Soluzioni <ul><li> Soluzione intracellulare di cellule gangliari (in mm): 100 K-gluconato, 8 KCl, 1 MgCl 2, 1 EGTA, 10 HEPES, 4 ATP, GTP 0,5, 90 mM solforodamina B (per la colorazione), portato a pH = 7,4 con KOH </li><li> Soluzione intracellulare di cellule bipolari (in mm): 90 K-gluconato, 8 KCl, 1 MgCl 2, 10 Bapta, 10 HEPES, 4 ATP, GTP 0,5, 90 mM solforodamina B (per la colorazione), portato a pH = 7,4 con KOH </li><li> Ringer extracellulare della soluzione (in mm): 112 NaCl, 5 Glucosio, 5 HEPES, 2 KCl, 2 CaCl 2, 1 MgCl 2, portato a pH = 7.75 con NaOH. Ossigenazione della soluzione non è necessario. </li></ul> Preparare camere di registrazione La nostra camera di registrazione è costituito da un vetrino da microscopio con un adesivo ben in cui blocchi di silicone piccolo ritagliato da un altro adesivo e sono in grado di dare stabilità al fette di tessuto. Preparazione di fette della retina Per evitare lo sbiancamento dei fotorecettori, la dissezione viene effettuata in IR o luce fioca luce rossa. Se uno è interessato a registrare le risposte dal sentiero asta, solo luce IR deve essere usato (IR dissezione microscopio e nessuna luce ambiente. Aggiuntive occhiali a infrarossi devono essere utilizzati per le procedure non fanno sotto il microscopio). Se uno è principalmente interessato a registrare le risposte cono di luce, fioca luce della stanza rossa o una luce del flash rosso può essere utilizzato. Il microscopio, tuttavia, deve ancora oculari IR. Se l&#39;ingresso dei fotorecettori è irrilevante per l&#39;esperimento, le procedure possono essere effettuate in luce ambiente normale utilizzando un microscopio normale. <ol><li> Preparare due vetrini da microscopio con un adesivo siliconico bene: creare due bande parallele di grasso al silicone (circa 0,5 centimetri di distanza) in ogni diapositiva e luogo un pezzo rettangolare di carta da filtro su un lato del vetrino, attraversando entrambe le bande grasso (spingere il filtro carta con parte di una lama di rasoio in modo che sia ben collegato alla diapositiva) </li><li> Sacrificare una salamandra secondo i protocolli stabiliti: l&#39;animale viene posto in un bagno di ghiaccio per 30 minuti, poi decapitato e doppio pithed. </li><li> Eliminare l&#39;effetto occhi dalla testa salamandra e metterla sotto il microscopio da dissezione su un pezzo di carta velina inumidita con soluzione ghiacciata di Ringer </li><li> Rimuovere il tessuto connettivo dall&#39;occhio </li><li> Usa lama di rasoio per fare un piccolo taglio nella cornea </li><li> Tenere taglio della cornea con una pinza, mentre la rimozione con le forbici lungo il suo attaccamento per l&#39;occhio </li><li> Rimuovere l&#39;obiettivo con una pinza </li><li> Tenere l&#39;iride con una pinza e taglio lungo la serrata per rimuovere l&#39;iride </li><li> Tagliare l&#39;oculare in due pezzi rettangolari </li><li> Prendete uno dei pezzi e mettetelo lato sclera sul filtro di carta (assicuratevi di appiattirsi il pezzo mentre si spinge verso il basso con molta attenzione) </li><li> Sollevare delicatamente la sclera al largo della retina, che ora dovrà essere allegata alla carta filer </li><li> Aggiungere rapidamente una soluzione ghiacciata di Ringer al pozzo </li><li> Ripetere lo stesso per il secondo pezzo </li><li> Utilizzare una lama di rasoio posto in una