Este trabalho foi financiado pelo NINDS - NIH R01NS060756

1. Antes de iniciar a preparação de fatias do hipocampo. <ol><li> Prepare o slicer tecido, colocando um pedaço de folha de teflon e montagem de uma nova lâmina. </li><li> Limpe a cultura de tecidos capô (TC) com etanol 70% e definir o interior microscópio de dissecação. Esterilizar o capô, microscópio, slicer tecido e todos os instrumentos de dissecação por 15 minutos com a luz UV. </li><li> Preparar seis pratos bem TC. Adicionar 750 mL da cultura de mídia fatia (SCM) por bem e colocar insere cultura de células em cada poço. Certifique-se que as membranas são completamente molhado com nenhuma bolha por baixo. Coloque as placas em estufa a 35 ° C gaseados com 5% de CO 2 até necessário. </li><li> Despeje 50 mL baixo Na + ACSF (dissecando solução) em um copo de 100 ml e coloque-o no gelo sal-mix. A bolha baixo Na + ACSF com 5% de CO 2 / 95% O 2 até que muda de cor e formas ACSF uma mistura de chorume de solução congelada e líquidos (10-20 min). </li><li> Obter um rato P5-P7 filhote. Até três filhotes podem ser usados. </li></ol> 2. Preparação fatias do hipocampo. <ol><li> Cortar a cabeça do animal com uma tesoura afiada utilitário. Cortar a pele e expor o crânio. Abrir o crânio, cortando de lado a lado ao longo da linha interaural e depois ao longo da sutura sagital com uma tesoura pequena. Um corte opcional de lado a lado na frente pode ser feito para facilitar a remoção dos ossos e da exposição do cérebro. Retire o cérebro rapidamente com uma espátula colher arredondada micro e colocá-lo na pasta de dissecar solução para refrigerar para ~ 1 minuto. Despeje ~ 10 mL de solução gelada de dissecação em um prato de 60 mm e transferir o cérebro do copo ao prato. O cérebro deve ser coberto com dissecação solução. </li><li> Sob o microscópio de dissecação: Coloque o cérebro e mantê-lo na linha média com a pinça de dissecação pressionado para o fundo do prato de 60 mm. Use a ferramenta de hipocampo de dissecação para separar os hemisférios deixando de fora o mesencéfalo. O hipocampo são expostos em cada hemisfério. Então suavemente colher o hipocampo com o hipocampo dissecar ferramenta. Use a agulha de dissecação para isolar completamente o hipocampo e limpá-lo, tanto quanto possível. </li><li> Usando uma ponta de um snipped P1000 ponteira de filtro, aspirar cuidadosamente o hipocampo e transferi-lo para a folha de Teflon na slicer tecido. Posição do hipocampo em seu lado côncavo. </li><li> Alinhar o hipocampo perpendicular à lâmina para obtenção de cortes coronal e drenar o excesso de líquido. </li><li> Corte o hipocampo cada mM 400. </li><li> Despeje ~ 10 mL frio SCM em um prato de 60 mm e de transferência de fatias do hipocampo slicer usando outro snipped P1000 ponta de filtro e frio SCM. Evite fazer bolhas. </li><li> Com a ajuda de uma espátula de íris e uma espátula reta separar delicadamente as fatias do outro. </li><li> Separe fatias bem definidos e sem danos de fatias danificado. </li></ol> 3. Cultura fatias do hipocampo <ol><li> Trazer as placas de seis bem com SCM e inserções de cultura de células da incubadora. Com a ajuda de uma outra ponta P1000 snipped filtro, transferência de fatias individuais para a membrana. Coloque fatias de 4-5 por membrana. Tenha cuidado para não colocar as fatias ou perto da parede inserir ou próximos uns dos outros. Quando necessário, use uma espátula de íris em fatias separadas. Remova o meio de excesso. Toque fatias tão pouco quanto possível uma vez que estão na membrana. </li><li> Mova placa de volta para incubadora e cultura a 35 ° CO C e 5% 2. </li><li> Alterar SCM cada 48 horas no interior do capô TC por aspiração do SCM com uma pipeta Pasteur. Adicionar 750 mL de produtos frescos pré-aquecido SCM por poço. Verifique se não há bolhas são formadas sob a membrana. </li></ol> 4. Soluções <ol><li> Baixa Na + ACSF - Solução Dissecting para culturas fatia Para deionizada e estéril H 2 O add: <table border="1"><tbody><tr><td></td><td> Para 500 mL </td><td> Para 1000 mL </td><td> Concentração Final </td></tr><tr><td> CaCl 2 (1 M) </td><td> 0,5 mL </td><td> 1 mL </td><td> 1 mM </td></tr><tr><td> D-Glicose </td><td> 0,901 g </td><td> 1,802 g </td><td> 10 mM </td></tr><tr><td> KCl </td><td> 0,149 g </td><td> 0,298 g </td><td> 4 mM </td></tr><tr><td> MgCl 2 (1 M) </td><td> 2,5 mL </td><td> 5 mL </td><td> 5 mM </td></tr><tr><td> NaHCO 3 </td><td> 1,092 g </td><td> 2,184 g </td><td> 26 mM </td></tr><tr><td> Sacarose </td><td> 40 g </td><td> 80 g </td><td> 234 mM </td></tr><tr><td> Solução Vermelho de fenol 0,5% em DPBS </td><td> 0,5 mL </td><td> 1 mL </td><td> 0,1% v / v </td></tr></tbody></table> Mix ~ 30 min Sterilize pela passagem através de filtro de 0.22μm Fazer 50 mL alíquotas e armazenar a 4 ° C no máximo dois meses. </li><li> Médio fatia Cultura (SCM) <table border="1"><tbody><tr><td></td><td> Para 500 mL </td><td> Para 1000 mL </td><td> Concentração Final </td></tr><tr><td> MEM de Eagle médio </td><td> 4,2 g </td><td> 8,4 g </td><td> 8,4 g / l </td></tr><tr><td> Cavalo de calor soro inativado </td><td> 100 mL </td><td> 200 mL </td><td> 20% </td></tr><tr><td> L-Glutamina (200 mM) </td><td> 2,5 mL </td><td> 5 mL </td><td> 1 mM </td></tr><tr><td> CaCl 2 (1 M) </td><td> 0,5 mL </td><td> 1 mL </td><td> 1 mM </td></tr><tr><td> MgSO 4 (1 M) </td><td> 1 mL </td><td> 2 mL </td><td> 2 mM </td></tr><tr><td> Insulina (1 mg / mL), dissolvido em HCl 0,01 N </td><td> 0,5 mL </td><td> 1 mL </td><td> 1 mg / l </td></tr><tr><td> Ácido ascórbico, solução (25% w / v) </td><td> 0,024 mL </td><td> 0,048 mL </td><td> 0,00125% </td></tr><tr><td> D-Glicose </td><td> 1,16 g </td><td> 2.32g </td><td> 13 mM </td></tr><tr><td> NaHCO 3 </td><td> 0.22g </td><td> 0.44g </td><td> 5,2 mM </td></tr><tr><td> Hepes </td><td> 3.58g </td><td> 7.16g </td><td> 30 mM </td></tr></tbody></table> Misture até ficar bem dissolvido e trazer à temperatura ambiente. Ajustar o pH a 7,27-7,28 com NaOH 1 N Osmolaridade medida. Ajuste a 320 mmol / kg com deionizada e esterilizados H 2 O. Espera adicionar aproximadamente 25-40 mL. Verifique osmolaridade novamente. *** PH pode mudar um pouco durante o ajuste da osmolaridade, isso é ok, é mais importante que a osmolaridade está na faixa correta (317-323). Esterilizar em passagem pelo filtro de 0,22 mM. Faça 20 mL alíquotas e armazenar por até 2-3 semanas a 4 ° C. Gluatamine estoque: prepare a uma concentração de 200 mM e armazenar a -20 ° C em alíquotas de 2,5 mL. Estoque de ácido ascórbico: prepare a uma concentração de 25% (w / v) e armazenadas a -20 ° C em alíquotas de 100 mL. </li></ol> 5. Resultados representativos: Fatias deve olhar branco sob um escopo dissecar sem manchas negras e bem definidas e sem danos CA1, CA3, e regiões do giro denteado. Contaminação bacteriana é facilmente visto como movendo pintas pretas no meio ou turvação da SCM. Quando colocado sob o microscópio, a superfície da fatia deve olhar limpo após 4 dias em cultura, com corpos celulares claro e perceptivelmente. Se nenhum corpo de células claras são vistas e detritos muito cobre a superfície após 4 dias, então não é uma fatia saudável.

