Authors would like to thank Peter Mombaerts for the generous gift of OR-GFP mice; Anne Lefranc and the CSGA animal facility for excellent animal care. Funding was provided by CNRS through an ATIP and ATIP Plus grants, by Conseil R&#233;gional de Bourgogne (FABER and PARI grants), by Universit&#233; de Bourgogne (BQR program).

Dieses Protokoll folgt den Tierpflege Richtlinien der Université de Bourgogne und wurde von der Université de Bourgogne Ethikkommission genehmigt. 1. Tiere <ol><li> Verwenden gentechnisch OR-IRES-tauGFP Mäuse verfügbar am Jackson Laboratory. Diese Mäuse wurden in Dr. Peter Mombaerts &#39;Labor, um Axon-Targeting und Entwicklung des olfaktorischen Systems 19 Analyse entwickelt. ZB die MOR23-IRES-tauGFP Linie, Fahrzeugnummer 006643, trägt den offiziellen Namen Stamm B6; 129P2- Olfr16 tm2Mom / MomJ; Auch die SR1-IRES-tauGFP Linie, Fahrzeugnummer 6717 trägt den offiziellen Namen B6; 129P2- Olfr124 tm1Mom / MomJ. </li><li> In Bezug auf das Alter der Tiere: für ein besseres Ergebnis der Protokoll verwenden Tieren zwischen 2 und 4 Wochen alt sind. In dieser Altersgruppe ist die Präparation leichter (weicher Knochen, festere Riechepithel) und die dendritischen Knöpfe sind bigger Vergleich zu älteren Tieren. </li></ol> 2. Herstellung von Elektroden und Lösungen <ol><li> Für die anregende Pipetten: Kauf prepulled anregende Pipetten. Andernfalls manuell vorzubereiten. <ol><li> Unter Verwendung einer Flamme, biegen sechs 1 mm Glaspipetten bei etwa 1 cm von der Spitze. Legen Sie diese sechs Pipetten sowie eine gerade 7. in 1,5 cm Schrumpfschlauch zu stärken durch eine Öse. </li><li> Schrumpf den Schlauch, um die Fässer miteinander verbunden zu halten. Bringen Sie eine zusätzliche Schrumpfschlauch, um das andere Ende der Fässer. Ziehen Sie diese anregende Pipette mit einem Multi-Barrel Magnet. </li><li> Fügen Sie etwas weiß Flüssigkleber rund um die Öse, um die gebogenen Spitzen zu stärken. Trocknen lassen O / N. </li></ol></li><li> Vorbereitung 1 oder 2 L normaler Ringer- extrazelluläre Lösung (in mM: NaCl 124, KCl 3, MgSO 4 1.3, CaCl 2 2, NaHCO 3 26, NaH 2 PO 4 1,25, Glucose 15, pH 7,6 und 305 mOsm). Halten bei 4 ° Cbis zur Verwendung. </li><li> Vorbereitung intrazellulärem Stammlösung (in mM): KCl 70, KOH 53, Methansulfonsäure 30, EGTA 5, HEPES 10, Saccharose 70; pH 7,2 (KOH) und 310 mOsm. Halten bei 4 ° C bis zur Verwendung. Gut für mehrere Wochen. </li><li> Bereiten intrazellulären Recording-Lösung mit Nystatin aus dem Stegreif (in letzter Minute), bevor Experiment. <ol><li> Wiegen 3 mg Nystatin, fügen Sie 50 ul DMSO; Wirbel 20 sec beschallen dann 2-3 Minuten, bis vollständig verdünnt. </li><li> Mit 20 &amp; mgr; l DMSO-Nystatin-Lösung in 5 ml Stammlösung intrazellulär. Vortex 20 sec, dann 3 min beschallen. Diese Lösung wird bei 4 ° C und vor direktem Licht schützen, ist Nystatin lichtempfindlich. Diese Lösung kann für einige Stunden verwendet werden. Jeden Tag zu ersetzen. </li><li> Sobald das Riechepithel Präparat unter dem Mikroskop, nehmen Sie etwas von dieser Lösung in einer 1-ml-Spritze mit einer Flamme und gedehnten gelber Spitze, um die Elektroden zu füllen; vor direktem Licht schützen. Sobald bei RT, der Nystatin-Lösungnicht stabil ist; ersetzen Sie die Lösung in der 1 ml Spritze jede Stunde oder halten Sie es in Eis. </li></ol></li><li> Ziehen Aufzeichnungselektroden mit einer Abziehvorrichtung langen Hals und kleine Spitze (~ 2 &amp; mgr; m) mit einem Widerstand von 15-20 MOhm mit dem internen Nystatin-Lösung zu erhalten. </li><li> Bereiten Geruchsstoff-Lösung mit 0,5 M in DMSO unter Abzug; aliquoten bringen und -20 ° C bis zur Verwendung. Verdünnte Riechstoff in Ringer-Lösung, bis die gewünschte Konzentration. Füllen Sie den stimulierenden Pipette. </li></ol> 3. Herstellung von Riechepithel Hinweis: oder-IRES-tauGFP Mäuse exprimieren das tauGFP unter der Steuerung der ODER-Promotor. Bei diesen Mäusen werden alle Neuronen, die oder von Interesse mit GFP markiert. Dieses Protokoll wird für die Regionen in äußerster Rand in allen Zonen ausgedrückt angepasst. Allerdings sind Dissektionen und Aufnahmen einfacher für OPs im Rückenbereich ausgedrückt. <ol><li> Betäuben das Tier durch Injektion einer Mischung aus Ketamin und Xylazin (150 mg / kg und 10 mg / kg BODy Gewicht, respectively). Enthauptung kann mit einer scharfen Schere für junge Mäuse oder mit einem ordnungsgemäß gewartet Nagetier Guillotine für ältere Mäuse durchgeführt