Nosso trabalho é apoiado pela National Science Foundation suíço (SNF), a Iniciativa Suíça em Biologia de Sistemas (SystemsX.ch), a Muscular Dystrophy Association EUA (MDA), a Associação Française contre les Miopatias (AFM), o United mitocondrial Doença Fundação (UMDF), a Gebert-Ruf Fundação Programa das Doenças Raras (GRF), a Sociedade Suíça de Investigação das doenças musculares (SSEM / FSRMM), a Swiss Life &quot;Jubiläumsstiftung für Volksgesundheit und Forschung medizinische&quot;, a Roche Research Foundation e da Universidade de Basileia.

1. Preparação da cultura de células humanas muscular primária <ol><li> Estabelecer as culturas de células humanas musculares de acordo com a técnica de explante-re explante-4. Primeiro, remova não-tecido muscular das biópsias. Em seguida, incorporar 1 mm 3 explantes musculares em um coágulo de plasma, que permite que os fibroblastos de emergir dos explantes. </li><li> Os explantes incorporados são transferidos para um prato de plasma gelatina revestido e deixá-los crescer em meio de crescimento normal (MEM suplementado com meio de 25% 199, 10% de soro fetal bovino [FBS], 1% de penicilina / estreptomicina, 10 insulina ug / ml, 10 ng / ml factor de crescimento epidérmico humano [EGF], 12,5 ng / ml factor de crescimento fibroblástico humano [FGF]) em uma monocamada. As células que surgem a partir dos explantes sob essas condições são as células musculares. Estas células continuam a crescer em uma monocamada após a remoção dos explantes. </li><li> Cultura das células aneurally 0,1% de gelatina em placas revestidas em meio de crescimento normal. As células podem seraneurally cultivadas e amplificadas, conforme necessário. É preferível utilizar células musculares em uma passagem entre 3 e 8 para executar os co-culturas. É fundamental para inervar miotubos jovens, após este ponto, as co-culturas têm um alto risco de fracassar. Além disso, miotubos não deve ser demasiado grande e muito espessa. </li><li> Dois dias antes da inervação está prevista placa, as células musculares em 35 pratos de tecido mm de cultura (ou 6 placas de poços) com uma densidade de 500.000 células por placa em meio de crescimento normal. Em que a densidade, as células estão na confluência adequada para iniciar a fusão no dia seguinte, e subsequente inervação do dia depois disso. Utilizando essas condições, os miotubos estão na fase certa para inervação ideal e contração das fibras, portanto, posterior. </li><li> No dia seguinte, substituir o meio de crescimento normal, com uma média de fusão composta de MEM suplementado com meio de 25% 199, 5% de FBS, a insulina 10 mg / ml e 1% de penicilina / estreptomicina. </li></ol> 2. Isolati<html> no do rato embrionárias Explantes da Medula Espinal Todo o procedimento para isolar os explantes da medula espinal é realizada sob um microscópio binocular, em Solução Salina Equilibrada de Hank (HBSS, Gibco / Invitrogen ref 14.170) contendo 10% de soro fetal bovino (FBS). <ol><li> É crucial que os embriões de ratos estão entre ED 13 e 14 como um estágio de desenvolvimento diferente comprometeria todo o processo. Sacrifique uma mulher grávida com CO 2 e recolher a cadeia embrião inteiro em meio HBSS. Isolar cada embrião e decapitar as crianças para a eutanásia. </li><li> Dissecar a medula espinal embrionária do resto do corpo de uma só peça e remover o músculo e tecido conjuntivo envolvente. Tenha muito cuidado para manter os gânglios da raiz dorsal (DRGs) ligados à medula espinhal para garantir a inervação funcional. </li><li> Cada fatia da medula espinal transversalmente de uma maneira que cada explante contém pelo menos 2 DRG ligada a ela (explantes de 1 mm 3). </li></ol><html> ove_title &quot;&gt; Inervação 3. das células musculares humanas embrionárias de rato com explantes da Medula Espinal <ol><li> Remover o meio de fusão sobre a cultura de células do músculo, deixando uma fina camada de meio sobre a monocamada. </li><li> Coloque os frascos cuidadosamente sobre a camada de células musculares, cinco explantes uniformemente espaçadas por 35 prato mm. </li><li> Adicionar muito lentamente, solte meio de fusão sábio, em cada explante. É necessário adicionar meio para as células musculares para sobreviver, mas não demasiado para permitir que os explantes a aderir primeiro e fazer contacto com as células. Se o meio não é adicionado corretamente (muito forte ou médio muito), os explantes irá flutuar e irá falhar para inervar as células musculares. </li><li> Uma vez que os explantes começar a aderir, no topo da média de fusão a 2 ml por 35 prato mm, e pôr os pratos com muito cuidado de volta para a incubadora. </li></ol> 4. Manutenção dos heterólogos nervo-músculo Co-culturas <ol><li> Alterar o meio de fusão duas vezes por semana. </li></ol>_title &quot;&gt; 5. resultados representativos Logo que dois dias depois da inervação, é possível ver as neurites que emergem de cada explante e estabelecimento de contactos com as células musculares, representados pelas estruturas botão-like (Fig. 1). Já em 4-6 dias após a inervação, algumas fibras individuais começará a se contrair. As contracções persistir durante vários meses, mantida simplesmente mudando o meio de cultura duas vezes por semana. Após cerca de 2 semanas, o explante medula espinal-se degenera, mas a inervação é conservada. Isto é normal. Uma fina camada de componente do nervo permanece na superfície da camada de células do músculo. Esta rede nervoso é suficiente para manter a funcionalidade do bloco do motor. Se os explantes flutuar no meio de um dia após a inervação, eles nunca irá aderir. Isto acontece quando a camada de células do músculo énão é suficientemente confluentes, ou quando o meio é adicionado demasiado aproximadamente. Às vezes, os explantes, mas não adere neuritos surgirão. Isto é provavelmente devido à falta de DRG ligado a ele. Neste caso também, a inervação não será estabelecida. Manipular os pratos com muito cuidado na primeira semana, como os explantes ainda pode se desprendem facilmente. Para trocar a mídia de fusão, adicionar o líquido gota a gota com uma velocidade mínima para evitar desprendimento de células. <img alt="A Figura 1" src="/files/ftp_upload/3616/3616fig1.jpg" /> Figura 1. Da medula espinhal célula muscular explantes co-culturas do dia 1 ao dia 15.

