The methodology was originally developed in Dr. Hongjun Song's laboratory at the Institute for Cell Engineering, Department of Neurology, Johns Hopkins School of Medicine. This work was funded by NIMH (R00MH090115), NARSAD, the Fraternal Order of Eagles' Mayo Cancer Research Fund and a start-up package from Mayo foundation awarded to M.H.J. and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (A3014385) awarded to W.R.K.

1. Pre-immunohistochemistry: Perfusion and Histology
<ol>
	<li>Perfuse mice as per a general transcardial protocol adapted for mice and extract the brains into 4% paraformaldehyde (PFA)9.</li>
	<li>Leave the brains in PFA overnight at 4 &#176;C (e.g. a 10 ml conical tube filled with PFA). Keep in PFA for at least 12-24 hr, no more than 36 hr for full fixation. After overnight fixation, empty out PFA from conical tube but leave brains inside. Pour 30% sucrose into tube and wash the brains for a brief 5 sec to remove any residual PFA. Finally, fill tube containing brains with 30% sucrose again. Keep brains in sucrose at 4 &#176;C until brains sink to the bottom of tube.</li>
	<li>Cut 40 &#956;m brain sections on a microtome. Consult a mouse brain atlas to start collecting sections from the beginning of the dentate gyrus till its end. Preserve sections in anti-freeze solution (a simple recipe is 300 g sucrose in 500 ml 0.1 M PBS and 300 ml ethylene glycol) until ready for immunohistochemistry.</li>
	<li>Mount the cut tissue on microscope slides specifically designed to adhere strongly to tissue. These slides provide a strong hold to tissue during the boiling stage. After mounting the tissue, please let the slide dry for 10 min or until it is fully dry. Drying can be expedited if the slide is rested against a vertical surface with the slide&#39;s bottom edge on a paper towel. If more than one slide is being mounted, the other slide(s) may be left dry during that time (1-2 hr is okay) until ready to proceed to the next step.</li>
	<li>Once slide is dry, wash with PBS three times for 5 min each and dry again (PBS buffer = 0.137 M NaCl, 0.0027 M KCl, 0.0119 M Na2PO4). This ensures any previous chemical (such as glycerol from anti-freeze storage solution) is sufficiently removed and cannot impair the tissue&#39;s adherence to the slide.</li>
</ol>
2. Preparation of Reagents and Minor Equipment
<ol>
	<li>Prepare Solution A (0.1 M or 19.21 g/l citric acid) and Solution B (0.1 M or 24.9 g/l tris-sodium citrate) in which tissue sections will be boiled.</li>
	<li>In a graduated cylinder, combine 9 ml of Solution A and 41 ml of Solution B. Add 450 ml of ddH2O to this mixture.</li>
	<li>Pour this mixture into an empty container (e.g. an empty pipette tips box) that is microwave safe.</li>
</ol>
3. Heat-induced Antigen Retrieval
<ol>
	<li>Boil solution made in step 2 for 5 min at standard setting in a standard microwave. The solution will start boiling at or above 100 &#176;C.</li>
	<li>Once boiling is complete, carefully remove container from microwave and place dried slides into it, ensuring the slide-face with hippocampal sections is facing down and fully exposed to the liquid. If possible, place slides at an angle against the walls of the box and stack other slides around them. Ensure their &#34;fit&#34; inside the box is tight so the slides have no room to move on top of each other.</li>
