We would like to thank William A. Eimer for imaging technical assistance. This work was supported by the Cure Alzheimer's Fund [to R.E.T], the National Institute of Health [R01AG014713 and R01MH60009 to R.E.T; R03AR063271 and R15EB019704 to A.L.], and the National Science Foundation [NSF1455613 to A.L.].

1. Experimental Preparation
<ol>
	<li>Prepare the following reagents: Dulbecco&#39;s phosphate buffered saline (PBS); Triton X-100; 0.2% PBST (PBS + 0.2% Triton X-100); 32% paraformaldehyde (PFA), diluted into 4% before use; silicone elastomer base and curing agent; antifade mounting medium (e.g., ProLong Gold); and fingernail polish.</li>
	<li>Prepare the following equipment: dissection microscope, two sharp forceps and a pair of scissors for microdissection, a number of pins for microdissection, a Petri dish...

<ol>
	<li>Wassle, H., Boycott, B. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+architecture+of+the+mammalian+retina.">Functional architecture of the mammalian retina.</a> Physiol Rev. 71 (2), 447-480 (1991).</li><li>MacNeil, M. A., Masland, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extreme+diversity+among+amacrine+cells:+implications+for+function.">Extreme diversity among amacrine cells: implications for function.</a> Neuron. 20 (5), 971-982 (1998).</li><li>Losonczy, A., Makara, J. K., Magee, J. 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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt+signaling+through+Dishevelled,+Rac+and+JNK+regulates+dendritic+development.">Wnt signaling through Dishevelled, Rac and JNK regulates dendritic development.</a> Nat Neurosci. 8 (1), 34-42 (2005).</li><li>Grueber, W. B., Jan, L. Y., Jan, Y. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Different+levels+of+the+homeodomain+protein+cut+regulate+distinct+dendrite+branching+patterns+of+Drosophila+multidendritic+neurons.">Different levels of the homeodomain protein cut regulate distinct dendrite branching patterns of Drosophila multidendritic neurons.</a> Cell. 112 (6), 805-818 (2003).</li><li>Sugimura, K., Satoh, D., Estes, P., Crews, S., Uemura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+morphological+diversity+of+dendrites+in+Drosophila+by+the+BTB-zinc+finger+protein+abrupt.">Development of morphological diversity of dendrites in Drosophila by the BTB-zinc finger protein abrupt.</a> Neuron. 43 (6), 809-822 (2004).</li><li>Jan, Y. N., Jan, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Branching+out:+mechanisms+of+dendritic+arborization.">Branching out: mechanisms of dendritic arborization.</a> Nat Rev Neurosci. 11 (5), 316-328 (2010).</li><li>Sears, J. C., Broihier, H. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=FoxO+regulates+microtubule+dynamics+and+polarity+to+promote+dendrite+branching+in+Drosophila+sensory+neurons.">FoxO regulates microtubule dynamics and polarity to promote dendrite branching in Drosophila sensory neurons.</a> Dev Biol. 418 (1), 40-54 (2016).</li><li>Li, 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=Silencing+of+the+Drosophila+ortholog+of+SOX5+leads+to+abnormal+neuronal+development+and+behavioral+impairment.">Silencing of the Drosophila ortholog of SOX5 leads to abnormal neuronal development and behavioral impairment.</a> Hum Mol Genet. 26 (8), 1472-1482 (2017).</li><li>Misra, 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=A+Genome-Wide+Screen+for+Dendritically+Localized+RNAs+Identifies+Genes+Required+for+Dendrite+Morphogenesis.">A Genome-Wide Screen for Dendritically Localized RNAs Identifies Genes Required for Dendrite Morphogenesis.</a> G3 (Bethesda). 6 (8), 2397-2405 (2016).