Nous remercions Bernard Charroux pour les discussions. Ce travail a été financé par l&#39;École KCL biomédicale.

1. Dissection de la rétine chez la drosophile <ol><li> Remplir un puits d&#39;une lame de verre 3 puits avec du tampon phosphate salin (PBS 1X), puis par les mouches anesthésier CO 2. Les mâles et les femelles peuvent être utilisés pour cette expérience. </li><li> Une fois que les mouches sont anesthésiés, ramasser une seule mouche à l&#39;aide de pinces et le déposer dans le petit plat de PBS. </li><li> Sous un microscope à dissection, pincez la trompe avec une pince, puis détacher la tête de l&#39;organisme par la rupture du cou en utilisant une deuxième série de pinces. </li><li> En tenant la tête de voler de la trompe, coupé en deux le long de la ligne médiane gauche / droite de la tête voler avec microciseaux de révéler le cerveau. </li><li> Utiliser un embout de pipette coupé pour ramasser la rétine, et le transfert à un deuxième puits de la lame de verre 3-bien rempli de milieu de Schneider. </li><li> Tout d&#39;abord, éplucher la plupart de la cuticule tête et puis enlever le cerveau avec une pince. Gardez la rétine en sandwich entre la lame et la cornée. </li><li> Ensuite, le transfert de la rétine sur un drop (50 pi) de milieu Schnieder fraîches placées directement sur la lame de verre. </li></ol> 2. Dissection de la ommatidies <ol><li> Selon le but final de la dissection (si l&#39;imagerie immédiate ou la culture) et sur l&#39;optique du microscope à fluorescence (directe ou inversée), cette étape peut se dérouler soit sur une lame de microscope ou dans une plaque de 24 puits. Pour le but final de cette dissection, les ommatidies seront disséquées directement sur la lame de verre. </li><li> Saisissez soit l&#39;extrémité la plus dorsale ou ventrale de la rétine avec une pince. Utiliser microciseaux, couper la rétine en deux le long de la ligne médiane dorsale / ventrale pour exposer les ommatidies dans le milieu de l&#39;œil. </li><li> Continuez à saisir la rétine telles que la cornée est orientée vers le bas et la lame vers le haut. En utilisant une aiguille de tungstène fines, détacher le ommatidies de la lame et la cornée. </li><li> Simple ommatidies et des groupes d&#39;ommatidies recueillera sur le fond du puits ou de diapositives. Enlevez tout débris importants qui peuvent avoir recueilli avant de procéder. </li></ol> 3. Le traitement, la coloration et l&#39;imagerie <ol><li> Pour analyser l&#39;autophagie, diluer 1:1000 Lysotracker dans la chute de Schneider (première diluée à 1:10 dans Schneider et puis ajouter 0,5 ul à la baisse sur la diapositive), mélanger et attendre 10 secondes. </li><li> Retirer l&#39;excès de liquide de la lame, en prenant soin de laisser derrière ommatidies. Il est préférable de faire avec une pointe de chargement de gel fine. </li><li> Ajouter une goutte de Vectashield pour couvrir les ommatidies, recouvrir d&#39;une lamelle et scellez avec vernis à ongles. </li></ol> 4. Les résultats représentatifs: La bonne exécution du protocole devrait laisser un certain nombre de ommatidies unique et de petits groupes d&#39;ommatidies maintenues ensemble par des fragments de la lame, mais bien séparés sur le côté cornée. Ceux-ci peuvent être imagées comme dans cet exemple de visualiser Atg8: GFP et Lysotracker, montrant autophagosomes, les lysosomes et autophagolysosomes (Fig. 3). La méthode peut être utilisée pour l&#39;imagerie en direct, mais dans ce cas il est à noter que l&#39;autofluorescence du milieu de l&#39;Schneider, il sera difficile de distinguer les signaux de faible intensité fluorescente. Un problème supplémentaire est que les granules pigmentaires qui restent attachés à la photorécepteurs sont intensément fluorescentes, en particulier dans le canal rouge. Une image en fond clair peuvent être nécessaires pour les distinguer des organites authentique. <img src="/files/ftp_upload/2882/2882fig1.jpg" alt="Figure 1"/> Figure 1. Organigramme de la procédure pour obtenir une dissection ommatidies simples ou de petits groupes d&#39;ommatidies de la rétine voler. <img src="/files/ftp_upload/2882/2882fig2.jpg" alt="Figure 2"/> Figure 2. Variantes possibles du protocole simple de décrire ici, qui impliquent génétique de la mouche et le vieillissement en amont de la dissection et la coloration ou de culture jusqu&#39;à 24 heures et en aval l&#39;administration du médicament de la dissection. <img src="/files/ftp_upload/2882/2882fig3.jpg" alt="Figure 3"/> Figure 3 scan confocale de autophagosomes et les lysosomes dans une seule ommatidie disséqué de aw; GMR-Gal4, UAS-Atro75QN; UAS-GFP.:: Atg8 / + fly, exprimant une polyglutamine Atrophin mutant et âgés de 12 jours à 29 ° C. Le panneau de fond clair (en haut à droite) affiche la structure presque intacte de l&#39;ommatidie et le cadre indique la zone numérisée. Marques rouges lysosomes, vert l&#39;autophagosomes, auto-lysosomes, résultant de la fusion des deux organites, apparaissent en jaune. Les flèches indiquent deux événements de fusion en cours entre autophagosomes et des lysosomes.

