Le travail a été soutenu par une NIH prix scientifique de développement clinique K08NS002083, une subvention de l&#39;Institut de recherche Shervert Frazier, et le Prix du jeune chercheur NARSAD à Edgar A. Buttner.

Une. Retard de développement / test de létalité: Le type sauvage (N2) et deux souches mutantes (MUT1 et Mut2) sont testés dans trois concentrations de clozapine dans une plaque de 12 puits <ol><li> Au jour 1, verser 2 ml NGM support 10 dans chaque puits d&#39;une plaque de 12 puits (chaque puits d&#39;un diamètre de 2 cm) et laisser durcir sur le banc à la température ambiante (RT) pendant la nuit. Le même jour, choisir une colonie de bactéries Escherichia coli OP50, infecter une bouteille de 50 ml de solution LB, et de la culture dans un shaker 37 ° C à 220 rpm rotation pendant la nuit. </li><li> Le jour 2, transférer 20 culture bactérienne ul OP50 sur le centre de chaque NGM bien. Incuber les plaques dans un incubateur à 37 ° C ou les laisser à la température ambiante pendant une nuit pour permettre au tapis bactérien de croître plus épais. </li><li> Faire une clozapine solution stock de 80 mM en dissolvant la clozapine dans le DMSO (diméthylsulfoxyde) solvant. Ensuite, faire une solution de travail de 80 pi avec la solution mère diluée dans 1,7 mM d&#39;acide acétique belon sur le tableau 1. Remarque: La solution de travail pour un médicament d&#39;intérêt particulier doit être déterminée en faisant une série de tests de concentration préliminaires pour trouver la concentration la plus appropriée pour distinguer le type sauvage des mutants. </li><li> Transfert de 80 ul solution de travail clozapine sur la plaque NGM ensemencé bien et agiter la plaque pour permettre la solution afin de répartir uniformément sur la surface. Attendez que la plaque sécher. Utilisation de la plaque pour le dosage, le même jour ou le placer dans un incubateur à 20 ° C pour être utilisé le jour suivant. Remarque: La solution de travail est une suspension de médicament en raison de la faible solubilité de la clozapine, en particulier à une concentration plus élevée. Par conséquent, le tube vortex avant de transférer la solution à la plaque de médicament, afin de garantir que la concentration de médicament est exacte. </li><li> Lavez vers une assiette de 3,5 cm contenant de nombreux adultes gravides avec le tampon M9 puis tournez-les dans un tube de 15 mlà 2000 rpm pendant 1 min. </li><li> Aspirer le surnageant. Ajouter 5 ml de solution d&#39;eau de Javel (NaOH: hypochlorite: le trou DDH 2 O à 04:01:05) et perturber les nématodes en retournant doucement les tubes. </li><li> Observer les animaux jusqu&#39;à ce que la moitié d&#39;entre eux sont dissous à environ 5 min. Centrifuger les œufs à 2000 rpm pendant 1 min. </li><li> Aspirer le surnageant et ajouter rapidement 14 ml de tampon M9. </li><li> Isoler les œufs à 2000 rpm pendant 1 min et aspirer le surnageant, laissant environ 100 solution ul. Vortex pour suspendre les oeufs. </li><li> Transfert 2 oeufs ul suspension dans M9 sur une plaque NGM régulière pour tester combien d&#39;oeufs sont transférés. Réglez le volume des œufs en suspension pour assurer qu&#39;il ya environ 30-35 œufs dans chaque transfert. Transférer 30 à 35 œufs dans chaque puits de la plaque de dosage et ensuite incuber dans un incubateur à 20 ° C pendant 24 heures. </li><li> Au premier jour de l&#39;essai, marquer le nombre d&#39;œufs éclos. Réglez le nombre total d&#39;animaux éclos à 25/well par picking hors les vers supplémentaires si nécessaire. </li><li> Les jours suivants, observer les animaux et de les marquer tous les 24 heures. Stade développement est reçu sur la base de la taille de l&#39;animal et la forme de la vulve 11. L&#39;expérience dure 5-6 jours avec l&#39;effet le plus robuste typiquement vu sur le troisième ou le quatrième jour. </li><li> Saisissez les données dans un fichier Excel et calculer le pourcentage d&#39;animaux à chaque étape de développement pour chaque jour de l&#39;expérience. Générer des graphiques avec la fonction &#39;100% Stacked colonne &quot;dans la colonne &#39;2 D &#39;menu. </li></ol> 2. Pharyngée pompage Dosage: Jeune adulte Animaux pour le type sauvage et souches mutantes sont notés sur la clozapine dosage plaques <ol><li> La plaque d&#39;essai est faite suivant le même protocole utilisé pour le dosage retard / de létalité de développement. </li><li> Choisissez 50 animaux L4 pour chaque souche de plaques NGM ensemencées 24 heures avant l&#39;essai et incuber les vers à 20 ° C. </li><li> Choisissez 10 animaux à un assay plaque bien. Ensuite, prenez 10 animaux à l&#39;autre et toutes les 15-20 minutes. </li><li> Après les animaux dans le premier puits ont été exposés au médicament pendant 30 minutes, commencer l&#39;essai en observant pharyngée pompage sous un microscope à dissection et marquer les pompes pendant 20 sec 9. Une fois pharyngée pompage est marqué, ramasser le ver de la plaque. </li></ol>

