Los autores desean agradecer Fondo de Investigación del Presidente de Saint Louis University adjudicado a WSN

1. Mantenimiento de las jaulas de población <ol><li> Mantener las jaulas de población a 25 ° C en un ciclo de luz-oscuridad de 12 horas. Mientras los grupos de control y experimentales se exponen a las mismas condiciones de iluminación, entonces esta técnica se puede realizar en un entorno de laboratorio estándar. </li><li> Permitir que las hembras pongan huevos durante la noche en placas de agar-jugo de manzana. </li><li> Recoger las larvas recién eclosionadas, manteniendo las placas con los huevos recién depositados a 25 ° C durante 24 horas. Coloque una pequeña cucharada de levadura en el centro del plato para atraer larvas eclosionadas. </li><li> Recoge 1 º estadio las larvas que han migrado a la pasta de levadura en el centro de la placa de jugo de manzana. Use una espátula de metal para transferirlo a una placa de jugo de manzana fresca. Pasta de levadura adicional puede ser añadido para asegurar que haya una alimentación adecuada hasta que se realizan los ensayos. Placas de zumo de uva también se pueden utilizar en lugar de placas de jugo de manzana. </li><li> Obtener la tarde 2-nd temprana 3 º estadio larvae al permitir que el 1 de instares a la edad de 40 a 48 h. Dentro de este rango las tasas de alimentación son constantes 13. La edad puede ser confirmado por examen de los ganchos de la boca, ya que hay distintos cambios en esta estructura con cada muda larval. </li><li> Tarde 2 3 º estadio las larvas-nd principios se recogen para los ensayos de comportamiento suavemente y extensamente usan platos de jugo de manzana con agua y la recolección de las larvas en un filtro de malla. Las larvas se transfieren después a una placa de agar. </li><li> Todos los análisis se realizan en paralelo usando animales control y experimentales. </li></ol> 2. Paradigma de comportamiento - Locomoción <ol><li> Coloque un solo 3 º estadio larva en un sustrato de agar al 2% en un 100 mm placa de cultivo de tejidos y permitir que la larva se aclimate durante 30 segundos. Las larvas utilizar sus Escleritos cefalofaríngeos (ganchos de la boca) para impulsar sus cuerpos a través de la superficie del sustrato de agar. Esto se hace en un plato aparte porque it es más difícil de visualizar las contracciones del cuerpo en la solución de levadura como el animal es casi el mismo color que la levadura. </li><li> Observar y registrar cada uno posterior para el movimiento anterior sobre el sustrato durante un periodo de 1 min. n = 20 para cada genotipo. No más de 10 animales deben ser analizadas por placa. </li></ol> 3. Paradigma de comportamiento - Alimentación <ol><li> Usando romos Inox # 5 pinzas, transferir cuidadosamente la larva de estadio 3 ª de la placa de agar locomotora al centro de una placa de agar-llenado superpuesta con 5 ml de solución de levadura 2% de panadero activado. Asegúrese de que la solución es homogénea como la levadura se asentará en el tiempo. Cuando en la solución de levadura, las larvas en gran medida se mantendrá en su lugar y alimentación, facilitando la observación de la conducta. La tasa de las contracciones de gancho de la boca se correlaciona directamente con la cantidad de comida ingerida 14. </li><li> Permita que la larva se aclimate durante 30 segundos. </li><li> Observar y registrar el número decontracciones de gancho en la boca durante un periodo de 1 min. n = 20 para cada genotipo. </li></ol> 4. Las disecciones intestino de la larva <ol><li> Prepare una solución de fijación de formaldehído EM-grado 4% en 1x tampón fosfato-salino (PBS) y se pone en un vaso punto 3 