Name: stereotaxic surgery for genetic manipulation in striatal cells of neonatal mouse brains
Uploaded: 2018-07-10T12:30:00.000+00:00
Duration: 9 min 44 s
Description: Watch this Scientific Journal Video about Stereotaxic Surgery for Genetic Manipulation in Striatal Cells of Neonatal Mouse Brains at JoVE.com

Este trabalho foi financiado pelo Ministério da ciência e tecnologia concede MOST104-2311-B-010-010-MY3, MOST106-2321-B-010-012, os institutos de pesquisa de saúde nacional conceder INDH-EX106-10429NI e programa de centro de pesquisa de áreas Indicados: concessão de o Ministério da educação, através do centro de pesquisa do cérebro, National Yang-Ming University, em Taiwan, e pós-doutorado concede MOST106-2811-B-010-031 (S.-Yc), MOST105-2811-B-010-036 e MOST106-2811-B-010-030 (YK-H.).

Os protocolos de animais descritos aqui foram aprovados pelo cuidado Animal e uso comissões da Universidade Nacional de Yang-Ming.
1. preparação do titular para filhotes Neonatal no aparato estereotáxica
<ol><li>Fazer a cabeça da bandeja: cortar o fundo de um tubo de centrífuga de 1,5 mL (15 mm de comprimento) na forma que se encaixa a cabeça dos filhotes neonatais através da remoção de 1/5 da parede do tubo.</li>
	<li>Pegue uma caixa de ponta de pipeta com o tamanho certo que se encaixa com o pedestal de aparelhos estereotáxicos e remover a tampa superior. Fixe a cabeça bandeja preparada no passo 1.1 e um estojo de incorporação de tecido na base da bandeja de ponta com adesivo dederretimento. A altura da fita tecido incorporação é de 7 mm, que é usado para suportar do filhote pescoço e corpo na posição de cabeça-corrigido.</li>
	<li>Coloque toda a configuração em um aparelho padrão estereotáxica.</li>
</ol>2. preparação de agulhas de aço inoxidável de injeção 30g
<ol><li>Limpeza prévia 30 agulhas de seringa G embebendo-os no clorofórmio durante 3 dias.</li>
	<li>Use fórceps para lentamente e com cuidado retire a agulha do seu hub de polipropileno em uma capa de química.</li>
	<li>Lave as agulhas com etanol absoluto por 20 min, seguido de lavagens de etanol 70% para 3 × 10 min num agitador a 50 rpm. Deixe o ar de agulhas para secar e armazenar as agulhas limpas em uma caixa limpa, à temperatura ambiente (RT) até o uso.</li>
</ol>3. prepare um adaptador para tubos de Microinjection
<ol><li>Conecte a seringa de microlitro de uma agulha de injeção de 30G com um tubo de polietileno PE10 (PE10 tubo). Prepare um adaptador de tubo (tubo PE20) PE20 polietileno para colmatar a agulha e a seringa microlitro. O uso do adaptador é necessário, porque o diâmetro do tubo PE10 é muito menor do que a agulha da seringa microlitro 26G.</li>
	<li>Preparar o tubo para a seringa de microlitro: Conecte a agulha de injeção de 30g previamente limpos com 5 cm de tubo PE20 e selar a junção com cola instantânea. Este adaptador de tubo é reutilizável. Nota: Se a agulha da seringa de microinjeção 30G, a preparação (passo 3.1) e o uso (passo 3.3) deste adaptador não é necessário.</li>
	<li>Conecte o adaptador de tubo (preparado no passo 3.1) com uma seringa de microlitro (10 µ l).</li>
	<li>Conecte uma extremidade do tubo PE10 (não mais de 60 cm) sobre a agulha 30G do adaptador de tubo PE20. Monte uma nova agulha de injeção de 30g na outra extremidade do tubo PE10.</li>
</ol>4. carregar o Microinjection tubo com água destilada esterilizada, corante e vírus
<ol><li>Remova o êmbolo da seringa microlitro. Use uma seringa 25g para carregar a seringa microlitro e seu tubo PE conectado com água destilada esterilizada para remover o ar do tubo.</li>
