Ringraziamo i membri della Matsunami laboratorio per la lettura critica di questo manoscritto.

1. Procedimento: La procedura si compone di tre parti completato in un tempo totale di 3 giorni: il trasferimento di cellule, trasfezione e immunocitochimica, un passo effettuato al giorno. Trasferimento e trasfezione delle cellule nei primi due giorni deve essere effettuato in condizioni sterili in una camera a flusso laminare. 1 ° giorno: Trasferimento di cellule HEK293T per test espressione sulla superficie. <ol><li> Trasferimento medio (M10): Mix minimo mezzo fondamentale integrato con il 10% (in volume) siero fetale bovino in confezione sterile. </li><li> Crescere le cellule ad una confluenza desiderata in una piastra di coltura 100mm, a seconda del numero di piatti necessari per impostare. E &#39;importante per determinare la frazione di cellule da trasferire per evitare cellule sparse o invasi: per esempio, da un 100% confluenti piatto 100 mm, si può trasferire circa il 3% a un piatto da 35 mm di ottenere circa il 30% confluenza nel quest&#39;ultimo. </li><li> Prima di trasferire le cellule, nella camera sterile a flusso laminare, cappotto 22 x 22 mm coperchio scivola in vetro con sterili poli D lisina (1 mg / ml) e inserire una in ogni piatto 35 colture cellulari mm, lato patinato per le cellule placcatura (Figura 1 ). Lasciare che la soluzione a secco per 5 - 10 minuti. Durante questo intervallo, la sorgente UV nella camera di laminare può essere attivata per sterilizzare il copri-oggetto, se lo si desidera. Poli D lisina aiuta le cellule eterologhe aderire al coprioggetto. </li><li> Per trasferire le cellule, aspirare la media esistenti nel piatto 100 mm, lavare con cura aggiungendo 8 ml PBS sterile, aspirare PBS e trypsinize le cellule in 3 mL 0,05% tripsina-EDTA, quando le cellule si staccano dal piatto, blocco di reazione enzimatica ulteriormente da M10 aggiungendo 5 ml. Triturare le cellule e il trasferimento di volume necessari in una provetta sterile conica; centrifugare a 200g per 5 minuti per far sedimentare le cellule. Aspirare fuori supernatante contenente tripsina-EDTA, lasciando il pellet di cellule intatte. Per trasferire le cellule a 35 piatti mm, aggiungere 1 mL M10 per ogni piatto e triturare dissociare le cellule. Aggiungere 1 ml di cellule risospese ad ogni piatto. Cellule incubare una notte a 37 ° C, 5% di CO 2. <img src="/files/ftp_upload/2405/2405fig1.jpg" alt="Figura 1" /> Figura 1. Coat 22 x 22 millimetri coprioggetto di vetro con poli D lisina e luogo da un lato rivestito in ogni piatto 35 mm. </li></ol> Giorno 2: Transfection delle cellule HEK293T. <ol><li> 18-24 ore dopo il trasferimento, le cellule sono pronte per la trasfezione del recettore da dosare. Usa recettore e RTP1S clonato nel vettore di espressione mammifero PCI, preparati da colture batteriche con Qiagen Miniprep seguente protocollo Kit descritto prima 4. Utilizzare i recettori che sono N terminali taggati con 20 aminoacidi lungo acido rodopsina epitopo per facilitare immunocolorazione. </li><li> L&#39;uso 1000ng di costruire recettore, 250 ng di RTP1S costruire e 50 ng di proteina verde fluorescente ogni trasfezione. Eseguire la trasfezione con Lipofectamine 2000, come da manuale produttori. </li></ol> 3 ° giorno: Immunocitochimica per visualizzare i recettori delle cellule macchiato di superficie. <ol><li> Prima di iniziare, preparare colorazione e soluzioni di lavaggio e raffreddare a 4 ° C. Colorazione medio: Medium minimo, 45 mL; siero fetale bovino, 5 ml; HEPES (1M), 500 microlitri (concentrazione finale 10 mM); azide di sodio (1,5 M), 500 microlitri (concentrazione finale 15 mm). Soluzione di lavaggio: HBSS, 500 ml; HEPES (1M), 5 mL (concentrazione finale 10 mM); azide di sodio (1,5 M), 5 mL (concentrazione finale 15 mm). Entrambe le soluzioni possono essere conservati a 4 ° C per il riutilizzo. Preparare le soluzioni di anticorpi diluendo gli anticorpi necessari alla colorazione media 100 volte. </li><li> Inizio