Financial support for the experiments presented in the study was provided by the Marie Heim-V&#246;gtlin program of the Swiss National Science Foundation.
We thank Ms. Johanna Nyffeler for developing a set of modified MATLAB programs for screening for statistically significant differences in real-time cell analyzer&#8217;s data and Dr. Yama Abassi for helpful discussion.

1. Vorbereitung <ol><li> Zeigen Station des Echtzeit-Zellanalysegeräts in einem Brutschrank bei 37 ° C und 5% CO 2. Führen Sie alle Zellkultur Handhabung und pharmakologische Behandlungen in einer Gewebekultur Haube unter sterilen Bedingungen. </li><li> HINWEIS: Neuronale Zelllinien im Vergleich zu Standardbedingungen für die Kultur, die unterschiedliche Temperatureinstellungen, sollte entsprechend angepasst werden. Für schwach adhärenten Zelllinien verwenden Überzugsmittel, um die Wechselwirkung von Zellen mit der Goldmikroelektroden in den Boden der Vertiefungen der E-Platte 96 zu erleichtern. </li><li> Bereiten 1,000X Stammlösungen der pharmakologischen Verbindungen für die Zellkultur-Behandlung (neuroprotektive Mittel oder Second-Messenger-Wege-Inhibitoren in dem entsprechenden Lösungsmittel - Dimethylsulfoxid oder sterilem Wasser) und im Kühlschrank bei -20 ° C. Verwenden Sie in den folgenden Behandlungen das Lösungsmittel als Fahrzeug. </li><li> Kultur menschlicher Neuroblastomzellen SK-N-SH-Zellen in DMEM / F12-Medium mit 10% fötalem Rinderserum (FBS) (Proliferationsmedium) in Zellkulturflaschen, ergänzt mit 175 cm 2 Oberfläche, um die Dichte von ca. 75%. Halten Zellpassage Zahl in einem Bereich (von etwa 10 Passagen), um die Konsistenz zwischen den Experimenten in Bezug auf Zellproliferationsrate und das Ansprechen auf die Zytotoxizität zu bestimmen. Niedergang Nummern werden bevorzugt. </li><li> Mit PBS waschen Die adhärenten SK-N-SH-Zellschicht und trypsinize mit 0,05% Trypsin-EDTA-Lösung für 5 min bei 37 ° C. Zentrifugation der Zellen bei 170 × g für 5 min auf Trypsin zu entfernen. Resuspendieren der Zellen in 10 ml Medium Proliferation. Zählen Sie die Zellen mit Scepter Zellzähler und stellen Sie die Zellzahl auf 300.000 Zellen / ml durch Verdünnung Zellen mit Proliferationsmedium. </li></ol> 2. Überzug und die Proliferation von SK-N-SH-Zellen <ol><li> 100 l Proliferationsmedium in jede Vertiefung der E-Plate 96 und lassen Sie es für 30 Minuten in der Gewebekultur Haube bei RT ins Gleichgewicht. Legen Sie die E-PlaTE 96 in der Echtzeit-Zellanalysestation in dem CO 2-Inkubator bei 37 ° C aufweist. </li><li> Starten des Echtzeit-Zellanalysesoftware. Auf der Seite Layout auswählen die Brunnen im Experiment enthalten und geben Sie in die Eingabefelder die Informationen über Zelltyp, Zellzahl, Namen und Konzentrationen von chemischen Verbindungen für die Zellbehandlung eingesetzt. HINWEIS: Für die Zwecke dieses Protokolls mindestens 4 Wiederholungsversuche für jede Behandlung empfohlen. </li><li> Auf dem Spielplan Software Seite bestimmen &quot;Steps&quot; enthalten in dem Experiment, indem Sie die Anzahl der Durchläufe Messzelle Index und das Intervall zwischen den Durchläufen für jeden Schritt. Seit Schritt 1 ist für die Hintergrundmessung vorgegeben, wählen Sie &quot;einen Schritt&quot; und stellen Sie Schritt 2, um die Zelle Index alle 15 min für 96 Stunden messen. HINWEIS: Für Behandlungen, in denen Effekte mit schnellen Kinetik zu erwarten sind, eingestellt Sweeps in kürzeren Abständen. </li><li> Klicken Sie auf Start, um die automatisch vorgegebenen Schritt einzuleiten 1und messen Sie den Hintergrund Impedanz der Medien. Dieser Wert wird automatisch durch die Software an jedem Datenpunkt abgezogen, sobald die Zellen in die Vertiefungen gegeben. </li><li> Verwenden Sie den zuvor in Schritt 1.5) hergestellten Zellsuspension von 300.000 Zellen / ml in Proliferationsmedium. 