Este trabalho é apoiado pelo NIH conceder NS065183 e fundos de arranque da Faculdade de Medicina Robert Wood Johnson Rutgers.

1. Preparando Rat Astrocyte Cultura para meios condicionados e Astrocyte neurônio-co-culturas. <ol><li> Preparar tampão de dissecção (BSS, ver Tabela 1 para receita) e armazenar a 4 ° C até que esteja pronto para uso. </li><li> Anestesiar filhotes de ratos neonatais (P0-P2) com isoflurano em um copo de 500 ml. </li><li> Quando os filhotes são imóveis, spray com etanol 70% e decapitar. </li><li> Remover o cérebro. <ol><li> Segure a cabeça com firmeza com um par de Dumont # 5 fórceps, e usar uma tesoura fina para fazer uma incisão na linha média através da pele e crânio. </li><li> Exponha o cérebro, refletindo o crânio para os lados, e remover o cérebro em um prato contendo frio BSS. </li></ol></li><li> Separa-se os hemisférios cerebrais do diencéfalo e do tronco cerebral, sob um escopo de dissecação. Retire com cuidado todas as meninges através da estabilização do tecido com um par de fórceps e puxando suavemente as meninges com outro par de fórceps. </li><li> Colete todos os hemisférios in um prato de 60 milímetros. Com uma tesoura pequena, tecido picada finamente quanto possível. Em seguida, transferir o tecido picada para um tubo cônico de 50 ml. </li><li> Adicionar 1,5 ml de 1% de DNase I e 1,5 ml de 2,5% de tripsina e 12 ml de BSS (volume total de 15 ml) para o cérebro. Incubar em um banho de água com agitação durante 15 min a 37 ° C. Para garantir uma boa mistura, o tubo é rodou pela mão a cada 5 min. </li><li> Transfira o sobrenadante através de um filtro de 70 mM celular sobre um novo tubo de 50 ml. Adicionar 3 ml de FBS a este sobrenadante. </li><li> Para as peças restantes, adicione 13,5 ml de BSS e 1,5 ml de 2,5% de tripsina e incubar em banho-maria com agitação durante mais 15 min. </li><li> Transferir o sobrenadante restante através do filtro de células e combinam-se com o sobrenadante do passo 1.8. </li><li> Centrifugar a 1000 rpm durante 5 min para sedimentar as células. </li><li> Ressuspender as peletes em 5 mL de meio gliais. O sobrenadante pode ser centrifugado novamente para sedimentar as restantes células. </li><li> Contagem de células utilizando um hemocitómetro. </li><li> Placa cells a uma densidade de 1 x 10 frasco 7 para 150 cm 2. </li><li> Mude de mídia para mídia gliais frescos do dia após o plaqueamento. Posteriormente, alimentar as células duas vezes por semana com meios glial. </li><li> Quando as células atingiram&gt; 80% de confluência (aproximadamente 10 dias após o plaqueamento), congelar células para baixo em 90% de soro de cavalo e 10% DMSO e manter estoques em nitrogênio líquido. As células são congeladas a 2 x 10 6 por frasco. Aproximadamente 5 frascos podem ser congeladas a partir de cada frasco. </li><li> Cerca de 10-14 dias antes da configuração da cultura do hipocampo, as células gliais são banhados dos estoques congelados. Costumamos chapa cinco placas de 6 poços, o que é suficiente para suportar o crescimento de 90 lamelas de neurônios do hipocampo (três lamelas de 15 milímetros rodada por poço). Também placa um oito a dez 60 milímetros pratos adicionais de células da glia, que é usado para a mídia condicionado N2.1 para transfecção. Um dia antes de cultura neuronal, as células devem ser alimentados com a mídia NB27. Os astrócitos deve ser idealmente&gt; 90% confluentes no thé o ponto. Descobrimos que o congelamento reduz grandemente o número de microglia nas culturas astrogliais. Desde aumentou neurotoxicidade é observado quando microglia está presente nas culturas astrogliais, usamos sempre a cultura astroglial preparados a partir de estoques congelados por co-cultura com os neurônios. </li></ol> 2. Neuronal Cultura <ol><li> Lamelas de vidro limpo de primeira lavagem em milliQ 2x água. Eles são, em seguida, embebidas em ácido nítrico concentrado, durante 24 horas, e lavado com água MilliQ para, pelo menos, cinco vezes durante um total de 2 horas. As lamelas são secos e esterilizados por cozimento num forno a 225 ° C durante 6 horas. </li><li> Transferência de lamelas de 60 milímetros pratos após a esterilização. Coloque quatro pontos de parafina estéril perto do bordo exterior de cada lamela para manter neurónios separar a partir de células da glia durante a cocultura. </li><li> Lamelas revestimento com 1 mg / ml de poli-L-lisina em tampão borato 0,1 M durante a noite a 37 ° C em incubadora. </li><li> No dia seguinte, lave lamelas duas vezes em m estérililliQ água por pelo menos 15 min cada. Eles são, então, incubadas durante a noite em meio de plaqueamento em 37 ° C incubadora. </li><li> Eutanásia ratos fêmeas grávidas (E18) pela anestesia isoflurano seguido por pneumotórax, e sacrificá ratos embrionárias por decapitação. Remover os cérebros e dissecar os hemisférios cerebrais, como descrito acima. </li><li> Dissecar o hipocampo do hemisfério cerebral. Coloque todos os hipocampos em um tubo de 15 ml, e digest com 0,25% de tripsina (0,5 ml de 2,5% de tripsina, 4,5 ml de BSS) a 37 ℃ durante 15 min. </li><li> Hipocampos digeridas são lavados em 3x BSS durante 5 minutos cada. Eles são, em seguida, triturado com uma pipeta de Pasteur de vidro, e a densidade de células é determinado por meio de um hemocitómetro. Os neurónios são então semeadas a uma densidade de 2 x 10 5 células por prato de 60 milímetros. </li><li> Sobre 2-4 horas após o plaqueamento, transferência lamelas com os neurônios ligados aos pratos contendo células gliais, com os neurônios virado para baixo em direção à glia. No DIV3, adicionar citosina arabinosido para oAs células a uma concentração final de 5 uM para parar a proliferação de células gliais. </li></ol> 3. A transfecção de cálcio <ol><li> Mídia Condição N2.1 em glia um dia antes da transfecção. </li><li> No dia da transfecção, tomar mídia N2.1 condicionado fora da glia e transferir para um novo prato. Transferência de lamelas com os neurônios na mídia N2.1 condicionado. Deixe-se equilibrar na incubadora durante 10-30 min. </li><li> Para um conjunto de tubos esterilizados, combinar 1-4 ug de ADN, 12,5 ul de 2 M de CaCl 2 e H 2 O estéril para um volume total de 100 ul. Para um segundo conjunto de tubos, adicione 100 ml de 2x HBS. </li><li> Adicionar o volume ⅛ de 2x HBS (12,5 ul) de cada vez que o tubo contendo a mistura de CaCl 2 / ADN, vortex durante alguns segundos de cada vez. Deixe os tubos em repouso por 15 min. </li><li> Após 15 minutos de incubação, adicionar a mistura de transfecção gota a gota às células. Incubar por 1-1,5 horas. Uma camada de precipitados areia-como deve ser visívelao microscópio utilizando uma objectiva de 10X. </li><li> Após a incubação, lavar lamelas duas vezes com tampão de lavagem HBS quente. </li><li> Retornar lamelas para pratos originais com glia, adicionar ácido kynurenic para uma concentração final de 0,5 mM. </li><li> Neurônios transfectadas podem ser visualizados ao vivo ou processados ​​para imunocitoquímica, logo no dia seguinte. Neurônios podem sobreviver até três semanas após a transfecção. </li></ol>

