Name: in vivo electroporation of developing mouse retina
Uploaded: 2011-06-24T15:00:00
Description: Watch this Scientific Journal Video about In vivo Electroporation of Developing Mouse Retina at JoVE.com

Ce travail a été financé par le NIH R01EY020560-01 et par un érudit WM Keck Young en bourse de recherche médicale. Les auteurs tiennent à remercier Joseph Bedont pour son aide lors de l&#39;imagerie de la rétine et de préparations injectables.

1. Préparation de plasmide pour l&#39;électroporation La concentration d&#39;ADN requis pour électroporation est 5μg/μl. Cela nécessite généralement des plasmides voulu être amplifié en utilisant un Maxi-prep (Qiagen) ou une méthode équivalente suivie d&#39;une purification et la concentration de l&#39;ADN à la quantité de travail. Les étapes suivantes décrivent la préparation de l&#39;ADN à la quantité de travail. <ol><li> Aliquot de 100 pg d&#39;ADN (de Maxi-prep ou é...

<ol>
	<li>Neumann, E., Rosenheck, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Permeability+changes+induced+by+electric+impulses+in+vesicular+membranes.">Permeability changes induced by electric impulses in vesicular membranes.</a> J. Membr. Biol. 10, 279-290 (1972).</li><li>Turnbull, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Letter:+Letter:+An+alternate+explanation+for+the+permeability+changes+induced+by+electrical+impulses+in+vesicular+membranes.">Letter: Letter: An alternate explanation for the permeability changes induced by electrical impulses in vesicular membranes.</a> J. Membr. Biol. 14, 193-196 (1973).</li><li>Zimmermann, U., Schulz, J., Pilwat, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcellular+ion+flow+in+Escherichia+coli+B+and+electrical+sizing+of+bacterias.">Transcellular ion flow in Escherichia coli B and electrical sizing of bacterias.</a> Biophys. J. 13, 1005-1013 (1973).</li><li>Kinosita, K., Tsong, T. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltage-induced+pore+formation+and+hemolysis+of+human+erythrocytes.">Voltage-induced pore formation and hemolysis of human erythrocytes.</a> Biochim. Biophys. Acta. 471, 227-242 (1977).</li><li>Neumann, E., Schaefer-Ridder, M., Wang, Y., Hofschneider, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+transfer+into+mouse+lyoma+cells+by+electroporation+in+high+electric+fields.">Gene transfer into mouse lyoma cells by electroporation in high electric fields.</a> EMBO J. 1, 841-845 (1982).</li><li>Swartz, M., Eberhart, J., Mastick, G. S., Krull, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sparking+new+frontiers:+using+in+vivo+electroporation+for+genetic+manipulations.">Sparking new frontiers: using in vivo electroporation for genetic manipulations.</a> Dev. Biol. 233, 13-21 (2001).</li><li>Matsuda, T., Cepko, 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=Electroporation+and+RNA+interference+in+the+rodent+retina+in+vivo+and+in+vitro.">Electroporation and RNA interference in the rodent retina in vivo and in vitro.</a> Proc. Natl. Acad. Sci. U. S. A. 101, 16-22 (2004).</li><li>Matsuda, T., Cepko, 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=Controlled+expression+of+transgenes+introduced+by+in+vivo+electroporation.">Controlled expression of transgenes introduced by in vivo electroporation.</a> Proc. Natl. Acad. Sci. U. S. A. 104, 1027-1032 (2007).</li><li>Onishi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pias3-dependent+SUMOylation+directs+rod+photoreceptor+development.">Pias3-dependent SUMOylation directs rod photoreceptor development.</a> Neuron. 61, 234-246 (2009).</li><li>Onishi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+orphan+nuclear+hormone+receptor+ERRbeta+controls+rod+photoreceptor+survival.">The orphan nuclear hormone receptor ERRbeta controls rod photoreceptor survival.</a> Proc. Natl. Acad. Sci. U. S. A. 107, 11579-11584 (2010).</li><li>Kim, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Core+Paired-Type+and+POU+Homeodomain-Containing+Transcription+Factor+Program+Drives+Retinal+Bipolar+Cell+Gene+Expression.">A Core Paired-Type and POU Homeodomain-Containing Transcription Factor Program Drives Retinal Bipolar Cell Gene Expression.</a> J. Neurosci. 28, 7748-7764 (2008).</li></ol>

In vivo électroporation représente une méthode rapide et efficace pour la transformation de cellules de la rétine avec des plasmides d&#39;expression d&#39;ADN. Cette méthode permet à l&#39;expérimentateur d&#39;effectuer des études de gain de fonction en introduisant ectopique un gène d&#39;intérêt sous le contrôle d&#39;un promoteur ubiquitaire ou pour effectuer des études de perte de fonction en utilisant des constructions shRNA ciblant des gènes d&#39;intérêt. Par ailleurs, plusieurs plasmid...

