Apoyado por el Premio de Desarrollo Profesional de Investigación para Prevención de la Ceguera, NIH EY 019312, y subvención sin restricciones de Investigación para Prevención de la Ceguera y EY 02687 (Departamento de Oftalmología y Ciencias Visuales en la Universidad de Washington).

Hacer electrodos <ol><li> Hacer los electrodos de registro utilizando un extractor de micropipeta y pulir los electrodos con filamento de calefacción bajo el microscopio. Para la grabación del ratón cono de succión de una sola célula, el diámetro interior en la punta del electrodo es de unos 6.7 micras. </li><li> Preparar electrodos de referencia. Pesar 1% de agar en agua destilada. Derretir la solución de agar en un baño de agua caliente. Llenar las pipetas de vidrio (L = 100 mm, OD / ID = 1/0.75 mm) con 1% de agar con una jeringa. Solidificar el agar a temperatura ambiente durante 10 minutos. </li><li> Cortar las pipetas en dos mitades con un cuchillo de diamante. </li><li> Sumerja los electrodos de referencia en la solución de referencia por lo menos 24 horas a 4 ° C. </li></ol> Configuración del experimento <ol start="5"><li> Dark adaptar un ratón en una jaula de negro durante la noche. </li><li> Prepare una solución de 100 ml de referencia y una solución de perfusión L (ver abajo) y el filtro de la solución. </li><li> Disolver 0,1% de BSA y 10 mM de glucosa en 20 ml de solución de referencia. </li><li> Calibrar la intensidad de la luz del estimulador óptico con fotómetro. </li><li> Monte la cámara de grabación en la platina del microscopio invertido. </li><li> La burbuja de la solución de perfusión con 95% O 2 / 5% CO 2, que se incuba a 40 ° C baño de agua para aumentar la solubilidad de CO 2. La solución de los flujos de la botella a la cámara de grabación que pasa a través de una resistencia de cerámica de calentamiento a 36-38 ° C. El calentador debe colocarse lo más cerca a la cámara de grabación como sea posible, idealmente en la platina del microscopio. </li><li> Ajuste el regulador de flujo para un caudal de alrededor de 1-1,5 ml / min. </li><li> Llenar el electrodo de registro con la solución de referencia. Insertar el electrodo en un porta-electrodos. Asegúrese de que no haya burbujas en el electrodo. Monte el soporte en el headstage del amplificador. Conecte el soporte a un dispositivo de succión, que se construye mediante la conexión de la tubería parcialmente llena con aceite mineral para el puerto lateral del porta-electrodos. El otro extremo del tubo está conectado a un pequeño depósito de aceite mineral, a la que la presión se puede aplicar por vía oral. </li><li> Conecte el electrodo de referencia al otro polo de la headstage. Obligar a la par térmico (TC) para el electrodo de referencia. Asegúrese de que las puntas de los electrodos y TC están muy juntos para que la lectura de la temperatura se toma como cerca de la célula como sea posible. </li><li> Encienda la iluminación infrarroja para visualizar el electrodo. El electrodo es visto por la cámara de infrarrojos conectada a un monitor. Centro del electrodo de la imagen en el campo visual y del monitor mediante un micromanipulador. </li><li> Ajustar la posición de la punta del electrodo de referencia cerca (2-4 mm) a la punta del electrodo de registro. </li><li> Ajustar el voltaje de CC para el calentador de modo que la temperatura de la solución es de 36-38 º C. </li><li> Realizar una prueba de sello para comprobar la resistencia de electrodo de registro, por lo general alrededor de 900 kW. </li></ol> Aislamiento de la retina del ratón <ol start="18"><li> Bajo tenue luz roja, la eutanasia el ratón adaptado a la oscuridad con el CO 2 y la dislocación cervical. Marcar los globos oculares con la punta de una antorcha de metal caliente de la cauterización de los punto más dorsal de la esclerótica un poco. Enucleación del globo ocular con unas tijeras. Todos los procedimientos posteriores se realizan bajo la luz infrarroja. </li><li> Hemisect los ojos bajo el microscopio con iluminación infrarroja y los convertidores de la imagen. </li><li> Retire la córnea y el cristalino. Eliminar la mayor cantidad de vítreo como sea posible. </li><li> Para grabar cono M-respuestas, eliminar la parte ventral de la ojera 4 con una cuchilla de afeitar a juzgar por la marca de la cauterización. </li><li> Pelar la retina de la capa de epitelio pigmentario. </li><li> Aplanar la retina y lo coloca en la parte inferior de la placa de Petri llenas de 1.2 ml solución de referencia. </li><li> Cortar la retina en pequeños trozos delgados con una cuchilla de afeitar y se incuba la preparación en una caja a prueba de luz saturada con oxígeno puro. </li></ol> Grabaciones <ol start="25"><li> Apague el calentador de forma temporal. Cambiar el flujo de perfusión a una tubería de derivación para evitar que la cámara de secado. </li><li> Drenan la mayor parte de la solución en la cámara usando un pedazo de tejido Kimwipe. Transferir la suspensión de la retina a la cámara de grabación con una pipeta de vidrio. </li><li> Espere unos 2 minutos hasta que las rodajas de retina se establecen. Interruptor de la perfusión de nuevo. Encender el calefactor. </li><li> Activar la iluminación infrarroja para visualizar la preparación. Búsqueda de un pedazo de retina tendido en la cámara con segmentos fotorreceptor exterior sobresaliendo (ver figura ejemplo). Dibuja los segmentos internos suavemente en el electrodo por la succión. En esta configuración, varios núcleos y segmentos internos debe ser elaborado en el electrodo. Registrar la photoresponse un destello brillante para probar si un segmento de cono interno está en el electrodo de la célula y si es curartu, a juzgar por la cinética de la respuesta y la amplitud. </li><li> Inferior del depósito mineral para aplicar una ligera presión negativa a la punta del electrodo para ayudar a sostener el segmento de interior en el electrodo. </li><li> Registro de flash de prueba, las respuestas de atenuar la intensidad luminosa vez que una célula se encuentra bien. Destellos de prueba son siempre de un estimulador de calibrado óptico de 5. La intensidad del flash y la longitud de onda son controlados por un conjunto de filtros de densidad neutra y filtros de interferencia de banda estrecha, respectivamente. Prueba de Flash duración (20 ms) es controlado por ordenador basada persianas. </li></ol> Soluciones <ol><li> Ratón solución de perfusión: 112,5 mM NaCl, 3,6 mM KCl, 2,4 mM MgCl 2, 1,2 mM CaCl 2, 10 mM HEPES (pH 7,4), 20 mM NaHCO 3, 3 mM Na succinato, 0,5 mM Na glutamato, 0,02 mM EDTA, y 10 mM de glucosa. </li><li> Grabación del ratón electrodo solución: 140 mM NaCl, 3,6 mM KCl, 2,4 mM MgCl 2, 1,2 mM CaCl 2, 3 mM HEPES (pH 7,4), 0,02 mM EDTA. </li></ol>

