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1. Manutenzione delle Gabbie Popolazione <ol><li> Mantenere gabbie popolazione a 25 ° C con un ciclo luce-buio 12 hr. Fintanto che i gruppi di controllo e sperimentali sono esposti alle stesse condizioni di illuminazione, allora questa tecnica può essere eseguita in un ambiente di laboratorio standard. </li><li> Consentire femmine depongono le uova durante la notte su piastre di agar succo di mela. </li><li> Raccogliere le larve neonate mantenendo piatti con le uova appena depositate a 25 ° C per 24 ore. Mettere un piccolo ciuffo di lievito nel centro della piastra per attirare le larve tratteggiata. </li><li> Raccogliere 1 ° instar larve che hanno migrato nel lievito in pasta nel centro della piastra di succo di mela. Utilizzare una spatola metallica per trasferirla a un piatto di succo di mela fresco. Ulteriori lievito in pasta può essere aggiunto a garantire il cibo adeguato finché vengono eseguiti i test. Piastre di succo d&#39;uva possono essere utilizzati anche al posto delle lastre di succo di mela. </li><li> Ottenere in ritardo 2 °-inizio 3 ° instar larvae consentendo il 1 ° stadi di età per 40-48 ore. All&#39;interno di questo campo le tariffe di alimentazione sono costanti 13. Età può essere confermata con l&#39;esame dei ganci bocca in quanto vi sono cambiamenti distinti in questa struttura ad ogni muta larvale. </li><li> Tardo 2 °-inizio 3 ° instar larve vengono raccolti per analisi di comportamento delicatamente e ampiamente lavaggio piatti succo di mela con acqua e raccogliere le larve su un filtro a rete. Le larve sono poi trasferiti ad una piastra di agar. </li><li> Tutte le analisi vengono eseguite in parallelo utilizzando controllo e animali da esperimento. </li></ol> 2. Paradigm Behavioral - Locomotion <ol><li> Posizionare un singolo 3 ° larva su un substrato di agar 2% in un piatto di coltura tissutale di 100 mm e consentono la larva acclimatare per 30 sec. Le larve usare i loro scleriti cephalopharyngeal (ganci bocca) per spingere i loro corpi attraverso la superficie del substrato agar. Questo viene fatto su un piatto a parte, perché it è più difficile da visualizzare le contrazioni del corpo nella soluzione lievito come l&#39;animale è quasi lo stesso colore del lievito. </li><li> Osservare e registrare ogni posteriormente al movimento anteriore sopra il substrato per un periodo di 1 min. n = 20 per ogni genotipo. Non più di 10 animali dovrebbero essere testati per piastra. </li></ol> 3. Comportamento Paradigm - Alimentazione <ol><li> Uso blunt Inox # 5 pinzette, trasferire accuratamente il 3 ° larva dalla piastra locomotore agar al centro di una piastra di agar-riempite sovrapposti con 5 ml di soluzione di lievito 2% del panettiere attivato. Assicurarsi che la soluzione sia omogenea come il lievito si depositerà nel tempo. Quando nella soluzione di lievito, larve in gran parte mantenute e mangimi, facilitando l&#39;osservazione del comportamento. Il tasso di bocca contrazioni gancio direttamente correlata con la quantità di cibo ingerito 14. </li><li> Lasciare larva di ambientarsi per 30 sec. </li><li> Osservare e registrare il numero dibocca contrazioni gancio per un periodo di 1 min. n = 20 per ogni genotipo. </li></ol> 4. Dissezioni Gut larvali <ol><li> Fare una soluzione di fissaggio di formaldeide al 4% EM-grade in 1x tampone fosfato salino (PBS) e mettere in un bicchiere posto a 3-bene. </li><li> Sezionare