Die Autoren möchten danke Yuliya Naumchuk (Loyola University Chicago) und Agne Žiniauskaitė (Experimentica GmbH), für hervorragende technische und videographische Unterstützung. Dr. Kaja Forschungsprogramm wird von Dr. John P. und Therese E. Mulcahy dotierte Professur für Augenheilkunde an der Loyola University Chicago unterstützt.

Alle Tiere wurden gemäß der ARVO-Erklärung für die Verwendung von Tieren in Ophthalmic und Vision Research und der EG-Richtlinie 86/609/EWG für Tierversuche, unter Verwendung von Protokollen genehmigt und überwacht durch das Tier Experiment Board of Finland behandelt.
(1) Laser-induced Maus CNV Modell 5
<ol><li>Die Augen des Tieres makroskopisch für alle mögliche Abweichungen zu überprüfen.</li>
	<li>Wiegen Sie die Maus.</li>
	<li>Berechnen Sie und bereiten Sie einen angemessenen Betrag von Anästhetika zu bedienen, bezogen auf das Gewicht des Tieres, z. B. eine Mischung aus Medetomidine (1 mg/kg), Ketamin (75 mg/kg) und destilliertes Wasser (0,9 % NaCl-Lösung) in einem Verhältnis von 1:1.5:2.5 oder Ketamin (40-75 mg/kg), Xylazin (5 mg/kg) und destilliertes Wasser (0,9 % NaCl-Lösung) in einem Verhältnis von 5:1 1:2.; Spritzen Sie für eine 20 g Maus 0,1 mL der Mischung.</li>
	<li>Intraperitoneal injizieren Sie Betäubungsmittel.</li>
	<li>Legen Sie Maus zurück in den Käfig und warten Sie, bis Tier betäubt ist. Bestätigen Sie, dass die Maus durch Mangel an einem Pedal Reflex richtig betäubt ist.</li>
	<li>Den Einsatz von Laser-Sicherheit persönlicher Schutzausrüstung zu gewährleisten.</li>
	<li>Aktivieren Sie eine Spaltlampe und einem 532 nm Diodenlaser.</li>
	<li>Entfernen Sie die Maus aus dem Käfig und auf das Heizkissen.</li>
	<li>Geben Sie einen Tropfen Tropicamid für Pupillen Dilatation. Warten Sie ca. 3-5 min für Pupillen Dilatation voll (3 mm).</li>
	<li>Platzieren Sie den Mauszeiger auf der Bühne an der Spaltlampe.</li>
	<li>Legen Sie einen Tropfen des Opthalmic liquid Gel auf ein Deckglas, Applanate der Hornhaut.</li>
	<li>Richten Sie das Maus-Auge mit dem Sehnerv Kopf in der Mitte.</li>
	<li>Legen Sie die Laserleistung auf 100 mW, die Dauer bis 100 ms und die Punktgröße bis 50 µm.</li>
	<li>Den Laserstrahl auf das retinale Pigmentepithel (RPE) konzentrieren.</li>
	<li>Machen Sie drei Laserschüsse in einem Auge Netzhautgefäße idealerweise auf die 4, 8 und 12:00 Positionen rund um den Sehnerv bzw. zu vermeiden. Den Fundus des Auges zu inspizieren, nachdem alle Aufnahmen für Abwesenheit von retinalen Blutungen laser. Der kontralaterale Auge dient als Kontrolle nicht gelasert.</li>
	<li>Entsorgen Sie die Deckglas und Ort Maus wieder auf das Heizkissen.</li>
	<li>Ein Tropfen von PEG Gel Tropfen auf beide Augen auftragen.</li>
</ol>2. SD-OCT 6,7
<ol><li>Platzieren Sie den Mauszeiger in das Nagetier Ausrichtung Stadium, und immobilisieren Sie den Kopf zu.</li>
	<li>Richten Sie das Objektiv von der SD-OCT-System (z. B.Bioptigen/Leica Envisu R2200) vor das Auge für die in-Vivo Bildgebung mit X - und Y-Stage Controller.</li>
	<li>SD-OCT Scans überprüfen, bricht der Bruch Membran durchführen: Sobald die SD-OCT das ganze Auge scannt, manuell verschieben die Betreff-Zeile auf den gelaserten Seiten. Bricht der Bruch Membran sollte in gelaserten Bereichen deutlich sichtbar sein (siehe Abbildung 1).</li>
</ol>(3) Fluorescein Angiographie 7,8,9
<ol><li>Entfernen Sie Maus mit dem Halter zu, und legen Sie es auf das FA-System (z.B.Heidelberg Spectralis HRA2).</li>
	<li>Fokus auf Laser brennen Bereichen des Augenhintergrundes des Auges mit Infrarot-Reflexionsvermögen-Modus mit dem Kopf des Sehnervs mitten in das Sichtfenster.</li>
	<li>Injizieren Sie 0,1 mL 5 % Fluorescein Natrium-Salz für eine 20 g-Maus, subkutan oder intraperitoneal.</li>
	<li>Im Mittelpunkt der Aderhaut Ebene.</li>
	<li>Nehmen Sie ein Bild von der Aderhaut Fokus-Ebene.</li>
	<li>Neuausrichtung auf die Netzhaut Ebene und nehmen Sie ein Bild.</li>
	<li>Warten Sie, bis 30 s und wiederholen Sie Schritte 3.4-3.6.</li>
	<li>Entfernen Sie die Maus aus der Halterung, und legen Sie es auf das Heizkissen.</li>
	<li>Umgekehrte Anästhesie durch α2-Antagonist für Medetomidine, Atipamezol (0,5 mg/kg, i.p.) oder warten Sie auf tierische Erholung aus der Narkose.</li>
	<li>Wiederholen Sie in Vivo SD-OCT und FA Bildgebung bei narkotisierten Tieren an den weiteren Tagen 5, 10 und 14.</li>
</ol>(4) CNV Verschneidung
<ol><li>Grad der Beschädigung der Bruch Membran aus OCT-Bildern und Aderhaut FA-Aufnahmen unmittelbar nach dem Lasern am Tag 0 wie folgt: 0 - Bruch Membran nicht beschädigt 1 - erfolgreiche Beschädigung der Bruch Membran</li>
	<li>Grade das Vorhandensein von CNV von gelaserten stellen, die Leckage wie durch den Vergleich der Dynamik von Fluorescein-Signal in einer Reihe von retinalen FA Bilder wie folgt festgestellt: 0 - normaler Auftritt der Netzhaut 0,5 - schwache Anfärbung der Leckage 1.0 - undichte CNV-Bereiche Hinweis: Verwenden der OCT-Bildgebung für zusätzliche Bestätigung der CNV oder fragwürdige FA wo würde das Vorhandensein intraretinalen Flüssigkeitsansammlungen im OCT Bilder vorschlagen CNV Verschneidung.</li>
</ol>5. die Netzhautdicke Messungen
<ol><li>Verwenden Sie eine automatische Segmentierung-Software zur Messung der Netzhautdicke. Sicherzustellen, dass die Netzhaut Gesamtdicke als die Dicke der alle Schichten von Nervenfaserschicht RPE (gesunde Messstellen) oder einer imaginären Verbindungslinie RPE rund um den Ort des Schadens (gelaserten Seiten) gilt (siehe auch Abbildung 7).</li>
</ol>

