Funding was provided by the Joint Science and Technology Office &#8211; Chemical Biological Defense (JSTO-CBD) Defense Threat Reduction Agency (DTRA) under sponsor project number CCAR# CB3675 and National Institutes of Health (1 R21 AI101387-01 and 5 U01AI082051-05).

プレート2万差別化マウスES細胞（MES）/ 96ウェルポリ-D-リジンコーティングしたプレートに5〜7日間運動ニューロン分化培地中で維持する。 のBoNT / A 1.化合物投与と中毒 CDC / NIHガイドラインの遵守を維持するために、BSL2エンクロージャに以下のすべての作業を実行します。 <ol><li>ポリプロピレン製96ウェルプレートに100％DMSO中の各ライブラリー化合物の10mMストック溶液を調製する。所望のスクリーニング濃度よりも10倍大きい中間希釈プレートを調製するために10mMのストックを使用する。 96ウェルプレートに10 mMストックを分配することによって100μMの中間板を準備し、培養培地を使用して、100μMのに希釈する。セル11上のメディアの90μlの上の化合物の10μlを分注する。 10μMの最終濃度で化合物を試験し、DMSOの最終的な割合が、0.5％を超えないように保証する。 </li><li>すべてのスタッドを実行バイオセーフティーレベル2の条件で、生細胞と活性毒素を利用IES。 12チャネルのマ​​ニュアルピペットを用いて、新鮮な最終分化培地を80μlの96ウェルプレートで古いメディアを交換してください。吸引を行い、外気にメディアを使用せず細胞の曝露を避けるために、行単位でのステップを分注する。 </li><li>吸引（2回）によって混合した12チャンネルピペットを使用してソースプレートからの10倍の化合物10μlを添加することにより、従来の毒素の適用化合物で細胞を前処理する。各96ウェルプレートの場合は、のような高信号と低信号のコントロールを提供するために培地で希釈し、10倍のDMSOで6ウエルの2つの列を扱う。のBoNT処理なしの列は、完全長SNAP-25（高信号制御）の最高レベルを示す。低信号制御などの（任意の化合物を含まない）を単独のBoNTを持つ他の列を扱います。 SNAP-25およびBACS抗体とその検出（ 図2ののBoNT切断の効率を観察するために低コントロールを使用して、）。 </li><li>細胞培養インキュベーター中で37℃で30分間、化合物および6％CO 2で細胞をインキュベートする。 </li><li>リン酸中1mg / mlの市販の供給源からのボツリヌス神経毒Aを調製ターミナル分化培地で希釈して、最終的な10倍ワーキングストックに緩衝食塩水（PBS）。 </li><li>マルチチャンネルピ ​​ペット（ 図2）を用いた治療と低信号のコントロールのために指定ウェルに10倍のBoNT /株式10μlのを追加して中毒を開始します。培地単独で高いコントロールとして指定された井戸を扱う。 </li><li>少なくとも20分間、水中の0.825パーセントの次亜塩素酸溶液中に浸漬することにより、研究中のBoNT / Aと接触するすべてのプラスチックの構造および他の消耗品を除染。バイオセーフティキャビネット内のすべてのプロシージャを実行し、そのようなマイクロケム液として5％の洗剤除菌洗浄剤を用いた実験の前と後の両方の作業領域を除染。 </li><li>毒素の使用とincubを示すためにはっきりとプレートにラベルを付ける細胞培養インキュベーター中でCO 2、37℃で4時間および6％を1nM / LのBoNT / Aで処理されたプレートを食べた。毒素は、実験室で使用されていることを同僚に知らせるために、適切な看板を表示する。 </li><li>ストップBONT /メタノール固定によるタンパク質分解切断。マルチチャンネルピペットで各ウェルから毒素および化合物を含む培地を取り出し、10％の漂白剤溶液中に捨てる。各ウェルに直接氷冷メタノール（100μl）を追加します。 </li><li>固定が起こることを可能にするために室温（RT）で15分間、プレートをインキュベートする。 </li><li>固定後、無事に1プロトコルバイオセーフティーレベル（中和考えられる）廃棄された試薬を処理し、それに応じて捨てる。 </li><li>メタノールを捨て、細胞を洗浄し、免疫染色前にそれらを再水和するために100μlのPBSを使用しています。二つの追加PBS洗浄を行います。 </li><li>最終洗浄後、分析まで4℃でマイクロプレート接着フィルムや店舗を有するウェル、シールプレート内のPBSを残す。 4℃FOで保存プレート数日rを。 </li></ol> 2.免疫染色免疫染色手順は、反復的な試薬の分注/吸引サイクルと重要な内陸地震と変動の潜在的な導入につながる可能性が大規模なプレート洗浄を含む労働集約型、多段階の操作です。半自動化されたアプローチは、実験者の時間を節約するアッセイのスループットを増加させ、免疫染色のばらつきを最小限にするために適用される。 <ol><li>このプロトコルのモジュラーデッキ上の異なる場所（材料および機器を参照）に実験器具を移動するために、ロボットグリッパアームで最大250μLまでと一体化ボリュームを転送できる96ウェルヘッドを備えた自動化されたワークステーションを使用してください。 <ol><li>モジュラーデッキは実験器具の異なるタイプをホストするように設計されており、一度に最大11項目をサポートすることができる。自動マイクロプレートハンドラーは保持するために、デュアルマガジンマイクロプレートスタッカーを備えているとサイクル当たり50プレートまで操作する。 </li><li>自動化されたワークステーションは、無菌性と安全性を提供するために、実験室の自動化機器用に設計されたクラスIIバイオセーフティキャビネットの内側に位置しています。自動免疫染色のために、デッキは、 図3に示すように、必要に応じて試薬のアクセスを可能にするために配置され、人間の介入なしている。 </li></ol></li><li>液体取扱い業務のために必要に応じてデッキにプレート雑誌や転送に固定された細胞を含む予圧プレート。ダウン10μlに井戸からPBSを吸引する250μlの先端装備96ピペットヘッドを使用してください。透過化緩衝液（0.1％のTriton-X 100）を用いて細胞内標的に結合する抗体を容易にするために、細胞膜を透過性にする。室温（RT）で15分間のインキュベーションのためにマイクロプレートスタッカーの第保管マガジンにプレートを返す前に、各ウェルに透過化緩衝液（100μl）を分配する。 </li><li>透過化バッファとPEを削除PBS（2回）とrformプレート洗浄は、先にステップ1.13に記載されて。 </li><li>最後の洗浄工程の後、PBS緩衝液を除去し、すべてにPBS中1％ウマ血清および0.1％Tween 20を含むブロッキング緩衝液100μlを分注RTで1時間インキュベートし、プレートマガジンに戻す前に、マイクロプレート。 </li><li> （材料および機器を参照）神経細胞の検出のための完全長SNAP-25マウスモノクローナル抗IIIチューブリン抗体の検出のために、ウサギポリクローナル抗マウスBACS抗体：免疫染色のための2つの一次抗体を使用する。インキュベーションの60分後、ブロッキングバッファー削除し、すべてのプレートにブロッキングバッファー中BACS抗体の4ug / mlの50μlの及びIIIチューブリン0.5μgの/ mlに分注する。 </li><li> RTで1時間インキュベートした一次抗体を除去し、0.05％のTween（PBST）を含むPBS100μlで3回洗浄する。 </li><li>アレクサFでタグ-IIIチューブリンおよび抗ウサギIgGを可視化するアレクサフルオロ647標識抗マウスIgGを使用BACS抗体を可視化するluor 568。ブロッキング緩衝液中2μg/ mlの希釈として両方の抗体を調製し、各ウェルに混合液50μlを分注する。 NOTE：免疫染色のために選択された二次抗体は、ハイコンテントイメージャの検出器内の異なるチャネルを使用して異なる波長で、その発せられた蛍光の検出を可能にするために、異なる蛍光体で標識されている。 </li><li>室温で1時間インキュベートする。二次抗体を吸引し、PBST100μlで3回洗浄する。 </li><li>最終洗浄後、核を検出するためのDNAを染色するためにHoechst色素（32μM）を含む100μlのPBSを追加。 </li><li>光退色から蛍光団を保護するために、光透過性フィルムでプレートをシール。プレートを4で保存することができる&#160;信号の有意な損失なしに数週間のために、Cを°。 </li></ol> 3.イメージング注：ハイコンテントイメージングのSysを使用して画像取得を実行TEM（材料および装置を参照してください）​​。 <ol><li>ハイコンテントイメージャ定義の仕様： <ol><li>セレクトプレートタイプ、レイアウト、フィールドの数、目的：グライナーU澄んだ、20X水をそれぞれ96ウェルフォーマット、16、。 </li><li>セレクトチャンネル：核励起EX：チャンネル4としては405nm。細胞質EX：チャネル2と644 nmの。抗原特異的抗体チャンネルEX：561チャンネル3としてnmおよび各レーザのセットアップ励起パワー、2エクスポージャーとしてセットアップ実験、644 nmで1励起、405 nmおよび561 nmにおける2励起による露光2の露光1。ビン2としてビニングを選択します。 </li><li> SNAP-25チャネルおよび最小強度のための低対照ウェルのような最大強度の露出を最適化するために、高いコントロールウェルを使用する。 </li><li>各チャネルの強度が飽和レベル（2,000〜2,500相対単位）の約半分になるように、露出を調整する。 </li><li>デルタ補正スクリプトを使用して、細胞マスクチャネルに最適なZ平面を識別する。 Fiを提供して参照してください。免疫染色およびイメージング後の結果のためのグレ5。画像解析ソフトが常駐しているサーバへデータをエクスポートします。 </li></ol></li></ol> 4.画像解析（図6） 注：次の手順は、コロンバスソフトウェアアルゴリズムの適用を説明します。 <ol><li>プライマリ·オブジェクト（核）セグメントに適切なアルゴリズムを選択します。必要に応じて、背景閾値及びコントラストパラメータを調整する。コロンブス·ソフトウェアは、4核検出法を提供する。視覚的に（Mが選択されているF igure 6aの方法で）セグメント化された核を検査することによって、正確にメソッドそのセグメント核を選択します。 </li><li>必要に応じて、セグメントに神経突起を神経突起アルゴリズム（CSIRO神経突起分析2）を選択して背景を削除するには、バックグラウンドのしきい値とコントラストのパラメータを調整する。神経突起を検出するために使用されるパラメータについて、図6bを参照してください。 </li><li>神経突起領域（神経突起セグメント）浅を識別マスク（ 図6c）として、β-IIIチューブリンチャネル（アレクサ小麦粉640）の-3画素拡張を使用して、セカンダリ·オブジェクト（神経突起）に編。 </li><li>神経突起領域およびβ-IIIチューブリンチャネル（ 図6d＆6E）用の信号チャネル（SNAP-25、（アレクサ小麦粉568）の強度を計算します。 </li><li>そのような神経突起の長さが、SNAP-25の平均強度は、β-IIIチューブリン、核数、神経突起セグメント番号等 （ 図6F）などの輸出用必要なパラメータを選択します。 </li><li>画像取得のためのハイコンテントイメージャへのロボットとロードを使用して、プレートスタッカからの転送プレート。 </li></ol> 5.データ分析： 設計されたアッセイの頑健性を評価するために、プレートベースの実験から、以下のパラメータを計算する。 <ol><li>バックグラウンド信号（B）から（S）：S / B = Hの信号制御の平均強度）/ロー信号制御の強度を意味する</li> &lt;液体ハンドリングの変動を決定するために、CV =（標準偏差（SD）のサンプル/平均値）×100（％）：LI&gt;シグナルとバックグラウンドの変動係数（CV）は、（特定の信号の均一性を測定する）試薬など</li><li>ノイズに対する信号：Sは、= - 低コントロールの/ SDを（信号の強さを意味する低い信号制御の強度を意味する） <ol><li> 1 96ウェルプレートの半分、残りの半分のモック中毒の中毒とのZ &#39;係数を計算。 Z &#39;= 1 - 3 *（低信号制御の高信号制御+ SDのSD）/（高信号制御の平均 - 低信号制御の平均を）。スクリーニングデータの更なる分析のために、プレート間および実験の異なる日の間の比較を可能にするためにプレート毎に主原料いくつかのパラメータを正規化する。 </li></ol></li><li> ％胸の谷間= 100％*（MEA：全長SNAP-25特異的抗体によって検出された（BACS）に関連する信号の減少を反映して切断のパーセント、高い信号制御のn個の強度 - 試料の強度）/高い信号制御の強度を意味する。 </li><li>切断の阻害のパーセント：％阻害= 100％*（サンプルの強度 - 低信号制御の平均強度）/（高信号制御の強度を意味する - 低信号制御の強度を意味する）。 </li></ol>