affettatrice su misura per tagliare 200-300μm fette larghe. </li><li> Usare un paio di pinze per prendere le fette a lato della carta da filtro, li girare così gli strati della retina diventano visibili, e metterli su bande grasso il vuoto </li><li> Scegli una fetta che sembra intatto e mostra fasce orizzontali che indicano gli strati della retina (i livelli sono a volte difficili da vedere al microscopio dissezione come l&#39;ingrandimento non è abbastanza alta, se si può riconoscere qualche stratificazione la fetta di solito è abbastanza buono. La decisione finale sull&#39;opportunità di utilizzare la fetta, comunque, è fatta una volta si è vista al microscopio in posizione verticale). Spostare alla diapositiva camera di registrazione con la costruzione di un ponte Ringer tra i due vetrini </li><li> Assicurarsi che la carta da filtro viene spinto contro i blocchi di gomma nella camera di registrazione in modo che la fetta non sia inclinato (cellule gangliari e fotorecettori dovrebbe essere a fuoco allo stesso tempo) </li></ol> Posizionamento del tessuto nel rig registrazione <ol><li> La slitta di registrazione è posto sotto il microscopio e perfusi con soluzioni di Ringer attraverso un syste perfusione gravità </li><li> La preparazione è visualizzato con un microscopio verticale con un obiettivo 10x e 40x acqua ad immersione. </li><li> Ancora una volta, usiamo solo la luce a infrarossi per prevenire lo sbiancamento dei fotorecettori. Una telecamera a infrarossi è collegato alla porta laterale del microscopio, che è collegato ad uno schermo TV. </li></ol> Stimolazione visiva Stimoli visivi sono programmati in Matlab utilizzando la Psychtoolbox e vengono proiettate sulla retina attraverso la porta superiore del microscopio utilizzando un microscopio immagine iniettore (MBF bioscienze). A Bits + + processore video digitale (Cambridge Research Systems) è usato per ottenere una scala a 14 bit di luminanza e di sincronoonize presentazione dello stimolo con l&#39;acquisizione dei dati. Gli stimoli visivi utilizzati in questo video sono barre chiare o scure (width = 460μm) del 100% di contrasto, che sono stati presentati per due secondi su uno sfondo uniforme costante (luminanza = 8 * 10 4 fotoni / micron / s, dimensioni: 1,84 x 1,38 millimetri). Elettrofisiologia <ul><li> Elettrodi di patch sono tirati da vetro borosilicato (OD:.. 1,5 mm, ID 84mm) con un estrattore micropipetta. Per le cellule gangliari, le resistenze sono tra 2 e 4 MOhm. Per le cellule bipolari, più resistenze tra 4 e 8 MOhm sono utilizzati. </li><li> Registrazioni morsetto di tensione sono eseguiti utilizzando una 700A Multiclamp (Molecular Devices), un amplificatore e software laboratorio interno programmato in Labview. </li><li> I farmaci sono perfusi attraverso un sistema a 8 canali perfusione. L&#39;elettrodo microperfusione si trova vicino alla fetta (il tessuto dovrebbe visibilmente muoversi quando si accende la perfusione e fuori, ma bisogna stare attenti che la pressione non è troppo forte in modo che la fetta potrebbero staccarsi dalla carta da filtro). Durante gli esperimenti il ​​microperfusione deve essere costantemente acceso (soluzione di controllo perfusione se non sono necessari farmaci) in modo che la registrazione non viene disturbato dal passaggio della perfusione e si spegne. </li></ul>

