この作品は、生命保険会社&quot;AG2Rラ-モンディアル&quot;、エコールデ神経科学パリ（ENP）、&quot;ERA - NET NEURONのフレームでアジャンス国立デラルシェルシュ&quot;ANR - 09 - neuro -の異形004&quot;によってサポートされていました&quot;欧州委員会、およびパスツール財団によるFP7のプログラムの。セバスチャンワグナーはLetten財団によってサポートされていました。

1。光学的キャリブレーション：測定LEDパワー<ol><li>積極的にファンや接辞によってコリメートレンズにこのLED /ヒートシンクのaparatusを冷却するヒートシンクにLEDアレイを取り付けます。 </li><li> LED /ヒートシンク/ファン/レンズ装置で明視野照明で使用されているランプを交換してください。この装置は慎重にコリメートLEDビームが集光レンズに向かってまっすぐな光路に沿って移動するように配置する必要があります。ヒートシンク/ファンが適切にシステムの共通のグランドに接地されていることを確認します。 </li><li>現在の高速かつ矩形パルスを与えることができる電源とLEDアレイを駆動する。この電源は、パルス発生器から発信された5VのTTLパルスによって制御されることがあります。 </li><li>中心視野絞りとコンデンサーレンズの間に定義された光路に沿って平行ビーム。理想的には、LEDの光がわずかに完全に開かれた視野絞りを入れすぎないでしょう。一般的に、より緊密にコリメートLEDビームが少ないこの口径を記入し、MORが生成されます均一性を犠牲にして、電子パワー。我々のセットアップでは、consenserのダイヤフラムで、その共役面にLEDアレイの若干拡大画像を投影コリメートレンズを選択することで、光の均一性を増加した。 </li><li>視野絞り（光源に最も近い絞り）の画像をスライスチャンバー（ 図1）に焦点を当てているようにコンデンサーを集中しケーラー照明を実現。レンズの紙の薄い組織は、他の深さで視野絞りの焦点像を可視化するために、投影するスクリーンとして機能することができます。 </li><li>不透明な材料で知られている直径のピンホールの一連のドリル。光パワーメータのセンサー上でこれらの小さなピンホールは1を置きます。それが最大の読みを与えるまで、単純にパワーメータを移動することにより、視野絞りの焦点画像の上に試料ステージと中央電力計の電力計を置きます。この位置に貼ってパワーメータ。 </li><li>完全にすべての開口部（アパーチャ絞りを開いて、視野絞り）。体系的に光学的光パスに接続されたスライスチャンバー/パワーメータの相対的に移動し、照射領域内の光パワーの均一性を計算する。お使いのシステムのための均一性のプロットを構築する。顕微鏡を正しく客観的の焦点を中心とするケーラー照明と設定されている場合、最大電力は、直接目的の下でなければ、そしてこの焦点の外側の領域は、現在、均一性のプロットに基づいて電力の既知量を受信する必要があります。 </li><li>ピンホールの各サイズについては、光パワー対ピンホールの表面積の標準曲線を構築する。 LEDアレイへの入力電流を調整することによって、複数のパワーレベルでこの曲線を生成し、それぞれの曲線からmm2当たりの電力を計算する。 LEDアレイは、パッチの光学系に使用する場合、パッチを適用する照明の下で送信されるどのくらいの光を知るためにパッチを適用するために必要な光学素子を（コンデンサ、ピンホールおよびフィルタ）を導入することを確認してください。 </li><li>パワーメータを反転水銀ランプがオンになっているときに客観的に直面し、470nmでの照度を計算する。 </li><li>チャンバーにライブスライスを追加し、散乱の脳組織を透過した光パワーを決定するための標準曲線を再構築する。 </li></ol> 2。スライシング手続きと電気生理学パート：スライス標本<ol><li>麻酔（60 mg / kgのケタミンとキシラジン2mg/kg）とマウスを刎ねる。の混合物でバブリング時〜310mOsm、pH7.4の、124のNaCl、3のKCl、1.3 MgSO 4を用い 、26のNaHCO 3、1.25 NaHPO 4、20グルコース、2のCaCl 2：MMの人工脳脊髄液（ACSF、に脳を解剖する嗅球を損傷しないように注意しながら95％O2、5％CO 2 5,1）、。一方のエッジ（水平方向のセクションの）でさえ腹側表面に寒天上の2つの半球と場所を区切ります。 </li><li>接着剤vibrに寒天と各半球皮質の背側表面atomeチャック、そしてゆっくりと氷冷ACSFでお風呂を埋める。 