Name: a rat model of ecohiv brain infection
Uploaded: 2021-01-21T14:30:00
Description: Watch this Scientific Journal Video about A Rat Model of EcoHIV Brain Infection at JoVE.com

Questo lavoro è stato finanziato da sovvenzioni NIH HD043680, MH106392, DA013137 e NS100624.

Tutti i protocolli sugli animali sono stati esaminati e approvati dal Comitato per la cura e l'uso degli animali presso l'Università della Carolina del Sud (numero di garanzia federale: D16-00028). Sei ratti adulti F344/N maschi sono stati alloggiati in un ambiente controllato sotto una luce 12/12: ciclo scuro con accesso ad libitum a cibo e acqua. Tutti gli animali sono stati curati utilizzando le linee guida stabilite dagli Istituti Nazionali di Sanità nella Guida per la cura e l'uso degli animali da laboratorio....

<ol>
	<li>Illenberger, J. 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=HIV+Infection+and+Neurocognitive+Disorders+in+the+Context+of+Chronic+Drug+Abuse:+Evidence+for+Divergent+Findings+Dependent+upon+Prior+Drug+History.">HIV Infection and Neurocognitive Disorders in the Context of Chronic Drug Abuse: Evidence for Divergent Findings Dependent upon Prior Drug History.</a> Journal of Neuroimmune Pharmacology. 15 (4), 715-728 (2020).</li><li>Joseph, S. B., Swanstrom, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+evolution+of+HIV-1+entry+phenotypes+as+a+guide+to+changing+target+cells.">The evolution of HIV-1 entry phenotypes as a guide to changing target cells.</a> Journal of Leukocyte Biology. 103 (3), 421-431 (2018).</li><li>Potash, M. 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=A+mouse+model+for+study+of+systemic+HIV-1+infection,+antiviral+immune+responses,+and+neuroinvasiveness.">A mouse model for study of systemic HIV-1 infection, antiviral immune responses, and neuroinvasiveness.</a> Proceedings of the National Academy of Sciences U S A. 102 (10), 3760-3765 (2005).</li><li>Albritton, L. M., Tseng, L., Scadden, D., Cunningham, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+putative+murine+ecotropic+retrovirus+receptor+gene+encodes+a+multiple+membrane-spanning+protein+and+confers+susceptibility+to+virus+infection.">A putative murine ecotropic retrovirus receptor gene encodes a multiple membrane-spanning protein and confers susceptibility to virus infection.</a> Cell. 57, 659-666 (1989).</li><li>Geraghty, P., Hadas, E., Kim, B. H., Dabo, A. J., Volsky, D. J., Foronjy, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIV+infection+model+of+chronic+obstructive+pulmonary+disease+in+mice.">HIV infection model of chronic obstructive pulmonary disease in mice.</a> American Journal of Physiology - Lung Cellular and Molecular Physiology. 312 (4), 500-509 (2017).</li><li>Gu, C. 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=EcoHIV+infection+of+mice+establishes+latent+viral+reservoirs+in+T+cells+and+active+viral+reservoirs+in+macrophages+that+are+sufficient+for+induction+of+neurocognitive+impairment.">EcoHIV infection of mice establishes latent viral reservoirs in T cells and active viral reservoirs in macrophages that are sufficient for induction of neurocognitive impairment.</a> PLoS Pathogens. 14 (6), 1007061 (2018).</li><li>Ellenbroek, B., Youn, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rodent+models+in+neuroscience+research:+is+it+a+rat+race.">Rodent models in neuroscience research: is it a rat race.</a> Disease Models, Mechanisms. 9 (10), 1079-1087 (2016).</li><li>Feduccia, A. A., Duvauchelle, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+apparatus+and+method+for+drug+reinforcement.">Novel apparatus and method for drug reinforcement.</a> Journal of Visualized Experiments. (42), e1998 (2010).</li><li>Bertrand, S. J., Mactutus, C. F., Harrod, S. B., Moran, L. M., Booze, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIV-1+proteins+dysregulate+motivational+processes+and+dopamine+circuitry.">HIV-1 proteins dysregulate motivational processes and dopamine circuitry.</a> Scientific Reports. 8 (1), 7869 (2018).</li><li>McGaughy, J., Sarter, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral+vigilance+in+rats:+task+validation+and+effects+of+age,+amphetamine,+and+benzodiazepine+receptor+ligands.">Behavioral vigilance in rats: task validation and effects of age, amphetamine, and benzodiazepine receptor ligands.</a> Psychopharmacology. 117 (3), 340-357 (1995).</li><li>Li, H., Aksenova, M., Bertrand, S., Mactutus, C. F., Booze, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+filamentous+actin+(F-actin)+puncta+in+rat+cortical+neurons.">Quantification of filamentous actin (F-actin) puncta in rat cortical neurons.</a> Journal of Visualized Experiments. (108), (2016).</li><li>McLaurin, K. A., Li, H., Booze, R. M., Mactutus, C. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disruption+of+Timing:+NeuroHIV+Progression+in+the+Post-cART+Era.">Disruption of Timing: NeuroHIV Progression in the Post-cART Era.</a> Scientific Reports. 9 (1), 827 (2019).</li><li>McLaurin, K. A., Moran, L. M., Li, H., Booze, R. M., Mactutus, C. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Power+of+Interstimulus+Interval+for+the+Assessment+of+Temporal+Processing+in+Rodents.">The Power of Interstimulus Interval for the Assessment of Temporal Processing in Rodents.</a> Journal of Visualized Experiments. (146), e58659 (2019).</li><li>Li, H., McLaurin, K. A., Mactutus, C. F., Booze, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ballistic+Labeling+of+Pyramidal+Neurons+in+Brain+Slices+and+in+Primary+Cell+Culture.">Ballistic Labeling of Pyramidal Neurons in Brain Slices and in Primary Cell Culture.</a> Journal of Visualized Experiments. (158), (2020).</li><li>Ko, 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=Macrophages+but+not+Astrocytes+Harbor+HIV+DNA+in+the+Brains+of+HIV-1-Infected+Aviremic+Individuals+on+Suppressive+Antiretroviral+Therapy.">Macrophages but not Astrocytes Harbor HIV DNA in the Brains of HIV-1-Infected Aviremic Individuals on Suppressive Antiretroviral Therapy.</a> Journal of Neuroimmune Pharmacology. 14 (1), 110-119 (2019).</li><li>Sopper, 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=The+effect+of+simian+immunodeficiency+virus+infection+in+vitro+and+in+vivo+on+the+cytokine+production+of+isolated+microglia+and+peripheral+macrophages+from+rhesus+monkey.">The effect of simian immunodeficiency virus infection in vitro and in vivo on the cytokine production of isolated microglia and peripheral macrophages from rhesus monkey.</a> Virology. 220 (2), 320-329 (1996).</li><li>Llewellyn, G. N., Alvarez-Carbonell, D., Chateau, M., Karn, J., Cannon, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HIV-1+infection+of+microglial+cells+in+a+reconstituted+humanized+mouse+model+and+identification+of+compounds+that+selectively+reverse+HIV+latency.">HIV-1 infection of microglial cells in a reconstituted humanized mouse model and identification of compounds that selectively reverse HIV latency.</a> Journal of NeuroVirology. 24 (2), 192-203 (2018).</li></ol>

In questo protocollo, abbiamo stabilito un modello di infezione da HIV indotto da EcoHIV nei ratti. In particolare, abbiamo descritto un'iniezione stereotassica bilaterale di EcoHIV nella corteccia che ha indotto con successo l'infezione attiva da HIV nel cervello del ratto 7 giorni dopo l'iniezione. Inoltre, dimostriamo che l'infezione da EcoHIV nei ratti potrebbe essere un buon sistema biologico per studiare gli aspetti chiave della MANO. Otto settimane dopo l'infezione da EcoHIV, i ratti hanno mostrato significativi d...

I sistemi biologici hanno migliorato la nostra comprensione dei disturbi neurocognitivi associati all'HIV-1 (HAND) e dei loro meccanismi neurali sottostanti2. La determinazione del sistema biologico più appropriato per un dato studio dipende spesso dalla questione dell'interesse2. La limitazione della gamma di modelli animali ospiti sfida gli studi sullo sviluppo della malattia dell'HIV-1. Per indagare la replicazione virale e la patogenesi dell'HIV-1, Potash etal. Dopo iniezioni di vene della coda nei topi dell'HIV chimerico (EcoHIV), sono state osservate molte caratteristiche simili a quelle degli individui sieropositivi HIV-1 (ad esempio linfociti infetti e macrofagi, mirati per risposte immunitarie antivirali einfiammazione 3,5,6).
Sebbene topi e ratti siano entrambi membri dei Muridae, le differenze fondamentali delle specie possono influenzare la loro idoneità per specifiche domande sperimentali7. Pertanto, l'estensione del modello di infezione EcoHIV ai ratti (comunemente usato negli studi sull'abuso di droghe e sui disturbi neurocognitivi) sarebbe vantaggiosa nello studio del neuroHIV. Ad esempio, le loro dimensioni maggiori rendono più pratico l'impianto giugulare del catetere per le procedure di auto-somministrazionedei farmaci 8. Le tecniche di auto-somministrazione dei farmaci nei ratti sono state utilizzate per valutare la motivazione nell'HIV-19. Inoltre, molti compiti neurocognitivi / comportamentali sono stati inizialmente progettati per i ratti10. Qui, segnalamo l'utilizzo di iniezioni stereotassiche di EcoHIV nei ratti per estendere il modello di infezione EcoHIV e offrire un'opportunità chiave per affrontare nuove domande relative al neuroHIV e alla MANO.

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	<tbody>
		<tr>
			<td>293FT cells</td>
			<td>ThermoFisher Scientific</td>
			<td>R70007</td>
			<td></td>
		</tr>
		<tr>
			<td>Antibiotic-Antimycotic solution</td>
			<td>Cellgro</td>
			<td>30004CI</td>
			<td>100X</td>
		</tr>
		<tr>
			<td>Corning BioCoatGelatin 75cm&#178; Rectangular Canted Neck Cell Culture Flask with Vented Cap</td>
			<td>Life Technologies</td>
			<td>354488</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning DMEM with L-Glutamine, 4.5 g/L Glucose and Sodium Pyruvate</td>
			<td>Life Technologies</td>
			<td>10013CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover glass</td>
			<td>VWR</td>
			<td>637-137</td>
			<td></td>
		</tr>
		<tr>
			<td>drill</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont #5 Forceps</td>
			<td>World Precision Instruments</td>
			<td>14095</td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont #7 Forceps</td>
			<td>World Precision Instruments</td>
			<td>14097</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf Snap-Cap Microcentrifuge Biopur Safe-Lock Tubes</td>
			<td>Life Technologies</td>
			<td>22600028</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethicon Vicryl Plus Antibacterial, 4-0 Polyglactin 910 Suture, 27in. FS-2</td>
			<td>Med Vet International</td>
			<td>VCP422H</td>
			<td></td>
		</tr>
		<tr>
			<td>Hamilton syringe</td>
			<td>Hamilton</td>
			<td>1701</td>
			<td></td>
		</tr>
		<tr>
			<td>Invitrogen Lipofectamine 3000 Transfection Reagent</td>
			<td>Life Technologies</td>
			<td>L3000015</td>
			<td></td>
		</tr>
		<tr>
			<td>Iris Forceps</td>
			<td>World Precision Instruments</td>
			<td>15914</td>
			<td></td>
		</tr>
		<tr>
			<td>Iris Scissors</td>
			<td>World Precision Instruments</td>
			<td>500216</td>
			<td></td>
		</tr>
		<tr>
			<td>Lentivirus-Associated p24 ELISA Kit</td>
			<td>Cell Biolabs, inc.</td>
			<td>VPK-107-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Lenti-X Concentrator</td>
			<td>Takara</td>
			<td>PT4421-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Opti-MEM I Reduced Serum Medium</td>
			<td>Life Technologies</td>
			<td>11058021</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma-Aldrich</td>
			<td>158127-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Sigma</td>
			<td>P6148</td>
			<td></td>
		</tr>
		<tr>
			<td>ProLong Gold</td>
			<td>Fisher Scientific</td>
			<td>P36930</td>
			<td></td>
		</tr>
		<tr>
			<td>Sevoflurane</td>
			<td>Merritt Veterinary Supply</td>
			<td>347075</td>
			<td></td>
		</tr>
		<tr>
			<td>stereotaxic apparatus</td>
			<td>Kopf Instruments</td>
			<td>Model 900</td>
			<td></td>
		</tr>
		<tr>
			<td>SuperFrost Plus Slides</td>
			<td>Fisher Scientific</td>
			<td>12-550-154%</td>
			<td></td>
		</tr>
		<tr>
			<td>Vannas Scissors</td>
			<td>World Precision Instruments</td>
			<td>500086</td>
			<td></td>
		</tr>
	</tbody>
</table>

a rat model of ecohiv brain infection

È stato ben studiato che il modello di topo infetto EcoHIV è di notevole utilità nello studio delle complicanze neurologiche associate all'HIV. L'istituzione del modello di ratto infetto EcoHIV per studi sull'abuso di droghe e sui disturbi neurocognitivi sarebbe utile nello studio dei disturbi neurocognitivi associati al neuroHIV e all'HIV-1 (HAND). Nel presente studio, dimostriamo la creazione di successo di un modello di ratto di infezione attiva da HIV utilizzando l'HIV chimerico (EcoHIV). In primo luogo, il costrutto lentivirale di EcoHIV è stato confezionato in celle colturate da 293 FT per 48 ore. Quindi, il mezzo condizionale è stato concentrato e piastrellato. Successivamente, abbiamo eseguito iniezioni stereotassiche bilaterali dell'EcoHIV-EGFP nel tessuto cerebrale del ratto F344/ N. Una settimana dopo l'infezione, sono stati rilevati segnali di fluorescenza EGFP nel tessuto cerebrale infetto, indicando che EcoHIV induce con successo un'infezione attiva da HIV nei ratti. Inoltre, è stata eseguita l'immunostaining per il marcatore cellulare microgliale, Iba1. I risultati indicavano che le microglia erano il tipo di cellula predominante che ospitava EcoHIV. Inoltre, i ratti EcoHIV hanno mostrato alterazioni nell'elaborazione temporale, un potenziale meccanismo neurocomportamentale sottostante della MANO e disfunzione sinaptica otto settimane dopo l'infezione. Collettivamente, il presente studio estende il modello EcoHIV dell'infezione da HIV-1 al ratto offrendo un prezioso sistema biologico per studiare i serbatoi virali dell'HIV-1 nel cervello, nonché la MANO e le comorbilità associate come l'abuso di droghe.

Il mezzo condizionato è stato raccolto dal lentivirus delle cellule 293FT infettate da EcoHIV-EGFP. Successivamente, è stato concentrato e titerato, quindi iniettato stereotassicamente nel cervello (regione corticale) dei ratti F344 / N. Sette giorni dopo l'iniezione, i ratti sono stati sacrificati e le immagini sono state prese da fette cerebrali coronali che vanno dal bregma 5,64 mm al bregma -4,68 mm. Nella figura 1A, ci sono significativi segnali EcoHIV-EGFP in tutto il cervello, speci...

Watch this Scientific Journal Video about A Rat Model of EcoHIV Brain Infection at JoVE.com

A Rat Model of EcoHIV Brain Infection

Qui, presentiamo un protocollo per stabilire un nuovo modello di ratto di infezione attiva da HIV utilizzando l'HIV chimerico (EcoHIV), che è fondamentale per migliorare la nostra comprensione dei serbatoi virali dell'HIV-1 nel cervello e offrire un sistema per studiare i disturbi neurocognitivi associati all'HIV e le comorbilità associate (cioè l'abuso di droghe).

Un modello di ratto di infezione cerebrale EcoHIV

It has been well studied that the EcoHIV infected mouse model is of significant utility in investigating HIV associated neurological complications. ...

Utilizzando ratti, questo protocollo può essere utilizzato per stabilire un nuovo modello di infezione attiva da HIV utilizzando l'HIV chimerico. con i ratti, l'istituzione del modello di infezione EcoHIV per gli studi sull'abuso di droghe e sui disturbi neurocognitivi potrebbe essere utile per lo studio dei disturbi neuro-HIV e HIV-1 associati alla neurocognizione. A dimostrare la procedura sarà Hailong Li, un ricercatore del mio laboratorio.Per il confezionamento del virus in 293 cellule T, seminare cinque volte 10 alla quinta 293 cellule T per millilitro di DMEM integrato con 10%FBS in ciascuno dei due contenitori di 75 centimetri quadrati rivestiti di gelatina e incubare le cellule a 37 gradi Celsius fino a quando le colture non raggiungono il 50% di confluenza. Il giorno della trasfezione, diluire 22,5 microlitri di reagente di trasfezione in 750 microlitri di mezzo per pallone in un tubo di microcentrifugo da 1,5 millilitri e vortice la soluzione per tre secondi. Diluire 20 microgrammi del DNA plasmide Chimerico EcoHIV in 750 microlitri di mezzo in un secondo tubo microcentrifugo da 1,5 millilitri per pallone con miscelazione accurata.Unire il DNA diluito con il reagente di trasfezione diluito con miscelazione delicata e incubare la soluzione risultante per 15 minuti a temperatura ambiente. Al termine dell'incubazione, aggiungere ogni sospensione del virus a 10 millilitri di mezzo DMEM prebellica e aggiungere ogni soluzione integrata da virus a un pallone da 293 cellule T. Dopo due giorni di coltura cellulare, mettere in comune il supernatante dai contenitori in un unico tubo conico da 50 millilitri per la centrifugazione e trasferire il supernatante chiarificato in un nuovo tubo da 50 millilitri.Aggiungere otto millilitri di Concentratore Lenti-X al supernatante chiarificato e mescolare con delicata inversione. Dopo un'incubazione di due giorni a quattro gradi Celsius, centrifugare la miscela e rimuovere con cura il supernatante, quindi rimescolare delicatamente il pellet con 100 microlitri di PBS millimolare e utilizzare un kit P24 ELISA per titolottare la concentrazione del virus. Per l'iniezione EcoHIV-EGFP, dopo aver confermato una mancanza di risposta al riflesso del pedale, radere i capelli dalla regione cerebrale e sterilizzare la pelle esposta due volte con il 70% di etanolo e uno scrub a base di clorexidina.Fissare il topo in una posizione incline in un apparato stereotassico e fare un'incisione da cinque a sei centimetri attraverso la pelle lungo la linea mediana del cuoio capelluto. Contrassegnare una posizione di foratura a 0,8 millimetri lateralmente e una da 1,2 millimetri rostrale a bregma e praticare un foro di 0,4 millimetri di diametro in ogni posizione del cranio. Caricare 1,04 volte 10 alla sesta unità di trasduzione per millilitro di soluzione di Lentivirus EcoHIV piastrellata in una siringa a iniezione da 10 microlitri e fissare la siringa all'apparato stereotassico.Spostare l'ago vicino alla superficie di un foro di perforazione e inserire l'ago 2,5 millilitri nel foro. Infondere un microlitri di soluzione virale ad una velocità di 0,2 microlitri di virus al minuto. Quando tutto il virus è stato iniettato, lasciare l'ago all'interno dell'area di iniezione per cinque minuti prima di ritrarre lentamente l'ago fino a quando non è al di fuori del cranio del ratto.Chiudere l'incisione cutanea con una sutura del filo di seta 4-0 e sterilizzare la soluzione con 70%etanolo, quindi posizionare il topo in una camera di recupero con una pastiglia riscaldante con monitoraggio fino a rimpasto. Da una a otto settimane dopo l'infusione virale, dopo aver confermato la mancanza di risposta al riflesso del pedale, fissare il topo in posizione supina all'interno di un cappuccio dei fumi e incidere la pelle lungo la linea mediana toracica. Tagliare il diaframma per aprire la cavità toracica e inserire un ago da 20 misura per 25 millimetri nel ventricolo sinistro.Aprire immediatamente l'atrio destro con forbici e perfondire 50 millilitri di PBS prerimorto da 100 millimolare a una portata di cinque millilitri al minuto. Una volta consegnato tutto il PBS, per infusione con 100 millilitri di paraformaldeide fredda al 4%. Una volta che tutto il fissatore è stato consegnato, rimuovere il cervello dal cranio e fissare il tessuto durante la notte in paraformaldeide fresca al 4%.La mattina seguente, posizionare il campione in 40 millilitri di saccarosio al 30% in PBS millimolare in un tubo da 50 millilitri per circa tre giorni fino a quando il cervello si deposita sul fondo del tubo prima di scattare congelando il tessuto cerebrale in butanolo metile per due minuti a meno 80 gradi Celsius. Dopo il congelamento, utilizzare un criostato di meno 20 gradi Celsius e un pennello fine per acquisire sezioni coronali spesse 50 micron. Una volta ottenute tutte le sezioni, coprire i campioni con 300 microlitri di mezzo anti-dissolvenza e montarli con 22 coverlips da 50 millilitri.Quando il mezzo si è asciugato, immagini le sezioni per microscopia confocale. Sette giorni dopo l'iniezione di Lentivirus, le immagini della fetta cerebrale coronale del ratto rivelano una presenza significativa di segnali EcoHIV-EGFP in tutto il tessuto cerebrale, specialmente all'interno della corteccia e del giro dentato ippocampale. La doppia etichettatura con le sonde Iba1 ed EcoHIV-EGFP fornisce una forte prova che le microglia sono il tipo di cellula predominante che ospita l'espressione EcoHIV nel cervello.Otto settimane dopo l'infezione, gli animali iniettati ecoHIV mostrano una relativa insensibilità alla manipolazione dell'intervallo interstimolo come evidenziato da una funzione a intervalli relativamente più piatta rispetto ai controlli salini. Inoltre, i ratti iniettati ecoHIV mostrano profonde alterazioni nella loro morfologia dendritica della colonna vertebrale, come evidenziato da una maggiore frequenza relativa di spine dendritiche più corte con un aumento del diametro della testa e del collo rispetto agli animali di controllo. La concentrazione e il titrating del mezzo di condizione prima dell'iniezione stereotassica è fondamentale per garantire i risultati coerenti e replicabili tra gli esperimenti.Questa specifica iniezione stereotassica regionale di EcoHIV fornisce un'efficiente infezione da HIV all'interno del cervello e produce deficit di elaborazione temporale nei ratti. L'utilizzo di iniezioni stereotassiche di HIV nei ratti per estendere il modello di infezione EcoHIV offre un'opportunità chiave per affrontare nuove questioni relative al neuro HIV a portata di mano.

Research

JoVE Journal

Neuroscience

Gene Delivery to Postnatal Rat Brain by Non-ventricular Plasmid Injection and Electroporation

Creation of transgenic animals is a standard approach in studying functions of a gene of interest in vivo. However, many knockout or transgenic animals are not viable in those cases where the modified gene is expressed or deleted in the whole organism. Moreover, a variety of compensatory mechanisms often make it difficult to interpret the results. The compensatory effects can be alleviated by either timing the gene expression or limiting the amount of transfected cells.
The method of postnatal non-ventricular microinjection and in vivo electroporation allows targeted delivery of genes, siRNA or dye molecules directly to a small region of interest in the newborn rodent brain. In contrast to conventional ventricular injection technique, this method allows transfection of non-migratory cell types. Animals transfected by means of the method described here can be used, for example, for two-photon in vivo imaging or in electrophysiological experiments on acute brain slices.

This protocol describes a non-viral method of delivery of genetic constructs to a certain area of living rodent brain. The method consists of plasmid preparation, micropipette fabrication, neonatal rat pup surgery, microinjection of the construct, and in vivo electroporation.

Gene consegna di cervello di ratto post-natale da parte di non-ventricolare iniezione plasmidi e Elettroporazione

Creation of transgenic animals is a standard approach in studying functions of a gene of interest in vivo. However, many knockout or transgenic animals ...

Ricerca

Neuroscienze

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

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

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

La chirurgia stereotassica della lesione eccitotossico di specifiche aree cerebrali nel ratto adulto

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

A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis

Intrauterine hypoperfusion/ischemia is one of the major causes of intrauterine/fetal growth restriction, preterm birth, and low birth weight. Most studies of this phenomenon have been performed in either models with severe intrauterine ischemia or models with gradient degree of intrauterine hypoperfusion. No study has been performed in a model on uniform mild intrauterine hypoperfusion (MIUH). Two models have been used for studies of MIUH: a model based on suture ligation of either side of the arterial arcade formed with the uterine and ovarian arteries, and a transient model based on clipping the bilateral ovarian arteries and aorta having patency. Those two rodent models of MIUH have some limitations, e.g., not all fetuses are subjected to MIUH, depending on their position in the uterine horn. In our MIUH model, all fetuses are subjected to a comparable level of intrauterine hypoperfusion. MIUH was achieved by mild stenosis of all four arteries feeding the uterus, i.e., the bilateral uterine and ovarian arteries.
Arterial stenosis was induced by metal microcoils wrapped around the feeding arteries. Producing arterial stenosis with microcoils allowed us to control, optimize, and reproduce decreased blood flow with very little inter-animal variability and a low mortality rate, thus enabling accurate evaluation. When microcoils with an inner diameter of 0.24 mm were used, the blood flow in both the placenta and fetus was mildly decreased (approximately 30% from the pre-stenosis level in the placenta). The offspring of our MIUH model clearly demonstrates long-lasting alterations in neurological, neuroanatomical and behavioral test results.

Mild intrauterine hypoperfusion was produced by artery stenosis with metal microcoils wrapped around the uterine and ovarian arteries in rats at embryonic day 17. This procedure produced prenatal hypoperfusion and intrauterine growth restriction.

Un modello del ratto dell'ipoperfusione lieve intrauterina con stenosi Microcoil

Intrauterine hypoperfusion/ischemia is one of the major causes of intrauterine/fetal growth restriction, preterm birth, and low birth weight. Most studies ...

An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

Ischemic stroke leads to vasogenic cerebral edema and subsequent primary brain injury, which is mediated through destruction of the blood-brain barrier (BBB). Rats with induced ischemic stroke were established and used as in vivo models to investigate the functional integrity of the BBB. Spectrophotometric detection of Evans blue (EB) in the brain samples with ischemic injury could provide reliable justification for the research and development of novel therapeutic modalities. This method generates reproducible results, and is applicable in any laboratory without a need for special equipment. Here, we present a visualized and technical guideline on the detection of the extravasation of EB following induction of ischemic stroke in rats.

An In Vivo Assessment of Blood-Brain Barrier Disruption in a Rat Model of Ischemic Stroke

The overall goal of this procedure is to provide a highly reproducible technique for in vivo assessment of the blood-brain barrier disruption in rat models of ischemic stroke.

Una valutazione In Vivo di rottura della barriera emato - encefalica in un modello del ratto del colpo ischemico

Ischemic stroke leads to vasogenic cerebral edema and subsequent primary brain injury, which is mediated through destruction of the blood-brain barrier ...

A Rat Model of Central Fatigue Using a Modified Multiple Platform Method

In this article, we introduced a rat model of central fatigue using the modified multiple platform method (MMPM). The Multiple Platform box was designed as a water tank with narrow platforms on the bottom. The model rats were put into the tank and stood on the platforms for 14 h (18:00 - 8:00) per day for a consecutive 21 days, with a blank control group set for contrast. At the end of modeling, rats in the model group showed an obvious fatigued appearance. To assess the model, we performed several behavioral tests, including the open field test (OFT), the elevated plus maze (EPM) test, and the exhaustive swimming (ES) test. The results showed that anxiety, spatial cognition impairment, poor muscle performance, and declined voluntary activity presented in model rats confirm the diagnosis of&#160;central fatigue. Changes of the central neurotransmitters also verified the result. In conclusion, the model successfully simulated central fatigue, and future study with the model may help reveal the pathological mechanism of the disease.

Here, we present a protocol to introduce a rat model of central fatigue using the modified multiple platform method (MMPM).

Un ratto di modello di affaticamento centrale utilizzando una versione modificata più piattaforma metodo

In this article, we introduced a rat model of central fatigue using the modified multiple platform method (MMPM). The Multiple Platform box was designed ...

An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

Despite&#160;numerous studies that attempt to develop reliable animal models&#160;which reflecting the primary processes underlying neurodegeneration, very few have been widely accepted. Here, we propose&#160;a new procedure&#160;adapted from the well-known ex vivo brain slice technique, which offers a closer in vivo-like scenario than in vitro preparations, for investigating the early events triggering cell degeneration, as observed in Alzheimer&#39;s disease (AD). This variation consists of simple and easily reproducible steps, which enable preservation of the anatomical cytoarchitecture of the selected brain region and its local functionality in a physiological milieu. Different anatomical areas can be obtained from the same brain, providing the opportunity to perform multiple experiments with the treatments in question in a site-, dose-, and time-dependent manner. Potential limitations&#160;which could affect the outcomes related to this methodology are related to the conservation of the tissue, i.e., the maintenance of its anatomical integrity during the slicing and incubation steps and the section thickness, which can influence the biochemical and immunohistochemical analysis. This approach can be employed for different purposes, such as exploring molecular mechanisms involved in physiological or pathological conditions, drug screening, or dose-response assays. Finally, this protocol could also reduce the number of animals employed in behavioral studies. The application reported here has been recently described and tested for the first time on ex vivo rat brain slices containing the basal forebrain (BF), which is one of the cerebral regions primarily affected in AD. Specifically, it has been demonstrated that the administration of a toxic peptide derived from the C-terminus of acetylcholinesterase (AChE) could prompt an AD-like profile, triggering, along the antero-posterior axis of the BF, a differential expression of proteins altered in AD, such as the alpha7 nicotinic receptor (&#945;7-nAChR), phosphorylated Tau (p-Tau), and amyloid beta (A&#946;).

An Alternative Approach to Study Primary Events in Neurodegeneration Using Ex Vivo Rat Brain Slices

We present a method which can&#160;provide further insights into the early events underlying neurodegeneration and based on the established ex-vivo brain technique, combining the advantages of in vivo and in vitro experiments. Moreover, it represents a unique opportunity for direct comparison of treated and untreated group in the same anatomical plane.

Un approccio alternativo per studiare eventi primari nella neurodegenerazione utilizzando fettine di cervello di ratto Ex Vivo

Despite&#160;numerous studies that attempt to develop reliable animal models&#160;which reflecting the primary processes underlying neurodegeneration, ...

A Benchtop Approach to the Location Specific Blood Brain Barrier Opening using Focused Ultrasound in a Rat Model

Stereotaxic surgery is the gold standard for localized drug and gene delivery to the rodent brain. This technique has many advantages over systemic delivery including precise localization to a target brain region and reduction of off target side effects. However, stereotaxic surgery is highly invasive which limits its translational efficacy, requires long recovery times, and provides challenges when targeting multiple brain regions. Focused ultrasound (FUS) can be used in combination with circulating microbubbles to transiently open the blood brain barrier (BBB) in millimeter sized regions. This allows intracranial localization of systemically delivered agents that cannot normally cross the BBB. This technique provides a noninvasive alternative to stereotaxic surgery. However, to date this technique has yet to be widely adopted in neuroscience laboratories due to the limited access to equipment and standardized methods. The overall goal of this protocol is to provide a benchtop approach to FUS BBB opening (BBBO) that is affordable and reproducible and can therefore be easily adopted by any laboratory.

Focused ultrasound with microbubble agents can open the blood brain barrier focally and transiently. This technique has been used to deliver a wide range of agents across the blood brain barrier. This article provides a detailed protocol for the localized delivery to the rodent brain with or without MRI guidance.

Un approccio da banco all'apertura della barriera ematica specifica della posizione utilizzando ultrasuoni focalizzati in un modello di ratto

Stereotaxic surgery is the gold standard for localized drug and gene delivery to the rodent brain. This technique has many advantages over systemic ...

