Cette recherche a été financée par des subventions du NIH / NIAAA (AA11852 et AA007471).

<ol>
	<li>Geiger, B. M., Frank, L. E., Caldera-Siu, A. D., Pothos, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Survivable+stereotaxic+surgery+in+rodents.">Survivable stereotaxic surgery in rodents.</a> J. Vis. Exp. (20), e880 (2008).</li><li>Howard, E. C., Schier, C. J., Wetzel, J. S., Gonzales, R. 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+dopamine+response+in+the+nucleus+accumbens+core-shell+border+differs+from+that+in+the+core+and+shell+during+operant+ethanol+self-administration.">The dopamine response in the nucleus accumbens core-shell border differs from that in the core and shell during operant ethanol self-administration.</a> Alcohol Clin. Exp. Res. 33, 1355-1365 (2009).</li><li>Doyon, W. M., York, J. L., Diaz, L. M., Samson, H. H., Czachowski, C. L., Gonzales, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopamine+activity+in+the+nucleus+accumbens+during+consummatory+phases+of+oral+ethanol+self-administration.">Dopamine activity in the nucleus accumbens during consummatory phases of oral ethanol self-administration.</a> Alcohol Clin. Exp. Res. 27, 1573-1582 (2003).</li><li>Pettit, H. O., Justice, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+dose+on+cocaine+self-administration+behavior+and+dopamine+levels+in+the+nucleus+accumbens.">Effect of dose on cocaine self-administration behavior and dopamine levels in the nucleus accumbens.</a> Brain Res. 539, 94-102 (1991).</li><li>Paxinos, G., Kus, L., Ashwell, K. W. S., Watson, 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> Chemoarchitectonic Atlas of The Rat Forebrain. , (1998).</li><li>Paxinos, G., Watson, 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> The Rat Brain in Stereotaxic Coordinates. , (1986).</li><li>Skoog, D. A., Holler, F. J., Nieman, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Principles of Instrumental Analysis. , (1998).</li><li>Doyon, W. M., Anders, S. K., Ramachandra, V. S., Czachowski, C. L., Gonzales, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+operant+self-administration+of+10%+ethanol+plus+10%+sucrose+on+dopamine+and+ethanol+concentrations+in+the+nucleus+accumbens.">Effect of operant self-administration of 10% ethanol plus 10% sucrose on dopamine and ethanol concentrations in the nucleus accumbens.</a> J Neurochem. 93, 1469-1481 (2005).</li><li>Carrillo, J., Gonzales, 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+single+exposure+to+voluntary+ethanol+self-administration+produces+adaptations+in+ethanol+consumption+and+accumbal+dopamine+signaling.">A single exposure to voluntary ethanol self-administration produces adaptations in ethanol consumption and accumbal dopamine signaling.</a> Alcohol. 45, 559-5566 (2011).</li><li>Howard, E. C., Schier, C. J., Wetzel, J. S., Duvauchelle, C. L., Gonzales, R. 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+shell+of+the+nucleus+accumbens+has+a+higher+dopamine+response+compared+with+the+core+after+non-contingent+intravenous+ethanol+administration.">The shell of the nucleus accumbens has a higher dopamine response compared with the core after non-contingent intravenous ethanol administration.</a> Neuroscience. 154, 1042-1053 (2008).</li><li>Robinson, D. L., Lara, J. A., Brunner, L. J., Gonzales, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+Ethanol+Concentrations+in+the+Extracellular+Fluid+of+the+Rat+Brain.">Quantification of Ethanol Concentrations in the Extracellular Fluid of the Rat Brain.</a> J. Neurochem. 75, 1685-1693 (2000).</li><li>Gonzales, R. A., McNabb, J., Yim, H. J., Ripley, T., Bungay, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+Microdialysis+of+Ethanol+in+Rat+Striatum.">Quantitative Microdialysis of Ethanol in Rat Striatum.</a> Alcohol Clin. Exp. Res. 22, 858-867 (1998).</li></ol>

