Questo lavoro è stato sostenuto dal National Institutes of Health di Grant NS-024572 (da RSW).

1. Colorare la preparazione con sopravitale Coloranti <ol><li> Per il protocollo dissezione serpente giarrettiera vedere Stewart et al. 5 e Teng et al. 6 tessuto Reptilian resta fisiologica per tempi più lunghi, e con meno contaminazione batterica, conservato a basse temperature (vedi sotto). Tessuti di mammiferi, di solito è mantenuta a temperatura ambiente o superiore. </li><li> Per lisosomiale colorante vitale colorazione, sciogliere il colorante in rettili freddi 1:5.000 soluzione Ringers (0,2 micron). Incubare a 4 ° C per 15 min. Lavare più volte con Ringers freddi. Immagine appena possibile. </li><li> Per FM1-43 colorazione utilizzando la stimolazione KCl, diluire il colorante in alto KCl Ringers 1:500 (7 micron). Incubare a 4 ° C per 30-60 sec massimo. Lavare rapidamente tre volte con Ringers fredde, ~ 1 min / risciacquo. Immagine appena possibile. </li><li> Per FM1-43 colorazione utilizzando la stimolazione ipertonica (saccarosio), diluire il colorante in 0,5 M Ringers saccarosio come sopra. Incubare a 4 &amp; #176, C per 2-5 min. Lavare come al punto 1.3 con Ringers freddi. Immagine appena possibile. </li><li> Per FM1-43 colorazione tramite stimolazione elettrica, vedere Teng et al. 6 Brevemente, la preparazione è posto un recipiente contenente soluzione salina fisiologica e il colorante. Il nervo viene stimolato con un treno programmato di 200 msec impulsi rettangolari (~ 7 V, 30 Hz, 18 msec). Lavare come al punto 1.3 con Ringers freddi. Immagine appena possibile. </li></ol> 2. Configurare la preparazione di Imaging <ol><li> Orientare la preparazione in modo che le strutture di interesse siano il più vicino possibile all&#39;obiettivo microscopio. </li><li> Se viene utilizzato un microscopio invertito, utilizzare una camera il cui fondo contiene un sottile giro copertura di slittamento. Tipicamente, la camera di imaging dovrebbe avere un fondo sottile in acciaio inossidabile con un diametro # 1 vetro spessore copertura antiscivolo 25 mm a centro. Se viene utilizzato un microscopio verticale, un coprioggetto inferiore non è necessaria ma è utileper consentire di imaging con luce trasmessa (ad esempio il contrasto di interferenza differenziale, DIC) per orientare il campione e localizzare oggetti di interesse. </li><li> Scegliere un obiettivo appropriato per ottenere la massima risoluzione 3D possibile. Ci sono dei compromessi tra apertura numerica (na), distanza di funzionamento, l&#39;ingrandimento e il tipo di lente (a secco, ad immersione in olio-acqua). Per i preparati sottili come colture di tessuti, gli obiettivi del petrolio sono i migliori. Utilizzando un microscopio verticale, mobile un vetrino sul bagno acquoso, e utilizzare olio per immersione tra la parte superiore del vetrino e l&#39;obiettivo. </li><li> Se si utilizza il software di deconvoluzione, il venditore potrebbe fornire funzioni di punto di spread predeterminati (PSF) per determinati obiettivi. Se tale informazione è fornita, o se si sceglie un obiettivo non supportato determinare il PSF da imaging di micropunti fluorescenti o oggetti di diffrazione limitata analoghi 7,8. </li></ol> 3. Stabilire la profondità di campo desiderata e numero di Images desiderati per Time-lapse con cornice <ol><li> Selezionare la profondità totale del campo in modo che lo spostamento o interagendo strutture di interesse non scompaiono o andare fuori fuoco, come si muovono nella direzione z. La z-campo dovrebbe superare leggermente la dimensione verticale del processo cellulare o la cellula viene esposta. Per i terminali del motore vertebrati, 15-20 micron è tipico. </li><li> Calcolare il passo asse z necessaria per ogni incremento di messa a fuoco. Risoluzione lungo l&#39;asse z varia a seconda proprietà del obiettivo; è circa un quarto della risoluzione piano xy. Se viene utilizzato sia confocale o software di deconvoluzione, risoluzione z è migliorata. Migliorare la risoluzione finale oversampling deliberata nella direzione z 5, ma si veda anche passo 3.3. Un intervallo tipico passo è nell&#39;intervallo da 400-1,500 nm per obiettivi 40-100X. Luce dovrebbe essere coperto off tra ogni immagine z-step. </li><li> Selezionare il numero di immagini per z-stack, cioè la profondità di campo desiderata divisodall&#39;intervallo passo. Tempo per completare una tipica z-stack è 1-10 sec. Oggetti in rapido movimento (100 nm / sec) possono apparire sfocata in una pila di immagini 3D perché ogni piano dell&#39;immagine corrisponde ad un punto temporale leggermente diverso. Inoltre, ogni immagine aggiuntiva contribuisce al photobleaching e fototossicità possibile (vedi discussione). Se una situazione riguarda, sceglierebbe una più grande z-passo per raccogliere un minor numero di immagini per stack. Compensare successivamente utilizzando il software di interpolazione dell&#39;immagine (fase 6.3). </li></ol> 4. Selezionare il Frame Rate Time-lapse Scegli sperimentazione un tasso che è appena sufficiente per risolvere agevolmente cambia con il tempo come il movimento, interazioni o eventi di fusione 9. Sotto il campionamento può produrre artefatti da movimento (errori di campionamento), mentre sovracampionamento aumenta inutilmente l&#39;esposizione alla luce. Raccogliere una singola sequenza lunga o più sequenze ripetute della stessa preparazione, ciascuno con un intervallo relativamente piccolo tempo totale ( <em&gt; eg 10 punti temporali x 30 sec intervallo = 5 min). Se possibile, vista la preparazione con la continua illuminazione epifluorescenza a circa stima velocità del movimento, tra cui deriva l&#39;intera preparazione, se presente. 5. Completa tutte le immagini dal vivo per una preparazione particolare Preparazioni Rettiliani in genere rimangono robusto per ~ 1-2 ore, più a lungo se raffreddato. 6. Analizzare i dati in base all&#39;uso desiderato <ol><li> Conservare tutti i file di dati grezzi. Mentre memorizzazione digitale di solito non è un problema, tempo di elaborazione è significativo anche con personal computer o workstation veloci. Per questo motivo, ritagliare le immagini in una regione di interesse [ROI]. Assicurare che l&#39;intera regione di interesse nella finestra ritagliata durante l&#39;intero corso del tempo. </li><li> Deconvolve immagine pile utilizzando il software appropriato e la funzione di punto di diffusione corretta. Verificare che la risoluzione è migliorata e che nessun manufatto è stato generato dallaalgoritmo di deconvoluzione. Figura 3 mostra immagini di esempio. </li><li> Utilizzare un algoritmo di interpolazione per espandere z risoluzione apparente. Un&#39;espansione 6X da un immagine reale di 1,5 micron piano di separazione di un apparente separazione 0,25 micron è suggerito. In alternativa, utilizzare una combinazione di sovracampionamento (punto 3.2) e l&#39;interpolazione. </li><li> Eseguire il contrasto, la luminosità, il filtraggio del rumore, fotoscolorimento e altre regolazioni tipiche di elaborazione delle immagini, se lo desideri. Norme di manipolazione della fotografia impongono che per la maggior parte lavoro scientifico, è opportuno che le stesse correzioni da applicare a tutte le immagini, sia all&#39;interno di uno stack e in diversi momenti. La conseguenza di una rettifica specifica dovrebbe essere valutata fra tutte le immagini 9. </li><li> Selezionare una modalità di visualizzazione particolare per l&#39;esportazione dei dati. Il display più semplice è video stereo utilizzando sia anaglifi rosso-verde o rosso-blu (esempi in figura 3), coppie stereo, o alternando sinistra / right occhio fotogrammi con occhiali. Anaglifi sono limitati a un solo colore. Migliorare la profondità dell&#39;immagine evidente se lo si desidera migliorare z risoluzione visiva. </li><li> Esperimento con varie filtraggio e di immagine tecniche di miglioramento. Ad esempio, il filtro laplaciano è utile per aumentare il contrasto di piccole strutture sopra sfondo. La luminosità del pixel al centro di una finestra di esecuzione è migliorata mentre la luminosità delle zone circostanti è ridotto. Nota che alcuni metodi di filtraggio non funzionano bene in combinazione. </li><li> Applicare correzione della deriva se vi è sostanziale movimento della preparazione nel tempo. Tale movimento è comune nel muscolo vivente, anche con farmaci aggiunti per sopprimere potenziali d&#39;azione e potenziali sinaptici. Un algoritmo di registrazione pixel (ad es. Imaris, Adobe AfterEffects, plug TurboReg per ImageJ) allinea le immagini time-lapse e può ridurre, ma di solito non eliminare completamente, tale movimento. </li></ol>

