Name: rapid in situ hybridization using oligonucleotide probes on paraformaldehyde-prefixed brain of rats with serotonin syndrome
Uploaded: 2015-09-23T15:00:00.000+00:00
Duration: 8 min 49 s
Description: Watch this Scientific Journal Video about Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome at JoVE.com

Questo studio è stato sostenuto dalla concessione NIH (R15DA029863), la concessione Florida Atlantic University di ricerca triennale (M30014) e la Scuola di Medicina Veterinaria assegno di ricerca Ross University. Vorremmo ringraziare il National Institute on Drug Abuse (Rockville, MD) per la fornitura di (±) 3,4-metilene (± MDMA) per questo lavoro.

Procedure per l&#39;uso degli animali descritti di seguito sono stati approvati dalla cura e l&#39;uso Comitato istituzionale animali (IACUC) Ross University School di Medicina Veterinaria e Florida Atlantic University. Anche se sono necessarie tecniche sterili e guanti, l&#39;ambiente privo di RNasi non è necessario durante l&#39;utilizzo di questo protocollo. 1. Preparazione <ol><li> Preparazione dei tessuti e sezionamento <ol><li> Assegnare i ratti a caso in tre gruppi: fresco / salina (SAL; 0,9% NaCl), il prefisso / SAL e prefissati / 3,4-metilene (MDMA; vedi dettagli nella tabella 1). </li><li> Somministrare tre dosi di 1 ml / kg SAL e 10 mg / kg per via intraperitoneale MDMA, rispettivamente, ai gruppi SAL e MDMA a intervalli 2 ore. Lasciare gli animali a sopravvivere il trattamento per 6 giorni. </li><li> Il giorno 7, somministrare 100 mg / kg di ketamina in combinazione di 5 mg / kg per via intraperitoneale xilazina ai ratti per una anestesia profonda (cioè, perdita di lampeggio corneale e tail pizzico riflessi). </li><li> Per il gruppo fresco / SAL, decapitate rapidamente ratti e rimuovere il cervello per il test del cervello fresco (vedi dettagli nel riferimento 5). </li><li> Per i gruppi / MDMA prefissati / SAL e prefissati, effettuare un taglio lungo lo sterno circa 10 -12 cm e quindi esporre l&#39;estremità dello sterno. </li><li> Tenere l&#39;estremità dello sterno con una pinza emostatica e tagliare il diaframma lateralmente da entrambi i lati con forbici affilate e poi tagliare verso l&#39;alto attraverso le costole e paralleli ai polmoni. </li><li> Con una mano, tenere la punta ventrale del cuore con piccole pinze. Con l&#39;altra mano, perforare il ventricolo sinistro con una G siringa 18 (notare il lato dell&#39;adattatore dell&#39;ago è collegato con un tubo flessibile di silicio a forma di Y per SAL e paraformaldeide contenitori ghiacciate e pompe peristaltiche, vedere il riferimento 9). </li><li> Accendere la pompa SAL al livello medio della portata (~ 5 ml / min) e forare l&#39;atrio destro con la pinza per consentire la fuoriuscita di ritorno circlamento. Mantenere SAL perfusione per 30 min. </li><li> Accendere la pompa paraformaldeide al livello medio e consentire il ghiacciata 4% paraformaldeide per defluire in all&#39;animale per 30 min. </li><li> Rimuovere strumento perfusione e decapitare il animali. Fare un postero tagliare la linea mediana del cranio, e poi sbattere il cranio per esporre la cavità del cranio 10. </li><li> Rimuovere il cervello con una spatola dalla cavità cranio e posizionare il cervello in una provetta da centrifuga da 50 ml contenente 25 ml di 4% paraformaldeide. Mantenere il cervello all&#39;interno del tubo-paraformaldeide contenente 4 ºC frigorifero per 24 ore. </li><li> Spostare il cervello in una provetta da centrifuga da 50 ml contenente 25 ml di soluzione di saccarosio al 30% a 4 ° C per 3 giorni. Infine, conservare il cervello in sacchetti di plastica a -80 ° C fino all&#39;uso. </li><li> Montare il cervello su un mandrino con i media embedding e congelare i media incorporamento contenenti cervello in un criostato ad una temperatura di -26 ° C. Tagliare il congelato frescon cervello in 20 sezioni micron e il cervello paraformaldeide-preceduti in sezioni di 10 micron. Trasferire la sezione di un vetrino da microscopio RT toccando la slitta alla sezione. </li><li> Asciugare a temperatura ambiente per 4 ore. Conservare i vetrini sezione in un sacchetto stretto sigillato a -80 ° C fino all&#39;uso. </li></ol></li><li> Disidratazione <ol><li> Prendere diapositive dal -80 ° C freezer e assegnare sezioni in una delle tre prove: HT2A, ppiB (controllo positivo) o dapB (controllo negativo); marchio e le sezioni di etichette con una penna a sfera (non usare una matita). Immergere i vetrini in 100% di alcol a temperatura ambiente per 5 minuti. Asciugare i vetrini per 5 minuti in una cappa aspirante. </li></ol></li><li> Pretrattamento <ol><li> Pipettare 20 ml di pretrattamento-1 (reagente inattivazione della fosfatasi alcalina), alle sezioni su vetrini. Porre i vetrini su una cremagliera in un vassoio di umidità (notare che il vassoio è coperta con un coperchio per mantenere una elevata umidità per prevenire evaporazione dal solutio reazionen). </li><li> Agitare delicatamente il vassoio di umidità su un agitatore