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).

Questo protocollo segue le linee guida per la cura degli animali della Université de Bourgogne ed è stato approvato dal comitato etico Université de Bourgogne. 1. Gli animali <ol><li> Utilizzare tecniche di ingegneria genetica topi OR-IRES-tauGFP disponibili presso il laboratorio di Jackson. Questi topi sono stati sviluppati in laboratorio Dr. Peter Mombaerts &#39;al fine di analizzare il targeting degli assoni e lo sviluppo del sistema olfattivo 19. Ad esempio, la linea di MOR23-IRES-tauGFP, fotografia numero 006.643, porta il nome della razza ufficiale B6; 129P2- Olfr16 tm2Mom / MomJ; allo stesso modo, la linea SR1-IRES-tauGFP, fotografia numero 6717 porta il nome di B6 ufficiale; 129P2- Olfr124 tm1Mom / MomJ. </li><li> Per quanto riguarda l&#39;età degli animali: per un migliore risultato del protocollo, utilizzare animali tra 2 e 4 settimane di età. In questa fascia di età, la dissezione è più facile (ossa più morbide, più solida epitelio olfattivo) e le manopole dendritiche sono bigger confrontare animali più vecchi. </li></ol> 2. Preparazione di elettrodi e soluzioni <ol><li> Per le pipette stimolanti: acquisto prepulled stimolante pipette. In caso contrario, li prepara manualmente. <ol><li> Utilizzando una fiamma, piegare sei pipette di vetro di 1 mm circa 1 cm dalla punta. Inserire queste sei pipette più un diritto 7 ° in 1,5 centimetri termoretraibile tubi rafforzare da un occhiello. </li><li> Termoretraibile il tubo per mantenere i barili legati insieme. Collegare un guaina termoretraibile supplementare agli altri estremità delle canne. Tirare la pipetta stimolante con un estrattore multi-barile. </li><li> Aggiungete un po &#39;di liquido colla bianca intorno l&#39;occhiello di rafforzare le punte piegate. Lasciate asciugare O / N. </li></ol></li><li> Preparare 1 o 2 L di soluzione extracellulare normale di Ringer (in mM: NaCl 124, KCl 3, MgSO4 1,3, CaCl 2 2, NaHCO3 26, NaH 2 PO 4 1.25, glucosio 15; pH 7,6 e 305 mOsm). Conservare a 4 ° Cfino al momento dell&#39;uso. </li><li> Preparare soluzione madre intracellulare (in mm): KCl 70, KOH 53, acido metansolfonico 30, EGTA 5, HEPES 10, di saccarosio 70; pH 7.2 (KOH) e 310 mOsm. Conservare a 4 ° C fino al momento dell&#39;uso. Buon per diverse settimane. </li><li> Preparare la soluzione intracellulare di registrazione con nistatina estemporanea (all&#39;ultimo minuto) prima dell&#39;esperimento. <ol><li> Pesare 3 mg di nistatina, aggiungere 50 ml di DMSO; vortex 20 sec poi sonicare 2-3 minuti fino a quando tutto diluito. </li><li> Aggiungere 20 ml di soluzione di DMSO-nystatin in 5 ml di soluzione madre intracellulare. Vortex 20 sec, poi sonicare 3 min. Conservare questa soluzione a 4 ° C e proteggere dalla luce diretta, nistatina è sensibile alla luce. Questa soluzione può essere utilizzata per alcune ore. Sostituire ogni giorno. </li><li> Una volta che la preparazione epitelio olfattivo è sotto il microscopio, prendere alcuni di questa soluzione in una siringa da 1 ml con una punta gialla allungata fiamma per riempire gli elettrodi; proteggere dalla luce diretta. Una volta a RT, la soluzione nistatinanon è stabile; sostituire la soluzione nella siringa da 1 ml ogni ora o tenerlo in ghiaccio. </li></ol></li><li> Tirare elettrodi di registrazione con un estrattore per ottenere il collo lungo e piccola mancia (~ 2 micron) con una resistenza di 15-20 MW con la soluzione nistatina interna. </li><li> Preparare la soluzione odorizzante a 0,5 M in DMSO sotto cappa; Un&#39;aliquota e conservare a -20 ° C fino al momento dell&#39;uso. Diluire odorizzante in soluzione di Ringer fino alla concentrazione desiderata. Riempire la pipetta stimolante. </li></ol> 3. Preparazione di epitelio olfattivo Nota: i topi OR-IRES-tauGFP esprimono il tauGFP sotto il controllo del promotore OR. In questi topi, tutti i neuroni che esprimono l&#39;OR di interesse sono etichettati con GFP. Questo protocollo è adattato per RUP espressi in tutte le zone. Tuttavia, dissezioni e registrazioni sono più facili per RUP espresse nella zona dorsale. <ol><li> Anestetizzare l&#39;animale iniettando una miscela di ketamina e xilazina (150 mg / kg e 10 mg / kg bodPeso y, rispettivamente). Decapitazione può essere effettuata con forbici affilate per i topi giovani o con ghigliottina roditore corretta manutenzione