<ol>
	<li>Frigault, M. M., Lacoste, J., Swift, J. L., Brown, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live-cell+microscopy-tips+and+tools.">Live-cell microscopy-tips and tools.</a> J. Cell Sci. 122 (6), 753-767 (2009).</li><li>Tinevez, J. -. Y., 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+quantitative+method+for+measuring+phototoxicity+of+a+live+cell+imaging+microscope.">A quantitative method for measuring phototoxicity of a live cell imaging microscope.</a> Meth. Enzymol. 506, 291-309 (2012).</li><li>Dunn, K. W., Kamocka, M. M., McDonald, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+practical+guide+to+evaluating+colocalization+in+biological+microscopy.">A practical guide to evaluating colocalization in biological microscopy.</a> Am. J. Physiol. Cell Physiol. 300, (2011).</li><li>Snapp, E. L., Hegde, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rational+design+and+evaluation+of+FRETexperiments+to+measure+proteinproximities+in+cells.">Rational design and evaluation of FRETexperiments to measure proteinproximities in cells.</a> Curr. Protoc. Cell Biol. 17, (2006).</li><li>Stewart, R. S., Teng, H., Wilkinson, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Late"+macroendosomes+and+acidic+endosomes+in+vertebrate+motor+nerve+terminals.">Late" macroendosomes and acidic endosomes in vertebrate motor nerve terminals.</a> J. Comp. Neurol. 520, 4275-4293 (2012).</li><li>Teng, H., Lin, M. Y., Wilkinson, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Macroendocytosis+and+endosome+processing+in+snake+motor+boutons.">Macroendocytosis and endosome processing in snake motor boutons.</a> J. Physiol. 582, 243-262 (2007).</li><li>McNally, J. G., Karpova, T., Cooper, J., Conchello, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+imaging+by+deconvolution+microscopy.">Three-dimensional imaging by deconvolution microscopy.</a> Methods. 19, 373-385 (1999).</li><li>Swedlow, J. R., Platani, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+cell+imaging+using+wide-field+microscopy+and+deconvolution.">Live cell imaging using wide-field microscopy and deconvolution.</a> Cell Struct. Funct. 27, 335-341 (2002).</li><li>Cromey, D. W., Taatjes, D. J., Roth, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Digital+images+are+data:+and+should+be+treated+as+such.">Digital images are data: and should be treated as such.</a> Methods Mol. Biol. 931, 1-27 (2013).</li><li>Teng, H., Wilkinson, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clathrin-mediated+endocytosis+near+active+zones+in+snake+motor+terminals.">Clathrin-mediated endocytosis near active zones in snake motor terminals.</a> J. Neurosci. 20 (21), 7986-7993 (2000).</li><li>Teng, H., Cole, J. C., Roberts, R. L., Wilkinson, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endocytic+active+zones:+hot+spots+for+endocytosis+in+vertebrate+nerve+terminals.">Endocytic active zones: hot spots for endocytosis in vertebrate nerve terminals.</a> J. Neurosci. 19 (12), 4855-4866 (1999).</li><li>Tan, T. T. T., Khaw, C., Ng, M. M. L., Mendez-Vilas, A., Diaz, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Challenges+and+recent+advances+in+live+cell+bioimaging.">Challenges and recent advances in live cell bioimaging.</a> Microscopy: Science, Technology, Applications and Education. , 1495-1505 (2010).</li><li>Verbrugghe, K. J. C., Chan, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+C.+elegans+embryos+using+an+epifluorescent+microscope+and+open+source+software.">Imaging C. elegans embryos using an epifluorescent microscope and open source software.</a> J. Vis. Exp. (49), (2011).</li></ol>

Gli autori dichiarano interessi finanziari concorrenti.