orizzontale a bassa velocità per 10 min. Lavare i vetrini due volte con acqua bidistillata (DDH 2 O) per 2 min. Immergere il vetrino in un becher da 200 ml contenente 150 ml del pretrattamento-2 reagente (rottura dei legami trasversali indotte da fissazione paraformaldeide). Lessare i vetrini per un totale di 5 min a 100 ° C (ripristino indotta dal calore della struttura dell&#39;RNA 11). </li><li> Lavare i vetrini due volte con DDH 2 O per 2 min. Porre i vetrini in 100% di alcol per 5 min. Essiccare i vetrini per 5 min in cappa. Utilizzare una penna idrofobico per disegnare un cerchio attorno all&#39;area selezionata nella sezione di tessuto (ad esempio, strutture non corticali, tra talamo e ipotalamo come delineate nella figura 2). </li><li> Pipettare 10 ml di pretrattamento-3 reagente (aumenti di penetrazione della sonda) per ogni area selezionata, e coprire il vassoio di umidità con il coperchio. Posizionare il vassoio nel forno di ibridazioneequipaggiato con lo shaker orizzontale e impostare la temperatura del forno a 40 ° C; scuotere delicatamente il cassetto per 30 min. Lavare i vetrini due volte con DDH 2 O per 2 min. </li></ol></li></ol> 2. Ibridazione e Amplificazione <ol><li> Pipettare 10 ml di HTR2A, ppiB e dapB reagenti sonda, rispettivamente, sulle aree selezionate. Coprire il vassoio di umidità con il coperchio per evitare l&#39;evaporazione del reagente. Agitare delicatamente l&#39;agitatore orizzontale impostato a bassa velocità. Incubare i vetrini a 40 ° C in forno per 2 ore. </li><li> Lavare i vetrini due volte con un tampone di lavaggio per 2 min. Pipettare 10 ml di amplificazione-1 reattivo su ogni area selezionata, agitare e incubare i vetrini a 40 ° C per 30 min. </li><li> Lavare i vetrini due volte con un tampone di lavaggio per 2 min. Pipettare 10 ml di reagente di amplificazione-2 per ogni area selezionata, agitare e incubare i vetrini a 40 ° C per 15 minuti. </li><li> Lavare i vetrini due volte with un tampone di lavaggio per 2 min. Pipettare 10 ml di amplificazione-3 reattivo su ogni area selezionata, agitare e incubare i vetrini a 40 ° C per 30 min. </li><li> Lavare i vetrini due volte con un tampone di lavaggio per 2 min. Pipettare 10 ml di reagente di amplificazione-4 per ogni area selezionata, agitare e incubare i vetrini a 40 ° C per 15 minuti. </li><li> Lavare i vetrini due volte con un tampone di lavaggio per 2 min. Pipettare 10 ml di reagente di amplificazione-5 per ogni area selezionata, agitare e incubare i vetrini a temperatura ambiente per 30 min. </li><li> Lavare i vetrini due volte con un tampone di lavaggio per 2 min. Pipettare 10 ml di reagente di amplificazione-6 su ogni area selezionata, agitare e incubare i vetrini a temperatura ambiente per 15 min. Lavare i vetrini due volte con un tampone di lavaggio per 2 min. </li></ol> 3. Rilevamento segnale <ol><li> Pipettare 10 ml di reagente Red a ciascuna area selezionata (Si noti che il reagente è una miscela di rosso-B e Red-A con un rapporto 1:60 e deve essere utilizzato imediatamente). Posizionare il vetrino nel cassetto umidità sulla agitatore orizzontale a temperatura ambiente e agitare delicatamente a bassa velocità per 10 min. </li><li> Lavare i vetrini due volte con (DDH 2 O) per 10 min. Essiccare i vetrini a 60 ° C in forno per 15 min. Porre i vetrini in xilene sotto la cappa per 5 min. Dispensare 20 ml di mezzo di montaggio a base di xilene, su ogni area selezionata e coprire con un coprioggetto. </li></ol> 4. Acquisizione Immagine <ol><li> Prendere microfotografie digitali delle aree selezionate (ad esempio, ipotalamo, le figure 1 e 3) con un ingrandimento di 4 × 20 × e lenti dell&#39;obiettivo. Salvare il file di immagine. </li></ol> Analisi Particle 5. Immagine <ol><li> Trascinare e rilasciare il file immagine nella finestra di ImageJ principale. Vai alla barra dei menu e selezionare &#39;Immagine&#39;, successiva selezionare &#39;Tipo&#39; dal menu a discesa, quindi selezionare &#39;8-bit&#39;. </li><li> Seleziona &#39;Regola&#39;, quindi selezionare &#39;Threshold &#39;per aprire la finestra di dialogo. Regolare il valore barra inferiore della finestra di dialogo in modo che il fondo indesiderato viene rimosso. Vai alla barra dei menu e selezionare &#39;Analizza&#39;, quindi selezionare &#39;Analizza Particelle&#39; per aprire una seconda finestra di dialogo. </li><li> Impostare la dimensione delle particelle a 10, prossimo selezionare &#39;Mostra delinea&#39; e selezionare &#39;Mostra risultati &quot;e&quot; scatole Riassumere&#39;. Infine, fare clic su &#39;OK&#39; per visualizzare i dati delle particelle nelle finestre di dialogo. </li></ol> 6. Foglio di calcolo <ol><li> Inserire i dati nel foglio Excel e la media dei numeri di particelle nel gruppo SAL come linea di base. Calcolare il livello percentuale di ogni sezione e fare un grafico di conseguenza (Figura 4). </li></ol>

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Gli autori dichiarano di non avere interessi finanziari in competizione.

