SG es apoyado por fondos de la Universidad Estatal de Nueva York en Buffalo y de John R. Oishei Fundación.

1. Preparación de los reactivos <ol><li> Prepare 1x Buffer disección de 128 mM NaCl, 4 mM CaCl 2, 4 mM MgCl 2, 2 mM KCl, HEPES 5 mM y sacarosa 36 mm. PH de la solución al 7,2 y el filtro de esterilización. </li><li> Preparar el fijador con una dilución 1:01 del 16% de formaldehído y el tampón de disección 1x. </li><li> Prepare 1x 1x PBT con tampón fosfato salino (PBS) a un pH de 7.2 y Triton X-100 en una proporción de 1:100. </li><li> Prepare un 5% albúmina de suero bovino (BSA) con 0,01% de azida Na en 1x PBS. </li></ol> 2. Preparación para la disección <ol><li> Sylgard platos se utilizan para la disección. Prepare los platos a base de verter Sylgard 184 elastómero de silicona y curado mezcla de agente en una placa de Petri. Dejar que la mezcla se solidifique por completo y seco antes de usar. </li><li> Antes de la disección, se reúnen un par limpio de # 5 pinzas, un par limpio de hoja recta Vannas tijeras y alfileres. </li></ol> 3. La disección de 3 º estadio las larvas <ol><li> Recoger vagando 3 º estadio las larvas de un genotipo específico en una placa de Petri. </li><li> Lavado de las larvas en agua desionizada para deshacerse de la comida. </li><li> Colocar una larva en el plato Sylgard, con el lado dorsal. Pin de la larva en sus extremos anterior y posterior. </li><li> Coloque una gota de tampón 1x disección de las larvas puestas. Usando tijeras finas cortar la larva en la línea media dorsal cerca del extremo posterior. Con las tijeras, corte la cutícula larval desde el extremo posterior hasta el final anterior. </li><li> Coloque una gota de tampón 1x nueva disección en la larva disecada. El uso de un PIN, elige uno de los bordes laterales de la cutícula, cerca de la mitad de la larva y el pin de la cutícula. El uso de otro pin, pin el segundo borde lateral de la cutícula como se muestra en el diagrama. Dos pines se utilizan en cada lado lateral. Vea el diagrama a continuación. </li><li> Retire con cuidado los intestinos, los órganos de la grasa, y la tráquea, dejando sólo el cerebro con los dos lóbulos ópticos y los ganglios ventrales de los nervios segmentarios adjunto. El resto del procedimiento se hace en el plato Sylgard. </li></ol> 4. La fijación de la larva disecados <ol><li> Incubar la larva disecados en solución durante 30 minutos, mediante la sustitución de la solución cada 15 minutos. </li><li> Después de la fijación, enjuague la larva en 1x PBT durante 30 minutos, sustituyendo el tampón cada 10 minutos. Es importante señalar que la larva debe estar siempre en un búfer. </li></ol> 5. La tinción de anticuerpos de la larva disecados <ol><li> Prepare el anticuerpo primario mediante la dilución a la concentración adecuada en el 5% BSA con Na azida en 1x PBT. Las concentraciones óptimas serán diferentes para diferentes anticuerpos. </li><li> Vuelva a colocar la última PBT 1x enjuague con la solución de anticuerpo primario preparado, y se incuba en una cámara húmeda a 4 ° C durante la noche. La cámara húmeda se construye por el forro un plato de plástico con kim-paños empapados en agua. </li><li> Al día siguiente, enjuagar la larva disecado en 1x PBT durante 30 minutos, sustituyendo el tampón cada 10 minutos. </li><li> Prepare la secundaria de anticuerpos mediante la dilución a la concentración adecuada en el 5% BSA con Na azida en 1x PBT, e incubar la larva con la solución de anticuerpo secundario a 25 ° C durante una hora. Envuelva la cámara húmeda en papel de aluminio para evitar que la luz, como anticuerpos secundarios son sensibles a la luz. </li><li> Después de la incubación, lavar la larva en 1x PBT durante 30 minutos, sustituyendo el tampón cada 10 minutos. </li></ol> 6. De montaje y visualización de la larva disecados <ol><li> Antes de montar la larva de la diapositiva, preparar la diapositiva mediante la difusión de dos líneas verticales de esmalte de uñas en el medio, con un espacio suficiente para una hoja de cubierta para sentarse (ver diagrama). Deja que el esmalte de uñas se seque por completo. </li><li> Coloque una gota de tampón de montaje en el espacio entre las líneas verticales pulir las uñas en la diapositiva (ver diagrama). La diapositiva está listo para el montaje. <img src="/files/ftp_upload/2128/2128.6.2.1.jpg" alt="Figura 1 paso 6.2" /> <img src="/files/ftp_upload/2128/2128.6.2.2.jpg" alt="Figura 2 Paso 6.2" /></li><li> Después del último enjuague PBT 1x, retire con cuidado las clavijas laterales. Tenga cuidado de no romper la cutícula. </li><li> Retire con cuidado las dos patillas restantes y recoger las larvas con pinzas y colocar la larva en posición horizontal sobre la diapositiva preparada. Asegúrese de que la larva no se dio la vuelta y es la parte ventral orientada hacia arriba. </li><li> Con cuidado, coloque una hoja de cubierta en la parte superior y selle los bordes con esmalte de uñas (ver diagrama). La larva ya está listo para la visualización en un microscopio de fluorescencia. <img src="/files/ftp_upload/2128/2128.6.5.jpg" alt="Figura 1 paso 6.5" /></li></ol> 7. Resultados representante <img src="/files/ftp_upload/2128/2128fig1.jpg" alt="Figura 1" /> Figura 1: Una imagen representativa de las larvas de los nervios segmentarios de un tipo salvaje LARVun uso de anticuerpos contra la proteína de vesículas sinápticas proteínas cadena cisteína (CSP, Zinsmaier et al. 1994). Tenga en cuenta que los nervios segmentarios están suavemente manchado. Bar = 20μm <img src="/files/ftp_upload/2128/2128fig2.jpg" alt="Figura 2" /> Figura 2: Una imagen representativa de las larvas de los nervios segmentarios de una larva de la proteína mutante motor usando anticuerpos contra la proteína de la vesícula sináptica proteína cadena cisteína (CSP). Tenga en cuenta que los nervios segmentarios muestran acumulaciones masivas que se tiñen intensamente para CSP (flechas).

