Name: mass histology to quantify neurodegeneration in drosophila
Uploaded: 2016-12-15T12:30:00.000+00:00
Duration: 6 min 34 s
Description: Watch this Scientific Journal Video about Mass Histology to Quantify Neurodegeneration in Drosophila at JoVE.com

This work was supported by grants to D.K. from the Medical Research Foundation of Oregon and from NIH/NINDS (NS047663). E.S. was supported by a training grant from the NIH (T32AG023477).

1. Fixação da cabeça em coleiras e inclusão em parafina Nota: Todos os passos no processo de fixação deve ser feito numa hotte. Metilbenzoato, embora não representam um risco para a saúde, tem um odor altamente distinta, que pode ser avassaladora se não for tratado em um exaustor. <ol><li> Antes de anestesiar as moscas, fazem-se 50 ml de solução de Carnoy por adição de 15 ml de clorofórmio e 5 ml de ácido acético glacial e 30 mL de etanol a 99% (não se misturam o clorofórmio e ácido acético). Derramá-lo num recipiente de vidro com um fundo plano, tal como um prato cristalizadas, para garantir que os colares podem estabelecer plana e são completamente cobertas com a solução. </li><li> Anestesiar as moscas com CO 2 ou éter. </li><li> moscas de rosca (até 20 com a maioria dos colares) por seus pescoços para os colares usando uma pinça. Recorde para alinhar todos os cabeças com a mesma orientação, como pode ser visto na Figura 1A, e ser suave para assegurar que não se verifiquem danos na cabeça ou olhos. </li><li> Incluir moscas seno Oculis (setas, Figura 1A) em posições aleatórias para que a ordem das moscas podem ser facilmente identificados nas secções. Além disso, se as moscas experimentais têm uma cor branca ou clara do olho, passe algumas moscas de olhos vermelhos, tais como o tipo selvagem, entre elas para assegurar que o pigmento está presente suficiente para corar a corrediça. Grave a ordem das moscas sobre a folha de protocolo em conjunto com o número colar se utilizar mais do que um anel. </li><li> Uma vez que um colar foi terminado, colocá-lo em solução de Carnoy preparado para 3,5-4 h. </li><li> Despejar a solução Carnoy dentro do recipiente eliminação adequada e começar as lavagens de etanol. Certifique-se lentamente para derramar, de modo a não perturbar a colocação dos colares no recipiente. </li><li> Lavar os colares durante 30 min em 99% de etanol duas vezes. </li><li> Lavar os colares em 100% de etanol durante 1 h. Certifique-se de alterar as lavagens a tempo para evitar overdehydration. </li><li> Coloque os colares em metilbenzoatoO / N à temperatura ambiente. Fecha-se o recipiente com parafilme para evitar a evaporação do metilbenzoato. </li><li> Verter a methylbenozate para dentro do recipiente descartável adequado na hotte. Adicionar uma mistura previamente preparada de 1: 1 de baixo ponto de fusão (56-57 ° C), cera de parafina e metilbenzoato de metilo. A partir deste ponto, os colares devem ser mantidas numa incubadora a 65 ° C para se certificar de que a parafina não endurece. </li><li> Deite a mistura de parafina e methylbenozate para dentro do recipiente descartável adequado, e derramar a cera de parafina puro fundido, mantido a 65 ° C, para os colares. </li><li> Alterar a parafina depois de 30 min e repita este pelo menos 5 vezes. Pelo menos 6 - 8 lavagens devem ser executadas. </li><li> Uma vez que as lavagens são completos, coloque os colares em uma bandeja de cubos de gelo de borracha com ranhuras de aproximadamente o tamanho dos colares. Despeje parafina derretida sobre eles até que esteja completamente coberto e deixe-a endurecer O / N (tentar evitar bolhas de ar). </li><li> Remova os blocos de parafina containing os colares da bandeja de cubos de gelo. Separa-se o bloco de parafina a partir da gola utilizando uma lâmina de barbear, suavemente romper o colar. As cabeças estará no bloco de parafina ao passo que os corpos vão ficar na gola. Os blocos podem ser mantidos à temperatura ambiente. </li><li> Para limpar os colares, mergulhe-os em um agente desparafinização a 65 ° C para remover a parafina, limpo esfregando-se ligeiramente, e lave em etanol antes de reutilizar. </li></ol> 2. corte e montagem <ol><li> Aquecer uma placa de aquecimento a 50 ° C. Coloque os titulares objeto (ou blocos de montagem de metal) e lâminas de barbear sobre a placa e deixá-los aquecer. </li><li> Dependendo da orientação desejada para a secção transversal, e anexar o bloco de parafina, quer com as cabeças para o lado (para secções horizontais) ou virada para cima (para secções frontais) a um bloco de montagem aquecida (derretendo brevemente o bloco no lado do contacto). Remover o bloco da placa de aquecimento e deixe-o esfriar por pelo menos 10 min para assegurar que a parafina é endurecido o suficiente para uma vedação adequada para o bloco de montagem. Manter a fila de cabeças alinhadas em paralelo com a superfície do bloco, tanto quanto possível para evitar desnivelamentos. </li><li> Pegue uma lâmina de barbear e aparar o excesso de parafina longe das cabeças de mosca de modo que apenas uma pequena fila com os chefes incorporados permanece (a lâmina de barbear pode ser aquecido para corte mais fácil). Certifique-se de não cortar muito para que a parafina não quebra durante o corte (mais corte pode ser feito durante o corte). </li><li> Colocar o bloco de montagem no suporte do objecto do micrótomo e assegurar que o alinhamento da fila de cabeças é tão paralela quanto possível da aresta da lâmina. </li><li> Preparar lâminas de microscópio, cobrindo-os com uma camada fina de-L-lisina de poli (PLL) solução e deixar secar durante 5 min. Cubra-os com água imediatamente antes da utilização. </li><li> Cortar 7 uM secções e transferir a fita de secções para a corrediça que flutua na água. &lt;br /&gt; NOTA: Para obter o cérebro inteiro para seções horizontais, recolhemos a fita de quando iniciar o corte no olho até que a cabeça foi completamente cortado (corte a partir a tromba para dentro do cérebro). Mais de um slide pode ser necessário para toda a cabeça. </li><li> Colocar a lâmina numa placa de calor a 37 ° C e permitir que a fita para expandir durante cerca de 1 min. </li><li> Retire o excesso de água (por vazamento-lo ou usando um tecido) e secar a diapositivos O / N. </li><li> Remover a cera de parafina a partir do slide, colocando os diapositivos numa altura, vertical frasco deslizante de coloração com um agente desparafinização (cobrindo completamente as secções). Realizar 3 lavagens de 30 min - 60 min cada. </li><li> Remover o slide da lavagem final. Coloque 2 gotas de meios de incorporação para o slide e cobri-lo com uma lamela grande. </li></ol> 3. fotografando e analisando as Secções <ol><li> Permitir que as lâminas preparadas para secar por 1-2 d. Em seguida, examiná-los em um microsc fluorescênciaope sob a luz azul. </li><li> Utilize uma ampliação menor para determinar a orientação das moscas e para encontrar a região de interesse se concentrando-se em uma região específica. NOTA: Para as moscas SWS (ver Figura 2), encontramos a seção que contém a grande comissura e tomar uma imagem (geralmente em 40X). Ao analisar todo o cérebro (como na Figura 3), que percorrer todas as secções de uma cabeça e quer fotografar a secção com o fenótipo mais grave ou todas as secções que mostram vacúolos. </li><li> Para uma análise duplo-cego, tomar e imagens numéricas sem saber o genótipo e anote o número colarinho e posição da cabeça na linha de identificá-los mais tarde. </li><li> Depois que as imagens foram tomadas, analisá-los usando um software de imagem. </li><li> Contar o número de vacúolos por secção ou por cabeça. Para medir o tamanho vacúolo, abrir as imagens em um programa de software e selecionar os vacúolos com uma seleção muitoeu. Determinar a quantidade de pixels nos vacúolos seleccionados. </li><li> Para a conversão para mm 2, tirar uma foto de um slide de calibração estágio micrômetro na ampliação usada para a aquisição de fotos. Determinar a quantidade de pixels em 100 uM 2 para calcular um factor de conversão. </li><li> Converter o número total de pixels em 2 uM dividindo o número de pixels de acordo com o factor de conversão calculado no passo acima. </li></ol>

