The authors want to thank Dr. Tadmiri Venkatesh for his encouragement to prepare this manuscript, Dova Brenman and Selwyn Chui for their constructive comments, Elyssa Burg and Wayne Rasband for designing the macro in ImageJ for all interfly distances and for nearest neighbor distances. The authors also want to thank the reviewers for their constructive comments.
A.A.A, M.C.C. and A.F.S were responsible for research design; S.N.J., A.A.A, M.N., Z.R., and A.J.M. performed the experiments. A.A.A, M.N., A.J.M. and M.C.C and A.F.S. analyzed the data; A.R.M. and A.F.S. wrote the manuscript.
This work was supported by PSC-CUNY research awards, jointly funded by The Professional Staff Congress and The City University of New York to A.F.S.; by internal funding from Western University to A.F.S.; by a Mathematics, Biology, Chemistry, and Geology majors scholarship for teachers-in-training and by a Louis Stokes Alliance for Minority Participation scholarship to A.A.A.

1. Equipment and Reagents Created In-house (See List of Materials for Others)
<ol>
	<li>Prepare a Drosophila cold anesthesia apparatus as previously described 8.</li>
	<li>Prepare a fly aspirator as previously described 13.</li>
	<li>Prepare social space chambers and holders.
	<ol>
		<li>Order or make glass panes and acrylic spacers to create the social space chambers. Each social space chamber consists of two square glass panes (17.6 cm by 17.6 cm, with a thickness of 0.3 cm), two right triangle acrylic spacers (with a height of 16.5 cm, a base of 8.9 cm, with a thickness of 0.3 cm), and two rectangular spaces (9 cm by 1.5 cm with a thickness of 0.3 cm) (Figure 1A).</li>
		<li>Assemble the glass and acrylic social space chamber such that it is identical to the chamber in Figure 1B. To do so, start by placing one triangular spacer flat on top of one square pane of glass such that the right angle of the triangular spacer is aligned with one of the corners of the square pane. Next, place the second triangular spacer flat on top of the square pane, mirroring the first triangular spacer. 
		NOTE: Make sure to wear gloves so as not to contaminate the pieces with oils and scents from your hands.</li>
		<li>Place two small rectangular spacers flat on top of the square pane, along the side of the pane that is not covered. The acrylic spacers on top of the square plane should now form a triangular arena.</li>
		<li>Place a second square pane of glass on top of the acrylic spacers such that it is aligned above the original pane of glass below.</li>
		<li>Use four binder clips to secure the panes and spacers together to form the social space chamber. Place one clip near the corner, over the long side of each of the triangular spacers, securing them inside the glass panes. On these same sides, place a clip in the adjacent corner, over each of the rectangular spacers, securing them inside the glass panes.</li>
		<li>Assemble a support stand and a flask clamp such that the clamp will maintain the social space chamber in an upright position, as the social space chamber rests on its edge on top of the work surface.</li>
		<li>For each repeat in the experiment, assemble a social space chamber and support stand.</li>
	</ol>
	</li>
	<li>Prepare a climbing assay response apparatus to check the climbing ability of the flies tested.
	<ol>
		<li>Use a countercurrent apparatus, as previously described 14,15.</li>
	</ol>
	</li>
	<li>Ensure homogeneous lighting conditions by performing the experiment on a work surface covered with a white bench cover and in front of a white background.</li>
</ol>
2. Preparing the Flies before the Experiment
<ol>
	<li>Maintain flies in bottles containing standard Drosophila fly food. Keep them in an incubation chamber at 25 &#176;C on a 12 hr light/dark cycle.</li>
	<li>One to two days prior to the experiment, collect and sex flies under cold anesthesia, as previously described 8.
	<ol>
		<li>Chill the cold anesthesia apparatus at -4 &#176;C. Place flies into 50 ml plastic tubes. Fully submerge the plastic tubes containing flies into ice in an insulated ice bucket, wait at least 5 min for flies to become immobile.</li>
		<li>Place the flies on the polyethylene sheet of the cold anesthesia apparatus. At RT, use a stereomicroscope to separate males from females. Maintain flies, in groups, in vials containing standard Drosophila fly food, not exceeding 40 flies per vial.</li>
	</ol>
	</li>
	<li>Two hours before the beginning of the experiment, ensure that the temperature of the room where the experiment will be performed is between 24&#8211;25 &#176;C and the humidity is approximately 50%.</li>
	<li>Transfer the flies into new vials containing food, and place them for 2 hr on the work surface where the experiment will be performed. 
	NOTE: For these experiments, the fly strains used were Drosophila melanogaster strains: Canton-Special or Canton-S (CS), w1118Cs10 (or W - w1118 outcrossed 10 times to Canton-S), Oregon and Samarkand flies were all from our laboratory stocks 16; Elwood flies were collected in Fall 2011 in the Elwood neighborhood of Huntington, on Long Island, New York, USA 8. Apart when specified otherwise, the results presented were obtained with Canton-S flies (in shades of red).</li>
</ol>
3. Performing the Experiment
<ol>