per i topi più anziani. <ol><li> Utilizzando anelli forbici dissezione fare una incisione longitudinale mediale attraverso la pelle dorsale. Togliere la pelle tirandolo a parte. Utilizzando le forbici, tagliare le ganasce inferiori alla mandibola. Rimuovere i denti anteriori superiori da un taglio coronale parallelo ai denti. </li><li> Fare un taglio coronale della testa dietro gli occhi e mantenere solo la parte anteriore della testa. Immergerlo in soluzione di Ringer ghiacciata per la dissezione nell&#39;ambito di applicazione. </li></ol></li><li> Sezionare nell&#39;ambito di applicazione: nel lato ventrale, un taglio longitudinale lungo la mascella superiore / i denti. Tagliare le ossa dorsali longitudinalmente, seguendo il lato dorso-laterale della cavità nasale. Rimuovere la maggior parte delle ossa e del palato; trasferire il setto e l&#39;epitelio collegato ad esso in ossigenato Ringer a RT. </li><li> Per la dissezione finale: Poco prima di iniziare la registrazionesessione, staccarsi l&#39;epitelio dal setto sottostante con una pinza. Staccare l&#39;epitelio con una pinza e con due tagli 4-5 mm forbice (uso microvannas forbici) alla parte anteriore del setto, dove l&#39;adesione è più forte. <ol><li> Rimuovere con cautela l&#39;organo vomeronasale, tagliando fuori lungo il suo collegamento dorsale all&#39;epitelio settale. Trasferire l&#39;epitelio ad una camera di registrazione con lo strato di muco rivolto verso l&#39;alto; tenere piatta nella camera con l&#39;arpa. </li></ol></li><li> Installare camera sotto un microscopio verticale dotato di ottica di fluorescenza e una macchina fotografica sensibile. Visualizzare la preparazione sullo schermo del computer ad alto ingrandimento attraverso un obiettivo 40X acqua-immersion (apertura numerica 0,8) e un 2X o 4X supplementare ottenuto da una lente di ingrandimento. Profumato continuamente con ossigenato Ringer a RT (1-2 ml / min). </li></ol> 4. sessione di registrazione <ol><li> Cerca cell fluorescente: eccitare la preparazione a 480nm per EGFP, che emette luce nel range 530-550 nm; indirizzare una manopola dendritiche, che è affidabile visibile in fluorescenza e in campo luminoso. </li><li> Riempire l&#39;elettrodo con la soluzione intracellulare con nystatin; rimuovere le bolle picchiettando delicatamente sul dell&#39;elettrodo. </li><li> Inserire elettrodo sul portaelettrodo, applicare una pressione positiva nella pipetta; La resistenza dovrebbe essere 15-20 MW. </li><li> Portare l&#39;elettrodo vicino alla cella; una volta che la resistenza raggiunge ~ 40 MW, scaricare la pressione positiva e applicare una leggera pressione negativa per raggiungere un gigaseal. </li><li> Raggiunta sigillo, impostare il potenziale di membrana a circa -75 mV; </li><li> Una volta che la cellula si apre, procedere con protocolli di stimolazione, trattamenti farmacologici. Per misurare la risposta ad una singola stimolazione odorizzante, annotazione 200-500 msec di attività spontanea, stimolare per 500 msec e misurare la risposta della cella fino a 10 sec 13. Per i trattamenti farmacologici, profumato gli agenti farmacologici inla concentrazione desiderata 20. </li></ol> Analisi 5. I dati <ol><li> Analizzare correnti indotte da stimolazione odorizzante come seguito: l&#39;ampiezza massima, il tempo di salita (tempo necessario per raggiungere il 90% della massima ampiezza, in msec), la corrente totale (area sotto la curva in PAS), il tempo al 50% (tempo tra l&#39;inizio e l&#39;offset della risposta al 50% della massima ampiezza, in msec). <ol><li> Utilizzando le correnti di picco di trasduzione (ampiezza massima raggiunta) a diverse concentrazioni, disegnare e montare una curva dose-risposta con la seguente equazione Hill: I = Imax / (1 ​​+ (K 1/2 / C) n), dove I rappresenta la corrente di picco , Imax la massima risposta a concentrazioni saturazione, K1 / 2 la concentrazione alla quale è stato raggiunto metà della risposta massima, C la concentrazione di odorizzante ed n il coefficiente di Hill. </li></ol></li><li> Analizzare registrazioni di potenziale di membrana a pinza per la massima depolarizzazione, la totapotenziale l suscitato (area sotto la curva in mVsec); registrazione spontanea attività spiking oltre 30 sec a 1 min registrazioni; record di eccitabilità attraverso picchi indotte da iniezione di correnti (5-10 Pa). </li></ol>

