Name: analyzing synaptic modulation of drosophila melanogaster photoreceptors after exposure to prolonged light
Uploaded: 2017-02-10T14:00:00
Description: Watch this Scientific Journal Video about Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light at JoVE.com

We are grateful to T. St&#252;rner for helpful corrections, discussions and comments on the manuscript; S.L. Zipursky for providing fly stocks; M Sch&#246;lling for performing image processing. Part of the image analysis was performed at A. Kakita&#39;s lab. This work was supported by Alexander von Humboldt Foundation and JSPS Fellowships for Research Abroad (A.S.), JSPS Fellows (S.H.-S.), Grant-In- Aid for Start-up (24800024), on Innovative Areas (25110713), Mochida, Takeda, Inamori, Daiichi-Sankyo, Toray Foundations (T.S.), DZNE core funding (G.T.) and DZNE Light Microscopy Facility (C.M.).

The experimental procedures described in this protocol involve exclusively work with Drosophila and are not subjected to animal welfare laws in Germany and Japan.
1. Light Exposure Conditions
<ol>
	<li>Prepare flies that carry sensless-flippase (sens-flp) and bruchpilot-FRT-STOP-FRT-gfp (brp-FSF-gfp)15 for visualizing Brp-GFP in photoreceptor R8 neurons (R8s). The genomic locus encoding brp within a Bacterial Artif...

<ol>
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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=Bruchpilot,+a+protein+with+homology+to+ELKS/CAST,+is+required+for+structural+integrity+and+function+of+synaptic+active+zones+in+Drosophila.">Bruchpilot, a protein with homology to ELKS/CAST, is required for structural integrity and function of synaptic active zones in Drosophila.</a> Neuron. 49 (6), 833-844 (2006).</li><li>Chen, 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=Cell-type-specific+labeling+of+synapses+in+vivo+through+synaptic+tagging+with+recombination.">Cell-type-specific labeling of synapses in vivo through synaptic tagging with recombination.</a> Neuron. 81 (2), 280-293 (2014).</li><li>Andlauer, T. F., Sigrist, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+analysis+of+Drosophila+larval+neuromuscular+junction+morphology.">Quantitative analysis of Drosophila larval neuromuscular junction morphology.</a> Cold Spring Harb Protoc. 2012 (4), 490-493 (2012).</li><li>Ippolito, D. M., Eroglu, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+synapses:+an+immunocytochemistry-based+assay+to+quantify+synapse+number.">Quantifying synapses: an immunocytochemistry-based assay to quantify synapse number.</a> J Vis Exp. (45), (2010).</li><li>Schmitz, S. 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=Automated+analysis+of+neuronal+morphology,+synapse+number+and+synaptic+recruitment.">Automated analysis of neuronal morphology, synapse number and synaptic recruitment.</a> J Neurosci Methods. 195 (2), 185-193 (2011).</li><li>Danielson, E., Lee, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SynPAnal:+software+for+rapid+quantification+of+the+density+and+intensity+of+protein+puncta+from+fluorescence+microscopy+images+of+neurons.">SynPAnal: software for rapid quantification of the density and intensity of protein puncta from fluorescence microscopy images of neurons.</a> PLoS One. 9 (12), e115298 (2014).</li><li>Sanders, J., Singh, A., Sterne, G., Ye, B., Zhou, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Learning-guided+automatic+three+dimensional+synapse+quantification+for+drosophila+neurons.">Learning-guided automatic three dimensional synapse quantification for drosophila neurons.</a> BMC Bioinformatics. 16, 177 (2015).</li><li>Peng, H., Ruan, Z., Atasoy, D., Sternson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automatic+reconstruction+of+3D+neuron+structures+using+a+graph-augmented+deformable+model.">Automatic reconstruction of 3D neuron structures using a graph-augmented deformable model.</a> Bioinformatics. 26 (12), i38-i46 (2010).</li><li>Sturt, B. L., Bamber, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+quantification+of+synaptic+fluorescence+in+C.+elegans.">Automated quantification of synaptic fluorescence in C. elegans.</a> J Vis Exp. (66), (2012).</li><li>Kremer, M. 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=Structural+long-term+changes+at+mushroom+body+input+synapses.">Structural long-term changes at mushroom body input synapses.</a> Curr Biol. 20 (21), 1938-1944 (2010).</li><li>Mosca, T. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Optic+Lobe+of+Drosophila-Melanogaster+.1+A+Golgi+Analysis+of+Wild-Type+Structure.">The Optic Lobe of Drosophila-Melanogaster .1 A Golgi Analysis of Wild-Type Structure.</a> Cell and Tissue Research. 258 (3), 441-475 (1989).</li><li>Berger-Muller, 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=Assessing+the+role+of+cell-surface+molecules+in+central+synaptogenesis+in+the+Drosophila+visual+system.">Assessing the role of cell-surface molecules in central synaptogenesis in the Drosophila visual system.</a> PLoS One. 8 (12), e83732 (2013).</li><li>Fouquet, 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=Maturation+of+active+zone+assembly+by+Drosophila+Bruchpilot.">Maturation of active zone assembly by Drosophila Bruchpilot.</a> J Cell Biol. 186 (1), 129-145 (2009).</li><li>Ke, M. 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In this study, we showed how to prepare the light conditions to expose flies to an equal light intensity. We quantified not only the number of a synaptic marker puncta but could also spatially resolve the density of synapses along axons and measure the delocalization level of the marker protein in cytoplasmic areas. These three assessments allow us to evaluate the details of synaptic dynamics at single neuron level in different environmental conditions. Our protocol can be adapted to different synaptic proteins but also ...

