Unterstützt von Career Development Award von der Forschung zur Blindheit, NIH EY 019312, und nicht zweckgebundenen Zuschuss von Forschung Prevent Blindness und EY 02687 (Department of Ophthalmology &amp; Visual Sciences an der Washington University) zu verhindern.

Herstellung von Elektroden <ol><li> Machen Sie die Aufnahme Elektroden mit einer Mikropipette Abzieher und polieren Sie die Elektroden mit Heizdraht unter dem Mikroskop. Für Maus Kegel Single-Cell-Saug-Aufnahme wird der innere Durchmesser der Elektrodenspitze ca. 6-7 um. </li><li> Bereiten Referenzelektroden. Wiegen Sie 1% Agar in destilliertem Wasser. Schmelzen Sie die Agar-Lösung in heißen Wasserbad. Füllen Sie das Glas Pipetten (L = 100 mm, OD / ID = 1/0.75 mm) mit 1% Agar mit Spritze. Festigen der Agar bei Raumtemperatur für 10 Minuten. </li><li> Schneiden Sie die Pipetten in zwei Hälften mit einem Diamant-Messer. </li><li> Weichen Sie die Referenz-Elektroden in Bezug Lösung für mindestens 24 Stunden bei 4 ° C. </li></ol> Einrichten des Tests <ol start="5"><li> Dunkle anzupassen einer Maus in einem schwarzen Käfig über Nacht. </li><li> Bereiten Sie 100 mL Referenz-Lösung und 1 L Perfusionslösung (siehe unten) und filtrieren. </li><li> Man löst 0,1% BSA und 10 mM Glucose in 20 mL Referenzlösung. </li><li> Kalibrieren Sie die Lichtintensität der optischen Stimulator mit Photometer. </li><li> Montieren Sie die Aufnahme Kammer auf der Bühne des inversen Mikroskop. </li><li> Blase die Perfusionslösung mit 95% O 2 / 5% CO 2 inkubieren es in 40 ° C Wasserbad, um die Löslichkeit von CO 2 zu erhöhen. Die Lösung fließt aus der Flasche, um die Aufnahme Kammer durch einen keramischen Widerstand Erwärmen auf 36-38 ° C. Die Heizung sollte möglichst nahe an der Aufnahme Kammer wie möglich, idealerweise in der Phase des Mikroskops liegen. </li><li> Passen Sie den Durchflussregler für einen Volumenstrom von ca. 1-1,5 mL / min. </li><li> Füllen Sie die Aufnahme-Elektrode mit Referenz-Lösung. Legen Sie die Elektrode in einen Elektrodenhalter. Stellen Sie sicher, es gibt keine Luftblasen in der Elektrode. Montieren Sie die Halterung auf der headstage des Verstärkers. Schließen Sie die Halterung an eine Absaugvorrichtung, die von Verbindungsschlauch teilweise mit Mineralöl auf die Seite-Port des Elektrodenhalter gefüllt gebaut wird. Das andere Ende des Schlauches ist zu einem kleinen Reservoir von Mineralöl verbunden, an dem Druck durch den Mund eingesetzt werden. </li><li> Schließen Sie die Referenz-Elektrode mit dem anderen Pol der headstage. Binden Sie die Thermoelement (TC) auf die Referenz-Elektrode. Sicherstellen, dass die Elektrode und TC Tipps sind nahe beieinander, so dass die Temperaturanzeige so nah an der Zelle wie möglich getroffen werden. </li><li> Schalten Sie den Infrarot-Beleuchtung, um die Elektrode zu visualisieren. Die Elektrode wird durch Infrarot-Kamera an einen Monitor. Zentrum der Elektrode Bild auf das Gesichtsfeld und der Monitor mit einem Mikro-Manipulator. </li><li> Passen Sie die Position der Referenzelektrode Spitze nahe (2-4 mm), um die Aufnahme Elektrodenspitze. </li><li> Stellen Sie die DC-Spannung für die Heizung, so dass