Name: determination of the spontaneous locomotor activity in drosophila melanogaster
Uploaded: 2014-04-10T16:00:00
Description: Watch this Scientific Journal Video about Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster at JoVE.com

This work was supported by a grant from the National Institutes of Health (AG023088 to B.R.).

Note: The Canton-S strain is the standard wild-type background line obtained from the Bloomington Stock Center.
1. Food Preparation and Recipe for 1,000 ml of Food
Note: This section describes the protocol for food preparation. Large metal pots are used to prepare about 18 L of food at a time. The protocol described here is downsized and uses 1,000 ml H2O. Food is autoclaved twice.
<ol>
	<li>Mix 113 g sucrose and 28 g brewers yeast in 643 ml water. Leav...

<ol>
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S., Martin, I., Bhandari, p., Cook-Wiends, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+senescence+in+Drosophila+melanogaster.">Functional senescence in Drosophila melanogaster.</a> Aging Res. Rev. 4 (3), 372-397 (2005).</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 (5), 386-395 (2005).</li><li>Nichols, C. D., Bechnel, J., Pandey, U. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+to+assay+Drosophila+behavior.">Methods to assay Drosophila behavior.</a> J. Vis. Exp. 61, 3791 (2012).</li><li>Long, T. A., Rice, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult+locomotor+activity+mediates+Intralocus+sexual+conflict+in+a+laboratory-adapted+population+of+Drosophila+melanogaster.">Adult locomotor activity mediates Intralocus sexual conflict in a laboratory-adapted population of Drosophila melanogaster.</a> Proc. Biol. Sci. 274 (1629), 3105-3112 (2007).</li><li>Slawson, J. B., Kim, E. Z., 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=High-resolution+video+tracking+of+locomotor+in+adult+Drosophila+melanogaster.">High-resolution video tracking of locomotor in adult Drosophila melanogaster.</a> J. Vis. Exp. 24 (24), 1096 (2009).</li><li>Marden, J. H., Rogina, B., Montooth, K. L., Helfand, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conditional+tradeoff+between+aging+and+organismal+performance+of+Indy+long-lived+mutant+flies.">Conditional tradeoff between aging and organismal performance of Indy long-lived mutant flies.</a> Proc. Natl. Acad. Sci. USA. 100 (6), 3369-3372 (2003).</li><li>Grover, D., Yang, J., Tavar&#233;, S., Tower, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+tracking+of+fly+movement+and+gene+expression+using+GFP.">Simultaneous tracking of fly movement and gene expression using GFP.</a> BMC Biotechnol. 8, 93 (2008).</li><li>Grover, D., Yang, J., Tavar&#233;, S., Tower, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+tracking+of+movement+and+gene+expression+in+multiple+Drosophila+melanogaster+flies+using+GFP+and+DsRED+fluorescent+reporter+transgenes.">Simultaneous tracking of movement and gene expression in multiple Drosophila melanogaster flies using GFP and DsRED fluorescent reporter transgenes.</a> BMC Res Notes. 2 (58), 1-11 (2009).</li><li>Ardekani, R., 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=Three-dimensional+tracking+and+behaviour+monitoring+of+multiple+fruit+flies.">Three-dimensional tracking and behaviour monitoring of multiple fruit flies.</a> J. R. Soc. Interface. 10 (78), (2013).</li><li>Branson, K. A., Robie, A. A., Bender, J., Perona, P., Dickinson, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+ethomics+in+large+groups+of+Drosophila.">High-throughput ethomics in large groups of Drosophila.</a> Nat Methods. 6 (6), 451-457 (2009).</li><li>Zou, 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=Recording+Lifetime+Behavior+and+Movement+in+an+Invertebrate+Model.">Recording Lifetime Behavior and Movement in an Invertebrate Model.</a> PLOS One. 6 (4), (2011).</li><li>Valente, D., Golani, I., Mitra, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+trajectory+of+Drosophila+melanogaster+in+a+circular+open+field+arena.">Analysis of the trajectory of Drosophila melanogaster in a circular open field arena.