked using a variety of stimulation protocols including electrical stimulation, light-activated channel-rhodopsin-mediated depolarization 4 and hyperosmotic saline, all of which will be briefly described.

Application of electrophysiology to accessible synapses provides a quantifiable measure of synaptic activity, useful in analyzing synaptic mutants. This article describes a dissection method used to expose the neuromuscular junctions (NMJ) of Caenorhabditis elegans (C. elegans) and briefly discusses some of the uses to which this preparation can be applied.

Dissection et d&#39;enregistrement de la jonction neuromusculaire C. Elegans

Neurotransmission is the process by which neurons transfer information via chemical signals to their post-synaptic targets, on a rapid time scale.   This ...

Electrophysiological Recording in the Drosophila Embryo

Drosophila is a premier genetic model for the study of both embryonic development and functional neuroscience. Traditionally, these fields are quite isolated from each other, with largely independent histories and scientific communities. However, the interface between these usually disparate fields is the developmental programs underlying acquisition of functional electrical signaling properties and differentiation of functional chemical synapses during the final phases of neural circuit formation. This interface is a critically important area for investigation. In Drosophila, these phases of functional development occur during a period of &lt;8 hours (at 25&deg;C) during the last third of embryogenesis. This late developmental period was long considered intractable to investigation owing to the deposition of a tough, impermeable epidermal cuticle. A breakthrough advance was the application of water-polymerizing surgical glue that can be locally applied to the cuticle to enable controlled dissection of late-stage embryos. With a dorsal longitudinal incision, the embryo can be laid flat, exposing the ventral nerve cord and body wall musculature to experimental investigation. Whole-cell patch-clamp techniques can then be employed to record from individually-identifiable neurons and somatic muscles. These recording configurations have been used to track the appearance and maturation of ionic currents and action potential propagation in both neurons and muscles. Genetic mutants affecting these electrical properties have been characterized to reveal the molecular composition of ion channels and associated signaling complexes, and to begin exploration of the molecular mechanisms of functional differentiation. A particular focus has been the assembly of synaptic connections, both in the central nervous system and periphery. The glutamatergic neuromuscular junction (NMJ) is most accessible to a combination of optical imaging and electrophysiological recording. A glass suction electrode is used to stimulate the peripheral nerve, with excitatory junction current (EJC) recordings made in the voltage-clamped muscle. This recording configuration has been used to chart the functional differentiation of the synapse, and track the appearance and maturation of presynaptic glutamate release properties. In addition, postsynaptic properties can be assayed independently via iontophoretic or pressure application of glutamate directly to the muscle surface, to measure the appearance and maturation of the glutamate receptor fields. Thus, both pre- and postsynaptic elements can be monitored separately or in combination during embryonic synaptogenesis. This system has been heavily used to isolate and characterize genetic mutants that impair embryonic synapse formation, and thus reveal the molecular mechanisms governing the specification and differentiation of synapse connections and functional synaptic signaling properties.

Electrophysiological Recording in the Drosophila Embryo

Electrophysiological recordings from Drosophila embryos allow analyses of developing muscle and neuron electrical properties, as well as characterization of functional synaptogenesis at the glutamatergic neuromuscular junction and central cholinergic and GABAergic synapses.

Enregistrement électrophysiologique dans le Drosophile Embryon

Drosophila is a premier genetic model for the study of both embryonic development and functional neuroscience. Traditionally, these fields are quite ...

Ambulatory ECG Recording in Mice

Telemetric ECG recording in mice is essential to understanding the mechanisms behind arrhythmias, conduction disorders, and sudden cardiac death. Although the surface ECG is utilized for short-term measurements of waveform intervals, it is not practical for long-term studies of heart rate variability or the capture of rare episodes of arrhythmias. Implantable ECG telemeters offer the advantages of simple surgical implantation, long-term recording of electrograms in ambulatory mice, and scalability with simultaneous recordings of multiple animals. Here, we present a step-by-step guide to the implantation of telemeters for ambulatory ECG recording in mice. Careful adherence to aseptic technique is required for favorable survival results with the possibility of implantation and recording from weeks to months. Thus, implantable ECG telemetry is a valuable tool for detection of critical information on cardiac electrophysiology in ambulatory animal models such as the mouse. 