<ol>
	<li>Alexander, A. G., Marfil, V., Li, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Caenorhabditis+elegans+as+a+model+to+study+Alzheimer's+disease+and+other+neurodegenerative+diseases.">Use of Caenorhabditis elegans as a model to study Alzheimer's disease and other neurodegenerative diseases.</a> Front Genet. 5, 279 (2014).</li><li>Bonini, N. M., Fortini, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+neurodegenerative+disease+modeling+using+Drosophila.">Human neurodegenerative disease modeling using Drosophila.</a> Annu Rev Neurosci. 26, 627-656 (2003).</li><li>Calahorro, F., Ruiz-Rubio, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caenorhabditis+elegans+as+an+experimental+tool+for+the+study+of+complex+neurological+diseases:+Parkinson's+disease,+Alzheimer's+disease+and+autism+spectrum+disorder.">Caenorhabditis elegans as an experimental tool for the study of complex neurological diseases: Parkinson's disease, Alzheimer's disease and autism spectrum disorder.</a> Invert Neurosci. 11, 73-83 (2011).</li><li>Chen, X., Barclay, J. W., Burgoyne, R. D., Morgan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+C.+elegans+to+discover+therapeutic+compounds+for+ageing-associated+neurodegenerative+diseases.">Using C. elegans to discover therapeutic compounds for ageing-associated neurodegenerative diseases.</a> Chemistry Central Journal. 9, 65 (2015).</li><li>Gama Sosa, M. A., De Gasperi, R., Elder, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+human+neurodegenerative+diseases+in+transgenic+systems.">Modeling human neurodegenerative diseases in transgenic systems.</a> Hum Genet. 131, 535-563 (2012).</li><li>Jaiswal, M., Sandoval, H., Zhang, K., Bayat, V., Bellen, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+mechanisms+that+underlie+human+neurodegenerative+diseases+in+Drosophila.">Probing mechanisms that underlie human neurodegenerative diseases in Drosophila.</a> Annu Rev Genet. 46, 371-396 (2012).</li><li>Konsolaki, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fruitful+research:+drug+target+discovery+for+neurodegenerative+diseases+in+Drosophila.">Fruitful research: drug target discovery for neurodegenerative diseases in Drosophila.</a> Expert Opin Drug Discov. 8, 1503-1513 (2013).</li><li>Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurodegenerative+mutants+in+Drosophila:+a+means+to+identify+genes+and+mechanisms+involved+in+human+diseases.">Neurodegenerative mutants in Drosophila: a means to identify genes and mechanisms involved in human diseases.</a> Invert Neurosci. 5, 97-109 (2005).</li><li>Kretzschmar, 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=Swiss+cheese+et+allii,+some+of+the+first+neurodegenerative+mutants+isolated+in+Drosophila.">Swiss cheese et allii, some of the first neurodegenerative mutants isolated in Drosophila.</a> J Neurogenet. 23, 34-41 (2009).</li><li>Li, J., Le, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+neurodegenerative+diseases+in+Caenorhabditis+elegans.">Modeling neurodegenerative diseases in Caenorhabditis elegans.</a> Exp Neurol. 250, 94-103 (2013).</li><li>Prussing, K., Voigt, A., Schulz, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+melanogaster+as+a+model+organism+for+Alzheimer's+disease.">Drosophila melanogaster as a model organism for Alzheimer's disease.</a> Mol Neurodegener. 8, (2013).</li><li>Wentzell, J., Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alzheimer's+disease+and+tauopathy+studies+in+flies+and+worms.">Alzheimer's disease and tauopathy studies in flies and worms.</a> Neurobiol Dis. 40, 21-28 (2010).</li><li>Ali, Y. O., Escala, W., Ruan, K., Zhai, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assaying+locomotor,+learning,+and+memory+deficits+in+Drosophila+models+of+neurodegeneration.">Assaying locomotor, learning, and memory deficits in Drosophila models of neurodegeneration.</a> J Vis Exp. , (2011).</li><li>Barone, M. C., Bohmann, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+neurodegenerative+phenotypes+in+Drosophila+dopaminergic+neurons+by+climbing+assays+and+whole+brain+immunostaining.">Assessing neurodegenerative phenotypes in Drosophila dopaminergic neurons by climbing assays and whole brain immunostaining.</a> J Vis Exp. , e50339 (2013).