<ol>
	<li>Dobi, E. T., Puliafito, C. A., Destro, 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+new+model+of+experimental+choroidal+neovascularization+in+the+rat.">A new model of experimental choroidal neovascularization in the rat.</a> Arch. Ophthalmol. Chic. Ill 1960. 107, 264-269 (1989).</li><li>Tobe, T., 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=Evolution+of+neovascularization+in+mice+with+overexpression+of+vascular+endothelial+growth+factor+in+photoreceptors.">Evolution of neovascularization in mice with overexpression of vascular endothelial growth factor in photoreceptors.</a> Invest. Ophthalmol. Vis. Sci. 39, 180-188 (1998).</li><li>Seo, M. 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=Dramatic+inhibition+of+retinal+and+choroidal+neovascularization+by+oral+administration+of+a+kinase+inhibitor.">Dramatic inhibition of retinal and choroidal neovascularization by oral administration of a kinase inhibitor.</a> Am. J. Pathol. 154, 1743-1753 (1999).</li><li>Grossniklaus, H. E., Kang, S. J., Berglin, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+choroidal+and+retinal+neovascularization.">Animal models of choroidal and retinal neovascularization.</a> Prog. Retin. Eye Res. 29, 500-519 (2010).</li><li>Shah, R. S., Soetikno, B. T., Lajko, M., Fawzi, A. A. <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+Laser-induced+Choroidal+Neovascularization.">A Mouse Model for Laser-induced Choroidal Neovascularization.</a> J Vis Exp. (106), e53502 (2015).</li><li>Giani, 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=In+vivo+evaluation+of+laser-induced+choroidal+neovascularization+using+spectral-domain+optical+coherence+tomography.">In vivo evaluation of laser-induced choroidal neovascularization using spectral-domain optical coherence tomography.</a> Invest. Ophthalmol. Vis. Sci. 52, 3880-3887 (2011).</li><li>Gong, 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=Optimization+of+an+Image-Guided+Laser-Induced+Choroidal+Neovascularization+Model+in+Mice.">Optimization of an Image-Guided Laser-Induced Choroidal Neovascularization Model in Mice.</a> PloS One. 10, e0132643 (2015).</li><li>Sheets, K. G., 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=Neuroprotectin+D1+attenuates+laser-induced+choroidal+neovascularization+in+mouse.">Neuroprotectin D1 attenuates laser-induced choroidal neovascularization in mouse.</a> Mol. Vis. 16, 320-329 (2010).</li><li>Hoerster, 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=In-vivo+and+ex-vivo+characterization+of+laser-induced+choroidal+neovascularization+variability+in+mice.">In-vivo and ex-vivo characterization of laser-induced choroidal neovascularization variability in mice.</a> Graefes Arch. Clin. Exp. Ophthalmol. Albrecht Von Graefes Arch. Klin. Exp. Ophthalmol. 250, 1579-1586 (2012).</li><li>Sulaiman, R. 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=A+Simple+Optical+Coherence+Tomography+Quantification+Method+for+Choroidal+Neovascularization.">A Simple Optical Coherence Tomography Quantification Method for Choroidal Neovascularization.</a> J. Ocul. Pharmacol. Ther. Off. J. Assoc. Ocul. Pharmacol. Ther. Off. J. Assoc. Ocul. Pharmacol. 31, 447-454 (2015).</li></ol>