<ol>
	<li>Gunawardena, S., Goldstein, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+Axonal+Transport+and+Neuronal+Viability+by+Amyoid+Precursor+Protein+Mutations+in+Drosophila.">Disruption of Axonal Transport and Neuronal Viability by Amyoid Precursor Protein Mutations in Drosophila.</a> Neuron. 32 (2), 389-401 (2001).</li><li>Gunawardena, S., Her, L. S., Brusch, R. G., Laymon, R. A., Niesman, I. R., Gordesky-Gold, B., Sintasath, L., Bonini, N. M., Goldstein, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+axonal+transport+by+loss+of+huntingtin+or+expression+of+pathogenic+polyQ+proteins+in+Drosophila.">Disruption of axonal transport by loss of huntingtin or expression of pathogenic polyQ proteins in Drosophila.</a> Neuron. 40 (1), 1-2 (2003).</li><li>Hurd, D. D., Saxton, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinesin+mutations+cause+motor+neuron+disease+phenotypes+by+disrupting+fast+axonal+transport+in+Drosophila.">Kinesin mutations cause motor neuron disease phenotypes by disrupting fast axonal transport in Drosophila.</a> Genetics. 144 (3), 1075-1085 (1996).</li><li>Zinsmaier, K. E., Eberle, K. K., Buchner, E., Walter, N., Benzer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Paralysis+and+early+death+in+cysteine+string+protein+mutants+of+Drosophila.">Paralysis and early death in cysteine string protein mutants of Drosophila.</a> Science. 263, 977-980 (1994).</li></ol>