One of the major concerns of in situ hybridization test is to choose appropriate techniques used for RNA preservation because of RNase enzymes. It is well known that these enzymes are widely present in the cells and environment which can affect the results. However, enzyme activity can be quickly distinguished by placing the tissue in the dry ice/alcohol solution5,12. Although quick preservation is critical for hybridization using a riboprobe13, little is known about experimental conditions for oligonucleotide probes. In this study using oligonucleotide probes, we found that there was no difference between the paraformaldehyde-prefixed and fresh brains quickly preserved in the ice/alcohol solution. This suggests that brain RNA prefixed by paraformaldehyde had no significant effect on the quality of hybridization using the oligonucleotide probe. Since the prefixed brain is easily sectioned compared to the fresh brain, this protocol provides an alternative tissue preparation for the hybridization test. 
We believe that keeping the brain tissue sections inside the sealed moisture tray with constant shaking on the horizontal shaker is essential for successful hybridization. Failure to follow those steps may result in uneven hybridization or high background. To eliminate possibilities of false-negative or false-positive results, tests should include necessary control slides. We found that the dapB probe did not show a visible signal. This is not surprising since dapB is a bacterial gene that is unlikely found in mammalian cells. In contrast, the area hybridized with the ppiB probe showed signals homogenously distributed throughout the region examined. This is predictable since the housekeeping gene should be present in any kind of mammalian cells. It has been suggested that 5-HT2A mRNA is distributed heterogeneously in the brain nuclei, including the hypothalamus14,15. As expected, htr2a signals are present in certain nuclei in the region of the hypothalamus although the probe has been applied to all of the selected areas. It should be kept in mind that the use of alcohol should be avoided after the Red reagent (step 3.1) since red signals can be easily decolored by alcohol. We found that, after cellular RNA stained with the Red reagent, cells cannot be counterstained with hematoxylin or crystal violet although the exact cause of counterstaining failure is unknown. In summary, a characteristic distribution of htr2a mRNA supports the idea that these oligonucleotide probes are gene-specific despite the shorter sequence relative to other probes16,17. 
Background signals are another major concern, which likely affects the quality and faithfulness of data analysis. Unlike the high background produced by riboprobes13, oligonucleotide probes normally show a very low background. Thus, image can be easily and reasonably quantified using publicly-available NIH ImageJ software. In this study, we showed an example of this technique by examining changes in htr2a expression in response to systemic MDMA at 10 mg/kg. We demonstrated that MDMA caused a 20% reduction in htr2a expression, supporting previous reports18. 
In addition to the three genes outlined above, this protocol has been validated with two other gene probes (trh, thyrotropin-release hormone gene, and trhr, thyrotropin-releasing hormone receptor gene; data not shown), demonstrating a high sensitivity and accuracy in detecting mRNA levels. Since most reactions require only 10 &#181;l of reagents, the cost of an assay is also significantly reduced, compared to radioactive riboprobes. Furthermore, it is important to note that this protocol does not require the RNase-free environment. In conclusion, this protocol improves the speed of in situ hybridization assay, and increases reproducibility with relatively low cost.

Serotonin (5-hydroxytryptamine; 5-HT) syndrome is an acute neurologic disorder caused by 5-HT-promoting drugs such as antidepressants1, while also occurring in situations of MDMA use for recreational purposes2. Molecular mechanisms responsible for mood swings, learning and memory deficits that occur in association with the acute syndrome are not well understood3,4. In situ hybridization is a powerful research tool allowing the detection and quantification of specific mRNAs expressed potentially at a single-cell level. The conventional way to perform in situ hybridization is to utilize a radioactive-labeled riboprobe that specifically hybridizes the gene of interest. However, a major drawback is that the method requires complicated and time-consuming probe preparation and hybridization steps, as well as access to fresh frozen tissues maintained in an RNase-free environment5,6. 
Oligonucleotide probes have been recently developed to hybridize shorter RNA fragments than those required for riboprobes7. Furthermore, the probes produce a low background signal without sacrificing specificity8. This newly-developed probe technology can be used in situ hybridization on paraformaldehyde-prefixed brain tissues commonly available in immunocytochemical laboratories.
Here, we describe a protocol for in situ hybridization using oligonucleotide probes on paraformaldehyde-prefixed rat brain and compare findings with those noted in a fresh frozen brain5,6. This protocol is used to test the hypothesis that MDMA substance abuse causes changes in 5-HT2A receptor gene htr2a mRNA in the brain. We began the procedure with MDMA treatment followed by paraformaldehyde tissue perfusion of the animal, in situ hybridization of the thr2a probe, and data analysis. Note that dapB (the bacterial gene coding for dihydrodipicolinate reductase) is used as a negative control, and ppiB (housekeeping gene coding for peptidylprolyl isomerase B) as a positive control.

<table><tbody><tr><td>RNAscope Negative Control Probe-DapB</td><td>Advanced cell diagnostic, INC</td><td>310098</td><td></td></tr><tr><td>RNAscope Pretreat 4</td><td>Advanced cell diagnostic, INC</td><td>320046</td><td></td></tr><tr><td>RNAscope 2.0 HD Reagent Kit - Red</td><td>Advanced cell diagnostic, INC</td><td>310036</td><td></td></tr><tr><td>RNAscope Probe - Rn-Ppib</td><td>Advanced cell diagnostic, INC</td><td>313921</td><td></td></tr><tr><td>Rat Htr2a</td><td>Advanced cell diagnostic, INC</td><td>300031</td><td></td></tr><tr><td>Cryostat</td><td>Leica</td><td>CM 1850</td><td></td></tr><tr><td>Horizontal shaker</td><td>VWR</td><td>88032-088</td><td></td></tr><tr><td>Hybridization oven</td><td>Thermo Fisher Scientific</td><td>222000</td><td></td></tr><tr><td>Superfrost Plus microscope slide</td><td>Fisher Scientific</td><td>12-550-15</td><td></td></tr><tr><td>Hydrophobic pen</td><td>Vector</td><td>H-4000</td><td></td></tr><tr><td>Microscope</td><td>Olympus</td><td>Provis AX70</td><td></td></tr></tbody></table>

rapid in situ hybridization using oligonucleotide probes on paraformaldehyde-prefixed brain of rats with serotonin syndrome

3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) toxicity may cause region-specific changes in serotonergic mRNA expression due to acute serotonin (5-hydroxytryptamine; 5-HT) syndrome. This hypothesis can be tested using in situ hybridization to detect the serotonin 5-HT2A receptor gene htr2a. In the past, such procedures, utilizing radioactive riboprobe, were difficult because of the complicated workflow that needs several days to perform and the added difficulty that the technique required the use of fresh frozen tissues maintained in an RNase-free environment. Recently, the development of short oligonucleotide probes has simplified in situ hybridization procedures and allowed the use of paraformaldehyde-prefixed brain sections, which are more widely available in laboratories. Here, we describe a detailed protocol using non-radioactive oligonucleotide probes on the prefixed brain tissues. Hybridization probes used for this study include dapB (a bacterial gene coding for dihydrodipicolinate reductase), ppiB (a housekeeping gene coding for peptidylprolyl isomerase B), and htr2a (a serotonin gene coding for 5-HT2A receptors). This method is relatively simply, cheap, reproducible and requires less than two days to complete.