	<li>Perform the experiment between 12 p.m. and 3 p.m. (Zeitgeber time &#8212; the time in hours after the onset of light &#8212; of ZT 4 to 7).</li>
	<li>Prepare the social space chamber for the transfer of flies.
	<ol>
		<li>Place a social space chamber flat on a work surface, with the side containing rectangular spacers closest to your body.</li>
		<li>Remove one clip nearest your body and slide one rectangular spacer outwards, creating a gap of approximately 1 cm between the rectangular spacers.</li>
		<li>Using tape and a marker, label the social space chamber in an upper corner with sex, strain, and repeat number. Take care to ensure the tape does not cover part of the inner triangular arena.</li>
	</ol>
	</li>
	<li>Transfer the flies into the social space chamber.
	<ol>
		<li>Transfer flies from their vial containing food into a new, empty vial. Aspirate flies from the empty vial and transfer them into the social space chamber.
		<ol>
			<li>Inhale to draw the flies into the tip of the aspirator. Place the tip into the 1 cm gap between the rectangular spacers of the social space chamber and exhale at a consistent rate to force the flies into the inner triangular arena.</li>
			<li>Immediately slide the rectangular spacer back into place, closing the base of the inner triangular arena, and place the binder clip back on.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>On a pounding pad, which is located on different bench than where the experimental work takes place, hold the social space chamber upright such that the rectangular spacers are on the bottom side. Pound three times to ensure all flies have fallen to the bottom of the arena. 
	NOTE: Due to the acrylic spacer sticking out of the smallest chamber size (Figure 1D), bang elbows on work surface while maintaining a secure hold on apparatus to ensure the flies have fallen to the bottom.</li>
	<li>Start a timer.</li>
	<li>Place the social space chamber on the work surface and use the support stand and flask clamp to keep it upright. Place a ruler or a sticker of known length flat against the social space chamber, but not covering any part of the inner triangular arena.
	<ol>
		<li>For horizontally positioned experiments, do not place the social space chamber in the support stand; instead lay the social space chamber flat on the work surface.</li>
	</ol>
	</li>
	<li>When the flies have settled, usually after around 30 min, take a picture of the social space chamber. Ensure that the frame contains the entire inner triangular arena, the ruler, and the label.</li>
	<li>Repeat the experiment for each genotype and condition (ideally 3 internal replicates and 3 independent repeats).</li>
</ol>
4. Analyzing the Social Space Data
<ol>
	<li>Import the following Macros in ImageJ 17
	<ol>
		<li>ImageJ is available here: http://rsbweb.nih.gov/ij/.</li>
		<li>You can create a &#39;Measure Distances&#39; command in the Plugins menu by saving the macros below in a file named &#39;Measure_Distances.txt&#39; in the ImageJ/plugins folder, in the macro subfolder, and using the Help&#62;Update Menus command.&#39;</li>
		<li>Copy in a .txt file the macros that are provided in supplementary data and were originally published in 3.</li>
	</ol>
	</li>
	<li>Upload the pictures to a computer, and open one picture using ImageJ.
	<ol>
		<li>Create a scale by drawing a line from the 0 cm to 1 cm marks on the ruler in the picture, and under the Analyze tab, choose the Set Scale feature to set a scale of 1 cm for that distance (same approach for the sticker of known length). Choose the Global option before applying the scale to the picture.</li>
		<li>Crop the picture using the Crop feature under the Image tab such that it includes all of the flies, while removing as much of the rest of the picture as possible.</li>
		<li>Make the picture black and white by choosing 8-bit from the Type option under the Image tab.</li>
		<li>Remove all background noise from the picture by going to the Threshold feature under the Adjust option of the Image tab. Drag the sliders to enhance or remove the contrast so that the body of each fly can be clearly seen without any other markings in the image. If there are markings that are not flies, capture them with the rectangular tool and delete them.</li>
		<li>Set the measurements by using the Set Measurements tool under the Analyze tab. Select Area, Center of Mass, Centroid, and Display Label. Next, choose the Analyze Particles feature under the Analyze tab to create a numbered list of all the black spots representing flies.
		<ol>
			<li>When using Analyze particles; set size 0.01-0.1 (do NOT choose pixel unit); circularity 0.00-1.00; show outlines; display results, and add to manager.</li>
			<li>Ensure that each black spot (each particle) is an accurate representation of the flies that are in the original picture, by comparing the numbered list to the original picture. 
			NOTE: If some flies that are very close together being counted as one particle, manually draw a white line to separate the two flies on the binary image.</li>
		</ol>
		</li>
		<li>While the list is selected, use the Nearest Neighbor &#8212; List Distances macro under the second Macros option in the Plugins tab to create a new list containing the distances, in cm, from each fly to their nearest neighbor.</li>