<ol>
	<li>Donohoe, D. R., Jarvis, R. A., Weeks, K., Aamodt, E. J., Dwyer, D. 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+adaptation+in+C.+elegans+produced+by+antipsychotic+drugs+requires+serotonin+and+is+associated+with+calcium+signaling+and+calcineurin+inhibition.">Behavioral adaptation in C. elegans produced by antipsychotic drugs requires serotonin and is associated with calcium signaling and calcineurin inhibition.</a> Neurosci. Res. 64, 280-289 (2009).</li><li>Karmacharya, 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=Clozapine+interaction+with+phosphatidyl+inositol+3-kinase+(PI3K)/insulin-signaling+pathway+in+Caenorhabditis+elegans.">Clozapine interaction with phosphatidyl inositol 3-kinase (PI3K)/insulin-signaling pathway in Caenorhabditis elegans.</a> Neuropsychopharmacology. 34, 1968-1978 (2009).</li><li>Rand, J. B., Johnson, C. D., Estein, H. F., Shakes, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Carnorhabditis elegans Modern Biological Analysis of an Organism. 48, 187-204 (1995).</li><li>Kwok, T. 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=A+small-molecule+screen+in+C.+elegans+yields+a+new+calcium+channel+antagonist.">A small-molecule screen in C. elegans yields a new calcium channel antagonist.</a> Nature. 441, 91-95 (2006).</li><li>Wang, X., Sliwoski, G. R., Buttner, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relevance+of+Caenorhabditis+elegans+genetics+for+understanding+human+psychiatric+disease.">The relevance of Caenorhabditis elegans genetics for understanding human psychiatric disease.</a> Harv. Rev. Psychiatry. 19, 210-218 (2011).</li><li>Donohoe, D. R., Aamodt, E. J., Osborn, E., Dwyer, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antipsychotic+drugs+disrupt+normal+development+in+Caenorhabditis+elegans+via+additional+mechanisms+besides+dopamine+and+serotonin+receptors.">Antipsychotic drugs disrupt normal development in Caenorhabditis elegans via additional mechanisms besides dopamine and serotonin receptors.</a> Pharmacol. Res. 54, 361-372 (2006).</li><li>Karmacharya, 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=Behavioral+effects+of+clozapine:+involvement+of+trace+amine+pathways+in+C.+elegans+and+M.+musculus.">Behavioral effects of clozapine: involvement of trace amine pathways in C. elegans and M. musculus.</a> Brain Res. 1393, 91-99 (2011).</li><li>Saur, T., 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+RNAi+Screen+in+Caenorhabditis+elegans+Identifies+the+Nicotinic+Acetylcholine+Receptor+Subunit+ACR-7+as+an+Antipsychotic+Drug+Target.">A Genome-Wide RNAi Screen in Caenorhabditis elegans Identifies the Nicotinic Acetylcholine Receptor Subunit ACR-7 as an Antipsychotic Drug Target.</a> PLoS Genet. 9, (2013).</li><li>Avery, L., You, Y. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> C. elegans feeding. WormBook, ed. The C. elegans Research Community, doi:10.1895/wormbook.1.150.1. , (2012).</li><li>Chaudhuri, J., Parihar, M., Pires-daSilva, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+introduction+to+worm+lab:+from+culturing+worms+to+mutagenesis.">An introduction to worm lab: from culturing worms to mutagenesis.</a> J Vis Exp. 47, (2011).</li><li>Lewis, J. A., Fleming, J. T., Estein, H. F., Shakes, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Carnorhabditis elegans Modern Biological Analysis of an Organism. 48, 3-29 (1995).</li><li>Davis, J. R., Li, Y., Rankin, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+developmental+exposure+to+ethanol+on+Caenorhabditis+elegans.">Effects of developmental exposure to ethanol on Caenorhabditis elegans.</a> Alcohol Clin. Exp. Res. 32, 853-867 (2008).</li><li>Kage-Nakadai, E., 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=Two+very+long+chain+fatty+acid+acyl-CoA+synthetase+genes,+acs-20+and+acs-22,+have+roles+in+the+cuticle+surface+barrier+in+Caenorhabditis+elegans.">Two very long chain fatty acid acyl-CoA synthetase genes, acs-20 and acs-22, have roles in the cuticle surface barrier in Caenorhabditis elegans.</a> PLoS One. 5, (2010).</li><li>Partridge, F. A., Tearle, A. W., Gravato-Nobre, M. J., Schafer, W. R., Hodgkin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+C.+elegans+glycosyltransferase+BUS-8+has+two+distinct+and+essential+roles+in+epidermal+morphogenesis.">The C. elegans glycosyltransferase BUS-8 has two distinct and essential roles in epidermal morphogenesis.</a> Dev. Biol. 317, 549-559 (2008).</li><li>Leung, C. K., Deonarine, A., Strange, K., Choe, K. P. <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+screening+and+biosensing+with+fluorescent+C.+elegans+strains.">High-throughput screening and biosensing with fluorescent C. elegans strains.</a> J. Vis. Exp. (51), (2011).</li></ol>