Telemetric ECG has emerged as an essential tool in evaluating animal models for cardiac arrhythmias and sudden cardiac death. Here, we present a stepwise guide to telemetric ECG recordings for application in long-term ambulatory ECG monitoring in mice.

Ambulatoires enregistrement de l&#39;ECG chez des souris

Telemetric ECG recording in mice is essential to understanding the mechanisms behind arrhythmias, conduction disorders, and sudden cardiac death. Although ...

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes

The protocol presented here is designed to study the activation of the large conductance, voltage- and Ca2+-activated K+ (BK) channels. The protocol may also be used to study the structure-function relationship for other ion channels and neurotransmitter receptors1. BK channels are widely expressed in different tissues and have been implicated in many physiological functions, including regulation of smooth muscle contraction, frequency tuning of inner hair cells and regulation of neurotransmitter release2-6. BK channels are activated by membrane depolarization and by intracellular Ca2+ and Mg2+ 6-9. Therefore, the protocol is designed to control both the membrane voltage and the intracellular solution. In this protocol, messenger RNA of BK channels is injected into Xenopus laevis oocytes (stage V-VI) followed by 2-5 days of incubation at 18&deg;C10-13. Membrane patches that contain single or multiple BK channels are excised with the inside-out configuration using patch clamp techniques10-13. The intracellular side of the patch is perfused with desired solutions during recording so that the channel activation under different conditions can be examined. To summarize, the mRNA of BK channels is injected into Xenopus laevis oocytes to express channel proteins on the oocyte membrane; patch clamp techniques are used to record currents flowing through the channels under controlled voltage and intracellular solutions.

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes

Ionic current of BK channels is recorded using patch clamp techniques. BK channels are expressed in Xenopus oocytes by injecting messenger RNA. The intracellular solution during patch clamp recordings is controlled by a perfusion system.

Patch Clamp et des techniques de perfusion pour étudier les canaux ioniques Exprimé en Xenopus Ovocytes

The protocol presented here is designed to study the activation of the large conductance, voltage- and Ca2+-activated K+ (BK) channels. The protocol may ...

Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography

Contraction or relaxation of smooth muscle cells within the walls of resistance arteries determines the artery diameter and thereby controls flow of blood through the vessel and contributes to systemic blood pressure. The contraction process is regulated primarily by cytosolic calcium concentration ([Ca2+]cyt), which is in turn controlled by a variety of ion transporters and channels. Ion channels are common intermediates in signal transduction pathways activated by vasoactive hormones to effect vasoconstriction or vasodilation. And ion channels are often targeted by therapeutic agents either intentionally (e.g. calcium channel blockers used to induce vasodilation and lower blood pressure) or unintentionally (e.g. to induce unwanted cardiovascular side effects).
Kv7 (KCNQ) voltage-activated potassium channels have recently been implicated as important physiological and therapeutic targets for regulation of smooth muscle contraction. To elucidate the specific roles of Kv7 channels in both physiological signal transduction and in the actions of therapeutic agents, we need to study how their activity is modulated at the cellular level as well as evaluate their contribution in the context of the intact artery.
The rat mesenteric arteries provide a useful model system. The arteries can be easily dissected, cleaned of connective tissue, and used to prepare isolated arterial myocytes for patch clamp electrophysiology, or cannulated and pressurized for measurements of vasoconstrictor/vasodilator responses under relatively physiological conditions. Here we describe the methods used for both types of measurements and provide some examples of how the experimental design can be integrated to provide a clearer understanding of the roles of these ion channels in the regulation of vascular tone.

Measurements of Kv7 (KCNQ) potassium channel activity in isolated arterial myocytes (using patch clamp electrophysiological techniques) in parallel with measurements of constrictor/dilator responses (using pressure myography) can reveal important information about the roles of Kv7 channels in vascular smooth muscle physiology and pharmacology.

