Supported by NIH Grants NS14837, R01 NS38537, R24 HD050838 to Dr. Michael E. Selzer; Shriners Research Grant SHC-85220 to Dr. Michael E Selzer; and Shriners Research Grant SHC-85310 to Dr. Michael I. Shifman. Dr. Ant&#243;n Barreiro-Iglesias was supported by the Fundaci&#243;n Barri&#233; (Spain) and the Xunta de Galicia (Galicia, Spain).

Ver Tabela 1 para todos os materiais utilizados neste protocolo. Os experimentos foram aprovados pelo Comitê de Uso e Cuidado Animal Institucional da Universidade de Temple. 1. Os animais <ol><li> Obter tipo selvagem lampreias marinhas larvais (Petromyzon marinus L.), 10-14 cm de comprimento (4-7 anos) dos córregos que alimentam o Lago Michigan, a partir de afluentes do rio Delaware (Pensilvânia) ou córregos em Maine. </li><li> No laboratório, a manter as larvas em grupos de 50 - 100 animais em tanques de água doce de 50 galões a 16 ° C. Linha de tanques com uma polegada de cascalho para as larvas de toca, e que a água é filtrada e carvão condicionado com pedras de ar por pelo menos 48 horas para remover o cloro e outras impurezas antes de colocar as lampreias neles. Não há necessidade de alimentar os animais, que reciclam seus próprios detritos, até o dia de uso. </li></ol> 2. completa SpinalCord transecção <ol><li> Antes da cirurgia da espinal medula preparar uma solução lampreia Ringer com a seguinte composição: NaCl 110 mM, KCl 2,1 mM, 2,6 mM de CaCl 2, 1,8 mM MgCl 2 e 10 mM de tampão Tris; pH 7,4. </li><li> Para realizar a transecção da medula espinhal, coloque as larvas em um pequeno recipiente a ser anestesiada com 1% de metano tricaina em solução Ringer gelada. </li><li> Uma vez anestesiados lugar os animais em uma placa de Petri com meio cheio Sylgard (de silicone) e quatro pinos de utilizar insectos (0,15 mm de diâmetro) para manter os animais em posição para a operação (um é colocado no focinho do animal, um na cauda e dois no nível de 5 º guelras). Encha o prato de petri quase até o topo com uma solução de Ringer. Coloque o prato com a larva no gelo durante a realização da cirurgia sob o microscópio estereoscópico. </li><li> Para realizar a transecção da medula espinal dorsal, mediano, fazer uma incisão longitudinal com um bisturi (# 11) ao nível de 5 ºbranquial para visualizar a medula espinhal. Inicialmente, a pele é aberta por inserção da ponta da lâmina do bisturi voltada para cima e, em seguida, o tecido muscular é cortado muito suavemente até que a coluna vertebral pode ser visto a partir de cima. Moda dois ganchos dos pinos de insetos e usá-los para segurar as paredes do corpo aberta durante a realização da transecção da medula espinhal. </li><li> Completamente transecção da medula espinal ao nível da 5 ª guelras por meio de um par de tesouras (Castroviejo # 8), inserir as tesouras perpendicularmente para a medula espinhal. A medula espinhal tem de ser completamente cortado transversalmente com um corte limpo. Visualizar a medula espinhal extremidades cortadas ao microscópio estereoscópico para confirmar que a espinal medula foi completamente cortado transversalmente. Em seguida, realinhar as extremidades cortadas da medula espinal após a transecção usando um par de pinças (5). </li><li> Depois de realizar a transecção da medula espinal fechar a ferida na parede dorsal do corpo com um par de pinças finas e colocado as larvas em gelo durante 1 h para permitir que a ferida to secar. Coloque um pedaço de papel de filtro entre o gelo e as larvas e mergulhe-o com uma solução de Ringer lampreia. A baixa temperatura mantém os animais vivos ao mesmo tempo que permite que a ferida se secar ao ar e, portanto, ajudar a evitar infecções. </li><li> Em seguida, transferir as larvas para pequenos tanques (1 larva por tanque) com água gelada por 24 horas. </li><li> Examinar o lesionado larvas 1 dia após a transecção espinal para comportamentalmente confirmar que não há movimento caudal ao local da lesão. A transecção da medula espinal é considerada completa se a larva possa mover apenas a sua cabeça rostral para o local da lesão (ao nível dos 5 th guelras). Se este for o caso, as larvas podem ser agora transferidos para tanques (1 larva por tanque) com água doce, à temperatura ambiente (23 ° C) para permitir a sua recuperação para os pontos de tempo seleccionados. </li><li> Durante o período de recuperação de mudar a água a cada 2 a 3 dias. </li></ol> 3. Cérebro Dissecção e Preparação deo cérebro por meio de hibridação in situ <ol><li> Nos momentos desejados após a lesão re-anestesiar as lampreias marinhas das larvas e lugar e fixá-los na placa de Petri com solução de Ringer para realizar a dissecação do cérebro como acima. </li><li> Para dissecar o cérebro, em primeiro lugar fazer uma incisão transversal com o bisturi entre a narina eo órgão pineal. A partir daqui, começa a cortar o tecido que envolve o cérebro, utilizando um par de tesouras Castroviejo, mantendo-a com uma pinça. </li><li> Uma vez que o cérebro está exposto, remover o plexo coróide, utilizando um par de pinças e utilizar os ganchos para espalhar a cabeça do animal, e expor os nervos cranianos. Em seguida, corte a forma transversal da medula espinhal com a tesoura Castroviejo. Segurar a medula espinal com um par de pinças, enquanto usando outro par de fórceps para cortar os nervos cranianos a dissecar o cérebro. </li><li> Após a dissecção, colocar o cérebro em um pequeno pedaço de silicone e mantenha-o em posição inserindo dois insect pinos no bulbos olfativos 1 e na medula espinal. Em seguida, corte a parte posterior e comissuras cerebrotectal do cérebro ao longo da linha média dorsal com a tesoura e desviar as placas alar lateralmente e fixá-los plana para o silicone com 4 pinos de insetos (Figura 2). </li><li> Transferir o pedaço de silicone com o cérebro de um tubo contendo 4% de paraformaldeído em tampão fosfato salino (pH 7,4) para ser fixada em temparature ambiente durante 3 horas num rotor. </li><li> Após a fixação usar o cérebro para wholemount hibridação in situ tal como descrito anteriormente (Swain et al., 1994). Os cérebros de animais de controlo ou sham operado deve ser executado sempre em paralelo com os cérebros de animais lesionados. O cérebro de larvas wholemounted pode ser estudada por hibridação in situ devido à sua forma plana e fina, e também devido à ausência de mielina 10, o que faz com que o cérebro relativamente translúcido. </li></ol>

