Ringraziamo Lisa Kretsge per il feedback critico e la modifica del manoscritto. Ringraziamo tutti gli assistenti di ricerca del laboratorio Cruz-Martín che sono stati preziosi nell'aiutare con le perfusioni e il conteggio cellulare dei cervelli comportamentali. Ringraziamo Andrzej Cwetsch per l'input nella progettazione dell'elettrodo tripolare, e Todd Blute e il Boston University Biology Imaging Core per l'uso del microscopio confocale. Questo lavoro è stato supportato da un NARSAD Young Investigator Grant (AC-M, #27202), dal Brenton R. Lutz Award (ALC), dall'I. Alden Macchi Award (ALC), dal NSF NRT UtB: Neurophotonics National Research Fellowship (ALC, #DGE1633516) e dal Boston University Undergraduate Research Opportunities Program (WWY). I finanziatori non hanno avuto alcun ruolo nella progettazione dello studio, nella raccolta e nell'analisi dei dati, nella decisione di pubblicare o preparare il manoscritto.

<ol>
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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=Genome-wide+meta-analysis+of+depression+identifies+102+independent+variants+and+highlights+the+importance+of+the+prefrontal+brain+regions.">Genome-wide meta-analysis of depression identifies 102 independent variants and highlights the importance of the prefrontal brain regions.</a> Nature Neuroscience. 22 (3), 343-352 (2019).</li><li>Grove, J., 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=Identification+of+common+genetic+risk+variants+for+autism+spectrum+disorder.">Identification of common genetic risk variants for autism spectrum disorder.</a> Nature Genetics. 51 (3), 431-444 (2019).</li><li>Comer, A. L., 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=Increased+expression+of+schizophrenia-associated+gene+C4+leads+to+hypoconnectivity+of+prefrontal+cortex+and+reduced+social+interaction.">Increased expression of schizophrenia-associated gene C4 leads to hypoconnectivity of prefrontal cortex and reduced social interaction.</a> PLoS Biology. 18 (1), 3000604 (2020).</li><li>Chini, 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=Resolving+and+Rescuing+Developmental+Miswiring+in+a+Mouse+Model+of+Cognitive+Impairment.">Resolving and Rescuing Developmental Miswiring in a Mouse Model of Cognitive Impairment.</a> Neuron. 105 (1), 60-74 (2020).</li><li>Clifton, N. E., 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=Dynamic+expression+of+genes+associated+with+schizophrenia+and+bipolar+disorder+across+development.">Dynamic expression of genes associated with schizophrenia and bipolar disorder across development.</a> Translational Psychiatry. 9 (1), 74 (2019).</li><li>Oberlander, V. C., Xu, X., Chini, M., Hanganu-Opatz, I. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+dysfunction+of+prefrontal-hippocampal+networks+in+mouse+models+of+mental+illness.">Developmental dysfunction of prefrontal-hippocampal networks in mouse models of mental illness.</a> European Journal of Neurosciences. 50 (6), 3072-3084 (2019).</li><li>Batista-Brito, R., 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=Developmental+Dysfunction+of+VIP+Interneurons+Impairs+Cortical+Circuits.">Developmental Dysfunction of VIP Interneurons Impairs Cortical Circuits.</a> Neuron. 95 (4), 884-895 (2017).</li><li>Luo, L., Callaway, E. M., Svoboda, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+Dissection+of+Neural+Circuits:+A+Decade+of+Progress.">Genetic Dissection of Neural Circuits: A Decade of Progress.</a> Neuron. 98 (2), 256-281 (2018).</li><li>DeNardo, L., Luo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+strategies+to+access+activated+neurons.">Genetic strategies to access activated neurons.</a> Current Opinion in Neurobiology. 45, 121-129 (2017).</li><li>Huang, Z. J., Zeng, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+approaches+to+neural+circuits+in+the+mouse.">Genetic approaches to neural circuits in the mouse.</a> Annual Reviews in Neurosciences. 36, 183-215 (2013).</li><li>Wu, Z., Yang, H., Colosi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+genome+size+on+AAV+vector+packaging.">Effect of genome size on AAV vector packaging.</a> Molecular Therapy. 18 (1), 80-86 (2010).</li><li>Callaway, E. M., Luo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monosynaptic+Circuit+Tracing+with+Glycoprotein-Deleted+Rabies+Viruses.">Monosynaptic Circuit Tracing with Glycoprotein-Deleted Rabies Viruses.</a> Journal of Neurosciences. 35 (24), 8979-8985 (2015).</li><li>Cruz-Mart&#237;n, A., 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=A+dedicated+circuit+links+direction-selective+retinal+ganglion+cells+to+the+primary+visual+cortex.">A dedicated circuit links direction-selective retinal ganglion cells to the primary visual cortex.</a> Nature. 507 (7492), 358-361 (2014).