<ol>
	<li>Karra, D., Dahm, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transfection+techniques+for+neuronal+cells.">Transfection techniques for neuronal cells.</a> J. Neurosci. 30, 6171-6177 (2010).</li><li>Zeitelhofer, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-efficiency+transfection+of+mammalian+neurons+via+nucleofection.">High-efficiency transfection of mammalian neurons via nucleofection.</a> Nat. Protoc. 2, 1692-1704 (2007).</li><li>Janas, J., Skowronski, J., Van Aelst, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lentiviral+delivery+of+RNAi+in+hippocampal+neurons.">Lentiviral delivery of RNAi in hippocampal neurons.</a> Method Enzymol. 406, 593-605 (2006).</li><li>Graham, F. L., vander Eb, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+technique+for+the+assay+of+infectivity+of+human+adenovirus+5+DNA.">A new technique for the assay of infectivity of human adenovirus 5 DNA.</a> Virology. 52, 456-467 (1973).</li><li>Craig, A. M., Banker, G. a. G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transfecting+cultured+neurons.">Transfecting cultured neurons.</a> Culturing Nerve Cells. , (1998).</li><li>Alavian, K. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bcl-xL+regulates+metabolic+efficiency+of+neurons+through+interaction+with+the+mitochondrial+F1FO+ATP+synthase.">Bcl-xL regulates metabolic efficiency of neurons through interaction with the mitochondrial F1FO ATP synthase.</a> Nat. Cell Biol. 13, 1224-1233 (2011).</li><li>Zhang, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+synaptic+function+by+VAC14,+a+protein+that+regulates+the+phosphoinositides+PI(3,5)P(2)+and+PI(5)P.">Modulation of synaptic function by VAC14, a protein that regulates the phosphoinositides PI(3,5)P(2) and PI(5)P.</a> EMBO J. 31, 3442-3456 (2012).</li><li>Dudek, H., Ghosh, A., Greenberg, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+phosphate+transfection+of+DNA+into+neurons+in+primary+culture.">Calcium phosphate transfection of DNA into neurons in primary culture.</a> Curr. Protoc. Neurosci. Chapter 3, Unit 3 11 (2001).</li><li>Goslin, K. A. H., Banker, G., Banker, G. a. G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+Hippocampal+Neurons+in+Low-Density+Culture.">Rat Hippocampal Neurons in Low-Density Culture.</a> Culturing Nerve Cells. , (1998).</li><li>Kohrmann, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast,+convenient,+and+effective+method+to+transiently+transfect+primary+hippocampal+neurons.">Fast, convenient, and effective method to transiently transfect primary hippocampal neurons.</a> J. Neurosci. Res. 58, 831-835 (1999).</li><li>Jiang, M., Chen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Ca2+-phosphate+transfection+efficiency+in+low-density+neuronal+cultures.">High Ca2+-phosphate transfection efficiency in low-density neuronal cultures.</a> Nat. Protoc. 1, 695-700 (2006).</li><li>Goetze, B., Grunewald, B., Baldassa, S., Kiebler, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemically+controlled+formation+of+a+DNA/calcium+phosphate+coprecipitate:+application+for+transfection+of+mature+hippocampal+neurons.">Chemically controlled formation of a DNA/calcium phosphate coprecipitate: application for transfection of mature hippocampal neurons.</a> J. Neurobiol. 60, 517-525 (2004).</li></ol>

