This work was supported by research grants to J.W.W. from the National Institute of Health (R01DK092640) and National Science Foundation (0920668).

1. Fly Collection and Starvation
<ol>
	<li>Rear the experimental flies under controlled temperature and humidity conditions (e.g. 21 &#176;C, 50-60% relative humidity) on a 12-hr light/dark cycle.</li>
	<li>Collect female flies on the day of eclosion and place them, along with 4-5 males, into new food vials (maximum 30 per vial). Age flies 2-5 days.</li>
	<li>Prepare the chambers for fly starvation.
	<ol>
		<li>Push a single tissue (4.8 x 8.4 inch) down to the bottom of an empty plastic vial. Completely soak t...

<ol>
	<li>Dethier, V. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The hungry fly : a physiological study of the behavior associated with feeding. , (1976).</li><li>Root, C. M., Ko, K. I., Jafari, A., Wang, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presynaptic+facilitation+by+neuropeptide+signaling+mediates+odor-driven+food+search.">Presynaptic facilitation by neuropeptide signaling mediates odor-driven food search.</a> Cell. 145, 133-144 (2011).</li><li>Root, C. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+presynaptic+gain+control+mechanism+fine-tunes+olfactory+behavior.">A presynaptic gain control mechanism fine-tunes olfactory behavior.</a> Neuron. 59, 311-321 (2008).</li><li>Semmelhack, J. L., Wang, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Select+Drosophila+glomeruli+mediate+innate+olfactory+attraction+and+aversion.">Select Drosophila glomeruli mediate innate olfactory attraction and aversion.</a> Nature. 459, 218-223 (2009).</li><li>Faucher, C., Forstreuter, M., Hilker, M., de Bruyne, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral+responses+of+Drosophila+to+biogenic+levels+of+carbon+dioxide+depend+on+life-stage,+sex+and+olfactory+context.">Behavioral responses of Drosophila to biogenic levels of carbon dioxide depend on life-stage, sex and olfactory context.</a> J. Exp. Biol. 209, 2739-2748 (2006).</li><li>Quinn, W. G., Harris, W. 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=Conditioned+behavior+in+Drosophila+melanogaster.">Conditioned behavior in Drosophila melanogaster.</a> Proc. Natl. Acad. Sci. U.S.A. 71, 708-712 (1974).</li><li>Fishilevich, E., Domingos, A. I., Asahina, K., Naef, F., Vosshall, L. B., Louis, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemotaxis+behavior+mediated+by+single+larval+olfactory+neurons+in+Drosophila.">Chemotaxis behavior mediated by single larval olfactory neurons in Drosophila.</a> Curr. Biol. 15, 2086-2096 (2005).</li><li>Venken, K. J., Simpson, J. H., Bellen, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+manipulation+of+genes+and+cells+in+the+nervous+system+of+the+fruit+fly.">Genetic manipulation of genes and cells in the nervous system of the fruit fly.</a> Neuron. 72, 202-230 (2011).</li><li>Hamada, F. 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=An+internal+thermal+sensor+controlling+temperature+preference+in+Drosophila.">An internal thermal sensor controlling temperature preference in Drosophila.</a> Nature. 454, 217-220 (2008).</li><li>Kitamoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conditional+modification+of+behavior+in+Drosophila+by+targeted+expression+of+a+temperature-sensitive+shibire+allele+in+defined+neurons.">Conditional modification of behavior in Drosophila by targeted expression of a temperature-sensitive shibire allele in defined neurons.</a> J. Neurobiol. 47, 81-92 (2001).</li><li>Sweeney, S. T., Broadie, K., Keane, J., Niemann, H., O'Kane, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+expression+of+tetanus+toxin+light+chain+in+Drosophila+specifically+eliminates+synaptic+transmission+and+causes+behavioral+defects.">Targeted expression of tetanus toxin light chain in Drosophila specifically eliminates synaptic transmission and causes behavioral defects.</a> Neuron. 14, 341-351 (1995).</li><li>Brand, A. H., Perrimon, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+gene+expression+as+a+means+of+altering+cell+fates+and+generating+dominant+phenotypes.">Targeted gene expression as a means of altering cell fates and generating dominant phenotypes.</a> Development. 118, 401-415 (1993).</li></ol>

The authors declare no competing financial interest.

