SG é apoiado por fundos da Universidade Estadual de Nova York em Buffalo e de John R. Oishei Foundation.

1. Preparação dos Reagentes <ol><li> Prepare 1x tampão Dissecção com 128 mM NaCl, 4 mM CaCl 2, 4mm MgCl 2, 2 mM KCl, HEPES 5mM e Sacarose 36mm. PH da solução a 7,2 e filtro de esterilizar. </li><li> Prepare o fixador utilizando 01:01 diluição de formaldeído 16% e solução tampão 1x Dissection. </li><li> Prepare 1x PBT usando 1x Tampão fosfato salino (PBS) em um PH de 7,2 e Triton X-100 em uma proporção de 1:100. </li><li> Prepare 5% albumina sérica bovina (BSA) com 0,01% Na Azida em 1x PBS. </li></ol> 2. Preparação para o Dissection <ol><li> Sylgard pratos são usados ​​para dissecção. Prepare os pratos derramando Sylgard 184 base de elastômero de silicone de cura e agente de mistura em uma placa de Petri. Deixe a mistura solidificar completamente e seco antes de usar. </li><li> Antes da dissecação, reunir um par limpo de # 5 fórceps, um par de tesouras limpas lâmina reta Vannas, e pinos. </li></ol> 3. Dissecção de 3 larvas rd <ol><li> Coletar vagando 3 ª larvas de um genótipo específico em uma placa de Petri. </li><li> Lavar as larvas em água deionizada para se livrar da comida. </li><li> Coloque uma larva no prato Sylgard, com o lado dorsal. Pin a larva em suas extremidades anterior e posterior. </li><li> Colocar uma gota de tampão Dissection 1x na larva fixado. Usando uma tesoura fina beliscar a larva na linha média dorsal, perto da extremidade posterior. Usando a tesoura, cortar a cutícula larval da extremidade posterior até o final anterior. </li><li> Colocar uma gota de tampão Dissection nova 1x para a larva dissecados. Com um pino, pegar uma borda lateral da cutícula perto do meio da larva alfinete e da cutícula. Usando outro pino, o pino da borda lateral do segundo cutícula, como mostrado no diagrama. Dois pinos são usados ​​em cada lado lateral. Veja o diagrama abaixo. </li><li> Remova cuidadosamente os intestinos, órgãos de gordura, e traqueia, deixando apenas o cérebro com os dois lobos ópticos e gânglios ventral com os nervos segmentares anexado. O restante do procedimento é feito no prato Sylgard. </li></ol> 4. Fixação da Larva Dissecada <ol><li> Incubar a larva dissecada em correção para 30 minutos, substituindo a correção a cada 15 minutos. </li><li> Após a fixação, enxaguar a larva em 1x PBT por 30 minutos, substituindo o buffer a cada 10 minutos. É importante notar que a larva deve ser sempre em um buffer. </li></ol> 5. Coloração de anticorpos da Larva Dissecada <ol><li> Prepare o anticorpo primário, diluindo-lo para a concentração adequada em BSA 5% com azida em 1x Na PBT. Concentrações ideais serão diferentes para diferentes anticorpos. </li><li> Substituir a última 1x PBT enxaguar com a solução de anticorpos preparados primária, e incubar em câmara úmida a 4 ° C durante a noite. A câmara úmida é construído por um prato de revestimento de plástico com kim-limpa embebido em água. </li><li> No dia seguinte, lave a larva dissecados em 1x PBT por 30 minutos, substituindo o buffer a cada 10 minutos. </li><li> Prepare o anticorpo secundário, diluindo-o para a concentração adequada em BSA 5% com azida em 1x Na PBT, e incubar a larva com a solução de anticorpo secundário a 25 ° C por uma hora. Enrole a câmara úmida em folha para evitar a luz, como anticorpos secundários são sensíveis à luz. </li><li> Após a incubação, lavar a larva em 1x PBT por 30 minutos, substituindo o buffer a cada 10 minutos. </li></ol> 6. Montagem e visualização da Larva Dissecada <ol><li> Antes de montar a larva no slide, prepare o slide, espalhando duas linhas verticais de unha polonês no meio, com um espaço suficiente para uma cobertura de vidro para se sentar (ver diagrama). Deixe a unha polonês secar completamente. </li><li> Coloque uma gota de tampão de montagem no espaço entre as linhas verticais unha polonês no slide (ver diagrama). O slide está pronto para a montagem. <img src="/files/ftp_upload/2128/2128.6.2.1.jpg" alt="Figura 6,2 passo 1" /> <img src="/files/ftp_upload/2128/2128.6.2.2.jpg" alt="Figura passo 2 6,2" /></li><li> Após o último enxágüe 1x PBT, remova os pinos lateral. Tenha cuidado para não rasgar a cutícula. </li><li> Remova cuidadosamente os dois pinos restantes e pegue a larva com uma pinça e coloque a larva horizontalmente no slide preparado. Certifique-se que a larva não é capotou e é orientada lado ventral para cima. </li><li> Delicadamente, coloque uma lamínula em cima e feche as bordas com unha polonês (ver diagrama). A larva está agora pronto para visualização sob um microscópio fluorescente. <img src="/files/ftp_upload/2128/2128.6.5.jpg" alt="Figura 1 6.5 passo" /></li></ol> 7. Resultados representante <img src="/files/ftp_upload/2128/2128fig1.jpg" alt="Figura 1" /> Figura 1: A imagem representativa da larval nervos segmentar a partir de um tipo selvagem larvum usando anticorpos contra a vesícula sináptica protéicas cadeia cisteína (CSP, Zinsmaier et al. 1994). Note-se que os nervos segmentares são suavemente manchado. Bar = 20Hm <img src="/files/ftp_upload/2128/2128fig2.jpg" alt="Figura 2" /> Figura 2: A imagem representativa da larval nervos segmentar a partir de uma larva mutante proteína motora utilizando anticorpos contra a proteína de vesícula sináptica proteína cadeia cisteína (CSP). Note-se que os nervos segmentares mostram acumulações maciças que mancha brilhante para CSP (setas).

