Esta investigación fue apoyada por las subvenciones del NIH / NIAAA (AA11852 y 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>

Este artículo fue financiado por Med Associates, Inc.

Aplicaciones y limitaciones Medicamentos auto-administración se utiliza en los roedores a la adicción de drogas modelo. Muchas drogas de abuso que se modelan de esta manera puede administrarse por vía intravenosa, en la que el fármaco se administra directamente en el compartimento central. Esto permite un control estricto de la dosis durante una sesión de auto-administración. Puesto que el etanol es habitualmente de forma oral auto-administrada, es mucho más difícil de controlar los niveles de fármaco debido a las diferencias individuales en la absorción y el metabolismo. Mediante el uso de microdiálisis a la muestra de la región cerebral de interés, no sólo son capaces de controlar el patrón de etanol de llegar a la región, pero también somos capaces de controlar simultáneamente los cambios de neurotransmisores en la misma región en el tiempo durante cada fase de auto-administración. Alteraciones neuroquímicas y las respuestas inducidas por las drogas en el cerebro están asociados con el abuso y dependencia de drogas, por lo que la capacidad para medir simultáneamenteneuroquímico seguro y las concentraciones de drogas específicas durante las fases de auto-administración es una herramienta muy poderosa y única. Una cuestión a tener en cuenta para la correlación de las concentraciones de analitos dializado con conductas son las características físicas de la tubería microdiálisis. Específicamente, el tiempo que tarda para que el líquido se transfiere desde el lumen de la sonda de microdiálisis para el tubo de recogida es crítica, y tiempos más cortos son mejores. En nuestro laboratorio, la construcción de las sondas de modo que el tiempo es de aproximadamente 90 segundos. Usando estas condiciones, hemos encontrado que hay un aumento de la dopamina accumbal en el inicio del consumo de etanol, lo que disminuye en el curso de los períodos de bebida y post-bebida al aumentar la concentración de etanol de dializado. 2,3,8,9 Estos experimentos , cuando se combinan con los datos de los estudios farmacológicos, nos han permitido analizar los efectos estrictamente farmacológicas de etanol y autoadministración señales ambientales asociadas en canalanges en las concentraciones de neurotransmisores. Cabe señalar que esta aplicación particular de la combinación del comportamiento de microdiálisis técnicas se adaptan a los intereses actuales de investigación de nuestro laboratorio. Está diseñado para evaluar el patrón temporal de etanol alcanza el cerebro en comparación con el patrón de cambios de neurotransmisores en la misma región, por lo que podemos relacionar estas medidas a síncronos de auto-administración comportamientos. Las concentraciones de etanol derivado de dializado no se corrigen por la sonda en la recuperación in vivo, y son sólo una fracción de la concentración de etanol en el tejido cerebral. Si microdiálisis cuantitativa de etanol se requiere, la fracción de extracción de etanol que se difunde desde el espacio extracelular en la sonda debe ser determinado experimentalmente. Ver publicaciones anteriores de nuestro laboratorio de métodos y nuevos debates. 