	<li>Boil this mixture with slides for 7 min at standard settings in the microwave. The solution will boil during this time at or above 100 &#176;C.</li>
	<li>During this boiling stage, fill two ice buckets halfway with ice.</li>
	<li>Once boiling in step 3.3 is complete, remove the container from the microwave and place it inside one of the ice buckets. Pour the rest of the ice from the other bucket all around the container and completely cover it. Let it sit for 1 hr.</li>
</ol>
4. Primary and Secondary Antibody Staining
<ol>
	<li>At the end of the 1 hr waiting period, remove the slides from the container and wash with TBS-T buffer 3x for 5 min each. Any apparatus may be used to perform these basic washes. (Buffer TBS = 50 mM Tris HCl, 150 mM NaCl, TBS-T = 0.05% Triton X-100 TBS buffer, TBS-TT = 4% donkey serum TBS-T buffer).</li>
	<li>After washing, let the slides dry in a dark place (e.g. inside a bench drawer, place a paper towel inside the drawer and tilt the slide against it) for 5-10 min or until slide is fully dry. During this period, prepare a chamber for overnight primary antibody staining. A simple staining chamber may include a container with large surface area filled with ddH2O and a stage inside the container, on top of which the slide may be rested above the ddH2O.</li>
	<li>Once the slide has dried, draw an outline around the tissue sections using a water-repellant pen. During step 4.5, this outline acts as a barrier preventing the antibody mixture from flowing over.</li>
	<li>Prepare the primary antibody mixture in TBS-TT. At least 500 &#956;l is required to cover one entire slide for instance, if antibody stock is at 1:500 concentration, add 1 &#956;l of particular antibody to 500 &#956;l of TBS-TT). Utilize primary antibodies as mentioned in the reagents table.</li>
	<li>Place the dried slide on top of the stage in the staining chamber. Add 500 &#956;l of the primary antibodies slowly and cover entire surface. Cover entire apparatus and wrap in aluminum foil to block external light. Let it sit overnight at room temperature.</li>
	<li>The next day, wash the slide three times for 5 min each with TBS-T buffer. Let it dry in a dark area as described in step 4.2.</li>
	<li>Prepare secondary antibody mixture similar to step 4.4. Refer to reagents table for secondary antibodies.</li>
	<li>Place the dried slide in the staining chamber as described in steps 4.2 and 4.5. Add 500 &#956;l of the secondary antibodies slowly and cover entire surface. Wrap the staining chamber in aluminum foil to protect it from external light. Let it sit covered and protected from external light for at least 2 hr at room temperature.</li>
	<li>After completion of secondary staining, wash the slide three times for 5 min each with TBS-T buffer. Let the slide dry in a dark area. After drying, put mounting solution and cover the slide with a cover slip carefully preventing any introduction of bubbles. Let the slide sit in a dark area for at least 2 hr before subsequent analysis.</li>
	<li>Perform time-lapse or confocal analysis on the stained tissue.</li>
</ol>

<ol>
	<li>Ming, G. L., Song, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult+neurogenesis+in+the+mammalian+central+nervous+system.">Adult neurogenesis in the mammalian central nervous system.</a> Annual Reviews of Neuroscience. 28, 223-250 (2005).</li><li>Santarelli, L., Saxe, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Requirement+of+hippocampal+neurogenesis+for+the+behavioral+effects+of+antidepressants.">Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants.</a> Science. 301 (5634), 805-809 (2003).</li><li>Sahay, 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=Increasing+adult+hippocampal+neurogenesis+is+sufficient+to+improve+pattern+separation.">Increasing adult hippocampal neurogenesis is sufficient to improve pattern separation.</a> Nature. 472 (7344), 466-4670 (2011).</li><li>Clelland, C. D., Choi, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+functional+role+for+adult+hippocampal+neurogenesis+in+spatial+pattern+separation.">A functional role for adult hippocampal neurogenesis in spatial pattern separation.</a> Science. 325 (5937), 210-213 (2009).</li><li>Wang, J. W., David, D. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+fluoxetine+stimulates+maturation+and+synaptic+plasticity+of+adult-born+hippocampal+granule+cells.">Chronic fluoxetine stimulates maturation and synaptic plasticity of adult-born hippocampal granule cells.</a> Journal of Neuroscience. 28 (6), 1374-1384 (2008).</li><li>D'Amico, F., Skarmoutsou, E., Stivala, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=State+of+the+art+in+antigen+retrieval+for+immunohistochemistry.">State of the art in antigen retrieval for immunohistochemistry.</a> Journal of Immunological Methods. 341 (1-2), 1-18 (2009).</li><li>Daneshtalab, N., 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=Troubleshooting+tissue+specificity+and+antibody+selection:+Procedures+in+immunohistochemical+studies.">Troubleshooting tissue specificity and antibody selection: Procedures in immunohistochemical studies.</a> Journal of Pharmacological and Toxicological Methods. 61 (2), 127-135 (2010).</li><li>Jang, M. H., Bonaguidi, M. 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=Secreted+frizzled-related+protein+3+regulates+activity-dependent+adult+hippocampal+neurogenesis.">Secreted frizzled-related protein 3 regulates activity-dependent adult hippocampal neurogenesis.</a> Cell Stem Cell. 12 (2), 215-223 (2013).</li><li>Gage, G. J., Kipke, D. R., Shain, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+Animal+Perfusion+Fixation+for+Rodents.">Whole Animal Perfusion Fixation for Rodents.</a> J. Vis. Exp. (65), e3564 (2012).</li><li>Porcelli, M., Cacciapuoti, 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=Non-thermal+effects+of+microwaves+on+proteins:+Thermophilic+enzymes+as+model+system.">Non-thermal effects of microwaves on proteins: Thermophilic enzymes as model system.</a> FEBS Letters. 402 (2-3), 102-106 (1997).</li><li>Stone, J. R., Walker, S. A., Povlishock, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+visualization+of+a+new+class+of+traumatically+injured+axons+through+the+use+of+a+modified+method+of+microwave+antigen+retrieval.">The visualization of a new class of traumatically injured axons through the use of a modified method of microwave antigen retrieval.</a> Acta Neuropathologica. 97 (4), 335-346 (1999).</li></ol>

The authors declare that they have no competing financial interests.

The most critical steps for successful antigen-retrieval and staining of progenitor cell types are: 1) utilizing well perfused and fixed tissue of the optimal coronal thickness; 2) allowing sufficient time for boiling and subsequent cooling during antigen retrieval; 3) manual dexterity in mounting fixed coronal sections and preventing their damage when doing so.
It is critical in IHC to use perfused tissue that has undergone sufficient fixation but not over-fixation. A primary difficulty can b...

Neurogenèse, la génération de nouveaux neurones à partir de cellules souches neurales, est maintenant connu pour se produire en permanence à l&#39;âge adulte dans deux régions spécialisées dans le cerveau. Il s&#39;agit notamment de la zone sous-ventriculaire (SVZ) du bulbe olfactif et la zone sous-granulaire (SGZ) du gyrus denté de l&#39;hippocampe. Au cours de la dernière décennie, le domaine de la neurogenèse hippocampique adulte a vu d&#39;importants travaux. La région a suscité beaucoup d&#39;intérêt depuis les nouveaux neurones dans le SGZ contribuent à une meilleure plasticité neuronale qui peut maintenir les fonctions spécifiques du cerveau 1-5. Adulte neurogenèse hippocampique a été impliqué à jouer un rôle important dans la régulation de l&#39;humeur, la régénération et l&#39;apprentissage et la mémoire. Ainsi, il ya eu un effort concerté pour comprendre le développement et la régulation des neurones dans cette riche niche neurogène. Un aspect inévitable et important d&#39;étudier la neurogenèse hippocampique adulte est l&#39;identification de station séparéeges qu&#39;une cellule souche neurale activé traverse sur son chemin pour devenir un neurone entièrement fonctionnel. Dans ce procédé, la cellule souche neurale de repos est activé et passe à travers une série de types de cellules progénitrices précoces actives actif et à la fin (Figure 1). Ces populations distinctes de cellules progénitrices neurales peuvent être identifiés par la morphologie et de leur expression de marqueurs moléculaires tels que MCM2, la nestine, TBR2 et Doublecortin (DCX) et NeuN qui guident la conversion de RGLs dans leurs types de cellules précurseurs respectifs. La nestine est une protéine de filament intermédiaire qui est exprimée dans les cellules gliales en forme radiales et certains types de cellules progénitrices précoces. Un autre marqueur est TBR2 qui est spécifiquement exprimé dans les cellules progénitrices amplification. L&#39;expression du transgène TBR2 est initialement désactivée dans les cellules de type 1 (radiale gliales comme), activé à travers les type 2a, progéniteurs de type-2ab et Type-2b et éteint parmi les plus différenciée de type 3 et immatureneurones (Figure 1). DCX est un marqueur de la migration neuronale qui est exprimé dans le type 2ab, Type-2b et de type 3 progéniteurs neuronaux. En utilisant cette combinaison de trois marqueurs, nous pouvons étiqueter sous-types distincts de cellules progénitrices neurales. Il s&#39;agit notamment du type 1 (MCM2 + nestine + TBR2-), de type 2a (MCM2 + nestine + TBR2 +), Type-2ab (MCM2 partielle + nestine-TBR2 + et partielle MCM2 + TBR2 + DCX-), Type-2b ( MCM2 + TBR2 + + DCX) et de type 3 (MCM2 + TBR2-DCX +). Cellules post-mitotiques tels que les neurones immatures et fonctionnellement intégrés peuvent être identifiés par l&#39;utilisation de DCX et le marqueur neuronal mature, NeuN. Les méthodes traditionnelles d&#39;IHC utilisent des anticorps pour identifier des antigènes de types de cellules spécifiques sur la base de leur expression des gènes. Après visualisation grâce à des techniques d&#39;imagerie à haute résolution telle que la microscopie confocale peut être utilisée pour leur identification. Toutefois, actuellement, il ya des problèmes qui existent avec ces méthodes qui ne permettent pas l&#39;identification efficace desles cellules gliales comme radiaux et progénitrices début types de cellules. Il est difficile d&#39;identifier ces différents types cellulaires particuliers, car l&#39;anticorps n&#39;est pas appliqué capable de pénétrer et de se lier de manière efficace la protéine nestine. La nestine est la protéine de filament intermédiaire qui comprend les processus radiales produites par la cellule de cellules gliales en forme radiale. La liaison inefficace d&#39;un anticorps à l&#39;antigène peut être le résultat de nombreux facteurs, y compris le temps de fixation, de la température et de la technique utilisée 7.6. Pour aider à résoudre ces problèmes, nous avons développé une réaction antigène-extraction, ou de méthode &quot;d&#39;ébullition&quot;. En plus de la nestine, ce procédé de récupération d&#39;antigène permet également d&#39;améliorer la coloration pour les autres marqueurs tels que Ki67, BrdU, la protéine acide fibrillaire gliale (GFAP), TBR2 et MCM2. Notre méthode combine ensemble des approches chimiques et physiques. Elle implique la fixation chimique du tissu dans du paraformaldéhyde et ultérieur à haute température d&#39;ébullition de minces sections coronales de l&#39;hippocampe dans un tampon d&#39;un dénaturant et chaotroptraitement ic. Cela améliore l&#39;accessibilité de l&#39;antigène à l&#39;anticorps, permet d&#39;améliorer la spécificité des anticorps et permet une meilleure identification des types de cellules progénitrices. Notre approche est simple à utiliser nécessitant des outils et des réactifs pour la plupart déjà disponibles dans le laboratoire. Nous avons utilisé intensivement pour étudier le développement des cellules souches neurales et leur régulation par des facteurs environnementaux génétiques ou extrinsèques intrinsèques 8.

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</td>
 </tr>
 <tr>
 <td>SuperFrost Plus Slide</td>
 <td>Fisherbrand</td>
 <td>12-550-15</td>
 <td>Provides strong adherence to hippocampal tissue during boiling</td>
 </tr>
 <tr>
 <td>PVA/DABCO Mounting Media</td>
 <td>Sigma Aldrich</td>
 <td>10981-100 ml</td>
 <td></td>
 </tr>
 <tr>
 <td>Nestin (chicken) </td>
 <td>Aves Lab</td>
 <td>NES</td>
 <td>Neural stem cell marker</td>
 </tr>
 <tr>
 <td>GFAP (rabbit)</td>
 <td>Dako North America</td>
 <td>Z033401-2</td>
 <td>Astrocyte and neural stem cell marker</td>
 </tr>
 <tr>
 <td>MCM2 (mouse)</td>
 <td>BD Transduction Laboratory</td>
 <td>610701</td>
 <td>Proliferation marker</td>
 </tr>
 <tr>
 <td>DCX (goat)</td>
 <td>Santa Cruz Biotechnology</td>
 <td>SC8066</td>
 <td>Immature neuron marker</td>
 </tr>
 <tr>
 <td>Tbr2 (rabbit)</td>
 <td>Abcam</td>
 <td>Ab23345</td>
 <td>Amplifying progenitor marker</td>
 </tr>
 <tr>
 <td>NeuN (mouse)</td>
 <td>Millipore</td>
 <td>MAB377</td>
 <td>Mature neuron marker</td>
 </tr>
 <tr>
 <td>Cy2 (anti-rabbit)</td>
 <td>Jackson Immunoresearch</td>
 <td>111-226-047</td>
 <td></td>
 </tr>
 <tr>
 <td>Cy2 (anti-chicken)</td>
 <td>Jackson Immunoresearch</td>
 <td>303-165-006</td>
 <td></td>
 </tr>
 <tr>
 <td>Cy5 (anti-mouse)</td>
 <td>Jackson Immunoresearch</td>
 <td>315-175-047</td>
 <td></td>
 </tr>
 <tr>
 <td>Cy5 (anti-goat)</td>
 <td>Jackson Immunoresearch</td>
 <td>305-165-047</td>
 <td></td>
 </tr>
 <tr>
 <td>DAPI</td>
 <td>Life Technologies Corporation</td>
 <td>D1306</td>
 <td></td>
 </tr>
 <tr>
 <td>Dako Pen</td>
 <td>S2002</td>
 <td>Dako</td>
 <td>Water-repellant pen</td>
 </tr>
 </tbody>
</table>

heat-induced antigen retrieval: an effective method to detect and identify progenitor cell types during adult hippocampal neurogenesis

Les méthodes traditionnelles de l&#39;immunohistochimie (IHC) suivantes fixation du tissu permettent de visualiser différents types de cellules. Ceux-ci se déroulent généralement avec l&#39;application de l&#39;anticorps à lier des antigènes et identifier les cellules dont les caractéristiques sont fonction de la biologie et de développement inhérente. Neurogenèse hippocampique adulte est un processus séquentiel, dans lequel une cellule souche neurale de repos peut être activée et de passer par les étapes de prolifération, la différenciation, la maturation et l&#39;intégration fonctionnelle. Chaque phase se distingue avec une morphologie caractéristique et la régulation positive des gènes. L&#39;identification de ces phases est important de comprendre les mécanismes de régulation en jeu et toute modification dans ce processus qui sous-tendent la physiopathologie des troubles débilitants. Notre approche d&#39;extraction de l&#39;antigène induit par la chaleur permet d&#39;améliorer l&#39;intensité du signal qui est détecté et permet une identification correcte du type de cellules progénitrices. Comme on le verra dans cepapier, il permet surtout de nous de contourner les problèmes actuels dans la détection de certains types de cellules souches.

Adult hippocampal neurogenesis is a sequential process where the representative progenitor cell type at each stage may be identified with a combination of markers. Careful chemical fixation and antigen-retrieval improves the effectiveness and accessibility of markers that are otherwise difficult to detect. One of these is nestin which is expressed among the radial glia-like neural stem cells and some early active progenitor cell types. Nestin can be a key protein in identifying early progenitor cell types as its expressi...

Watch this Scientific Journal Video about Heat-Induced Antigen Retrieval: An Effective Method to Detect and Identify Progenitor Cell Types during Adult Hippocampal Neurogenesis at JoVE.com

Heat-Induced Antigen Retrieval: An Effective Method to Detect and Identify Progenitor Cell Types during Adult Hippocampal Neurogenesis

During adult hippocampal neurogenesis, a distinct set of genetic markers are expressed when a quiescent neural stem cell sequentially progresses and develops into a functionally integrated neuron in the circuit. Using heat-induced antigen retrieval, progenitor cell types that are otherwise difficult to detect are identified with improved effectiveness.

La chaleur induite par un antigène de récupération: une méthode efficace pour détecter et identifier les types de cellules progénitrices adultes au cours de l&#39;hippocampe neurogenèse

Traditional  methods of immunohistochemistry (IHC) following tissue fixation allow visualization  of various cell types. These typically proceed with the ...

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12.4K vues.  Mayo Clinic College of Medicine. During adult hippocampal neurogenesis, a distinct set of genetic markers are expressed when a quiescent neural stem cell sequentially progresses and develops into a functionally integrated neuron in the circuit. Using heat-induced antigen retrieval, progenitor cell types that are otherwise difficult to detect are identified with improved effectiveness.

Vidéo: Heat-Induced Antigen Retrieval: An Effective Method to Detect and Identify Progenitor Cell Types during Adult Hippocampal Neurogenesis

Growth and Differentiation of Adult Hippocampal Arctic Ground Squirrel Neural Stem Cells

Arctic ground squirrels (Urocitellus parryii, AGS) are unique in their ability to hibernate with a core body temperature near or below freezing 1. These animals also resist ischemic injury to the brain in vivo 2,3 and oxygen-glucose deprivation in vitro 4,5. These unique qualities provided the impetus to isolate AGS neurons to examine inherent neuronal characteristics that could account for the capacity of AGS neurons to resist injury and cell death caused by ischemia and extremely cold temperatures. Identifying proteins or gene targets that allow for the distinctive properties of these cells could aid in the discovery of effective therapies for a number of ischemic indications and for the study of cold tolerance. Adult AGS hippocampus contains neural stem cells that continue to proliferate, allowing for easy expansion of these stem cells in culture. We describe here methods by which researchers can utilize these stem cells and differentiated neurons for any number of purposes. By closely following these steps the AGS neural stem cells can be expanded through two passages or more and then differentiated to a culture high in TUJ1-positive neurons (~50%) without utilizing toxic chemicals to minimize the number of dividing cells. Ischemia induces neurogenesis 6 and neurogenesis which proceeds via MEK/ERK and PI3K/Akt survival signaling pathways contributes to ischemia resistance in vivo7 and in vitro 8 (Kelleher-Anderson, Drew et al., in preparation). Further characterization of these unique neural cells can advance on many fronts, using some or all of these methods.

Neural stem cells were prepared from the hippocampus of adult non-hibernating yearling Arctic ground squirrels (AGS). These neural stem cells can be expanded through numerous passages, differentiated and maintained as a nearly 50:50 neuron to glial culture.

Croissance et différenciation des cellules adultes hippocampe Arctic écureuil souches neurales au sol

Arctic ground squirrels (Urocitellus parryii, AGS) are unique in their ability to hibernate with a core body temperature near or below freezing 1. These ...