<ol>
	<li>Lowe, G., Gold, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonlinear+amplification+by+calcium-dependent+chloride+channels+in+olfactory+receptor+cells.">Nonlinear amplification by calcium-dependent chloride channels in olfactory receptor cells.</a> Nature. 366 (6452), 283-286 (1993).</li><li>Ponissery Saidu, S., Dibattista, M., Matthews, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant-induced+responses+recorded+from+olfactory+receptor+neurons+using+the+suction+pipette+technique.">Odorant-induced responses recorded from olfactory receptor neurons using the suction pipette technique.</a> J Vis Exp. (62), e3862 (2012).</li><li>Moss, R. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophysiological+and+biochemical+responses+of+mouse+vomeronasal+receptor+cells+to+urine-derived+compounds:+possible+mechanism+of+action.">Electrophysiological and biochemical responses of mouse vomeronasal receptor cells to urine-derived compounds: possible mechanism of action.</a> Chem Senses. 23 (4), 483-489 (1998).</li><li>Kaur, A., Dey, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Live+cell+calcium+imaging+of+dissociated+vomeronasal+neurons.">Live cell calcium imaging of dissociated vomeronasal neurons.</a> Methods Mol Biol. 1068, 189-200 (2013).</li><li>Ma, M., Chen, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrophysiological+characterization+of+rat+and+mouse+olfactory+receptor+neurons+from+an+intact+epithelial+preparation.">Electrophysiological characterization of rat and mouse olfactory receptor neurons from an intact epithelial preparation.</a> J Neurosci Methods. 92 (1-2), 31-40 (1999).</li><li>Axel, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+multigene+family+may+encode+odorant+receptors:+a+molecular+basis+for+odor+recognition.">A novel multigene family may encode odorant receptors: a molecular basis for odor recognition.</a> Cell. 65 (1), 175-187 (1991).</li><li>Bozza, T., Feinstein, P., Zheng, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant+receptor+expression+defines+functional+units+in+the+mouse+olfactory+system.">Odorant receptor expression defines functional units in the mouse olfactory system.</a> J Neurosci. 22 (8), 3033-3043 (2002).</li><li>Bozza, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+of+class+I+and+class+II+odorant+receptors+to+glomerular+domains+by+two+distinct+types+of+olfactory+sensory+neurons+in+the+mouse.">Mapping of class I and class II odorant receptors to glomerular domains by two distinct types of olfactory sensory neurons in the mouse.</a> Neuron. 61 (2), 220-233 (2009).</li><li>Vassalli, A., Rothman, A., Feinstein, P., Zapotocky, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minigenes+impart+odorant+receptor-specific+axon+guidance+in+the+olfactory+bulb.">Minigenes impart odorant receptor-specific axon guidance in the olfactory bulb.</a> Neuron. 35 (4), 681-696 (2002).</li><li>Feinstein, P., Bozza, T., Rodriguez, I., Vassalli, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Axon+guidance+of+mouse+olfactory+sensory+neurons+by+odorant+receptors+and+the+beta2+adrenergic+receptor.">Axon guidance of mouse olfactory sensory neurons by odorant receptors and the beta2 adrenergic receptor.</a> Cell. 117 (6), 833-846 (2004).</li><li>Mombaerts, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genes+and+ligands+for+odorant,+vomeronasal+and+taste+receptors.">Genes and ligands for odorant, vomeronasal and taste receptors.</a> Nat Rev Neurosci. 5 (4), 263-278 (2004).</li><li>Grosmaitre, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SR1,+a+mouse+odorant+receptor+with+an+unusually+broad+response+profile.">SR1, a mouse odorant receptor with an unusually broad response profile.</a> J Neurosci. 29 (46), 14545-14552 (2009).</li><li>Grosmaitre, X., Vassalli, A., Mombaerts, P., Shepherd, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant+responses+of+olfactory+sensory+neurons+expressing+the+odorant+receptor+MOR23:+a+patch+clamp+analysis+in+gene-targeted+mice.">Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: a patch clamp analysis in gene-targeted mice.</a> Proc Natl Acad Sci U S A. 103 (6), 1970-1975 (2006).