<ol>
	<li>Yau, K. W., Lamb, T. D., Baylor, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-induced+fluctuations+in+membrane+current+of+single+toad+rod+outer+segments.">Light-induced fluctuations in membrane current of single toad rod outer segments.</a> Nature. 269, 78-80 (1977).</li><li>Nikonov, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoreceptors+of+Nrl+-/-+mice+coexpress+functional+S-+and+M-cone+opsins+having+distinct+inactivation+mechanisms.">Photoreceptors of Nrl -/- mice coexpress functional S- and M-cone opsins having distinct inactivation mechanisms.</a> J Gen Physiol. 125, 287-304 (2005).</li><li>Nikonov, S. S., Kholodenko, R., Lem, J., Pugh, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+features+of+the+S-+and+M-cone+photoreceptors+of+wild-type+mice+from+single-cell+recordings.">Physiological features of the S- and M-cone photoreceptors of wild-type mice from single-cell recordings.</a> J Gen Physiol. 127, 359-374 (2006).</li><li>Applebury, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+murine+cone+photoreceptor:+a+single+cone+type+expresses+both+S+and+M+opsins+with+retinal+spatial+patterning.">The murine cone photoreceptor: a single cone type expresses both S and M opsins with retinal spatial patterning.</a> Neuron. 27, 513-523 (2000).</li><li>Cornwall, M. C., Fein, A., MacNichol, E. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+mechanisms+that+underlie+bleaching+and+background+adaptation.">Cellular mechanisms that underlie bleaching and background adaptation.</a> J Gen Physiol. 96, 345-372 (1990).</li><li>Calvert, 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=Phototransduction+in+transgenic+mice+after+targeted+deletion+of+the+rod+transducin+alpha+-subunit.">Phototransduction in transgenic mice after targeted deletion of the rod transducin alpha -subunit.</a> Proc Natl Acad Sci U S A. 97, 13913-13918 (2000).</li></ol>