</li><li>Dutta, S., Rieche, F., Eckl, N., Duch, C., Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glial+expression+of+Swiss-cheese+(SWS),+the+Drosophila+orthologue+of+Neuropathy+Target+Esterase,+is+required+for+neuronal+ensheathment+and+function.">Glial expression of Swiss-cheese (SWS), the Drosophila orthologue of Neuropathy Target Esterase, is required for neuronal ensheathment and function.</a> Dis Model Mech. , (2015).</li><li>Iijima, K., 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=Abeta42+mutants+with+different+aggregation+profiles+induce+distinct+pathologies+in+Drosophila.">Abeta42 mutants with different aggregation profiles induce distinct pathologies in Drosophila.</a> PLoS One. 3, e1703 (2008).</li><li>Krishnan, N., 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=Loss+of+circadian+clock+accelerates+aging+in+neurodegeneration-prone+mutants.">Loss of circadian clock accelerates aging in neurodegeneration-prone mutants.</a> Neurobiol Dis. 45, 1129-1135 (2012).</li><li>Liu, 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=Automated+rapid+iterative+negative+geotaxis+assay+and+its+use+in+a+genetic+screen+for+modifiers+of+Abeta(42)-induced+locomotor+decline+in+Drosophila.">Automated rapid iterative negative geotaxis assay and its use in a genetic screen for modifiers of Abeta(42)-induced locomotor decline in Drosophila.</a> Neurosci Bull. 31, 541-549 (2015).</li><li>Papanikolopoulou, K., Skoulakis, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporally+distinct+phosphorylations+differentiate+Tau-dependent+learning+deficits+and+premature+mortality+in+Drosophila.">Temporally distinct phosphorylations differentiate Tau-dependent learning deficits and premature mortality in Drosophila.</a> Hum Mol Genet. 24, 2065-2077 (2015).</li><li>Ping, Y., 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=Linking+abeta42-induced+hyperexcitability+to+neurodegeneration,+learning+and+motor+deficits,+and+a+shorter+lifespan+in+an+Alzheimer's+model.">Linking abeta42-induced hyperexcitability to neurodegeneration, learning and motor deficits, and a shorter lifespan in an Alzheimer's model.</a> PLoS Genet. 11, e1005025 (2015).</li><li>Sujkowski, A., Rainier, S., Fink, J. K., Wessells, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+Induction+of+Human+NTE+(PNPLA6)+Rescues+Neurodegeneration+and+Mobility+Defects+of+Drosophila+swiss+cheese+(sws)+Mutants.">Delayed Induction of Human NTE (PNPLA6) Rescues Neurodegeneration and Mobility Defects of Drosophila swiss cheese (sws) Mutants.</a> PLoS One. 10, e0145356 (2015).</li><li>Barone, M. C., Sykiotis, G. P., Bohmann, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+activation+of+Nrf2+signaling+is+sufficient+to+ameliorate+neurodegenerative+phenotypes+in+a+Drosophila+model+of+Parkinson's+disease.">Genetic activation of Nrf2 signaling is sufficient to ameliorate neurodegenerative phenotypes in a Drosophila model of Parkinson's disease.</a> Dis Model Mech. 4, 701-707 (2011).</li><li>Coulom, H., Birman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+exposure+to+rotenone+models+sporadic+Parkinson's+disease+in+Drosophila+melanogaster.">Chronic exposure to rotenone models sporadic Parkinson's disease in Drosophila melanogaster.</a> J Neurosci. 24, 10993-10998 (2004).</li><li>Navarro, J. 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=Analysis+of+dopaminergic+neuronal+dysfunction+in+genetic+and+toxin-induced+models+of+Parkinson's+disease+in+Drosophila.">Analysis of dopaminergic neuronal dysfunction in genetic and toxin-induced models of Parkinson's disease in Drosophila.</a> J Neurochem. 131, 369-382 (2014).</li><li>Heisenberg, M., B&#246;hl, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+anatomical+brain+mutants+of+Drosophila+by+histological+means.">Isolation of anatomical brain mutants of Drosophila by histological means.</a> Zeitschrift f&#252;r Naturforschung C. 34, 143 (1979).</li><li>Han, P. L., Meller, V., Davis, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Drosophila+brain+revisited+by+enhancer+detection.">The Drosophila brain revisited by enhancer detection.</a> J Neurobiol. 31, 88-102 (1996).</li><li>Lin, C. W., 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=Automated+in+situ+brain+imaging+for+mapping+the+Drosophila+connectome.">Automated in situ brain imaging for mapping the Drosophila connectome.</a> J Neurogenet. 29, 157-168 (2015).