	<li>Coloque o êmbolo volta à seringa microlitro e empurrar o êmbolo até 2 µ l de água destilada permanece no cano. Não deixe que o volume de água destilada, tornar-se inferior a 2 µ l.</li>
	<li>Monte cuidadosamente a seringa microlitro para a bomba de seringa de taxa de fluxo micro.</li>
	<li>Pipetar pequenas quantidades de corante rápido verde de 0.1% (preparada em soro fisiológico a 0,9% e filtrada com filtro de 0,22 µm) e os líquidos de vírus para um pedaço de parafilme.</li>
	<li>Retire uma pequena quantidade de ar tornar visível uma bolha de ar na junção entre a agulha de injeção de 30g e PE10 tubo seguido por 0,7 µ l de filtrado verde rápido a carregar para dentro do tubo para testar o fluxo de fluidos em tubulação microinjeção.</li>
	<li>Retire outra pequena quantidade de ar para fazer uma bolha de ar segunda seguida por carregar os líquidos de vírus para o tubo de microinjeção.</li>
	<li>Anexar e fixe a agulha de microinjeção de 30g para o braço do aparelho estereotáxica.</li>
</ol>5. anestesia de ratos Neonatal por hipotermia
<ol><li>Coloque o filhote em uma luva de látex da luva e mergulhe-a em gelo picado até o pescoço por 5 min.</li>
	<li>Belisca os pés do filhote com fórceps para certificar-se de não resposta de retirada de seus pés.</li>
	<li>Coloque o filhote com luva de látex luva na bandeja da cabeça e Coloque gelo triturado em torno a luva de látex para mantê-lo frio para anestesia de hipotermia.</li>
	<li>Aplica o vet pomada nos olhos do filhote para evitar ressecamento enquanto sob anestesia, se possível.</li>
</ol>6. microinjection
<ol><li>Prepare a cirurgia estéril limpando o instrumento estereotáxica com etanol a 70%. Esterilize o instrumento cirúrgico imergindo-os em etanol a 70%.</li>
	<li>Esfrega a cabeça do filhote com 70% de etanol. Localizar o lambda de marco no crânio e marcar o lambda com uma caneta. Aponte a ponta da agulha para o lambda e definir o ântero-posterior (AP) e médio-lateral (ML) coordenadas como zero.</li>
	<li>Mova o braço para injeções no site de destino de acordo com as coordenadas X e Y do local de destino. Para o corpo estriado do dia pós-natal (P) 2 filhotes, as coordenadas são: AP, +2,4 mm anterior o lambda; ML, 1,0 milímetros lateral da linha média; dorso-ventral (DV), −1.7 mm do crânio. Marca a posição de corante verde rápido em PE10 tubo com uma caneta.</li>
	<li>Trazer a agulha de injeção de 30g lentamente penetrar através da pele e o crânio e então trazer a ponta da agulha até que ele para na superfície do crânio. Defina a coordenada DV como zero.</li>
	<li>Derrubar a agulha 30G lentamente até atingir a coordenada DV do local de destino. Espere 1 min permitir que o parênquima, retomando a sua forma normal. Execute o programa de microinjeção (100 nL/min).</li>
	<li>Certifique-se de que a marca da tintura verde rápido está se movendo no tubo de PE, para garantir que o líquido do vírus é injetado no cérebro.</li>
	<li>Aguardar 1 min após o término da microinjeção e então lentamente e progressivamente trazer a agulha até a altura de 1/2 de profundidade DV dentro de 30 s. Após 30 s, lentamente, retirar a agulha da cabeça do filhote.</li>
	<li>Repita o passo 6.2 a 6.7 até os alevinos de todos os sites alvo sejam concluídos.</li>
</ol>7. pós-cirúrgica recuperação do filhote
<ol><li>Aquecer o filhote por 20 min em uma incubadora de 33 ° C. Verificar a recuperação do filhote da anestesia hipotermia cada 5 min até que o filhote recuperou a consciência suficiente para manter a prostração esternal.</li>
	<li>Retorna o filhote para a barragem, depois que o filhote está totalmente recuperado.</li>
</ol>