werden. <ol><li> Verwendung Ring Präparierscheren einen mittleren Längsschnitt durch die Rückenhaut. Entfernen Sie die Haut, indem Sie sie auseinander. Mit der Schere, schneiden Sie die Unterkiefer im Kiefergelenk. Entfernen Sie die oberen Frontzähne durch einen koronalen Schnitt parallel zu den Zähnen. </li><li> Machen Sie einen koronalen Schnitt des Kopfes hinter den Augen, und nur den vorderen Teil des Kopfes zu halten. Tauchen sie in eiskaltes Ringer-Lösung für die Präparation in den Geltungsbereich. </li></ol></li><li> Sezieren in den Anwendungsbereich: in der Bauchseite, stellen einen Längsschnitt entlang der Oberkiefer / Zähne. Schneiden Sie die dorsalen Knochen in Längsrichtung nach der dorsolateralen Seite der Nasenhöhle. Entfernen Sie die meisten Knochen und Gaumen; übertragen die Scheidewand und das Epithel mit ihm verbunden in Sauerstoff angereichert Ringer bei RT. </li><li> Für die endgültige Präparation: Kurz vor Beginn der AufzeichnungSitzung, abziehen der Epithel von der zugrunde liegenden Septum mit einer Pinzette. Nehmen Sie das Epithel mit einer Pinzette und mit zwei 4-5 mm Scherenschnitte (Verwendung microvannas Schere) auf den vorderen Teil der Nasenscheidewand, wo die Haftung ist stärker. <ol><li> Entfernen Sie vorsichtig die Vomeronasalorgans durch Ausschneiden entlang der dorsalen Verbindung zum Septum-Epithel. Übertragen Sie das Epithel zu einer Aufzeichnungskammer, die mit der Schleimschicht nach oben; halten Sie es flach in der Kammer mit einer Harfe. </li></ol></li><li> Installieren Kammer unter einem aufrechten Mikroskop mit Fluoreszenzoptik und einer empfindlichen Kamera ausgestattet. Visualisieren Sie die Vorbereitung auf dem Computerbildschirm bei hoher Vergrößerung durch ein 40-fach Wasserimmersionsobjektiv (numerische Apertur 0,8) und ein extra 2X oder 4X Vergrößerung durch eine Vergrößerungslinse erreicht. Perfundieren kontinuierlich mit Sauerstoff angereichert Ringer bei RT (1-2 ml / min). </li></ol> 4. Recording Session <ol><li> Suchen Sie für fluoreszierende Zelle: regen die Herstellung bei 480nm für EGFP, die Licht im Bereich 530-550 nm emittiert; Ziel einer dendritischen Knopf, der in der Fluoreszenz und unter Hellfeld zuverlässig sichtbar ist. </li><li> Füllen Elektrode mit intrazellulären Lösung mit Nystatin; entfernen Luftblasen durch leichtes Antippen auf der Elektrode. </li><li> Einfügen Elektrode auf Elektrodenhalter, gelten positive Druck in der Pipette; Widerstand sollte 15-20 MOhm sein. </li><li> Bringen Elektrode in der Nähe der Zelle; einmal Widerstand erreicht ~ 40 MOhm, lassen Druck und mit leichtem Unterdruck wird eine undurchlässige erreichen. </li><li> Sobald Dichtung erreicht ist, setzen Sie das Membranpotential von etwa -75 mV; </li><li> Sobald die Zelle geöffnet wird, fahren Sie mit Stimulationsprotokolle, pharmakologische Behandlungen. Um die Antwort auf eine einzelne Riechstoff Stimulation Rekord 200-500 ms von spontaner Aktivität zu messen, zu stimulieren für 500 ms und messen die Antwort der Zelle bis zu 10 sec 13. Für pharmakologische Behandlungen, durchströmen die pharmakologischen Mitteln andie gewünschte Konzentration 20. </li></ol> 5. Datenanalyse <ol><li> Analysieren von Geruchsstoffströme Stimulation ausgelöst wie folgt: die maximale Amplitude, die Anstiegszeit (Zeit notwendig, 90% der Maximalamplitude erreichen, in msec), dem Gesamtstrom (Fläche unter der Kurve in PAS), die Zeit, zu 50% (Zeit zwischen dem Beginn und dem Versatz der Reaktion bei 50% der maximalen Amplitude in ms). <ol><li> Mit den Spitzenübertragungsströme (maximale Amplitude erreicht) in unterschiedlichen Konzentrationen, ziehen und passen eine Dosis-Wirkungs-Kurve mit der Hill-Gleichung: I = Imax / (1 ​​+ (K 1/2 / C) n), wobei I den Spitzenstrom Imax die maximale Antwort bei sättigenden Konzentrationen, K1 / 2 die Konzentration, bei der die Hälfte der maximalen Reaktion erreicht war, C die Konzentration des Geruchsstoffs und n der Hill-Koeffizient. </li></ol></li><li> Analysieren Sie Aufnahmen von Membranpotential in Stromzange für die maximale Depolarisation, die total Potential ausgelöst (Fläche unter der Kurve in mVsec); Rekord spontane spiking Aktivität über 30 sec bis 1 min-Aufnahmen; Rekord Erregbarkeit durch Spikes durch Injektion von Strömen (5-10 pA) ausgelöst. </li></ol>

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The authors declare that they have no competing financial interest.