</li><li>Strausfeld, N. J., Sinakevitch, I., Vilinsky, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mushroom+bodies+of+Drosophila+melanogaster:+an+immunocytological+and+golgi+study+of+Kenyon+cell+organization+in+the+calyces+and+lobes.">The mushroom bodies of Drosophila melanogaster: an immunocytological and golgi study of Kenyon cell organization in the calyces and lobes.</a> Microsc Res Tech. 62, 151-169 (2003).</li><li>Bettencourt da Cruz, A., Wentzell, J., Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Swiss+Cheese,+a+protein+involved+in+progressive+neurodegeneration,+acts+as+a+noncanonical+regulatory+subunit+for+PKA-C3.">Swiss Cheese, a protein involved in progressive neurodegeneration, acts as a noncanonical regulatory subunit for PKA-C3.</a> J Neurosci. 28, 10885-10892 (2008).</li><li>Bolkan, B. J., Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loss+of+Tau+results+in+defects+in+photoreceptor+development+and+progressive+neuronal+degeneration+in+Drosophila.">Loss of Tau results in defects in photoreceptor development and progressive neuronal degeneration in Drosophila.</a> Dev Neurobiol. 74, 1210-1225 (2014).</li><li>Cook, M., Mani, P., Wentzell, J. S., Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+RhoA+prenylation+in+the+loechrig+(loe)+mutant+leads+to+progressive+neurodegeneration.">Increased RhoA prenylation in the loechrig (loe) mutant leads to progressive neurodegeneration.</a> PLoS One. 7, e44440 (2012).</li><li>Wittmann, C. W., 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=Tauopathy+in+Drosophila:+neurodegeneration+without+neurofibrillary+tangles.">Tauopathy in Drosophila: neurodegeneration without neurofibrillary tangles.</a> Science. 293, 711-714 (2001).</li><li>Rasmuson, B., Green, M. M., Ewertson, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=QUALITATIVE+AND+QUANTITATIVE+ANALYSES+OF+EYE+PIGMENTS+AND+PTERIDINES+IN+BACK-MUTATIONS+OF+THE+MUTANT+wa+IN+DROSOPHILA+MELANOGASTER.">QUALITATIVE AND QUANTITATIVE ANALYSES OF EYE PIGMENTS AND PTERIDINES IN BACK-MUTATIONS OF THE MUTANT wa IN DROSOPHILA MELANOGASTER.</a> Hereditas. 46, 635-650 (1960).</li><li>Bettencourt da Cruz, 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=Disruption+of+the+MAP1B-related+protein+FUTSCH+leads+to+changes+in+the+neuronal+cytoskeleton,+axonal+transport+defects,+and+progressive+neurodegeneration+in+Drosophila.">Disruption of the MAP1B-related protein FUTSCH leads to changes in the neuronal cytoskeleton, axonal transport defects, and progressive neurodegeneration in Drosophila.</a> Mol Biol Cell. 16, 2433-2442 (2005).</li><li>Kretzschmar, D., Hasan, G., Sharma, S., Heisenberg, M., 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=The+swiss+cheese+mutant+causes+glial+hyperwrapping+and+brain+degeneration+in+Drosophila.">The swiss cheese mutant causes glial hyperwrapping and brain degeneration in Drosophila.</a> J Neurosci. 17, 7425-7432 (1997).</li><li>Dutta, S., Rieche, F., Eckl, N., Duch, C., Kretzschmar, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glial+expression+of+Swiss+cheese+(SWS),+the+Drosophila+orthologue+of+neuropathy+target+esterase+(NTE),+is+required+for+neuronal+ensheathment+and+function.">Glial expression of Swiss cheese (SWS), the Drosophila orthologue of neuropathy target esterase (NTE), is required for neuronal ensheathment and function.</a> Dis Model Mech. 9, 283-294 (2016).</li><li>Davis, M. Y., 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=Glucocerebrosidase+Deficiency+in+Drosophila+Results+in+alpha-Synuclein-Independent+Protein+Aggregation+and+Neurodegeneration.">Glucocerebrosidase Deficiency in Drosophila Results in alpha-Synuclein-Independent Protein Aggregation and Neurodegeneration.</a> PLoS Genet. 12, e1005944 (2016).</li><li>Dias-Santagata, D., Fulga, T. A., Duttaroy, A., Feany, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+stress+mediates+tau-induced+neurodegeneration+in+Drosophila.">Oxidative stress mediates tau-induced neurodegeneration in Drosophila.</a> J Clin Invest. 117, 236-245 (2007).</li><li>Kretzschmar, 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=Glial+and+neuronal+expression+of+polyglutamine+proteins+induce+behavioral+changes+and+aggregate+formation+in+Drosophila.">Glial and neuronal expression of polyglutamine proteins induce behavioral changes and aggregate formation in Drosophila.</a> Glia. 49, 59-72 (2005).</li><li>Li, Y., 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+Drosophila+model+for+TDP-43+proteinopathy.">A Drosophila model for TDP-43 proteinopathy.</a> Proc Natl Acad Sci U S A. 107, 3169-3174 (2010).</li></ol>

