Este trabajo es apoyado por el NIH subvención NS065183 y los fondos de puesta en marcha de la Escuela de Medicina Robert Wood Johnson de Rutgers.

1. Preparación Rata Astrocyte la cultura para el medio condicionado y astrocitos-neuronas cocultivos. <ol><li> Prepare el tampón de disección (BSS, véase la Tabla 1 para la receta) y se almacena a 4 ° C hasta que esté listo para su uso. </li><li> Anestesie crías de ratas neonatales (P0-P2) con isoflurano en un vaso de 500 ml. </li><li> Cuando los cachorros son inmóviles, rocíe con etanol al 70% y decapitar. </li><li> Retire el cerebro. <ol><li> Sostenga firmemente la cabeza con un par de Dumont # 5 pinzas, y utilizar tijeras finas para hacer una incisión en la línea media a través de la piel y el cráneo. </li><li> Exponer el cerebro al reflejar el cráneo a los lados, y retire el cerebro en un recipiente lleno de frío BSS. </li></ol></li><li> Separar los hemisferios cerebrales desde el diencéfalo y el tronco cerebral bajo un microscopio de disección. Retire con cuidado todas las meninges al estabilizar el tejido con un par de pinzas y tirando suavemente las meninges con otro par de pinzas. </li><li> Recoge todos los hemisferios in una placa de 60 mm. Utilizando unas tijeras pequeñas, tejido picada lo más fino posible. A continuación, transferir el tejido picado a un tubo cónico de 50 ml. </li><li> Añadir 1,5 ml de 1% de DNasa I y 1,5 ml de 2,5% de tripsina y 12 ml de BSS (volumen total de 15 ml) a los cerebros. Incubar en un baño de agua en agitación durante 15 min a 37 ° C. Para asegurar una buena mezcla, el tubo se agita manualmente cada 5 minutos. </li><li> Transferir el sobrenadante a través de un filtro de 70 micras de células en un nuevo tubo cónico de 50 ml. Añadir 3 ml de FBS a este sobrenadante. </li><li> Para las piezas restantes, añadir 13,5 ml de BSS y 1,5 ml de 2,5% de tripsina y se incuba en un baño de agua agitando durante otros 15 min. </li><li> Transferir el sobrenadante restante a través del filtro celular y combinar con el sobrenadante de la Etapa 1.8. </li><li> Centrifugar a 1000 rpm durante 5 min para sedimentar las células. </li><li> Volver a suspender las pellas en 5 ml de medio gliales. El sobrenadante se puede centrifugar de nuevo para sedimentar las células restantes. </li><li> Contar las células utilizando un hemocitómetro. </li><li> Cel PlateLS a una densidad de 2 matraz de 1 x 10 7 por 150 cm. </li><li> Cambie medios de comunicación para medios gliales frescas del día después de la siembra. Después, las células alimentar dos veces por semana con los medios de comunicación de la glía. </li><li> Cuando las células han alcanzado&gt; 80% de confluencia (aproximadamente 10 días después de la siembra), congelar las células en 90% de suero de caballo y 10% de DMSO y mantener las existencias en nitrógeno líquido. Las células se congelaron a 2 x 10 6 por vial. Aproximadamente 5 viales se pueden congelar de cada matraz. </li><li> Acerca de 10-14 días antes de la creación de la cultura del hipocampo, las células gliales se siembran de las existencias congeladas. Por lo general, la placa de cinco placas de 6 pocillos, lo cual es suficiente para apoyar el crecimiento de 90 cubreobjetos de las neuronas del hipocampo (tres cubreobjetos de 15 mm redondo por pocillo). También PLACA un adicional de ocho a diez platos de 60 mm de las células gliales, que se utiliza para medios acondicionado N2.1 para la transfección. El día antes del cultivo neuronal, las células deben ser alimentados con medios NB27. Los astrocitos idealmente deben ser&gt; 90% de confluencia en el thes el punto. Encontramos que la congelación reduce en gran medida el número de microglia en las culturas astroglial. Dado que se observa una mayor neurotoxicidad cuando microglia está