The authors would like to thank Dr. Osama Refai from Dr. Randy Blakely&#39;s lab for guidance with the automated analysis of SWIP. This work was supported by funding from NIH R01 DA042156 to LC.

1. Preparation of Solutions and Media
<ol>
	<li>Prepare M9 buffer by dissolving KH2PO4 3.0 g (22.05 mM), Na2HPO4 6.0 g (42.2 mM), and NaCl 5.0 g (85.5 mM) in 1 L of autoclaved deionized water. Add 1.0 mL of 1 M MgSO4 (12 g in a final volume of 100 mL autoclaved deionized water) after autoclaving. Mix 100 mL of the resulting 10x M9 with 900 mL of autoclaved deionized water to make a 1x solution.</li>
	<li>To make egg buffer, dissolve 6.896 g of NaCl (118 mM), 3.578 ...

<ol>
	<li>de Bono, M., Villu Maricq, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuronal+Substrates+of+Complex+Behaviors+in+C.+elegans.">Neuronal Substrates of Complex Behaviors in C. elegans.</a> Annual Review of Neuroscience. 28 (1), 451-501 (2005).</li><li>Sawin, E. R., Ranganathan, R., Horvitz, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=C.+elegans+Locomotory+Rate+Is+Modulated+by+the+Environment+through+a+Dopaminergic+Pathway+and+by+Experience+through+a+Serotonergic+Pathway.">C. elegans Locomotory Rate Is Modulated by the Environment through a Dopaminergic Pathway and by Experience through a Serotonergic Pathway.</a> Neuron. 26 (3), 619-631 (2000).</li><li>McDonald, P. 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=Vigorous+Motor+Activity+in+Caenorhabditis+elegans+Requires+Efficient+Clearance+of+Dopamine+Mediated+by+Synaptic+Localization+of+the+Dopamine+Transporter+DAT-1.">Vigorous Motor Activity in Caenorhabditis elegans Requires Efficient Clearance of Dopamine Mediated by Synaptic Localization of the Dopamine Transporter DAT-1.</a> Journal of Neuroscience. 27 (51), 14216-14227 (2007).</li><li>Carvelli, L., Blakely, R. D., DeFelice, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopamine+Transporter/Syntaxin+1A+Interactions+Regulate+Transporter+Channel+Activity+and+Dopaminergic+Synaptic+Transmission.">Dopamine Transporter/Syntaxin 1A Interactions Regulate Transporter Channel Activity and Dopaminergic Synaptic Transmission.</a> Proceedings of the National Academy of Sciences of the United States of America. 105 (37), 14192 (2008).</li><li>Carvelli, L., Matthies, D. S., Galli, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mechanisms+of+amphetamine+actions+in+Caenorhabditis+elegans.">Molecular mechanisms of amphetamine actions in Caenorhabditis elegans.</a> Molecular Pharmacology. 78 (1), 151-156 (2010).</li><li>Refai, O., Blakely, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blockade+and+reversal+of+swimming-induced+paralysis+in+C.+elegans+by+the+antipsychotic+and+D2-type+dopamine+receptor+antagonist+azaperone.">Blockade and reversal of swimming-induced paralysis in C. elegans by the antipsychotic and D2-type dopamine receptor antagonist azaperone.</a> Neurochemistry International. , (2018).</li><li>Bermingham, D. P., 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+Atypical+MAP+Kinase+SWIP-13/ERK8+Regulates+Dopamine+Transporters+through+a+Rho-Dependent+Mechanism.">The Atypical MAP Kinase SWIP-13/ERK8 Regulates Dopamine Transporters through a Rho-Dependent Mechanism.</a> The Journal of Neuroscience. 37 (38), 9288-9304 (2017).</li><li>Nass, 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=A+genetic+screen+in+Caenorhabditis+elegans+for+dopamine+neuron+insensitivity+to+6-hydroxydopamine+identifies+dopamine+transporter+mutants+impacting+transporter+biosynthesis+and+trafficking.">A genetic screen in Caenorhabditis elegans for dopamine neuron insensitivity to 6-hydroxydopamine identifies dopamine transporter mutants impacting transporter biosynthesis and trafficking.</a> Journal of Neurochemistry. 94 (3), 774-785 (2005).</li><li>Hardaway, J. 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=Forward+genetic+analysis+to+identify+determinants+of+dopamine+signaling+in+Caenorhabditis+elegans+using+swimming-induced+paralysis.">Forward genetic analysis to identify determinants of dopamine signaling in Caenorhabditis elegans using swimming-induced paralysis.</a> G3. 2 (8), 961-975 (2012).</li><li>Hardaway, J. 