</li><li>Emoto, 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=Control+of+dendritic+branching+and+tiling+by+the+Tricornered-kinase/Furry+signaling+pathway+in+Drosophila+sensory+neurons.">Control of dendritic branching and tiling by the Tricornered-kinase/Furry signaling pathway in Drosophila sensory neurons.</a> Cell. 119 (2), 245-256 (2004).</li><li>Olesnicky, E. C., 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=Extensive+use+of+RNA-binding+proteins+in+Drosophila+sensory+neuron+dendrite+morphogenesis.">Extensive use of RNA-binding proteins in Drosophila sensory neuron dendrite morphogenesis.</a> G3 (Bethesda). 4 (2), 297-306 (2014).</li><li>Parrish, J. Z., Xu, P., Kim, C. C., Jan, L. Y., Jan, Y. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+microRNA+bantam+functions+in+epithelial+cells+to+regulate+scaling+growth+of+dendrite+arbors+in+drosophila+sensory+neurons.">The microRNA bantam functions in epithelial cells to regulate scaling growth of dendrite arbors in drosophila sensory neurons.</a> Neuron. 63 (6), 788-802 (2009).</li><li>Schindelin, 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=Fiji:+an+open-source+platform+for+biological-image+analysis.">Fiji: an open-source platform for biological-image analysis.</a> Nat Methods. 9 (7), 676-682 (2012).</li><li>Corty, M. M., Matthews, B. J., Grueber, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecules+and+mechanisms+of+dendrite+development+in+Drosophila.">Molecules and mechanisms of dendrite development in Drosophila.</a> Development. 136 (7), 1049-1061 (2009).</li><li>Jinushi-Nakao, S., 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=Knot/Collier+and+cut+control+different+aspects+of+dendrite+cytoskeleton+and+synergize+to+define+final+arbor+shape.">Knot/Collier and cut control different aspects of dendrite cytoskeleton and synergize to define final arbor shape.</a> Neuron. 56 (6), 963-978 (2007).</li><li>Crozatier, M., Vincent, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+multidendritic+neuron+differentiation+in+Drosophila:+the+role+of+Collier.">Control of multidendritic neuron differentiation in Drosophila: the role of Collier.</a> Dev Biol. 315 (1), 232-242 (2008).</li><li>Copf, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Importance+of+gene+dosage+in+controlling+dendritic+arbor+formation+during+development.">Importance of gene dosage in controlling dendritic arbor formation during development.</a> Eur J Neurosci. 42 (6), 2234-2249 (2015).</li><li>Rosso, S. B., Inestrosa, N. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=WNT+signaling+in+neuronal+maturation+and+synaptogenesis.">WNT signaling in neuronal maturation and synaptogenesis.</a> Front Cell Neurosci. 7, 103 (2013).</li><li>Engel, T., Hernandez, F., Avila, J., Lucas, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Full+reversal+of+Alzheimer's+disease-like+phenotype+in+a+mouse+model+with+conditional+overexpression+of+glycogen+synthase+kinase-3.">Full reversal of Alzheimer's disease-like phenotype in a mouse model with conditional overexpression of glycogen synthase kinase-3.</a> J Neurosci. 26 (19), 5083-5090 (2006).</li><li>Longair, M. H., Baker, D. A., Armstrong, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simple+Neurite+Tracer:+open+source+software+for+reconstruction,+visualization+and+analysis+of+neuronal+processes.">Simple Neurite Tracer: open source software for reconstruction, visualization and analysis of neuronal processes.</a> Bioinformatics. 27 (17), 2453-2454 (2011).</li><li>Pool, M., Thiemann, J., Bar-Or, A., Fournier, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NeuriteTracer:+a+novel+ImageJ+plugin+for+automated+quantification+of+neurite+outgrowth.">NeuriteTracer: a novel ImageJ plugin for automated quantification of neurite outgrowth.</a> J Neurosci Methods. 168 (1), 134-139 (2008).</li></ol>

