すべての動物実験は、国立機関の健康動物使用のガイドラインに従って実施されています。この作品は、一部に C. 区国立衛生研究所 (R01NS093073 と R21AA024873) からの助成金によって支えられました。

<ol>
	<li>Niki&#263;, 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+reversible+form+of+axon+damage+in+experimental+autoimmune+encephalomyelitis+and+multiple+sclerosis.">A reversible form of axon damage in experimental autoimmune encephalomyelitis and multiple sclerosis.</a> Nat. Med. 17, 495-499 (2011).</li><li>Yang, J., 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=Regulation+of+axon+degeneration+after+injury+and+in+development+by+the+endogenous+calpain+inhibitor+calpastatin.">Regulation of axon degeneration after injury and in development by the endogenous calpain inhibitor calpastatin.</a> Neuron. 80 (5), 1175-1189 (2013).</li><li>Debanne, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Information+processing+in+the+axon.">Information processing in the axon.</a> Nat. Rev. Neurosci. 5, 304-316 (2004).</li><li>Gu, Y., Jukkola, P., Wang, Q., Esparza, T., Zhao, Y., Brody, D., Gu, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polarity+of+varicosity+initiation+in+central+neuron+mechanosensation.">Polarity of varicosity initiation in central neuron mechanosensation.</a> J Cell Biol. 216 (7), 2179-2199 (2017).</li><li>Chung, R. 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=Mild+axonal+stretch+injury+in+vitro+induces+a+progressive+series+of+neurofilament+alterations+ultimately+leading+to+delayed+axotomy.">Mild axonal stretch injury in vitro induces a progressive series of neurofilament alterations ultimately leading to delayed axotomy.</a> J. Neurotrauma. 22 (10), 1081-1091 (2005).</li><li>Staal, J. A., Dickson, T. C., Chung, R. S., Vickers, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclosporin-A+treatment+attenuates+delayed+cytoskeletal+alterations+and+secondary+axotomy+following+mild+axonal+stretch+injury.">Cyclosporin-A treatment attenuates delayed cytoskeletal alterations and secondary axotomy following mild axonal stretch injury.</a> Dev. Neurobiol. 67 (14), 1831-1842 (2007).</li><li>Tang-Schomer, M. D., Johnson, V. E., Baas, P. W., Stewart, W., Smith, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Partial+interruption+of+axonal+transport+due+to+microtubule+breakage+accounts+for+the+formation+of+periodic+varicosities+after+traumatic+axonal+injury.">Partial interruption of axonal transport due to microtubule breakage accounts for the formation of periodic varicosities after traumatic axonal injury.</a> Exp. Neurol. 233 (1), 364-372 (2012).</li><li>Donkin, J. J., Vink, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+cerebral+edema+in+traumatic+brain+injury:+therapeutic+developments.">Mechanisms of cerebral edema in traumatic brain injury: therapeutic developments.</a> Curr Opin Neurol. 23 (3), 293-299 (2010).</li><li>Gardner, A., Jukkola, P., Gu, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myelination+of+rodent+hippocampal+neurons+in+culture.">Myelination of rodent hippocampal neurons in culture.</a> Nat Protoc. 7 (10), 1774-1782 (2012).</li><li>Wang, Q., Zhang, X., Zhao, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micromechanical+stimulator+for+localized+cell+loading:+fabrication+and+strain+analysis.">Micromechanical stimulator for localized cell loading: fabrication and strain analysis.</a> J. Micromech. Microeng. 23, 015002 (2013).</li><li>Lu, Y. 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=Viscoelastic+properties+of+individual+glial+cells+and+neurons+in+the+CNS.">Viscoelastic properties of individual glial cells and neurons in the CNS.</a> Proc. Natl. Acad. Sci. USA. 103 (47), 17759-17764 (2006).</li><li>Elkin, B. S., Azeloglu, E. U., Costa, K. D., Morrison, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+heterogeneity+of+the+rat+hippocampus+measured+by+atomic+force+microscope+indentation.">Mechanical heterogeneity of the rat hippocampus measured by atomic force microscope indentation.</a> J. Neurotrauma. 24 (5), 812-822 (2007).</li><li>Franze, K., 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=Neurite+branch+retraction+is+caused+by+a+threshold-dependent+mechanical+impact.">Neurite branch retraction is caused by a threshold-dependent mechanical impact.</a> Biophys. J. 97 (7), 1883-1890 (2009).</li><li>Camp&#224;s, O., 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=Quantifying+cell-generated+mechanical+forces+within+living+embryonic+tissues.">Quantifying cell-generated mechanical forces within living embryonic tissues.</a> Nat. Methods. 11 (2), 183-189 (2014).</li></ol>