<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>

Não há conflitos de interesse declarados.

Os nervos Drosophila larval segmentares são um poderoso sistema para estudar mecanismos de transporte axonal. Se o 3 º instar larval dissecção é realizada corretamente, todos os componentes do SNC, SNP e tecidos associados, tais como os músculos e NMJs, pode ser examinado dentro de uma larva único. Nós adaptamos este protocolo a partir do que foi publicado por Hurd e Saxton (1996). Este protocolo também pode ser adaptado para testar outros anticorpos neuronal, mas a otimização de anticorpos deve ser feito. Os tempos de incubação primária e secundária de anticorpos pode ser alterado ou um passo de bloqueio pode ser adicionado. Temos utilizado com sucesso este protocolo para investigar o papel da proteína precursora de amilóide 1 e 2 Huntingtin no transporte axonal.

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

Drosophila melanogaster está emergindo como um sistema poderoso modelo para estudar o desenvolvimento e função do sistema nervoso, particularmente por causa de sua genética e conveniente genoma completamente seqüenciado. Além disso, o sistema nervoso das larvas é um sistema modelo ideal para estudar mecanismos de transporte axonal como os nervos larval segmentar contêm feixes de axônios com seus corpos celulares localizados dentro do cérebro e os seus terminais terminação nervosa ao longo do comprimento do corpo. Aqui nós descrevemos o procedimento para a visualização de proteínas dentro das vesículas sinápticas larval nervos segmentares. Se feito corretamente, todos os componentes do sistema nervoso, juntamente com tecidos associados, tais como músculos e NMJs, permanecem intactas, não danificadas, e pronto para ser visualizado. 3 º larvas carregando várias mutações são dissecados, fixo, incubado com anticorpos das vesículas sinápticas, visualizados e comparados com larvas do tipo selvagem. Este procedimento pode ser adaptado para vários diferentes anticorpos synaptic ou neuronal e as mudanças na distribuição de uma variedade de proteínas pode ser facilmente observado dentro larval nervos segmentares.

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 fornecer um modelo de sistema ideal para investigar os mecanismos de transporte axonal dentro larval nervos segmentares. Usando este procedimento, 3 de larvas portadores de mutações diferentes podem ser comparadas às larvas do tipo selvagem.

Visualização de Larval Nervos segmentar em 3 Rd Instar Drosophila Preparações larval

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 visualizações.  SUNY-University at Buffalo. Drosophila melanogaster larvas fornecer um modelo de sistema ideal para investigar os mecanismos de transporte axonal dentro larval nervos segmentares. Usando este procedimento, 3 de larvas portadores de mutações diferentes podem ser comparadas às larvas do tipo selvagem.

Vídeo: 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.

Em Visualization vivo das vesículas sinápticas Dentro Drosophila larval Axônios segmentar

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

Neurociência

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.

Mapeamento e Aplicação de Enhancer-trap Expressão Flippase em larval e Adultos Drosophila CNS

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.

Análise morfológica de Drosophila Larval sensorial periférica Dendrites Neuron e axônios Usando 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.

Dissecção e imunohistoquímica de larvas, pupa e 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 gravação eletrofisiológico em 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 ...

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.

Análise Funcional do circuito de alimentação das larvas em 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.

Transecção medular nos 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 ...

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.

Imagens ao vivo de<em&gt; Drosophila</em&gt; larval 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 Quantificação Matérias: Caracterização de fenótipos na<em&gt; Drosophila</em&gt; Larval Junção 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.

Usando Canais Linear de agarose para o Estudo<em&gt; Drosophila</em&gt; Comportamento larval Crawling

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