Diese Arbeit wird durch das Office of Research and Development, Medical Research Service, Department of Veterans Affairs unterstützt. Diese Studie wurde von einer VA Merit Review Award (MCL) und der University of Tennessee Health Science Center Multiple Sclerosis Research Fund finanziert.

Ein. Antibody Labeling (Abbildung 1) <ol><li> Machen 0,1 M NaHCO 3-Puffer: <ul type="circle"><li> 8,4 g NaHCO 3 </li><li> 29,2 g NaCl </li><li> 1 Liter H 2 O </li></ul></li><li> Bringen der Puffer bis zu einem pH von 8,4 mit dieser Lösung (10,6 g Na 2 CO 3, 29,2 g NaCl, 1 Liter H 2 0). </li><li> Fügen Sie 35 ul Atto550 NHS bis 70 ul anti-hnRNPA1 und 500 ul NaHCO 3-Puffer und drehen für 1 Stunde bei Raumtemperatur. Nach dem einstündigen Rotation, spritzen die Mischung in einen Dialysator und dialysieren in 2 l PBS über Nacht. </li><li> Am nächsten Tag konzentrieren die dialysierte Atto550 NHS anti-hnRNPA1 unter Verwendung eines Spin-Säule (Amicon Ultra 0.5). </li><li> Nachdem die Atto550 NHS markierten Anti-Antikörper hnRNPA1 konzentriert worden ist, Nano-Drop Probe zur Bestimmung der Konzentration. </li></ol> 2. Antikörper Transfektion (Abbildung 2) <ol><li> Seed 10 5 Zellen / Well in 500 ul Dulbecco s Modified Eagle Medium (DMEM/F12 +10% FBS +1% Antibiotikum) in einem 8 sowie Schlitten 24 Stunden vor der Transfektion. Zellkonfluenz sollte mindestens 70% betragen. </li><li> Vierundzwanzig Stunden nach dem Aussäen, fügen 2 ul Ab-deliverin Reagenz in ein Eppendorf-Röhrchen. </li><li> Anschließend fügen 2 ug Atto550 NHS markierten Anti-Antikörper hnRNPA1 (0,5 ug / ul) an dieselbe Eppendorfröhrchen Inkubation und 10-15 min bei RT. </li><li> Während der Inkubation anzusaugen Medien und fügen 394 ml frisches DMEM-Medium zu den Zellen. </li></ol> Hinweis: In 500 ul DMEM zu einer Kammer der unberührten Zellen als Kontrolle dienen. <ol start="5"><li> Nach der Inkubation mit 100 ul DMEM an den Antikörper Mischung, mischen durch Pipettieren rauf und runter, und fügen Sie zu den Zellen in DMEM mit einem Gesamtvolumen von 500 ul. </li><li> Ändern Sie die Medien nach 48 h von Antikörper Lieferung. </li></ol> Hinweis: Das Protokoll wurde mit FITC als positive Kontrolle markierten Rigg wiederholt. 3. Live und Fixed Imaging Effizienz bestimmen <ol><li> Bildzellen bei 48 h unter Verwendung der Cy3-Filter auf einem Fluoreszenzmikroskop Die zur Bebilderung der transfizierten Atto550 NHS markierten Antikörpern. </li><li> Nach Live-Bildgebung abgeschlossen ist, saugen die Medien und fix Zellen. </li><li> Nach Absaugen Medien behandeln Zellen mit 0,4% Paraformaldehyd für 15 Min. bei Raumtemperatur. Waschen der Zellen 4 x 5 min mit jeweils PBS. Dann montieren Zellen mit Eindeckmedium enthält DAPI Reagenz und fix Deckglas. Messen Transfektionseffizienz der fixierten Zellen mit AxioVision Software. Wenn Axiovision Software ist nicht auf der Hand, zählen Sie einfach die Ereignisse aus dem Bild mit der Hand und stecken Ergebnisse in die Berechnung bei 3,7. Alternativ kann ImageJ Software für diese Berechnungen verwendet werden. </li><li> Erstens, die &quot;Events&quot;-Messung, um die Gesamtzahl der Zellen in Ihrem Bild der Wahl zählen 20-facher Vergrößerung. </li><li> Weiter, verwenden Sie die &quot;Events&quot;-Messung, um die Zellen, die nicht zählenerfolgreich mit Antikörpern in der gleichen 20-facher Vergrößerung Bild transfiziert. </li><li> Um die gemessenen &quot;Events&quot; in einer Excel-Stil-Format zuzugreifen, auf &quot;Eigenschaften&quot; klicken, klicken Sie auf die &quot;Measurement&quot;-Registerkarte, und klicken Sie auf, um anzuzeigen &quot;Wie die Tabelle.&quot; </li><li> Schließlich verwenden Sie die folgende Berechnung, um Ihre Transfektionseffizienz zu bestimmen, indem die beiden zuvor gemessenen Ereignisse: ((Summe Zellen - transfizierten Zellen) / Total Cells) x 100 = Transfektionseffizienz. </li></ol> 4. Repräsentative Ergebnisse Die Live-Bilder von untransfizierten (3A) auf transfizierten (3B) Neuronen im Vergleich zeigen, dass die Markierung der Antikörper (rot oder grün in jeder Figur) ist klar innerhalb der Zellen (3B, C, D) beobachtet. Nach Absaugen und Waschen mit Medien, um Antikörper zwischen oder Anhänger der Oberfläche von Zellen zu entfernen, sind noch vorhandenen markierten Antikörpern in Neuronen (3C, D).<html> Um die Transfektionseffizienz zu berechnen, verwenden Sie die Software AxioVision zur gesamten Zellen im Vergleich zu Zellen, die nicht erfolgreich transfiziert wurden zu berechnen. Diese Werte wurden in einen Transfektionseffizienz Formel, um die Transfektionseffizienz als Prozentsatz der gesamten Zellen (Abbildung 4) übernehmen wird. <img alt="Abbildung 1" src="/files/ftp_upload/4154/4154fig1.jpg" /> Abbildung 1. Ablaufschema der Verfahren zur Markierung von Antikörpern mit der Atto 550 NHS-Ester gefolgt von den Schritten erforderlich, um die markierten Antikörpern zu konzentrieren. <a href="http://www.jove.com/files/ftp_upload/4154/4154fig1large.jpg" target="_blank">Klicken Sie hier für eine größere Abbildung zu sehen</a> . <img alt="Abbildung 2" src="/files/ftp_upload/4154/4154fig2.jpg" /> Abbildung 2. Ablaufschema der Verfahren verwendet werden, um markierte Antikörper in lebende Zellen in Kultur zu transfizieren.arge.jpg &quot;target =&quot; _blank &quot;&gt; Klicken Sie hier für eine größere Abbildung zu sehen. <img alt="Abbildung 3" src="/files/ftp_upload/4154/4154fig3.jpg" /> Abbildung 3. Live-Bilder der transfizierten Neuronen 48 hr nach Transfektion. <img alt="Abbildung 4" src="/files/ftp_upload/4154/4154fig4.jpg" /> Abbildung 4. Behoben und Bilder gespült mit Ereignissen, um gezählt, um die Transfektionseffizienz zu bestimmen.

