Diese Arbeit wurde vom kanadischen Institutes of Health Research (CIHR) Grant zu Wayne S. Sossin unterstützt. Carole A. Farah ist der Empfänger ein Postdoc-Stipendium aus dem Fonds de la Recherche en Santé du Québec (FRSQ) und Conrad Harrington Gemeinschaft. Die Autoren bedanken sich bei Joanna Bougie, Margaret Hastings und Margaret Labban für die Hilfe bei der Video-Dreh und Madeline Richmond Pool für die Hilfe bei der grafischen Übersicht danken.

1. Erstellung und Pflege von Sf9-Monolayer Kulturen <ol><li> Sf9-Zellkultur und Wartung in einer Gewebekultur Abzug durchgeführt. </li><li> Sf9-Zellen werden aus Spodoptera frugiperda Eierstock-Zellen (Sf21 Zellen) abgeleitet und kann als eingefrorene Zellen in Grace Medien von Invitrogen erworben werden. </li><li> Platz 8 ml Insektenmedium Grace, ergänzt (1X), zu dem 30% fötales Rinderserum (FBS) hat in einer 75 cm 2 Zellkulturflasche mit einer verkantet Hals aufgenommen worden. </li><li> Auftauen gefrorenen Rohr Sf9 Zellen schnell im 37 ° C Wasserbad, indem Sie den Schlauch hin und her (ca. 1-2 Minuten). </li><li> Transfer Sf9-Zellen, die 75 cm 2 Zellkulturflasche und Rock Platte vorsichtig von Hand, um die Zellen gleichmäßig zu verteilen. </li><li> Inkubieren 1-2 Stunden bei 27 ° C, bis die Zellen angeschlossen sind. </li><li> Entfernen Sie altes Medium und ersetzen mit 10 ml Insektenmedium freshGrace ist mit 30% FBS. </li><li> Inkubation bei 27 ° C, bis die Zellen konfluent sind. </li><li> Zur Aufrechterhaltung Monolayerkulturen, entfernen Sie alte Medium aus dem konfluenten Flasche Sf9-Zellen und 5 ml Medium Insekten Grace mit 10% FBS. </li><li> Leicht auf der Seite der Flasche Leitungswasser mehrmals Sf9-Zellen zu lösen. </li><li> Mit einem 10 mL Pipette und eine Pipette, die Medien Pipette nach oben und unten einmal sanft, Spritzen Kolbenwand beim Pipettieren unten. Übertragen Sie die Zellen in ein steriles 15 mL Polysterene Röhre. </li><li> Geben Sie 2 ml Sf9 Zellsuspension bis 8 ml Insektenmedium Grace mit 10% FBS (1:5 Verdünnung auf log-Phase Wachstum aufrecht zu erhalten) in neue 75 cm 2 Zellkulturflasche und Rock Platte vorsichtig mit der Hand. </li><li> Inkubation bei 27 ° C, bis die Zellen konfluent sind. </li></ol> 2. Expression von fluoreszenzmarkierten PKCs in Sf9 Zellen <ol><li> Für Live-Imaging-Experiment, Kultur Sf9-Zellen auf 35 mm MatTek Glasboden Kultur disheswith eine Glasfläche von 14 mm und einem Deckglas Dicke von 0,16 bis 0,19 mm. </li><li> PKCs mit fluoreszierenden Proteinen markiert sind in Sf9-Zellen mit Cellfectin II Transfektionsreagenz folgende Empfehlung des Herstellers mit den Änderungen detaillierte unten angegeben. </li><li> Tag 1: Vor dem Ausplattieren der Zellen, behandeln jeden MatTek Gericht mit Insekten Medium Grace mit 10% FBS für mindestens 30 Minuten. </li><li> Graf Sf9-Zellen aus Schritt 11 (oben) unter Verwendung eines Hämozytometers. </li><li> Platte 0,05 x 10 6 Zellen pro MatTek Deckglas in einem Gesamtvolumen von 150 ul. Lassen Sie die Zellen für 30 Minuten bei Raumtemperatur befestigen. </li><li> Geben Sie 2 ml Grace mit 10% FBS zu jedem Gericht 1 mL der zu einer Zeit, langsam zu vermeiden Ablösen der Zellen ergänzt. </li><li> Inkubation bei 27 ° C über Nacht. </li><li> Von diesem Punkt an, verwenden Sie der Empfehlung des Herstellers für die Transfektion von Sf9-Zellen mit Plasmid-DNA. </li><li> Tag 2: Transfektion von Sf9-Zellen mit fluoreszenzmarkierten PKCs mit Cellfectin II Transfektionsreagenz. Wir haben oft in diesem System PKCs mit verbesserter Green Fluorescent Protein (eGFP) und monomeren Red Fluorescent Protein (mRFP) (Details für Plasmid-Konstruktion wurden bisher 2,5) beschrieben getaggt co-exprimiert. Expression eines fluoreszierenden Proteins in einem Zeit-Ausbeuten zwischen 70-80% exprimierende Zellen 72 Stunden nach der Transfektion. Co-Expression von zwei fluoreszierenden Proteinen verringert Transfektionseffizienz zu etwa 30% co-exprimierenden Zellen. Als Co-exprimierenden eGFP-markierten PKC und mRFP-markierten PKC, verwenden Sie 2x mehr Plasmid-DNA für die mRFP-markierte Protein für eine optimale Protein-Expression. </li><li> Führen Sie Live-imaging 48-72 Stunden nach der Transfektion (für eine optimale Protein-Expression, warten Sie 72 Stunden). </li></ol> 3. Expression von fluoreszenzmarkierten PKCs in Aplysia sensorischen Neuronen <ol><li> Vorbereitung der Aplysia neuronalen Zellkulturen hat in einer Video-Artikel wurde von Zhao und seine Kollegen 4 beschrieben. </li><li> PKCs mit fluoreszierenden Proteinen markiert sind in Aplysia sensorischen Neuronen mit Mikroinjektion Verfahren detaillierte unten angegeben. </li><li> Bereiten Sie eine Stammlösung von 1% Fast Green (FCF) in destilliertem Wasser, Filter mit einer Spritze und einer 28 mm Spritzenfilter (0,20 um). Aliquotieren und bei -20 ° C. </li><li> Mikroinjektion der sensorischen Neuronen können am Tag 1 oder Tag 2 nach der Isolierung der Nervenzellen durchgeführt werden, aber wir finden, die darauf warten 2 Tage ermöglicht eine bessere Zelle Einhaltung der Deckglas. </li><li> Am Tag 2 nach der Isolierung der sensorischen Neuronen, Tauwetter ein Aliquot Fast Green und Filter wieder mit einer Spritze und einer 