<ol>
	<li>Lamanna, 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+most+poisonous+poison.">The most poisonous poison.</a> Science. 130, 763-772 (1959).</li><li>Dover, N., Barash, J. R., Hill, K. K., Xie, G., Arnon, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Characterization+of+a+Novel+Botulinum+Neurotoxin+Type+H+Gene.">Molecular Characterization of a Novel Botulinum Neurotoxin Type H Gene.</a> J. Infect. Dis. , (2013).</li><li>Hakami, R. M., Ruthel, G., Stahl, A. M., Bavari, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gaining+ground:+assays+for+therapeutics+against+botulinum+neurotoxin.">Gaining ground: assays for therapeutics against botulinum neurotoxin.</a> Trends in microbiology. 18, 164-172 (2010).</li><li>Yersin, A., 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=Interactions+between+synaptic+vesicle+fusion+proteins+explored+by+atomic+force+microscopy.">Interactions between synaptic vesicle fusion proteins explored by atomic force microscopy.</a> Proceedings of the National Academy of Sciences of the United States of America. 100, 8736-8741 (2003).</li><li>Dong, M., Tepp, W. H., Johnson, E. A., Chapman, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+fluorescent+sensors+to+detect+botulinum+neurotoxin+activity+in+vitro+and+in+living+cells.">Using fluorescent sensors to detect botulinum neurotoxin activity in vitro and in living cells.</a> Proceedings of the National Academy of Sciences of the United States of America. 101, 14701-14706 (2004).</li><li>Stahl, A. M., Adler, M., and, C. B. M., Gilfillan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accelerating+botulism+therapeutic+product+development+in+the+Department+of+Defense.">Accelerating botulism therapeutic product development in the Department of Defense.</a> Drug Development Research. 70, 303-326 (2009).</li><li>Nuss, J. E., 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=Development+of+cell-based+assays+to+measure+botulinum+neurotoxin+serotype+A+activity+using+cleavage-sensitive+antibodies.">Development of cell-based assays to measure botulinum neurotoxin serotype A activity using cleavage-sensitive antibodies.</a> Journal of biomolecular screening. 15, 42-51 (2010).</li><li>Opsenica, I., 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=A+chemotype+that+inhibits+three+unrelated+pathogenic+targets:+the+botulinum+neurotoxin+serotype+A+light+chain,+P.+falciparum+malaria,+and+the+Ebola+filovirus.">A chemotype that inhibits three unrelated pathogenic targets: the botulinum neurotoxin serotype A light chain, P. falciparum malaria, and the Ebola filovirus.</a> Journal of medicinal chemistry. 54, 1157-1169 (2011).</li><li>Opsenica, I., 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=The+synthesis+of+2,5-bis(4-amidinophenyl)thiophene+derivatives+providing+submicromolar-range+inhibition+of+the+botulinum+neurotoxin+serotype+A+metalloprotease.">The synthesis of 2,5-bis(4-amidinophenyl)thiophene derivatives providing submicromolar-range inhibition of the botulinum neurotoxin serotype A metalloprotease.</a> European journal of medicinal chemistry. 53, 374-379 (2012).</li><li>Nuss, J. E., 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=Pharmacophore+Refinement+Guides+the+Rational+Design+of+Nanomolar-Range+Inhibitors+of+the+Botulinum+Neurotoxin+Serotype+A+Metalloprotease.">Pharmacophore Refinement Guides the Rational Design of Nanomolar-Range Inhibitors of the Botulinum Neurotoxin Serotype A Metalloprotease.</a> ACS medicinal chemistry letters. 1, 301-305 (2010).</li><li>Kiris, E., 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=Embryonic+stem+cell-derived+motoneurons+provide+a+highly+sensitive+cell+culture+model+for+botulinum+neurotoxin+studies,+with+implications+for+high-throughput+drug+discovery.">Embryonic stem cell-derived motoneurons provide a highly sensitive cell culture model for botulinum neurotoxin studies, with implications for high-throughput drug discovery.</a> Stem cell research. 6, 195-205 (2011).</li><li>Pellett, 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=Neuronal+targeting,+internalization,+and+biological+activity+of+a+recombinant+atoxic+derivative+of+botulinum+neurotoxin+A.">Neuronal targeting, internalization, and biological activity of a recombinant atoxic derivative of botulinum neurotoxin A.</a> Biochemical and biophysical research communications. 405, 673-677 (2011).</li><li>McNutt, P., Celver, J., Hamilton, T., Mesngon, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryonic+stem+cell-derived+neurons+are+a+novel,+highly+sensitive+tissue+culture+platform+for+botulinum+research.">Embryonic stem cell-derived neurons are a novel, highly sensitive tissue culture platform for botulinum research.</a> Biochemical and biophysical research communications. 405, 85-90 (2011).</li><li>Fischer, A., 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=Bimodal+modulation+of+the+botulinum+neurotoxin+protein-conducting+channel.">Bimodal modulation of the botulinum neurotoxin protein-conducting channel.</a> Proceedings of the National Academy of Sciences of the United States of America. 106, 1330-1335 (2009).</li></ol>

Krishna P Kota is an employee of Perkin Elmer Inc. Waltham, MA, that produces instruments and software used in this manuscript. The content of this publication does not necessarily reflect the views or policies of the U.S. Department of Health and Human Services, the U.S. Department of Defense, the U.S. Department of the Army, or the institutions and companies affiliated with the authors.