30.000 Zellen / Well für die Zelltoxizität / Neuroprotektion Studien und 15.000 Zellen / Well für die Zellproliferation Studien. Nehmen Sie die E-Plate und 100 l Zellsuspension pro Well für die Zelltoxizität / Neuroprotektion Studien und 50 ul Zellsuspension und 50 ul Proliferationsmedium pro Vertiefung für die Zellproliferation Studien. Die Anzahl der Zellen pro Vertiefung plattiert muss für jede Zelllinie empirisch optimiert werden. </li><li> Vorsichtig schwenken, die E-Plate 96 für noch Plattierung der Zellen. Verlassen Sie die E-Plate 96 für 30 min in der Gewebekultur Haube bei RT, damit sich die Zellen absetzen gleichmäßig auf den Boden der Vertiefungen. </li><li> Legen Sie die E-Platte 96 in der Echtzeit-Zellanalysestation und starten Sie Schritt 2 auf dem Spielplan S.Alter. Überwachungszelle Indexwerte während des Experiments, indem Sie die Zelle Kurven auf der Profilseite und der Ausgangszell Index-Daten auf dem Handy Index Seite der Software. </li></ol> 3. Serumentzug <ol><li> 24 Stunden nach dem Ausstreichen der Zellen, Pause das Experiment, und entfernen Sie die E-Plate 96 von der Echtzeit-Zellanalysestation. Verdünnen second messenger-Inhibitoren aus 1,000X Aktien mit DMEM / F12 Serum-freien Medium - bis 200 × Endkonzentration. Gönnen Zellen mit 1 ul Inhibitoren der zweiten Botenwege, um für ihre Beteiligung an der Neurotoxizität / Neuroprotektion 30 min vor Beginn der Zytotoxizität getestet werden, um die jeweiligen Signalwege hemmen. Bringen Sie die E-Plate 96 bis zum Bahnhof und wieder experimentelle Zellindex-Messungen. </li><li> Nach 30 Minuten Pause, das Experiment wieder. Proliferationsmedium sorgfältig vollständig zu entfernen aus der E-Plate 96 Brunnen mit einer Pipette (oder Multi-Kanal-Pipette), kümmert sich nicht um die adhärenten Zellschicht störenindem der Rand der Pipettenspitze an der Ecke des Bohrloches. Nach Zugabe von 200 ul / Vertiefung serumfreies DMEM / F12-Medium (Medium Serumentzug). Sicherzustellen, schnellen Austausch von Zellkulturmedium zur mechanischen Bewegung der Zellen zu minimieren. </li><li> Verdünnen Verbindungen auf ihre neuroprotektive Wirkung von 1,000X Lager mit Serum-freiem DMEM / F12-Medium und 200 × Endkonzentration getestet werden. 1 ul Verbindungen auf ihre neuroprotektive Wirkung und 1 ul Inhibitoren der Second-Messenger-Pfade in den einzelnen Vertiefungen nach dem Versuchsplan getestet werden. </li><li> In Zellen, die für die Proliferation Studien Medium nicht zu ändern. Verdünnen Verbindungen von 1,000X Lager auf 200 × Endkonzentration in Proliferationsmedium getestet werden, behandeln mit 1 ul pro Well und weiter zu Kultur in Proliferationsmedium. </li><li> Wieder aufnehmen, das Experiment mit Zellindex-Messungen alle 15 min für 96 Stunden weiter wie vorher eingestellt wurde. </li></ol> 4. Daten Analyse <ol><li> Für Neurotoxizität / Neuroprotektion Daten normalisieren Zell Index bis zum letzten Zeitpunkt vor pharmakologische Behandlung oder mittlere Veränderung der Variation zwischen den Experimenten durch Auswahl von &quot;normalisierten Zell Index&quot; auf der Profilseite zu reduzieren und &quot;normalisieren Zeit&quot;. </li><li> Markieren Sie die Brunnen auf dem Grundstück Seite für den Versuchsbedingungen von Interesse und klicken Sie auf &quot;Hinzufügen&quot;, um die normierten Zell Index-Kurven zeichnen. Beobachten der Kinetik der neurotoxischen / neuroprotektive Wirkung oder der zweiten Boten-Hemmung als normierte Zellenindex-Kurven als eine Funktion der Zeit. </li><li> Beachten Sie die Zellenindex-Kurven für die getesteten medikamentöse Behandlungen in Proliferationsmedium als Funktion der Zeit zu beurteilen, ob ein Effekt auf die Proliferation in der neuroprotektive / neurotoxische Wirkung beteiligt. </li><li> Exportieren Sie die Informationen für alle experimentellen Zell Index Zeitpunkten aus der Zelle Index Software Seite in eine Excel-Datei, um die statistische Auswertung der Ergebnisse zu initiieren <br/&gt; Hinweis: Als ein erster Schritt in der statistischen Analyse eine Reihe von MATLAB-Programme geändert, dass die Welch-t-Test zu verwenden, mit dem p-Wert aufgetragen halblogarithmisch, nutzen umgekehrte Achse gegen die Zeitskala (als Zusatzcode-Dateien zur Verfügung gestellt). Diese Programme erlauben, den p-Werte über den Zeitverlauf eines gesamten Echtzeit-Zellanalyseexperiment und somit helfen die Auswahl der Zeitpunkte für weitere detaillierte statistische Analyse. Siehe die Zusatzmaterial für die detaillierte Informationen zu den Programmen. </li><li> Für die statistische Analyse der Unterschiede in der Zellindexwerte unter verschiedenen Behandlungsbedingungen zu bestimmten Zeitpunkten, markieren Sie die Zelle Indexwerte an den jeweiligen Zeitpunkten aus der exportierten Excel-Datei. Analysieren Sie die Handy-Index-Werte für die ausgewählten Zeitpunkten mit One-Way-oder Zwei-Wege-Varianzanalyse (ANOVA), gefolgt von einer post-hoc-Test unter Verwendung statistischer Software. </li></ol>