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No presente estudo, vamos demonstrar um método simples e confiável de estereotáxica para injetar o vírus AAV para o corpo estriado do cérebro do rato neonatal. Nós injetadas vírus AAV-eGFP-Cre para o corpo estriado de ratos de repórter Ai14 em P2 e então analisados a expressão do gene repórter no P14. Nós encontramos que AAV transfectadas células GFP-positivo em todo o corpo estriado em níveis rostrocaudal. Além disso, quase todas as células GFP-positivo co expressaram o gene do repórter de tdTomato nas ...

Estudos modernos da estrutura e função do cérebro normalmente requerem manipulação genética de genes específicos nas células neuronais. Para sondar as funções dos genes diferentes, ratos transgénicos carregando alelos mutantes, incluindo foram rotineiramente gerados nocaute e bater-em alelos. Cirurgia cerebral estereotáxica para roedores adultos é um método padrão para localmente entregar drogas, vírus, marcadores e outros reagentes para regiões específicas do cérebro de roedor1,2. Aplicando a cirurgia estereotáxica cerebral de ratos transgénicos permite um de manipular geneticamente a função dos genes e a atividade neuronal em específicas populações neuronais do cérebro do rato. A manipulação do tipo específico de célula fornece uma poderosa abordagem para decifrar funções neuronais em complexos circuitos neurais do cérebro3,,4,5.
Desenvolvimento neural do sistema nervoso começa em estágios embrionários iniciais, e os processos de desenvolvimento continuam após o nascimento, até o período juvenil. Maturação pós-natal do sistema nervoso inclui a fiação sináptica precisa de circuitos neurais, que é essencial para funções fisiológicas e cognitivas do cérebro6. Portanto, estudar o desenvolvimento eventos que ocorrem em janelas de tempo neonatal é importante não só para compreender o desenvolvimento neural normal, mas também pode fornecer insights sobre a patogênese do desenvolvimento neurológico e transtornos neuropsiquiátricos7 ,8. Embora os métodos de cirurgia cerebral estereotáxica para roedores adultos estão prontamente disponíveis2,9, alguns protocolos estão disponíveis na internet para uma cirurgia estereotáxica cerebral em ratos neonatal10,11. Na verdade, estereotáxicos microinjeções de reagentes no cérebro de filhotes de rato neonatal são difíceis, porque a cabeça do filhote neonatal é demasiado frágil para ser fixada no aparelho estereotáxica padrão. No entanto, a aplicação da cirurgia estereotáxica cerebral de ratos transgênicos é viável para ratos neonatal12. Aqui, descrevemos um método simples com uma armadilha caseira para realizar cirurgia cerebral estereotáxica em filhotes de rato recém-nascido. Vamos demonstrar que essa técnica permite excluir condicionalmente genes de floxed por microinjecting recombinase AAV-expressando Cre DNA para o corpo estriado de ratos de gene repórter e condicionalmente floxed ratos transgénicos. Esta técnica também é aplicável para entregar os reagentes para o neonatal corpo estriado de ratos tipo selvagem.

<table><tbody><tr><td>30G PrecisionGlide Needle</td><td>Becton Dickinson</td><td>REF 305106</td><td></td></tr><tr><td>Chloroform</td><td>JT Baker</td><td>9180-03</td><td></td></tr><tr><td>Hamilton MICROLITER Syringe</td><td>Hamilton&amp;nbsp;</td><td>80300</td><td>30G needle fit for PE10 tube; 26G needle needs a PE20 adaptor</td></tr><tr><td>Polyethylene tubing PE20</td><td>Becton Dickinson</td><td>427406</td><td></td></tr><tr><td>Polyethylene tubing PE10</td><td>Becton Dickinson</td><td>427401</td><td></td></tr><tr><td>Micro Flow Rate Syringe Pump</td><td>Longer Precision Pump Co.</td><td>TJ-2A (Controller) and L0107-2A (Drive Unit)</td><td></td></tr><tr><td>25G syringe</td><td>Becton Dickinson</td><td>REF 302105</td><td></td></tr><tr><td>Fast green</td><td>Sigma-Aldrich</td><td>F-7252</td><td>0.1%</td></tr><tr><td>Standard Stereotaxic Instruments</td><td>RWD Life Science</td><td>68037</td><td>Without using 68030 Mouse/Neonatal Rat Adaptor</td></tr><tr><td>Anti-FOXP2 antibody</td><td>Abcam</td><td>ab16046</td><td>Rabbit polyclonal to FOXP2, 1:4,000</td></tr><tr><td>Anti-RFP antibody</td><td>Abcam</td><td>ab65856</td><td>Mouse monoclonal to RFP, 1:1,000</td></tr><tr><td>BX63 microscope</td><td>Olympus</td><td>BX63</td><td></td></tr><tr><td>LSM 880 confocal microscope</td><td>Zeiss</td><td>LSM 880</td><td></td></tr><tr><td>Goat anti-rabbit conjugated Alexa fluor594</td><td>Jackson lmmunoReserch Laboratories Inc.</td><td>111-585-003</td><td></td></tr><tr><td>AAV9.hSynapsin.HI.eGFP-Cre.WPRE.SV40</td><td>Penn Vector Core</td><td>AV-9-PV1848</td><td>Lot # CS0987, 5.506x10&lt;sup&gt;13&lt;/sup&gt; (GC/mL)</td></tr><tr><td>AAV9.chicken actin-eGFP</td><td>AAV core, Institute of Biomedical Sciences, Academia Sinica, Taiwan</td><td>N/A</td><td>1x10&lt;sup&gt;14&lt;/sup&gt; (GC/ml)</td></tr><tr><td>B6.Cg-Gt(ROSA)26Sortm14(CAG-tdTomato)Hze/J</td><td>The Jackson Labtorary&amp;nbsp;</td><td>007914</td><td>Ai14</td></tr><tr><td>B6(Cg)-Foxp2tm1.1Sfis/CfreJ</td><td>The Jackson Labtorary&amp;nbsp;</td><td>026259</td><td>Foxp2&lt;sup&gt;fl/fl&lt;/sup&gt;</td></tr><tr><td>Dulbecco&amp;rsquo;s phosphate buffered saline</td><td>Corning&amp;nbsp;cellgro</td><td>21-030-CVR</td><td></td></tr></tbody></table>

stereotaxic surgery for genetic manipulation in striatal cells of neonatal mouse brains