	</ol>
	</li>
	<li>Copy the nearest neighbor distances from ImageJ and paste into a column of a spreadsheet program.
	<ol>
		<li>Compile all of the data from each repeat onto the same spreadsheet and organize by genotype and condition.</li>
	</ol>
	</li>
	<li>Perform data analysis using statistical software. In this experiment, Graph Pad Prism (version 6 for MacOSX, GraphPad Software, San Diego California USA, www.graphpad.com) was used to conduct one-way ANOVA, and Kruskal-Wallis Tests, Tukey&#8217;s and Dunnet&#8217;s Post-Hoc Tests.</li>
	<li>The distribution of the distances follows a non parametric distribution 1, and data are represented as box and Tukey&#8217;s whiskers (to eliminate outliers).</li>
</ol>
5. Climbing Assay (Control Behavior)
<ol>
	<li>Use a climbing assay as a control to test flies climbing ability 14,15,18.
	<ol>
		<li>Use the countercurrent apparatus such that three trials can be run in parallel.</li>
	</ol>
	</li>
	<li>Transfer 50 to 100 na&#239;ve flies (flies that have not been tested before) in three different test vials, and snap them into the 1st, 3rd and last slots at the bottom of countercurrent apparatus, with fresh empty vials in the opposite locations.</li>
	<li>Place fresh, empty vials in the empty slots at the bottom of the apparatus.</li>
	<li>Tap down the apparatus three times, such that all the flies are at the bottom of each tube, to initiate the experiment.</li>
	<li>Start the timer for 15 sec (time sufficient for ~100% of 3&#8211;7 days old Canton-S to reach the top vial &#8212; see Figure&#160;3F).</li>
	<li>Slide the upper portion of the counter-current apparatus, to displace the top vials by one slot.</li>
	<li>Collect flies by tapping the apparatus down, to bring all flies in the bottom vials.
	<ol>
		<li>1st and 2nd tubes (or 3rd and 4th, 5th and 6th) correspond respectively to the flies that did not reach to top and the flies that reached the top vial.</li>
	</ol>
	</li>
	<li>Calculate the Performance Index (PI).
	<ol>
		<li>Count the number of flies in each vial.</li>
		<li>The PI is the percentage of flies able to climb on the upper tube.</li>
		<li>The means of the PI follow a normal distribution1, and data are represented as column graphs of mean plus or minus standard error to the mean (SEM). 
		NOTE: Alternatively, the PI can be calculated as the percentage of flies able to reach the upper part of the lower vial (for older flies, 5 sec is the time sufficient to quantify a difference in climbing ability between infected and non infected 12 days old Canton-S quantified from a still picture: see results). Others have used different measures of performance in startle-induced negative geotaxis, that are also appropriate to quantify climbing ability 19-22.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Simon, A. F., 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+simple+assay+to+study+social+behavior+in+Drosophila.:+measurement+of+social+space+within+a+group.">A simple assay to study social behavior in Drosophila.: measurement of social space within a group.</a> Genes Brain Behav. 11, 243-252 (2012).</li><li>Kaur, K., Simon, A. F., Chauhan, V., Chauhan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+bisphenol+A+on+the+behavior+of+Drosophila+melanogaster.+-+Potential+use+of+Drosophila+as+a+model+in+the+study+of+neurodevelopmental+disorders.">Effect of bisphenol A on the behavior of Drosophila melanogaster. - Potential use of Drosophila as a model in the study of neurodevelopmental disorders.</a> Behavioural Brain Research. , (2015).</li><li>Burg, E. D., Langan, S. T., Nash, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+social+clustering+is+disrupted+by+anesthetics+and+in+narrow+abdomen+ion+channel+mutants.">Drosophila social clustering is disrupted by anesthetics and in narrow abdomen ion channel mutants.</a> Genes Brain Behav. 12, 338-347 (2013).</li><li>Wise, 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=The+autism+candidate+gene+Neurobeachin+(Rugose)+mutants+in+Drosophila+exhibit+neuro-developmental+disorders,+aberrant+synaptic+properties,+altered+locomotion,+impaired+adult+social+behavior+and+activity+patterns.">The autism candidate gene Neurobeachin (Rugose) mutants in Drosophila exhibit neuro-developmental disorders, aberrant synaptic properties, altered locomotion, impaired adult social behavior and activity patterns.</a> J Neurosci. , 1-9 (2015).</li><li>Parrish, J. K., Edelstein-Keshet, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complexity,+pattern,+and+evolutionary+trade-offs+in+animal+aggregation.">Complexity, pattern, and evolutionary trade-offs in animal aggregation.</a> Science. 284, 99-101 (1999).</li><li>Sokolowski, 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=Social+interactions+in+&#8216;&#8216;simple&#8217;&#8217;+model+systems.">Social interactions in &#8216;&#8216;simple&#8217;&#8217; model systems.</a> Neuron. 65, 780-794 (2010).</li><li>Rittschof, C. C., Robinson, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genomics:+moving+behavioural+ecology+beyond+the+phenotypic+gambit.">Genomics: moving behavioural ecology beyond the phenotypic gambit.</a> Animal Behaviour. 92, 263-270 (2014).</li><li>Fernandez, R. 