Cet article a été financée par les Associés Med, Inc

Applications et les limites L&#39;auto-administration de médicaments est utilisé chez les rongeurs à la toxicomanie modèle. Beaucoup de médicaments d&#39;abus qui sont modélisés dans ce mode peut être administré par voie intraveineuse, dans laquelle le médicament est administré directement dans le compartiment central. Cela permet une surveillance étroite de la dose au cours d&#39;une session d&#39;auto-administration. L&#39;éthanol est généralement auto-administré par voie orale, il est beaucoup plus difficile de surveiller les concentrations de médicaments dues aux différences individuelles dans l&#39;absorption et le métabolisme. En utilisant la microdialyse pour l&#39;échantillon de la région du cerveau d&#39;intérêt, nous sommes non seulement en mesure de suivre le modèle de l&#39;éthanol pour atteindre la région, mais nous sommes également en mesure de surveiller simultanément les modifications des neurotransmetteurs dans la même région au fil du temps au cours de chaque phase d&#39;auto-administration. Modifications neurochimiques induites par les médicaments et les réactions dans le cerveau sont associés à la toxicomanie et de la dépendance: ainsi, en même temps que la capacité de meaneurochimique et que les concentrations de médicament pendant certaines phases d&#39;auto-administration fournit un outil très puissant et unique. Une question à garder à l&#39;esprit pour corréler les concentrations d&#39;analytes dialysat ayant des comportements sont les caractéristiques physiques de la plomberie microdialyse. Plus précisément, le temps qu&#39;il faut pour que le fluide soit transféré à partir de la lumière de la sonde de microdialyse pour le tube collecteur est critique, et des temps plus courts sont meilleurs. Dans notre laboratoire, nous construisons les sondes de sorte que le temps est d&#39;environ 90 secondes. En utilisant ces conditions, nous avons constaté qu&#39;il ya une augmentation de la dopamine accumbal au début de la consommation d&#39;éthanol, ce qui diminue au cours des périodes de boissons et de post-boisson avec l&#39;augmentation de la concentration d&#39;éthanol de dialysat. 2,3,8,9 Ces expériences , lorsqu&#39;il est combiné avec des données provenant d&#39;études pharmacologiques, nous ont permis d&#39;analyser les effets pharmacologiques strictement d&#39;éthanol et de l&#39;auto-administration des signaux environnementaux associés à changes des concentrations de neurotransmetteurs. Il convient de noter que cette application particulière de combinés comportementale microdialyse techniques est adapté aux intérêts de recherche actuels de notre laboratoire. Il est conçu pour évaluer la structure temporelle de l&#39;éthanol atteint le cerveau par rapport à la tendance de l&#39;évolution des neurotransmetteurs dans la même région, de sorte que nous pouvons relier ces mesures synchrones auto-administration comportements. Les concentrations d&#39;éthanol provenant de dialysat ne sont pas corrigés pour la récupération in vivo sonde, et ne représentent qu&#39;une fraction de la concentration du tissu cérébral éthanol. Si microdialyse quantitative de l&#39;éthanol est requis, la fraction d&#39;extraction de l&#39;éthanol qui diffuse à partir de l&#39;espace extracellulaire dans la sonde doit être déterminée expérimentalement. Voir les publications antérieures de notre laboratoire pour les méthodes et la discussion plus loin. 10,11,12 Bien que ce protocole illustre l&#39;utilisation du gaz chromatography avec microextraction en phase solide de l&#39;éthanol à partir de l&#39;espace de tête d&#39;échantillons de microdialyse, d&#39;autres méthodes pour l&#39;analyse de la teneur en éthanol de l&#39;échantillon de micro-dialyse peut être utilisé. Toutefois, d&#39;autres méthodes peuvent souffrir de quelques inconvénients. Par exemple, moins sensibles méthodes analytiques peuvent exiger un plus grand volume d&#39;échantillon qui nécessite