The modulation of synaptic function contributes to the remarkable ability of the nervous system to precisely respond or adapt to changing environmental stimuli. Adjusting the presynaptic vesicle release probability is one way of controlling synaptic strength1. Synaptic vesicle release takes place at the Active Zone (AZ), a specialized region of the presynaptic membrane2. The AZ is characterized by a cassette of specific proteins3,4. Most proteins contributing to AZ assembly are highly conserved in nematodes, insects and mammals5. Recent studies suggest that the level of neuronal activity regulates the molecular composition of the AZ, which in turn contributes to the regulation of the functional output both in vitro and in vivo6,7,8. We previously found that photoreceptor AZs undergo molecular remodeling in Drosophila after prolonged exposure to natural ambient light9. In this condition, we observed that the number of Bruchpilot (Brp)-positive AZs was reduced in the photoreceptor axons.
The Brp/CAST/ELKS family proteins are fundamental building blocks of AZs in vertebrate and invertebrate synapses10. In Drosophila brp mutants, evoked vesicle release is suppressed11,12. The 17 C-terminal amino acid residues of Brp are essential for synaptic vesicle clustering at the Drosophila Neuromuscular Junction (NMJ)13,14. These studies demonstrated the central role of this molecule in AZ organization and function. With a recently developed genetic tool, Synaptic Tagging with Recombination (STaR), Brp can be observed in vivo in specific cell types, at endogenous expression levels and at a single synapse resolution15. This tool makes it feasible to evaluate the endogenous dynamics of synapses quantitatively in the complex central nervous system.
There have been several studies including synapse quantifications based on data obtained from confocal microscopy. Synaptic alterations have been evaluated by measuring the length, the area, the volume, the density and counting the number based on sophisticated software applications. For instance, the freeware ImageJ provides a quantification method for total synaptic area and synaptic density measures at the Drosophila NMJ16. The number of colocalization sites of pre and postsynaptic markers have been quantified using the plugin &#34;Puncta Analyzer&#34; available on the ImageJ software platform17. Alternatively, a multi-paradigm numerical computing environment based program, Synapse Detector (SynD), can automatically trace dendrites of neurons labeled with a fluorescent marker, and then quantifies the synaptic protein levels as a function of distance from the cell body18. The software Synaptic Puncta Analysis (SynPAnal), has been designed for the rapid analysis of 2D images of neurons acquired from confocal or fluorescent microscopy. The primary function of this software is the automatic and rapid quantification of density and intensity of protein puncta19. Recently, an automatic learning-based synapse detection algorithm has been generated for quantification of synaptic number in 3D20, taking advantage of the 3D Visualization-Assisted Analysis (Vaa3D) software21.
Commercial image analysis software are also powerful tools for synaptic quantifications. For instance, the fluorescently labeled neurotransmitter receptors or a presynaptic AZ component have been quantified in three dimensions with single-synapse resolution in C. elegans22 or the Drosophila olfactory system23,24, allowing hundreds of synapses to be rapidly characterized within a single sample.
Here, we present a method by a customized image analysis software plug-in implemented in a multi-paradigm numerical computing environment that allows to analyze semi-automatically multiple aspects of AZs, including their number, distribution and the level of enrichment of molecular components to the AZ. Thus, this complex analysis allowed us to evaluate the dynamics of synaptic components in axon terminals under different environmental conditions. We investigated the effect of light exposure on the output synapses of adult fly photoreceptors. The procedure is performed in three steps: 1) preparation for light exposure, 2) dissection, immunohistochemistry and confocal imaging, and 3) image analysis.