</a> PLoS One. 2 (10), 1083 (2007).</li><li>Inan, O. T., Marcu, O., Sanchez, M. E., Bhattacharya, S., Kovacs, K. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+portable+system+for+monitoring+the+behavioral+activity+of+Drosophila.">A portable system for monitoring the behavioral activity of Drosophila.</a> J Neurosci. Methods. 202 (1), 45-52 (2011).</li><li>Parashar, V., Rogina, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=dSir2+mediates+the+increased+spontaneous+physical+activity+in+flies+on+calorie+restriction.">dSir2 mediates the increased spontaneous physical activity in flies on calorie restriction.</a> Aging. 1 (6), 529-541 (2009).</li><li>Kaneuchi, T., Togawa, T., Matsuo, T., Fuyama, Y., Aigaki, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+measurement+of+H2O2+resistance+in+Drosophila+using+an+activity+monitor.">Efficient measurement of H2O2 resistance in Drosophila using an activity monitor.</a> Biogerontology. 4 (3), 157-165 (2003).</li><li>Carey, J. R., 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=Age-specific+and+lifetime+behavior+patterns+in+Drosophila+melanogaster+and+the+Mediterranean+fruit+fly,+Ceratitis+capitata.">Age-specific and lifetime behavior patterns in Drosophila melanogaster and the Mediterranean fruit fly, Ceratitis capitata.</a> Exp. Gerontol. 41 (1), 93-97 (2006).</li><li>Rhodenizer, D., Martin, I., Bhandari, P., Pletcher, S. D., Grotewiel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+and+environmental+factors+impact+age-related+impairment+of+negative+geotaxis+in+Drosophila+by+altering+age-dependent+climbing+speed.">Genetic and environmental factors impact age-related impairment of negative geotaxis in Drosophila by altering age-dependent climbing speed.</a> Exp. Gerontol. 43 (8), 739-749 (2008).</li><li>Osterwalder, T., Yoon, K. S., White, B. H., Keshishian, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+conditional+tissue-specific+transgene+expression+system+using+inducible+GAL4.">A conditional tissue-specific transgene expression system using inducible GAL4.</a> Proc. Natl. Acad. Sci. USA. 98 (22), 12596-12601 (2001).</li><li>Dietzl, G., 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+transgenic+RNAi+library+for+conditional+gene+inactivation+in+Drosophila.">A genome-wide transgenic RNAi library for conditional gene inactivation in Drosophila.</a> Nature. 448 (7150), 151-156 (2007).</li><li>Chiu, J. C., Low, K. H., Pike, D. H., Yildirim, E., Edery, I. <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+activity+to+study+circadian+rhythms+and+sleep+parameters+in+Drosophila.">Assaying locomotor activity to study circadian rhythms and sleep parameters in Drosophila.</a> J. Vis. Exp. 43, 2157 (2010).</li><li>Pfeiffenberger, C., Lear, B. C., Keegan, K. P., Allada, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Locomotor+activity+level+monitoring+using+the+Drosophila+Activity+Monitoring+(DAM)+System.">Locomotor activity level monitoring using the Drosophila Activity Monitoring (DAM) System.</a> Cold Spring Harbor Protoc. 11, (2010).</li><li>Pfeiffenberger, C., Lear, B. C., Keegan, K. P., Allada, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Processing circadian data collected from the Drosophila Activity Monitoring (DAM) System. Protoc. 11, (2010).</li><li>Ardekani, R., Tavar&#233;, S., Tower, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessing+senescence+in+Drosophila+using+video+tracking.">Assessing senescence in Drosophila using video tracking.</a> Methods Mol. Biol. 965, 501-516 (2013).</li></ol>

Spontaneous locomotor activity of flies is influenced by many factors such as age, genetic background, and gender2,13,18,19. In addition, environmental factors such as caloric content of the food, temperature of the environment, addition of different drugs, and day/night light cycle can affect fly activity. For instance, male flies of the same age have a higher spontaneous physical activity compared to females (Figure 1). Therefore, flies of the same age and gender should be compared to each o...