<ol>
	<li>Rodicio, M. C., Barreiro-Iglesias, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lampreys+as+an+animal+model+in+regeneration+studies+after+spinal+cord+injury.">Lampreys as an animal model in regeneration studies after spinal cord injury.</a> Rev Neurol. 55, 157-166 (2012).</li><li>Davis, G. R., McClellan, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extent+and+time+course+of+restoration+of+descending+brainstem+projections+in+spinalcord-transected+lamprey.">Extent and time course of restoration of descending brainstem projections in spinalcord-transected lamprey.</a> J Comp Neurol. 344, 65-82 (1994).</li><li>Jacobs, A. J., Swain, G. P., Snedeker, J. A., Pijak, D. S., Gladstone, L. J., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+of+neurofilament+expression+selectively+in+regenerating+reticulospinal+neurons.">Recovery of neurofilament expression selectively in regenerating reticulospinal neurons.</a> J Neurosci. 17, 5206-5220 (1997).</li><li>Shifman, M. I., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+the+netrin+receptor+UNC-5+in+lamprey+brain+modulation+by+spinal+cord+transection.">Expression of the netrin receptor UNC-5 in lamprey brain modulation by spinal cord transection.</a> Neurorehabil Neural Repair. 14, 49-58 (2000).</li><li>Barreiro-Iglesias, A., Laramore, C., Shifman, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+sea+lamprey+UNC5+receptors+cDNA+cloning,+phylogenetic+analysis+and+expression+in+reticulospinal+neurons+at+larval+and+adult+stages+of+development.">The sea lamprey UNC5 receptors cDNA cloning, phylogenetic analysis and expression in reticulospinal neurons at larval and adult stages of development.</a> J Comp Neurol. 520, 4141-4156 (2012).</li><li>Shifman, M. I., Yumu, l. R. E., Laramore, C., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+the+repulsive+guidance+molecule+RGM+and+its+receptor+neogenin+after+spinal+cord+injury+in+sea+lamprey.">Expression of the repulsive guidance molecule RGM and its receptor neogenin after spinal cord injury in sea lamprey.</a> Exp Neurol. 217, 242-251 (2009).</li><li>Busch, D. J., Morgan, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synuclein+accumulation+is+associated+with+cell-specific+neuronal+death+after+spinal+cord+injury.">Synuclein accumulation is associated with cell-specific neuronal death after spinal cord injury.</a> J Comp Neurol. 520, 1751-1771 (2012).</li><li>Shifman, M. I., Zhang, G., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+death+of+identified+reticulospinal+neurons+after+spinal+cord+injury+in+lampreys.">Delayed death of identified reticulospinal neurons after spinal cord injury in lampreys.</a> J Comp Neurol. 510, 269-282 (2008).</li><li>Swain, G. P., Jacobs, A. J., Frei, E., Selzer, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+in+situ+hybridization+in+wholemounted+lamprey+brain+neurofilament+expression+in+larvae+and+adults.">A method for in situ hybridization in wholemounted lamprey brain neurofilament expression in larvae and adults.</a> Exp. Neurol. 126, 256-269 (1994).</li><li>Bullock, T. H., Moore, J. K., Fields, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+myelin+sheaths:+both+lamprey+and+hagfish+lack+myelin.">Evolution of myelin sheaths: both lamprey and hagfish lack myelin.</a> Neurosci Lett. 48, 145-148 (1984).</li><li>Cohen, A. H., Kiemel, T., Pate, V., Blinder, J., Guan, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+can+alter+the+function+outcome+of+spinal+cord+regeneration+in+larval+lampreys.">Temperature can alter the function outcome of spinal cord regeneration in larval lampreys.</a> Neuroscience. 90, 957-965 (1999).</li></ol>

