Este trabalho foi financiado em parte por um Instituto Nacional de Saúde (NIH) para conceder AI063433 Laurence G. Rahme, um Instituto Nacional Institutes of Health (NIH) Centro de Grant (P50GM021700) para Ronald G. Tompkins (A. Aria Tzika, Diretor de o núcleo de RMN), e um Hospital Shriners para Crianças Bolsa de Investigação (# 8893) para A. Aria Tzika. Agradecemos a Dionyssios Mintzopoulos Ph.D. de assistência nas fases iniciais de desenvolvimento deste protocolo e Ovidiu C. Andronesi Ph.D. de assistência com a seqüência de pulso TOBSY.

Parte 1: Preparando-se para Drosophila Medidas HRMAS <ol><li> Usando o padrão flylab procedimentos 1, recolher recém eclosing moscas durante 3 dias e transferi-los para voar frascos contendo alimentos fly fresco. Incubar as moscas coletadas por 5 dias para que as moscas se tornará 5-8 dias de idade um pouco antes do experimento. Apenas um sexo (geralmente machos) é usada para experimentos. </li><li> Use saudável, do tipo selvagem intacta voa para comparar com tratados por exemplo, traumatizados ou moscas geneticamente alterados 1. </li><li> Lugar moscas única em tubos de 2ml contendo um pedaço (~ 0,2 ml) de mosca de alimentos 24 horas antes do experimento. Estes tubos têm um furo no copo tubo feito usando uma agulha de insulina chama-aquecido. </li><li> Pesar os tubos imediatamente antes e após a inserção voar utilizando uma balança de alta precisão e definir o peso de cada fly s subtraindo-se o primeiro valor do segundo. A única mosca macho pesa geralmente 0,7-1 mg. </li></ol> Parte 2: Preparação HRMAS Rotor. <ol><li> Coloque um único tubo em gelo por menos de um minuto para anestesiar o interior voar. </li><li> Lay a mosca em uma camada de papel alumínio colocado sobre o gelo e empurre a voar delicadamente no espaço semi-esférica oca da inserção rotor NMR utilizando uma escova macia para garantir a inserção voar completa, evitando lesões voar. </li><li> Coloque a inserir no óxido de zircônio (ZrO 2) tubo de rotor (4 mm de diâmetro, 50 ul) para localizar as moscas entre o rotor e inserir na parte inferior do rotor (ver figura 1). </li><li> Feche a inserção com um parafuso e cobri-lo com parafilme (ver figura 1) para evitar o contato entre a mosca eo TSP solução-padrão (TSP: trimetilsilil-propiônico-2 ,2,3,3-d4 ácido, Mw = 172, δ = 0,00 ppm, 50 mM em água deuterada-D 2 O, que funcionam como uma referência tanto para deslocamento químico ressonância e quantificação). </li><li> Adicionar 8 mL de solução padrão TSP em cima do insert rotor. (Ver figura 1). </li><li> Aperte bem todo o conjunto em que os rotores com uma tampa superior (ver figura 1). </li></ol> Parte 3: HRMAS Aquisição de Dados <ol><li> Introduzir o rotor na sonda HRMAS e posicioná-la no ângulo mágico 54,7 ° (ver figura 1). </li><li> Ajuste de temperatura de 4 ° C por uma unidade de BTO-2000 em conjunto com a unidade pneumática MAS. Moscas são mantidos a 4 ° C, enquanto no espectrômetro para manter a anestesia. </li><li> Definir a taxa de HRMAS 1 H MRS girando em 2 MAS kHz. </li><li> Estabilizar a freqüência de rotação MAS de 2,0 ± 0,001 kHz por um controlador de velocidade MAS (freqüência de rotação). </li><li> Para a preparação de ímã: sintonia e combinar a bobina para um melhor desempenho e calço o ímã para ótima qualidade de espectros. </li><li> Adquirir uma dimensão um espectro de H usando rotor sincronizado Carr-Purcell-Meiboom-Gill (CPMG) spin echo seqüência de pulsos 2, [90 ° - (τ-180 ° - τ) n-aquisição], que funciona como um filtro para 2 T remover o alargamento espectral 1 H RMN único voar para adquirida unidimensional dados sobre todas as amostras. Sincronizar o atraso inter-pulso (τ = 500μs) para a frequência de rotação MAS (2 kHz). Definir o número de transientes em 256 com 32,768 (32k) pontos de dados. Aquisição em tempo 9 min. </li><li> Aquisição de duas dimensões (2D) 1 H-1 H RMN HRMAS único voar em todas as amostras usando uma seqüência TOBSY com pulsos adiabáticos 3. Parâmetros de aquisição são: pontos de dados de dimensão 2k direta (11 ppm largura