con attenzione vagando tardi 3 ° instar budella larvali in un piatto di vetro 3-bene usando la soluzione 1x PBS, assicurandosi che ogni volta che proventricolo è lasciata intatta. Con una pinza, tenere l&#39;estremità posteriore, e con l&#39;altra, tenere i ganci bocca. Tenendo l&#39;immobile estremità posteriore, tirare delicatamente i ganci bocca per accedere alle budella. Rimuovere eventuali relativi tessuti (ghiandole salivari, al cervello, corpo grasso, ecc), quindi trasferire ogni intestino al piatto 3-pozzetto contenente la correzione di formaldeide. Vagando 3 ° instar larva vengono utilizzati perché in questa fase di sviluppo, la larva cessa di alimentazione in preparazione per pupariation, e proventricolo viene cancellata di lievito. </li> &lt;li&gt; Incubare coraggio a 4 ° C per una notte in una scatola di coltura di tessuti opachi. </li><li> Prima di rimuovere la soluzione di fissazione di formaldeide dai pozzi, rimuovere il caeca gastrica e agganciare il midgut ~ 150 micron 2 dal proventricolo in modo che le proiezioni possono essere chiaramente visualizzate senza impedimenti. </li><li> Rimuovere formaldeide correzione dai pozzetti e sostituirla con 1x PBT (1x PBS, 0,1% privo di proteasi albumina di siero bovino, 0,1% Triton X-100) soluzione tampone. Lavare accuratamente le budella 6x per 10 min in 1x PBT. Mettere campioni di tessuto su un rotatore meccanico, mentre facendo lavaggi. </li><li> Incubare a 4 ° C per 1 ora a 10 -6 M 5-HT che permettono di migliorare serotonina. Lavare accuratamente le budella 6x per 10 min in 1x PBT. Studi precedenti hanno dimostrato che questa concentrazione di esogeno 5-HT non influisce architettura neuronale o densità varici in analisi immunoistochimica e semplicemente migliora il rapporto segnale-rumore 15-16. </li><li> Incubare a 4 &amp;# 176; C durante la notte in anti-serotonina anticorpo primario (monoclonale cresciuto a mouse o policlonali in coniglio). Lavare accuratamente le budella 6x per 10 min in 1x PBT. Mettere campioni di tessuto su un rotatore meccanico, mentre facendo lavaggi. </li><li> Incubare a 4 ° C per 90 min in anticorpo secondario (Alexa Fluor 568 IgG di capra anti-topo o anti-coniglio; 1:400 diluizione). Lavare accuratamente le budella 6x per 10 min in 1x PBT. Mettere campioni di tessuto su un rotatore meccanico, mentre facendo lavaggi. </li><li> Incubare a 4 mM di carbonato di sodio per 10 minuti su un agitatore rotante, quindi montare in 4% n-propile gallate/20 mM di carbonato di sodio, e vista in fluorescenza. Carbonato di sodio è usato per convertire i campioni al tampone e pH utilizzato nei mezzi di montaggio. </li><li> Cattura immagini di campioni di tessuto immunostained a 400X per l&#39;analisi. </li></ol> 5. Analisi dei circuiti neurali <ol><li> Fibre neurite sono stati quantificati (numero e dimensioni delle varicie grado di ramificazione) utilizzando Neuroleucida e Neuroexplorer. Tuttavia, questo può anche essere effettuata manualmente o utilizzando semplici neuriti Tracer (una applicazione che può essere scaricato online gratuito). </li><li> Tracciare le singole proiezioni fibra dal cervello al proventricolo e quantificare il numero varici, le filiali e il numero di grandi varicosità per unità di lunghezza. Le fibre assonali sporgenti dal cervello vengono raggruppati nel nervo Recurrens e non sono accessibili per l&#39;analisi fino a raggiungere proventricolo dove si separano e fasciculate. </li></ol>