The authors declare that they have no competing financial interests.

Aqui apresentamos um protocolo detalhado para executar uma transecção medular completa e dissecção cerebral posterior em lampreias marinhas larvais. Este procedimento permite que as diferenças de análise da expressão gênica entre medula espinhal identificável salientes neurônios após a lesão medular por meio de um cérebro inteiro de montagem de hibridização in situ. O passo crítico no processo é o correcto desempenho de uma completa transecção da medula espinal, o que pode ser controlado através da o...

Nos mamíferos lesão medular (LM) é uma condição devastadora que leva à perda permanente da função abaixo do local da lesão, porque os axônios lesionados não se regeneram através da zona de trauma e se reconectar com suas metas adequadas. Em contraste com os mamíferos, lampreia recuperar locomoção após uma lesão completa da medula espinal. Uma forma interessante, a lampreia tem um conjunto de 36 projectando neurónios da medula espinal que são identificáveis ​​individualmente em conjunto de montagem em preparações de cérebro devido ao seu grande tamanho 2,3 (Figura 1) . Todos esses neurônios espinhais de projeção são axotomizados por um alto nível de transecção completa da medula espinhal. Estudos anteriores de nosso grupo e outros mostraram que, mesmo na presença de recuperação funcional após SCI alguns destes neurónios mostram uma muito baixa capacidade de regeneração (que são considerados &quot;maus regeneradores&quot;), enquanto outros geralmente regenerar seu axónio através do local da lesão (que são consideradas de &quot;gregeneradores ood &quot;). 2,3 Esta característica faz com que as lampreias um modelo vertebrado interessante estudar as diferenças na expressão gênica entre o bem eo mal regenerador neurônios espinhais-projetando que por sua vez levará para as diferenças na capacidade de regeneração intrínseca dos neurônios que tentar regenerar seus axônios no mesmo ambiente extrínseca. 1 Usando esse modelo, já haviam demonstrado que a medula de projeção neurônios com baixa capacidade regenerativa show de expressão de receptores de moléculas orientação axonal como UNC5 4,5 e neogenin 6, que medeiam a ação inibitória da netrin e RGM respectivamente. Além disso, utilizando este método nosso grupo também mostrou que apenas as boas regeneradores mostram uma recuperação da expressão de neurofilamentos após o ferimento e durante o processo de regeneração. Recentemente, Busch e Morgan 7 por imunofluorescência demonstraram que os regeneradores maus mostrará um increased expressão de sinucleína após a lesão, o que tem sido relacionado pelos autores para o fato de que o &quot;mau regenerador&quot; neurônios espinhais-projetando morrer lentamente após um completo medula espinhal transection 5,7,8. Assim, o modelo de lampreia de uma lesão completa da medula espinhal tem emergido como um modelo muito útil para entender o que faz um cordão espinhal neurônio projetando um &quot;mau regenerador&quot; após axotomia. Para realizar os estudos que estão executando um protocolo completo cirurgia espinal medula transecção e uma dissecção cerebral posterior nos pontos de tempo desejado após a lesão para realizar wholemount hibridação in situ. No presente artigo metodológico apresentamos um protocolo detalhado para o bom desempenho de uma medula cirurgia completa lesão da medula em lampreias larvais, a posterior manutenção dos animais ea dissecação cerebral final e preparação do cérebro para uma wholemount hibridização in situ. Um protocolo detalhado para perform o wholemount hibridização in situ no cérebro de lampreias larvais foi relatada anteriormente. 9 Além disso, o protocolo de lesão medular e dissecação do cérebro pode ser usado também para, em seguida, processar os cérebros para imuno-histoquímica ou outros métodos histológicos.