</li><li>Lam, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant+responsiveness+of+embryonic+mouse+olfactory+sensory+neurons+expressing+the+odorant+receptors+S1+or+MOR23.">Odorant responsiveness of embryonic mouse olfactory sensory neurons expressing the odorant receptors S1 or MOR23.</a> Eur J Neurosci. 38 (2), 2210-2217 (2013).</li><li>Zhang, J., Huang, G., Dewan, A., Feinstein, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uncoupling+stimulus+specificity+and+glomerular+position+in+the+mouse+olfactory+system.">Uncoupling stimulus specificity and glomerular position in the mouse olfactory system.</a> Mol Cell Neurosci. 51 (3-4), 79-88 (2012).</li><li>Zhang, J., Pacifico, R., Cawley, D., Feinstein, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasensitive+detection+of+amines+by+a+trace+amine-associated+receptor.">Ultrasensitive detection of amines by a trace amine-associated receptor.</a> J Neurosci. 33 (7), 3228-3239 (2013).</li><li>Lee, A. C., Tian, H., Grosmaitre, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+patterns+of+odorant+receptors+and+response+properties+of+olfactory+sensory+neurons+in+aged+mice.">Expression patterns of odorant receptors and response properties of olfactory sensory neurons in aged mice.</a> Chem Senses. 34 (8), 695-703 (2009).</li><li>Cadiou, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postnatal+odorant+exposure+induces+peripheral+olfactory+plasticity+at+the+cellular+level.">Postnatal odorant exposure induces peripheral olfactory plasticity at the cellular level.</a> J Neurosci. 34 (14), 4857-4870 (2014).</li><li>Mombaerts, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Axonal+wiring+in+the+mouse+olfactory+system.">Axonal wiring in the mouse olfactory system.</a> Annu Rev Cell Dev Biol. 22, 713-737 (2006).</li><li>Grosmaitre, X., Santarelli, L. C., Tan, J., Luo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dual+functions+of+mammalian+olfactory+sensory+neurons+as+odor+detectors+and+mechanical+sensors.">Dual functions of mammalian olfactory sensory neurons as odor detectors and mechanical sensors.</a> Nat Neurosci. 10 (3), 348-354 (2007).</li><li>Duchamp-Viret, P., Chaput, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odor+response+properties+of+rat+olfactory+receptor+neurons.">Odor response properties of rat olfactory receptor neurons.</a> Science. 284 (5423), 2171-2174 (1999).</li><li>Heydel, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant-binding+proteins+and+xenobiotic+metabolizing+enzymes:+implications+in+olfactory+perireceptor+events.">Odorant-binding proteins and xenobiotic metabolizing enzymes: implications in olfactory perireceptor events.</a> Anat Rec (Hoboken). 296 (9), 1333-1345 (2013).</li><li>Pelosi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perireceptor+events+in+olfaction).">Perireceptor events in olfaction).</a> J Neurobiol. 30 (1), 3-19 (1996).</li><li>Spehr, M., Wetzel, C. H., Hatt, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3-phosphoinositides+modulate+cyclic+nucleotide+signaling+in+olfactory+receptor+neurons.">3-phosphoinositides modulate cyclic nucleotide signaling in olfactory receptor neurons.</a> Neuron. 33, 731-739 (2002).</li><li>Chen, S., Lane, A. P., Bock, R., Leinders-Zufall, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blocking+adenylyl+cyclase+inhibits+olfactory+generator+currents+induced+by+'IP(3)-odors.">Blocking adenylyl cyclase inhibits olfactory generator currents induced by 'IP(3)-odors.</a> J Neurophysiol. 84 (1), 575-580 (2000).</li><li>Savigner, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+spontaneous+and+odorant-evoked+activity+of+rat+olfactory+sensory+neurons+by+two+anorectic+peptides,+insulin+and+leptin.">Modulation of spontaneous and odorant-evoked activity of rat olfactory sensory neurons by two anorectic peptides, insulin and leptin.</a> J Neurophysiol. 101 (6), 2898-2906 (2009).</li><li>Ukhanov, K., Brunert, D., Corey, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphoinositide+3-kinase-dependent+antagonism+in+mammalian+olfactory+receptor+neurons.">Phosphoinositide 3-kinase-dependent antagonism in mammalian olfactory receptor neurons.</a> J Neurosci. 31 (1), 273-280 (2011).</li></ol>