espectral), a água 1 s pré-saturação durante o atraso de relaxamento, 8 varreduras por incremento, 128 incrementos, o tempo de 2 s repetição total, 45 ms de tempo de mistura, e um total de aquisição tempo de 29 min. </li></ol> Parte 4: Processamento de Dados / Análise <ol><li> Analisar a MRspectra de espécimes usando MestReC software (Mestrelab Research, www.mestrec.com) </li><li> Use uma linha de alargamento função apodização de 0,5 Hz e se aplicam a todos os 1 HRMAS FIDs H antes da transformação de Fourier. </li><li> Referência o espectro MR em relação ao TSP em δ = 0,0 ppm (padrão externo). </li><li> Fase de espectros manualmente e aplicar um estimador base Whittaker para subtrair os componentes ampla da linha de base antes de cálculos de área de pico. </li><li> Estimativa de áreas dos picos usando software MestReC. Escala de alturas de pico em relação a TSP para cada espectro adquirido (altura do pico TSP = 1). Use t-testes (bicaudal, p &lt;0,05) para comparação dentro do grupo-a entre-grupos rácios. </li><li> Parâmetros de processo 2D TOBSY são: QSINE = função de janela 2 em ambas as dimensões, FT com 2k pontos na dimensão diretos e zero-enchimento para 1k na segunda dimensão, correção de fase em ambas as dimensões e correção de linha de base na segunda dimensão. </li><li> Produzir os espectros 2D utilizando Sparky programa (TD Goddard e DG Kneller, SPARKY 3, USCF, <a href="http://www.cgl.ucsf.edu/home/sparky/">http://www.cgl.ucsf.edu/</a>home / sparky /) </li></ol> Parte 5: Spectra Representante do Live moscas Drosophila melanogaster Os procedimentos descritos acima permitem coletar espectros reprodutíveis das moscas Drosophila melanogaster ao vivo. Figuras 2 e 3 mostram representante MR espectros adquiridos no tipo selvagem (wt) Oregon-R moscas. A Figura 2 apresenta 1D 1 H HRMAS espectros CPMG. Principais componentes lipídicos [H 3 C (0,89 ppm), (C H 2) n (1,33 ppm), C H 2 C-CO (1.58ppm), C H 2 C = C (2,02 ppm), H 2 C = C O (2,24 ppm), C = C H H (5,33 ppm)] glicerol, (1,3-C H 4,10 ppm e 4,30 ppm; 2-CH 2 5,24 ppm), e metabólitos pequeno: β-alanina (Ala-β , 2,57 ppm), acetato (Ac, 1,97 ppm), fosfocolina (PC, 3,22 ppm) e phophoetanolamine (PE, 3.23ppm) foram detectadas e atribuídas de acordo com relatórios anteriores 4, 5. Sinais em 2,02 ppm foram atribuídos aos prótons de metileno do H2-CH = CH C porção de mono-ácidos graxos insaturados (ie palmitoléico). Os ácidos insaturados foram identificados por um sinal em 5,33 ppm produzidas por prótons do-CH = CH-metade. Metabólitos de pequeno porte que não poderia ser atribuído ou não eram visíveis a utilização do espectro 1D foram detectadas utilizando 2D 1 H-1 H TOBSY HRMAS (ver figura 3). <img src="/files/ftp_upload/1710/1710fig1.jpg" alt="Figura 1" /> Figura 1. Experimental criação de in vivo HRMAS 1H MRS para a investigação de viver Drosophila em 14,1 T. externo padrão trimetilsilil-propiônico-2 ,2,3,3-ácido d4 em água deuterada (TSP / D 2 O). Na praça: a posição do rotor no ângulo mágico em HRMAS sonda. <img src="/files/ftp_upload/1710/1710fig2.jpg" alt="Figura 2" /> Figura 2. In vivo 1D 1 H HRMAS espectros CPMG de uma mosca Drosophila melanogaster ao vivo wt. Componentes lipídicos: C H 3 (0,89 ppm), (C H 2) n (1,33 ppm), C H 2 C-CO (1.58ppm), acetato (Ac), C H 2 C = C (2,02 ppm), C H 2 C = O glicerol (2,24 ppm), β-alanina (β-Ala), fosfocolina (PC) e phophoetanolamine (PE), (1,3-C H 4,10, 4,30 ppm; 2-H 2 C 5,22 ppm) , C H H = C (5,33 ppm). <img src="/files/ftp_upload/1710/1710fig3.jpg" alt="Figura 3" /> Figura 3. In vivo 2D 1H-1H TOBSY HRMAS espectro de uma mosca Drosophila melanogaster ao vivo em peso a 14,1 metabólitos T. Pequenas e componentes lipídicos foram identificados. Metabolitos: alanina (Ala), β-alanina (β-Ala), arginina (Arg), glutamina (Gln), glutamato (Glu), PC fosfocolina (PC), phophoetanolamine (PE), taurina (Tau), α-glicose (α-Glc) e glicerol. Lipídios componentes: C H 3 (0,89 ppm), (C H 2) n (1,33 ppm), C H 2 C-CO (1,58 ppm), C H 2 C = C (2,02 ppm), C H 2 C = O (2,24 ppm), C = C H H (5,33 ppm).