Los nervios larvas de Drosophila segmentaria es un poderoso sistema para estudiar los mecanismos en el transporte axonal. Si el 3 º estadio larval disección se realiza correctamente, todos los componentes del sistema nervioso central, sistema nervioso periférico, y los tejidos asociados, como los músculos y NMJs, puede ser examinado dentro de una sola larva. Hemos adaptado el protocolo a partir de la publicada por Hurd y Saxton (1996). Este protocolo también se puede adaptar a otra prueba de anticuerpos neuronales, pero la optimización de los anticuerpos se debe hacer. Los tiempos de anticuerpos primaria y secundaria de incubación puede ser cambiado o el bloqueo de un paso se puede añadir. Hemos utilizado con éxito este protocolo para investigar el papel de la proteína precursora de amiloide 1 y 2 huntingtina en el transporte axonal.

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visualization of larval segmental nerves in 3rd instar drosophila larval preparations

Drosophila melanogaster se está convirtiendo en un modelo de sistema de gran alcance para el estudio del desarrollo y la función del sistema nervioso, sobre todo por su genética y conveniente genoma secuenciado en su totalidad. Además, el sistema nervioso de larvas es un sistema modelo ideal para estudiar los mecanismos de transporte axonal de los nervios segmentarios larvas contienen haces de axones con sus cuerpos celulares situados en el cerebro y sus terminales de las terminaciones nerviosas a lo largo de la longitud del cuerpo. A continuación se describe el procedimiento para la visualización de proteínas de vesículas sinápticas en las larvas nervios segmentarios. Si se hace correctamente, todos los componentes del sistema nervioso, junto con los tejidos correspondientes, tales como los músculos y NMJs, permanecen intactos y en buen estado y listo para ser visualizado. 3 º estadio las larvas portadoras de mutaciones diferentes se disecan, fijo, se incubaron con anticuerpos vesículas sinápticas, visualizar y en comparación con las larvas de tipo salvaje. Este procedimiento se puede adaptar a varios anticuerpos diferentes sináptica o neuronal y los cambios en la distribución de una variedad de proteínas pueden ser fácilmente observado en larvas de los nervios segmentarios.

Watch this Scientific Journal Video about Visualization of Larval Segmental Nerves in 3rd Instar Drosophila Larval Preparations at JoVE.com

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

Drosophila melanogaster larvas de disponer de un sistema modelo ideal para investigar los mecanismos de transporte axonal en larvas de los nervios segmentarios. El uso de este procedimiento, 3 de larvas portadoras de mutaciones diferentes pueden ser comparados a las larvas de tipo salvaje.

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 ...

visualization-larval-segmental-nerves-3rd-instar-drosophila-larval

Nanyang Technological University

Research

JoVE Journal

Neuroscience

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

10.3K vistas.  SUNY-University at Buffalo. Drosophila melanogaster larvas de disponer de un sistema modelo ideal para investigar los mecanismos de transporte axonal en larvas de los nervios segmentarios. El uso de este procedimiento, 3 de larvas portadoras de mutaciones diferentes pueden ser comparados a las larvas de tipo salvaje.

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

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 ...

Investigación

Neurociencias

Mapping and Application of Enhancer-trap Flippase Expression in Larval and Adult Drosophila CNS

The Gal4/ UAS binary method is powerful for gene and neural circuitry manipulation in Drosophila. For most neurobiological studies, however, Gal4 expression is rarely tissue-specific enough to allow for precise correlation of the circuit with behavioral readouts. To overcome this major hurdle, we recently developed the FINGR method to achieve a more restrictive Gal4 expression in the tissue of interest. The FINGR method has three components: 1) the traditional Gal4/UAS system; 2) a set of FLP/FRT-mediated Gal80 converting tools; and 3) enhancer-trap FLP (ET-FLP). Gal4 is used to define the primary neural circuitry of interest. Paring the Gal4 with a UAS-effector, such as UAS-MJD78Q or UAS-Shits, regulates the neuronal activity, which is in turn manifested by alterations in the fly behavior. With an additional UAS-reporter such as UAS-GFP, the neural circuit involved in the specific behavior can be simultaneously mapped for morphological analysis. For Gal4 lines with broad expression, Gal4 expression can be restricted by using two complementary Gal80-converting tools: tubP&gt;Gal80&gt; ('flip out') and tubP&gt;stop&gt;Gal80 ('flip in'). Finally, investigators can turn Gal80 on or off, respectively, with the help of tissue-specific ET-FLP. In the flip-in mode, Gal80 will repress Gal4 expression wherever Gal4 and ET-FLP intersect. In the flip-out mode, Gal80 will relieve Gal4 repression in cells in which Gal4 and FLP overlap. Both approaches enable the restriction of the number of cells in the Gal4-defined circuitry, but in an inverse pattern. The FINGR method is compatible with the vast collection of Gal4 lines in the fly community and highly versatile for traditional clonal analysis and for neural circuit mapping. In this protocol, we demonstrate the mapping of FLP expression patterns in select ET-FLPx2 lines and the effectiveness of the FINGR method in photoreceptor cells. The principle of the FINGR method should also be applicable to other genetic model organisms in which Gal4/UAS, Gal80, and FLP/FRT are used.