ボツリヌス神経毒とその兵器の相対的な容易さの高い効力は、米国疾病管理予防センターによるカテゴリーA（最優先）biothreat剤としてのそれらの分類をもたらした。残念ながら、FDAは毒素が運動ニューロンによって内在された後のBoNT中毒に対抗するための治療薬を承認していないがあります。のBoNT中毒から神経細胞の回復を促進する任意のドラッガブルメカニズムが、この生物学的脅威に?...

細菌ボツリヌス菌はボツリヌス神経毒、男1に知られている最も強力な生物毒素の1を生成します。 7明確なのBoNT血清型（のBoNT / AG）があります。のBoNT / A-ガルによりSNARE複雑なタンパク質分解2,3に神経筋接合部で麻痺を誘発する。 SNAREタンパク質分解は、神経伝達物質小胞の膜融合を防止し、したがって、ブロックはエキソサイトーシス4神経伝達物質。特定のSNAREターゲットは中毒過程に関与する特定のBoNT血清型に依存します。のBoNT / AおよびBoNT / E切断するSNAP-25のBoNT / Cを切断SNAP-25およびシンタキシン5両方のに対し。また、小胞関連膜タンパク質（VAMP）と呼ばれる残りの血清型クリーブシナプトブレビンは（。BoNT / Aには、それが天然に存在するボツリヌス中毒の割合が高いために責任があるとして、アッセイ開発のために選択された小分子の作用6。開発の最長持続時間を有した。 BoNT / A型に対する治療薬はのための主要な目標である創薬プログラムと活性部位のタンパク質分解阻害剤7、8-10を識別するために、従来のターゲットベースの方法を利用している。しかし、複数の血清型と、露光後の有効性に対する広域スペクトル活性を有する活性部位阻害剤の作成が困難な可能性が高いであろう。 したがって、我々は、のBoNT媒介運動ニューロン中毒をブロックすることができる小分子を同定するための機能的なエンドポイントとしてのBoNT SNAP-25の切断を使用して、革新的な、表現型の創薬アプローチを実施しています。 SNAP-25の分解はin vivoでの麻痺や致死性の予測となるようにSNAP-25は、神経伝達物質放出のために必要とされる。例えば、細胞ベースのスクリーニングは、毒素の不活化または標的細胞内部で毒素経路の阻害に関与する細胞因子の新たな調節因子の発見につながる可能性があります。表現型アッセイの開発における重要な因子は、生理学的に関連する生物学的モデルを選択することである。 WEなどは、SNAP-25 11- 13の発現を含む一次運動ニューロンの免疫学的性質を再現するマウス胚性幹（ES）細胞由来の運動ニューロンを、説明してきた。重要なことに、これらのセルラーシステムは、BoNT / A中毒に非常に敏感であり、毒素11,12の濃度を増加さに応じて、SNAP-25の用量依存的切断を実証している。分化した運動ニューロンはまた、ハイスループットプレートベースの分析のために十分であり、細胞アッセイのアレイの設計を可能にした量で産生される。 表現型のアッセイは、BoNT /マウスの運動ニューロン培養物の中毒の間内因的​​に発現完全長SNAP-25の切断を定量化するために二つの別個の抗体を利用する免疫蛍光法である。唯一の完全長SNAP-25を認識し、カルボキシル末端のBoNT / A切断感受性（BACS）抗体は、BoNT / Aの評価は、SNAP-25のタンパク質分解を仲介できますマウスの運動ニューロンにおける発現10。 HCIアッセイの概略図を図1に示されている。

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			<td height="21" style="height:21px;width:255px;">Name of Reagent/ Equipment</td>
			<td style="width:180px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:280px;">Comments/Description</td>
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		<tr height="21">
			<td height="21" style="height:21px;">Botulinum neurotoxin A&#160;</td>
			<td style="width:180px;">Metabiologics</td>
			<td style="width:119px;">NA</td>
			<td style="width:280px;">No catalog number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Microtitre plates</td>
			<td style="width:180px;">Greiner&#160;</td>
			<td style="width:119px;">655946</td>
			<td style="width:280px;">Poly-D-Lysine 96-well plates</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">BACs antibody</td>
			<td style="width:180px;">Lampire Biological</td>
			<td style="width:119px;">NA</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Microchem</td>
			<td style="width:180px;">National&#160;</td>
			<td style="width:119px;">0255</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Methanol</td>
			<td style="width:180px;">Thermo Scientific</td>
			<td style="width:119px;">A412-20</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Formaldehyde</td>
			<td style="width:180px;">Thermo Scientific</td>
			<td style="width:119px;">28908</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Horse serum</td>
			<td style="width:180px;">Invitrogen</td>
			<td style="width:119px;">16050</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:255px;">PE JANUS MDT Mini Automated Workstation</td>
			<td style="width:180px;">Perkin Elmer</td>
			<td style="width:119px;">AJMDT01</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Opera</td>
			<td style="width:180px;">Perkin Elmer</td>
			<td>OP-QEHS-01</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Triton X 100</td>
			<td style="width:180px;">Sigma-Aldrich</td>
			<td style="width:119px;">9002-93-1</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">BIII tubulin antibody</td>
			<td style="width:180px;">R&#38;D Systems</td>
			<td style="width:119px;">BAM1195</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Tween 20</td>
			<td style="width:180px;">Sigma</td>
			<td style="width:119px;">P1379-1L</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hoechst 33342dye&#160;</td>
			<td style="width:180px;">Invitrogen</td>
			<td style="width:119px;">3570</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Antimouse IgG</td>
			<td style="width:180px;">Invitrogen</td>
			<td style="width:119px;">A21236</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Anti rabbit IgG</td>
			<td style="width:180px;">Invitrogen</td>
			<td style="width:119px;">A10042</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Columbus Image analysis software</td>
			<td style="width:180px;">Perkin Elmer</td>
			<td style="width:119px;">Ver 2.4</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Spotfire</td>
			<td style="width:180px;">Perkin Elmer</td>
			<td style="width:119px;">Ver 5.5</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Clorox bleach</td>
			<td style="width:180px;">Fisher Scientific</td>
			<td style="width:119px;">18-861-284</td>
			<td style="width:280px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">PlateStack</td>
			<td style="width:180px;"></td>
			<td style="width:119px;"></td>
			<td style="width:280px;"></td>
		</tr>
	</tbody>
</table>