Una sola célula de grabación de aspiración de las células fotorreceptoras se desarrolló hace 3 décadas. Que nos permite grabar través de la membrana cambio de corriente inducida por la estimulación de la luz, sin penetrar la membrana celular. Debido a la alta adhesión célula-célula, es difícil aislar la barra saludable único y el cono de la retina del ratón, como la retina de anfibios y es difícil de encontrar conos individuales debido al bajo porcentaje (3%) y pequeño tamaño. El segmento de interior-en...

single-cell suction recordings from mouse cone photoreceptors

Fotorreceptores de los bastones y conos en la retina es responsable de la detección de la luz. En la oscuridad, los nucleótidos cíclicos-cerrada (CNG) de canales en el segmento externo están abiertos y permiten el flujo de cationes a ritmo constante hacia el interior a través de la membrana, despolarización de la célula. Exposición a la luz desencadena el cierre de los canales de GNC, bloquea el flujo de cationes corriente de entrada, por lo que resulta en la hiperpolarización de la célula. Con base en la polaridad de los fotorreceptores, un método de grabación de succión se desarrolló en 1970 que, a diferencia de la clásica técnica de patch-clamp, no requiere penetrar en la membrana plasmática<sup&gt; 1</sup&gt;. Dibujar el segmento externo en una pipeta de vidrio bien instalados llena con solución extracelular permite registrar los cambios actuales en las células individuales a la exposición de pruebas flash. Sin embargo, esta bien establecido &quot;exterior del segmento en el (OS-in)&quot; de grabación de succión no es adecuado para las grabaciones de cono del ratón, por el bajo porcentaje de conos en la retina del ratón (3%) y las dificultades para identificar el cono segmentos exteriores. Recientemente, un segmento interno-en (IS-in) de registro de configuración ha sido desarrollado para dibujar el segmento de interior / región nuclear de los fotorreceptores en la pipeta de grabación<sup&gt; 2,3</sup&gt;. En este video, vamos a mostrar cómo grabar desde cada photoresponses ratón cono con una sola célula de electrodos de succión.

Watch this Scientific Journal Video about Single-cell Suction Recordings from Mouse Cone Photoreceptors at JoVE.com

Single-cell Suction Recordings from Mouse Cone Photoreceptors

Le mostraremos cómo registrar las respuestas de flash de conos ratón utilizando un electrodo de succión.

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 ...

single-cell-suction-recordings-from-mouse-cone-photoreceptors

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

11.7K vistas.  Washington University in St. Louis, School of Medicine. Le mostraremos cómo registrar las respuestas de flash de conos ratón utilizando un electrodo de succión.

Video: Single-cell Suction Recordings from Mouse Cone Photoreceptors

Patch Clamp Recordings from Mouse Retinal Neurons in a Dark-adapted Slice Preparation

Our visual experience is initiated when the visual pigment in our retinal photoreceptors absorbs photons of light energy and initiates a cascade of intracellular events that lead to closure of cyclic-nucleotide-gated channels in the cell membrane. The resulting change in membrane potential leads in turn to reductions in the amount of neurotransmitter release from both rod and cone synaptic terminals. To measure how the light-evoked change in photoreceptor membrane potential leads to downstream activity in the retina, scientists have made electrophysiological recordings from retinal slice preparations for decades1,2. In the past these slices have been cut manually with a razor blade on retinal tissue that is attached to filter paper; in recent years another method of slicing has been developed whereby retinal tissue is embedded in low gelling temperature agar and sliced in cool solution with a vibrating microtome3,4. This preparation produces retinal slices with less surface damage and very robust light-evoked responses. Here we document how this procedure can be done under infrared light to avoid bleaching the visual pigment.

Here we describe a procedure for generating dark-adapted slices of the mouse retina for electrophysiological recordings.