著者が明らかに何もありません。

この microbiomechanical のアッセイのプロシージャはまっすぐ進むです。そのすべてのステップは慎重に行われている場合信頼性の高い結果が生成されます。正常なデータ収集の妨げになる場合は、不適切な実行、いくつかの主要な手順があります。重要なステップが始まる上流たばこを吸う刺激の実際に適用しました。細かく、養殖と一次ニューロンの文化のケアが最も重要です。培養神経細?...

静脈瘤の形成、または腫れ/ビーズ, 軸索に沿っては多くの障害やパーキンソン病、アルツハイマー病、多発性硬化症を含む中枢神経系の損傷で観察した神経変性疾患の顕著な特徴と外傷性脳損傷1,2。活動電位伝搬とシナプス伝達3軸索下肢の生理学的な影響にもかかわらず、下肢の生成方法は不明のまま。最近、齧歯動物から培養海馬神経細胞の新設 microbiomechanical 試金を使用して、機械的刺激が下肢機能を非常に魅力的なこれらのニューロンを引き起こすことができることがわかった。最初に、静脈瘤の誘導は急速な (< 10 s)、このプロセスは予期せず元に戻せる。第二に、静脈瘤開始が圧力を吹きかける強さ依存: より高い圧力、高速の開始。第三に、静脈瘤の発生は神経年齢に依存します。若いニューロンの軸索はより古いニューロンのそれらと比較して、機械的ストレスに対する応答表示されます。第四に、樹枝状結晶およびこれらのニューロンの軸索の初期セグメント中の海馬ニューロンの軸索に沿って下肢のフォームには、同じたばこを吸う条件変更は表示されません。したがって、我々 の研究は、神経細胞の極性の新規機能を明らかにしました。体外システムこれらの発見は、生理学的に関連しています。軽度外傷性脳損傷 (mTBI)生体内でモデルを使用して、軸索の下肢が閉じる頭蓋骨への影響、私たち体外で一貫した後すぐにマウスの体性感覚野における多焦点方式で開発を示した結果4。私たちの染色・ イメージング mTBI マウスの神経の形態学的変化のスナップ ショットを提供するだけで、体内の実行以来機械的衝撃に神経細胞形態のタイムラプス イメージングはまだ不可能することが重要です。
この液体に吹きかけるシステム機械的応力誘起静脈瘤形成に関連するユニークな機能をキャプチャするのみならず、基になるメカニズムを決定することができました。細胞外のさまざまなソリューション、ブロッカーと機械刺激感受性イオン チャネル、細胞電気生理学の別候補のオープナをテストすることにより一時的な受容器の潜在的な陽イオン チャネル亜科 V メンバー 4 (TRPV4) ことがわかりました吹き込むことによってアクティブ化される Ca2 + +の Na に透過性チャネルは軸索静脈瘤形成4の間に初期の機械的応力を検出を主に担当。これはさらに、siRNA ノックアウト アプローチで確認されました。まとめると、海馬ニューロンの文化を開発したこの新しいアッセイ システム、他の技術との組み合わせでは特に、脳のニューロンのマイクロメカニックスによるプロパティの勉強にとって非常に貴重です。
設けてこのマイクロ システムはユニークないくつかの主要な側面で既存システムとは異なります。まず、このシステムは、ニューロンは圧縮とせん断の形態で面外応力を経験します。機械的衝撃に神経突起 coverslip 表面に接続したまま、移動しないでください。その他実験的曲げ、平面でストレッチを主に含んだシステム (または張力) からこれとは異なり、文字列5,6を移動またはマイクロパターニングゲル上に成長した軸索を伸ばす例えば、バンドルされた軸索の偏向のようなチャンネルと伸縮性膜7,8。また、軸索の下肢に誘起することが流体に吹きかけるシステムでこれらの設定のプロセスのようなこれらの試金が表示されます (数時間6,7,810 分) からのより多くの時間がかかると不可逆的です。最後に、ローカル流体息を切らしを用いてできます静脈瘤形成の空間的特徴の検討 (e.g。、樹状突起スパイン、相馬、軸索の初期セグメント、軸索端末)、時空間特徴のほか。このシステムを使用すると、予期しない、ユニークな機能がいくつか軸索静脈瘤形成、特に急激な発症、低速の可逆性と軸索・樹状突起の極性を発見しました。
本稿で述べるシステムは分子の多くの技術との互換性と、細胞生物学。例えば、機械的ストレスが神経細胞の形態と機能に及ぼす影響を研究するそれと共に使用できますミエリン共、タイムラプス蛍光共鳴エネルギー移動 (FRET) の全内部反射蛍光 (TIRF) イメージングカルシウム イメージング、およびパッチ ・ クランプ記録。本稿で我々 はシステムのコア ・ コンポーネントに焦点を当てます。海馬ニューロンの文化、流体パフィング セットアップ、軸索輸送のための高分解能のタイムラプス イメージングおよびカルシウム イメージングを以下順を追って示します。