<ol>
	<li>Cavallucci, V., D'Amelio, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Matter+of+life+and+death:+the+pharmacological+approaches+targeting+apoptosis+in+brain+diseases.">Matter of life and death: the pharmacological approaches targeting apoptosis in brain diseases.</a> Curr. Pharm. Des. 17 (3), 215-229 (2011).</li><li>Bull, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HPA+CHaPD+001:+Review+of+Environmental+Chemicals+and+Neurotoxicity.">HPA CHaPD 001: Review of Environmental Chemicals and Neurotoxicity.</a> Focus on Neurological Diseases. , (2007).</li><li>Ke, N., Wang, X., Xu, X., Abassi, Y. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+xCELLigence+system+for+real-time+and+label-free+monitoring+of+cell+viability.">The xCELLigence system for real-time and label-free monitoring of cell viability.</a> Methods Mol. Biol. 740, 33-43 (2011).</li><li>Limame, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+dynamic+cell+viability,+migration+and+invasion+assessments+by+novel+real-time+technology+and+classic+endpoint+assays.">Comparative analysis of dynamic cell viability, migration and invasion assessments by novel real-time technology and classic endpoint assays.</a> PLoS One. 7 (10), e46536 (2012).</li><li>Diemert, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impedance+measurement+for+real-time+detection+of+neuronal+cell+death.">Impedance measurement for real-time detection of neuronal cell death.</a> J. Neurosci. Methods. 203 (1), 69-77 (2012).</li><li>Kustermann, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+label-free,+impedance-based+real+time+assay+to+identify+drug-induced+toxicities+and+differentiate+cytostatic+from+cytotoxic+effects.">A label-free, impedance-based real time assay to identify drug-induced toxicities and differentiate cytostatic from cytotoxic effects.</a> Toxicol In Vitro. 27 (5), 1589-1595 (2013).</li><li>Marinova, Z., Walitza, S., Gr&#252;nblatt, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=5-HT2A+serotonin+receptor+agonist+DOI+alleviates+cytotoxicity+in+neuroblastoma+cells:+role+of+the+ERK+pathway.">5-HT2A serotonin receptor agonist DOI alleviates cytotoxicity in neuroblastoma cells: role of the ERK pathway.</a> Prog. Neuropsychopharmacol. Biol. Psychiatry. 44, 64-72 (2013).</li><li>Gonz&#225;lez-Maeso, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hallucinogens+recruit+specific+cortical+5-HT(2A)+receptor-mediated+signaling+pathways+to+affect+behavior.">Hallucinogens recruit specific cortical 5-HT(2A) receptor-mediated signaling pathways to affect behavior.</a> Neuron. 53 (3), 439-452 (2007).</li><li>Tsuchioka, M., Takebayashi, M., Hisaoka, K., Maeda, N., Nakata, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+(5-HT)+induces+glial+cell+line-derived+neurotrophic+factor+(GDNF)+mRNA+expression+via+the+transactivation+of+fibroblast+growth+factor+receptor+2+(FGFR2)+in+rat+C6+glioma+cells.">Serotonin (5-HT) induces glial cell line-derived neurotrophic factor (GDNF) mRNA expression via the transactivation of fibroblast growth factor receptor 2 (FGFR2) in rat C6 glioma cells.</a> J. Neurochem. 106 (1), 244-257 (2008).</li><li>Galante, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+toxicity,+conformation+and+morphology+of+typical+initial+aggregation+states+of+A&#946;1-42+and+A&#946;py3-42+beta-amyloids.">Differential toxicity, conformation and morphology of typical initial aggregation states of A&#946;1-42 and A&#946;py3-42 beta-amyloids.</a> Int. J. Biochem. Cell. Biol. 44 (11), 2085-2093 (2012).</li><li>Sheline, C. T., Cai, A. L., Zhu, J., Shi, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum+or+target+deprivation-induced+neuronal+death+causes+oxidative+neuronal+accumulation+of+Zn2+and+loss+of+NAD.">Serum or target deprivation-induced neuronal death causes oxidative neuronal accumulation of Zn2+and loss of NAD.</a> Eur. J. Neurosci. 32, 894-904 (2010).</li></ol>

Publikationskosten für den aktuellen Video-Artikel wurden von &quot;ACEA Biosciences&quot; gesponsert.

Das aktuelle Protokoll stellt den Nutzen eines Echtzeit-Zellanalyse kontinuierlich und unter Label-freien Bedingungen bewerten die neuroprotektive / neurotoxischen Wirkungen von Verbindungen in neuronalen Zelllinien und einen Einblick in die Second-Messenger-Signalwege in der Wirkung beteiligt zu gewinnen. Obwohl Dienstprogramm des Echtzeit-Zellanalysegerät zur Zytotoxizität und Wirkungen von Arzneimitteln auf die Zellproliferation zu untersuchen ist allgemein bekannt, haben nur wenige Stu...