</li><li>Saito, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+electroporation+in+the+embryonic+mouse+central+nervous+system.">In vivo electroporation in the embryonic mouse central nervous system.</a> Nature Protocols. 1 (3), 1552-1558 (2006).</li><li>Cruz-Mart&#237;n, A., Crespo, M., Portera-Cailliau, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delayed+stabilization+of+dendritic+spines+in+fragile+X+mice.">Delayed stabilization of dendritic spines in fragile X mice.</a> Journal of Neurosciences. 30 (23), 7793-7803 (2010).</li><li>Zhang, J. H., Adikaram, P., Pandey, M., Genis, A., Simonds, W. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+genome+editing+through+CRISPR-Cas9+engineering.">Optimization of genome editing through CRISPR-Cas9 engineering.</a> Bioengineered. 7 (3), 166-174 (2016).</li><li>Strecker, J., 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=RNA-guided+DNA+insertion+with+CRISPR-associated+transposases.">RNA-guided DNA insertion with CRISPR-associated transposases.</a> Science. 365 (6448), 48-53 (2019).</li><li>Cruz-Mart&#237;n, A., Crespo, M., Portera-Cailliau, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glutamate+induces+the+elongation+of+early+dendritic+protrusions+via+mGluRs+in+wild+type+mice,+but+not+in+fragile+X+mice.">Glutamate induces the elongation of early dendritic protrusions via mGluRs in wild type mice, but not in fragile X mice.</a> PLoS One. 7 (2), 32446 (2012).</li><li>LoTurco, J., Manent, J. B., Sidiqi, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+and+improved+tools+for+in+utero+electroporation+studies+of+developing+cerebral+cortex.">New and improved tools for in utero electroporation studies of developing cerebral cortex.</a> Cerebral Cortex. 19, 120-125 (2009).</li><li>Kolk, S. M., de Mooij-Malsen, A. J., Martens, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatiotemporal+Molecular+Approach+of+in+utero+Electroporation+to+Functionally+Decipher+Endophenotypes+in+Neurodevelopmental+Disorders.">Spatiotemporal Molecular Approach of in utero Electroporation to Functionally Decipher Endophenotypes in Neurodevelopmental Disorders.</a> Frontiers in Molecular Neurosciences. 4, 37 (2011).</li><li>Szczurkowska, J., 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=Targeted+in+vivo+genetic+manipulation+of+the+mouse+or+rat+brain+by+in+utero+electroporation+with+a+triple-electrode+probe.">Targeted in vivo genetic manipulation of the mouse or rat brain by in utero electroporation with a triple-electrode probe.</a> Nature Protocols. 11 (3), 399-412 (2016).</li><li>dal Maschio, 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-performance+and+site-directed+in+utero+electroporation+by+a+triple-electrode+probe.">High-performance and site-directed in utero electroporation by a triple-electrode probe.</a> Nature Communications. 3, 960 (2012).</li><li>Zhan, 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=Deficient+neuron-microglia+signaling+results+in+impaired+functional+brain+connectivity+and+social+behavior.">Deficient neuron-microglia signaling results in impaired functional brain connectivity and social behavior.</a> Nature Neurosciences. 17 (3), 400-406 (2014).</li><li>Mathis, A., 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=DeepLabCut:+markerless+pose+estimation+of+user-defined+body+parts+with+deep+learning.">DeepLabCut: markerless pose estimation of user-defined body parts with deep learning.</a> Nature Neurosciences. 21 (9), 1281-1289 (2018).</li><li>Bullmann, T., Arendt, T., Frey, U., Hanashima, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+transportable,+inexpensive+electroporator+for+in+utero+electroporation.">A transportable, inexpensive electroporator for in utero electroporation.</a> Development Growth and Differentiation. 57 (5), 369-377 (2015).</li><li>Li, Z., 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=Genome-wide+association+analysis+identifies+30+new+susceptibility+loci+for+schizophrenia.">Genome-wide association analysis identifies 30 new susceptibility loci for schizophrenia.</a> Nature Genetics. 49 (11), 1576-1583 (2017).</li><li>Ripke, S., 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=Genome-wide+association+analysis+identifies+13+new+risk+loci+for+schizophrenia.">Genome-wide association analysis identifies 13 new risk loci for schizophrenia.</a> Nature Genetics. 45 (10), 1150-1159 (2013).</li><li>De Marco Garcia, N. V., Fishell, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subtype-selective+electroporation+of+cortical+interneurons.">Subtype-selective electroporation of cortical interneurons.</a> Journal of Visualized Experiment. (90), e51518 (2014).</li><li>Borrell, V., Yoshimura, Y., Callaway, E. 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Gli autori non dichiarano interessi concorrenti.