Les auteurs déclarent qu&#39;il n&#39;y a pas de conflit d&#39;intérêt en cause.

Ici, nous décrivons les méthodes pour tester les effets des APD sur le développement et le comportement de C. elegans. DMSO ou de l&#39;éthanol est utilisé pour dissoudre la clozapine, étant donné que le médicament est relativement insoluble dans l&#39;eau. Parce que les solvants ont été signalés à affecter C. elegans biologie 12, le DMSO seul ou groupes de contrôle éthanol seul sont essentiels. La plus forte concentration de DMSO utilisés dans nos essais est jusqu&#39;à 3%, ...

Caenorhabditis elegans est un organisme génétique simple prêtent à grande échelle écrans génétiques avant et arrière et des écrans génétiques chimiques. C. elegans est sensible à un large spectre de composés bioactifs et a donc été utilisée avec succès pour déterminer les mécanismes d&#39;action de ces divers composés. Par exemple, les composés bioactifs étudiés en utilisant la pharmacogénétique à vis sans fin comprennent des agonistes des récepteurs de l&#39;acétylcholine (par exemple, lévamisole, la nicotine, morantel, et pyrantel), anesthésiques (par exemple, l&#39;halothane), la caféine, les inhibiteurs de cholinestérase (par exemple, l&#39;aldicarbe, Lannate, et trichlorfon), le fluorure, le GABA-connexes composés (par exemple GABA et muscimol), l&#39;ivermectine, le paraquat, les esters de phorbol et les médicaments liés à la sérotonine (par exemple, la sérotonine et imiprimine) 3. Par ailleurs, C. elegans a été utilisé pour les écrans de petites molécules à grande échelle, permettant la découverte d&#39;un nouveau composé bioactifs et l&#39;identification de cibles génétiques nouveaux 4. Le C. génome elegans comprend médicament antipsychotique potentiel (APD) des cibles conservées chez l&#39;homme, y compris les gènes codant pour des protéines nécessaires à la synthèse des neurotransmetteurs et pour la structure et la fonction synaptique 5. Ainsi, C. elegans neurogénétique et offre de neurobiologie méthodes pour découvrir de nouveaux mécanismes moléculaires d&#39;action des APD. Dans les nématodes, exposition APD tôt dans le développement produit un retard de développement, et à des concentrations plus élevées, la létalité 2,6. Exposition APD à l&#39;âge adulte produit phénotypes comportementaux. Par exemple, l&#39;exposition clozapine inhibe la locomotion et du pharynx pompage et améliore la ponte 1,2,7. Retard de développement APD-induite et la létalité sont des phénotypes puissants pour grands écrans génétiques chimiques. Ces phénotypes sont complexes dans la mesure où ils ont probablement plus d&#39;un basi cellulaires et génétiquess. Par conséquent, ces écrans génétiques devraient donner une variété de cibles indirectes de drogue. Cependant, notre laboratoire a effectué des écrans de gènes candidats et un écran ARNi à grande échelle pour des suppresseurs de retard de développement APD-induite et de la létalité et les gènes qui codent probablement des cibles directes, y compris la dopamine, l&#39;insuline et les récepteurs nicotiniques de l&#39;acétylcholine 2,8 a réussi à récupérer. Cribles génétiques basés sur les comportements APD-induits chez l&#39;adulte ont également conduit à l&#39;identification de nouvelles cibles APD, et nous sommes maintenant la validation de cibles à partir des écrans à la fois développement et de comportement chez les mammifères 7. Ainsi, une approche génétique chimique invertébrés de découvrir de nouveaux mécanismes moléculaires d&#39;action des APD semble réalisable 5,8. Le C. elegans pharynx est un organe qui comprend 20 neurones, 20 des cellules musculaires, et les 20 cellules accessoires, enveloppés par une membrane basale. Semblable à cœur de mammifère, le pharynx est un autonomend pompes constamment aliment depuis l&#39;environnement externe 9. Inhibition de la vitesse de pompage du pharynx compromet l&#39;absorption de nourriture, et donc des mutations ou des médicaments qui inhibent pharyngée pompage cause de retard de développement ou arrêter 9. APD inhibent le taux de pompage du pharynx, soit dans le cadre de leurs effets sur le développement et la viabilité 1,2. Ici, nous utilisons la clozapine APD atypique comme un exemple pour démontrer dosages de médicaments pour le développement des nématodes et du pharynx pompage.