Neuronale Zelltod spielt eine wichtige Rolle in der Pathophysiologie von zahlreichen Gehirn 1-bedingten Erkrankungen. Die Verfügbarkeit von zuverlässigen und Hochdurchsatz in vitro Toxizitätstests ist entscheidend, um einen besseren Einblick in die Mechanismen der Neurotoxizität zu gewinnen und zu helfen, wählen Sie neuroprotektive Moleküle als therapeutische Kandidaten in der Medikamentenentwicklung 2. Allerdings gibt es viele Einschränkungen am häufigsten in vitro Neurotoxizität assays.They verwendet beurteilen Neurotoxizität / Neuroprotektion zu einem einzigen Zeitpunkt Punkt nicht erlaubt kinetische Auflösung; oft Etikett oder Sonde, die mit den Signalwegen stören können und weitere Studien in der gleichen Zellpopulation zu begrenzen, und sind oft arbeitsintensiv, und in vielen Fällen nicht bieten Einblick in den Mechanismus. In der vorliegenden Studie zeigen wir, den Nutzen eines Echtzeit-Impedanz-basierte Zellanalyse zu Neurotoxizität und Neuroprotektion in einer neuronalen Zelllinie in Echtzeit und unter bestimmen markierungsfreieBedingungen und um einen Einblick in nachgeschalteten Mechanismen, durch Analyse der sekundären Botenwege in der Wirkung beteiligt ist. Frühere Studien haben die Wirksamkeit der Echtzeit-Zellanalyse bestätigt Zytotoxizität sowie Effekte auf die Zellproliferation in Zelllinien im Vergleich zu Standardtechniken 3,4,5,6 bestimmen. Zum Beispiel wurde eine gute Korrelation zwischen den Ablesungen der Standardzelle Lebensfähigkeit WST-1-Assay und Zellindexwerte zu verschiedenen Zeitpunkten unter basalen Bedingungen und Proliferation nach zwei verschiedenen toxischen Paradigmen in HeLa-Zellen 3 beobachtet. A549 und MDA-MB-231-Zellen-Proliferation und Zytotoxizität der Mikrotubuli-Stabilisator Paclitaxel provoziert zeigten sehr ähnliche Werte, wenn sie von Zellenindex-Messungen bewertet und zur standard Sulforhodamin B (SRB) Test 4. In der neuronalen Zelllinie verewigt Neuronen im Hippocampus wurden HT-22 Zellindex-Messungen für ihre Fähigkeit t validierto detect Zellproliferation, Glutamat-Cytotoxizität und Zellschutz gegen die verbreiteten 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazoliumbromid-(MTT)-Assay 5. In der gleichen Studie die MTT-Test Ergebnisse und Zellindex-Messungen auch gut in der Messung der neuronalen Vorläuferzellen Proliferation, Zytotoxizität nach Wachstumsfaktoren Not und Rettung der Zytotoxizität von der Pan-Caspase-Inhibitor QVD 5 korreliert. Zytotoxizität in NIH 3T3-Zellen durch Vandetanib (vaskulärer endothelialer Wachstumsfaktor-Rezeptor und den epidermalen Wachstumsfaktor-Rezeptor-Inhibitor) induziert zeigte mit Zellenindex-Werte oder Neutralrot-Aufnahmetest gemessen 6 ähnliche Ergebnisse. Wir haben vor kurzem verwendet das Echtzeit-Zellanalysesystems neuroprotektiven Wirkungen des Serotonin-2A beurteilen (5-HT 2A)-Rezeptor-Agonisten (±) -2,5-Dimethoxy-4-iodoamphetamine Hydrochlorid (DOI) in einer neuronalen Zelllinie ( SK-N-SH-Zellen) und für die Einbeziehung seco gescreentnd messenger Wege durch Überwachen der Wirkung der chemischen Hemmung der beobachteten Neuroprotektion 7. Interessanterweise hat der 5-HT 2A-Rezeptor sowohl halluzinogene und nonhallucinogenic Agonisten (wie DOI und Lisurid, beziehungsweise), die sowohl gemeinsame als auch unterschiedliche Second-Messenger-Signalwege aktivieren kann 8. Die Vorteile der vorgestellten Technik sind, dass sie es ermöglicht, Informationen in Echtzeit auf das Überleben der Zellen im Laufe der Tage zu sammeln, zu beschreiben zweiten Botenwegen beteiligt, um den möglichen Beitrag der Proliferation Effekte auf die Neuroprotektion zu bewerten und eine optimale Zeit wählen für zusätzliche Endpunktstudien auf der gleichen Zellpopulation. Eine schematische Darstellung des Arbeitsablaufs in der Protokoll ist in 1 dargestellt.

<table border="0" cellpadding="0" cellspacing="0" width="1015">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Name of Material/ Equipment</td>
			<td style="width:161px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:457px;">Comments/Description</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:279px;">xCELLigence&#160; RTCA SP system bundle</td>
			<td style="width:161px;">ACEA Biosciences</td>
			<td style="width:119px;">No: 00380601030</td>
			<td>consists of RTCA Analyzer, RTCA SP Station and RTCA Control Unit</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:279px;">E-plate 96</td>
			<td style="width:161px;">ACEA Biosciences</td>
			<td style="width:119px;">No: 05232368001</td>
			<td>for culturing the cells, inserted in the RTCA SP Station</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:279px;">SK-N-SH cells</td>
			<td style="width:161px;">ATCC - (in partnership with LGC Standards)</td>
			<td style="width:119px;">HTB-11</td>
			<td>can be replaced by another adherent neuronal cell line of interest</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">DMEM/F12&#160;</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">D8437</td>
			<td>cell culture medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">fetal bovine serum</td>
			<td style="width:161px;">Life Technologies</td>
			<td style="width:119px;">16140-063</td>
			<td>supplements proliferation, but not serum deprivation medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">tisue culture flask T175</td>
			<td style="width:161px;">Sarstedt</td>
			<td style="width:119px;">83.1812.302&#160;</td>
			<td>for culturing cells, which will be later plated on the E-Plate 96</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">0.05% Trypsin-EDTA</td>
			<td style="width:161px;">Life Technologies</td>
			<td style="width:119px;">25300-054</td>
			<td>for trypsinization of cells cultured in tissue culture flasks</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Scepter 2.0 cell counter</td>
			<td style="width:161px;">Merck Millipore</td>
			<td style="width:119px;">PHCC20060</td>
			<td>automated cell counter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">phosphate-buffered saline</td>
			<td style="width:161px;">Life Technologies</td>
			<td style="width:119px;">10010-015</td>
			<td>for washing the cells</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">(&#177;)-DOI hydrochloride</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">D101</td>
			<td>5-HT2A agonist for cell culture treatment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">LY-294,002 hydrochloride</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">L9908</td>
			<td>PI3-K inhibitor for cell culture treatment&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">lisuride maleate</td>
			<td style="width:161px;">Tocris Bioscience</td>
			<td align="right" style="width:119px;">4052</td>
			<td>compound with 5-HT2A agonistic activity for cell culture treatment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">dimethyl sulfoxide</td>
			<td style="width:161px;">Sigma-Aldrich</td>
			<td style="width:119px;">D4540</td>
			<td>for dissolving LY-294,002 and lisuride maleate</td>
		</tr>
	</tbody>
</table>