<ol>
	<li>Weiss, E., Maness, P., Lauder, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+do+neurotransmitters+act+like+growth+factors?.">Why do neurotransmitters act like growth factors?.</a> Perspect Dev Neurobiol. 5, 323-335 .</li><li>Herlenius, E., Lagercrantz, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurotransmitters+and+neuromodulators+during+early+human+development.">Neurotransmitters and neuromodulators during early human development.</a> Early Hum. Dev. 65, 21-37 .</li><li>Budnik, V., Wu, C., White, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Altered+branching+of+serotonin-containing+neurons+in+Drosophila+mutants+unable+to+synthesize+serotonin+and+dopamine.">Altered branching of serotonin-containing neurons in Drosophila mutants unable to synthesize serotonin and dopamine.</a> J. Neurosci. 9, 2866-2877 (1989).</li><li>Sodhi, M., Sanders-Bush, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+and+brain+development.">Serotonin and brain development.</a> International Review of Neurobiol. 59, 111-174 (2004).</li><li>Goldberg, J., Kater, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+and+function+of+the+neurotransmitter+serotonin+during+development+of+the+Helisoma+nervous+system.">Expression and function of the neurotransmitter serotonin during development of the Helisoma nervous system.</a> Dev. Biol. 131, 483-495 (1989).</li><li>Goldberg, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+regulation+of+neurite+outgrowth+in+identified+neurons+from+mature+and+embryonic+Helisoma+triyolvis.">Serotonin regulation of neurite outgrowth in identified neurons from mature and embryonic Helisoma triyolvis.</a> Perspect Dev Neurobiol. 5, 373-387 (1998).</li><li>Haydon, P., McCobb, P., Kater, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+selectively+inhibits+growth+cone+motility+and+synaptogenesis+of+specific+identified+neurons.">Serotonin selectively inhibits growth cone motility and synaptogenesis of specific identified neurons.</a> Sci. 226, 561-564 (1984).</li><li>Neckameyer, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+trophic+role+for+serotonin+in+the+development+of+a+simple+feeding+circuit.">A trophic role for serotonin in the development of a simple feeding circuit.</a> Dev. Neurosci. 32, 217-237 .</li><li>De Vry, J., Schreiber, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+selected+serotonin+5-HT+1+and+5-HT+2+receptor+agonists+on+feeding+behavior:+possible+mechanisms+of+action.">Effects of selected serotonin 5-HT 1 and 5-HT 2 receptor agonists on feeding behavior: possible mechanisms of action.</a> Neurosci. Biobehav. Rev. 24, 341-353 (2000).</li><li>Schoofs, A., Niederegger, S., van Ooyen, A., Heinzel, H., Spie&#223;, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+brain+can+eat:+Establishing+the+existence+of+a+central+pattern+generator+for+feeding+in+third+instar+larvae+of+Drosophila+virilis+and+Drosophila+melanogaster.">The brain can eat: Establishing the existence of a central pattern generator for feeding in third instar larvae of Drosophila virilis and Drosophila melanogaster.</a> J. Insect Physiol. 56, 695-705 (2010).</li><li>Spie&#223;, R., Schoofs, A., Heinzel, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomy+of+the+stomatogastric+nervous+system+associated+with+the+foregut+in+Drosophila+melanogaster+and+Calliphora+vicin+third+instar+larvae.">Anatomy of the stomatogastric nervous system associated with the foregut in Drosophila melanogaster and Calliphora vicin third instar larvae.</a> J. Morphol. 269, 272-282 (2008).</li><li>Neckameyer, W. S., Bhatt, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurotrophic+actions+of+dopamine+on+the+development+of+a+serotonergic+feeding+circuit+in+Drosophila+melanogaster.">Neurotrophic actions of dopamine on the development of a serotonergic feeding circuit in Drosophila melanogaster.</a> Biomed Cent NeuroSci. 13, 26 (2012).</li><li>Sewall, D., Burnet, B., Connolly, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+analysis+of+larval+feeding+behavior+in+Drosophila+melanogaste.">Genetic analysis of larval feeding behavior in Drosophila melanogaste.</a> Genet. Res. 24, 163-173 (1975).</li><li>Joshi, A., Mueller, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+higher+feeding+rate+in+Drosophila+due+to+density-dependent+natural+selection.">Evolution of higher feeding rate in Drosophila due to density-dependent natural selection.</a> Evolution. 42, 1090-1093 (1988).</li><li>Budnik, V., Wu, C., White, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Altered+branching+of+serotonin-containing+neurons+in+Drosophila+mutants+unable+to+synthesize+serotonin+and+dopamine.">Altered branching of serotonin-containing neurons in Drosophila mutants unable to synthesize serotonin and dopamine.</a> J. Neurosci. 9, 2866-2877 (1989).</li><li>Sykes, P., Condron, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+sensitivity+to+serotonin+of+Drosophila+varicosities+in+the+central+nervous+system.">Development and sensitivity to serotonin of Drosophila varicosities in the central nervous system.</a> Dev. Biol. 286, 207-216 (2005).</li><li>Garrity, P. A., Goodman, M. B., Samuel, A. D., Sengupta, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Running+hot+and+cold:+behavioral+strategies,+neural+circuits,+and+the+molecular+machinery+for+thermotaxis+inC.+elegansand+Drosophila.">Running hot and cold: behavioral strategies, neural circuits, and the molecular machinery for thermotaxis inC. elegansand Drosophila.</a> Genes Dev. 24, 2365-2382 (2010).</li><li>McKemy, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+sensing+across+species.">Temperature sensing across species.</a> Pflugers Archives. 454, 777-791 (2007).</li></ol>