<ol>
	<li>Cook, P. B., Lukasiewicz, P. D., McReynnolds, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GABA(C)+receptors+control+adaptive+changes+in+a+glycinergic+inhibitory+pathway+in+salamander+retina.">GABA(C) receptors control adaptive changes in a glycinergic inhibitory pathway in salamander retina.</a> Journal of Neuroscience. 20, 806-812 (2000).</li><li>Heflin, S. J., Cook, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Narrow+and+wide+field+amacrine+cells+fire+action+potentials+in+response+to+depolarization+and+light+stimulation.">Narrow and wide field amacrine cells fire action potentials in response to depolarization and light stimulation.</a> Visual Neuroscience. 24, 197-206 (2007).</li><li>Ichinose, T., Shields, C. R., Lukasiewicz, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sodium+Channels+in+the+Transient+Retinal+Bipolar+Cells+Enhance+Visual+Responses+in+Ganglion+Cells.">Sodium Channels in the Transient Retinal Bipolar Cells Enhance Visual Responses in Ganglion Cells.</a> J Neurosci.. 25, 1856-1865 (2005).</li></ol>

Vantaggi: <ol><li> Tutti i tipi di cellule sono accessibili </li><li> Facile identificazione dei tipi di cellule, in particolare se un colorante fluorescente viene aggiunto alla soluzione elettrodo </li><li> Agenti farmacologici possono facilmente raggiungere le cellule bersaglio </li><li> La tecnica di patch clamp consente di indagare il ruolo dei canali ionici diversi nei calcoli della retina. Le stesse informazioni non possono essere ottenute attraverso le registrazioni extracellulare picco o registrazioni con elett...

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		<th>Comment</th>
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<td>Multiclamp 700A</td>
<td>Patch Clamp Amplifier</td>
<td>Molecular Devices</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>SZX9</td>
<td>Dissection Micropscope</td>
<td>Olympus</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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<td>BX50WI</td>
<td>Upright Microscope</td>
<td>Olympus</td>
<td>&nbsp;</td>
<td>Equipped with 40x, 10x water immersion objective, fluorescent filters and mercury lamp</td>
</tr>
<tr>
<td>P-97</td>
<td>Micropipette Puller</td>
<td>Sutter Instruments</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Lucivid</td>
<td>Microscope image injector</td>
<td>Mbf bioscience</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>8-channel perfusion system</td>
<td>Microperfusion</td>
<td>Parker Hannfin corporation</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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<td>Bits++</td>
<td>Digital Video Processor</td>
<td>Cambridge Research Systems</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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<td>Infrared Oculars</td>
<td>Other</td>
<td>ITT</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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<td>Adhesive silicone wells</td>
<td>Other</td>
<td>Molecular Probes</td>
<td>&nbsp;</td>
<td>20mm diameter, 1.0mm deep</td>
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<td>Membrane Filters</td>
<td>Filter</td>
<td>Milipore</td>
<td>HAWPO1300</td>
<td>.45&#181;m HA</td>
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<tr>
<td>Borosilicate Glass Capillaries</td>
<td>Electrode glass</td>
<td>World Precision Instruments</td>
<td>1B150-4</td>
<td>&nbsp;</td>
<tr>
<td>Syringe Filters</td>
<td>Filter</td>
<td>Whatman</td>
<td>6789-0402</td>
<td>4mm filters, .2um Nylon Membrane, Polypropylene housing</td>
</tr>
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<td>IR camera</td>
<td>Micropscope mounted camera</td>
<td>Sony</td>
<td>SPT-M324</td>
<td>Extrawave HAD, B7W video camera</td>
</tr>
<tr>
<td>Picrotoxin</td>
<td>Reagent</td>
<td>Sigma</td>
<td>P1675</td>
<td>&nbsp;</td>
<tr>
<td>Strychnine</td>
<td>Reagent</td>
<td>Sigma</td>
<td>S0532</td>
<td>&nbsp;</td>
<tr>
<td>Imidazole-4-acetic acid sodium salt</td>
<td>Reagent</td>
<td>Sigma</td>
<td>I7013</td>
<td>&nbsp;</td>
<tr>
<td>Larval tiger salamanders</td>
<td>Animal</td>
<td>Charles E. Sullivan (Nashville, TN)</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
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whole-cell recordings of light evoked excitatory synaptic currents in the retinal slice