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Dis. 186, 1514-1517 (2002).</li><li>Lee, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+potential+link+between+autoimmunity+and+neurodegeneration+in+immune-mediated+neurological+disease.">A potential link between autoimmunity and neurodegeneration in immune-mediated neurological disease.</a> J. Neuroimmunol. 235, 56-69 (2011).</li><li>Smeenk, R. 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Neuroimmunol. 204, 140-148 (2008).</li><li>Reisinger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum-free+transfection+of+CHO+cells+with+chemically+defined+transfection+systems+and+investigation+of+their+potential+for+transient+and+stable+transfection.">Serum-free transfection of CHO cells with chemically defined transfection systems and investigation of their potential for transient and stable transfection.</a> Cytotechnology. 60, 115-123 (2009).</li><li>Weill, C. O., Biri, S., Erbacher, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cationic+lipid-mediated+intracellular+delivery+of+antibodies+into+live+cells.">Cationic lipid-mediated intracellular delivery of antibodies into live cells.</a> Biotechniques. 44, Pvii-Pxi (2008).</li><li>Radic, M. 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Keine Interessenskonflikte erklärt.

Um Hypothesen über spezifische Moleküle und deren Expression zu testen, werden Gene und andere Vektoren üblicherweise in Zellen transfiziert. Die Besonderheit dieses Verfahrens ist die Fähigkeit, leicht transfizieren Antikörper in Zielzellen. Wir führten diese Methode in fünf getrennten Experimenten jeweils in Duplikaten. Transfektionseffizienz Ergebnisse waren ähnlich bei allen Experimenten. Insbesondere erlaubt der Verfahrenseintrag von Antikörpern in die Zelle ohne Veränderung Antikörper Struktur oder Funk...

