This work was supported by grants from the Pharmaceutical Research and Manufacturers Association of America (PhRMA) Foundation (to B. Gulbransen), National Institutes of Health (Building Interdisciplinary Research Careers in Women&#8217;s Health) grant K12 HD065879 (B. Gulbransen) and start-up funds from Michigan State University (B. Gulbransen).

NOTA: Os procedimentos a seguir que envolvem o tecido de animais de laboratório são consistentes com as Diretrizes AVMA para a eutanásia de animais para 2013 e foram aprovados com antecedência pela Michigan State University IACUC. 1. Preparação do Tecido <ol><li> Anestesiar pesquisa animal numa câmara contendo 2,5% de isoflurano em oxigénio ou colocando 3-5 ml de isoflurano líquido sobre um material absorvente sobre o chão da câmara, assegurando que uma barreira física impede os animais de um contacto directo com o isoflurano. Teste para a profundidade da anestesia, apertando a pata. NOTA: A profundidade da anestesia é considerado apropriado quando não há reflexo de retirada do membro posterior. Uma vez devidamente anestesiados, sacrificar o mouse por deslocamento cervical </li><li> Colocar o animal em decúbito dorsal e limpar a pele abdominal com etanol 70%. Use uma pinça para beliscar a pele abdominal na linha média e usar uma tesoura cirúrgica para fazer uma media 6 centímetrosl incisão ao longo da linha alba para expor órgãos digestivos internos. </li><li> Use uma pinça sem corte para localizar e expor o íleo dentro do peritônio. Corte o mesentério ileal / cólon com uma tesoura e começar a desvendar o intestino. </li><li> Uma vez que o comprimento do intestino delgado é adequadamente desvendados, cortar o intestino distai para o estômago e proximal do ceco para uma preparação de íleo. Para uma grande preparação intestino, cortar o cólon distai ao ceco e proximal ao recto. </li><li> Remover rapidamente o segmento intestinal e colocá-lo num copo com meio DMEM / F12 suplementado com cloridrato nicardipine 3? M e 1 PM cloridrato de escopolamina (doravante referida como &quot;media&quot;) em gelo. A adição destes inibidores facilita microdissection e imagem posterior por paralisar o músculo liso do intestino. </li><li> Cortar segmento de interesse (por exemplo, jejuno, íleo, cólon distai ou proximal) com base em marcadores anatómicos estabelecidos. Normalmente utilize tecido do íleo terminal ou o cólon distai. No entanto, utilize o mesmo procedimento básico para isolar, de carga e de imagem neurônios mioentéricos e glia em todas as regiões intestinais. </li><li> Retirar um pequeno segmento (4-6 cm) do segmento de intestino desejada e coloque em uma placa de Petri Sylgard revestido preenchido com media gelada. </li><li> Fixar as extremidades proximal e distal do segmento intestinal com os pinos de insetos e abrir o tubo intestinal, por fazer uma sequência no sentido do comprimento cortado ao longo da fronteira mesentérica. </li><li> Tecido Pin plana sob tensão luz com o lado mucosa e dissecar cuidadosamente afastado camada mucosa usando uma pinça fina (# 5 e # 5/45 trabalho melhor) e tesoura primavera muito finas. NOTA: A remoção da mucosa pode ser bastante traumático para o ENS se não for feita correctamente. Para as preparações de qualidade, tome cuidado para limitar a remoção abrupta da mucosa por descamação ou raspagem. A melhor prática é para levantar a mucosa e cortar por baixo com uma tesoura fina. </li><li> Corte o tecido em preparação menors (aproximadamente 0,5 cm 2) e pinos em placas de imagem (4 cantos com camada muscular circular voltada para cima) colocados no gelo com meio fresco. </li><li> Dissecar cuidadosamente afastado músculo circular por provocando distante com uma pinça fina para expor o plexo mioentérico. Evitar o alongamento excessivo. </li><li> Coloque imaging prato de volta no gelo e na mudança solução por meio fresco. </li><li> Prepare a 2 ml de mistura de enzima por prato [Dispase 1 U / ml (4,48 mg / 8 ml), colagenase tipo II 150 U / ml (5,45 mg / 8 ml) em meio]. </li><li> Retirar pratos de gelo e adicione a mistura de enzimas a partir do passo 1.13. </li><li> Incubar pratos à TA durante 15 min com 5% de CO2 / 95% ar. </li><li> Preparações de tecido lavar com mídia 3 vezes e cantos re-pin. </li></ol> 2. Carregando Fluo-4 Dye NOTA: Evite a fotodegradação, trabalhando com luz limitada durante o manuseio de corantes fluorescentes e tecidos carregados com corantes indicadores. <ol><li> Prepare 4 uM Fluo-4 solução de carregamento. <ol><li> Adicionar 1,5 ml de mídia e 1,2 l de um estoque probenecida 250 mm a uma alíquota de 1,5 mL de 4 mM Fluo-4 estoque. 