Este trabajo fue financiado por becas del Decano de Stanford (SEJdV), los Institutos Nacionales de Premio Pioneer del Director de Salud (TRC DP0035350), Premio de la Fundación McKnight Scholar (TRC) y R01 EY022638 (TRC).

1. Generar moscas canalrodopsina <ol><li> Cruz UAS-ChR2 moscas con el controlador de Gal4 de su elección, se utiliza G105-Gal4, que se expresa en Foma-1 neuronas en el lóbulo óptico. </li><li> Para eliminar la posibilidad de una respuesta visual a la estimulación de la luz azul, ambas líneas de mosca son en fondo aw + Norpa. </li><li> Resultado final: w + Norpa; G105-Gal4/UAS-ChR2 + </li><li> Después de moscas adultas eclose, poner las hembras seleccionadas en alimentos frescos, complementado con 10 mM todo-trans-retinal (un co-factor necesario para ChR2) y protegido de la luz, durante 3 días antes de realizar el ensayo de comportamiento. </li></ol> 2. Hacer 10 mM todo-trans-retinal Food mejorada <ol><li> Disolver 100 mg de todo-trans-retinal en 17,6 ml de etanol al 95% para hacer 20 mM de retina. Mantener todo-trans-retinal protegido de la luz en todo momento. </li><li> Derrita la comida estándar mosca harina de maíz en el microondas y dejar enfriar hasta que esté caliente al tacto. </li><li> Mezclar 50 l de 20 mMtodo-trans-retinal en viales de 10 ml de alimentos mosca. </li><li> Deje enfriar los viales y mantener protegido de la luz. </li></ol> 3. Equipo <ol><li> Puntas de pipeta estándar: 1.000 puntas de pipeta mu l se cortan cerca de la punta, creando un diámetro de poro de ~ 2,25 mm. </li><li> Plataforma (ver Figura 1). <ol><li> Una base de Delrin, 17 cm x 25 cm, se construyó con agujeros roscados en cada esquina para adaptarse a ¼ &quot;NPT conectores de mangueras de refrigerante. </li><li> Un soporte vertical, hecha de Delrin, está unida al centro de la base. Las dimensiones totales son de 25 mm X 40 mm X 65 mm (ancho x profundidad x altura). Una ranura 10 mm de ancho corre a lo largo del soporte, con un tornillo de pulgar en la parte inferior. Una plataforma está unida a la parte superior del soporte, 25 mm X 40 mm X 10 mm, con un agujero de 3,5 mm de diámetro alineado con la ranura en el soporte. </li></ol></li><li> Matrices de LED (ver Figura 1). <ol><li> Cuatro brazos de manguera de refrigerante, ~ 18 cm de largo, están fijadas a la plataforma base utilizando el conector de la manguera del refrigerante. Refrigeracion sólo se utiliza como soporte estructural y no se utiliza para fines de refrigeración. </li><li> Ranuras adecuadamente espaciados se cortan en la pieza final de una manguera de refrigerante de cada brazo para la colocación del disipador de calor al extremo de cada brazo. </li><li> A Rebel LED azul Tri-Stars está montado en cada disipador de calor con pre-corte de cinta adhesiva térmica. Un Carclo 18 ° Tri-lente está fijado a cada Tri Star-. </li><li> LED Tri-Star se conectan a los conductores BuckPuck de CC y una fuente de alimentación como se especifica. Hemos organizado nuestra puesta a punto con cada BuckPuck alimentar dos Tri-Stars en serie. </li><li> La iluminación de los cuatro LED Tri-Stars a 700 mA produjo una irradiancia de 713 W / m 2 en nuestra plataforma. </li></ol></li><li> Cámara: La cámara está montada en un trípode pequeño y centrado en la parte superior de la plataforma. </li></ol> 4. Ensayo de comportamiento <ol><li> En pocas palabras anestesiar a las moscas en hielo. </li><li> Coloque las moscas individuales en puntas de pipeta, utilizando cinta adhesiva para cerrarAmbos extremos de la punta. </li><li> Después de que las moscas se han despertado y están explorando activamente la punta de la pipeta, retire la cinta y coloque una pipeta en la ranura en el soporte vertical. El tornillo de apriete manual se utiliza para asegurar la punta de la pipeta en su lugar y para cerrar la parte inferior de la punta. </li><li> Como la mosca explora la punta de la pipeta (típicamente 30 - 60 seg), inicie la grabación de la cámara justo antes de la mosca emerge desde la punta a la plataforma. </li><li> Después de la marcha se ha convertido en la plataforma, espere 1-2 seco, y encienda el LED azul. Use un cronómetro para medir manualmente el tiempo hasta que la mosca inicia vuelo. </li></ol>