Der Autor Symantas Ragauskas, Ph.d. ist ein Mitarbeiter (wissenschaftlicher Mitarbeiter) und Gesellschafter der Experimentica GmbH, die Angebote Recherchediensten beschäftigen die präklinische CNV-Modell in diesem Artikel verwendeten Vertrag.
Die Autorin Eva Kielczewski ist ein Mitarbeiter (Forschung Anwendungstechniker, OCT) von Leica Microsystems, die in diesem Artikel verwendeten SD-OCT-Systeme produziert.
Der Autor Joseph Vance ist ein Mitarbeiter (NA OCT Sales Director) von Leica Microsystems, die in diesem Artikel verwendeten SD-OCT-Systeme produziert. Joseph Vance ist auch Präsident und managing Director von Perspektive, LLC.
Der Autor Simon Kaja, Ph.d. ist Berater Chief Scientific Officer und Gesellschafter der Experimentica GmbH, eine präklinische Vertrag Forschungseinrichtung, die Angebote Vertrag Recherchedienste, inkl. der präklinische CNV-Modell in diesem Artikel verwendet. Simon Kaja, Ph.d. ist auch CEO von K & P Scientific, LLC, einer consulting-Firma, Biowissenschaften und dient als Dr. John P. und Therese E. Mulcahy ausgestattet Professor für Augenheilkunde an der Loyola University Chicago, Stritch School of Medicine. Die Bedingungen dieser Vereinbarung haben überprüft und genehmigt von Loyola University Chicago im Einklang mit seinen Interessenkonflikt Politik wurde.
Der Autor Giedrius Kalesnykas, Ph.d. ist ein Mitarbeiter (CEO) und Gesellschafter der Experimentica GmbH, die Angebote Recherchediensten beschäftigen die präklinische CNV-Modell in diesem Artikel verwendeten Vertrag.

Multimodale Bildgebung bietet wertvolle Werkzeuge für CNV Pathologie Bewertung. Hier präsentierten wir eine bildgebende Protokoll bestehend aus FA, SD-OCT und automatische Segmentierung für die schnelle, reproduzierbare und zuverlässige Bewertung der CNV Pathologie. Ein Bruch des Bruchs Membran nach Laser Verwaltung bestätigt wurde. Darüber hinaus erlaubt die Verwendung von SD-OCT in diesem Stadium auch sofortige Visualisierung der möglichen intraretinalen und subretinalen Blutungen, die die Interpretation der Erg...

Der erste erfolgreiche Versuch, die Pathologie der menschlichen CNV bei Nagetieren zu imitieren wurde vor fast drei Jahrzehnten mit einer Krypton-Laser in Long-Evans Ratten1demonstriert. Danach wurde ein Krypton-Laser verwendet, um Bruch Membran in den beliebtesten Maus-Stamm C57BL/6J2,3,4zu brechen. Die Erfolgsquote der CNV Induktion wurde mit FA und histologischen Flecke verifiziert. Eine rasante Entwicklung der nicht-invasive bildgebende Verfahren wie OCT, förderte das Wachstum im Bereich der Nager präklinischen Modellen. Die Möglichkeit, morphologische Veränderungen in der Netzhaut zu mehreren Zeitpunkten auf den gleichen Auge deutlich überwachen trägt zur Verringerung von Tierversuchen und steigert die Effizienz in experimentellen Studien. Histologische Auswertung der CNV Läsionen ist relativ einfach und erfordert Kennzeichnung von abnormen Gefäßwachstum auf dem Gelände des Laser-Verwaltung, Bildaufnahme und Fläche/Volumen Schätzung mit einer Bildanalyse-Software. Im Gegensatz dazu stellen in Vivo bildgebender Verfahren komplexere Analysen der CNV Pathologie und seine Auslegung.
Hier präsentieren wir Ihnen eine einfache und relativ schnelle Methode, um Grade Induktion, Progression und Regression von CNV mit FA, SD-OCT, und die automatische Segmentierung Methode in der Maus Laser-induzierte CNV Modell.