4 mM de Fluo-4 é preparada por adição de 11,4 ul de Pluronic F-127 (20% em DMSO; suplementado com 0,25% cremaphor-EL) a 50 ug de Fluo-4, AM. </li></ol></li><li> Incubar preps em Fluo-4 solução de carga durante 45 min numa incubadora de escuro a 37 ° C. </li><li> Remover da incubadora e lave preparações à mídia 3 vezes. </li><li> Meios de troca para meio contendo 200 uM de probenecid e incubar 15 min a 37 ° C antes de imagem. NOTA: Probenecid é uma droga que inibe transportadores multirresistência em neurônios. A adição desta droga inibe a capacidade dos neurónios para extrudir corantes e aumenta a marcação neuronal. -Carregamento a granel de Ca 2+ corantes indicadores na ausência de probenecida produz célula de carga, principalmente glial. A adição de probenecid permite a visualização das respostas neuronais e gliais. </li><li> Prepare Modificado Kretampão bs. <ol><li> Adicione um tampão de Krebs modificada de tal modo que as concentrações finais (em mm) dos componentes são como se segue: 121 de NaCl, 5,9 de KCl, 2,5 de CaCl2, 1,2 de MgCl2, 1,2 de NaH 2 PO 4, 10 HEPES, 21,2 NaHCO3, 1 pirúvico e ácido 8 glicose (pH ajustado para 7,4 com NaOH). Adiciona-se 3 uM de nicardipina e 1 uM escopolamina para inibir as contracções musculares durante Ca 2+ imagiologia e todo o monte dissecações. </li></ol></li></ol> 3. Imagem e Análise NOTA: Utilize pelo menos um equipamento básico de imagem com uma fonte de luz fluorescente, microscópio, uma câmera CCD qualidade e software de aquisição apropriado. Variar a adição de outros componentes, dependendo da fonte de luz e da aplicação específica. A roda de filtros e do obturador deve ser usado com uma fonte de luz xenon arco tradicional. No entanto, fontes de luz LED e sistemas de iluminação não requerem esses componentes. <ol><li> Posicione o recording câmara sob o microscópio e utilizando um sistema de perfusão de escoamento por gravidade, com vários reservatórios de seringas aquecidas estabelecer uma taxa de perfusão contínua de 2-3 ml / min de 37 ° C tampão de Krebs. Certifique-se para impedir a formação de bolhas de ar em ambas as linhas de entrada e de sucção ligada a um sifão de vácuo. </li><li> Traga o plexo desejados em foco sob iluminação de campo claro. Evitar overexposing tecido, o que pode levar a foto branqueamento. </li><li> Examine o Fluo-4 loading dentro de gânglios e selecione gânglios saudável para a imagem latente. / Gânglios danificadas insalubres irá apresentar autofluorescência ou pontuada morfologia e não deve ser usada para imprimir. </li><li> Uma vez gânglio é selecionado, desviar a trajetória da luz para a câmera e obter uma imagem ao vivo com software de aquisição de imagem. Certifique-se de que gânglio está em foco e definir a taxa de aquisição de imagens e tempos de exposição. NOTA: as taxas de aquisição de imagem e tempos vão variar de acordo com os eventos investigadores deseja gravar. Para a maioria dos experimentos, imagenssão tradicionalmente adquiridas a 0,5-1 Hz para as células gliais e até 10/02 Hz para os neurônios, porque as respostas glial Ca 2+ não são tão rápido como Ca 2+ transientes em neurônios. </li><li> Comece a experiência e estabelecer actividade de base por 30 s. </li><li> Aplicar drogas pré-aquecidas de interesse, tais como agonistas e antagonistas utilizando o sistema de perfusão de fluxo por gravidade a um caudal de 2-3 ml / min. Siga aplicação de agonistas / antagonistas de retorno a uma perfusão de tampão normal e permitir um período de lavagem / recuperação de pelo menos 10 min. NOTA: Os tempos de aplicação de drogas pode variar dependendo do composto individual e desenho experimental. Em geral, uma aplicação de 20-30 seg agonista é suficiente para activar a proteína G de receptores acoplados em neurónios e células gliais. Entretanto, os canais iónicos dependentes de ligante (como receptores nicotínicos de acetilcolina) exigem épocas de aplicação de, no máximo, 5-10 seg. As exposições da duração causará canais iônicos ligando fechado para dese rapidamentensitize. Antagonistas deve ser aplicada durante aproximadamente 3-15 minutos para assegurar o bloqueio completo das vias do receptor. No entanto, esta é uma generalização grosseira e os investigadores devem sempre otimizar qualquer droga experimental em seu paradigma particular. </li><li> Parar a gravação e exibição de filme de lapso de tempo do experimento. Selecionar cuidadosamente regiões de interesse (de ROI) usando o software de análise de imagem adequada. </li><li> Use software para normalizar e comparar ROI intensidade de fluorescência contra o seu valor fluorescente linha de base inicial. Alterações na fluorescência normalizada são directamente proporcionais às variações na [Ca 2+]. <ol><li> Utilize uma modificação de um método descrito anteriormente 26 utilizando Af / F = ((F 1 - 0 F) / F 0) ROI - ((F 1 - F 0) / 0 F) do fundo, em que F1 é a fluorescência em qualquer ponto e F0 é a fluorescência de base, para melhorar a precisão de avaliação. Isso ajuda a modificaçãona redução do ruído a partir de alterações de fluorescência em preparações de tecidos que apresentam movimento da camada muscular subjacente ao plexo mioentérico. </li></ol></li></ol>