Grabaciones de patch clamp de neuronas de ratón de retina en una rebanada preparación adaptada a la oscuridad

Our visual experience is initiated when the visual pigment in our retinal photoreceptors absorbs photons of light energy and initiates a cascade of ...

Investigación

Neurociencias

An Isolated Retinal Preparation to Record Light Response from Genetically Labeled Retinal Ganglion Cells

The first steps in vertebrate vision take place when light stimulates the rod and cone photoreceptors of the retina 1. This information is then segregated into what are known as the ON and OFF pathways. The photoreceptors signal light information to the bipolar cells (BCs), which depolarize in response to increases (On BCs) or decreases (Off BCs) in light intensity. This segregation of light information is maintained at the level of the retinal ganglion cells (RGCs), which have dendrites stratifying in either the Off sublamina of the inner plexiform layer (IPL), where they receive direct excitatory input from Off BCs, or stratifying in the On sublamina of the IPL, where they receive direct excitatory input from On BCs. This segregation of information regarding increases or decreases in illumination (the On and Off pathways) is conserved and signaled to the brain in parallel.
The RGCs are the output cells of the retina, and are thus an important cell to study in order to understand how light information is signaled to visual nuclei in the brain. Advances in mouse genetics over recent decades have resulted in a variety of fluorescent reporter mouse lines where specific RGC populations are labeled with a fluorescent protein to allow for identification of RGC subtypes 2 3 4 and specific targeting for electrophysiological recording. Here, we present a method for recording light responses from fluorescently labeled ganglion cells in an intact, isolated retinal preparation. This isolated retinal preparation allows for recordings from RGCs where the dendritic arbor is intact and the inputs across the entire RGC dendritic arbor are preserved. This method is applicable across a variety of ganglion cell subtypes and is amenable to a wide variety of single-cell physiological techniques.

This article provides a description of how to dissect and record from the isolated retinal preparation in mouse. In particular, we describe how to record light responses from a fluorescently labeled ganglion cell population and subsequently identify and analyze its morphology.

Una preparación aislada de retina para registrar la respuesta de la luz a partir de semillas etiquetadas las células ganglionares retinianas

The first steps in vertebrate vision take place when light stimulates the rod and cone photoreceptors of the retina 1.  This information is then ...

Transretinal ERG Recordings from Mouse Retina: Rod and Cone Photoresponses

There are two distinct classes of image-forming photoreceptors in the vertebrate retina: rods and cones. Rods are able to detect single photons of light whereas cones operate continuously under rapidly changing bright light conditions. Absorption of light by rod- and cone-specific visual pigments in the outer segments of photoreceptors triggers a phototransduction cascade that eventually leads to closure of cyclic nucleotide-gated channels on the plasma membrane and cell hyperpolarization. This light-induced change in membrane current and potential can be registered as a photoresponse, by either classical suction electrode recording technique1,2 or by transretinal electroretinogram recordings (ERG) from isolated retinas with pharmacologically blocked postsynaptic response components3-5. The latter method allows drug-accessible long-lasting recordings from mouse photoreceptors and is particularly useful for obtaining stable photoresponses from the scarce and fragile mouse cones. In the case of cones, such experiments can be performed both in dark-adapted conditions and following intense illumination that bleaches essentially all visual pigment, to monitor the process of cone photosensitivity recovery during dark adaptation6,7. In this video, we will show how to perform rod- and M/L-cone-driven transretinal recordings from dark-adapted mouse retina. Rod recordings will be carried out using retina of wild type (C57Bl/6) mice. For simplicity, cone recordings will be obtained from genetically modified rod transducin &alpha;-subunit knockout (T&alpha;-/-) mice which lack rod signaling8.

We describe a relatively simple method of transretinal electroretinogram (ERG) recordings for obtaining rod and cone photoresponses from intact mouse retina. This approach takes advantage of the block of synaptic transmission from photoreceptors to isolate their light responses and record them using field electrodes placed across the isolated flat-mounted retina.

Transretinal Grabaciones ERG de retina del ratón: Rod y el Cono Photoresponses

There are two distinct classes of image-forming photoreceptors in the vertebrate retina: rods and cones. Rods are able to detect single photons of light ...