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Existem vários parâmetros-chave que precisam ser cuidadosamente controlado para transfections consistentemente bem sucedidos 10,11. O parâmetro mais crítico para a transfecção de fosfato de cálcio é o valor de 2x HBS, que nas nossas mãos geralmente varia entre 7,10-7,15 pH. Recomendamos fazer três lotes de ações com valores de pH em 0,05 incrementos para explicar a diferença entre os medidores de pH. Alternativamente, o kit de transfecção de mamíferos Clontech fornece 2x HBS que sempre rende u...

Neurónios primários são um dos tipos de células difíceis de transfectar, como eles são pós-mitótico e são muito sensíveis às alterações de micro-ambientais. Existem quatro tipos vulgarmente utilizados para os métodos de expressão de genes exógenos e RNAs de curto hairpin (shRNAs) nestas células 1. Cada um tem suas próprias vantagens e desvantagens. Por exemplo, a electroporação, são geralmente realizados em neurónios recentemente isolados 2, como as células têm de ser transferidos para cuvetes de transfecção. Infecção pelo vírus geralmente pode alcançar uma eficiência muito alta 3, mas é mais trabalhoso e arriscado para os operadores. Muitos reagentes de transfecção mediada por lipidos são disponíveis comercialmente, com variados graus de sucesso em neurónios e diferentes níveis de citotoxicidade. Transfecção com fosfato de cálcio representa um método conveniente e económico para a introdução de genes estranhos em neurónios. O método foi usado pela primeira vez para introduzir o DNA do adenovírus em cel mamíferosls por Graham e Van der Eb (1973) 4. A transfecção foi realizada por mistura de cloreto de cálcio com o ADN recombinante, em tampão fosfato. Isto permite a formação de fosfato de DNA / precipitados de cálcio que, quando gradualmente libertado para uma monocamada de células, aderem à superfície da célula, são ocupados por endocitose e, finalmente, entrar no núcleo 5. Este processo conduzirá à expressão de genes estranhos introduzidos na célula alvo. Eficiência típicos de cálcio gama de transfecção de fosfato de entre 0,5-5% 6-8. No entanto, com cuidado e optimização execução consistente do protocolo experimental, é possível atingir uma eficiência de transfecção de quase 50%. Aqui, descrevemos a protocolo detalhado para a transfecção com fosfato de cálcio de neurónios do hipocampo primárias, que são co-cultivadas com células gliais em um formato de sanduíche 9.