<ol>
	<li>Venken, K., Simpson, J., Bellen, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+manipulations+of+genes+and+cells+in+the+nervous+system+of+the+fruit+fly.">Genetic manipulations of genes and cells in the nervous system of the fruit fly.</a> Neuron. 72, 202-230 (2011).</li><li>Gordon, M., Scott, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+control+in+a+Drosophila+taste+circuit.">Motor control in a Drosophila taste circuit.</a> Neuron. 61, 373-384 (2009).</li><li>Suh, G. S. B., 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=Light+activation+of+an+innate+olfactory+avoidance+response+in+Drosophila.">Light activation of an innate olfactory avoidance response in Drosophila.</a> Current Biology. 17, 905-908 (2007).</li><li>Zhang, W., Ge, W., Wang, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+toolbox+for+light+control+of+Drosophila+behaviors+through+Channelrhodopsin+2-mediated+photoactivation+of+targeted+neurons.">A toolbox for light control of Drosophila behaviors through Channelrhodopsin 2-mediated photoactivation of targeted neurons.</a> European Journal of Neuroscience. 26, 2405-2416 (2007).</li><li>Nagel, G., 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=Channelrhodopsin-2,+a+directly+light-gated+cation-selective+membrane+channel.">Channelrhodopsin-2, a directly light-gated cation-selective membrane channel.</a> Proceedings of the National Academy of Science. 100, 13940-13945 (2003).</li><li>de Vries, S., Clandinin, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loom-sensitive+neurons+link+computation+to+action+in+the+Drosophila+visual+system.">Loom-sensitive neurons link computation to action in the Drosophila visual system.</a> Current Biology. 22, 353-362 (2012).</li><li>Card, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Escape+behaviors+in+insects.">Escape behaviors in insects.</a> Current Opinion in Neurobiology. 22, 1-7 (2012).</li><li>Card, G., Dickinson, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visually+mediated+motor+planning+in+the+escape+response+of+Drosophila.">Visually mediated motor planning in the escape response of Drosophila.</a> Current Biology. 18, 1300-1307 (2008).</li><li>Fotowat, H., Fayyazuddin, A., Bellen, H. J., Gabbiani, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+neuronal+pathway+for+visually+guided+escape+in+Drosophila+melanogaster.">A novel neuronal pathway for visually guided escape in Drosophila melanogaster.</a> Journal of Neurophysiology. 102, 875-885 (2009).</li><li>Card, G., Dickinson, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performance+trade-offs+in+the+flight+initiation+of+Drosophila+melanogaster.">Performance trade-offs in the flight initiation of Drosophila melanogaster.</a> The Journal of Experimental Biology. 211, 341-353 (2008).</li><li>Hammond, S., O'Shea, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Escape+flight+initiation+in+the+fly.">Escape flight initiation in the fly.</a> Journal of Comparative Phsyiology A. 193, 471-476 (2007).</li><li>Benzer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral+mutants+of+Drosophila+isolated+by+countercurrent+distribution.">Behavioral mutants of Drosophila isolated by countercurrent distribution.</a> PNAS. 58, 1112-1119 (1967).</li><li>Bloomquist, B., 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=Isolation+of+a+putative+phospholipase+C+gene+of+Drosophila,+norpA,+and+its+role+in+phototransduction.">Isolation of a putative phospholipase C gene of Drosophila, norpA, and its role in phototransduction.</a> Cell. 54, 723-733 (1988).</li><li>Gohl, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+versatile+in+vivo+system+for+directed+dissection+of+gene+expression+patterns.">A versatile in vivo system for directed dissection of gene expression patterns.</a> Nature Methods. 8, 231-237 (2011).</li><li>Zhang, F., 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=Red-shifted+optogenetic+excitation:+a+tool+for+fast+neural+control+derived+from+Volvox+cateri.">Red-shifted optogenetic excitation: a tool for fast neural control derived from Volvox cateri.</a> Nature Neuroscience. 11, 631-633 (2008).</li></ol>

No hay conflictos de interés declarado.