immunochimica per la colorazione della superficie per circa 24 recettori olfattivi dopo trasfezione ore. Per eseguire la colorazione delle cellule vive, il set up sperimentale deve essere raffreddato a 4 ° C: riempire un grande contenuto di ghiaccio e tamponare la superficie di ghiaccio per renderlo il più uniforme possibile, posto un vassoio sul ghiaccio e spruzzare con il 70% etanolo. Tagliare un pezzo di parafilm (inferiore alla lunghezza del vassoio) e apporre sul vassoio etanolo spruzzato, per ottenere una superficie liscia. Trasferire il coperchio in vetro contenenti cellule transfettate scivola sul parafilm, uno alla volta, lato cella in alto, utilizzando una pinzetta. Ogni strato di copertura antiscivolo con 100 ul soluzione fredda colorazione primaria, estrusione con cura da un angolo della ricevuta (Figura 2). Dopo stratificazione tutte le polizze di copertura con soluzione di anticorpi, coprire il vassoio per evitare prosciugamento della soluzione in aria. Effettuare incubazione primaria per 45-60 minuti. </li><li> Dopo l&#39;incubazione primaria, trasferire rapidamente scivola coprire la cultura piatti originali 35mm, contenente il supporto. Aspirare i media e aggiungere 2 mL di soluzione di lavaggio refrigerato delicatamente dal bordo del piatto per evitare di perdere le cellule dal vetrino. Aspirare la soluzione di lavaggio e ripetere due volte per completare tre lavaggi. Alla fine del terzo lavaggio, non aspirare la soluzione di wash out. </li><li> Preparare secondaria anticorpi SOLUZIOsui media colorazione e trasferire il coprioggetto dalla soluzione di lavaggio in un livello di parafilm nuova apposta nello stesso cassetto. Anche in questo caso delicatamente estrudere 100 l di soluzione di anticorpi a ogni strato antiscivolo copertina, da un angolo, come l&#39;incubazione primario. Effettuare incubazione secondaria per 30 - 45 minuti e trasferimento al soluzione di lavaggio in originale 35 piatti mm. Ancora una volta, lavare il coperchio scivola tre volte come descritto. </li><li> Aspirare soluzione di lavaggio da ultimo lavaggio e aggiungere 2 mL di paraformaldeide 1% refrigerata. Fissare le cellule in refrigerata soluzione paraformaldeide 1%, in ghiaccio per 15 minuti. </li><li> Montare il coperchio scivola sul vetro microscopio pulito diapositive usando Mowiol reagente di montaggio, con il lato cellula verso il basso e cautela escludere tutte le bolle d&#39;aria (Figura 3). Una volta che si asciuga all&#39;aria Mowiol, lavare scivola coprire delicatamente con l&#39;aggiunta di acqua distillata sulla superficie ed aspirando immediatamente. <img src="/files/ftp_upload/2405/2405fig2.jpg" alt="Figura 2" /> Figura 2. Layer ogni coprioggetto con 100 ul soluzione fredda colorazione primaria. <img src="/files/ftp_upload/2405/2405fig3.jpg" alt="Figura 3" /> Figura 3. Montare il copri con la parte delle cellule verso il basso microscopio vetro pulito diapositive usando Mowiol reagente di montaggio. </li></ol> 2. Rappresentante dei risultati: Colorazione delle cellule vive permette di visualizzare le proteine ​​sulla superficie delle cellule, sulla trasfezione di recettori con accompagnatori (in questo caso Olfr62 recettore olfattivo, con RTP1S proteina recettore trasporto) (Figura 4). Colorazione della superficie delle cellule dei recettori è caratterizzata da modello puntata della colorazione (Figura 4B, nel riquadro). Colorazione effettuata inappropriato può determinare un aumento del rumore, rendendo difficile per l&#39;osservatore di distinguere la colorazione reale superficie da rumore. <img src="/files/ftp_upload/2405/2405fig4.jpg" alt="Figura 4" /> Transfection Figura 4. Dei recettori con accompagnatori consente la visualizzazione delle proteine ​​sulla superficie delle cellule mediante colorazione delle cellule vive. Trasfezione del recettore odorizzante Olfr62 solo (A) e la transfezione di Olfr62 con chaperone RTP1S (B). Livelli di espressione GFP Come controllo della trasfezione (A &#39;e B&#39;).