<ol>
	<li>Furness, 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=Types+of+neurons+in+the+enteric+nervous+system.">Types of neurons in the enteric nervous system.</a> Journal of the Autonomic Nervous System. 81 (1-3), 87-96 (2000).</li><li>Furness, 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=The+organization+of+the+autonomic+nervous+system:+peripheral+connections.">The organization of the autonomic nervous system: peripheral connections.</a> Neuroscience. 130 (1-2), 1-5 (2006).</li><li>Pham, T. D., Gershon, M. D., Rothman, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time+of+origin+of+neurons+in+the+murine+enteric+nervous+system:+sequence+in+relation+to+phenotype.">Time of origin of neurons in the murine enteric nervous system: sequence in relation to phenotype.</a> Journal of Comparative Neurology. 314 (4), 789-798 (1991).</li><li>Nasser, Y., 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=Role+of+enteric+glia+in+intestinal+physiology:+effects+of+the+gliotoxin+fluorocitrate+on+motor+and+secretory+function.">Role of enteric glia in intestinal physiology: effects of the gliotoxin fluorocitrate on motor and secretory function.</a> Am J Physiol Gastrointest Liver Physiol. 291, G912-927 (2006).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glial+cells+in+the+gut.">Glial cells in the gut.</a> Neurogastroenterology &amp; Motility. 17 (6), 777-790 (2005).</li><li>Broadhead, M. J., Bayguinov, P. O., Okamoto, T., Heredia, D. J., Smith, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca2++transients+in+myenteric+glial+cells+during+the+colonic+migrating+motor+complex+in+the+isolated+murine+large+intestine.">Ca2+ transients in myenteric glial cells during the colonic migrating motor complex in the isolated murine large intestine.</a> J. Physiol. 590, 335-350 (2012).</li><li>Gulbransen, B. D., Bains, J. S., Sharkey, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enteric+glia+are+targets+of+the+sympathetic+innervation+of+the+myenteric+plexus+in+the+guinea+pig+distal+colon.">Enteric glia are targets of the sympathetic innervation of the myenteric plexus in the guinea pig distal colon.</a> J. Neurosci. 30, 6801-6809 (2010).</li><li>McClain, J. L., 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=Ca2++Responses+in+Enteric+Glia+Are+Mediated+by+Connexin-43+Hemichannels+and+Modulate+Colonic+Transit+in+Mice.">Ca2+ Responses in Enteric Glia Are Mediated by Connexin-43 Hemichannels and Modulate Colonic Transit in Mice.</a> Gastroenterology. 146 (2), 497-507 (2014).</li><li>Chandrasekharan, 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=Colonic+motor+dysfunction+in+human+diabetes+is+associated+with+enteric+neuronal+loss+and+increased+oxidative+stress.">Colonic motor dysfunction in human diabetes is associated with enteric neuronal loss and increased oxidative stress.</a> Neurogastroenterology &amp; Motility. 23 (2), e131-e126 (2011).</li><li>Abdo, H., 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=Enteric+glial+cells+protect+neurons+from+oxidative+stress+in+part+via+reduced+glutathione.">Enteric glial cells protect neurons from oxidative stress in part via reduced glutathione.</a> FASEB J. 24, 1082-1092 (2010).</li><li>Aube, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Changes+in+enteric+neurone+phenotype+and+intestinal+functions+in+a+transgenic+mouse+model+of+enteric+glia+disruption.">Changes in enteric neurone phenotype and intestinal functions in a transgenic mouse model of enteric glia disruption.</a> Gut. 55, 630-637 (2006).</li><li>Berridge, M. J., Lipp, P., Bootman, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+versatility+and+universality+of+calcium+signalling.">The versatility and universality of calcium signalling.</a> Nature Reviews Molecular cell biology. 1 (1), 11-21 (2000).</li><li>Gulbransen, B. 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=Activation+of+neuronal+P2X7+receptor-pannexin-1+mediates+death+of+enteric+neurons+during+colitis.">Activation of neuronal P2X7 receptor-pannexin-1 mediates death of enteric neurons during colitis.</a> Nat Med. 18, 600-604 (2012).</li><li>Bayguinov, P. O., Hennig, G. W., Smith, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+activity+in+different+classes+of+myenteric+neurons+underlying+the+migrating+motor+complex+in+the+murine+colon.">Calcium activity in different classes of myenteric neurons underlying the migrating motor complex in the murine colon.</a> J Physiol. 588, 399-421 (2010).</li><li>Okamoto, T., Bayguinov, P. O., Broadhead, M. J., Smith, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca(2+)+transients+in+submucous+neurons+during+the+colonic+migrating+motor+complex+in+the+isolated+murine+large+intestine.">Ca(2+) transients in submucous neurons during the colonic migrating motor complex in the isolated murine large intestine.</a> Neurogastroenterol Motil. 24 (8), 769-778 (2012).</li><li>Kunze, W. A., Clerc, N., Furness, J. B., Gola, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+soma+and+neurites+of+primary+afferent+neurons+in+the+guinea-pig+intestine+respond+differentially+to+deformation.">The soma and neurites of primary afferent neurons in the guinea-pig intestine respond differentially to deformation.</a> J Physiol. 526, 375-385 (2000).</li><li>Schemann, M., Michel, K., Peters, S., Bischoff, S. C., Neunlist, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+and+the+gastrointestinal+tract:+mapping+the+human+enteric+nervous+system.">Imaging and the gastrointestinal tract: mapping the human enteric nervous system.</a> Am J Physiol. 282, G919-G925 (2002).</li><li>Hennig, G. W., 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=Visualization+of+spread+of+pacemaker+activity+in+through+ICC+in+guinea-pig+antrum.">Visualization of spread of pacemaker activity in through ICC in guinea-pig antrum.</a> Neurogastro Motil. 14, 575 (2001).</li><li>Stevens, R. J., Publicover, N. G., Smith, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+and+organization+of+Ca2++waves+by+enteric+neural+reflexes.">Induction and organization of Ca2+ waves by enteric neural reflexes.</a> Nature. 399, 62-66 (1999).</li><li>Stevens, R. J., Publicover, N. G., Smith, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Propagation+and+neural+regulation+of+calcium+waves+in+longitudinal+and+circular+muscle+layers+of+guinea-pig+small+intestine.">Propagation and neural regulation of calcium waves in longitudinal and circular muscle layers of guinea-pig small intestine.</a> Gastroenterology. 118, 982-984 (2000).</li><li>Jessen, K. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Astrocyte-like+glia+in+the+peripheral+nervous+system:+an+immunohistochemical+study+of+enteric+glia.">Astrocyte-like glia in the peripheral nervous system: an immunohistochemical study of enteric glia.</a> Journal of Neuroscience. 3 (11), 2206-2218 (1983).</li><li>Gulbransen, B. D., Sharkey, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+functional+roles+for+enteric+glia+in+the+gastrointestinal+tract.">Novel functional roles for enteric glia in the gastrointestinal tract.</a> Nat Rev Gastroenterol Hepatol. 9, 625-632 (2012).</li><li>Gomes, P., 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=ATP-dependent+paracrine+communication+between+enteric+neurons+and+glia+in+a+primary+cell+culture+derived+from+embryonic+mice.">ATP-dependent paracrine communication between enteric neurons and glia in a primary cell culture derived from embryonic mice.</a> Neurogastroenterology &amp; Motility. 21 (8), e870-e862 (2009).</li><li>Gulbransen, B. D., Sharkey, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purinergic+neuron-to-glia+signaling+in+the+enteric+nervous+system.">Purinergic neuron-to-glia signaling in the enteric nervous system.</a> Gastroenterology. 136, 1349-1358 (2009).</li><li>Ren, J., Bertrand, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purinergic+receptors+and+synaptic+transmission+in+enteric+neurons.">Purinergic receptors and synaptic transmission in enteric neurons.</a> Purinergic Signal. 4, 255-266 (2008).</li><li>Takahashi, A., Camacho, P., Lechleiter, J. D., Herman, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+intracellular+calcium.">Measurement of intracellular calcium.</a> Physiol Rev. 79, 1089-1125 (1999).</li><li>Dongcheng, Z., 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=Neural+crest+regionalisation+for+enteric+nervous+system+formation:+implications+for+Hirschsprung's+disease+and+stem+cell+therapy.">Neural crest regionalisation for enteric nervous system formation: implications for Hirschsprung's disease and stem cell therapy.</a> Developmental Biology. 339 (2), 280-294 (2010).</li><li>Gershon, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behind+an+enteric+neuron+there+may+lie+a+glial+cell.">Behind an enteric neuron there may lie a glial cell.</a> J Clin Invest. 121, 3386-3389 (2011).</li><li>Boesmans, W., 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=Imaging+neuron-glia+interactions+in+the+enteric+nervous+system.">Imaging neuron-glia interactions in the enteric nervous system.</a> Frontiers in Cellular Neuroscience. 7, (2013).</li></ol>