Qui viene descritta una pipeline che combina la manipolazione di nuovi geni di interesse in grandi popolazioni di neuroni corticali frontali con saggi comportamentali nei topi. Inoltre, questa pipeline consente lo studio longitudinale del comportamento negli stessi topi sia durante lo sviluppo postnatale precoce che in età adulta. Questa tecnica ignora la necessità di fare affidamento su modelli genetici di animali che possono essere costosi in termini di tempo e spese. Il punto di forza di questo protocollo è che pu?...

Studi di associazione a livello genomico (GWAS) hanno guidato la scoperta di nuovi geni candidati associati a patologiecerebrali 1,2,3,4. Questi studi sono stati particolarmente utili nella comprensione di devastanti disturbi neuropsichiatrici come la schizofrenia (SCZ), dove l'indagine di nuovi geni è servita come punto di partenza per nuove linee di ricerca e intervento terapeutico5,6. I geni che ospitano il rischio per la SCZ mostrano un'espressione distorta nella corteccia prefrontale (PFC) durante lo sviluppo postnatale prenatale e precoce, una regione implicata nella patologia di diversi disturbi neuropsichiatrici7. Inoltre, i modelli di topo dei disturbi psichiatrici mostrano attività anomala nellereti PFC 6,8,9. Questi risultati suggeriscono che i geni associati alla SZC potrebbero svolgere un ruolo nel cablaggio dello sviluppo di questa regione. Ulteriori indagini utilizzando modelli animali sono necessarie per comprendere il contributo di questi geni candidati alla creazione di connessioni nel PFC e per determinare se questi geni hanno un ruolo causale nella patogenesi dei disturbi neuropsichiatrici. Le tecniche di manipolazione genetica nei topi che consentono lo studio dei cambiamenti di espressione genica su specifici circuiti neuronali durante lo sviluppo postnatale prenatale e precoce sono un metodo promettente per comprendere i meccanismi molecolari che collegano i cambiamenti di espressione genica alla disfunzione PFC.
Le linee genetiche del topo offrono un metodo per studiare l'impatto di particolari geni sullo sviluppo e sulla funzione cerebrale. Tuttavia, affidarsi a topi transgenici può essere limitante poiché non ci sono sempre linee disponibili in commercio per esaminare gli effetti di specifici geni sullo sviluppo di circuiti neurali. Inoltre, può essere estremamente costoso e dispendioso in termini di tempo sviluppare linee di mouse personalizzate. L'uso di strategie di manipolazione genetica intersezionale che combinano topi transgenici con approcci virali harivoluzionato la comprensione del cervello 10,11,12. Nonostante molti progressi, le strategie virali hanno alcune limitazioni a seconda del tipo di vettore virale, inclusi limiti nella capacità di confezionamento che possono limitarel'espressione virale 13 e la tossicità cellulare associata all'espressionevirale 14. Inoltre, nella maggior parte delle condizioni sperimentali, l'espressione genica robusta che utilizza virus adeno-associato (AAV) richiede circa 2-4 settimane15, rendendo le strategie virali di routine irrealizzabili per manipolare i geni durante lo sviluppo postnatale precoce.
In utero l'elettroporazione (IUE) è un approccio alternativo che consente un rapido ed economico trasferimento genico16,17 che, se abbinato all'etichettatura fluorescente e agli approcci farmacogenetici o optogenetici, fornisce una potente piattaforma per sezionare la funzione dei circuiti neuronali. Inoltre, con lo sviluppo di geni di editing del genoma CRISPR-Cas9 possono essere sovraespressi o alterati con precisione attraverso il knock-down specifico di tipo cellulare o il knock-out di geni specifici o attraverso lamodulazione dei promotori 18,19. Gli approcci di manipolazione genica che utilizzano iUE sono particolarmente vantaggiosi quando l'effetto dei geni sui circuiti neuronali deve essere testato durante le strette finestre disviluppo 20. IUE è una tecnica versatile e l'iperespressione può essere facilmente realizzata inserendo un gene in un vettore di espressione sotto uno specifico promotore. Un ulteriore controllo dell'espressione genica può essere ottenuto guidando l'espressione utilizzando promotori di diversi punti di forza o utilizzando promotori inducibili in grado di controllare temporaneamentel'espressione genica 21,22. Inoltre, IUE consente il targeting di cellule all'interno di specifici strati corticali, tipi di cellule e regioni cerebrali, il che non è sempre fattibileutilizzando altri approcci 5,17. Recenti progressi nella configurazione IUE basati sull'uso di tre elettrodi, che generano una distribuzione del campo elettrico più efficiente, hanno ampliato il repertorio funzionale di questo metodo e permesso agli scienziati di indirizzare nuovi tipi di cellule e aumentare l'efficienza, la precisione e il numero di cellule che possono essere prese dimira 23,24. Questa tecnica è stata recentemente utilizzata per determinare il ruolo causale della componente complementare 4A (C4A), un gene legato alla SCZ, nella funzione PFC e nella cognizioneprecoce 5.
Qui è presentata una pipeline sperimentale che combina approcci di trasferimento genico per colpire grandi popolazioni di neuroni eccitatori nella corteccia frontale, incluso il PFC, con paradigmi comportamentali che non solo consentono lo studio dei cambiamenti cellulari e a livello di circuito, ma consentono anche di monitorare il comportamento durante lo sviluppo postnatale precoce e l'età adulta. Il primo descritto è un metodo per trasfetto bilateralmente grandi popolazioni di neuroni piramidali di livello (L) 2/3 nelle regioni corticali frontali. Successivamente, vengono delineati i compiti per saggiare il comportamento sociale nei topi giovani e adulti. Il conteggio delle cellule può essere ottenuto al completamento delle attività comportamentali per quantificare l'estensione e la posizione della trasfezione cellulare. Inoltre, il numero di cellule trasfette può essere correlato con i dati comportamentali per determinare se un maggior numero di cellule trasfette porta a maggiori perturbazioni nel comportamento.