real-time impedance-based cell analyzer as a tool to delineate molecular pathways involved in neurotoxicity and neuroprotection in a neuronal cell line

Viele Gehirn-bedingten Erkrankungen haben den Zelltod in ihrer Pathophysiologie beteiligt. In-vitro-Modellen verbessert, um neuroprotektive oder neurotoxischen Wirkungen von Drogen-und nachgelagerten Wegen beteiligt würde helfen, einen Einblick in die molekularen Mechanismen der Neuroprotektion / Neurotoxizität und Wirkstoffentwicklung könnte potenziell zu erleichtern studieren. Allerdings haben viele der vorhandenen In-vitro-Toxizitätstests wesentliche Einschränkungen - die meisten Neurotoxizität und Neuroprotektion beurteilen an einem einzigen Zeitpunkt, ohne dass sich die Zeit-Verlauf und die Kinetik der Wirkung zu beobachten. Darüber hinaus würde die Möglichkeit, Informationen über nachgeschaltete Signalwege bei der Neuroprotektion in Echtzeit beteiligt sammeln von großer Bedeutung sein. In der aktuellen Protokoll beschreiben wir die Verwendung einer Echtzeit-Impedanz-basierte Zellanalyse neuroprotektive Effekte von Serotonin 2A (5-HT 2A)-Rezeptor-Agonisten in einer neuronalen Zelllinie unter markierungsfreie Echtzeit-Condit bestimmenIonen unter Verwendung von Impedanzmessungen. Weiterhin zeigen wir, dass Inhibitoren der Second-Messenger-Pfade können verwendet werden, um Moleküle der in der neuroprotektiven Wirkung beteiligt abzugrenzen. Wir beschreiben auch die Nützlichkeit dieser Technik zur Bestimmung, ob eine Wirkung auf die Zellproliferation trägt zu einer beobachteten neuroprotektive Wirkung. Das System nutzt spezielle mikroPlatten als E-Platten, die alternierend Gold enthalten Mikroelektrodenarrays an der Bodenfläche der Vertiefungen als Zell-Sensoren dienen bezeichnet. Die Impedanz wird durch Auslesen der Anzahl der anhaftenden Zellen, Zelllebensfähigkeit, Morphologie und Adhäsion modifiziert. Ein dimensionsloser Parameter genannt Zellenindex wird aus den elektrischen Impedanzmessungen abgeleitet und wird verwendet, um den Zellstatus repräsentieren. Insgesamt ermöglicht die Echtzeit-Impedanz-basierten Zell-Analysator für Echtzeit-, markierungsfreie Beurteilung der Neuroprotektion und Neurotoxizität, und die Bewertung der zweiten Messenger-Pfade Beteiligung, einen Beitrag zu mehrdetaillierte und hohem Durchsatz Beurteilung potenzieller neuroprotektive Verbindungen in vitro, zum Auswählen therapeutischen Kandidaten.

<html> Serumentzug führt zu einer Zellenindex-Werte, die ständig mit dem Echtzeit-Zellanalysegerät überwacht werden kann, zu verringern Neuro Stimuli zu den Zellen zu einer Abnahme in der Zell-Index-Werte, die in Echtzeit mit den vorgestellte Technik und die Dynamik der abhängig ist von der spezifischen neuro Stimulus und dem Zelltyp sucht überwacht werden können. Abbildung 2 zeigt die Zunahme der Zell Index bei SK-N-SH-Zellen in Proliferationsmedium b...

Watch this Scientific Journal Video about Real-Time Impedance-based Cell Analyzer as a Tool to Delineate Molecular Pathways Involved in Neurotoxicity and Neuroprotection in a Neuronal Cell Line at JoV

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

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 ...

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Research

JoVE Journal

Neuroscience

11.3K Aufrufe.  University of Zürich. 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.