<ol>
	<li>Buck, L., 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, 175-187 (1991).</li><li>Malnic, B., Hirono, J., Sato, T., Buck, L. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combinatorial+receptor+codes+for+odors.">Combinatorial receptor codes for odors.</a> Cell. 96, 713-723 (1999).</li><li>Saito, H., Kubota, M., Roberts, R. W., Chi, Q., Matsunami, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RTP+family+members+induce+functional+expression+of+mammalian+odorant+receptors.">RTP family members induce functional expression of mammalian odorant receptors.</a> Cell. 119, 679-691 (2004).</li><li>Zhuang, H., Matsunami, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+cell-surface+expression+and+measuring+activation+of+mammalian+odorant+receptors+in+heterologous+cells.">Evaluating cell-surface expression and measuring activation of mammalian odorant receptors in heterologous cells.</a> Nat Protoc. 3, 1402-1413 (2008).</li></ol>

Nessun conflitto di interessi dichiarati.

Ogni passo deve essere effettuata con cura per garantire la colorazione della superficie prominente e distintivo. L&#39;intero processo di colorazione deve essere eseguita a freddo (su ghiaccio), e il vassoio su cui sono previsti slittamenti di copertura deve essere raffreddato prima dell&#39;uso per assicurare cellule rimanere in vita. Inoltre la fissazione avviene al termine del processo di colorazione della superficie. Ciò è in netto contrasto con la colorazione interna in cui la fissazione precede colorazione a permeabilize la membrana cellulare di anticorpi primari e secondari. Tempo di esposizione di scivola copertura di aria deve essere ridotto al minimo per evitare che le cellule di prosciugamento, e quindi la stratificazione delle polizze di copertura con soluzioni di anticorpi, trasferendo coprioggetto per lavare soluzione, lo scambio di soluzione di lavaggio tra un lavaggio e deve essere fatta rapidamente e uno alla volta quando si maneggia coprioggetto multipli. A seconda del tag epitopo e gli anticorpi si usa, si può avere per regolare il tempo di incubazione, il numero di lavaggi, e piega di diluizione degli anticorpi. Il rumore di fondo può essere evitato diluendo gli anticorpi più o aumentando il numero di lavaggi, o accorciando il tempo di incubazione.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Cover slip 22 X 22 mm (#1)</td>
<td>&nbsp;</td>
<td>Thermo Scientific</td>
<td>72200-11</td>
<td>&nbsp;</td>
<tr>
<td>Fetal bovine serum</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>16000</td>
<td>&nbsp;</td>
<tr>
<td>Lipofectamine 2000</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>11668-019</td>
<td>&nbsp;</td>
<tr>
<td>Minimal essential medium</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>M4655</td>
<td>With L glutamate, Earle&#x2019;s salt and bicarbonate</td>
</tr>
<tr>
<td>Mowiol</td>
<td>&nbsp;</td>
<td>Calbiochem</td>
<td>475904</td>
<td>&nbsp;</td>
<tr>
<td>Paraformaldehyde</td>
<td>&nbsp;</td>
<td>EMS</td>
<td>19208</td>
<td>&nbsp;</td>
<tr>
<td>Hanks Balanced Salt Solution (HBSS) 1X </td>
<td>&nbsp;</td>
<td>Gibco </td>
<td>14025</td>
<td>With calcium chloride and magnesium chloride</td>
</tr>
<tr>
<td>HEPES Buffer Solution</td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>15630</td>
<td>&nbsp;</td>
<tr>
<td>Phosphate Buffer Saline (PBS)</td>
<td>&nbsp;</td>
<td>Cellgro</td>
<td>21-040-CV</td>
<td>Without calcium and magnesium</td>
</tr>
<tr>
<td>Poly D Lysine Hydrobromide</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>P7280</td>
<td>&nbsp;</td>
<tr>
<td>Sodium Azide</td>
<td>&nbsp;</td>
<td>EM Science</td>
<td>SX0299-1</td>
<td>&nbsp;</td>
<tr>
<td>Tissue culture dish 35 X 10 mm</td>
<td>&nbsp;</td>
<td>Falcon</td>
<td>353801</td>
<td>&nbsp;</td>
<tr>
<td>Trypsin-EDTA </td>
<td>&nbsp;</td>
<td>Gibco</td>
<td>25300</td>
<td>0.05%</td>
</tr>		</tbody>
		</table>
		</div>