Muitos genes são expressos no cérebro embrionário, e alguns deles são continuamente expressas no cérebro após o nascimento. Para tais genes persistentemente expressos, eles podem funcionar para regular o processo de desenvolvimento e/ou função fisiológica no cérebro neonatal. Para investigar as funções neurobiológicas de genes específicos no cérebro, é essencial para inativar genes no cérebro. Aqui, descrevemos um método simples estereotáxica para inactivar a expressão gênica no corpo estriado de ratos transgênicos em janelas de tempo neonatal. O vírus AAV-eGFP-Cre foram injetado para o corpo estriado de ratos de gene repórter Ai14 em dia pós-natal (P) 2 por cirurgia cerebral estereotáxica. A expressão do gene repórter tdTomato foi detectada no corpo estriado de P14, sugerindo um sucesso Cre-loxP mediada por recombinação de DNA em células transfectadas-AAV striatal. Nós validado ainda mais esta técnica por microinjecting o vírus AAV-eGFP-Cre em camundongos P2Foxp2fl/fl . Dupla rotulagem de GFP e Foxp2 mostrou que as células GFP-positivo faltavam Foxp2 imunorreatividade no corpo estriado P9, sugerindo que a perda de proteína Foxp2 em AAV-eGFP-Cre transfectada striatal células. Tomados em conjunto, estes resultados demonstram uma exclusão genética eficaz por stereotaxically microinjected vírus AAV-eGFP-Cre em específicas populações neuronais no cérebro neonatal de floxed ratos transgénicos. Em conclusão, nossa técnica estereotáxica fornece uma plataforma simples e fácil para manipulação genética em cérebro de rato neonatal. A técnica não pode somente ser usada para excluir genes em regiões específicas do cérebro neonatal, mas também pode ser usada para injetar drogas farmacológicas, marcadores neuronais, optogenetics geneticamente modificados e chemogenetics proteínas, indicadores de atividade neuronal e outros reagentes para o corpo estriado do cérebro do rato neonatal.

Para o primeiro conjunto de experiência, nós injetadas 200 nL de AAV9.hSynapsin.HI.eGFP-Cre.WPRE.SV40 vírus (AAV-eGFP-Cre, diluição de 1/10 em solução salina de tampão fosfato de Dulbecco) que expressam a recombinase Cre DNA fundidos com GFP em P2 corpo estriado de ratos Ai14. Os ratos Ai14 expressam tdTomato gene repórter sobre exclusão Cre-mediada de loxP-flanqueado (floxed) STOP gaveta (Figura 2F). Os cérebros foram colhidos no P14 para imunocol...

Watch this Scientific Journal Video about Stereotaxic Surgery for Genetic Manipulation in Striatal Cells of Neonatal Mouse Brains at JoVE.com

Stereotaxic Surgery for Genetic Manipulation in Striatal Cells of Neonatal Mouse Brains

Cirurgia estereotáxica para manipulação genética em células estriadas de cérebro de rato Neonatal

Descreveremos um protocolo de cirurgia estereotáxica com um dispositivo caseiro de cabeça-corrigido para reagentes microinjecting para o corpo estriado do cérebro do rato neonatal. Esta técnica permite a manipulação genética em células neuronais de regiões específicas do cérebro de rato neonatal.

Many genes are expressed in embryonic brains, and some of them are continuously expressed in the brain after birth. For such persistently expressed genes, ...

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Research

JoVE Journal

Neuroscience

14.8K visualizações.  National Yang-Ming University. Descreveremos um protocolo de cirurgia estereotáxica com um dispositivo caseiro de cabeça-corrigido para reagentes microinjecting para o corpo estriado do cérebro do rato neonatal. Esta técnica permite a manipulação genética em células neuronais de regiões específicas do cérebro de rato neonatal.

