This work is supported by a Canadian Health Research Institute (CIHR) Team Grant to Dr. Bolduc (co-PI) and Dr. Guy Rouleau (PI). We would like to thank Dr. Oksana Suchowersky, Dr. Kathryn Todd, the members of the University of Alberta fly club and Dr. Clayton Dickson for help in development of the method and statistical analysis.

La ricerca sulle Drosophila melanogaster era conforme con l&#39;Università di linee di ricerca di Alberta. 1. Fly Collection <ol><li> Raccogliere 20 mosche con CO 2 (g), anestesia e posto in una fiala di raccolta 25 millimetri x 95 millimetri contenente cibo. </li><li> Fiale magazzini contenenti mosche orizzontalmente per evitare di intrappolare le mosche in liquidi che possono accumularsi sul fondo della fiala. </li><li> Incubare mosche per almeno 21 ore a 22 ° C a 45% di umidità in un incubatore per circa per 15 h. Impostare l&#39;incubatore con una luce 12 ore: ciclo scuro. </li></ol> 2. Arrampicata Assay <ol><li> La mattina seguente, il trasferimento di 20 mosche da una singola fiala in un bicchiere da 250 ml cilindro graduato. Segnare la posizione del cilindro per mantenere costante quotidiana. Utilizzare un cilindro di vetro per il genotipo per evitare la contaminazione incrociata tra i genotipi. Lavarsi alla fine di ogni esperimento e roli tate tra genotipi. <ol><li> Condurre gli esperimenti in luce ambiente (o la luce rossa se esiste un potenziale difetto visivo) rispettivamente a temperatura e umidità di 22 ° C e 40%. Per evitare di confondere circadiano ritmo, sempre esperimenti alla stessa ora del giorno. </li></ol></li><li> Chiudere la parte superiore del cilindro con un film barriera (strato di cera) per evitare fuoriuscite di linea (Figura 2). </li><li> Impostare la videocamera su un treppiede. Fotocamera Focus sulla linea di 190 ml dei 250 ml cilindro graduato (17.5 cm). </li><li> Contare il numero di mosche morte sul fondo del cilindro e nelle fiale alimentari. Registrare questo numero come la mortalità. </li><li> Molto battere leggermente il cilindro contro un tappetino in gomma a cellule chiuse ripetutamente con forza sufficiente a spostare le mosche per la superficie inferiore interna. Toccare 5-10 volte, mentre con l&#39;altra mano per premere registrare sulla fotocamera. </li><li> Premere il pulsante &quot;Record&quot; sulla fotocamera. </li><li> Avviare il video registrazione della videocamera e toccare il cilindro sei volte in un modello non ritmico distinti. </li><li> Condurre ogni prova per 2 minuti dal momento in cui le mosche sono ultimo sfruttato e registrare il numero di mosche che attraversano l&#39;altezza di 17,5 cm (190 ml) per ogni punto temporale prescelto (quantificare ogni 10 sec). Nota: La marcatura sul cilindro ml varierà da un cilindro modello all&#39;altro a seconda del diametro. Per evitare errori, misurare l&#39;altezza di ogni cilindro utilizzato. </li><li> Una volta che il processo è terminato, disporre di mosche in etanolo al 95%. </li><li> Ripetere i passaggi 2,1-2,9 fino a quando tutte le repliche sono stati testati con mosche freschi ogni volta. Nota: Anche se 5 repliche possono essere sufficiente con una mutazione che ha un forte effetto sulla locomozione, 10 replicati biologici di 20 mosche (200 mosche) si consiglia di rilevare le differenze più piccole. </li><li> Al termine dell&#39;esperimento, lavare i cilindri in lavastoviglie laboratorio e O secco / N per essere riutilizzato. </li></ol> 3. Analisi <ol><li> Analyvideo ze di ogni volano prova. Ogni 10 secondi, registrare il numero totale di mosche che passano la linea di tiro. <ol><li> Se una mosca si arrampica indietro o scende, record che volano come -1 e contare il prossimo volo per attraversare la linea di destinazione come lo stesso numero del volo che è risalito verso il basso o è caduto. Ad esempio, se il 15 fly scende al di sotto della linea di tiro, il prossimo volo per attraversare la linea (16 th volano) è considerato il 15 ° volo e non 16 °. </li></ol></li><li> Sottrarre mortalità dal numero totale di linea (20) per ottenere il numero di mosche che rimangono nel processo. Ad ogni punto di tempo, ottenere la frazione di mosche sopra la linea di destinazione. </li><li> Tracciare ogni percentuale in ogni momento (vedi figura 3). </li><li> Analizzare le prestazioni al punto dati 120 secondi ed eseguire studente t-test quando sono presenti 2 gruppi o ANOVA e post-test per confronti multipli (con modifica Bonferroni per pianificati e non pianificati Tukey per comparisons). Il Kolmogorov-Smirnov test 17 ​​viene eseguita per l&#39;accertamento normalità e varianza uguale ma anche per confrontare le distribuzioni del gruppo mutante al controllo. </li><li> Per presentare i dati su invecchiamento, tracciare la percentuale di mosche arrampicata a 120 secondi con le mosche di età diverse (2 giorni, 1 settimana, 2 settimane) per vedere se c&#39;è un deficit progressivo (Figura 4). </li></ol>

