Os autores não têm nada a divulgar.

1. Montagem do Dispositivo de Strike ( Figura 1 ) <ol><li> Remova o êmbolo de uma seringa de tuberculina de 1 ml. Corte o barril na marca de 1 mL. </li><li> Remova uma barreira de aerossol (3 mm de altura x 4 mm de diâmetro) de uma ponta de pipeta de 200 μL e use-a como pêndulo. Coloque o pêndulo dentro do tambor da seringa. Toque suavemente o cano para mover o pêndulo para a extremidade da ponta, com o lado plano cobrindo a abertura do bico. </li><li> Conecte a extremidade da ponta do barril a uma tubulação de plástico que esteja conectada ao regulador de fluxo de dióxido de carbono (CO 2 ) de uma estação de anestesia de Drosophila . </li><li> Segure o tambor verticalmente e aperte-o em um suporte de suporte de braçadeira padrão para que o pêndulo permaneça na parte inferior do barril. </li><li> Modifique uma ponta de pipeta de 200 μL para fazer o suporte da mosca. <ol><li> Corte 4 mm da ponta para fazer uma abertura de 0,8 mm de diâmetro, permitindo que apenas a cabeça da mosca seja exposta. NOTA: o thoRax e todas as outras partes do corpo da mosca permanecerão dentro da ponta da pipeta. </li></ol></li><li> Modifique uma ponta de pipeta de 1000 μL e uma tampa de agulha de seringa de 1 mL para fazer o conector. <ol><li> Cortar 44 mm da abertura da ponta. Pegue um comprimento de 6 mm de uma tampa da agulha de seringa de 1 mL e empurre-o firmemente no segmento restante da ponta da pipeta de 1.000 μL. </li></ol></li></ol> 2. Operação do Dispositivo de Strike <ol><li> Anestesiar uma única mosca feminina adulta de 2 dias usando CO 2 em uma almofada de mosca. </li><li> Mude-o com cuidado para o suporte da mosca usando uma escova fina. Toque o suporte suavemente para que a cabeça da mosca seja vista fora do extremo da ponta. Se a probabilidade de mosca estiver exposta fora da ponta, remova-a suavemente dentro da ponta com uma agulha de seringa de 1 mL embotada. NOTA: Certifique-se de manter a probabilidade de mosca dentro do suporte. Caso contrário, a mosca pode morrer por uma lesão de proboscis de sucção. </li><li> Aperte a mosca hoPara o tambor da seringa com o conector para que a cabeça da mosca esteja voltada para baixo. </li><li> Ajuste a pressão do gás a 100 kPa. Ajuste o caudal de acordo com o desenho da experiência. </li><li> Ligue e desligue rapidamente o interruptor alternativo do regulador de fluxo para que o pêndulo acerque a cabeça da mosca uma vez. </li><li> Levante o suporte da mosca e mova-o sobre uma almofada de mosca. Inverta o suporte da mosca e toque suavemente o lado para deixar a mosca sair. Deixe a mosca em um frasco vazio para se recuperar. </li></ol> 3. Rastreamento de movimento assistido por vídeo <ol><li> Encha uma placa de Petri de 6 cm de diâmetro com elastômero de silício transparente para fazer a arena de rastreamento. Deixe um espaço de 3 mm entre o silício e a tampa do prato para permitir que as moscas caminhem livremente, mas não voam. </li><li> Anestesiar quatro moscas do grupo sham ou tratado cada vez e colocá-las na arena. Deixe as moscas a 22 ° C durante 1 h. </li><li> Posicione uma câmera de dispositivo acoplado por carga (CCD) acima das arenas e grave durante 5 min.</li><li> Analise as trajetórias de movimento gravadas usando o software Ctrax (disponível gratuitamente na Caltech) 16 . Exporte os dados rastreados em um formato compatível com a linguagem de programação (por exemplo, Matlab) e analise os dados com base na distância percorrida por quadro 17 . Calcule a distância média a pé para cada mosca e combine-a com todas as outras moscas / grupos gravados para obter uma distância cumulativa média percorrida pela população de arquivos no mesmo grupo. </li></ol>