Vídeo: Stereotaxic Surgery for Genetic Manipulation in Striatal Cells of Neonatal Mouse Brains

Stable and Efficient Genetic Modification of Cells in the Adult Mouse V-SVZ for the Analysis of Neural Stem Cell Autonomous and Non-autonomous Effects

Relatively quiescent somatic stem cells support life-long cell renewal in most adult tissues. Neural stem cells in the adult mammalian brain are restricted to two specific neurogenic niches: the subgranular zone of the dentate gyrus in the hippocampus and the ventricular-subventricular zone (V-SVZ; also called subependymal zone or SEZ) in the walls of the lateral ventricles. The development of in vivo gene transfer strategies for adult stem cell populations (i.e. those of the mammalian brain) resulting in long-term expression of desired transgenes in the stem cells and their derived progeny is a crucial tool in current biomedical and biotechnological research. Here, a direct in vivo method is presented for the stable genetic modification of adult mouse V-SVZ cells that takes advantage of the cell cycle-independent infection by LVs and the highly specialized cytoarchitecture of the V-SVZ niche. Specifically, the current protocol involves the injection of empty LVs (control) or LVs encoding specific transgene expression cassettes into either the V-SVZ itself, for the in vivo targeting of all types of cells in the niche, or into the lateral ventricle lumen, for the targeting of ependymal cells only. Expression cassettes are then integrated into the genome of the transduced cells and fluorescent proteins, also encoded by the LVs, allow the detection of the transduced cells for the analysis of cell autonomous and non-autonomous, niche-dependent effects in the labeled cells and their progeny.

Here we describe a procedure based on the use of lentiviral particles for the long-term genetic modification of neural stem cells and/or their adjacent ependymal cells in the adult ventricular-subventricular neurogenic niche which allows the separate analysis of cell autonomous and non-autonomous, niche-dependent effects on neural stem cells.

Estável e eficiente modificação genética de células do rato adulto V-SVZ para a Análise da Neural Stem Cell Autónoma e Efeitos não autónomos

Relatively quiescent somatic stem cells support life-long cell renewal in most adult tissues. Neural stem cells in the adult mammalian brain are ...

Biologia do Desenvolvimento

Stereotaxic Surgery for Excitotoxic Lesion of Specific Brain Areas in the Adult Rat

Many behavioral functions in mammals, including rodents and humans, are mediated principally by discrete brain regions. A common method for discerning the function of various brain regions for behavior or other experimental outcomes is to implement a localized ablation of function. In humans, patient populations with localized brain lesions are often studied for deficits, in hopes of revealing the underlying function of the damaged area. In rodents, one can experimentally induce lesions of specific brain regions.
Lesion can be accomplished in several ways. Electrolytic lesions can cause localized damage but will damage a variety of cell types as well as traversing fibers from other brain regions that happen to be near the lesion site. Inducible genetic techniques using cell-type specific promoters may also enable site-specific targeting. These techniques are complex and not always practical depending on the target brain area. Excitotoxic lesion using stereotaxic surgery, by contrast, is one of the most reliable and practical methods of lesioning excitatory neurons without damaging local glial cells or traversing fibers.
Here, we present a protocol for stereotaxic infusion of the excitotoxin, N-methyl-D-aspartate (NMDA), into the basolateral amygdala complex. Using anatomical indications, we apply stereotaxic coordinates to determine the location of our target brain region and lower an injection needle in place just above the target. We then infuse our excitotoxin into the brain, resulting in excitotoxic death of nearby neurons. While our experimental subject of choice is a rat, the same methods can be applied to other mammals, with the appropriate adjustments in equipment and coordinates.
This method can be used on a variety of brain regions, including the basolateral amygdala1-6, other amygdala nuclei6, 7, hippocampus8, entorhinal cortex9 and prefrontal cortex10. It can also be used to infuse biological compounds such as viral vectors1, 11. The basic stereotaxic technique could also be adapted for implantation of more permanent osmotic pumps, allowing more prolonged exposure to a compound of interest.

Targeted ablation of specific brain region(s) by infusion of an excitotoxin using stereotaxic coordinates is described. This technique could also be adapted for infusion of other chemicals into the rat brain.

Cirurgia estereotáxica para lesão excitotóxica de áreas específicas do cérebro do rato adulto

Many behavioral functions in mammals, including rodents and humans, are mediated principally by discrete brain regions. A common method for discerning the ...

Neurociência

Expansion of Embryonic and Adult Neural Stem Cells by In Utero Electroporation or Viral Stereotaxic Injection