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The authors have nothing to disclose.

Drosophila ha già dimostrato di essere un ottimo modello di malattia 14 e altre malattie neurodegenerative 1,2 di Parkinson. Oltre agli strumenti genetici disponibili in Drosophila, suo genoma è altamente conservata per geni coinvolti nei disordini neurologici 19. L&#39;avvento di ampi metodi di screening genetico genoma (compresi sequenziamento dell&#39;intero esoma) è probabile che continuerà a fornire una più grande lista di geni candidati associati con disturbi...

Malattie neurodegenerative devastanti come il morbo di Parkinson, la sclerosi laterale amiotrofica, e paraplegia spastica ereditaria sono sempre più riconosciuti. Sfortunatamente, la maggior parte di questi disturbi neurodegenerativi sono ancora senza trattamenti. L&#39;uso clinico diffuso di test genetici, imparziali genoma come il sequenziamento dell&#39;esoma ha portato ad un numero sempre maggiore di geni di essere coinvolto in disturbi locomotiva umani. Nonostante questi progressi, la progressione patologica dalla mattina presto alla fase avanzata, rimane inafferrabile in questi disturbi. Drosophila fornisce uno con gli strumenti genetici per lo studio requisito gene in modo spaziale e temporale controllato. Inoltre, Drosophila è dimostrato utile nello screening farmaci per malattie neurologiche come il Parkinson 1, il morbo di Alzheimer 2, ritardo mentale ed epilessia 3,4 5,6 tra gli altri. Il nostro obiettivo era quello di sviluppare un costo effettivoe il dosaggio affidabile che permetta di alta analisi rendimento che sarebbe ancora abbastanza sensibile per rilevare piccole variazioni nelle prestazioni del motore. Ci sono diversi test utilizzati per quantificare gli effetti di mutazione genetica e / o le condizioni ambientali sul comportamento arrampicata Drosophila. La maggior parte dei saggi capitalizzare la naturale tendenza di mosche da scalare, noti come geotassi negativi, o il saggio arrampicata. Benzer 7 suggerito nel 1967 che l&#39;apparato controcorrente utilizzato per lo studio di fototassi potrebbe anche essere usato per studiare gravitaxis. Da allora, Ganetsky 8 e molti altri 9 -12 hanno costruito sul dosaggio iniziale. Il principio è quello di mettere un numero noto di mosche in una fiala e toccare la fiala fortemente contro una superficie dura, causando linea a cadere sul fondo della fiala. Dato che è un comportamento innato, linea tenteranno di salire fino alla cima del flaconcino, al contrario di gravità. Questo test è quantitativa e measures quanti mosche sono saliti oltre un marcatore sul flacone nel corso di un periodo di tempo assegnato. Misurazione della velocità invece del numero totale di mosche arrampicata è diventata un parametro affidabile e mostrato difetti nei casi in cui il numero dei criteri mosche non era significativo 13. Il dosaggio arrampicata è dimostrata utile nello studio di molte malattie neurodegenerative come il morbo di Parkinson 14. Tuttavia, abbiamo notato che i difetti locomotiva non deve essere rilevabile al momento in cui la neurodegenerazione è già visto in studi patologici 14. Pertanto, l&#39;uso del test tradizionale può limitare la capacità di studiare le prime fasi della patogenesi della malattia. La comparsa di difetti locomotiva durante le fasi successive di patologia può riflettere una malattia la cui progressione è troppo avanzato per la completa salvataggio. Ciò solleva un potenziale problema con la sensibilità del tradizionale test arrampicata. Il potenziale incapacità del tradizionale arrampicata test di rilevare difetti locomotiva lievi può essere attribuito alla quota alla quale linea devono salire. Le tradizionali misure assay 15,16 il numero di mosche a salire con successo su un&#39;altezza di 2 a 5 cm di 10 a 20 sec.

