Soluciones <ul><li> Solución intracelular de las células ganglionares (en mM): 100 K-gluconato, 8 KCl, 1 MgCl 2, 1 EGTA, 10 HEPES, 4 ATP, GTP 0,5, 90 mM sulforodamina B (para la tinción), ajustada a pH = 7,4 con KOH </li><li> Solución intracelular de las células bipolares (en mm): 90 K-gluconato, 8 KCl, 1 MgCl 2, 10 BAPTA, 10 HEPES, 4 ATP, GTP 0,5, 90 mM sulforodamina B (para la tinción), ajustada a pH = 7,4 con KOH </li><li> Ringer extracelular de solución (en mM): 112 NaCl, 5 de glucosa, HEPES 5, 2 KCl, CaCl2 2, 1 MgCl 2, ajustada a pH = 7,75 con NaOH. La oxigenación de la solución, no es necesario. </li></ul> Prepare las cámaras de grabación Nuestra cámara de registro consiste en un portaobjetos de microscopio con un adhesivo y en el que pequeños bloques de silicona cortada de otro adhesivo y se colocan para dar estabilidad a las secciones de tejidos. Preparación de rodajas de retina Para evitar la decoloración de los fotorreceptores, la disección se lleva a cabo a la luz tenue luz infrarroja o roja. Si uno está interesado en registrar las respuestas de la vía de la barra, sólo la luz infrarroja se debe utilizar (IR microscopio de disección y sin luz de la habitación. Adicionales gafas de IR se debe utilizar para los procedimientos no se realiza bajo el microscopio). Si uno está interesado principalmente en el registro de respuesta de los conos de luz, con poca luz ambiente de color rojo o una linterna de color rojo se puede utilizar. El microscopio, sin embargo, todavía debe tener oculares IR. Si la entrada de los fotorreceptores es irrelevante para el experimento, los procedimientos pueden llevarse a cabo a la luz normal de la habitación utilizando un microscopio normal. <ol><li> Prepare dos portaobjetos con un adhesivo de silicona, así: crear dos bandas paralelas de grasa de silicona (alrededor de 0,5 cm de distancia) en cada diapositiva y colocar un trozo rectangular de papel de filtro en un lado de la diapositiva, cruzando las dos bandas de grasa (empuje el filtro papel con parte de una hoja de afeitar para que se agarra bien a la diapositiva) </li><li> Sacrificio de una salamandra de acuerdo a los protocolos establecidos: el animal se coloca en un baño de hielo durante 30 minutos, y luego decapitado y doble pithed. </li><li> Eliminar los ojos de la cabeza de salamandra y lo coloca bajo la lupa en un pañuelo de papel humedecido con una solución helada de Ringer </li><li> Eliminar el tejido conjuntivo del ojo </li><li> Use una hoja de afeitar para hacer una pequeña incisión en la córnea </li><li> Mantenga cortar la córnea con una pinza mientras se retira con unas tijeras a lo largo de su adhesión a los ojos </li><li> Retire el objetivo con fórceps </li><li> Sostenga el iris con una pinza y corte a lo largo de la ora serrata para eliminar el iris </li><li> Cortar el ocular en dos piezas rectangulares </li><li> Recoger una de las piezas y el lugar que parte esclerótica hasta en el papel de filtro (asegúrate de que para aplanar la pieza, mientras que empuja hacia abajo con mucho cuidado) </li><li> Con cuidado, levante la esclerótica en la retina, que ahora deberá adjuntarse al documento de servidor de archivos </li><li> Añadir rápidamente una solución helada de Ringer para el bienestar </li><li> Repita lo mismo con la segunda pieza </li><li> Use una hoja de afeitar colocado en una máquina de cortar por encargo de cortar 200-300μm rebanadas de ancho. </li><li> Use un par de pinzas para recoger las rebanadas en el lado del papel de filtro, darles la vuelta para las capas de la retina se hacen visibles, y colocarlos en las bandas de grasa de vacío </li><li> Escoja un sector que se ve en buen estado y muestra las bandas horizontales que indican las capas de la retina (las capas son a veces difíciles de ver bajo el microscopio de disección como la ampliación no es suficiente, sin embargo, si se puede reconocer algunas capas de la rebanada es generalmente suficiente. La decisión final sobre si se debe usar el corte, sin embargo, se hace una vez que se observa bajo el microscopio en posición vertical). Mover a la cámara de registro de diapositivas mediante la construcción de un puente de timbre entre las dos diapositivas </li><li> Asegúrese de que el papel de filtro es empujado contra los bloques de caucho en la cámara de grabación, por lo que el sector no está inclinado (células ganglionares y los fotorreceptores se debe enfocar en, al mismo tiempo) </li></ol> Colocar el tejido en el equipo de grabación <ol><li> La diapositiva de grabación se coloca bajo el microscopio y perfundidos con Ringer a través de una perfusión syste gravedad </li><li> La preparación se visualiza con un microscopio vertical, con un objetivo de inmersión en agua 10x y 40x. </li><li> Una vez más, sólo usamos luz infrarroja para prevenir la decoloración de los fotorreceptores. Una cámara de infrarrojos se conecta al puerto lateral del microscopio, que está conectado a una pantalla de televisión. </li></ol> La estimulación visual Los estímulos visuales son programadas en Matlab utilizando el Psychtoolbox y se proyectan en la retina a través del puerto de la parte superior del microscopio utilizando una imagen de microscopía de inyector (MBF biociencias). A Bits + + procesador de vídeo digital (Cambridge Research Systems) se utiliza para obtener una escala de luminosidad de 14 bits y Synchronize la presentación del estímulo a la adquisición de datos. Los estímulos visuales que se utilizan en este video son las barras brillantes u oscuros (width = 460μm) del 100% de contraste, que se presentaron durante dos segundos sobre un fondo uniforme, constante (luminancia = 8 * 10 4 fotones / m / s, tamaño: 1,84 x 1.38mm). Electrofisiología <ul><li> Electrodos de parche se tira de vidrio de borosilicato (OD:.. Identificación de 1,5 mm, 84 mm) con un extractor de micropipeta. De las células ganglionares, las resistencias se sitúan entre 2 y 4 MOhms. De las células bipolares, el aumento de las resistencias entre 4 y 8 MOhms se utilizan. </li><li> Grabaciones de pinza de voltaje se realizan con un 700A MultiClamp (Molecular Devices), un amplificador y software de laboratorio interno programado en Labview. </li><li> Las drogas son perfundidos a través de un sistema de perfusión de 8 canales. El electrodo microperfusión se coloca cerca de la corte (el tejido visiblemente debe moverse cuando se enciende la perfusión dentro y fuera, pero hay que tener cuidado de que la presión no es demasiado fuerte para que el sector podría desprenderse del papel de filtro). Durante los experimentos microperfusión debe estar constantemente encendido (solución de control de la perfusión de drogas si no son necesarios) para que la grabación no se inquiete por el cambio de la perfusión de encendido y apagado. </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>