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J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Method+to+Inflict+Closed+Head+Traumatic+Brain+Injury+in+Drosophila.">A Method to Inflict Closed Head Traumatic Brain Injury in Drosophila.</a> J Vis Exp. (e52905), (2015).</li><li>Branson, K., Robie, A. A., Bender, J., Perona, P., Dickinson, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+ethomics+in+large+groups+of+Drosophila.">High-throughput ethomics in large groups of Drosophila.</a> Nat Methods. 6 (6), 451-457 (2009).</li><li>Straw, A. D., Dickinson, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motmot,+an+open-source+toolkit+for+realtime+video+acquisition+and+analysis.">Motmot, an open-source toolkit for realtime video acquisition and analysis.</a> Source Code Biol Med. 4 (5), 1-10 (2009).</li><li>Talavage, T. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functionally-detected+cognitive+impairment+in+high+school+football+players+without+clinically-diagnosed+concussion.">Functionally-detected cognitive impairment in high school football players without clinically-diagnosed concussion.</a> J Neurotrauma. 31 (4), 327-338 (2014).</li><li>Theadom, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency+and+impact+of+recurrent+traumatic+brain+injury+in+a+population-based+sample.">Frequency and impact of recurrent traumatic brain injury in a population-based sample.</a> J Neurotrauma. 32 (10), 674-681 (2015).</li><li>Drobysheva, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+optimized+method+for+histological+detection+of+dopaminergic+neurons+in+Drosophila+melanogaster.">An optimized method for histological detection of dopaminergic neurons in Drosophila melanogaster.</a> J Histochem Cytochem. 56 (12), 1049-1063 (2008).</li></ol>

Este trabalho foi apoiado pelo fundo de iniciação da faculdade de medicina da Universidade Johns Hopkins para LC

Modelos de animais que modelam fielmente as características de CTE, incluindo alterações neurofisiológicas, características neuropatológicas e déficits neurocomportamentais, são essenciais para descobrir mecanismos de doenças e para desenvolver alvos diagnósticos e terapêuticos. É compreensível que nenhum modelo animal de uma doença humana seja perfeito na imitação de todos os pontos finais clinicamente relevantes. No entanto, acreditamos que um modelo CTE robusto deve satisfazer os seguintes três requi...