L&#39;aspetto più critico dell&#39;imaging 4D è la gestione della durata e intensità di esposizione alla luce. Fotoscolorimento diminuisce immagine rapporto segnale-rumore e può essere problematico o meno a seconda di vari fattori, tra cui la scelta di fluorofori. Danni aspecifica di tessuto vivente (fototossicità) è legato alla photobleaching, e talvolta può essere identificato utilizzando sonde fluorescenti progettati per lo scopo 2,12 o di un esame della morfologia con opportune ottiche chiaro, come...

Time-lapse imaging di tessuto vivente fornisce l&#39;accesso visivo dinamici relazioni struttura-funzione che non può essere apprezzato in preparazioni fissi o che vivono impressi in un unico punto nel tempo. Spesso, tuttavia, il compromesso per l&#39;accesso alle informazioni temporali è una diminuzione della risoluzione ottica. Obiettivi ad immersione in olio ad alta apertura numerica sono impraticabili nel tessuto vivo a causa della loro ristretta gamma di messa a fuoco, lasciando immersione in acqua o obiettivi a secco come le uniche alternative. Inoltre, la maggiore risoluzione ottenibile con ottica confocale non può essere utilizzato in alcune preparazioni vivere a causa della fototossicità dai livelli relativamente alti di illuminazione richiesti 1,2. Infine, mentre diverse real-time o time-lapse tecniche ottiche sono disponibili che offrono una maggiore risoluzione, la loro applicabilità è limitata a preparazioni in cui le strutture di interesse possono essere posizionati a poche centinaia di nanometri dell&#39;obiettivo 1. Il metodo descritto, a strumenti relativamente a basso costo, è versatile, ma offre una migliore risoluzione rispetto alle tecniche time lapse più comunemente usati. Esso è destinato all&#39;uso nei laboratori individuali nonché strutture di imaging. Il metodo utilizza epifluorescenza convenzionale, combinato con una fotocamera digitale sensibile e con hardware progettato per acquisire rapidamente gruppi di immagini a leggermente differenti piani focali (Z-stack). Ogni z-stack è digitalmente deconvolved per aumentare la risoluzione. Una caratteristica del 3D time-lapse (4D) imaging è tracciamento preciso di organelli o altre strutture in movimento. Se correttamente impostato, strutture impressi non vanno fuori fuoco, e il movimento in tutte e tre le direzioni possono essere osservati e quantificati. Così è impossibile per una struttura macchiato eliminata nell&#39;arco di uno o più frame time lapse semplicemente alla deriva sopra o al di sotto di un piano focale stretta. Il metodo serve anche come strumento sensibile per valutare le interazioni e possibile fusione di piccole strutture. Epifluorescenza convenzionale o immagini confocali di strutture in prossimità del limite di diffrazione (a poche centinaia di nm) non confermano la fusione anche se le immagini mostrano unite sovrapposizione delle rispettive etichette 3. Fusion è suggerito, ma rimane la possibilità che gli oggetti sono separati orizzontalmente o verticalmente da una distanza che è inferiore al limite di diffrazione. Tre o immagini quadridimensionale, al contrario, consente la visualizzazione degli oggetti in ciascuna delle tre direzioni ortogonali. L&#39;aspetto della fusione in tutte e tre le viste aumenta il livello di certezza. E, in alcune preparazioni viventi, diretto o moto browniano di oggetti ipoteticamente fuse fornisce un&#39;ulteriore prova quando entrambi i marchi si muovono insieme nel tempo. Naturalmente, quando in prossimità del limite di diffrazione il livello di certezza in strutture esigenti da sfondo, o mostrando che esse contengono due coloranti (fusione), non è assoluto. Se, tecniche specializzate, ad esempio la risonanza di fluorescenza trasferimento di energia (FRET)4, sono più appropriato.