die Temperatur der Lösung beträgt etwa 36-38 ° C. </li><li> Run eine Dichtheitsprüfung, um den Widerstand der Aufnahme Elektrode überprüfen, in der Regel ca. 900 kOhm. </li></ol> Isolieren Sie die Maustaste Netzhaut <ol start="18"><li> Unter dim rotes Licht, euthanize Dunkeln angepasst Maus mit CO 2 und Genickbruch. Markieren Sie die Augäpfel mit der Spitze eines heißen Metalls Fackel durch Ausbrennen der dorsale Punkt der Sklera leicht. Entkernen die Augäpfel mit einer Schere. Alle nachfolgenden Verfahren sind unter Infrarot-Licht durchgeführt. </li><li> Hemisect die Augäpfel unter dem Mikroskop mit Infrarot-Beleuchtung und Bildwandler. </li><li> Entfernen Sie die Hornhaut und Linse. Entfernen Sie so viel von dem Glaskörper wie möglich. </li><li> Zur Aufnahme M-Kegel Antworten, entfernen Sie die ventralen Teil der Augenmuschel 4 mit einer Rasierklinge die Beurteilung aus dem Kauter zu markieren. </li><li> Peel die Netzhaut vom Pigmentepithel Schicht. </li><li> Flatten der Netzhaut und stelle sie auf den Boden der Petrischale mit 1-2 ml Referenzlösung gefüllt. </li><li> Scheiben der Netzhaut in kleine dünne Stücke mit einer Rasierklinge und inkubieren Sie die Zubereitung in einem lichtdichten Gehäuse mit reinem Sauerstoff gesättigt. </li></ol> Recordings <ol start="25"><li> Schalten Sie die Heizung vorübergehend. Schalten Sie die Perfusion Strömung zu einem Bypass-Schlauch, um die Kammer vor dem Austrocknen zu verhindern. </li><li> Lassen Sie die meisten der Lösung in die Kammer mit einem Stück Kimwipe Gewebe. Übertragen Sie die Netzhaut Federung, um die Aufnahme Kammer mit einer Glaspipette. </li><li> Warten Sie ca. 2 Minuten, bis die Netzhaut Scheiben nieder. Schalten Sie die Durchblutung wieder an. Schalten Sie die Heizung. </li><li> Schalten Sie Infrarot-Beleuchtung für die Vorbereitung zu visualisieren. Suche nach einem Stück der Netzhaut liegen auf der Kammer mit Photorezeptor äußeren Segmente herausragen (siehe Beispiel Abbildung). Draw inneren Segmente sanft in die Elektrode durch Absaugen. In dieser Konfiguration sollte mehrere Kerne und inneren Segmente in die Elektrode gezogen werden. Notieren Sie sich die Photoreaktion zu einem hellen Blitz zu testen, ob ein Kegel innere Segment in der Elektrode ist und ob die Zelle zu heilendein, die Beurteilung durch die Reaktion Kinetik und Amplitude. </li><li> Senken Sie den Mineral-Reservoir zu leichten Unterdruck an der Spitze der Elektrode zu helfen, halten Sie die innere Segment in der Elektrode gelten. </li><li> Rekord-Test-Flash-Reaktionen zwischen schwach und stark Intensität einmal eine gute Zelle gefunden wird. Testen Blitze aus einer kalibrierten optischen Stimulator 5 vorgesehen. Flash-Intensität und Wellenlänge sind durch eine Reihe von Neutralfilter und Schmalband-Interferenzfilter gesteuert. Testen Sie Blitzdauer (20 ms) wird vom Computer-gesteuerte Jalousien gesteuert. </li></ol> Lösungen <ol><li> Maus Perfusionslösung: 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-Succinat, 0,5 mM Na Glutamat, 0,02 mM EDTA, und 10 mM Glukose. </li><li> Maus Aufzeichnung Elektrode Lösung: 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>