A Encefalopatia Traumática Crônica (CTE) recentemente foi reconhecida como um distúrbio neurodegenerativo distinto, separado de outras tauopatias, como a doença de Alzheimer 1 . Ao contrário da doença de Alzheimer e outras tauopatias comuns - cujos fatores de risco mais importantes estão avançando em idade e história familiar de demência, o CTE, como indicado pelo seu nome, implica uma estreita associação com história de trauma cerebral, muito provavelmente visto em atletas de esportes de contato, Como boxers e jogadores de futebol, bem como em veteranos militares 2 , 3 , 4 , 5 . É pensado para ser iniciado por golpes repetidos de concussão e subconcussão na cabeça. Os pacientes podem apresentar sintomas e sinais como déficits cognitivos, mudanças de humor e comportamento e disfunção do movimento, que se sobrepõem significativamente com a doença de Alzheimer, frontotemporalDemência, demência do corpo de Lewy e doença de Parkinson 6 . Em contrapartida, os exames pós-mortem do tecido cerebral revelam um padrão distinto de acumulação de tau hiperfosforilada em torno de pequenos vasos sanguíneos nas profundezas dos sulcos corticais, uma característica patognomônica não observada nas outras condições degenerativas 7 . No entanto, até agora, muito pouco se sabe sobre a patogênese que leva à manifestação da doença. Isto é em grande parte devido à falta de um modelo animal fiel - apenas recentemente foram gerados modelos de roedores 5 , 8 . Esses organismos modelo apresentam as desvantagens dos cuidados intensivos em custos e uma vida útil relativamente longa, que não são adequadas para estudos de doenças neurodegenerativas. Em comparação com homólogos de mamíferos, animais invertebrados, como Drosophila, são uma excelente alternativa, com sua manutenção econômica,Ferramentas extensivas para dissecar determinantes genéticos e vida útil relativamente curta 9 . Notavelmente, a mosca e os cérebros humanos compartilham caminhos molecular e celular evolutivamente conservados, bem como semelhanças anatômicas 10 , 11 , 12 . Dois modelos engenhosos de Drosophila para estudar lesão cerebral traumática foram relatados anteriormente 13 , 14 . O primeiro dispositivo &quot;High Impact Trauma&quot; (HIT) projetado por Katzenberger e colegas continha moscas de movimento livre em um frasco de plástico que estava ligado à extremidade livre de uma mola metálica 13 , 15 . Quando o frasco de plástico foi inclinado verticalmente e liberado, ele atingiu uma almofada de poliuretano e transmitiu trauma para as moscas enquanto eles saltavam para a parede do frasco e se recuperaram. Em contraste, Barekat e colegas desenharam um método de entrega diferente, nósNa plataforma de homogeneizador Omni Bead Ruptor-24 14 . As moscas foram incapacitadas com CO 2 e colocadas em um tubo de rosca de rosca de 2 mL que foi fixado ao homogeneizador e submetido a condições de agitação pré-programadas. Um dos benefícios do uso do sistema de homogeneizador de tecido é que o experimentador poderia modular a intensidade do ferimento, a duração da lesão e o número de episódios de lesões. No entanto, ambos os regimes sofrem a mesma desvantagem: lesões primárias na cabeça são inflacionadas aleatoriamente em termos de localização e força de impacto. Além disso, ambos os métodos resultaram em mortalidade considerável, causada por danos colaterais inevitáveis ​​a outras partes do corpo e órgãos internos. Aqui, descrevemos um novo método para induzir o mTBI nas moscas da fruta. Nosso aparelho consiste em um pêndulo balístico a gás. Comparado com os modelos Drosophila existentes 14 , 15 , nosso método tem a vantagem única de fornecer medidasImpacto de urable, dirigido apenas para a cabeça de mosca de movimento livre, permitindo o controle preciso de vários fatores, como a gravidade do impacto, o intervalo de tempo entre os impactos e o número total de impactos sofridos.

<table><tbody><tr><td>Aerosol Barrier</td><td>USA Scientific</td><td>1120-8810</td><td>Used as an impactor</td></tr><tr><td>200 &amp;#956;L Pipette Tip</td><td>USA Scientific</td><td>1111-0706</td><td>Used as a fly head holder</td></tr><tr><td>1000 &amp;#956;L Pipette Tip</td><td>USA Scientific</td><td>1122-1830</td><td>Used as a connector</td></tr><tr><td>1 mL Tuberculin Syringe</td><td>Becton Dickinson</td><td>309625</td><td></td></tr><tr><td>60 mm Petri Dishes</td><td>Fisher Scientific</td><td>FB0875713A</td><td>Used as a tracking arenas</td></tr><tr><td>Flow Regulator</td><td>Genesee Scientific</td><td>59-122WC</td><td></td></tr><tr><td>Standard Clamp Holder/stand</td><td>EISCO Scientific</td><td>CH0688</td><td></td></tr><tr><td>Fine Brush</td><td>Genesee Scientific</td><td>59-204</td><td></td></tr><tr><td>Flypad</td><td>Genesee Scientific</td><td>59-114</td><td></td></tr><tr><td>Sylgard Silicone Elastomer</td><td>Dow Corning</td><td>4019862</td><td></td></tr><tr><td>CCD Camera</td><td>Microsoft&amp;nbsp;</td><td>HD-5000</td><td></td></tr><tr><td>Ctrax Walking Fly Tracker</td><td>Caltech</td><td>Ctrax 0.2.11</td><td></td></tr><tr><td>MATLAB Image Processing Toolbox</td><td>MATLAB</td><td>R2015b</td><td></td></tr></tbody></table>