The authors declare that they have no competing financial interest.

La capacità di questo protocollo per monitorare correttamente le proprietà di OSNs sani dipende fortemente dalla qualità della preparazione. Pertanto, la procedura di dissezione sono fondamentali. Innanzitutto è fondamentale prestare attenzione alla qualità (pH, osmolarità), l&#39;ossigenazione e temperatura (ghiacciata ma non congelato) del mezzo dissezione. In secondo luogo, la manipolazione dell&#39;epitelio con strumenti di dissezione deve essere limitata come possibile per evitare danni. Infine, è fondamenta...

Neuroni sensoriali olfattivi (OSN) rappresentano il primo passo della percezione olfattiva. Situato nell&#39;epitelio olfattivo rivestimento della cavità nasale nei roditori, trasformano l&#39;informazione chimica di odori in potenziali d&#39;azione inviati attraverso il loro assone al cervello. Per meglio comprendere i meccanismi di codifica olfattive, è necessario caratterizzare le proprietà di trasduzione e membrana di OSNs. Fino a poco tempo fa, la maggior parte delle tecniche utilizzate per caratterizzare le proprietà di OSNs mammiferi sono stati effettuati su dissociato OSNs 1-4. Il processo di dissociazione utilizza diversi (ad esempio, enzimi) processi meccanici e chimici per liberare i OSNs dal loro ambiente. Questi processi inducono un basso numero di cellule disponibili per le registrazioni. Questo numero basso può essere ancora più critico nel caso di cellule GFP etichettati. Dissociazione rimuove anche le interazioni locali cellula-cellula tra OSNs e altre cellule dell&#39;epitelio olfattivo che possono aumentare survivabilityAl e modulazione delle proprietà OSN. Al fine di bypassare la procedura di dissociazione, una preparazione intatto è stato sviluppato 5. Ogni OSN esprime un recettore olfattivo (OR) selezionati da una famiglia numerosa multigene 6. Ci sono ~ 1000 RUP espresse nella principale epitelio olfattivo nel topo. A causa del gran numero di OR in tipo animali selvatici, le possibilità di registrare OSNs esprimono la stessa OR sono molto basse. Per superare queste limitazioni, gene targeting topi sono disponibili in cui tutti OSNs esprimono un identificato o sono etichettati con una proteina fluorescente 7-9. Questi OSNs etichettati sono stati usati per fare l&#39;analisi funzionale in preparazioni dissociate 7,10,11 con gli inconvenienti citati in precedenza. Un intatto preparazione epitelio 5 da topi geneticamente etichettati elude quindi questi problemi. Esso consente il monitoraggio dell&#39;attività di OSNs esprimenti RUP precisamente definite in un ambiente il più vicino in vivo possibile. Inoltre, patch-clamp di OSNs consentono anche l&#39;analisi precisa di proprietà di membrana, via di trasduzione del farmacologia, ligando / o interazioni. Tutti questi argomenti difficilmente possono essere analizzati utilizzando registrazioni extracellulari. Abbiamo usato questa tecnica per monitorare le risposte dei