<html> Hemos demostrado la estimulación optogenético de conductas de escape por el baño de caminar libremente las moscas a la luz azul brillante. Este enfoque puede ser fácilmente adaptado para examinar otros comportamientos en moscas libremente a pie, y se puede escalar a grandes plataformas simplemente embaldosado las matrices de LED se utilizan sobre un área mayor. Utilizando cualquiera de la cámara de bajo costo que estamos describiendo, o en otros sistemas de cámara disponibles, el usuario puede adaptar la ve...

Un creciente arsenal de herramientas codificados genéticamente han sido desarrollados para manipular la actividad neural en células específicas en Drosophila melanogaster 1. Estas herramientas permiten la activación no invasivo o el silenciamiento de neuronas específicas en el animal intacto y moverse libremente. Entre estos, Channelrhodopsin2 (ChR2), un canal catiónico activado por la luz, ofrece ventajas, ya que puede ser controlado temporalmente y se indujo rápidamente. Cuando las neuronas que expresan ChR2 están expuestos al brillante azul (470 nm) que rápidamente despolarizar y presentan elevadas tasas de disparo 3-5. Esa activación selectiva de neuronas específicas en animales libres de movimiento ha puesto de manifiesto la suficiencia de las neuronas particulares de comportamientos tales como el CO 2 evitación 3, probóscide extensión 2,4, y el gigante de fibra respuestas de sobresalto mediadas 4. Sin embargo, como las fuentes de luz intensa necesarias para estimular ChR2 también estimular fotorreceptores, aplicando optécnicas genéticos en el sistema visual ha sido limitada. Mediante la combinación de un enfoque optogenético con una mutación que afecta la fototransducción, hemos demostrado que la activación de un conjunto específico de neuronas en el lóbulo óptico de la mosca puede conducir el comportamiento de escape utilizado para evitar la colisión 6. La mayoría, si no todos, los animales visuales exhiben un comportamiento de escape para evitar colisiones con objetos que se aproximan. Caminar o moscas estacionario, cuando se le presenta una colisión inminente, el despegue en el vuelo, alejándose de la colisión inminente 7-9. Los despegues se caracterizan por las alas planteadas antes del despegue y una trayectoria de vuelo inestable 10,11. Esta respuesta es distinta de la gigante de fibra de la respuesta mediada por sobresalto, saltos que no van precedidos de alas levantadas, y suele dar lugar a una caída en caída libre 4,9. Después de haber identificado un grupo específico de neuronas sensibles al telar en el lóbulo óptico, Foma-1 las neuronas, que son uniquely sintonizado para codificar objetos que se aproximan, hemos tratado de investigar su implicación en el comportamiento de la mosca telar escape. Aquí se demuestra el uso de la optogenética para activar selectivamente estas neuronas y provocar el comportamiento de la mosca de escape. Utilizamos el sistema transcripcional Gal4-UAS activador para conducir la expresión de ChR2 en las neuronas Foma-1. ChR2 requiere el cofactor todo-trans-retinal y como esta se encuentra en niveles bajos en la Drosophila sistema nervioso central que debe ser complementado en la dieta de las moscas. 3,4 Cuando la luz brillante se utiliza para activar ChR2 y moscas exhiben comportamientos fuertes fototácticas 12, hemos tratado de eliminar la posibilidad de una respuesta al estímulo visual. Para ello, se utilizaron animales que eran mutantes homocigóticos para un alelo nulo del gen Norpa, que codifica un componente crítico de la cascada de la fototransducción, fosfolipasa C-β. Los fotorreceptores en estas moscas mutantes son incapaces de resd a la luz 13. Para probar la estimulación optogenético de la respuesta de escape, tenemos que aislar una sola mosca y se bañan en luz azul brillante. Para ello, ponemos moscas individuales en puntas de pipeta. Una punta de la pipeta se coloca en un soporte de ratón, de tal manera que la mosca geotactically caminará hasta la punta y hacia fuera sobre una plataforma rectangular. La mosca es capaz de caminar libremente alrededor de la parte superior de esta plataforma. La plataforma está rodeada por cuatro matrices de LED de color azul, cada uno con 3 LEDs, centrados en la parte superior de la plataforma. Después de la mosca está en la plataforma, los LED se iluminan, y la respuesta de la mosca se graba con una cámara de alta velocidad 6.