<table border="1"><tbody><tr><td> Name des Reagenz </td><td> Firma </td><td> Katalog-Nummer </td></tr><tr><td> Fluoreszenzmikroskop AxioObserver A1 </td><td> Zeiss </td><td></td></tr><tr><td> Axiovision Version 4.2 </td><td> Zeiss </td><td></td></tr><tr><td> Anti-rhnRNPA1 </td><td> Abcam </td><td> Ab4791 </td></tr><tr><td> FITC markierten Anti-Rigg </td><td> OZ Biosciences </td><td> AI20100 </td></tr><tr><td> Atto550 NHS-Ester </td><td> Sigma </td><td> 92835 </td></tr><tr><td> Ab-deliverin </td><td> OZ Biosciences </td><td> AI20100 </td></tr><tr><td> DMEM/F12 10% FBS 1% Antibiotika </td><td> Gibco </td><td> 11320-033 </td></tr><tr><td> Poly-D-Lysin-8-Well-Kultur Slides </td><td> BD </td><td> 354632 </td></tr><tr><td> Multi-Purpose Rotator </td><td> Scientific Industries Inc </td><td> Modell 151 </td></tr><tr><td> DAPI Mounting Medien </td><td> Millipore </td><td> S7113 </td></tr><tr><td> PBS </td><td> Ambion </td><td> 9626 </td></tr><tr><td> Dialysator </td><td> Thermo Fisher Scientific </td><td> 66380 </td></tr><tr><td> Amicon Ultra-0.5 </td><td> Millipore </td><td> UFC501096 </td></tr><tr><td> Paraformaldehyd (4% ige Lösung) </td><td> Electron Microscopy Sciences </td><td></td></tr><tr><td> Nano-Drop </td><td> Thermo Fisher Scientific </td><td></td></tr></tbody></table>

antibody transfection into neurons as a tool to study disease pathogenesis

Antikörper bieten die Möglichkeit, neue Einblicke in die verschiedenen Ereignisse in lebenden Systemen zu gewinnen. Die Fähigkeit, hochspezifische Antikörper zu produzieren Zielproteine ​​wurde für sehr präzise biologischer Fragestellungen gelassen adressiert werden. Wichtigerweise haben Antikörper in die Pathogenese einer Reihe von menschlichen Erkrankungen, einschließlich systemischem Lupus erythematodes (SLE), rheumatoider Arthritis (RA), paraneoplastischen Syndromen, Multiple Sklerose (MS) und menschlichen T-lymphotropen Virus Typ 1 (HTLV-1) in Verbindung gebracht assoziierte Myelopathie / tropische spastische Paraparese (HAM / TSP) 1-9. Wie Krankheiten verursachen Antikörper ist ein Bereich der laufenden Untersuchung und Daten nahe, dass Wechselwirkungen zwischen Antikörpern und verschiedene intrazelluläre Moleküle führt zu Entzündung, zellulärer verändert Messaging und Apoptose 10. Es hat sich gezeigt, dass Patienten mit MS und HAM / TSP Autoantikörper produzieren, um die intrazelluläre RNA-Bindeprotein heterogenen ribonuclear Protein A1 (hnRNP A1) 3, 5-7, 9, 11. Neuere Daten weisen darauf hin, dass Antikörper, sowohl Intra-neuronale und Oberflächenantigene pathogenen 3, 5-9, 11 sind. So ein Verfahren, das für die Untersuchung der intrazellulären Antikörpers ermöglicht: Protein Interaktionen würde großen Einblick in Krankheitsentstehung verleihen. Gene häufig in primären Zellen und Zelllinien in Kultur transfiziert wurde jedoch Transfektion von Antikörpern in Zellen durch Änderung des Antikörpers Struktur oder schlechte Transfektionseffizienz 12 behindert. Andere Transfektionsmethoden sind Antikörper Transfektion auf kationischen Liposomen (bestehend aus DOTAP / DOPE) und Polyethylenimine (PEI) bezogen, welche beide in einem Zehn-fache Abnahme der Antikörper Transfektion resultierte, verglichen mit Kontrollen 12. Das Verfahren unserer Studie durchgeführt ähnelt kationische Lipid-vermittelte Methoden und verwendet eine Lipid-basierten Mechanismus zur nicht-kovalente Komplexe mit den Antikörpern zu bilden, durch elektrostatische und hydrophobic Wechselwirkungen 13. Wir verwendeten Ab-deliverin Reagenz, das eine Lipidformulierung einfangen kann Antikörper durch nichtkovalente elektrostatische und hydrophobe Wechselwirkungen und liefert sie innerhalb der Zellen ist. So chemischen und genetischen Kupplungen sind nicht notwendig für die Lieferung von funktionellen Antikörpern in lebenden Zellen. Dieses Verfahren ermöglichte es uns, führen verschiedene Antikörper Tracing und Proteinlokalisierung Versuche sowie die Analysen der molekularen Folgen von intrazellulären Antikörper: Protein Wechselwirkungen 9. In diesem Protokoll wird gezeigt, wie an Antikörper zu Neuronen transfizieren rasch, reproduzierbar und mit einem hohen Grad der Transfektionseffizienz. Als ein Beispiel verwenden wir anti-hnRNP A1 und Anti-IgG-Antikörpern. Für die einfache Quantifizierung der Transfektionseffizienz verwendet man Anti-Antikörper mit hnRNP A1 Atto-550-NHS und FITC-markierten-IgG markiert. Atto550 NHS ist ein neues Label mit hochmolekularen Absorption und Quanten-yield. Anregungsquelle und fluoreszierenden Filter für Atto550 ähneln Cy3 (Ex. 556 Em. 578). Darüber hinaus hat Atto550 hohe Photostabilität. FITC-markiertes IgG wurden als Kontrolle verwendet, um anzuzeigen, dass dieses Verfahren vielseitig und nicht färben abhängig ist. Dieser Ansatz und die Daten, die erzeugt wird Verständnis der Rolle, dass Antikörper gegen Zielantigene intrazelluläre könnte in der Pathogenese von Erkrankungen des Menschen spielen, zu unterstützen.