<table border="0" cellpadding="0" cellspacing="0" style="width:720px;" width="720">
	<colgroup>
		<col span="4" />
	</colgroup>
	<tbody>
		<tr height="41">
			<td height="41" style="height:42px;width:180px;">Name of Material/ Equipment</td>
			<td style="width:180px;">Company</td>
			<td style="width:180px;">Catalog Number</td>
			<td style="width:180px;">Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Reagents:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SGC5</td>
			<td>Biotium [Hayward, CA]</td>
			<td>70057</td>
			<td>Final conc:10 mM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FM1-43FX</td>
			<td>Invitrogen [Carlsbad, CA]</td>
			<td>F35335</td>
			<td>Final conc:7 mM</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">LysoTracker Red</td>
			<td>Invitrogen [Carlsbad, CA]</td>
			<td>L7528</td>
			<td>Final conc:0.2 mM</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Solutions:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Reptilian Ringers pH 7.2</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NaCl</td>
			<td>145 mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">KCl</td>
			<td>2.5&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">CaCl2</td>
			<td>3.6&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">MgSO4</td>
			<td>1.8&#160; mM</td>
			<td style="width:180px;"></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">KH2PO4 (Dibasic)</td>
			<td>1.0&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">HEPES</td>
			<td>5.0&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td colspan="2" height="20" style="height:21px;">High KCL Reptilian Ringers pH 7.2</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NaCl</td>
			<td>&#160;86&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">KCl</td>
			<td>&#160;60&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">CaCl2</td>
			<td>3.6&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">MgSO4</td>
			<td>1.8&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">KH2PO4 (Dibasic)</td>
			<td>1.0&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">HEPES</td>
			<td>5.0&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td colspan="2" height="20" style="height:21px;">High Sucrose Ringers pH 7.2</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">NaCl</td>
			<td>145 mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">KCl</td>
			<td>2. 5 mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">CaCl2</td>
			<td>3.6&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">MgSO4</td>
			<td>1.8&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;">KH2PO4 (Dibasic)</td>
			<td>1.0&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">HEPES</td>
			<td>5.0&#160; mM</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sucrose</td>
			<td>0.5 M (17.1 gm/50 mL)</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Equipment:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Name</td>
			<td>Company</td>
			<td>Comments</td>
			<td>Comments(website)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Axioplan 200 inverted microscope</td>
			<td colspan="2">Carl Zeiss [Thornwood, NY]</td>
			<td><a href="http://www.zeiss.com/">www.zeiss.com</a></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">N-Achroplan 63X water objective; n.a.=0.9; Working distance=2.4mm&#160;</td>
			<td colspan="2">Carl Zeiss [Thornwood, NY]</td>
			<td><a href="http://www.zeiss.com/">www.zeiss.com</a></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">DG4 combination light source/excitation filterwheel switcher</td>
			<td>Sutter instruments [Novato, CA]</td>
			<td>175W Xenon arc lamp</td>
			<td><a href="http://www.sutter.com/">www.sutter.com</a></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Lambda 10-2&#160; emission filterwheel switcher</td>
			<td colspan="2">Sutter instruments [Novato, CA]</td>
			<td><a href="http://www.sutter.com/">www.sutter.com</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sensicam CCD camera</td>
			<td colspan="2">Cooke Instruments [Tonawanda, NY]</td>
			<td><a href="http://www.cookecorp.com/">www.cookecorp.com</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cascade 512 CCD camera</td>
			<td colspan="2">Photometrics [Tucson, AZ]</td>
			<td><a href="http://www.photometrics.com/">www.photometrics.com</a></td>
		</tr>
		<tr height="20">
			<td colspan="4" height="20" style="height:20px;">Imaging dishes- made in-house-11cm dia.; 25 mm dia. #1 coverslip embedded; magnetic pins</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Software:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Name</td>
			<td>Company</td>
			<td>Comments</td>
			<td>Comments(website)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Slidebook 5.0</td>
			<td>Intelligent Imaging Innovations [Denver, CO]</td>
			<td>Deconvolution; Drift correction;3D and 4D data presentation</td>
			<td><a href="http://www.intelligent-imaging.com/">www.intelligent-imaging.com</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">IMARIS 7.5.2</td>
			<td>Bitplane [South Windsor, CT]</td>
			<td>Drift correction; 3D and 4D data presentation</td>
			<td><a href="http://www.bitplane.com/">www.bitplane.com</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">AfterEffects CS6</td>
			<td>Adobe [San Jose, CA]</td>
			<td>Drift correction</td>
			<td><a href="http://www.adobe.com/">www.adobe.com</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ImageJ 1.46</td>
			<td>National Institutes of Health [Bethesda, MD]</td>
			<td>Multiple plugins available;Stereo pair construction</td>
			<td><a href="http://rsbweb.nih.gov/ij">http://rsbweb.nih.gov/ij</a></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Zeiss LSM</td>
			<td>Carl Zeiss [Thornwood, NY]</td>
			<td>Stereo pair construction</td>
			<td><a href="http://www.zeiss.com/">www.zeiss.com</a></td>
		</tr>
	</tbody>
</table>

visualization of endosome dynamics in living nerve terminals with four-dimensional fluorescence imaging

Quadridimensionale (4D) immagini poco è stato utilizzato per studiare il comportamento di piccole strutture nel raggio di terminali dei nervi motori del sottile trasverso dell&#39;addome muscolo del serpente giarrettiera. I dati grezzi comprende sequenze time-lapse di 3D z-stack. Ogni stack contiene 4-20 immagini acquisite con ottica epifluorescenza a piani focali separati da 400-1,500 nm. Passi nella acquisizione di pile di immagini, quali la regolazione della messa a fuoco, la commutazione di lunghezze d&#39;onda di eccitazione, e il funzionamento della fotocamera digitale, sono automatizzate per quanto possibile per massimizzare la velocità di immagine e minimizzare danni ai tessuti da esposizione alla luce. Dopo l&#39;acquisizione, una serie di pile di immagini è deconvolved per migliorare la risoluzione spaziale, convertito nel formato 3D desiderato, e utilizzato per creare un &quot;film&quot; 4D che è adatto per diverse analisi basati su computer, a seconda dei dati sperimentali richiesti. Una applicazione è lo studio del comportamento dinamico di due classi di endosomi trovati in terminali nervosi-macroendosomes (MES)e endosomi acidi (AES)-le cui dimensioni (200-800 nm per entrambi i tipi) sono in prossimità o al limite di diffrazione. L&#39;accesso alle informazioni 3D in ogni tempo offre diversi vantaggi rispetto ai tradizionali time-lapse imaging. In particolare, le dimensioni e la velocità di movimento delle strutture possono essere quantificati nel tempo senza perdita di fuoco. Esempi di dati di immagini 4D rivelano che ME avvicinano alla membrana plasmatica e scompaiono, suggerendo che essi sono exocytosed piuttosto che semplicemente spostando verticalmente distanti un unico piano di messa a fuoco. Ha anche rivelato è la fusione putativo di ME e AES, attraverso la visualizzazione di sovrapposizione tra i due strutture colorante contenente come visto in ogni tre proiezioni ortogonali.