des temps d&#39;échantillonnage supérieure à la 5-7 min illustré ici. Le type de système discuté ici utilise une micro-extraction en phase solide qui concentre l&#39;éthanol dans la phase vapeur dans la cuvette pour échantillon scellé en permettant l&#39;absorption de la fibre placée dans l&#39;espace de tête du flacon. Ce qui améliore la limite de détection par rapport à l&#39;espace de tête de prélèvement direct qui permet typiquement 50-100 microlitres de la vapeur à injecter. Un autre avantage majeur de la méthode de l&#39;espace de tête est que l&#39;échantillon injecté pour l&#39;analyse est extrêmement propre et exempte de sels. L&#39;injection directe de l&#39;échantillon microdialyse liquide peut également être utilisé avec une plus grande SENSITivité, mais cela nécessitera plus de temps d&#39;arrêt instrument pour cause de maintenance régulière requise pour nettoyer les sels injectés. Dépannage et autres notes <ol><li> Avant que votre expérience commence, vous donner beaucoup de temps pour vérifier que vos microdialyse set-ups fonctionnent correctement et pour dépanner les problèmes éventuels. Nous suggérons que vous avez un supplément de set-up, perfusés avec ACSF, prêt à basculer avec un dysfonctionnement set-up pour gagner du temps, comme la plupart des séances opérant tendance à se produire à une heure précise chaque jour. </li><li> S&#39;assurer que les sondes de microdialyse sont insérés sur une période d&#39;environ 5 minutes à minimiser les dommages aux tissus produite par cisaillement du tissu que la sonde pénètre dans le cerveau. </li><li> Lors du transfert du rat dans la chambre opérante, il est utile d&#39;avoir une deuxième personne assister afin que la ligne de transfert (partie de la microdialyse set-up) ne devient embrouillée, et afin que le programme peut être opérant à initiated à temps. </li><li> Assurez-vous que vous donnez le bain d&#39;eau beaucoup passeur de temps pour atteindre la température appropriée. Notre système nécessite généralement deux heures pour atteindre 50 ° C. En outre, veiller à ce que vos échantillons sont entièrement vaporisé avant d&#39;analyser les échantillons. En général, nous confirmer visuellement que cela s&#39;est produit avant d&#39;entreprendre l&#39;analyse des échantillons. </li><li> Standard des bonnes pratiques de chimie analytique doivent être suivies. Ceux-ci incluent, mais ne sont pas limités à, la validation des individus, des équipements et des procédures. En bref, nous employons les lignes directrices suivantes: Les utilisateurs individuels doivent démontrer leur capacité à générer des valeurs reproductibles hauteur de pic des concentrations standard et linéaires courbes standard (R2 ≥ 0,99) sur plusieurs jours. Pour vérifier le système GC-FID fonctionne correctement, les normes doivent être toujours être analysés avant tout prélèvement d&#39;échantillons de dialysat sont injectés. La courbe standard générée doit avoir un R2 ≥ 0,99. </li><li> La plupart des équipements que nous utilisonsa été acheté par Varian, Inc, qui a été acquise par Agilent Technologies en 2010. A cette époque, Bruker Instruments scientifiques obtenus Varian laboratoire chromatographie en phase gazeuse instruments affaires. Pour les achats futurs, consultez quelconque de ces sociétés. </li><li> Le présent protocole indique comportement opérant sur des rats, mais le spectateur doit être conscient que plus la perturbation du comportement est susceptible de se produire avec le modèle plus petit de la souris. Une autre question à prendre en compte est que le placement d&#39;une sonde de microdialyse dans d&#39;autres régions cérébrales que le cortex médial préfrontal ou noyau accumbens peut perturber le comportement opérant à un degré plus élevé que montré ici. Il est important d&#39;examiner attentivement de nombreux paramètres comportementaux pour déterminer si les dommages causés par placement de la sonde produit des changements dans le comportement graves. </li></ol>