Usando le sonde oligonucleotidi RNA (&lt;25 nt), ibridazione può essere rilevato come punti rossi nelle cellule dell&#39;ipotalamo preparate dal cervello paraformaldeide-prefissato e freschi congelati. Le molecole di mRNA HTR2A sono presenti in alcune cellule (indicati dalle frecce solidi), ma non altri (frecce aperti). Abbiamo osservato che non vi è alcuna differenza tra la paraformaldeide-prefissato e tessuti freschi congelati (Figura 1). Un ibridazione successo può essere valutato per primo occhio nudo (Figura 2). Abbiamo trovato che l&#39;area selezionata (contrassegnata con cerchi) ibridato con la sonda dapB non ha mostrato un segnale visibile ad occhio nudo (Figure 2A-B). Al contrario, l&#39;area ibridato con la sonda ppiB presenta segnali omogeneamente distribuite in tutta la regione in esame (figure 2C-D). Mentre nel test HTR2A, segnali sono presenti in alcuni nuclei (indicata dalle frecce; <strong&gt; Figure 2E-F), anche se tutta la zona cerchiata è stato ibridato con la sonda HTR2A. È interessante notare che i segnali di diapositive MDMA erano relativamente debole rispetto alle diapositive SAL. Dettagli sostanziali di segnali di ibridazione possono essere valutati nell&#39;ambito di uno strumento microscopica. Non vi è alcun punto rosso (Figura 3A-B) nelle cellule ibridati con la sonda dapB mentre segnali può essere visto in tutto il campo microscopico ibridato con la sonda ppiB (Figura 3C-D). I segnali HTR2A si trovano prevalentemente in certi nuclei dell&#39;ipotalamo (Figura 3E-F). Abbiamo osservato una riduzione dei segnali HTR2A nei tessuti cerebrali precedentemente trattati con MDMA sistemica a 10 mg / kg, che può essere determinato quantitativamente mediante analisi ImageJ. Come mostrato in figura 4, abbiamo trovato una riduzione del 20% in espressione HTR2A. In conclusione, i nostri risultati hanno dimostrato che utilizzando oligosonde nucleotidiche è specifica, e adatti per il tessuto cerebrale prefissato. Inoltre, le procedure di protocollo, anche in ibridazione in situ, l&#39;analisi dei dati e il rilevamento del segnale può essere completato nel giro di due giorni. <img alt="Figura 1" src="/files/ftp_upload/53165/53165fig1.jpg" /> Figura 1. Confronto dei tessuti freschi e congelati prefissati. Le procedure utilizzate per cervelli freschi congelati, sono state descritte altrove 5. Si noti che le sezioni freschi congelati sono stati tagliati a 20 micron di spessore, mentre le sezioni congelate fissato a 10 micron. La sonda oligonucleotide era HTR2A che ibrida il 5-HT mRNA del recettore 2A nell&#39;ipotalamo. Frecce continue indicano cellule contenenti molecole di mRNA HTR2A nel fresco congelato (A) e tessuti prefissate (B). Frecce Open, non molecole di mRNA HTR2A rilevati. Bar: 20 micron. Utilizzando NIHAnalisi ImageJ, HTR2A è stato contato. Numero di conteggi HTR2A non sono diversi tra i tessuti congelati freschi e paraformaldeide-prefisso (C). <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53165/53165fig1large.jpg" target="_blank">Cliccate qui per vedere una versione più grande di questa figura.</a> <img alt="Figura 2" src="/files/ftp_upload/53165/53165fig2.jpg" /> Figura 2. Una vista ad occhio nudo di segnali di ibridazione. I tessuti sono stati preceduti dal prefisso paraformaldeide in ratti anestetizzati profondamente precedentemente trattati con soluzione salina (SAL) e 3,4-Metilendiossinaetanfetamina (MDMA). Le linee bianche tratteggiate indicano la regione ibridato con sonde oligonucleotidiche. Il colore rosso denota segnali di mRNA a occhio nudo. Nessun segnale rosso si osserva mentre si utilizza la sonda dapB ibridato alle sezioni di SAL-pretrattati (A) o topi pre-trattati con MDMA (B </strong&gt;). Al contrario, i segnali rossi sono omogeneamente distribuiti nelle regioni ipotalamiche mentre si utilizza la sonda ppiB (CD). È interessante notare che i segnali rossi prodotti dalla sonda HTR2A sono solo in alcune regioni (EF, frecce indicano l&#39;area ipotalamica). Coordinate stereotassica: -3.50 ~ -3,80 rispetto al bregma. 3V, il terzo ventricolo. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53165/53165fig2large.jpg" target="_blank">Clicca qui per vedere una versione più grande di questa figura.</a> <img alt="Figura 3" src="/files/ftp_upload/53165/53165fig3.jpg" /> Figura 3. Una vista microscopico luce di segnali di ibridazione. I tessuti sono stati preceduti dal prefisso paraformaldeide in ratti anestetizzati profondamente precedentemente trattati con soluzione salina (SAL) e 3,4-Metilendiossinaetanfetamina (MDMA). Sonde oligonucleotidiche sono dapB (AB), ppiB (CD) e HTR2A (EF). Segnali di ibridazione sono identificati come punti rossi con poteri di ingrandimento oggettivi che vanno da 4 × (bar: 200 micron). A 20 × (microfotografie inserto) <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/53165/53165fig3large.jpg" target="_blank">Cliccate qui per vedere una versione più grande di questa figura.</a> <img alt="Figura 4" src="/files/ftp_upload/53165/53165fig4.jpg" /> Figura 4. Effetti sul espressione HTR2A ipotalamo nei ratti precedentemente trattati con MDMA. I campioni sono stati analizzati in duplicato e ripetuti tre volte. I dati sono espressi come percentuale media ± SEM del gruppo SAL (un totale di 8 ratti utilizzati in questo studio). * P &lt;0,05 vs. il gruppo SAL mediante test t di Student. <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><t<html> d&gt; </td><td> Fresco </td><td></td><td colspan="2"> Paraformaldeide prefissa un </td></tr><tr><td></td><td> SAL b </td><td></td><td> SAL b </td><td> MDMA c </td></tr><tr><td> Sonda Target (HTR2A) </td><td> √ </td><td></td><td> √ </td><td> √ </td></tr><tr><td> Sonda positiva (ppiB) </td><td> - </td><td></td><td> √ </td><td> √ </td></tr><tr><td> Sonda negativo (dapB) </td><td> - </td><td></td><td> √ </td><td> √ </td></tr></tbody></table> √, indica il gruppo in esame con sonda oligonucleotide in questo studio. -, Non esaminati; un, ciascun gruppo contiene 4 animali diversi; b, il gruppo pretrattato con soluzione salina per via intraperitoneale fisica (SAL; 0,9% NaCl); c, pretrattati per via intraperitoneale con 10 mg / kg di MDMA. Tabella 1. Disegno jove_content &quot;&gt; sperimentale

Watch this Scientific Journal Video about Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome at JoVE.com

Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome

This protocol describes a rapid and simplified in situ hybridization method ideal forparaformaldehyde-prefixed brain, thus reducing the need for prolonged complex steps while using fresh frozen tissues. The method is validated using the identification of the serotonin 5-HT2A receptor gene htr2a in rats.

Rapido<em&gt; In Situ</em&gt; Ibridazione utilizzando oligonucleotidi sonde su Paraformaldeide prefissa cervello di ratti con Sindrome serotoninergica

3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) toxicity may cause region-specific changes in serotonergic mRNA expression due to acute serotonin ...

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Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome

8.8K Views.  Ross University School of Veterinary Medicine. This protocol describes a rapid and simplified in situ hybridization method ideal forparaformaldehyde-prefixed brain, thus reducing the need for prolonged complex steps while using fresh frozen tissues. The method is validated using the identification of the serotonin 5-HT2A receptor gene htr2a in rats.

Video: Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome

Double Fluorescence in situ Hybridization in Fresh Brain Sections

Here we describe a modified version of a double fluorescence in situ hybridization (dFISH) method optimized for detecting two mRNAs of interest in fresh frozen brain sections. Our group has successfully used this approach to study gene co-regulation. More specifically, we have used this dFISH method to explore the anatomical organization, neurochemical properties, and the impact of sensory experience in central sensory circuits, at single cell resolution. This protocol has been validated in brain tissue from mice, rats and songbirds but is expected to be easily adaptable to other vertebrate species, as well as to an array of non-neural tissues. In this film we provide a detailed demonstration of the main steps of this procedure.

Double Fluorescence in situ Hybridization in Fresh Brain Sections

This protocol involves a non-radioactive in-situ hybridization procedure that enables the simultaneous identification of two transcript species, at a single cell resolution, in thin sections of the vertebrate brain.

Doppia fluorescenza In situ</emIbridazione> nelle sezioni cervello fresco

Here we describe a modified version of a double fluorescence in situ hybridization (dFISH) method optimized for detecting two mRNAs of interest in fresh ...

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Neuroscienze

Biomarkers in an Animal Model for Revealing Neural, Hematologic, and Behavioral Correlates of PTSD

Identification of biomarkers representing the evolution of the pathophysiology of Post Traumatic Stress Disorder (PTSD) is vitally important, not only for objective diagnosis but also for the evaluation of therapeutic efficacy and resilience to trauma. Ongoing research is directed at identifying molecular biomarkers for PTSD, including traumatic stress induced proteins, transcriptomes, genomic variances and genetic modulators, using biologic samples from subjects' blood, saliva, urine, and postmortem brain tissues. However, the correlation of these biomarker molecules in peripheral or postmortem samples to altered brain functions associated with psychiatric symptoms in PTSD remains unresolved. Here, we present an animal model of PTSD in which both peripheral blood and central brain biomarkers, as well as behavioral phenotype, can be collected and measured, thus providing the needed correlation of the central biomarkers of PTSD, which are mechanistic and pathognomonic but cannot be collected from people, with the peripheral biomarkers and behavioral phenotypes, which can.
Our animal model of PTSD employs restraint and tail shocks repeated for three continuous days - the inescapable tail-shock model (ITS) in rats. This ITS model mimics the pathophysiology of PTSD 17, 7, 4, 10. We and others have verified that the ITS model induces behavioral and neurobiological alterations similar to those found in PTSD subjects 17, 7, 10, 9. Specifically, these stressed rats exhibit (1) a delayed and exaggerated startle response appearing several days after stressor cessation, which given the compressed time scale of the rat's life compared to a humans, corresponds to the one to three months delay of symptoms in PTSD patients (DSM-IV-TR PTSD Criterian D/E 13), (2) enhanced plasma corticosterone (CORT) for several days, indicating compromise of the hypothalamopituitary axis (HPA), and (3) retarded body weight gain after stressor cessation, indicating dysfunction of metabolic regulation.
The experimental paradigms employed for this model are: (1) a learned helplessness paradigm in the rat assayed by measurement of acoustic startle response (ASR) and a charting of body mass; (2) microdissection of the rat brain into regions and nuclei; (3) enzyme-linked immunosorbent assay (ELISA) for blood levels of CORT; (4) a gene expression microarray plus related bioinformatics tools 18. This microarray, dubbed rMNChip, focuses on mitochondrial and mitochondria-related nuclear genes in the rat so as to specifically address the neuronal bioenergetics hypothesized to be involved in PTSD.

We describe a rat model of post traumatic stress disorder (PTSD) that reveals the persistent alterations in neuroendocrine function and the delayed long-term, exaggerated fear response, characteristic of PTSD patients. The animal model and methods described here are useful for correlating biomarkers in brain nuclei, which are mechanistic but cannot be measured in patients, with biomarkers in peripheral white blood cells, which can.

Biomarcatori in un modello animale per Rivelare correlati neurali, ematologiche, e comportamentali di PTSD

Identification of biomarkers representing the evolution of the pathophysiology of Post Traumatic Stress Disorder (PTSD) is vitally important, not only for ...

Medicina

DetectSyn: A Rapid, Unbiased Fluorescent Method to Detect Changes in Synapse Density

Synapses are the site of communication between neurons. Neuronal circuit strength is related to synaptic density, and the breakdown of synapses is characteristic of disease states like major depressive disorder (MDD) and Alzheimer's disease. Traditional techniques to investigate synapse numbers include genetic expression of fluorescent markers (e.g., green fluorescent protein (GFP)), dyes that fill a neuron (e.g., carbocyanine dye, DiI), and immunofluorescent detection of spine markers (e.g., postsynaptic density 95 (PSD95)). A major caveat to these proxy techniques is that they only identify postsynaptic changes. Yet, a synapse is a connection between a presynaptic terminal and a postsynaptic spine. The gold standard for measuring synapse formation/elimination requires time-consuming electron microscopy or array tomography techniques. These techniques require specialized training and costly equipment. Further, only a limited number of neurons can be assessed and are used to represent changes to an entire brain region. DetectSyn is a rapid fluorescent technique that identifies changes to synapse formation or elimination due to a disease state or drug activity. DetectSyn utilizes a rapid proximity ligation assay to detect juxtaposed pre- and postsynaptic proteins and standard fluorescent microscopy, a technique readily available to most laboratories. Fluorescent detection of the resulting puncta allows for quick and unbiased analysis of experiments. DetectSyn provides more representative results than electron microscopy because larger areas can be analyzed than a limited number of fluorescent neurons. Moreover, DetectSyn works for in vitro cultured neurons and fixed tissue slices. Finally, a method is provided to analyze the data collected from this technique. Overall, DetectSyn offers a procedure for detecting relative changes in synapse density across treatments or disease states and is more accessible than traditional techniques.

DetectSyn is an unbiased, rapid fluorescent assay that measures changes in relative synapse (pre- and postsynaptic engagement) number across treatments or disease states. This technique utilizes a proximity ligation technique that can be used both in cultured neurons and fixed tissue.

DetectSyn: un metodo fluorescente rapido e imparziale per rilevare i cambiamenti nella densità delle sinapsi

Synapses are the site of communication between neurons. Neuronal circuit strength is related to synaptic density, and the breakdown of synapses is ...