<table border="0" cellpadding="0" cellspacing="0" width="917">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:275px;">Medetomidine (commercial name Domitor)</td>
			<td style="width:123px;">Orion</td>
			<td style="width:344px;">Vnr 01 56 02</td>
			<td style="width:177px;">Anesthesia</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Ketamine</td>
			<td>Intervet</td>
			<td>Vnr 51 14 85</td>
			<td>Anesthesia</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">0,9% NaCl</td>
			<td>B Braun</td>
			<td>357 0340</td>
			<td>Anesthesia</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Xylazine (commercial name Rompun vet)</td>
			<td>Bayer</td>
			<td>vnr 14 89 99</td>
			<td>Anesthesia</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Tropicamide</td>
			<td>Santen</td>
			<td>Vnr 04 12 36</td>
			<td>Mydriatic agent</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Viscotears</td>
			<td>Alcon</td>
			<td>Vnr 44 54 81</td>
			<td>Lubricant</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Systane</td>
			<td>Alcon</td>
			<td>&#160;-</td>
			<td>Lubricant</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">5% Fluorescein sodium salt</td>
			<td>Sigma Aldrich</td>
			<td>F6377-100G</td>
			<td>Fluoresent agent</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Atipamezole (commercial name Antisedane)</td>
			<td>Orion</td>
			<td>Vnr 47 19 53</td>
			<td>Anesthesia</td>
		</tr>
	</tbody>
</table>

in vivo multimodal imaging and analysis of mouse laser-induced choroidal neovascularization model

Laserinduzierte choroidale Neovaskularisation (CNV) ist ein etabliertes Modell die feuchte Form der altersbedingten Makula-Degeneration (AMD) zu imitieren. Wir wollen in diesem Protokoll führen den Leser nicht einfach durch die Überlegungen der Generierung von Laser-induzierte Läsionen auslösen neovaskulären Prozesse, sondern auf die mächtigen Informationen, die Multimodal längs- beigezogen werden kann konzentrieren in-vivo Bildgebung in der Folgezeit.
Die Laser-induzierte Maus CNV Modell wurde durch eine Diode Laser Verwaltung generiert. Multimodale in Vivo bildgebenden Verfahren wurden verwendet, um CNV Induktion, Progression und Regression zu überwachen. Erste, spectral-Domain optische Kohärenztomographie (SD-OCT) erfolgte unmittelbar nach der Laserung um zu überprüfen, eine Pause von Bruch Membran. Nachfolgende in-Vivo Bildgebung mit Fluorescein-Angiographie (FA) bestätigt erfolgreiche Beschädigung der Bruch Membran aus seriellen Bildern auf der Aderhaut Ebene erworben. Longitudinal Follow-up von CNV Verbreitung und Regression auf 5, 10 und 14 Tage nach dem Lasern erfolgte mittels SD-OCT und FA. Einfache und zuverlässige Einstufung des undichten CNV Leasions von FA Bilder präsentiert. Automatische Segmentierung zur Messung der Netzhaut Gesamtdicke, kombiniert mit manueller Kaliber Anwendung zur Messung der Netzhautdicke CNV Standorten ermöglichen objektive Bewertung der Anwesenheit von Ödemen. Schließlich wird die histologischen Überprüfung der CNV mit Isolectin GS-IB4 Flecken auf choroidale Flatmounts durchgeführt. Die Färbung ist thresholded und Isolectin-positiven Bereich mit ImageJ berechnet wird.
Dieses Protokoll eignet sich besonders in Therapeutika Studien erfordern hohen Durchsatz wie Screening von CNV Pathologie, da es schnell, multimodale erlaubt und zuverlässige Klassifizierung von CNV Pathologie und Netzhaut Ödem. Hoher Auflösung SD-OCT ermöglicht darüber hinaus die Aufnahme von anderen pathologischen Merkmale wie die Ansammlung von subretinalen oder intraretinalen Flüssigkeit. Diese Methode bietet jedoch keine Möglichkeit um CNV-Volumen-Analyse von SD-OCT Bilder zu automatisieren, die manuell durchgeführt werden.

Eine Blase oder subretinalen Blutungen sofort nach dem Lasern ist nicht immer sichtbar. SD-OCT ist daher besonders wichtig, um Schäden der Bruch Membran zu überprüfen. Abbildung 1 zeigt ein Beispiel der OCT-Bildgebung zu verschiedenen Zeitpunkten nach der Laser-Verabreichung.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56173/56173fig1.jpg"> Abbildung 1</stro...

Watch this Scientific Journal Video about In Vivo Multimodal Imaging and Analysis of Mouse Laser-Induced Choroidal Neovascularization Model at JoVE.com

In Vivo Multimodal Imaging and Analysis of Mouse Laser-Induced Choroidal Neovascularization Model

In Vivo Multimodale Bildgebung und Analyse der laserinduzierten choroidale Neovaskularisation Mausmodell

Hier präsentieren wir Ihnen die Nützlichkeit der längs in-Vivo Bildgebung bei der Nachbereitung der morphologischen Veränderungen der laserinduzierten choroidale Neovaskularisation bei Mäusen.