<ol>
	<li>Martin, S. J., Grimwood, P. D., Morris, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptic+plasticity+and+memory:+an+evaluation+of+the+hypothesis.">Synaptic plasticity and memory: an evaluation of the hypothesis.</a> Annu Rev Neurosci. 23, 649-711 (2000).</li><li>Bliss, T. V., Collingridge, G. L., Morris, R. G. I. n. t. r. o. d. u. c. t. i. o. n. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+potentiation+and+structure+of+the+issue.">Long-term potentiation and structure of the issue.</a> Philos Trans R Soc Lond B Biol Sci. 358, 607-611 (2003).</li><li>Shepherd, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The synaptic organization of the brain. , (2004).</li><li>Malinow, R., Tsien, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presynaptic+enhancement+shown+by+whole-cell+recordings+of+long-term+potentiation+in+hippocampal+slices.">Presynaptic enhancement shown by whole-cell recordings of long-term potentiation in hippocampal slices.</a> Nature. 346, 177-180 (1990).</li><li>Malinow, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Introduction+of+green+fluorescent+protein+(GFP)+into+hippocampal+neurons+through+viral+infection.">Introduction of green fluorescent protein (GFP) into hippocampal neurons through viral infection.</a> Cold Spring Harb Protoc. , (2010).</li><li>Shi, S., Hayashi, Y., Esteban, J. A., Malinow, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subunit-specific+rules+governing+AMPA+receptor+trafficking+to+synapses+in+hippocampal+pyramidal+neurons.">Subunit-specific rules governing AMPA receptor trafficking to synapses in hippocampal pyramidal neurons.</a> Cell. 105, 331-343 (2001).</li><li>Woods, G., Zito, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+gene+gun+bullets+and+biolistic+transfection+of+neurons+in+slice+culture.">Preparation of gene gun bullets and biolistic transfection of neurons in slice culture.</a> J Vis Exp. , (2008).</li><li>Esteban, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PKA+phosphorylation+of+AMPA+receptor+subunits+controls+synaptic+trafficking+underlying+plasticity.">PKA phosphorylation of AMPA receptor subunits controls synaptic trafficking underlying plasticity.</a> Nat Neurosci. 6, 136-143 (2003).</li><li>Mainen, Z. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-photon+imaging+in+living+brain+slices.">Two-photon imaging in living brain slices.</a> Methods. 18, 231-239 (1999).</li><li>Barria, A., Malinow, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subunit-specific+NMDA+receptor+trafficking+to+synapses.">Subunit-specific NMDA receptor trafficking to synapses.</a> Neuron. 35, 345-353 (2002).</li><li>Stoppini, L., Buchs, P. A., Muller, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+method+for+organotypic+cultures+of+nervous+tissue.">A simple method for organotypic cultures of nervous tissue.</a> J Neurosci Methods. 37, 173-182 (1991).</li><li>Simoni, A. D. e., Griesinger, C. B., Edwards, F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+rat+CA1+neurones+in+acute+versus+organotypic+slices:+role+of+experience+in+synaptic+morphology+and+activity.">Development of rat CA1 neurones in acute versus organotypic slices: role of experience in synaptic morphology and activity.</a> J Physiol. 550, 135-147 (2003).</li></ol>