assaying surface expression of chemosensory receptors in heterologous cells

Il mondo vivido degli odori è riconosciuto dal senso dell&#39;olfatto. Olfatto nei topi è mediata da un repertorio di circa 1200 recettori delle proteine ​​G accoppiate (GPCR) 1 che sono postulate di legare molecole odoranti volatili e convertendo il segnale extracellulare in un segnale intracellulare mediante accoppiamento con proteine ​​G Gαolf. Legame del odoranti ai recettori si pensa di seguire una regola combinatoria, cioè, un odorizzante può legare i recettori diversi e un recettore può legare odori diversi a vari livelli 2. Biochimiche, di segnalazione e studi di binding ligando sono stati opportunamente eseguiti per la maggior parte GPCR utilizzando cellule eterologhe. Tuttavia l&#39;uso di cellule eterologhe per lo studio dei recettori olfattivi, è stato precluso per molto tempo da quando il transfezione non sono riusciti ad esportare verso la superficie. Saito et al hanno dimostrato singolo passaggio del recettore di membrana Il trasporto delle proteine ​​(RTP) accompagnatori famiglia mostrano maggiore espressione nei neuroni olfattivi e sensoriali agiscono come accompagnatori di recettori olfattivi traffico in superficie in cellule eterologhe, quando co transfettate insieme 3. Per effettuare test biochimici per i recettori utilizzando cellule eterologhe, si deve prima determinare se il recettore mostra espressione robusta superficie nella linea cellulare. Questo può essere dosati con iperespressione del recettore con i RTP1S chaperone seguita da cellule vive colorazione fluorescente di etichettare il dominio extracellulare o di un tag nel dominio extracellulare in esclusiva. Qui mostriamo un protocollo di effettuare colorazione delle cellule vive, che può essere utilizzato per rilevare recettori olfattivi sulla superficie delle cellule HEK293T conveniente. Inoltre, può anche essere usata per test per l&#39;espressione superficiale di altri recettori chemosensoriali o GPCR.

Watch this Scientific Journal Video about Assaying Surface Expression of Chemosensory Receptors in Heterologous Cells at JoVE.com

Assaying Surface Expression of Chemosensory Receptors in Heterologous Cells

Qui mostriamo un protocollo di effettuare colorazione delle cellule vive, che può essere utilizzato per rilevare recettori olfattivi sulla superficie delle cellule HEK293T conveniente. Inoltre, può anche essere usata per test per l&#39;espressione superficiale di altri recettori chemosensoriali o GPCR.

Saggio espressione di superficie dei recettori chemosensoriali in cellule eterologhe

The vivid world of odors is recognized by the sense of olfaction. Olfaction in mice is mediated by a repertoire of about 1200 G Protein Coupled Receptors ...

assaying-surface-expression-chemosensory-receptors-heterologous

Universidad San Sebastian

Research

JoVE Journal

Neuroscience

10.8K Views.  Duke University. Qui mostriamo un protocollo di effettuare colorazione delle cellule vive, che può essere utilizzato per rilevare recettori olfattivi sulla superficie delle cellule HEK293T conveniente. Inoltre, può anche essere usata per test per l'espressione superficiale di altri recettori chemosensoriali o GPCR.