pocillos. </li><li> Diseccionar cuidadosamente deambulando tarde 3 º estadio larval agallas en un plato de cristal 3-bien utilizando la solución PBS 1x, asegurándose de que cada vez que el proventrículo se deja intacta. Con una pinza, mantenga el extremo posterior, y con la otra, sostenga los ganchos de la boca. Mientras sujeta el extremo posterior inmóvil, tire suavemente de los ganchos de la boca para poder acceder a las tripas. Retire todos los tejidos asociados (glándulas salivales, el cerebro, la grasa corporal, etc), a continuación, transferir cada tripa al plato 3 pocillos que contiene la solución de formaldehído. Vagando 3 º estadio larva se utilizan porque en esta etapa del desarrollo, la larva deja de alimentarse en la preparación para pupariation y proventrículo se borra de la levadura. </li> &lt;Li&gt; Incubar las tripas a 4 ° C durante la noche en una caja de cultivo de tejidos opaca. </li><li> Antes de retirar la solución de fijación de formaldehído de los pozos, retire el ciegos gástricos y clip del intestino medio ~ 150 m 2 del proventrículo de manera que las proyecciones se pueden ver claramente y sin impedimento. </li><li> Retire solución de formaldehído de los pocillos y reemplazar con 1x PBT (1x PBS, 0,1% de albúmina de suero bovino libre de proteasa, X-100 0,1% de Triton) solución tampón. Lávese bien las tripas 6x durante 10 min en 1x PBT. Coloque las muestras de tejido sobre un agitador rotatorio mientras se hace lavados. </li><li> Se incuba a 4 ° C durante 1 hora en 10 -6 M 5-HT para mejorar la señalización de la serotonina. Lávese bien las tripas 6x durante 10 min en 1x PBT. Estudios anteriores han demostrado que esta concentración de exógena 5-HT no afecta a la arquitectura neuronal o la densidad de várices en los análisis inmunohistoquímicos y simplemente mejora la relación señal a ruido 15-16. </li><li> Incubar a 4 y# 176; C durante la noche en el anticuerpo primario anti-serotonina (monoclonal de ratón o policlonal de conejo). Lávese bien las tripas 6x durante 10 min en 1x PBT. Coloque las muestras de tejido sobre un agitador rotatorio mientras se hace lavados. </li><li> Incubar a 4 º C durante 90 min en anticuerpo secundario (Alexa Fluor 568 cabra anti-ratón o anti-IgG de conejo; 1:400 dilución). Lávese bien las tripas 6x durante 10 min en 1x PBT. Coloque las muestras de tejido sobre un agitador rotatorio mientras se hace lavados. </li><li> Incubar en carbonato de sodio 4 mM durante 10 minutos sobre un agitador rotatorio, a continuación, montar en 4% de carbonato de sodio mM gallate/20 n-propilo, y vista en virtud de la fluorescencia. El carbonato de sodio se utiliza para convertir las muestras en la memoria intermedia y el pH utilizado en los medios de comunicación medio de montaje. </li><li> Captura imágenes de muestras de tejidos immunostained con un aumento de 400X para el análisis. </li></ol> 5. Análisis de circuitos neuronales <ol><li> Fibras neuritas se cuantificaron (número y tamaño de las varicesy el grado de ramificación) usando Neuroleucida y Neuroexplorer. Sin embargo, esto también puede realizarse de forma manual o mediante simple Neurite trazador (una aplicación gratuita que se puede descargar en línea). </li><li> Trazar las proyecciones de fibras individuales desde el cerebro hasta el proventrículo y cuantificar el número de várices, las ramas y el número de las várices grandes por unidad de longitud. Las fibras axonales que se proyectan desde el cerebro se encuentran agrupados en el nervio Recurrens y no son accesibles para el análisis hasta que alcanzan el proventrículo donde se separan y fasciculada. </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>