300μm以下のセクションでは腹側表面からスライス、彼らが30〜45分で回復できるように、温めておいた（34-36 ° C）と酸素ACSFに各セクションを転送する。 </li></ol>パートB：スパイクのしきい値のルースパッチの測定<ol start="3"><li> 30分間室温にスライスをもたらすの後、静かに酸素ACSFの一定灌流下で顕微鏡のチャンバーの記録室内のスライスを配置します。 過度にChR2感染した神経細胞を刺激するの危険にさらされ、EYFP - ChR2の存在は、落射蛍光（図2A）で確認することができます</li><li>ピペットプラー（サッターP - 97）上にガラス電極を引き抜きます。 ACSFでこの電極を埋める。 ACSF槽内に配置するときにチップ抵抗は7-10 Mohmを間でなければなりません。 </li><li>蛍光灯照明下では、スライスで成熟した形態を持つ健康なChR2 - EYFPニューロンを探します。また、パッチの光学系では、このニューロンの細胞体を探します。 </li><li>電極の先端を通過した光の正圧と、特定された蛍​​光ニューロンに向かってパッチ電極を下げる。膜の接触が行われると、すぐに正圧を解放し、チップを通して吸引の小さいと簡単に金額を適用します。ギガオームシールは、原形質膜とパッチ電極の壁の間になされるべきである。 </li><li>場合であっても電極が活動をスパイク蛍光ニューロンに十分に近い場合ギガシールは、測定可能な局所電場電位を生成するか、形成されていません。光の異なる投与量を点滅させることで、このニューロンのChR2をアクティブにします。光用量は、電源LEDと持続時間の両方の関数であるため、多くの光が複数の力と持続時間（図2B）で活動電位を喚起する必要があるか計算する。スパイクは、水銀灯の照明下で発生したどの程度も観察。 </li></ol> 3。代表的な結果： 私たちの顕微鏡（オリンパスBX51WI）で、私たちのLEDは私です2開口と集光レンズとn個のライン、このように工場出荷時にインストールアークランプのオリジナルの光パスを維持する。視野絞りとアパーチャ横隔膜の両方を閉じることで、我々は、パッチクランプ記録（ 図1B）のための十分な明コントラストを実現することができます。すべてのダイヤフラムで完全に我々はchannelrhodopsin活性化（ 図1A）の最大光パワーにスライスを公開開きます。私たちの顕微鏡では、このパッチの設定は（4.1μW/ mm 2の対6.88 MW / mm 2）の最大のフルフィールドの密度より大きさの約3桁小さい光密度を生成します。 独身の成人生まれChR2 - EYFPは顆粒細胞を表現することを示して私たちは、吻側渡り鳥ストリーム（ 図2A）から疎パッチ録音で神経芽細胞の移行のレンチウイルス感染後の成人生まれの嗅球の顆粒と糸球体ニューロンの数週間の堅牢な標識を参照してください。格言で5ミリ秒の刺激UM電力（6.88 mWの/ MM 2）スパイク（ 図2B）を呼び起こすのに十分です。発現レベルが細胞の間で変化するので、スパイクにしきい値を通過する光の量は変わるし、関心の各セルのタイプのために統計的に記述する必要があります。 <img src="/files/ftp_upload/3379/3379fig1.jpg" alt="図1" /> フルフィールド光刺激とパッチクランプ法スライスの電気生理学1。LEDアレイのセットアップ図 。 channelrhodopsinを有効にするには（ChR2）我々は、オープンバックの開口部とコンデンサー光学系（）を介して平行ビームを投影する。この設定は、完全に視野絞りと視野絞りの変調幅（b）を閉じることにより、高コントラストのパッチの光学系に変更することができます。略語：A.ファン、B.ヒートシンク、C. LEDの配列、D.コリメータレンズ、E.ミラー、F.の視野絞り、G.開口絞り、H.コンデンサーレンズ、I. SAmpleステージ、J.目標。 <img src="/files/ftp_upload/3379/3379fig2.jpg" alt="図2" /> 図2パッチクランプと全体のフィールド光刺激のための嗅球の300μmの水平スライス（）のイメージ。 ChR2 - EYFPの発現Lentivirally感染した成人生まれの顆粒細胞は、嗅球の中心から放射状に見ることができます。スパイクを呼び起こすために必要な光用量は、LEDフラッシュ（B）の持続時間を増加させることによって見つけることができます。この顆粒細胞のしきい値は、完全なLEDの輝度（2.43mW/mm 2）で5msのだ。 （B）= 50msので=500μm、スケール（）でスケール。