Video: Assaying Surface Expression of Chemosensory Receptors in Heterologous Cells

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

Most life forms exhibit daily rhythms in cellular, physiological and behavioral phenomena that are driven by endogenous circadian (&equiv;24 hr) pacemakers or clocks. Malfunctions in the human circadian system are associated with numerous diseases or disorders. Much progress towards our understanding of the mechanisms underlying circadian rhythms has emerged from genetic screens whereby an easily measured behavioral rhythm is used as a read-out of clock function. Studies using Drosophila have made seminal contributions to our understanding of the cellular and biochemical bases underlying circadian rhythms. The standard circadian behavioral read-out measured in Drosophila is locomotor activity. In general, the monitoring system involves specially designed devices that can measure the locomotor movement of Drosophila. These devices are housed in environmentally controlled incubators located in a darkroom and are based on using the interruption of a beam of infrared light to record the locomotor activity of individual flies contained inside small tubes. When measured over many days, Drosophila exhibit daily cycles of activity and inactivity, a behavioral rhythm that is governed by the animal's endogenous circadian system. The overall procedure has been simplified with the advent of commercially available locomotor activity monitoring devices and the development of software programs for data analysis. We use the system from Trikinetics Inc., which is the procedure described here and is currently the most popular system used worldwide. More recently, the same monitoring devices have been used to study sleep behavior in Drosophila. Because the daily wake-sleep cycles of many flies can be measured simultaneously and only 1 to 2 weeks worth of continuous locomotor activity data is usually sufficient, this system is ideal for large-scale screens to identify Drosophila manifesting altered circadian or sleep properties.

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

We describe procedures for recording daily locomotor activity rhythms of Drosophila and subsequent data analysis. Locomotor activity rhythms are a reliable behavioral output of animal circadian clocks and are used as the standard readout of clock function when studying circadian mutants or examining how the environment regulates the circadian system.

Saggio attività locomotoria per studiare ritmi circadiani del sonno e parametri in Drosophila</em

Most life forms exhibit daily rhythms in cellular, physiological and behavioral phenomena that are driven by endogenous circadian (&equiv;24 hr) ...

Ricerca

Neuroscienze

Assaying &beta;-amyloid Toxicity using a Transgenic C. elegans Model

Accumulation of the &beta;-amyloid peptide (A&beta;) is generally believed to be central to the induction of Alzheimer's disease, but the relevant mechanism(s) of toxicity are still unclear. A&beta; is also deposited intramuscularly in Inclusion Body Myositis, a severe human myopathy. The intensely studied nematode worm Caenorhabditis elegans can be transgenically engineered to express human A&beta;. Depending on the tissue or timing of A&beta; expression, transgenic worms can have readily measurable phenotypes that serve as a read-out of A&beta; toxicity. For example, transgenic worms with pan-neuronal A&beta; expression have defects is associative learning (Dosanjh et al. 2009), while transgenic worms with constitutive muscle-specific expression show a progressive, age-dependent paralysis phenotype (Link, 1995; Cohen et al. 2006). One particularly useful C. elegans model employs a temperature-sensitive mutation in the mRNA surveillance system to engineer temperature-inducible muscle expression of an A&beta; transgene, resulting in a reproducible paralysis phenotype upon temperature upshift (Link et al. 2003). Treatments that counter A&beta; toxicity in this model [e.g., expression of a protective transgene (Hassan et al. 2009) or exposure to Ginkgo biloba extracts (Wu et al. 2006)] reproducibly alter the rate of paralysis induced by temperature upshift of these transgenic worms. Here we describe our protocol for measuring the rate of paralysis in this transgenic C. elegans model, with particular attention to experimental variables that can influence this measurement.

Assaying &amp;#946;-amyloid Toxicity using a Transgenic C. elegans Model

The intensely studied nematode worm Caenorhabditis elegans can be transgenically engineered to express the human &beta;-amyloid peptide (A&beta;). Induced expression of A&beta; in C. elegans muscle leads to a rapid, reproducible paralysis phenotype that can be used to monitor treatments that modulate A&beta; toxicity.

Saggio β-amiloide tossicità utilizzando un transgenici C. elegans Modello

Accumulation of the &beta;-amyloid peptide (A&beta;) is generally believed to be central to the induction of Alzheimer's disease, but the relevant ...

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination2. Here we use behavioral assays, including the negative geotaxis assay3 and the aversive phototaxic suppression assay (APS assay)4,5, to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies.

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Behavior assays for measuring locomotor functions, learning, and memory abilities in Drosophila.

Deficit Locomotore dosaggio, apprendimento e memoria in Drosophila Modelli di neurodegenerazione

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of ...