a high content imaging assay for identification of botulinum neurotoxin inhibitors

Synaptosomal-associated protein-25 (SNAP-25) is a component of the soluble NSF attachment protein receptor (SNARE) complex that is essential for synaptic neurotransmitter release. Botulinum neurotoxin serotype A (BoNT/A) is a zinc metalloprotease that blocks exocytosis of neurotransmitter by cleaving the SNAP-25 component of the SNARE complex. Currently there are no licensed medicines to treat BoNT/A poisoning after internalization of the toxin by motor neurons. The development of effective therapeutic measures to counter BoNT/A intoxication has been limited, due in part to the lack of robust high-throughput assays for screening small molecule libraries. Here we describe a high content imaging (HCI) assay with utility for identification of BoNT/A inhibitors. Initial optimization efforts focused on improving the reproducibility of inter-plate results across multiple, independent experiments. Automation of immunostaining, image acquisition, and image analysis were found to increase assay consistency and minimize variability while enabling the multiparameter evaluation of experimental compounds in a murine motor neuron system.

ハイとローのコントロールからのデータは、3標準偏差（図7A）を超える2中央値の差が2の異なる集団を作成しました。スクリーニングプロセスの目標は、サンプル集団（ 図7B（i））を内正規分布を仮定し、近い正の対照集団に対する値とサンプル集団内の化合物を見出すことである。平均の3標準偏差を超えているデータ点は、ノイズ統計的に異なると考えられ、ア?...

Watch this Scientific Journal Video about A High Content Imaging Assay for Identification of Botulinum Neurotoxin Inhibitors at JoVE.com

A High Content Imaging Assay for Identification of Botulinum Neurotoxin Inhibitors

Botulinum neurotoxin is one of the most potent toxins among Category-A biothreat agents, yet a post-exposure therapeutic is not available. The high content imaging approach is a powerful methodology for identifying novel inhibitors as it enables multiparameter screening using biologically relevant motor neurons, the primary target of this toxin.

ボツリヌス神経毒素阻害剤の同定のためのハイコンテントイメージングアッセイ

Synaptosomal-associated protein-25 (SNAP-25) is a component of the soluble NSF attachment protein receptor (SNARE) complex that is essential for synaptic ...

a-high-content-imaging-assay-for-identification-botulinum-neurotoxin

Research

JoVE Journal

Neuroscience

8.5K ビュー.  Perkin Elmer Inc.. Botulinum neurotoxin is one of the most potent toxins among Category-A biothreat agents, yet a post-exposure therapeutic is not available. The high content imaging approach is a powerful methodology for identifying novel inhibitors as it enables multiparameter screening using biologically relevant motor neurons, the primary target of this toxin.

ビデオ: A High Content Imaging Assay for Identification of Botulinum Neurotoxin Inhibitors

An Organotypic Slice Assay for High-Resolution Time-Lapse Imaging of Neuronal Migration in the Postnatal Brain

Neurogenesis in the postnatal brain depends on maintenance of three biological events: proliferation of progenitor cells, migration of neuroblasts, as well as differentiation and integration of new neurons into existing neural circuits. For postnatal neurogenesis in the olfactory bulbs, these events are segregated within three anatomically distinct domains: proliferation largely occurs in the subependymal zone (SEZ) of the lateral ventricles, migrating neuroblasts traverse through the rostral migratory stream (RMS), and new neurons differentiate and integrate within the olfactory bulbs (OB). The three domains serve as ideal platforms to study the cellular, molecular, and physiological mechanisms that regulate each of the biological events distinctly. This paper describes an organotypic slice assay optimized for postnatal brain tissue, in which the extracellular conditions closely mimic the in vivo environment for migrating neuroblasts. We show that our assay provides for uniform, oriented, and speedy movement of neuroblasts within the RMS. This assay will be highly suitable for the study of cell autonomous and non-autonomous regulation of neuronal migration by utilizing cross-transplantation approaches from mice on different genetic backgrounds.

This protocol describes an organotypic slice assay optimized for the postnatal brain and high-resolution time-lapse imaging of neuroblast migration in the rostral migratory stream.

出生後の脳における神経細胞の移動の高分解能タイムラプスイメージングのための器官型スライスアッセイ

Neurogenesis in the postnatal brain depends on maintenance of three biological events: proliferation of progenitor cells, migration of neuroblasts, as ...