<table><tbody><tr><td>12 mm coverslips&amp;nbsp;</td><td>Warner Instruments&amp;nbsp;</td><td>64-0702</td><td>for 24-well plate&amp;nbsp;</td></tr><tr><td>25 mm coverslips&amp;nbsp;</td><td>Fisher Scientific&amp;nbsp;</td><td>12-545-102&amp;nbsp;</td><td>for 6-well plate&amp;nbsp;</td></tr><tr><td>Acetic acid</td><td>Fisher Scientific&amp;nbsp;</td><td>A38-212</td><td></td></tr><tr><td>Poly-D-lysine</td><td>Sigma&amp;nbsp;</td><td>P6407</td><td></td></tr><tr><td>Rat tail collagen&amp;nbsp;</td><td>Roche&amp;nbsp;</td><td>11 179 179 001&amp;nbsp;</td><td></td></tr><tr><td>10X PBS&amp;nbsp;</td><td>National Diagnostics&amp;nbsp;</td><td>CL-253</td><td></td></tr><tr><td>Na&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;</td><td>Fisher Scientific&amp;nbsp;</td><td>S373-500</td><td></td></tr><tr><td>K&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;</td><td>Fisher Scientific&amp;nbsp;</td><td>P304-500</td><td></td></tr><tr><td>HEPES&amp;nbsp;</td><td>Fisher Scientific&amp;nbsp;</td><td>BP410-500</td><td></td></tr><tr><td>D-glucose&amp;nbsp;</td><td>Fisher Scientific&amp;nbsp;</td><td>D16-500</td><td></td></tr><tr><td>MgCl&lt;sub&gt;2&lt;/sub&gt;</td><td>Fisher Scientific&amp;nbsp;</td><td>BP214-500</td><td></td></tr><tr><td>NaOH</td><td>Fisher Scientific&amp;nbsp;</td><td>SS255-1</td><td></td></tr><tr><td>Protease enzyme&amp;nbsp;</td><td>Sigma&amp;nbsp;</td><td>P4032</td><td></td></tr><tr><td>FBS</td><td>Gibco&amp;nbsp;</td><td>26140</td><td></td></tr><tr><td>Sodium pyruvate&amp;nbsp;</td><td>Gibco&amp;nbsp;</td><td>11360-070</td><td></td></tr><tr><td>L-glutamine&amp;nbsp;</td><td>Gibco&amp;nbsp;</td><td>25030081</td><td></td></tr><tr><td>Penicillin/Streptomycin 100x (P/S)</td><td>Gibco&amp;nbsp;</td><td>15140122</td><td></td></tr><tr><td>MEM Earle&#039;s Salts&amp;nbsp;</td><td>Gibco&amp;nbsp;</td><td>11090</td><td></td></tr><tr><td>B27 supplement&amp;nbsp;</td><td>Gibco&amp;nbsp;</td><td>17504-044</td><td></td></tr><tr><td>Neurobasal&amp;nbsp;</td><td>Gibco&amp;nbsp;</td><td>21103-049</td><td></td></tr><tr><td>Arabinosylcytosine (Ara-C)</td><td>Sigma&amp;nbsp;</td><td>147-94-4</td><td></td></tr><tr><td>Opti-MEM media&amp;nbsp;</td><td>Gibco&amp;nbsp;</td><td>31985-070</td><td></td></tr><tr><td>Lipofectamine 2000</td><td>Invitrogen&amp;nbsp;</td><td>1854313</td><td>transfection reagent&amp;nbsp;</td></tr><tr><td>Borosilicate rods&amp;nbsp;</td><td>World Precision Instruments Inc.&amp;nbsp;</td><td>PG52151-4</td><td>for puffing pipette&amp;nbsp;</td></tr><tr><td>rubber tubing&amp;nbsp;</td><td>Fisher Scientific&amp;nbsp;</td><td>14-169-1A</td><td></td></tr><tr><td>10cc plastic syringe and plunger</td><td>Becton Dickinson&amp;nbsp;</td><td></td><td></td></tr><tr><td>micromanipulator&amp;nbsp;</td><td>Sutter Instruments&amp;nbsp;</td><td></td><td></td></tr><tr><td>NaCl&amp;nbsp;</td><td>Fisher Scientific&amp;nbsp;</td><td>S640-3</td><td></td></tr><tr><td>KCl&amp;nbsp;</td><td>Fisher Scientific&amp;nbsp;</td><td>BP366-500</td><td></td></tr><tr><td>CaCl&lt;sub&gt;2&lt;/sub&gt;</td><td>Fisher Scientific&amp;nbsp;</td><td>C70-500</td><td></td></tr><tr><td>Cell culture dish (35 mm x 10 mm)</td><td>Corning&amp;nbsp;</td><td>3294</td><td></td></tr><tr><td>Fluo-4 AM</td><td>Molecular Probes</td><td>F14201</td><td>for calcium imaging&amp;nbsp;</td></tr><tr><td>Mito-YFP construct&amp;nbsp;</td><td>Takara Bio Inc.&amp;nbsp;</td><td></td><td>for cell transfection&amp;nbsp;</td></tr><tr><td>YFP-N1 construct&amp;nbsp;</td><td>Takara Bio Inc.&amp;nbsp;</td><td></td><td>for cell transfection&amp;nbsp;</td></tr><tr><td>Model P-1000 Flaming/Brown Micropipette puller&amp;nbsp;</td><td>Sutter Instruments&amp;nbsp;</td><td></td><td></td></tr><tr><td>Eclipse TE2000-U Mcroscope&amp;nbsp;</td><td>Nikon</td><td></td><td></td></tr><tr><td>Plan Fluor ELWD 20x lens&amp;nbsp;&amp;nbsp;</td><td>Nikon</td><td>062933</td><td>objective&amp;nbsp;</td></tr><tr><td>Apo TIRF 100x/1.49 oil lens&amp;nbsp;</td><td>Nikon</td><td>MRD01991</td><td>objective&amp;nbsp;</td></tr></tbody></table>