<table border="0" cellpadding="0" cellspacing="0" width="406">
	<tbody>
		<tr height="22">
			<td>Clozapine</td>
			<td>Sigma</td>
			<td>C6305</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Dimethyl sulfoxide (DMSO)</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:119px;">D8418</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Acetic acid (HAC)</td>
			<td style="width:71px;">Fisher</td>
			<td style="width:119px;">BP2401</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Sodium hydroxide(NaOH)</td>
			<td style="width:71px;">EMD</td>
			<td style="width:119px;">SX0590-13</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:216px;">Hypochlorite</td>
			<td style="width:71px;">Sigma-Aldrich</td>
			<td style="width:119px;">425044</td>
		</tr>
		<tr height="32">
			<td height="32" style="height:32px;width:236px;">Centrifuge 5810</td>
			<td style="width:188px;">Eppendorf</td>
			<td style="width:200px;">5810 000.017</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:236px;">Incubator shaker</td>
			<td style="width:188px;">New Brunswick Scientific</td>
			<td style="width:200px;">M1246-0006</td>
		</tr>
		<tr height="31">
			<td height="31" style="height:31px;width:236px;">Low temperature incubator 815</td>
			<td style="width:188px;">Precision Scientific</td>
			<td style="width:200px;">J1790-1B</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:236px;">Stereo microscope</td>
			<td style="width:188px;">Olympus</td>
			<td style="width:200px;">SZX12</td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:236px;">Petri dish 35 x 10 mm</td>
			<td style="width:188px;">Fisher Scientific</td>
			<td style="width:200px;">NC9434271</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;width:236px;">12-well tissue culture plate</td>
			<td style="width:188px;">BD Falcon</td>
			<td style="width:200px;">REF 353043</td>
		</tr>
	</tbody>
</table>

methods for studying the mechanisms of action of antipsychotic drugs in caenorhabditis elegans

Caenorhabditis elegans est un organisme génétique simple prêtent à grande échelle avant et arrière écrans génétiques et les écrans génétiques chimiques. Le C. génome elegans comprend médicament antipsychotique potentiel (APD) des cibles conservées chez l&#39;homme, y compris les gènes codant pour des protéines nécessaires à la synthèse des neurotransmetteurs et pour la structure et la fonction synaptique. Exposition APD produit retard et / ou la létalité chez les nématodes de développement d&#39;une manière dépendante de la concentration. Ces phénotypes sont dus, en partie, par l&#39;inhibition induite APD de 1,2 pharyngée pompage. Ainsi, le phénotype de développement a une base neuromusculaire, ce qui est utile pour des études pharmacogénétiques des neuroleptiques. Ici, nous démontrons des procédures détaillées pour tester les effets APD sur le développement des nématodes et du pharynx pompage. Pour le dosage du développement, les embryons sont placés synchronisés sur un milieu de croissance de nématodes (NGM) des plaques contenant APDs, et les stades de développement de l&#39;anusmaux sont ensuite marqués quotidien. Pour le test de débit de pompage du pharynx, mis en scène de jeunes animaux adultes sont testés sur des plaques NGM contenant APD. Le nombre de pompes du pharynx par unité de temps est enregistré, et le débit de pompage est calculé. Ces dosages peuvent être utilisés pour l&#39;étude de nombreux autres types de petites molécules ou même de grandes molécules.

Une. Le retard de développement / résultat du test de létalité Un résultat typique pour le dosage de retard / de létalité de développement est mise en évidence sur les figures 1a et 1b. Lorsque les animaux sauvages dans le groupe de contrôle ont grandi à l&#39;âge adulte gravide (figure 1a), les animaux de type sauvage exposées à la clozapine sont encore dans les jeunes stades larvaires ou sont morts (figure 1b). Figure 1c...