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Sviluppo aberrante del circuito stomatogastric serotoninergico, che si verifica durante la tarda embriogenesi, influenzerà la sua funzione maturo. Modifiche della struttura neurite innervano l&#39;intestino può essere correlato con l&#39;uscita funzionale del circuito, che sta alimentando tasso (misurato dalla bocca contrazioni gancio in una soluzione di lievito) (Figura 1). L&#39;utilizzo del sistema bipartito UAS-GAL4 in Drosophila permette di indirizzare specificamente up-o down-regolato e...

Drosophila è estremamente potente sistema modello per lo studio dello sviluppo del circuito neurale a causa di tempi rapidi generazione, a basso costo sperimentale, e la capacità di manipolare e controllare i fattori genetici e ambientali. Neurogenesi, constatazione percorso neuronale e la sinaptogenesi sono conservati tra l&#39;uomo e Drosophila, quindi i meccanismi di creazione, il mantenimento e la modifica dei circuiti neurali sono conservati pure. Neurotrasmettitori, come la serotonina (5-idrossitriptamina, o 5-HT) possono servire come fattori di crescita prima di adottare il loro ruolo di molecole di segnalazione nel maturo circuito neurale 1-3 Studi precedenti hanno dimostrato che perturbato livelli di 5-HT durante l&#39;embriogenesi alterare la connettività dei neuroni maturi 4. Altri hanno dimostrato che l&#39;applicazione ectopica di 5-HT a neuroni in coltura Helisoma reprimere neuriti e sinaptogenesi 5-7. In Drosophila, sviluppo livelli di 5-HT sono inversamente proporzionali al numero di varici e dimensione, nonché il grado di aborization, lungo la lunghezza dei neuriti sporgenti al foregut dal CNS 8. Neurotrasmissione serotoninergica ha dimostrato di modulare i comportamenti alimentari di specie diverse, tra cui Drosophila 8-9. Il circuito di alimentazione in Drosophila è relativamente semplice circuito che può essere utilizzato come modello per correlare l&#39;uscita funzionale (alimentazione) con alterazioni nello sviluppo delle proiezioni assonale dal cervello foregut. Schoofs et al. hanno dimostrato che larvale Drosophila è regolata da generatori di pattern centrali che influenzano la muscolatura 10. Mentre l&#39;anatomia muscolare specifico non è completamente compreso, è stato dimostrato che il nervo antenne, nervo mascellare, e prothoracic nervo accessorio sono responsabili dei bersagli muscolari coinvolte nellacomportamento alimentare. La maggior parte dei dati che coinvolgono la muscolatura e del nervo anatomia di alimentazione invertebrato è limitata a Calliphora larve. Il tasso di alimentazione del secondo larve instar può essere valutato retrazione delle scleriti cephalopharyngeal (ganci bocca), ed è riproducibile e high-throughput. Le piastre cephalopharyngeal sono innervati da fibre di centrali neuroni 5-HT attraverso il nervo frontale. Il proventricolo, o foregut, è innervato da fibre serotoninergici (Recurrens del nervo) che fasciculate nel midgut e sono responsabili per la contrazione del foregut (Figura 1), 11-12. Cambiamenti nella ramificazione assonale, e il numero e le dimensioni delle varici lungo la lunghezza dei neuriti, possono essere quantizzati utilizzando tecniche immunoistochimiche. Manipolazione neuronale 5-HT durante lo sviluppo, direttamente o indirettamente, può modificare la potenza funzionale di questo circuito di alimentazione, che può essere valutato e correlata con i cambiamenti nel morphology dell&#39;architettura neurite.

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			<td height="40" style="height:40px;width:217px;">Eclipse E-800 Microscope</td>
			<td style="width:175px;">Nikon Instruments</td>
			<td style="width:115px;"></td>
			<td style="width:251px;"></td>
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		<tr height="60">
			<td height="60" style="height:60px;width:217px;">Neuroleucida</td>
			<td style="width:175px;">MBF Biosciences</td>
			<td style="width:115px;">NL-15</td>
			<td style="width:251px;">Used to analyze gut fiber architecture, not necessary to have</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:217px;">Northern Eclipse</td>
			<td style="width:175px;">Empix Inc</td>
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			<td style="width:251px;">Imaging software</td>
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		<tr height="60">
			<td height="60" style="height:60px;width:217px;">G-2E/C TRITC EX 528-553</td>
			<td style="width:175px;">Nikon Instruments</td>
			<td style="width:115px;">96312</td>
			<td style="width:251px;">Filter for specific secondary antibody</td>
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		<tr height="80">
			<td height="80" style="height:80px;width:217px;">N.A. 0.75; W.D. 0.72 mm; DIC Prism: 40xI, 40x I-C; Spring loaded</td>
			<td style="width:175px;">Nikon Instruments</td>
			<td style="width:115px;">MRH00400</td>
			<td style="width:251px;">Objective used for imaging</td>
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		<tr height="41">
			<td height="41" style="height:41px;width:217px;">Simple Neurite Tracer</td>
			<td style="width:175px;">NIH Image J</td>
			<td style="width:115px;"></td>
			<td style="width:251px;"><a href="http://fiji.sc/Simple_Neurite_Tracer">http://fiji.sc/Simple_Neurite_Tracer</a></td>
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functional analysis of the larval feeding circuit in drosophila

Il circuito di alimentazione serotoninergico in Drosophila melanogaster larve può essere usato per studiare substrati neuronali di importanza critica durante lo sviluppo del circuito. Utilizzando l&#39;uscita funzionale del circuito di alimentazione, modifiche della struttura neuronale del sistema stomatogastric può essere visualizzata. Comportamento alimentare può essere registrato osservando il tasso di retrazione dei ganci bocca, che ricevono innervazione dal cervello. Comportamento locomotorio viene utilizzato come controllo fisiologico per l&#39;alimentazione, poiché larve utilizzare loro bocca ganci attraversare le un substrato di agar. Cambiamenti nel comportamento alimentare possono essere correlati con l&#39;architettura assonale dei neuriti innervano l&#39;intestino. Usando immunoistochimica è possibile visualizzare e quantificare questi cambiamenti. L&#39;uso improprio delle larve durante paradigmi di comportamento in grado di alterare i dati in quanto sono molto sensibili alle manipolazioni. La corretta rappresentazione dell&#39;architettura neurite innervanol&#39;intestino è critico per la quantificazione precisa del numero e delle dimensioni delle varici nonché l&#39;entità di nodi ramo. Analisi della maggior parte dei circuiti consentono solo per la visualizzazione di architettura neurite o effetti comportamentali, tuttavia, questo modello permette di correlare l&#39;uscita funzionale del circuito con menomazioni dell&#39;architettura neuronale.