Biochimica

Detection of Axonally Localized mRNAs in Brain Sections Using High-Resolution In Situ Hybridization

mRNAs are frequently localized to vertebrate axons and their local translation is required for axon pathfinding or branching during development and for maintenance, repair or neurodegeneration in postdevelopmental periods. High throughput analyses have recently revealed that axons have a more dynamic and complex transcriptome than previously expected. These analysis, however have been mostly done in cultured neurons where axons can be isolated from the somato-dendritic compartments. It is virtually impossible to achieve such isolation in whole tissues in vivo. Thus, in order to verify the recruitment of mRNAs and their functional relevance in a whole animal, transcriptome analyses should ideally be combined with techniques that allow the visualization of mRNAs in situ. Recently, novel ISH technologies that detect RNAs at a single-molecule level have been developed. This is especially important when analyzing the subcellular localization of mRNA, since localized RNAs are typically found at low levels. Here we describe two protocols for the detection of axonally-localized mRNAs using a novel ultrasensitive RNA ISH technology. We have combined RNAscope ISH with axonal counterstain using fluorescence immunohistochemistry or histological dyes to verify the recruitment of Atf4 mRNA to axons in vivo in the mature mouse and human brains.

Detection of Axonally Localized mRNAs in Brain Sections Using High-Resolution In Situ Hybridization

RNA in situ hybridization (ISH) enables the visualization of RNAs in cells and tissues. Here we show how combination of RNAscope ISH with immunohistochemistry or histological dyes can be successfully used to detect mRNAs localized to axons in sections of mouse and human brains.

Rilevazione di assoni localizzato mRNA nelle sezioni del cervello Utilizzando ad alta risoluzione<em&gt; In Situ</em&gt; Ibridazione

mRNAs are frequently localized to vertebrate axons and their local translation is required for axon pathfinding or branching during development and for ...

Combining Double Fluorescence In Situ Hybridization with Immunolabelling for Detection of the Expression of Three Genes in Mouse Brain Sections

Detection of gene expression in different types of brain cells e.g., neurons, astrocytes, oligodendrocytes, oligodendrocyte precursors and microglia, can be hampered by the lack of specific primary or secondary antibodies for immunostaining. Here we describe a protocol to detect the expression of three different genes in the same brain section using double fluorescence in situ hybridization with two gene-specific probes followed by immunostaining with an antibody of high specificity directed against the protein encoded by a third gene. The Aspartoacyclase (ASPA) gene, mutations of which can lead to a rare human white matter disease - Canavan disease - is thought to be expressed in oligodendrocytes and microglia but not in astrocytes and neurons. However, the precise expression pattern of ASPA in the brain has yet to be established. This protocol has allowed us to determine that ASPA is expressed in a subset of mature oligodendrocytes and it can be generally applied to a wide range of gene expression pattern studies.

Combining Double Fluorescence In Situ Hybridization with Immunolabelling for Detection of the Expression of Three Genes in Mouse Brain Sections

Localizing gene expression to specific cell types can be challenging due to the lack of specific antibodies. Here we describe a protocol for simultaneous triple detection of gene expression by combining double fluorescence RNA in situ hybridization with immunostaining.

La combinazione di doppio Fluorescenza<em&gt; In Situ</em&gt; Ibridazione con Immunolabelling per il rilevamento della Manifestazione di tre geni nel cervello di topo Sezioni

Detection of gene expression in different types of brain cells e.g., neurons, astrocytes, oligodendrocytes, oligodendrocyte precursors and microglia, can ...

Identification of Dopamine D1-Alpha Receptor Within Rodent Nucleus Accumbens by an Innovative RNA In Situ Detection Technology

In the central nervous system, the D1-alpha subtype receptor (Drd1&#945;) is the most abundant dopamine (DA) receptor, which plays a vital role in regulating neuronal growth and development. However, the mechanisms underlying Drd1&#945; receptor abnormalities mediating behavioral responses and modulating working memory function are still unclear. Using a novel RNA in situ hybridization assay, the current study identified dopamine Drd1&#945; receptor and tyrosine hydroxylase (TH) RNA expression from DA-related circuitry in the nucleus accumbens (NAc) area and substantia nigra region (SNR), respectively. Drd1&#945; expression in the NAc shows a &#34;discrete dot&#34; staining pattern. Clear sex differences in Drd1&#945; expression were observed. In contrast, TH shows a &#34;clustered&#34; staining pattern. Regarding TH expression, female rats displayed a higher signal expression per cell relative to male animals. The methods presented here provide a novel in situ hybridization technique for investigating changes in dopamine system dysfunction during the progression of central nervous system diseases.

Identification of Dopamine D1-Alpha Receptor Within Rodent Nucleus Accumbens by an Innovative RNA In Situ Detection Technology

Identification of dopamine D1-alpha receptor in the nucleus accumbens is critical for clarifying D1 receptor dysfunction during a central nervous system disease. We performed a novel RNA in situ hybridization assay to visualize single RNA molecules in a specific brain area.

Identificazione della dopamina D1-alfa del ricevitore all'interno del roditore Nucleus Accumbens da un innovativo RNA In Situ Detection Technology

In the central nervous system, the D1-alpha subtype receptor (Drd1&#945;) is the most abundant dopamine (DA) receptor, which plays a vital role in ...