Watch this Scientific Journal Video about Methods for Studying the Mechanisms of Action of Antipsychotic Drugs in Caenorhabditis elegans at JoVE.com

Methods for Studying the Mechanisms of Action of Antipsychotic Drugs in Caenorhabditis elegans

Approches pour tester les effets des médicaments antipsychotiques (APDS) dans Caenorhabditis elegans sont démontrés. Les dosages sont décrits pour tester les effets des médicaments sur le développement et sur la viabilité et le taux de pompage du pharynx. Ces méthodes sont également applicables pour les expériences pharmacogénétiques avec d&#39;autres classes de médicaments que les PDA.

Méthodes pour étudier les mécanismes d&#39;action des antipsychotiques dans<em&gt; Caenorhabditis elegans</em

Caenorhabditis elegans is a simple genetic organism amenable to  large-scale forward and reverse genetic screens and chemical genetic screens. The C.  ...

methods-for-studying-mechanisms-action-antipsychotic-drugs

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JoVE Journal

Neuroscience

Methods for Studying the Mechanisms of Action of Antipsychotic Drugs in Caenorhabditis elegans

11.4K vues.  Harvard Medical School.  Approches pour tester les effets des médicaments antipsychotiques (APDS) dans Caenorhabditis elegans sont démontrés. Les dosages sont décrits pour tester les effets des médicaments sur le développement et sur la viabilité et le taux de pompage du pharynx. Ces méthodes sont également applicables pour les expériences pharmacogénétiques avec d'autres classes de médicaments que les PDA. 

Vidéo: Methods for Studying the Mechanisms of Action of Antipsychotic Drugs in Caenorhabditis elegans

Mouse in Utero Electroporation: Controlled Spatiotemporal Gene Transfection

In order to understand the function of genes expressed in specific region of the developing brain, including signaling molecules and axon guidance molecules, local gene transfer or knock- out is required. Gene targeting knock-in or knock-out into local regions is possible to perform with combination with a specific CRE line, which is laborious, costly, and time consuming. Therefore, a simple transfection method, an in utero electroporation technique, which can be performed with short time, will be handy to test the possible function of candidate genes prior to the generation of transgenic animals 1,2. In addition to this, in utero electroporation targets areas of the brain where no specific CRE line exists, and will limit embryonic lethality 3,4. Here, we present a method of in utero electroporation combining two different types of electrodes for simple and convenient gene transfer into target areas of the developing brain. First, a unique holding method of embryos using an optic fiber optic light cable will make small embryos (from E9.5) visible for targeted DNA solution injection into ventricles and needle type electrodes insertion to the targeted brain area 5,6. The patterning of the brain such as cortical area occur at early embryonic stage, therefore, these early electroporation from E9.5 make a big contribution to understand entire area patterning event. Second, the precise shape of a capillary prevents uterine damage by making holes by insertion of the capillary. Furthermore, the precise shape of the needle electrodes are created with tungsten and platinum wire and sharpened using sand paper and insulated with nail polish 7, a method which is described in great detail in this protocol. This unique technique allows transfection of plasmid DNA into restricted areas of the brain and will enable small embryos to be electroporated. This will help to, open a new window for many scientists who are working on cell differentiation, cell migration, axon guidance in very early embryonic stage. Moreover, this technique will allow scientists to transfect plasmid DNA into deep parts of the developing brain such as thalamus and hypothalamus, where not many region-specific CRE lines exist for gain of function (GOF) or loss of function (LOF) analyses.

Mouse in Utero Electroporation: Controlled Spatiotemporal Gene Transfection

A gene transfer method into the developing mouse brain is described by using a unique surgical method and special shape of electrodes. This unique technique allows transfection of plasmid DNA temporally and spatially, which will aid many neuroscientists in studying brain development.

Souris dans Utero électroporation: contrôlé Transefection Gene spatio-temporelle

In order to understand the function of genes expressed in specific region of the developing brain, including signaling molecules and axon guidance ...

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Neurosciences

Direct Intraventricular Delivery of Drugs to the Rodent Central Nervous System

Due to an inability to cross the blood brain barrier, certain drugs need to be directly delivered into the central nervous system (CNS). Our lab focuses specifically on antisense oligonucleotides (ASOs), though the techniques shown in the video here can also be used to deliver a plethora of other drugs to the CNS. Antisense oligonucleotides (ASOs) have the capability to knockdown sequence-specific targets 1 as well as shift isoform ratios of specific genes 2. To achieve widespread gene knockdown or splicing in the CNS of mice, the ASOs can be delivered into the brain using two separate routes of administration, both of which we demonstrate in the video.
The first uses Alzet osmotic pumps, connected to a catheter that is surgically implanted into the lateral ventricle. This allows the ASOs to be continuously infused into the CNS for a designated period of time. The second involves a single bolus injection of a high concentration of ASO into the right lateral ventricle. Both methods use the mouse cerebral ventricular system to deliver the ASO to the entire brain and spinal cord, though depending on the needs of the study, one method may be preferred over the other.