a novel method to model chronic traumatic encephalopathy in drosophila

A encefalopatia traumática crônica (CTE) é uma doença neurodegenerativa estabelecida que está intimamente associada à exposição a lesões cerebrais traumáticas leves repetitivas (mTBI). Os mecanismos responsáveis ​​por suas complexas mudanças patológicas permanecem bastante evasivos, apesar de um consenso recente para definir os critérios neuropatológicos. Aqui, descrevemos um novo método para desenvolver um modelo de CTE em Drosophila melanogaster ( Drosophila ), na tentativa de identificar os genes e caminhos chave que levam ao acúmulo de tau hiperfosforilizado característico e a morte neuronal no cérebro. Os impactos de resistência ajustável para infligir feridas fechadas leves são entregues diretamente na cabeça da mosca, submetendo a cabeça a aceleração e desaceleração rápidas. Nosso método elimina os problemas potenciais inerentes a outros modelos de mTBI de Drosophila ( por exemplo, a morte de animais pode ser induzida por danos aOutras partes do corpo ou órgãos internos). O menor cuidado de animais com uso intensivo de mão-de-obra e custo, vida curta e extensas ferramentas genéticas tornam a mosca da fruta ideal para estudar a patogênese do CTE e possibilitar a realização de telas genéticas e farmacológicas avançadas em grande escala, genômicas. Prevemos que a caracterização contínua do modelo gerará importantes insights mecanísticos sobre prevenção de doenças e abordagens terapêuticas.

Para estabelecer um modelo CTE usando Drosophila adulta, determinamos a eficácia do nosso dispositivo ao infligir um único ferimento na cabeça fechada. Para eliminar as variações relativas ao genótipo, ao sexo ou à idade, utilizamos moscas fêmeas Canton-S WT de 2 dias na experiência. Poderíamos facilmente controlar a força do pêndulo, regulando a taxa de fluxo de CO 2 a uma pressão de gás constante de 100 kPa. As moscas expostas a uma única greve com a ...

Watch this Scientific Journal Video about A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila at JoVE.com

A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

Aqui, descrevemos uma nova abordagem para infligir lesões cerebrais traumáticas de cabeça fechada em Drosophila melanogaster . Nosso método tem a vantagem de entregar diretamente impactos repetitivos com força ajustável para a cabeça sozinho. Uma maior exploração do sistema de invertebrados ajudará a iluminar a patogênese da encefalopatia traumática crônica.

Um novo método para modelar a encefalopatia traumática crônica em<em&gt; Drosophila</em

Chronic Traumatic Encephalopathy (CTE) is an established neurodegenerative disease that is closely associated with exposure to repetitive mild Traumatic ...

a-novel-method-to-model-chronic-traumatic-encephalopathy-in-drosophila

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

8.2K visualizações.  Johns Hopkins University School of Medicine.  Aqui, descrevemos uma nova abordagem para infligir lesões cerebrais traumáticas de cabeça fechada em Drosophila melanogaster . Nosso método tem a vantagem de entregar diretamente impactos repetitivos com força ajustável para a cabeça sozinho. Uma maior exploração do sistema de invertebrados ajudará a iluminar a patogênese da encefalopatia traumática crônica. 

Vídeo: A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination2. Here we use behavioral assays, including the negative geotaxis assay3 and the aversive phototaxic suppression assay (APS assay)4,5, to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies.

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Behavior assays for measuring locomotor functions, learning, and memory abilities in Drosophila.

Locomotor ensaio, Aprendizagem e Memória Os déficits no Drosophila Modelos de neurodegeneração

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of ...

Neurociência

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

Dissecção e imunofluorescência coloração de cogumelo corpo e fotoreceptor neurônios em cérebros adultos Drosophila melanogaster