<table border="1"><tbody><tr><th> Nom de réactif </th><th> Société </th><th> Numéro de catalogue </th><th> Commentaires </th></tr><tr><td> Tampon phénol saturé </td><td> Invitrogen </td><td> 15513-039 </td><td> N / A </td></tr><tr><td> Chloroforme </td><td> JT Baker </td><td> 9180-03 </td><td> N / A </td></tr><tr><td> Acétate de sodium </td><td> JT Baker </td><td> 3470-05 </td><td> 3 M d&#39;actions </td></tr><tr><td> Fast Green FCF </td><td> Fisher Biotech </td><td> BP123-10 </td><td> Stock de 10% </td></tr><tr><td> L&#39;alcool isopropylique de préparation </td><td> Tyco Healthcare </td><td> 6918 </td><td> N / A </td></tr><tr><td> 30-guage aiguille </td><td> Terumo Medical Corp </td><td> SG2-3013 </td><td> N / A </td></tr><tr><td> Exmire microseringue </td><td> Ito Corporation </td><td> MS * E05 </td><td> N / A </td></tr><tr><td> Tweezertrode (électrode pince) </td><td> BTX Instrument, Inc Genetronics </td><td> 522 </td><td> N / A </td></tr><tr><td> Electro Place Porator (électroporateur) </td><td> BTX Instrument, Inc Genetronics </td><td> ECM 830 </td><td> N / A </td></tr><tr><td> Composé OCT </td><td> Sakura Finetek USA </td><td> 4583 </td><td> N / A </td></tr></tbody></table>

in vivo electroporation of developing mouse retina

La caractérisation fonctionnelle des gènes exprimés au cours du développement des mammifères rétine demeure un défi important. Le ciblage de gènes pour générer une perte constitutive ou conditionnelle de KOs fonction reste des coûts et de main-d&#39;oeuvre, ainsi que beaucoup de temps. Ajoutant à ces défis, la rétine peut gènes exprimés ont un rôle essentiel en dehors de la rétine conduisant à confond involontaires lors de l&#39;utilisation d&#39;une approche à élimination directe. Par ailleurs, la capacité à exprimer un gène ectopique par un gain d&#39;expérience fonction peut être extrêmement précieux lorsque l&#39;on tente d&#39;identifier un rôle dans la spécification du destin cellulaire et / ou la différenciation terminale. Nous présentons une méthode pour l&#39;incorporation rapide et efficace de plasmides ADN dans la rétine de souris néonatales par électroporation. L&#39;application de courtes impulsions électriques au dessus d&#39;un certains résultats intensité du champ dans une augmentation transitoire de la perméabilité de la membrane plasmatique, en facilitant le transfert de matériel à travers la membrane 1,2,3,4. Travail de pionnier a démontré que l&#39;électroporation pourrait être utilisé comme une méthode de transfert de gène dans les cellules de mammifères en induisant la formation de pores hydrophiles membrane plasmique permettant le passage de l&#39;ADN hautement chargé à travers la bicouche lipidique 5. Continue le développement technique a conduit à la viabilité de l&#39;électroporation comme une méthode pour le transfert de gènes in vivo dans les tissus de souris multiples, y compris la rétine, la méthode pour ce qui est décrit aux présentes 6, 7, 8, 9, 10. Solution d&#39;ADN est injecté dans l&#39;espace sous-rétinien, de sorte que l&#39;ADN est placé entre les épithélium pigmentaire rétinien et la rétine de l&#39;néonatale (P0) de la souris et impulsions électriques sont appliquées en utilisant une électrode de pincette. Le placement latéral de l&#39;oeil chez la souris permet de s&#39;orienter facilement de l&#39;électrode de pince à l&#39;alignement nécessaire pole pôle négatif de l&#39;ADN-rétine positif. L&#39;incorporation étendue et l&#39;expression des gènes transférés peuvent être identifiés par jour postnatal 2 (P2). En raison de l&#39;absence de migration latérale importante des cellules de la rétine, des régions et non électroporées électroporées sont générés. Non-électroporées régions peuvent servir de contrôles internes histologique, le cas échéant. Électroporation la rétine peut être utilisé pour exprimer un gène sous un promoteur ubiquitaire, comme l&#39;ACG, ou de perturber la fonction des gènes en utilisant des constructions ou des shRNA Cre-recombinase. Expression plus ciblée peut être atteint par la conception des constructions avec des promoteurs de gènes spécifiques de cellules. Visualisation des cellules par électroporation est réalisée en utilisant des constructions bicistronique exprimant la GFP ou par co-électroporation une expression de la GFP construire. Par ailleurs, les constructions peuvent être multiples électroporées pour l&#39;étude des effets des gènes combinatoire ou le gain simultané et perte de fonction des gènes différents. Électroporation rétine peut également être utilisé pour l&#39;analyse de la génomique éléments cis-régulateurs en générant des constructions d&#39;expression approprié et mutants de délétion. De telles expériences peuvent être utilisés pour identifier les régions cis-régulatrices suffisante ou nécessaire pour l&#39;expression des gènes cellulaires spécifiques 11. Expériences potentielles ne sont limitées que par la disponibilité de construire.