Odorant-induced Responses Recorded from Olfactory Receptor Neurons using the Suction Pipette Technique

Animals sample the odorous environment around them through the chemosensory systems located in the nasal cavity. Chemosensory signals affect complex behaviors such as food choice, predator, conspecific and mate recognition and other socially relevant cues. Olfactory receptor neurons (ORNs) are located in the dorsal part of the nasal cavity embedded in the olfactory epithelium. These bipolar neurons send an axon to the olfactory bulb (see Fig. 1, Reisert &amp; Zhao1, originally published in the Journal of General Physiology) and extend a single dendrite to the epithelial border from where cilia radiate into the mucus that covers the olfactory epithelium. The cilia contain the signal transduction machinery that ultimately leads to excitatory current influx through the ciliary transduction channels, a cyclic nucleotide-gated (CNG) channel and a Ca2+-activated Cl- channel (Fig. 1). The ensuing depolarization triggers action potential generation at the cell body2-4.
In this video we describe the use of the "suction pipette technique" to record odorant-induced responses from ORNs. This method was originally developed to record from rod photoreceptors5 and a variant of this method can be found at jove.com modified to record from mouse cone photoreceptors6. The suction pipette technique was later adapted to also record from ORNs7,8. Briefly, following dissociation of the olfactory epithelium and cell isolation, the entire cell body of an ORN is sucked into the tip of a recording pipette. The dendrite and the cilia remain exposed to the bath solution and thus accessible to solution changes to enable e.g. odorant or pharmacological blocker application. In this configuration, no access to the intracellular environment is gained (no whole-cell voltage clamp) and the intracellular voltage remains free to vary. This allows the simultaneous recording of the slow receptor current that originates at the cilia and fast action potentials fired by the cell body9. The difference in kinetics between these two signals allows them to be separated using different filter settings. This technique can be used on any wild type or knockout mouse or to record selectively from ORNs that also express GFP to label specific subsets of ORNs, e.g. expressing a given odorant receptor or ion channel.

Olfactory receptor neurons (ORNs) convert odor signals first into a receptor current that in turn triggers action potentials that are conveyed to second order neurons in the olfactory bulb. Here we describe the suction pipette technique to record simultaneously the odorant-induced receptor current and action potentials from mouse ORNs.

Inducidas Odorante-respuestas registradas de neuronas olfativas del receptor utilizando la técnica de aspiración con una pipeta

Animals sample the odorous environment around them through the chemosensory systems located in the nasal cavity. Chemosensory signals affect complex ...

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation

One of the central tasks in retinal neuroscience is to understand the circuitry of retinal neurons and how those connections are responsible for shaping the signals transmitted to the brain. Photons are detected in the retina by rod and cone photoreceptors, which convert that energy into an electrical signal, transmitting it to other retinal neurons, where it is processed and communicated to central targets in the brain via the optic nerve. Important early insights into retinal circuitry and visual processing came from the histological studies of Cajal1,2 and, later, from electrophysiological recordings of the spiking activity of retinal ganglion cells - the output cells of the retina3,4.
A detailed understanding of visual processing in the retina requires an understanding of the signaling at each step in the pathway from photoreceptor to retinal ganglion cell. However, many retinal cell types are buried deep in the tissue and therefore relatively inaccessible for electrophysiological recording. This limitation can be overcome by working with vertical slices, in which cells residing within each of the retinal layers are clearly visible and accessible for electrophysiological recording.
Here, we describe a method for making vertical sections of retinas from larval tiger salamanders (Ambystoma tigrinum). While this preparation was originally developed for recordings with sharp microelectrodes5,6, we describe a method for dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells in which we manipulate the photoreceptor's membrane potential while simultaneously recording post-synaptic responses in horizontal or bipolar cells. The photoreceptors of the tiger salamander are considerably larger than those of mammalian species, making this an ideal preparation in which to undertake this technically challenging experimental approach. These experiments are described with an eye toward probing the signaling properties of the synaptic ribbon - a specialized synaptic structure found in a only a handful of neurons, including rod and cone photoreceptors, that is well suited for maintaining a high rate of tonic neurotransmitter release7,8 - and how it contributes to the unique signaling properties of this first retinal synapse.