Die Fähigkeit dieses Protokoll, um die Eigenschaften der gesunden OSNs korrekt überwachen hängt stark von der Qualität der Vorbereitung. Daher sind die Dissektion Schritte kritisch. Zunächst ist es wichtig, auf die Qualität (pH, Osmolarität), Sauerstoffzufuhr und Temperatur (eiskalten, aber nicht gefroren) der Dissektion Medium zu zahlen. Zweitens müssen die Manipulation der Epithel mit Präparierbesteck so begrenzt wie möglich ist, Schäden zu vermeiden. Schließlich ist es wichtig, eine Zubereitung so flach w...

Riechzellen (OSN) stellen den ersten Schritt der Geruchswahrnehmung. Das Hotel liegt im Riechepithel Auskleidung der Nasenhöhle in Nagetieren, verwandeln sie die chemische Informationen von Geruchsstoffen in Aktionspotentiale durch ihre Axon an das Gehirn gesendet. Die Duftverarbeitung Mechanismen besser zu verstehen, ist es notwendig, die Transduktion und Membraneigenschaften OSNs charakterisieren. Bis vor kurzem waren die meisten Techniken verwendet werden, um die Eigenschaften von Säugetier OSNs charakterisieren wurden an dissoziierten OSNs 1-4 durchgeführt. Die Dissoziation Verfahren verwendet verschiedene mechanische und chemische (dh Enzyme) Prozesse, die OSNs aus ihrer Umgebung zu befreien. Diese Prozesse führen zu einer geringen Anzahl von verfügbaren Zellen für Aufzeichnungen. Diese geringe Zahl kann im Fall von GFP markierten Zellen noch kritisch. Dissoziation entfernt auch die lokale Zell-Zell-Wechselwirkungen zwischen OSNs und anderen Zellen des olfaktorischen Epithels surviv erhöhen kannal und Modulation OSNs &#39;Eigenschaften. Um die Dissoziation Verfahren umgehen, wurde ein intaktes Präparat 5 entwickelt. Jedes OSN drückt eine Geruchsrezeptor (OR), die aus einer großen Multigenfamilie 6. Es gibt ~ 1.000 OPs im Haupt Riechepithel in der Maus zum Ausdruck gebracht. Aufgrund der großen Anzahl von OR in Wildtyp-Tiere, die Chancen zu OSNs exprimieren denselben Datensatz oder sehr gering sind. Um diese Einschränkungen zu überwinden, sind Gen gerichtet Mäusen vorhanden, in der alle OSNs exprimieren eine bestimmte oder mit einem fluoreszierenden Protein, 7-9 bezeichnet. Diese markierten OSNs wurden verwendet, um Funktionsanalyse in dissoziierten Vorbereitungen 7,10,11 mit den bereits erwähnten Nachteilen zu tun. Ein intaktes Epithel Vorbereitung 5 aus genetisch markierten Mäusen umgeht daher diese Fragen. Es erlaubt die Überwachung der Aktivität des OSNs exprimieren genau definierten ORs in einer Umgebung so dicht in vivo wie möglich. Außerdem Patch-Clamp-Aufnahmen von OSNs erlauben auch genaue Analyse der Membraneigenschaften, Übertragungsweg Pharmakologie, Ligand / oder Wechselwirkungen. Alle diese Themen kaum mit extrazellulären Aufnahmen analysiert werden. Wir nutzten diese Technik, um die Reaktionen der OSNs Expression der Geruchsrezeptoren SR1 und MOR23 12,13 überwachen. Die Machbarkeit der Technik wurde von anderen Gruppen auf MOR23 ausdrücken OSNs 14 sowie auf andere Regionen in äußerster Rand exprimierenden Neuronen 15,16 bestätigt. Die Überwachung eines definierten Population von OSNs können zur Analyse ihrer Eigenschaften in vielen verschiedenen Zusammenhängen wie Entwicklung 14 führen, Alterung 17, Geruchsstoff induzierter Plastizität 18, und die Rolle der Veränderungen in Folge der Geruchsrezeptor in Duftkodierung 15. Dieses Protokoll stellt somit ein leistungsfähiges Werkzeug, um die funktionellen Eigenschaften definiert OSNs an der Membranebene zu überwachen.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td colspan="4">heavy equipment</td>
		</tr>
		<tr>
			<td>vibration table with Faraday cage</td>
			<td>TMC</td>
			<td>63-500 SERIES</td>
			<td>required : isolates the recording system from vibrations induced by the environment (movements of experimenter, vibrations of equipment such as fans for cooling computers, etc); can also be purchased with a Faraday cage, or equipped by a custom made Faraday cage; this cage is recommended to avoid electric noise from the environment</td>
		</tr>
		<tr>
			<td colspan="4">optics</td>
		</tr>
		<tr>
			<td>microscope</td>
			<td>Olympus</td>
			<td>BX51WI</td>
			<td>upright microcope equipped with epifluorescence; fixed or moving stage depending on the user&#39;s preference</td>
		</tr>
		<tr>
			<td>objectives</td>
			<td>Olympus</td>
			<td>LUMPLFL40XW</td>
			<td>at least 2 objectives required: a 4x or 10x for coarse approach to the cell; and a 40x immersion long distance example Olympus LUMPLFL40XW/IR/0,8/WD:3.3 MM</td>
		</tr>
		<tr>
			<td>magnifier</td>
			<td>Olympus</td>
			<td>U-TVCAC</td>
			<td>ABSOLUTELY REQUIRED: placed in the light path between the objective and the camera; allows to magnify the image on the screen in order to reach precisely the knob with the recording electrode</td>
		</tr>
		<tr>
			<td>camera</td>
			<td>Olympus</td>
			<td>DP72</td>
			<td>a good camera is required to see the neurons in fluorescence as well as in bright field; the controlling software is simple and allows to take pictures and do live camera image to monitor the approach of the electrode to the cell. An ultrasensitive camera is not necessary</td>
		</tr>
		<tr>