<table><tbody><tr><td>Drosophila stocks</td><td></td><td></td><td>The stocks are selected depending on the experiments. The temperature and humidity in the room and in the incubator must be controled and consistent to avoid flies being too staticky or too wet.</td></tr><tr><td>Video camera</td><td></td><td></td><td>Any digital camcorder will do. Make sure they can focus on close object.</td></tr><tr><td>Graduated cylinder</td><td>Kimble</td><td>20028W</td><td>Different models of graduated cylinder may have different diameter. It is therefore imporant to measure the height.</td></tr><tr><td>Computer</td><td></td><td></td><td>Any model will do. We used the computer to monitor the climbing of the flies and record the number of flies at each time point.</td></tr></tbody></table>

quantitative analysis of climbing defects in a drosophila model of neurodegenerative disorders

Difetti Locomotive derivanti da malattie neurodegenerative possono essere un sintomo di esordio tardivo della malattia, dopo anni di degenerazione subclinica, e quindi attuali strategie di trattamento terapeutico non sono curativi. Attraverso l&#39;uso di sequenziamento exome, un numero crescente di geni sono stati identificati per giocare un ruolo nella locomozione umana. Nonostante l&#39;identificazione di questi geni, non è noto come questi geni sono essenziali al funzionamento normale locomotiva. Pertanto, un test affidabile, che utilizza organismi modello per chiarire il ruolo di questi geni per identificare nuovi bersagli di interesse terapeutico, è necessaria più che mai. Abbiamo progettato una versione sensibilizzata del test geotassi negativi che consente il rilevamento di difetti lievi anteriore e ha la capacità di valutare questi difetti nel tempo. Il saggio viene eseguito in un cilindro graduato in vetro, che è sigillato con un film barriera di cera. Aumentando la distanza limite ad essere scalata a 17,5 cm ed aumentando la durata dell&#39;esperimento per 2 min abbiamo osservato una maggiore sensibilità nella rilevazione disfunzioni mobilità lievi. Il test è conveniente e non richiede una formazione completa per ottenere risultati altamente riproducibili. Questo lo rende una tecnica eccellente per lo screening candidati farmaci in mutanti di Drosophila con difetti di locomozione.

L&#39;arrampicata è un comportamento forte e riproducibile. Infatti, un giorno di vita in linea wild-type di raggiungere le prestazioni arrampicata distanza del bersaglio in rapido (25 - 30 sec). Mosche mutanti presentano una serie di prestazioni da lieve (o ritardato) per completare l&#39;incapacità di salire al bersaglio. Illustriamo questo qui con due diversi alleli mutanti. Il primo è una grave allele del gene spastin causata da una delezione completa del gene spastin (terme 5,75) 18. In questa linea (...

Watch this Scientific Journal Video about Quantitative Analysis of Climbing Defects in a Drosophila Model of Neurodegenerative Disorders at JoVE.com

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

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.

Analisi quantitativa dei difetti arrampicata in un modello Drosophila di malattie neurodegenerative

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

quantitative-analysis-climbing-defects-drosophila-model

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

18.5K Views.  University of Alberta. 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. 

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

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.

Deficit Locomotore dosaggio, apprendimento e memoria in Drosophila Modelli di neurodegenerazione

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

Ricerca

Neuroscienze

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 Avanti Schermo Genetico per Identificare Nuovi Geni Neuroprotettivi in Drosophila melanogaster

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

Genetica

An Automated Rapid Iterative Negative Geotaxis Assay for Analyzing Adult Climbing Behavior in a Drosophila Model of Neurodegeneration

Neurodegenerative diseases are frequently associated with a progressive loss of movement ability, reduced life span, and age-dependent neurodegeneration. To understand the mechanism of these cellular events, and their causal relationships with each other, Drosophila melanogaster, with its sophisticated genetic tools and diverse behavioral features, are used as disease models for assessing neurodegenerative phenotypes. Here we describe a high-throughput method to analyze Drosophila adult negative geotaxis behavior, as an indication for possible motor defects associated with neurodegeneration. An automated machine is designed and developed to drive fly synchronization using an initial electric impulse, later allowing the recording of negative geotaxis behavior over a course of secs to mins. Images from the digitally recorded video are then processed with the self-designed RflyDetection software for statistical data manipulation. Different from the manually controlled negative geotaxis assay based on single fly, this precise, fast, and high-throughput protocol allows data acquisition from more than hundreds of flies simultaneously, providing an efficient approach to advance our understanding in the underlying mechanism of locomotor deficits associated with neurodegeneration.