<table border="0" cellpadding="0" cellspacing="0" width="879">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="24">
			<td height="24" style="height:24px;width:284px;">Dumont #5 forceps</td>
			<td style="width:207px;">Fine Science Tools</td>
			<td style="width:119px;">11251-20</td>
			<td style="width:269px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Fine scissors</td>
			<td style="width:207px;">Fine Science Tools</td>
			<td style="width:119px;">14090-09</td>
			<td>straight / sharp 8.5 cm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Vannas-Tubinger spring scissors</td>
			<td style="width:207px;">Fine Science Tools</td>
			<td style="width:119px;">15008-08</td>
			<td>angled / sharp / 8.5 cm / 5 mm cutting edge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Standard pattern forceps</td>
			<td style="width:207px;">Fine Science Tools</td>
			<td style="width:119px;">11000-16</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Student surgical scissors</td>
			<td style="width:207px;">Fine Science Tools</td>
			<td style="width:119px;">91401-14</td>
			<td>blunt / 14.5 cm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Spring scissors</td>
			<td style="width:207px;">Fine Science Tools</td>
			<td style="width:119px;">15006-09</td>
			<td>angled to side / 9 cm / 10 mm cutting edge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Isoflurane</td>
			<td style="width:207px;">Webster Veterinary</td>
			<td style="width:119px;">14043-225-06</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Poly-L-lysine</td>
			<td>Sigma</td>
			<td style="width:119px;">P2636</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MEM</td>
			<td>Sigma</td>
			<td>M2279</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">100 mM Sodium pyruvate</td>
			<td style="width:207px;">Sigma</td>
			<td style="width:119px;">S8636</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Glucose</td>
			<td style="width:207px;">Sigma</td>
			<td style="width:119px;">G8270</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10x HBSS</td>
			<td>Sigma</td>
			<td>H4385</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">1 M HEPES, pH 7.3</td>
			<td>Gibco/Invitrogen</td>
			<td>15630-080</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">GlutaMAX</td>
			<td>Gibco/Invitrogen</td>
			<td>35050-061</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Neurobasal Media</td>
			<td>Gibco/Invitrogen</td>
			<td>21130-049</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">B27 Supplement (50x)</td>
			<td>Gibco/Invitrogen</td>
			<td>17504-044</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">N2 Supplement</td>
			<td>Gibco/Invitrogen</td>
			<td>17502-048</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ovalbumin</td>
			<td style="width:207px;">Sigma</td>
			<td style="width:119px;">A5503</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Penicillin/Streptomycin</td>
			<td>Gibco/Invitrogen</td>
			<td style="width:119px;">15070-063</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">2.5% Trypsin</td>
			<td>Gibco/Invitrogen</td>
			<td style="width:119px;">15090-046</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">DNase I</td>
			<td style="width:207px;">Sigma</td>
			<td style="width:119px;">DN-25</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:284px;">Cytosine arabinoside</td>
			<td style="width:207px;">Calbiochem/EMD Millipore</td>
			<td align="right" style="width:119px;">251010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:284px;">Kynurenic acid</td>
			<td style="width:207px;">Sigma</td>
			<td style="width:119px;">K3375</td>
			<td></td>
		</tr>
	</tbody>
</table>

calcium phosphate transfection of primary hippocampal neurons

Precipitação com fosfato de cálcio é um método conveniente e económico para a transfecção de células em cultura. Com a otimização, é possível usar esse método em células de difícil transfecção como neurônios primários. Aqui nós descrevemos o nosso protocolo detalhado para a transfecção de fosfato de cálcio dos neurônios do hipocampo co-cultivadas com células gliais.

Quando os diferentes parâmetros de transfecção são optimizados e cuidadosamente controlada de experiência para experiência, é possível obter eficiências de transfecção de até 50%. Figura 1 mostra um campo de neurónios que são transfectadas com GFP em DIV4. O campo contém um total de 28 neurónios, entre os quais 16 foram transfectadas. Isto representa um rendimento de mais de 50%. Uma amostragem de outros campos na mesma lamela mostra a eficiência global é de cerca de 50% (dados não mo...

Watch this Scientific Journal Video about Calcium Phosphate Transfection of Primary Hippocampal Neurons at JoVE.com

Calcium Phosphate Transfection of Primary Hippocampal Neurons

Fosfato de cálcio transfecção de primário neurônios do hipocampo

Calcium phosphate precipitation is a convenient and economical method for transfection of cultured cells. With optimization, it is possible to use this ...

calcium-phosphate-transfection-of-primary-hippocampal-neurons

Research

JoVE Journal

Neuroscience

25.1K visualizações.  Rutgers University.  Precipitação com fosfato de cálcio é um método conveniente e económico para a transfecção de células em cultura. Com a otimização, é possível usar esse método em células de difícil transfecção como neurônios primários. Aqui nós descrevemos o nosso protocolo detalhado para a transfecção de fosfato de cálcio dos neurônios do hipocampo co-cultivadas com células gliais. 