Somatic stem cells can divide to generate additional stem cells (expansion) or more differentiated cell types (differentiation), which is fundamental for tissue formation during embryonic development and tissue homeostasis during adulthood 1. Currently, great efforts are invested towards controlling the switch of somatic stem cells from expansion to differentiation because this is thought to be fundamental for developing novel strategies for regenerative medicine 1,2. However, a major challenge in the study and use of somatic stem cell is that their expansion has been proven very difficult to control.
Here we describe a system that allows the control of neural stem/progenitor cell (altogether referred to as NSC) expansion in the mouse embryonic cortex or the adult hippocampus by manipulating the expression of the cdk4/cyclinD1 complex, a major regulator of the G1 phase of the cell cycle and somatic stem cell differentiation 3,4. Specifically, two different approaches are described by which the cdk4/cyclinD1 complex is overexpressed in NSC in vivo. By the first approach, overexpression of the cell cycle regulators is obtained by injecting plasmids encoding for cdk4/cyclinD1 in the lumen of the mouse telencephalon followed by in utero electroporation to deliver them to NSC of the lateral cortex, thus, triggering episomal expression of the transgenes 5-8. By the second approach, highly concentrated HIV-derived viruses are stereotaxically injected in the dentate gyrus of the adult mouse hippocampus, thus, triggering constitutive expression of the cell cycle regulators after integration of the viral construct in the genome of infected cells 9. Both approaches, whose basic principles were already described by other video protocols 10-14, were here optimized to i) reduce tissue damage, ii) target wide portions of very specific brain regions, iii) obtain high numbers of manipulated cells within each region, and iv) trigger high expression levels of the transgenes within each cell. Transient overexpression of the transgenes using the two approaches is obtained by different means i.e. by natural dilution of the electroporated plasmids due to cell division or tamoxifen administration in Cre-expressing NSC infected with viruses carrying cdk4/cyclinD1 flanked by loxP sites, respectively 9,15.
These methods provide a very powerful platform to acutely and tissue-specifically manipulate the expression of any gene in the mouse brain. In particular, by manipulating the expression of the cdk4/cyclinD1 complex, our system allows the temporal control of NSC expansion and their switch to differentiation, thus, ultimately increasing the number of neurons generated in the mammalian brain. Our approach may be critically important for basic research and using somatic stem cells for therapy of the mammalian central nervous system while providing a better understanding of i) stem cell contribution to tissue formation during development, ii) tissue homeostasis during adulthood, iii) the role of adult neurogenesis in cognitive functions, and perhaps, iv) better using somatic stem cells in models of neurodegenerative diseases.

Expansion of Embryonic and Adult Neural Stem Cells by In Utero Electroporation or Viral Stereotaxic Injection

Controlling the expansion of somatic stem cells is a major factor hampering their study and use in therapy. Here we describe a system to temporally control neural stem cells expansion during development and adulthood, which can be used to increase the number of neurons generated in the mouse brain.

Expansão da embrionárias e adultas células-tronco neurais por<em&gt; In Utero</em&gt; Eletroporação ou injeção estereotáxica Viral

Somatic stem cells can divide to generate additional stem cells (expansion) or more differentiated cell types (differentiation), which is fundamental for ...

Stereotaxic Injection of a Viral Vector for Conditional Gene Manipulation in the Mouse Spinal Cord

Intraparenchymal injection of a viral vector enables conditional gene manipulation in distinct populations of neurons or particular regions of the central nervous system. We demonstrate a stereotaxic injection technique that allows targeted gene expression or silencing in the dorsal horn of the mouse spinal cord. The surgical procedure is brief. It requires laminectomy of a single vertebra, providing for quick recovery of the animal and unimpaired motility of the spine. Controlled injection of a small vector suspension volume at low speed and use of a microsyringe with beveled glass cannula minimize the tissue lesion. The local immune response to the vector depends on the intrinsic properties of the virus employed; in our experience, it is minor and short-lived when a recombinant adeno-associated virus is used. A reporter gene such as enhanced green fluorescent protein facilitates monitoring spatial distribution of the vector, and the efficacy and cellular specificity of the transfection.

Viral vectors allow for targeted gene manipulation. We demonstrate a method for conditional gene expression or ablation in the mouse spinal cord, using stereotaxic injection of a viral vector into the dorsal horn, a prominent site of synaptic contact between primary somatosensory afferents and neurons of the central nervous system.

Injeção estereotáxica de um vetor viral para manipulação genética condicional no Cabo de Rato Spinal

Intraparenchymal injection of a viral vector enables conditional gene manipulation in distinct populations of neurons or particular regions of the central ...

Genetic Manipulation of the Mouse Developing Hypothalamus through In utero Electroporation

Genetic modification of specific regions of the developing mammalian brain is a very powerful experimental approach. However, generating novel mouse mutants is often frustratingly slow. It has been shown that access to the mouse brain developing in utero with reasonable post-operatory survival is possible. Still, results with this procedure have been reported almost exclusively for the most superficial and easily accessible part of the developing brain, i.e. the cortex. The thalamus, a narrower and more medial region, has proven more difficult to target. Transfection into deeper nuclei, especially those of the hypothalamus, is perhaps the most challenging and therefore very few results have been reported. Here we demonstrate a procedure to target the entire hypothalamic neuroepithelium or part of it (hypothalamic regions) for transfection through electroporation. The keys to our approach are longer narcosis times, injection in the third ventricle, and appropriate kind and positioning of the electrodes. Additionally, we show results of targeting and subsequent histological analysis of the most recessed hypothalamic nucleus, the mammillary body.