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			<td height="85" style="height:85px;width:64px;">Name of the reagent</td>
			<td style="width:83px;">Company</td>
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			<td style="width:71px;">Comments (optional)</td>
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		<tr height="148">
			<td height="148" style="height:148px;width:64px;">Tricaine methane sulfonate</td>
			<td style="width:83px;">Spectrum</td>
			<td style="width:64px;">TR108</td>
			<td style="width:71px;">Benzocaine saturated solution in PBS for sacrifice</td>
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			<td height="85" style="height:85px;width:64px;">Scalpel #3</td>
			<td style="width:83px;">Fine Science Tools (FST)</td>
			<td style="width:64px;">10003-12</td>
			<td style="width:71px;"></td>
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		<tr height="85">
			<td height="85" style="height:85px;width:64px;">Blades for scalpel: #11</td>
			<td style="width:83px;">Fine Science Tools&#160;</td>
			<td style="width:64px;">10011-00</td>
			<td style="width:71px;"></td>
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		<tr height="85">
			<td height="85" style="height:85px;width:64px;">Castroviejo scissors #8</td>
			<td style="width:83px;">Fine Science Tools&#160;</td>
			<td style="width:64px;">15002-08</td>
			<td style="width:71px;"></td>
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		<tr height="190">
			<td height="190" style="height:190px;width:64px;">Forceps #4 &#38; #5</td>
			<td style="width:83px;">Dumont, Switzerland</td>
			<td style="width:64px;">Roboz RS4955</td>
			<td style="width:71px;">#4 for dissection of Spinal cord; #5 for stripping menninges</td>
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		<tr height="85">
			<td height="85" style="height:85px;width:64px;">Dissecting Microscope</td>
			<td style="width:83px;">Olympus</td>
			<td style="width:64px;">SZ51</td>
			<td style="width:71px;"></td>
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			<td height="63" rowspan="2" style="height:63px;width:64px;">Sylgard</td>
			<td rowspan="2" style="width:83px;">Dow Corning Co.</td>
			<td rowspan="2" style="width:64px;">184</td>
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			<td height="189" rowspan="2" style="height:189px;width:64px;">Insect pins 0.15, 0.20 mm</td>
			<td rowspan="2" style="width:83px;">Austerlitz</td>
			<td rowspan="2" style="width:64px;">No catalogue #</td>
			<td rowspan="2" style="width:71px;">0.15 mm for pinning brain and spinal cord; 0.20 mm for the body</td>
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		<tr height="21">
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		<tr height="127">
			<td height="127" style="height:127px;width:64px;">7 ml HDPE Scintillation Tubes with Caps</td>
			<td style="width:83px;">Fisher Scientific</td>
			<td style="width:64px;">03-337-1</td>
			<td style="width:71px;"></td>
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		<tr height="106">
			<td height="106" style="height:106px;width:64px;">Paraformaldehyde 16%</td>
			<td style="width:83px;">Electron Microscopy Science (EMS)</td>
			<td style="width:64px;">19210</td>
			<td style="width:71px;">Dilute to 4% in PBS</td>
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complete spinal cord injury and brain dissection protocol for subsequent wholemount in situ hybridization in larval sea lamprey

Depois de uma lesão completa da medula espinhal, lampreias marinhas no primeiro estão paralisados ​​abaixo do nível da transecção. No entanto, eles se recuperam locomoção depois de várias semanas, e isso é acompanhado por regeneração curta distância (alguns mm) dos axônios propriospinal e axônios espinal-se projectam a partir do tronco cerebral. Entre os 36 grandes neurônios espinhais-projetando identificáveis, alguns são bons e outros são regeneradores maus regeneradores. Esses neurônios podem ser mais facilmente identificados em preparações wholemount SNC. A fim de compreender os mecanismos neuronais intrínsecos que favorecem ou inibem a regeneração do axônio após a lesão nos vertebrados do SNC, podemos determinar diferenças na expressão gênica entre os bons e maus regeneradores, e como expressão é influenciada pela medula transecção espinhal. Este artigo ilustra as técnicas para larval habitação e lampreias marinhas adultas recentemente transformados em tanques de água, produzindo completos transecções da medula espinhal sob visão microscópica, e preparando brain e wholemounts da medula espinhal para hibridização in situ. Resumidamente, os animais são mantidos em 16 &#160; ° C e anestesiados em 1% benzocaína na lampreia Ringer. A medula espinal é seccionado com tesoura iridectomia através de uma abordagem dorsal e o animal é deixado recuperar em tanques de água a 23 ° C. Para a hibridização in situ, os animais são reanesthetized e o cérebro e medula removido por meio de uma abordagem dorsal.