<ol>
	<li>Nissant, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult+neurogenesis+promotes+synaptic+plasticity+in+the+olfactory+bulb.">Adult neurogenesis promotes synaptic plasticity in the olfactory bulb.</a> Nature Neuroscience. 12, 728-730 (2009).</li><li>Apicella, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pyramidal+Cells+in+Piriform+Cortex+Receive+Convergent+Input+from+Distinct+Olfactory+Bulb+Glomeruli.">Pyramidal Cells in Piriform Cortex Receive Convergent Input from Distinct Olfactory Bulb Glomeruli.</a> Journal of Neuroscience. 30, 14255-14260 (2010).</li><li>Boyden, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=genetically+targeted+optical+control+of+neural+activity.">genetically targeted optical control of neural activity.</a> Nature. 8, 1263-1263 (2005).</li><li>Bardy, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=where+new+inhibitory+neurons+release+neurotransmitters+in+the+adult+olfactory+bulb.">where new inhibitory neurons release neurotransmitters in the adult olfactory bulb.</a> The Journal of Neuroscience. 30, 17023-17034 (2010).</li><li>Grubb, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+maturation+of+the+first+synapse+in+olfaction:+development+and+adult+neurogenesis.">Functional maturation of the first synapse in olfaction: development and adult neurogenesis.</a> The Journal of neuroscience. 28, 2919-2932 (2008).</li><li>Zhang, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circuit-breakers:+optical+technologies+for+probing+neural+signals+and+systems.">Circuit-breakers: optical technologies for probing neural signals and systems.</a> Nature reviews. Neuroscience. 8, 577-581 (2007).</li><li>Grossman, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-site+optical+excitation+using+ChR2+and+micro-LED+array.">Multi-site optical excitation using ChR2 and micro-LED array.</a> Journal of neural engineering. 7, 16004-16004 (2010).</li><li>Dhawale, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-redundant+odor+coding+by+sister+mitral+cells+revealed+by+light+addressable+glomeruli+in+the+mouse.">Non-redundant odor coding by sister mitral cells revealed by light addressable glomeruli in the mouse.</a> Nature neuroscience. 13, 1404-1412 (2010).</li><li>Weick, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+control+of+transplantable+human+ESC-derived+neurons+via+optogenetic+targeting.">Functional control of transplantable human ESC-derived neurons via optogenetic targeting.</a> Stem cells. 28, 2008-2016 (2010).</li><li>Toni, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurons+born+in+the+adult+dentate+gyrus+form+functional+synapses+with+target+cells.">Neurons born in the adult dentate gyrus form functional synapses with target cells.</a> Nature Neuroscience. 11, 901-907 (2008).</li><li>Grubb, M. S., Burrone, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Channelrhodopsin-2+Localised+to+the+Axon+Initial+Segment.">Channelrhodopsin-2 Localised to the Axon Initial Segment.</a> PLoS ONE. 5, e13761-e13761 .</li><li>Tye, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amygdala+circuitry+mediating+reversible+and+bidirectional+control+of+anxiety.">Amygdala circuitry mediating reversible and bidirectional control of anxiety.</a> Nature. 471, 358-362 (2011).</li></ol>

利害の衝突は宣言されません。

近年は神経科学研究6 optogeneticツールの人気が爆発的に見てきました。その結果、これらの新しいツールを使用し始めることを希望するラボのエントリの障壁を低くすることがますます重要です。ここではそれがchannelrhodopsin発現ニューロンのフルフィールド光刺激を行うことができるように、従来のパッチクランプリグのシンプルで低コストの改修とキャリブレーションを実施する方...

<table border="1">
	<tbody>
		<tr>
			<td>Material</td>
			<td>Type</td>
			<td>Company</td>
			<td>Catalogue No.</td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>100 mg/ml</td>
			<td>Imalg&egrave;ne 1000</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>2%</td>
			<td>Rompun</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>&nbps;</td>
			<td>Sigma </td>
			<td>S5886</td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>P5405</td>
		</tr>
		<tr>
			<td>MgSO4</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>M1880</td>
		</tr>
		<tr>
			<td>NaHCO3</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>S5761</td>
		</tr>
		<tr>
			<td>NaHPO4</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>S5011</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>G7021</td>
		</tr>
		<tr>
			<td>CaCl2</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>C7902</td>
		</tr>
		<tr>
			<td>Agarose</td>
			<td>&nbsp;</td>
			<td>Sigma </td>
			<td>A9539</td>
		</tr>
		<tr>
			<td>Pipette Puller</td>
			<td>P-97</td>
			<td>Sutter</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Glass Capillaries</td>
			<td>1.5 mm O.D./1.17 mm I.D.</td>
			<td>Harvard Apparatus</td>
			<td>GC150T-10</td>
		</tr>
		<tr>
			<td>LED array</td>
			<td>&nbsp;</td>
			<td>Bridgelux</td>
			<td>BXRA-C2000</td>
		</tr>
		<tr>
			<td>Collimating lens</td>
			<td>40 mm beam diameter</td>
			<td>Thor Labs</td>
			<td>LEDC1</td>
		</tr>
		<tr>
			<td>Power supply</td>
			<td>2.8 amp</td>
			<td>A1W Electronik</td>
			<td>HKO2800</td>
		</tr>
		<tr>
			<td>Optical power meter</td>
			<td>&nbsp;</td>
			<td>Thor Labs</td>
			<td>PM 100</td>
		</tr>
		<tr>
			<td>Heatsink </td>
			<td>Silent Boost K8</td>
			<td>Thermaltake</td>
			<td>A1838</td>
		</tr>
		<tr>
			<td>Fan</td>
			<td>Silent Boost K8</td>
			<td>Thermaltake</td>
			<td>A1838</td>
		</tr>
		<tr>
			<td>Vibratome</td>
			<td>&nbsp;</td>
			<td>Leica</td>
			<td>VT1200S</td>
		</tr>
	</tbody>
</table>