Watch this Scientific Journal Video about Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis at JoVE.com

Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis

Eine schnelle Annäherung an Interaktionen und Wirkungen auf molekularer Mechanismen in Bezug auf die Anwesenheit von Antikörpern in einer intrazellulären Umgebung untersucht wird beschrieben. Das Verfahren beinhaltet die Transfektion von Antikörpern in lebende Zellen mit einem nicht-kovalenten Komplex-Bildung auf einem Lipid Formulierung. Die Technik ist anpassbar an immortalisierten Zelllinien und primäre Zellen.

Antikörper Transfektion in Neuronen als Werkzeug zur Pathogenese der Erkrankung Studieren

Antibodies provide the ability to gain novel insight into various events taking place in living systems.  The ability to produce highly specific ...

antibody-transfection-into-neurons-as-tool-to-study-disease

Research

JoVE Journal

Neuroscience

10.7K Aufrufe.  Veterans Administration Medical Center, Memphis, TN. Eine schnelle Annäherung an Interaktionen und Wirkungen auf molekularer Mechanismen in Bezug auf die Anwesenheit von Antikörpern in einer intrazellulären Umgebung untersucht wird beschrieben. Das Verfahren beinhaltet die Transfektion von Antikörpern in lebende Zellen mit einem nicht-kovalenten Komplex-Bildung auf einem Lipid Formulierung. Die Technik ist anpassbar an immortalisierten Zelllinien und primäre Zellen.

Serie: Antibody Transfection into Neurons as a Tool to Study Disease Pathogenesis