Laser-induced choroidal neovascularization (CNV) is a well-established model to mimic the wet form of age-related macular degeneration (AMD). In this ...

in-vivo-multimodal-imaging-analysis-mouse-laser-induced-choroidal

Research

JoVE Journal

Neuroscience

In Vivo Multimodal Imaging and Analysis of Mouse Laser-Induced Choroidal Neovascularization Model

9.0K Aufrufe.  Experimentica Ltd.. Hier präsentieren wir Ihnen die Nützlichkeit der längs in-Vivo Bildgebung bei der Nachbereitung der morphologischen Veränderungen der laserinduzierten choroidale Neovaskularisation bei Mäusen.

Serie: In Vivo Multimodal Imaging and Analysis of Mouse Laser-Induced Choroidal Neovascularization Model

Multiple-mouse Neuroanatomical Magnetic Resonance Imaging

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and evaluating mouse models of human disease. MRI is an excellent modality for investigating genetically altered animals. It is capable of whole brain coverage, can be used in vivo, and provides multiple contrast mechanisms for investigating different aspects of neuranatomy and physiology. The advent of high-field scanners along with the ability to scan multiple mice simultaneously allows for rapid phenotyping of novel mutations.
Effective mouse MRI studies require attention to many aspects of experiment design. In this article, we will describe general methods to acquire quality images for mouse phenotyping using a system that images mice concurrently in shielded transmit/receive radio frequency (RF) coils in a common magnet (Bock et al., 2003). We focus particularly on anatomical phenotyping, an important and accessible application that has shown a high potential for impact in many mouse models at our imaging centre. Before we can provide the detailed steps to acquire such images, there are important practical considerations for both in vivo brain imaging (Dazai et al., 2004) and ex vivo brain imaging (Spring et al., 2007) that should be noted. These are discussed below.

Magnetic resonance imaging (MRI) has become an increasingly popular tool for examining the phenotype of genetically altered mice. This article illustrates the methods necessary to achieve high-throughput phenotyping of genetically altered mice using multiple-mouse MRI.

Multiple-Maus Neuroanatomische Magnetic Resonance Imaging

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and ...

Forschung

Neurowissenschaften

Multimodal Imaging of Stem Cell Implantation in the Central Nervous System of Mice

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, both in preclinical and clinical studies. However, to date results regarding functional outcome and/or tissue regeneration following stem cell transplantation are quite diverse. Generally, a clinical benefit is observed without profound understanding of the underlying mechanism(s)1. Therefore, multiple efforts have led to the development of different molecular imaging modalities to monitor stem cell grafting with the ultimate aim to accurately evaluate survival, fate and physiology of grafted stem cells and/or their micro-environment. Changes observed in one or more parameters determined by molecular imaging might be related to the observed clinical effect. In this context, our studies focus on the combined use of bioluminescence imaging (BLI), magnetic resonance imaging (MRI) and histological analysis to evaluate stem cell grafting.
BLI is commonly used to non-invasively perform cell tracking and monitor cell survival in time following transplantation2-7, based on a biochemical reaction where cells expressing the Luciferase-reporter gene are able to emit light following interaction with its substrate (e.g. D-luciferin)8, 9. MRI on the other hand is a non-invasive technique which is clinically applicable10 and can be used to precisely locate cellular grafts with very high resolution11-15, although its sensitivity highly depends on the contrast generated after cell labeling with an MRI contrast agent. Finally, post-mortem histological analysis is the method of choice to validate research results obtained with non-invasive techniques with highest resolution and sensitivity. Moreover end-point histological analysis allows us to perform detailed phenotypic analysis of grafted cells and/or the surrounding tissue, based on the use of fluorescent reporter proteins and/or direct cell labeling with specific antibodies.
In summary, we here visually demonstrate the complementarities of BLI, MRI and histology to unravel different stem cell- and/or environment-associated characteristics following stem cell grafting in the CNS of mice. As an example, bone marrow-derived stromal cells, genetically engineered to express the enhanced Green Fluorescent Protein (eGFP) and firefly Luciferase (fLuc), and labeled with blue fluorescent micron-sized iron oxide particles (MPIOs), will be grafted in the CNS of immune-competent mice and outcome will be monitored by BLI, MRI and histology (Figure 1).

This article describes an optimized sequence of events for multimodal imaging of cellular grafts in rodent brain using: (i) in vivo bioluminescence and magnetic resonance imaging, and (ii) post mortem histological analysis. Combining these imaging modalities on a single animal allows cellular graft evaluation with high resolution, sensitivity and specificity.

Multimodale Bildgebung von Stem Cell Implantation in das zentrale Nervensystem der Mäuse

During the past decade, stem cell transplantation has gained increasing interest as primary or secondary therapeutic modality for a variety of diseases, ...