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

Automated Sholl Analysis of Digitized Neuronal Morphology at Multiple Scales

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3. Specifically, it affects the ability of neurons to receive inputs from other cells2 and contributes to the propagation of action potentials4,5. The morphology of the neurites also affects how information is processed. The diversity of dendrite morphologies facilitate local and long range signaling and allow individual neurons or groups of neurons to carry out specialized functions within the neuronal network6,7. Alterations in dendrite morphology, including fragmentation of dendrites and changes in branching patterns, have been observed in a number of disease states, including Alzheimer's disease8, schizophrenia9,10, and mental retardation11. The ability to both understand the factors that shape dendrite morphologies and to identify changes in dendrite morphologies is essential in the understanding of nervous system function and dysfunction.
Neurite morphology is often analyzed by Sholl analysis and by counting the number of neurites and the number of branch tips. This analysis is generally applied to dendrites, but it can also be applied to axons. Performing this analysis by hand is both time consuming and inevitably introduces variability due to experimenter bias and inconsistency. The Bonfire program is a semi-automated approach to the analysis of dendrite and axon morphology that builds upon available open-source morphological analysis tools. Our program enables the detection of local changes in dendrite and axon branching behaviors by performing Sholl analysis on subregions of the neuritic arbor. For example, Sholl analysis is performed on both the neuron as a whole as well as on each subset of processes (primary, secondary, terminal, root, etc.) Dendrite and axon patterning is influenced by a number of intracellular and extracellular factors, many acting locally. Thus, the resulting arbor morphology is a result of specific processes acting on specific neurites, making it necessary to perform morphological analysis on a smaller scale in order to observe these local variations12.
The Bonfire program requires the use of two open-source analysis tools, the NeuronJ plugin to ImageJ and NeuronStudio. Neurons are traced in ImageJ, and NeuronStudio is used to define the connectivity between neurites. Bonfire contains a number of custom scripts written in MATLAB (MathWorks) that are used to convert the data into the appropriate format for further analysis, check for user errors, and ultimately perform Sholl analysis. Finally, data are exported into Excel for statistical analysis. A flow chart of the Bonfire program is shown in Figure 1.

We have developed a computer program to analyze neuronal morphology. In combination with two existing open source analysis tools, our program performs Sholl analysis and determines the number of neurites, branch points, and neurite tips. The analyses are performed so that local changes in neurite morphology can be observed.

Automatisierte Sholl Analyse digitalisierter neuronale Morphologie bei Multiple Scales

Neuronal morphology plays a significant role in determining how neurons function and communicate1-3.  Specifically, it affects the ability of neurons to ...

Forschung

Neurowissenschaften

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

Effiziente Ableitung von humanen neuronalen Vorläuferzellen und Neuronen aus pluripotenten humanen embryonalen Stammzellen mit Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Simultaneous Electroencephalography, Real-time Measurement of Lactate Concentration and Optogenetic Manipulation of Neuronal Activity in the Rodent Cerebral Cortex

Although the brain represents less than 5% of the body by mass, it utilizes approximately one quarter of the glucose used by the body at rest1. The function of non rapid eye movement sleep (NREMS), the largest portion of sleep by time, is uncertain. However, one salient feature of NREMS is a significant reduction in the rate of cerebral glucose utilization relative to wakefulness2-4. This and other findings have led to the widely held belief that sleep serves a function related to cerebral metabolism. Yet, the mechanisms underlying the reduction in cerebral glucose metabolism during NREMS remain to be elucidated.
	One phenomenon associated with NREMS that might impact cerebral metabolic rate is the occurrence of slow waves, oscillations at frequencies less than 4 Hz, in the electroencephalogram5,6. These slow waves detected at the level of the skull or cerebral cortical surface reflect the oscillations of underlying neurons between a depolarized/up state and a hyperpolarized/down state7. During the down state, cells do not undergo action potentials for intervals of up to several hundred milliseconds. Restoration of ionic concentration gradients subsequent to action potentials represents a significant metabolic load on the cell8; absence of action potentials during down states associated with NREMS may contribute to reduced metabolism relative to wake.
	Two technical challenges had to be addressed in order for this hypothetical relationship to be tested. First, it was necessary to measure cerebral glycolytic metabolism with a temporal resolution reflective of the dynamics of the cerebral EEG (that is, over seconds rather than minutes). To do so, we measured the concentration of lactate, the product of aerobic glycolysis, and therefore a readout of the rate of glucose metabolism in the brains of mice. Lactate was measured using a lactate oxidase based real time sensor embedded in the frontal cortex. The sensing mechanism consists of a platinum-iridium electrode surrounded by a layer of lactate oxidase molecules. Metabolism of lactate by lactate oxidase produces hydrogen peroxide, which produces a current in the platinum-iridium electrode. So a ramping up of cerebral glycolysis provides an increase in the concentration of substrate for lactate oxidase, which then is reflected in increased current at the sensing electrode. It was additionally necessary to measure these variables while manipulating the excitability of the cerebral cortex, in order to isolate this variable from other facets of NREMS.
	We devised an experimental system for simultaneous measurement of neuronal activity via the elecetroencephalogram, measurement of glycolytic flux via a lactate biosensor, and manipulation of cerebral cortical neuronal activity via optogenetic activation of pyramidal neurons. We have utilized this system to document the relationship between sleep-related electroencephalographic waveforms and the moment-to-moment dynamics of lactate concentration in the cerebral cortex. The protocol may be useful for any individual interested in studying, in freely behaving rodents, the relationship between neuronal activity measured at the electroencephalographic level and cellular energetics within the brain.

A procedure is described for manipulating the activity of cerebral cortical pyramidal neurons optogenetically while the electroencephalogram, electromyogram, and cerebral lactate concentration are monitored. Experimental recordings are performed on cable-tethered mice while they undergo spontaneous sleep/wake cycles. Optogenetic equipment is assembled in our laboratory; recording equipment is commercially available.

Gleichzeitige Elektroenzephalographie, Real-time Messung der Laktat-Konzentration und optogenetische Manipulation der neuronalen Aktivität in der Nagetier Cerebral Cortex

Although the brain represents less than 5% of the body  by mass, it utilizes approximately one quarter of the glucose used by the body  at rest1. The ...

Fast Micro-iontophoresis of Glutamate and GABA: A Useful Tool to Investigate Synaptic Integration

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of the dendritic tree, which eventually leads to neuronal output of action potentials at the axon. The influence of diverse spatial and temporal parameters of specific synaptic input on neuronal output is currently under investigation, e.g. the distance-dependent attenuation of dendritic inputs, the location-dependent interaction of spatially segregated inputs, the influence of GABAergig inhibition on excitatory integration, linear and non-linear integration modes, and many more.
With fast micro-iontophoresis of glutamate and GABA it is possible to precisely investigate the spatial and temporal integration of glutamatergic excitation and GABAergic inhibition. Critical technical requirements are either a triggered fluorescent lamp, light-emitting diode (LED), or a two-photon scanning microscope to visualize dendritic branches without introducing significant photo-damage of the tissue. Furthermore, it is very important to have a micro-iontophoresis amplifier that allows for fast capacitance compensation of high resistance pipettes. Another crucial point is that no transmitter is involuntarily released by the pipette during the experiment.
Once established, this technique will give reliable and reproducible signals with a high neurotransmitter and location specificity. Compared to glutamate and GABA uncaging, fast iontophoresis allows using both transmitters at the same time but at very distant locations without limitation to the field of view. There are also advantages compared to focal electrical stimulation of axons: with micro-iontophoresis the location of the input site is definitely known and it is sure that only the neurotransmitter of interest is released. However it has to be considered that with micro-iontophoresis only the postsynapse is activated and presynaptic aspects of neurotransmitter release are not resolved. In this article we demonstrate how to set up micro-iontophoresis in brain slice experiments.

In this article we introduce fast micro-iontophoresis of neurotransmitters as a technique to investigate integration of postsynaptic signals with high spatial and temporal precision.

Schnelle Micro-Iontophorese von Glutamat und GABA: Ein nützliches Tool, um Synaptic Integration Untersuchen

One of the fundamental interests in neuroscience is to understand the integration of excitatory and inhibitory inputs along the very complex structure of ...

Sex Stratified Neuronal Cultures to Study Ischemic Cell Death Pathways

Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms responsible for those differences remain unclear. Primary disassociated embryonic neuronal culture provides a simplified experimental model with which to investigate the neuronal cell signaling involved in cell death as a result of ischemia or disease; however, most neuronal cultures used in research today are mixed sex. Researchers can and do test the effects of sex steroid treatment in mixed sex neuronal cultures in models of neuronal injury and disease, but accumulating evidence suggests that the female brain responds to androgens, estrogens, and progesterone differently than the male brain. Furthermore, neonate male and female rodents respond differently to ischemic injury, with males experiencing greater injury following cerebral ischemia than females. Thus, mixed sex neuronal cultures might obscure and confound the experimental results; important information might be missed. For this reason, the Herson Lab at the University of Colorado School of Medicine routinely prepares sex-stratified primary disassociated embryonic neuronal cultures from both hippocampus and cortex. Embryos are sexed before harvesting of brain tissue and male and female tissue are disassociated separately, plated separately, and maintained separately. Using this method, the Herson Lab has demonstrated a male-specific role for the ion channel TRPM2 in ischemic cell death. In this manuscript, we share and discuss our protocol for sexing embryonic mice and preparing sex-stratified hippocampal primary disassociated neuron cultures. This method can be adapted to prepare sex-stratified cortical cultures and the method for embryo sexing can be used in conjunction with other protocols for any study in which sex is thought to be an important determinant of outcome.

Primary disassociated embryonic hippocampal neuronal cultures are useful for investigating the signaling mechanisms involved in neuron death. Sexing the embryos before the isolation and dissociation of the hippocampus allows the preparation of separate male and female cultures, which enables the researcher to identify and investigate sex-specific cell signaling.

Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms ...

Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be stimulated by neuronally-released transmitter. However, the ability of astrocytic receptors to exhibit plasticity in response to changes in neuronal activity has received little attention. Here we describe a model system that can be used to globally scale up or down astrocytic group I metabotropic glutamate receptors (mGluRs) in acute brain slices. Included are methods on how to prepare parasagittal hippocampal slices, construct chambers suitable for long-term slice incubation, bidirectionally manipulate neuronal action potential frequency, load astrocytes and astrocyte processes with fluorescent Ca2+ indicator, and measure changes in astrocytic Gq GPCR activity by recording spontaneous and evoked astrocyte Ca2+ events using confocal microscopy. In essence, a &#8220;calcium roadmap&#8221; is provided for how to measure plasticity of astrocytic Gq GPCRs. Applications of the technique for study of astrocytes are discussed. Having an understanding of how astrocytic receptor signaling is affected by changes in neuronal activity has important implications for both normal synaptic function as well as processes underlying neurological disorders and neurodegenerative disease.

Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity.

Induktion von Plastizität Astrozytäre Rezeptoren durch Manipulation der neuronalen Feuerraten

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be ...