using affordable led arrays for photo-stimulation of neurons

標準スライスの電気生理学は、研究者は電気的または薬理学的操作の1,2に対応して単一細胞の電気的応答を記録することによって、神経回路の個々のコンポーネントをプローブすることができました。光学的に遺伝的に標的ニ​​ューロンを（optogenetics）を制御する方法の発明で、研究者は今、標準のスライス標本におけるニューロンの特定のグループを制御するための前例のないレベルを持っている。特に、感光channelrhodopsin - 2（ChR2）研究者が光3,4でニューロンを活性化することができます。標準スライスの電気生理学とChR2のLEDベースの光刺激を慎重にキャリブレーションを組み合わせることで、我々はより詳細で嗅球、嗅覚系の最初の中心的なリレーの成人生まれの介在の役割を調べることができます。成人生まれのニューロンで特異的にChR2 - YFPのウイルスの式を使用して、我々は選択的に古いの環境では若い成人生まれのニューロンを制御することができますD成熟ニューロン。私たちの光制御が簡単で安価なLEDシステムを使用して、そして我々は、このシステムは、光が単一のニューロンのスパイク活動を喚起するために必要とされるどの程度理解するためにキャリブレーションする方法を示しています。したがって、青色光の短い点滅は、リモートChR2形質導入新生児の細胞の発火パターンを制御することができます。

Watch this Scientific Journal Video about Using Affordable LED Arrays for Photo-Stimulation of Neurons at JoVE.com

Using Affordable LED Arrays for Photo-Stimulation of Neurons

ChR2を表現成人生まれのニューロンは嗅覚神経回路の機能に向けての貢献を検討するために、スライスの電気生理学的な準備に操作することができます。

ニューロンの光刺激のために手ごろな価格のLEDアレイを使用する

Standard slice electrophysiology has allowed researchers to probe individual components of neural circuitry by recording electrical responses of single ...

using-affordable-led-arrays-for-photo-stimulation-of-neurons

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

18.5K ビュー.  Institut Pasteur and Centre National de la Recherche Scientifique (CNRS). ChR2を表現成人生まれのニューロンは嗅覚神経回路の機能に向けての貢献を検討するために、スライスの電気生理学的な準備に操作することができます。

ビデオ: Using Affordable LED Arrays for Photo-Stimulation of Neurons

Scalable Fluidic Injector Arrays for Viral Targeting of Intact 3-D Brain Circuits

Our understanding of neural circuits--how they mediate the computations that subserve sensation, thought, emotion, and action, and how they are corrupted in neurological and psychiatric disorders--would be greatly facilitated by a technology for rapidly targeting genes to complex 3-dimensional neural circuits, enabling fast creation of "circuit-level transgenics." We have recently developed methods in which viruses encoding for light-sensitive proteins can sensitize specific cell types to millisecond-timescale activation and silencing in the intact brain. We here present the design and implementation of an injector array capable of delivering viruses (or other fluids) to dozens of defined points within the 3-dimensional structure of the brain (Figure. 1A, 1B). The injector array comprises one or more displacement pumps that each drive a set of syringes, each of which feeds into a polyimide/fused-silica capillary via a high-pressure-tolerant connector. The capillaries are sized, and then inserted into, desired locations specified by custom-milling a stereotactic positioning board, thus allowing viruses or other reagents to be delivered to the desired set of brain regions. To use the device, the surgeon first fills the fluidic subsystem entirely with oil, backfills the capillaries with the virus, inserts the device into the brain, and infuses reagents slowly (&lt;0.1 microliters/min). The parallel nature of the injector array facilitates rapid, accurate, and robust labeling of entire neural circuits with viral payloads such as optical sensitizers to enable light-activation and silencing of defined brain circuits. Along with other technologies, such as optical fiber arrays for light delivery to desired sets of brain regions, we hope to create a toolbox that enables the systematic probing of causal neural functions in the intact brain. This technology may not only open up such systematic approaches to circuit-focused neuroscience in mammals, and facilitate labeling of brain regions in large animals such as non-human primates, but may also open up a clinical translational path for cell-specific optical control prosthetics, whose precision may enable improved treatment of intractable brain disorders. Finally, such devices as described here may facilitate precisely-timed fluidic delivery of other payloads, such as stem cells and pharmacological agents, to 3-dimensional structures, in an easily user-customizable fashion.