In this protocol, we describe a step-by-step procedure for the food search behavior assay. In addition to food related odors, it may also be adapted for the study of the fly&#39;s ability to locate other odor objects. For example, it may be applied toward the study of mate localization behavior in male flies3 .There are several additional considerations for this protocol that we will mention here regarding this procedure:
First, the rearing temperature determines how long experiment...

States of hunger promote two types of appetitive behaviors: food search and food consumption1. This simple behavioral assay is useful for the study of chemotactic behaviors associated with foraging2,3. Specifically, it tracks fly position, walking speed and latency to locating a food odor target. Latency of food finding serves as metric for measuring changes in the sensitivity of the fly&#39;s odor detection system downstream of changes in its internal appetitive state. A manual version of this assay was previously used to show GABA-B receptor signaling is important for odor localization behavior in adult flies3. The current automated version of the assay was instrumental in the study of how short neuropeptide-F (sNPF) signaling reshapes the olfactory map in Drosophila and influences appetitive behaviors2.
Testing is done in a dark, temperature and humidity controlled room. Digital video cameras set above the clear acrylic testing plates track flies backlit by 660-nm LED illumination. Information from the camera is processed in real time by a computer stationed next to the testing area. We use data acquisition software to record and save the coordinates of fly positions during the testing period.
In this paradigm, the subject is released into an arena that contains a food odor at the center; the odor object creates a food odor gradient within the arena that induces food search behavior in the fly. A similar odor search protocol has been applied toward the study of chemosensation in single Drosophila larvae7. While other behavioral assays such as the four-field olfactometer4,5 or the t-maze6 evaluate odor aversion or attraction behaviors, this paradigm is best suited to evaluate olfactory sensitivity and chemotaxis behaviors.
Several key advantages accompany this assay. First, it permits rapid acquisition of large data sets, because data collection and analysis are mostly automated. Second, this assay isolates and measures the behavior of single flies, thus eliminating social olfactory cues that may influence their behaviors. Third, the simplicity of the protocol and simple experimental design make the assay efficient and easy to teach others.
In addition, this assay may be used to further probe neural circuits underlying food search behavior by combining it with the extensive genetic toolkit available to Drosophila melanogaster8. Targeted expression of transgenes that silence or excite neurons can be achieved with tools such as the GAL4-UAS system as well as the UAS-shibirets1, UAS-tetanus-toxin, and UAS-TrpA1(B) transgenes9-12.