Il circuito di alimentazione serotoninergico nella larva Drosophila può servire come un modello estremamente efficace per osservare l&#39;influenza di fattori particolari sullo sviluppo del sistema nervoso. Con quantificazione tasso di alimentazione, è possibile collegare l&#39;architettura assonale del circuito di alimentazione con la sua uscita funzionale (Figura 1). Il dosaggio locomotore viene utilizzato come controllo fisiologico per le retrazioni dei ganci bocca, poiché larve utilizzar...

Watch this Scientific Journal Video about Functional Analysis of the Larval Feeding Circuit in Drosophila at JoVE.com

Functional Analysis of the Larval Feeding Circuit in Drosophila

Il circuito di alimentazione in Drosophila melanogaster larve propone un modello semplice ma potente che consente modifiche del tasso di alimentazione per essere correlati con alterazioni della circuiti neurali stomatogastric. Questo circuito è composto di neuroni serotoninergici centrali che inviano proiezioni ai ganci bocca e foregut.

Analisi funzionale del circuito di alimentazione larvale in Drosophila</i

The serotonergic  feeding circuit in Drosophila  melanogaster larvae can be used to investigate neuronal substrates of  critical importance during the ...

functional-analysis-of-the-larval-feeding-circuit-in-drosophila

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

Functional Analysis of the Larval Feeding Circuit in Drosophila

10.2K Views.  Saint Louis University School of Medicine.  Il circuito di alimentazione in Drosophila melanogaster larve propone un modello semplice ma potente che consente modifiche del tasso di alimentazione per essere correlati con alterazioni della circuiti neurali stomatogastric. Questo circuito è composto di neuroni serotoninergici centrali che inviano proiezioni ai ganci bocca e foregut. 

Video: Functional Analysis of the Larval Feeding Circuit in Drosophila

Visualization of Larval Segmental Nerves in 3rd Instar Drosophila Larval Preparations

Drosophila melanogaster is emerging as a powerful model system for studying the development and function of the nervous system, particularly because of its convenient genetics and fully sequenced genome. Additionally, the larval nervous system is an ideal model system to study mechanisms of axonal transport as the larval segmental nerves contain bundles of axons with their cell bodies located within the brain and their nerve terminals ending along the length of the body. Here we describe the procedure for visualization of synaptic vesicle proteins within larval segmental nerves. If done correctly, all components of the nervous system, along with associated tissues such as muscles and NMJs, remain intact, undamaged, and ready to be visualized. 3rd instar larvae carrying various mutations are dissected, fixed, incubated with synaptic vesicle antibodies, visualized and compared to wild type larvae. This procedure can be adapted for several different synaptic or neuronal antibodies and changes in the distribution of a variety of proteins can be easily observed within larval segmental nerves.

Visualization of Larval Segmental Nerves in 3rd Instar Drosophila Larval Preparations

Drosophila melanogaster larvae provide an ideal model system to investigate the mechanisms of axonal transport within larval segmental nerves. Using this procedure, 3rd instar larvae carrying various mutations can be compared to wild type larvae.

Visualizzazione dei nervi larvali segmentale in 3 Rd Instar Drosophila I preparativi larvali

Drosophila melanogaster is emerging as a powerful model system for studying the development and function of the nervous system, particularly because of ...

Ricerca

Neuroscienze

In vivo Visualization of Synaptic Vesicles Within Drosophila Larval Segmental Axons

Elucidating the mechanisms of axonal transport has shown to be very important in determining how defects in long distance transport affect different neurological diseases. Defects in this essential process can have detrimental effects on neuronal functioning and development. We have developed a dissection protocol that is designed to expose the Drosophila larval segmental nerves to view axonal transport in real time. We have adapted this protocol for live imaging from the one published by Hurd and Saxton (1996) used for immunolocalizatin of larval segmental nerves. Careful dissection and proper buffer conditions are critical for maximizing the lifespan of the dissected larvae. When properly done, dissected larvae have shown robust vesicle transport for 2-3 hours under physiological conditions. We use the UAS-GAL4 method 1 to express GFP-tagged APP or synaptotagmin vesicles within a single axon or many axons in larval segmental nerves by using different neuronal GAL4 drivers. Other fluorescently tagged markers, for example mitochrondria (MitoTracker) or lysosomes (LysoTracker), can be also applied to the larvae before viewing. GFP-vesicle movement and particle movement can be viewed simultaneously using separate wavelengths.