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Biologia do Desenvolvimento

Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining

Drosophila melanogaster is a valuable model organism to study aging and pathological degenerative processes in the nervous system. The advantages of the fly as an experimental system include its genetic tractability, short life span and the possibility to observe and quantitatively analyze complex behaviors. The expression of disease-linked genes in specific neuronal populations of the Drosophila brain, can be used to model human neurodegenerative diseases such as Parkinson's and Alzheimer's 5.
Dopaminergic (DA) neurons are among the most vulnerable neuronal populations in the aging human brain. In Parkinson's disease (PD), the most common neurodegenerative movement disorder, the accelerated loss of DA neurons leads to a progressive and irreversible decline in locomotor function. In addition to age and exposure to environmental toxins, loss of DA neurons is exacerbated by specific mutations in the coding or promoter regions of several genes. The identification of such PD-associated alleles provides the experimental basis for the use of Drosophila as a model to study neurodegeneration of DA neurons in vivo. For example, the expression of the PD-linked human &alpha;-synuclein gene in Drosophila DA neurons recapitulates some features of the human disease, e.g. progressive loss of DA neurons and declining locomotor function 2. Accordingly, this model has been successfully used to identify potential therapeutic targets in PD 8.
Here we describe two assays that have commonly been used to study age-dependent neurodegeneration of DA neurons in Drosophila: a climbing assay based on the startle-induced negative geotaxis response and tyrosine hydroxylase immunostaining of whole adult brain mounts to monitor the number of DA neurons at different ages. In both cases, in vivo expression of UAS transgenes specifically in DA neurons can be achieved by using a tyrosine hydroxylase (TH) promoter-Gal4 driver line 3, 10.

Assessing Neurodegenerative Phenotypes in Drosophila Dopaminergic Neurons by Climbing Assays and Whole Brain Immunostaining

Here we describe two assays that have been established to study age-dependent neurodegeneration of dopaminergic (DA) neurons in Drosophila: the climbing/startle-induced negative geotaxis assay which allows to study the functional effects of DA neurons degeneration and the tyrosine hydroxylase immunostaining which is used to identify and count DA neurons in whole brain mounts.

Avaliando fenótipos Neurodegenerativas em<em&gt; Drosophila</em&gt; Neurônios dopaminérgicos subindo Ensaios e toda Imunocoloração Cérebro

Drosophila melanogaster is a valuable model organism to study aging and pathological degenerative processes in the nervous system. The advantages of the ...

Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders

Locomotive defects resulting from neurodegenerative disorders can be a late onset symptom of disease, following years of subclinical degeneration, and thus current therapeutic treatment strategies are not curative. Through the use of whole exome sequencing, an increasing number of genes have been identified to play a role in human locomotion. Despite identifying these genes, it is not known how these genes are crucial to normal locomotive functioning. Therefore, a reliable assay, which utilizes model organisms to elucidate the role of these genes in order to identify novel targets of therapeutic interest, is needed more than ever. We have designed a sensitized version of the negative geotaxis assay that allows for the detection of milder defects earlier and has the ability to evaluate these defects over time. The assay is performed in a glass graduated cylinder, which is sealed with a wax barrier film. By increasing the threshold distance to be climbed to 17.5 cm and increasing the experiment duration to 2 min&#160;we have observed a greater sensitivity in detecting mild mobility dysfunctions. The assay is cost effective and does not require extensive training to obtain highly reproducible results. This makes it an excellent technique for screening candidate drugs in Drosophila mutants with locomotion defects.

We present an optimized inexpensive and reliable negative geotaxis assay in Drosophila melanogaster as a model for neurodegenerative disorders. Being more sensitive to mild locomotor defects, this assay will help screen for potential genetic interactions and drug targets.

Análise Quantitativa de Defeitos de escalada em um modelo de Drosophila de doenças neurodegenerativas

Locomotive defects resulting from neurodegenerative disorders can be a late onset symptom of disease, following years of subclinical degeneration, and ...

A Method to Inflict Closed Head Traumatic Brain Injury in Drosophila

Traumatic brain injury (TBI) affects millions of people each year, causing impairment of physical, cognitive, and behavioral functions and death. Studies using Drosophila have contributed important breakthroughs in understanding neurological processes. Thus, with the goal of understanding the cellular and molecular basis of TBI pathologies in humans, we developed the High Impact Trauma (HIT) device to inflict closed head TBI in flies. Flies subjected to the HIT device display phenotypes consistent with human TBI such as temporary incapacitation and progressive neurodegeneration. The HIT device uses a spring-based mechanism to propel flies against the wall of a vial, causing mechanical damage to the fly brain. The device is inexpensive and easy to construct, its operation is simple and rapid, and it produces reproducible results. Consequently, the HIT device can be combined with existing experimental tools and techniques for flies to address fundamental questions about TBI that can lead to the development of diagnostics and treatments for TBI. In particular, the HIT device can be used to perform large-scale genetic screens to understand the genetic basis of TBI pathologies.