28 mm Spritzenfilter (0,20 um). </li><li> Bereiten Sie eine Lösung von Plasmid-DNA in destilliertem Wasser mit 0,5% Fast Green. Die Konzentrationen von Plasmid-DNA so hoch wie 0,4 ug / ul kann verwendet werden, aber es wird nicht empfohlen, über diesen Werten gehen. </li><li> Filtern Sie die Plasmid-DNA / Fast Green-Lösung mit einer 1 ml Spritze und einem 4-mm-Spritzenvorsatzfilter (0,20 um). </li><li> Centrifuge die Plasmid-DNA / Fast Green Lösung bei 16110 xg für 15 Minuten mit einem Mikrofonrocentrifuge. </li><li> Bereiten scharfen Elektroden für die Mikroinjektion von Neuronen mit einer Mikroelektrode Puller (Sutter Flaming / Brown Micropipette Puller, Modell P-97). Verwenden einer Box Faden ziehen Glasmikroelektroden mit 1 mm Außendurchmesser, 0,75 mm Innendurchmesser und 100 mm Länge mit dünnwandigen Glaskapillaren mit einem Faden im Inneren (World Precision Instruments TW100F-4). Für weitere Informationen über Ziehen Mikroinjektion Elektroden entnehmen Sie bitte Sutter Elektrode Kochbuch. </li><li> Füllen Sie jede Elektrode mit 2 ul von Plasmid-DNA / Fast Green-Lösung mit Microloader Pipettenspitze (Eppendorf CA32950-050). </li><li> Übertragen Sie die MatTek Glasboden Kulturschale mit Aplysia neuronalen Kulturen, die Mikroinjektion Station. </li><li> Die Mikroinjektion Station besteht aus folgenden Komponenten: eine hausgemachte großen Glas Bühne, um die Kulturschalen auf einer Schwingungsisolierung Tabelle (Kinetic Systems Schwingungsisolierung Workstation), ein Stereo-scope mit externen Halogen-Beleuchtung, einem Mikromanipulator (Sutter Huxley Wandtyp Micromanipulator halten welches sowohl Grob-und ultra-feine Positionierung in den drei-Achse), einer Mikroelektrode Halter verbunden, um eine pneumatische Pumpe (World Precision Instruments PV820 Pneumatische Pico-Pump). Der Druck Eingang der pneumatischen Pumpe ist eine komprimierte Stickstoff Tank verbunden. </li><li> Legen Sie eine Mikroelektrode in die Mikroelektroden-Halter. </li><li> Profil unter einem Stereomikroskop, legen Sie die Spitze der Mikropipette in den Zellkern. </li><li> Deliver kurze Druckimpulse von Stickstoff (10 bis 100 ms Dauer, 20 lb / in 2), bis der Kern wird gleichmäßig durchdringt und grün. </li><li> Inkubieren Sie die Zellen für 4 Stunden bei Raumtemperatur und halten bei 4 ° C bis zur Verwendung. Für eine optimale PKC-Translokation, live-imaging Experiment 20 bis 24 Stunden nach der Injektion. </li></ol> 4. Visualisierung von PKC-Translokation in Living Cells Sf9 und in Aplysia sensorischen Neuronen <ol><li> Für die Bildgebung, verwenden wir ein Zeiss LSM510 invertierten konfokalen Mikroskop mit einem Axiovert 200. </li><li> Imaging-Protokoll ist das gleiche für Sf9-Zellen und für die Aplysia sensorischen Neuronen mit Ausnahme der folgenden: Sf9 Zellen werden mit einem x63 Ölimmersionsobjektiv abgebildet, während Aplysia sensorischen Neuronen mit einem x40 Ölimmersionsobjektiv abgebildet werden. Sf9-Zellen werden in einem temperierten Raum bei 26-27 o C gehalten abgebildet, während Aplysia sensorischen Neuronen bei Raumtemperatur etwa 18-20 o C gehalten werden abgebildet </li><li> Wir verwenden einen 30 mW Argon-Laser (Anregung bei 488 nm) mit 50% Laserleistung zum Bild PKC mit eGFP-Protein und ein HeNe-Laser (Anregung bei 543nm), um Bild PKC mit mRFP Protein markiert markiert. Die Argon-und HeNe-Laser-Linien abgeschwächt bis 4% und 50% Sendeleistung bzw. vor der Aufnahme und der Lochkamera ist eine angepasst. </li><li> Es ist wichtig, die Kulturschale auf dem Imaging-Bühne stabilisiert zu haben und Bewegung oder Vibration zu vermeiden. </li><li> Nehmen Sie 1 ml Kulturmedium aus der Schale vorsichtig mit einer 10 ml Pipette Verlassen 1 mL Gesamtvolumen in die Schüssel. </li><li> Nehmen Sie Bilder im mittleren Bereich der Zellen, wo der Kern zu sehen sind. </li><li> Richten Sie eine Zeitreihe von 10-20 konfokalen Bildern der Aufnahme eines Bildes alle 30 Sekunden. </li><li> Starten Sie den Zeitreihen. </li><li> Nach 2 Bilder aufgenommen werden (nach Ablauf der 30 Sekunden Zeit, Punkt), 1 mL des Medikaments (2X-Konzentration) sanft Drop-by-drop auf den Zellen mit einer Pipette P1000. Das Medikament wird kontinuierlich für etwa 30 Sekunden aufgenommen. </li><li> Einige Medikamente verursachen eine schnelle Translokation, die sichtbar sein können unmittelbar nach medikamentöse Behandlung (bei 60 Sekunden Zeitpunkt), während andere induzieren eine langsame Translokation, die nur optimal 5-10 Minuten nach der Behandlung (Movie 1 und Movie 2) ist. </li><li> Wenn das Medikament muss abgewaschen werden, verwenden Sie 2 x 10 ml Pipetten, um die Wäsche zu tun, Pipettieren Waschpuffer vorsichtig nach unten, mit einer Pipette auf der einen Seite des Tellers und Pipettieren bis die Medien auf der anderen Seite. </li><li> Wenn die Wäsche wirksam war und ob die Wirkung des Medikaments reversibel ist, kehrt PKC zurück zum Cytosol innerhalb von 30-60 Sekunden. </li><li> Speichern Sie den Film als LSM-Datei. </li><li> Verwenden NIH Image J Software, um die LSM-Dateien zu öffnen und zu quantifizieren, die Bilder vor und nach medikamentöser Behandlung. Die Quantifizierung wurde an anderer Stelle 1 beschrieben. </li></ol>