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=Glial+Expression+of+the+Caenorhabditis+elegans+Gene+swip-10+Supports+Glutamate+Dependent+Control+of+Extrasynaptic+Dopamine+Signaling.">Glial Expression of the Caenorhabditis elegans Gene swip-10 Supports Glutamate Dependent Control of Extrasynaptic Dopamine Signaling.</a> Journal of Neuroscience. 35 (25), 9409-9423 (2015).</li><li>Felton, C. M., Johnson, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopamine+signaling+in+C.+elegans+is+mediated+in+part+by+HLH-17-dependent+regulation+of+extracellular+dopamine+levels.">Dopamine signaling in C. elegans is mediated in part by HLH-17-dependent regulation of extracellular dopamine levels.</a> G3. 4 (6), 1081-1089 (2014).</li><li>Lanzo, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silencing+of+Syntaxin+1A+in+the+Dopaminergic+Neurons+Decreases+the+Activity+of+the+Dopamine+Transporter+and+Prevents+Amphetamine-Induced+Behaviors+in+C.+elegans.">Silencing of Syntaxin 1A in the Dopaminergic Neurons Decreases the Activity of the Dopamine Transporter and Prevents Amphetamine-Induced Behaviors in C. elegans.</a> Frontiers in Physiology. 9 (576), (2018).</li><li>Safratowich, B. D., Lor, C., Bianchi, L., Carvelli, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amphetamine+activates+an+amine-gated+chloride+channel+to+generate+behavioral+effects+in+Caenorhabditis+elegans.">Amphetamine activates an amine-gated chloride channel to generate behavioral effects in Caenorhabditis elegans.</a> The Journal of Biological Chemistry. 288 (30), 21630-21637 (2013).</li><li>Safratowich, B. D., Hossain, M., Bianchi, L., Carvelli, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amphetamine+Potentiates+the+Effects+of+-Phenylethylamine+through+Activation+of+an+Amine-Gated+Chloride+Channel.">Amphetamine Potentiates the Effects of -Phenylethylamine through Activation of an Amine-Gated Chloride Channel.</a> Journal of Neuroscience. 34 (13), 4686-4691 (2014).</li><li>Carvelli, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amphetamine+activates+/+potentiates+a+ligand-gated+ion+channel.">Amphetamine activates / potentiates a ligand-gated ion channel.</a> Channels (Austin). 8 (4), 294-295 (2014).</li><li>Hardaway, J. 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=et+al.An+open-source+analytical+platform+for+analysis+of+C.+elegans+swimming-induced+paralysis.">et al.An open-source analytical platform for analysis of C. elegans swimming-induced paralysis.</a> Journal of Neuroscience Methods. 232, 58-62 (2014).</li><li>L&#252;ersen, K., Faust, U., Gottschling, D. -. C., D&#246;ring, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gait-specific+adaptation+of+locomotor+activity+in+response+to+dietary+restriction+in+Caenorhabditis+elegans.">Gait-specific adaptation of locomotor activity in response to dietary restriction in Caenorhabditis elegans.</a> The Journal of Experimental Biology. 217, 2480-2488 (2014).</li><li>Porta-de-la-Riva, M., Fontrodona, L., Villanueva, A., Cer&#243;n, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+Caenorhabditis+elegans+methods:+synchronization+and+observation.">Basic Caenorhabditis elegans methods: synchronization and observation.</a> Journal of Visualized Experiments. (64), e4019 (2012).</li><li>Lamitina, S. T., Morrison, R., Moeckel, G. W., Strange, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptation+of+the+nematode+Caenorhabditis+elegans.+to+extreme+osmotic+stress.">Adaptation of the nematode Caenorhabditis elegans. to extreme osmotic stress.</a> American Journal of Physiology-Cell Physiology. 286 (4), 785-791 (2004).</li><li>Masoudi, N., Ibanez-Cruceyra, P., Offenburger, S. -. L., Holmes, A., Gartner, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tetraspanin+(TSP-17)+Protects+Dopaminergic+Neurons+against+6-OHDA-Induced+Neurodegeneration+in+C.+elegans.">Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in C. elegans.</a> PLoS Genetics. 10 (12), 1004767 (2014).</li><li>Jayanthi, L. D., 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+Caenorhabditis+elegans+gene+T23G5.5+encodes+an+antidepressant-+and+cocaine-sensitive+dopamine+transporter.">The Caenorhabditis elegans gene T23G5.5 encodes an antidepressant- and cocaine-sensitive dopamine transporter.</a> Molecular Pharmacology. 54 (4), 601-609 (1998).</li></ol>

The authors have nothing to disclose.

