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

この作品は、F31NS086765（KAC）、F31NS076235（MAP）、およびR01 NS052669（GKP）とEIA9100012によってサポートされていました。著者らは、分子生物学および組織培養に関する専門知識と支援のためのアイリーンKasperekに感謝。そしてジェイソン·マイヤーズ早期前頭前皮質ニューロンから得られたデータを共有するための。

1。細胞培養およびタンパク質発現<ol><li> HEK293細胞を、10％ウシ胎児血清（FBS）を補充したDMEM中で単層培養中で、ATCCにより行わ通路を含み、通路22と40との間（ATCC番号CRL-1573）、および5％CO 2で1％ペニシリン/ストレプトマイシン混合物を維持する37℃実験の間、10mlの最終体積の5〜20倍希釈でT25フラスコに継代細胞。注：これらの通路の間に細胞を使用することで、最適なシール形成?...

<ol>
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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. 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Sakmann and E Neher. , (1995).</li></ol>

イオンチャネルフィールドで、研究の重要な領域は、開口部またはチャネルのゲート機構をチャネルにつながるイベントのシーケンスを理解するに捧げられています。ほとんどのチャネルの場合、このプロセスは複雑であり、巨視的なマルチチャネル信号から推定することができないいくつかの動力学的工程を含む。対照的に、実験は、単一チャネル記録内のオープン/クローズイベントのシ...

生体膜を横切る高速通信は、一般にチャネルと呼ば膜タンパク質を形成するオリゴマーの細孔にほぼ排他的に依存している。これらのタンパク質は、活性化信号、ゲーティングメカニズム、コンダクタンス特性において大きく異なっている。細孔がイオンに対して選択的であるチャネルタンパク質をイオンチャネルとして分類される;それらの活性化は、膜を横切るイオン電流を生成し、その応答は、電気生理学的技術を使用して、即座に高解像度で記録することができる。活性化信号は、濃度勾配、機械的および電気的な力、および温度などの化学的および物理的入力の幅広いまたがる。従って、さらなるゲートさリガンドへのイオンチャネルを分類する機械受容電圧は、ゲート、または敏感型を加熱する。この記事では、プロトコルは、パッチクランプ技術を用いて、リガンド依存性チャネル、NMDA受容体、および機械受容チャネル​​、PIEZO1から1チャンネル活性を記録するために記載されている。0; パッチクランプ電気生理学は、単一分子1,2の観察を可能にするのに十分な感度最初の最も広く使用された実験方法である。この優れた感度に加えて、それは非常に電気生理学的記録に従う生物学的製剤を拡大しており、また、無傷の膜におけるイオンチャネルの観察を可能にした。電圧クランプと電流の記録の両方が同じ電極を用いて達成されているので、まず、小さな細胞または膜パッチを横切って信号を記録するために使用することができる。技術は、イオンチャンネルがカエルの筋肉、ウナギelectroplaques、またはイカ巨大軸索3,4の興奮性膜に限定されないことが明らかになったのではなく、それらは、膜貫通シグナル伝達機構のユビキタス器具を表し、単方向または全ての細胞膜の種類に固有であること多細胞生物、また細胞内膜へ。インポートantly、単に無傷の細胞にガラスピペットを取り付けることにより、貫通電流を記録する機能は、ネイティブ破壊されていない膜内のイオンチャネルからの活動を記録するために前例のない機会を提供した。したがって、このプロトコルに記載されているセル取り付けパッチクランプ技術は、数十分又はそれらの天然の環境においてより長い連続イオンチャネルの活性をモニター可能にする。 通常の熱揺らぎの下では、イオンチャネルタンパク質を含む全てのタンパク質は、側鎖の動きと全体の再配置によって表される非常に遅く、あまり頻繁に変更することによって最も可能性の高い表現最速かつ最も頻繁に再編成に、幅広い時間スケールにわたる構造的な変化を受けるドメインまたはサブユニット、または翻訳後修飾またはタンパク質-タンパク質相互作用5,6によっていくつかの場合において。 1分子によって生成された活動の長い期間を観察すると、機能を理解するのに役立ちます完全な生理的膜におけるイオンチャネルのtionalダイナミクスと観測され、分子の動作メカニズムについての貴重な情報を提供します。 細胞型および発生段階を横切るイオンチャネルの多様性の増加理解とは対照的に、天然の膜におけるイオンチャネルの分子組成についての知識は、依然として限られている。すべてのイオンチャネルは、多量体タンパク質であり、天然イオンチャネルの大部分は、多くの場合、多様なコンダクタンスとゲーティング特性を伴う広い分子多様性のタンパク質を産生するサブユニットのいくつかのタイプから組み立てる。このため、規定された分子組成物のイオンチャネルは、異種系での発現の際に検討されている。具体的には、不死化したヒト胚性腎細胞のクローンライン7であるHEK293細胞は、組換え型イオンチャネルの異種発現のための好適なシステムとして広く受け入れを得た。男の中イオンチャネルの電気生理学のための選択シス​​テムは、培養の容易さと低価格であり、長寿命、安定した培養物を維持するように、哺乳動物タンパク質の翻訳後フォールディング、プロセシングおよび輸送を行う能力をHEK293細胞を上昇yの利点は、多くの場合、その低レベルまたは対象7、8のチャネルのための内因性発現のさえない状態。組換えイオンチャネルを発現し、HEK293細胞におけるそれらの機能的特性を研究することは構造 - 機能イオンチャネルの特性ならびにイオンチャネルアイソフォームおよび天然組織におけるそれらの役割の特定のプロパティに関する情報を取得する価値のあるアプローチであり続けている。この資料に記載されているプロトコルは、HEK293細胞において発現された組換えイオンチャネルおよび天然イオンチャネルにも同様に適用することができる。 要約すると、その前例のない能力を介してパッチクランプ技術は、信号を解決するために一つの分子からのsは、今日まで、単一分子の挙動を観察するための最も直接的な方法のままである。その細胞結合型モードでは、パッチクランプ記録は、一分子のために行わ、長い観察期間を可能にするイオンチャネルの動作中に例外的な洞察を提供することができる。以下に一つのイオンチャネルタンパク質を含む細胞取り付けパッチから高分解能電流記録を取得するためのプロトコルが提供される。