<ol>
	<li>Farah, C. A., Nagakura, I., Weatherill, D., Fan, X. &. a. m. p. ;. a. m. p., Sossin, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+role+for+phosphatidic+acid+in+the+translocation+of+the+novel+protein+kinase+C+Apl+II+in+Aplysia+neurons.">Physiological role for phosphatidic acid in the translocation of the novel protein kinase C Apl II in Aplysia neurons.</a> Mol Cell Biol. 28, 4719-4733 (2008).</li><li>Zhao, Y., Leal, K., Abi-Farah, C., Martin, K. C., Sossin, W. S. &. a. m. p. ;. a. m. p., Klein, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=M.Isoform+specificity+of+PKC+translocation+in+living+Aplysia+sensory+neurons+and+a+role+for+Ca2+-dependent+PKC+APL+I+in+the+induction+of+intermediate-term+facilitation.">M.Isoform specificity of PKC translocation in living Aplysia sensory neurons and a role for Ca2+-dependent PKC APL I in the induction of intermediate-term facilitation.</a> J Neurosci. 26, 8847-8856 (2006).</li><li>Farah, C. A., Weatherill, D., Dunn, T. W. &. a. m. p. ;. a. m. p., Sossin, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PKC+differentially+translocates+during+spaced+and+massed+training+in+Aplysia.">PKC differentially translocates during spaced and massed training in Aplysia.</a> J Neurosci. 29, 10281-10286 (2009).</li><li>Zhao, Y., Wang, D. O., Martin, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Aplysia+sensory-motor+neuronal+cell+cultures.">Preparation of Aplysia sensory-motor neuronal cell cultures.</a> J Vis Exp. , (2009).</li><li>Manseau, F., Fan, X., Hueftlein, T., Sossin, W. S., Castellucci, V. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca2+-independent+PKC+Apl+II+mediates+the+serotonin+induced+facilitation+at+depressed+synapses+in+Aplysia.">Ca2+-independent PKC Apl II mediates the serotonin induced facilitation at depressed synapses in Aplysia.</a> J. Neuroscience. 21, 1247-1256 (2001).</li></ol>