Vídeo: Calcium Phosphate Transfection of Primary Hippocampal Neurons

Nucleofection and Primary Culture of Embryonic Mouse Hippocampal and Cortical Neurons

Hippocampal and cortical neurons have been used extensively to study central nervous system (CNS) neuronal polarization, axon/dendrite outgrowth, and synapse formation and function. An advantage of culturing these neurons is that they readily polarize, forming distinctive axons and dendrites, on a two dimensional substrate at very low densities. This property has made them extremely useful for determining many aspects of neuronal development. Furthermore, by providing glial conditioning for these neurons they will continue to develop, forming functional synaptic connections and surviving for several months in culture. In this protocol we outline a technique to dissect, culture and transfect embryonic mouse hippocampal and cortical neurons. Transfection is accomplished by electroporating DNA into the neurons before plating via nucleofection. This protocol has the advantage of expressing fluorescently-tagged fusion proteins early in development (~4-8hrs after plating) to study the dynamics and function of proteins during polarization, axon outgrowth and branching. We have also discovered that this single transfection before plating maintains fluorescently-tagged fusion protein expression at levels appropriate for imaging throughout the lifetime of the neuron (&gt; 2 months in culture). Thus, this methodology is useful for studying protein localization and function throughout CNS development with little or no disruption of neuronal function.

This protocol outlines the steps required to dissect, transfect via electroporation and culture mouse hippocampal and cortical neurons. Short-term cultures may be used for studies of axon outgrowth and guidance, while long-term cultures can be used for studies of synaptogenesis and dendritic spine analysis.

Nucleofection e Cultura Primária de Neurônios do hipocampo do rato embrionárias e Cortical

Hippocampal and cortical neurons have been used extensively to study central nervous system (CNS) neuronal polarization, axon/dendrite outgrowth, and ...

Neurociência

Isolation and Culture of Hippocampal Neurons from Prenatal Mice

Primary cultures of rat and murine hippocampal neurons are widely used to reveal cellular mechanisms in neurobiology. By isolating and growing individual neurons, researchers are able to analyze properties related to cellular trafficking, cellular structure and individual protein localization using a variety of biochemical techniques. Results from such experiments are critical for testing theories addressing the neural basis of memory and learning. However, unambiguous results from these forms of experiments are predicated on the ability to grow neuronal cultures with minimum contamination by other brain cell types. In this protocol, we use specific media designed for neuron growth and careful dissection of embryonic hippocampal tissue to optimize growth of healthy neurons while minimizing contaminating cell types (i.e. astrocytes). Embryonic mouse hippocampal tissue can be more difficult to isolate than similar rodent tissue due to the size of the sample for dissection. We show detailed dissection techniques of hippocampus from embryonic day 19 (E19) mouse pups. Once hippocampal tissue is isolated, gentle dissociation of neuronal cells is achieved with a dilute concentration of trypsin and mechanical disruption designed to separate cells from connective tissue while providing minimum damage to individual cells. A detailed description of how to prepare pipettes to be used in the disruption is included. Optimal plating densities are provided for immuno-fluorescence protocols to maximize successful cell culture. The protocol provides a fast (approximately 2 hr) and efficient technique for the culture of neuronal cells from mouse hippocampal tissue.

We provide a protocol for the culture of highly purified hippocampal neurons from prenatal mouse brains without the use of a feeder glial cell layer.

Isolamento e Cultura de neurônios do hipocampo de ratos pré-natal

Primary cultures of rat and murine hippocampal neurons are widely used to reveal cellular mechanisms in neurobiology. By isolating and growing individual ...

Imaging Dendritic Spines of Rat Primary Hippocampal Neurons using Structured Illumination Microscopy