Usiamo la cellula intera tecnica di patch clamp per lo studio dei circuiti sinaptici che sottende l&#39;elaborazione delle informazioni visive nella retina. In questo video, vi guiderà attraverso il processo di esecuzione a cellula intera registrazioni di luce correnti evocato delle singole cellule nella preparazione fetta della retina. Usiamo il acquatici tigre salamandra come un modello animale. Cominciamo con la descrizione della dissezione degli occhi e mostrare come le fette sono montati per le registrazioni elettrofisiologiche. Una volta che la fetta si trova nella camera di registrazione, dimostriamo come eseguire a cellula intera registrazioni clamp di tensione. Abbiamo poi progetto stimoli visivi sul fotorecettori nella fetta di suscitare luce evocata attuali risposte. Durante la registrazione abbiamo profumato la fetta con agenti farmacologici, per cui un sistema a 8 canali perfusione ci permette di passare velocemente tra diversi agenti. La preparazione fetta della retina è ampiamente usato per le registrazioni di patch clamp nella retina, in particolare per studiare amacrine e cellule bipolari, che non sono accessibili in un tutto-mount preparazione.

Watch this Scientific Journal Video about Whole-cell Recordings of Light Evoked Excitatory Synaptic Currents in the Retinal Slice at JoVE.com

Whole-cell Recordings of Light Evoked Excitatory Synaptic Currents in the Retinal Slice

Questo video mostra il processo di registrazione di tensione a cellula intera pinza nella fetta della retina della tigre salamandra acquatica. Dimostriamo la preparazione della fetta e come effettuare registrazioni di patch clamp durante la stimolazione visiva della retina.

A cellula intera Recordings of Light Evocati eccitatorio Correnti Synaptic nel Slice Retinal

We use the whole-cell patch clamp technique to study the synaptic circuitry that underlies visual information processing in the retina. In this video, we ...

whole-cell-recordings-light-evoked-excitatory-synaptic-currents

Research

JoVE Journal

Biology

12.7K Views.  Boston University. Questo video mostra il processo di registrazione di tensione a cellula intera pinza nella fetta della retina della tigre salamandra acquatica. Dimostriamo la preparazione della fetta e come effettuare registrazioni di patch clamp durante la stimolazione visiva della retina.

Video: Whole-cell Recordings of Light Evoked Excitatory Synaptic Currents in the Retinal Slice

Horizontal Slice Preparation of the Retina

Traditionally the vertical slice and the whole-mount preparation of the retina have been used to study the function of retinal circuits. However, many of retinal neurons, such as amacrine cells, expand their dendrites horizontally, so that the morphology of the cells is supposed to be severely damaged in the vertical slices. In the whole-mount preparation, especially for patch-clamp recordings, retinal neurons in the middle layer are not easily accessible due to the extensive coverage of glial cell (Mueller cell) s endfeets. Here, we describe the novel slicing method to preserve the dendritic morphology of retinal neurons intact. The slice was made horizontally at the inner layer of the retina using a vibratome slicer after the retina was embedded in the low-temperature melting agarose gel. In this horizontal slice preparation of the retina, we studied the function of retinal neurons compared with their morphology, by using patch-clamp recording, calcium imaging technique, immunocytochemistry, and single-cell RT-PCR.

Traditionally the vertical slice and the whole-mount preparation of the retina have been used to study the function of retinal circuits. Here, we describe the novel slicing method to preserve the dendritic morphology of retinal neurons intact.

Slice preparazione orizzontale della Retina

Traditionally the vertical slice and the whole-mount preparation of the retina have been used to study the function of retinal circuits. However, many of ...

Ricerca

Biologia

Whole Cell Recordings from Brain of Adult Drosophila

In this video, we demonstrate the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons. We begin by describing the dissecting solution and capture of the adult females used in our studies. The procedure for removing the whole brain intact, including both optic lobes, is illustrated. Dissection of the overlying trachea is also shown.  The isolated brain is not only small but needs special care in handling at this stage to prevent damage to the neurons, many of which are close to the outer surface of the tissue. We show how a special holder we developed is used to stabilize the brain in the recording chamber. A standard electrophysiology set up is used for recording from single neurons or pairs of neurons. A fluorescent image, viewed through the recording microscope, from a GAL4 line driving GFP expression (GH146) illustrates how projection neurons (PNs) are identified in the live brain. A high power Nomarski image shows a view of a single neuron that is being targeted for whole cell recording. When the brain is successfully removed without damage, the majority of the neurons are spontaneously active, firing action potentials and/or exhibiting spontaneous synaptic input. This in situ preparation, in which whole cell recording of identified neurons in the whole brain can be combined with genetic and pharmacological manipulations, is a useful model for exploring cellular physiology and plasticity in the adult CNS.