<ol>
	<li>Marsh, J. L., Thompson, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+in+the+study+of+neurodegenerative+disease.">Drosophila in the study of neurodegenerative disease.</a> Neuron. 52, 169-178 (2006).</li><li>Mizushima, N., Levine, B., Cuervo, A. M., Klionsky, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autophagy+fights+disease+through+cellular+self-digestion.">Autophagy fights disease through cellular self-digestion.</a> Nature. 451, 1069-1075 (2008).</li><li>Nisoli, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurodegeneration+by+polyglutamine+Atrophin+is+not+rescued+by+induction+of+autophagy.">Neurodegeneration by polyglutamine Atrophin is not rescued by induction of autophagy.</a> Cell Death Differ. 17, 1577-1587 (2010).</li><li>Charroux, B., Fanto, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+fine+line+between+waste+disposal+and+recycling:+DRPLA+fly+models+illustrate+the+importance+of+completing+the+autophagy+cycle+for+rescuing+neurodegeneration.">The fine line between waste disposal and recycling: DRPLA fly models illustrate the importance of completing the autophagy cycle for rescuing neurodegeneration.</a> Autophagy. 6, 667-669 (2010).</li><li>Hardie, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltage-sensitive+potassium+channels+in+Drosophila+photoreceptors.">Voltage-sensitive potassium channels in Drosophila photoreceptors.</a> J Neurosci. 11, 3079-3095 (1991).</li><li>Lee, T., Luo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mosaic+analysis+with+a+repressible+cell+marker+(MARCM)+for+Drosophila+neural+development.">Mosaic analysis with a repressible cell marker (MARCM) for Drosophila neural development.</a> Trends in neurosciences. 24, 251-254 (2001).</li><li>Xu, T., Rubin, 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=Analysis+of+genetic+mosaics+in+developing+and+adult+Drosophila+tissues.">Analysis of genetic mosaics in developing and adult Drosophila tissues.</a> Development. 117, 1223-1237 (1993).</li><li>Gambis, A., Dourlen, P., Steller, H., Mollereau, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-color+in+vivo+imaging+of+photoreceptor+apoptosis+and+development+in+Drosophila.">Two-color in vivo imaging of photoreceptor apoptosis and development in Drosophila.</a> Dev Biol. 351, 128-1234 (2011).</li><li>Napoletano, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polyglutamine+Atrophin+provokes+neurodegeneration+in+Drosophila+by+repressing+fat.">Polyglutamine Atrophin provokes neurodegeneration in Drosophila by repressing fat.</a> The EMBO journal. 30, 945-958 (2011).</li><li>Ravikumar, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+of+mTOR+induces+autophagy+and+reduces+toxicity+of+polyglutamine+expansions+in+fly+and+mouse+models+of+Huntington+disease.">Inhibition of mTOR induces autophagy and reduces toxicity of polyglutamine expansions in fly and mouse models of Huntington disease.</a> Nature. 36, 585-595 (2004).</li><li>Zou, S., Meadows, S., Sharp, L., Jan, L. Y., Jan, Y. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome-wide+study+of+aging+and+oxidative+stress+response+in+Drosophila+melanogaster.">Genome-wide study of aging and oxidative stress response in Drosophila melanogaster.</a> Proceedings of the National Academy of Sciences of the United States of America. 97, 13726-13731 (2000).</li></ol>