In vivo Visualization of Synaptic Vesicles Within Drosophila Larval Segmental Axons

This protocol discusses the live dissection of Drosophila larvae for the purpose of imaging the movement of GFP tagged axonal vesicles on microtubule tracks.

Nella visualizzazione in vivo delle vescicole sinaptiche In Drosophila assoni larvali segmentale

Elucidating the mechanisms of axonal transport has shown to be very important in determining how defects in long distance transport affect different ...

Morphological Analysis of Drosophila Larval Peripheral Sensory Neuron Dendrites and Axons Using Genetic Mosaics

Nervous system development requires the correct specification of neuron position and identity, followed by accurate neuron class-specific dendritic development and axonal wiring. Recently the dendritic arborization (DA) sensory neurons of the Drosophila larval peripheral nervous system (PNS) have become powerful genetic models in which to elucidate both general and class-specific mechanisms of neuron differentiation.
There are four main DA neuron classes (I-IV)1. They are named in order of increasing dendrite arbor complexity, and have class-specific differences in the genetic control of their differentiation2-10. The DA sensory system is a practical model to investigate the molecular mechanisms behind the control of dendritic morphology11-13 because: 1) it can take advantage of the powerful genetic tools available in the fruit fly, 2) the DA neuron dendrite arbor spreads out in only 2 dimensions beneath an optically clear larval cuticle making it easy to visualize with high resolution in vivo, 3) the class-specific diversity in dendritic morphology facilitates a comparative analysis to find key elements controlling the formation of simple vs. highly branched dendritic trees, and 4) dendritic arbor stereotypical shapes of different DA neurons facilitate morphometric statistical analyses.
DA neuron activity modifies the output of a larval locomotion central pattern generator14-16. The different DA neuron classes have distinct sensory modalities, and their activation elicits different behavioral responses14,16-20. Furthermore different classes send axonal projections stereotypically into the Drosophila larval central nervous system in the ventral nerve cord (VNC)21. These projections terminate with topographic representations of both DA neuron sensory modality and the position in the body wall of the dendritic field7,22,23. Hence examination of DA axonal projections can be used to elucidate mechanisms underlying topographic mapping7,22,23, as well as the wiring of a simple circuit modulating larval locomotion14-17.
We present here a practical guide to generate and analyze genetic mosaics24 marking DA neurons via MARCM (Mosaic Analysis with a Repressible Cell Marker)1,10,25 and Flp-out22,26,27 techniques (summarized in Fig. 1).

Morphological Analysis of Drosophila Larval Peripheral Sensory Neuron Dendrites and Axons Using Genetic Mosaics

The dendritic arborization sensory neurons of the Drosophila larval peripheral nervous system are useful models to elucidate both general and neuron class-specific mechanisms of neuron differentiation. We present a practical guide to generate and analyze dendritic arborization neuron genetic mosaics.

Analisi morfologica del Drosophila Larvale dendriti sensoriali e periferico Neuron assoni utilizzo Mosaici genetici

Nervous system development requires the correct specification of neuron position and identity, followed by accurate neuron class-specific dendritic ...

Visualization of Proprioceptors in Drosophila Larvae and Pupae

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other insects proprioception is provided by specialized sensory organs termed chordotonal organs (ChOs) 2. Like many other organs in Drosophila, ChOs develop twice during the life cycle of the fly. First, the larval ChOs develop during embryogenesis. Then, the adult ChOs start to develop in the larval imaginal discs and continue to differentiate during metamorphosis.
The development of larval ChOs during embryogenesis has been studied extensively 10,11,13,15,16. The centerpiece of each ChO is a sensory unit composed of a neuron and a scolopale cell. The sensory unit is stretched between two types of accessory cells that attach to the cuticle via specialized epidermal attachment cells 1,9,14. When a fly larva moves, the relative displacement of the epidermal attachment cells leads to stretching of the sensory unit and consequent opening of specific transient receptor potential vanilloid (TRPV) channels at the outer segment of the dendrite 8,12. The elicited signal is then transferred to the locomotor central pattern generator circuit in the central nervous system.
Multiple ChOs have been described in the adult fly 7. These are located near the joints of the adult fly appendages (legs, wings and halters) and in the thorax and abdomen. In addition, several hundreds of ChOs collectively form the Johnston's organ in the adult antenna that transduce acoustic to mechanical energy 3,5,17,4.
In contrast to the extensive knowledge about the development of ChOs in embryonic stages, very little is known about the morphology of these organs during larval stages. Moreover, with the exception of femoral ChOs 18 and Johnston's organ, our knowledge about the development and structure of ChOs in the adult fly is very fragmentary.
Here we describe a method for staining and visualizing ChOs in third instar larvae and pupae. This method can be applied together with genetic tools to better characterize the morphology and understand the development of the various ChOs in the fly.

Visualization of Proprioceptors in Drosophila Larvae and Pupae

A method to immunostain and visualize chordotonal organs in larvae and pupae of Drosophila melanogaster is described.