<table border="1">
	<tbody>
		<tr>
			<td>Name of Reagent/Material</td>
			<td>Company </td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Apple Cider Vinegar</td>
			<td>Spectrum</td>
			<td></td>
			<td>commercially available</td>
		</tr>
		<tr>
			<td>Agarose, Type VII</td>
			<td>Sigma-Aldrich</td>
			<td>A0701</td>
			<td>low gelling temperature agarose</td>
		</tr>
		<tr>
			<td>Acrylic Testing Plate</td>
			<td></td>
			<td>custom</td>
			<td>Plate contains 6 arenas. Each arena is 60 mm in diameter 6 mm in height. See testing plate diagrams for specific measurements.</td>
		</tr>
		<tr>
			<td>LabVIEW V.8.5</td>
			<td>National Instruments</td>
			<td>776670-09</td>
			<td>platform for programs: PositioningTool.vi, FlyTracking--Six Zones.vi NOTE: &#34;elapsed time.vi&#34;, &#34;time into file.vi&#34;, and &#34;two object detect.vi&#34; are included subroutines that must be available in order for the main data acquisition program &#34;FlyTracking--Six zones.vi&#34; to run.</td>
		</tr>
		<tr>
			<td>LabVIEW Vision 8.5</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LabVIEW Vision Acquisition Software 8.5</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LabVIEW Vision Builder AI 3.5</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Igor Pro V.6</td>
			<td>Wavemetric, Inc.</td>
			<td></td>
			<td>platform for macro: Data Analysis for Fly Tracking--Six Zones</td>
		</tr>
		<tr>
			<td>Basler scA1390-17fm</td>
			<td>National Instruments</td>
			<td>779980-01</td>
			<td>Digital Camera NOTE: driver for camera available at Baslerweb.com</td>
		</tr>
		<tr>
			<td>8 mm lens</td>
			<td>National Instruments</td>
			<td>780024-01</td>
			<td>Lens for Basler Digital Camera</td>
		</tr>
		<tr>
			<td>Ground Glass Diffuser Plate</td>
			<td>Edmund Optics</td>
			<td>custom</td>
			<td>Diffuses light, 25 cm x 30 cm</td>
		</tr>
		<tr>
			<td>US Std. No. 100</td>
			<td>Fischer Scientific</td>
			<td>04-881X</td>
			<td>Sieve with nominal opening of 150 &#956;m</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Lighting Option 1</td>
		</tr>
		<tr>
			<td>LED backlight 660 nm (20 cm x 20 cm)</td>
			<td>Spectra West</td>
			<td>BL47192</td>
			<td>a simpler but more expensive lighting option.</td>
		</tr>
		<tr>
			<td>Power Supply for LED Backlight</td>
			<td>Spectra West</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Lighting Option 2</td>
		</tr>
		<tr>
			<td>660 nm LEDs</td>
			<td>Superbrightleds</td>
			<td>RL5R1330</td>
			<td>Wavelength 660 nm (approximately 7 x 7 LED array for a 14.7 inch x 9.75 inch panel)</td>
		</tr>
		<tr>
			<td>Linear DC Power Supply</td>
			<td>GW Instek</td>
			<td>GPS-1830D</td>
			<td>Power supply for LED Panel</td>
		</tr>
		<tr>
			<td>Solderless Breadboard</td>
			<td>Digikey</td>
			<td>922354-ND</td>
			<td>Breadboard for LEDs</td>
		</tr>
	</tbody>
</table>

a single-fly assay for foraging behavior in drosophila

For many animals, hunger promotes changes in the olfactory system in a manner that facilitates the search for appropriate food sources. In this video article, we describe an automated assay to measure the effect of hunger or satiety on olfactory dependent food search behavior in the adult fruit fly Drosophila melanogaster. In a light-tight box illuminated by red light that is invisible to fruit flies, a camera linked to custom data acquisition software monitors the position of six flies simultaneously. Each fly is confined to walk in individual arenas containing a food odor at the center. The testing arenas rest on a porous floor that functions to prevent odor accumulation. Latency to locate the odor source, a metric that reflects olfactory sensitivity under different physiological states, is determined by software analysis. Here, we discuss the critical mechanics of running this behavioral paradigm and cover specific issues regarding fly loading, odor contamination, assay temperature, data quality, and statistical analysis.

The data analysis software and the layout, an example of which can be seen in Figure 1, are used to evaluate each fly&#39;s performance during its 10 min trial according to a set of analysis criteria. The following criteria are used to determine whether data from each fly will be used for data analysis and are designed to eliminate those flies that are unable to perform the food search task due to injury, illness, stress, or lack of motivation.
Flies that are inactive for more...

Watch this Scientific Journal Video about A Single-fly Assay for Foraging Behavior in Drosophila at JoVE.com

A Single-fly Assay for Foraging Behavior in Drosophila

In this video article, we describe an automated assay to measure the effect of hunger or satiety on olfactory dependent food search behavior in the adult fruit fly Drosophila melanogaster.

A Single-fly Assay for Foraging Behavior in Drosophila

For many animals, hunger promotes changes in the olfactory system in a manner that facilitates the search for appropriate food sources. In this video ...

a-single-fly-assay-for-foraging-behavior-in-drosophila

Research

JoVE Journal

Neuroscience

13.1K vistas.  University of California-San Diego.  En este artículo de vídeo, se describe un ensayo automatizado para medir el efecto del hambre o la saciedad en el comportamiento de búsqueda de comida dependiente olfativo en la mosca adulta fruta Drosophila melanogaster. 