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Não temos nada a divulgar.

Uma ferramenta fisiológica in vitro para estudar a função da célula muscular em contexto normal e patológico é do maior interesse para os myologists, porque as culturas de células musculares geralmente não recapitular a importância de várias células e células do tipo conexões. A adição de neurónios motores purificado para as células musculares não é suficiente para alcançar uma unidade de motor funcional uma vez que a presença de células de Schwann é necessária para a inervação para se...

<table border="1"><tbody><tr><td> Nome do reagente </td><td> Companhia </td><td> Número de Catálogo </td></tr><tr><td> HBSS </td><td> Gibco / Invitrogen </td><td> 14170 </td></tr><tr><td> MEM </td><td> Gibco / Invitrogen </td><td> 31095 </td></tr><tr><td> Meio 199 </td><td> Gibco / Invitrogen </td><td> 31153 </td></tr><tr><td> Soro Fetal Bovino </td><td> Fetal Clone Perbio </td><td> SH30066.03 </td></tr><tr><td> Insulina </td><td> Sigma </td><td> I9278 </td></tr><tr><td> EGF humano </td><td> Sigma </td><td> E9644 </td></tr><tr><td> FGF humano </td><td> Sigma </td><td> F0291 </td></tr><tr><td> A penicilina / estreptomicina solução </td><td> Gibco </td><td> 15140 </td></tr></tbody></table>

a functional motor unit in the culture dish: co-culture of spinal cord explants and muscle cells