			<td>filters</td>
			<td>Olympus/Chroma</td>
			<td></td>
			<td>depending on the fluorescent protein used in the mice; example for GFP: excitation : BP460-490: emission: HQ530/50m</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">recording electrodes /system</td>
		</tr>
		<tr>
			<td>amplifier</td>
			<td>HEKA</td>
			<td>EPC10 USB</td>
			<td>monitors the currents flowing through the recording electrode and also controls the puffing by sending a TTL signal to the spritzer; the EPC10 setup is controled by computer</td>
		</tr>
		<tr>
			<td>software</td>
			<td>HEKA</td>
			<td>Patchmaster</td>
			<td>controls the amplifier during the experiment</td>
		</tr>
		<tr>
			<td>micromanipulator</td>
			<td>Sutter</td>
			<td>MP225</td>
			<td>precision micromanipulator, allows precise movements down to 1/1Oth of a micrometer; this model is very stable; avoid hydraulic manipulators that may drift</td>
		</tr>
		<tr>
			<td>electrode puller</td>
			<td>sutter</td>
			<td>P97</td>
			<td>with a FT345-B wide trough filament;&#160; to prepare recording pipets of about 2&#181;m diameter with a long tip to reach the cells; the resistance should be 15 to 20Mohm with perforated patch clamp solution</td>
		</tr>
		<tr>
			<td>glass</td>
			<td>sutter</td>
			<td>BF120-69-10</td>
			<td>in our recording conditions, this glass is ideal for recording pipets</td>
		</tr>
		<tr>
			<td>recording chamber</td>
			<td>warner instruments</td>
			<td>RC-26G</td>
			<td>a chamber is needed to set the preparation under the microscope. To maintain the preparation in the center of the chamber, a net/anchor should be used.</td>
		</tr>
		<tr>
			<td colspan="4">stimulation</td>
		</tr>
		<tr>
			<td>glass</td>
			<td>WPI</td>
			<td>TW100F-4</td>
			<td>attached in groups of 7, these pipettes are used to prepare prepulled stimulating pipettes</td>
		</tr>
		<tr>
			<td>multibarrel puller</td>
			<td>MDI</td>
			<td>PMP-107-Z</td>
			<td>by association of pull and twist, this puller allows us to prepare puffing electrodes with 7 barrels</td>
		</tr>
		<tr>
			<td>precision pressure injector&#160;</td>
			<td>Toohey Company</td>
			<td>P/N T25-1-900 Single Channel&#160;&#160;&#160;</td>
			<td>this precision pressure injector&#160; controls the pressure ejected in the multibarrel puller; it is controlled manually or by the amplifier by a 5V&#160; TTLs</td>
		</tr>
		<tr>
			<td>micromanipulator</td>
			<td>Narishige</td>
			<td>YOU-1</td>
			<td>a coarse manipulator is enough to bring the puffing electrode close to the recording site</td>
		</tr>
		<tr>
			<td>tubings</td>
			<td>N/A</td>
			<td></td>
			<td>tygon tubing to bring the pressure from the puffer to the puffing pipette</td>
		</tr>
		<tr>
			<td colspan="4">solutions/perfusion/chemicals</td>
		</tr>
		<tr>
			<td>vacuum pump</td>
			<td>gardner denver</td>
			<td>300 series</td>
			<td>a vibrating membrane pump is more quiet and efficient than other types of pumps</td>
		</tr>
		<tr>
			<td>perfusion system</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>gravity perfusion system with polyethlylen tubing to bring in and out the external solution from the recording chamber</td>
		</tr>
		<tr>
			<td>nystatin</td>
			<td>Sigma-Aldrich</td>
			<td>N3503</td>
			<td>mandatory to perpare internal solution for perforated patch clamp</td>
		</tr>
		<tr>
			<td>DIMETHYL SULFOXIDE</td>
			<td>Sigma-Aldrich</td>
			<td>D5879</td>
			<td>used to disolve nystatin for internal solution for perforated patch&#160;</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Sigma-Aldrich</td>
			<td>S9625</td>
			<td>extracellular solution</td>
		</tr>
		<tr>
			<td>Potassium chloride</td>
			<td>Sigma-Aldrich</td>
			<td>P4504</td>
			<td>intracellular/extracellular solution</td>
		</tr>
		<tr>
			<td>Calcium chloride di hydrate</td>
			<td>Sigma-Aldrich</td>
			<td>C7902</td>
			<td>extracellular solution</td>
		</tr>
		<tr>
			<td>Sodium phosphate monobasic monohydrate (NaH2PO4)</td>
			<td>Sigma-Aldrich</td>
			<td>S9638</td>
			<td>extracellular solution</td>
		</tr>
		<tr>
			<td>Magnesium sulfate heptahydrate (MgSO4 7H2O)</td>
			<td>Sigma-Aldrich</td>
			<td>63140</td>
			<td>extracellular solution</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Sigma-Aldrich</td>
			<td>G8270</td>
			<td>extracellular solution</td>
		</tr>
		<tr>
			<td>Sodium bicarbonate</td>
			<td>Sigma-Aldrich</td>
			<td>S6297</td>
			<td>extracellular solution</td>
		</tr>
		<tr>
			<td>EGTA (Ethylene glycol-bis(2-aminoethylether)-N,N,N&#8242;,N&#8242;-tetraacetic acid)</td>
			<td>Sigma-Aldrich</td>
			<td>E3889</td>
			<td>internal solution</td>
		</tr>
		<tr>
			<td>Potassium hydroxyde</td>
			<td>Sigma-Aldrich</td>
			<td>P1767</td>
			<td>internal solution</td>
		</tr>
		<tr>
			<td>MethylSulfoxide</td>
			<td>Sigma-Aldrich</td>
			<td>47,135-6</td>
			<td>intracellular solution</td>
		</tr>
		<tr>
			<td>Hepes-Na</td>
			<td>Sigma-Aldrich</td>
			<td>H7006</td>
			<td>intracellular solution</td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Sigma-Aldrich</td>
			<td>S0389</td>
			<td>intracellular solution</td>
		</tr>
	</tbody>
</table>

perforated patch-clamp recording of mouse olfactory sensory neurons in intact neuroepithelium: functional analysis of neurons expressing an identified odorant receptor

Analysieren der physiologischen Reaktionen von Riechzellen (OSN), wenn sie mit spezifischen Liganden stimuliert ist kritisch, um die Basis der olfaktorischen getriebenen Verhaltensweisen und deren Modulation zu verstehen. Diese Codierungseigenschaften hängen stark von der anfänglichen Interaktion zwischen Geruchsmolekülen und der Geruchsrezeptor (OR), ausgedrückt in der OSN. Die Identität, Spezifität und Ligandenspektrum der ausdrücklich oder kritisch sind. Die Wahrscheinlichkeit, den Liganden des OR finden Ausdruck in einer nach dem Zufallsprinzip im Epithel gewählt OSN ist sehr gering. Um dieser Herausforderung zu begegnen, wird in diesem Protokoll genetisch tagged Mäusen das fluoreszierende Protein GFP unter der Kontrolle des Promotors des definierten Randlage zum Ausdruck. OSNs sind in einer engen und organisierte Epithel der Nasenhöhle gelegen, mit Nachbarzellen zu beeinflussen ihre Reifung und Funktion. Hier beschreiben wir eine Methode, um eine intakte Riechepithel zu isolieren und durch Patch-Clamp-Aufnahmen erfassen die Eigenschaften OSNs expressing definierten Geruchsrezeptoren. Das Protokoll kann eine OSN Membraneigenschaften zu charakterisieren, während der Einfluss der benachbarten Gewebe. Analyse der Patch-Clamp-Ergebnisse ergibt eine präzise Quantifizierung der Ligand / oder Wechselwirkungen, Übertragungswege und Pharmakologie, OSNs &quot;Kodierungseigenschaften und deren Modulation an der Membranebene.

Das Ergebnis dieses Protokolls ist abhängig von der Qualität der Präparation. Diese Dissektion Schritte müssen kurz (weniger als 10 bis 15 min) und präzise (dh auf Schäden des Epithels zu vermeiden) sein. Die 1 veranschaulicht, wie eine ideale Vorbereitung sieht aus wie bei verschiedenen Vergrößerungsstufen. Bei einer niedrigen Vergrößerung unter Hellfeld die verschiedenen Zelltypen (wie Knöpfe OSNs, Stützzellen) sind zu unterscheiden (Abbildung 1A). Bei der höchst...

Watch this Scientific Journal Video about Perforated Patch-clamp Recording of Mouse Olfactory Sensory Neurons in Intact Neuroepithelium: Functional Analysis of Neurons Expressing an Identified Odorant

Perforated Patch-clamp Recording of Mouse Olfactory Sensory Neurons in Intact Neuroepithelium: Functional Analysis of Neurons Expressing an Identified Odorant Receptor

Analyzing the physiological properties of olfactory sensory neurons still faces technical limitations. Here we record them through perforated patch-clamp in an intact preparation of the olfactory epithelium in gene-targeted mice. This technique allows the characterization of membrane properties and responses to specific ligands of neurons expressing defined olfactory receptors.

Perforated-Patch-Clamp-Aufzeichnung der Maus Riechzellen in Intact Neuroepithel: Funktionelle Analyse von Neuronen, die eine bestimmte Geruchsrezeptor

Analyzing the physiological responses of olfactory sensory neurons (OSN) when stimulated with specific ligands is critical to understand the basis of ...

perforated-patch-clamp-recording-mouse-olfactory-sensory-neurons

Research

JoVE Journal

Neuroscience

26.6K Aufrufe.  Université de Bourgogne. Analyzing the physiological properties of olfactory sensory neurons still faces technical limitations. Here we record them through perforated patch-clamp in an intact preparation of the olfactory epithelium in gene-targeted mice. This technique allows the characterization of membrane properties and responses to specific ligands of neurons expressing defined olfactory receptors.

Serie: Perforated Patch-clamp Recording of Mouse Olfactory Sensory Neurons in Intact Neuroepithelium: Functional Analysis of Neurons Expressing an Identified Odorant Receptor

Analyzing Responses of Mouse Olfactory Sensory Neurons Using the Air-phase Electroolfactogram Recording

Animals depend on olfaction for many critical behaviors, such as finding food sources, avoiding predators, and identifying conspecifics for mating and other social interactions. The electroolfactogram (EOG) recording is an informative, easy to conduct, and reliable method to assay olfactory function at the level of the olfactory epithelium. Since the 1956 description of the EOG by Ottoson in frogs1, the EOG recording has been applied in many vertebrates including salamanders, rabbits, rats, mice, and humans (reviewed by Scott and Scott-Johnson, 2002, ref. 2). The recent advances in genetic modification in mice have rekindled interest in recording the EOG for physiological characterization of olfactory function in knock-out and knock-in mice. EOG recordings have been successfully applied to demonstrate the central role of olfactory signal transduction components3-8, and more recently to characterize the contribution of certain regulatory mechanisms to OSN responses9-12.
Odorant detection occurs at the surface of the olfactory epithelium on the cilia of OSNs, where a signal transduction cascade leads to opening of ion channels, generating a current that flows into the cilia and depolarizes the membrane13. The EOG is the negative potential recorded extracellularly at the surface of the olfactory epithelium upon odorant stimulation, resulting from a summation of the potential changes caused by individual responsive OSNs in the recording field2. Comparison of the amplitude and kinetics of the EOG thus provide valuable information about how genetic modification and other experimental manipulations influence the molecular signaling underlying the OSN response to odor. 
Here we describe an air-phase EOG recording on a preparation of mouse olfactory turbinates. Briefly, after sacrificing the mouse, the olfactory turbinates are exposed by bisecting the head along the midline and removing the septum. The turbinate preparation is then placed in the recording setup, and a recording electrode is placed at the surface of the olfactory epithelium on one of the medial turbinates. A reference electrode is electrically connected to the tissue through a buffer solution. A continuous stream of humidified air is blown over the surface of the epithelium to keep it moist. The vapor of odorant solutions is puffed into the stream of humidified air to stimulate the epithelium. Responses are recorded and digitized for further analysis.

The electroolfactogram (EOG) recording is an informative, easy-to-conduct, and reliable way of assessing olfactory function at the level of the olfactory epithelium. This protocol describes a recording setup, mouse tissue preparation, data collection, and basic data analysis.

Analysieren Antworten der Maus Riechzellen Mit der Air-Phase Electroolfactogram Recording

Animals depend on olfaction for many critical behaviors, such as finding food sources, avoiding predators, and identifying conspecifics for mating and ...

Forschung

Neurowissenschaften

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 ...

Lentivirus-mediated Genetic Manipulation and Visualization of Olfactory Sensory Neurons in vivo

Development of a precise olfactory circuit relies on accurate projection of olfactory sensory neuron (OSN) axons to their synaptic 
targets in the olfactory bulb (OB). The molecular mechanisms of OSN axon growth and targeting are not well understood. Manipulating gene expression and subsequent 
visualizing of single OSN axons and their terminal arbor morphology have thus far been challenging. To study gene function at the single cell level within a specified 
time frame, we developed a lentiviral based technique to manipulate gene expression in OSNs in vivo. Lentiviral particles are delivered to OSNs by microinjection 
into the olfactory epithelium (OE). Expression cassettes are then permanently integrated into the genome of transduced OSNs. Green fluorescent protein expression 
identifies infected OSNs and outlines their entire morphology, including the axon terminal arbor. Due to the short turnaround time between microinjection and 
reporter detection, gene function studies can be focused within a very narrow period of development. With this method, we have detected GFP expression within as 
few as three days and as long as three months following injection. We have achieved both over-expression and shRNA mediated knock-down by lentiviral microinjection. 
This method provides detailed morphologies of OSN cell bodies and axons at the single cell level in vivo, and thus allows characterization of candidate gene function 
during olfactory development.

Lentivirus-mediated Genetic Manipulation and Visualization of Olfactory Sensory Neurons in vivo

We present a lentiviral technique for genetic manipulation and visualization of single olfactory sensory neuron axon and its terminal arborization in vivo.