Spinal Cord Electrophysiology II: Extracellular Suction Electrode Fabrication

Development of neural circuitries and locomotion can be studied using neonatal rodent spinal cord central pattern generator (CPG) behavior. We demonstrate a method to fabricate suction electrodes that are used to examine CPG activity, or fictive locomotion, in dissected rodent spinal cords. The rodent spinal cords are placed in artificial cerebrospinal fluid and the ventral roots are drawn into the suction electrode. The electrode is constructed by modifying a commercially available suction electrode. A heavier silver wire is used instead of the standard wire given by the commercially available electrode. The glass tip on the commercial electrode is replaced with a plastic tip for increased durability. We prepare hand drawn electrodes and electrodes made from specific sizes of tubing, allowing consistency and reproducibility. Data is collected using an amplifier and neurogram acquisition software. Recordings are performed on an air table within a Faraday cage to prevent mechanical and electrical interference, respectively.

A demonstration of the fabrication and use of an extracellular suction electrode used to measure electrophysiological recordings of neonatal rodent spinal cords in vitro

Spinal Cord Elettrofisiologia II: extracellulare fabbricazione di elettrodi di aspirazione

Development of neural circuitries and locomotion can be studied using neonatal rodent spinal cord central pattern generator (CPG) behavior. We demonstrate ...

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding fundamental biological mechanisms. Striking progress has been particularly evident in Drosophila, whose extensive toolkit of mutants and transgenic lines provides a convenient model to study evolutionarily-conserved developmental and cell biological mechanisms. We are interested in understanding the mechanisms that control cell fate specification in the adult peripheral nervous system (PNS) in Drosophila. Bristles that cover the head, thorax, abdomen, legs and wings of the adult fly are individual mechanosensory organs, and have been studied as a model system for understanding mechanisms of Notch-dependent cell fate decisions. Sensory organ precursor (SOP) cells of the microchaetes (or small bristles), are distributed throughout the epithelium of the pupal thorax, and are specified during the first 12 hours after the onset of pupariation. After specification, the SOP cells begin to divide, segregating the cell fate determinant Numb to one daughter cell during mitosis. Numb functions as a cell-autonomous inhibitor of the Notch signaling pathway.
Here, we show a method to follow protein dynamics in SOP cell and its progeny within the intact pupal thorax using a combination of tissue-specific Gal4 drivers and GFP-tagged fusion proteins 1,2.This technique has the advantage over fixed tissue or cultured explants because it allows us to follow the entire development of an organ from specification of the neural precursor to growth and terminal differentiation of the organ. We can therefore directly correlate changes in cell behavior to changes in terminal differentiation. Moreover, we can combine the live imaging technique with mosaic analysis with a repressible cell marker (MARCM) system to assess the dynamics of tagged proteins in mitotic SOPs under mutant or wildtype conditions. Using this technique, we and others have revealed novel insights into regulation of asymmetric cell division and the control of Notch signaling activation in SOP cells (examples include references 1-6,7 ,8).

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

In this video, we describe a method for live cell imaging of asymmetrically dividing sensory organ progenitor cells and epidermal cells in intact Drosophila pupae

Live-cellula Imaging di cellule sensoriali Precursore in Organo intatto Drosophila Pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding ...