Laser Capture Microdissection of Drosophila Peripheral Neurons

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the molecular mechanisms underlying class-specific dendrite morphogenesis1,2. To facilitate molecular analyses of class-specific da neuron development, it is vital to obtain these cells in a pure population. Although a range of different cell, and tissue-specific RNA isolation techniques exist for Drosophila cells, including magnetic bead based cell purification3,4, Fluorescent Activated Cell Sorting (FACS)5-8, and RNA binding protein based strategies9, none of these methods can be readily utilized for isolating single or multiple class-specific Drosophila da neurons with a high degree of spatial precision. Laser Capture Microdissection (LCM) has emerged as an extremely powerful tool that can be used to isolate specific cell types from tissue sections with a high degree of spatial resolution and accuracy. RNA obtained from isolated cells can then be used for analyses including qRT-PCR and microarray expression profiling within a given cell type10-16. To date, LCM has not been widely applied in the analysis of Drosophila tissues and cells17,18, including da neurons at the third instar larval stage of development. 
Here we present our optimized protocol for isolation of Drosophila da neurons using the infrared (IR) class of LCM. This method allows for the capture of single, class-specific or multiple da neurons with high specificity and spatial resolution. Age-matched third instar larvae expressing a UAS-mCD8::GFP19 transgene under the control of either the class IV da neuron specific ppk-GAL420 driver or the pan-da neuron specific 21-7-GAL421 driver were used for these experiments. RNA obtained from the isolated da neurons is of very high quality and can be directly used for downstream applications, including qRT-PCR or microarray analyses. Furthermore, this LCM protocol can be readily adapted to capture other Drosophila cell types a various stages of development dependent upon the cell type specific, GAL4-driven expression pattern of GFP.

Laser Capture Microdissection of Drosophila Peripheral Neurons

In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses.

Laser Capture Mikrodissektion von Drosophila Peripheren Neuronen

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the ...

Forschung

Neurowissenschaften

Cut-loading: A Useful Tool for Examining the Extent of Gap Junction Tracer Coupling Between Retinal Neurons

In addition to chemical synaptic transmission, neurons that are connected by gap junctions can also communicate rapidly via electrical synaptic transmission. Increasing evidence indicates that gap junctions not only permit electrical current flow and synchronous activity between interconnected or coupled cells, but that the strength or effectiveness of electrical communication between coupled cells can be modulated to a great extent1,2. In addition, the large internal diameter (~1.2 nm) of many gap junction channels permits not only electric current flow, but also the diffusion of intracellular signaling molecules and small metabolites between interconnected cells, so that gap junctions may also mediate metabolic and chemical communication. The strength of gap junctional communication between neurons and its modulation by neurotransmitters and other factors can be studied by simultaneously electrically recording from coupled cells and by determining the extent of diffusion of tracer molecules, which are gap junction permeable, but not membrane permeable, following iontophoretic injection into single cells. However, these procedures can be extremely difficult to perform on neurons with small somata in intact neural tissue.
Numerous studies on electrical synapses and the modulation of electrical communication have been conducted in the vertebrate retina, since each of the five retinal neuron types is electrically connected by gap junctions3,4. Increasing evidence has shown that the circadian (24-hour) clock in the retina and changes in light stimulation regulate gap junction coupling3-8. For example, recent work has demonstrated that the retinal circadian clock decreases gap junction coupling between rod and cone photoreceptor cells during the day by increasing dopamine D2 receptor activation, and dramatically increases rod-cone coupling at night by reducing D2 receptor activation7,8. However, not only are these studies extremely difficult to perform on neurons with small somata in intact neural retinal tissue, but it can be difficult to adequately control the illumination conditions during the electrophysiological study of single retinal neurons to avoid light-induced changes in gap junction conductance.
Here, we present a straightforward method of determining the extent of gap junction tracer coupling between retinal neurons under different illumination conditions and at different times of the day and night. This cut-loading technique is a modification of scrape loading9-12, which is based on dye loading and diffusion through open gap junction channels. Scrape loading works well in cultured cells, but not in thick slices such as intact retinas. The cut-loading technique has been used to study photoreceptor coupling in intact fish and mammalian retinas7, 8,13, and can be used to study coupling between other retinal neurons, as described here.

An easy and convenient method to determine the extent of gap junction tracer coupling between retinal neurons is described. This technique enables one to investigate the function of the electrical synapses between neurons in the intact retina under different illumination conditions and at different times of the day and night.

Cut-loading: ein nützliches Werkzeug für die Prüfung des Umfangs der Gap Junction Tracer Kopplung zwischen Netzhautneuronen

In addition to chemical synaptic transmission, neurons that are connected by gap junctions can also communicate rapidly via electrical synaptic ...

Calcium Phosphate Transfection of Primary Hippocampal Neurons

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this method on hard-to-transfect cells like primary neurons. Here we describe our detailed protocol for calcium phosphate transfection of hippocampal neurons cocultured with astroglial cells.

Calciumphosphat-Transfektion von primären Hippocampus-Neuronen

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this ...

Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic effects of drugs and downstream pathways involved would help gain insight into the molecular mechanisms of neuroprotection/neurotoxicity and could potentially facilitate drug development. However, many existing in vitro toxicity assays have major limitations &#8211; most assess neurotoxicity and neuroprotection at a single time point, not allowing to observe the time-course and kinetics of the effect. Furthermore, the opportunity to collect information about downstream signaling pathways involved in neuroprotection in real-time would be of great importance. In the current protocol we describe the use of a real-time impedance-based cell analyzer to determine neuroprotective effects of serotonin 2A (5-HT2A) receptor agonists in a neuronal cell line under label-free and real-time conditions using impedance measurements. Furthermore, we demonstrate that inhibitors of second messenger pathways can be used to delineate downstream molecules involved in the neuroprotective effect. We also describe the utility of this technique to determine whether an effect on cell proliferation contributes to an observed neuroprotective effect. The system utilizes special microelectronic plates referred to as E-Plates which contain alternating gold microelectrode arrays on the bottom surface of the wells, serving as cell sensors. The impedance readout is modified by the number of adherent cells, cell viability, morphology, and adhesion. A dimensionless parameter called Cell Index is derived from the electrical impedance measurements and is used to represent the cell status. Overall, the real-time impedance-based cell analyzer allows for real-time, label-free assessment of neuroprotection and neurotoxicity, and the evaluation of second messenger pathways involvement, contributing to more detailed and high-throughput assessment of potential neuroprotective compounds in vitro, for selecting therapeutic candidates.

Improved in vitro neurotoxicity assays would aid the identification of new neuroprotective compounds. The utility of a real-time impedance-based cell analyzer to determine cytotoxicity and cytoprotection in neuronal cell lines and to delineate the involvement of second messenger pathways, thus gaining insight in the mechanism of neuroprotection is presented.

Echtzeit-Impedanz-basierte Zellanalyse als Werkzeug, um molekulare Signalwege in Neurotoxizität und Neuroprotektion in einem neuronalen Zelllinie; Delineate

Many brain-related disorders have neuronal cell death involved in their pathophysiology. Improved in vitro models to study neuroprotective or neurotoxic ...

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of the olfactory epithelium continuously give rise to new sensory neurons that extend their axons into the olfactory bulb, where they face the challenge to integrate into existing circuitry. Because of this particular feature, the olfactory system represents a unique opportunity to monitor axonal wiring and guidance, and to investigate synapse formation. Here we describe a procedure for in vivo labeling of sensory neurons and subsequent visualization of axons in the olfactory system of larvae of the amphibian Xenopus laevis. To stain sensory neurons in the olfactory organ we adopt the electroporation technique. In vivo electroporation is an established technique for delivering fluorophore-coupled dextrans or other macromolecules into living cells. Stained sensory neurons and their axonal processes can then be monitored in the living animal either using confocal laser-scanning or multiphoton microscopy. By reducing the number of labeled cells to few or single cells per animal, single axons can be tracked into the olfactory bulb and their morphological changes can be monitored over weeks by conducting series of in vivo time lapse imaging experiments. While the described protocol exemplifies the labeling and monitoring of olfactory sensory neurons, it can also be adopted to other cell types within the olfactory and other systems.

The Olfactory System as a Model to Study Axonal Growth Patterns and Morphology In Vivo

We describe a protocol for in vivo labeling of olfactory sensory neurons by electroporation and subsequent confocal laser-scanning or multiphoton microscopy to visualize neuronal morphology and its development over time.

Das olfaktorische System als Modell zur Axonal Wachstumsmuster und Morphologie Studieren<em&gt; In Vivo</em

The olfactory system has the unusual capacity to generate new neurons throughout the lifetime of an organism. Olfactory stem cells in the basal portion of ...

Intramuscular Injections Along the Motor End Plates: A Minimally Invasive Approach to Shuttle Tracers Directly into Motor Neurons

Diseases affecting the integrity of spinal cord motor neurons are amongst the most debilitating neurological conditions. Over the last decades, the development of several animal models of these neuromuscular disorders has provided the scientific community with different therapeutic scenarios aimed at delaying or reversing the progression of these conditions. By taking advantage of the retrograde machinery of neurons, one of these approaches has been to target skeletal muscles in order to shuttle therapeutic genes into corresponding spinal cord motor neurons. Although once promising, the success of such gene delivery approach has been hampered by the sub-optimal number of transduced motor neurons it has so far shown to yield. Motor end plates (MEPs) are highly specialized regions on the skeletal musculature that are in direct synaptic contact to the spinal cord &#945; motor neurons. In this regard, it is important to note that, so far, the efforts to retrogradely transfer genes into motor neurons were made without reference to the location of the MEP region in the targeted muscles. Here, we describe a simple protocol 1) to reveal the exact location of the MEPs on the surface of skeletal muscles and 2) to use this information to guide the intramuscular delivery and subsequent optimal retrograde transport of retrograde tracers into motor neurons. We hope to utilize the results from these tracing experiments in further studies into investigating retrograde transport of therapeutic genes to spinal cord motor neurons through the targeting of MEPs.