Controlling and analyzing neural circuits in vivo would be facilitated by a technology for delivery of viruses and other reagents to desired 3-dimensional sets of brain regions. We demonstrate customized fluidic injector array fabrication, and delivery of virally-encoded optical sensitizers, enabling optical manipulation of complex brain circuits.

無傷の3 - D脳の回路のウイルス標的のためのスケーラブルな流体インジェクタの配列

Our understanding of neural circuits--how they mediate the computations that subserve sensation, thought, emotion, and action, and how they are corrupted ...

神経科学

Quantitative Analysis of Synaptic Vesicle Pool Replenishment in Cultured Cerebellar Granule Neurons using FM Dyes

After neurotransmitter release in central nerve terminals, SVs are rapidly retrieved by endocytosis. Retrieved SVs are then refilled with neurotransmitter and rejoin the recycling pool, defined as SVs that are available for exocytosis1,2. The recycling pool can generally be subdivided into two distinct pools - the readily releasable pool (RRP) and the reserve pool (RP). As their names imply, the RRP consists of SVs that are immediately available for fusion while RP SVs are released only during intense stimulation1,2. It is important to have a reliable assay that reports the differential replenishment of these SV pools in order to understand 1) how SVs traffic after different modes of endocytosis (such as clathrin-dependent endocytosis and activity-dependent bulk endocytosis) and 2) the mechanisms controlling the mobilisation of both the RRP and RP in response to different stimuli.
FM dyes are routinely employed to quantitatively report SV turnover in central nerve terminals3-8. They have a hydrophobic hydrocarbon tail that allows reversible partitioning in the lipid bilayer, and a hydrophilic head group that blocks passage across membranes. The dyes have little fluorescence in aqueous solution, but their quantum yield increases dramatically when partitioned in membrane9. Thus FM dyes are ideal fluorescent probes for tracking actively recycling SVs. The standard protocol for use of FM dye is as follows. First they are applied to neurons and are taken up during endocytosis (Figure 1). After non-internalised dye is washed away from the plasma membrane, recycled SVs redistribute within the recycling pool. These SVs are then depleted using unloading stimuli (Figure 1). Since FM dye labelling of SVs is quantal10, the resulting fluorescence drop is proportional to the amount of vesicles released. Thus, the recycling and fusion of SVs generated from the previous round of endocytosis can be reliably quantified.
Here, we present a protocol that has been modified to obtain two additional elements of information. Firstly, sequential unloading stimuli are used to differentially unload the RRP and the RP, to allow quantification of the replenishment of specific SV pools. Secondly, each nerve terminal undergoes the protocol twice. Thus, the response of the same nerve terminal at S1 can be compared against the presence of a test substance at phase S2 (Figure 2), providing an internal control. This is important, since the extent of SV recycling across different nerve terminals is highly variable11.
Any adherent primary neuronal cultures may be used for this protocol, however the plating density, solutions and stimulation conditions are optimised for cerebellar granule neurons (CGNs)12,13.

A live fluorescence imaging technique to quantify the replenishment and mobilisation of specific synaptic vesicle (SV) pools in central nerve terminals is described. Two rounds of SV recycling are monitored in the same nerve terminals providing an internal control.

FM染料を用いて培養小脳顆粒神経細胞のシナプス小胞プールの補充の定量分析

After neurotransmitter release in central nerve terminals, SVs are rapidly retrieved by endocytosis.  Retrieved SVs are then refilled with ...

Optogenetic Activation of Zebrafish Somatosensory Neurons using ChEF-tdTomato

Larval zebrafish are emerging as a model for describing the development and function of simple neural circuits. Due to their external fertilization, rapid development, and translucency, zebrafish are particularly well suited for optogenetic approaches to investigate neural circuit function. In this approach, light-sensitive ion channels are expressed in specific neurons, enabling the experimenter to activate or inhibit them at will and thus assess their contribution to specific behaviors. Applying these methods in larval zebrafish is conceptually simple but requires the optimization of technical details. Here we demonstrate a procedure for expressing a channelrhodopsin variant in larval zebrafish somatosensory neurons, photo-activating single cells, and recording the resulting behaviors. By introducing a few modifications to previously established methods, this approach could be used to elicit behavioral responses from single neurons activated up to at least 4 days post-fertilization (dpf). Specifically, we created a transgene using a somatosensory neuron enhancer, CREST3, to drive the expression of the tagged channelrhodopsin variant, ChEF-tdTomato. Injecting this transgene into 1-cell stage embryos results in mosaic expression in somatosensory neurons, which can be imaged with confocal microscopy. Illuminating identified cells in these animals with light from a 473 nm DPSS laser, guided through a fiber optic cable, elicits behaviors that can be recorded with a high-speed video camera and analyzed quantitatively. This technique could be adapted to study behaviors elicited by activating any zebrafish neuron. Combining this approach with genetic or pharmacological perturbations will be a powerful way to investigate circuit formation and function.

Optogenetic techniques have made it possible to study the contribution of specific neurons to behavior. We describe a method in larval zebrafish for activating single somatosensory neurons expressing a channelrhodopsin variant (ChEF) with a diode-pumped solid state (DPSS) laser and recording the elicited behaviors with a high-speed video camera.

CHEF-tdTomatoを使用してゼブラフィッシュ体性感覚ニューロンのOptogeneticアクティベーション

Larval  zebrafish are emerging as a model for describing the development and function  of simple neural circuits. Due to their  external fertilization, ...

A Procedure for Implanting Organized Arrays of Microwires for Single-unit Recordings in Awake, Behaving Animals

In vivo electrophysiological recordings in the awake, behaving animal provide a powerful method for understanding neural signaling at the single-cell level. The technique allows experimenters to examine temporally and regionally specific firing patterns in order to correlate recorded action potentials with ongoing behavior. Moreover, single-unit recordings can be combined with a plethora of other techniques in order to produce comprehensive explanations of neural function. In this article, we describe the anesthesia and preparation for microwire implantation. Subsequently, we enumerate the necessary equipment and surgical steps to accurately insert a microwire array into a target structure. Lastly, we briefly describe the equipment used to record from each individual electrode in the array. The fixed microwire arrays described are well-suited for chronic implantation and allow for longitudinal recordings of neural data in almost any behavioral preparation. We discuss tracing electrode tracks to triangulate microwire positions as well as ways to combine microwire implantation with immunohistochemical techniques in order to increase the anatomical specificity of recorded results.

Implanting organized arrays of microwires for use in single-unit electrophysiological recordings presents a number of technical challenges.&#160;Methods for performing this technique and the equipment necessary are described.&#160;Also, the beneficial use of organized microwire arrays to record from distinct neural subregions with high spatial selectivity is discussed.

動物を振る舞う、覚醒中のシングルユニット記録のためにマイクロワイヤの組織化された配列を移植するための手順

In vivo electrophysiological recordings in the awake, behaving animal provide a powerful method for understanding neural signaling at the single-cell ...

Imaging Dendritic Spines of Rat Primary Hippocampal Neurons using Structured Illumination Microscopy

Dendritic spines are protrusions emerging from the dendrite of a neuron and represent the primary postsynaptic targets of excitatory inputs in the brain. Technological advances have identified these structures as key elements in neuron connectivity and synaptic plasticity. The quantitative analysis of spine morphology using light microscopy remains an essential problem due to technical limitations associated with light's intrinsic refraction limit. Dendritic spines can be readily identified by confocal laser-scanning fluorescence microscopy. However, measuring subtle changes in the shape and size of spines is difficult because spine dimensions other than length are usually smaller than conventional optical resolution fixed by light microscopy's theoretical resolution limit of 200 nm.
Several recently developed super resolution techniques have been used to image cellular structures smaller than the 200 nm, including dendritic spines. These techniques are based on classical far-field operations and therefore allow the use of existing sample preparation methods and to image beyond the surface of a specimen. Described here is a working protocol to apply super resolution structured illumination microscopy (SIM) to the imaging of dendritic spines in primary hippocampal neuron cultures. Possible applications of SIM overlap with those of confocal microscopy. However, the two techniques present different applicability. SIM offers higher effective lateral resolution, while confocal microscopy, due to the usage of a physical pinhole, achieves resolution improvement at the expense of removal of out of focus light. In this protocol, primary neurons are cultured on glass coverslips using a standard protocol, transfected with DNA plasmids encoding fluorescent proteins and imaged using SIM. The whole protocol described herein takes approximately 2 weeks, because dendritic spines are imaged after 16-17 days in vitro, when dendritic development is optimal. After completion of the protocol, dendritic spines can be reconstructed in 3D from series of SIM image stacks using specialized software.