Como um exemplo dos resultados que podem ser obtidos quando se usa este método, as imagens representativas dos cérebros wholemounted que mostram a expressão dos transcritos neogenin em neurónios projectam-medulares identificáveis ​​de controlo e 2 semanas após a lesão a lampreia mar larvas são mostrados na Figura 2. Os leitores são referidos num estudo anterior 6 relatando a relação entre a expressão de neogenin após uma transecção medular completa ea capacidade de regenera...

Watch this Scientific Journal Video about Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey at JoVE.com

Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey

As lampreias recuperar locomoção após uma lesão completa da medula espinhal. No entanto, alguns neurônios espinhais de projeção são bons regeneradores e outros não. Este artigo ilustra as técnicas para larvas de lampreia mar habitação (e adultos recém-transformados), produzindo completos transecções medulares e preparar cérebros wholemount e medulas espinhais de hibridização in situ.

Spinal Cord Injury completo e Cérebro Dissection Protocolo para Wholemount Subsequente<em&gt; In Situ</em&gt; Hibridização em larval da lampreia de mar

After a complete spinal cord injury, sea lampreys at first are paralyzed below the level of transection. However, they recover locomotion after several ...

complete-spinal-cord-injury-brain-dissection-protocol-for-subsequent

Research

JoVE Journal

Neuroscience

Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey

9.8K visualizações.  University of Edinburgh.  As lampreias recuperar locomoção após uma lesão completa da medula espinhal. No entanto, alguns neurônios espinhais de projeção são bons regeneradores e outros não. Este artigo ilustra as técnicas para larvas de lampreia mar habitação (e adultos recém-transformados), produzindo completos transecções medulares e preparar cérebros wholemount e medulas espinhais de hibridização in situ. 

Vídeo: Complete Spinal Cord Injury and Brain Dissection Protocol for Subsequent Wholemount In Situ Hybridization in Larval Sea Lamprey

Dissection and Culture of Commissural Neurons from Embryonic Spinal Cord

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies of these neurons are located in the dorsal spinal cord and their axons follow stereotyped trajectories during embryonic development. Commissural axons initially project ventrally towards the floorplate. After crossing the midline, these axons turn anteriorly and project towards the brain. Each of these steps is regulated by the action of several guidance cues. Cultures highly enriched in commissural neurons are ideally suited for many experiments addressing the mechanisms of axon pathfinding, including turning assays, immunochemistry and biochemistry. Here, we describe a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. First, the spinal cord is isolated and dorsal strips are dissected out. The dorsal tissue is then dissociated into a cell suspension by trypsinization and mechanical disruption. Neurons are plated onto poly-L-lysine-coated glass coverslips or tissue-culture dishes. After 30 hours in vitro, most neurons have extended an axon. The purity of the culture (Yam et al. 2009), typically over 90%, can be assessed by immunolabeling with the commissural neuron markers DCC, LH2 and TAG1 (Helms and Johnson, 1998). This neuronal preparation is a useful tool for in vitro studies of the cellular and molecular mechanisms of commissural axon growth and guidance during spinal cord development.

This video demonstrates a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. Dissociated commissural neurons are useful to study the cellular and molecular mechanisms of axon growth and guidance.

Dissecção e Cultura de Neurônios da Medula Espinhal comissural embrionárias

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies ...

Neurociência

Double Fluorescence in situ Hybridization in Fresh Brain Sections

Here we describe a modified version of a double fluorescence in situ hybridization (dFISH) method optimized for detecting two mRNAs of interest in fresh frozen brain sections. Our group has successfully used this approach to study gene co-regulation. More specifically, we have used this dFISH method to explore the anatomical organization, neurochemical properties, and the impact of sensory experience in central sensory circuits, at single cell resolution. This protocol has been validated in brain tissue from mice, rats and songbirds but is expected to be easily adaptable to other vertebrate species, as well as to an array of non-neural tissues. In this film we provide a detailed demonstration of the main steps of this procedure.

Double Fluorescence in situ Hybridization in Fresh Brain Sections

This protocol involves a non-radioactive in-situ hybridization procedure that enables the simultaneous identification of two transcript species, at a single cell resolution, in thin sections of the vertebrate brain.

Fluorescência dupla In situ Hibridação nas Seções cérebro fresco

Here we describe a modified version of a double fluorescence in situ hybridization (dFISH) method optimized for detecting two mRNAs of interest in fresh ...

Lateral Fluid Percussion: Model of Traumatic Brain Injury in Mice

Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and mortality. Based on the nature of primary injury following TBI, complex and heterogeneous secondary consequences result, which are followed by regenerative processes 1,2. Primary injury can be induced by a direct contusion to the brain from skull fracture or from shearing and stretching of tissue causing displacement of brain due to movement 3,4. The resulting hematomas and lacerations cause a vascular response 3,5, and the morphological and functional damage of the white matter leads to diffuse axonal injury 6-8. Additional secondary changes commonly seen in the brain are edema and increased intracranial pressure 9. Following TBI there are microscopic alterations in biochemical and physiological pathways involving the release of excitotoxic neurotransmitters, immune mediators and oxygen radicals 10-12, which ultimately result in long-term neurological disabilities 13,14. Thus choosing appropriate animal models of TBI that present similar cellular and molecular events in human and rodent TBI is critical for studying the mechanisms underlying injury and repair.
Various experimental models of TBI have been developed to reproduce aspects of TBI observed in humans, among them three specific models are widely adapted for rodents: fluid percussion, cortical impact and weight drop/impact acceleration 1. The fluid percussion device produces an injury through a craniectomy by applying a brief fluid pressure pulse on to the intact dura. The pulse is created by a pendulum striking the piston of a reservoir of fluid. The percussion produces brief displacement and deformation of neural tissue 1,15. Conversely, cortical impact injury delivers mechanical energy to the intact dura via a rigid impactor under pneumatic pressure 16,17. The weight drop/impact model is characterized by the fall of a rod with a specific mass on the closed skull 18. Among the TBI models, LFP is the most established and commonly used model to evaluate mixed focal and diffuse brain injury 19. It is reproducible and is standardized to allow for the manipulation of injury parameters. LFP recapitulates injuries observed in humans, thus rendering it clinically relevant, and allows for exploration of novel therapeutics for clinical translation 20.
We describe the detailed protocol to perform LFP procedure in mice. The injury inflicted is mild to moderate, with brain regions such as cortex, hippocampus and corpus callosum being most vulnerable. Hippocampal and motor learning tasks are explored following LFP.

Lateral fluid percussion (LFP), an established model of traumatic brain injury in mice, is demonstrated. LFP fulfills three major criteria for animal models: validity, reliability and clinical relevance. The procedure, consisting of surgical craniotomy, fixation of hub followed by induction of injury, resulting in focal and diffuse injuries, is described.

Percussão Fluid lateral: Modelo de Lesão em Ratos

Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and ...

Spinal Cord Transection in the Larval Zebrafish

Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability to reinitiate spinal neurogenesis. However, some anamniotes including the zebrafish Danio rerio exhibit both sensory and functional recovery even after complete transection of the spinal cord. The adult zebrafish is an established model organism for studying regeneration following spinal cord injury, with sensory and motor recovery by 6&#160;weeks post-injury. To take advantage of in vivo analysis of the regenerative process available in the transparent larval zebrafish as well as genetic tools not accessible in the adult, we use the larval zebrafish to study regeneration after spinal cord transection. Here we demonstrate a method for reproducibly and verifiably transecting the larval spinal cord. After transection, our data shows sensory recovery beginning at 2&#160;days post-injury (dpi), with the C-bend movement detectable by 3 dpi and resumption of free swimming by 5 dpi. Thus we propose the larval zebrafish as a companion tool to the adult zebrafish for the study of recovery after spinal cord injury.

After spinal transection, adult zebrafish have functional recovery by six weeks post-injury. To take advantage of larval transparency and faster recovery, we present a method for transecting the larval spinal cord. After transection, we observe sensory recovery beginning at 2&#160;days post-injury, and C-bend movement by 3 days post-injury.

Transecção medular nos larval Zebrafish

Mammals fail in sensory and motor recovery following spinal cord injury due to lack of axonal regrowth below the level of injury as well as an inability ...