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=Straightforward+assay+for+quantification+of+social+avoidance+in+Drosophila+melanogaster.">Straightforward assay for quantification of social avoidance in Drosophila melanogaster.</a> JoVE. (94), e52011 (2014).</li><li>Hahn, 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=Monogenic+heritable+autism+gene+neuroligin+impacts+Drosophila.+social+behaviour.">Monogenic heritable autism gene neuroligin impacts Drosophila. social behaviour.</a> Behav Brain Res. 252, 450-457 (2013).</li><li>Mogilner, A., Edelstein-Keshet, L., Bent, L., Spiros, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutual+interactions,+potentials,+and+individual+distance+in+a+social+aggregation.">Mutual interactions, potentials, and individual distance in a social aggregation.</a> J Math Biol. 47, 353-389 (2003).</li><li>Liu, L., Davis, R. L., Roman, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exploratory+activity+in+Drosophila+requires+the+kurtz+nonvisual+arrestin.">Exploratory activity in Drosophila requires the kurtz nonvisual arrestin.</a> Genetics. 175, 1197-1212 (2007).</li><li>Soibam, B., 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=Open-field+arena+boundary+is+a+primary+object+of+exploration+for+Drosophila.">Open-field arena boundary is a primary object of exploration for Drosophila.</a> Brain Behav. 2, 97-108 (2012).</li><li>Ejima, A., Griffith, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ch.+30.">Ch. 30.</a> Drosophila Neurobiology - A laboratory Manual., Ch. , 475-481 (2010).</li><li>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=Behavioral+mutants+of+Drosophila+melanogaster.+isolated+by+countercurrent+distribution.">Behavioral mutants of Drosophila melanogaster. isolated by countercurrent distribution.</a> PNAS. 58, 1112-1119 (1967).</li><li>Connolly, J. B., Tully, T., Roberts, D. 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:+A+practical+approach.">Drosophila: A practical approach.</a> 1, 265-317 (1998).</li><li>Simon, A. F., Shih, C., Mack, A., 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=Steroid+control+of+longevity+in+Drosophila+melanogaster.">Steroid control of longevity in Drosophila melanogaster.</a> Science. 299, 1407-1410 (2003).</li><li>Rasband, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> ImageJ. , (1997).</li><li>Simon, A. F., 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=Drosophila,+vesicular+monoamine+transporter+mutants+can+adapt+to+reduced+or+eliminated+vesicular+stores+of+dopamine+and+serotonin.">Drosophila, vesicular monoamine transporter mutants can adapt to reduced or eliminated vesicular stores of dopamine and serotonin.</a> Genetics. 181, 525-541 (2009).</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> JoVE. (74), e50339 (2013).</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> JoVE. , e2504 (2011).</li><li>Gargano, J. W., Martin, I., Bhandari, P., Grotewiel, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+iterative+negative+geotaxis+(RING):+a+new+method+for+assessing+age-related+locomotor+decline+in+Drosophila.">Rapid iterative negative geotaxis (RING): a new method for assessing age-related locomotor decline in Drosophila.</a> Exp Gerontol. 40, 386-395 (2005).</li><li>Simon, A. F., Liang, D. T., Krantz, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+decline+in+behavioral+performance+of+Drosophila+melanogaster.+with+age.">Differential decline in behavioral performance of Drosophila melanogaster. with age.</a> Mech Ageing Dev. 127, 647-650 (2006).</li><li>Khalil, S., Jacobson, E., Chambers, M. C., Lazzaro, B. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systemic+bacterial+infection+and+immune+defense+phenotypes+in+Drosophila+melanogaster.">Systemic bacterial infection and immune defense phenotypes in Drosophila melanogaster.</a> JoVE. , (2015).</li><li>Fernandez, R. W., Akinleye, A. A., Nurilov, M., Rouzyi, Z., Simon, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> , (2013).</li><li>Suh, G. S. B., 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+single+population+of+olfactory+sensory+neurons+mediates+an+innate+avoidance+behaviour+in+Drosophila.">A single population of olfactory sensory neurons mediates an innate avoidance behaviour in Drosophila.</a> Nature. 431, 854-859 (2004).</li><li>Helfrich-Fo&#776;rster, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+control+of+morning+and+evening+components+in+the+activity+rhythm+of+Drosophila+melanogaster.--Sex-specific+differences+suggest+a+different+quality+of+activity.">Differential control of morning and evening components in the activity rhythm of Drosophila melanogaster.--Sex-specific differences suggest a different quality of activity.</a> J. Biol. Rhythms. 15, 135-154 (2000).</li><li>Fujii, S., Krishnan, P., Hardin, P. E., Amrein, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nocturnal+male+sex+drive+in+Drosophila.">Nocturnal male sex drive in Drosophila.</a> Curr Biol. 17, 244-251 (2007).</li><li>Pellegrino, A. 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=Weather+forecasting+by+insects:+modified+sexual+behaviour+in+response+to+atmospheric+pressure+changes.">Weather forecasting by insects: modified sexual behaviour in response to atmospheric pressure changes.</a> PLoS One. 8, e75004 (2013).</li></ol>