Isolating Nasal Olfactory Stem Cells from Rodents or Humans

The olfactory mucosa, located in the nasal cavity, is in charge of detecting odours. It is also the only nervous tissue that is exposed to the external environment and easily accessible in every living individual. As a result, this tissue is unique for anyone aiming to identify molecular anomalies in the pathological brain or isolate adult stem cells for cell therapy. 
Molecular abnormalities in brain diseases are often studied using nervous tissue samples collected post-mortem. However, this material has numerous limitations. In contrast, the olfactory mucosa is readily accessible and can be biopsied safely without any loss of sense of smell1. Accordingly, the olfactory mucosa provides an "open window" in the adult human through which one can study developmental (e.g. autism, schizophrenia)2-4 or neurodegenerative (e.g. Parkinson, Alzheimer) diseases4,5. Olfactory mucosa can be used for either comparative molecular studies4,6 or in vitro experiments on neurogenesis3,7.
The olfactory epithelium is also a nervous tissue that produces new neurons every day to replace those that are damaged by pollution, bacterial of viral infections. This permanent neurogenesis is sustained by progenitors but also stem cells residing within both compartments of the mucosa, namely the neuroepithelium and the underlying lamina propria8-10. We recently developed a method to purify the adult stem cells located in the lamina propria and, after having demonstrated that they are closely related to bone marrow mesenchymal stem cells (BM-MSC), we named them olfactory ecto-mesenchymal stem cells (OE-MSC)11.
Interestingly, when compared to BM-MSCs, OE-MSCs display a high proliferation rate, an elevated clonogenicity and an inclination to differentiate into neural cells. We took advantage of these characteristics to perform studies dedicated to unveil new candidate genes in schizophrenia and Parkinson's disease4. We and others have also shown that OE-MSCs are promising candidates for cell therapy, after a spinal cord trauma12,13, a cochlear damage14 or in an animal models of Parkinson's disease15 or amnesia16.
In this study, we present methods to biopsy olfactory mucosa in rats and humans. After collection, the lamina propria is enzymatically separated from the epithelium and stem cells are purified using an enzymatic or a non-enzymatic method. Purified olfactory stem cells can then be either grown in large numbers and banked in liquid nitrogen or induced to form spheres or differentiated into neural cells. These stem cells can also be used for comparative omics (genomic, transcriptomic, epigenomic, proteomic) studies.

We describe here a method for biopsying olfactory mucosa from rat and human nasal cavities. These biopsies can be used for either identifying molecular anomalies in brain diseases or isolating multipotent adult stem cells that can be utilized for cell transplantation in animal models of brain trauma/disease.

Isolare cellule staminali olfattivo nasale da roditori o Umani

The olfactory mucosa, located in the nasal cavity, is in charge of detecting odours. It is also the only nervous tissue that is exposed to the external ...

High-resolution Live Imaging of Cell Behavior in the Developing Neuroepithelium

The embryonic spinal cord consists of cycling neural progenitor cells that give rise to a large percentage of the neuronal and glial cells of the central nervous system (CNS). Although much is known about the molecular mechanisms that pattern the spinal cord and elicit neuronal differentiation1, 2, we lack a deep understanding of these early events at the level of cell behavior. It is thus critical to study the behavior of neural progenitors in real time as they undergo neurogenesis.
In the past, real-time imaging of early embryonic tissue has been limited by cell/tissue viability in culture as well as the phototoxic effects of fluorescent imaging. Here we present a novel assay for imaging such tissue for long periods of time, utilizing a novel ex vivo slice culture protocol and wide-field fluorescence microscopy (Fig. 1). This approach achieves long-term time-lapse monitoring of chick embryonic spinal cord progenitor cells with high spatial and temporal resolution.
This assay may be modified to image a range of embryonic tissues3, 4 In addition to the observation of cellular and sub-cellular behaviors, the development of novel and highly sensitive reporters for gene activity (for example, Notch signaling5) makes this assay a powerful tool with which to understand how signaling regulates cell behavior during embryonic development.

Imaging embryonic tissue in real-time is challenging over long periods of time. Here we present an assay for monitoring cellular and sub-cellular changes in chick spinal cord for long periods with high spatial and temporal resolution. This technique can be adapted for other regions of the nervous system and developing embryo.

Imaging ad alta risoluzione dal vivo del comportamento delle cellule in via di sviluppo neuroepitelio

The embryonic spinal cord consists of cycling neural progenitor cells that give rise to a large percentage of the neuronal and glial cells of the central ...

Assaying DNA Damage in Hippocampal Neurons Using the Comet Assay

A number of drugs target the DNA repair pathways and induce cell kill by creating DNA damage. Thus, processes to directly measure DNA damage have been extensively evaluated. Traditional methods are time consuming, expensive, resource intensive and require replicating cells. In contrast, the comet assay, a single cell gel electrophoresis assay, is a faster, non-invasive, inexpensive, direct and sensitive measure of DNA damage and repair. All forms of DNA damage as well as DNA repair can be visualized at the single cell level using this powerful technique.
	The principle underlying the comet assay is that intact DNA is highly ordered whereas DNA damage disrupts this organization. The damaged DNA seeps into the agarose matrix and when subjected to an electric field, the negatively charged DNA migrates towards the cathode which is positively charged. The large undamaged DNA strands are not able to migrate far from the nucleus. DNA damage creates smaller DNA fragments which travel farther than the intact DNA. Comet Assay, an image analysis software, measures and compares the overall fluorescent intensity of the DNA in the nucleus with DNA that has migrated out of the nucleus. Fluorescent signal from the migrated DNA is proportional to DNA damage. Longer brighter DNA tail signifies increased DNA damage. Some of the parameters that are measured are tail moment which is a measure of both the amount of DNA and distribution of DNA in the tail, tail length and percentage of DNA in the tail. This assay allows to measure DNA repair as well since resolution of DNA damage signifies repair has taken place. The limit of sensitivity is approximately 50 strand breaks per diploid mammalian cell 1,2. Cells treated with any DNA damaging agents, such as etoposide, may be used as a positive control. Thus the comet assay is a quick and effective procedure to measure DNA damage.