<table border="1"><tbody><tr><td></td><td></td><td></td><td> Reactivo </td></tr><tr><td> Todo-trans retinal </td><td> Avance Científico y Química Inc </td><td> R3041 </td><td></td></tr><tr><td></td><td></td><td></td><td> Equipo </td></tr><tr><td> Heat Sink 9.2 C / W </td><td> Luxeonstar </td><td> LPD30-30B </td><td> 30 mm X 30 mm cuadrado alto </td></tr><tr><td> Carclo 18 ° Tri-Lens </td><td> Luxeonstar </td><td> 10507 </td><td></td></tr><tr><td> Rebel LED azul en Tri-Star Base </td><td> Luxeonstar </td><td> MR-B0030-20T </td><td> 470 nm, 174 lm @ 700 mA. </td></tr><tr><td> 700 mA DC BuckPuck controlador </td><td> Luxeonstar </td><td> 3021-DE-700 </td><td></td></tr><tr><td> Arnés de cableado para el controlador BuckPuck </td><td> Luxeonstar </td><td> 3021-HE </td><td></td></tr><tr><td> Pre-corte de cinta adhesiva térmica </td><td> Luxeonstar </td><td> LXT-S-12 </td><td> 20 mm Base hexagonal </td></tr><tr><td> Snap-Loc Refrigeracion, ¼ &quot;ID </td><td> McMaster-Carr </td><td> 5307K49 </td><td></td></tr><tr><td> Snap-Loc Conector de la manguera del refrigerante </td><td> McMaster-Carr </td><td> 5307K39 </td><td> ¼ &quot;NPT macho </td></tr><tr><td> Laboratorio Grado de cambio de modo programable DC Power Supply </td><td> BK Precision </td><td> 1698 </td><td></td></tr><tr><td> Exilim cámara </td><td> Casio </td><td> EX-FH20 </td><td></td></tr></tbody></table>

optogenetic stimulation of escape behavior in drosophila melanogaster

Un número creciente de herramientas codificados genéticamente se están haciendo disponibles que permiten la manipulación no invasiva de la actividad neuronal de neuronas específicas en Drosophila melanogaster 1. El principal de ellos son herramientas optogenética, que permiten la activación o silenciamiento de neuronas específicas en el animal intacto y moverse libremente con luz brillante. Canalrodopsina (ChR2) es un canal catiónico activado por la luz que, al ser activado por luz azul, causa la despolarización de las neuronas que lo expresan. ChR2 ha sido eficaz para la identificación de las neuronas esenciales para comportamientos específicos, como el CO 2 evitación, la extensión y la probóscide gigante de fibra de respuesta de sobresalto mediada por 2-4. Sin embargo, como las fuentes de luz intensas utilizados para estimular ChR2 también estimular fotorreceptores, estas técnicas optogenético no se han usado previamente en el sistema visual. Aquí, combinamos un enfoque optogenético con una mutación que afecta a la fototransducción demostraciónnstrate que la activación de un grupo de neuronas sensibles al telar en lóbulo óptico de la mosca, Foma-1 neuronas, puede conducir a un comportamiento de escape utilizado para evitar la colisión. Se utilizó un alelo nulo de un componente crítico de la cascada de la fototransducción, fosfolipasa C-β, codificada por el gen Norpa, para hacer que la recta ciego y también utilizar el sistema de transcripción Gal4-UAS activador para conducir la expresión de ChR2 en la Foma-1 neuronas. Moscas individuales están colocados en una pequeña plataforma rodeada por LEDs azules. Cuando los LEDs se iluminan, las moscas rápidamente despegue en vuelo, de una manera similar a la impulsada visualmente telar de escape de comportamiento. Creemos que esta técnica se puede adaptar fácilmente para examinar otras conductas en movimiento libre moscas.

Blind vuela manifieste ChR2 o el controlador G105 sólo muestran una baja tasa de despegue después de su iluminación con luz azul brillante. Blind vuela exhibió la misma velocidad de despegue sin iluminación (Figura 2), lo que sugiere que estos despegues eran espontáneas y no debido a la iluminación con luz azul. Cuando el ChR2 se expresa en las neuronas Foma1, sin embargo, la irradiación con luz azul provoca la respuesta de escape. Más del 50% de las moscas ensayadas despegó dentro de 1 segund...