We describe the preparation of thin retinal slices from aquatic tiger salamanders (Ambystoma tigrinum) and explain how we use these slices to study synaptic processing in the retina by obtaining dual whole-cell voltage clamp recordings from photoreceptors and second-order horizontal and bipolar cells.

Simultáneas registros de células de fotorreceptores y las neuronas de segundo orden en una rebanada preparación retina Anfibios

One of the central tasks in retinal neuroscience  is to understand the circuitry of retinal neurons and how those connections are  responsible for shaping ...

Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures

The retina is a part of the central nervous system that has organized architecture, with neurons in layers from the photoreceptors, both rods and cones in contact with the retinal pigmented epithelium in the most distant part on the retina considering the direction of light, and the ganglion cells in the most proximal distance. This architecture allows the isolation of the photoreceptor layer by vibratome sectioning. The dissected neural retina of a mouse aged 8 days is flat-embedded in 4% gelatin on top of a slice of 20% gelatin photoreceptor layer facing down. Using a vibratome and a double edged razor blade, the 100 &#181;m thick inner retina is sectioned. This section contains the ganglion cells and the inner layer with notably the bipolar cells. An intermediary section of 15 &#181;m is discarded before 200 &#181;m of the outer retina containing the photoreceptors is recovered. The gelatin is removed by heating at 37 &#176;C. Pieces of outer layer are incubated in 500 &#181;l of Ringer&#39;s solution with 2 units of activated papain for 20 min at 37 &#176;C. The reaction is stopped by adding 500 &#181;l 10% fetal calf serum (FCS) in Dulbecco&#39;s Modified Eagle Medium (DMEM), then 25 units of DNAse I is added before centrifugation at RT, washed several times to remove serum and the cells are resuspended in 500 &#181;l of DMEM and seeded at 1 x 105 cells/cm2. The cells are grown to 5 days in vitro and their viability scored using live/dead assay. The purity of the culture is first determined by microscopic observation during the experiment. The purity is then validated by seeding and fixing cells on a histological slide and analyzing using a rabbit polyclonal anti-SAG, a photoreceptor marker and mouse monoclonal anti-RHO, a rod photoreceptor specific marker. Alternatively, the photoreceptor layer (97% rods) can be used for gene or protein expression analysis and for transplantation.

Neural retina of a mouse aged 8 days is on top of a 4% gelatin block. After isolation of the photoreceptor layer (200 &#181;m) by vibratome, the photoreceptors are seeded after mechanical and enzymatic dissociation for culture. The photoreceptor layer can be used for molecular, biochemical analyses or transplantation.

Vibratome Seccionamiento retina del ratón para preparar cultivos de fotorreceptores

The retina is a part of the central nervous system that has organized architecture, with neurons in layers from the photoreceptors, both rods and cones in ...

Recording Light-evoked Postsynaptic Responses in Neurons in Dark-adapted, Mouse Retinal Slice Preparations Using Patch Clamp Techniques

The retina is the gateway to the visual system. To understand visual signal processing mechanisms, we investigate retinal neural network functions. Retinal neurons in the network comprise of numerous subtypes. More than 10 subtypes of bipolar cells, ganglion cells, and amacrine cells have been identified by morphological studies. Multiple subtypes of retinal neurons are thought to encode distinct features of visual signaling, such as motion and color, and form multiple neural pathways. However, the functional roles of each neuron in visual signal processing are not fully understood. The patch clamp method is useful to address this fundamental question. Here, a protocol to record light-evoked synaptic responses in mouse retinal neurons using patch clamp recordings in dark-adapted conditions is provided. The mouse eyes are dark-adapted O/N, and retinal slice preparations are dissected in a dark room using infrared illumination and viewers. Infrared light does not activate mouse photoreceptors and thus preserves their light responsiveness. Patch clamp is used to record light-evoked responses in retinal neurons. A fluorescent dye is injected during recordings to characterize neuronal morphological subtypes. This procedure enables us to determine the physiological functions of each neuron in the mouse retina.

We will demonstrate how to prepare retinal slices from the mouse eye and record light responses in retinal neurons. The entire procedure is conducted in dark-adapted conditions.

Grabación Luz evocó-Respuestas postsinápticos en las neuronas en adaptadas oscuro, Preparaciones ratón retina Slice Uso de técnicas Patch Clamp

The retina is the gateway to the visual system. To understand visual signal processing mechanisms, we investigate retinal neural network functions. ...