We describe a method to target drugs to the central nervous system by either implanting a catheter or performing a bolus injection into the right lateral ventricle in mice. We focus specifically on the delivery of antisense oligonucleotides. This technique is readily adaptable to other drugs and to rats.

Livraison intraventriculaire directe des médicaments pour le système nerveux central rongeurs

Due to an inability to cross the blood brain barrier, certain drugs need to be directly delivered into the central nervous system (CNS). Our lab focuses ...

A Caenorhabditis elegans Model System for Amylopathy Study

Amylopathy is a term that describes abnormal synthesis and accumulation of amyloid beta (A&beta;) in tissues with time. A&beta; is a hallmark of Alzheimer's disease (AD) and is found in Lewy body dementia, inclusion body myositis and cerebral amyloid angiopathy 1-4. Amylopathies progressively develop with time. For this reason simple organisms with short lifespans may help to elucidate molecular aspects of these conditions. Here, we describe experimental protocols to study A&beta;-mediated neurodegeneration using the worm Caenorhabditis elegans. Thus, we construct transgenic worms by injecting DNA encoding human A&beta;42 into the syncytial gonads of adult hermaphrodites. Transformant lines are stabilized by a mutagenesis-induced integration. Nematodes are age synchronized by collecting and seeding their eggs. The function of neurons expressing A&beta;42 is tested in opportune behavioral assays (chemotaxis assays). Primary neuronal cultures obtained from embryos are used to complement behavioral data and to test the neuroprotective effects of anti-apoptotic compounds.

A Caenorhabditis elegans Model System for Amylopathy Study

We describe methods to study aspects of amylopathies in the worm C. elegans. We show how to construct worms expressing human A&beta;42 in neurons and how to test their function in behavioral assays. We further show how to obtain primary neuronal cultures that can be used for pharmacological testing.

A<em&gt; Caenorhabditis elegans</em&gt; Système modèle pour l&#39;étude de Amylopathy

Amylopathy is a term that describes abnormal synthesis and accumulation of amyloid beta (A&beta;) in tissues with time. A&beta; is a hallmark of ...

Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna

Odorant molecules bind to their target receptors in a precise and coordinated manner. Each receptor recognizes a specific signal and relays this information to the brain. As such, determining how olfactory information is transferred to the brain, modifying both perception and behavior, merits investigation. Interestingly, there is emerging evidence that cellular transduction and transcriptional factors are involved in the diversification of olfactory receptor neuron. Here we provide a robust whole mount immunological labeling method to assay in vivo olfactory receptor neuron organization. Using this method, we identified all olfactory receptor neurons with anti-ELAV antibody, a known pan-neural marker and Or49a-mCD8::GFP, an olfactory receptor neuron specifically expressed in Nba neuron using anti-GFP antibody.

Whole Mount Immunolabeling of Olfactory Receptor Neurons in the Drosophila Antenna

Herein we describe the process of whole mount immunostaining of Drosophila antennae, which enables us to better understand the molecular mechanisms involved in the diversification of olfactory receptor neurons (ORN)s.

Tout le mont immunomarquage des récepteurs olfactifs neurones dans le<em&gt; Drosophila</em&gt; Antenne

Odorant molecules bind to their target receptors in a precise and coordinated manner. Each receptor recognizes a specific signal and relays this ...

An Assay for Measuring the Effects of Ethanol on the Locomotion Speed of Caenorhabditis elegans

Alcohol use disorders are a significant public health concern, for which there are few effective treatment strategies. One difficulty that has delayed the development of more effective treatments is the relative lack of understanding of the molecular underpinnings of the effects of ethanol on behavior. The nematode, Caenorhabditis elegans (C.&#160;elegans), provides a useful model in which to generate and test hypotheses about the molecular effects of ethanol. Here, we describe an assay that has been developed and used to examine the roles of particular genes and environmental factors in behavioral responses to ethanol, in which locomotion is the behavioral output. Ethanol dose-dependently causes an acute depression of crawling on an agar surface. The effects are dynamic; animals exposed to a high concentration demonstrate an initial strong depression of crawling, referred to here as initial sensitivity, and then partially recover locomotion speed despite the continued presence of the drug. This ethanol-induced behavioral plasticity is referred to here as the development of acute functional tolerance. This assay has been used to demonstrate that these two phenotypes are distinct and genetically separable. The straightforward locomotion assay described here is suitable for examining the effects of both genetic and environmental manipulations on these acute behavioral responses to ethanol in C.&#160;elegans.

An Assay for Measuring the Effects of Ethanol on the Locomotion Speed of Caenorhabditis elegans

C. elegans is a useful model for studying the effects of ethanol on behavior. We present a behavioral assay that quantifies the effects of ethanol on the locomotion speed of crawling worms; both initial sensitivity and the development of acute functional tolerance to ethanol can be measured with this assay.