Watch this Scientific Journal Video about Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster at JoVE.com

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

Codificados genéticamente herramientas optogenético permitir la manipulación no invasiva de neuronas específicas en el<em&gt; Drosophila</em&gt; Cerebro. Estas herramientas pueden identificar neuronas cuya activación es suficiente para provocar o suprimir conductas particulares. Aquí presentamos un método para activar Channelrhodopsin2 que se expresa en neuronas específicas en las moscas con libertad para caminar.

Optogenético estimulación de comportamiento de escape en<em&gt; Drosophila melanogaster</em

A  growing number of genetically encoded tools are becoming available that allow non-invasive  manipulation of the neural activity of specific neurons in ...

optogenetic-stimulation-of-escape-behavior-in-drosophila-melanogaster

Research

JoVE Journal

Neuroscience

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

17.3K vistas.  Stanford University. Codificados genéticamente herramientas optogenético permitir la manipulación no invasiva de neuronas específicas en el Drosophila Cerebro. Estas herramientas pueden identificar neuronas cuya activación es suficiente para provocar o suprimir conductas particulares. Aquí presentamos un método para activar Channelrhodopsin2 que se expresa en neuronas específicas en las moscas con libertad para caminar.

Video: Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

Single Sensillum Recordings in the Insects Drosophila melanogaster and Anopheles gambiae

The sense of smell is essential for insects to find foods, mates, predators, and oviposition sites3. Insect olfactory sensory neurons (OSNs) are enclosed in sensory hairs called sensilla, which cover the surface of olfactory organs. The surface of each sensillum is covered with tiny pores, through which odorants pass and dissolve in a fluid called sensillum lymph, which bathes the sensory dendrites of the OSNs housed in a given sensillum. The OSN dendrites express odorant receptor (OR) proteins, which in insects function as odor-gated ion channels4, 5. The interaction of odorants with ORs either increases or decreases the basal firing rate of the OSN. This neuronal activity in the form of action potentials embodies the first representation of the quality, intensity, and temporal characteristics of the odorant6, 7.
Given the easy access to these sensory hairs, it is possible to perform extracellular recordings from single OSNs by introducing a recording electrode into the sensillum lymph, while the reference electrode is placed in the lymph of the eye or body of the insect. In Drosophila, sensilla house between one and four OSNs, but each OSN typically displays a characteristic spike amplitude. Spike sorting techniques make it possible to assign spiking responses to individual OSNs. This single sensillum recording (SSR) technique monitors the difference in potential between the sensillum lymph and the reference electrode as electrical spikes that are generated by the receptor activity on OSNs1, 2, 8. Changes in the number of spikes in response to the odorant represent the cellular basis of odor coding in insects. Here, we describe the preparation method currently used in our lab to perform SSR on Drosophila melanogaster and Anopheles gambiae, and show representative traces induced by the odorants in a sensillum-specific manner.

Single Sensillum Recordings in the Insects Drosophila melanogaster and Anopheles gambiae

Electrophysiological responses of olfactory sensory neurons to odorants can be measured in insects using single sensillum recordings. In this video article we will demonstrate how to perform single sensillum recordings in the antennae of the vinegar fly (Drosophila melanogaster) and the maxillary palps of the malaria mosquito (Anopheles gambiae).

Grabaciones solo Sensillum en los insectos Drosophila melanogaster Y Anopheles gambiae</em

The sense of smell is essential for insects to find foods, mates, predators, and oviposition sites3. Insect olfactory sensory neurons (OSNs) are enclosed ...