I dati riportati sono da terminali serpente neuromuscolari (vedi visite basse e alte ingrandimento nella figura 3, il colorante endocitica (FM1-43) assorbimento crea una nebbia che riempie ogni bouton) e, in particolare, macroendosomes (MES) e endosomi acidi (AES) all&#39;interno di questi terminali 5. ME sono creati da endocitosi massa durante l&#39;attività neuronale 10 e il loro numero declina esponenzialmente con il tempo dopo l&#39;attività è cessata 6. L&#39;uso...

Watch this Scientific Journal Video about Visualization of Endosome Dynamics in Living Nerve Terminals with Four-dimensional Fluorescence Imaging at JoVE.com

Visualization of Endosome Dynamics in Living Nerve Terminals with Four-dimensional Fluorescence Imaging

Quadridimensionale (4D) di imaging viene utilizzato per studiare il comportamento e le interazioni tra i due tipi di endosomi a vivere terminazioni nervose vertebrati. Movimento di queste piccole strutture è caratterizzata in tre dimensioni, permettendo conferma di eventi come endosomi fusione ed esocitosi.

Visualizzazione del endosome Dynamics in Vivere terminazioni nervose con quattro-dimensionale imaging di fluorescenza

Four-dimensional (4D) light imaging has been used to study behavior of small structures within motor nerve terminals of the thin transversus abdominis ...

visualization-endosome-dynamics-living-nerve-terminals-with-four

Research

JoVE Journal

Neuroscience

8.9K Views.  Washington University School of Medicine.  Quadridimensionale (4D) di imaging viene utilizzato per studiare il comportamento e le interazioni tra i due tipi di endosomi a vivere terminazioni nervose vertebrati. Movimento di queste piccole strutture è caratterizzata in tre dimensioni, permettendo conferma di eventi come endosomi fusione ed esocitosi. 

Video: Visualization of Endosome Dynamics in Living Nerve Terminals with Four-dimensional Fluorescence Imaging

Preparation of Living Isolated Vertebrate Photoreceptor Cells for Fluorescence Imaging

In the vertebrate retina, phototransduction, the conversion of light to an electrical signal, is carried out by the rod and cone photoreceptor cells1-4. Rod photoreceptors are responsible for vision in dim light, cones in bright light. Phototransduction takes place in the outer segment of the photoreceptor cell, a specialized compartment that contains a high concentration of visual pigment, the primary light detector. The visual pigment is composed of a chromophore, 11-cis retinal, attached to a protein, opsin. A photon absorbed by the visual pigment isomerizes the chromophore from 11-cis to all-trans. This photoisomerization brings about a conformational change in the visual pigment that 
initiates a cascade of reactions culminating in a change in membrane potential, and bringing about the transduction of the light stimulus to an electrical signal. The 
recovery of the cell from light stimulation involves the deactivation of the intermediates activated by light, and the reestablishment of the membrane potential. Ca2+ modulates the activity of several of the enzymes involved in phototransduction, and its concentration is reduced upon light stimulation. In this way, Ca2+ plays an important role in the recovery of the cell from light stimulation and its adaptation to background light.
Another essential part of the recovery process is the regeneration of the visual pigment that has been destroyed during light-detection by the 
photoisomerization of its 11-cis chromophore to all-trans5-7. This regeneration begins with the release of all-trans retinal by 
the photoactivated pigment, leaving behind the apo-protein opsin. The released all-trans retinal is rapidly reduced in a reaction utilizing NADPH to all-
trans retinol, and opsin combines with fresh 11-cis retinal brought into the outer segment to reform the visual pigment. All-trans retinol is 
then transferred out of the outer segment and into neighboring cells by the specialized carrier Interphotoreceptor Retinoid Binding Protein (IRBP).
Fluorescence imaging of single photoreceptor cells can be used to study their physiology and cell biology. Ca2+-sensitive fluorescent dyes can be used to examine in detail the interplay between outer 
segment Ca2+ changes and response to light8-12 as well as the role of inner segment Ca2+ stores in Ca2+ homeostasis13,14. 
Fluorescent dyes can also be used for measuring Mg2+ concentration15, pH, and as tracers of aqueous and membrane compartments16. 
Finally, the intrinsic fluorescence of all-trans retinol (vitamin A) can be used to monitor the kinetics of its formation and removal in single 
photoreceptor cells17-19.

A method is described for the preparation of single living photoreceptor cells from different vertebrate species for fluorescence imaging. The method can be used to image the fluorescence of endogenous fluorophores, such as NADH or vitamin A, or that of exogenously added fluorescent dyes sensitive to Ca2+ or other factors.

Preparazione delle condizioni di vita isolata fotorecettori dei Vertebrati per l&#39;imaging di fluorescenza

In the vertebrate retina, phototransduction, the conversion of light to an electrical signal, is carried out by the rod and cone photoreceptor cells1-4.  ...

Ricerca

Neuroscienze

Patch-clamp Capacitance Measurements and Ca2+ Imaging at Single Nerve Terminals in Retinal Slices