Using Near-infrared Fluorescence and High-resolution Scanning to Measure Protein Expression in the Rodent Brain

Neuroscience is the study of how cells in the brain mediate various functions. Measuring protein expression in neurons and glia is critical for the study of neuroscience as cellular function is determined by the composition and activity of cellular proteins. In this article, we describe how immunocytochemistry can be combined with near-infrared high-resolution scanning to provide a semi-quantitative measure of protein expression in distinct brain regions. This technique can be used for single or double protein expression in the same brain region. Measuring proteins in this fashion can be used to obtain a relative change in protein expression with an experimental manipulation, molecular signature of learning and memory, activity in molecular pathways, and neural activity in multiple brain regions. Using the correct proteins and statistical analysis, functional connectivity among brain regions can be determined as well. Given the ease of implementing immunocytochemistry in a laboratory, using immunocytochemistry with near-infrared high-resolution scanning can expand the ability of the neuroscientist to examine neurobiological processes at a systems level.

Here, we present a protocol that uses near-infrared dyes in conjunction with immunohistochemistry and high-resolution scanning to assay proteins in brain regions.

Utilizzo della fluorescenza Near-Infrared e scansione ad alta risoluzione per misurare l'espressione proteica nel cervello del roditore

Neuroscience is the study of how cells in the brain mediate various functions. Measuring protein expression in neurons and glia is critical for the study ...

Combining Multiplex Fluorescence In Situ Hybridization with Fluorescent Immunohistochemistry on Fresh Frozen or Fixed Mouse Brain Sections

Fluorescent in situ hybridization (FISH) is a molecular technique that identifies the presence and spatial distribution of specific RNA transcripts within cells. Neurochemical phenotyping of functionally identified neurons usually requires concurrent labelling with multiple antibodies (targeting protein) using immunohistochemistry (IHC) and optimization of in situ hybridization (targeting RNA), in tandem. A &#34;neurochemical signature&#34; to characterize particular neurons may be achieved however complicating factors include the need to verify FISH and IHC targets before combining the methods, and the limited number of RNAs and proteins that may be targeted simultaneously within the same tissue section.
Here we describe a protocol, using both fresh frozen and fixed mouse brain preparations, which detects multiple mRNAs and proteins in the same brain section using RNAscope FISH followed by fluorescence immunostaining, respectively. We use the combined method to describe the expression pattern of low abundance mRNAs (e.g., galanin receptor 1) and high abundance mRNAs (e.g., glycine transporter 2), in immunohistochemically identified brainstem nuclei.
Key considerations for protein labelling downstream of the FISH assay extend beyond tissue preparation and optimization of FISH probe labelling. For example, we found that antibody binding and labelling specificity can be detrimentally affected by the protease step within the FISH probe assay. Proteases catalyze hydrolytic cleavage of peptide bonds, facilitating FISH probe entry into cells, however they may also digest the protein targeted by the subsequent IHC assay, producing off target binding. The subcellular location of the targeted protein is another factor contributing to IHC success following FISH probe assay. We observed IHC specificity to be retained when the targeted protein is membrane bound, whereas IHC targeting cytoplasmic protein required extensive troubleshooting. Finally, we found handling of slide-mounted fixed frozen tissue more challenging than fresh frozen tissue, however IHC quality was overall better with fixed frozen tissue, when combined with RNAscope.

Combining Multiplex Fluorescence In Situ Hybridization with Fluorescent Immunohistochemistry on Fresh Frozen or Fixed Mouse Brain Sections

This protocol describes a method for combining fluorescence in situ hybridization (FISH) and fluorescence immunohistochemistry (IHC) in both fresh frozen and fixed mouse brain sections, with the goal of achieving multilabel FISH and fluorescence IHC signal. IHC targeted cytoplasmic and membrane attached proteins.

Combinazione dell'ibridazione in situ a fluorescenza multiplex con immunoistochimica fluorescente su sezioni cerebrali di topo fresche, congelate o fisse

Fluorescent in situ hybridization (FISH) is a molecular technique that identifies the presence and spatial distribution of specific RNA transcripts within ...

In Situ Hybridization Using Oligonucleotide Probes to Study RNA Expression in Rat Brain Sections

Source: Shokry, I. M., et al. <a href="https://app-jove-com.bdigitaluss.remotexs.co/v/53165">Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome.</a>&#160;J. Vis. Exp.&#160;(2015).
This video demonstrates the detection of serotonin receptor RNA synthesis using oligonucleotide probes in rat brain tissue affected by serotonin syndrome. The protocol includes tissue pretreatment, probe hybridization, and enzymatic detection to visualize and quantify serotonin receptor RNA expression under a microscope.

Source: Shokry, I. M., et al. Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin ...

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Neuropathology

Neurodegenerative Diseases

 Performing Double Fluorescence In Situ Hybridization to Detect Gene Expression in Mouse Brain Sections

<a href='https://app-jove-com.bdigitaluss.remotexs.co/v/53976/combining-double-fluorescence-situ-hybridization-with-immunolabelling'>Source: Jolly, S., et.al. Combining Double Fluorescence In Situ Hybridization with Immunolabelling for Detection of the Expression of Three Genes in Mouse Brain Sections. J. Vis. Exp. (2016).</a>This video demonstrates the use of double fluorescence in situ hybridization to visualize the expression of two RNA targets in mouse brain sections. The protocol involves sequential detection of RNA using probes labeled with fluorescein isothiocyanate and digoxigenin, followed by enzymatic signal amplification to enhance sensitivity. The resulting fluorescence enables co-localization analysis of the target RNAs within the tissue.

Source: Jolly, S., et.al. Combining Double Fluorescence In Situ Hybridization with Immunolabelling for Detection of the Expression of Three Genes in Mouse ...

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Doppia fluorescenza In situ nelle sezioni cervello fresco