Investigación

Neurociencias

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated. Thus, simultaneous recordings of neuronal activity and behavior are essential to correlate brain activity to behavior. For such behavioral analyses, the fruit fly, Drosophila melanogaster, allows us to incorporate genetically encoded calcium indicators such as GCaMP1, to monitor neuronal activity, and to use sophisticated genetic manipulations for optogenetic or thermogenetic techniques to specifically activate identified neurons2-5. Use of a thermogenetic technique has led us to find critical neurons for feeding behavior (Flood et al., under revision). As a main part of feeding behavior, a Drosophila adult extends its proboscis for feeding6 (proboscis extension response; PER), responding to a sweet stimulus from sensory cells on its proboscis or tarsi. Combining the protocol for PER7 with a calcium imaging technique8 using GCaMP3.01, 9, I have established an experimental system, where we can monitor activity of neurons in the feeding center &#x2013; the suboesophageal ganglion (SOG), simultaneously with behavioral observation of the proboscis. I have designed an apparatus ("Fly brain Live Imaging and Electrophysiology Stage": "FLIES") to accommodate a Drosophila adult, allowing its proboscis to freely move while its brain is exposed to the bath for Ca2+ imaging through a water immersion lens. The FLIES is also appropriate for many types of live experiments on fly brains such as electrophysiological recording or time lapse imaging of synaptic morphology. Because the results from live imaging can be directly correlated with the simultaneous PER behavior, this methodology can provide an excellent experimental system to study information processing of neuronal networks, and how this cellular activity is coupled to plastic processes and memory.

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

The fruit fly, Drosophila melanogaster, extends its proboscis for feeding, responding to a sugar stimulus from its proboscis or tarsus. I have combined observations of the proboscis extension response (PER) with a calcium imaging technique, allowing us to monitor the activity of neurons in the brain, simultaneously with behavioral observation.

La grabación simultánea de señales de calcio en neuronas identificadas y comportamiento de alimentación de Drosophila melanogaster</em

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated.  Thus, ...

Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such behavior is spontaneous locomotor activity. Here we describe our protocol that utilizes Drosophila population monitors and a tracking system that allows continuous monitoring of the spontaneous locomotor activity of flies for several days at a time. This method is simple, reliable, and objective and can be used to examine the effects of aging, sex, changes in caloric content of food, addition of drugs, or genetic manipulations that mimic human diseases.

Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster

Drosophila melanogaster are useful in studying genetic or environmental manipulations that affect behaviors such as spontaneous locomotor activity.&#160; Here we describe a protocol that utilizes monitors with infrared beams and data analysis software to quantify spontaneous locomotor activity.&#160;

Determinación de la actividad locomotora espontánea en<em&gt; Drosophila melanogaster</em

Drosophila melanogaster has been used as an excellent model organism to study environmental and genetic manipulations that affect behavior. One such ...

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution has been a long sought tool for neuroscientists in the systems-level search for the neural circuitry governing complex behavioral states. Optogenetics is a cutting-edge tool that is revolutionizing the field of neuroscience and represents one of the first systematic approaches to enable causal testing regarding the relation between neural signaling events and behavior. By combining optical and genetic approaches, neural signaling can be bi-directionally controlled through expression of light-sensitive ion channels (opsins) in mammalian cells. The current protocol describes delivery of specific wavelengths of light to opsin-expressing cells in deep brain structures of awake, freely-moving rodents for neural circuit modulation. Theoretical principles of light transmission as an experimental consideration are discussed in the context of performing in vivo optogenetic stimulation. The protocol details the design and construction of both simple and complex laser configurations and describes tethering strategies to permit simultaneous stimulation of multiple animals for high-throughput behavioral testing.

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

Optogenetics has become a powerful tool for use in behavioral neuroscience experiments. This protocol offers a step-by-step guide to the design and set-up of laser systems, and provides a full protocol for carrying out multiple and simultaneous in vivo optogenetic stimulations compatible with most rodent behavioral testing paradigms.

In vivo optogenético la estimulación del sistema nervioso central de roedores

The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution ...

Optogenetic Stimulation of the Auditory Nerve

Direct electrical stimulation of spiral ganglion neurons (SGNs) by cochlear implants (CIs) enables open speech comprehension in the majority of implanted deaf subjects1-6. Nonetheless, sound coding with current CIs has poor frequency and intensity resolution due to broad current spread from each electrode contact activating a large number of SGNs along the tonotopic axis of the cochlea7-9. Optical stimulation is proposed as an alternative to electrical stimulation that promises spatially more confined activation of SGNs and, hence, higher frequency resolution of coding. In recent years, direct infrared illumination of&#160;the cochlea has been used to evoke responses in the auditory nerve10. Nevertheless it requires higher energies than electrical stimulation10,11 and uncertainty remains as to the underlying mechanism12. Here we describe a method based on optogenetics to stimulate SGNs with low intensity blue light, using transgenic mice with neuronal expression of channelrhodopsin 2 (ChR2)13 or virus-mediated expression of the ChR2-variant CatCh14. We used micro-light emitting diodes (&#181;LEDs) and fiber-coupled lasers to stimulate ChR2-expressing SGNs through a small artificial opening (cochleostomy) or the round window. We assayed the responses by scalp recordings of light-evoked potentials (optogenetic auditory brainstem response: oABR) or by microelectrode recordings from the auditory pathway and compared them with acoustic and electrical stimulation.