a microbiomechanical system for studying varicosity formation and recovery in central neuron axons

軸索の下肢は、不均一性の高度で軸索の軸に沿って拡大構造です。彼らが神経変性疾患や外傷、脳は通常の脳だけではなく存在です。ここでは、我々 静脈瘤形成と異種タンパク質組成を支配するメカニズムを理解すること急速に、確実に、かつ可逆的に軸索の下肢を誘導するために新設された微小力学系をについて説明します。このシステムは、ニューロン、他の培養システム主に及ぼす伸張の影響に焦点を当てる別の細胞内コンパートメントに及ぼす圧縮と剪断応力を評価するための新しい手段を表します。重要なは、我々 のシステムの固有の機能のおかげで我々 は最近、加圧流体のアプリケーション迅速かつ可逆的に誘発することが一時的な受容器の潜在的なチャネルの活性化を介して軸索の下肢を示す新規発見をしました。私たちの生体力学的システムは、薬剤灌流、ライブセル イメージング、カルシウム イメージング、およびパッチ ・ クランプ記録との組み合わせで便利に利用できます。したがって、このメソッドは、機械刺激感受性イオン チャネル、軸索輸送規制、軸索細胞骨格のダイナミクス、カルシウム シグナル伝達、および形態変化関連外傷性脳損傷を研究するため採用することができます。

息を切らし前、軸索は通常小さな静脈瘤形成を示します。次は私たちの標準圧力 (190 mmH2O 高さ)、多くのビーズのような下肢を開発する軸索開始と息を切らし。下肢の形成は、次の 10 分回復期 (図 2A B) 事前息切れの状態を返す軸索の領域で示すように、部分的に可逆です。回復の長い期間後 (> 20 分)、いくつかの軸索は完全?...