The authors have nothing to disclose.

The methodologies described in this manuscript provide a consistent approach to effectively study neurons and enteric glia in the ENS. Although imaging neurons and enteric glia in culture has yielded a wealth of insight into the function of individual cells, studying these cells in their native, multi-cellular environment is crucial for our understanding their physiology and pathophysiology. Fluorescence microscopy is a crucial technique for assessing multidirectional interactions of cells in the ENS. Loading cells of the ENS with selective fluorescent markers and image acquisition with high-resolution microscopy permits quantitative observations of cellular activity in the ENS. Imaging live tissue samples of the ENS is performed relatively quickly and generates large amounts of in-depth functional and spatial data. Mouse myenteric and submucosal plexus preparations used in these experiments allow for molecular and genetic manipulation approaches. Ca2+ imaging in whole-mount preparations provides a useful tool for the assessment of neuron-glia interactions.
In advanced experimental paradigms, several probes can be combined to obtain information about different events within the cells. Fluorescence microscopy can record images with enhanced contrast of specific molecules, if an appropriate fluorescent label is used. Fluo-4 was chosen because it possesses a large dynamic range. Sufficient incubation time is vital when using the AM dyes in ENS. Dye concentration and loading method may need to be adjusted to achieve best results. Ideal preparations should be loaded with sufficient dye to visualize changes in fluorescence but not so much so that the dye chelates the target ions and interferes with intracellular signaling. Exposure to fluorescent light should be limited to prevent phototoxicity in cells and photobleaching of dyes. 
Investigators must be careful with several steps of this experiment, especially solution and tissue preparation. Particular care has to be taken during processing and dissection of ENS tissue in order to maintain cellular functions. The GI tract contains several layers and tissue varieties, which pose challenges for dissection and imaging quality in these whole-mount preparations 27. Furthermore, the interconnecting fiber tracts of the MP are wider and ganglia are larger than those of the SMP 2. The neuronal density of the myenteric plexus is higher compared to that of the submucosal plexus 28. Slow and imprecise dissections will have detrimental effects on the quality of the plexus preparations and thus the overall success of the experiments. Therefore, clean/undamaged tools, practice and manual dexterity are critical to this procedure. 
In whole-mount tissue preparations, careful consideration should be taken when drawing the regions of interest (ROI) to correctly assess the kinetics and degree of observed change in fluorescence intensity of the desired cell type. As the ganglia are located on a contractile muscle layer, motion artifacts caused by gut motility are a primary concern during in situ imaging. Thus, suppressing these motion disturbances through re-pinning tissue preparations after incubation with enzymes and the addition of pharmacological inhibition (nicardipine/scopolamine) to buffers permits clear and reliable image acquisition. Aside from pharmacology and mechanical approaches to prevent tissue movement, recent studies illustrate the application of advanced software methodologies and cell type response characteristics to correct for residual tissue movement in the recordings and improve the accuracy of analysis 29. Barring these technical hurdles, this method provides physiologically relevant conditions to assess morphologic and quantitative characteristics of neurons and enteric glia in the ENS.

O sistema nervoso entérico (ENS) está organizado em dois plexos ganglionados embutidas na parede do trato digestivo 1. Estes circuitos neurais intramusculares, o plexo mientérico (MP) e plexo submucosa (PMS), são compostas de neurónios e células da glia entérico (Figura 1) 2. O MP e SMP regular gastrointestinais (GI) funções tais como a motilidade intestinal e absorção epitelial e secreção, respectivamente 3. Glia Entérico estão localizados em estreita proximidade com os neurônios dentro gânglios mas populações de glia entérico também existem dentro interligando tratos de fibras e porções extra-ganglionares da parede do intestino 3,4. Glia entéricos foram originalmente acreditado para fornecer apenas suporte nutritivo para os neurônios. No entanto, estudos recentes sugerem fortemente que as interações neurônio-glia são essenciais para ENS funciona 5,6. Por exemplo, os dados mostram que as células da glia entérico &quot;ouvir&quot; a actividade neuronal 7e modulam circuitos neuronais 6,8, proteger os neurônios entéricos de estresse oxidativo 9 e são capazes de gerar novos neurônios entéricos em resposta à lesão 10,11. O protocolo apresentado nesta revisão técnica fornece um método simples e robusta para examinar a complexa interação entre neurônios e células gliais entéricas usando in situ Ca2 + intracelular de imagem. Ca 2+ é uma molécula de sinalização onipresente em células excitáveis ​​e desempenha um papel essencial em eventos de sinalização sináptica no sistema nervoso 12. Excitação de neurônios ou células gliais entéricas provoca uma elevação na concentração citoplasmática de Ca2 + ou pelo influxo através de canais de Ca2 + -permeable ou Ca 2+ liberação dos estoques intracelulares de cálcio. Imagem Ca 2 + transientes em neurônios e células gliais com corantes fluorescentes é uma técnica amplamente utilizada para estudar a organização funcional e dinâmica do estabelecido ea 13-17 ENS. Ca 2+ de imagem tem se mostrado uma ferramenta importante no estudo de segmentos de tecido GI intactas para elucidar a propagação da excitabilidade por meio de redes de marcapasso ICC 18 e intestino músculo liso 19,20. Ele permite que os pesquisadores para investigar um amplo espectro de parâmetros fisiológicos e fornece informação sobre as sua distribuição espacial e dinâmica temporal. As células podem ser eficientemente manchado de forma minimamente invasiva por meio de indicadores fluorescentes à membrana permeável e protocolos de coloração otimizados 21. Isto oferece a oportunidade de monitorizar um grande número de neurónios e células da glia entérico em preparações funcionalmente conservados 14-16,22, bem como in vivo 23. Whole mount-preparações de tecido são granel carregado com um corante indicador de afinidade elevada de Ca 2+, tais como Fluo-4 que aumenta a sua fluorescência quando ligados a Ca 2+. Mudanças na fluorescência são registradas por uma câmera CCD e analisadas digitalmente 6. O advento da Ca 2+ proporcionou a oportunidade de acompanhar de neurônios e células glia interações, a capacidade de resposta a vários estímulos, e o envolvimento desses tipos de células em processos gastrointestinais em tempo real. In situ Ca 2+ imaging rendeu grande visão sobre os mecanismos de sinalização de neurônios entéricos e glia e possui diversas vantagens em relação aos modelos de cultura de células 6,24. Primeiro, in situ preparações manter o ambiente da matriz nativa de neurônios e células gliais e deixar a maior parte de suas conexões para atingir tecido intacto. Em segundo lugar, a genética e morfologia da glia entérico culta é significativamente alterada em comparação com in vivo 6,24. Terceiro, muitas interacções heterotípicos são perdidos em cultura de células primárias e estabelecer limites, que avaliam as interacções célula-célula. Embora as células cultivadas são bem adequados para a investigação de propriedades fundamentais, a sua usefulness para o estudo de interações complexas entre glia e neurônios entéricos é limitado. Investigando interação neurônio-glia utilizando uma abordagem in situ é mais fisiologicamente relevante como as vias sinápticas permanecem intactos 25. Em comparação com as abordagens de cultura de células, uma abordagem em situ oferece melhores condições para compreender sistematicamente as interações complexas entre neurônios e glia entérico. Além disso, a organização planar do plexo ganglionados em preparações inteiras de montagem é ideal para imagens fluorescentes de Ca 2+ intracelular transientes e esta técnica fornece uma abordagem simples para avaliar a atividade do neurônio-glia na ENS.