Explorer muscle lisse artériel KV7 fonction des canaux potassiques à l&#39;aide d&#39;électrophysiologie patch-clamp et myographie pression

Contraction  or relaxation of smooth muscle cells within the walls of resistance arteries  determines the artery diameter and thereby controls flow of ...

Giant Liposome Preparation for Imaging and Patch-Clamp Electrophysiology

The reconstitution of ion channels into chemically defined lipid membranes for electrophysiological recording has been a powerful technique to identify and explore the function of these important proteins. However, classical preparations, such as planar bilayers, limit the manipulations and experiments that can be performed on the reconstituted channel and its membrane environment. The more cell-like structure of giant liposomes permits traditional patch-clamp experiments without sacrificing control of the lipid environment.
Electroformation is an efficient mean to produce giant liposomes &gt;10 &mu;m in diameter which relies on the application of alternating voltage to a thin, ordered lipid film deposited on an electrode surface. However, since the classical protocol calls for the lipids to be deposited from organic solvents, it is not compatible with less robust membrane proteins like ion channels and must be modified. Recently, protocols have been developed to electroform giant liposomes from partially dehydrated small liposomes, which we have adapted to protein-containing liposomes in our laboratory.
We present here the background, equipment, techniques, and pitfalls of electroformation of giant liposomes from small liposome dispersions. We begin with the classic protocol, which should be mastered first before attempting the more challenging protocols that follow. We demonstrate the process of controlled partial dehydration of small liposomes using vapor equilibrium with saturated salt solutions. Finally, we demonstrate the process of electroformation itself. We will describe simple, inexpensive equipment that can be made in-house to produce high-quality liposomes, and describe visual inspection of the preparation at each stage to ensure the best results.

Reconstituting functional membrane proteins into giant liposomes of defined composition is a powerful approach when combined with patch-clamp electrophysiology. However, conventional giant liposome production may be incompatible with protein stability. We describe protocols for producing giant liposomes from pure lipids or small liposomes containing ion channels.

Préparation des liposomes de géant pour l&#39;imagerie et de patch-clamp électrophysiologie

The reconstitution of ion channels into chemically defined lipid membranes for electrophysiological recording has been a powerful technique to identify ...

Reconstitution of a Transmembrane Protein, the Voltage-gated Ion Channel, KvAP, into Giant Unilamellar Vesicles for Microscopy and Patch Clamp Studies

Giant Unilamellar Vesicles (GUVs) are a popular biomimetic system for studying membrane associated phenomena. However, commonly used protocols to grow GUVs must be modified in order to form GUVs containing functional transmembrane proteins. This article describes two dehydration-rehydration methods &#8212; electroformation and gel-assisted swelling &#8212; to form GUVs containing the voltage-gated potassium channel, KvAP. In both methods, a solution of protein-containing small unilamellar vesicles is partially dehydrated to form a stack of membranes, which is then allowed to swell in a rehydration buffer. For the electroformation method, the film is deposited on platinum electrodes so that an AC field can be applied during film rehydration. In contrast, the gel-assisted swelling method uses an agarose gel substrate to enhance film rehydration. Both methods can produce GUVs in low (e.g., 5 mM) and physiological (e.g., 100 mM) salt concentrations. The resulting GUVs are characterized via fluorescence microscopy, and the function of reconstituted channels measured using the inside-out patch-clamp configuration. While swelling in the presence of an alternating electric field (electroformation) gives a high yield of defect-free GUVs, the gel-assisted swelling method produces a more homogeneous protein distribution and requires no special equipment.

The reconstitution of the transmembrane protein, KvAP, into giant unilamellar vesicles (GUVs) is demonstrated for two dehydration-rehydration methods &#8212; electroformation, and gel-assisted swelling. In both methods, small unilamellar vesicles containing the protein are fused together to form GUVs that can then be studied by fluorescence microscopy and patch-clamp electrophysiology.

Reconstitution d&#39;une protéine transmembranaire, le Ion canal de voltage-dépendants, KvAP, en géant vésicules unilamellaires pour la microscopie et Patch études Clamp

Giant Unilamellar Vesicles (GUVs) are a popular biomimetic system for studying membrane associated phenomena. However, commonly used protocols to grow ...