<ol>
	<li>Apidianakis, Y., Rahme, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drosophila+melanogaster+as+a+model+host+for+studying+Pseudomonas+aeruginosa+infection.">Drosophila melanogaster as a model host for studying Pseudomonas aeruginosa infection.</a> Nat Protoc. 4, 1285-1294 (2009).</li><li>Meiboom, S., Gill, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modified+spin-echo+method+for+measuring+nuclear+relaxation+time.">Modified spin-echo method for measuring nuclear relaxation time.</a> Rev Sci Instrum. 29, 688-691 (1958).</li><li>Andronesi, O. C., Mintzopoulos, D., Struppe, J., Black, P. M., Tzika, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solid-state+NMR+adiabatic+TOBSY+sequences+provide+enhanced+sensitivity+for+multidimensional+high-resolution+magic-angle-spinning+1H+MR+spectroscopy.">Solid-state NMR adiabatic TOBSY sequences provide enhanced sensitivity for multidimensional high-resolution magic-angle-spinning 1H MR spectroscopy.</a> J Magn Reson. 193, 251-258 (2008).</li><li>Astrakas, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proton+NMR+spectroscopy+shows+lipids+accumulate+in+skeletal+muscle+in+response+to+burn+trauma-induced+apoptosis.">Proton NMR spectroscopy shows lipids accumulate in skeletal muscle in response to burn trauma-induced apoptosis.</a> Faseb J. 19, 1431-1440 (2005).</li><li>Fan, T. W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolite+profiling+by+one-+and+two+dimensional+NMR+analysis+of+complex+mixtures.">Metabolite profiling by one- and two dimensional NMR analysis of complex mixtures.</a> Prog Nuc Magn Reson Spec. 28, 161-219 (1996).</li><li>Null, B., Liu, C. W., Hedehus, M., Conolly, S., Davis, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution,+in+vivo+magnetic+resonance+imaging+of+Drosophila+at+18.8+Tesla.">High-resolution, in vivo magnetic resonance imaging of Drosophila at 18.8 Tesla.</a> PLoS One. 3, e2817-e2817 (2008).</li><li>Zektzer, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+signal+to+noise+in+high-resolution+magic+angle+spinning+total+correlation+spectroscopy+studies+of+prostate+tissues+using+rotor-synchronized+adiabatic+pulses.">Improved signal to noise in high-resolution magic angle spinning total correlation spectroscopy studies of prostate tissues using rotor-synchronized adiabatic pulses.</a> Magn Reson Med. 53, 41-48 (2005).</li></ol>

Experimentos em animais foram realizados de acordo com as diretrizes e regulamentos estabelecidos pelo Massachusetts General Hospital Institucional animal Comité de Investigação Review Board.