<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

イオンチャネルタンパク質は、生体膜を通過高速通信用の汎用デバイスである。それらが生成するイオン流束の時間的なシグネチャは、各チャネルタンパク質ならびにその生成および制御される機構の固有の性質に依存しており、現在の研究の重要な領域を表す。イオンチャネルタンパク質の操作動力学に関する情報は、単一の分子によって生成される電流の長いストレッチを観察することによって得ることができる。リガンド依存性イオンチャネル、NMDA受容体に対する1チャネルセル付きパッチクランプ電流記録を取得するためのプロトコルがここに記載され、皮質ニューロンでHEK293細胞においてネイティブまたは異種発現。また、機械刺激感受性チャネルPIEZO1の例を提示することによって、関心のある他のイオンチャネルにメソッドを適応させる方法についても提供される。この方法は、チャネルのコンダクタンス特性とOPEの時系列に関するデータを提供することができますこのように健康と病気にそれらの機能を理解するために貢献し、チャネルの活性化機構を構成しているN-クローズコンフォメーション。

組換えNMDA受容体 NMDA受容体は、結合して、2コアゴニストの同時動作に対応：グルタミン酸およびグリシン。彼らはGluN1サブユニットとGluN2サブユニットを結合2グルタミン酸結合2グリシンのヘテロ四として組み立てる。 GluN2サブユニットは、4つの遺伝子（A〜D）でエンコードされており、これらの脳の中で最も広く、転写形式はGluN2A少年動物で大人とGluN2Bで?...

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

One-channel Cell-attached Patch-clamp Recording

ここで説明するには、セルに接続されたパッチクランプ技術を用いて1イオンチャネルから現在の記録の長いストレッチを取得するための手順です。この方法は、リアルタイムで、観察するための生体信号の基礎となる開閉チャネルコンフォメーションのパターンを可能にする。これらのデータは、邪魔されずに生体膜におけるチャネルのプロパティをお知らせ。

一チャネルセル付パッチクランプ法

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.

がくからパッチクランプの静電容量の録音のための方法

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

生物学

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.

アフリカツメガエルの卵母細胞で発現イオンチャネルのパッチクランプ記録

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.

改善されたパッチクランプ記録のための圧力 - 研磨ピペット

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.

解離性とC. elegansの神経筋接合部から録音する

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.

の電気生理学的記録ショウジョウバエ胚

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.

マウスにおけるホルター心電図の記録

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.

イオンチャネル研究のためのパッチクランプおよび灌流のテクニックで表さアフリカツメガエル卵母細胞

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.

パッチクランプ電気生理学および圧力筋運動記録法を用いた動脈平滑筋KV7カリウムチャネル機能を探る

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.

イメージングとパッチクランプ電気生理学用ジャイアントリポソーム製剤

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.

膜貫通タンパク質の再構成、顕微鏡およびパッチクランプ研究のための巨大単膜小胞への電位依存性イオンチャネル、KvAP、

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