presente en las culturas astrogliales, siempre utilizamos la cultura astroglial preparado a partir de material congelado por cocultivo con las neuronas. </li></ol> 2. Cultivos neuronales <ol><li> Limpie cubreobjetos de vidrio por primera enjuague en agua 2x milliQ. A continuación, se sumergen en ácido nítrico concentrado durante 24 horas, y se aclararon con agua MilliQ durante al menos cinco veces durante un total de 2 horas. Los cubreobjetos se secan y se esterilizan por cocción en un horno a 225 ° C durante 6 horas. </li><li> Transferencia cubreobjetos de 60 mm platos después de la esterilización. Coloque cuatro puntos de parafina estéril cerca del borde exterior de cada cubreobjetos para mantener las neuronas se separan a partir de células gliales durante cocultivo. </li><li> Cubreobjetos capa con 1 mg / ml de poli-L-lisina en tampón de borato 0,1 M durante la noche en 37 ° C incubadora. </li><li> El día siguiente, enjuague cubreobjetos dos veces en m estérililliQ agua durante al menos 15 minutos cada uno. A continuación, se incubaron durante la noche en medio de siembra en un 37 ° C incubadora. </li><li> La eutanasia a ratas preñadas (E18) por la anestesia isoflurano seguido de neumotórax, y la eutanasia a las ratas embrionarias por decapitación. Eliminar cerebros y diseccionar los hemisferios cerebrales, como se describe más arriba. </li><li> Diseccionar los hipocampos del hemisferio cerebral. Coloque todos los hipocampos en un tubo cónico de 15 ml, y digerir con tripsina al 0,25% (0,5 ml de 2,5% de tripsina, 4,5 ml de BSS) a 37 ℃ durante 15 min. </li><li> Hipocampos digeridos se enjuagan en BSS 3x durante 5 minutos cada uno. A continuación, se trituró con una pipeta Pasteur de vidrio, y la densidad celular se determina usando un hemocitómetro. Las neuronas se sembraron a continuación a una densidad de 2 x 10 5 células por placa de 60 mm. </li><li> Acerca de 2-4 horas después de la siembra, la transferencia cubreobjetos con las neuronas asociadas a las placas que contienen células astroglial, con las neuronas hacia abajo hacia la glía. En DIV3, añadir arabinósido de citosina a lacélulas a una concentración final de 5 mM para detener la proliferación de células gliales. </li></ol> 3. La transfección de calcio <ol><li> Medios N2.1 Condición de glia el día antes de la transfección. </li><li> En el día de la transfección, los medios de comunicación tomar N2.1 acondicionado fuera de la glía y transferir a un nuevo plato. Transferencia cubreobjetos con las neuronas en los medios de comunicación N2.1 acondicionado. Deje que equilibre en incubadora durante 10 a 30 min. </li><li> Para un conjunto de tubos estériles, combine 1-4 g de ADN, 12,5 l de 2 M de CaCl 2 y H 2 O estéril para un volumen total de 100 l. Para un segundo conjunto de tubos, añadir 100 ml de 2x HBS. </li><li> Añadir un volumen ⅛ de 2x HBS (12,5 l) a la vez para el tubo que contiene la mezcla de CaCl 2 / ADN, vórtice durante unos pocos segundos cada vez. Dejar que los tubos para sentarse durante 15 minutos. </li><li> Después de 15 min de incubación, añadir gota a gota la mezcla de transfección a las células. Incubar durante 1 a 1,5 horas. Una capa de precipitados como la arena debe ser visiblebajo el microscopio utilizando un objetivo de 10X. </li><li> Después de la incubación, enjuague cubreobjetos dos veces con tampón de lavado caliente HBS. </li><li> Cubreobjetos Volver a platos originales con glía, añadir ácido quinurénico a una concentración final de 0,5 mM. </li><li> Neuronas transfectadas se pueden obtener imágenes en vivo o procesadas para la inmunocitoquímica tan pronto como al día siguiente. Las neuronas pueden sobrevivir hasta tres semanas después de la transfección. </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>

No hay conflictos de interés declarado.

Hay varios parámetros clave que deben ser cuidadosamente controlada para transfecciones consistentemente exitosos 10,11. El parámetro más crítico para la transfección de fosfato de calcio es el valor de pH de 2x HBS, que en nuestras manos por lo general varía entre 7.10 hasta 7.15. Se recomienda hacer tres lotes de acciones con valores de pH en incrementos de 0.05 para dar cuenta de la diferencia entre los medidores de pH. Alternativamente, el kit de transfección de mamíferos Clontech proporciona 2x H...

Neuronas primarias son uno de los tipos de células más difíciles de transfectar ya que son postmitotic y son muy sensibles a los cambios micro-ambiental. Hay cuatro tipos de uso común de los métodos para la expresión de genes exógenos y los ARN corto horquilla (shRNAs) en estas células 1. Cada uno tiene sus propias ventajas y desventajas. Por ejemplo, electroporación se realiza generalmente en las neuronas recién aisladas 2, como las células deben ser transferidos en las cubetas para la transfección. Infección por el virus generalmente se puede lograr una eficiencia muy alta 3, pero es y arriesgado para los operadores más intensivos en mano de obra. Muchos reactivos de transfección mediadas por lípidos están disponibles comercialmente, con diversos grados de éxito en las neuronas y diferentes niveles de citotoxicidad. Transfección con fosfato de calcio representa un método conveniente y económico para la introducción de genes extraños en las neuronas. El método fue utilizado por primera vez para introducir ADN adenovirus en cel mamíferosls por Graham y Van Der Eb (1973) 4. La transfección se realizó mediante la mezcla de cloruro de calcio con el ADN recombinante en un tampón de fosfato. Esto permite la formación de fosfato de ADN / calcio precipitados que, cuando se deja caer poco a poco sobre una monocapa de células, se adhieren a la superficie celular, son absorbidos por endocitosis y finalmente entrar en el núcleo 5. Este proceso daría lugar a la expresión de genes extraños introducidos en la célula diana. Eficiencias típicas de calcio gama transfección con fosfato de entre 0,5-5% 6-8. Sin embargo, con la optimización cuidadosa y ejecución consistente del protocolo experimental, es posible llegar a una eficacia de transfección de casi el 50%. Aquí describimos nuestro protocolo detallado para la transfección de fosfato de calcio de las neuronas del hipocampo primarias, que se co-cultivaron con células astroglial en un formato sándwich 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

Precipitación con fosfato de calcio es un método conveniente y económico para la transfección de células cultivadas. Con la optimización, es posible utilizar este método en las células difíciles de transfectar tales como neuronas primarias. A continuación se describe el protocolo detallado para la transfección de fosfato de calcio de las neuronas del hipocampo cocultured con células astroglial.

Cuando los diferentes parámetros de la transfección se optimizan y controlan cuidadosamente de experimento a experimento, es posible obtener eficiencias de transfección de hasta el 50%. La Figura 1 muestra un campo de neuronas que están transfectadas con GFP en DIV4. El campo contiene un total de 28 neuronas, entre los cuales 16 fueron transfectadas. Esto representa un rendimiento de más del 50%. Un muestreo de otros campos de la misma cubreobjetos muestra la eficiencia global es de alrededor de 50...

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 Calcio La transfección de Primaria neuronas del 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 vistas.  Rutgers University.  Precipitación con fosfato de calcio es un método conveniente y económico para la transfección de células cultivadas. Con la optimización, es posible utilizar este método en las células difíciles de transfectar tales como neuronas primarias. A continuación se describe el protocolo detallado para la transfección de fosfato de calcio de las neuronas del hipocampo cocultured con células astroglial. 

Video: 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 y cultivos primarios de neuronas del hipocampo de embriones de ratón y corticales

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

Investigación

Neurociencias

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.

Aislamiento y cultivo de neuronas del hipocampo de ratones prenatales

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.

Imaging las espinas dendríticas de las neuronas del hipocampo de rata primaria utilizando Estructurado Iluminación Microscopía

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.

Cultivo primario de ratón neuronas dopaminérgicas

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.

Baja densidad primaria del hipocampo Neurona Cultura

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.

Medición de endocitosis vesícula sináptica en neuronas Hippocampal cultivadas

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.

Generación de neuroesferas a partir de neuronas de hipocampo primario mixto y cortical esinas aisladas del 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 ...

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 Las Neuronas Del Hipocampo Cultivadas Primarias Para Estudiar El Ensamblaje De Los Segmentos Iniciales Axón

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.

Cultivo primario de baja densidad fácil y reproducible utilizando existencias congeladas de neuronas embrionarias del 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 Imágenes de calcio de conjuntos neuronales en redes de neuronas sensoriales primarias en ganglios intactos de la raíz dorsal

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

Methods Article

Fosfato de Calcio La transfección de Primaria neuronas del hipocampo