<table border="0" cellpadding="0" cellspacing="0" style="width:664px;" width="663">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">13mm Silk Black Braided Suture</td>
			<td style="width:121px;">Havel&#39;s</td>
			<td style="width:161px;">SB77D</td>
			<td style="width:167px;">Suture skin</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adson Forceps</td>
			<td style="width:121px;">F.S.T.</td>
			<td style="width:161px;">11006-12</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">C270 Webcam</td>
			<td style="width:121px;">Logitech</td>
			<td style="width:161px;">N/A</td>
			<td>Record behavior</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Electroporator</td>
			<td style="width:121px;">Custom-built</td>
			<td style="width:161px;">N/A</td>
			<td>See Figure 1 and 2 and Bullmann et al, 2015</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EZ-500 Spin Column Plasmid DNA Maxi-preps Kit, 20preps</td>
			<td>Bio Basic Inc.</td>
			<td style="width:161px;">BS466</td>
			<td>Pladmid preparation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Fast Green FCF</td>
			<td style="width:121px;">Sigma</td>
			<td>F7252-5G</td>
			<td>Dye for DNA solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Fine scissors- sharp</td>
			<td style="width:121px;">F.S.T.</td>
			<td style="width:161px;">14060-09</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fisherbrand Gauze Sponges</td>
			<td>Fisher Scientific</td>
			<td>1376152</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Gaymar Heating/Cooling</td>
			<td style="width:121px;">Braintree</td>
			<td style="width:161px;">TP-700</td>
			<td style="width:167px;">Heating Pad</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Glass pipette puller</td>
			<td>Sutter Instrument,</td>
			<td style="width:161px;">P-97</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Glass pipettes</td>
			<td>Sutter Instrument,</td>
			<td>BF150-117-10</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Hair Removal Lotion</td>
			<td style="width:121px;">Nair</td>
			<td style="width:161px;">N/A</td>
			<td>Hair removal</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hartman Hemostats</td>
			<td style="width:121px;">F.S.T.</td>
			<td style="width:161px;">13002-10</td>
			<td>IUE</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:215px;">Open field maze- homemade acrylic arena</td>
			<td style="width:121px;">Custom-built</td>
			<td style="width:161px;">N/A</td>
			<td>50 &#215; 50 &#215; 30 cm length-width-height</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">pCAG-GFP</td>
			<td style="width:121px;">Addgene</td>
			<td>11150</td>
			<td>Mammalian expression vector for expression of GFP</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Picospritzer III</td>
			<td>Parker Hannifin</td>
			<td style="width:161px;">N/A</td>
			<td>pressure injector</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Retractor - 2 Pronged Blunt</td>
			<td style="width:121px;">F.S.T.</td>
			<td style="width:161px;">17023-13</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Ring forceps</td>
			<td style="width:121px;">F.S.T.</td>
			<td style="width:161px;">11103-09</td>
			<td>IUE</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Sterilizer, dry bead</td>
			<td style="width:121px;">Sigma</td>
			<td>Z378569</td>
			<td>sterelize surgical tools</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SUTURE, 3/0 PGA, FS-2, VIOLET FOR VET USE ONLY</td>
			<td>Havel&#39;s</td>
			<td>HJ398</td>
			<td>Suture muscle</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:215px;">Water bath</td>
			<td style="width:121px;">Cole-Parmer</td>
			<td>EW-12105-84</td>
			<td style="width:167px;">warming sterile saline</td>
		</tr>
	</tbody>
</table>

a pipeline using bilateral in utero electroporation to interrogate genetic influences on rodent behavior