Genetic Manipulation of the Mouse Developing Hypothalamus through In utero Electroporation

Despite the functional and medical importance of the hypothalamus, in utero genetic manipulation of its development has rarely been attempted. We show a detailed procedure for in utero electroporation into the mouse hypothalamus and show representative results of total and partial (regional) hypothalamic transfection.

Manipulação genética do rato em desenvolvimento Hipotálamo através<em&gt; In utero</em&gt; Eletroporação

Genetic  modification of specific regions of the developing mammalian brain is a very  powerful experimental approach. However, generating novel mouse ...

Intracerebroventricular Viral Injection of the Neonatal Mouse Brain for Persistent and Widespread Neuronal Transduction

With the pace of scientific advancement accelerating rapidly, new methods are needed for experimental neuroscience to quickly and easily manipulate gene expression in the mouse brain. Here we describe a technique first introduced by Passini and Wolfe for direct intracranial delivery of virally-encoded transgenes into the neonatal mouse brain. In its most basic form, the procedure requires only an ice bucket and a microliter syringe. However, the protocol can also be adapted for use with stereotaxic frames to improve consistency for researchers new to the technique. The method relies on the ability of adeno-associated virus (AAV) to move freely from the cerebral ventricles into the brain parenchyma while the ependymal lining is still immature during the first 12-24 hr after birth. Intraventricular injection of AAV at this age results in widespread transduction of neurons throughout the brain. Expression begins within days of injection and persists for the lifetime of the animal. Viral titer can be adjusted to control the density of transduced neurons, while co-expression of a fluorescent protein provides a vital label of transduced cells. With the rising availability of viral core facilities to provide both off-the-shelf, pre-packaged reagents and custom viral preparation, this approach offers a timely method for manipulating gene expression in the mouse brain that is fast, easy, and far less expensive than traditional germline engineering.

Here we demonstrate a technique for widespread neuronal transduction by intraventricular injection of adeno-associated virus into the neonatal mouse brain. This method provides a rapid and easy way to attain lifelong expression of virally-delivered transgenes.

Injection Viral intracerebroventricular do Neonatal do rato do cérebro para a transdução neuronal persistente e generalizada

With the pace of scientific advancement accelerating rapidly, new methods are needed for experimental neuroscience to quickly and easily manipulate gene ...

Cortex-, Hippocampus-, Thalamus-, Hypothalamus-, Lateral Septal Nucleus- and Striatum-specific In Utero Electroporation in the C57BL/6 Mouse

In utero electroporation is a widely used technique for fast and efficient spatiotemporal manipulation of various genes in the rodent central nervous system. Overexpression of desired genes is just as possible as shRNA mediated loss-of-function studies. Therefore it offers a wide range of applications. The feasibility to target particular cells in a distinct area further increases the range of potential applications of this very useful method. For efficiently targeting specific regions knowledge about the subtleties, such as the embryonic stage, the voltage to apply and most importantly the position of the electrodes, is indispensable.
Here, we provide a detailed protocol that allows for specific and efficient in utero electroporation of several regions of the C57BL/6 mouse central nervous system. In particular it is shown how to transfect regions the develop into the retrosplenial cortex, the motor cortex, the somatosensory cortex, the piriform cortex, the cornu ammonis 1-3, the dentate gyrus, the striatum, the lateral septal nucleus, the thalamus and the hypothalamus. For this information about the appropriate embryonic stage, the appropriate voltage for the corresponding embryonic stage is provided. Most importantly an angle-map, which indicates the appropriate position of the positive pole, is depicted. This standardized protocol helps to facilitate efficient in utero electroporation, which might also lead to a reduced number of animals.

Cortex-, Hippocampus-, Thalamus-, Hypothalamus-, Lateral Septal Nucleus- and Striatum-specific In Utero Electroporation in the C57BL/6 Mouse

This protocol describes in detail how to specifically transfect different regions in the C57BL/6 central nervous system via in utero electroporation. Included in this protocol are detailed instructions for transfections of regions that develop into the cortex, hippocampus, thalamus, hypothalamus, lateral septal nucleus and striatum.

Específicos do Striatum Cortex-, Hippocampus-, Thalamus-, Hypothalamus-, Lateral Septal Nucleus- e<em&gt; In Utero</em&gt; A electroporação em ratinhos C57BL / 6 mouse

In utero electroporation is a widely used technique for fast and efficient spatiotemporal manipulation of various genes in the rodent central nervous ...