Aucun conflit d&#39;intérêt déclaré.

La dissection ommatidie seule présentée ici permet de collecter des informations plus profondes sur les processus biologiques cellulaires, comme la neurodégénérescence, quand modélisés dans l&#39;œil de drosophile. Les neurones photorécepteurs sont plus facilement accessibles que d&#39;autres neurones et ils cytoplasme est particulièrement importante, et donc adapté pour étudier la dynamique des vésicules, dans les cellules mêmes utilisé avec compétence dans de nombreux modèles pour quantifier ...

<table border="1"><tbody><tr><th> Nom du réactif </th><th> Société </th><th> Numéro de catalogue </th><th> Commentaires (optionnel) </th></tr><tr><td> Portable Distributeur de CO2 </td><td> Flystuff </td><td> 59-150 </td><td> Recharges également disponible </td></tr><tr><td> DUMONT brucelles n ° 5 </td><td> AGAR scientifique </td><td> T5034 </td><td></td></tr><tr><td> 3-Bien lame de verre </td><td> EMS </td><td> 71561-01 </td><td></td></tr><tr><td> Ciseaux Micro </td><td> VWR </td><td> HAMMHSB516-09 </td><td></td></tr><tr><td> Schneider Medium </td><td> VWR </td><td> 733-1663 </td><td></td></tr><tr><td> Lysotracker Rouge MDN-99 </td><td> Invitrogen </td><td> L7528 </td><td></td></tr><tr><td> Diapositives Superfrost </td><td> VWR </td><td> 631-0108 </td><td></td></tr><tr><td> Vectashield au DAPI </td><td> Vector Labs </td><td> H-1200 </td><td></td></tr><tr><td> Lamelles </td><td> VWR </td><td> 631-1336 </td><td></td></tr></tbody></table>

single drosophila ommatidium dissection and imaging

La mouche des fruits Drosophila melanogaster a apporté une contribution inestimable à la recherche en neurosciences et a été largement utilisée comme modèle pour les maladies neurodégénératives en raison de sa puissante génétique 1. L&#39;œil de la mouche en particulier, a été l&#39;organe de choix pour la recherche neurodégénérescence, étant la partie la plus accessible et la vie-dispensable de la drosophile système nerveux. Cependant la mise en garde importante des yeux intacts, c&#39;est la difficulté, à cause de l&#39;autofluorescence intense du pigment, dans les événements d&#39;imagerie intracellulaire, telles que l&#39;autophagie dynamiques 2, qui sont primordiales pour la compréhension de la neurodégénérescence. Nous avons récemment utilisé la dissection et la culture du seul ommatidies 3 qui a été essentielle pour notre compréhension des dysfonctionnements autophagie dans un modèle de vol du Dentatorubro-pallido Atrophie (DRPLA) 3, 4. Nous avons maintenant le rapport une description complète de cette technique (fig. 1), adapté de 5 études électrophysiologiques, qui est susceptible d&#39;augmenter considérablement la possibilité de voler pour les modèles neurodégénérescence. Cette méthode peut être adaptée aux images en direct des événements subcellulaire et de surveiller l&#39;administration de médicaments efficaces sur les cellules photoréceptrices (Fig. 2). Si elle est utilisée en combinaison avec 6-8 techniques de mosaïque, les réponses des cellules génétiquement différentes peuvent être dosés en parallèle (Fig. 2).