神経科学

High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon measuring activity on the surface of cerebral cortex rather than in subcortical regions such as midbrain and brainstem. Subcortical fMRI must overcome two challenges: spatial resolution and physiological noise. Here we describe an optimized set of techniques developed to perform high-resolution fMRI in human SC, a structure on the dorsal surface of the midbrain; the methods can also be used to image other brainstem and subcortical structures.
High-resolution (1.2 mm voxels) fMRI of the SC requires a non-conventional approach. The desired spatial sampling is obtained using a multi-shot (interleaved) spiral acquisition1. Since, T2* of SC tissue is longer than in cortex, a correspondingly longer echo time (TE ~ 40 msec) is used to maximize functional contrast. To cover the full extent of the SC, 8-10 slices are obtained. For each session a structural anatomy with the same slice prescription as the fMRI is also obtained, which is used to align the functional data to a high-resolution reference volume.
In a separate session, for each subject, we create a high-resolution (0.7 mm sampling) reference volume using a T1-weighted sequence that gives good tissue contrast. In the reference volume, the midbrain region is segmented using the ITK-SNAP software application2. This segmentation is used to create a 3D surface representation of the midbrain that is both smooth and accurate3. The surface vertices and normals are used to create a map of depth from the midbrain surface within the tissue4.
Functional data is transformed into the coordinate system of the segmented reference volume. Depth associations of the voxels enable the averaging of fMRI time series data within specified depth ranges to improve signal quality. Data is rendered on the 3D surface for visualization.
In our lab we use this technique for measuring topographic maps of visual stimulation and covert and overt visual attention within the SC1. As an example, we demonstrate the topographic representation of polar angle to visual stimulation in SC.

This article describes techniques to perform high-resolution functional magnetic resonance imaging with 1.2 mm sampling in human midbrain and subcortical structures using a 3T scanner. Use of these techniques to resolve topographic maps of visual stimulation in the human superior colliculus (SC) is given as an example.

人間の中脳の高解像度機能的磁気共鳴画像法

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon ...

Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI

Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal models, including monkeys, ferrets, bats, rodents, and cats. In order to draw suitable parallels between human and animal models of auditory function, it is important to establish a bridge between human functional imaging studies and animal electrophysiological studies. Functional magnetic resonance imaging (fMRI) is an established, minimally invasive method of measuring broad patterns of hemodynamic activity across different regions of the cerebral cortex. This technique is widely used to probe sensory function in the human brain, is a useful tool in linking studies of auditory processing in both humans and animals and has been successfully used to investigate auditory function in monkeys and rodents. The following protocol describes an experimental procedure for investigating auditory function in anesthetized adult cats by measuring stimulus-evoked hemodynamic changes in auditory cortex using fMRI. This method facilitates comparison of the hemodynamic responses across different models of auditory function thus leading to a better understanding of species-independent features of the mammalian auditory cortex.

Functional studies of the auditory system in mammals have traditionally been conducted using spatially-focused techniques such as electrophysiological recordings. The following protocol describes a method of visualizing large-scale patterns of evoked hemodynamic activity in the cat auditory cortex using functional magnetic resonance imaging.

ハイフィールドのfMRIを使って大人の猫における聴覚皮質の機能イメージング

Current knowledge of sensory processing in the mammalian auditory system is mainly derived from electrophysiological studies in a variety of animal ...

Isolation and Quantification of Botulinum Neurotoxin From Complex Matrices Using the BoTest Matrix Assays

Accurate detection and quantification of botulinum neurotoxin (BoNT) in complex matrices is required for pharmaceutical, environmental, and food sample testing. Rapid BoNT testing of foodstuffs is needed during outbreak forensics, patient diagnosis, and food safety testing while accurate potency testing is required for BoNT-based drug product manufacturing and patient safety. The widely used mouse bioassay for BoNT testing is highly sensitive but lacks the precision and throughput needed for rapid and routine BoNT testing. Furthermore, the bioassay&#39;s use of animals has resulted in calls by drug product regulatory authorities and animal-rights proponents in the US and abroad to replace the mouse bioassay for BoNT testing. Several in vitro replacement assays have been developed that work well with purified BoNT in simple buffers, but most have not been shown to be applicable to testing in highly complex matrices. Here, a protocol for the detection of BoNT in complex matrices using the BoTest Matrix assays is presented. The assay consists of three parts: The first part involves preparation of the samples for testing, the second part is an immunoprecipitation step using anti-BoNT antibody-coated paramagnetic beads to purify BoNT from the matrix, and the third part quantifies the isolated BoNT&#39;s proteolytic activity using a fluorogenic reporter. The protocol is written for high throughput testing in 96-well plates using both liquid and solid matrices and requires about 2 hr of manual preparation with total assay times of 4-26 hr depending on the sample type, toxin load, and desired sensitivity. Data are presented for BoNT/A testing with phosphate-buffered saline, a drug product, culture supernatant, 2% milk, and fresh tomatoes and includes discussion of critical parameters for assay success.

The BoTest Matrix botulinum neurotoxin (BoNT) detection assays rapidly purify and quantify BoNT from a range of sample matrices.&#160;Here, we present a protocol for the detection and quantification of BoNT from both solid and liquid matrices and demonstrate the assay with BOTOX, tomatoes, and milk.

BoTestマトリックスアッセイを使用して複雑なマトリックスからの単離およびボツリヌス神経毒素の定量化

Accurate detection and quantification of botulinum neurotoxin (BoNT) in complex matrices is required for pharmaceutical, environmental, and food sample ...