The authors declare that they have no competing financial interests.

In this protocol, a detailed procedure for the quantification of social space was described. Some crucial steps to ensure the experiment is successful are: 1) always use gloves when cleaning and setting up the apparatus, to keep your own oils and scents off the inner chamber of the apparatus, 2) ensure flies are collected at least one day before the experiment to reduce any potential effects of cold anesthesia, 3) 2 hr before the experiment provide new vials containing fresh food to ensure the flies are not starved, and ...

Social interactions are crucial to the proper development and health of individuals within a group as a whole, and can be observed across numerous species, from humans (Homo sapiens) to simpler organisms such as fruit flies (Drosophila melanogaster) 5,6. An individual fruit fly or human share common means to process sensory information during these interactions, whether it be: auditory, visual, olfactory, tactile, or gustation. We and others hypothesize that there is a potentially shared neurocircuitry underlying behavioral responses to social interactions and that the neuronal cells and genes involved might be evolutionary conserved 7. Once the initial interaction has occurred, social space between the interacting individuals will either increase (social avoidance 8) or decrease (group formation/aggregation 5). More complicated interactions, like aggression or courtship, can then take place.
Neither sophisticated tools and methods, nor large investments in time and training are required to quantify this simple form of social behavior, making it a powerful analytical tool. Here, we explain a straightforward protocol that quantifies inter-fly distance, or social space, to assess social interaction in stable groups of Drosophila melanogaster, as used in the following studies 1-4,9. Social space refers to a measure of the distance between a fly and its closest neighbor 10. Social space is consistent for a given population of D. melanogaster when experimental conditions are preserved (averaging approximately within 1-2 body lengths), and varies with respect to the social experience of the flies, increasing if the individual has been kept in isolation 1. Proper vision is necessary to maintain normal social distance, but not classical odorants or cVA perception 1. Measure of social space can thus be used as a diagnostic tool to analyze social interactions and quantify social behavior in D. melanogaster 1. We describe here in details how to perform this quantification, and to what extent common experimental variables affect this behavior.
We show that the orientation of the chamber in which the assay is performed, as well as the number of flies &#8212; to an extent &#8212; do affects social space. It was previously shown that chamber geometry affects spontaneous exploratory movement of flies 11,12, and this phenomena may ultimately impact where they decide to settle. However, as long as the fly density (fly / cm2) and chamber orientation is kept the same, the social space of the flies also remains constant. The robustness of this assay is illustrated by the fact that independent laboratories using different chamber sizes, shape, and orientation can replicate the result displayed by mutants of the white gene (affecting eye pigmentation), which is an increase social space (vertical triangle or horizontal circle in 1, horizontal square with airflow in 3).
Our results also indicate that maintaining the time at which the social space experiment is performed is crucial to the consistency of the results, as we show that males, but not females, are further apart in the evenings. However, the differences seen between daytime and evening hours are not due to activity differences of the flies, and we discuss arguments indicating that activity levels are not correlated with social space.
Finally, there are genetic underpinnings to the determination of social space, as indicated by the white mutant already described 1,3, and the differences between various inbred and wild-caught strains of flies that we present here.
Therefore, this assay makes an excellent tool for studying the effects of genetic as well as environmental factors.

<table><tbody><tr><td>Stereo Zoom Microscope&amp;nbsp;</td><td>Nikon&amp;nbsp;&amp;nbsp;</td><td>SMZ-645</td><td>Any other standard scope for fly handling would work</td></tr><tr><td>Small paint brushes&amp;nbsp;</td><td></td><td></td><td>for pushing flies</td></tr><tr><td>Jazz-mix</td><td>Fisher</td><td>33545</td><td>any other standard drosophila food would work</td></tr><tr><td></td><td></td><td></td><td></td></tr><tr><td>Mini-Alarm Timer/Stopwatch</td><td></td><td></td><td></td></tr><tr><td>&amp;nbsp;Sharpie pens</td><td></td><td></td><td></td></tr><tr><td>Adhesive Tape</td><td></td><td></td><td></td></tr><tr><td>Medium size binder clips</td><td>Staples</td><td></td><td>to hold the chambers together: 1-1/4&quot; (32mm) medium clips with 5/8&quot; capacity</td></tr><tr><td>small SupportStands</td><td>Carolina&amp;nbsp;</td><td>707161</td><td>to hold the chambers in a vertical orientation</td></tr><tr><td>Buret clamps</td><td>Carolina</td><td>707362</td><td></td></tr><tr><td>Digital Camera</td><td>Nikon</td><td>&amp;nbsp;Coolpix S8000&amp;nbsp;</td><td>to take the still pictures</td></tr><tr><td>small ruler</td><td></td><td></td><td>to be able to scale the picture</td></tr><tr><td>trifold board and white bench cover</td><td></td><td></td><td>to provide a white background, and a homogeneous light.</td></tr><tr><td>pounding pad</td><td></td><td></td><td>any mouse pad works.</td></tr><tr><td></td><td></td><td></td><td></td></tr><tr><td>Prism 6</td><td>GraphPad Software Inc.</td><td>Prism 6 for Mac OS X</td><td>Any statistical analysis software with t-test, one-way and two ANOVA would work</td></tr></tbody></table>

conditions affecting social space in drosophila melanogaster

The social space assay described here can be used to quantify social interactions of Drosophila melanogaster &#8212; or other small insects &#8212; in a straightforward manner. As we previously demonstrated 1, in a two-dimensional chamber, we first force the flies to form a tight group, subsequently allowing them to take their preferred distance from each other. After the flies have settled, we measure the distance to the closest neighbor (or social space), processing a static picture with free online software (ImageJ). The analysis of the distance to the closest neighbor allows researchers to determine the effects of genetic and environmental factors on social interaction, while controlling for potential confounding factors. Diverse factors such as climbing ability, time of day, sex, and number of flies, can modify social spacing of flies. We thus propose a series of experimental controls to mitigate these confounding effects. This assay can be used for at least two purposes. First, researchers can determine how their favorite environmental shift (such as isolation, temperature, stress or toxins) will impact social spacing 1,2. Second, researchers can dissect the genetic and neural underpinnings of this basic form of social behavior 1,3. Specifically, we used it as a diagnostic tool to study the role of orthologous genes thought to be involved in social behavior in other organisms, such as candidate genes for autism in humans 4.

The social space chamber can be used as a tool to quantify the social behavior of Drosophila melanogaster. Acrylic spacers and glass panes are clipped together to form an inner triangular arena that provides a two-dimensional area in which flies can form stable groups without the presence of many potentially confounding cues. When flies are transferred to the vertical arena, they are startled by being tapped down, and they respond by an escape behavior: negative geotaxis. They climb to the vertex of the upright ...

Watch this Scientific Journal Video about Conditions Affecting Social Space in Drosophila melanogaster at JoVE.com

Conditions Affecting Social Space in Drosophila melanogaster

The effect of genes and environment on social space of Drosophila melanogaster can be quantified through a powerful but straightforward analytical paradigm. We show here different factors that can affect this social space, and thus need to be taken into consideration when designing experiments in this paradigm.