Here, we describe a step-by-step protocol to perform a behavioral assay, SWIP, in C. elegans. This protocol is simple and straightforward with no major technical hurdles making this assay very user friendly. Nevertheless, there are some critical aspects that need to be considered in order to effectively perform the assay.
Care should be taken to ensure that the worms used for the assay are well fed, since dietary restriction affects SWIP17. Gentle handling of w...

Animals perform a variety of innate and complex behaviors that are mediated by different neurotransmitters coordinated by intricate signaling processes. The neurotransmitter dopamine (DA) mediates highly conserved behaviors across species, including learning, motor function and reward processing.
The soil nematode C. elegans, with a relatively simple and well mapped nervous system consisting of only 302 neurons, shows markedly complex behaviors, including many that are regulated by DA such as mating, learning, foraging, locomotion and egg laying1. Among other features, short life cycle, ease of handling and the conservation of signaling molecules, highlight the advantages of using C. elegans as a model for studying the neural basis of conserved behaviors.
The hermaphrodite C. elegans contains eight dopaminergic neurons; In addition to these, the male contains six extra pairs for mating purposes. As in mammals, these neurons synthesize DA and express the DA transporter (DAT-1), a membrane protein found exclusively in dopaminergic neurons, which transports DA released in the synaptic cleft back into the dopaminergic neurons. Moreover, most of the proteins involved in each step of synthesis, packaging and release of DA are highly conserved between worms and humans and, like in mammals, DA modulates feeding behaviors and locomotion in C. elegans2.
C. elegans crawls on solid surfaces and swims with a characteristic thrashing behavior in water. Interestingly, mutants lacking expression of DAT-1 (dat-1) crawl normally on solid surface but fail to sustain swimming when immersed in water. This behavior was termed swimming induced paralysis, or SWIP. Previous experiments demonstrated that SWIP, in part, is caused by an excess of DA in the synaptic cleft that ultimately overstimulates the D2-like postsynaptic receptors (DOP-3). Although originally identified in dat-1 knockout animals3, SWIP is also observed in wild-type animals treated with drugs that block the activity of DAT (e.g., imipramine4) and/or induce DA release (e.g., amphetamine5). On the other hand, pharmacological or genetic manipulations averting synthesis and release of DA and blocking DOP-3 receptor function prevent SWIP6. Taken together, these already published data have established SWIP as a reliable tool to study the behavioral effects caused by mutated proteins within dopaminergic synapses3,4,7 and to be employed for forward genetic screens for the identification of novel regulatory pathways involved in DA signaling7,8,9,10,11,12. Additionally, by providing an easily quantifiable readout of drug-induced behavior in living animals, SWIP enables the elucidation of mechanisms of action of drugs like amphetamine (AMPH) and azaperone at the dopaminergic synapses5,6,13,14,15.
Protocols for performing the SWIP assays have been described before16. Here, we describe in detail the methodology and setup to perform the assay with the goal of providing a visual guide for the C. elegans community to effectively perform SWIP.