Dendritic spines are protrusions emerging from the dendrite of a neuron and represent the primary postsynaptic targets of excitatory inputs in the brain. Technological advances have identified these structures as key elements in neuron connectivity and synaptic plasticity. The quantitative analysis of spine morphology using light microscopy remains an essential problem due to technical limitations associated with light's intrinsic refraction limit. Dendritic spines can be readily identified by confocal laser-scanning fluorescence microscopy. However, measuring subtle changes in the shape and size of spines is difficult because spine dimensions other than length are usually smaller than conventional optical resolution fixed by light microscopy's theoretical resolution limit of 200 nm.
Several recently developed super resolution techniques have been used to image cellular structures smaller than the 200 nm, including dendritic spines. These techniques are based on classical far-field operations and therefore allow the use of existing sample preparation methods and to image beyond the surface of a specimen. Described here is a working protocol to apply super resolution structured illumination microscopy (SIM) to the imaging of dendritic spines in primary hippocampal neuron cultures. Possible applications of SIM overlap with those of confocal microscopy. However, the two techniques present different applicability. SIM offers higher effective lateral resolution, while confocal microscopy, due to the usage of a physical pinhole, achieves resolution improvement at the expense of removal of out of focus light. In this protocol, primary neurons are cultured on glass coverslips using a standard protocol, transfected with DNA plasmids encoding fluorescent proteins and imaged using SIM. The whole protocol described herein takes approximately 2 weeks, because dendritic spines are imaged after 16-17 days in vitro, when dendritic development is optimal. After completion of the protocol, dendritic spines can be reconstructed in 3D from series of SIM image stacks using specialized software.

This article describes a working protocol to image dendritic spines from hippocampal neurons in vitro using Structured Illumination Microscopy (SIM). Super-resolution microscopy using SIM provides image resolution significantly beyond the light diffraction limit in all three spatial dimensions, allowing the imaging of individual dendritic spines with improved detail.

Imagiologia espinhas dendríticas dos neurônios do hipocampo de rato primária usando Structured Illumination Microscopy

Dendritic spines are protrusions emerging from the dendrite of a neuron and represent the primary postsynaptic targets of excitatory inputs in the brain. ...

Primary Culture of Mouse Dopaminergic Neurons

Dopaminergic neurons represent less than 1% of the total number of neurons in the brain. This low amount of neurons regulates important brain functions such as motor control, motivation, and working memory. Nigrostriatal dopaminergic neurons selectively degenerate in Parkinson&#39;s disease (PD). This progressive neuronal loss is unequivocally associated with the motors symptoms of the pathology (bradykinesia, resting tremor, and muscular rigidity). The main agent responsible of dopaminergic neuron degeneration is still unknown. However, these neurons appear to be extremely vulnerable in diverse conditions. Primary cultures constitute one of the most relevant models to investigate properties and characteristics of dopaminergic neurons. These cultures can be submitted to various stress agents that mimic PD pathology and to neuroprotective compounds in order to stop or slow down neuronal degeneration. The numerous transgenic mouse models of PD that have been generated during the last decade further increased the interest of researchers for dopaminergic neuron cultures. Here, the video protocol focuses on the delicate dissection of embryonic mouse brains. Precise excision of ventral mesencephalon is crucial to obtain neuronal cultures sufficiently rich in dopaminergic cells to allow subsequent studies. This protocol can be realized with embryonic transgenic mice and is suitable for immunofluorescence staining, quantitative PCR, second messenger quantification, or neuronal death/survival assessment.

Dopaminergic neurons play a vital regulatory role in the brain. Their loss is associated with Parkinson's disease. In this video, we show how to generate primary cultures of central dopaminergic neurons from embryonic mouse mesencephalon. Such cultures are useful to study the extreme vulnerability of these neurons to various stresses.

Cultura primária de neurônios dopaminérgicos mouse

Dopaminergic neurons represent less than 1% of the total number of neurons in the brain. This low amount of neurons regulates important brain functions ...

Low-Density Primary Hippocampal Neuron Culture

The ability to probe the structure and physiology of individual nerve cells in culture is crucial to the study of neurobiology, and allows for flexibility in genetic and chemical manipulation of individual cells or defined networks. Such ease of manipulation is simpler in the reduced culture system when compared to the intact brain tissue. While many methods for the isolation and growth of these primary neurons exist, each has its own limitations. This protocol describes a method for culturing low-density and high-purity rodent embryonic hippocampal neurons on glass coverslips, which are then suspended over a monolayer of glial cells. This &#39;sandwich culture&#39; allows for exclusive long-term growth of a population of neurons while allowing for trophic support from the underlying glial monolayer. When neurons are of sufficient age or maturity level, the neuron coverslips can be flipped-out of the glial dish and used in imaging or functional assays. Neurons grown by this method typically survive for several weeks and develop extensive arbors, synaptic connections, and network properties.

This article describes the protocol for culturing low-density primary hippocampal neurons growing on glass coverslips inverted over a glial monolayer. The neuron and glial layers are separated by paraffin wax beads. The neurons grown by this method are suitable for high-resolution optical imaging and functional assays.