Poiché gli studi di associazione a livello genomico fanno luce sulle basi genetiche eterogenee di molte malattie neurologiche, aumenta la necessità di studiare il contributo di specifici geni allo sviluppo cerebrale e alla funzione. Affidarsi a modelli di topi per studiare il ruolo di manipolazioni genetiche specifiche non è sempre fattibile poiché le linee transgeniche del topo sono piuttosto costose e molti nuovi geni associati alle malattie non hanno ancora linee genetiche disponibili in commercio. Inoltre, possono essere necessario anni di sviluppo e convalida per creare una linea del mouse. In utero l'elettroporazione offre un metodo relativamente semplice e veloce per manipolare l'espressione genica in un modo specifico di tipo cellulare in vivo che richiede solo lo sviluppo di un plasmide di DNA per ottenere una particolare manipolazione genetica. L'elettroporazione bilaterale in utero può essere utilizzata per colpire grandi popolazioni di neuroni piramidali della corteccia frontale. La combinazione di questo metodo di trasferimento genico con approcci comportamentali consente di studiare gli effetti delle manipolazioni genetiche sulla funzione delle reti di corteccia prefrontale e il comportamento sociale dei topi giovani e adulti.

Sviluppo e implementazione di successo di un elettroporatore su misura e di tre elettrodi a prong. Per le IUE, è stato costruito un elettroporatore su misura economico basato su un progetto27 descritto in precedenza (Figura 1A e Figura 2). Un elettrodo a tre punte èstato realizzato 23,24 utilizzando pini di plastica con 2 elettrodi negativi attaccati alle pun...

Watch this Scientific Journal Video about A Pipeline using Bilateral In Utero Electroporation to Interrogate Genetic Influences on Rodent Behavior at JoVE.com

A Pipeline using Bilateral In Utero Electroporation to Interrogate Genetic Influences on Rodent Behavior

Il ruolo dei geni associati alle malattie recentemente scoperti nella patogenesi dei disturbi neuropsichiatrici rimane oscuro. Un bilaterale modificato nella tecnica di elettroporazione utero consente il trasferimento genico in grandi popolazioni di neuroni e l'esame degli effetti causali dei cambiamenti di espressione genica sul comportamento sociale.

Una pipeline che utilizza l'elettroporazione bilaterale in utero per interrogare le influenze genetiche sul comportamento dei roditori

As genome-wide association studies shed light on the heterogeneous genetic underpinnings of many neurological diseases, the need to study the contribution ...

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4.0K Views.  Boston University. Il ruolo dei geni associati alle malattie recentemente scoperti nella patogenesi dei disturbi neuropsichiatrici rimane oscuro. Un bilaterale modificato nella tecnica di elettroporazione utero consente il trasferimento genico in grandi popolazioni di neuroni e l'esame degli effetti causali dei cambiamenti di espressione genica sul comportamento sociale.

Video: A Pipeline using Bilateral In Utero Electroporation to Interrogate Genetic Influences on Rodent Behavior

In Utero Intraventricular Injection and Electroporation of E16 Rat Embryos

In-utero in-vivo injection and electroporation of the embryonic rat neocortex provides a powerful tool for the manipulation of individual progenitors lining the walls of the lateral ventricle. This technique is now widely used to study the processes involved in corticogenesis by over-expressing or knocking down genes and observing the effects on cellular proliferation, migration, and differentiation. In comparison to traditional knockout strategies, in-utero electroporation provides a rapid means to manipulate a population of cells during a specific temporal window. In this video protocol, we outline the experimental methodology for preparing rats for surgery, exposing the uterine horns through laporatomy, injecting DNA into the lateral ventricles of the developing embryo, electroporating DNA into the progenitors lining the lateral wall, and caring for animals post-surgery. Our laboratory uses this protocol for surgeries on E15-E21 rats, however it is most commonly performed at E16 as shown in this video.