Com exceção do recente relatório sobre a viabilidade de ressonância magnética in vivo em moscas de fruta 6, in vivo MRS estudos em Drosophila ainda não foram relatados. No protocolo, descrevemos a implementação de um romance in vivo HRMAS uma abordagem H-MRS para a detecção de moléculas biologicamente importantes. Especificamente, nós detectamos lipídios e metabólitos em pequena viver Drosophila voa a 14,1 T em aproximadamente 45 min, o que...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Deuterium oxide</td>
<td>Reagent</td>
<td>Sigma-Aldrich</td>
<td>7789-20-0</td>
<td>&nbsp;</td>
<tr>
<td>3-(trimethylsilyl)propionic-2,2,3,3-d4 acid</td>
<td>Reagent</td>
<td>Sigma-Aldrich</td>
<td>24493-21-8</td>
<td>&nbsp;</td>
<tr>
<td>agar, sucrose, yeast, cornmeal</td>
<td>Food</td>
<td>Genesee Scientific Corporation</td>
<td>&nbsp;</td>
<td><a href="http://www.flystuff.com/">http://www.flystuff.com/</a></td>
</tr>
<tr>
<td>Oregon RS or Canton-S flies</td>
<td>Adult fly lines</td>
<td>Bloomington Stock Center</td>
<td>&nbsp;</td>
<td><a href="http://flystocks.bio.indiana.edu/">http://flystocks.bio.indiana.edu/</a></td>
</tr>
<tr>
<td>Paintbrush</td>
<td>Equipment</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>(size 0)</td>
</tr>
<tr>
<td>2ml tubes</td>
<td>Equipment</td>
<td>Fisher Scientific</td>
<td>K749521-1590</td>
<td>&nbsp;</td>
<tr>
<td>Fly incubators</td>
<td>Equipment</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>high humidity capacity (60-75%), adjustable temperature, and a 12 h:12 h light: dark cycle.</td>
</tr>
<tr>
<td>Bruker Bio-Spin Avance NMR spectrometer (600.13 MHz) 4mm triple resonance (1H, 13C, 2H) HRMAS probe </td>
<td>Equipment</td>
<td>Bruker Bio-Spin</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>BTO-2000 unit in combination with a MAS pneumatic unit</td>
<td>Equipment</td>
<td>Bruker Bio-Spin</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>4mm zirconium oxide rotor (capacity 50 ul)</td>
<td>Equipment</td>
<td>Bruker Bio-Spin</td>
<td>B3829 (Bruker store)</td>
<td>&nbsp;</td>
<tr>
<td>MestReC (Mestrelab Research) </td>
<td>Software</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>1D NMR spectra analysis <a href="http://mestrelab.com/">http://mestrelab.com/</a></td>
</tr>
<tr>
<td>SPARKY 3, USCF</td>
<td>Software</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>2D NMR spectra
analysis
 <a href="http://www.cgl.ucsf.edu/home/sparky/">http://www.cgl.ucsf.edu/home/sparky/</a></td>
</tr>		</tbody>
		</table>
		</div>

magnetic resonance spectroscopy of live drosophila melanogaster using magic angle spinning

Alta Resolução Angle Spinning Magia (HRMAS) espectroscopia de prótons por ressonância magnética (<sup&gt; 1</sup&gt; H-MRS) é uma técnica não destrutiva romance que melhora espectral da linha de larguras e permite que espectros de alta resolução a ser obtido a partir de extratos, células intactas, culturas de células, tecidos e mais importante ainda intacta para investigar as relações entre metabolitos e processos celulares.<em&gt; In vivo</em&gt; HRMAS<sup&gt; 1</sup&gt; H-MRS estudos ainda não foram relatados na mosca da fruta ao vivo<em&gt; Drosophila melanogaster.</em&gt;<em&gt; Drosophila,</em&gt; Como um simples organismo genética, permite que as múltiplas funções biológicas e vários evolutivamente conservadas vias de sinalização a ser examinada em nível organismo inteiro e é um modelo útil para a investigação genética e fisiologia. Para este fim, desenvolvido e implementado um<em&gt; In vivo</em&gt; HRMAS<sup&gt; 1</sup&gt; H-MRS método para investigar ao vivo<em&gt; Drosophila</em&gt; 14,1 em T. Aqui, esboçamos uma HRMAS<sup&gt; 1</sup&gt; H-MRS protocolo para a caracterização molecular de<em&gt; Drosophila</em&gt; Com um espectrômetro MR convencional equipado com uma sonda HRMAS. Esta técnica é um romance,<em&gt; In vivo,</em&gt; Não-destrutivos<em&gt; Drosophila</em&gt; Abordagem de medição metabólito, que permite a identificação de biomarcadores da doença e, portanto, pode contribuir para o desenvolvimento terapêutico romance.

Watch this Scientific Journal Video about Magnetic Resonance Spectroscopy of live Drosophila melanogaster using Magic Angle Spinning at JoVE.com

Magnetic Resonance Spectroscopy of live Drosophila melanogaster using Magic Angle Spinning

Esta técnica permite o uso de alta resolução, ângulo mágico de prótons girando MR espectroscopia (HRMAS 1H-MRS) para a caracterização molecular de viver<em&gt; Drosophila melanogaster</em&gt; Com um espectrômetro convencional 14,1 tesla equipado com uma sonda HRMAS.

Espectroscopia de Ressonância Magnética de viver Drosophila melanogaster Usando Angle Spinning Magia

High-Resolution Magic Angle Spinning (HRMAS) proton magnetic resonance spectroscopy (1H-MRS) is a novel non-destructive technique that improves spectral ...

magnetic-resonance-spectroscopy-live-drosophila-melanogaster-using

Research

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Neuroscience

Magnetic Resonance Spectroscopy of live Drosophila melanogaster using Magic Angle Spinning

12.4K visualizações.  Massachusetts General Hospital, Harvard Medical School. Esta técnica permite o uso de alta resolução, ângulo mágico de prótons girando MR espectroscopia (HRMAS 1H-MRS) para a caracterização molecular de viver Drosophila melanogaster Com um espectrômetro convencional 14,1 tesla equipado com uma sonda HRMAS.

Vídeo: Magnetic Resonance Spectroscopy of live Drosophila melanogaster using Magic Angle Spinning

Multiple-mouse Neuroanatomical Magnetic Resonance Imaging

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and evaluating mouse models of human disease. MRI is an excellent modality for investigating genetically altered animals. It is capable of whole brain coverage, can be used in vivo, and provides multiple contrast mechanisms for investigating different aspects of neuranatomy and physiology. The advent of high-field scanners along with the ability to scan multiple mice simultaneously allows for rapid phenotyping of novel mutations.
Effective mouse MRI studies require attention to many aspects of experiment design. In this article, we will describe general methods to acquire quality images for mouse phenotyping using a system that images mice concurrently in shielded transmit/receive radio frequency (RF) coils in a common magnet (Bock et al., 2003). We focus particularly on anatomical phenotyping, an important and accessible application that has shown a high potential for impact in many mouse models at our imaging centre. Before we can provide the detailed steps to acquire such images, there are important practical considerations for both in vivo brain imaging (Dazai et al., 2004) and ex vivo brain imaging (Spring et al., 2007) that should be noted. These are discussed below.

Magnetic resonance imaging (MRI) has become an increasingly popular tool for examining the phenotype of genetically altered mice. This article illustrates the methods necessary to achieve high-throughput phenotyping of genetically altered mice using multiple-mouse MRI.

Múltiplas mouse-Imagem por Ressonância Magnética neuroanatômicos

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and ...

Neurociência

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

A growing number of genetically encoded tools are becoming available that allow non-invasive manipulation of the neural activity of specific neurons in Drosophila melanogaster1. Chief among these are optogenetic tools, which enable the activation or silencing of specific neurons in the intact and freely moving animal using bright light. Channelrhodopsin (ChR2) is a light-activated cation channel that, when activated by blue light, causes depolarization of neurons that express it. ChR2 has been effective for identifying neurons critical for specific behaviors, such as CO2 avoidance, proboscis extension and giant-fiber mediated startle response2-4. However, as the intense light sources used to stimulate ChR2 also stimulate photoreceptors, these optogenetic techniques have not previously been used in the visual system. Here, we combine an optogenetic approach with a mutation that impairs phototransduction to demonstrate that activation of a cluster of loom-sensitive neurons in the fly's optic lobe, Foma-1 neurons, can drive an escape behavior used to avoid collision. We used a null allele of a critical component of the phototransduction cascade, phospholipase C-&beta;, encoded by the norpA gene, to render the flies blind and also use the Gal4-UAS transcriptional activator system to drive expression of ChR2 in the Foma-1 neurons. Individual flies are placed on a small platform surrounded by blue LEDs. When the LEDs are illuminated, the flies quickly take-off into flight, in a manner similar to visually driven loom-escape behavior. We believe that this technique can be easily adapted to examine other behaviors in freely moving flies.