Lentivirus-vermittelte Gen-Manipulation und Visualisierung von Riechzellen In vivo</em

Development of a precise olfactory circuit relies on accurate projection of olfactory sensory neuron (OSN) axons to their synaptic 
targets in the ...

Flash Photolysis of Caged Compounds in the Cilia of Olfactory Sensory  Neurons

Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds1. Caged compounds are molecules made physiologically inactive by a chemical cage that can be broken by a flash of ultraviolet light. Here, we show how to obtain patch-clamp recordings combined with photolysis of caged compounds for the study of olfactory transduction in dissociated mouse olfactory sensory neurons. The process of olfactory transduction (Figure 1) takes place in the cilia of olfactory sensory neurons, where odorant binding to receptors leads to the increase of cAMP that opens cyclic nucleotide-gated (CNG) channels2. Ca entry through CNG channels activates Ca-activated Cl channels. We show how to dissociate neurons from the mouse olfactory epithelium3 and how to activate CNG channels or Ca-activated Cl channels by photolysis of caged cAMP4 or caged Ca5. We use a flash lamp6,7 to apply ultraviolet flashes to the ciliary region to uncage cAMP or Ca while patch-clamp recordings are taken to measure the current in the whole-cell voltage-clamp configuration8-11.

Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds. Here, we show how to obtain patch-clamp recordings combined with photolysis of caged cAMP or caged Ca for the study of olfactory transduction in dissociated mouse olfactory sensory neurons.

Flash-Photolyse von Caged Compounds in den Zilien der Riechzellen

Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds1. ...

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated. Thus, simultaneous recordings of neuronal activity and behavior are essential to correlate brain activity to behavior. For such behavioral analyses, the fruit fly, Drosophila melanogaster, allows us to incorporate genetically encoded calcium indicators such as GCaMP1, to monitor neuronal activity, and to use sophisticated genetic manipulations for optogenetic or thermogenetic techniques to specifically activate identified neurons2-5. Use of a thermogenetic technique has led us to find critical neurons for feeding behavior (Flood et al., under revision). As a main part of feeding behavior, a Drosophila adult extends its proboscis for feeding6 (proboscis extension response; PER), responding to a sweet stimulus from sensory cells on its proboscis or tarsi. Combining the protocol for PER7 with a calcium imaging technique8 using GCaMP3.01, 9, I have established an experimental system, where we can monitor activity of neurons in the feeding center &#x2013; the suboesophageal ganglion (SOG), simultaneously with behavioral observation of the proboscis. I have designed an apparatus ("Fly brain Live Imaging and Electrophysiology Stage": "FLIES") to accommodate a Drosophila adult, allowing its proboscis to freely move while its brain is exposed to the bath for Ca2+ imaging through a water immersion lens. The FLIES is also appropriate for many types of live experiments on fly brains such as electrophysiological recording or time lapse imaging of synaptic morphology. Because the results from live imaging can be directly correlated with the simultaneous PER behavior, this methodology can provide an excellent experimental system to study information processing of neuronal networks, and how this cellular activity is coupled to plastic processes and memory.

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

The fruit fly, Drosophila melanogaster, extends its proboscis for feeding, responding to a sugar stimulus from its proboscis or tarsus. I have combined observations of the proboscis extension response (PER) with a calcium imaging technique, allowing us to monitor the activity of neurons in the brain, simultaneously with behavioral observation.

Gleichzeitige Aufnahme von Calcium-Signale von identifizierten Neuronen und Fressverhalten von Drosophila melanogaster</em

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated.  Thus, ...

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 ...

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from individual neurons are critical for understanding how neural circuits function under natural conditions. Traditionally, these recordings have been performed 'blind', meaning the identity of the recorded cell is unknown at the start of the recording. Cellular identity can be subsequently determined via intracellular1, juxtacellular2 or loose-patch3 iontophoresis of dye, but these recordings cannot be pre-targeted to specific neurons in regions with functionally heterogeneous cell types. Fluorescent proteins can be expressed in a cell-type specific manner permitting visually-guided single-cell electrophysiology4-6. However, there are many model systems for which these genetic tools are not available. Even in genetically accessible model systems, the desired promoter may be unknown or genetically homogenous neurons may have varying projection patterns. Similarly, viral vectors have been used to label specific subgroups of projection neurons7, but use of this method is limited by toxicity and lack of trans-synaptic specificity. Thus, additional techniques that offer specific pre-visualization to record from identified single neurons in vivo are needed. Pre-visualization of the target neuron is particularly useful for challenging recording conditions, for which classical single-cell recordings are often prohibitively difficult8-11. The novel technique described in this paper uses retrograde transport of a fluorescent dye applied using tungsten needles to rapidly and selectively label a specific subset of cells within a particular brain region based on their unique axonal projections, thereby providing a visual cue to obtain targeted electrophysiological recordings from identified neurons in an intact circuit within a vertebrate CNS.
The most significant novel advancement of our method is the use of fluorescent labeling to target specific cell types in a non-genetically accessible model system. Weakly electric fish are an excellent model system for studying neural circuits in awake, behaving animals12. We utilized this technique to study sensory processing by "small cells" in the anterior exterolateral nucleus (ELa) of weakly electric mormyrid fish. "Small cells" are hypothesized to be time comparator neurons important for detecting submillisecond differences in the arrival times of presynaptic spikes13. However, anatomical features such as dense myelin, engulfing synapses, and small cell bodies have made it extremely difficult to record from these cells using traditional methods11, 14. Here we demonstrate that our novel method selectively labels these cells in 28% of preparations, allowing for reliable, robust recordings and characterization of responses to electrosensory stimulation.