This video demonstrates the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons using standard whole cell technology. It includes images of GFP labeled cells and neurons viewed during recording.

Registrazioni cella intero cervello di adulti Drosophila

In this video, we demonstrate the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons. We begin by ...

Major Components of the Light Microscope

The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

I componenti principali del microscopio ottico

The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for ...

Recordings of Neural Circuit Activation in Freely Behaving Animals

The relationship between patterns of neural activity and corresponding behavioral expression is difficult to establish in unrestrained animals. Traditional non-invasive methods require at least partially restrained research subjects, and they only allow identification of large numbers of simultaneously activated neurons. On the other hand, small ensembles of neurons or individual neurons can only be measured using single-cell recordings obtained from largely reduced preparations. Since the expression of natural behavior is limited in restrained and dissected animals, the underlying neural mechanisms that control such behavior are difficult to identify. 
Here, I present a non-invasive physiological technique that allows measuring neural circuit activation in freely behaving animals. Using a pair of wire electrodes inside a water-filled chamber, the bath electrodes record neural and muscular field potentials generated by juvenile crayfish during natural or experimentally evoked escape responses. The primary escape responses of crayfish are mediated by three different types of tail-flips which move the animals away from the point of stimulation. Each type of tail-flip is controlled by its own neural circuit; the two fastest and most powerful escape responses require activation of different sets of large &#8220;command&#8221; neurons. In combination with behavioral observations, the bath electrode recordings allow unambiguous identification of these neurons and the associated neural circuits. Thus activity of neural circuitry underlying naturally occurring behavior can be measured in unrestrained animals and in different behavioral contexts.

Non-invasive measurements of neural activity patterns in freely behaving animals are obtained by combining neurophysiological recordings with high speed videography.

Le registrazioni di attivazione circuito neurale in Liberamente Comportarsi Animali

The relationship between patterns of neural activity and corresponding behavioral expression is difficult to establish in unrestrained animals. ...

Single-cell Suction Recordings from Mouse Cone Photoreceptors

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment are open and allow cations to flow steadily inwards across the membrane, depolarizing the cell. Light exposure triggers the closure of the CNG channels, blocks the inward cation current flow, and thus results in cell hyperpolarization. Based on the polarity of photoreceptors, a suction recording method was developed in 1970s that, unlike the classic patch-clamp technique, does not require penetrating the plasma membrane 1. Drawing the outer segment into a tightly-fitting glass pipette filled with extracellular solution allows recording the current changes in individual cells upon test-flash exposure. However, this well-established "outer-segment-in (OS-in)" suction recording is not suitable for mouse cone recordings, because of the low percentage of cones in the mouse retina (3%) and the difficulties in identifying the cone outer segments. Recently, an inner-segment-in (IS-in) recording configuration was developed to draw the inner segment/nuclear region of the photoreceptor into the recording pipette 2,3. In this video, we will show how to record from individual mouse cone photoresponses using single-cell suction electrode.

We will show how to record flash responses from single mouse cones using a suction electrode.

Unicellulari registrazioni di aspirazione da Fotorecettori Cone mouse

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment ...

Whole-Cell Recording of Calcium Release-Activated Calcium (CRAC) Currents in Human T Lymphocytes