High-resolution In Vivo Manual Segmentation Protocol for Human Hippocampal Subfields Using 3T Magnetic Resonance Imaging

The human hippocampus has been broadly studied in the context of memory and normal brain function and its role in different neuropsychiatric disorders has been heavily studied. While many imaging studies treat the hippocampus as a single unitary neuroanatomical structure, it is, in fact, composed of several subfields that have a complex three-dimensional geometry. As such, it is known that these subfields perform specialized functions and are differentially affected through the course of different disease states. Magnetic resonance (MR) imaging can be used as a powerful tool to interrogate the morphology of the hippocampus and its subfields. Many groups use advanced imaging software and hardware (&#62;3T) to image the subfields; however this type of technology may not be readily available in most research and clinical imaging centers. To address this need, this manuscript provides a detailed step-by-step protocol for segmenting the full anterior-posterior length of the hippocampus and its subfields: cornu ammonis (CA) 1, CA2/CA3, CA4/dentate gyrus (DG), strata radiatum/lacunosum/moleculare (SR/SL/SM), and subiculum. This protocol has been applied to five subjects (3F, 2M; age 29-57, avg. 37). Protocol reliability is assessed by resegmenting either the right or left hippocampus of each subject and computing the overlap using the Dice&#39;s kappa metric. Mean Dice&#39;s kappa (range) across the five subjects are: whole hippocampus, 0.91 (0.90-0.92); CA1, 0.78 (0.77-0.79); CA2/CA3, 0.64 (0.56-0.73); CA4/dentate gyrus, 0.83 (0.81-0.85); strata radiatum/lacunosum/moleculare, 0.71 (0.68-0.73); and subiculum 0.75 (0.72-0.78). The segmentation protocol presented here provides other laboratories with a reliable method to study the hippocampus and hippocampal subfields in vivo using commonly available MR tools.

High-resolution In Vivo Manual Segmentation Protocol for Human Hippocampal Subfields Using 3T Magnetic Resonance Imaging

The goal of this manuscript is to study the hippocampus and hippocampal subfields using MRI. The manuscript describes a protocol for segmenting the hippocampus and five hippocampal substructures: cornu ammonis (CA) 1, CA2/CA3, CA4/dentate gyrus, strata radiatum/lacunosum/moleculare, and subiculum.

高解像度<em&gt;インビボ</em&gt; 3T磁気共鳴画像を用いたヒト海馬サブフィールドのためのマニュアルセグメンテーションプロトコル

The human hippocampus has been broadly studied in the context of memory and normal brain function and its role in different neuropsychiatric disorders has ...

Non-invasive Parenchymal, Vascular and Metabolic High-frequency Ultrasound and Photoacoustic Rat Deep Brain Imaging

Photoacoustics and high frequency ultrasound stands out as powerful tools for neurobiological applications enabling high-resolution imaging on the central nervous system of small animals. However, transdermal and transcranial neuroimaging is frequently affected by low sensitivity, image aberrations and loss of space resolution, requiring scalp or even skull removal before imaging. To overcome this challenge, a new protocol is presented to gain significant insights in brain hemodynamics by photoacoustic and high-frequency ultrasounds imaging with the animal skin and skull intact. The procedure relies on the passage of ultrasound (US) waves and laser directly through the fissures that are naturally present on the animal cranium. By juxtaposing the imaging transducer device exactly in correspondence to these selected areas where the skull has a reduced thickness or is totally absent, one can acquire high quality deep images and explore internal brain regions that are usually difficult to anatomically or functionally describe without an invasive approach. By applying this experimental procedure, significant data can be collected in both sonic and optoacoustic modalities, enabling to image the parenchymal and the vascular anatomy far below the head surface. Deep brain features such as parenchymal convolutions and fissures separating the lobes were clearly visible. Moreover, the configuration of large and small blood vessels was imaged at several millimeters of depth, and precise information were collected about blood fluxes, vascular stream velocities and the hemoglobin chemical state. This repertoire of data could be crucial in several research contests, ranging from brain vascular disease studies to experimental techniques involving the systemic administration of exogenous chemicals or other objects endowed with imaging contrast enhancement properties. In conclusion, thanks to the presented protocol, the US and PA techniques become an attractive noninvasive performance-competitive means for cortical and internal brain imaging, retaining a significant potential in many neurologic fields.

The present work describes a new protocol to perform non-invasive high-frequency ultrasound and photoacoustic based imaging on rat brain, to efficiently visualize deep subcortical regions and their vascular patterns by directing signals on skull foramina naturally present on animal cranium.

非侵襲的実質細胞、血管および代謝高周波超音波および光音響ラット脳深部イメージング

Photoacoustics and high frequency ultrasound stands out as powerful tools for neurobiological applications enabling high-resolution imaging on the central ...

High-resolution Structural Magnetic Resonance Imaging of the Human Subcortex In Vivo and Postmortem

The focus of this study was to test the resolution limits of structural MRI of a postmortem brain compared to living human brains. The resolution of structural MRI in vivo is ultimately limited by physiological noise, including pulsation, respiration and head movement. Although imaging hardware continues to improve, it is still difficult to resolve structures on the millimeter scale. For example, the primary visual sensory pathways synapse at the lateral geniculate nucleus (LGN), a visual relay and control nucleus in the thalamus that normally is organized into six interleaved monocular layers. Neuroimaging studies have not been able to reliably distinguish these layers due their small size that are less than 1 mm thick.
The resolving limit of structural MRI, in a postmortem brain was tested using multiple images averaged over a long duration (~24 h). The purpose was to test whether it was possible to resolve the individual layers of the LGN in the absence of physiological noise. A proton density (PD)1 weighted pulse sequence was used with varying resolution and other parameters to determine the minimum number of images necessary to be registered and averaged to reliably distinguish the LGN and other subcortical regions. The results were also compared to images acquired in living human brains. In vivo subjects were scanned in order to determine the additional effects of physiological noise on the minimum number of PD scans needed to differentiate subcortical structures, useful in clinical applications.

High-resolution Structural Magnetic Resonance Imaging of the Human Subcortex In Vivo and Postmortem

Here we present a protocol to determine the minimum number images that needed to be registered and averaged to resolve subcortical structures and test whether the individual layers of the LGN could be resolved in the absence of physiological noise.

ヒト皮質下の高分解能構造磁気共鳴イメージング<I&gt;インビボ</I&gt;と死後

The focus of this study was to test the resolution limits of structural MRI of a postmortem brain compared to living human brains. The resolution of ...