Os autores não têm nada para revelar.

O método descrito fornece um meio para quantificar a neurodegeneração no cérebro de Drosophila. Enquanto que outros métodos, tais como contagem de um tipo celular específico, pode ser usado para identificar a neurodegeneração, a vantagem deste método é que ele pode ser aplicada de modo mais geral. Contar as células requer que estas células podem ser identificadas com fiabilidade utilizando quer um anticorpo específico ou a expressão de um marcador específico de células, a qual não está sempre ...

Com o aumento da expectativa de vida, doenças neurodegenerativas, como a doença de Alzheimer ou de Parkinson tornaram-se uma ameaça crescente de saúde para a população em geral. De acordo com os Institutos Nacionais de Saúde, 115 milhões de pessoas em todo o mundo estão previstos para ser afetada pela demência em 2050. Embora um progresso significativo tem sido feito na identificação de genes e fatores de risco envolvidos em pelo menos algumas dessas doenças, para muitos deles, o subjacente mecanismos moleculares ainda são desconhecidos ou não bem compreendida. Simples organismos modelo de invertebrados como Caenorhabditis elegans e Drosophila melanogaster oferecem uma variedade de vantagens experimentais para estudar os mecanismos de doenças neurodegenerativas, incluindo um ciclo de vida curta, grande número de descendentes, e da disponibilidade de métodos genéticos e moleculares bem estabelecidas e, por vezes únicas 1 -12. Além disso, estes organismos são passíveis de imparcialtelas de interação que podem identificar fatores que contribuem para estas doenças por seus efeitos agravantes ou melhorar em fenótipos neurodegenerativas. Analisar tais interações genéticas e avaliar os efeitos do envelhecimento requer protocolos quantitativos para detectar neurodegeneração e medir a sua gravidade. Esta avaliação pode ser feita de forma relativamente fácil quando se mede aspectos comportamentais em Drosophila, como a aprendizagem olfactiva, geotaxis negativos, ou fototaxia rápido, que fornecem um valor de desempenho numérico 13-21. É também possível determinar os efeitos sobre a sobrevivência neuronal contando os neurónios. No entanto, isso só é possível quando o foco em uma população específica que é claramente identificável, como os neurónios dopaminérgicos que são afectados na doença de Parkinson, e mesmo assim, os resultados têm sido controversos 22-24. O protocolo aqui descrito utiliza o método de colar para realizar cortes seriados de parafina, um métodoque foi originalmente desenvolvido por Heisenberg e Böhl, que o usou para isolar mutantes cerebrais anatômicas em Drosophila 25. A utilização do método de colar foi subsequentemente adaptado, incluindo em criocortes, vibratome secções, e secções de plástico 26-28. Aqui, este método é empregue para obter secções em série de toda a cabeça da mosca, que pode então ser utilizado para medir os vacúolos que se desenvolvem em moscas com fenótipos 16,21,29-32 neurodegenerativas. Estas medições podem ser feitas em regiões específicas do cérebro, ou pode cobrir todo o cérebro; esta última abordagem permite um para identificar os fenótipos fracos mesmo degenerativas, como observado durante o envelhecimento. Finalmente, quando se utiliza os colares, até 20 moscas pode ser processada como uma preparação, que não só é menos demorado, mas também permite a análise de controlo e as moscas experimentais na mesma preparação, minimizando artefactos devido a ligeiras alterações na a preparação.