Humanos células musculares primárias cultivadas em monocamada aneurally raramente contrato espontaneamente, porque, na ausência de um componente do nervo, diferenciação celular é limitada e motor estimulação neuronal está ausente 1. Estas limitações dificultar o estudo in vitro de muitas doenças neuromusculares em células musculares em cultura. Importante, as restrições experimentais de monolayered, células musculares em cultura pode ser superado pela inervação funcional de miofibras com explantes da medula espinal em co-cultura. Aqui, nós mostram os diferentes passos necessários para atingir um inervação, eficiente adequado de células musculares humanos primários, levando à completa contracção diferenciação e de fibras de acordo com o método desenvolvido por Askanas 2. Para fazer isso, as células musculares são co-cultivadas com explantes espinal medula de embriões de ratos em ED 13,5, com o gânglio da raiz dorsal ainda ligado às fatias de medula espinhal. Depois de alguns dias, o músculo fibros começar a contrato e, eventualmente, tornar-se cruz-estriado através inervação por neurites funcionais projetando a partir dos explantes da medula espinhal que ligam para as células musculares. Esta estrutura pode ser mantida durante vários meses, simplesmente por troca regular do meio de cultura. As aplicações desta ferramenta de valor inestimável são numerosas, pois representa um modelo funcional para análises multidisciplinares de desenvolvimento muscular humana e inervação. Na verdade, uma completa de novo instalação junção neuromuscular ocorre em um prato de cultura, permitindo uma fácil medição de muitos parâmetros em cada passo, num contexto fundamental e fisiológico. Só para citar alguns exemplos, genômicos e / ou estudos de proteômica pode ser realizada diretamente sobre as co-culturas. Além disso, os efeitos pré e pós-sináptica pode ser e especificamente avaliados separadamente na junção neuromuscular, porque ambos os componentes vêm de diferentes espécies,de rato e humano, respectivamente. O nervo músculo-co-cultura pode também ser realizada com células musculares humanas isoladas de pacientes que sofrem de músculo ou doenças neuromusculares 3, e assim pode ser usado como uma ferramenta de rastreio de drogas candidatas. Finalmente, nenhum equipamento especial, mas uma instalação de BSL2 regular é necessária para reproduzir uma unidade de motor funcional em um prato de cultura. Este método, assim, é valiosa para ambos o músculo, bem como as comunidades de investigação neuromusculares para estudos fisiológicos e mecanicista da função neuromuscular, num contexto normal e doença.

Watch this Scientific Journal Video about A Functional Motor Unit in the Culture Dish: Co-culture of Spinal Cord Explants and Muscle Cells at JoVE.com

A Functional Motor Unit in the Culture Dish: Co-culture of Spinal Cord Explants and Muscle Cells

Células musculares cultivadas são um modelo inadequado para recapitular músculo inervado<em&gt; In vivo</em&gt;. Uma unidade de motor funcional pode ser reproduzida<em&gt; In vitro</em&gt; Por inervação diferenciados humanos células musculares de ratos embrionários primários usando explantes da medula espinhal. Este artigo descreve como co-culturas de explantes da espinal medula e células musculares são estabelecidos.

A Unidade Funcional Motor na placa de cultura: Co-cultivo de explantes da Medula Espinhal e as células musculares

Human primary muscle cells cultured  aneurally in monolayer rarely contract spontaneously because, in the absence of  a nerve component, cell ...

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JoVE Journal

Neuroscience

15.2K visualizações.  University of Basel. Células musculares cultivadas são um modelo inadequado para recapitular músculo inervado In vivo. Uma unidade de motor funcional pode ser reproduzida In vitro Por inervação diferenciados humanos células musculares de ratos embrionários primários usando explantes da medula espinhal. Este artigo descreve como co-culturas de explantes da espinal medula e células musculares são estabelecidos.

Vídeo: A Functional Motor Unit in the Culture Dish: Co-culture of Spinal Cord Explants and Muscle Cells

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

Dissection and Culture of Chick Statoacoustic Ganglion and Spinal Cord Explants in Collagen Gels for Neurite Outgrowth Assays