The comet assay is an efficient way of detecting single- and double-strand breaks, including alkali-labile sites and DNA-DNA/DNA-protein cross-links on the DNA in all cells including hippocampal neurons. The method takes advantage of the differential migration of DNA in an electric field due to differences in amount of DNA damage.

Il saggio danneggiare il DNA in neuroni ippocampali Utilizzo del Comet Assay

A number of drugs target the DNA repair pathways and induce cell kill by creating DNA damage. Thus, processes to directly measure DNA damage have been ...

Proprioception and Tension Receptors in Crab Limbs: Student Laboratory Exercises

The primary purpose of these procedures is to demonstrate for teaching and research purposes how to record the activity of living primary sensory neurons responsible for proprioception as they are detecting joint position and movement, and muscle tension. Electrical activity from crustacean proprioceptors and tension receptors is recorded by basic neurophysiological instrumentation, and a transducer is used to simultaneously measure force that is generated by stimulating a motor nerve. In addition, we demonstrate how to stain the neurons for a quick assessment of their anatomical arrangement or for permanent fixation. Staining reveals anatomical organization that is representative of chordotonal organs in most crustaceans. Comparing the tension nerve responses to the proprioceptive responses is an effective teaching tool in determining how these sensory neurons are defined functionally and how the anatomy is correlated to the function. Three staining techniques are presented allowing researchers and instructors to choose a method that is ideal for their laboratory.

Physiological and anatomical techniques are demonstrated to address function and structure for joint proprioceptors and muscle tension receptors in crustacean walking limbs.

Propriocezione e la tensione recettori in Crab Arti: Esercizi di laboratorio per studenti

The primary purpose of these procedures is to demonstrate for teaching and research purposes how to record the activity of living primary sensory neurons ...

Inducing Plasticity of Astrocytic Receptors by Manipulation of Neuronal Firing Rates

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be stimulated by neuronally-released transmitter. However, the ability of astrocytic receptors to exhibit plasticity in response to changes in neuronal activity has received little attention. Here we describe a model system that can be used to globally scale up or down astrocytic group I metabotropic glutamate receptors (mGluRs) in acute brain slices. Included are methods on how to prepare parasagittal hippocampal slices, construct chambers suitable for long-term slice incubation, bidirectionally manipulate neuronal action potential frequency, load astrocytes and astrocyte processes with fluorescent Ca2+ indicator, and measure changes in astrocytic Gq GPCR activity by recording spontaneous and evoked astrocyte Ca2+ events using confocal microscopy. In essence, a &#8220;calcium roadmap&#8221; is provided for how to measure plasticity of astrocytic Gq GPCRs. Applications of the technique for study of astrocytes are discussed. Having an understanding of how astrocytic receptor signaling is affected by changes in neuronal activity has important implications for both normal synaptic function as well as processes underlying neurological disorders and neurodegenerative disease.

Here we describe an adaptation of protocols used to induce homeostatic plasticity in neurons for the study of plasticity of astrocytic G protein-coupled receptors. Recently used to examine changes in astrocytic group I mGluRs in juvenile mice, the method can be applied to measure scaling of various astrocytic GPCRs, in tissue from adult mice in situ and in vivo, and to gain a better appreciation of the sensitivity of astrocytic receptors to changes in neuronal activity.

Indurre Plasticità di astrociti recettori per manipolazione del neuronali di cottura Prezzi

Close to two decades of research has established that astrocytes in situ and in vivo express numerous G protein-coupled receptors (GPCRs) that can be ...