Watch this Scientific Journal Video about Single Drosophila Ommatidium Dissection and Imaging at JoVE.com

Single Drosophila Ommatidium Dissection and Imaging

Le facteur limitant dans l&#39;utilisation de l&#39;adulte<em&gt; Drosophile</emOeil&gt; pour étudier la neurodégénérescence et de biologie cellulaire est l&#39;imagerie difficile de processus intracellulaires. Nous décrivons la dissection des ommatidies simple pour générer un bona fide culture primaire de cellules neuronales, qui peut être soumis à un traitement médicamenteux et d&#39;imagerie de pointe.

Simple Drosophile Dissection ommatidie et imagerie

The fruit fly Drosophila melanogaster has made invaluable contributions to neuroscience research and has been used widely as a model for neurodegenerative ...

single-drosophila-ommatidium-dissection-and-imaging

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JoVE Journal

Neuroscience

Single Drosophila Ommatidium Dissection and Imaging

14.0K vues.  King's College London. Le facteur limitant dans l'utilisation de l'adulte Drosophile pour étudier la neurodégénérescence et de biologie cellulaire est l'imagerie difficile de processus intracellulaires. Nous décrivons la dissection des ommatidies simple pour générer un bona fide culture primaire de cellules neuronales, qui peut être soumis à un traitement médicamenteux et d'imagerie de pointe.

Vidéo: Single Drosophila Ommatidium Dissection and Imaging

Single Sensillum Recordings in the Insects Drosophila melanogaster and Anopheles gambiae

The sense of smell is essential for insects to find foods, mates, predators, and oviposition sites3. Insect olfactory sensory neurons (OSNs) are enclosed in sensory hairs called sensilla, which cover the surface of olfactory organs. The surface of each sensillum is covered with tiny pores, through which odorants pass and dissolve in a fluid called sensillum lymph, which bathes the sensory dendrites of the OSNs housed in a given sensillum. The OSN dendrites express odorant receptor (OR) proteins, which in insects function as odor-gated ion channels4, 5. The interaction of odorants with ORs either increases or decreases the basal firing rate of the OSN. This neuronal activity in the form of action potentials embodies the first representation of the quality, intensity, and temporal characteristics of the odorant6, 7.
Given the easy access to these sensory hairs, it is possible to perform extracellular recordings from single OSNs by introducing a recording electrode into the sensillum lymph, while the reference electrode is placed in the lymph of the eye or body of the insect. In Drosophila, sensilla house between one and four OSNs, but each OSN typically displays a characteristic spike amplitude. Spike sorting techniques make it possible to assign spiking responses to individual OSNs. This single sensillum recording (SSR) technique monitors the difference in potential between the sensillum lymph and the reference electrode as electrical spikes that are generated by the receptor activity on OSNs1, 2, 8. Changes in the number of spikes in response to the odorant represent the cellular basis of odor coding in insects. Here, we describe the preparation method currently used in our lab to perform SSR on Drosophila melanogaster and Anopheles gambiae, and show representative traces induced by the odorants in a sensillum-specific manner.

Single Sensillum Recordings in the Insects Drosophila melanogaster and Anopheles gambiae

Electrophysiological responses of olfactory sensory neurons to odorants can be measured in insects using single sensillum recordings. In this video article we will demonstrate how to perform single sensillum recordings in the antennae of the vinegar fly (Drosophila melanogaster) and the maxillary palps of the malaria mosquito (Anopheles gambiae).

Enregistrements Sensillum simple chez les insectes Drosophila melanogaster Et Anopheles gambiae</em

The sense of smell is essential for insects to find foods, mates, predators, and oviposition sites3. Insect olfactory sensory neurons (OSNs) are enclosed ...