Cochlear implants (CIs) enable hearing by direct electrical stimulation of the auditory nerve. However, poor frequency and intensity resolution limits the quality of hearing with CIs. Here we describe optogenetic stimulation of the auditory nerve in mice as an alternative strategy for auditory research and developing future CIs.

Estimulación Optogenética del nervio auditivo

Direct electrical stimulation of spiral ganglion neurons (SGNs) by cochlear implants (CIs) enables open speech comprehension in the majority of implanted ...

Conditions Affecting Social Space in Drosophila melanogaster

The social space assay described here can be used to quantify social interactions of Drosophila melanogaster &#8212; or other small insects &#8212; in a straightforward manner. As we previously demonstrated 1, in a two-dimensional chamber, we first force the flies to form a tight group, subsequently allowing them to take their preferred distance from each other. After the flies have settled, we measure the distance to the closest neighbor (or social space), processing a static picture with free online software (ImageJ). The analysis of the distance to the closest neighbor allows researchers to determine the effects of genetic and environmental factors on social interaction, while controlling for potential confounding factors. Diverse factors such as climbing ability, time of day, sex, and number of flies, can modify social spacing of flies. We thus propose a series of experimental controls to mitigate these confounding effects. This assay can be used for at least two purposes. First, researchers can determine how their favorite environmental shift (such as isolation, temperature, stress or toxins) will impact social spacing 1,2. Second, researchers can dissect the genetic and neural underpinnings of this basic form of social behavior 1,3. Specifically, we used it as a diagnostic tool to study the role of orthologous genes thought to be involved in social behavior in other organisms, such as candidate genes for autism in humans 4.

Conditions Affecting Social Space in Drosophila melanogaster

The effect of genes and environment on social space of Drosophila melanogaster can be quantified through a powerful but straightforward analytical paradigm. We show here different factors that can affect this social space, and thus need to be taken into consideration when designing experiments in this paradigm.

Condiciones que afectan Espacio Social en<em&gt; Drosophila melanogaster</em

The social space assay described here can be used to quantify social interactions of Drosophila melanogaster &#8212; or other small insects &#8212; in a ...

High-resolution Quantification of Odor-guided Behavior in Drosophila melanogaster Using the Flywalk Paradigm

In their natural environment, insects such as the vinegar fly Drosophila melanogaster are bombarded with a huge amount of chemically distinct odorants. To complicate matters even further, the odors detected by the insect nervous system usually are not single compounds but mixtures whose composition and concentration ratios vary. This leads to an almost infinite amount of different olfactory stimuli which have to be evaluated by the nervous system.
To understand which aspects of an odor stimulus determine its evaluation by the fly, it is therefore desirable to efficiently examine odor-guided behavior towards many odorants and odor mixtures. To directly correlate behavior to neuronal activity, behavior should be quantified in a comparable time frame and under identical stimulus conditions as in neurophysiological experiments. However, many currently used olfactory bioassays in Drosophila neuroethology are rather specialized either towards efficiency or towards resolution.
Flywalk, an automated odor delivery and tracking system, bridges the gap between efficiency and resolution. It allows the determination of exactly when an odor packet stimulated a freely walking fly, and to determine the animal&#180;s dynamic behavioral reaction.

High-resolution Quantification of Odor-guided Behavior in Drosophila melanogaster Using the Flywalk Paradigm

The automated tracking system Flywalk is used for high-resolution quantification of odor-guided behavior in Drosophila melanogaster.

De alta resolución de cuantificación del comportamiento guiado Olor en<em&gt; Drosophila melanogaster</em&gt; Uso de la<em&gt; Flywalk</em&gt; Paradigma

In their natural environment, insects such as the vinegar fly Drosophila melanogaster are bombarded with a huge amount of chemically distinct odorants. To ...