Não há conflitos de interesse declarados.

Este método é baseado no método descrito pela primeira vez por Stoppini et al. 11 e oferece uma forma rápida de fatias do hipocampo cultura. O aspecto mais importante deste protocolo é para manter fatias de estéril e por isso é fundamental para o uso adequado de técnicas estéreis e adequadamente desinfectar e esterilizar todo o material em contato com o tecido. Fontes diferentes soros podem influenciar a qualidade das fatias. É aconselhável testar vários lotes...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Cell culture inserts</td>
<td>&nbsp;</td>
<td>Millipore</td>
<td>PICM03050</td>
<td>&nbsp;</td>
<tr>
<td>6 well plates</td>
<td>&nbsp;</td>
<td>BD Falcon</td>
<td>353046</td>
<td>&nbsp;</td>
<tr>
<td>Tissue Slicer</td>
<td>&nbsp;</td>
<td>Stoelting</td>
<td>51425/51415</td>
<td>&nbsp;</td>
<tr>
<td>Microscope</td>
<td>&nbsp;</td>
<td>Olympus</td>
<td>SZX7-ILLD2-100</td>
<td>&nbsp;</td>
<tr>
<td> Hippocampus dissecting tool</td>
<td>&nbsp;</td>
<td>F.S.T</td>
<td>10099-15</td>
<td>&nbsp;</td>
<tr>
<td>Large utility scissors. Perfection</td>
<td>&nbsp;</td>
<td>F.S.T</td>
<td>37500-00/37000-00 Right/ Left handed</td>
<td>&nbsp;</td>
<tr>
<td>Iris Spatula</td>
<td>&nbsp;</td>
<td>F.S.T</td>
<td>10093-13</td>
<td>&nbsp;</td>
<tr>
<td>Straight spatula</td>
<td>&nbsp;</td>
<td>F.S.T</td>
<td>10094-13</td>
<td>&nbsp;</td>
<tr>
<td>Rounded spoon micro spatula</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>57949-039</td>
<td>&nbsp;</td>
<tr>
<td>Dissecting single cutting edge needle</td>
<td>&nbsp;</td>
<td>Electron Microscopy Science</td>
<td>72946</td>
<td>&nbsp;</td>
<tr>
<td>Dissecting tweezers</td>
<td>&nbsp;</td>
<td>Dummont</td>
<td>#2</td>
<td>&nbsp;</td>
<tr>
<td>Small dissecting scissors</td>
<td>&nbsp;</td>
<td>F.S.T</td>
<td>14060-10</td>
<td>&nbsp;</td>
<tr>
<td>MEM Eagle medium</td>
<td>&nbsp;</td>
<td>Cellgro</td>
<td>50-019 PB</td>
<td>&nbsp;</td>
<tr>
<td>Horse serum heat inactivated</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>26050-88</td>
<td>&nbsp;</td>
<tr>
<td>L-Glutamine (200 mM)</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>25030081</td>
<td>&nbsp;</td>
<tr>
<td>CaCl2 (1 M)</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>C3881</td>
<td>&nbsp;</td>
<tr>
<td>MgSO4 (1 M)</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>M2773</td>
<td>&nbsp;</td>
<tr>
<td>Insulin (1 mg/ml), dissolved in HCl 0.01 N</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>I0516</td>
<td>&nbsp;</td>
<tr>
<td>Ascorbic Acid, solution (25%)</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>A4544</td>
<td>&nbsp;</td>
<tr>
<td>D-Glucose</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>G5767</td>
<td>&nbsp;</td>
<tr>
<td>NaHCO3</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>S6014</td>
<td>&nbsp;</td>
<tr>
<td>Hepes</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>H7523</td>
<td>&nbsp;</td>
<tr>
<td>Sucrose</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>S5016</td>
<td>&nbsp;</td>
<tr>
<td>Phenol Red Solution 0.5% in DPBS</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>P0290</td>
<td>&nbsp;</td>
<tr>
<td>KCl</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>P3911</td>
<td>&nbsp;</td>
<tr>
<td>MgCl2 (1 M)</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>M9272</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