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.

Imagen Ca<sup&gt; 2 +</sup&gt; Dinámica de Terminales cono fotorreceptor axón de la retina del ratón

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

Preparation of Horizontal Slices of Adult Mouse Retina for Electrophysiological Studies

Vertical slice preparations are well established to study circuitry and signal transmission in the adult mammalian retina. The plane of sectioning in these preparations is perpendicular to the retinal surface, making it ideal for the study of radially oriented neurons like photoreceptors and bipolar cells. However, the large dendritic arbors of horizontal cells, wide-field amacrine cells, and ganglion cells are mostly truncated, leaving markedly reduced synaptic activity in these cells. Whereas ganglion cells and displaced amacrine cells can be studied in a whole-mounted preparation of the retina, horizontal cells and amacrine cells located in the inner nuclear layer are only poorly accessible for electrodes in whole retina tissue.
To achieve maximum accessibility and synaptic integrity, we developed a horizontal slice preparation of the mouse retina, and studied signal transmission at the synapse between photoreceptors and horizontal cells. Horizontal sectioning allows&#160;(1) easy and unambiguous visual identification of horizontal cell bodies for electrode targeting, and (2) preservation of the extended horizontal cell dendritic fields, as a prerequisite for intact and functional cone synaptic input to horizontal cell dendrites.
Horizontal cells from horizontal slices exhibited tonic synaptic activity in the dark, and they responded to brief flashes of light with a reduction of inward current and diminished synaptic activity. Immunocytochemical evidence indicates that almost all cones within the dendritic field of a horizontal cell establish synapses with its peripheral dendrites. The horizontal slice preparation is therefore well suited to study the physiological properties of horizontally extended retinal neurons as well as sensory signal transmission and integration across selected synapses.

We developed a horizontal slice preparation of the adult mammalian retina with the plane of sectioning parallel to the retinal surface. Dendritic fields of nonradially oriented retinal neurons were not truncated, allowing the study of signal processing with patch-clamp and imaging techniques.

Preparación de cortes horizontales de ratón adulto Retina de Estudios electrofisiológicos

Vertical slice preparations are well established to study circuitry and signal transmission in the adult mammalian retina. The plane of sectioning in ...

Single-cell RNA-Seq of Defined Subsets of Retinal Ganglion Cells

The discovery of cell type-specific markers can provide insight into cellular function and the origins of cellular heterogeneity. With a recent push for the improved understanding of neuronal diversity, it is important to identify genes whose expression defines various subpopulations of cells. The retina serves as an excellent model for the study of central nervous system diversity, as it is composed of multiple major cell types. The study of each major class of cells has yielded genetic markers that facilitate the identification of these populations. However, multiple subtypes of cells exist within each of these major retinal cell classes, and few of these subtypes have known genetic markers, although many have been characterized by morphology or function. A knowledge of genetic markers for individual retinal subtypes would allow for the study and mapping of brain targets related to specific visual functions and may also lend insight into the gene networks that maintain cellular diversity. Current avenues used to identify the genetic markers of subtypes possess drawbacks, such as the classification of cell types following sequencing. This presents a challenge for data analysis and requires rigorous validation methods to ensure that clusters contain cells of the same function. We propose a technique for identifying the morphology and functionality of a cell prior to isolation and sequencing, which will allow for the easier identification of subtype-specific markers. This technique may be extended to non-neuronal cell types, as well as to rare populations of cells with minor variations. This protocol yields excellent-quality data, as many of the libraries have provided read depths greater than 20 million reads for single cells. This methodology overcomes many of the hurdles presented by Single-cell RNA-Seq and may be suitable for researchers aiming to profile cell types in a straightforward and highly efficient manner.

Here, we present a combinatorial approach for classifying neuronal cell types prior to isolation and for the subsequent characterization of single-cell transcriptomes. This protocol optimizes the preparation of samples for successful RNA Sequencing (RNA-Seq) and describes a methodology designed specifically for the enhanced understanding of cellular diversity.

RNA-Seq de una sola célula de subconjuntos definidos de células de ganglio retiniano

The discovery of cell type-specific markers can provide insight into cellular function and the origins of cellular heterogeneity. With a recent push for ...