In Utero iniezione intraventricolare e Elettroporazione di embrioni di ratto E16

In-utero in-vivo injection and electroporation of the embryonic rat neocortex provides a powerful tool for the manipulation of individual progenitors ...

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Biologia

In Utero Intraventricular Injection and Electroporation of E15 Mouse Embryos

In-utero in-vivo injection and electroporation of the embryonic mouse neocortex provides a powerful tool for the manipulation of individual progenitors lining the walls of the lateral ventricle. This technique is now widely used to study the processes involved in corticogenesis by over-expressing or knocking down genes and observing the effects on cellular proliferation, migration, and differentiation. In comparison to traditional knockout strategies, in-utero electroporation provides a rapid means to manipulate a population of cells during a specific temporal window. In this video protocol we outline the experimental methodology for preparing mice for surgery, exposing the uterine horns through laporatomy, injecting DNA into the lateral ventricles of the developing embryo, electroporating DNA into the progenitors lining the lateral wall, and caring for animals post-surgery. Our laboratory uses this protocol for surgeries on E13-E16 mice, however, it is most commonly performed at E15, as shown in this video. 

In Utero iniezione intraventricolare e Elettroporazione di E15 embrioni di topo

In-utero in-vivo injection and electroporation of the embryonic mouse neocortex provides a powerful tool for the manipulation of individual progenitors ...

Method for Culture of Early Chick Embryos ex vivo (New Culture)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  the formation and patterning of brain, neural tube, somite and heart primordia. Applications of chick embryo culture include electroporation of DNA or RNA constructs in order to analyze gene function, grafts of growth factor coated beads such as FGFs and BMPs , as well as whole mount in situ hybridization and immunohistochemistry. This video demonstrates the different steps in chick embryo culture; First, the embryo is explanted in saline. Then, the embryo is centered on a glass ring. The membranes surrounding the embryo are lifted along the walls of the ring. The ring is then placed in a culture dish containing a pool of albumine. The culture dish is sealed and placed in a humid chamber, where the embryo is cultured for up to 24 hrs. Finally, the embryo is removed from the ring, fixed and processed for further applications. A troubleshooting guide is also presented.

Method for Culture of Early Chick Embryos ex vivo New Culture

This video demonstrates New culture, a method by which chick embryos are cultured outside the egg for up to 24 hr. This method enables one to study early development (primitive streak to 14 som.), a period corresponding to E7-9 in mouse. Applications of this technique include electroporation, in situ hybridization and immunohistochemistry.

Metodo per la Cultura di Chick primi embrioni ex vivo (Nuova Cultura)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Double Whole Mount in situ Hybridization of Early Chick Embryos

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  gene expression in brain, neural tube, somite and heart primordia formation. This video demonstrates the different steps in 2-color whole mount in situ hybridization; First, the embryo is dissected from the egg and fixed in paraformaldehyde. Second, the embryo is processed for prehybridization. The embryo is then hybridized with two different probes, one coupled to DIG, and one coupled to FITC.  Following overnight hybridization, the embryo is incubated with DIG coupled antibody. Color reaction for DIG substrate is performed, and the region of interest appears blue. The embryo is then incubated with FITC coupled antibody. The embryo is processed for color reaction with FITC, and the region of interest appears red. Finally, the embryo is fixed and processed for phtograph and sectioning. A troubleshooting guide is also presented.

This video demonstrates 2-color whole mount in situ hybridization, a method by which the spatial and temporal expression pattern of 2 different genes can be visualized in young chick embryos. This method was originally introduced by David Wilkinson, Domingos Henrique, Phil Ingham and David Ish -Horowicz.

Doppia Monte intero ibridazione in situ di embrioni di pollo primi

Method for Whole Mount Antibody Staining in Chick

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying antibody expression in developing brain, neural tube and somite. This video demonstrates the different steps in whole-mount antibody staining using HRP conjugated secondary antibodies; First, the embryo is dissected from the egg and fixed in paraformaldehyde. Second, endogenous peroxidase is inactivated; The embryo is then exposed to primary antibody. After several washes, the embryo is incubated with secondary antibody conjugated to HRP. Peroxidase activity is revealed using reaction with diaminobenzidine substrate. Finally, the embryo is fixed and processed for photography and sectioning. The advantage of this method over the use of fluorescent antibodies is that embryos can be processed for wax sectioning, thus enabling the study of antigen sites in cross section. This method was originally introduced by Jane Dodd and Tom Jessell 1.

This video demonstrates whole mount immunohistochemistry, a method by which the spatial and temporal expression pattern of an antigen can be visualized in young chick embryos. This method was originally introduced by Jane Dodd and Tom Jessell.