Un test pour mesurer les effets de l&#39;éthanol sur la vitesse de Locomotion<em&gt; Caenorhabditis elegans</em

Alcohol use disorders are a significant public health concern, for which there are few effective treatment strategies. One difficulty that has delayed the ...

Agarose Microchambers for Long-term Calcium Imaging of Caenorhabditis elegans

Behavior is controlled by the nervous system. Calcium imaging is a straightforward method in the transparent nematode Caenorhabditis elegans to measure the activity of neurons during various behaviors. To correlate neural activity with behavior, the animal should not be immobilized but should be able to move. Many behavioral changes occur during long time scales and require recording over many hours of behavior. This also makes it necessary to culture the worms in the presence of food. How can worms be cultured and their neural activity imaged over long time scales? Agarose Microchamber Imaging (AMI) was previously developed to culture and observe small larvae and has now been adapted to study all life stages from early L1 until the adult stage of C. elegans. AMI can be performed on various life stages of C. elegans. Long-term calcium imaging is achieved without immobilizing the animals by using short externally triggered exposures combined with an electron multiplying charge-coupled device (EMCCD) camera recording. Zooming out or scanning can scale up this method to image up to 40 worms in parallel. Thus, a method is described to image behavior and neural activity over long time scales in all life stages of C. elegans.

Agarose Microchambers for Long-term Calcium Imaging of Caenorhabditis elegans

Imaging behavior and neural activity over long time scales without immobilization of the animal is a prerequisite to understand behavior. Agarose microfluidic chambers imaging (AMI) can be used to image neural activity and behavior for all life stages of Caenorhabditis elegans.

Microchambres agarose à long terme de l&#39;imagerie calcique<em&gt; Caenorhabditis elegans</em

Behavior is controlled by the nervous system. Calcium imaging is a straightforward method in the transparent nematode Caenorhabditis elegans to measure ...

Novel Metrics to Characterize Embryonic Elongation of the Nematode Caenorhabditis elegans

Dissecting the signaling pathways that control the alteration of morphogenic processes during embryonic development requires robust and sensitive metrics. Embryonic elongation of the nematode Caenorhabditis elegans is a late developmental stage consisting of the elongation of the embryo along its longitudinal axis. This developmental stage is controlled by intercellular communication between hypodermal cells and underlying body-wall muscles. These signaling mechanisms control the morphology of hypodermal cells by remodeling the cytoskeleton and the cell-cell junctions. Measurement of embryonic lethality and developmental arrest at larval stages as well as alteration of cytoskeleton and cell-cell adhesion structures in hypodermal and muscle cells are classical phenotypes that have been used for more than 25 years to dissect these signaling pathways. Recent studies required the development of novel metrics specifically targeting either early or late elongation and characterizing morphogenic defects along the antero-posterior axis of the embryo. Here, we provide detailed protocols enabling the accurate measurement of the length and the width of the elongating embryos as well as the length of synchronized larvae. These methods constitute useful tools to identify genes controlling elongation, to assess whether these genes control both early and late phases of this stage and are required evenly along the antero-posterior axis of the embryo.

Novel Metrics to Characterize Embryonic Elongation of the Nematode Caenorhabditis elegans

Here we detail protocols specifically designed to monitor morphogenic defects that occur during early and late phases of embryonic elongation of the nematode Caenorhabditis elegans. Ultimately, these protocols are designed to identify genes that regulate these phases and to characterize their differential requirements along the antero-posterior axis of the embryo.

Novel Metrics à Caractériser Embryonic Allongement du nématode<em&gt; Caenorhabditis elegans</em

Dissecting the signaling pathways that control the alteration of morphogenic processes during embryonic development requires robust and sensitive metrics. ...

A Caenorhabditis elegans Nutritional-status Based Copper Aversion Assay

To ensure survival, organisms must be capable of avoiding unfavorable habitats while ensuring a consistent food source. Caenorhabditis elegans alter their locomotory patterns upon detection of diverse environmental stimuli and can modulate their suite of behavioral responses in response to starvation conditions. Nematodes typically exhibit a decreased aversive response when removed from a food source for over 30 min. Observation of behavioral changes in response to a changing nutritional status can provide insight into the mechanisms that regulate the transition from a well-fed to starved state.
We have developed an assay that measures a nematode&#39;s ability to cross an aversive barrier (i.e. copper) then reach a food source over a prolonged period of time. This protocol builds upon previous work by integrating multiple variables in a manner that allows for continued data collection as the organisms shift towards an increasingly starved condition. Moreover, this assay permits an increased sample size so that larger populations of nematodes can be simultaneously evaluated.
Organisms defective for the ability to detect or respond to copper immediately cross the chemical barrier, while wild type nematodes are initially repelled. As wild type worms are increasingly starved, they begin to cross the barrier and reach the food source. We designed this assay to evaluate a mutant that is incapable of responding to diverse environmental cues, including food sensation or detection of aversive chemicals. When evaluated via this protocol, the defective organisms immediately crossed the barrier, but were also incapable of detecting a food source. Hence, these mutants repeatedly cross the chemical barrier despite temporarily reaching a food source. This assay can straightforwardly test populations of worms to evaluate potential pathway defects related to aversion and starvation.

A Caenorhabditis elegans Nutritional-status Based Copper Aversion Assay

Here, we present a Caenorhabditis elegans-specific assay designed to evaluate changes in copper aversion behavior and the ability to locate a common food source, as the organism progresses from a well-fed to starved nutritional state.

UNE<em&gt; Caenorhabditis elegans</em&gt; Ensemble d&#39;aversion en cuivre à base d&#39;état nutritionnel

To ensure survival, organisms must be capable of avoiding unfavorable habitats while ensuring a consistent food source. Caenorhabditis elegans alter their ...

Ratiometric Calcium Imaging of Individual Neurons in Behaving Caenorhabditis Elegans

It has become increasingly clear that neural circuit activity in behaving animals differs substantially from that seen in anesthetized or immobilized animals. Highly sensitive, genetically encoded fluorescent reporters of Ca2+ have revolutionized the recording of cell and synaptic activity using non-invasive optical approaches in behaving animals. When combined with genetic and optogenetic techniques, the molecular mechanisms that modulate cell and circuit activity during different behavior states can be identified.
Here we describe methods for ratiometric Ca2+ imaging of single neurons in freely behaving Caenorhabditis elegans worms. We demonstrate a simple mounting technique that gently overlays worms growing on a standard Nematode Growth Media (NGM) agar block with a glass coverslip, permitting animals to be recorded at high-resolution during unrestricted movement and behavior. With this technique, we use the sensitive Ca2+ reporter GCaMP5 to record changes in intracellular Ca2+ in the serotonergic Hermaphrodite Specific Neurons (HSNs) as they drive egg-laying behavior. By co-expressing mCherry, a Ca2+-insensitive fluorescent protein, we can track the position of the HSN within ~ 1 &#181;m and correct for fluctuations in fluorescence caused by changes in focus or movement. Simultaneous, infrared brightfield imaging allows for behavior recording and animal tracking using a motorized stage. By integrating these microscopic techniques and data streams, we can record Ca2+ activity in the C. elegans egg-laying circuit as it progresses between inactive and active behavior states over tens of minutes.

Ratiometric Calcium Imaging of Individual Neurons in Behaving Caenorhabditis Elegans

This protocol describes the use of genetically encoded Ca2+ reporters to record changes in neural activity in behaving Caenorhabditis elegans worms. &#8195;

Imagerie ratiométrique Calcium des neurones individuels en comportement Caenorhabditis Elegans

It has become increasingly clear that neural circuit activity in behaving animals differs substantially from that seen in anesthetized or immobilized ...

Imaging Dendritic Spines in Caenorhabditis elegans

Dendritic spines are specialized sites of synaptic innervation modulated by activity and serve as substrates for learning and memory. Recently, dendritic spines have been described for DD GABAergic neurons as the input sites from presynaptic cholinergic neurons in the motor circuit of Caenorhabditis elegans. This synaptic circuit can now serve as a powerful new in vivo model of spine morphogenesis and function that exploits the facile genetics and ready accessibility of C. elegans to live-cell imaging. 
This protocol describes experimental strategies for assessing DD spine structure and function. In this approach, a super-resolution imaging strategy is used to visualize the intricate shapes of actin-rich dendritic spines. To evaluate the DD spine function, the light-activated opsin, Chrimson, stimulates the presynaptic cholinergic neurons, and the calcium indicator, GCaMP, reports the evoked calcium transients in postsynaptic DD spines. Together, these methods comprise powerful approaches for identifying genetic determinants of dendritic spines in C. elegans that could also direct spine morphogenesis and function in the brain.

Imaging Dendritic Spines in Caenorhabditis elegans

Dendritic spines are important cellular features of the nervous system. Here live imaging methods are described for assessing the structure and function of dendritic spines in C. elegans.&#160;These approaches support the development of mutant screens for genes that define dendritic spine shape or function.

Imagerie des épines dendritiques chez Caenorhabditis elegans

Dendritic spines are specialized sites of synaptic innervation modulated by activity and serve as substrates for learning and memory. Recently, dendritic ...