The sensory organs of the chicken inner ear are innervated by the peripheral processes of statoacoustic ganglion (SAG) neurons. Sensory organ innervation depends on a combination of axon guidance cues1 and survival factors2 located along the trajectory of growing axons and/or within their sensory organ targets. For example, functional interference with a classic axon guidance signaling pathway, semaphorin-neuropilin, generated misrouting of otic axons3. Also, several growth factors expressed in the sensory targets of the inner ear, including Neurotrophin-3 (NT-3) and Brain Derived Neurotrophic Factor (BDNF), have been manipulated in transgenic animals, again leading to misrouting of SAG axons4. These same molecules promote both survival and neurite outgrowth of chick SAG neurons in vitro5,6.
Here, we describe and demonstrate the in vitro method we are currently using to test the responsiveness of chick SAG neurites to soluble proteins, including known morphogens such as the Wnts, as well as growth factors that are important for promoting SAG neurite outgrowth and neuron survival. Using this model system, we hope to draw conclusions about the effects that secreted ligands can exert on SAG neuron survival and neurite outgrowth. 
SAG explants are dissected on embryonic day 4 (E4) and cultured in three-dimensional collagen gels under serum-free conditions for 24 hours. First, neurite responsiveness is tested by culturing explants with protein-supplemented medium. Then, to ask whether point sources of secreted ligands can have directional effects on neurite outgrowth, explants are co-cultured with protein-coated beads and assayed for the ability of the bead to locally promote or inhibit outgrowth. We also include a demonstration of the dissection (modified protocol7) and culture of E6 spinal cord explants. We routinely use spinal cord explants to confirm bioactivity of the proteins and protein-soaked beads, and to verify species cross-reactivity with chick tissue, under the same culture conditions as SAG explants. These in vitro assays are convenient for quickly screening for molecules that exert trophic (survival) or tropic (directional) effects on SAG neurons, especially before performing studies in vivo. Moreover, this method permits the testing of individual molecules under serum-free conditions, with high neuron survival8.

We demonstrate how to dissect and culture chick E4 statoacoustic ganglion and E6 spinal cord explants. Explants are cultured under serum-free conditions in 3D collagen gels for 24 hours. Neurite responsiveness is tested with growth factor-supplemented medium and with protein-coated beads.

Dissecção e Cultura do Gânglio pintainho Statoacoustic e Explantes da Medula Espinhal em géis de colágeno para Ensaios crescimento de neuritos

The sensory organs of the chicken inner ear are innervated by the peripheral processes of statoacoustic ganglion (SAG) neurons. Sensory organ innervation ...

Chicken Embryo Spinal Cord Slice Culture Protocol

Slice cultures can facilitate the manipulation of embryo development both pharmacologically and through gene manipulations. In this reduced system, potential lethal side effects due to systemic drug applications can be overcome. However, culture conditions must ensure that normal development proceeds within the reduced environment of the slice. We have focused on the development of the spinal cord, particularly that of spinal motor neurons. We systematically varied culture conditions of chicken embryo slices from the point at which most spinal motor neurons had been born. We assayed the number and type of motor neurons that survived during the culture period and the position of those motor neurons compared to that in vivo. We found that serum type and neurotrophic factors were required during the culture period and were able to keep motor neurons alive for at least 24 hr and allow those motor neurons to migrate to appropriate positions in the spinal cord. We present these culture conditions and the methodology of preparing the embryo slice cultures using eviscerated chicken embryos embedded in agarose and sliced using a vibratome.

Slice cultures facilitate the manipulation of embryo development by gene and pharmacological perturbations. However, culture conditions must ensure that normal development can proceed within the reduced environment of the slice. We illustrate a protocol that facilitates normal spinal cord development to proceed for at least 24 hr.

Embrião de galinha Spinal Cord Protocolo Cultura Slice

Slice cultures can facilitate the manipulation of  embryo development both pharmacologically and through gene manipulations. In  this reduced system, ...

Analysis of Developing Tooth Germ Innervation Using Microfluidic Co-culture Devices

Innervation plays a key role in the development, homeostasis and regeneration of organs and tissues. However, the mechanisms underlying these phenomena are not well understood yet. In particular, the role of innervation in tooth development and regeneration is neglected.
Several in vivo studies have provided important information about the patterns of innervation of dental tissues during development and repair processes of various animal models. However, most of these approaches are not optimal to highlight the molecular basis of the interactions between nerve fibres and target organs and tissues.
Co-cultures constitute a valuable method to investigate and manipulate the interactions between nerve fibres and teeth in a controlled and isolated environment. In the last decades, conventional co-cultures using the same culture medium have been performed for very short periods (e.g., two days) to investigate the attractive or repulsive effects of developing oral and dental tissues on sensory nerve fibres. However, extension of the culture period is required to investigate the effects of innervation on tooth morphogenesis and cytodifferentiation.
Microfluidics systems allow co-cultures of neurons and different cell types in their appropriate culture media. We have recently demonstrated that trigeminal ganglia (TG) and teeth are able to survive for a long period of time when co-cultured in microfluidic devices, and that they maintain in these conditions the same innervation pattern that they show in vivo.
On this basis, we describe how to isolate and co-culture developing trigeminal ganglia and tooth germs in a microfluidic co-culture system.This protocol describes a simple and flexible way to co-culture ganglia/nerves and target tissues and to study the roles of specific molecules on such interactions in a controlled and isolated environment.