Mapping and Application of Enhancer-trap Flippase Expression in Larval and Adult Drosophila CNS

We describe a Flippase-induced intersectional Gal80/Gal4 repression (FINGR) method, allowing tissue-specific FLP to determine Gal80 expression patterns. Wherever Gal4 and FLP overlap, Gal4 expression is turned on (Gal80 flipped out) or off (Gal80 flipped in). The FINGR method is versatile for clonal analysis and neural circuit mapping.

La cartografía y la aplicación de potenciador de la trampa de expresión Flippase en larvas y adultos Drosophila SNC

The Gal4/ UAS binary method is powerful for gene and neural circuitry manipulation in Drosophila. For most neurobiological studies, however, Gal4 ...

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 ...

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 ...

Forebrain Electrophysiological Recording in Larval Zebrafish

Epilepsy affects nearly 3 million people in the United States and up to 50 million people worldwide. Defined as the occurrence of spontaneous unprovoked seizures, epilepsy can be acquired as a result of an insult to the brain or a genetic mutation. Efforts to model seizures in animals have primarily utilized acquired insults (convulsant drugs, stimulation or brain injury) and genetic manipulations (antisense knockdown, homologous recombination or transgenesis) in rodents. Zebrafish are a vertebrate model system1-3 that could provide a valuable alternative to rodent-based epilepsy research. Zebrafish are used extensively in the study of vertebrate genetics or development, exhibit a high degree of genetic similarity to mammals and express homologs for ~85% of known human single-gene epilepsy mutations. Because of their small size (4-6 mm in length), zebrafish larvae can be maintained in fluid volumes as low as 100 &mu;l during early development and arrayed in multi-well plates. Reagents can be added directly to the solution in which embryos develop, simplifying drug administration and enabling rapid in vivo screening of test compounds4. Synthetic oligonucleotides (morpholinos), mutagenesis, zinc finger nuclease and transgenic approaches can be used to rapidly generate gene knockdown or mutation in zebrafish5-7. These properties afford zebrafish studies an unprecedented statistical power analysis advantage over rodents in the study of neurological disorders such as epilepsy. Because the "gold standard" for epilepsy research is to monitor and analyze the abnormal electrical discharges that originate in a central brain structure (i.e., seizures), a method to efficiently record brain activity in larval zebrafish is described here. This method is an adaptation of conventional extracellular recording techniques and allows for stable long-term monitoring of brain activity in intact zebrafish larvae. Sample recordings are shown for acute seizures induced by bath application of convulsant drugs and spontaneous seizures recorded in a genetically modified fish.

A simple method to record extracellular field potentials in the larval zebrafish forebrain is described. The method provides a robust in vivo read-out of seizure-like activity. This technique can be used with genetically modified zebrafish larvae carrying epilepsy-related genes or seizures evoked by administration of convulsant drugs.

Prosencéfalo electrofisiológico de grabación en larvas de pez cebra

Epilepsy affects nearly 3 million people in the United States and up to 50 million people worldwide. Defined as the occurrence of spontaneous unprovoked ...