<table border="0" cellpadding="0" cellspacing="0" width="764">
	<tbody>
		<tr height="43">
			<td height="43" style="height:43px;width:391px;">Name</td>
			<td style="width:245px;">Company</td>
			<td style="width:128px;">Catalog Number</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">BubbleStop Syringe Heater&#160;</td>
			<td style="width:245px;">AutoMate Scientific</td>
			<td style="width:128px;">10-4-35-G</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">CaCl2</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">C3306</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Collagenase, Type II, powder</td>
			<td style="width:245px;">Gibco</td>
			<td style="width:128px;">17101-015</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Dispase</td>
			<td style="width:245px;">Sigma-Aldrich</td>
			<td style="width:128px;">42613-33-2</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Dissection tools</td>
			<td style="width:245px;">Roboz&#160;</td>
			<td style="width:128px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">DMSO</td>
			<td style="width:245px;">Sigma-Aldrich</td>
			<td style="width:128px;">D5879</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Fixed-stage microscope</td>
			<td style="width:245px;">Olympus&#160;</td>
			<td style="width:128px;">BX51WI</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Fluo-4 AM dye</td>
			<td style="width:245px;">Invitrogen</td>
			<td style="width:128px;">F-14201</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Glucose</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">G8270</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Insect pins</td>
			<td style="width:245px;">Fine Science Tools</td>
			<td style="width:128px;">Minutien Pins</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">iQ Live Cell Imaging Software</td>
			<td style="width:245px;">Andor</td>
			<td style="width:128px;">Andor iQ3</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">KCl</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">P3911</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">MgCl2</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">M9272</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">NaCl</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">S9888</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">NaH2PO4</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">S8282</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">NaHCO3</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">S6014</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Neo sCMOS camera</td>
			<td style="width:245px;">Andor</td>
			<td style="width:128px;">Neo 5.5 sCMOS</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Nicardipine</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">N7510</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Perfusion chamber</td>
			<td style="width:245px;">Custom</td>
			<td style="width:128px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Peristaltic pump</td>
			<td style="width:245px;">Harvard Apparatus</td>
			<td style="width:128px;">Model 720</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Pluronic F-127&#160;</td>
			<td style="width:245px;">Invitrogen</td>
			<td style="width:128px;">P3000MP</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Probenecid</td>
			<td style="width:245px;">Molecular Probes</td>
			<td style="width:128px;">P36400</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Scopolamine</td>
			<td style="width:245px;">Sigma</td>
			<td style="width:128px;">S1013&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Sutter Lambda DG-4</td>
			<td style="width:245px;">Sutter</td>
			<td style="width:128px;">DG-4</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Sylgard&#160;</td>
			<td style="width:245px;">Dow Corning</td>
			<td style="width:128px;">184</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:391px;">Temperature Controller</td>
			<td style="width:245px;">Warner Instruments</td>
			<td style="width:128px;">TC-344C</td>
		</tr>
	</tbody>
</table>

in situ ca2+ imaging of the enteric nervous system

Reflex behaviors of the intestine are controlled by the enteric nervous system (ENS). The ENS is an integrative network of neurons and glia in two ganglionated plexuses housed in the gut wall. Enteric neurons and enteric glia are the only cell types within the enteric ganglia. The activity of enteric neurons and glia is responsible for coordinating intestinal functions. This protocol describes methods for observing the activity of neurons and glia within the intact ENS by imaging intracellular calcium (Ca2+) transients with fluorescent indicator dyes. Our technical discussion focuses on methods for Ca2+ imaging in whole-mount preparations of the myenteric plexus from the rodent bowel. Bulk loading of ENS whole-mounts with a high-affinity Ca2+ indicator such as Fluo-4 permits measurements of Ca2+ responses in individual neurons or glial cells. These responses can be evoked repeatedly and reliably, which permits quantitative studies using pharmacological tools. Ca2+ responses in cells of the ENS are recorded using a fluorescence microscope equipped with a cooled charge-coupled device (CCD) camera. Fluorescence measurements obtained using Ca2+ imaging in whole-mount preparations offer a straightforward means of characterizing the mechanisms and potential functional consequences of Ca2+ responses in enteric neurons and glial cells.