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal degeneration. Lack of growth cone formation, regeneration, and loss of additional myelinated axonal projections within the spinal cord greatly limits neurological recovery following injury. To assess how central myelinated axons of the spinal cord respond to injury, we developed an ex vivo living spinal cord model utilizing transgenic mice that express yellow fluorescent protein in axons and a focal and highly reproducible laser-induced spinal cord injury to document the fate of axons and myelin (lipophilic fluorescent dye Nile Red) over time using two-photon excitation time-lapse microscopy. Dynamic processes such as acute axonal injury, axonal retraction, and myelin degeneration are best studied in real-time. However, the non-focal nature of contusion-based injuries and movement artifacts encountered during in vivo spinal cord imaging make differentiating primary and secondary axonal injury responses using high resolution microscopy challenging. The ex vivo spinal cord model described here mimics several aspects of clinically relevant contusion/compression-induced axonal pathologies including axonal swelling, spheroid formation, axonal transection, and peri-axonal swelling providing a useful model to study these dynamic processes in real-time. Major advantages of this model are excellent spatiotemporal resolution that allows differentiation between the primary insult that directly injures axons and secondary injury mechanisms; controlled infusion of reagents directly to the perfusate bathing the cord; precise alterations of the environmental milieu (e.g., calcium, sodium ions, known contributors to axonal injury, but near impossible to manipulate in vivo); and murine models also offer an advantage as they provide an opportunity to visualize and manipulate genetically identified cell populations and subcellular structures. Here, we describe how to isolate and image the living spinal cord from mice to capture dynamics of acute axonal injury.

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

We present a protocol utilizing two-photon excitation time-lapse microscopy to simultaneously visualize the dynamics of axon and myelin injuries in real time. This proposed protocol permits studies of both intrinsic and extrinsic factors which can influence central myelinated axon fate after injury and contribute to permanent clinical disability.

Um<em&gt; Ex Vivo</em&gt; Induzida por laser Lesão Medular modelo para avaliar mecanismos de axonal Degeneration em tempo real

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal ...

Zebrafish In Situ Spinal Cord Preparation for Electrophysiological Recordings from Spinal Sensory and Motor Neurons

Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing organisms, combined with the embryonic optical clarity, served as initial compelling attributes of this model. Over the past two decades, the success of this model has been further propelled by its amenability to large-scale mutagenesis screens and by the ease of transgenesis. More recently, gene-editing approaches have extended the power of the model.
For neurodevelopmental studies, the zebrafish embryo and larva provide a model to which multiple methods can be applied. Here, we focus on methods that allow the study of an essential property of neurons, electrical excitability. Our preparation for the electrophysiological study of zebrafish spinal neurons involves the use of veterinarian suture glue to secure the preparation to a recording chamber. Alternative methods for recording from zebrafish embryos and larvae involve the attachment of the preparation to the chamber using a fine tungsten pin1,2,3,4,5. A tungsten pin is most often used to mount the preparation in a lateral orientation, although it has been used to mount larvae dorsal-side up4. The suture glue has been used to mount embryos and larvae in both orientations. Using the glue, a minimal dissection can be performed, allowing access to spinal neurons without the use of an enzymatic treatment, thereby avoiding any resultant damage. However, for larvae, it is necessary to apply a brief enzyme treatment to remove the muscle tissue surrounding the spinal cord. The methods described here have been used to study the intrinsic electrical properties of motor neurons, interneurons, and sensory neurons at several developmental stages6,7,8,9.

Zebrafish In Situ Spinal Cord Preparation for Electrophysiological Recordings from Spinal Sensory and Motor Neurons

This manuscript describes methods for electrophysiological recordings from spinal neurons of zebrafish embryos and larvae. The preparation maintains neurons in situ and often involves minimum dissection. These methods allow for the electrophysiological study of a variety of spinal neurons, from the initial electrical excitability acquisition through the early larval stages.

zebrafish<em&gt; In Situ</em&gt; Spinal Cord Preparação para gravações eletrofisiológicas da Spinal Sensorial e Motor Neurons

Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing ...

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in adult mammalian animals remains elusive. In this study, we describe an experimental procedure for measuring calcium dynamics through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy. This method enables recordings and quantifications of neural activity in bilateral mouse brain regions one at a time in the same experiment for a prolonged period in vivo. Key aspects of this method, which can be completed within an hour, include minimally invasive surgery procedures for creating dual optical windows, and the use of 2P imaging. Although we only demonstrate the technique in the S1 area, the method can be applied to other regions of the living brain facilitating the elucidation of structural and functional complexities of brain neural networks.

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

We describe an experimental procedure for measuring neuronal activity through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy in vivo.

Imagem de atividade Neural no córtex somatossensorial primário usando Thy1-GCaMP6s de ratos transgênicos

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in ...