Metodo per la colorazione intero anticorpi Monte a Chick

Assay for Neural Induction in the Chick Embryo

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying the formation and initial patterning of the nervous system. This video demonstrates how to graft organizer tissue into a host, a method by which Hensen s node (the organizer in the chick embryo) is grafted to a host competent ectoderm. The organizer graft instructs overlying na ve tissue to adopt a neural fate via neural inducing signals. This mechanism is referred to as neural induction, and constitutes the initial step in the formation of brain and spinal cord in amniotes. This method is essentially used for the characterization of putative neural inducing molecules in chick. This video demonstrates the different steps in the assay for neural induction; First, the donnor embryo is explanted and pinned on a dish. Then, the host embryo is prepared for New culture. The graft is excised and transplanted to the host area pellucida margin. The host is cultured for 18-22 hrs. The assembly is fixed and processed for further applications (e.g. in situ hybridization). This method was originally devised by Waddington 1,2 and Gallera 3,4.

Neural induction is the first step in the formation of the brain. It is a mechanism by which Hensen's node (organizer), instructs adjacent tissue to adopt a neural fate, i.e. to give rise to the nervous system. This video demonstrates an assay for neural induction in chick embryo.

Test di induzione neurale nell&#39;embrione Chick

In utero and ex vivo Electroporation for Gene Expression in Mouse Retinal Ganglion Cells

The retina and its sole output neuron, the retinal ganglion cell (RGC), comprise an excellent model in which to examine biological questions such as cell differentiation, axon guidance, retinotopic organization and synapse formation[1]. One drawback is the inability to efficiently and reliably manipulate gene expression in RGCs in vivo, especially in the otherwise accessible murine visual pathways. Transgenic mice can be used to manipulate gene expression, but this approach is often expensive, time consuming, and can produce unwanted side effects. In chick, in ovo electroporation is used to manipulate gene expression in RGCs for examining retina and RGC development. Although similar electroporation techniques have been developed in neonatal mouse pups[2], adult rats[3], and embryonic murine retinae in vitro[4], none of these strategies allow full characterization of RGC development and axon projections in vivo. To this end, we have developed two applications of electroporation, one in utero and the other ex vivo, to specifically target embryonic murine RGCs[5, 6]. 
With in utero retinal electroporation, we can misexpress or downregulate specific genes in RGCs and follow their axon projections through the visual pathways in vivo, allowing examination of guidance decisions at intermediate targets, such as the optic chiasm, or at target regions, such as the lateral geniculate nucleus. Perturbing gene expression in a subset of RGCs in an otherwise wild-type background facilitates an understanding of gene function throughout the retinal pathway. Additionally, we have developed a companion technique for analyzing RGC axon growth in vitro. We electroporate embryonic heads ex vivo, collect and incubate the whole retina, then prepare explants from these retinae several days later. Retinal explants can be used in a variety of in vitro assays in order to examine the response of electroporated RGC axons to guidance cues or other factors. In sum, this set of techniques enhances our ability to misexpress or downregulate genes in RGCs and should greatly aid studies examining RGC development and axon projections.

In utero and ex vivo Electroporation for Gene Expression in Mouse Retinal Ganglion Cells

Here we present two techniques for manipulating gene expression in murine retinal ganglion cells (RGCs) by in utero and ex vivo electroporation. These techniques enable one to examine how alterations in gene expression affect RGC development, axon guidance, and functional properties.

In elettroporazione in vivo ed ex utero per l&#39;espressione genica in cellule gangliari della retina del mouse

The retina and its sole output neuron, the retinal ganglion cell (RGC), comprise an excellent model in which to examine biological questions such as cell ...