Optogenetic Stimulation of Escape Behavior in Drosophila melanogaster

Genetically encoded optogenetic tools enable noninvasive manipulation of specific neurons in the Drosophila brain. Such tools can identify neurons whose activation is sufficient to elicit or suppress particular behaviors. Here we present a method for activating Channelrhodopsin2 that is expressed in targeted neurons in freely walking flies.

Optogenética estimulação do comportamento de fuga em<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 ...

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;

Determinação da atividade locomotora espontânea em<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 ...

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood 33. To help improve this understanding, proton magnetic resonance spectroscopy (1H-MRS) can be used as it allows the in vivo quantification of brain metabolites such as &#947;-aminobutyric acid (GABA) and glutamate in a region-specific manner 41. In fact, a recent study demonstrated that 1H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration 34. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with 1H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices 27,30,31. Methodological factors to consider and possible modifications to the protocol are also discussed.

This article aims to describe a basic protocol for combining transcranial direct current stimulation (tDCS) with proton magnetic resonance spectroscopy (1H-MRS) measurements to investigate the effects of bilateral stimulation on primary motor cortex metabolism.

O Uso de Espectroscopia de Ressonância Magnética como ferramenta para a Medição do Bi-hemisféricas transcranianas Estimulação Elétrica Efeitos sobre Motor Primário Cortex Metabolismo

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of ...

Live Imaging of Drosophila Larval Neuroblasts

Stem cells divide asymmetrically to generate two progeny cells with unequal fate potential: a self-renewing stem cell and a differentiating cell. Given their relevance to development and disease, understanding the mechanisms that govern asymmetric stem cell division has been a robust area of study. Because they are genetically tractable and undergo successive rounds of cell division about once every hour, the stem cells of the Drosophila central nervous system, or neuroblasts, are indispensable models for the study of stem cell division. About 100 neural stem cells are located near the surface of each of the two larval brain lobes, making this model system particularly useful for live imaging microscopy studies. In this work, we review several approaches widely used to visualize stem cell divisions, and we address the relative advantages and disadvantages of those techniques that employ dissociated versus intact brain tissues. We also detail our simplified protocol used to explant whole brains from third instar larvae for live cell imaging and fixed analysis applications.

Live Imaging of Drosophila Larval Neuroblasts

This protocol details a streamlined method used to conduct live cell imaging in the context of an intact larval brain. Live cell imaging approaches are invaluable for the study of asymmetric neural stem cell divisions as well as other neurogenic and developmental processes, consistently uncovering mechanisms that were previously overlooked.

Imagens ao vivo de<em&gt; Drosophila</em&gt; larval Neuroblastos

Stem cells divide asymmetrically to generate two progeny cells with unequal fate potential: a self-renewing stem cell and a differentiating cell. Given ...

Metabolomic Analysis of Rat Brain by High Resolution Nuclear Magnetic Resonance Spectroscopy of Tissue Extracts

Studies of gene expression on the RNA and protein levels have long been used to explore biological processes underlying disease. More recently, genomics and proteomics have been complemented by comprehensive quantitative analysis of the metabolite pool present in biological systems. This strategy, termed metabolomics, strives to provide a global characterization of the small-molecule complement involved in metabolism. While the genome and the proteome define the tasks cells can perform, the metabolome is part of the actual phenotype. Among the methods currently used in metabolomics, spectroscopic techniques are of special interest because they allow one to simultaneously analyze a large number of metabolites without prior selection for specific biochemical pathways, thus enabling a broad unbiased approach. Here, an optimized experimental protocol for metabolomic analysis by high-resolution NMR spectroscopy is presented, which is the method of choice for efficient quantification of tissue metabolites. Important strengths of this method are (i) the use of crude extracts, without the need to purify the sample and/or separate metabolites; (ii) the intrinsically quantitative nature of NMR, permitting quantitation of all metabolites represented by an NMR spectrum with one reference compound only; and (iii) the nondestructive nature of NMR enabling repeated use of the same sample for multiple measurements. The dynamic range of metabolite concentrations that can be covered is considerable due to the linear response of NMR signals, although metabolites occurring at extremely low concentrations may be difficult to detect. For the least abundant compounds, the highly sensitive mass spectrometry method may be advantageous although this technique requires more intricate sample preparation and quantification procedures than NMR spectroscopy. We present here an NMR protocol adjusted to rat brain analysis; however, the same protocol can be applied to other tissues with minor modifications.