In T lymphocytes, depletion of Ca2+ from the intracellular Ca2+ store leads to activation of plasmalemmal Ca2+ channels, called Calcium Release-Activated Calcium (CRAC) channels. CRAC channels play important role in regulation of T cell proliferation and gene expression. Abnormal CRAC channel function in T cells has been linked to severe combined immunodeficiency and autoimmune diseases 1, 2 . Studying CRAC channel function in human T cells may uncover new molecular mechanisms regulating normal immune responses and unravel the causes of related human diseases. Electrophysiological recordings of membrane currents provide the most accurate assessment of functional channel properties and their regulation. Electrophysiological assessment of CRAC channel currents in Jurkat T cells, a human leukemia T cell line, was first performed more than 20 years ago 3, however, CRAC current measurements in normal human T cells remains a challenging task. The difficulties in recording CRAC channel currents in normal T cells are compounded by the fact that blood-derived T lymphocytes are much smaller in size than Jurkat T cells and, therefore, the endogenous whole-cell CRAC currents are very low in amplitude. Here, we give a step-by-step procedure that we routinely use to record the Ca2+ or Na+ currents via CRAC channels in resting human T cells isolated from the peripheral blood of healthy volunteers. The method described here was adopted from the procedures used for recording the CRAC currents in Jurkat T cells and activated human T cells 4-8.

Whole-Cell Recording of Calcium Release-Activated Calcium CRAC Currents in Human T Lymphocytes

We provide a step-by-step protocol for whole-cell patch clamp recording of Calcium Release-Activated Calcium (CRAC) currents in peripheral blood mononuclear cell-derived human T lymphocytes.

Whole-Cell Registrazione del calcio Release-Activated di calcio (CRAC) Correnti in Human Linfociti T

In T lymphocytes, depletion of Ca2+ from the intracellular Ca2+ store leads to activation of plasmalemmal Ca2+ channels, called Calcium Release-Activated ...

Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations

Equal distribution of chromosomes between the two daughter cells during cell division is a prerequisite for guaranteeing genetic stability 1. Inaccuracies during chromosome separation are a hallmark of malignancy and associated with progressive disease 2-4. The spindle assembly checkpoint (SAC) is a mitotic surveillance mechanism that holds back cells at metaphase until every single chromosome has established a stable bipolar attachment to the mitotic spindle1. The SAC exerts its function by interference with the activating APC/C subunit Cdc20 to block proteolysis of securin and cyclin B and thus chromosome separation and mitotic exit. Improper attachment of chromosomes prevents silencing of SAC signaling and causes continued inhibition of APC/CCdc20 until the problem is solved to avoid chromosome missegregation, aneuploidy and malignant growths1.
Most studies that addressed the influence of improper chromosomal attachment on APC/C-dependent proteolysis took advantage of spindle disruption using depolymerizing or microtubule-stabilizing drugs to interfere with chromosomal attachment to microtubules. Since interference with microtubule kinetics can affect the transport and localization of critical regulators, these procedures bear a risk of inducing artificial effects 5.
To study how the SAC interferes with APC/C-dependent proteolysis of cyclin B during mitosis in unperturbed cell populations, we established a histone H2-GFP-based system which allowed the simultaneous monitoring of metaphase alignment of mitotic chromosomes and proteolysis of cyclin B 6.
To depict proteolytic profiles, we generated a chimeric cyclin B reporter molecule with a C-terminal SNAP moiety 6 (Figure 1). In a self-labeling reaction, the SNAP-moiety is able to form covalent bonds with alkylguanine-carriers (SNAP substrate) 7,8 (Figure 1). SNAP substrate molecules are readily available and carry a broad spectrum of different fluorochromes. Chimeric cyclin B-SNAP molecules become labeled upon addition of the membrane-permeable SNAP substrate to the growth medium 7 (Figure 1). Following the labeling reaction, the cyclin B-SNAP fluorescence intensity drops in a pulse-chase reaction-like manner and fluorescence intensities reflect levels of cyclin B degradation 6 (Figure 1). Our system facilitates the monitoring of mitotic APC/C-dependent proteolysis in large numbers of cells (or several cell populations) in parallel. Thereby, the system may be a valuable tool to identify agents/small molecules that are able to interfere with proteolytic activity at the metaphase to anaphase transition. Moreover, as synthesis of cyclin B during mitosis has recently been suggested as an important mechanism in fostering a mitotic block in mice and humans by keeping cyclin B expression levels stable 9,10, this system enabled us to analyze cyclin B proteolysis as one element of a balanced equilibrium 6.