Fruit flies, Drosophila melanogaster, have been used as a valuable model organism to study mechanisms underlying complex behaviors, such as learning and memory, social interaction, aggression, drug abuse, sleep, sensory function, courtship, and mating1,2. One behavior that has been studied through multiple protocols is spontaneous locomotor activity. Negative geotaxis was one of the first methods developed for measuring Drosophila activity, and this protocol involves measuring the percentage of flies that reach a certain height of the vial after flies were shaken to the bottom of the container1,3.&#160; This method has advantages of being straightforward, inexpensive, and since it does not require any special equipment it can be performed in any laboratory. It has been used as a valuable screening tool to study effects of different genetic manipulations on fly mobility3. However, it is time and labor intensive and has the possibility of bias due to variable shaking of the vials and human recordings.&#160;
The negative geotaxis method was improved upon by development of the Rapid Iterative Negative Geotaxis (RING) method4,5, which takes photographs of the fly vials following shaking of the flies to the bottom. The advantage of this protocol is its sensitivity and the possibility of testing a large number of fly vials at the same time. However, this protocol still has the potential for human error, and only measures negative geotaxis. Other laboratories have used simple observation in culture vials to determine locomotor activity6.
Recently several video recording systems for measuring fly locomotor activity have been developed.&#160; One video monitoring protocol provides time for adjustment before recording7.&#160; The method described by Slawson et al.&#160;also uses an air pulse to stop movement until the start of recording, which could potentially be a stressor to the animals7.&#160; This method provides information on average speed, max speed, time spend in motion, etc.&#160; Another three-dimensional tracking system measures the maximal velocity of individual flies during ~0.2 seconds of free flight takeoff8. A three-dimensional video monitoring protocol uses flies expressing GFP and multiple cameras fitted with filters allowing for detection of fluorescence to determine fly mobility9. Flies in this protocol tend to exhibit cylindrical flight patterns, which is potentially due to the shape of Drosophila culture vials10. This method was improved by using a dome that allows measuring spontaneous movement of two flies11. A high-throughput method that uses a camera to automatically monitor and quantify the individual and social behavior of Drosophila has been also described12.&#160; Zou et al. developed a behavioral monitor system (BMS) that uses two computer-assisted cameras to record lifetime behavior and movements such as resting, moving, flying, eating, drinking, or deaths of individual tephritid fruit flies13. Several other video systems have been developed to monitor fly behavioral activity14,15. &#160;
Here we describe a method for quantifying Drosophila activity that utilizes population monitors. These monitors are housed in temperature- and humidity-controlled incubators at 25 &#176;C on a 12 hour day-night light cycle. Each population monitor has infrared beams placed in rings positioned at three different heights. Every time a fly moves across the rings it interrupts the infrared beam, which is recorded by a microprocessor that independently records and counts the activity of flies within the vial. A microprocessor uploads the total activity within the vial to the computer at user-defined intervals that could vary from 1 second to 60 minutes. The method described here provides ample time for flies to adjust to the new environment and allows for simultaneous measuring of the spontaneous locomotor activity of as many as 120 populations of flies. In addition, we describe preparation of the food, fly maintenance, setting up the mobility population monitors in temperature controlled incubators, and potential factors that may affect results. This method can be used to study how different environmental or genetic modifications affect spontaneous locomotor activity of the flies.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Sucrose FCC Food Grade 100 LB,</td>