Conditions Affecting Social Space in Drosophila melanogaster

The social space assay described here can be used to quantify social interactions of Drosophila melanogaster &#8212; or other small insects &#8212; in a ...

conditions-affecting-social-space-in-drosophila-melanogaster

Research

JoVE Journal

Neuroscience

12.1K Views.  University of Western Ontario. The effect of genes and environment on social space of Drosophila melanogaster can be quantified through a powerful but straightforward analytical paradigm. We show here different factors that can affect this social space, and thus need to be taken into consideration when designing experiments in this paradigm.

Video: Conditions Affecting Social Space in Drosophila melanogaster

Rearing the Fruit Fly Drosophila melanogaster Under Axenic and Gnotobiotic Conditions

The influence of microbes on myriad animal traits and behaviors has been increasingly recognized in recent years. The fruit fly Drosophila melanogaster is a model for understanding microbial interactions with animal hosts, facilitated by approaches to rear large sample sizes of Drosophila under microorganism-free (axenic) conditions, or with defined microbial communities (gnotobiotic). This work outlines a method for collection of Drosophila embryos, hypochlorite dechorionation and sterilization, and transfer to sterile diet. Sterilized embryos are transferred to sterile diet in 50 ml centrifuge tubes, and developing larvae and adults remain free of any exogenous microbes until the vials are opened. Alternatively, flies with a defined microbiota can be reared by inoculating sterile diet and embryos with microbial species of interest. We describe the introduction of 4 bacterial species to establish a representative gnotobiotic microbiota in Drosophila. Finally, we describe approaches for confirming bacterial community composition, including testing if axenic Drosophila remain bacteria-free into adulthood.

Rearing the Fruit Fly Drosophila melanogaster Under Axenic and Gnotobiotic Conditions

A method for rearing Drosophila melanogaster under axenic and gnotobiotic conditions is presented. Fly embryos are dechorionated in sodium hypochlorite, transferred aseptically to sterile diet, and reared in closed containers. Inoculating diet and embryos with bacteria leads to gnotobiotic associations, and bacterial presence is confirmed by plating whole-body Drosophila homogenates.

The influence of microbes on myriad animal traits and behaviors has been increasingly recognized in recent years. The fruit fly Drosophila melanogaster is ...

Developmental Biology

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors remains poorly understood. In Drosophila melanogaster, environmental cues, such as food availability, affect mating activity offering a tractable system to investigate the mechanisms modulating sexual behavior. In D. melanogaster, environmental cues are often sensed via the chemosensory gustatory and olfactory systems. Here, we present a method to test the effect of environmental chemical cues on mating behavior. The assay consists of a small mating arena containing food medium and a mating couple. The mating frequency for each couple is continuously monitored for 24 h. Here we present the applicability of this assay to test environmental compounds from an external source through a pressurized air system as well as manipulation of the environmental components directly in the mating arena. The use of a pressurized air system is especially useful to test the effect of very volatile compounds, while manipulating components directly in the mating arena can be of value to ascertain a compound's presence. This assay can be adapted to answer questions about the influence of genetic and environmental cues on mating behavior and fecundity as well as other male and female reproductive behaviors.

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

We demonstrate an assay to analyze the environmental and genetic cues that influence mating behavior in the fruit fly Drosophila melanogaster.

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors ...

Behavior

Methods to Assay Drosophila Behavior

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular disease and various neurological diseases1. We have optimized simple and robust behavioral assays for determining larval locomotion, adult climbing ability (RING assay), and courtship behaviors of Drosophila. These behavioral assays are widely applicable for studying the role of genetic and environmental factors on fly behavior. Larval crawling ability can be reliably used for determining early stage changes in the crawling abilities of Drosophila larvae and also for examining effect of drugs or human disease genes (in transgenic flies) on their locomotion. The larval crawling assay becomes more applicable if expression or abolition of a gene causes lethality in pupal or adult stages, as these flies do not survive to adulthood where they otherwise could be assessed. This basic assay can also be used in conjunction with bright light or stress to examine additional behavioral responses in Drosophila larvae. Courtship behavior has been widely used to investigate genetic basis of sexual behavior, and can also be used to examine activity and coordination, as well as learning and memory. Drosophila courtship behavior involves the exchange of various sensory stimuli including visual, auditory, and chemosensory signals between males and females that lead to a complex series of well characterized motor behaviors culminating in successful copulation. Traditional adult climbing assays (negative geotaxis) are tedious, labor intensive, and time consuming, with significant variation between different trials2-4. The rapid iterative negative geotaxis (RING) assay5 has many advantages over more widely employed protocols, providing a reproducible, sensitive, and high throughput approach to quantify adult locomotor and negative geotaxis behaviors. In the RING assay, several genotypes or drug treatments can be tested simultaneously using large number of animals, with the high-throughput approach making it more amenable for screening experiments.

Methods to Assay Drosophila Behavior

Drosophila melanogaster is a genetically and behaviorally tractable model system that has been used to understand the molecular and cellular basis of many important biological processes for over a century 1. Drosophila has been well exploited to gain insights into the genetic basis of fly behavior.

Drosophila melanogaster, the fruit fly, has been used to study molecular mechanisms of a wide range of human diseases such as cancer, cardiovascular ...