<table border="1"><tbody><tr><td> Nom du réactif </td><td> Entreprise </td><td> Numéro de catalogue </td></tr><tr><td> Ethanol à 95% </td><td> AAPER alcool et Chemical Co., Shelbyville, KY </td><td> E190, 111000190 </td></tr><tr><td> Ultra-Pure saccharose </td><td> MP Biomedicals, LLC, Cleveland, OH </td><td> 821721 </td></tr><tr><td> Ultra High Purity hélium </td><td> Gaz Air </td><td> SE UHP300 </td></tr><tr><td> Air </td><td> Gaz Air </td><td> AIZ300 </td></tr><tr><td> Hydrogène </td><td> Gaz Air </td><td> AIZ300 </td></tr><tr><td> GC 2 flacons ml </td><td> Agilent </td><td> # 8010-0015 </td></tr><tr><td> Bouchons des flacons de GC avec PTFE / silicone septa </td><td> Agilent </td><td> # 8010-0084 </td></tr></tbody></table> Tableau 1. Réactifs spécifiques

microdialysis of ethanol during operant ethanol self-administration and ethanol determination by gas chromatography

Opérant auto-administration méthodes sont couramment utilisées pour étudier les effets comportementaux et pharmacologiques de nombreux médicaments d&#39;abus, y compris l&#39;éthanol. Cependant, l&#39;éthanol est généralement auto-administré par voie orale plutôt que par voie intraveineuse comme beaucoup d&#39;autres drogues. La pharmacocinétique des médicaments administrés par voie orale sont plus complexes que les médicaments administrés par voie intraveineuse. Parce que la compréhension de la relation entre les effets pharmacologiques et comportementaux de l&#39;éthanol nécessite la connaissance de l&#39;évolution dans le temps de l&#39;éthanol atteint le cerveau pendant et après avoir bu, nous utilisons la microdialyse in vivo et chromatographie en phase gazeuse avec détection par ionisation de flamme pour surveiller les concentrations cérébrales de dialysat éthanol au fil du temps. Combinés microdialyse-comportementales expériences impliquent l&#39;utilisation de plusieurs techniques. Dans cet article, la chirurgie stéréotaxique, la formation comportementale et microdialyse, qui peut être adapté pour tester une multitude d&#39;auto-administration et neupétrochimique hypothèses centrée, sont inclus uniquement pour illustrer la façon dont ils se rapportent à des phases ultérieures de prélèvement et d&#39;analyse d&#39;éthanol dialysat. Dialysat analyse de la concentration d&#39;éthanol par chromatographie en phase gazeuse avec détection à ionisation de flamme, qui est spécifique aux études d&#39;éthanol, est décrit en détail. Les données produites par ces méthodes révèlent le motif d&#39;éthanol atteint le cerveau au cours de la procédure d&#39;auto-administration, et quand il est associé avec l&#39;analyse neurochimique des échantillons de dialysat mêmes, permet de tirer des conclusions concernant les effets pharmacologiques et comportementaux de l&#39;éthanol.

Watch this Scientific Journal Video about Microdialysis of Ethanol During Operant Ethanol Self-administration and Ethanol Determination by Gas Chromatography at JoVE.com

Microdialysis of Ethanol During Operant Ethanol Self-administration and Ethanol Determination by Gas Chromatography

Une méthode pour déterminer l&#39;évolution temporelle de la concentration d&#39;éthanol dans le cerveau des rats au cours de l&#39;éthanol opérant auto-administration est décrite. Chromatographie en phase gazeuse avec détection par ionisation de flamme est utilisée pour quantifier l&#39;éthanol dans les échantillons de dialysat, parce qu&#39;il a la sensibilité requise pour les petits volumes qui sont générés.

Microdialyse d&#39;éthanol au cours de l&#39;éthanol détermination opérant auto-administration et d&#39;éthanol par chromatographie en phase gazeuse

Operant self-administration methods are commonly used to study the behavioral and pharmacological effects of many drugs of abuse, including ethanol.  ...

microdialysis-ethanol-during-operant-ethanol-self-administration

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Neuroscience

17.4K vues.  The University of Texas at Austin. Une méthode pour déterminer l'évolution temporelle de la concentration d'éthanol dans le cerveau des rats au cours de l'éthanol opérant auto-administration est décrite. Chromatographie en phase gazeuse avec détection par ionisation de flamme est utilisée pour quantifier l'éthanol dans les échantillons de dialysat, parce qu'il a la sensibilité requise pour les petits volumes qui sont générés.

Vidéo: Microdialysis of Ethanol During Operant Ethanol Self-administration and Ethanol Determination by Gas Chromatography

Assessment of Ultrasonic Vocalizations During Drug Self-administration in Rats

Drug self-administration procedures are commonly used to study behavioral and neurochemical changes associated with human drug abuse, addiction and relapse. Various types of behavioral activity are commonly utilized as measures of drug motivation in animals. However, a crucial component of drug abuse relapse in abstinent cocaine users is "drug craving", which is difficult to model in animals, as it often occurs in the absence of overt behaviors. Yet, it is possible that a class of ultrasonic vocalizations (USVs) in rats may be a useful marker for affective responses to drug administration, drug anticipation and even drug craving. Rats vocalize in ultrasonic frequencies that serve as a communicatory function and express subjective emotional states. Several studies have shown that different call frequency ranges are associated with negative and positive emotional states. For instance, high frequency calls ("50-kHz") are associated with positive affect, whereas low frequency calls ("22-kHz") represent a negative emotional state. This article describes a procedure to assess rat USVs associated with daily cocaine self-administration. For this procedure, we utilized standard single-lever operant chambers housed within sound-attenuating boxes for cocaine self-administration sessions and utilized ultrasonic microphones, multi-channel recording hardware and specialized software programs to detect and analyze USVs. USVs measurements reflect emotionality of rats before, during and after drug availability and can be correlated with commonly assessed drug self-administration behavioral data such lever responses, inter-response intervals and locomotor activity. Since USVs can be assessed during intervals prior to drug availability (e.g., anticipatory USVs) and during drug extinction trials, changes in affect associated with drug anticipation and drug abstinence can also be determined. In addition, determining USV changes over the course of short- and long-term drug exposure can provide a more detailed interpretation of drug exposure effects on affective functioning.