Recherche

Neurosciences

Dissection and Imaging of Active Zones in the Drosophila Neuromuscular Junction

The Drosophila larvae neuromuscular junction (NMJ) is an excellent model for the study of synaptic structure and function. Drosophila is well known for the ease of powerful genetic manipulations and the larval nervous system has proven particularly useful in studying not only normal function but also perturbations that accompany some neurological disease (Lloyd and Taylor, 2010). Many key synaptic molecules found in Drosophila are also found in mammals and like most CNS excitatory synapses in mammals, the Drosophila NMJ is glutamatergic and demonstrates activity-dependent remodeling (Kohet al. , 2000). Additionally, Drosophila neurons can be individually identified because their innervation patterns are stereotyped and repetitive making it possible to study identified synaptic terminals, such as those between motor neurons and the body-wall muscle fibers that they innervate (Keshishian and Kim, 2004). The existence of evolutionarily conserved synapse components along with the ease of genetic and physical manipulation make the Drosophila model ideal for investigating the mechanisms underlying synaptic function (Budnik, 1996).
The active zones at synaptic terminals are of particular interest because these are the sites of neurotransmitter release. NC82 is a monoclonal antibody that recognizes the Drosophila protein Bruchpilot (Brp), a CAST1/ERC family member that is an important component of the active zone (Waghet al. , 2006). Brp was shown to directly shape the active zone T-bar and is responsible for effectively clustering Ca2+ channels beneath the T-bar density (Fouquetet al. , 2009). Mutants of Brp have reduced Ca2+ channel density, depressed evoked vesicle release, and altered short-term plasticity (Kittelet al. , 2006). Alterations to active zones have been observed in Drosophila disease models. For example, immunofluorescence using the NC82 antibody showed that the active zone density was decreased in models of amyotrophic lateral sclerosis and Pitt-Hopkins syndrome (Ratnaparkhiet al. , 2008; Zweieret al. , 2009). Thus, evaluation of active zones, or other synaptic proteins, in Drosophila larvae models of disease may provide a valuable initial clue to the presence of a synaptic defect.
Preparing whole-mount dissected Drosophila larvae for immunofluorescence analysis of the NMJ requires some skill, but can be accomplished by most scientists with a little practice. Presented is a method that provides for multiple larvae to be dissected and immunostained in the same dissection dish, limiting environmental differences between each genotype and providing sufficient animals for confidence in reproducibility and statistical analysis.

Dissection and Imaging of Active Zones in the Drosophila Neuromuscular Junction

The neuromuscular junction (NMJ) of Drosophila melanogaster is an important model system for studying normal synaptic function as well as perturbations to synaptic function found in certain neurological diseases. We present a protocol for dissection of the Drosophila larval motor system and immunostaining for active zone proteins within the NMJ.

Dissection et l&#39;imagerie de zones actives dans le Drosophile Jonction neuromusculaire

The Drosophila  larvae neuromuscular junction (NMJ) is an excellent model for the study of synaptic structure and function. Drosophila  is well known for ...

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.

Dissection et immunohistochimique de larve, de nymphe et adulte<em&gt; Drosophila</em&gt; Rétines

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

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

In this article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the lipophilic fluorescent membrane marker DiI. This method allows the visualization of neuronal cell morphology in great detail. It is possible to label any cell in the CNS: cell bodies of target neurons are visualized under DIC optics or by expression of a fluorescent genetic marker such as GFP. After labeling, the DiI can be transformed into a permanent brown stain by photoconversion to allow visualization of cell morphology with transmitted light and DIC optics. Alternatively, the DiI-labeled cells can be observed directly with confocal microscopy, enabling genetically introduced fluorescent reporter proteins to be colocalised. The technique can be used in any animal, irrespective of genotype, making it possible to analyze mutant phenotypes at single cell resolution.

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy.

Étiquetage des cellules isolées dans le système nerveux central des<em&gt; Drosophila melanogaster</em

In this  article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the ...

A Single-fly Assay for Foraging Behavior in Drosophila

For many animals, hunger promotes changes in the olfactory system in a manner that facilitates the search for appropriate food sources. In this video article, we describe an automated assay to measure the effect of hunger or satiety on olfactory dependent food search behavior in the adult fruit fly Drosophila melanogaster. In a light-tight box illuminated by red light that is invisible to fruit flies, a camera linked to custom data acquisition software monitors the position of six flies simultaneously. Each fly is confined to walk in individual arenas containing a food odor at the center. The testing arenas rest on a porous floor that functions to prevent odor accumulation. Latency to locate the odor source, a metric that reflects olfactory sensitivity under different physiological states, is determined by software analysis. Here, we discuss the critical mechanics of running this behavioral paradigm and cover specific issues regarding fly loading, odor contamination, assay temperature, data quality, and statistical analysis.

A Single-fly Assay for Foraging Behavior in Drosophila

In this video article, we describe an automated assay to measure the effect of hunger or satiety on olfactory dependent food search behavior in the adult fruit fly Drosophila melanogaster.

Une simple mouche Essai de comportement alimentaire dans<em&gt; Drosophila</em

For many animals, hunger promotes changes in the olfactory system in a manner that facilitates the search for appropriate food sources. In this video ...

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.

Imagerie en direct de<em&gt; Drosophila</em&gt; larves Neuroblastes

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

A Simple One-step Dissection Protocol for Whole-mount Preparation of Adult Drosophila Brains

There is an increasing interest in using Drosophila to model human brain degenerative diseases, map neuronal circuitries in adult brains, and study the molecular and cellular basis of higher brain functions. A whole-mount preparation of adult brains with well-preserved morphology is critical for such whole brain-based studies, but can be technically challenging and time-consuming. This protocol describes an easy-to-learn, one-step dissection approach of an adult fly head in less than 10 s, while keeping the intact brain attached to the rest of the body to facilitate subsequent processing steps. The procedure helps remove most of the eye and tracheal tissues normally associated with the brain that can interfere with the later imaging step, and also places less demand on the quality of the dissecting forceps. Additionally, we describe a simple method that allows convenient flipping of the mounted brain samples on a coverslip, which is important for imaging both sides of the brains with similar signal intensity and quality. As an example of the protocol, we present an analysis of dopaminergic (DA) neurons in adult brains of WT (w1118) flies. The high efficacy of the dissection method makes it particularly useful for large-scale adult brain-based studies in Drosophila.

A Simple One-step Dissection Protocol for Whole-mount Preparation of Adult Drosophila Brains

The adult Drosophila brain is a valuable system for studying neuronal circuitry, higher brain functions, and complex disorders. An efficient method to dissect whole brain tissue from the small fly head will facilitate brain-based studies. Here we describe a simple, one-step dissection protocol of adult brains with well-preserved morphology.

Une seule étape simple protocole Dissection pour Whole-mount Préparation des adultes<em&gt; Drosophila</em&gt; Brains

There is an increasing interest in using Drosophila to model human brain degenerative diseases, map neuronal circuitries in adult brains, and study the ...

In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal

An increasing number of super-resolution microscopy techniques are helping to uncover the mechanisms that govern the nanoscale cellular world. Single-molecule imaging is gaining momentum as it provides exceptional access to the visualization of individual molecules in living cells. Here, we describe a technique that we developed to perform single-particle tracking photo-activated localization microscopy (sptPALM) in Drosophila larvae. Synaptic communication relies on key presynaptic proteins that act by docking, priming, and promoting the fusion of neurotransmitter-containing vesicles with the plasma membrane. A range of protein-protein and protein-lipid interactions tightly regulates these processes and the presynaptic proteins therefore exhibit changes in mobility associated with each of these key events. Investigating how mobility of these proteins correlates with their physiological function in an intact live animal is essential to understanding their precise mechanism of action. Extracting protein mobility with high resolution in vivo requires overcoming limitations such as optical transparency, accessibility, and penetration depth. We describe how photoconvertible fluorescent proteins tagged to the presynaptic protein Syntaxin-1A can be visualized via slight oblique illumination and tracked at the motor nerve terminal or along the motor neuron axon of the third instar Drosophila larva.