An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time

Temperature is a ubiquitous environmental factor that affects how species distribute and behave. Different species of Drosophila fruit flies have specific responses to changing temperatures according to their physiological tolerance and adaptability. Drosophila flies also possess a temperature sensing system that has become fundamental to understanding the neural basis of temperature processing in ectotherms. We present here a temperature-controlled arena that permits fast and precise temperature changes with temporal and spatial control to explore the response of individual flies to changing temperatures. Individual flies are placed in the arena and exposed to pre-programmed temperature challenges, such as uniform gradual increases in temperature to determine reaction norms or spatially distributed temperatures at the same time to determine preferences. Individuals are automatically tracked, allowing the quantification of speed or location preference. This method can be used to rapidly quantify the response over a large range of temperatures to determine temperature performance curves in Drosophila or other insects of similar size. In addition, it can be used for genetic studies to quantify temperature preferences and reactions of mutants or wild-type flies. This method can help uncover the basis of thermal speciation and adaptation, as well as the neural mechanisms behind temperature processing.

An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time

Here we present a protocol to automatically determine the locomotor performance of Drosophila at changing temperatures using a programmable temperature-controlled arena that produces fast and accurate temperature changes in time and space.

Temperature is a ubiquitous environmental factor that affects how species distribute and behave. Different species of Drosophila fruit flies have specific ...

Flypub To Study Ethanol Induced Behavioral Disinhibition and Sensitization

Alcohol use disorder (AUD) remains a serious problem in our society. To develop effective interventions for addiction, it is important to understand the underlying neurobiological mechanisms, for which diverse experimental approaches and model systems are needed. The main ingredient of alcoholic beverages is ethanol, which causes adaptive changes in the central nervous system and behavior upon chronic intake. Behavioral sensitization (i.e., escalated responses) in particular represents a key adaptive change underlying addiction. Most ethanol-induced behavioral sensitization studies in animal models have been conducted on the locomotor activating effect of ethanol. A prominent effect of ethanol is behavioral disinhibition. Behavioral sensitization to the disinhibition effect of ethanol, however, is underrepresented. To address this issue, we developed the Flypub assay that allows measuring the escalated increase in disinhibited courtship activities upon recurring ethanol exposure in Drosophila melanogaster.&#160;Here, we report the step-by-step Flypub assay including assembly of ethanol exposure chambers, setup of the assay station, criteria for fly care and collection, ethanol delivery, quantification of disinhibited courtship activities, data processing and statistical analysis. Also provided are how to troubleshoot critical steps, overcome limitations and expand its utility to assess additional ethanol-induced behaviors. The Flypub assay in combination with powerful genetic tools in Drosophila melanogaster will facilitate the task of discovering the mechanism underlying ethanol-induced behavioral sensitization.

The Flypub assay measures the behaviors that the fruit fly Drosophila melanogaster displays under the influence of ethanol. The assay can be readily mastered by experimenters at all levels and applied to various vaporized stimuli, facilitating substance abuse and addiction studies.

Alcohol use disorder (AUD) remains a serious problem in our society. To develop effective interventions for addiction, it is important to understand the ...

Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such behavior is spontaneous locomotor activity. Here we describe our protocol that utilizes Drosophila population monitors and a tracking system that allows continuous monitoring of the spontaneous locomotor activity of flies for several days at a time. This method is simple, reliable, and objective and can be used to examine the effects of aging, sex, changes in caloric content of food, addition of drugs, or genetic manipulations that mimic human diseases.

Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

Drosophila melanogaster are useful in studying genetic or environmental manipulations that affect behaviors such as spontaneous locomotor activity.&#160; Here we describe a protocol that utilizes monitors with infrared beams and data analysis software to quantify spontaneous locomotor activity.&#160;

Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such ...

Straightforward Assay for Quantification of Social Avoidance in Drosophila melanogaster

Drosophila melanogaster is an emerging model to study different aspects of social interactions. For example, flies avoid areas previously occupied by stressed conspecifics due to an odorant released during stress known as the Drosophila stress odorant (dSO). Through the use of the T-maze apparatus, one can quantify the avoidance of the dSO by responder flies in a very affordable and robust assay. Conditions necessary to obtain a strong performance are presented here. A stressful experience is necessary for the flies to emit dSO, as well as enough emitter flies to cause a robust avoidance response to the presence of dSO. Genetic background, but not their group size, strongly altered the avoidance of the dSO by the responder flies. Canton-S and Elwood display a higher performance in avoiding the dSO than Oregon and Samarkand strains. This behavioral assay will allow identification of mechanisms underlying this social behavior, and the assessment of the influence of genes and environmental conditions on both emission and avoidance of the dSO. Such an assay can be included in batteries of simple diagnostic tests used to identify social deficiencies of mutants or environmental conditions of interest.

Straightforward Assay for Quantification of Social Avoidance in Drosophila melanogaster

Here, we present a protocol to quantify the avoidance of stressed individuals. This paradigm is powerful yet user-friendly and can be used to assess the influence of genes and environment on one kind of social interaction in Drosophila melanogaster.

Drosophila melanogaster is an emerging model to study different aspects of social interactions. For example, flies avoid areas previously occupied by ...