The neurochemistry of mammalian brain is changed in many neurological and systemic diseases. Characteristic profiles of cerebral metabolites can be efficiently obtained based on crude extracts of brain tissue. To this end, high-resolution NMR spectroscopy is employed, enabling detailed quantitative analysis of metabolite concentrations (metabolomics).

Metabolômica Análise do cérebro de um rato de alta resolução Espectroscopia de Ressonância Magnética Nuclear de Extratos de Tecidos

Studies of gene expression on the RNA and protein levels have long been used to explore biological processes underlying disease. More recently, genomics ...

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.

Condições que afetam Espaço Social em<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 resolução Quantificação do Comportamento Odor-guiada em<em&gt; Drosophila melanogaster</em&gt; Usando a<em&gt; Flywalk</em&gt; Paradigm

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

Foraging Path-length Protocol for Drosophila melanogaster Larvae

The Drosophila melanogaster larval path-length phenotype is an established measure used to study the genetic and environmental contributions to behavioral variation. The larval path-length assay was developed to measure individual differences in foraging behavior that were later linked to the foraging gene. Larval path-length is an easily scored trait that facilitates the collection of large sample sizes, at minimal cost, for genetic screens. Here we provide a detailed description of the current protocol for the larval path-length assay first used by Sokolowski. The protocol details how to reproducibly handle test animals, perform the behavioral assay and analyze the data. An example of how the assay can be used to measure behavioral plasticity in response to environmental change, by manipulating feeding environment prior to performing the assay, is also provided. Finally, appropriate test design as well as environmental factors that can modify larval path-length such as food quality, developmental age and day effects are discussed.

Foraging Path-length Protocol for Drosophila melanogaster Larvae

We provide a detailed protocol for a Drosophila melanogaster foraging path-length assay. We discuss the preparation and handling of test animals, how to perform the assay and analyze the data.

Forrageamento Protocolo Caminho de comprimento para<em&gt; Drosophila melanogaster</em&gt; Larvas

The Drosophila melanogaster larval path-length phenotype is an established measure used to study the genetic and environmental contributions to behavioral ...

Metabolic Analysis of Drosophila melanogaster Larval and Adult Brains

This protocol describes a method for measuring the metabolism in Drosophila melanogaster larval and adult brains. Quantifying metabolism in whole organs provides a tissue-level understanding of energy utilization that cannot be captured when analyzing primary cells and cell lines. While this analysis is ex vivo, it allows for the measurement from a number of specialized cells working together to perform a function in one tissue and more closely models the in vivo organ. Metabolic reprogramming has been observed in many neurological diseases, including neoplasia, and neurodegenerative diseases. This protocol was developed to assist the D. melanogaster community&#39;s investigation of metabolism in neurological disease models using a commercially available metabolic analyzer. Measuring metabolism of whole brains in the metabolic analyzer is challenging due to the geometry of the brain. This analyzer requires samples to remain at the bottom of a 96-well plate. Cell samples and tissue punches can adhere to the surface of the cell plate or utilize spheroid plates, respectively. However, the spherical, three-dimensional shape of D. melanogaster brains prevents the tissue from adhering to the plate. This protocol requires a specially designed and manufactured micro-tissue restraint that circumvents this problem by preventing any movement of the brain while still allowing metabolic measurements from the analyzer&#39;s two solid-state sensor probes. Oxygen consumption and extracellular acidification rates are reproducible and sensitive to a treatment with metabolic inhibitors. With a minor optimization, this protocol can be adapted for use with any whole tissue and/or model system, provided that the sample size does not exceed the chamber generated by the restraint. While basal metabolic measurements and an analysis after a treatment with mitochondrial inhibitors are described within this protocol, countless experimental conditions, such as energy source preference and rearing environment, could be interrogated.

Metabolic Analysis of Drosophila melanogaster Larval and Adult Brains

We present a protocol for measuring oxygen consumption and extracellular acidification in Drosophila melanogaster larval and adult brains. A metabolic analyzer is utilized with an adapted and optimized protocol. Micro-tissue restraints are a critical component of this protocol and were designed and created specifically for their use in this analysis.

Análise metabólica do melanogaster da drosófila Larval e adulto cérebros

This protocol describes a method for measuring the metabolism in Drosophila melanogaster larval and adult brains. Quantifying metabolism in whole organs ...