Low-Density hipocampo Cultura Neuron primária

The ability to probe the structure and physiology of individual nerve cells in culture is crucial to the study of neurobiology, and allows for flexibility ...

Measuring Synaptic Vesicle Endocytosis in Cultured Hippocampal Neurons

During endocytosis, fused synaptic vesicles are retrieved at nerve terminals, allowing for vesicle recycling and thus the maintenance of synaptic transmission during repetitive nerve firing. Impaired endocytosis in pathological conditions leads to decreases in synaptic strength and brain functions. Here, we describe methods used to measure synaptic vesicle endocytosis at the mammalian hippocampal synapse in neuronal culture. We monitored synaptic vesicle protein endocytosis by fusing a synaptic vesicular membrane protein, including synaptophysin and VAMP2/synaptobrevin, at the vesicular lumenal side, with pHluorin, a pH-sensitive green fluorescent protein that increases its fluorescence intensity as the pH increases. During exocytosis, vesicular lumen pH increases, whereas during endocytosis vesicular lumen pH is re-acidified. Thus, an increase of pHluorin fluorescence intensity indicates fusion, whereas a decrease indicates endocytosis of the labelled synaptic vesicle protein. In addition to using the pHluorin imaging method to record endocytosis, we monitored vesicular membrane endocytosis by electron microscopy (EM) measurements of Horseradish peroxidase (HRP) uptake by vesicles. Finally, we monitored the formation of nerve terminal membrane pits at various times after high potassium-induced depolarization. The time course of HRP uptake and membrane pit formation indicates the time course of endocytosis.

Synaptic vesicle endocytosis is detected by light microscopy of pHluorin fused with synaptic vesicle protein and by electron microscopy of vesicle uptake.

Medindo a endocitose da vesícula sináptica nos neurônios Hippocampal culturas

During endocytosis, fused synaptic vesicles are retrieved at nerve terminals, allowing for vesicle recycling and thus the maintenance of synaptic ...

Generation of Neurospheres from Mixed Primary Hippocampal and Cortical Neurons Isolated from E14-E16 Sprague Dawley Rat Embryo

Primary neuron culture is an essential technique in the field of neuroscience. To gain deeper mechanistic insights into the brain, it is essential to have a robust in vitro model that can be exploited for various neurobiology studies. Though primary neuron cultures (i.e., long-term hippocampal cultures) have provided scientists with models, it does not yet represent the complexity of brain network completely. In the wake of these limitations, a new model has emerged using neurospheres, which bears a closer resemblance to the brain tissue. The present protocol describes the plating of high and low densities of mixed cortical and hippocampal neurons isolated from the embryo of embryonic day 14-16 Sprague Dawley rats. This allows for the generation of neurospheres and long-term primary neuron culture as two independent platforms to conduct further studies. This process is extremely simple and cost-effective, as it minimizes several steps and reagents previously deemed essential for neuron culture. This is a robust protocol with minimal requirements that can be performed with achievable results and further used for a diversity of studies related to neuroscience.

Presented here is a protocol for the spontaneous generation of neurospheres enriched in neural progenitor cells from high density plated neurons. During the same experiment, when neurons are plated at a lower density, the protocol also results in prolonged primary rat neuron cultures.

Geração de neuroesferas do hipocampal preliminar misturado e dos neurônios corticais isolados de E14-E16 embrião do rato de Sprague Dawley

Primary neuron culture is an essential technique in the field of neuroscience. To gain deeper mechanistic insights into the brain, it is essential to have ...

Use of Primary Cultured Hippocampal Neurons to Study the Assembly of Axon Initial Segments

Neuronal axon initial segments (AIS) are sites of initiation of action potentials and have been extensively studied for their molecular structure, assembly and activity-dependent plasticity. Giant ankyrin-G, the master organizer of AIS, directly associates with membrane-spanning voltage gated sodium (VSVG) and potassium channels (KCNQ2/3), as well as 186 kDa neurofascin, a L1CAM cell adhesion molecule. Giant ankyrin-G also binds to and recruits cytoplasmic AIS molecules including beta-4-spectrin, and the microtubule-binding proteins, EB1/EB3 and Ndel1. Giant ankyrin-G is sufficient to rescue AIS formation in ankyrin-G deficient neurons. Ankyrin-G also includes a smaller 190 kDa isoform located at dendritic spines instead of the AIS, which is incapable of targeting to the AIS or rescuing the AIS in ankyrin-G-deficient neurons. Here, we described a protocol using cultured hippocampal neurons from ANK3-E22/23-flox mice, which, when transfected with Cre-BFP exhibit loss of all isoform of ankyrin-G and impair the formation of AIS. Combined a modified Banker glia/neuron co-culture system, we developed a method to transfect ankyrin-G null neurons with a 480 kDa ankyrin-G-GFP plasmid, which is sufficient to rescue the formation of AIS. We further employ a quantification method, developed by Salzer and colleagues to deal with variation in AIS distance from the neuronal cell bodies that occurs in hippocampal neuron cultures. This protocol allows quantitative studies of the de novo assembly and dynamic behavior of AIS.