A Simple Way to Measure Alterations in Reward-seeking Behavior Using Drosophila melanogaster

We describe a protocol for measuring ethanol self-administration in fruit flies (Drosophila melanogaster) as a proxy for changes in reward states. We demonstrate a simple way to tap into the fly reward system, modify experiences related to natural reward, and use voluntary ethanol consumption as a measure for changes in reward states. The approach serves as a relevant tool to study the neurons and genes that play a role in experience-mediated changes of internal state. The protocol is composed of two discrete parts: exposing the flies to rewarding and nonrewarding experiences, and assaying voluntary ethanol consumption as a measure of the motivation to obtain a drug reward. The two parts can be used independently to induce the modulation of experience as an initial step for further downstream assays or as an independent two-choice feeding assay, respectively. The protocol does not require a complicated setup and can therefore be applied in any laboratory with basic fly culture tools.

A Simple Way to Measure Alterations in Reward-seeking Behavior Using Drosophila melanogaster

We describe a protocol for inducing rewarding and nonrewarding experiences in fruit flies (Drosophila melanogaster) using voluntary ethanol consumption as a measure for changes in reward states.

Una manera sencilla de medir alteraciones en el comportamiento de búsqueda de recompensa Uso<em&gt; Drosophila melanogaster</em

We describe a protocol for measuring ethanol self-administration in fruit flies (Drosophila melanogaster) as a proxy for changes in reward states. We ...

Quantification of Drosophila Grooming Behavior

Drosophila grooming behavior is a complex multi-step locomotor program that requires coordinated movement of both forelegs and hindlegs. Here we present a grooming assay protocol and novel chamber design that is cost-efficient and scalable for either small or large-scale studies of Drosophila grooming. Flies are dusted all over their body with Brilliant Yellow dye and given time to remove the dye from their bodies within the chamber. Flies are then deposited in a set volume of ethanol to solubilize the dye. The relative spectral absorbance of dye-ethanol samples for groomed versus ungroomed animals are measured and recorded. The protocol yields quantitative data of dye accumulation for individual flies, which can be easily averaged and compared across samples. This allows experimental designs to easily evaluate grooming ability for mutant animal studies or circuit manipulations. This efficient procedure is both versatile and scalable. We show work-flow of the protocol and comparative data between WT animals and mutant animals for the Drosophila type I Dopamine Receptor (DopR).

This protocol describes a scalable individual grooming assay technique in Drosophila that yields robust, quantitative data to measure grooming behavior. The method is based on comparing the difference in dye accumulation on the bodies of un-groomed versus groomed animals over a set period of time.

Cuantificación de la Drosophila Grooming Comportamiento

Drosophila grooming behavior is a complex multi-step locomotor program that requires coordinated movement of both forelegs and hindlegs. Here we present a ...

Optogenetic Entrainment of Hippocampal Theta Oscillations in Behaving Mice

Extensive data on relationships of neural network oscillations to behavior and organization of neuronal discharge across brain regions call for new tools to selectively manipulate brain rhythms. Here we describe an approach combining projection-specific optogenetics with extracellular electrophysiology for high-fidelity control of hippocampal theta oscillations (5-10 Hz) in behaving mice. The specificity of the optogenetic entrainment is achieved by targeting channelrhodopsin-2 (ChR2) to the GABAergic population of medial septal cells, crucially involved in the generation of hippocampal theta oscillations, and a local synchronized activation of a subset of inhibitory septal afferents in the hippocampus. The efficacy of the optogenetic rhythm control is verified by a simultaneous monitoring of the local field potential (LFP) across lamina of the CA1 area and/or of neuronal discharge. Using this readily implementable preparation we show efficacy of various optogenetic stimulation protocols for induction of theta oscillations and for the manipulation of their frequency and regularity. Finally, a combination of the theta rhythm control with projection-specific inhibition addresses the readout of particular aspects of the hippocampal synchronization by efferent regions.

We describe the use of optogenetics and electrophysiological recordings for selective manipulations of hippocampal theta oscillations (5-10 Hz) in behaving mice. The efficacy of the rhythm entrainment is monitored using local field potential. A combination of opto- and pharmacogenetic inhibition addresses the efferent readout of hippocampal synchronization.

Optogenetic de arrastre de las oscilaciones Theta Hippocampal en comportarse ratones

Extensive data on relationships of neural network oscillations to behavior and organization of neuronal discharge across brain regions call for new tools ...