			<td>Fisher Scientific MP Biomedicals</td>
			<td>ICN90471380</td>
			<td></td>
		</tr>
		<tr>
			<td>Brewer&#8217;s Yeast</td>
			<td>Fisher Scientific MP Biomedicals</td>
			<td>ICN90331280</td>
			<td></td>
		</tr>
		<tr>
			<td>Drosophila Agar Fine</td>
			<td>SciMart</td>
			<td>DR-820-25F</td>
			<td></td>
		</tr>
		<tr>
			<td>Cornmeal</td>
			<td>Fisher Scientific MP Biomedicals</td>
			<td>ICN90141125</td>
			<td></td>
		</tr>
		<tr>
			<td>Methyl4-hydroxybenzoate, tegosept</td>
			<td>Sigma</td>
			<td>H5501-5KG</td>
			<td></td>
		</tr>
		<tr>
			<td>EtOH</td>
			<td>Pharmco-AAPER</td>
			<td>111000200</td>
			<td></td>
		</tr>
		<tr>
			<td>Active Dry Yeast</td>
			<td>Fisher Scientific</td>
			<td>ICN10140001</td>
			<td></td>
		</tr>
		<tr>
			<td>Fly CO2 pad</td>
			<td>LabScientific</td>
			<td>BGSU-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereo Microscope</td>
			<td>Olympus</td>
			<td>SZ40</td>
			<td></td>
		</tr>
		<tr>
			<td>Drosophila carbon dioxide (CO2) tank</td>
			<td>Airgas</td>
			<td>UN1013</td>
			<td></td>
		</tr>
		<tr>
			<td>Small paint brush for pushing the flies</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Shell vial wide</td>
			<td>Fischer Scientific</td>
			<td>AS519</td>
			<td></td>
		</tr>
		<tr>
			<td>Buzzplugs for wide plastic vials</td>
			<td>Fischer Scientific</td>
			<td>AS275</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass vials (25x95mm)</td>
			<td>Fischer Scientific Kimble 60931-8</td>
			<td>AS-574</td>
			<td></td>
		</tr>
		<tr>
			<td>Sponge plugs for glass vials</td>
			<td>SciMart</td>
			<td>DR-750</td>
			<td></td>
		</tr>
		<tr>
			<td>Drosophila Food Dispenser</td>
			<td>Applied Scientific (Fischer Scientific)</td>
			<td>AS780Q</td>
			<td></td>
		</tr>
		<tr>
			<td>DPM Drosophila Population Monitor</td>
			<td>Trikinetics Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DC Power Supply with line cord</td>
			<td>Trikinetics Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>PSIU9 The Power Supply Interface Unit</td>
			<td>Trikinetics Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Telephone cables and 5 way splitters</td>
			<td>Trikinetics Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Universal Serial Bus (USB) hardware</td>
			<td>Trikinetics Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Macintosh or Windows PC with UCB port</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DAMSystem308X Data Acquisition Software for Macintoch OSX (Intel)</td>
			<td>www.trikinetics.com</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DAMSystem308 Data Acquisition Software for Windows PC (XP/Vista/7)</td>
			<td>www.trikinetics.com</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DAMFileScan108X software for Macintosh</td>
			<td>www.trikinetics.com</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DAMFileScan108X software for Windows PC (XP/Vista/7)</td>
			<td>www.trikinetics.com</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>USB software (PSIUdrivers.zip)</td>
			<td>www.trikinetics.com</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DAMSystem Notes 308</td>
			<td><a href="http://www.trikinetics.com/Downloads/DAMSystem%20Notes%20308.pdf">(http://www.trikinetics.com/Downloads/DAMSystem%20Notes%20308.pdf</a></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