A utilização adequada desta técnica permite aos investigadores para medir com precisão de Ca2 + intracelular [Ca2 +] i transientes em neurônios entéricos e glia em todo o monte preparações de tecido. Um exemplo representativo de um evocou-agonistas Ca 2+ respostas em glia dentro de um gânglio myenteric do cólon do rato é mostrado no vídeo 1. Os resultados a seguir são destinadas a ilustrar alguns resultados representativos temos obtidos utilizando este método. Em primeiro lugar, a Figura 2 ilustra os resultados de uma experiência de medição da glia entérico [Ca 2+] i alterações em resposta à estimulação por ATP dentro do cólon de cobaia longitudinal do plexo mientérico do músculo (PMLM preparações). Especificamente, esta figura mostra o método de análise apropriada do protocolo experimental listadas acima, incluindo o contorno do gânglio e asteriscos denotam a localização dos neurónios entéricos mientérico analisados. Estes resultados também illustrate a dose ideal de cem ATP micromolar sobre a mobilização de [Ca2 +] i em cobaias glia myenteric. Esta resposta pode ser utilizado para calibrar a estimulação da glia entérico e normalizar as respostas a estímulos testar. A seguir, a figura 3 elucida como seleccionar adequadamente as regiões de interesse (ROI) que envolve as células gliais, mostrado com circundante círculos amarelos. Estes resultados também mostram que as alterações de fluorescência desejadas em condições basais e em resposta a estímulos farmacológicos. Finalmente, a Figura 4 mostra as considerações espaciais para a escolha de glia entérico e neurônios para [Ca2 +] i respostas em preparações Todo-mount. <img alt="Figura 1" src="/files/ftp_upload/52506/52506fig1highres.jpg" /> Figura 1. Organização das ENS. A ENS contém dois principais plexos ganglionados. O plexo mioentérico está localizado entre o lcamadas musculares ongitudinal e circulares. O plexo submucosa está situado entre a mucosa e da camada muscular circular. A ENS é exclusivamente composta de neurônios e células gliais entérico. Tratos de fibras do nervo conectar os gânglios. <a href="https://www.jove.com/files/ftp_upload/52506/52506fig1large.jpg" target="_blank">Por favor, clique aqui para ver uma versão maior desta figura.</a> <img alt="Figura 2" src="/files/ftp_upload/52506/52506fig2highres.jpg" /> Figura 2. Entérico glia na cobaia colônica plexo mioentérico respondem ao ATP in situ. (A) Fluo-4 fluorescência em um gânglio myenteric (delineado pela linha tracejada) em condições basais. As setas apontam para feixes de fibras interganglionic espessura. (B) Após a estimulação com 100 mmol / L ATP, as células gliais, mas não neurônios, aumentar rapidamente Fluo-4 fluorescência indicando um aumento da [Ca 2+] <sub&gt; i. Note-se que as células que respondem são pequenos e rodear os neurónios muito maiores (espaços escuros marcados por asteriscos). (C) glia entérico responder ao ATP de um modo dependente da dose com 1 mmol / L eliciar respostas máximas de 24. <a href="https://www.jove.com/files/ftp_upload/52506/52506fig2large.jpg" target="_blank">Por favor clique aqui para ler um versão maior desta figura.</a> <img alt="Figura 3" src="/files/ftp_upload/52506/52506fig3highres.jpg" /> Figura 3. Murino células S-100-GFP + no cólon respondem plexo mientérico de ATP in situ. (A) células gliais (verde) em um rato do cólon gânglio mientérico S-100-GFP + (descritos pela linha tracejada). Seis regiões de interesse (ROI) que envolve as células gliais dentro do gânglio são mostrados como círculos amarelos. As setas indicam tratos de fibras grossas que levam até o gânglio. Os asteriscos dlocalização enote de 2 neurônios entéricos. (B) Same gânglio mostrando Rhod-2 de fluorescência em condições basais. (C) Após a estimulação com 100 mmol / L ATP, as células gliais responder com aumento [Ca2 +] i, como mostrado pelo aumento Rhod- 2 de fluorescência. (D) Traces correspondente a cada ROI mostrado na A-C. (E) resposta média (média ± SEM) das 6 ROIs mostrados na D 24. <a href="https://www.jove.com/files/ftp_upload/52506/52506fig3large.jpg" target="_blank">Por favor, clique aqui para ver uma versão maior desta figura.</a> <img alt="Figura 4" src="/files/ftp_upload/52506/52506fig4highres.jpg" /> Figura 4. Em imagiologia in situ de comunicação entérico neurónio-glia-a. (A) (Imagens representativas pseudocolored) a partir de uma experiência de imagem Ca 2+ onde um todo-mountpreparação de plexo mientérico foi desafiado com o agonista do receptor P2X7 neuronal BzATP (100 pM, 30 s). Note-se que o agonista neuronal provoca um aumento na fluorescência Fluo4 no neurónio (A &#39;), antes de as células gliais circundantes entéricos (A &quot;). (B) Análise da alteração na fluorescência ao longo do tempo em células da glia (azul) e os neurónios (vermelho ) após a aplicação do agonista neuronal, BzATP. (C) neuronal e da glia respostas de BzATP em tampão normais (linhas sólidas) e em tampão com baixo Ca 2+ e Mg 2+ (linhas tracejadas) para potenciar receptores P2X7 neuronais 13. <a href="https://www.jove.com/files/ftp_upload/52506/52506fig4large.jpg" target="_blank">Por favor clique aqui para ver uma versão maior desta figura.</a> Vídeo 1. evocada pelo agonista Ca 2+ em resposta glia entéricositu. Este vídeo mostra um gânglio myenteric do cólon distal do rato carregado com o Ca 2+ corante indicador, Fluo-4. O agonista de células da glia, ADP, é adicionado ao banho, quando indicado. ADP provoca um aumento intracelular de Ca2 + em glia entérico como observado pela elevação transitória em Fluo-4 fluorescência. <a href="https://www.jove.com/files/ftp_upload/52506/JOVE.mp4" target="_blank">Por favor clique aqui para ver este vídeo.</a>

Watch this Scientific Journal Video about In Situ Ca2+ Imaging of the Enteric Nervous System at JoVE.com

In Situ Ca2+ Imaging of the Enteric Nervous System

The enteric nervous system (ENS) is a network of neurons and glia located in the gut wall that controls intestinal reflexes. This protocol describes methods for recording the activity of enteric neurons and glia in live preparations of ENS using Ca2+ imaging.

In Situ Ca 2+ Imagem do Sistema Nervoso Entérico

Reflex behaviors of the intestine are controlled by the enteric nervous system (ENS). The ENS is an integrative network of neurons and glia in two ...

in-situ-ca2-imaging-of-the-enteric-nervous-system

Research

JoVE Journal

Neuroscience

In Situ Ca2+ Imaging of the Enteric Nervous System

17.0K visualizações.  Michigan State University. The enteric nervous system (ENS) is a network of neurons and glia located in the gut wall that controls intestinal reflexes. This protocol describes methods for recording the activity of enteric neurons and glia in live preparations of ENS using Ca2+ imaging. 

Vídeo: In Situ Ca2+ Imaging of the Enteric Nervous System

Oral Administration of Rotenone using a Gavage and Image Analysis of Alpha-synuclein Inclusions in the Enteric Nervous System

In Parkinson's disease (PD) patients, the associated pathology follows a characteristic pattern involving inter alia the enteric nervous system (ENS) 1,2, the olfactory bulb (OB), the dorsal motor nucleus of the vagus (DMV)3, the intermediolateral nucleus of the spinal cord 4 and the substantia nigra, providing the basis for the neuropathological staging of the disease4,5. The ENS and the OB are the most exposed nervous structures and the first ones to be affected. Interestingly, PD has been related to pesticide exposure6-8. Here we show in detail two methods used in our previous study 9. In order to analyze the effects of rotenone acting locally on the ENS, we administered rotenone using a gavage to one-year old C57/BL6 mice. Rotenone is a widely used pesticide that strongly inhibits mitochondrial Complex I 10. It is highly lipophylic and poorly absorbed in the gastrointestinal tract 11. Our results showed that the administration of 5 mg/kg of rotenone did not inhibit mitochondrial Complex I activity in the muscle or the brain. Thus, suggesting that using our administration method rotenone did not cross the hepatoportal system and was acting solely on the ENS. Here we show a method to administer pesticides using a gavage and the image analysis protocol used to analyze the effects of the pesticide in alpha-synuclein accumulation in the ENS. The first part shows a method that allows intragastric administration of pesticides (rotenone) at a desired precise concentration. The second method shows a semi-automatic image analysis protocol to analyze alpha-synuclein accumulation in the ENS using an image analysis software.