Dissection of Hippocampal Dentate Gyrus from Adult Mouse

The hippocampus is one of the most widely studied areas in the brain because of its important functional role in memory processing and learning, its remarkable neuronal cell plasticity, and its involvement in epilepsy, neurodegenerative diseases, and psychiatric disorders. The hippocampus is composed of distinct regions; the dentate gyrus, which comprises mainly granule neurons, and Ammon's horn, which comprises mainly pyramidal neurons, and the two regions are connected by both anatomic and functional circuits. Many different mRNAs and proteins are selectively expressed in the dentate gyrus, and the dentate gyrus is a site of adult neurogenesis; that is, new neurons are continually generated in the adult dentate gyrus. To investigate mRNA and protein expression specific to the dentate gyrus, laser capture microdissection is often used. This method has some limitations, however, such as the need for special apparatuses and complicated handling procedures. In this video-recorded protocol, we demonstrate a dissection technique for removing the dentate gyrus from adult mouse under a stereomicroscope. Dentate gyrus samples prepared using this technique are suitable for any assay, including transcriptomic, proteomic, and cell biology analyses. We confirmed that the dissected tissue is dentate gyrus by conducting real-time PCR of dentate gyrus-specific genes, tryptophan 2,3-dioxygenase (TDO2) and desmoplakin (Dsp), and Ammon's horn enriched genes, Meis-related gene 1b (Mrg1b) and TYRO3 protein tyrosine kinase 3 (Tyro3). The mRNA expressions of TDO2 and Dsp in the dentate gyrus samples were detected at obviously higher levels, whereas Mrg1b and Tyro3 were lower levels, than those in the Ammon's horn samples. To demonstrate the advantage of this method, we performed DNA microarray analysis using samples of whole hippocampus and dentate gyrus. The mRNA expression of TDO2 and Dsp, which are expressed selectively in the dentate gyrus, in the whole hippocampus of alpha-CaMKII+/- mice, exhibited 0.037 and 0.10-fold changes compared to that of wild-type mice, respectively. In the isolated dentate gyrus, however, these expressions exhibited 0.011 and 0.021-fold changes compared to that of wild-type mice, demonstrating that gene expression changes in dentate gyrus can be detected with greater sensitivity. Taken together, this convenient and accurate dissection technique can be reliably used for studies focused on the dentate gyrus.

A dissection technique for removal of the dentate gyrus from adult mouse under a stereomicroscope was demonstrated in this video-recorded protocol.

Dissezione di giro dentato ippocampale di topo adulto

The hippocampus is one of the most widely studied areas in the brain because of its important functional role in memory processing and learning, its ...

Genetic Studies of Human DNA Repair Proteins Using Yeast as a Model System 

Understanding the roles of human DNA repair proteins in genetic pathways is a formidable challenge to many researchers. Genetic studies in mammalian systems have been limited due to the lack of readily available tools including defined mutant genetic cell lines, regulatory expression systems, and appropriate selectable markers. To circumvent these difficulties, model genetic systems in lower eukaryotes have become an attractive choice for the study of functionally conserved DNA repair proteins and pathways. We have developed a model yeast system to study the poorly defined genetic functions of the Werner syndrome helicase-nuclease (WRN) in nucleic acid metabolism. Cellular phenotypes associated with defined genetic mutant backgrounds can be investigated to clarify the cellular and molecular functions of WRN through its catalytic activities and protein interactions. The human WRN gene and associated variants, cloned into DNA plasmids for expression in yeast, can be placed under the control of a regulatory plasmid element. The expression construct can then be transformed into the appropriate yeast mutant background, and genetic function assayed by a variety of methodologies. Using this approach, we determined that WRN, like its related RecQ family members BLM and Sgs1, operates in a Top3-dependent pathway that is likely to be important for genomic stability. This is described in our recent publication [1] at <a href="http://www.impactaging.com">www.impactaging.com</a>. Detailed methods of specific assays for genetic complementation studies in yeast are provided in this paper.

Genetic Studies of Human DNA Repair Proteins Using Yeast as a Model System

Genetic studies in yeast can be employed to investigate the molecular and cellular functions of human genes in cellular DNA metabolism. Methods are described for the genetic characterization of the human WRN gene product defective in the premature aging disorder Werner syndrome in functionally conserved pathways using yeast as a tractable model system.

Studi genetici di proteine ​​umane di riparazione del DNA Utilizzando lievito come sistema modello

Understanding the roles of human DNA repair proteins in genetic pathways is a formidable challenge to many researchers.  Genetic studies in mammalian ...

Using the Gene Pulser MXcell Electroporation System to Transfect Primary Cells with High Efficiency

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell electroporation system and Gene Pulser electroporation buffer (Bio-Rad) were specifically developed to easily transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells. We will demonstrate how to perform a simple experiment to quickly identify the best electroporation conditions. We will demonstrate how to run several samples through a range of electroporation conditions so that an experiment can be conducted at the same time as optimization is performed. We will also show how optimal conditions identified using 96-well electroporation plates can be used with standard electroporation cuvettes, facilitating the switch from electroporation plates to electroporation cuvettes while maintaining the same electroporation efficiency. In the video, we will also discuss some of the key factors that can lead to the success or failure of electroporation experiments.

This procedure shows how to use the Gene Pulser MXcell electroporation system to rapidly and easily identify the best electroporation conditions for mouse embryonic fibroblasts (MEFs) or other primary cells. Considerations for troubleshooting are also discussed in the associated video.

Utilizzando il sistema di elettroporazione Gene Pulser MXcell per trasfettare cellule primarie con alta efficienza

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser ...