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 Preparazione <ol><li> Posizionare la stazione analizzatore cella in tempo reale di un incubatore di coltura tissutale a 37 ° C e con il 5% di CO 2. Effettuare tutte movimentazione coltura cellulare e trattamenti farmacologici in una cappa coltura tissutale in condizioni sterili. </li><li> NOTA: neuronale linee cellulari che richiedono diverse impostazioni di temperatura rispetto alle condizioni standard per la cultura, dovrebbero essere adeguati di conseguenza. Per le linee di cellule debolmente aderenti, usare agenti di rivestimento per facilitare l&#39;interazione delle cellule con i microelettrodi d&#39;oro nel fondo dei pozzetti della E-Plate 96. </li><li> Preparare soluzioni 1,000X azionari dei composti farmacologici per il trattamento delle colture cellulari (agenti neuroprotettivi o inibitori di seconda percorsi messaggero nel solvente appropriato - dimetilsolfossido o acqua sterile) e conservarli a -20 ° C. Utilizzare il solvente come veicolo per i seguenti trattamenti. </li><li> Cellule di neuroblastoma umano SK Cultura-N-SH in DMEM / F12 media integrato con 10% di siero fetale bovino (FBS) (media proliferazione) in fiasche di coltura cellulare con 175 centimetri 2 superficie densità di circa il 75%. Mantenere numero di cellulare di passaggio all&#39;interno di un intervallo (di circa 10 passaggi) per verificare la coerenza tra le esperienze in termini di tasso di proliferazione cellulare e la risposta alla citotossicità. Numeri passaggio più bassi sono preferiti. </li><li> Lavare lo strato di cellule SK-N-SH aderente con PBS, e trypsinize con soluzione di tripsina-EDTA 0,05% per 5 min a 37 ° C. Centrifugare le cellule a 170 × g per 5 minuti per rimuovere tripsina. Risospendere le cellule in 10 ml di mezzo proliferazione. Contare le cellule con contatore di cellule Scettro e regolare il numero di cellule a 300.000 cellule / ml diluendo cellule con terreno di proliferazione. </li></ol> 2 placcatura e la proliferazione delle cellule SK-N-SH <ol><li> Aggiungere 100 microlitri di media proliferazione a ciascun pozzetto della piastra E-96 e lasciarlo per 30 minuti nella cappa coltura tissutale a temperatura ambiente per equilibrare. Inserire la E-PlaTE 96 nella stazione analizzatore cella in tempo reale in CO 2 incubatore a 37 ° C. </li><li> Avviare il software analizzatore di cellule in tempo reale. Nella pagina di layout selezionare i pozzi inclusi nell&#39;esperimento ed entrano nelle caselle di modifica delle informazioni sul tipo di cellule, numero di cellulare, i nomi e le concentrazioni di composti chimici utilizzati per il trattamento delle cellule. NOTA: Ai fini del presente protocollo almeno 4 repliche sono raccomandati per ogni trattamento. </li><li> Nella pagina software Pianificazione determinare &quot;Steps&quot; inclusi nell&#39;esperimento, selezionando il numero di passate cella di misura Index e l&#39;intervallo fra le passate per ogni passo. Dal Passo 1 è predeterminato per la misurazione di sfondo, selezionare &quot;Aggiungi un passo&quot; e impostare Fase 2 per misurare l&#39;Indice cellulare ogni 15 minuti per 96 ore. NOTA: Per i trattamenti, in cui sono attesi effetti con cinetica rapida, impostare scansioni ad intervalli più brevi. </li><li> Fare clic su Start per avviare la Fase predeterminata automaticamente 1e misurare l&#39;impedenza dei mezzi di sfondo. Questo valore viene sottratto automaticamente dal software in ciascun punto di dati una volta che le cellule vengono aggiunti ai pozzetti. </li><li> Utilizzare il preparato in precedenza al punto 1.5) sospensione cellulare di 300.000 cellule / ml nel terreno di proliferazione. 30.000 cellule / pozzetto per tossicità cellulare / studi di neuroprotezione e 15.000 cellule / pozzetto per gli studi di proliferazione cellulare. Estrarre la E-piastra e aggiungere 100 microlitri di sospensione cellulare per bene per tossicità delle cellule / studi di neuroprotezione e aggiungere sospensione cellulare 50 ml e 50 ml di media per la proliferazione e per gli studi di proliferazione cellulare. Il numero di cellule piastrate per pozzetto deve essere ottimizzato per ciascuna linea cellulare empiricamente. </li><li> Agitare delicatamente la E-Plate 96 anche per la placcatura delle cellule. Lasciare la E-piastra 96 ​​per 30 min nella cappa coltura tissutale a temperatura ambiente per permettere alle cellule depositano uniformemente sul fondo dei