Beneficios: <ol><li> Todos los tipos de células son accesibles </li><li> Fácil identificación de los tipos de células, en particular si un tinte fluorescente se añade a la solución de electrodos </li><li> Agentes farmacológicos pueden llegar fácilmente a las células diana </li><li> La técnica de patch clamp permite investigar el papel de los diferentes canales iónicos en los cálculos de la retina. La misma información no se puede obtener a través de grabaciones extracelulares pico o grabaciones con electr...

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		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
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<tr>
<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>
<tr>
<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>
<tr>
<td>Bits++</td>
<td>Digital Video Processor</td>
<td>Cambridge Research Systems</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Infrared Oculars</td>
<td>Other</td>
<td>ITT</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Adhesive silicone wells</td>
<td>Other</td>
<td>Molecular Probes</td>
<td>&nbsp;</td>
<td>20mm diameter, 1.0mm deep</td>
</tr>
<tr>
<td>Membrane Filters</td>
<td>Filter</td>
<td>Milipore</td>
<td>HAWPO1300</td>
<td>.45&#181;m HA</td>
</tr>
<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>
<tr>
<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>
		</table>
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whole-cell recordings of light evoked excitatory synaptic currents in the retinal slice

Utilizamos la técnica de patch clamp de célula entera para estudiar los circuitos sinápticos que subyace en el procesamiento de información visual en la retina. En este vídeo, le guía a través del proceso de desarrollo de células enteras grabaciones de la luz corrientes evocadas de células individuales en la preparación rebanada de la retina. Usamos el medio ambiente acuático salamandra tigre como un modelo animal. Comenzamos con la descripción de la disección de los ojos y mostrar cómo se montan las rebanadas de registros electrofisiológicos. Una vez que el corte se coloca en la cámara de grabación, que muestran cómo realizar grabaciones de células enteras de fijación de voltaje. A continuación, los proyectos de estímulos visuales en los fotorreceptores en el corte de luz para obtener respuestas evocadas actual. Durante la grabación que perfundir en el sector con agentes farmacológicos, por un sistema de perfusión de 8 canales que nos permite cambiar rápidamente entre los diferentes agentes. La preparación rebanada de retina es ampliamente utilizado para las grabaciones de patch clamp en la retina, en particular para estudiar amacrinas o células bipolares, que no son accesibles en una preparación de todo el montaje.

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

Este vídeo muestra el proceso de células enteras grabaciones pinza de voltaje en la porción de retina de la salamandra tigre acuático. Se demuestra la preparación de la corte, así como la forma de realizar grabaciones de patch clamp durante la estimulación visual de la retina.

De células enteras grabaciones de la Luz evocados excitatorios de las corrientes sinápticas en la porción de retina

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 vistas.  Boston University. Este vídeo muestra el proceso de células enteras grabaciones pinza de voltaje en la porción de retina de la salamandra tigre acuático. Se demuestra la preparación de la corte, así como la forma de realizar grabaciones de patch clamp durante la estimulación visual de la 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.

Preparación de corte horizontal de la 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 ...

Investigación

Biología

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.

Las grabaciones de células enteras del cerebro del adulto de 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.

Los componentes principales del microscopio de luz

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.

Grabaciones de la activación de circuitos neuronales en animales comportarse libremente

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.

Una sola célula grabaciones de succión de los conos del ratón

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.

De células enteras de grabación de calcio activados por calcio de lanzamiento (CRAC) Las corrientes en los linfocitos T humanos

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.

El estudio de la proteólisis de ciclina B en el nivel de células individuales en poblaciones de células enteras

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.

El método de cultivo de la rebanada por Siguiendo desarrollo de gérmenes de dientes en Explante 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.

En Vivo Tracking 4-Dimensional de madre hematopoyéticas y células progenitoras en ratones adultos de calota de Médula Ósea

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.

Método para la Evaluación de los efectos de un rango de longitudes de onda e intensidades de / Terapia de luz del infrarrojo cercano Red sobre el estrés oxidativo<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 ...