The efficacy of intramuscular uptake and retrograde transport of molecules to corresponding motor neurons depends on the location of the injection sites with respect to the motor end plates (MEPs). Here, we describe how to locate MEPs on skeletal muscles to optimise retrograde transport of tracers into motor neurons.

Intramuskuläre Injektionen Entlang der motorischen Endplatten: eine minimal-invasive Ansatz zur Shuttle Tracers Direkt in Motoneuronen

Diseases affecting the integrity of spinal cord motor neurons are amongst the most debilitating neurological conditions. Over the last decades, the ...

Stripe Assay to Study the Attractive or Repulsive Activity of a Protein Substrate Using Dissociated Hippocampal Neurons

Growing axons develop a highly motile structure at their tip, termed the growth cone. The growth cone contacts extracellular environmental cues to navigate axonal growth. Netrin, slit, semaphorin, and ephrins are known guidance molecules that can attract or repel axons upon binding to receptors and co-receptors on the axon. The activated receptors initiate various signaling molecules in the growth cone that alter the structure and movement of the neuron. Here, we describe the detailed protocol for a stripe assay to assess the ability of a guidance molecule to attract or repel neurons. In this method, dissociated hippocampal neurons from E15.5 mice are cultured on laminin-coated dishes processed with alternating stripes of ectodomain of fibronectin and leucine-rich transmembrane protein-2 (FLRT2) and control immunoglobulin G (IgG) fragment crystallizable region (Fc) protein. Both axons and cell bodies were strongly repelled from the FLRT2-coated stripe regions after 24 h of culture. Immunostaining with tau1 showed that ~90% of the neurons were distributed on the Fc-coated stripes compared to the FLRT2-Fc-coated stripes (~10%). This result indicates that FLRT2 has a strong repulsive effect on these neurons. This powerful method is applicable not only for primary cultured neurons but also for a variety of other cells, such as neuroblasts.

Axon guidance molecules regulate neuronal migration and targeted growth-cone navigation. We present a powerful method, the stripe assay, to assess the ability of guidance molecules to attract or repulse neurons. In this protocol, we demonstrate the stripe assay by showing FLRT2's ability to repel cultured hippocampal neurons.

Stripe Assay die anziehende oder abstoßende Aktivität eines Proteins Substrat unter Verwendung Dissociated Neuronen im Hippocampus zu studieren

Growing axons develop a highly motile structure at their tip, termed the growth cone. The growth cone contacts extracellular environmental cues to ...

Organotypic Hippocampal Slice Cultures As a Model to Study Neuroprotection and Invasiveness of Tumor Cells

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. This model is suitable for addressing different research questions that involve studies on neuroprotection, electrophysiological experiments on neurons, neuronal networks or tumor invasion. The hippocampal architecture and neuronal activity in multisynaptic circuits are well conserved in OHSC, even though the slicing procedure itself initially lesions and leads to formation of a glial scar. The scar formation alters presumably the mechanical properties and diffusive behavior of small molecules, etc. Slices allow the monitoring of time dependent processes after brain injury without animal surgery, and studies on interactions between various brain-derived cell types, namely astrocytes, microglia and neurons under both physiological and pathological conditions. An ambivalent aspect of this model is the absence of blood flow and immune blood cells. During the progression of the neuronal injury, migrating immune cells from the blood play an important role. As those cells are missing in slices, the intrinsic processes in the culture may be observed without external interference. Moreover, in OHSC the composition of the medium-external environment is precisely controlled. A further advantage of this method is the lower number of sacrificed animals compared to standard preparations. Several OHSC can be obtained from one animal making simultaneous studies with multiple treatments in one animal possible. For these reasons, OHSC are well suited to analyze the effects of new protective therapeutics after tissue damage or during tumor invasion. 
The protocol presented here describes a preparation method of OHSC that allows generating highly reproducible, well preserved slices that can be used for a variety of experimental research, like neuroprotection or tumor invasion studies.