The spontaneous locomotor activity in Drosophila depends on fly gender (Figure 3A), calorie content of the food (Figure 3B) and the light/dark cycle. Once the light is switched off fly activity dramatically decreases. Figure 3A illustrates 24 hours of locomotor activity recordings of male and female flies. An asterisk on the x-axis marks the time when the light was switched off and the transition to dark cycle. Figure 3B illustrates the standard...

Watch this Scientific Journal Video about Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster at JoVE.com

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;

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 ...

determination-spontaneous-locomotor-activity-drosophila

Research

JoVE Journal

Neuroscience

Single Sensillum Recordings in the Insects Drosophila melanogaster and Anopheles gambiae

The sense of smell is essential for insects to find foods, mates, predators, and oviposition sites3. Insect olfactory sensory neurons (OSNs) are enclosed in sensory hairs called sensilla, which cover the surface of olfactory organs. The surface of each sensillum is covered with tiny pores, through which odorants pass and dissolve in a fluid called sensillum lymph, which bathes the sensory dendrites of the OSNs housed in a given sensillum. The OSN dendrites express odorant receptor (OR) proteins, which in insects function as odor-gated ion channels4, 5. The interaction of odorants with ORs either increases or decreases the basal firing rate of the OSN. This neuronal activity in the form of action potentials embodies the first representation of the quality, intensity, and temporal characteristics of the odorant6, 7.
Given the easy access to these sensory hairs, it is possible to perform extracellular recordings from single OSNs by introducing a recording electrode into the sensillum lymph, while the reference electrode is placed in the lymph of the eye or body of the insect. In Drosophila, sensilla house between one and four OSNs, but each OSN typically displays a characteristic spike amplitude. Spike sorting techniques make it possible to assign spiking responses to individual OSNs. This single sensillum recording (SSR) technique monitors the difference in potential between the sensillum lymph and the reference electrode as electrical spikes that are generated by the receptor activity on OSNs1, 2, 8. Changes in the number of spikes in response to the odorant represent the cellular basis of odor coding in insects. Here, we describe the preparation method currently used in our lab to perform SSR on Drosophila melanogaster and Anopheles gambiae, and show representative traces induced by the odorants in a sensillum-specific manner.

Single Sensillum Recordings in the Insects Drosophila melanogaster and Anopheles gambiae

Electrophysiological responses of olfactory sensory neurons to odorants can be measured in insects using single sensillum recordings. In this video article we will demonstrate how to perform single sensillum recordings in the antennae of the vinegar fly (Drosophila melanogaster) and the maxillary palps of the malaria mosquito (Anopheles gambiae).

The sense of smell is essential for insects to find foods, mates, predators, and oviposition sites3. Insect olfactory sensory neurons (OSNs) are enclosed ...

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

Most life forms exhibit daily rhythms in cellular, physiological and behavioral phenomena that are driven by endogenous circadian (&equiv;24 hr) pacemakers or clocks. Malfunctions in the human circadian system are associated with numerous diseases or disorders. Much progress towards our understanding of the mechanisms underlying circadian rhythms has emerged from genetic screens whereby an easily measured behavioral rhythm is used as a read-out of clock function. Studies using Drosophila have made seminal contributions to our understanding of the cellular and biochemical bases underlying circadian rhythms. The standard circadian behavioral read-out measured in Drosophila is locomotor activity. In general, the monitoring system involves specially designed devices that can measure the locomotor movement of Drosophila. These devices are housed in environmentally controlled incubators located in a darkroom and are based on using the interruption of a beam of infrared light to record the locomotor activity of individual flies contained inside small tubes. When measured over many days, Drosophila exhibit daily cycles of activity and inactivity, a behavioral rhythm that is governed by the animal's endogenous circadian system. The overall procedure has been simplified with the advent of commercially available locomotor activity monitoring devices and the development of software programs for data analysis. We use the system from Trikinetics Inc., which is the procedure described here and is currently the most popular system used worldwide. More recently, the same monitoring devices have been used to study sleep behavior in Drosophila. Because the daily wake-sleep cycles of many flies can be measured simultaneously and only 1 to 2 weeks worth of continuous locomotor activity data is usually sufficient, this system is ideal for large-scale screens to identify Drosophila manifesting altered circadian or sleep properties.

Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila

We describe procedures for recording daily locomotor activity rhythms of Drosophila and subsequent data analysis. Locomotor activity rhythms are a reliable behavioral output of animal circadian clocks and are used as the standard readout of clock function when studying circadian mutants or examining how the environment regulates the circadian system.

Most life forms exhibit daily rhythms in cellular, physiological and behavioral phenomena that are driven by endogenous circadian (&equiv;24 hr) ...