<table border="0" cellpadding="0" cellspacing="0" style="width:992px;" width="991">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Aluminum foil</td>
			<td style="width:260px;">Reynolds wrap</td>
			<td style="width:267px;">1091835</td>
			<td style="width:171px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Amphetamine</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:267px;">51-63-8&#160;&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Autoclave</td>
			<td style="width:260px;"></td>
			<td style="width:267px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Bacterial Incubator</td>
			<td style="width:260px;">New Brunswick scientific</td>
			<td style="width:267px;">M1352-0000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Bacteriological grade, Agar</td>
			<td style="width:260px;">Lab Scientific, Inc</td>
			<td>&#160;A466</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Bacto (TM) Peptone</td>
			<td style="width:260px;">BD</td>
			<td>REF 211677</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Calcium Chloride (dihydrate)</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">C3881</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Camera&#160;</td>
			<td style="width:260px;">Thorlabs</td>
			<td style="width:267px;">U-CMAD3</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Centrifuge&#160;</td>
			<td style="width:260px;">Eppendorf 5810R 15amp</td>
			<td style="width:267px;">E215059</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Cholesterol</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">57-88-5</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Deionised water</td>
			<td style="width:260px;">Millipore</td>
			<td style="width:267px;">Z00QSV0WW</td>
			<td>Milli-Q</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Depression glass spot plate</td>
			<td style="width:260px;">Corning</td>
			<td style="width:267px;">Corning, Inc. 722085</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Erlenmeyer flask</td>
			<td style="width:260px;">ThermoFisher</td>
			<td style="width:267px;">4103-0250PK</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Eye lash</td>
			<td style="width:260px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Glass slide</td>
			<td style="width:260px;">Fisherbrand</td>
			<td>12-550-15</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Graphing and statistical software</td>
			<td style="width:260px;">Prism</td>
			<td style="width:267px;"></td>
			<td>Graphpad 5</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">HEPES</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">RB=H3375 &#38; H7006</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Hypochlorite</td>
			<td style="width:260px;">Hawkins</td>
			<td style="width:267px;">Sodium Hypochlorite 4-6%, USP&#34; 1 gal</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">LB Broth, Miller</td>
			<td style="width:260px;">Fisher</td>
			<td style="width:267px;">BP1426</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Magnesium Chloride (Hexahydrate)</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">RB=M0250</td>
			<td>500g</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Magnesium sulfate (heptahydrate)</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">M1880</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Magnetic stir bar</td>
			<td style="width:260px;">Fisherbrand</td>
			<td style="width:267px;">16-800-510&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Microcentrifuge tubes</td>
			<td style="width:260px;">ThermoFisher</td>
			<td style="width:267px;">69715</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">NA 22 bacteria</td>
			<td style="width:260px;">CGC</td>
			<td style="width:267px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Nystatin</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:267px;">1400-61-9</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Osmometer</td>
			<td style="width:260px;">Advanced Instruments, Inc</td>
			<td style="width:267px;">Model 3320</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Pasteur Pipettes</td>
			<td style="width:260px;">Fisherbrand</td>
			<td style="width:267px;">13-678-20A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Petriplates</td>
			<td style="width:260px;">Falcon</td>
			<td style="width:267px;">351007</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">pH Meter</td>
			<td style="width:260px;">Orion VersaStar Pro</td>
			<td style="width:267px;">IS-68X591202-B 0514</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Polystrine conical tubes</td>
			<td style="width:260px;">Falcon</td>
			<td style="width:267px;">352095</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Potassium Chloride</td>
			<td style="width:260px;">Sigma-Aldrich&#160;</td>
			<td style="width:267px;">P9541</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Potassium dihydrogen phosphate</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">7778-77-0</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Potassium Phosphate - DIBASIC</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td>P-8281</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Potassium Phosphate - MONOBASIC</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td>P0662</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Serological pipettes</td>
			<td style="width:260px;">VWR</td>
			<td style="width:267px;">10ml=89130-898</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Shaker</td>
			<td style="width:260px;">Reliable Scientific</td>
			<td>55S 12x16</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Sodium Chloride</td>
			<td style="width:260px;">Fisher</td>
			<td>RB=BP358-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Sodium dihydrogen Phosphate</td>
			<td style="width:260px;">Fisher</td>
			<td style="width:267px;">RB=S381</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Spreadsheet</td>
			<td style="width:260px;">MS office</td>
			<td style="width:267px;"></td>
			<td>Microsoft Excel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Stereo Microscope</td>
			<td style="width:260px;">Zeiss</td>
			<td style="width:267px;">Model tlb3. 1 stemi2000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Sterile Pipette tips</td>
			<td style="width:260px;">Various</td>
			<td style="width:267px;">02-707-400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Sucrose</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:267px;">RB=S5016</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Superglue</td>
			<td style="width:260px;">Loctite</td>
			<td style="width:267px;">1647358 .14 oz.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">SwimR sofware</td>
			<td style="width:260px;">10.18129/B9.bioc.SwimR</td>
			<td style="width:267px;"></td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:295px;">Tracker 2</td>
			<td style="width:260px;">Worm Tracker 2.0</td>
			<td style="width:267px;">www.mrc-lmb.cam.ac.uk/wormtracker/</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">Video recording software</td>
			<td>Virtualdub</td>
			<td style="width:267px;">http://www.virtualdub.org/</td>
			<td></td>
		</tr>
	</tbody>
</table>

swimming induced paralysis to assess dopamine signaling in caenorhabditis elegans

The swimming assay described in this protocol is a valid tool to identify proteins regulating the dopaminergic synapses. Similar to mammals, dopamine (DA) controls several functions in C. elegans including learning and motor activity. Conditions that stimulate DA release (e.g., amphetamine (AMPH) treatments) or that prevent DA clearance (e.g., animals lacking the DA transporter (dat-1) which are incapable of reaccumulating DA into the neurons) generate an excess of extracellular DA ultimately resulting in inhibited locomotion. This behavior is particularly evident when animals swim in water. In fact, while wild-type animals continue to swim for an extended period, dat-1 null mutants and wild-type treated with AMPH or inhibitors of the DA transporter sink to the bottom of the well and do not move. This behavior is termed "Swimming Induced Paralysis" (SWIP). Although the SWIP assay is well established, a detailed description of the method is lacking. Here, we describe a step-by-step guide to perform SWIP. To perform the assay, late larval stage-4 animals are placed in a glass spot plate containing control sucrose solution with or without AMPH. Animals are scored for their swimming behavior either manually by visualization under a stereoscope or automatically by recording with a camera mounted on the stereoscope. Videos are then analyzed using a tracking software, which yields a visual representation of thrashing frequency and paralysis in the form of heat maps. Both the manual and automated systems guarantee an easily quantifiable readout of the animals' swimming ability and thus facilitate screening for animals bearing mutations within the dopaminergic system or for auxiliary genes. In addition, SWIP can be used to elucidate the mechanism of action of drugs of abuse such as AMPH.

We present an example of SWIP assay induced by AMPH treatment. Figure 1 shows a schematic representation of the assay setup as described above. For the manual assay, about 8-10 age synchronized late L4 stage worms are collected with an eyelash or platinum pick and placed into a glass spot plate filled with 40 &#181;L of 200 mOsm/L sucrose (control solution) or sucrose with 0.5 mM AMPH and tested for SWIP.
<p class="jove_content" fo:keep-together.within-pa...

Watch this Scientific Journal Video about Swimming Induced Paralysis to Assess Dopamine Signaling in Caenorhabditis elegans at JoVE.com

Swimming Induced Paralysis to Assess Dopamine Signaling in Caenorhabditis elegans

Swimming induced paralysis (SWIP) is a well-established behavioral assay used to study the underlying mechanisms of dopamine signaling in Caenorhabditis elegans (C. elegans). However, a detailed method to perform the assay is lacking. Here, we describe a step-by-step protocol for SWIP.

Swimming Induced Paralysis to Assess Dopamine Signaling in Caenorhabditis elegans

The swimming assay described in this protocol is a valid tool to identify proteins regulating the dopaminergic synapses. Similar to mammals, dopamine (DA) ...