OSNs che esprimono i recettori olfattivi SR1 e MOR23 12,13. La fattibilità della tecnica è stata confermata da altri gruppi su MOR23 esprimenti OSNs 14 nonché su altri RUP esprimenti neuroni 15,16. Il monitoraggio di una popolazione definita di OSNs può portare alla analisi delle loro proprietà in diversi contesti quali lo sviluppo 14, invecchiamento 17, odorizzante indotta plasticità 18, e il ruolo delle variazioni di sequenza del recettore odorizzante in odore codifica 15. Questo protocollo prevede quindi un potente strumento per monitorare le proprietà funzionali di OSNs definiti a livello della membrana.

<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

Analizzando le risposte fisiologiche dei neuroni sensoriali olfattivi (OSN) quando stimolato con specifici ligandi è fondamentale per comprendere la base dei comportamenti olfattive-driven e la loro modulazione. Queste proprietà di codifica dipendono fortemente dalla interazione iniziale tra molecole di odore e il recettore olfattivo (OR) espresse nei OSNs. L&#39;identità, specificità e ligando spettro della espressa o sono critici. La probabilità di trovare il ligando della OR esprime in OSN scelto casualmente all&#39;interno dell&#39;epitelio è molto bassa. Per affrontare questa sfida, questo protocollo utilizza geneticamente i topi con tag che esprimono la proteina fluorescente GFP sotto il controllo del promotore di RUP definiti. OSNs sono situati in un epitelio stretto e organizzato che riveste la cavità nasale, con le cellule vicine che influenzano la loro maturazione e funzione. Qui si descrive un metodo per isolare un epitelio olfattivo intatto e registrare tramite patch-clamp le proprietà di OSNs expressing recettori olfattivi definiti. Il protocollo consente di caratterizzare le proprietà della membrana OSN mantenendo l&#39;influenza del tessuto adiacente. Analisi dei risultati di patch-clamp produce una precisa quantificazione del ligando / o interazioni, vie di trasduzione e farmacologia, codifica le proprietà OSN e la loro modulazione a livello della membrana.

Il risultato di questo protocollo dipende dalla qualità della dissezione. Questa procedura dissezione deve essere breve (meno di 10 a 15 minuti) e preciso (ad esempio, per evitare danni del epitelio). La figura 1 illustra come una preparazione ideale assomiglia a diversi livelli di ingrandimento. Ad un basso ingrandimento in campo luminoso i diversi tipi di cellule (ad esempio le manopole di OSNs, sostenendo le cellule) sono distinguibili (Figura 1A). Al livello più alto ingr...

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.

Perforato Patch-clamp registrazione di topo neuroni sensoriali olfattivi In neuroepithelium intatto: Analisi funzionale di neuroni Esprimendo un Identificato odorizzante Receptor

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 Views.  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.

Video: 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.