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Advances in genetic methods have enabled the study of genes involved in human neurodegenerative diseases using Drosophila as a model system1. Most of these diseases, including Alzheimer's, Parkinson's and Huntington's disease are characterized by age-dependent deterioration in learning and memory functions and movement coordination2. Here we use behavioral assays, including the negative geotaxis assay3 and the aversive phototaxic suppression assay (APS assay)4,5, to show that some of the behavior characteristics associated with human neurodegeneration can be recapitulated in flies. In the negative geotaxis assay, the natural tendency of flies to move against gravity when agitated is utilized to study genes or conditions that may hinder locomotor capacities. In the APS assay, the learning and memory functions are tested in positively-phototactic flies trained to associate light with aversive bitter taste and hence avoid this otherwise natural tendency to move toward light. Testing these trained flies 6 hours post-training is used to assess memory functions. Using these assays, the contribution of any genetic or environmental factors toward developing neurodegeneration can be easily studied in flies.

Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration

Behavior assays for measuring locomotor functions, learning, and memory abilities in Drosophila.

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

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

In this article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the lipophilic fluorescent membrane marker DiI. This method allows the visualization of neuronal cell morphology in great detail. It is possible to label any cell in the CNS: cell bodies of target neurons are visualized under DIC optics or by expression of a fluorescent genetic marker such as GFP. After labeling, the DiI can be transformed into a permanent brown stain by photoconversion to allow visualization of cell morphology with transmitted light and DIC optics. Alternatively, the DiI-labeled cells can be observed directly with confocal microscopy, enabling genetically introduced fluorescent reporter proteins to be colocalised. The technique can be used in any animal, irrespective of genotype, making it possible to analyze mutant phenotypes at single cell resolution.

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy.

In this  article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the ...

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

A growing number of genetically encoded tools are becoming available that allow non-invasive manipulation of the neural activity of specific neurons in Drosophila melanogaster1. Chief among these are optogenetic tools, which enable the activation or silencing of specific neurons in the intact and freely moving animal using bright light. Channelrhodopsin (ChR2) is a light-activated cation channel that, when activated by blue light, causes depolarization of neurons that express it. ChR2 has been effective for identifying neurons critical for specific behaviors, such as CO2 avoidance, proboscis extension and giant-fiber mediated startle response2-4. However, as the intense light sources used to stimulate ChR2 also stimulate photoreceptors, these optogenetic techniques have not previously been used in the visual system. Here, we combine an optogenetic approach with a mutation that impairs phototransduction to demonstrate that activation of a cluster of loom-sensitive neurons in the fly's optic lobe, Foma-1 neurons, can drive an escape behavior used to avoid collision. We used a null allele of a critical component of the phototransduction cascade, phospholipase C-&beta;, encoded by the norpA gene, to render the flies blind and also use the Gal4-UAS transcriptional activator system to drive expression of ChR2 in the Foma-1 neurons. Individual flies are placed on a small platform surrounded by blue LEDs. When the LEDs are illuminated, the flies quickly take-off into flight, in a manner similar to visually driven loom-escape behavior. We believe that this technique can be easily adapted to examine other behaviors in freely moving flies.

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

Genetically encoded optogenetic tools enable noninvasive manipulation of specific neurons in the Drosophila brain. Such tools can identify neurons whose activation is sufficient to elicit or suppress particular behaviors. Here we present a method for activating Channelrhodopsin2 that is expressed in targeted neurons in freely walking flies.

A  growing number of genetically encoded tools are becoming available that allow non-invasive  manipulation of the neural activity of specific neurons in ...

Optogenetic Perturbation of Neural Activity with Laser Illumination in Semi-intact Drosophila Larvae in Motion

Drosophila larval locomotion is a splendid model system in developmental and physiological neuroscience, by virtue of the genetic accessibility of the underlying neuronal components in the circuits1-6. Application of optogenetics7,8 in the larval neural circuit allows us to manipulate neuronal activity in spatially and temporally patterned ways9-13. Typically, specimens are broadly illuminated with a mercury lamp or LED, so specificity of the target neurons is controlled by binary gene expression systems such as the Gal4-UAS system14,15. In this work, to improve the spatial resolution to "sub-genetic resolution", we locally illuminated a subset of neurons in the ventral nerve cord using lasers implemented in a conventional confocal microscope. While monitoring the motion of the body wall of the semi-intact larvae, we interactively activated or inhibited neural activity with channelrhodopsin16,17 or halorhodopsin18-20, respectively. By spatially and temporally restricted illumination of the neural tissue, we can manipulate the activity of specific neurons in the circuit at a specific phase of behavior. This method is useful for studying the relationship between the activities of a local neural assembly in the ventral nerve cord and the spatiotemporal pattern of motor output.