Einzel-Zell-Saug-Aufnahme von Sehzellen war 3 Jahrzehnten entwickelt. Es ermöglicht uns, trans-Membran Stromänderung durch Licht Stimulation ohne die Zellmembran überwinden induzierte aufzunehmen. Wegen der hohen Zell-Zell-Adhäsion, ist es schwierig, gesunde einzelnen Stäbchen und Zapfen von der Maus Netzhaut wie Amphibien Netzhaut zu isolieren und es ist schwer, einzelne Zapfen aufgrund der geringen Prozentsatz (3%) und kleine Größe zu finden. Die Innen-Segment-in (IS-in)-Aufzeichnungsverfahren überwindet diese...

single-cell suction recordings from mouse cone photoreceptors

Rod und Zapfen-Photorezeptoren in der Netzhaut sind verantwortlich für light detection. In der Dunkelheit sind zyklisch Nukleotid-gesteuerten (CNG)-Kanäle in das äußere Segment offen und ermöglichen Kationen stetig nach innen fließen durch die Membran, depolarisierende der Zelle. Belichtung löst die Schließung des CNG-Kanäle, die Blöcke der inneren Kationen Stromfluss und damit Ergebnisse in Zelle Hyperpolarisation. Basierend auf der Polarität von Photorezeptoren, wurde eine Saug-Aufnahme-Methode in den 1970er Jahren, dass, im Gegensatz zu den klassischen Patch-Clamp-Technik, nicht erforderlich ist Eindringen in die Plasmamembran entwickelt<sup&gt; 1</sup&gt;. Drawing das äußere Segment in ein eng anliegendes Glaspipette mit extrazellulären Lösung gefüllt ermöglicht die Aufzeichnung des aktuellen Veränderungen in einzelnen Zellen auf Test-Blitzbelichtung. Doch diese gut etablierte &quot;outer-Segment-in (OS-in)&quot; Saug-Aufnahme ist nicht geeignet für Maus Konus-Aufnahmen, da der geringe Anteil der Zapfen in der Netzhaut der Maus (3%) und die Schwierigkeiten bei der Identifizierung des Kegels äußeren Segmente. Kürzlich wurde eine innere-Segment-in (IS-in) Aufnahme-Konfiguration entwickelt, um das innere Segment / Kernregion des Photorezeptors in die Aufnahme Pipette ziehen<sup&gt; 2,3</sup&gt;. In diesem Video zeigen wir, wie man aus einzelnen Maus Kegel Photomorphosen mit Single-Cell-Saugelektrode aufzunehmen.

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

Wir werden zeigen, wie man Flash-Antworten von einfachen Mausklick Kegel mit einem Saug-Elektrode aufnehmen.

Einzel-Zell-Saug-Recordings aus Maus Zapfen-Photorezeptoren

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 Aufrufe.  Washington University in St. Louis, School of Medicine. Wir werden zeigen, wie man Flash-Antworten von einfachen Mausklick Kegel mit einem Saug-Elektrode aufnehmen.

Serie: 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.

Patch Clamp Messungen von Mouse Netzhautneuronen in einem Dark-Scheiben angepasst Vorbereitung

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

Forschung

Neurowissenschaften

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.

Eine isolierte Retinal Vorbereitung auf leichte Ansprache aus genetisch markierten retinalen Ganglienzellen Rekord

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 ERG Recordings aus Maus-Retina: Stäbchen und Zapfen Photomorphosen

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.

Odorant-induzierten Reaktionen aus olfaktorischen Rezeptor-Neuronen mit der Saugpipette Technik aufgenommen

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.

Gleichzeitige Ganzzellableitungen von Photorezeptoren und Neuronen zweiter Ordnung in eine Amphibie Retinal Scheibe Vorbereitung

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.

Vibratom Schnitte Maus-Retina zu Photorezeptor Kulturen vorbereiten

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.

Recording Licht-evozierte Postsynaptische Antworten in Neuronen im Dunkel-adaptierten, Maus retinalen Scheibe Vorbereitungen Verwendung Patch-Clamp-Techniken

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.

Imaging Ca<sup&gt; 2+</sup&gt; Dynamik in Cone Photorezeptor Axonterminalen des Maus-Retina

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.

Vorbereitung von Horizontal Scheiben der erwachsenen Maus Retina für elektrophysiologische Untersuchungen

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.

Einzelzell-RNA-Seq von definierten Subsets von Retinal-Ganglion-Zellen

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