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			<td>Vial</td>
			<td>Hightech, Japan</td>
			<td>MKC-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Plug</td>
			<td>Thermo Fisher Sciehtific, USA</td>
			<td>AS-275</td>
			<td></td>
		</tr>
		<tr>
			<td>Customized transparent rack made of acrylic resin&#160;</td>
			<td>Shin-Shin Corporation, Japan</td>
			<td></td>
			<td>a height of 41 cm, a base of 21 cm, a thickness of 4 cm and a height of 13 cm for each step</td>
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		<tr>
			<td>Cool incubator</td>
			<td>MITSUBISHI ELECTRIC, Japan</td>
			<td>CN-40A</td>
			<td></td>
		</tr>
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			<td>LED panel</td>
			<td>MISUMI, Japan</td>
			<td>LEDXC170-W</td>
			<td></td>
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		<tr>
			<td>Digital light meter</td>
			<td>CEM</td>
			<td>DT-1301</td>
			<td></td>
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		<tr>
			<td>Fly pad</td>
			<td>Tokken, Japan</td>
			<td>TK-HA03-S</td>
			<td></td>
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			<td>Petri dish (35 x 10 mm)</td>
			<td>Greiner Bio-One International, Germany</td>
			<td>627102</td>
			<td></td>
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			<td>PBS tablet</td>
			<td>Takara, Japan</td>
			<td>T900</td>
			<td></td>
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			<td>Triton X-100</td>
			<td>Wako, Japan</td>
			<td>160-24751</td>
			<td></td>
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			<td>Dumont #5 Forceps</td>
			<td>Fine Science Tools</td>
			<td>11251-20</td>
			<td></td>
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		<tr>
			<td>1.5 ml tube</td>
			<td>Sarstedt, Germany</td>
			<td>A. 152X</td>
			<td></td>
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			<td>Formaldehyde 16%</td>
			<td>NEM, Japan</td>
			<td>3152</td>
			<td></td>
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			<td>Pipetman P-200</td>
			<td>Gilson</td>
			<td>F123601&#160;</td>
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			<td>Pipetman P-20</td>
			<td>Gilson</td>
			<td>F123600</td>
			<td></td>
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			<td>Pipetman P-2</td>
			<td>Gilson</td>
			<td>F144801</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-chaoptin antibody</td>
			<td>DSHB</td>
			<td>24B10</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa568-conjugated anti-mouse antibody</td>
			<td>Life Technologies</td>
			<td>A-11031</td>
			<td></td>
		</tr>
		<tr>
			<td>VECTASHIELD Mounting Medium</td>
			<td>Vector Laboratories, Inc.</td>
			<td>H-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope slide (76 x 26 mm)</td>
			<td>Thermo Fisher Scientific Gerhard Menzel B.V. &#38; Co. KG, Germany</td>
			<td></td>
			<td></td>
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			<td>Coverslip (18 x 18 mm, 0.17 mm)</td>
			<td>Zeiss, Germany</td>
			<td>474030-9000-000</td>
			<td></td>
		</tr>
		<tr>
			<td>Industrial Microscopes</td>
			<td>Olympus, Japan</td>
			<td>SZ61-C-SET</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereo Microscope Lighting</td>
			<td>Olympus, Japan</td>
			<td>KL 1600 LED</td>
			<td></td>
		</tr>
		<tr>
			<td>confocal microscopy</td>
			<td>Zeiss, Germany</td>
			<td>LSM780</td>
			<td></td>
		</tr>
		<tr>
			<td>Imaris</td>
			<td>Bitplane, Switzerland</td>
			<td></td>
			<td>Version 7.6.4 or above</td>
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			<td>Matlab</td>
			<td>The MathWorks, Inc., USA</td>
			<td></td>
			<td></td>
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		<tr>
			<td>Excel for Mac&#160;</td>
			<td>Microsoft</td>
			<td></td>
			<td></td>
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analyzing synaptic modulation of drosophila melanogaster photoreceptors after exposure to prolonged light