No tenemos nada que revelar.

Desarrollo aberrante del circuito stomatogastric serotoninérgico, que ocurre durante la embriogénesis tardía, afectará a su función maduro. Los cambios en la arquitectura de neuritas que inervan el intestino puede ser correlacionada con la salida funcional del circuito, que es la tasa de alimentación (medido por contracciones de gancho de la boca en una solución de levadura) (Figura 1). El uso del sistema bipartito UAS-Gal4 en Drosophila hace que sea posible se dirigen específicamente h...

Drosophila es un sistema de modelo muy potente para estudiar el desarrollo de circuitos neuronales debido a un rápido tiempo de generación, coste experimental bajo, y la capacidad para manipular y controlar los factores genéticos y ambientales. La neurogénesis, hallazgo camino neuronal y la sinaptogénesis se conservan entre los humanos y Drosophila, por lo que los mecanismos de la creación, mantenimiento y modificación de los circuitos neuronales se conservan también. Neurotransmisores clásicos, como la serotonina (5-hidroxitriptamina o 5-HT) pueden servir como factores de crecimiento, antes de adoptar su papel como moléculas de señalización en el circuito neural madura 1-3 Estudios anteriores han demostrado que perturbado niveles de 5-HT durante la embriogénesis alterar la conectividad de las neuronas maduras 4. Otros han demostrado que la aplicación ectópica de 5-HT a las neuronas cultivadas Helisoma reprimir el crecimiento de neuritas, así como la sinaptogénesis 5-7. En Drosophila, de desarrollo los niveles de 5-HT están inversamente relacionada con el número de varicosidades y tamaño, así como el grado de aborization, a lo largo de la longitud de las neuritas que se proyectan hacia el intestino anterior del SNC 8. La neurotransmisión serotonérgica se ha demostrado que modulan los comportamientos de alimentación en diversas especies, incluyendo Drosophila 8-9. El circuito de alimentación en Drosophila es un circuito relativamente simple que se puede utilizar como un modelo para correlacionar la salida funcional (alimentación) con alteraciones en el desarrollo de las proyecciones axonales desde el cerebro hasta el intestino anterior. Schoofs et al. han demostrado que la alimentación de las larvas de Drosophila está regulado por generadores de patrones centrales que influyen en la musculatura 10. Mientras que la anatomía muscular específico no se comprende completamente, se ha demostrado que el nervio antenal, nervio maxilar, y el nervio accesorio protorácica son responsables de los objetivos musculares implicados en lael comportamiento de alimentación. La mayoría de los datos relacionados con la musculatura y nervios Anatomía de la alimentación de invertebrados se limita a las larvas Calliphora. La tasa de alimentación de larvas de segundo instar se puede evaluar por la retracción de las Escleritos cefalofaríngeos (ganchos de la boca), y es reproducible y de alto rendimiento. Las placas cefalofaríngeos están inervadas por fibras de las neuronas centrales 5-HT a través del nervio frontal. El proventrículo o intestino anterior, está inervado por fibras serotoninérgicos (Recurrens nervio) que fasciculada en el intestino medio y son responsables de las contracciones del intestino anterior (Figura 1) 11-12. Los cambios en la ramificación axonal, y el número y tamaño de las varices a lo largo de la longitud de las neuritas, se pueden cuantificar utilizando técnicas inmunohistoquímicas. Manipulación de 5-HT neuronal durante el desarrollo, ya sea directamente o indirectamente, puede cambiar la salida funcional de este circuito de alimentación, que puede ser evaluado y se correlacionó con los cambios en la morfologíasGy de la arquitectura de las neuritas.

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		<tr height="40">
			<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>
			<td style="width:115px;"></td>
			<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

El circuito de alimentación serotonérgica en larvas de Drosophila melanogaster se puede utilizar para investigar los sustratos neuronales de importancia crítica durante el desarrollo del circuito. Uso de la salida funcional del circuito, la alimentación, los cambios en la arquitectura neuronal del sistema stomatogastric puede ser visualizado. El comportamiento de alimentación se puede grabar mediante la observación de la tasa de retracción de los ganchos de la boca, que reciben inervación desde el cerebro. El comportamiento locomotor se utiliza como un control fisiológico de la alimentación, ya que las larvas utilizar sus ganchos de la boca para atravesar a través de un sustrato de agar. Los cambios en el comportamiento de alimentación se pueden correlacionar con la arquitectura axonal de las neuritas que inervan el intestino. El uso de inmunohistoquímica es posible visualizar y cuantificar estos cambios. Un manejo inadecuado de las larvas durante los paradigmas de comportamiento puede alterar los datos, ya que son muy sensibles a las manipulaciones. Imagen adecuada de la arquitectura de axones inervanel intestino es crítico para la cuantificación precisa de número y tamaño de las varices, así como el grado de los nodos de ramificación. El análisis de la mayoría de los circuitos permite sólo para la visualización de la arquitectura de axones o efectos en el comportamiento, sin embargo, este modelo permite correlacionar la salida funcional del circuito con las deficiencias en la arquitectura neuronal.