Functional Neuroimaging Using Ultrasonic Blood-brain Barrier Disruption and Manganese-enhanced MRI

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains technically challenging. One approach, Activation-Induced Manganese-enhanced MRI (AIM MRI), has been used successfully to map neuronal activity in rodents 1-5. In AIM MRI, Mn2+ acts a calcium analog and accumulates in depolarized neurons 6,7. Because Mn2+ shortens the T1 tissue property, regions of elevated neuronal activity will enhance in MRI. Furthermore, Mn2+ clears slowly from the activated regions; therefore, stimulation can be performed outside the magnet prior to imaging, enabling greater experimental flexibility. However, because Mn2+ does not readily cross the blood-brain barrier (BBB), the need to open the BBB has limited the use of AIM MRI, especially in mice.
One tool for opening the BBB is ultrasound. Though potentially damaging, if ultrasound is administered in combination with gas-filled microbubbles (i.e., ultrasound contrast agents), the acoustic pressure required for BBB opening is considerably lower. This combination of ultrasound and microbubbles can be used to reliably open the BBB without causing tissue damage 8-11.
Here, a method is presented for performing AIM MRI by using microbubbles and ultrasound to open the BBB. After an intravenous injection of perflutren microbubbles, an unfocused pulsed ultrasound beam is applied to the shaved mouse head for 3 minutes. For simplicity, we refer to this technique of BBB Opening with Microbubbles and UltraSound as BOMUS 12. Using BOMUS to open the BBB throughout both cerebral hemispheres, manganese is administered to the whole mouse brain. After experimental stimulation of the lightly sedated mice, AIM MRI is used to map the neuronal response.
To demonstrate this approach, herein BOMUS and AIM MRI are used to map unilateral mechanical stimulation of the vibrissae in lightly sedated mice 13. Because BOMUS can open the BBB throughout both hemispheres, the unstimulated side of the brain is used to control for nonspecific background stimulation. The resultant 3D activation map agrees well with published representations of the vibrissae regions of the barrel field cortex 14. The ultrasonic opening of the BBB is fast, noninvasive, and reversible; and thus this approach is suitable for high-throughput and/or longitudinal studies in awake mice.

A technique is described for broadly opening the blood-brain barrier in the mouse using microbubbles and ultrasound. Using this technique, manganese can be administered to the mouse brain. Because manganese is an MRI contrast agent that accumulates in depolarized neurons, this approach enables imaging of neuronal activity.

Funktionelle Bildgebung mit Ultraschall-Blut-Hirnschranke Störung und Mangan-MRT

Although mice are the dominant model system for studying the genetic and molecular underpinnings of neuroscience, functional neuroimaging in mice remains ...

Ex vivo Live Imaging of Single Cell Divisions in Mouse Neuroepithelium

We developed a system that integrates live imaging of fluorescent markers and culturing slices of embryonic mouse neuroepithelium. We took advantage of existing mouse lines for genetic cell lineage tracing: a tamoxifen-inducible Cre line and a Cre reporter line expressing dsRed upon Cre-mediated recombination. By using a relatively low level of tamoxifen, we were able to induce recombination in a small number of cells, permitting us to follow individual cell divisions. Additionally, we observed the transcriptional response to Sonic Hedgehog (Shh) signaling using an Olig2-eGFP transgenic line 1-3 and we monitored formation of cilia by infecting the cultured slice with virus expressing the cilia marker, Sstr3-GFP 4. In order to image the neuroepithelium, we harvested embryos at E8.5, isolated the neural tube, mounted the neural slice in proper culturing conditions into the imaging chamber and performed time-lapse confocal imaging. Our ex vivo live imaging method enables us to trace single cell divisions to assess the relative timing of primary cilia formation and Shh response in a physiologically relevant manner. This method can be easily adapted using distinct fluorescent markers and provides the field the tools with which to monitor cell behavior in situ and in real time.

Ex vivo Live Imaging of Single Cell Divisions in Mouse Neuroepithelium

Here we develop the tools necessary for ex vivo live imaging to trace single cell divisions in the mouse E8.5 neuroepithelium

Ex vivo Live-Imaging von Single Cell Divisionen in Maus Neuroepithel

We developed a system that integrates live imaging of fluorescent markers and culturing slices of embryonic mouse neuroepithelium. We took advantage of ...

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal degeneration. Lack of growth cone formation, regeneration, and loss of additional myelinated axonal projections within the spinal cord greatly limits neurological recovery following injury. To assess how central myelinated axons of the spinal cord respond to injury, we developed an ex vivo living spinal cord model utilizing transgenic mice that express yellow fluorescent protein in axons and a focal and highly reproducible laser-induced spinal cord injury to document the fate of axons and myelin (lipophilic fluorescent dye Nile Red) over time using two-photon excitation time-lapse microscopy. Dynamic processes such as acute axonal injury, axonal retraction, and myelin degeneration are best studied in real-time. However, the non-focal nature of contusion-based injuries and movement artifacts encountered during in vivo spinal cord imaging make differentiating primary and secondary axonal injury responses using high resolution microscopy challenging. The ex vivo spinal cord model described here mimics several aspects of clinically relevant contusion/compression-induced axonal pathologies including axonal swelling, spheroid formation, axonal transection, and peri-axonal swelling providing a useful model to study these dynamic processes in real-time. Major advantages of this model are excellent spatiotemporal resolution that allows differentiation between the primary insult that directly injures axons and secondary injury mechanisms; controlled infusion of reagents directly to the perfusate bathing the cord; precise alterations of the environmental milieu (e.g., calcium, sodium ions, known contributors to axonal injury, but near impossible to manipulate in vivo); and murine models also offer an advantage as they provide an opportunity to visualize and manipulate genetically identified cell populations and subcellular structures. Here, we describe how to isolate and image the living spinal cord from mice to capture dynamics of acute axonal injury.