organotypic hippocampal slice cultures

O hipocampo, um componente do sistema límbico, desempenha um papel importante na memória de longo prazo e navegação espacial 1. Neurônios do hipocampo pode modificar a força de suas conexões, após breves períodos de forte ativação. Esse fenômeno, conhecido como potenciação de longa duração (LTP) pode durar horas ou dias e tornou-se o mecanismo melhor candidato para o aprendizado ea memória 2. Além disso, a anatomia bem definidos e conectividade do hipocampo 3 tornou um sistema modelo clássico para estudar a transmissão sináptica e 4 plasticidade sináptica. Como nossa compreensão da fisiologia das sinapses do hipocampo cresceu e jogadores molecular tornou-se identificado, a necessidade de manipular proteínas sinápticas tornou-se imperativo. Organotípicas culturas hipocampais oferecer a possibilidade de manipulação genética fácil e intervenção farmacológica, mas precisa manter a organização sináptica que é fundamental para a compreensão da função sinapse em um contexto mais naturalista do que rotina métodos cultura dissociada neurônios. Aqui apresentamos um método para preparar e cultura fatias do hipocampo que pode ser facilmente adaptado a outras regiões do cérebro. Este método permite fácil acesso às fatias para a manipulação genética usando abordagens diferentes, como infecção viral ou 5,6 Biolistics 7. Além disso, as fatias podem ser facilmente recuperados para ensaios bioquímicos 8, ou transferidos para microscópios para imagens de 9 ou 10 experimentos eletrofisiológicos.

Watch this Scientific Journal Video about Organotypic Hippocampal Slice Cultures at JoVE.com

Organotypic Hippocampal Slice Cultures

Nós descrevemos um método para preparar organotípicas fatias do hipocampo que pode ser facilmente adaptado a outras regiões do cérebro. Fatias de cérebro são colocadas em membranas porosas e meios de cultura está autorizado a formar uma interface. Este método preserva a arquitetura bruta do hipocampo para até duas semanas em cultura.

Organotípicas Hippocampal Culturas Slice

The hippocampus, a component of the limbic system, plays important roles in long-term memory and spatial navigation 1. Hippocampal neurons can modify the ...

Research

JoVE Journal

Neuroscience

36.9K visualizações.  University of Washington School of Medicine. Nós descrevemos um método para preparar organotípicas fatias do hipocampo que pode ser facilmente adaptado a outras regiões do cérebro. Fatias de cérebro são colocadas em membranas porosas e meios de cultura está autorizado a formar uma interface. Este método preserva a arquitetura bruta do hipocampo para até duas semanas em cultura.

Vídeo: Organotypic Hippocampal Slice Cultures

The Organotypic Hippocampal Slice Culture Model for Examining Neuronal Injury

Organotypic hippocampal slice culture is an in vitro method to examine mechanisms of neuronal injury in which the basic architecture and composition of the hippocampus is relatively preserved 1. The organotypic culture system allows for the examination of neuronal, astrocytic and microglial effects, but as an ex vivo preparation, does not address effects of blood flow, or recruitment of peripheral inflammatory cells. To that end, this culture method is frequently used to examine excitotoxic and hypoxic injury to pyramidal neurons of the hippocampus, but has also been used to examine the inflammatory response. Herein we describe the methods for generating hippocampal slice cultures from postnatal rodent brain, administering toxic stimuli to induce neuronal injury, and assaying and quantifying hippocampal neuronal death.