<table><tbody><tr><td>Name of the Reagent/Equipment</td><td>Company</td><td>Catalog Number</td><td></td></tr><tr><td>Collar</td><td>Genesee Scientific</td><td>TS 48-100</td><td>We are using custom made collars that are made from one piece of metal instead of layers as the ones by Genesee. A description on how to make collars can be found at http://flybrain.neurobio.arizona.edu/Flybrain/html/atlas/fluorescent/index.html&amp;nbsp;</td></tr><tr><td>Rubber ice cube tray for embedding</td><td>Household store</td><td></td><td>The size can be made-to-fit by glueing in additional walls&amp;nbsp;</td></tr><tr><td>Crystallizing dish</td><td>Fisher Scientific company</td><td>08-762-3</td><td></td></tr><tr><td>Ether</td><td>Fisher Scientific Company</td><td>E138-1</td><td></td></tr><tr><td>Ethanol</td><td>Decon Laboratories Inc.</td><td>2701</td><td></td></tr><tr><td>Choloroform</td><td>Fisher Scientific Company</td><td>C298-500</td><td></td></tr><tr><td>Glacial Acetic Acid</td><td>Fisher Scientific Company</td><td>A38-212</td><td></td></tr><tr><td>Methylbenzoate</td><td>Fisher Scientific Company</td><td>M205-500</td><td>Distinct Odor - Use in fume hood!</td></tr><tr><td>Low Melting Point Paraffin Wax</td><td>Fisher Scientific Company</td><td>T565</td><td>Make sure to keep extra melted in a 65&amp;deg;C waterbath</td></tr><tr><td>Microtome</td><td>Leica Biosystems</td><td>Reichert Jung 2040 Autocut</td><td></td></tr><tr><td>Microscope Slide</td><td>Fisher Scientific Company</td><td>12-550D</td><td></td></tr><tr><td>Microscope Cover Glass</td><td>Fisher Scientific Company</td><td>12-545-M</td><td></td></tr><tr><td>SafeClear</td><td>Fisher Scientific Company</td><td>314-629</td><td>Three different containers for washes</td></tr><tr><td>Vertical Staining Jar with Cover</td><td>Ted Pella Inc.&amp;nbsp;</td><td>432-1</td><td></td></tr><tr><td>Permount</td><td>Fisher Scientific Company</td><td>SP15-500</td><td></td></tr><tr><td>Poly-L-Lysine Solution (PLL)</td><td>Sigma Life Science</td><td>P8290-500</td><td></td></tr></tbody></table>

mass histology to quantify neurodegeneration in drosophila

doenças neurodegenerativas progressivas como a doença de Alzheimer (AD) ou a doença de Parkinson (DP) é uma ameaça crescente para a saúde humana em todo o mundo. Embora os modelos de mamíferos forneceram importantes insights sobre os mecanismos subjacentes da patogenicidade, a complexidade dos sistemas de mamíferos, juntamente com seus altos custos estão limitando a sua utilização. Portanto, o simples, mas bem estabelecida modelo de sistema de Drosophila fornece uma alternativa para investigar as vias moleculares que são afetados nessas doenças. Além défices comportamentais, doenças neurodegenerativas são caracterizadas por fenótipos histológicos, tais como a morte neuronal e axonopatia. Para quantificar a degeneração neuronal e determinar como ela é afetada por fatores genéticos e ambientais, usamos uma abordagem histológica que é baseado na medição dos vacúolos no cérebro mosca adulta. Para minimizar os efeitos do erro sistemático e comparar diretamente as seções de controle e expmoscas erimental em uma preparação, usamos o método &quot;colar&quot; para cortes de parafina. A neurodegeneração é então avaliada medindo o tamanho e / ou o número de vacúolos que se desenvolveram no cérebro da mosca. Isto pode ser feito concentrando-se em uma região específica de interesse ou analisando todo o cérebro através da obtenção de cortes seriados que se estendem da cabeça completa. Por conseguinte, este método permite um para medir não só a degeneração severa mas também fenótipos relativamente suaves que só são detectáveis ​​em algumas secções, como ocorre durante o envelhecimento normal.

Usando os resultados do método descrito em cortes seriados corados pelo pigmento do olho 33, que abrangem toda a cabeça da mosca. Uma parte desta é mostrado na Figura 1B, em que as secções de uma cabeça individual são mostrados de cima para baixo. As secções de diferentes moscas são vistos esquerda para a direita neste exemplo. Para facilitar a orientação e a identificação das moscas, de uma mosca sem olhos (oculis seno) é inserido como...