An In Vivo Duo-color Method for Imaging Vascular Dynamics Following Contusive Spinal Cord Injury

Spinal cord injury (SCI) causes significant vascular disruption at the site of injury. Vascular pathology occurs immediately after SCI and continues throughout the acute injury phase. In fact, endothelial cells appear to be the first to die after a contusive SCI. The early vascular events, including increased permeability of the blood-spinal cord barrier (BSCB), induce vasogenic edema and contribute to detrimental secondary injury events caused by complex injury mechanisms. Targeting the vascular disruption, therefore, could be a key strategy to reduce secondary injury cascades that contribute to histological and functional impairments after SCI. Previous studies were mostly performed on postmortem samples and were unable to capture the dynamic changes of the vascular network. In this study, we have developed an in vivo duo-color two-photon imaging method to monitor acute vascular dynamic changes following contusive SCI. This approach allows detecting blood flow, vessel diameter, and other vascular pathologies at various sites of the same rat pre- and post-injury. Overall, this method provides an excellent venue for investigating vascular dynamics.

An In Vivo Duo-color Method for Imaging Vascular Dynamics Following Contusive Spinal Cord Injury

We introduce an in vivo imaging method using two different fluorescent dyes to track dynamic spinal vascular changes following a contusive spinal cord injury in adult Sprague-Dawley rats.

Um Vivo em Método de dupla-cor de imagem dinâmica Vascular após lesão da medula espinhal Contusive

Spinal cord injury (SCI) causes significant vascular disruption at the site of injury. Vascular pathology occurs immediately after SCI and continues ...

Intra-Arterial Delivery of Neural Stem Cells to the Rat and Mouse Brain: Application to Cerebral Ischemia

Neural stem cell (NSC) therapy is an emerging innovative treatment for stroke, traumatic brain injury and neurodegenerative disorders. As compared to intracranial delivery, intra-arterial administration of NSCs is less invasive and produces a more diffuse distribution of NSCs within the brain parenchyma. Further, intra-arterial delivery allows the first-pass effect in the brain circulation, lessening the potential for trapping of cells in peripheral organs, such as liver and spleen, a complication associated with peripheral injections. Here, we detail the methodology, in both mice and rats, for delivery of NSCs through the common carotid artery (mouse) or external carotid artery (rat) to the ipsilateral hemisphere after an ischemic stroke. Using GFP-labeled NSCs, we illustrate the widespread distribution achieved throughout the rodent ipsilateral hemisphere at 1 d, 1 week and 4 weeks after postischemic delivery, with a higher density in or near the ischemic injury site. In addition to long-term survival, we show evidence of differentiation of GFP-labeled cells at 4 weeks. The intra-arterial delivery approach described here for NSCs can also be used for administration of therapeutic compounds, and thus has broad applicability to varied CNS injury and disease models across multiple species.

A method for delivering neural stem cells, adaptable for injecting solutions or suspensions, through the common carotid artery (mouse) or external carotid artery (rat) after ischemic stroke is reported. Injected cells are distributed broadly throughout the brain parenchyma and can be detected up to 30 d after delivery.

Entrega intra-arterial de células-tronco neurais ao cérebro de ratos e ratos: aplicação à isquemia cerebral

Neural stem cell (NSC) therapy is an emerging innovative treatment for stroke, traumatic brain injury and neurodegenerative disorders. As compared to ...

Induction of Complete Transection-Type Spinal Cord Injury in Mice

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, such as cell transplantation methods, are being researched to overcome the debilitating disabilities arising from SCI. Most pre-clinical animal trials are conducted in rodent models of SCI. While rat models of SCI have been widely used, mouse models have received less attention, even though mouse models can have significant advantages over rat models. The small size of mice equates to lower animal maintenance costs than for rats, and the availability of numerous transgenic mouse models is advantageous for many types of studies. Inducing repeatable and precise injury in the animals is the primary challenge for SCI research, which in small rodents requires high-precision surgery. The transection-type injury model has been a commonly used injury model over the last decade for transplantation-based therapeutic research, however a standardized method for inducing a complete transection-type injury in mice does not exist. We have developed a surgical protocol for inducing a complete transection type injury in C57BL/6 mice at thoracic vertebral level 10 (T10). The procedure uses a small tip drill instead of rongeurs to precisely remove the lamina, after which a thin blade with rounded cutting edge is used to induce the spinal cord transection. This method leads to reproducible transection-type injury in small rodents with minimal collateral muscle and bone damage and therefore minimizes confounding factors, specifically where behavioral functional outcomes are analyzed.

This protocol describes how to create a precise laminectomy for induction of stable transection-type spinal cord injury in the mouse model, with minimal collateral damage for spinal cord injury research.

Indução da lesão da medula espinhal tipo transssecção completa em camundongos

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, ...