Analizzando le risposte di topo neuroni olfattivi sensoriali che utilizzano l&#39;aria in fase di registrazione Electroolfactogram

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

Ricerca

Neuroscienze

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.

Fotolisi lampo di composti Caged nel Cilia di neuroni sensoriali olfattivi

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

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.

Odorizzante indotte risposte registrate da neuroni recettori olfattivi con la tecnica della pipetta di aspirazione

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.

Retrograda Etichettatura fluorescente Consente mirata extracellulare singola unità di registrazione da parte dei neuroni identificati<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.

La registrazione dell&#39;attività elettrica dai neuroni identificati nel cervello intatto di pesci transgenici

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.

Isolamento dei neuroni sensoriali<em&gt; Aplysia californica</em&gt; Per Bloccare Registrazioni patch di correnti glutamatergico

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.

Intracellulare di registrazione, sensoriale Campo Mapping, e la coltura neuroni identificata nel Leech, Hirudo medicinalis</i

The freshwater leech, Hirudo medicinalis, is a versatile model organism that has been used to address scientific questions in the fields of ...

Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna

Odorant molecules bind to their target receptors in a precise and coordinated manner. Each receptor recognizes a specific signal and relays this information to the brain. As such, determining how olfactory information is transferred to the brain, modifying both perception and behavior, merits investigation. Interestingly, there is emerging evidence that cellular transduction and transcriptional factors are involved in the diversification of olfactory receptor neuron. Here we provide a robust whole mount immunological labeling method to assay in vivo olfactory receptor neuron organization. Using this method, we identified all olfactory receptor neurons with anti-ELAV antibody, a known pan-neural marker and Or49a-mCD8::GFP, an olfactory receptor neuron specifically expressed in Nba neuron using anti-GFP antibody.

Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna

Herein we describe the process of whole mount immunostaining of Drosophila antennae, which enables us to better understand the molecular mechanisms involved in the diversification of olfactory receptor neurons (ORN)s.

Tutta Monte immunomarcatura di recettore olfattivo neuroni nel<em&gt; Drosophila</em&gt; Antenna

Odorant molecules bind to their target receptors in a precise and coordinated manner. Each receptor recognizes a specific signal and relays this ...

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.

Registrazione Light-evocato Risposte postsinaptica nei neuroni in Dark-adattati, i preparativi della retina del mouse Slice Utilizzando tecniche di patch clamp

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

Preparations and Protocols for Whole Cell Patch Clamp Recording of Xenopus laevis Tectal Neurons

The Xenopus tadpole retinotectal circuit, comprised of the retinal ganglion cells (RGCs) in the eye which form synapses directly onto neurons in the optic tectum, is a popular model to study how neural circuits self-assemble. The ability to carry out whole cell patch clamp recordings from tectal neurons and to record RGC-evoked responses, either in vivo or using a whole brain preparation, has generated a large body of high-resolution data about the mechanisms underlying normal, and abnormal, circuit formation and function. Here we describe how to perform the in vivo preparation, the original whole brain preparation, and a more recently developed horizontal brain slice preparation for obtaining whole cell patch clamp recordings from tectal neurons. Each preparation has unique experimental advantages. The in vivo preparation enables the recording of the direct response of tectal neurons to visual stimuli projected onto the eye. The whole brain preparation allows for the RGC axons to be activated in a highly controlled manner, and the horizontal brain slice preparation allows recording from across all layers of the tectum.

Preparations and Protocols for Whole Cell Patch Clamp Recording of Xenopus laevis Tectal Neurons

In this paper, we discuss three brain preparations used for whole cell patch clamp recording to study the retinotectal circuit of Xenopus laevis tadpoles. Each preparation, with its own specific advantages, contributes to the experimental tractability of the Xenopus tadpole as a model to study neural circuit function.

Preparazioni e protocolli per l'intera cella Patch Clamp registrazione dei neuroni Tectal Xenopus laevis

The Xenopus tadpole retinotectal circuit, comprised of the retinal ganglion cells (RGCs) in the eye which form synapses directly onto neurons in the optic ...