A New Approach that Eliminates Handling for Studying Aggression and the "Loser" Effect in Drosophila melanogaster

Aggressive behavior in Drosophila melanogaster is composed of the sequential expression of stereotypical behavioral patterns (for analysis see 1). This complex behavior is influenced by genetic, hormonal and environmental factors. As in many organisms, previous fighting experience influences the fighting strategy of flies and the outcome of later contests: losing a fight increases the probability of losing later contests, revealing &#34;loser&#34; effects that likely involve learning and memory 2-4. The learning and memory that accompanies expression of complex social behaviors like aggression, is sensitive to pre-test handling of animals 5,6. Many experimental procedures are used in different laboratories to study aggression 7-9, however, no routinely used protocol that excludes handling of flies is currently available. Here, we report a new behavioral apparatus that eliminates handling of flies, using instead their innate negative geotactic responses to move animals into or out of fighting chambers. In this protocol, small circular fight arenas containing a food cup are divided into two equal halves by a removable plastic slider prior to introduction of flies. Flies enter chambers from their home isolation vials via sliding chamber doors and geotaxis. Upon removal of plastic sliders, flies are free to interact. After specified time periods, flies are separated again by sliders for subsequent experimentation. All of this is done easily without handling of individual flies. This apparatus offers a novel approach to study aggression and the associated learning and memory, including the formation of &#34;loser&#34; effects in fly fights. In addition, this new general-purpose behavioral apparatus can be employed to study other social behaviors of flies and should, in general, be of interest for investigating experience-related changes in fundamental behavioral processes.

A New Approach that Eliminates Handling for Studying Aggression and the "Loser" Effect in Drosophila melanogaster

During fruit fly fights, the behavioral patterns observed, fight dynamics, and associated learning and memory are influenced by experimental conditions. The protocol presented here describes a novel procedure that entirely eliminates handling of flies during experiments. This improves fight dynamics and allows formation of strong &#34;loser&#34; effects.

Aggressive behavior in Drosophila melanogaster is composed of the sequential expression of stereotypical behavioral patterns (for analysis see 1). This ...

Measuring and Altering Mating Drive in Male Drosophila melanogaster

Despite decades of investigation, the neuronal and molecular bases of motivational states remain mysterious. We have recently developed a novel, reductionist, and scalable system for in-depth investigation of motivation using the mating drive of male Drosophila&#160;melanogaster (Drosophila), the methods for which we detail here. The behavioral paradigm centers on the finding that male mating drive decreases alongside fertility over the course of repeated copulations and recovers over ~3 d. In this system, the powerful neurogenetic tools available in the fly converge with the genetic accessibility and putative wiring diagram available for sexual behavior. This convergence allows rapid isolation and interrogation of small neuronal populations with specific motivational functions. Here we detail the design and execution of the satiety assay that is used to measure and alter courtship motivation in the male fly. Using this assay, we also demonstrate that low male mating drive can be overcome by stimulating dopaminergic neurons. The satiety assay is simple, affordable, and robust to influences of genetic background. We expect the satiety assay to generate many new insights into the neurobiology of motivational states.

Measuring and Altering Mating Drive in Male Drosophila melanogaster

This article describes a behavioral assay that uses male mating drive in Drosophila melanogaster to study motivation. Using this method, researchers can utilize advanced fly neurogenetic techniques to uncover the genetic, molecular, and cellular mechanisms that underlie this motivation.

Despite decades of investigation, the neuronal and molecular bases of motivational states remain mysterious. We have recently developed a novel, ...

Drosophila Courtship Conditioning As a Measure of Learning and Memory

Many insights into the molecular mechanisms underlying learning and memory have been elucidated through the use of simple behavioral assays in model organisms such as the fruit fly, Drosophila melanogaster. Drosophila is useful for understanding the basic neurobiology underlying cognitive deficits resulting from mutations in genes associated with human cognitive disorders, such as intellectual disability (ID) and autism. This work describes a methodology for testing learning and memory using a classic paradigm in Drosophila known as courtship conditioning. Male flies court females using a distinct pattern of easily recognizable behaviors. Premated females are not receptive to mating and will reject the male&#39;s copulation attempts. In response to this rejection, male flies reduce their courtship behavior. This learned reduction in courtship behavior is measured over time, serving as an indicator of learning and memory. The basic numerical output of this assay is the courtship index (CI), which is defined as the percentage of time that a male spends courting during a 10 min interval. The learning index (LI) is the relative reduction of CI in flies that have been exposed to a premated female compared to na&#239;ve flies with no previous social encounters. For the statistical comparison of LIs between genotypes, a randomization test with bootstrapping is used. To illustrate how the assay can be used to address the role of a gene relating to learning and memory, the pan-neuronal knockdown of Dihydroxyacetone phosphate acyltransferase (Dhap-at) was characterized here. The human ortholog of Dhap-at, glyceronephosphate O-acyltransferase (GNPT), is involved in rhizomelic chondrodysplasia punctata type 2, an autosomal-recessive syndrome characterized by severe ID. Using the courtship conditioning assay, it was determined that Dhap-at is required for long-term memory, but not for short-term memory. This result serves as a basis for further investigation of the underlying molecular mechanisms.

Drosophila Courtship Conditioning As a Measure of Learning and Memory

This protocol describes a Drosophila learning and memory assay called courtship conditioning. This classic assay is based on a reduction of male courtship behavior after sexual rejection by a non-receptive premated female. This natural form of behavioral plasticity can be used to test learning, short-term memory, and long-term memory.

Many insights into the molecular mechanisms underlying learning and memory have been elucidated through the use of simple behavioral assays in model ...

Conditions Affecting Social Space in Drosophila melanogaster

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