A Method to Inflict Closed Head Traumatic Brain Injury in Drosophila

Here we describe a method to inflict closed head traumatic brain injury (TBI) in Drosophila. This method provides a gateway to investigate the cellular and molecular mechanisms that underlie TBI pathologies using the vast array of experimental tools and techniques available for flies.

Um Método para infligir Cabeça Fechada Lesão cerebral traumático em<em&gt; Drosophila</em

Traumatic brain injury (TBI) affects millions of people each year, causing impairment of physical, cognitive, and behavioral functions and death. Studies ...

Mass Histology to Quantify Neurodegeneration in Drosophila

Progressive neurodegenerative diseases like Alzheimer&#39;s disease (AD) or Parkinson&#39;s disease (PD) are an increasing threat to human health worldwide. Although mammalian models have provided important insights into the underlying mechanisms of pathogenicity, the complexity of mammalian systems together with their high costs are limiting their use. Therefore, the simple but well-established Drosophila model-system&#160;provides an alternative for investigating the molecular pathways that are affected in these diseases. Besides behavioral deficits, neurodegenerative diseases are characterized by histological phenotypes such as neuronal death and axonopathy. To quantify neuronal degeneration and to determine how it is affected by genetic and environmental factors, we use a histological approach that is based on measuring the vacuoles in adult fly brains. To minimize the effects of systematic error and to directly compare sections from control and experimental flies in one preparation, we use the &#39;collar&#39; method for paraffin sections. Neurodegeneration is then assessed by measuring the size and/or number of vacuoles that have developed in the fly brain. This can either be done by focusing on a specific region of interest or by analyzing the entire brain by obtaining serial sections that span the complete head. Therefore, this method allows one to measure not only severe degeneration but also relatively mild phenotypes that are only detectable in a few sections, as occurs during normal aging.

Mass Histology to Quantify Neurodegeneration in Drosophila

Drosophila is widely used as a model system to study neurodegeneration. This protocol describes a method by which degeneration, as determined by vacuole formation in the brain, can be quantified. It also minimizes effects due to the experimental procedure by processing and sectioning control and experimental flies as one sample.

Mass Histologia para quantificar neurodegeneração em<em&gt; Drosophila</em

Progressive neurodegenerative diseases like Alzheimer&#39;s disease (AD) or Parkinson&#39;s disease (PD) are an increasing threat to human health ...

Purification of Transcripts and Metabolites from Drosophila Heads

For the last decade, we have tried to understand the molecular and cellular mechanisms of neuronal degeneration using Drosophila as a model organism. Although fruit flies provide obvious experimental advantages, research on neurodegenerative diseases has mostly relied on traditional techniques, including genetic interaction, histology, immunofluorescence, and protein biochemistry. These techniques are effective for mechanistic, hypothesis-driven studies, which lead to a detailed understanding of the role of single genes in well-defined biological problems. However, neurodegenerative diseases are highly complex and affect multiple cellular organelles and processes over time. The advent of new technologies and the omics age provides a unique opportunity to understand the global cellular perturbations underlying complex diseases. Flexible model organisms such as Drosophila are ideal for adapting these new technologies because of their strong annotation and high tractability. One challenge with these small animals, though, is the purification of enough informational molecules (DNA, mRNA, protein, metabolites) from highly relevant tissues such as fly brains. Other challenges consist of collecting large numbers of flies for experimental replicates (critical for statistical robustness) and developing consistent procedures for the purification of high-quality biological material. Here, we describe the procedures for collecting thousands of fly heads and the extraction of transcripts and metabolites to understand how global changes in gene expression and metabolism contribute to neurodegenerative diseases. These procedures are easily scalable and can be applied to the study of proteomic and epigenomic contributions to disease.

Purification of Transcripts and Metabolites from Drosophila Heads

We describe here the procedures for the extraction and purification of mRNA and metabolites from Drosophila heads. We are applying these techniques to better understand the cellular perturbations underlying neuronal degeneration. These methodologies can be easily scaled and adapted for other "omic" projects.

Purificação de Transcrições e metabolitos de<em&gt; Drosophila</em&gt; Cabeças

For the last decade, we have tried to understand the molecular and cellular mechanisms of neuronal degeneration using Drosophila as a model organism. ...

Biologia

Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster

Axon degeneration is a shared feature in neurodegenerative disease and when nervous systems are challenged by mechanical or chemical forces. However, our understanding of the molecular mechanisms underlying axon degeneration remains limited. Injury-induced axon degeneration serves as a simple model to study how severed axons execute their own disassembly (axon death). Over recent years, an evolutionarily conserved axon death signaling cascade has been identified from flies to mammals, which is required for the separated axon to degenerate after injury. Conversely, attenuated axon death signaling results in morphological and functional preservation of severed axons and their synapses. Here, we present three simple and recently developed protocols that allow for the observation of axonal morphology, or axonal and synaptic function of severed axons that have been cut-off from the neuronal cell body, in the fruit fly Drosophila. Morphology can be observed in the wing, where a partial injury results in axon death side-by-side of uninjured control axons within the same nerve bundle. Alternatively, axonal morphology can also be observed in the brain, where the whole nerve bundle undergoes axon death triggered by antennal ablation. Functional preservation of severed axons and their synapses can be assessed by a simple optogenetic approach coupled with a post-synaptic grooming behavior. We present examples using a highwire loss-of-function mutation and by over-expressing dnmnat, both capable of delaying axon death for weeks to months. Importantly, these protocols can be used beyond injury; they facilitate the characterization of neuronal maintenance factors, axonal transport, and axonal mitochondria.

Morphological and Functional Evaluation of Axons and their Synapses during Axon Death in Drosophila melanogaster

Here, we provide protocols to perform three simple injury-induced axon degeneration (axon death) assays in Drosophila melanogaster to evaluate the morphological and functional preservation of severed axons and their synapses.

Avaliação morfológica e funcional de Axons e suas sinapses durante a morte de Axon em Drosophila melanogaster

Axon degeneration is a shared feature in neurodegenerative disease and when nervous systems are challenged by mechanical or chemical forces. However, our ...

Tracking Freely Walking Flies: A Method to Assess Locomotion in Drosophila

Source: Sun, M. and Chen, L. L. <a href="https://jove.unicartagenaproxy.elogim.com/video/55602/" target="_blank">A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila</a>. J. Vis. Exp. (2017).
This video describes how to track freely walking flies to assess their general locomotion ability. The featured protocol demonstrates the assay&#39;s setup and data analysis using video tracking software.

Rastreando moscas que andam livremente: um método para avaliar a locomoção em Drosophila

Source: Sun, M. and Chen, L. L. A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila. J. Vis. Exp. (2017).
This video describes how to ...

JoVE Encyclopedia of Experiments

Drosophila melanogaster (mosca da fruta)

Adulto

A Technique to Inflict Closed-Head Traumatic Brain Injury in Drosophila Flies

Source: Sun, M., et al. <a href="https://appjove.unicartagenaproxy.elogim.com/v/55602">A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila.</a> J. Vis. Exp. (2017).
This video demonstrates a procedure to inflict a closed-head traumatic injury in anesthetized Drosophila flies using a strike device with a gas-propelled impactor. The injury affects neuronal function and impairs walking ability.

Uma técnica para infligir lesão cerebral traumática de cabeça fechada em moscas Drosophila

1. Assembly of the Strike Device (Figure 1)

	Remove the plunger from a 1 mL tuberculin syringe. Cut the barrel at the 1 mL mark.
	Remove an aerosol ...

Um novo método para modelar a encefalopatia traumática crônica em

Resumo

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