Co-cultures represent a valuable method to study the interactions between nerves and target tissues and organs. Microfluidic systems allow co-culturing ganglia and whole developing organs or tissues in different culture media, thus representing a valuable tool for the in vitro study of the crosstalk between neurons and their targets.

Análise de Desenvolvimento de dente Germ Innervation Utilizar dispositivos microfluídicos Co-cultura

Innervation plays a key role in the development, homeostasis and regeneration of organs and tissues. However, the mechanisms underlying these phenomena ...

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 ...

Laminectomy and Spinal Cord Window Implantation in the Mouse

This protocol describes a method for spinal cord laminectomy and glass window implantation for in vivo imaging of the mouse spinal cord. An integrated digital vaporizer is utilized to achieve a stable plane of anesthesia at a low-flow rate of isoflurane. A single vertebral spine is removed, and a commercially available cover-glass is overlaid on a thin agarose bed. A 3D-printed plastic backplate is then affixed to the adjacent vertebral spines using tissue adhesive and dental cement. A stabilization platform is used to reduce motion artifact from respiration and heartbeat. This rapid and clamp-free method is well-suited for acute multi-photon fluorescence microscopy. Representative data are included for an application of this technique to two-photon microscopy of the spinal cord vasculature in transgenic mice expressing eGFP:Claudin-5 &#8212; a tight junction protein.

This protocol describes implantation of a glass window onto the spinal cord of a mouse to facilitate visualization by intravital microscopy.

Implante de janela de laminectomia e medula espinhal no mouse

This protocol describes a method for spinal cord laminectomy and glass window implantation for in vivo imaging of the mouse spinal cord. An integrated ...

Identifying Cell Surface Markers of Primary Neural Stem and Progenitor Cells by Metabolic Labeling of Sialoglycan

Neural stem and progenitor cells (NSPCs) are the cellular basis for the complex structures and functions of the brain. They are located in specialized niches in vivo and can be isolated and expanded in vitro, serving as an important resource for cell transplantation to repair brain damage. However, NSPCs are heterogeneous and not clearly defined at the molecular level or purified due to a lack of specific cell surface markers. The protocol presented, which has been previously reported, combines a neural-endothelial co-culture system with a metabolic glycan labeling method to identify the surface sialoglycoproteome of primary NSPCs. The NSPC-endothelial co-culture system allows self-renewal and expansion of primary NSPCs in vitro, generating a sufficient number of NSPCs. Sialoglycans in cultured NSPCs are labeled using an unnatural sialic acid metabolic reporter with bioorthogonal functional groups. By comparing the sialoglycoproteome from self-renewing NSPCs expanded in an endothelial co-culture with differentiating neural culture, we identify a list of membrane proteins that are enriched in NSPCs. In detail, the protocol involves: 1) set-up of an NSPC-endothelial co-culture and NSPC differentiating culture; 2) labeling with azidosugar per-O-acetylated N-azidoacetylmannosamine (Ac4ManNAz); and 3) biotin conjugation to modified sialoglycan for imaging after fixation of neural culture or protein extraction from neural culture for mass spectrometry analysis. Then, the NSPC-enriched surface marker candidates are selected by comparative analysis of mass spectrometry data from both the expanded NSPC and differentiated neural cultures. This protocol is highly sensitive for identifying membrane proteins of low abundance in the starting materials, and it can be applied to marker discovery in other systems with appropriate modifications

Presented here is a protocol that combines an in vitro neural-endothelial co-culture system and metabolic incorporation of sialoglycan with bioorthogonal functional groups to expand primary neural stem and progenitor cells and label their surface sialoglycoproteins for imaging or mass-spectrometry analysis of cell surface markers.