10,11,12 Aunque este protocolo ilustra el uso de gas chromatography junto con microextracción en fase sólida de etanol del espacio de cabeza de muestras de microdiálisis, otros métodos para el análisis del contenido de etanol de la muestra de microdiálisis se podría utilizar. Sin embargo, los métodos alternativos pueden sufrir de algunas desventajas. Por ejemplo, los métodos analíticos menos sensibles pueden requerir un volumen de muestra más grande que requiere tiempos de muestreo mayor que el 7.5 min ilustra aquí. El tipo de sistema discutido aquí utiliza una microextracción en fase sólida que concentra el etanol en la fase de vapor en el vial de muestra sellada, permitiendo la absorción de la fibra colocada en el espacio de cabeza del vial. Esto mejora el límite de detección en comparación con el muestreo del espacio de cabeza directo que permite típicamente 50-100 microlitros de la que se inyecta vapor. Otra ventaja importante del método del espacio de cabeza es que la muestra inyectada para el análisis es extremadamente limpio y libre de sales. La inyección directa de la muestra de microdiálisis líquido también se puede usar con mayor Sensitividad, pero esto requerirá más tiempo de inactividad instrumento debido a un mantenimiento regular necesario para la limpieza de las sales inyectadas. Solución de problemas y otras notas <ol><li> Antes de que su experimento comienza, te dan un montón de tiempo para comprobar que sus microdiálisis montajes están funcionando correctamente y para localizar averías cualquier problema. Nosotros sugerimos que usted tiene un extra de puesta a punto, perfundidos con ACSF, dispuesto a cambiar con un mal funcionamiento del set-up para ahorrar tiempo, ya que la mayoría de las sesiones operantes tienden a ocurrir a una hora específica cada día. </li><li> Asegúrese de que las sondas de microdiálisis se insertan en un período de aproximadamente 5 min para minimizar el daño tisular producido por cizallamiento del tejido como la sonda penetra en el cerebro. </li><li> Cuando la transferencia de la rata en la cámara operante es útil tener una segunda persona ayudar de manera que la línea de transferencia (parte de la microdiálisis set-up) no se enreden, y para que el programa operante puede ser initiated a tiempo. </li><li> Asegúrese de que usted le debe suministrar agua suficiente automuestreador bañera de tiempo para alcanzar la temperatura adecuada. Nuestro sistema requiere normalmente dos horas para llegar a los 50 ° C. Además, aseguran que sus muestras están completamente vaporizado antes de analizar las muestras. Normalmente nos confirme visualmente que esto ha ocurrido antes de iniciar el análisis de la muestra. </li><li> Estándar de buenas prácticas de química analítica deben ser seguidas. Estos incluyen, pero no se limitan a, la validación de los individuos, equipos, y procedimientos. En resumen, contamos con los siguientes lineamientos: Los usuarios individuales deben demostrar la capacidad de generar reproducibles valores de altura de pico para las concentraciones estándar y curvas lineales estándar (R2 ≥ 0,99) a través de varios días. Para verificar el sistema GC-FID está trabajando correctamente, las normas deben ser siempre ser analizados antes de cualquier muestra de dializado se inyectan. La curva estándar generada debe tener un R2 ≥ 0,99. </li><li> La mayor parte del equipo que utilizamosfue comprado a través de Varian, Inc., que fue adquirida por Agilent Technologies en 2010. En este momento, Bruker Scientific Instruments laboratorio obtenido de Varian de cromatografía de gases de negocios instrumentos. Para futuras compras, consultar cualquiera de estas sociedades. </li><li> El presente protocolo muestra un comportamiento operante con ratas, pero el espectador debe ser consciente de que más interrupción de comportamiento es probable que ocurra con el modelo de ratón más pequeño. Otra cuestión a tener en cuenta es que la colocación de una sonda de microdiálisis en otras regiones del cerebro de la corteza medial prefrontal o núcleo accumbens puede perturbar el comportamiento operante a un mayor grado que se muestra aquí. Es importante examinar de cerca numerosos parámetros de comportamiento para determinar si el daño causado por la colocación de la sonda produce graves cambios en el comportamiento. </li></ol>