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time

We present a protocol utilizing two-photon excitation time-lapse microscopy to simultaneously visualize the dynamics of axon and myelin injuries in real time. This proposed protocol permits studies of both intrinsic and extrinsic factors which can influence central myelinated axon fate after injury and contribute to permanent clinical disability.

Ein<em&gt; Ex vivo</em&gt; Laser-induzierte Rückenmarksverletzungen Modell zu Mechanismen der axonalen Degeneration Beurteilen Sie in Echtzeit

Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal ...

3-D Imaging and Analysis of Neurons Infected In Vivo with Toxoplasma gondii

Toxoplasma gondii is an obligate, intracellular parasite with a broad host range, including humans and rodents. In both humans and rodents, Toxoplasma establishes a lifelong persistent infection in the brain. While this brain infection is asymptomatic in most immunocompetent people, in the developing fetus or immunocompromised individuals such as acquired immune deficiency syndrome (AIDS) patients, this predilection for and persistence in the brain can lead to devastating neurologic disease. Thus, it is clear that the brain-Toxoplasma interaction is critical to the symptomatic disease produced by Toxoplasma, yet we have little understanding of the cellular or molecular interaction between cells of the central nervous system (CNS) and the parasite. In the mouse model of CNS toxoplasmosis it has been known for over 30 years that neurons are the cells in which the parasite persists, but little information is available about which part of the neuron is generally infected (soma, dendrite, axon) and if this cellular relationship changes between strains. In part, this lack is secondary to the difficulty of imaging and visualizing whole infected neurons from an animal. Such images would typically require serial sectioning and stitching of tissue imaged by electron microscopy or confocal microscopy after immunostaining. By combining several techniques, the method described here enables the use of thick sections (160 &#181;m) to identify and image whole cells that contain cysts, allowing three-dimensional visualization and analysis of individual, chronically infected neurons without the need for immunostaining, electron microscopy, or serial sectioning and stitching. Using this technique, we can begin to understand the cellular relationship between the parasite and the infected neuron.

3-D Imaging and Analysis of Neurons Infected In Vivo with Toxoplasma gondii

Using this protocol, we were able to image 160 &#181;m thick brain sections from mice infected with the parasite Toxoplasma gondii, which enables visualization and analysis of the spatial relationship between the encysting parasite and the infected neuron.

3-D-Bildgebung und Analyse von Neuronen Infizierte<em&gt; In-vivo-</em&gt; Mit<em&gt; Toxoplasma gondii</em

Toxoplasma gondii is an obligate, intracellular parasite with a broad host range, including humans and rodents. In both humans and rodents, Toxoplasma ...

M&#252;ller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish

A fascinating difference between teleost and mammals is the lifelong potential of the teleost retina for retinal neurogenesis and regeneration after severe damage. Investigating the regeneration pathways in zebrafish might bring new insights to develop innovative strategies for the treatment of retinal degenerative diseases in mammals. Herein, we focused on the induction of a focal lesion to the outer retina in adult zebrafish by means of a 532 nm diode laser. A localized injury allows investigating biological processes that take place during retinal degeneration and regeneration directly at the area of damage. Using non-invasive optical coherence tomography (OCT), we were able to define the location of the damaged area and monitor subsequent regeneration in vivo. Indeed, OCT imaging produces high-resolution, cross-sectional images of the zebrafish retina, providing information which was previously only available with histological analyses. In order to confirm the data from real-time OCT, histological sections were performed and regenerative response after the induction of the retinal injury was investigated by immunohistochemistry.

The zebrafish is a popular animal model to study mechanisms of retinal degeneration/regeneration in vertebrates. This protocol describes a method to induce localized injury disrupting the outer retina with minimal damage to the inner retina. Subsequently, we monitor in vivo the retinal morphology and the M&#252;ller glia response throughout retinal regeneration.

Müller Glia-Zell-Aktivierung in einer laserinduzierten Netzhautdegeneration und Regeneration Modell im Zebrafisch

A fascinating difference between teleost and mammals is the lifelong potential of the teleost retina for retinal neurogenesis and regeneration after ...