Visualizzazione dei Propriorecettori in<em&gt; Drosophila</em&gt; Larve e pupe

Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other ...

Dissection and Immunohistochemistry of Larval, Pupal and Adult Drosophila Retinas

The compound eye of Drosophila melanogaster consists of about 750 ommatidia (unit eyes). Each ommatidium is composed of about 20 cells, including lens-secreting cone cells, pigment cells, a bristle cell and eight photoreceptors (PRs) R1-R8 2. The PRs have specialized microvillar structures, the rhabdomeres, which contain light-sensitive pigments, the Rhodopsins (Rhs). The rhabdomeres of six PRs (R1-R6) form a trapezoid and contain Rh1 3 4. The rhabdomeres of R7 and R8 are positioned in tandem in the center of the trapezoid and share the same path of light. R7 and R8 PRs stochastically express different combinations of Rhs in two main subtypes5: In the 'p' subtype, Rh3 in pR7s is coupled with Rh5 in pR8s, whereas in the 'y' subtype, Rh4 in yR7s is associated with Rh6 in yR8s 6 7 8.
Early specification of PRs and development of ommatidia begins in the larval eye-antennal imaginal disc, a monolayer of epithelial cells. A wave of differentiation sweeps across the disc9 and initiates the assembly of undifferentiated cells into ommatidia10-11. The 'founder cell' R8 is specified first and recruits R1-6 and then R7 12-14. Subsequently, during pupal development, PR differentiation leads to extensive morphological changes 15, including rhabdomere formation, synaptogenesis and eventually rh expression.
In this protocol, we describe methods for retinal dissections and immunohistochemistry at three defined periods of retina development, which can be applied to address a variety of questions concerning retinal formation and developmental pathways. Here, we use these methods to visualize the stepwise PR differentiation at the single-cell level in whole mount larval, midpupal and adult retinas (Figure 1).

Dissection and Immunohistochemistry of Larval, Pupal and Adult Drosophila Retinas

The Drosophila retina is a crystal-like lattice composed of a small number of cell types that are generated in a stereotyped manner 1. Its amenability to sophisticated genetic analysis allows the study of complex developmental programs. This protocol describes dissections and immunohistochemistry of retinas at three discrete developmental stages, with a focus on photoreceptor differentiation.

Dissezione e immunoistochimica di larvale, pupa e adulto<em&gt; Drosophila</em&gt; Retine

The compound eye of Drosophila melanogaster consists of about 750 ommatidia (unit eyes). Each ommatidium is composed of about 20 cells, including ...

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 ...

Live Imaging of Drosophila Larval Neuroblasts

Stem cells divide asymmetrically to generate two progeny cells with unequal fate potential: a self-renewing stem cell and a differentiating cell. Given their relevance to development and disease, understanding the mechanisms that govern asymmetric stem cell division has been a robust area of study. Because they are genetically tractable and undergo successive rounds of cell division about once every hour, the stem cells of the Drosophila central nervous system, or neuroblasts, are indispensable models for the study of stem cell division. About 100 neural stem cells are located near the surface of each of the two larval brain lobes, making this model system particularly useful for live imaging microscopy studies. In this work, we review several approaches widely used to visualize stem cell divisions, and we address the relative advantages and disadvantages of those techniques that employ dissociated versus intact brain tissues. We also detail our simplified protocol used to explant whole brains from third instar larvae for live cell imaging and fixed analysis applications.

Live Imaging of Drosophila Larval Neuroblasts

This protocol details a streamlined method used to conduct live cell imaging in the context of an intact larval brain. Live cell imaging approaches are invaluable for the study of asymmetric neural stem cell divisions as well as other neurogenic and developmental processes, consistently uncovering mechanisms that were previously overlooked.

Immagini dal vivo di<em&gt; Drosophila</em&gt; larvali neuroblasti

Stem cells divide asymmetrically to generate two progeny cells with unequal fate potential: a self-renewing stem cell and a differentiating cell. Given ...

Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction

Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic pathways. Quantitative descriptions are rarely performed, although genetic manipulations produce a range of phenotypic effects and variations are observed even among individuals within control groups.&#160;Emerging evidence shows that morphology, size and location of organelles play a previously underappreciated, yet fundamental role in cell function and survival. Here we provide step-by-step instructions for performing quantitative analyses of phenotypes at the Drosophila larval neuromuscular junction (NMJ). We use several reliable immuno-histochemical markers combined with bio-imaging techniques and morphometric analyses to examine the effects of genetic mutations on specific cellular processes. In particular, we focus on the quantitative analysis of phenotypes affecting morphology, size and position of nuclei within the striated muscles of Drosophila larvae. The Drosophila larval NMJ is a valuable experimental model to investigate the molecular mechanisms underlying the structure and the function of the neuromuscular system, both in health and disease. However, the methodologies we describe here can be extended to other systems as well.

Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction

Morphology, size and location of intracellular organelles are evolutionarily conserved and appear to directly affect their function. Understanding the molecular mechanisms underlying these processes has become an important goal of modern biology. Here we show how these studies can be facilitated by the application of quantitative techniques.

Perché Quantificazione Matters: Caratterizzazione dei fenotipi al<em&gt; Drosophila</em&gt; Larvale Giunzione neuromuscolare

Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic ...

Removal of Drosophila Muscle Tissue from Larval Fillets for Immunofluorescence Analysis of Sensory Neurons and Epidermal Cells

Drosophila larval dendritic arborization (da) neurons are a popular model for investigating mechanisms of neuronal morphogenesis. Da neurons develop in communication with the epidermal cells they innervate and thus their analysis benefits from in situ visualization of both neuronally and epidermally expressed proteins by immunofluorescence. Traditional methods of preparing larval fillets for immunofluorescence experiments leave intact the muscle tissue that covers most of the body wall, presenting several challenges to imaging neuronal and epidermal proteins. Here we describe a method for removing muscle tissue from Drosophila larval fillets. This protocol enables imaging of proteins that are otherwise obscured by muscle tissue, improves signal to noise ratio, and facilitates the use of super-resolution microscopy to study da neuron development.

Removal of Drosophila Muscle Tissue from Larval Fillets for Immunofluorescence Analysis of Sensory Neurons and Epidermal Cells

Studies of neuronal morphogenesis using Drosophila larval dendritic arborization (da) neurons benefit from in situ visualization of neuronal and epidermal proteins by immunofluorescence. We describe a procedure that improves immunofluorescence analysis of da neurons and surrounding epidermal cells by removing muscle tissue from the larval body wall.

Rimozione di<em&gt; Drosophila</em&gt; Tessuto muscolare da larvali Filetti per l&#39;analisi di immunofluorescenza dei neuroni sensoriali e cellule epidermiche

Drosophila larval dendritic arborization (da) neurons are a popular model for investigating mechanisms of neuronal morphogenesis. Da neurons develop in ...

High-throughput Analysis of Locomotor Behavior in the Drosophila Island Assay

Advances in next-generation sequencing technologies contribute to the identification of (candidate) disease genes for movement disorders and other neurological diseases at an increasing speed. However, little is known about the molecular mechanisms that underlie these disorders. The genetic, molecular, and behavioral toolbox of Drosophila melanogaster makes this model organism particularly useful to characterize new disease genes and mechanisms in a high-throughput manner. Nevertheless, high-throughput screens require efficient and reliable assays that, ideally, are cost-effective and allow for the automatized quantification of traits relevant to these disorders. The island assay is a cost-effective and easily set-up method to evaluate Drosophila locomotor behavior. In this assay, flies are thrown onto a platform from a fixed height. This induces an innate motor response that enables the flies to escape from the platform within seconds. At present, quantitative analyses of filmed island assays are done manually, which is a laborious undertaking, particularly when performing large screens.
This manuscript describes the &#34;Drosophila Island Assay&#34; and &#34;Island Assay Analysis&#34; algorithms for&#160;high-throughput, automated data processing and quantification of island assay data. In the setup, a simple webcam connected to a laptop collects an image series of the platform while the assay is performed. The &#34;Drosophila Island Assay&#34; algorithm developed for the open-source software Fiji processes these image series and quantifies, for each experimental condition, the number of flies on the platform over time. The &#34;Island Assay Analysis&#34; script, compatible with the free software R, was developed to automatically process the obtained data and to calculate whether treatments/genotypes are statistically different. This greatly improves the efficiency of the island assay and makes it a powerful readout for basic locomotion and flight behavior. It can thus be applied to large screens investigating fly locomotor ability, Drosophila models of movement disorders, and drug efficacy.

High-throughput Analysis of Locomotor Behavior in the Drosophila Island Assay

The island assay is a relatively new, cost-effective assay that can be used to evaluate the basic locomotor behavior of Drosophila melanogaster. This manuscript describes algorithms for automatic data processing and objective quantification of island assay data, making this assay a sensitive, high-throughput readout for large genetic or pharmacological screens.

Analisi funzionale del circuito di alimentazione larvale in Drosophila

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Visualizzazione dei nervi larvali segmentale in 3^Rd Instar Drosophila I preparativi larvali

Nella visualizzazione in vivo delle vescicole sinaptiche In Drosophila assoni larvali segmentale

Analisi morfologica del Drosophila Larvale dendriti sensoriali e periferico Neuron assoni utilizzo Mosaici genetici

Visualizzazione dei Propriorecettori in

Dissezione e immunoistochimica di larvale, pupa e adulto

Tutta Monte immunomarcatura di recettore olfattivo neuroni nel

Immagini dal vivo di

Perché Quantificazione Matters: Caratterizzazione dei fenotipi al

Rimozione di

High-throughput analisi del comportamento motorio nell'analisi di Isola della drosofila