Utilizing Combined Methodologies to Define the Role of Plasma Membrane Delivery During Axon Branching and Neuronal Morphogenesis

During neural development, growing axons extend to multiple synaptic partners by elaborating axonal branches. Axon branching is promoted by extracellular guidance cues like netrin-1 and results in dramatic increases to the surface area of the axonal plasma membrane. Netrin-1-dependent axon branching likely involves temporal and spatial control of plasma membrane expansion, the components of which are supplied through exocytic vesicle fusion. These fusion events are preceded by formation of SNARE complexes, comprising a v-SNARE, such as VAMP2 (vesicle-associated membrane protein 2), and plasma membrane t-SNAREs, syntaxin-1 and SNAP25 (synaptosomal-associated protein 25). Detailed herein isa multi-pronged approach used to examine the role of SNARE mediated exocytosis in axon branching. The strength of the combined approach is data acquisition at a range of spatial and temporal resolutions, spanning from the dynamics of single vesicle fusion events in individual neurons to SNARE complex formation and axon branching in populations of cultured neurons. This protocol takes advantage of established biochemical approaches to assay levels of endogenous SNARE complexes and Total Internal Reflection Fluorescence (TIRF) microscopy of cortical neurons expressing VAMP2 tagged with a pH-sensitive GFP (VAMP2-pHlourin) to identify netrin-1 dependent changes in exocytic activity in individual neurons. To elucidate the timing of netrin-1-dependent branching, time-lapse differential interference contrast (DIC) microscopy of single neurons over the order of hours is utilized. Fixed cell immunofluorescence paired with botulinum neurotoxins that cleave SNARE machinery and block exocytosis demonstrates that netrin-1 dependent axon branching requires SNARE-mediated exocytic activity.

Light microscopy techniques coupled with biochemical assays elucidate the involvement of SNARE-mediated exocytosis in netrin-dependent axon branching. This combination of techniques permits identification of molecular mechanisms controlling axon branching and cell shape change.

Kombinierte Methodiken Verwendung der Rolle der Plasmamembran Lieferung Während Axon Branching und Neuronale Morphogenese zu definieren

During neural development, growing axons extend to multiple synaptic partners by elaborating axonal branches. Axon branching is promoted by extracellular ...

Microglia as a Surrogate Biosensor to Determine Nanoparticle Neurotoxicity

Nanoparticles found in air pollutants can alter neurotransmitter profiles, increase neuroinflammation, and alter brain function. Therefore, the assay described here will aid in elucidating the role of microglia in neuroinflammation and neurodegenerative diseases. The use of microglia, resident immune cells of the brain, as a surrogate biosensor provides novel insight into how inflammatory responses mediate neuronal insults. Here, we utilize an immortalized murine microglial cell line, designated BV2, and describe a method for nanoparticle exposure using silver nanoparticles (AgNPs) as a standard. We describe how to expose microglia to nanoparticles, how to remove nanoparticles from supernatant, and how to use supernatant from activated microglia to determine toxicity, using hypothalamic cell survival as a measure. Following AgNP exposure, BV2 microglial activation was validated using a tumor necrosis factor alpha (TNF-&#945;) enzyme linked immunosorbent assay (ELISA). The supernatant was filtered to remove the AgNP and to allow cytokines and other secreted factors to remain in the conditioned media. Hypothalamic cells were then exposed to supernatant from AgNP activated microglia and survival of neurons was determined using a resazurin-based fluorescent assay. This technique is useful for utilizing microglia as a surrogate biomarker of neuroinflammation and determining the effect of neuroinflammation on other cell types.

Microglia (immune cells of the brain), are used as a surrogate biosensor to determine how nanoparticles influence neurotoxicity. We describe a series of experiments designed to assay microglial response to nanoparticles and exposure of hypothalamic neurons to supernatant from activated microglia to determine neurotoxicity.

Mikroglia als Surrogate Biosensor Nanoparticle Neurotoxicity zu ermitteln

Nanoparticles found in air pollutants can alter neurotransmitter profiles, increase neuroinflammation, and alter brain function. Therefore, the assay ...

In Utero Electroporation Approaches to Study the Excitability of Neuronal Subpopulations and Single-cell Connectivity

The nervous system is composed of an enormous range of distinct neuronal types. These neuronal subpopulations are characterized by, among other features, their distinct dendritic morphologies, their specific patterns of axonal connectivity, and their selective firing responses. The molecular and cellular mechanisms responsible for these aspects of differentiation during development are still poorly understood.
Here, we describe combined protocols for labeling and characterizing the structural connectivity and excitability of cortical neurons. Modification of the in utero electroporation (IUE) protocol allows the labeling of a sparse population of neurons. This, in turn, enables the identification and tracking of the dendrites and axons of individual neurons, the precise characterization of the laminar location of axonal projections, and morphometric analysis. IUE can also be used to investigate changes in the excitability of wild-type (WT) or genetically modified neurons by combining it with whole-cell recording from acute slices of electroporated brains. These two techniques contribute to a better understanding of the coupling of structural and functional connectivity and of the molecular mechanisms controlling neuronal diversity during development. These developmental processes have important implications on axonal wiring, the functional diversity of neurons, and the biology of cognitive disorders.

In Utero Electroporation Approaches to Study the Excitability of Neuronal Subpopulations and Single-cell Connectivity

This manuscript provides protocols that use in utero electroporation (IUE) to describe the structural connectivity of neurons at the single-cell level and the excitability of fluorescently labeled neurons. Histology is used to characterize dendritic and axonal projections. Whole-cell recording in acute slices is used to investigate excitability.

In Utero Ansätze Elektroporation die Erregbarkeit neuronaler Subpopulationen und Einzelzell - Konnektivität zu studieren

The nervous system is composed of an enormous range of distinct neuronal types. These neuronal subpopulations are characterized by, among other features, ...

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. ...