Dendrites that innervate the epidermis are the input regions of neurons, and their morphologies determine how information is received and processed by individual neurons. Development dendrite morphology reflects gene modulation of dendrite organization. The Drosophila larval da neuron of the peripheral nervous system is an important model for studying dendrite development because of: 1) the functional similarity with mammals11,12; 2) four class distincti...

Dendrites, which are the branched projections of a neuron, cover the field that encompasses the neuron&#39;s sensory and synaptic inputs from other neurons1,2. Dendrites are an important component of synapse formation and play a critical role in integrating synaptic inputs, as well as propagating the electrochemical stimulation in a neuron. Dendritic arborization (da) is a process by which neurons form new dendritic trees and branches to create new synapses. The development and morphology of da, such as branch density and grouping patterns, result from multi-step biological processes and are highly correlated to neuronal function. The goal of this protocol is to provide a method for quantitative analysis of neuronal dendritric arborization complexity in Drosophila. 
The complexity of dendrites determines the synaptic types, connectivity, and inputs from partner neurons. Branching patterns and the density of dendrites are involved in processing the signals that converge onto the dendritic field3,4. Dendrites have the flexibility for adjustment in development. For instance, synaptic signaling has an effect on dendrite organization in the somatosensory neuron during the developmental phase and in the mature nervous system5. The establishment of neuronal connectivity relies on the morphogenesis and maturation of dendrites. Malformation of dendrites is associated with impaired neuronal function. Studies have shown that the abnormality of da neuron morphogenesis might contribute to the etiologies of multiple neurodegenerative diseases, including Alzheimer&#39;s disease (AD), Parkinson&#39;s disease (PD), Huntington&#39;s disease (HD), and Lou Gehrig&#39;s disease/Amyotrophic lateral sclerosis (ALS)6,7,8. Synaptic alterations appear in the early stage of AD, in concert with the decline and impairment of neuron function7,8. However, the specifics of how dendrite pathology contributes to pathogenesis in these neurodegenerative diseases remains elusive.
The development of dendrites is regulated by genes that encode a complex network of regulators, such as the Wnt family of proteins9,10, transcription factors, and ligands on cell surface receptors11,12. Drosophila da neurons consist of four classes (Class I, II III, IV), of which class IV da neurons have the most complex branching patterns and have been employed as a powerful experimental system for better understanding morphogenesis13,14. During early morphogenesis, overexpression and/or RNAi silencing of genes in class IV da neurons result in changes in branching patterns and dendrite pruning13. It is important to develop a practical method for quantitative analysis of the neuronal dendritic arborization.
We have previously shown that silencing of the Drosophila ortholog of SOX5, Sox102F, led to shorter dendrites of da neurons and reduced complexity in class IV da neurons15. Here, we present the procedure of quantitative analysis for the neuronal dendritic arborization complexity (NDAC) in Drosophila. This protocol, adapted from the previous described methodology, provides a brief method to assay the development of da sensory neurons. It illustrates the robust image labeling and the da neuron in the third instar larval body wall16,17,18,19. It is a valuable protocol for researchers who wish to investigate the NDAC and developmental differences in vivo.

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	<tbody>
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			<td height="21" style="height:21px;width:363px;">Phosphate buffered saline(PBS)</td>
			<td style="width:223px;">Gibco Life Sciences</td>
			<td style="width:197px;">10010-023</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:363px;">TritonX-100</td>
			<td style="width:223px;">Fisher Scientific</td>
			<td style="width:197px;">9002-93-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:22px;width:363px;">Paraformaldehyde(PFA)</td>
			<td style="width:223px;">Electron Microscopy Sciences</td>
			<td style="width:197px;">15714-S</td>
			<td></td>
		</tr>
		<tr height="28">
			<td height="28" style="height:29px;width:363px;">Sylgard 184 silicone elastomer base and curing agent</td>
			<td style="width:223px;">Dow Corning Corportation</td>
			<td style="width:197px;">3097366-0516;3097358-1004</td>
			<td></td>
		</tr>
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			<td height="24" style="height:25px;width:363px;">ProLong Gold Antifade Mountant</td>
			<td style="width:223px;">Thermo Fisher Scientific</td>
			<td style="width:197px;">P36931</td>
			<td></td>
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			<td height="21" style="height:21px;width:363px;">Fingernail polish&#160;</td>
			<td style="width:223px;">CVS</td>
			<td style="width:197px;">72180</td>
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			<td height="21" style="height:21px;width:363px;">Stereo microscope</td>
			<td style="width:223px;">Nikon</td>
			<td style="width:197px;">SMZ800</td>
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			<td height="21" style="height:21px;width:363px;">Confocal microscope</td>
			<td style="width:223px;">Nikon</td>
			<td style="width:197px;">Eclipse Ti-E</td>
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			<td height="21" style="height:21px;width:363px;">Petri dish</td>
			<td style="width:223px;">Falcon</td>
			<td style="width:197px;">353001</td>
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			<td height="21" style="height:21px;width:363px;">Forceps</td>
			<td style="width:223px;">Dumont</td>
			<td style="width:197px;">11255-20</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:363px;">Scissors&#160;</td>
			<td style="width:223px;">Roboz Surgical Instrument Co</td>
			<td style="width:197px;">RS-5611</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:363px;">Insect Pins&#160;</td>
			<td style="width:223px;">Roboz Surgical Instrument Co</td>
			<td style="width:197px;">RS-6082-25</td>
			<td></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:363px;">Microscope slides and cover slips</td>
			<td style="width:223px;">Fisher Scientific</td>
			<td style="width:197px;">15-188-52</td>
			<td></td>
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</table>

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.

The dendrites of da neurons were labeled by co-overexpressing GFP (UAS-GFP; ppk-GAL4) in the da neural soma and dendritic arbors for GFP fluorescence imaging analysis. The morphology of da neuron dendrites was imaged by an inverted confocal microscope (Figure 2).
The dendrites of da neurons were traced using Fiji ImageJ software. The file was used to estimate the dendrite length (<strong class="xfig...

Watch this Scientific Journal Video about Quantitative Analysis of Neuronal Dendritic Arborization Complexity in Drosophila at JoVE.com

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.