Parkinson's disease has been related to the exposure to pesticides. Here we show a method to deliver pesticides using a gastric tube at the desired concentration and a method to analyze their effect in alpha-synuclein accumulation in the enteric nervous system.

Administração oral de rotenona usando um Gavage e Análise de Imagem de Alpha-sinucleína Inclusões no sistema nervoso entérico

In Parkinson's disease (PD) patients, the associated pathology follows a characteristic pattern involving inter alia the enteric nervous system (ENS) 1,2, ...

Neurociência

Visualization of the Embryonic Nervous System in Whole-mount Drosophila Embryos

The Drosophila embryo is an attractive model system for investigating the cellular and molecular basis of neuronal development. Here we describe the procedure for the visualization of Drosophila embryonic nervous system using antibodies to neuronal proteins. Since the entire embryonic peripheral nervous and central nervous systems are well characterized at the level of individual cells (Dambly-Chaudi&egrave;re et al., 1986; Bodmer et al., 1987; Bodmer et al., 1989), any aberrations to these systems can be easily identified using antibodies to different neuronal proteins. The developing embryos are collected at certain times to ensure that the embryos are in the proper developmental stages for visualization. After collection, the outer layers of the embryo, the chorion membrane and the vitelline envelope that surrounds the embryo, are removed before fixation. Embryos are then incubated with neuronal antibodies and visualized using fluorescently labeled secondary antibodies. Embryos at stages 12-17 are visualized to access the embryonic nervous system. At stage 12 the CNS germ band starts shortening and by stage 15 the definitive pattern of the commissure has been achieved. By stage 17 the CNS contracts and the PNS is fully developed (Campos-Ortega et al. 1985). Thus changes in the pattern of the PNS and CNS can be easily observed during these developmental stages.

Visualization of the Embryonic Nervous System in Whole-mount Drosophila Embryos

We describe the procedure to prepare staged Drosophila embryos for the visualization of the embryonic nervous system during embryogenesis.

Visualização do Sistema Nervoso embrionárias no Whole-mount Drosophila Os embriões

The Drosophila embryo is an attractive model system for investigating the cellular and molecular basis of neuronal development. Here we describe the ...

Multimodal Imaging of Stem Cell Implantation in the Central Nervous System of Mice

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, both in preclinical and clinical studies. However, to date results regarding functional outcome and/or tissue regeneration following stem cell transplantation are quite diverse. Generally, a clinical benefit is observed without profound understanding of the underlying mechanism(s)1. Therefore, multiple efforts have led to the development of different molecular imaging modalities to monitor stem cell grafting with the ultimate aim to accurately evaluate survival, fate and physiology of grafted stem cells and/or their micro-environment. Changes observed in one or more parameters determined by molecular imaging might be related to the observed clinical effect. In this context, our studies focus on the combined use of bioluminescence imaging (BLI), magnetic resonance imaging (MRI) and histological analysis to evaluate stem cell grafting.
BLI is commonly used to non-invasively perform cell tracking and monitor cell survival in time following transplantation2-7, based on a biochemical reaction where cells expressing the Luciferase-reporter gene are able to emit light following interaction with its substrate (e.g. D-luciferin)8, 9. MRI on the other hand is a non-invasive technique which is clinically applicable10 and can be used to precisely locate cellular grafts with very high resolution11-15, although its sensitivity highly depends on the contrast generated after cell labeling with an MRI contrast agent. Finally, post-mortem histological analysis is the method of choice to validate research results obtained with non-invasive techniques with highest resolution and sensitivity. Moreover end-point histological analysis allows us to perform detailed phenotypic analysis of grafted cells and/or the surrounding tissue, based on the use of fluorescent reporter proteins and/or direct cell labeling with specific antibodies.
In summary, we here visually demonstrate the complementarities of BLI, MRI and histology to unravel different stem cell- and/or environment-associated characteristics following stem cell grafting in the CNS of mice. As an example, bone marrow-derived stromal cells, genetically engineered to express the enhanced Green Fluorescent Protein (eGFP) and firefly Luciferase (fLuc), and labeled with blue fluorescent micron-sized iron oxide particles (MPIOs), will be grafted in the CNS of immune-competent mice and outcome will be monitored by BLI, MRI and histology (Figure 1).

This article describes an optimized sequence of events for multimodal imaging of cellular grafts in rodent brain using: (i) in vivo bioluminescence and magnetic resonance imaging, and (ii) post mortem histological analysis. Combining these imaging modalities on a single animal allows cellular graft evaluation with high resolution, sensitivity and specificity.

Imagem Multimodal de implante de células-tronco no sistema nervoso central de camundongos

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, ...

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

In this article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the lipophilic fluorescent membrane marker DiI. This method allows the visualization of neuronal cell morphology in great detail. It is possible to label any cell in the CNS: cell bodies of target neurons are visualized under DIC optics or by expression of a fluorescent genetic marker such as GFP. After labeling, the DiI can be transformed into a permanent brown stain by photoconversion to allow visualization of cell morphology with transmitted light and DIC optics. Alternatively, the DiI-labeled cells can be observed directly with confocal microscopy, enabling genetically introduced fluorescent reporter proteins to be colocalised. The technique can be used in any animal, irrespective of genotype, making it possible to analyze mutant phenotypes at single cell resolution.

Labeling of Single Cells in the Central Nervous System of Drosophila melanogaster

We present a technique for labeling single neurons in the central nervous system (CNS) of Drosophila embryos, which allows the analysis of neuronal morphology by either transmitted light or confocal microscopy.

Marcação de células individuais no Sistema Nervoso Central de<em&gt; Drosophila melanogaster</em

In this  article we describe how to individually label neurons in the embryonic CNS of Drosophila melanogaster by juxtacellular injection of the ...

Direct Intraventricular Delivery of Drugs to the Rodent Central Nervous System

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

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

Entrega intraventricular direta de medicamentos para o Sistema Nervoso Central Rodent

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

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 Optogenetic estimulação do sistema nervoso 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 ...

Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina

Retinal cone photoreceptors (cones) serve daylight vision and are the basis of color discrimination. They are subject to degeneration, often leading to blindness in many retinal diseases. Calcium (Ca2+), a key second messenger in photoreceptor signaling and metabolism, has been proposed to be indirectly linked with photoreceptor degeneration in various animal models. Systematically studying these aspects of cone physiology and pathophysiology has been hampered by the difficulties of electrically recording from these small cells, in particular in the mouse where the retina is dominated by rod photoreceptors. To circumvent this issue, we established a two-photon Ca2+ imaging protocol using a transgenic mouse line that expresses the genetically encoded Ca2+ biosensor TN-XL exclusively in cones and can be crossbred with mouse models for photoreceptor degeneration. The protocol described here involves preparing vertical sections (&#8220;slices&#8221;) of retinas from mice and optical imaging of light stimulus-evoked changes in cone Ca2+ level. The protocol also allows &#8220;in-slice measurement&#8221; of absolute Ca2+ concentrations; as the recordings can be followed by calibration. This protocol enables studies into functional cone properties and is expected to contribute to the understanding of cone Ca2+ signaling as well as the potential involvement of Ca2+ in photoreceptor death and retinal degeneration.

Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina

We describe a protocol to monitor Ca2+ dynamics in the axon terminals of cone photoreceptors using an ex-vivo&#160;slice preparation of the mouse retina. This protocol allows comprehensive studies of cone Ca2+ signaling in an important mammalian model system, the mouse.

Imagem Ca<sup&gt; 2+</sup&gt; Dynamics nos terminais Cone fotorreceptores Axon do mouse Retina

Retinal cone photoreceptors (cones) serve daylight vision and are the basis of color discrimination. They are subject to degeneration, often leading to ...

Transplantation of Chemogenetically Engineered Cortical Interneuron Progenitors into Early Postnatal Mouse Brains

Neuronal development is regulated by a complex combination of environmental and genetic factors. Assessing the relative contribution of each component is a complicated task, which is particularly difficult in regards to the development of &#947;-aminobutyric acid (GABA)ergic cortical interneurons (CIs). CIs are the main inhibitory neurons in the cerebral cortex, and they play key roles in neuronal networks, by regulating both the activity of individual pyramidal neurons, as well as the oscillatory behavior of neuronal ensembles. They are generated in transient embryonic structures (medial and caudal ganglionic eminences -&#160;MGE and CGE) that are very difficult to efficiently target using in utero electroporation approaches. Interneuron progenitors migrate long distances during normal embryonic development, before they integrate in the cortical circuit. This remarkable ability to disperse and integrate into a developing network can be hijacked by transplanting embryonic interneuron precursors into early post-natal host cortices. Here, we present a protocol that allows genetic modification of embryonic interneuron progenitors using focal ex vivo electroporation. These engineered interneuron precursors are then transplanted into early post-natal host cortices, where they will mature into easily identifiable CIs. This protocol allows the use of multiple genetically encoded tools, or the ability to regulate the expression of specific genes in interneuron progenitors, in order to investigate the impact of either genetic or environmental variables on the maturation and integration of CIs.

Here we present a protocol, designed to use chemogenetic tools to manipulate the activity of cortical interneuron progenitors transplanted into the cortex of early postnatal mice.

Transplantação dos progenitors corticais Quimiogenetically projetados do interneuron em cérebros Postnatal adiantados do rato

Neuronal development is regulated by a complex combination of environmental and genetic factors. Assessing the relative contribution of each component is ...

Intrathecal Delivery of Antisense Oligonucleotides in the Rat Central Nervous System

The blood brain barrier (BBB) is an important defense against the entrance of potentially toxic or pathogenic agents from the blood into the central nervous system (CNS). However, its existence also dramatically lowers the accessibility of systemically administered therapeutic agents to the CNS. One method to overcome this, is to inject those agents directly into the cerebrospinal fluid (CSF), thus bypassing the BBB. This can be done via implantation of a catheter for either continuous infusion using an osmotic pump, or for single bolus delivery. In this article, we describe a surgical protocol for delivery of CNS-targeting antisense oligonucleotides (ASOs) via a catheter implanted directly into the cauda equina space of the adult rat spine. As representative results, we show the efficacy of a single bolus ASO intrathecal (IT) injection via this catheterization system in knocking down the target RNA in different regions of the rat CNS. The procedure is safe, effective and does not require expensive equipment or surgical tools. The technique described here can be adapted to deliver drugs in other modalities as well.

Here, we describe a method for delivering drugs to the rat central nervous system by implanting a catheter into the lumbar intrathecal space of the spine. We focus on the delivery of antisense oligonucleotides, though this method is suitable for delivery of other therapeutic modalities as well.

Entrega intrathecal de oligonucleotides do antisense no sistema nervoso central do rato

The blood brain barrier (BBB) is an important defense against the entrance of potentially toxic or pathogenic agents from the blood into the central ...

Imaging Mitochondrial Ca2+ Uptake in Astrocytes and Neurons using Genetically Encoded Ca2+ Indicators (GECIs)

Mitochondrial Ca2+ plays a critical role in controlling cytosolic Ca2+ buffering, energy metabolism, and cellular signal transduction. Overloading of mitochondrial Ca2+ contributes to various pathological conditions, including neurodegeneration and apoptotic cell death in neurological diseases. Here we present a cell-type specific and mitochondria targeting molecular approach for mitochondrial Ca2+ imaging in astrocytes and neurons in vitro and in vivo. We constructed DNA plasmids encoding mitochondria-targeting genetically encoded Ca2+ indicators (GECIs) GCaMP5G or GCaMP6s (GCaMP5G/6s) with astrocyte- and neuron-specific promoters gfaABC1D and CaMKII and mitochondria-targeting sequence (mito-). For in vitro mitochondrial Ca2+ imaging, the plasmids were transfected in cultured astrocytes and neurons to express GCaMP5G/6s. For in vivo mitochondrial Ca2+ imaging, adeno-associated viral vectors (AAVs) were prepared and injected into the mouse brains to express GCaMP5G/6s in mitochondria in astrocytes and neurons. Our approach provides a useful means to image mitochondrial Ca2+ dynamics in astrocytes and neurons to study the relationship between cytosolic and mitochondrial Ca2+ signaling, as well as astrocyte-neuron interactions.

Imaging Mitochondrial Ca2+ Uptake in Astrocytes and Neurons using Genetically Encoded Ca2+ Indicators GECIs

This proctocol aims to provide a method for in vitro and in vivo mitochondrial Ca2+ imaging in astrocytes and neurons.

Imagem Mitocondrial Ca2+ Absorção em Astrócitos e Neurônios usando Indicadores Ca2+ Codificados Geneticamente (GECIs)

Mitochondrial Ca2+ plays a critical role in controlling cytosolic Ca2+ buffering, energy metabolism, and cellular signal transduction. Overloading of ...