A Hydrophobic Tissue Clearing Method for Rat Brain Tissue

Hydrophobic tissue clearing methods are easily adjustable, fast, and low-cost procedures that allows for the study of a molecule of interest in unaltered tissue samples. Traditional immunolabeling procedures require cutting the sample into thin sections, which restricts the ability to label and examine intact structures. However, if brain tissue can remain intact during processing, structures and circuits can remain intact for the analysis. Previously established clearing methods take significant time to completely clear the tissue, and the harsh chemicals can often damage sensitive antibodies. The iDISCO method quickly and completely clears tissue, is compatible with many antibodies, and requires no special lab equipment. This technique was initially validated for the use in mice tissue, but the current protocol adapts this method to image hemispheres of control and transgenic rat brains. In addition to this, the present protocol also makes several adjustments to preexisting protocol to provide clearer images with less background staining. Antibodies for Iba-1 and tyrosine hydroxylase were validated in the HIV-1 transgenic rat and in F344/N control rats using the present hydrophobic tissue clearing method. The brain is an interwoven network, where structures work together more often than separately of one another. Analyzing the brain as a whole system as opposed to a combination of individual pieces is the greatest benefit of this whole brain clearing method.

Here we present a hydrophobic tissue clearing method that allows for the viewing of target molecules as part of intact brain structures. This technique has now been validated for F344/N control and HIV-1 transgenic rats of both sexes.

Un metodo di compensazione del tessuto idrofobico per il tessuto cerebrale del ratto

Hydrophobic tissue clearing methods are easily adjustable, fast, and low-cost procedures that allows for the study of a molecule of interest in unaltered ...

Induction and Assessment of Levodopa-induced Dyskinesias in a Rat Model of Parkinson's Disease

Levodopa (L-DOPA) remains the gold-standard therapy used to treat Parkinson&#39;s disease (PD) motor symptoms. However, unwanted involuntary movements known as L-DOPA-induced dyskinesias (LIDs) develop with prolonged use of this dopamine precursor.&#160;It is estimated that the incidence of LIDs escalates to approximately 90% of individuals with PD within 10&#8211;15 years of treatment. Understanding the mechanisms of this malady and developing both novel and effective anti-dyskinesia treatments requires consistent and accurate modeling for pre-clinical testing of therapeutic interventions. A detailed method for reliable induction and comprehensive rating of LIDs following 6-OHDA-induced nigral lesioning in a rat model of PD is presented here. Dependable LID assessment in rats provides a powerful tool that can be readily utilized across laboratories to test emerging therapies focused on reducing or eliminating this common treatment-induced burden for individuals with PD.

Induction and Assessment of Levodopa-induced Dyskinesias in a Rat Model of Parkinson&#039;s Disease

This article describes methods to induce and evaluate levodopa-induced dyskinesias in a rat model of Parkinson&#39;s disease. The protocol offers detailed information regarding the intensity and frequency of a range of dyskinetic behaviors, both dystonic and hyperkinetic, providing a reliable tool to test treatments targeting this unmet medical need.

Induzione e valutazione delle discinesie indotte da levodopa in un modello di ratto della malattia di Parkinson

Levodopa (L-DOPA) remains the gold-standard therapy used to treat Parkinson&#39;s disease (PD) motor symptoms. However, unwanted involuntary movements ...

Convalida della risposta alle lesioni e delle valutazioni comportamentali in un modello di ratto mTBI

Rat Model of Closed-Head Mild Traumatic Injury and its Validation

Animal models are crucial for advancing our understanding of mild traumatic brain injury (mTBI) and guiding clinical research. To achieve meaningful insights, developing a stable and reproducible animal model is essential. In this study, we report a detailed description of a closed-head mTBI model and a representative validation method using Sprague-Dawley rats to verify the modeling effect. The model involves dropping a 550 g mass weight from a height of 100 cm directly onto the head of a rat on a destructible surface, followed by a 180-degree turn. To assess the injury, rats underwent a series of neurobehavioral assessments 10 min post-injury, including time of loss of consciousness, first seeking-behavior time, escape ability, and beam balance ability test. During the acute and subacute stages following the injury, behavioral tests were conducted to assess motor coordination ability (Beam task), anxiety (Open Field test), and learning and memory abilities (Morris Water Maze test). The closed-head mTBI model produced a consistent injury response with minimal mortality and replicated real-life situations. The validation method effectively verified the model development and ensured the stability and consistency of the model.

Autore in primo piano: Avanzamento della ricerca sulle lesioni cerebrali traumatiche - Un modello a testa chiusa per una replicazione accurata e una valutazione rapida 

Here, we present a closed-head mild traumatic brain injury (mTBI) rat model and its validation exhibiting remarkable similarity to human mTBI concerning behavioral manifestations during the acute and subacute stages.

Modello di ratto di lesione traumatica lieve a testa chiusa e sua convalida

Animal models are crucial for advancing our understanding of mild traumatic brain injury (mTBI) and guiding clinical research. To achieve meaningful ...