<table border="1"><tbody><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td></tr><tr><td> 95% de etanol </td><td> AAPER Alcohol and Chemical Co., Shelbyville, KY </td><td> E190, 111000190 </td></tr><tr><td> Ultra-Pure sacarosa </td><td> MP Biomedicals, LLC, Solon, OH </td><td> 821721 </td></tr><tr><td> Ultra Alta Pureza helio </td><td> Mezcla combustible </td><td> HE UHP300 </td></tr><tr><td> Aire </td><td> Mezcla combustible </td><td> AIZ300 </td></tr><tr><td> Hidrógeno </td><td> Mezcla combustible </td><td> AIZ300 </td></tr><tr><td> GC 2 ml viales </td><td> Agilent </td><td> # 8010-0015 </td></tr><tr><td> GC tapas de los viales con PTFE / silicona septa </td><td> Agilent </td><td> # 8010-0084 </td></tr></tbody></table> Tabla 1. Reactivos específicos

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

Operantes de auto-administración métodos se utiliza comúnmente para estudiar los efectos conductuales y farmacológicas de muchas drogas de abuso, incluyendo el etanol. Sin embargo, el etanol es típicamente auto-administrarse por vía oral, en lugar de por vía intravenosa como muchas otras drogas de abuso. La farmacocinética de los fármacos administrados por vía oral son más complejos que los medicamentos administrados por vía intravenosa. Debido a la comprensión de la relación entre los efectos farmacológicos y de comportamiento de etanol requiere el conocimiento de la evolución en el tiempo de etanol alcanza el cerebro durante y después de beber, utilizamos microdiálisis in vivo y cromatografía de gases con detección de ionización de llama para supervisar el cerebro concentraciones de etanol de dializado a través del tiempo. Combinados de comportamiento microdiálisis-experimentos implican el uso de varias técnicas. En este artículo, la cirugía estereotáxica, y la formación del comportamiento de microdiálisis, que puede ser adaptado para probar una multitud de auto-administración y neupetroquímicas hipótesis centrada, sólo se incluyen para ilustrar cómo se relacionan con las fases posteriores de la toma de muestras y análisis de etanol dializado. Dializado análisis etanol concentración por cromatografía de gases con detección de ionización de llama, que es específico para los estudios de etanol, se describe en detalle. Los datos producidos por estos métodos revelar el patrón de etanol alcanza el cerebro durante el procedimiento de auto-administración, y cuando se combina con el análisis neuroquímico de las muestras de dializado mismas, permite conclusiones que se haya efectuado sobre los efectos farmacológicos y de comportamiento de etanol.

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

Un método para determinar el curso temporal de la concentración de etanol en el cerebro de ratas durante etanol operante auto-administración se describe. La cromatografía de gases con detección de ionización de llama se utiliza para cuantificar de etanol en las muestras de dializado, debido a que tiene la sensibilidad necesaria para los pequeños volúmenes que se generan.

Microdiálisis de etanol durante etanol operante determinación y la auto-administración de etanol por cromatografía de gases

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

Research

JoVE Journal

Neuroscience

17.4K vistas.  The University of Texas at Austin. Un método para determinar el curso temporal de la concentración de etanol en el cerebro de ratas durante etanol operante auto-administración se describe. La cromatografía de gases con detección de ionización de llama se utiliza para cuantificar de etanol en las muestras de dializado, debido a que tiene la sensibilidad necesaria para los pequeños volúmenes que se generan.

Video: 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.

Evaluación de las vocalizaciones de ultrasonidos durante autoadministración de drogas en ratas

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

Investigación

Neurociencias

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.

Sensación operante Buscando en el ratón

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.

Una manera sencilla de medir la sensibilidad de etanol en las moscas

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.

Los métodos para Autoadministración intravenosa en un modelo de ratón

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.

La identificación de los compuestos volátiles olfativas utilizando cromatografía de gases-de varias unidades Grabaciones (GCMR) en el lóbulo antenal insectos

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.

Microinyección insulina hipocampo y<em&gt; En vivo</em&gt; Microdiálisis durante la prueba de memoria espacial

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 ensayo de conducta Barato, escalable para medir etanol Sedación La sensibilidad y la tolerancia rápida en<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 ensayo para medir los efectos del etanol sobre la velocidad de locomoción<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.

Por encargo Microdiálisis Sonda Diseño

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.

Evaluación de la Homeostasis dopaminérgica en ratones por medio de análisis de cromatografía líquida de alto rendimiento y absorción de la dopamina Synaptosomal

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