Watch this Scientific Journal Video about In vivo Electroporation of Developing Mouse Retina at JoVE.com

In vivo Electroporation of Developing Mouse Retina

Une méthode pour l&#39;incorporation de l&#39;ADN plasmidique dans des cellules murines rétine dans le but d&#39;effectuer soit du gain ou de perte d&#39;études de la fonction<em&gt; In vivo</em&gt; Est présenté. Cette méthode s&#39;appuie sur l&#39;augmentation transitoire de la perméabilité des membranes plasmiques cellulaire induite par l&#39;application d&#39;un champ électrique externe.

En électroporation in vivo de la rétine de souris en développement

The functional characterization of genes expressed during mammalian retinal development remains a significant challenge.  Gene targeting to generate ...

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JoVE Journal

Neuroscience

In vivo Electroporation of Developing Mouse Retina

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

The targeting and refinement of RGC projections to the midbrain is a popular and powerful model system for studying how precise patterns of neural connectivity form during development. In mice, retinofugal projections are arranged in a topographic manner and form eye-specific layers in the Lateral Geniculate Nucleus (dLGN) of the thalamus and the Superior Colliculus (SC). The development of these precise patterns of retinofugal projections has typically been studied by labeling populations of RGCs with fluorescent dyes and tracers, such as horseradish peroxidase1-4. However, these methods are too coarse to provide insight into developmental changes in individual RGC axonal arbor morphology that are the basis of retinotopic map formation. They also do not allow for the genetic manipulation of RGCs.
Recently, electroporation has become an effective method for providing precise spatial and temporal control for delivery of charged molecules into the retina5-11. Current retinal electroporation protocols do not allow for genetic manipulation and tracing of retinofugal projections of a single or small cluster of RGCs in postnatal mice. It has been argued that postnatal in vivo electroporation is not a viable method for transfecting RGCs since the labeling efficiency is extremely low and hence requires targeting at embryonic ages when RGC progenitors are undergoing differentiation and proliferation6. 
In this video we describe an in vivo electroporation protocol for targeted delivery of genes, shRNA, and fluorescent dextrans to murine RGCs postnatally. This technique provides a cost effective, fast and relatively easy platform for efficient screening of candidate genes involved in several aspects of neural development including axon retraction, branching, lamination, regeneration and synapse formation at various stages of circuit development. In summary we describe here a valuable tool which will provide further insights into the molecular mechanisms underlying sensory map development.

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

We demonstrate an in vivo electroporation protocol for transfecting single or small clusters of retinal ganglion cells (RGCs) and other retinal cell types in postnatal mice over a wide range of ages. The ability to label and genetically manipulate postnatal RGCs in vivo is a powerful tool for developmental studies.