Watch this Scientific Journal Video about Mass Histology to Quantify Neurodegeneration in Drosophila at JoVE.com

Mass Histology to Quantify Neurodegeneration in Drosophila

Drosophila é amplamente usado como um sistema modelo para estudar a neurodegeneração. Este protocolo descreve um método pelo qual a degeneração, como determinado pela formação de vacúolo no cérebro, podem ser quantificados. Ela também minimiza os efeitos devido ao procedimento experimental por meio de processamento e controlo de moscas e de seccionamento experimentais como uma amostra.

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 ...

mass-histology-to-quantify-neurodegeneration-in-drosophila

Research

JoVE Journal

Neuroscience

Mass Histology to Quantify Neurodegeneration in Drosophila

10.1K visualizações.  Oregon Health & Sciences University.  Drosophila é amplamente usado como um sistema modelo para estudar a neurodegeneração. Este protocolo descreve um método pelo qual a degeneração, como determinado pela formação de vacúolo no cérebro, podem ser quantificados. Ela também minimiza os efeitos devido ao procedimento experimental por meio de processamento e controlo de moscas e de seccionamento experimentais como uma amostra. 

Vídeo: Mass Histology to Quantify Neurodegeneration 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

In Vivo Forward Genetic Screen to Identify Novel Neuroprotective Genes in Drosophila melanogaster

There is much to understand about the onset and progression of neurodegenerative diseases, including the underlying genes responsible. Forward genetic screening using chemical mutagens is a useful strategy for mapping mutant phenotypes to genes among Drosophila and other model organisms that share conserved cellular pathways with humans. If the mutated gene of interest is not lethal in early developmental stages of flies, a climbing assay can be conducted to screen for phenotypic indicators of decreased brain functioning, such as low climbing rates. Subsequently, secondary histological analysis of brain tissue can be performed in order to verify the neuroprotective function of the gene by scoring neurodegeneration phenotypes. Gene mapping strategies include meiotic and deficiency mapping that rely on these same assays can be followed by DNA sequencing to identify possible nucleotide changes in the gene of interest.

In Vivo Forward Genetic Screen to Identify Novel Neuroprotective Genes in Drosophila melanogaster

We present a protocol using a forward genetic approach to screen for mutants exhibiting neurodegeneration in Drosophila melanogaster. It incorporates a climbing assay, histology analysis, gene mapping and DNA sequencing to ultimately identify novel genes related to the process of neuroprotection.

In vivo Forward genética Screen para identificar novos genes neuroprotetores em Drosophila melanogaster

There is much to understand about the onset and progression of neurodegenerative diseases, including the underlying genes responsible. Forward genetic ...

Genética

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 ...

A Simple Neuronal Mechanical Injury Methodology to Study Drosophila Motor Neuron Degeneration

The degeneration of neurons occurs during normal development and in response to injury, stress, and disease. The cellular hallmarks of neuronal degeneration are remarkably similar in humans and invertebrates as are the molecular mechanisms that drive these processes. The fruit fly, Drosophila melanogaster, provides a powerful yet simple genetic model organism to study the cellular complexities of neurodegenerative diseases. In fact, approximately 70% of disease-associated human genes have a Drosophila homolog and a plethora of tools and assays have been described using flies to study human neurodegenerative diseases. More specifically the neuromuscular junction (NMJ) in Drosophila has proven to be an effective system to study neuromuscular diseases because of the ability to analyze the structural connections between the neuron and the muscle. Here, we report on an in vivo motor neuron injury assay in Drosophila, which reproducibly induces neurodegeneration at the NMJ by 24 h. Using this methodology, we have described a temporal sequence of cellular events resulting in motor neuron degeneration. The injury method has diverse applications and has also been utilized to identify specific genes required for neurodegeneration and to dissect transcriptional responses to neuronal injury.

A Simple Neuronal Mechanical Injury Methodology to Study Drosophila Motor Neuron Degeneration

Here we describe a simple and widely accessible method to injure segmental nerves in Drosophila larvae to visualize and quantify neurodegeneration of motor neurons at the neuromuscular junction (NMJ) of third instar larvae.

Uma Metodologia de Lesão Mecânica Neuronal Simples para Estudar<em&gt; Drosophila</em&gt; Degeneração do Neurônio do Motor

The degeneration of neurons occurs during normal development and in response to injury, stress, and disease. The cellular hallmarks of neuronal ...

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal dysfunction and loss. Fluorescence-based imaging tools and technologies enable unprecedented analysis of subcellular neurobiological processes, yet there is still a need for unbiased, reproducible, and accessible approaches for extracting quantifiable data from imaging studies. We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-based imaging studies using Drosophila models of neurodegeneration. Specifically, we describe an easy-to-follow, semi-automated approach using Fiji/ImageJ to analyze two cellular processes: first, we quantify protein aggregate content and profile in the Drosophila optic lobe using fluorescent-tagged mutant huntingtin proteins; and second, we assess autophagy-lysosome flux in the Drosophila visual system with ratiometric-based quantification of a tandem fluorescent reporter of autophagy. Importantly, the protocol outlined here includes a semi-automated segmentation step to ensure all fluorescent structures are analyzed to minimize selection bias and to increase resolution of subtle comparisons. This approach can be extended for the analysis of other cell biological structures and processes implicated in neurodegeneration, such as proteinaceous puncta (stress granules and synaptic complexes), as well as membrane-bound compartments (mitochondria and membrane trafficking vesicles). This method provides a standardized, yet adaptable reference point for image analysis and quantification, and could facilitate reliability and reproducibility across the field, and ultimately enhance mechanistic understanding of neurodegeneration.