Watch this Scientific Journal Video about A Microbiomechanical System for Studying Varicosity Formation and Recovery in Central Neuron Axons at JoVE.com

A Microbiomechanical System for Studying Varicosity Formation and Recovery in Central Neuron Axons

このプロトコルでは、ニューロンの下肢の急速かつ可逆的誘導の生理学的に関連する、加圧液体のアプローチについて説明します。

静脈瘤形成と中枢神経の軸索の回復を研究するための Microbiomechanical システム

Axonal varicosities are enlarged structures along the shafts of axons with a high degree of heterogeneity. They are present not only in brains with ...

a-microbiomechanical-system-for-studying-varicosity-formation

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

6.2K ビュー.  The Ohio State University. このプロトコルでは、ニューロンの下肢の急速かつ可逆的誘導の生理学的に関連する、加圧液体のアプローチについて説明します。

ビデオ: A Microbiomechanical System for Studying Varicosity Formation and Recovery in Central Neuron Axons

Mechanical Manipulation of Neurons to Control Axonal Development

Cell manipulations and extension of neuronal axons can be accomplished with calibrated glass micro-fibers capable of measuring and applying forces in the 10-1000 &mu;dyne range1,2. Force measurements are obtained through observation of the Hookean bending of the glass needles, which are calibrated by a direct and empirical method3. Equipment requirements and procedures for fabricating, calibrating, treating, and using the needles on cells are fully described. The force regimes previously used and different cell types to which these techniques have been applied demonstrate the flexibility of the methodology and are given as examples for future investigation4-6. The technical advantages are the continuous 'visualization' of the forces produced by the manipulations and the ability to directly intervene in a variety of cellular events. These include direct stimulation and regulation of axonal growth and retraction7; as well as detachment and mechanical measurements on any type of cultured cell8.

Application and direct measurements of forces on neurons in the 2-1000 microdyne range are achieved with high precision using calibrated glass needles. This methodology can be used to control and measure several aspects of axonal development, including axonal initiation, axonal tension, velocity of axonal elongation, and force vectors.

軸索の開発を制御する神経細胞の機械的な操作

Cell manipulations and extension of neuronal axons can be accomplished with calibrated glass micro-fibers capable of measuring and applying forces in the ...

神経科学

Laser Nanosurgery of Cerebellar Axons In Vivo

Only a few neuronal populations in the central nervous system (CNS) of adult mammals show local regrowth upon dissection of their axon. In order to understand the mechanism that promotes neuronal regeneration, an in-depth analysis of the neuronal types that can remodel after injury is needed. Several studies showed that damaged climbing fibers are capable of regrowing also in adult animals1,2. The investigation of the time-lapse dynamics of degeneration and regeneration of these axons within their complex environment can be performed by time-lapse two-photon fluorescence (TPF) imaging in vivo3,4. This technique is here combined with laser surgery, which proved to be a highly selective tool to disrupt fluorescent structures in the intact mouse cortex5-9.
This protocol describes how to perform TPF time-lapse imaging and laser nanosurgery of single axonal branches in the cerebellum in vivo. Olivocerebellar neurons are labeled by anterograde tracing with a dextran-conjugated dye and then monitored by TPF imaging through a cranial window. The terminal portion of their axons are then dissected by irradiation with a Ti:Sapphire laser at high power. The degeneration and potential regrowth of the damaged neuron are monitored by TPF in vivo imaging during the days following the injury.

Laser Nanosurgery of Cerebellar Axons In Vivo

Two-photon imaging, coupled to laser nanodissection, are useful tools to study degenerative and regenerative processes in the central nervous system with subcellular resolution. This protocol shows how to label, image, and dissect single climbing fibers in the cerebellar cortex in vivo.

小脳軸索のレーザーNanosurgery<em&gt;インビボ</em

Only a few neuronal populations in the central nervous system (CNS) of adult mammals show local regrowth upon dissection of their axon. In order to ...