The overall goal of this procedure is to demonstrate Swimming-Induced Paralysis or SWIP, a behavioral assay to assess dopamine signaling in C.elegans. SWIP allows the quick identification of genes within or related to the dopaminergic synapsis. This method allows the investigation of the effects produced by an excess of extracellular dopamine that is caused for example by drugs or by mutations at the dopamine transporter.To ensure that all of the worms tested during the assay swim for the same amount of time, the animals must be transferred quickly into the solution. Demonstrating the procedure will be Sirisha Kudumala and Serene Sossi. They both work in my laboratory.To set up worm starter cultures, use a sterile spatula to cut small pieces of agar from a plate containing well fed C.elegans and transfer the agar pieces into individual NA22 E.coli plates. After incubating the plates at 20 degrees Celsius for three to four days, visually confirm the presence of gravid adults under a stereo microscope. To obtain a synchronized population of worms, squirt water onto a plate full of gravid adults.Gently swirl the plate to dislodge the worms and use a disposal pipette to transfer the worms into a 15 milliliter polystyrene conical tube. After pulling the worms from a second plate into the tube, collect the worms by centrifugation for three washes in 15 milliliters of autoclaved water per wash. The water should appear clear after the last wash.After the last centrifugation, add five milliliters of a freshly prepared sodium hypochloride sodium hydroxide solution to the worms and mix rapidly with a vortex. Incubate the tube on a rocker, place a drop of worm solution onto a glass microscope slide and check for worm lysis under a stereoscope every two minutes for four to eight minutes. When about 70%of the worms have been lysed and the eggs had been released, immediately stop the lysis with the addition of egg buffer.Then centrifuge the embryos and worm carcasses four times resuspending the pellet with fresh egg buffer between washes to remove any remaining bleach. After the last wash, the pellet should appear white. Resuspend the pellet in five milliliters of autoclaved water and five milliliters of 60%sucrose to separate the embryos from the carcasses by centrifugation.Remove the tube carefully from the centrifuge after the density gradient separation and use a glass Pasteur pipette to transfer three to four milliliters of the embryos floating at the upper meniscus into a new 15 milliliter conical tube. Wash the embryos three times with autoclaved water to remove the sucrose followed by three washes in M9 buffer. After the last wash, incubate the embryos on a shaker overnight in 10 milliliters of fresh M9 buffer to allow the eggs to hatch and remain at the L1 larval stage.After no more than 14 hours on the shaker, wash the L1 larvae three times with the autoclaved water to remove any pheromones released by the larvae and resuspend the larval pellet in one milliliter of water. Dilute an aliquot of worms to a one to 10 ratio and add 1:10 microliter drop onto a glass slide and count the worms under the stereo microscope. Repeat to obtain an average number of worms.Use a pipette to add enough droplets of the worm solution onto a room temperature NA22 plate to seed approximately one times 10 to the third worms for the culture and leave the plate half open until the drops dry out. Then incubate the plate covered and upside down at 20 degrees Celsius for about 44 to 48 hours or until the worms reach late L4 stage as confirmed visually under a stereo microscope. For manual assessment of SWIP, add 40 microliters of control solution with or without 0.5 millimolar amphetamine into a glass spot plate.Under a stereoscope, pick eight to 10 late L4 stage worms with an eyelash pick and submerge the pick in the well containing the solution until the worms move off the pick and swim into the solution. Start the timer. Note the number of worms released into the well and observe and record the number of worms exhibiting SWIP at each minute mark for a total of 10 minutes.At the end of the procedure, copy the raw data into a spreadsheet and calculate the percent of worms paralyzed by dividing the number of worms paralyzed at each minute by the total number of worms tested throughout the assay and multiplying by 100. Copy the percent values into any graphing and statistical software and plot the data with percent values of SWIP on the y-axis and time on the x-axis using the XY graph format. Statistical analysis among the control and amphetamine-treated groups and the time of treatment can be performed, for example by using two-way ANOVA and post hoc analysis.For automated analysis of swimming-induced paralysis, set up the camera, worm tracker software, and script to run the tracking software analysis and use an eyelash pick to place a single late stage L4 worm into a glass spot plate as shown earlier. Then record swimming videos of one worm at a time and use the worm tracker software to calculate the frequency of body bends, following the script provided with the tracking software to obtain the worm thrashing frequency, and to generate heat maps from the worm thrashing data. Most of the worms tested in the control solution swim continuously for at least 10 minutes.Worms exposed to either control or amphetamine do not show SWIP in the first minute of observation. However, while worms treated with the control solution continue to swim for 10 minutes, worms treated with amphetamine begin to exhibit SWIP after two minutes of treatment. And after 10 minutes, 66%of animals show SWIP.Here examples of heat maps of animals exposed to the control or to amphetamine are shown with an expected considerable increase in paralysis observed in the amphetamine-treated animals. Before attempting this assay, one should be well acquainted with the picking and developmental staging of C.elegans. The involvement of the dopaminergic system in SWIP behavior should be confirmed using animals lacking the expression of dopaminergic proteins or by the depletion of dopamine vesicles with Reserpine.SWIP can be instrumental in identifying new proteins involved in the mechanism of action of drugs acting at the dopaminergic synapsis.

swimming-induced-paralysis-to-assess-dopamine-signaling

Research

JoVE Journal

Behavior

7.5K vistas.  Florida Atlantic University, John D MacArthur Campus. El objetivo general de este procedimiento es demostrar parálisis inducida por la natación o SWIP, un ensayo conductual para evaluar la señalización de dopamina en C.elegans. SWIP permite la identificación rápida de genes dentro o relacionados con la sinapsis dopaminérgica. Este método permite la investigación de los efectos producidos por un exceso de dopamina extracelular que es causada por ejemplo por fármacos o por mutaciones en el transportador de dopamina.Para garantizar...