The organoptypic hippocampal slice culture model is an in vitro model used to examine neuronal injury in a variety of paradigms. In this article, we describe the methods for generating slice cultures and quantifying neuronal injury.

O modelo de Cultura organotípicas Hippocampal Slice para o exame das lesões neuronais

Organotypic hippocampal slice culture is an in vitro method to examine mechanisms of neuronal injury in which the basic architecture and composition of ...

Neurociência

Whole Cell Recording from an Organotypic Slice Preparation of Neocortex

We have been studying the expression and functional roles of voltage-gated potassium channels in pyramidal neurons from rat neocortex. Because of the lack of specific pharmacological agents for these channels, we have taken a genetic approach to manipulating channel expression. We use an organotypic culture preparation (16) in order to maintain cell morphology and the laminar pattern of cortex. We typically isolate acute neocortical slices at postnatal days 8-10 and maintain the slices in culture for 3-7 days. This allows us to study neurons at a similar age to those in our work with acute slices and minimizes the development of exuberant excitatory connections in the slice. We record from visually-identified pyramidal neurons in layers II/III or V using infrared illumination (IR-) and differential interference contrast microscopy (DIC) with whole cell patch clamp in current- or voltage-clamp. We use biolistic (Gene gun) transfection of wild type or mutant potassium channel DNA to manipulate expression of the channels to study their function. The transfected cells are easily identified by epifluorescence microscopy after co-transfection with cDNA for green fluorescent protein (GFP). We compare recordings of transfected cells to adjacent, untransfected neurons in the same layer from the same slice.

This is a protocol to prepare and maintain a neocortical slice preparation in organotypic culture for the purpose of making electrical recordings from pyramidal neurons.

Gravação de células inteiras a partir de uma preparação Slice organotípicas de Neocortex

We have been studying the expression and functional roles of voltage-gated potassium channels in pyramidal neurons from rat neocortex.  Because of the ...

Organotypic Slice Cultures of Embryonic Ventral Midbrain: A System to Study Dopaminergic Neuronal Development in vitro

The mouse is an excellent model organism to study mammalian brain development due to the abundance of molecular and genetic data. However, the developing mouse brain is not suitable for easy manipulation and imaging in vivo since the mouse embryo is inaccessible and opaque. Organotypic slice cultures of embryonic brains are therefore widely used to study murine brain development in vitro. Ex-vivo manipulation or the use of transgenic mice allows the modification of gene expression so that subpopulations of neuronal or glial cells can be labeled with fluorescent proteins. The behavior of labeled cells can then be observed using time-lapse imaging. Time-lapse imaging has been particularly successful for studying cell behaviors that underlie the development of the cerebral cortex at late embryonic stages 1-2. Embryonic organotypic slice culture systems in brain regions outside of the forebrain are less well established. Therefore, the wealth of time-lapse imaging data describing neuronal cell migration is restricted to the forebrain 3,4. It is still not known, whether the principles discovered for the dorsal brain hold true for ventral brain areas. In the ventral brain, neurons are organized in neuronal clusters rather than layers and they often have to undergo complicated migratory trajectories to reach their final position. The ventral midbrain is not only a good model system for ventral brain development, but also contains neuronal populations such as dopaminergic neurons that are relevant in disease processes. While the function and degeneration of dopaminergic neurons has been investigated in great detail in the adult and ageing brain, little is known about the behavior of these neurons during their differentiation and migration phase 5. We describe here the generation of slice cultures from the embryonic day (E) 12.5 mouse ventral midbrain. These slice cultures are potentially suitable for monitoring dopaminergic neuron development over several days in vitro. We highlight the critical steps in generating brain slices at these early stages of embryonic development and discuss the conditions necessary for maintaining normal development of dopaminergic neurons in vitro. We also present results from time lapse imaging experiments. In these experiments, ventral midbrain precursors (including dopaminergic precursors) and their descendants were labeled in a mosaic manner using a Cre/loxP based inducible fate mapping system 6.

Organotypic Slice Cultures of Embryonic Ventral Midbrain: A System to Study Dopaminergic Neuronal Development in vitro

A method to generate organotypic slices from the E12.5 murine embryonic midbrain is described. The organotypic slice cultures can be used to observe the behavior of dopaminergic neurons or other ventral midbrain neurons.

Organotípicas culturas de mesencéfalo ventral Slice Embrionárias: Um Sistema para o Estudo de Desenvolvimento Neuronal dopaminérgicos In vitro</em

The  mouse is an excellent model organism to study mammalian brain development due  to the abundance of molecular and genetic data. However, the ...

The Analysis of Purkinje Cell Dendritic Morphology in Organotypic Slice Cultures

Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly oriented in the sagittal plane and develops mostly in the postnatal period in small rodents 3. Furthermore, several antibodies are available which selectively and intensively label Purkinje cells including all processes, with anti-Calbindin D28K being the most widely used. For viewing of dendrites in living cells, mice expressing EGFP selectively in Purkinje cells 11 are available through Jackson labs. Organotypic cerebellar slice cultures cells allow easy experimental manipulation of Purkinje cell dendritic development because most of the dendritic expansion of the Purkinje cell dendritic tree is actually taking place during the culture period 4. We present here a short, reliable and easy protocol for viewing and analyzing the dendritic morphology of Purkinje cells grown in organotypic cerebellar slice cultures. For many purposes, a quantitative evaluation of the Purkinje cell dendritic tree is desirable. We focus here on two parameters, dendritic tree size and branch point numbers, which can be rapidly and easily determined from anti-calbindin stained cerebellar slice cultures. These two parameters yield a reliable and sensitive measure of changes of the Purkinje cell dendritic tree. Using the example of treatments with the protein kinase C (PKC) activator PMA and the metabotropic glutamate receptor 1 (mGluR1) we demonstrate how differences in the dendritic development are visualized and quantitatively assessed. The combination of the presence of an extensive dendritic tree, selective and intense immunostaining methods, organotypic slice cultures which cover the period of dendritic growth and a mouse model with Purkinje cell specific EGFP expression make Purkinje cells a powerful model system for revealing the mechanisms of dendritic development.

We present a protocol that permits to view and to quantitatively asses the morphology of the dendritic tree of individual Purkinje cells grown in organotypic cerebellar slice cultures. This protocol is intended to promote studies on the mechanisms of Purkinje cell dendritic development.

A Análise de Purkinje Morfologia de células dendríticas em Culturas fatia organotípicas

Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly ...

Post-embedding Immunogold Labeling of Synaptic Proteins in Hippocampal Slice Cultures

Immunoelectron microscopy is a powerful tool to study biological molecules at the subcellular level. Antibodies coupled to electron-dense markers such as colloidal gold can reveal the localization and distribution of specific antigens in various tissues1. The two most widely used techniques are pre-embedding and post-embedding techniques. In pre-embedding immunogold-electron microscopy (EM) techniques, the tissue must be permeabilized to allow antibody penetration before it is embedded. These techniques are ideal for preserving structures but poor penetration of the antibody (often only the first few micrometers) is a considerable drawback2. The post-embedding labeling methods can avoid this problem because labeling takes place on sections of fixed tissues where antigens are more easily accessible. Over the years, a number of modifications have improved the post-embedding methods to enhance immunoreactivity and to preserve ultrastructure3-5.
Tissue fixation is a crucial part of EM studies. Fixatives chemically crosslink the macromolecules to lock the tissue structures in place. The choice of fixative affects not only structural preservation but also antigenicity and contrast. Osmium tetroxide (OsO4), formaldehyde, and glutaraldehyde have been the standard fixatives for decades, including for central nervous system (CNS) tissues that are especially prone to structural damage during chemical and physical processing. Unfortunately, OsO4 is highly reactive and has been shown to mask antigens6, resulting in poor and insufficient labeling. Alternative approaches to avoid chemical fixation include freezing the tissues. But these techniques are difficult to perform and require expensive instrumentation. To address some of these problems and to improve CNS tissue labeling, Phend et al. replaced OsO4 with uranyl acetate (UA) and tannic acid (TA), and successfully introduced additional modifications to improve the sensitivity of antigen detection and structural preservation in brain and spinal cord tissues7. We have adopted this osmium-free post-embedding method to rat brain tissue and optimized the immunogold labeling technique to detect and study synaptic proteins.
We present here a method to determine the ultrastructural localization of synaptic proteins in rat hippocampal CA1 pyramidal neurons. We use organotypic hippocampal cultured slices. These slices maintain the trisynaptic circuitry of the hippocampus, and thus are especially useful for studying synaptic plasticity, a mechanism widely thought to underlie learning and memory. Organotypic hippocampal slices from postnatal day 5 and 6 mouse/rat pups can be prepared as described previously8, and are especially useful to acutely knockdown or overexpress exogenous proteins. We have previously used this protocol to characterize neurogranin (Ng), a neuron-specific protein with a critical role in regulating synaptic function8,9 . We have also used it to characterize the ultrastructural localization of calmodulin (CaM) and Ca2+/CaM-dependent protein kinase II (CaMKII)10. As illustrated in the results, this protocol allows good ultrastructural preservation of dendritic spines and efficient labeling of Ng to help characterize its distribution in the spine8. Furthermore, the procedure described here can have wide applicability in studying many other proteins involved in neuronal functions.

The localization and distribution of proteins provide important information for understanding their cellular functions. The superior spatial resolution of electron microscopy (EM) can be used to determine the subcellular localization of a given antigen following immunohistochemistry. For tissues of the central nervous system (CNS), preserving structural integrity while maintaining antigenicity has been especially difficult in EM studies. Here, we adopt a procedure that has been used to preserve structures and antigens in the CNS to study and characterize synaptic proteins in rat hippocampal CA1 pyramidal neurons.