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. ...

The overall goal of this procedure is to observe the impact of the SOX5 gene on the complexity of the dendritic arborization neurons during the neuronal development in Drosophila. This method can help study morphogenesis of neuro-dendrites, and the gene function in the development of nervous system, to better understand neurodegenerative disease genes. Ultimately this technique provides a quantitative analysis of dendrites complexity, which can be used in many different types of neuro-dendrites.The implications of this technique extend toward genetic mechanism of neuro-degenerative disease, because mutation holds the key to understanding gene function. Set-up crosses of UAS-GFP;ppk-GAL4 with the UAS-Sox102F-RNAi strain flies or W118 controls. Culture the flies under standard conditions at 25 degrees Celsius.In about five to six days, use forceps to carefully collect the third instar larvae for dissection. Place a larva in a dissection dish made of silicon elastomer base, and a tissue-culture Petri dish. Then place the dish under the dissection microscope.Now pin the tail of the larva to expose the midline. Then pin the larva mouth hooks so the larva's dorsal side is up. Now add 200 microliters of PBS to the dish to immerse the larva in solution.Next, cut the tail and mouth of larva with small incisions. Then cut the larva open along the dorsal midline and between the two tracheas, going from caudal to rostral. Then place a pin at each of the four corners of the body so the body lies flat.Now fix the larva body wall in four percent PFA for 25 minutes at room temperature. Then wash the larva with PBS three times for five minutes per wash. After the washes, remove the pins and transfer the tissue onto a glass slide.Then immerse the tissue in antifade mounting medium, and mount it with a cover slip. Allow the mounted tissue to air dry for an hour before sealing on the cover slip with fingernail polish. Store these slides in the dark at four degrees Celsius.Capture z-series images with a confocal microscope using a 20X objective. First, set the range of the z-steps to include all of the DA neurons in the larva body wall, and set the step size to a half micrometer. Then store the images as TIF or ND2 files for processing.Next, evaluate the number and morphology of the dendrites on the DA neurons. Begin with assessing their lengths. First, in Fiji ImageJ, split the images into separate channels if necessary.Only the GFP channel needs to be assessed. Next, make a z-projection. In the new window, select max intensity for projection type, and choose the start and stop slices.Then click OK to produce a z-projection image with clear dendrite projections. Now trace the neurites using the plug-in tool. First, go to the soma of the neuron of interest and click where one dendrite emerges from the cell body.Then click at the tip of this dendrite. If the blue line that connects the two points runs the length of the neurite, press Y for yes. Then if this line fits the complete path of the neurite, click complete path.If the line does not fit the path, then click on points further along this neurite to bend the path into multiple line segments that will fit the length of the neurite. Then, click complete path and proceed with marking the path for the next neurite. After completing all the tracing paths, select the Analysis, Measure Paths option to export the paths to a CSV file.Use this data to calculate and average value of path lengths for analysis. Next, calculate the surface area of the neuron. First, select the free hand drawing tool from the Fiji ImageJ window.Then, connect the end points of the neuron of interest. Then, select the Measure option from the Analyze window. The result appears in a new box with the value for the area selected.Copy this value to the data analysis software. Finally, calculate the total number of branches using the Analyze Skeletonized Paths plugin. The dendrites of DA neurons were labeled by co-overexpressing GFP in their soma and dendrite arbors for GFP florescence imaging analysis.The morphology of dendrites was imaged using an inverted confocal microscope. The dendrites of DA neurons were traced as described. The file was used to estimate the dendrite length.Silencing of Sox102F in DA neurons in the third instar larva led to a significant reduction in the total number of dendrites with about half of the branch length and with a simpler structure, showing only half the number of branches. Logically, this led to reduction in arbor surface area. This protocol provides a quick method to assess development of DA sensory neurons.While attempting this procedure, be sure to take an ample number of images of each group of DA neurons to get a good coverage. Following this procedure, other methods like dendrite analysis can be performed in order to answer additional questions about dendrite development. Since it's development, this technique has helped researchers in the field of neurosciences make inferences into neurodegenerative disease such as Alzheimer's using model systems.

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13.8K visualizações.  Mass General Institute of Neurodegenerative Disease. O objetivo geral deste procedimento é observar o impacto do gene SOX5 na complexidade dos neurônios de arborização dendrítica durante o desenvolvimento neuronal em Drosophila. Este método pode ajudar a estudar a morfogênese de neurodndritos, e a função genética no desenvolvimento do sistema nervoso, para entender melhor os genes da doença neurodegenerativa. Em última análise, esta técnica fornece uma análise quantitativa da complexidade dos dendritos, que pode ser usada em muit...