Drug self-administration and ultrasonic vocalizations (USV) are used as behavioral assessments in animal research, but rarely in combination. The purpose of this article is to describe the advantages of recording USVs during drug self-administration procedures to assess affective responses to drug experience.

Évaluation de vocalisations ultrasoniques Pendant médicaments auto-administration chez le rat

Drug self-administration procedures are commonly used to study behavioral and neurochemical changes associated with human drug abuse, addiction and ...

Recherche

Neurosciences

Operant Sensation Seeking in the Mouse

Operant methods are powerful behavioral tools for the study of motivated behavior. These 'self-administration' methods have been used extensively in drug addiction research due to their high construct validity. Operant studies provide researchers a tool for preclinical investigation of several aspects of the addiction process. For example, mechanisms of acute reinforcement (both drug and non-drug) can be tested using pharmacological or genetic tools to determine the ability of a molecular target to influence self-administration behavior1-6. Additionally, drug or food seeking behaviors can be studied in the absence of the primary reinforcer, and the ability of pharmacological compounds to disrupt this process is a preclinical model for discovery of molecular targets and compounds that may be useful for the treatment of addiction3,7-9. One problem with performing intravenous drug self-administration studies in the mouse is the technical difficulty of maintaining catheter patency. Attrition rates in these experiments are high and can reach 40% or higher10-15. Another general problem with drug self-administration is discerning which pharmacologically-induced effects of the reinforcer produce specific behaviors. For example, measurement of the reinforcing and neurological effects of psychostimulants can be confounded by their psychomotor effects. Operant methods using food reinforcement can avoid these pitfalls, although their utility in studying drug addiction is limited by the fact that some manipulations that alter drug self-administration have a minimal impact on food self-administration. For example, mesolimbic dopamine lesion or knockout of the D1 dopamine receptor reduce cocaine self-administration without having a significant impact on food self-administration 12,16. 
Sensory stimuli have been described for their ability to support operant responding as primary reinforcers (i.e. not conditioned reinforcers)17-22. Auditory and visual stimuli are self-administered by several species18,21,23, although surprisingly little is known about the neural mechanisms underlying this reinforcement. The operant sensation seeking (OSS) model is a robust model for obtaining sensory self-administration in the mouse, allowing the study of neural mechanisms important in sensory reinforcement24. An additional advantage of OSS is the ability to screen mutant mice for differences in operant behavior that may be relevant to addiction. We have reported that dopamine D1 receptor knockout mice, previously shown to be deficient in psychostimulant self-administration, also fail to acquire OSS24. This is a unique finding in that these mice are capable of learning an operant task when food is used as a reinforcer. While operant studies using food reinforcement can be useful in the study of general motivated behavior and the mechanisms underlying food reinforcement, as mentioned above, these studies are limited in their application to studying molecular mechanisms of drug addiction. Thus, there may be similar neural substrates mediating sensory and psychostimulant reinforcement that are distinct from food reinforcement, which would make OSS a particularly attractive model for the study of drug addiction processes. The degree of overlap between other molecular targets of OSS and drug reinforcers is unclear, but is a topic that we are currently pursuing. While some aspects of addiction such as resistance to extinction may be observed with OSS, we have found that escalation 25 is not observed in this model24. Interestingly, escalation of intake and some other aspects of addiction are observed with self-administration of sucrose26. Thus, when non-drug operant procedures are desired to study addiction-related processes, food or sensory reinforcers can be chosen to best fit the particular question being asked. 
In conclusion, both food self-administration and OSS in the mouse have the advantage of not requiring an intravenous catheter, which allows a higher throughput means to study the effects of pharmacological or genetic manipulation of neural targets involved in motivation. While operant testing using food as a reinforcer is particularly useful in the study of the regulation of food intake, OSS is particularly apt for studying reinforcement mechanisms of sensory stimuli and may have broad applicability to novelty seeking and addiction.

In this protocol we describe a method of operant learning using sensory stimuli as a reinforcer in the mouse. It requires no prior training or food restriction, and it allows the study of motivated behavior without the use of a pharmacological or natural reinforcer such as food.

Sensation opérant dans la recherche de souris

Operant methods are powerful behavioral tools for the study of motivated behavior.  These 'self-administration' methods have been used extensively in drug ...

A Simple Way to Measure Ethanol Sensitivity in Flies

Low doses of ethanol cause flies to become hyperactive, while high doses are sedating. The sensitivity to ethanol-induced sedation of a given fly strain is correlated with that strain s ethanol preference, and therefore sedation is a highly relevant measure to study the genetics of alcohol responses and drinking. We demonstrate a simple way to expose flies to ethanol and measure its intoxicating effects. The assay we describe can determine acute sensitivity, as well as ethanol tolerance induced by repeat exposure. It does not require a technically involved setup, and can therefore be applied in any laboratory with basic fly culture tools.

A simple assay to measure the sedating effects of ethanol on Drosophila flies, based on the loss of righting reflex, is described.

Une façon simple de mesurer la sensibilité d&#39;éthanol dans les mouches

Low doses of ethanol cause flies to become hyperactive, while high doses are sedating. The sensitivity to ethanol-induced sedation of a given fly strain ...

Methods for Intravenous Self Administration in a Mouse Model

Animal models have been developed to study the reinforcing effects of drugs, including the intravenous self-administration (IVSA) paradigm. The advantages of using an IVSA paradigm to study the reinforcing properties of drugs of abuse such as cocaine include the fact that the drug is self-administered instead of experimenter-administered, the schedule of reinforcement can be altered, and accurate measurement of the quantities of drug consumed as well as the timing and pattern of IV injections can be obtained. Furthermore, the intravenous route of administration avoids potential confounds related to first pass metabolism or taste, and produces rapid increases in blood and brain drug levels. As outlined in this video, intravenous self-administration can be obtained without prior food restriction or prior drug training following careful catheter placement during surgery and meticulous daily catheter flushing and maintenance. Experimental procedures outlined in this paper include a description of animal housing and acclimation methods, operant training using sweetened milk solutions, and catheter implantation surgery.

The intravenous self-administration (IVSA) paradigm is considered to be the gold standard in examining the reinforcing properties of drugs of abuse in rodents. This manuscript outlines the experimental procedures and surgical techniques necessary to obtain reliable IVSA data. In particular, meticulous catheter implantation and maintenance are highlighted.

Les méthodes de l&#39;administration par voie intraveineuse auto dans un modèle de souris

Animal models have been developed to study the reinforcing effects of drugs, including the intravenous self-administration (IVSA) paradigm. The advantages ...

Identification of Olfactory Volatiles using Gas Chromatography-Multi-unit Recordings (GCMR) in the Insect Antennal Lobe

All organisms inhabit a world full of sensory stimuli that determine their behavioral and physiological response to their environment. Olfaction is especially important in insects, which use their olfactory systems to respond to, and discriminate amongst, complex odor stimuli. These odors elicit behaviors that mediate processes such as reproduction and habitat selection1-3. Additionally, chemical sensing by insects mediates behaviors that are highly significant for agriculture and human health, including pollination4-6, herbivory of food crops7, and transmission of disease8,9. Identification of olfactory signals and their role in insect behavior is thus important for understanding both ecological processes and human food resources and well-being.
	To date, the identification of volatiles that drive insect behavior has been difficult and often tedious. Current techniques include gas chromatography-coupled electroantennogram recording (GC-EAG), and gas chromatography-coupled single sensillum recordings (GC-SSR)10-12. These techniques proved to be vital in the identification of bioactive compounds. We have developed a method that uses gas chromatography coupled to multi-channel electrophysiological recordings (termed 'GCMR') from neurons in the antennal lobe (AL; the insect's primary olfactory center)13,14. This state-of-the-art technique allows us to probe how odor information is represented in the insect brain. Moreover, because neural responses to odors at this level of olfactory processing are highly sensitive owing to the degree of convergence of the antenna's receptor neurons into AL neurons, AL recordings will allow the detection of active constituents of natural odors efficiently and with high sensitivity. Here we describe GCMR and give an example of its use.
	Several general steps are involved in the detection of bioactive volatiles and insect response. Volatiles first need to be collected from sources of interest (in this example we use flowers from the genus Mimulus (Phyrmaceae)) and characterized as needed using standard GC-MS techniques14-16. Insects are prepared for study using minimal dissection, after which a recording electrode is inserted into the antennal lobe and multi-channel neural recording begins. Post-processing of the neural data then reveals which particular odorants cause significant neural responses by the insect nervous system.
	Although the example we present here is specific to pollination studies, GCMR can be expanded to a wide range of study organisms and volatile sources. For instance, this method can be used in the identification of odorants attracting or repelling vector insects and crop pests. Moreover, GCMR can also be used to identify attractants for beneficial insects, such as pollinators. The technique may be expanded to non-insect subjects as well.

Identification of Olfactory Volatiles using Gas Chromatography-Multi-unit Recordings GCMR in the Insect Antennal Lobe

Olfactory cues mediate many different behaviors in insects, and are often complex mixtures comprised of tens to hundreds of volatile compounds. Using gas chromatography with multi-channel recording in the insect antennal lobe, we describe a method for the identification of bioactive compounds.

L&#39;identification des composés volatils olfactifs chromatographie en phase gazeuse-à logements multiples enregistrements (GCMR) dans le lobe antennaire des insectes

All  organisms inhabit a world full of sensory stimuli that determine their  behavioral and physiological response to their environment. Olfaction is ...

Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing

Glucose metabolism is a useful marker for local neural activity, forming the basis of methods such as 2-deoxyglucose and functional magnetic resonance imaging. However, use of such methods in animal models requires anesthesia and hence both alters the brain state and prevents behavioral measures. An alternative method is the use of in vivo microdialysis to take continuous measurement of brain extracellular fluid concentrations of glucose, lactate, and related metabolites in awake, unrestrained animals. This technique is especially useful when combined with tasks designed to rely on specific brain regions and/or acute pharmacological manipulation; for example, hippocampal measurements during a spatial working memory task (spontaneous alternation) show a dip in extracellular glucose and rise in lactate that are suggestive of enhanced glycolysis1-3,4-5, and intrahippocampal insulin administration both improves memory and increases hippocampal glycolysis6. Substances such as insulin can be delivered to the hippocampus via the same microdialysis probe used to measure metabolites. The use of spontaneous alternation as a measure of hippocampal function is designed to avoid any confound from stressful motivators (e.g. footshock), restraint, or rewards (e.g. food), all of which can alter both task performance and metabolism; this task also provides a measure of motor activity that permits control for nonspecific effects of treatment. Combined, these methods permit direct measurement of the neurochemical and metabolic variables regulating behavior.

Hippocampal Insulin Microinjection and In vivo Microdialysis During Spatial Memory Testing

Modulation of hippocampally-dependent spatial working memory by direct intrahippocampal microinjection, accompanied and followed by in vivo microdialysis for metabolites in conscious, behaving animals.

La micro-injection d&#39;insuline de l&#39;hippocampe et<em&gt; In vivo</emMicrodialyse&gt; Test de la mémoire spatiale cours

Glucose metabolism is a useful marker for local neural activity, forming the basis of methods such as 2-deoxyglucose and functional magnetic resonance ...

An Inexpensive, Scalable Behavioral Assay for Measuring Ethanol Sedation Sensitivity and Rapid Tolerance in Drosophila

Alcohol use disorder (AUD) is a serious health challenge. Despite a large hereditary component to AUD, few genes have been unambiguously implicated in their etiology. The fruit fly, Drosophila melanogaster, is a powerful model for exploring molecular-genetic mechanisms underlying alcohol-related behaviors and therefore holds great promise for identifying and understanding the function of genes that influence AUD. The use of the Drosophila model for these types of studies depends on the availability of assays that reliably measure behavioral responses to ethanol. This report describes an assay suitable for assessing ethanol sensitivity and rapid tolerance in flies. Ethanol sensitivity measured in this assay is influenced by the volume and concentration of ethanol used, a variety of previously reported genetic manipulations, and also the length of time the flies are housed without food immediately prior to testing. In contrast, ethanol sensitivity measured in this assay is not affected by the vigor of fly handling, sex of the flies, and supplementation of growth medium with antibiotics or live yeast. Three different methods for quantitating ethanol sensitivity are described, all leading to essentially indistinguishable ethanol sensitivity results. The scalable nature of this assay, combined with its overall simplicity to set-up and relatively low expense, make it suitable for small and large scale genetic analysis of ethanol sensitivity and rapid tolerance in Drosophila.

An Inexpensive, Scalable Behavioral Assay for Measuring Ethanol Sedation Sensitivity and Rapid Tolerance in Drosophila

Straightforward assays for measuring ethanol sensitivity and rapid tolerance in Drosophila facilitate the use of this model organism for investigating these important ethanol-related behaviors. Here, a relatively simple, scalable assay for measuring ethanol sensitivity and rapid tolerance in flies is described.

Un, test de comportement évolutives et économiques pour mesurer l&#39;éthanol sédation sensibilité et la tolérance rapide dans<em&gt; Drosophila</em

Alcohol use disorder (AUD) is a serious health challenge. Despite a large hereditary component to AUD, few genes have been unambiguously implicated in ...

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 ...

Custom-made Microdialysis Probe Design

Microdialysis is a commonly used technique in neuroscience research. Therefore commercial probes are in great demand to monitor physiological, pharmacological and pathological changes in cerebrospinal fluid. Unfortunately, commercial probes are expensive for research groups in public institutions. In this work, a probe assembly is explained in detail to build a reliable, concentric, custom-made microdialysis probe for less than $10. The microdialysis probe consists of a polysulfone membrane with a molecular cut-off of 30 kDa. Probe in vitro recoveries of substances with different molecular weight (in the range of 100-1,600 Da) and different physicochemical properties are compared. The probe yields an in vitro recovery of approximately 20% for the small compounds glucose, lactate, acetylcholine and ATP. In vitro recoveries for neuropeptides with a molecular weight between 1,000-1,600 Da amount to 2-6%. Thus, while the higher molecular weight of the neuropeptides lowered in vitro recovery values, dialysis of compounds in the lower range (up to 500 Da) of molecular weights has no great impact on the in vitro recovery rate. The present method allows utilization of a dialysis membrane with other cut-off value and membrane material. Therefore, this custom-made probe assembly has the advantage of sufficient flexibility to dialyze substances in a broad molecular weight range. Here, we introduce a microdialysis probe with an exchange length of 2 mm, which is applicable for microdialysis in mouse and rat brain regions. However, dimensions of the probe can easily be adapted for larger exchange lengths to be used in larger animals.

Microdialysis is a commonly used technique in neuroscience research. Therefore commercial probes are in great demand.In this work a probe assembly is explained in detail to build a reliable, concentric, custom-made microdialysis probe for less than $10.

Sur mesure Microdialyse Probe Conception

Microdialysis is a commonly used technique in neuroscience research. Therefore commercial probes are in great demand to monitor physiological, ...

Assessment of Dopaminergic Homeostasis in Mice by Use of High-performance Liquid Chromatography Analysis and Synaptosomal Dopamine Uptake

Dopamine (DA) is a modulatory neurotransmitter controlling motor activity, reward processes and cognitive function. Impairment of dopaminergic (DAergic) neurotransmission is strongly associated with several central nervous system-associated diseases such as Parkinson&#39;s disease, attention-deficit-hyperactivity disorder and drug addiction1,2,3,4. Delineating disease mechanisms involving DA imbalance is critically dependent on animal models to mimic aspects of the diseases, and thus protocols that assess specific parts of the DA homeostasis are important to provide novel insights and possible therapeutic targets for these diseases.
Here, we present two useful experimental protocols that when combined provide a functional read-out of the DAergic system in mice. Biochemical and functional parameters on DA homeostasis are obtained through assessment of DA levels and dopamine transporter (DAT) functionality5. When investigating the DA system, the ability to reliably measure endogenous levels of DA from adult brain is essential. Therefore, we present how to perform high-performance liquid chromatography (HPLC) on brain tissue from mice to determine levels of DA. We perform the experiment on tissue from dorsal striatum (dStr) and nucleus accumbens (NAc), but the method is also suitable for other DA-innervated brain areas.
DAT is essential for reuptake of DA into the presynaptic terminal, thereby controlling the temporal and spatial activity of released DA. Knowing the levels and functionality of DAT in the striatum is of major importance when assessing DA homeostasis. Here, we provide a protocol that allows to simultaneously deduce information on surface levels and function using a synaptosomal6 DA uptake assay.
Current methods combined with standard immunoblotting protocols provide the researcher with relevant tools to characterize the DAergic system.

Synaptosomal dopamine uptake and high-performance liquid chromatography analysis represent experimental tools to investigate dopamine homeostasis in mice by assessing the function of the dopamine transporter and levels of dopamine in striatal tissue, respectively. Here we present protocols to measure dopamine tissue content and assess the functionality of the dopamine transporter.

Évaluation de l’homéostasie des dopaminergiques chez les souris par l’utilisation de l’analyse de chromatographie liquide à haute performance et l’absorption de la Dopamine

Dopamine (DA) is a modulatory neurotransmitter controlling motor activity, reward processes and cognitive function. Impairment of dopaminergic (DAergic) ...