Metaphase to anaphase transition is triggered through anaphase-promoting complex (APC/C)-dependent ubiquitination and subsequent destruction of cyclin B. Here, we established a system which, following pulse-chase labeling, allows monitoring cyclin B proteolysis in entire cell populations and facilitates the detection of interference by the mitotic checkpoint.

Studiare proteolisi della ciclina B a livello di singola cellula in popolazioni di cellule intere

Equal distribution of chromosomes between the two daughter cells during cell division is a prerequisite for guaranteeing genetic stability 1. Inaccuracies ...

The Slice Culture Method for Following Development of Tooth Germs In Explant Culture

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental biologist. For many organs it is difficult to access developing tissue to allow monitoring during ex vivo culture. The slice culture method allows access to tissue so that morphogenetic movements can be followed and specific cell populations can be targeted for manipulation or lineage tracing.
In this paper we describe a method of slice culture that has been very successful for culture of tooth germs in a range of species. The method provides excellent access to the tooth germs, which develop at a similar rate to that observed in vivo, surrounded by the other jaw tissues. This allows tissue interactions between the tooth and surrounding tissue to be monitored. Although this paper concentrates on tooth germs, the same protocol can be applied to follow development of a number of other organs, such as salivary glands, Meckel&#39;s cartilage, nasal glands, tongue, and ear.

Here we detail a method to culture tooth germs in mandible slices using a tissue chopper. This method allows unique access to the tooth during development, providing excellent opportunity for manipulation and lineage tracing, not available using more traditional culture methods.

Il Metodo Culture Slice per seguire lo sviluppo dei germi dente Espianto Cultura

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

In Vivo inseguimento 4-dimensionale di emopoietiche staminali e progenitrici celle di topo adulto cranica di Midollo Osseo

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro

Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of central nervous system injuries in vivo, possibly by reducing oxidative stress. However, effects of R/NIR-LT on oxidative stress have been shown to vary depending on wavelength or intensity of irradiation. Studies comparing treatment parameters are lacking, due to absence of commercially available devices that deliver multiple wavelengths or intensities, suitable for high through-put in vitro optimization studies. This protocol describes a technique for delivery of light at a range of wavelengths and intensities to optimize therapeutic doses required for a given injury model. We hypothesized that a method of delivering light, in which wavelength and intensity parameters could easily be altered, could facilitate determination of an optimal dose of R/NIR-LT for reducing reactive oxygen species (ROS) in vitro.
Non-coherent Xenon light was filtered through narrow-band interference filters to deliver varying wavelengths (center wavelengths of 440, 550, 670 and 810nm) and fluences (8.5 x 10-3 to 3.8 x 10-1 J/cm2) of light to cultured cells. Light output from the apparatus was calibrated to emit therapeutically relevant, equal quantal doses of light at each wavelength. Reactive species were detected in glutamate stressed cells treated with the light, using DCFH-DA and H2O2 sensitive fluorescent dyes.&#160;
We successfully delivered light at a range of physiologically and therapeutically relevant wavelengths and intensities, to cultured cells exposed to glutamate as a model of CNS injury. While the fluences of R/NIR-LT used in the current study did not exert an effect on ROS generated by the cultured cells, the method of light delivery is applicable to other systems including isolated mitochondria or more physiologically relevant organotypic slice culture models, and could be used to assess effects on a range of outcome measures of oxidative metabolism.

Method for the Assessment of Effects of a Range of Wavelengths and Intensities of Red/near-infrared Light Therapy on Oxidative Stress In Vitro

Non-coherent Xenon light was passed through narrow-band interference and neutral density filters to deliver light of varying wavelength and intensity to cultured cells. This protocol was used to assess the effects of red/near-infrared light therapy on production of reactive species in vitro: no effects were observed using the tested parameters.

Metodo per la valutazione degli effetti di un intervallo di lunghezze d&#39;onda e intensità di / vicino-infrarosso di terapia della luce rossa sullo stress ossidativo<em&gt; In Vitro</em

Red/near-infrared light therapy (R/NIR-LT), delivered by laser or light emitting diode (LED), improves functional and morphological outcomes in a range of ...