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

We have developed a simple and adaptable workflow to extract quantitative data from fluorescence-imaging-based cell biological studies of protein aggregation and autophagic flux in the central nervous system of Drosophila models of neurodegeneration.

Biologia celular quantitativa de neurodegeneração em Drosophila , através de uma análise imparcial das proteínas fluorescente etiquetadas usando o ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal ...

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 ...

Visualizing Synaptic Degeneration in Adult Drosophila in Association with Neurodegeneration

Drosophila serves as a useful model for assessing synaptic structure and function associated with neurodegenerative diseases. While much work has focused on neuromuscular junctions (NMJs) in Drosophila larvae, assessing synaptic integrity in adult Drosophila has received much less attention. Here we provide a straightforward method for dissection of the dorsal longitudinal muscles (DLMs), which are required for flight ability. In addition to flight as a behavioral readout, this dissection allows for the both DLM synapses and muscle tissue to be amenable to structural analysis using fluorescently labeled antibodies for synaptic markers or proteins of interest. This protocol allows for the evaluation of the structural integrity of synapses in adult Drosophila during aging to model the progressive, age-dependent nature of most neurodegenerative diseases.

Visualizing Synaptic Degeneration in Adult Drosophila in Association with Neurodegeneration

The goal of this procedure is to dissect the dorsal longitudinal muscle (DLM) tissue to assess the structural integrity of DLM neuromuscular junctions (NMJs) in neurodegenerative disease models using Drosophila melanogaster.

Visualização da Degeneração Sináptica em Drosophila Adulta em Associação com Neurodegeneração

Drosophila serves as a useful model for assessing synaptic structure and function associated with neurodegenerative diseases. While much work has focused ...

Direct Cryosectioning of Drosophila Heads for Enhanced Brain Fluorescence Staining and Immunostaining

Immunostaining Drosophila melanogaster brains is essential for exploring the mechanisms behind complex behaviors, neural circuits, and protein expression patterns. Traditional methods often involve challenges such as performing complex dissection, maintaining tissue integrity, and visualizing specific expression patterns during high-resolution imaging. We present an optimized protocol that combines cryosectioning with fluorescence staining and immunostaining. This method improves tissue preservation and signal clarity and reduces the need for laborious dissection for Drosophila brain imaging. The method entails rapid dissection, optimal fixation, cryoprotection, and cryosectioning, followed by fluorescent staining and immunostaining. The protocol significantly reduces tissue damage, enhances antibody penetration, and yields sharp, well-defined images. We demonstrate the effectiveness of this approach by visualizing specific neural populations and synaptic proteins with high fidelity. This versatile method allows for the analysis of various protein markers in the adult brain across multiple z-planes and can be adapted for other tissues and model organisms. The protocol provides a reliable and efficient tool for researchers conducting high-quality immunohistochemistry in Drosophila neurobiology studies. This method's detailed visualization facilitates comprehensive analysis of neuroanatomy, pathology, and protein localization, making it particularly valuable for neuroscience research.

This study presents a simplified protocol for tissue processing involving decapitation, fixation, cryosectioning, fluorescence staining, immunostaining, and imaging, which can be extended to confocal and multiphoton imaging. The method maintains efficacy comparable to complex dissections, bypassing the need for advanced motor skills. Quantitative image analysis provides extensive investigative potential.

Crioseccionamento direto de cabeças de Drosophila para coloração e imunocoloração aprimoradas de fluorescência cerebral

Immunostaining Drosophila melanogaster brains is essential for exploring the mechanisms behind complex behaviors, neural circuits, and protein expression ...

Assessing the Structural Integrity of the Dorsal Longitudinal Muscle Neuromuscular Junctions in Drosophila

Source: Sidisky, J. M., et al. <a href="https://app.jove.com/v/61363">Visualizing Synaptic Degeneration in Adult Drosophila in Association with Neurodegeneration.</a> J. Vis. Exp. (2020).
This video demonstrates a protocol for assessing the structural integrity of neuromuscular junctions in the dorsal longitudinal muscles of Drosophila. The procedure involves staining neurons and muscles with two distinct antibodies and comparing fluorescence patterns between mutant and wild-type flies. A reduction in neuronal staining in mutant flies indicates neurodegeneration, while the muscle structure remains intact.

Avaliação da integridade estrutural das junções neuromusculares do músculo longitudinal dorsal em Drosophila

1. Flash freezing and thorax bisection

	Before beginning the bisections, fill a Dewar flask with liquid nitrogen wearing proper cryo-protective gloves ...

Mass Histologia para quantificar neurodegeneração em

Resumo

Explore mais vídeos

Capítulos neste vídeo