El circuito de alimentación serotoninérgicos en la larva de Drosophila puede servir como un modelo muy eficaz para observar la influencia de determinados factores en el desarrollo del sistema nervioso. Por la cuantificación de la tasa de alimentación, es posible vincular la arquitectura axonal del circuito de alimentación con su salida funcional (Figura 1). El ensayo del aparato locomotor se utiliza como un control fisiológico de las retracciones de los ganchos de la boca, ya que las larv...

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

El circuito de alimentación en larvas de Drosophila melanogaster sirve un modelo simple pero potente que permite a los cambios en la tasa de alimentación que se correlacionan con las alteraciones en los circuitos neurales stomatogastric. Este circuito se compone de las neuronas serotoninérgicas centrales que envían proyecciones a los ganchos de la boca así como el intestino anterior.

Análisis funcional del circuito de alimentación de las larvas en 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

Research

JoVE Journal

Neuroscience

Functional Analysis of the Larval Feeding Circuit in Drosophila

10.2K vistas.  Saint Louis University School of Medicine.  El circuito de alimentación en larvas de Drosophila melanogaster sirve un modelo simple pero potente que permite a los cambios en la tasa de alimentación que se correlacionan con las alteraciones en los circuitos neurales stomatogastric. Este circuito se compone de las neuronas serotoninérgicas centrales que envían proyecciones a los ganchos de la boca así como el intestino anterior. 

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.

La visualización de larvas Nervios segmentarios en 3 Rd Instar Drosophila Preparación de larvas

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

Investigación

Neurociencias

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.

Visualización en vivo de las vesículas sinápticas En Drosophila segmentaria axones larvas

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.

Análisis morfológico de Drosophila Larvas dendritas neurona sensorial periférica y axones Con mosaicos genéticos

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.

Visualización de los propioceptores<em&gt; Drosophila</em&gt; Las larvas y pupas

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.

La disección e inmunohistoquímica de larva, pupa y adulto<em&gt; Drosophila</em&gt; Retinas

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.

Todo el montaje de Immunolabeling olfativa del receptor de las neuronas en el<em&gt; Drosophila</em&gt; Antena

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.

Imágenes en vivo de<em&gt; Drosophila</em&gt; larvales neuroblastos

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.

¿Por qué importa la cuantificación: Caracterización de fenotipos en el<em&gt; Drosophila</em&gt; Larval unión neuromuscular

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.

Eliminación de<em&gt; Drosophila</em&gt; Tejido muscular de larvas Filetes para el análisis de inmunofluorescencia de las neuronas sensoriales y las células epidérmicas

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

Focal Macropatch Recordings of Synaptic Currents from the Drosophila Larval Neuromuscular Junction

Drosophila neuromuscular junction (NMJ) is an excellent model system to study glutamatergic synaptic transmission. We describe the technique of focal macropatch recordings of synaptic currents from visualized boutons at the Drosophila larval NMJ. This technique requires customized fabrication of recording micropipettes, as well as a compound microscope equipped with a high magnification, long-distance water immersion objective, differential interference contrast (DIC) optics, and a fluorescent attachment. The recording electrode is positioned on the top of a selected synaptic bouton visualized with DIC optics, epi-fluorescence, or both. The advantage of this technique is that it allows monitoring the synaptic activity of a limited number of sites of release. The recording electrode has&#160;a diameter of several microns, and the release sites positioned outside of the electrode rim do&#160;not significantly affect the recorded currents. The recorded synaptic currents have fast kinetics and can be readily resolved. These advantages are especially important for the studies of mutant fly lines with enhanced spontaneous or asynchronous synaptic activity.

Focal Macropatch Recordings of Synaptic Currents from the Drosophila Larval Neuromuscular Junction

Synaptic currents can be recorded focally from visualized synaptic boutons at the Drosophila third instar larvae neuromuscular junction. This technique enables monitoring the activity of a single synaptic bouton.

Grabaciones de Macropatch focal de corrientes sinápticas de la Unión Neuromuscular larvaria de Drosophila

Drosophila neuromuscular junction (NMJ) is an excellent model system to study glutamatergic synaptic transmission. We describe the technique of focal ...