The nervous system has the remarkable ability to adapt and respond to various stimuli. This neural adjustment is largely achieved through plasticity at the synaptic level. The Active Zone (AZ) is the region at the presynaptic membrane that mediates neurotransmitter release and is composed of a dense collection of scaffold proteins. AZs of Drosophila melanogaster (Drosophila) photoreceptors undergo molecular remodeling after prolonged exposure to natural ambient light. Thus the level of neuronal activity can rearrange the molecular composition of the AZ and contribute to the regulation of the functional output.
Starting from the light exposure set-up preparation to the immunohistochemistry, this protocol details how to quantify the number, the spatial distribution, and the delocalization level of synaptic molecules at AZs in Drosophila photoreceptors. Using image analysis software, clusters of the GFP-fused AZ component Bruchpilot were identified for each R8 photoreceptor (R8) axon terminal. Detected Bruchpilot spots were automatically assigned to individual R8 axons. To calculate the distribution of spot frequency along the axon, we implemented a customized software plugin. Each axon&#39;s start-point and end-point were manually defined and the position of each Bruchpilot spot was projected onto the connecting line between start and end-point. Besides the number of Bruchpilot clusters, we also quantified the delocalization level of Bruchpilot-GFP within the clusters. These measurements reflect in detail the spatially resolved synaptic dynamics in a single neuron under different environmental conditions to stimuli.

The compound eye of Drosophila comprises ~780 ommatidia, each containing eight types of photoreceptors (R1-8). R7 and R8 project their axons to the second optic ganglion, the medulla, where they form synapses in layers M6 and M3, respectively26. To investigate the effect of prolonged exposure to light on the molecular composition of photoreceptor R8 active zones, we took advantage of the STaR method15. Endogenous expression levels o...

Watch this Scientific Journal Video about Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light at JoVE.com

Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light

Here we show how to quantify the number and spatial distribution of synaptic active zones in Drosophila melanogaster&#160;photoreceptors, highlighted with a genetically encoded molecular marker, and their modulation after prolonged exposure to light.

Analyzing Synaptic Modulation of Drosophila melanogaster Photoreceptors after Exposure to Prolonged Light

The nervous system has the remarkable ability to adapt and respond to various stimuli. This neural adjustment is largely achieved through plasticity at ...

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High Throughput Assay to Examine Egg-Laying Preferences of Individual Drosophila melanogaster

Recently, egg-laying preference of Drosophila has emerged as a genetically tractable model to study the neural basis of simple decision-making processes. ...

Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

Electrophysiological Method for Recording Intracellular Voltage Responses of Drosophila Photoreceptors and Interneurons to Light Stimuli In Vivo

Voltage responses of insect photoreceptors and visual interneurons can be accurately recorded with conventional sharp microelectrodes. The method ...

Electrophysiological Method for Whole-cell Voltage Clamp Recordings from Drosophila Photoreceptors

Electrophysiological Method for Whole-cell Voltage Clamp Recordings from Drosophila Photoreceptors

Whole-cell voltage clamp recordings from Drosophila melanogaster photoreceptors have revolutionized the field of invertebrate visual transduction, ...

Desensitization and Recovery of Crayfish Photoreceptors Upon Delivery of a Light Stimulus

A method to study desensitization and recovery of crayfish photoreceptors is presented. We performed intracellular electrical recordings of photoreceptor ...

Monitoring Cell-to-cell Transmission of Prion-like Protein Aggregates in Drosophila Melanogaster

Monitoring Cell-to-cell Transmission of Prion-like Protein Aggregates in Drosophila Melanogaster

Protein aggregation is a central feature of most neurodegenerative diseases, including Alzheimer&#39;s disease (AD), Parkinson&#39;s disease (PD), ...

Metabolic Analysis of Drosophila melanogaster Larval and Adult Brains

Metabolic Analysis of Drosophila melanogaster Larval and Adult Brains

This protocol describes a method for measuring the metabolism in Drosophila melanogaster larval and adult brains. Quantifying metabolism in whole organs ...