Visual stimuli are detected and conveyed over a wide dynamic range of light intensities and frequency changes by specialized neurons in the vertebrate retina. Two classes of retinal neurons, photoreceptors and bipolar cells, accomplish this by using ribbon-type active zones, which enable sustained and high-throughput neurotransmitter release over long time periods. ON-type mixed bipolar cell (Mb) terminals in the goldfish retina, which depolarize to light stimuli and receive mixed rod and cone photoreceptor input, are suitable for the study of ribbon-type synapses both due to their large size (~10-12 &mu;m diameter) and to their numerous lateral and reciprocal synaptic connections with amacrine cell dendrites. Direct access to Mb bipolar cell terminals in goldfish retinal slices with the patch-clamp technique allows the measurement of presynaptic Ca2+ currents, membrane capacitance changes, and reciprocal synaptic feedback inhibition mediated by GABAA and GABAC receptors expressed on the terminals. Presynaptic membrane capacitance measurements of exocytosis allow one to study the short-term plasticity of excitatory neurotransmitter release 14,15. In addition, short-term and long-term plasticity of inhibitory neurotransmitter release from amacrine cells can also be investigated by recordings of reciprocal feedback inhibition arriving at the Mb terminal 21. Over short periods of time (e.g. ~10 s), GABAergic reciprocal feedback inhibition from amacrine cells undergoes paired-pulse depression via GABA vesicle pool depletion 11. The synaptic dynamics of retinal microcircuits in the inner plexiform layer of the retina can thus be directly studied.
The brain-slice technique was introduced more than 40 years ago but is still very useful for the investigation of the electrical properties of neurons, both at the single cell soma, single dendrite or axon, and microcircuit synaptic level 19. Tissues that are too small to be glued directly onto the slicing chamber are often first embedded in agar (or placed onto a filter paper) and then sliced 20, 23, 18, 9. In this video, we employ the pre-embedding agar technique using goldfish retina. Some of the giant bipolar cell terminals in our slices of goldfish retina are axotomized (axon-cut) during the slicing procedure. This allows us to isolate single presynaptic nerve terminal inputs, because recording from axotomized terminals excludes the signals from the soma-dendritic compartment. Alternatively, one can also record from intact Mb bipolar cells, by recording from terminals attached to axons that have not been cut during the slicing procedure. Overall, use of this experimental protocol will aid in studies of retinal synaptic physiology, microcircuit functional analysis, and synaptic transmission at ribbon synapses.

Patch-clamp Capacitance Measurements and Ca2+ Imaging at Single Nerve Terminals in Retinal Slices

Here we describe a protocol for the preparation of agar-embedded retinal slices that are suitable for electrophysiology and Ca2+ imaging. This method allows one to study ribbon-type synapses in retinal microcircuits using direct patch-clamp recordings of single presynaptic nerve terminals.

Patch-clamp Misure di capacità e Ca 2 + Imaging terminazioni nervose della retina singola in Fette

Visual stimuli are detected and conveyed over a wide dynamic range of light intensities and frequency changes by specialized neurons in the vertebrate ...

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other insects proprioception is provided by specialized sensory organs termed chordotonal organs (ChOs) 2. Like many other organs in Drosophila, ChOs develop twice during the life cycle of the fly. First, the larval ChOs develop during embryogenesis. Then, the adult ChOs start to develop in the larval imaginal discs and continue to differentiate during metamorphosis.
The development of larval ChOs during embryogenesis has been studied extensively 10,11,13,15,16. The centerpiece of each ChO is a sensory unit composed of a neuron and a scolopale cell. The sensory unit is stretched between two types of accessory cells that attach to the cuticle via specialized epidermal attachment cells 1,9,14. When a fly larva moves, the relative displacement of the epidermal attachment cells leads to stretching of the sensory unit and consequent opening of specific transient receptor potential vanilloid (TRPV) channels at the outer segment of the dendrite 8,12. The elicited signal is then transferred to the locomotor central pattern generator circuit in the central nervous system.
Multiple ChOs have been described in the adult fly 7. These are located near the joints of the adult fly appendages (legs, wings and halters) and in the thorax and abdomen. In addition, several hundreds of ChOs collectively form the Johnston's organ in the adult antenna that transduce acoustic to mechanical energy 3,5,17,4.
In contrast to the extensive knowledge about the development of ChOs in embryonic stages, very little is known about the morphology of these organs during larval stages. Moreover, with the exception of femoral ChOs 18 and Johnston's organ, our knowledge about the development and structure of ChOs in the adult fly is very fragmentary.
Here we describe a method for staining and visualizing ChOs in third instar larvae and pupae. This method can be applied together with genetic tools to better characterize the morphology and understand the development of the various ChOs in the fly.

Visualization of Proprioceptors in Drosophila Larvae and Pupae

A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.

Visualizzazione dei Propriorecettori in<em&gt; Drosophila</em&gt; Larve e pupe

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other ...

Deep Brain Stimulation with Simultaneous fMRI in Rodents

In order to visualize the global and downstream neuronal responses to deep brain stimulation (DBS) at various targets, we have developed a protocol for using blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to image rodents with simultaneous DBS. DBS fMRI presents a number of technical challenges, including accuracy of electrode implantation, MR artifacts created by the electrode, choice of anesthesia and paralytic to minimize any neuronal effects while simultaneously eliminating animal motion, and maintenance of physiological parameters, deviation from which can confound the BOLD signal.&#160;Our laboratory has developed a set of procedures that are capable of overcoming most of these possible issues. For electrical stimulation, a homemade tungsten bipolar microelectrode is used, inserted stereotactically at the stimulation site in the anesthetized subject. In preparation for imaging, rodents are fixed on a plastic headpiece and transferred to the magnet bore. For sedation and paralysis during scanning, a cocktail of dexmedetomidine and pancuronium is continuously infused, along with a minimal dose of isoflurane; this preparation minimizes the BOLD ceiling effect of volatile anesthetics. In this example experiment, stimulation of the subthalamic nucleus (STN) produces BOLD responses which are observed primarily in ipsilateral cortical regions, centered in motor cortex. Simultaneous DBS and fMRI allows the unambiguous modulation of neural circuits dependent on stimulation location and stimulation parameters, and permits observation of neuronal modulations free of regional bias. This technique may be used to explore the downstream effects of modulating neural circuitry at nearly any brain region, with implications for both experimental and clinical DBS.

This protocol describes a standard method for simultaneous functional magnetic resonance imaging and deep brain stimulation in the rodent. The combined use of these experimental tools allows for the exploration of global downstream activity in response to electrical stimulation at virtually any brain target.

La stimolazione cerebrale profonda con simultanea fMRI in Roditori

In order to visualize the global and downstream neuronal responses to deep brain stimulation (DBS) at various targets, we have developed a protocol for ...