In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal

Here we illustrate how single molecule photo-activated localization microscopy can be carried out on the motor nerve terminal of a live Drosophila melanogaster third instar larva.

In Vivo Simple-molécule suivi du terminal de nerf moteur présynaptique Drosophila

An increasing number of super-resolution microscopy techniques are helping to uncover the mechanisms that govern the nanoscale cellular world. ...

Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain Culture

The circadian pacemaker circuit orchestrates rhythmic behavioral and physiological outputs coordinated with environmental cues, such as day/night cycles. The molecular clock within each pacemaker neuron generates circadian rhythms in gene expression, which underlie the rhythmic neuronal functions essential to the operation of the circuit. Investigation of the properties of the individual molecular oscillators in different subclasses of pacemaker neurons and their interaction with neuronal signaling yields a better understanding of the circadian pacemaker circuit. Here, we present a time-lapse fluorescent microscopy approach developed to monitor the molecular clockwork in clock neurons of cultured Drosophila larval brain. This method allows the multi-day recording of the rhythms of genetically encoded fluorescent circadian reporters at single-cell resolution. This setup can be combined with pharmacological manipulations to closely analyze real-time response of the molecular clock to various compounds. Beyond circadian rhythms, this multipurpose method in combination with powerful Drosophila genetic techniques offers the possibility to study diverse neuronal or molecular processes in live brain tissue.

Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain Culture

The goal of this protocol is to establish ex vivo Drosophila larval brain culture optimized to monitor circadian molecular rhythms with long-term fluorescence time-lapse imaging. The application of this method to pharmacological assays is also discussed.

Fluorescence de cellule unique résolution vivre Imaging of Drosophila horloges circadiennes dans cerveau larvaire Culture

The circadian pacemaker circuit orchestrates rhythmic behavioral and physiological outputs coordinated with environmental cues, such as day/night cycles. ...

Dissection of Single Skeletal Muscle Fibers for Immunofluorescent and Morphometric Analyses of Whole-Mount Neuromuscular Junctions

The neuromuscular junction (NMJ) is a specialized point of contact between the motor nerve and the skeletal muscle. This peripheral synapse exhibits high morphological and functional plasticity. In numerous nervous system disorders, NMJ is an early pathological target resulting in neurotransmission failure, weakness, atrophy, and even in muscle fiber death. Due to its relevance, the possibility to quantitatively assess certain aspects of the relationship between NMJ components can help to understand the processes associated with its assembly/disassembly. The first obstacle when working with muscles is to gain the technical expertise to quickly identify and dissect without damaging their fibers. The second challenge is to utilize high-quality detection methods to obtain NMJ images that can be used to perform quantitative analysis. This article presents a step-by-step protocol for dissecting extensor digitorum longus and soleus muscles from rats. It also explains the use of immunofluorescence to visualize pre and postsynaptic elements of whole-mount NMJs. Results obtained demonstrate that this technique can be used to establish the microscopic anatomy of the synapsis and identify subtle changes in the status of some of its components under physiological or pathological conditions.

The ability to accurately detect neuromuscular junction components is crucial in evaluating modifications in its architecture because of pathological or developmental processes. Here we present a complete description of a straightforward method to obtain high-quality images of whole-mount neuromuscular junctions that can be used to perform quantitative measurements.

Dissection des fibres musculaires squelettiques simples pour les analyses immunofluorescentes et morphométriques des jonctions neuromusculaires de mont entier

The neuromuscular junction (NMJ) is a specialized point of contact between the motor nerve and the skeletal muscle. This peripheral synapse exhibits high ...