Functional Analysis of the Larval Feeding Circuit in Drosophila

The serotonergic feeding circuit in Drosophila melanogaster larvae can be used to investigate neuronal substrates of critical importance during the development of the circuit. Using the functional output of the circuit, feeding, changes in the neuronal architecture of the stomatogastric system can be visualized. Feeding behavior can be recorded by observing the rate of retraction of the mouth hooks, which receive innervation from the brain. Locomotor behavior is used as a physiological control for feeding, since larvae use their mouth hooks to traverse across an agar substrate. Changes in feeding behavior can be correlated with the axonal architecture of the neurites innervating the gut. Using immunohistochemistry it is possible to visualize and quantitate these changes. Improper handling of the larvae during behavior paradigms can alter data as they are very sensitive to manipulations. Proper imaging of the neurite architecture innervating the gut is critical for precise quantitation of number and size of varicosities as well as the extent of branch nodes. Analysis of most circuits allow only for visualization of neurite architecture or behavioral effects; however, this model allows one to correlate the functional output of the circuit with the impairments in neuronal architecture.

Functional Analysis of the Larval Feeding Circuit in Drosophila

The feeding circuit in Drosophila melanogaster larvae serves a simple yet powerful model that allows changes in feeding rate to be correlated with alterations in the stomatogastric neural circuitry. This circuit is composed of central serotonergic neurons that send projections to the mouth hooks as well as the foregut.

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 ...

Spinal Cord Transection in the Larval Zebrafish

Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability to reinitiate spinal neurogenesis. However, some anamniotes including the zebrafish Danio rerio exhibit both sensory and functional recovery even after complete transection of the spinal cord. The adult zebrafish is an established model organism for studying regeneration following spinal cord injury, with sensory and motor recovery by 6&#160;weeks post-injury. To take advantage of in vivo analysis of the regenerative process available in the transparent larval zebrafish as well as genetic tools not accessible in the adult, we use the larval zebrafish to study regeneration after spinal cord transection. Here we demonstrate a method for reproducibly and verifiably transecting the larval spinal cord. After transection, our data shows sensory recovery beginning at 2&#160;days post-injury (dpi), with the C-bend movement detectable by 3 dpi and resumption of free swimming by 5 dpi. Thus we propose the larval zebrafish as a companion tool to the adult zebrafish for the study of recovery after spinal cord injury.

After spinal transection, adult zebrafish have functional recovery by six weeks post-injury. To take advantage of larval transparency and faster recovery, we present a method for transecting the larval spinal cord. After transection, we observe sensory recovery beginning at 2&#160;days post-injury, and C-bend movement by 3 days post-injury.

La transección de la médula espinal en el pez cebra larval

Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability ...

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 ...

Using Linear Agarose Channels to Study Drosophila Larval Crawling Behavior

Drosophila larval crawling is emerging as a powerful model to study neural control of sensorimotor behavior. However, larval crawling behavior on flat open surfaces is complex,&#160;including: pausing, turning, and meandering. This complexity in the repertoire of movement hinders detailed analysis of the events occurring during a single crawl stride cycle. To overcome this obstacle, linear agarose channels were made that constrain larval behavior to straight, sustained, rhythmic crawling. In principle, because agarose channels and the Drosophila larval body are both optically clear, the movement of larval structures labeled by genetically-encoded fluorescent probes can be monitored in intact, freely-moving larvae. In the past, larvae were placed in linear channels and crawling at the level of whole organism, segment, and muscle were analyzed1. In the future, larvae crawling in channels can be used for calcium imaging to monitor neuronal activity. Moreover, these methods can be used with larvae of any genotype and with any researcher-designed channel. Thus the protocol presented below is widely applicable for studies using the Drosophila larva as a model to understand motor control.

Using Linear Agarose Channels to Study Drosophila Larval Crawling Behavior

The Drosophila larva is a powerful model system to study neural control of behavior. This publication describes the use of linear agarose channels to elicit sustained bouts of linear crawling and methods to quantify the dynamics of larval structures during repetitive crawling behavior.

Uso de los canales lineales de agarosa para estudiar<em&gt; Drosophila</em&gt; Comportamiento de las larvas de arrastre

Drosophila larval crawling is emerging as a powerful model to study neural control of sensorimotor behavior. However, larval crawling behavior on flat ...