In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice

The rodent visual system encompasses retinal ganglion cells and their axons that form the optic nerve to enter thalamic and midbrain centers, and postsynaptic projections to the visual cortex. Based on its distinct anatomical structure and convenient accessibility, it has become the favored structure for studies on neuronal survival, axonal regeneration, and synaptic plasticity. Recent advancements in MR imaging have enabled the in vivo visualization of the retino-tectal part of this projection using manganese mediated contrast enhancement (MEMRI). Here, we present a MEMRI protocol for illustration of the visual projection in mice, by which resolutions of (200 &#181;m)3 can be achieved using common 3 Tesla scanners. We demonstrate how intravitreal injection of a single dosage of 15 nmol MnCl2 leads to a saturated enhancement of the intact projection within 24 hr. With exception of the retina, changes in signal intensity are independent of coincided visual stimulation or physiological aging. We further apply this technique to longitudinally monitor axonal degeneration in response to acute optic nerve injury, a paradigm by which Mn2+ transport completely arrests at the lesion site. Conversely, active Mn2+ transport is quantitatively proportionate to the viability, number, and electrical activity of axon fibers. For such an analysis, we exemplify Mn2+ transport kinetics along the visual path in a transgenic mouse model (NF-&#954;B p50KO) displaying spontaneous atrophy of sensory, including visual, projections. In these mice, MEMRI indicates reduced but not delayed Mn2+ transport as compared to wild type mice, thus revealing signs of structural and/or functional impairments by NF-&#954;B mutations.
In summary, MEMRI conveniently bridges in vivo assays and post mortem histology for the characterization of nerve fiber integrity and activity. It is highly useful for longitudinal studies on axonal degeneration and regeneration, and investigations of mutant mice for genuine or inducible phenotypes.

In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice

This video illustrates a method, using a clinical 3 T scanner, for contrast-enhanced MR imaging of the na&#239;ve mouse visual projection and for repetitive and longitudinal in vivo studies of optic nerve degeneration associated with acute optic nerve crush injury and chronic optic nerve degeneration in knock-out mice (p50KO).

In vivo imaging di Optic Nerve Fiber Integrity by MRI Contrast-Enhanced nei topi

The rodent visual system encompasses retinal ganglion cells and their axons that form the optic nerve to enter thalamic and midbrain centers, and ...

Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina

Retinal cone photoreceptors (cones) serve daylight vision and are the basis of color discrimination. They are subject to degeneration, often leading to blindness in many retinal diseases. Calcium (Ca2+), a key second messenger in photoreceptor signaling and metabolism, has been proposed to be indirectly linked with photoreceptor degeneration in various animal models. Systematically studying these aspects of cone physiology and pathophysiology has been hampered by the difficulties of electrically recording from these small cells, in particular in the mouse where the retina is dominated by rod photoreceptors. To circumvent this issue, we established a two-photon Ca2+ imaging protocol using a transgenic mouse line that expresses the genetically encoded Ca2+ biosensor TN-XL exclusively in cones and can be crossbred with mouse models for photoreceptor degeneration. The protocol described here involves preparing vertical sections (&#8220;slices&#8221;) of retinas from mice and optical imaging of light stimulus-evoked changes in cone Ca2+ level. The protocol also allows &#8220;in-slice measurement&#8221; of absolute Ca2+ concentrations; as the recordings can be followed by calibration. This protocol enables studies into functional cone properties and is expected to contribute to the understanding of cone Ca2+ signaling as well as the potential involvement of Ca2+ in photoreceptor death and retinal degeneration.

Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina

We describe a protocol to monitor Ca2+ dynamics in the axon terminals of cone photoreceptors using an ex-vivo&#160;slice preparation of the mouse retina. This protocol allows comprehensive studies of cone Ca2+ signaling in an important mammalian model system, the mouse.

Imaging Ca<sup&gt; 2+</sup&gt; Dinamica a cono fotorecettore Axon Terminali della retina di topo

Retinal cone photoreceptors (cones) serve daylight vision and are the basis of color discrimination. They are subject to degeneration, often leading to ...

Optical Monitoring of Living Nerve Terminal Labeling in Hair Follicle Lanceolate Endings of the Ex Vivo Mouse Ear Skin

A novel dissection and recording technique is described for optical monitoring staining and de-staining of lanceolate terminals surrounding hair follicles in the skin of the mouse pinna. The preparation is simple and relatively fast, reliably yielding extensive regions of multiple labeled units of living nerve terminals to study uptake and release of styryl pyridinium dyes extensively used in studies of vesicle recycling. Subdividing the preparations before labeling allows test vs. control comparisons in the same ear from a single individual. Helpful tips are given for improving the quality of the preparation, the labeling and the imaging parameters. This new system is suitable for assaying pharmacologically and mechanically-induced uptake and release of these vital dyes in lanceolate terminals in both wild-type and genetically modified animals. Examples of modulatory influences on labeling intensity are given.

Optical Monitoring of Living Nerve Terminal Labeling in Hair Follicle Lanceolate Endings of the Ex Vivo Mouse Ear Skin

Here we describe a novel preparation for imaging live lanceolate sensory terminals of palisade endings that innervate mouse ear skin hair follicles during staining and destaining with styryl pyridinium dyes.

Il monitoraggio ottico di Living nervo terminale Etichettatura nel follicolo pilifero lanceolate Endings del<em&gt; Ex Vivo</em&gt; Mouse Ear pelle

A novel dissection and recording technique is described for optical monitoring staining and de-staining of lanceolate terminals surrounding hair follicles ...

Quantification of Endosome and Lysosome Motilities in Cultured Neurons Using Fluorescent Probes

In the brain, membrane trafficking systems play important roles in regulating neuronal functions, such as neuronal morphology, synaptic plasticity, survival, and glial communications. To date, numerous studies have reported that defects in these systems cause various neuronal diseases. Thus, understanding the mechanisms underlying vesicle dynamics may provide influential clues that could aid in the treatment of several neuronal disorders. Here, we describe a method for quantifying vesicle motilities, such as motility distance and rate of movement, using a software plug-in for the ImageJ platform. To obtain images for quantification, we labeled neuronal endosome-lysosome structures with EGFP-tagged vesicle marker proteins and observed the movement of vesicles using a time-lapse microscopy. This method is highly useful and simplify measuring vesicle motility in neurites, such as axons and dendrites, as well as in the soma of both neurons and glial cells. Furthermore, this method can be applied to other cell lines, such as fibroblasts and endothelial cells. This approach could provide a valuable advancement of our understanding of membrane trafficking.

The investigation of membrane trafficking is crucial for understanding neuronal functions. Here, we introduce a method for quantifying vesicle motility in neurons. This is a convenient method that can be adapted to the quantification of membrane trafficking in the nervous system.

Quantificazione delle endosomi e dei motivi di lisosomi nei neuroni coltivati ​​utilizzando sonde fluorescenti

In the brain, membrane trafficking systems play important roles in regulating neuronal functions, such as neuronal morphology, synaptic plasticity, ...

Visualization of Amyloid &#946; Deposits in the Human Brain with Matrix-assisted Laser Desorption/Ionization Imaging Mass Spectrometry

The neuropathology of Alzheimer&#39;s disease (AD) is characterized by the accumulation and aggregation of amyloid &#946; (A&#946;) peptides into extracellular plaques of the brain. The A&#946; peptides, composed of 40 amino acids, are generated from amyloid precursor proteins (APP) by &#946;- and &#947;-secretases. A&#946; is deposited not only in cerebral parenchyma but also in leptomeningeal and cerebral vessel walls, known as cerebral amyloid angiopathy (CAA). While a variety of A&#946; peptides were identified, the detailed production and distribution of individual A&#946; peptides in pathological tissues of AD and CAA have not been fully addressed. Here, we develop a protocol of matrix-assisted laser desorption/ionization-based imaging mass spectrometry (MALDI-IMS) on human autopsy brain tissues to obtain comprehensive protein mapping. For this purpose, human cortical specimens were obtained from the Brain Bank at the Tokyo Metropolitan Institute of Gerontology. Frozen cryosections are cut and transferred to indium-tin-oxide (ITO)-coated glass slides. Spectra are acquired using the MALDI system with a spatial resolution up to 20 &#181;m. Sinapinic acid (SA) is uniformly deposited on the slide using either an automatic or a manual sprayer. With the current technical advantages of MALDI-IMS, a typical data set of various A&#946; species within the same sections of human autopsied brains can be obtained without specific probes. Furthermore, high-resolution (20 &#181;m) imaging of an AD brain and severe CAA sample clearly shows that A&#946;1-36 to A&#946;1-41 were deposited into leptomeningeal vessels, while A&#946;1-42 and A&#946;1-43 were deposited in cerebral parenchyma as senile plaque (SP). It is feasible to adopt MALDI-IMS as a standard approach in combination with clinical, genetic, and pathological observations in understanding the pathology of AD, CAA, and other neurological diseases based on the current strategy.

Visualization of Amyloid &amp;#946; Deposits in the Human Brain with Matrix-assisted Laser Desorption/Ionization Imaging Mass Spectrometry

Molecular imaging with matrix-assisted laser desorption/ionization-based imaging mass spectrometry (MALDI-IMS) allows the simultaneous mapping of multiple analytes in biological samples. Here, we present a protocol for the detection and visualization of amyloid &#946; protein on brain tissues of Alzheimer&#39;s disease and cerebral amyloid angiopathy samples using MALDI-IMS.

Visualizzazione dei depositi β amiloide nel cervello umano con Matrix-assisted Laser Desorption/Ionization Imaging spettrometria di massa

The neuropathology of Alzheimer&#39;s disease (AD) is characterized by the accumulation and aggregation of amyloid &#946; (A&#946;) peptides into ...

Preparation of Newborn Rat Brain Tissue for Ultrastructural Morphometric Analysis of Synaptic Vesicle Distribution at Nerve Terminals

Our laboratory and many others have exploited the high resolving power of transmission electron microscopy to study the morphology and spatial organization of synaptic vesicles. In order to obtain high-quality electron micrographs that can yield the degree of morphological detail necessary for quantitative analysis of pre-synaptic vesicle distribution, optimal specimen preparation is critical. Chemical fixation is the first step in the process of specimen preparation, and of utmost importance to preserve fine ultrastructure. Vascular fixation with a glutaraldehyde-formaldehyde solution, followed by treatment of vibratome-sectioned specimens with osmium tetroxide, stabilizes the maximum number of molecules, especially proteins and lipids, and results in superior conservation of ultrastructure. Tissue is then processed with counterstaining, sequential dehydration and resin-embedding. En bloc staining with uranyl acetate (i.e., staining of vibratome-sectioned tissue before resin embedding) enhances endogenous contrast and stabilizes cell components against extraction during specimen processing. Contrast can be further increased by applying uranyl acetate as a post-stain on ultrathin sections. Double-staining of ultrathin sections with lead citrate after uranyl acetate treatment also improves image resolution, by intensifying electron-opacity of nucleic acid-containing structures through selective binding of lead to uranyl acetate. Transmission electron microscopy is a powerful tool for characterization of the morphological details of synaptic vesicles and quantification of their size and spatial organization in the terminal bouton. However, because it uses fixed tissue, transmission electron microscopy can only provide indirect information regarding living or evolving processes. Therefore, other techniques should be considered when the main objective is to study dynamic or functional aspects of synaptic vesicle trafficking and exocytosis.

We describe procedures for processing newborn rat brain tissue to obtain high-resolution electron micrographs for morphometric analysis of synaptic vesicle distribution at nerve terminals. The micrographs obtained with these methods can also be used to study the morphology of a number of other cellular components and their dimensional structural relationships.

Preparazione del tessuto cerebrale del ratto neonato per l'analisi Morfolometrica ultrastrutturale della distribuzione delle vescicole sinaptiche nei terminali nervosi