Laser-Induced Brain Injury in the Motor Cortex of Rats

A common technique for inducing stroke in experimental rodent models involves the transient (often denoted as MCAO-t) or permanent (designated as MCAO-p) occlusion of the middle cerebral artery (MCA) using a catheter. This generally accepted technique, however, has some limitations, thereby limiting its extensive use. Stroke induction by this method is often characterized by high variability in the localization and size of the ischemic area, periodical occurrences of hemorrhage, and high death rates. Also, the successful completion of any of the transient or permanent procedures requires expertise and often lasts for about 30 minutes. In this protocol, a laser irradiation technique is presented that can serve as an alternative method for inducing and studying brain injury in rodent models.
When compared to rats in the control and MCAO groups, the brain injury by laser induction showed reduced variability in body temperature, infarct volume, brain edema, intracranial hemorrhage, and mortality. Furthermore, the use of a laser-induced injury caused damage to the brain tissues only in the motor cortex unlike in the MCAO experiments where destruction of both the motor cortex and striatal tissues is observed.
Findings from this investigation suggest that laser irradiation could serve as an alternative and effective technique for inducing brain injury in the motor cortex. The method also shortens the time for completing the procedure and does not require expert handlers.

The protocol presented here shows a technique to create a rodent model of brain injury. The method described here uses laser irradiation and targets motor cortex.

Laserinduzierte Hirnverletzung im Motor Cortex von Ratten

A common technique for inducing stroke in experimental rodent models involves the transient (often denoted as MCAO-t) or permanent (designated as MCAO-p) ...

Imaging and Analysis of Neurofilament Transport in Excised Mouse Tibial Nerve

Neurofilament protein polymers move along axons in the slow component of axonal transport at average speeds of ~0.35-3.5 mm/day. Until recently the study of this movement in situ was only possible using radioisotopic pulse-labeling, which permits analysis of axonal transport in whole nerves with a temporal resolution of days and a spatial resolution of millimeters. To study neurofilament transport in situ with higher temporal and spatial resolution, we developed a hThy1-paGFP-NFM transgenic mouse that expresses neurofilament protein M tagged with photoactivatable GFP in neurons. Here we describe fluorescence photoactivation pulse-escape and pulse-spread methods to analyze neurofilament transport in single myelinated axons of tibial nerves from these mice ex vivo. Isolated nerve segments are maintained on the microscope stage by perfusion with oxygenated saline and imaged by spinning disk confocal fluorescence microscopy. Violet light is used to activate the fluorescence in a short axonal window. The fluorescence in the activated and flanking regions is analyzed over time, permitting the study of neurofilament transport with temporal and spatial resolution on the order of minutes&#160;and microns, respectively. Mathematical modeling can be used to extract kinetic parameters of neurofilament transport including the velocity, directional bias and pausing behavior from the resulting data. The pulse-escape and pulse-spread methods can also be adapted to visualize neurofilament transport in other nerves. With the development of additional transgenic mice, these methods could also be used to image and analyze the axonal transport of other cytoskeletal and cytosolic proteins in axons.

We describe fluorescence photoactivation methods to analyze the axonal transport of neurofilaments in single myelinated axons of peripheral nerves from transgenic mice that express a photoactivatable neurofilament protein.

Bildgebung und Analyse des Neurofilamenttransports in verbraucheten Maus-Tibialnerv

Neurofilament protein polymers move along axons in the slow component of axonal transport at average speeds of ~0.35-3.5 mm/day. Until recently the study ...

Transpupillary Two-Photon In Vivo Imaging of the Mouse Retina

The retina transforms light signals from the environment into electrical signals that are propagated to the brain. Diseases of the retina are prevalent and cause visual impairment and blindness. Understanding how such diseases progress is critical to formulating new treatments. In vivo&#160;microscopy in animal models of disease is a powerful tool for understanding neurodegeneration and has led to important progress towards treatments of conditions ranging from Alzheimer&#39;s disease to stroke. Given that the retina is the only central nervous system structure inherently accessible by optical approaches, it naturally lends itself towards in vivo imaging. However, the native optics of the lens and cornea present some challenges for effective imaging access.
This protocol outlines methods for in vivo two-photon imaging of cellular cohorts and structures in the mouse retina at cellular resolution, applicable for both acute- and chronic-duration imaging experiments. It presents examples of retinal ganglion cell (RGC), amacrine cell, microglial, and vascular imaging using a suite of labeling techniques including adeno-associated virus (AAV) vectors, transgenic mice, and inorganic dyes. Importantly, these techniques extend to all cell types of the retina, and suggested methods for accessing other cellular populations of interest are described. Also detailed are example strategies for manual image postprocessing for display and quantification. These techniques are directly applicable to studies of retinal function in health and disease.

In vivo imaging is a powerful tool for the study of biology in health and disease. This protocol describes transpupillary imaging of the mouse retina with a standard two-photon microscope. It also demonstrates different in vivoimaging methods to fluorescently label multiple cellular cohorts of the retina.

Transpupille Zwei-Photonen-In-vivo-Bildgebung der Netzhaut der Maus

The retina transforms light signals from the environment into electrical signals that are propagated to the brain. Diseases of the retina are prevalent ...