La transfection des cellules ganglionnaires de la rétine de la souris par In vivo L&#39;électroporation

The targeting and refinement of RGC projections to the midbrain is a popular and powerful model system for studying how precise patterns of neural ...

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Neurosciences

Quantifying the Activity of cis-Regulatory Elements in the Mouse Retina by Explant Electroporation

Transcription factors within cellular gene networks control the spatiotemporal pattern and levels of expression of their target genes by binding to cis-regulatory elements (CREs), short (&tilde;300-600 bp) stretches of genomic DNA which can lie upstream, downstream, or within the introns of the genes they control. CREs (i.e., enhancers/promoters) typically consist of multiple clustered binding sites for both transcriptional activators and repressors1-3. They serve as logical integrators of transcriptional input giving a unitary output in the form of spatiotemporally precise and quantitatively exact promoter activity. Most studies of mammalian cis-regulation to date have relied on mouse transgenesis as a means of assaying the enhancer function of CREs4-5. This technique is time-consuming, costly and, on account of insertion site effects, largely non-quantitative. On the other hand, quantitative assays for mammalian CRE function have been developed in tissue culture systems (e.g., dual luciferase assays), but the in vivo relevance of these results is often uncertain. 
Electroporation offers an excellent alternative to traditional mouse transgenesis in that it permits both spatiotemporal and quantitative assessment of cis-regulatory activity in living mammalian tissue. This technique has been particularly useful in the analysis of cis-regulation in the central nervous system, especially in the cerebral cortex and the retina6-8. While mouse retinal electroporation, both in vivo and ex vivo, has been developed and extensively described by Matsuda and Cepko6-7,9, we have recently developed a simple approach to quantify the activity of photoreceptor-specific CREs in electroporated mouse retinas10. Given that the amount of DNA that is introduced into the retina by electroporation can vary from experiment to experiment, it is necessary to include a co-electroporated 'loading control' in all experiments. In this respect, the technique is very similar to the dual luciferase assay used to quantify promoter activity in cultured cells. 
When assaying photoreceptor cis-regulatory activity, electroporation is usually performed in newborn mice (postnatal day 0, P0) which is the time of peak rod production11-12. Once retinal cell types become post-mitotic, electroporation is much less efficient. Given the high rate of rod birth in newborn mice and the fact that rods constitute more than 70% of the cells in the adult mouse retina, the majority of cells that are electroporated at P0 are rods. For this reason, rod photoreceptors are the easiest retinal cell type to study via electroporation. The technique we describe here is primarily useful for quantifying the activity of photoreceptor CREs.

Quantifying the Activity of cis-Regulatory Elements in the Mouse Retina by Explant Electroporation

This protocol describes a simple and inexpensive way to quantify the activity of cis-regulatory elements (i.e., enhancer/promoters) in living mouse retinas via explant electroporation. DNA preparation, retinal dissection, electroporation, retinal explant culture, and post-fixation analysis and quantification are described.

Quantifier l&#39;activité des Cis Éléments de la réglementation-dans la rétine de souris par électroporation explantation

Transcription factors within cellular gene networks control the spatiotemporal pattern and levels of expression of their target genes by binding to ...

Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation

The mammalian inner ear has 6 distinct sensory epithelia: 3 cristae in the ampullae of the semicircular canals; maculae in the utricle and saccule; and the organ of Corti in the coiled cochlea. The cristae and maculae contain vestibular hair cells that transduce mechanical stimuli to subserve the special sense of balance, while auditory hair cells in the organ of Corti are the primary transducers for hearing 1. Cell fate specification in these sensory epithelia and morphogenesis of the semicircular canals and cochlea take place during the second week of gestation in the mouse and are largely completed before birth 2,3. Developmental studies of the mouse inner ear are routinely conducted by harvesting transgenic embryos at different embryonic or postnatal stages to gain insight into the molecular basis of cellular and/or morphological phenotypes 4,5. We hypothesize that gene transfer to the developing mouse inner ear in utero in the context of gain- and loss-of-function studies represents a complimentary approach to traditional mouse transgenesis for the interrogation of the genetic mechanisms underlying mammalian inner ear development6.
The experimental paradigm to conduct gene misexpression studies in the developing mouse inner ear demonstrated here resolves into three general steps: 1) ventral laparotomy; 2) transuterine microinjection; and 3) in vivo electroporation. Ventral laparotomy is a mouse survival surgical technique that permits externalization of the uterus to gain experimental access to the implanted embryos7. Transuterine microinjection is the use of beveled, glass capillary micropipettes to introduce expression plasmid into the lumen of the otic vesicle or otocyst. In vivo electroporation is the application of square wave, direct current pulses to drive expression plasmid into progenitor cells8-10. 
We previously described this electroporation-based gene transfer technique and included detailed notes on each step of the protocol11. Mouse experimental embryological techniques can be difficult to learn from prose and still images alone. In the present work, we demonstrate the 3 steps in the gene transfer procedure. Most critically, we deploy digital video microscopy to show precisely how to: 1) identify embryo orientation in utero; 2) reorient embryos for targeting injections to the otocyst; 3) microinject DNA mixed with tracer dye solution into the otocyst at embryonic days 11.5 and 12.5; 4) electroporate the injected otocyst; and 5) label electroporated embryos for postnatal selection at birth. We provide representative examples of successfully transfected inner ears; a pictorial guide to the most common causes of otocyst mistargeting; discuss how to avoid common methodological errors; and present guidelines for writing an in utero gene transfer animal care protocol.

Gene Transfer to the Developing Mouse Inner Ear by In Vivo Electroporation

The mouse inner ear is a placode-derived sensory organ whose developmental program is elaborated during gestation. We define an in utero gene transfer technique consisting of three steps: mouse ventral laparotomy, transuterine microinjection, and in vivo electroporation. We use digital video microscopy to demonstrate the critical experimental embryological techniques.

Transfert de gènes à l&#39;oreille de souris en développement intérieur par<em&gt; In Vivo</em&gt; Électroporation

The mammalian inner ear has 6 distinct sensory epithelia: 3 cristae in the ampullae of the semicircular canals; maculae in the utricle and saccule; and ...

Genetic Manipulation of the Mouse Developing Hypothalamus through In utero Electroporation

Genetic modification of specific regions of the developing mammalian brain is a very powerful experimental approach. However, generating novel mouse mutants is often frustratingly slow. It has been shown that access to the mouse brain developing in utero with reasonable post-operatory survival is possible. Still, results with this procedure have been reported almost exclusively for the most superficial and easily accessible part of the developing brain, i.e. the cortex. The thalamus, a narrower and more medial region, has proven more difficult to target. Transfection into deeper nuclei, especially those of the hypothalamus, is perhaps the most challenging and therefore very few results have been reported. Here we demonstrate a procedure to target the entire hypothalamic neuroepithelium or part of it (hypothalamic regions) for transfection through electroporation. The keys to our approach are longer narcosis times, injection in the third ventricle, and appropriate kind and positioning of the electrodes. Additionally, we show results of targeting and subsequent histological analysis of the most recessed hypothalamic nucleus, the mammillary body.

Genetic Manipulation of the Mouse Developing Hypothalamus through In utero Electroporation

Despite the functional and medical importance of the hypothalamus, in utero genetic manipulation of its development has rarely been attempted. We show a detailed procedure for in utero electroporation into the mouse hypothalamus and show representative results of total and partial (regional) hypothalamic transfection.

Manipulation génétique de la souris en développement à travers l&#39;hypothalamus<em&gt; In utero</em&gt; Électroporation

Genetic  modification of specific regions of the developing mammalian brain is a very  powerful experimental approach. However, generating novel mouse ...

Whole Mount Immunofluorescent Staining of the Neonatal Mouse Retina to Investigate Angiogenesis In vivo

Angiogenesis is the complex process of new blood vessel formation defined by the sprouting of new blood vessels from a pre-existing vessel network. Angiogenesis plays a key role not only in normal development of organs and tissues, but also in many diseases in which blood vessel formation is dysregulated, such as cancer, blindness and ischemic diseases. In adult life, blood vessels are generally quiescent so angiogenesis is an important target for novel drug development to try and regulate new vessel formation specifically in disease. In order to better understand angiogenesis and to develop appropriate strategies to regulate it, models are required that accurately reflect the different biological steps that are involved. The mouse neonatal retina provides an excellent model of angiogenesis because arteries, veins and capillaries develop to form a vascular plexus during the first week after birth. This model also has the advantage of having a two-dimensional (2D) structure making analysis straightforward compared with the complex 3D anatomy of other vascular networks. By analyzing the retinal vascular plexus at different times after birth, it is possible to observe the various stages of angiogenesis under the microscope. This article demonstrates a straightforward procedure for analyzing the vasculature of a mouse retina using fluorescent staining with isolectin and vascular specific antibodies.

Whole Mount Immunofluorescent Staining of the Neonatal Mouse Retina to Investigate Angiogenesis In vivo

The neonatal murine retina provides a well characterized physiological model of angiogenesis, which permits investigations of the roles of different genes or drugs that modulate angiogenesis in an in vivo context. Immunofluorescent staining to accurately visualize the vascular plexus is pivotal to the success of these types of studies.

Mont entiers immunofluorescence de la rétine de souris néonatal chargé d&#39;enquêter sur l&#39;angiogenèse<em&gt; In vivo</em

Angiogenesis  is the complex process of new blood vessel formation defined by the sprouting  of new blood vessels from a pre-existing vessel network. ...

In vivo Postnatal Electroporation and Time-lapse Imaging of Neuroblast Migration in Mouse Acute Brain Slices

The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal brain. Here, neural progenitors proliferate and give rise to neuroblasts able to move along the rostral migratory stream (RMS) towards the olfactory bulb (OB). This long-distance migration is required for the subsequent maturation of newborn neurons in the OB, but the molecular mechanisms regulating this process are still unclear. Investigating the signaling pathways controlling neuroblast motility may not only help understand a fundamental step in neurogenesis, but also have therapeutic regenerative potential, given the ability of these neuroblasts to target brain sites affected by injury, stroke, or degeneration.
In this manuscript we describe a detailed protocol for in vivo postnatal electroporation and subsequent time-lapse imaging of neuroblast migration in the mouse RMS. Postnatal electroporation can efficiently transfect SVZ progenitor cells, which in turn generate neuroblasts migrating along the RMS. Using confocal spinning disk time-lapse microscopy on acute brain slice cultures, neuroblast migration can be monitored in an environment closely resembling the in vivo condition. Moreover, neuroblast motility can be tracked and quantitatively analyzed. As an example, we describe how to use in vivo postnatal electroporation of a GFP-expressing plasmid to label and visualize neuroblasts migrating along the RMS. Electroporation of shRNA or CRE recombinase-expressing plasmids in conditional knockout mice employing the LoxP system can also be used to target genes of interest. Pharmacological manipulation of acute brain slice cultures can be performed to investigate the role of different signaling molecules in neuroblast migration. By coupling in vivo electroporation with time-lapse imaging, we hope to understand the molecular mechanisms controlling neuroblast motility and contribute to the development of novel approaches to promote brain repair.

In vivo Postnatal Electroporation and Time-lapse Imaging of Neuroblast Migration in Mouse Acute Brain Slices

Neuroblast migration is a fundamental event in postnatal neurogenesis. We describe a protocol for efficient labeling of neuroblasts by in vivo postnatal electroporation and subsequent visualization of their migration using time-lapse imaging of acute brain slices. We include a description for the quantitative analysis of neuroblast dynamics by video tracking.

In vivo postnatale électroporation et imagerie time-lapse de neuroblaste migrations dans Souris aiguë tranches du cerveau

The subventricular zone (SVZ) is one of the main neurogenic niches in the postnatal brain. Here, neural progenitors proliferate and give rise to ...

Assessment of Vascular Regeneration in the CNS Using the Mouse Retina

The rodent retina is perhaps the most accessible mammalian system in which to investigate neurovascular interplay within the central nervous system (CNS). It is increasingly being recognized that several neurodegenerative diseases such as Alzheimer&#8217;s, multiple sclerosis, and amyotrophic lateral sclerosis present elements of vascular compromise. In addition, the most prominent causes of blindness in pediatric and working age populations (retinopathy of prematurity and diabetic retinopathy, respectively) are characterized by vascular degeneration and failure of physiological vascular regrowth. The aim of this technical paper is to provide a detailed protocol to study CNS vascular regeneration in the retina. The method can be employed to elucidate molecular mechanisms that lead to failure of vascular growth after ischemic injury. In addition, potential therapeutic modalities to accelerate and restore healthy vascular plexuses can be explored. Findings obtained using the described approach may provide therapeutic avenues for ischemic retinopathies such as that of diabetes or prematurity and possibly benefit other vascular disorders of the CNS.

The rodent retina has long been recognized as an accessible window to the brain. In this technical paper we provide a protocol that employs the mouse model of oxygen-induced retinopathy to study the mechanisms that lead to failure of vascular regeneration within the central nervous system after ischemic injury. The described system can also be harnessed to explore strategies to promote regrowth of functional blood vessels within the retina and CNS.

Évaluation de la régénération vasculaire dans le SNC Utilisation de la rétine de souris

The rodent retina is perhaps the most accessible mammalian system in which to investigate neurovascular interplay within the central nervous system (CNS). ...

Investigating Mammalian Axon Regeneration: In Vivo Electroporation of Adult Mouse Dorsal Root Ganglion

Electroporation is an essential non-viral gene transfection approach to introduce DNA plasmids or small RNA molecules into cells. A sensory neuron in the dorsal root ganglion (DRGs) extends a single axon with two branches. One branch goes to the peripheral nerve (peripheral branch), and the other branch enters the spinal cord through the dorsal root (central branch). After the neural injury, the peripheral branch regenerates robustly whereas the central branch does not regenerate. Due to the high regenerative capacity, sensory axon regeneration has been widely used as a model system to study mammalian axon regeneration in both the peripheral nervous system (PNS) and the central nervous system (CNS). Here, we describe a previously established approach protocol to manipulate gene expression in mature sensory neurons in vivo via electroporation. Based on transfection with plasmids or small RNA oligos (siRNAs or microRNAs), the approach allows for both loss- and gain-of-function experiments to study the roles of genes-of-interests or microRNAs in regulation of axon regeneration in vivo. In addition, the manipulation of gene expression in vivo can be controlled both spatially and temporally within a relatively short time course. This model system provides a unique tool to investigate the molecular mechanisms by which mammalian axon regeneration is regulated in vivo.

Investigating Mammalian Axon Regeneration: In Vivo Electroporation of Adult Mouse Dorsal Root Ganglion

Electroporation is an effective approach to deliver genes of interests into cells. By applying this approach in vivo on the neurons of adult mouse dorsal root ganglion (DRG), we describe a model to study axon regeneration in vivo.

Chargée de l’enquête la régénération axonale mammifères : In Vivo électroporation du Ganglion de la racine dorsale de souris adulte

Electroporation is an essential non-viral gene transfection approach to introduce DNA plasmids or small RNA molecules into cells. A sensory neuron in the ...

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.

Transpupillaire Imagerie in vivo à deux photons de la rétine de souris

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

In vivo Calcium Imaging in Mouse Inferior Olive

Inferior olive (IO), a nucleus in the ventral medulla, is the only source of climbing fibers that form one of the two input pathways entering the cerebellum. IO has long been proposed to be crucial for motor control and its activity is currently considered to be at the center of many hypotheses of both motor and cognitive functions of the cerebellum. While its physiology and function have been relatively well studied on single-cell level in vitro, presently there are no reports on the organization of the IO network activity in living animals. This is largely due to the extremely challenging anatomical location of the IO, making it difficult to subject to conventional fluorescent imaging methods, where an optic path must be created through the entire brain located dorsally to the region of interest.
Here we describe an alternative method for obtaining state-of-the-art -level calcium imaging data from the IO network. The method takes advantage of the extreme ventral location of the IO and involves a surgical procedure for inserting a gradient-refractive index (GRIN) lens through the neck viscera to come into contact with the ventral surface of the calcium sensor GCaMP6s-expressing IO in anesthetized mice. A representative calcium imaging recording is shown to demonstrate the feasibility to record IO neuron activity after the surgery. While this is a non-survival surgery and the recordings must be conducted under anesthesia, it avoids damage to life-critical brainstem nuclei and allows conducting large variety of experiments investigating spatiotemporal activity patterns and input integration in the IO. This procedure with modifications could be used for recordings in other, adjacent regions of the ventral brainstem.

In vivo Calcium Imaging in Mouse Inferior Olive

We present a protocol to expose the brainstem of adult mouse from the ventral side. By using a gradient-refractive index lens with a miniature microscope, calcium imaging can be used to examine the activity of inferior olive neural somata in vivo.