pozzetti. </li><li> Inserire la E-Plate 96 nella stazione di analizzatore di cellule in tempo reale e iniziare a passo 2 a Schedule petà. Monitorare i valori dell&#39;Indice cellulare in tutto l&#39;esperimento visualizzando le curve cellulari sulla pagina Plot ed i dati grezzi dell&#39;Indice cellulare sull&#39;Indice di pagina cella del software. </li></ol> 3 Siero Privazione <ol><li> 24 ore dopo la placcatura le cellule, mettere in pausa l&#39;esperimento, e rimuovere la E-Plate 96 dalla stazione di analizzatore di cellule in tempo reale. Diluire inibitori secondi messaggeri provenienti dalle scorte 1,000X con / F12 terreno privo di siero DMEM - a 200 × la concentrazione finale. Trattare le cellule con 1 ml inibitori di seconde vie Messenger per essere testati per il loro coinvolgimento in neurotossicità / neuroprotezione 30 minuti prima di iniziare la citotossicità, per inibire i rispettivi percorsi. Riportare la E-piastra 96 ​​alla stazione e riprendere le misure sperimentali Indice cellulare. </li><li> Dopo 30 min di pausa di nuovo l&#39;esperimento. Rimuovere con cautela medio proliferazione completamente da E-Piastra a 96 pozzetti con una pipetta (o pipetta multicanale), facendo attenzione a non disturbare lo strato di cellule aderentidirigendo il bordo della punta della pipetta all&#39;angolo del pozzo. Aggiungere 200 ml / pozzetto di DMEM privo di siero / F12 (siero medio privazione). Garantire scambio rapido di mezzo di coltura cellulare per minimizzare agitazione meccanica delle cellule. </li><li> Diluire composti da testare per i loro effetti neuroprotettivi di 1,000X magazzino con serum-free DMEM / F12 medio 200 × la concentrazione finale. Aggiungere 1 microlitri composti da testare per i loro effetti neuroprotettivi e 1 ml inibitori di secondi messaggeri percorsi nei singoli pozzetti secondo il piano sperimentale. </li><li> Nelle cellule per studi di proliferazione non cambiare mezzo. Diluire composti da testare da 1,000X magazzino a 200 × la concentrazione finale nel medio proliferazione, il trattamento con 1 ml per pozzetto e continuare a cultura medio proliferazione. </li><li> Riprendere l&#39;esperimento per continuare con cellulare Indice misurazioni ogni 15 minuti per 96 ore come precedentemente impostato. </li></ol> 4 Dati AANALISI <ol><li> Per neurotossicità / dati neuroprotezione normalizzare cellulare Index per l&#39;ultimo punto prima del trattamento farmacologico o medio modifica a ridurre le variazioni tra esperimenti selezionando &quot;normalizzato Indice Cell&quot; e &quot;normalizzare Time&quot; sulla pagina Plot. </li><li> Evidenziare i pozzi nella pagina della trama per le condizioni sperimentali di interesse e cliccare su &quot;Aggiungi&quot; per tracciare le curve normalizzate Indice cellulare. Osservare la cinetica di effetto neurotossico / neuroprotettivo, o di seconda messaggeri inibizione come curve normalizzate Index cellulare in funzione del tempo. </li><li> Osservare le curve Indice cellulare per i trattamenti farmacologici testati in media la proliferazione in funzione del tempo per valutare se un effetto sulla proliferazione è coinvolta nell&#39;effetto neuroprotettivo / neurotossico. </li><li> Esportare le informazioni sperimentale per tutti i punti di cellulare temporali Indice dalla pagina del software Indice cellulare in un file di Excel per avviare la valutazione statistica dei risultati <br/&gt; NOTA: Come primo passo nell&#39;analisi statistica di una serie di programmi MATLAB modificati che utilizzano t-test di Welch, con il p-value tracciato semilogarithmically, utilizzare l&#39;asse invertito contro la scala del tempo (fornito come file di codice supplementari). Questi programmi consentono il rilevamento dei valori p nel tempo-corso di un intero esperimento analizzatore cella in tempo reale, e quindi facilitare la selezione dei punti di tempo per l&#39;analisi statistica più dettagliata. Vedere il materiale supplementare per informazioni dettagliate sui programmi. </li><li> Per l&#39;analisi statistica delle differenze di cella Valori indice sotto diverse condizioni di trattamento in punti temporali specifici, selezionare i valori dell&#39;Indice cellulare a rispettivi punti di tempo dal file Excel esportato. Analizzare i valori dell&#39;Indice cellulare per i punti di tempo selezionati con unidirezionale o bidirezionale analisi della varianza (ANOVA) seguita da un test post-hoc utilizzando il software statistico. </li></ol>

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	<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>

Spese di pubblicazione per i video articolo sono stati sponsorizzati da &quot;ACEA Biosciences&quot;.

Il protocollo attuale presenta l&#39;utilità di un analizzatore di cellule in tempo reale per valutare in modo continuo e in condizioni di libera-label / gli effetti neurotossici neuroprotettivi dei composti in linee cellulari neuronali e al fine di conoscere le seconde vie messaggeri coinvolti nell&#39;effetto. Anche se l&#39;utilità analizzatore di cellule in tempo reale di studiare la citotossicità e gli effetti dei farmaci sulla proliferazione cellulare è generalmente riconosciuto, s...

Morte cellulare neuronale svolge un ruolo critico nella fisiopatologia di molti disturbi cerebrali correlati 1. La disponibilità di throughput elevato e affidabile nelle prove di tossicità in vitro è fondamentale per ottenere una migliore comprensione dei meccanismi di neurotossicità e per contribuire a selezionare le molecole neuroprotettive come candidati terapeutici in sviluppo dei farmaci 2. Tuttavia, ci sono molte limitazioni per più utilizzato in vitro neurotossicità assays.They valutare neurotossicità / neuroprotezione in una sola volta punto di non consentire la risoluzione cinetica; spesso utilizzare l&#39;etichetta o la sonda che può interferire con le vie di segnalazione e limitare ulteriori studi nella stessa popolazione di cellule, e sono spesso ad alta intensità di manodopera, e in molti casi non forniscono informazioni meccanicistica. Nel presente studio abbiamo dimostrato l&#39;utilità di un analizzatore di cellule di impedenza-based in tempo reale per determinare neurotossicità e neuroprotezione in una linea cellulare neuronale in tempo reale e sotto libero-labelcondizioni e forniscono informazioni sui meccanismi a valle attraverso l&#39;analisi delle seconde vie messaggeri coinvolti nell&#39;effetto. Precedenti studi hanno confermato la validità dell&#39;analizzatore cella in tempo reale per determinare la citotossicità nonché effetti sulla proliferazione cellulare in linee cellulari in confronto con tecniche standard 3,4,5,6. Ad esempio, una buona correlazione è stata osservata tra le letture della norma vitalità cellulare WST-1 test e cellulari valori dell&#39;Indice in diversi punti del tempo in condizioni di proliferazione basali e dopo due diversi paradigmi tossici nelle cellule HeLa 3. In A549 e MDA-MB-231 cellule proliferazione e citotossicità provocato con il paclitaxel stabilizzatore microtubuli hanno mostrato valori molto simili quando valutati da misurazioni dell&#39;indice cellulare e il modo standard utilizzato solforodamina B (SRB) test 4. Nella linea cellulare neuronale dei neuroni dell&#39;ippocampo immortalati HT-22 cellule Indice misurazioni sono stati convalidati per la loro capacità to rilevare la proliferazione cellulare, glutammato citotossicità e citoprotezione contro il diffuso 3 (4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium-bromuro (MTT) 5. Nello stesso studio i risultati del test MTT e misurazioni Indice cellulare anche correlati bene in misura neuronale cellule progenitrici proliferazione, citotossicità dopo fattori di crescita deprivazione e salvataggio di citotossicità dal pan-caspasi inibitore QVD 5. Citotossicità indotta in cellule NIH 3T3 da Vandetanib (vascular endothelial growth factor recettore e inibitore del recettore del fattore di crescita epidermico) ha mostrato risultati simili misurati con i valori dell&#39;Indice cellulare o neutro saggio di uptake rosso 6. Abbiamo recentemente usato il sistema analizzatore di cellule in tempo reale per valutare gli effetti neuroprotettivi della 2A della serotonina (5-HT 2A) agonista del recettore cloridrato (±) -2,5-dimetossi-4-iodoamphetamine (DOI) in una linea cellulare neuronale ( cellule SK-N-SH) e screening per il coinvolgimento di second percorsi Messenger tramite il monitoraggio dell&#39;effetto della loro inibizione chimica sulla neuroprotezione osservata 7. È interessante notare che il recettore 5-HT 2A ha agonisti sia allucinogeni e nonhallucinogenic (come il DOI e lisuride, rispettivamente), che possono attivare sia secondo percorsi comuni e distinte Messenger 8. I vantaggi della tecnica sono presentati che permette di raccogliere informazioni in tempo reale sulla sopravvivenza cellulare nel corso dei giorni, per delineare percorsi di secondo messaggero coinvolti, per valutare il possibile contributo degli effetti proliferazione a neuroprotezione, e per selezionare un tempo ottimale per ulteriori studi end-point sulla stessa popolazione cellulare. Un diagramma schematico del flusso di lavoro nel protocollo attuale è presentato in figura 1.

<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

Molti disturbi cerebrali connesse sono morte delle cellule neuronali coinvolti nella loro fisiopatologia. Migliorata in modelli in vitro per studiare gli effetti neuroprotettivi o neurotossici di farmaci e vie a valle coinvolti aiuterebbe ottenere informazioni sui meccanismi molecolari di neuroprotezione / neurotossicità e potrebbe potenzialmente facilitare lo sviluppo di farmaci. Tuttavia, molti saggi di tossicità esistenti in vitro hanno importanti limitazioni - più valutare neurotossicità e neuroprotezione in un unico punto di tempo, non permettendo di osservare il tempo-corso e cinetica dell&#39;effetto. Inoltre, la possibilità di raccogliere informazioni sulle vie di segnalazione a valle coinvolti nella neuroprotezione in tempo reale sarebbe di grande importanza. Nel protocollo corrente viene descritto l&#39;uso di un analizzatore di cellule di impedenza-based in tempo reale per determinare gli effetti neuroprotettivi di serotonina 2A (5-HT 2A) agonisti dei recettori in una linea cellulare neuronale sotto senza etichetta e in tempo reale Conditioni che utilizzano misure di impedenza. Inoltre, abbiamo dimostrato che gli inibitori di secondi messaggeri percorsi possono essere usate per delineare molecole a valle che l&#39;effetto neuroprotettivo. Noi descriviamo anche l&#39;utilità di questa tecnica per determinare se un effetto sulla proliferazione cellulare contribuisce ad un effetto neuroprotettivo osservato. Il sistema utilizza piastre microelettronici speciali denominati E-tavole che contengono alternati matrici di microelettrodi d&#39;oro sulla superficie inferiore dei pozzetti, che servono come sensori cellulari. La lettura impedenza viene modificato dal numero delle cellule aderenti, la vitalità cellulare, morfologia e adesione. Un parametro adimensionale chiamato cella indice è derivato dalle misure di impedenza elettrica e viene utilizzato per rappresentare lo stato delle cellule. Nel complesso, l&#39;analizzatore di cellule di impedenza-based in tempo reale permette in tempo reale, la valutazione libero-label di neuroprotezione e neurotossicità, e la valutazione dei percorsi di coinvolgimento secondo messaggero, contribuendo a piùvalutazione dettagliata e high-throughput di potenziali composti neuroprotettivi in vitro, per la selezione dei candidati terapeutici.

<html> Deprivazione di siero porta a diminuire in cella i valori dell&#39;Indice, che possono essere monitorati continuamente con l&#39;analizzatore di cellule in tempo reale Stimoli neurotossici verso le cellule portano ad una diminuzione della cella i valori dell&#39;Indice, che può essere monitorato in tempo reale con la tecnica presentata e la cui dinamica dipende dallo stimolo neurotossico specifica e il tipo di cella studiata. Figura 2 illustra l&#39;a...

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.

Cell Analyzer a base di impedenza in tempo reale come strumento per delineare molecolari meccanismi coinvolti nella neurotossicità e neuroprotezione in una linea cellulare neuronale

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 Views.  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.

Video: 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.

Analisi automatizzata Sholl di Digitized morfologia neuronale a scale multiple

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

Ricerca

Neuroscienze

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.

Derivazione efficiente di progenitori neuronali umane e Neuroni pluripotenti da cellule staminali embrionali umane con induzione piccole molecole

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.

Elettroencefalografia simultanea, in tempo reale misura della concentrazione di lattato e la manipolazione Optogenetic di attività neuronale nella corteccia cerebrale Rodentia

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.

Veloce micro-ionoforesi di glutammato e GABA: un utile strumento per indagare l&#39;integrazione Synaptic

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.

Indurre Plasticità di astrociti recettori per manipolazione del neuronali di cottura Prezzi

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.

Utilizzando metodologie combinati per definire il ruolo della membrana plasmatica di consegna Durante Axon ramificazione e neuronale morfogenesi

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.

Microglia come un biosensore surrogato per determinare nanoparticelle neurotossicità

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.

Elettroporazione in utero approcci per studiare l&#39;eccitabilità neuronale sottopopolazioni e connettività single-cell

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.

Colture Hippocampal Fetta organotipiche come modello di studio Neuroprotection e l'invasività delle cellule del tumore

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