Adaptable Angled Stereotactic Approach for Versatile Neuroscience Techniques

Stereotactic surgery is an essential tool in the modern neuroscience lab. However, the ability to precisely and accurately target difficult-to-reach brain regions still presents a challenge, particularly when targeting brain structures along the midline. These challenges include avoiding of the superior sagittal sinus and third ventricle and the ability to consistently target selective and discrete brain nuclei. In addition, more advanced neuroscience techniques (e.g., optogenetics, fiber photometry, and two-photon imaging) rely on targeted implantation of significant hardware to the brain, and spatial limitations are a common hindrance. Presented here is a modifiable protocol for stereotactic targeting of rodent brain structures using an angled coronal approach. It can be adapted to 1) mouse or rat models, 2) various neuroscience techniques, and 3) multiple brain regions. As a representative example, it includes the calculation of stereotactic coordinates for targeting of the mouse hypothalamic ventromedial nucleus (VMN) for an optogenetic inhibition experiment. This procedure begins with the bilateral microinjection of an adeno-associated virus (AAV) encoding a light-sensitive chloride channel (SwiChR++) to a Cre-dependent mouse model, followed by the angled bilateral implantation of fiberoptic cannulae. Using this approach, findings show that activation of a subset of VMN neurons is required for intact glucose counterregulatory responses to insulin-induced hypoglycemia.

Described here is a stereotactic procedure that can target challenging and difficult-to-reach brain regions (due to spatial limitations) using an angled coronal approach. This protocol is adaptable to both mouse and rat models and can be applied to diverse neuroscientific applications, including cannula implantation and microinjections of viral constructs.

Abordagem estereotática angular adaptável para técnicas versáteis de neurociência

Stereotactic surgery is an essential tool in the modern neuroscience lab. However, the ability to precisely and accurately target difficult-to-reach brain ...

Stereotaxic Intracranial Delivery of Chemicals, Proteins or Viral Vectors to Study Parkinson's Disease

Parkinson's disease (PD) is a progressive disorder traditionally defined by resting tremor and akinesia, primarily due to loss of dopaminergic neurons in the substantia nigra. Affected brain areas display intraneuronal fibrillar inclusions consisting mainly of alpha-synuclein (asyn) proteins. No animal model thus far has recapitulated all characteristics of this disease. Here, we describe the use of stereotaxic injection to deliver chemicals, proteins, or viral vectors intracranially in order to mimic various aspects of PD. These methods are well-established and widely used throughout the PD field. Stereotaxic injections are incredibly flexible; they can be adjusted in concentration, age of animal used for injection, brain area targeted and in animal species used. Combinations of substances allow for rapid variations to assess treatments or alter severity of the pathology or behavioral deficits. By injecting toxins into the brain, we can mimic inflammation and/or a severe loss of dopaminergic neurons resulting in substantial motor phenotypes. Viral vectors can be used to transduce cells to mimic genetic or mechanistic aspects. Preformed fibrillar asyn injections best recapitulate the progressive phenotype over an extended period of time. Once these methods are established, it can be economical to generate a new model compared to creating a new transgenic line. However, this method is labor intensive as it requires 30 minutes to four hours per animal depending on the model used. Each animal will have a slightly different targeting and therefore create a diverse cohort which on one hand can be challenging to interpret results from; on the other hand, help mimic a more realistic diversity found in patients. Mistargeted animals can be identified using behavioral or imaging readouts, or only after being sacrificed leading to smallercohort size after the study has already been concluded. Overall, this method is a rudimentary but effective way to assess a diverse set of PD aspects.

We describe how to successfully inject solutions into specific brain areas of rodents using a stereotaxic frame. This survival surgery is a well-established method used to mimic various aspects of Parkinson's disease.

Parkinson's disease (PD) is a progressive disorder traditionally defined by resting tremor and akinesia, primarily due to loss of dopaminergic neurons in ...

Rodent Stereotaxic Surgery

Stereotaxic (or stereotactic) surgery is a method used to manipulate the brain of living animals. This technique allows researchers to accurately target deep structures within the brain through the use of a stereotaxic atlas, which provides the 3D coordinates of each area with respect to anatomical landmarks on the skull. After the skull is exposed, anesthetized animals are mounted on a specialized instrument known as a stereotaxic frame, which enables the precise placement of experimental tools at the defined coordinates. Stereotaxic surgery is a versatile approach that can be used to generate lesions, manipulate gene expression, or deliver experimental agents to the brain.This video-article provides a general overview of the principles behind stereotaxic surgery, including instructions for using a stereotaxic atlas and the stereotaxic frame, and an introduction to reading the Vernier scale for measurement of probe movements. The subsequent discussion outlines the steps required to perform the surgical procedure. Lastly, a broad range of technical applications are presented, such as the insertion of electrical probes to measure brain activity and genetic manipulation of brain tissue.

Cirurgia Estereotáxica em Roedores

Stereotaxic (or stereotactic) surgery is a method used to manipulate the brain of living animals. This technique allows researchers to accurately target ...

Cirurgia estereotáxica para manipulação genética em células estriadas de cérebro de rato Neonatal

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