Here, we described a protocol to quantitatively study the assembly and structure of the axon initial segments (AIS) of hippocampal neurons that lack pre-assembled AIS due to the absence of a giant ankyrin-G.

Uso de neurônios hipocampais primários para estudar a montagem de segmentos iniciais de Axon

Neuronal axon initial segments (AIS) are sites of initiation of action potentials and have been extensively studied for their molecular structure, ...

Easy and Reproducible Low-Density Primary Culture using Frozen Stock of Embryonic Hippocampal Neurons

Neuronal culture is a valuable system for evaluating synaptic functions and drug screenings. In particular, a low-density culture of primary hippocampal neurons allows the study of individual neurons or subcellular components. We have shown subcellular protein localization within a neuron by immunocytochemistry, neuronal polarity, synaptic morphology, and its developmental change using a low-density primary hippocampal culture. Recently, ready-to-use frozen stocks of neurons have become commercially available. These frozen stocks of neurons reduce the time needed to prepare animal experiments and also contribute to the reduction of the number of animals used. Here, we introduce a reproducible low-density primary culture method using a 96-well plate. We used a commercially available frozen stock of neurons from the rat embryonic hippocampus. The neurons can be stably cultured long-term without media changes by reducing the growth of glial cells at particular timepoints. This high-throughput assay using low-density culture allows reproducible imaging-based evaluations of synaptic plasticity.

A ready-to-use frozen stock of neurons is a powerful tool for evaluating synaptic functions. Here, we introduce an easy low-density primary culture from frozen stock using a 96-well plate.

Cultura Primária de Baixa Densidade Fácil e Reprodutível usando Estoque Congelado de Neurônios Embrionários do Hipocampo

Neuronal culture is a valuable system for evaluating synaptic functions and drug screenings. In particular, a low-density culture of primary hippocampal ...

In Vivo Calcium Imaging of Neuronal Ensembles in Networks of Primary Sensory Neurons in Intact Dorsal Root Ganglia

Ca2+ imaging can be used as a proxy for cellular activity, including action potentials and various signaling mechanisms involving Ca2+ entry into the cytoplasm or the release of intracellular Ca2+ stores. Pirt-GCaMP3-based Ca2+ imaging of primary sensory neurons of the dorsal root ganglion (DRG) in mice offers the advantage of simultaneous measurement of a large number of cells. Up to 1,800 neurons can be monitored, allowing neuronal networks and somatosensory processes to be studied as an ensemble in their normal physiological context at a populational level in vivo. The large number of neurons monitored allows the detection of activity patterns that would be challenging to detect using other methods. Stimuli can be applied to the mouse hindpaw, allowing the direct effects of stimuli on the DRG neuron ensemble to be studied. The number of neurons producing Ca2+ transients as well as the amplitude of Ca2+ transients indicates sensitivity to specific sensory modalities. The diameter of neurons provides evidence of activated fiber types (non-noxious mechano vs. noxious pain fibers, A&#946;, A&#948;, and C fibers). Neurons expressing specific receptors can be genetically labeled with td-Tomato and specific Cre recombinases together with Pirt-GCaMP. Therefore, Pirt-GCaMP3 Ca2+ imaging of DRG provides a powerful tool and model for the analysis of specific sensory modalities and neuron subtypes acting as an ensemble at the populational level to study pain, itch, touch, and other somatosensory signals.

In Vivo Calcium Imaging of Neuronal Ensembles in Networks of Primary Sensory Neurons in Intact Dorsal Root Ganglia

This protocol describes the surgical exposure of the dorsal root ganglion (DRG) followed by GCaMP3 (genetically-encoded Ca2+ indicator; Green Fluorescent Protein-Calmodulin-M13 Protein 3) Ca2+ imaging of the neuronal ensembles using Pirt-GCaMP3 mice while applying a variety of stimuli to the ipsilateral hind paw.

In vivo Imagem com cálcio de conjuntos neuronais em redes de neurônios sensoriais primários em gânglios intactos da raiz dorsal

Ca2+ imaging can be used as a proxy for cellular activity, including action potentials and various signaling mechanisms involving Ca2+ entry into the ...