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal degeneration. Lack of growth cone formation, regeneration, and loss of additional myelinated axonal projections within the spinal cord greatly limits neurological recovery following injury. To assess how central myelinated axons of the spinal cord respond to injury, we developed an ex vivo living spinal cord model utilizing transgenic mice that express yellow fluorescent protein in axons and a focal and highly reproducible laser-induced spinal cord injury to document the fate of axons and myelin (lipophilic fluorescent dye Nile Red) over time using two-photon excitation time-lapse microscopy. Dynamic processes such as acute axonal injury, axonal retraction, and myelin degeneration are best studied in real-time. However, the non-focal nature of contusion-based injuries and movement artifacts encountered during in vivo spinal cord imaging make differentiating primary and secondary axonal injury responses using high resolution microscopy challenging. The ex vivo spinal cord model described here mimics several aspects of clinically relevant contusion/compression-induced axonal pathologies including axonal swelling, spheroid formation, axonal transection, and peri-axonal swelling providing a useful model to study these dynamic processes in real-time. Major advantages of this model are excellent spatiotemporal resolution that allows differentiation between the primary insult that directly injures axons and secondary injury mechanisms; controlled infusion of reagents directly to the perfusate bathing the cord; precise alterations of the environmental milieu (e.g., calcium, sodium ions, known contributors to axonal injury, but near impossible to manipulate in vivo); and murine models also offer an advantage as they provide an opportunity to visualize and manipulate genetically identified cell populations and subcellular structures. Here, we describe how to isolate and image the living spinal cord from mice to capture dynamics of acute axonal injury.

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

We present a protocol utilizing two-photon excitation time-lapse microscopy to simultaneously visualize the dynamics of axon and myelin injuries in real time. This proposed protocol permits studies of both intrinsic and extrinsic factors which can influence central myelinated axon fate after injury and contribute to permanent clinical disability.

アン<em&gt;エクスビボ</em&gt;レーザー誘起脊髄損傷モデルがリアルタイムで軸索変性のメカニズムを評価するために

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal ...

Intravital Imaging of Axonal Interactions with Microglia and Macrophages in a Mouse Dorsal Column Crush Injury

Traumatic spinal cord injury causes an inflammatory reaction involving blood-derived macrophages and central nervous system (CNS)-resident microglia. Intra-vital two-photon microscopy enables the study of macrophages and microglia in the spinal cord lesion in the living animal. This can be performed in adult animals with a traumatic injury to the dorsal column. Here, we describe methods for distinguishing macrophages from microglia in the CNS using an irradiation bone marrow chimera to obtain animals in which only macrophages or microglia are labeled with a genetically encoded green fluorescent protein. We also describe a injury model that crushes the dorsal column of the spinal cord, thereby producing a simple, easily accessible, rectangular lesion that is easily visualized in an animal through a laminectomy. Furthermore, we will outline procedures to sequentially image the animals at the anatomical site of injury for the study of cellular interactions during the first few days to weeks after injury.

Two-photon intravital imaging can be used to investigate interactions among different cell types in the spinal cord in their native tissue environment in a bone marrow chimeric animal with a dorsal column traumatic spinal cord crush injury.

マウス背側列のクラッシュ損傷におけるミクログリアおよびマクロファージと軸索の相互作用の生体内イメージング

Traumatic spinal cord injury causes an inflammatory reaction involving blood-derived macrophages and central nervous system (CNS)-resident microglia. ...

Rewiring Neuronal Circuits: A New Method for Fast Neurite Extension and Functional Neuronal Connection

Brain and spinal cord injury may lead to permanent disability and death because it is still not possible to regenerate neurons over long distances and accurately reconnect them with an appropriate target. Here a procedure is described to rapidly initiate, elongate, and precisely connect new functional neuronal circuits over long distances. The extension rates achieved reach over 1.2 mm/h, 30-60 times faster than the in vivo rates of the fastest growing axons from the peripheral nervous system (0.02 to 0.04 mm/h)28 and 10 times faster than previously reported for the same neuronal type at an earlier stage of development4. First, isolated populations of rat hippocampal neurons are grown for 2-3 weeks in microfluidic devices to precisely position the cells, enabling easy micromanipulation and experimental reproducibility. Next, beads coated with poly-D-lysine (PDL) are placed on neurites to form adhesive contacts and pipette micromanipulation is used to move the resulting bead-neurite complex. As the bead is moved, it pulls out a new neurite that can be extended over hundreds of micrometers and functionally connected to a target cell in less than 1 h. This process enables experimental reproducibility and ease of manipulation while bypassing slower chemical strategies to induce neurite growth. Preliminary measurements presented here demonstrate a neuronal growth rate far exceeding physiological ones. Combining these innovations allows for the precise establishment of neuronal networks in culture with an unprecedented degree of control. It is a novel method that opens the door to a plethora of information and insights into signal transmission and communication within the neuronal network as well as being a playground in which to explore the limits of neuronal growth. The potential applications and experiments are widespread with direct implications for therapies that aim to reconnect neuronal circuits after trauma or in neurodegenerative diseases.