Wir haben eine Technik zur Bild Translokation von fluoreszenzmarkierten PKCs beschrieben in Echtzeit in Sf9-Zellen und in Aplysia sensorischen Neuronen. Sf9-Zellen bieten ein einfaches System, um Bild PKC-Translokation seit Kultivierung und Transfektion von ihnen ist ziemlich geradlinig. Im Gegensatz dazu nimmt die Mikroinjektion von Aplysia sensorischen Neuronen einiger Zeit zu meistern, bis zu einigen Monaten. Schwierigkeiten im Zusammenhang mit dieser Technik gehören Elektrode verstopfen. Filterung...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Sf9 frozen cells</td>
<td>Spodoptera frugiperda ovarian cells</td>
<td>Invitrogen</td>
<td>B825-01</td>
<td>&nbsp;</td>
<tr>
<td>Grace&#x2019;s Insect Medium, Supplemented (1X), liquid</td>
<td>Reagent</td>
<td>Gibco</td>
<td>11605-094</td>
<td>Use to culture Sf9 cells</td>
</tr>
<tr>
<td>Corning 75cm2 canted neck cell culture flask</td>
<td>Tool</td>
<td>Corning</td>
<td>430720</td>
<td>Use to culture Sf9 cells</td>
</tr>
<tr>
<td>Fetal Bovine Serum</td>
<td>Reagent</td>
<td>CanSera</td>
<td>CS-C08-500</td>
<td>Supplement Grace's media with FBS prior to use</td>
</tr>
<tr>
<td>Syringe</td>
<td>Tool</td>
<td>Becton Dickinson</td>
<td>309604</td>
<td>Use to filter Fast Green solution</td>
</tr>
<tr>
<td>Syringe</td>
<td>Tool</td>
<td>Becton Dickinson</td>
<td>309602</td>
<td>Use to filter plasmid DNA / Fast Green solution</td>
</tr>
<tr>
<td>Filter</td>
<td>Tool</td>
<td>Corning</td>
<td>431229</td>
<td>Use to filter Fast Green solution</td>
</tr>
<tr>
<td>Filter</td>
<td>Tool</td>
<td>Corning</td>
<td>431212</td>
<td>Use to filter plasmid DNA / Fast Green solution</td>
</tr>
<tr>
<td>Glass Bottom Dish</td>
<td>Tool</td>
<td>Mattek</td>
<td>P35G-1.5-14-C</td>
<td>Use to culture Sf9 cells prior to transfection and imaging</td>
</tr>
<tr>
<td>Cellfectin II Reagent</td>
<td>Reagent</td>
<td>Invitrogen</td>
<td>10362-100</td>
<td>Used to express fluorescently tagged PKCs in Sf9 cells</td>
</tr>
<tr>
<td>Fast Green FCF</td>
<td>Reagent</td>
<td>Sigma-Aldrich</td>
<td>F-7252</td>
<td>Use to visualize microinjection of plasmid DNA solution into Aplysia sensory neurons</td>
</tr>
<tr>
<td>Thin wall glass capillaries</td>
<td>Tool</td>
<td>World Precision Instruments</td>
<td>TW100F-4</td>
<td>Use to make microelectrodes for microinjection</td>
</tr>
<tr>
<td>Microloader pipette tip</td>
<td>Tool</td>
<td>Eppendorf</td>
<td>CA32950-050</td>
<td>Autoclave before using to fill up the microelectrodes for microinjection</td>
</tr>
<tr>
<td>PV820 Pneumatic PicoPump </td>
<td>Tool</td>
<td>World Precision Instruments</td>
<td>SYS-PV820</td>
<td>Part of microinjection station</td>
</tr>
<tr>
<td>Microelectrode holder</td>
<td>Tool</td>
<td>World Precision Instruments</td>
<td>MPH6S</td>
<td>Use to hold microelectrode </td>
</tr>
<tr>
<td>Micromanipulator</td>
<td>Tool</td>
<td>Sutter</td>
<td>MP-85</td>
<td>Use to position microelectrode in the three-axis</td>
</tr>		</tbody>
		</table>
		</div>

live-imaging of pkc translocation in sf9 cells and in aplysia sensory neurons

Protein-Kinase-Cs (PKCS) sind Serin-Threonin-Kinasen, die eine zentrale Rolle spielen bei der Regulation einer Vielzahl von zellulären Prozessen wie Zellwachstum und Lernen und Gedächtnis. Es gibt vier bekannte Familien von PKC-Isoformen bei Wirbeltieren: klassische PKCs (α, ßi, βII und γ), Roman Typ I PKCs (ε und η), neuartige II PKCs (δ und θ) und atypische PKC (ζ und ι ). Die klassische PKCs werden durch Ca 2 + aktiviert und diacylclycerol (DAG), während der Roman PKCs durch DAG aktiviert werden, sondern sind Ca 2 +-unabhängig. Die atypische PKC sind weder durch Ca 2 + noch DAG aktiviert. In Aplysia californica, unser Modellsystem zur Gedächtnisbildung Studie, gibt es drei Nervensystem spezifischen PKC-Isoformen einer aus jeder großen Klasse, nämlich der konventionellen PKC Apl I, die neue Typ-I-PKC Apl II und der atypischen PKC Apl III. PKCS Lipid-Kinasen aktiviert und damit die Aktivierung der klassischen und neuen PKC als Reaktion auf extrazelluläre Signale wurde häufig mit PKC-Translokation aus dem Zytoplasma an die Plasmamembran korreliert. Daher hat die Visualisierung PKC-Translokation in Echtzeit in lebenden Zellen werden ein unschätzbares Werkzeug für die Aufklärung der Signalwege, die PKC-Aktivierung führen. Zum Beispiel hat diese Technik für uns erlaubt festzustellen, dass verschiedene Isoformen der PKC unter verschiedenen Bedingungen translozieren, um verschiedene Arten von synaptischer Plastizität vermitteln und dass Serotonin (5HT) Aktivierung von PKC Apl II erfordert die Herstellung der beiden DAG und Phosphatidsäure (PA) für Translokation 1-2. Wichtig ist, dass die Fähigkeit, die gleichen Neuron visualisieren wiederholt hat uns erlaubt, zum Beispiel zu einer Desensibilisierung der PKC Reaktion in exquisite detail 3 zu messen. In diesem Video haben wir jeden Schritt der Herstellung Sf9-Zellkulturen zu demonstrieren, haben Kulturen der Aplysia sensorischen Neuronen in einem anderen Video Artikel 4 beschrieben worden sind, zum Ausdruck fluoreszenzmarkierten PKCs in Sf9-Zellen und in Aplysia sensorischen Neuronen und Live-Darstellung von PKC-Translokation in Reaktion auf verschiedene Aktivatoren mittels Laser-Scanning-Mikroskopie.

Watch this Scientific Journal Video about Live-imaging of PKC Translocation in Sf9 Cells and in Aplysia Sensory Neurons at JoVE.com

Live-imaging of PKC Translocation in Sf9 Cells and in Aplysia Sensory Neurons

In diesem Video zeigen wir, Visualisierung von PKC-Translokation in lebenden Zellen mit fluoreszenzmarkierten PKCs.

Live-Darstellung von PKC-Translokation in Sf9-Zellen und in Aplysia sensorischen Neuronen

Protein kinase Cs (PKCs) are serine threonine kinases that play a central role in regulating a wide variety of cellular processes such as cell growth and ...

live-imaging-pkc-translocation-sf9-cells-aplysia-sensory

Research

JoVE Journal

Neuroscience

11.9K Aufrufe.  McGill University. In diesem Video zeigen wir, Visualisierung von PKC-Translokation in lebenden Zellen mit fluoreszenzmarkierten PKCs.

Serie: Live-imaging of PKC Translocation in Sf9 Cells and in Aplysia Sensory Neurons

Dissection and Culture of Commissural Neurons from Embryonic Spinal Cord

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies of these neurons are located in the dorsal spinal cord and their axons follow stereotyped trajectories during embryonic development. Commissural axons initially project ventrally towards the floorplate. After crossing the midline, these axons turn anteriorly and project towards the brain. Each of these steps is regulated by the action of several guidance cues. Cultures highly enriched in commissural neurons are ideally suited for many experiments addressing the mechanisms of axon pathfinding, including turning assays, immunochemistry and biochemistry. Here, we describe a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. First, the spinal cord is isolated and dorsal strips are dissected out. The dorsal tissue is then dissociated into a cell suspension by trypsinization and mechanical disruption. Neurons are plated onto poly-L-lysine-coated glass coverslips or tissue-culture dishes. After 30 hours in vitro, most neurons have extended an axon. The purity of the culture (Yam et al. 2009), typically over 90%, can be assessed by immunolabeling with the commissural neuron markers DCC, LH2 and TAG1 (Helms and Johnson, 1998). This neuronal preparation is a useful tool for in vitro studies of the cellular and molecular mechanisms of commissural axon growth and guidance during spinal cord development.

This video demonstrates a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. Dissociated commissural neurons are useful to study the cellular and molecular mechanisms of axon growth and guidance.

Dissection und Kultur kommissuralen Nervenzellen aus embryonalen Rückenmark

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies ...

Forschung

Neurowissenschaften

Time-lapse Live Imaging of Clonally Related Neural Progenitor Cells in the Developing Zebrafish Forebrain

Precise patterns of division, migration and differentiation of neural progenitor cells are crucial for proper brain development and function1,2. To understand the behavior of neural progenitor cells in the complex in vivo environment, time-lapse live imaging of neural progenitor cells in an intact brain is critically required. In this video, we exploit the unique features of zebrafish embryos to visualize the development of forebrain neural progenitor cells in vivo. We use electroporation to genetically and sparsely label individual neural progenitor cells. Briefly, DNA constructs coding for fluorescent markers were injected into the forebrain ventricle of 22 hours post fertilization (hpf) zebrafish embryos and electric pulses were delivered immediately. Six hours later, the electroporated zebrafish embryos were mounted with low melting point agarose in glass bottom culture dishes. Fluorescently labeled neural progenitor cells were then imaged for 36hours with fixed intervals under a confocal microscope using water dipping objective lens. The present method provides a way to gain insights into the in vivo development of forebrain neural progenitor cells and can be applied to other parts of the central nervous system of the zebrafish embryo.

The present video demonstrates a method which takes advantage of the combination of electroporation and confocal microscopy to perform live imaging on individual neural progenitor cells in the developing zebrafish forebrain. In vivo analysis of the development of forebrain neural progenitor cells at a clonal level can be achieved in this way.

Zeitraffer-Live-Imaging von klonal verbundenen neuronalen Vorläuferzellen in der Entwicklung von Zebrafisch Vorderhirnneuronen

Precise patterns of division, migration and differentiation of neural progenitor cells are crucial for proper brain development and function1,2. To ...

Neuromodulation and Mitochondrial Transport: Live Imaging in Hippocampal Neurons over Long Durations

To understand the relationship between mitochondrial transport and neuronal function, it is critical to observe mitochondrial behavior in live cultured neurons for extended durations1-3. This is now possible through the use of vital dyes and fluorescent proteins with which cytoskeletal components, organelles, and other structures in living cells can be labeled and then visualized via dynamic fluorescence microscopy. For example, in embryonic chicken sympathetic neurons, mitochondrial movement was characterized using the vital dye rhodamine 1234. In another study, mitochondria were visualized in rat forebrain neurons by transfection of mitochondrially targeted eYFP5. However, imaging of primary neurons over minutes, hours, or even days presents a number of issues. Foremost among these are: 1) maintenance of culture conditions such as temperature, humidity, and pH during long imaging sessions; 2) a strong, stable fluorescent signal to assure both the quality of acquired images and accurate measurement of signal intensity during image analysis; and 3) limiting exposure times during image acquisition to minimize photobleaching and avoid phototoxicity.
Here, we describe a protocol that permits the observation, visualization, and analysis of mitochondrial movement in cultured hippocampal neurons with high temporal resolution and under optimal life support conditions. We have constructed an affordable stage-top incubator that provides good temperature regulation and atmospheric gas flow, and also limits the degree of media evaporation, assuring stable pH and osmolarity. This incubator is connected, via inlet and outlet hoses, to a standard tissue culture incubator, which provides constant humidity levels and an atmosphere of 5-10% CO2/air. This design offers a cost-effective alternative to significantly more expensive microscope incubators that don't necessarily assure the viability of cells over many hours or even days. To visualize mitochondria, we infect cells with a lentivirus encoding a red fluorescent protein that is targeted to the mitochondrion. This assures a strong and persistent signal, which, in conjunction with the use of a stable xenon light source, allows us to limit exposure times during image acquisition and all but precludes photobleaching and phototoxicity. Two injection ports on the top of the stage-top incubator allow the acute administration of neurotransmitters and other reagents intended to modulate mitochondrial movement. In sum, lentivirus-mediated expression of an organelle-targeted red fluorescent protein and the combination of our stage-top incubator, a conventional inverted fluorescence microscope, CCD camera, and xenon light source allow us to acquire time-lapse images of mitochondrial transport in living neurons over longer durations than those possible in studies deploying conventional vital dyes and off-the-shelf life support systems.

We describe a protocol that allows imaging of mitochondria in living neurons via fluorescence microscopy over long durations. Imaging over extended periods is accomplished through lentivirus-mediated expression of a mitochondrially targeted fluorescent protein and use of an inexpensive stage-top incubator that was designed and built in our laboratory.

Neuromodulation und Mitochondriale Transport: Live Imaging in Hippocampus-Neuronen über lange Zeiträume

To understand the relationship between mitochondrial transport and neuronal function, it is critical to observe mitochondrial behavior in live cultured ...

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding fundamental biological mechanisms. Striking progress has been particularly evident in Drosophila, whose extensive toolkit of mutants and transgenic lines provides a convenient model to study evolutionarily-conserved developmental and cell biological mechanisms. We are interested in understanding the mechanisms that control cell fate specification in the adult peripheral nervous system (PNS) in Drosophila. Bristles that cover the head, thorax, abdomen, legs and wings of the adult fly are individual mechanosensory organs, and have been studied as a model system for understanding mechanisms of Notch-dependent cell fate decisions. Sensory organ precursor (SOP) cells of the microchaetes (or small bristles), are distributed throughout the epithelium of the pupal thorax, and are specified during the first 12 hours after the onset of pupariation. After specification, the SOP cells begin to divide, segregating the cell fate determinant Numb to one daughter cell during mitosis. Numb functions as a cell-autonomous inhibitor of the Notch signaling pathway.
Here, we show a method to follow protein dynamics in SOP cell and its progeny within the intact pupal thorax using a combination of tissue-specific Gal4 drivers and GFP-tagged fusion proteins 1,2.This technique has the advantage over fixed tissue or cultured explants because it allows us to follow the entire development of an organ from specification of the neural precursor to growth and terminal differentiation of the organ. We can therefore directly correlate changes in cell behavior to changes in terminal differentiation. Moreover, we can combine the live imaging technique with mosaic analysis with a repressible cell marker (MARCM) system to assess the dynamics of tagged proteins in mitotic SOPs under mutant or wildtype conditions. Using this technique, we and others have revealed novel insights into regulation of asymmetric cell division and the control of Notch signaling activation in SOP cells (examples include references 1-6,7 ,8).

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

In this video, we describe a method for live cell imaging of asymmetrically dividing sensory organ progenitor cells and epidermal cells in intact Drosophila pupae

Live-Cell-Imaging von Sinnesorgan Vorläuferzellen im Intact Drosophila Puppen

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding ...

Lentivirus-mediated Genetic Manipulation and Visualization of Olfactory Sensory Neurons in vivo

Development of a precise olfactory circuit relies on accurate projection of olfactory sensory neuron (OSN) axons to their synaptic 
targets in the olfactory bulb (OB). The molecular mechanisms of OSN axon growth and targeting are not well understood. Manipulating gene expression and subsequent 
visualizing of single OSN axons and their terminal arbor morphology have thus far been challenging. To study gene function at the single cell level within a specified 
time frame, we developed a lentiviral based technique to manipulate gene expression in OSNs in vivo. Lentiviral particles are delivered to OSNs by microinjection 
into the olfactory epithelium (OE). Expression cassettes are then permanently integrated into the genome of transduced OSNs. Green fluorescent protein expression 
identifies infected OSNs and outlines their entire morphology, including the axon terminal arbor. Due to the short turnaround time between microinjection and 
reporter detection, gene function studies can be focused within a very narrow period of development. With this method, we have detected GFP expression within as 
few as three days and as long as three months following injection. We have achieved both over-expression and shRNA mediated knock-down by lentiviral microinjection. 
This method provides detailed morphologies of OSN cell bodies and axons at the single cell level in vivo, and thus allows characterization of candidate gene function 
during olfactory development.

Lentivirus-mediated Genetic Manipulation and Visualization of Olfactory Sensory Neurons in vivo

We present a lentiviral technique for genetic manipulation and visualization of single olfactory sensory neuron axon and its terminal arborization in vivo.

Lentivirus-vermittelte Gen-Manipulation und Visualisierung von Riechzellen In vivo</em

Development of a precise olfactory circuit relies on accurate projection of olfactory sensory neuron (OSN) axons to their synaptic 
targets in the ...

Flash Photolysis of Caged Compounds in the Cilia of Olfactory Sensory  Neurons

Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds1. Caged compounds are molecules made physiologically inactive by a chemical cage that can be broken by a flash of ultraviolet light. Here, we show how to obtain patch-clamp recordings combined with photolysis of caged compounds for the study of olfactory transduction in dissociated mouse olfactory sensory neurons. The process of olfactory transduction (Figure 1) takes place in the cilia of olfactory sensory neurons, where odorant binding to receptors leads to the increase of cAMP that opens cyclic nucleotide-gated (CNG) channels2. Ca entry through CNG channels activates Ca-activated Cl channels. We show how to dissociate neurons from the mouse olfactory epithelium3 and how to activate CNG channels or Ca-activated Cl channels by photolysis of caged cAMP4 or caged Ca5. We use a flash lamp6,7 to apply ultraviolet flashes to the ciliary region to uncage cAMP or Ca while patch-clamp recordings are taken to measure the current in the whole-cell voltage-clamp configuration8-11.

Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds. Here, we show how to obtain patch-clamp recordings combined with photolysis of caged cAMP or caged Ca for the study of olfactory transduction in dissociated mouse olfactory sensory neurons.

Flash-Photolyse von Caged Compounds in den Zilien der Riechzellen

Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds1. ...

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.
This extracellular technique has advantages. First, extracellular electrodes can stimulate and record neurons through the sheath5, so it does not need to be removed. Thus, neurons will be healthier in extracellular experiments than in intracellular ones. Second, if ganglia are rotated by appropriate pinning of the sheath, extracellular electrodes can access neurons on both sides of the ganglion, which makes it easier and more efficient to identify multiple neurons in the same preparation. Third, extracellular electrodes do not need to penetrate cells, and thus can be easily moved back and forth among neurons, causing less damage to them. This is especially useful when one tries to record multiple neurons during repeating motor patterns that may only persist for minutes. Fourth, extracellular electrodes are more flexible than intracellular ones during muscle movements. Intracellular electrodes may pull out and damage neurons during muscle contractions. In contrast, since extracellular electrodes are gently pressed onto the sheath above neurons, they usually stay above the same neuron during muscle contractions, and thus can be used in more intact preparations.
To uniquely identify motor neurons for a motor pool (in particular, the I1/I3 muscle in Aplysia) using extracellular electrodes, one can use features that do not require intracellular measurements as criteria: soma size and location, axonal projection, and muscle innervation4,6,7. For the particular motor pool used to illustrate the technique, we recorded from buccal nerves 2 and 3 to measure axonal projections, and measured the contraction forces of the I1/I3 muscle to determine the pattern of muscle innervation for the individual motor neurons.
We demonstrate the complete process of first identifying motor neurons using muscle innervation, then characterizing their timing during motor patterns, creating a simplified diagnostic method for rapid identification. The simplified and more rapid diagnostic method is superior for more intact preparations, e.g. in the suspended buccal mass preparation8 or in vivo9. This process can also be applied in other motor pools10,11,12 in Aplysia or in other animal systems2,3,13,14.

Extracellularly Identifying Motor Neurons for a Muscle Motor Pool in Aplysia californica

In animals with large identified neurons (e.g. mollusks), analysis of motor pools is done using intracellular techniques1,2,3,4. Recently, we developed a technique to extracellularly stimulate and record individual neurons in Aplysia californica5. We now describe a protocol for using this technique to uniquely identify and characterize motor neurons within a motor pool.

Extrazellulär identifizieren Motor Neurons für einen Muscle Motor Pool in<em&gt; Aplysia californica</em

In animals with large  identified neurons (e.g. mollusks), analysis of motor pools is done using  intracellular techniques1,2,3,4. Recently,  we developed ...

Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

The marine gastropod mollusk Aplysia californica has a venerable history as a model of nervous system function, with particular significance in studies of learning and memory. The typical preparations for such studies are ones in which the sensory and motoneurons are left intact in a minimally dissected animal, or a technically elaborate neuronal co-culture of individual sensory and motoneurons. Less common is the isolated neuronal preparation in which small clusters of nominally homogeneous neurons are dissociated into single cells in short term culture. Such isolated cells are useful for the biophysical characterization of ion currents using patch clamp techniques, and targeted modulation of these conductances. A protocol for preparing such cultures is described. The protocol takes advantage of the easily identifiable glutamatergic sensory neurons of the pleural and buccal ganglia, and describes their dissociation and minimal maintenance in culture for several days without serum.

Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

We describe the dissection of the nervous system of the marine sea hare Aplysia after anesthesia, the isolation of neurons for short term-tissue culture, and recordings of single cell ion currents via the patch clamp technique.

Isolation von sensorischen Neuronen von<em&gt; Aplysia californica</em&gt; Für Patch-Clamp-Recordings von Glutamaterge Currents

The marine gastropod mollusk Aplysia californica has a venerable  history as a model of nervous system function, with particular significance in  studies ...

Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna

Odorant molecules bind to their target receptors in a precise and coordinated manner. Each receptor recognizes a specific signal and relays this information to the brain. As such, determining how olfactory information is transferred to the brain, modifying both perception and behavior, merits investigation. Interestingly, there is emerging evidence that cellular transduction and transcriptional factors are involved in the diversification of olfactory receptor neuron. Here we provide a robust whole mount immunological labeling method to assay in vivo olfactory receptor neuron organization. Using this method, we identified all olfactory receptor neurons with anti-ELAV antibody, a known pan-neural marker and Or49a-mCD8::GFP, an olfactory receptor neuron specifically expressed in Nba neuron using anti-GFP antibody.

Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna

Herein we describe the process of whole mount immunostaining of Drosophila antennae, which enables us to better understand the molecular mechanisms involved in the diversification of olfactory receptor neurons (ORN)s.

Ganze Berge Immunmarkierung der olfaktorischen Rezeptorneuronen in der<em&gt; Drosophila</em&gt; Antennen

Odorant molecules bind to their target receptors in a precise and coordinated manner. Each receptor recognizes a specific signal and relays this ...

A Method to Target and Isolate Airway-innervating Sensory Neurons in Mice

Somatosensory nerves transduce thermal, mechanical, chemical, and noxious stimuli caused by both endogenous and environmental agents. The cell bodies of these afferent neurons are located within the sensory ganglia. Sensory ganglia innervate a specific organ or portion of the body. For instance, the dorsal root ganglia (DRG) are located in the vertebral column and extend processes throughout the body and limbs. The trigeminal ganglia are located in the skull and innervate the face, and upper airways. Vagal afferents of the nodose ganglia extend throughout the gut, heart, and lungs. The nodose neurons control a diverse array of functions such as: respiratory rate, airway irritation, and cough reflexes. Thus, to understand and manipulate their function, it is critical to identify and isolate airway specific neuronal sub-populations. In the mouse, the airways are exposed to a fluorescent tracer dye, Fast Blue, for retrograde tracing of airway-specific nodose neurons. The nodose ganglia are dissociated and fluorescence activated cell (FAC) sorting is used to collect dye positive cells. Next, high quality ribonucleic acid (RNA) is extracted from dye positive cells for next generation sequencing. Using this method airway specific neuronal gene expression is determined.

Organ specific sensory neurons are difficult to identify. Fast Blue tracing is used to identify nodose neurons innervating the airways for cell sorting. Sorted nodose neurons are used to extract high quality ribonucleic acid (RNA) for sequencing. Using this protocol, gene expression of airway specific neurons is determined.

Eine Methode zum Ziel und Isolieren Airway-innervating sensorischen Neuronen bei Mäusen

Somatosensory nerves transduce thermal, mechanical, chemical, and noxious stimuli caused by both endogenous and environmental agents. The cell bodies of ...