High-throughput Analysis of Locomotor Behavior in the Drosophila Island Assay

Advances in next-generation sequencing technologies contribute to the identification of (candidate) disease genes for movement disorders and other neurological diseases at an increasing speed. However, little is known about the molecular mechanisms that underlie these disorders. The genetic, molecular, and behavioral toolbox of Drosophila melanogaster makes this model organism particularly useful to characterize new disease genes and mechanisms in a high-throughput manner. Nevertheless, high-throughput screens require efficient and reliable assays that, ideally, are cost-effective and allow for the automatized quantification of traits relevant to these disorders. The island assay is a cost-effective and easily set-up method to evaluate Drosophila locomotor behavior. In this assay, flies are thrown onto a platform from a fixed height. This induces an innate motor response that enables the flies to escape from the platform within seconds. At present, quantitative analyses of filmed island assays are done manually, which is a laborious undertaking, particularly when performing large screens.
This manuscript describes the &#34;Drosophila Island Assay&#34; and &#34;Island Assay Analysis&#34; algorithms for&#160;high-throughput, automated data processing and quantification of island assay data. In the setup, a simple webcam connected to a laptop collects an image series of the platform while the assay is performed. The &#34;Drosophila Island Assay&#34; algorithm developed for the open-source software Fiji processes these image series and quantifies, for each experimental condition, the number of flies on the platform over time. The &#34;Island Assay Analysis&#34; script, compatible with the free software R, was developed to automatically process the obtained data and to calculate whether treatments/genotypes are statistically different. This greatly improves the efficiency of the island assay and makes it a powerful readout for basic locomotion and flight behavior. It can thus be applied to large screens investigating fly locomotor ability, Drosophila models of movement disorders, and drug efficacy.

High-throughput Analysis of Locomotor Behavior in the Drosophila Island Assay

The island assay is a relatively new, cost-effective assay that can be used to evaluate the basic locomotor behavior of Drosophila melanogaster. This manuscript describes algorithms for automatic data processing and objective quantification of island assay data, making this assay a sensitive, high-throughput readout for large genetic or pharmacological screens.

ショウジョウバエ島アッセイにおける歩行行動の高スループット解析

Advances in next-generation sequencing technologies contribute to the identification of (candidate) disease genes for movement disorders and other ...

Assay Development for High Content Quantification of Sod1 Mutant Protein Aggregate Formation in Living Cells

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that can be caused by inherited mutations in the gene encoding copper-zinc superoxide dismutase 1 (SOD1). The structural instability of SOD1 and the detection of SOD1-positive inclusions in familial-ALS patients supports a potential causal role for misfolded and/or aggregated SOD1 in ALS pathology. In this study, we describe the development of a cell-based assay designed to quantify the dynamics of SOD1 aggregation in living cells by high content screening approaches. Using lentiviral vectors, we generated stable cell lines expressing wild-type and mutant A4V SOD1 tagged with yellow fluorescent protein and found that both proteins were expressed in the cytosol without any sign of aggregation. Interestingly, only SOD1 A4V stably expressed in HEK-293, but not in U2OS or SH-SY5Y cell lines, formed aggregates upon proteasome inhibitor treatment. We show that it is possible to quantify aggregation based on dose-response analysis of various proteasome inhibitors, and to track aggregate-formation kinetics by time-lapse microscopy. Our approach introduces the possibility of quantifying the effect of ALS mutations on the role of SOD1 in aggregate formation as well as screening for small molecules that prevent SOD1 A4V aggregation.

We describe a method to quantify the aggregation of misfolded proteins. Our protocol details lentiviral induced stable cell line generation, automated confocal imaging, and image analysis of protein aggregates. As an illustrative application, we studied the effect of small molecules in promoting SOD1 aggregation in a time- and dose-dependent manner.

Sod1 突然変異体蛋白質集計における細胞の高いコンテンツ定量化のための分析法の開発

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that can be caused by inherited mutations in the gene encoding copper-zinc ...

Using a Microfluidics Device for Mechanical Stimulation and High Resolution Imaging of C. elegans

One central goal of mechanobiology is to understand the reciprocal effect of mechanical stress on proteins and cells. Despite its importance, the influence of mechanical stress on cellular function is still poorly understood. In part, this knowledge gap exists because few tools enable simultaneous deformation of tissue and cells, imaging of cellular activity in live animals, and efficient restriction of motility in otherwise highly mobile model organisms, such as the nematode Caenorhabditis elegans. The small size of C. elegans makes them an excellent match to microfluidics-based research devices, and solutions for immobilization have been presented using microfluidic devices. Although these devices allow for high-resolution imaging, the animal is fully encased in polydimethylsiloxane (PDMS) and glass, limiting physical access for delivery of mechanical force or electrophysiological recordings. Recently, we created a device that integrates pneumatic actuators with a trapping design that is compatible with high-resolution fluorescence microscopy. The actuation channel is separated from the worm-trapping channel by a thin PDMS diaphragm. This diaphragm is deflected into the side of a worm by applying pressure from an external source. The device can target individual mechanosensitive neurons. The activation of these neurons is imaged at high-resolution with genetically-encoded calcium indicators. This article presents the general method using C. elegans strains expressing calcium-sensitive activity indicator (GCaMP6s) in their touch receptor neurons (TRNs). The method, however, is not limited to TRNs nor to calcium sensors as a probe, but can be expanded to other mechanically-sensitive cells or sensors.

Using a Microfluidics Device for Mechanical Stimulation and High Resolution Imaging of C. elegans

New tools for mechanobiology research are needed to understand how mechanical stress activates biochemical pathways and elicits biological responses. Here, we showcase a new method for selective mechanical stimulation of immobilized animals with a microfluidic trap allowing high-resolution imaging of cellular responses.