This procedure describes how to rapidly initiate, extend and connect neurites organized in microfluidic chambers using poly-D-lysine-coated beads fixed to micropipettes that guide neurite elongation.

ニューロン回路の再学習：速い神経突起伸長と機能的ニューロン結合の新しい方法

Brain and spinal cord injury may lead to permanent disability and death because it is still not possible to regenerate neurons over long distances and ...

A Simple Neuronal Mechanical Injury Methodology to Study Drosophila Motor Neuron Degeneration

The degeneration of neurons occurs during normal development and in response to injury, stress, and disease. The cellular hallmarks of neuronal degeneration are remarkably similar in humans and invertebrates as are the molecular mechanisms that drive these processes. The fruit fly, Drosophila melanogaster, provides a powerful yet simple genetic model organism to study the cellular complexities of neurodegenerative diseases. In fact, approximately 70% of disease-associated human genes have a Drosophila homolog and a plethora of tools and assays have been described using flies to study human neurodegenerative diseases. More specifically the neuromuscular junction (NMJ) in Drosophila has proven to be an effective system to study neuromuscular diseases because of the ability to analyze the structural connections between the neuron and the muscle. Here, we report on an in vivo motor neuron injury assay in Drosophila, which reproducibly induces neurodegeneration at the NMJ by 24 h. Using this methodology, we have described a temporal sequence of cellular events resulting in motor neuron degeneration. The injury method has diverse applications and has also been utilized to identify specific genes required for neurodegeneration and to dissect transcriptional responses to neuronal injury.

A Simple Neuronal Mechanical Injury Methodology to Study Drosophila Motor Neuron Degeneration

Here we describe a simple and widely accessible method to injure segmental nerves in Drosophila larvae to visualize and quantify neurodegeneration of motor neurons at the neuromuscular junction (NMJ) of third instar larvae.

研究のための単純な神経細胞学的損傷法<em&gt;ショウジョウバエ</em&gt;運動ニューロン変性

The degeneration of neurons occurs during normal development and in response to injury, stress, and disease. The cellular hallmarks of neuronal ...

A Drosophila In Vivo Injury Model for Studying Neuroregeneration in the Peripheral and Central Nervous System

The regrowth capacity of damaged neurons governs neuroregeneration and functional recovery after nervous system trauma. Over the past few decades, various intrinsic and extrinsic inhibitory factors involved in the restriction of axon regeneration have been identified. However, simply removing these inhibitory cues is insufficient for successful regeneration, indicating the existence of additional regulatory machinery. Drosophila melanogaster, the fruit fly, shares evolutionarily conserved genes and signaling pathways with vertebrates, including humans. Combining the powerful genetic toolbox of flies with two-photon laser axotomy/dendriotomy, we describe here the Drosophila sensory neuron &#8211; dendritic arborization (da) neuron injury model as a platform for systematically screening for novel regeneration regulators. Briefly, this paradigm includes a) the preparation of larvae, b) lesion induction to dendrite(s) or axon(s) using a two-photon laser, c) live confocal imaging post-injury and d) data analysis. Our model enables highly reproducible injury of single labeled neurons, axons, and dendrites of well-defined neuronal subtypes, in both the peripheral and central nervous system.

A Drosophila In Vivo Injury Model for Studying Neuroregeneration in the Peripheral and Central Nervous System

Here, we present a protocol using the Drosophila sensory neuron - dendritic arborization (da) neuron injury model, which combines in vivo live imaging, two-photon laser axotomy/dendriotomy, and the powerful fly genetic toolbox, as a platform for screening potential promoters and inhibitors of neuroregeneration.

再生に関する末梢および中枢神経系を研究するため生体内でショウジョウバエ損傷モデル

The regrowth capacity of damaged neurons governs neuroregeneration and functional recovery after nervous system trauma. Over the past few decades, various ...