Pós-incorporação de Etiquetagem immunogold de proteínas sinápticas em culturas de hipocampo

Immunoelectron microscopy is a powerful tool to study biological molecules at the subcellular level. Antibodies coupled to electron-dense markers such as ...

Organotypic Slice Cultures to Study Oligodendrocyte Dynamics and Myelination

NG2 expressing cells (polydendrocytes, oligodendrocyte precursor cells) are the fourth major glial cell population in the central nervous system. During embryonic and postnatal development they actively proliferate and generate myelinating oligodendrocytes. These cells have commonly been studied in primary dissociated cultures, neuron cocultures, and in fixed tissue. Using newly available transgenic mouse lines slice culture systems can be used to investigate proliferation and differentiation of oligodendrocyte lineage cells in both gray and white matter regions of the forebrain and cerebellum. Slice cultures are prepared from early postnatal mice and are kept in culture for up to 1 month. These slices can be imaged multiple times over the culture period to investigate cellular behavior and interactions. This method allows visualization of NG2 cell division and the steps leading to oligodendrocyte differentiation while enabling detailed analysis of region-dependent NG2 cell and oligodendrocyte functional heterogeneity. This is a powerful technique that can be used to investigate the intrinsic and extrinsic signals influencing these cells over time in a cellular environment that closely resembles that found in vivo.

A technique to study NG2 cells and oligodendrocytes using a slice culture system of the forebrain and cerebellum is described. This method allows examination of the dynamics of proliferation and differentiation of cells within the oligodendrocyte lineage where the extracellular environment can be easily manipulated while maintaining tissue cytoarchitecture.

Culturas Organotípicas fatia para Estudar Oligodendrocyte Dynamics e Myelination

NG2 expressing cells (polydendrocytes, oligodendrocyte precursor cells) are the fourth major glial cell population in the central nervous system. During ...

Paired Whole Cell Recordings in Organotypic Hippocampal Slices

Pair recordings involve simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling not only direct electrophysiological characterization of the synaptic connections between individual neurons, but also pharmacological manipulation of either the presynaptic or the postsynaptic neuron. When carried out in organotypic hippocampal slice cultures, the probability that two neurons are synaptically connected is significantly increased. This preparation readily enables identification of cell types, and the neurons maintain their morphology and properties of synaptic function similar to that in native brain tissue. A major advantage of paired whole cell recordings is the highly precise information it can provide on the properties of synaptic transmission and plasticity that are not possible with other more crude techniques utilizing extracellular axonal stimulation. Paired whole cell recordings are often perceived as too challenging to perform. While there are challenging aspects to this technique, paired recordings can be performed by anyone trained in whole cell patch clamping provided specific hardware and methodological criteria are followed. The probability of attaining synaptically connected paired recordings significantly increases with healthy organotypic slices and stable micromanipulation allowing independent attainment of pre- and postsynaptic whole cell recordings. While CA3-CA3 pyramidal cell pairs are most widely used in the organotypic slice hippocampal preparation, this technique has also been successful in CA3-CA1 pairs and can be adapted to any neurons that are synaptically connected in the same slice preparation. In this manuscript we provide the detailed methodology and requirements for establishing this technique in any laboratory equipped for electrophysiology.

Pair recordings are simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling precise electrophysiological and pharmacological characterization of the synapses between individual neurons. Here we describe the detailed methodology and requirements for establishing this technique in organotypic hippocampal slice cultures in any laboratory equipped for electrophysiology.

Emparelhados Recordings células inteiras em organotï¿½icas fatias do hipocampo

Pair recordings involve simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling not only direct ...

The Analysis of Neurovascular Remodeling in Entorhino-hippocampal Organotypic Slice Cultures

Ischemic brain injury is among the most common and devastating conditions compromising proper brain function and often leads to persisting functional deficits in the affected patients. Despite intensive research efforts, there is still no effective treatment option available that reduces neuronal injury and protects neurons in the ischemic areas from delayed secondary death. Research in this area typically involves the use of elaborate and problematic animal models. Entorhino-hippocampal organotypic slice cultures challenged with oxygen and glucose deprivation (OGD) are established in&#160;vitro models which mimic cerebral ischemia. The novel aspect of this study is that changes of the brain blood vessels are studied in addition to neuronal changes and the reaction of both the neuronal compartment and the vascular compartment can be compared and correlated. The methods presented in this protocol substantially broaden the potential applications of the organotypic slice culture approach. The induction of OGD or hypoxia alone can be applied by rather simple means in organotypic slice cultures and leads to reliable and reproducible damage in the neural tissue. This is in stark contrast to the complicated and problematic animal experiments inducing stroke and ischemia in vivo. By broadening the analysis to include the study of the reaction of the vasculature could provide new ways on how to preserve and restore brain functions. The slice culture approach presented here might develop into an attractive and important tool for the study of ischemic brain injury and might be useful for testing potential therapeutic measures aimed at neuroprotection.