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde transport of fluorescent dye labels a sub-population of neurons based on anatomical projection. Labeled axons can be visually targeted in vivo, permitting extracellular recording from identified axons. This technique facilitates recording when neurons cannot be labeled through genetic manipulation or are difficult to isolate using 'blind' in vivo approaches.

Retrograde Fluoreszenzmarkierung Ermöglicht Gezielte Extracellular Einzel-Einheit Aufnahme von identifizierten Neuronen<em&gt; In vivo</em

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Recording Electrical Activity from Identified Neurons in the Intact Brain of Transgenic Fish

Understanding the cell physiology of neural circuits that regulate complex behaviors is greatly enhanced by using model systems in which this work can be performed in an intact brain preparation where the neural circuitry of the CNS remains intact. We use transgenic fish in which gonadotropin-releasing hormone (GnRH) neurons are genetically tagged with green fluorescent protein for identification in the intact brain. Fish have multiple populations of GnRH neurons, and their functions are dependent on their location in the brain and the GnRH gene that they express1 . We have focused our demonstration on GnRH3 neurons located in the terminal nerves (TN) associated with the olfactory bulbs using the intact brain of transgenic medaka fish (Figure 1B and C). Studies suggest that medaka TN-GnRH3 neurons are neuromodulatory, acting as a transmitter of information from the external environment to the central nervous system; they do not play a direct role in regulating pituitary-gonadal functions, as do the well-known hypothalamic GnRH1 neurons2, 3 .The tonic pattern of spontaneous action potential firing of TN-GnRH3 neurons is an intrinsic property4-6, the frequency of which is modulated by visual cues from conspecifics2 and the neuropeptide kisspeptin 15. In this video, we use a stable line of transgenic medaka in which TN-GnRH3 neurons express a transgene containing the promoter region of Gnrh3 linked to enhanced green fluorescent protein7 to show you how to identify neurons and monitor their electrical activity in the whole brain preparation6.

In this video, we will demonstrate how to record electrical activity from identified single neurons in a whole brain preparation, which preserves complex neural circuits. We use transgenic fish in which gonadotropin-releasing hormone (GnRH) neurons are genetically tagged with a fluorescent protein for identification in the intact brain preparation.

Aufzeichnung der elektrischen Aktivität von identifizierten Neuronen im intakten Gehirn von transgenen Fischen

Understanding the cell physiology of neural circuits that regulate complex behaviors is greatly enhanced by using model systems in which this work can be ...

Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

The marine gastropod mollusk Aplysia californica has a venerable history as a model of nervous system function, with particular significance in studies of learning and memory. The typical preparations for such studies are ones in which the sensory and motoneurons are left intact in a minimally dissected animal, or a technically elaborate neuronal co-culture of individual sensory and motoneurons. Less common is the isolated neuronal preparation in which small clusters of nominally homogeneous neurons are dissociated into single cells in short term culture. Such isolated cells are useful for the biophysical characterization of ion currents using patch clamp techniques, and targeted modulation of these conductances. A protocol for preparing such cultures is described. The protocol takes advantage of the easily identifiable glutamatergic sensory neurons of the pleural and buccal ganglia, and describes their dissociation and minimal maintenance in culture for several days without serum.

Isolation of Sensory Neurons of Aplysia californica for Patch Clamp Recordings of Glutamatergic Currents

We describe the dissection of the nervous system of the marine sea hare Aplysia after anesthesia, the isolation of neurons for short term-tissue culture, and recordings of single cell ion currents via the patch clamp technique.

Isolation von sensorischen Neuronen von<em&gt; Aplysia californica</em&gt; Für Patch-Clamp-Recordings von Glutamaterge Currents

The marine gastropod mollusk Aplysia californica has a venerable  history as a model of nervous system function, with particular significance in  studies ...

Intracellular Recording, Sensory Field Mapping, and Culturing Identified Neurons in the Leech, Hirudo medicinalis

The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of neurophysiology, neuroethology, and developmental biology. The goal of this report is to consolidate experimental techniques from the leech system into a single article that will be of use to physiologists with expertise in other nervous system preparations, or to biology students with little or no electrophysiology experience. We demonstrate how to dissect the leech for recording intracellularly from identified neural circuits in the ganglion. Next we show how individual cells of known function can be removed from the ganglion to be cultured in a Petri dish, and how to record from those neurons in culture. Then we demonstrate how to prepare a patch of innervated skin to be used for mapping sensory or motor fields. These leech preparations are still widely used to address basic electrical properties of neural networks, behavior, synaptogenesis, and development. They are also an appropriate training module for neuroscience or physiology teaching laboratories.

Intracellular Recording, Sensory Field Mapping, and Culturing Identified Neurons in the Leech, Hirudo medicinalis

This article describes three nervous system preparations using leeches: intracellular recording from neurons in ventral ganglia, culturing neurons from ventral ganglia, and recording from a patch of innervated skin to map sensory fields.