医学

In vivo Assessment of Microtubule Dynamics and Orientation in Caenorhabditis elegans Neurons

In neurons, microtubule orientation has been a key assessor to identify axons that have plus-end out microtubules and dendrites that generally have mixed orientation. Here we describe methods to label, image, and analyze the microtubule dynamics and growth during the development and regeneration of touch neurons in C. elegans. Using genetically encoded fluorescent reporters of microtubule tips, we imaged the axonal microtubules. The local changes in microtubule behavior that initiates axon regeneration following axotomy can be quantified using this protocol. This assay is adaptable to other neurons and genetic backgrounds to investigate the regulation of microtubule dynamics in various cellular processes.

In vivo Assessment of Microtubule Dynamics and Orientation in Caenorhabditis elegans Neurons

A protocol for imaging the dynamic microtubules in vivo using fluorescently labeled End binding protein has been presented. We described the methods to label, image, and analyze the dynamic microtubules in the Posterior lateral microtubule (PLM) neuron of C. elegans.

インビボカエノハブディティス・エレガンスニューロンにおける微小管動態と向きの評価

In neurons, microtubule orientation has been a key assessor to identify axons that have plus-end out microtubules and dendrites that generally have mixed ...

Expanding the Toolkit for In Vivo Imaging of Axonal Transport

Axonal transport maintains neuronal homeostasis by enabling the bidirectional trafficking of diverse organelles and cargoes. Disruptions in axonal transport have devastating consequences for individual neurons and their networks, and contribute to a plethora of neurological disorders. As many of these conditions involve both cell autonomous and non-autonomous mechanisms, and often display a spectrum of pathology across neuronal subtypes, methods to accurately identify and analyze neuronal subsets are imperative.
This paper details protocols to assess in vivo axonal transport of signaling endosomes and mitochondria in sciatic nerves of anesthetized mice. Stepwise instructions are provided to 1) distinguish motor from sensory neurons in vivo, in situ, and ex vivo by using mice that selectively express fluorescent proteins within cholinergic motor neurons; and 2) separately or concurrently assess in vivo axonal transport of signaling endosomes and mitochondria. These complementary intravital approaches facilitate the simultaneous imaging of different cargoes in distinct peripheral nerve axons to quantitatively monitor axonal transport in health and disease.

Expanding the Toolkit for In Vivo Imaging of Axonal Transport

Using transgenic fluorescent mice, detailed protocols are described to assess in vivo axonal transport of signaling endosomes and mitochondria within motor and sensory axons of the intact sciatic nerve in live animals.

軸索輸送の In Vivo イメージングのためのツールキットの拡張

Axonal transport maintains neuronal homeostasis by enabling the bidirectional trafficking of diverse organelles and cargoes. Disruptions in axonal ...

Inducing Axonal Varicosities with a Micromechanical Stimulus on Neurons

Source: Servello, D., et al. <a href="https://appjove.unicartagenaproxy.elogim.com/v/57202">A Microbiomechanical System for Studying Varicosity Formation and Recovery in Central Neuron Axons.</a> J. Vis. Exp. (2018).
This video demonstrates the induction of axonal varicosities by applying micromechanical stimulus on neurons. The system comprises a micropipette attached to a syringe containing buffer via tubing. Using a micromanipulator, the micropipette is positioned above the neurons. Fluid pressure is then applied to induce varicosities in axons.

静脈瘤形成と中枢神経の軸索の回復を研究するための Microbiomechanical システム

要約

さらに動画を探す

この動画の章

軸索の開発を制御する神経細胞の機械的な操作

小脳軸索のレーザーNanosurgery

アン

マウス背側列のクラッシュ損傷におけるミクログリアおよびマクロファージと軸索の相互作用の生体内イメージング

ニューロン回路の再学習：速い神経突起伸長と機能的ニューロン結合の新しい方法

研究のための単純な神経細胞学的損傷法

再生に関する末梢および中枢神経系を研究するため生体内でショウジョウバエ損傷モデル

インビボカエノハブディティス・エレガンスニューロンにおける微小管動態と向きの評価

軸索輸送の In Vivo イメージングのためのツールキットの拡張

ニューロンに対する微小機械的刺激による軸索静脈瘤の誘導