A protocol for entorhino-hippocampal organotypic slice cultures, which allows reproducing many aspects of ischemic brain injury, is presented. By studying changes of the neurovasculature in addition to changes in the neurons, this protocol is a versatile tool to study plastic changes in neural tissue after injury.

A Análise de Neurovascular Remodelação em Entorhino-hipocampal culturas Organotípicas Fatia

Ischemic brain injury is among the most common and devastating conditions compromising proper brain function and often leads to persisting functional ...

Organotypic Hippocampal Slice Cultures As a Model to Study Neuroprotection and Invasiveness of Tumor Cells

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. This model is suitable for addressing different research questions that involve studies on neuroprotection, electrophysiological experiments on neurons, neuronal networks or tumor invasion. The hippocampal architecture and neuronal activity in multisynaptic circuits are well conserved in OHSC, even though the slicing procedure itself initially lesions and leads to formation of a glial scar. The scar formation alters presumably the mechanical properties and diffusive behavior of small molecules, etc. Slices allow the monitoring of time dependent processes after brain injury without animal surgery, and studies on interactions between various brain-derived cell types, namely astrocytes, microglia and neurons under both physiological and pathological conditions. An ambivalent aspect of this model is the absence of blood flow and immune blood cells. During the progression of the neuronal injury, migrating immune cells from the blood play an important role. As those cells are missing in slices, the intrinsic processes in the culture may be observed without external interference. Moreover, in OHSC the composition of the medium-external environment is precisely controlled. A further advantage of this method is the lower number of sacrificed animals compared to standard preparations. Several OHSC can be obtained from one animal making simultaneous studies with multiple treatments in one animal possible. For these reasons, OHSC are well suited to analyze the effects of new protective therapeutics after tissue damage or during tumor invasion. 
The protocol presented here describes a preparation method of OHSC that allows generating highly reproducible, well preserved slices that can be used for a variety of experimental research, like neuroprotection or tumor invasion studies.

Organotypic hippocampal slice cultures (OHSC) represent an in vitro model that simulates the in vivo situation very well. Here we describe a vibratome-based improved slicing protocol to obtain high quality slices for use in assessing the neuroprotective potential of novel substances or the biological behavior of tumor cells.

Organotypic fatias Hippocampal culturas como um modelo para estudo neuroproteção e invasão de células tumorais

In organotypic hippocampal slice cultures (OHSC), the morphological and functional characteristics of both neurons and glial cells are well preserved. ...

Ex Utero Electroporation and Organotypic Slice Cultures of Embryonic Mouse Brains for Live-Imaging of Migrating GABAergic Interneurons

GABAergic interneurons (INs) are critical components of neuronal networks that drive cognition and behavior. INs destined to populate the cortex migrate tangentially from their place of origin in the ventral telencephalon (including from the medial and caudal ganglionic eminences (MGE, CGE)) to the dorsal cortical plate in response to a variety of intrinsic and extrinsic cues. Different methodologies have been developed over the years to genetically manipulate specific pathways and investigate how they regulate the dynamic cytoskeletal changes required for proper IN migration. In utero electroporation has been extensively used to study the effect of gene repression or overexpression in specific IN subtypes while assessing the impact on morphology and final position. However, while this approach is readily used to modify radially migrating pyramidal cells, it is more technically challenging when targeting INs. In utero electroporation generates a low yield given the decreased survival rates of pups when electroporation is conducted before e14.5, as is customary when studying MGE-derived INs. In an alternative approach, MGE explants provide easy access to the MGE and facilitate the imaging of genetically modified INs. However, in these explants, INs migrate into an artificial matrix, devoid of endogenous guidance cues and thalamic inputs. This prompted us to optimize a method where INs can migrate in a more naturalistic environment, while circumventing the technical challenges of in utero approaches. In this paper, we describe the combination of ex utero electroporation of embryonic mouse brains followed by organotypic slice cultures to readily track, image and reconstruct genetically modified INs migrating along their natural paths in response to endogenous cues. This approach allows for both the quantification of the dynamic aspects of IN migration with time-lapse confocal imaging, as well as the detailed analysis of various morphological parameters using neuronal reconstructions on fixed immunolabeled tissue.

Ex Utero Electroporation and Organotypic Slice Cultures of Embryonic Mouse Brains for Live-Imaging of Migrating GABAergic Interneurons

Here, we provide a low-cost and reliable method to generate electroporated brain organotypic slice cultures from mouse embryos suitable for confocal microscopy and live-imaging techniques.

Ex Utero Eletroporação e culturas Organotypic fatia do cérebro embrionário Mouse para imagens ao vivo de migração gabaérgica interneurônios

GABAergic interneurons (INs) are critical components of neuronal networks that drive cognition and behavior. INs destined to populate the cortex migrate ...