Organotypic hippocampal slice cultures (OHSC) represent an in vitro model that simulates the in vivo situation very well. Here we describe a vibratome-based improved slicing protocol to obtain high quality slices for use in assessing the neuroprotective potential of novel substances or the biological behavior of tumor cells.

Organotypischen Hippocampal Slice Kulturen als Modell zur Studie Neuroprotektion und Invasivität der Tumorzellen

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. ...

Exogenous Administration of Microsomes-associated Alpha-synuclein Aggregates to Primary Neurons As a Powerful Cell Model of Fibrils Formation

For years, the inability of replicating formation of insoluble alpha-synuclein (&#945;S) inclusions in cell cultures has been a great limitation in the study of &#945;S aggregation in Parkinson&#39;s Disease (PD). Recently, the development of new animal models through the exogenous inoculation of brain extracts from diseased &#945;S transgenic mice or PD patients has given new hopes to the possibility of creating more adequate cell models of &#945;S aggregation. Unfortunately, when it comes to cells in cultures, administration of raw brain extracts has not proven as successful as in mice and the source of choice of exogenous aggregates is still in vitro preformed &#945;S fibrils.
We have developed a method to induce the formation of intracellular &#945;S inclusions in primary neurons through the exogenous administration of native microsomes-associated &#945;S aggregates, a highly toxic &#945;S species isolated from diseased areas of transgenic mice. This fraction of &#945;S aggregates that is associated with the microsomes vesicles, is efficiently internalized and induces the formation of intracellular inclusions positive for aggregated and phosphorylated &#945;S. Compared to in vitro-preformed fibrils which are made from recombinant &#945;S, our method is faster and guarantees that the pathogenic seeding is made with authentic &#945;S aggregates extracted from diseased animal models of PD, mimicking more closely the type of inclusions obtained in vivo. As a result, availability of tissues rich in &#945;S inclusions is mandatory.
We believe that this method will provide a versatile cell-based model to study the microscopic aspects of &#945;S aggregation and the related cellular pathophysiology in vivo and will be a starting point for the creation of more accurate and sophisticated cell paradigm of PD.

The goal of this protocol is to provide a cell-based system that replicates the formation of alpha-synuclein aggregates in vivo. Intracellular alpha-synuclein inclusions are seeded in primary neurons by the internalization and propagation of exogenous administered native microsomes-associated alpha-synuclein aggregates isolated from diseased alpha-synuclein transgenic mice.

Exogene Verabreichung von Alpha-Synuclein Microsomen verbundenen Aggregate zur primären Neuronen als eine mächtige Zellmodell der Fibrillen Bildung

For years, the inability of replicating formation of insoluble alpha-synuclein (&#945;S) inclusions in cell cultures has been a great limitation in the ...

Cell-based Assay to Study Antibody-mediated Tau Clearance by Microglia

Alzheimer&#39;s disease (AD) is a progressive neurodegenerative condition in which aggregated tau and amyloid proteins accumulate in the brain causing neuronal dysfunction which eventually leads to cognitive decline. Hyperphosphorylated tau aggregates in the neuron are believed to cause most of the pathology associated with AD. These aggregates are assumed to be released into the extracellular compartment and taken up by adjacent healthy neurons where they induce further tau aggregation. This &#34;prion-like&#34; spreading can be interrupted by antibodies capable of binding and &#34;neutralizing&#34; extracellular tau aggregates as shown in preclinical mouse models of AD. One of the proposed mechanisms by which therapeutic antibodies reduce pathology is antibody-mediated uptake and clearance of pathological aggregated forms of tau by microglia. Here, we describe a quantitative cell-based assay to assess tau uptake by microglia. This assay uses the mouse microglial cell line BV-2, allows for high specificity, low variability and medium throughput. Data generated with this assay can contribute to a better characterization of anti-tau antibody effector functions.

Here we describe a cell-based assay to quantitatively assess tau uptake by microglia with the aim of creating an investigational tool to better characterize the mechanisms of action of anti-tau antibodies.

Zellbasierte Assays, Antikörper-vermittelten Tau Clearance von Mikroglia zu studieren

Alzheimer&#39;s disease (AD) is a progressive neurodegenerative condition in which aggregated tau and amyloid proteins accumulate in the brain causing ...