This article describes a working protocol to image dendritic spines from hippocampal neurons in vitro using Structured Illumination Microscopy (SIM). Super-resolution microscopy using SIM provides image resolution significantly beyond the light diffraction limit in all three spatial dimensions, allowing the imaging of individual dendritic spines with improved detail.

構造化照明顕微鏡を用いてラット初代海馬ニューロンの樹状突起棘を画像化

Dendritic spines are protrusions emerging from the dendrite of a neuron and represent the primary postsynaptic targets of excitatory inputs in the brain. ...

Production and Isolation of Axons from Sensory Neurons for Biochemical Analysis Using Porous Filters

Neuronal axons use specific mechanisms to mediate extension, maintain integrity, and induce degeneration. An appropriate balance of these events is required to shape functional neuronal circuits. The protocol described here explains how to use cell culture inserts bearing a porous membrane (filter) to obtain large amounts of pure axonal preparations suitable for examination by conventional biochemical or immunocytochemical techniques. The functionality of these filter inserts will be demonstrated with models of developmental pruning and Wallerian degeneration, using explants of embryonic dorsal root ganglion. Axonal integrity and function is compromised in a wide variety of neurodegenerative pathologies. Indeed, it is now clear that axonal dysfunction appears much earlier in the course of the disease than neuronal soma loss in several neurodegenerative diseases, indicating that axonal-specific processes are primarily targeted in these disorders. By obtaining pure axonal samples for analysis by molecular and biochemical techniques, this technique has the potential to shed new light into mechanisms regulating the physiology and pathophysiology of axons. This in turn will have an impact in our understanding of the processes that drive degenerative diseases of the nervous system.

This article describes a neuronal culture system that can be used to obtain large quantities of pure axonal samples for biochemical and immunocytochemical analyses. This technique will allow an improved understanding of normal axonal physiology and signaling pathways leading to neurodegeneration.

多孔質フィルタを使用した生化学分析のための感覚ニューロンからの軸索の産生および単離

Neuronal axons use specific mechanisms to mediate extension, maintain integrity, and induce degeneration. An appropriate balance of these events is ...

Optical Control of a Neuronal Protein Using a Genetically Encoded Unnatural Amino Acid in Neurons

Photostimulation is a noninvasive way to control biological events with excellent spatial and temporal resolution. New methods are desired to photo-regulate endogenous proteins expressed in their native environment. Here, we present an approach to optically control the function of a neuronal protein directly in neurons using a genetically encoded unnatural amino acid (Uaa). By using an orthogonal tRNA/aminoacyl-tRNA synthetase pair to suppress the amber codon, a photo-reactive Uaa 4,5-dimethoxy-2-nitrobenzyl-cysteine (Cmn) is site-specifically incorporated in the pore of a neuronal protein Kir2.1, an inwardly rectifying potassium channel. The bulky Cmn physically blocks the channel pore, rendering Kir2.1 non-conducting. Light illumination instantaneously converts Cmn into a smaller natural amino acid Cys, activating Kir2.1 channel function. We express these photo-inducible inwardly rectifying potassium (PIRK) channels in rat hippocampal primary neurons, and demonstrate that light-activation of PIRK ceases the neuronal firing due to the outflux of K+ current through the activated Kir2.1 channels. Using in utero electroporation, we also express PIRK in the embryonic mouse neocortex in vivo, showing the light-activation of PIRK in neocortical neurons. Genetically encoding Uaa imposes no restrictions on target protein type or cellular location, and a family of photoreactive Uaas is available for modulating different natural amino acid residues. This technique thus has the potential to be generally applied to many neuronal proteins to achieve optical regulation of different processes in brains. The current protocol presents an accessible procedure for intricate Uaa incorporation in neurons in vitro and in vivo to achieve photo control of neuronal protein activity on the molecular level.

Here, a procedure to selectively activate a neuronal protein with a short pulse of light by genetically encoding a photo-reactive unnatural amino acid into a target neuronal protein expressed in neurons in culture or in vivo is presented.

ニューロンに遺伝的にコードされた非天然アミノ酸を用いた神経タンパク質の光制御

Photostimulation is a noninvasive way to control biological events with excellent spatial and temporal resolution. New methods are desired to ...

Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy

Type 2 diabetes mellitus (T2DM) is a global health crisis which is characterized by insulin signaling impairment and chronic inflammation in peripheral tissues. The hypothalamus in the central nervous system (CNS) is the control center for energy and insulin signal response regulation. Chronic inflammation in peripheral tissues and imbalances of certain chemokines (such as CCL5, TNF&#945;, and IL-6) contribute to diabetes and obesity. However, the functional mechanism(s) connecting chemokines and hypothalamic insulin signal regulation still remain unclear.
In vitro primary neuron culture models are convenient and simple models which can be used to investigate insulin signal regulation in hypothalamic neurons. In this study, we introduced exogeneous GLUT4 protein conjugated with GFP (GFP-GLUT4) into primary hypothalamic neurons to track GLUT4 membrane translocation upon insulin stimulation. Time-lapse images of GFP-GLUT4 protein trafficking were recorded by deconvolution microscopy, which allowed users to generate high-speed, high-resolution images without damaging the neurons significantly while conducting the experiment. The contribution of CCR5 in insulin regulated GLUT4 translocation was observed in CCR5 deficient hypothalamic neurons, which were isolated and cultured from CCR5 knockout mice. Our results demonstrated that the GLUT4 membrane translocation efficiency was reduced in CCR5 deficient hypothalamic neurons after insulin stimulation.

This protocol describes a technique for observation of real-time Green Fluorescence Protein (GFP) tagged Glucose Transporter 4 (GLUT4) protein trafficking upon insulin stimulation and characterization of the biological role of CCR5 in the insulin&#8211;GLUT4 signaling pathway with Deconvolution Microscopy.

GLUT4 タンパク質デコンボリューション顕微鏡を用いたマウス一次視床下部ニューロンにおける人身売買のライブ映像

Type 2 diabetes mellitus (T2DM) is a global health crisis which is characterized by insulin signaling impairment and chronic inflammation in peripheral ...

An In Vitro Model for Studying Tau Aggregation Using Lentiviral-mediated Transduction of Human Neurons

Aberrant aggregation of the protein tau is pathogenically involved in a number of neurodegenerative diseases, including Alzheimer&#8217;s disease (AD). Although mouse models of tauopathy have provided a valuable resource for investigating the neurotoxic mechanisms of aggregated tau, it is becoming increasingly apparent that, due to interspecies differences in neurophysiology, the mouse brain is unsuitable for modeling the human condition. Advances in cell culture methods have made human neuronal cultures accessible for experimental use in vitro and have aided in the development of neurotherapeutics. However, despite the adaptation of human neuronal cell cultures, in vitro models of human tauopathy are not yet widely available. This protocol describes a cellular model of tau aggregation in which human neurons are transduced with lentiviral-derived vectors that code for pathogenically mutated tau fused to a yellow fluorescent protein (YFP) reporter. Transduced cultures produce tau aggregates that stain positively for thioflavin and display markers of neurotoxicity, such as decreased axonal length and increased lysosomal volume. This procedure may be a useful and cost-effective model for studying human tauopathies.

This protocol details a procedure in which human neuronal cultures are transduced with lentiviral constructs coding for mutant human tau. Transduced cultures display tau aggregates and associated pathologies.

ヒトニューロンのレンチウイルス媒介性形質導入を用いたタウ凝集を研究するための in Vitro モデル

Aberrant aggregation of the protein tau is pathogenically involved in a number of neurodegenerative diseases, including Alzheimer&#8217;s disease (AD). ...

Chronic Implantation of Multiple Flexible Polymer Electrode Arrays

Simultaneous recordings from large populations of individual neurons across distributed brain regions over months to years will enable new avenues of scientific and clinical development. The use of flexible polymer electrode arrays can support long-lasting recording, but the same mechanical properties that allow for longevity of recording make multiple insertions and integration into a chronic implant a challenge. Here is a methodology by which multiple polymer electrode arrays can be targeted to a relatively spatially unconstrained set of brain areas.
The method utilizes thin-film polymer devices, selected for their biocompatibility and capability to achieve long-term and stable&#160;electrophysiologic recording interfaces. The resultant implant allows accurate and flexible targeting of anatomically distant regions, physical stability for months, and robustness to electrical noise. The methodology supports up to sixteen serially inserted devices across eight different anatomic targets. As previously demonstrated, the methodology is capable of recording from 1024 channels. Of these, the 512 channels in this demonstration used for single neuron recording yielded 375 single units distributed across six recording sites. Importantly, this method also can record single units for at least 160 days.
This implantation strategy, including temporarily bracing each device with a retractable silicon insertion shuttle, involves tethering of devices at their target depths to a skull-adhered plastic base piece that is custom-designed for each set of recording targets, and stabilization/protection of the devices within a silicone-filled, custom-designed plastic case. Also covered is the preparation of devices for implantation, and design principles that should guide adaptation to different combinations of brain areas or array designs.

Described below is a method for implantation of multiple polymer electrode arrays across anatomically distant brain regions for chronic electrophysiological recording in freely moving rats. Preparation and surgical implantation are described in detail, with emphasis on design principles to guide adaptation of these methods for use in other species.

複数のフレキシブルポリマー電極アレイの慢性移植

Simultaneous recordings from large populations of individual neurons across distributed brain regions over months to years will enable new avenues of ...