Optogenetic Perturbation of Neural Activity with Laser Illumination in Semi-intact Drosophila Larvae in Motion

Here we describe a protocol for optogenetic manipulation of motoneuronal activity while monitoring changes in motor output (muscle contraction) in semi-intact Drosophila larvae using lasers within a conventional confocal microscope. This technique enables researchers to achieve local perturbation of neural activity in a few neuromeres to elucidate the dynamics of motor circuits.

Drosophila larval locomotion is a splendid model system in developmental and physiological neuroscience, by virtue of the genetic accessibility of the ...

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 ...

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.

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.

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

High-resolution Quantification of Odor-guided Behavior in Drosophila melanogaster Using the Flywalk Paradigm

In their natural environment, insects such as the vinegar fly Drosophila melanogaster are bombarded with a huge amount of chemically distinct odorants. To complicate matters even further, the odors detected by the insect nervous system usually are not single compounds but mixtures whose composition and concentration ratios vary. This leads to an almost infinite amount of different olfactory stimuli which have to be evaluated by the nervous system.
To understand which aspects of an odor stimulus determine its evaluation by the fly, it is therefore desirable to efficiently examine odor-guided behavior towards many odorants and odor mixtures. To directly correlate behavior to neuronal activity, behavior should be quantified in a comparable time frame and under identical stimulus conditions as in neurophysiological experiments. However, many currently used olfactory bioassays in Drosophila neuroethology are rather specialized either towards efficiency or towards resolution.
Flywalk, an automated odor delivery and tracking system, bridges the gap between efficiency and resolution. It allows the determination of exactly when an odor packet stimulated a freely walking fly, and to determine the animal&#180;s dynamic behavioral reaction.

High-resolution Quantification of Odor-guided Behavior in Drosophila melanogaster Using the Flywalk Paradigm

The automated tracking system Flywalk is used for high-resolution quantification of odor-guided behavior in Drosophila melanogaster.

In their natural environment, insects such as the vinegar fly Drosophila melanogaster are bombarded with a huge amount of chemically distinct odorants. To ...

A Behavioral Assay for Mechanosensation of MARCM-based Clones in Drosophila melanogaster

Because of the structural and functional homology to the hair cells of the mammalian inner ear, the neurons that innervate the Drosophila external sense organs provide an excellent model system for the study of mechanosensation. This protocol describes a simple touch behavior in fruit flies which can be used to identify mutations that interfere with mechanosensation. The tactile stimulation of a macrochaete bristle on the thorax of flies elicits a grooming reflex from either the first or third leg. Mutations that interfere with mechanotransduction (such as NOMPC), or with other aspects of the reflex arc, can inhibit the grooming response. A traditional screen of adult behaviors would have missed mutants that have essential roles during development. Instead, this protocol combines the touch screen with mosaic analysis with a repressible cell marker (MARCM) to allow for only limited regions of homozygous mutant cells to be generated and marked by the expression of green fluorescent protein (GFP). By testing MARCM clones for abnormal behavioral responses, it is possible to screen a collection of lethal p-element mutations to search for new genes involved in mechanosensation that would have been missed by more traditional methods.

A Behavioral Assay for Mechanosensation of MARCM-based Clones in Drosophila melanogaster

In order to identify novel mutations affecting mechanosensation, we designed an assay that measures the behavioral response to tactile stimulation of fly bristles in mutant clones generated by the MARCM method. The combination of techniques allows for the identification of mechanosensitive mutations that would otherwise be lethal.

Because of the structural and functional homology to the hair cells of the mammalian inner ear, the neurons that innervate the Drosophila external sense ...