Identificando marcadores de superfície celular da haste neural primária e células progenitoras por rotulagem metabólica de Sialoglycan

Neural stem and progenitor cells (NSPCs) are the cellular basis for the complex structures and functions of the brain. They are located in specialized ...

Direct Injection of a Lentiviral Vector Highlights Multiple Motor Pathways in the Rat Spinal Cord

Introducing proteins of interest into cells in the nervous system is challenging due to innate biological barriers that limit access to most molecules. Injection directly into spinal cord tissue bypasses these barriers, providing access to cell bodies or synapses where molecules can be incorporated. Combining viral vector technology with this method allows for introduction of target genes into nervous tissue for the purpose of gene therapy or tract tracing. Here a virus engineered for highly efficient retrograde transport (HiRet) is introduced at the synapses of propriospinal interneurons (PNs) to encourage specific transport to neurons in the spinal cord and brainstem nuclei. Targeting PNs takes advantage of the numerous connections they receive from motor pathways such as the rubrospinal and reticulospinal tracts, as well as their interconnection with each other throughout spinal cord segments. Representative tracing using the HiRet vector with constitutively active green fluorescent protein (GFP) shows high fidelity details of cell bodies, axons and dendritic arbors in thoracic PNs and in reticulospinal neurons in the pontine reticular formation. HiRet incorporates well into brainstem pathways and PNs but shows age dependent integration into corticospinal tract neurons. In summary, spinal cord injection using viral vectors is a suitable method for introduction of proteins of interest into neurons of targeted tracts.

This protocol demonstrates injection of a retrogradely transportable viral vector into rat spinal cord tissue. The vector is taken up at the synapse and transported to the cell body of target neurons. This model is suitable for retrograde tracing of important spinal pathways or targeting cells for gene therapy applications.

Injeção direta de um vetor de Lentivirus destaca várias vias motoras na medula espinhal de ratos

Introducing proteins of interest into cells in the nervous system is challenging due to innate biological barriers that limit access to most molecules. ...

Conversion of Human Induced Pluripotent Stem Cells (iPSCs) into Functional Spinal and Cranial Motor Neurons Using PiggyBac Vectors

We describe here a method to obtain functional spinal and cranial motor neurons from human induced pluripotent stem cells (iPSCs). Direct conversion into motor neuron is obtained by ectopic expression of alternative modules of transcription factors, namely Ngn2, Isl1 and Lhx3 (NIL) or Ngn2, Isl1 and Phox2a (NIP). NIL and NIP specify, respectively, spinal and cranial motor neuron identity. Our protocol starts with the generation of modified iPSC lines in which NIL or NIP are stably integrated in the genome via a piggyBac transposon vector. Expression of the transgenes is then induced by doxycycline and leads, in 5 days, to the conversion of iPSCs into MN progenitors. Subsequent maturation, for 7 days, leads to homogeneous populations of spinal or cranial MNs. Our method holds several advantages over previous protocols: it is extremely rapid and simplified; it does not require viral infection or further MN isolation; it allows generating different MN subpopulations (spinal and cranial) with a remarkable degree of maturation, as demonstrated by the ability to fire trains of action potentials. Moreover, a large number of motor neurons can be obtained without purification from mixed populations. iPSC-derived spinal and cranial motor neurons can be used for in vitro modeling of Amyotrophic Lateral Sclerosis and other neurodegenerative diseases of the motor neuron. Homogeneous motor neuron populations might represent an important resource for cell type specific drug screenings.

Conversion of Human Induced Pluripotent Stem Cells iPSCs into Functional Spinal and Cranial Motor Neurons Using PiggyBac Vectors

This protocol allows rapid and efficient conversion of induced pluripotent stem cells into motor neurons with a spinal or cranial identity, by ectopic expression of transcription factors from inducible piggyBac vectors.

Conversão de pilhas de haste pluripotentes induzidas humanas (iPSCs) em neurônios de motor espinal e craniano funcionais usando vetores de PiggyBac

We describe here a method to obtain functional spinal and cranial motor neurons from human induced pluripotent stem cells (iPSCs). Direct conversion into ...

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 ...