An Automated Rapid Iterative Negative Geotaxis Assay for Analyzing Adult Climbing Behavior in a Drosophila Model of Neurodegeneration

This step-by-step protocol analyzes Drosophila negative geotaxis behavior using an automated multi-cylinder system that hosts hundreds of flies and synchronizes their action by an electric motor. Upon synchronization, fly negative geotaxis behavior is assayed, digitally recorded, and analyzed using the self-designed RflyDetection software.

Un dosaggio di geotassi negativa iterativo rapido automatizzato per l'analisi del comportamento adulto arrampicata in un modello di Drosophila di neurodegenerazione

Neurodegenerative diseases are frequently associated with a progressive loss of movement ability, reduced life span, and age-dependent neurodegeneration. ...

Comportamento

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.

Valutare fenotipi neurodegenerative<em&gt; Drosophila</em&gt; Neuroni dopaminergici mediante saggi arrampicata e 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 ...

A Simple Technique to Assay Locomotor Activity in Drosophila

Drosophila melanogaster is an ideal model organism for studying various diseases due to its abundance of advanced genetic manipulation techniques and diverse behavioral features. Identifying behavioral deficiency in animal models is a crucial measure of disease severity, for example, in neurodegenerative diseases where patients often experience impairments in motor function. However, with the availability of various systems to track and assess motor deficits in fly models, such as drug-treated or transgenic individuals, an economical and user-friendly system for precise evaluation from multiple angles is still lacking. A method based on the AnimalTracker application programming interface (API) is developed here, which is compatible with the Fiji image processing program, to systematically evaluate the movement activities of both adult and larval individuals from recorded video, thus allowing for the analysis of their tracking behavior. This method requires only a high-definition camera and a computer peripheral hardware integration to record and analyze behavior, making it an affordable and effective approach for screening fly models with transgenic or environmental behavioral deficiencies. Examples of behavioral tests using pharmacologically treated flies are given to show how the techniques can detect behavioral changes in both adult flies and larvae in a highly repeatable manner.

A Simple Technique to Assay Locomotor Activity in Drosophila

The present protocol assesses the locomotor activity of Drosophila by tracking and analyzing the movement of flies in a hand-made arena using open-source software Fiji, compatible with plugins to segment pixels of each frame based on high-definition video recording to calculate parameters of speed, distance, etc.

Una semplice tecnica per analizzare l'attività locomotoria nella Drosophila

Drosophila melanogaster is an ideal model organism for studying various diseases due to its abundance of advanced genetic manipulation techniques and ...

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.

Perché Quantificazione Matters: Caratterizzazione dei fenotipi al<em&gt; Drosophila</em&gt; Larvale Giunzione neuromuscolare

Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic ...

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.

Messa Istologia per quantificare neurodegenerazione in<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 ...

Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila

Dendrites are the branched projections of a neuron, and dendritic morphology reflects synaptic organization during the development of the nervous system. Drosophila larval neuronal dendritic arborization (da) is an ideal model for studying morphogenesis of neural dendrites and gene function in the development of nervous system. There are four classes of da neurons. Class IV is the most complex with a branching pattern that covers almost the entire area of the larval body wall. We have previously characterized the effect of silencing the Drosophila ortholog of SOX5 on class IV neuronal dendritic arborization complexity (NDAC) using four parameters: the length of dendrites, the surface area of dendrite coverage, the total number of branches, and the branching structure. This protocol presents the workflow of NDAC quantitative analysis, consisting of larval dissection, confocal microscopy, and image analysis procedures using ImageJ software. Further insight into da neuronal development and its underlying mechanisms will improve the understanding of neuronal function and provide clues about the fundamental causes of neurological and neurodevelopmental disorders.

Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila

This protocol focuses on quantitative analysis of neuronal dendritic arborization complexity (NDAC) in Drosophila, which can be used for studies of dendritic morphogenesis.

Analisi quantitativa di un neurone Arborization dentritico complessità in Drosophila

Dendrites are the branched projections of a neuron, and dendritic morphology reflects synaptic organization during the development of the nervous system. ...

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 cellulare quantitativa della neurodegenerazione in Drosophila attraverso analisi imparziale delle proteine fluorescente contrassegnate usando ImageJ

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

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.

Visualizzazione della degenerazione sinaptica nella Drosophila adulta in associazione con la neurodegenerazione

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

Analisi quantitativa dei difetti arrampicata in un modello Drosophila di malattie neurodegenerative

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