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Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding fundamental biological mechanisms. Striking progress has been particularly evident in Drosophila, whose extensive toolkit of mutants and transgenic lines provides a convenient model to study evolutionarily-conserved developmental and cell biological mechanisms. We are interested in understanding the mechanisms that control cell fate specification in the adult peripheral nervous system (PNS) in Drosophila. Bristles that cover the head, thorax, abdomen, legs and wings of the adult fly are individual mechanosensory organs, and have been studied as a model system for understanding mechanisms of Notch-dependent cell fate decisions. Sensory organ precursor (SOP) cells of the microchaetes (or small bristles), are distributed throughout the epithelium of the pupal thorax, and are specified during the first 12 hours after the onset of pupariation. After specification, the SOP cells begin to divide, segregating the cell fate determinant Numb to one daughter cell during mitosis. Numb functions as a cell-autonomous inhibitor of the Notch signaling pathway.
Here, we show a method to follow protein dynamics in SOP cell and its progeny within the intact pupal thorax using a combination of tissue-specific Gal4 drivers and GFP-tagged fusion proteins 1,2.This technique has the advantage over fixed tissue or cultured explants because it allows us to follow the entire development of an organ from specification of the neural precursor to growth and terminal differentiation of the organ. We can therefore directly correlate changes in cell behavior to changes in terminal differentiation. Moreover, we can combine the live imaging technique with mosaic analysis with a repressible cell marker (MARCM) system to assess the dynamics of tagged proteins in mitotic SOPs under mutant or wildtype conditions. Using this technique, we and others have revealed novel insights into regulation of asymmetric cell division and the control of Notch signaling activation in SOP cells (examples include references 1-6,7 ,8).

Live-cell Imaging of Sensory Organ Precursor Cells in Intact Drosophila Pupae

In this video, we describe a method for live cell imaging of asymmetrically dividing sensory organ progenitor cells and epidermal cells in intact Drosophila pupae

Imagerie des cellules vivantes des cellules sensorielles de précurseurs d&#39;organes en Intact Drosophile Les chrysalides

Since the discovery of Green Fluorescent Protein (GFP), there has been a revolutionary change in the use of live-cell imaging as a tool for understanding ...

Functional Interrogation of Adult Hypothalamic Neurogenesis with Focal Radiological Inhibition

The functional characterization of adult-born neurons remains a significant challenge. Approaches to inhibit adult neurogenesis via invasive viral delivery or transgenic animals have potential confounds that make interpretation of results from these studies difficult. New radiological tools are emerging, however, that allow one to noninvasively investigate the function of select groups of adult-born neurons through accurate and precise anatomical targeting in small animals. Focal ionizing radiation inhibits the birth and differentiation of new neurons, and allows targeting of specific neural progenitor regions. In order to illuminate the potential functional role that adult hypothalamic neurogenesis plays in the regulation of physiological processes, we developed a noninvasive focal irradiation technique to selectively inhibit the birth of adult-born neurons in the hypothalamic median eminence. We describe a method for Computer tomography-guided focal irradiation (CFIR) delivery to enable precise and accurate anatomical targeting in small animals. CFIR uses three-dimensional volumetric image guidance for localization and targeting of the radiation dose, minimizes radiation exposure to nontargeted brain regions, and allows for conformal dose distribution with sharp beam boundaries. This protocol allows one to ask questions regarding the function of adult-born neurons, but also opens areas to questions in areas of radiobiology, tumor biology, and immunology. These radiological tools will facilitate the translation of discoveries at the bench to the bedside.

The function of adult-born mammalian neurons remains an active area of investigation. Ionizing radiation inhibits the birth of new neurons. Using computer tomography-guided focal irradiation (CFIR), three-dimensional anatomical targeting of specific neural progenitor populations can now be used to assess the functional role of adult neurogenesis.

Interrogation fonctionnelle des adultes hypothalamique neurogenèse avec Focal radiologique inhibition

The functional characterization of adult-born neurons remains a significant challenge. Approaches to inhibit adult neurogenesis via invasive viral ...

Methods for the Modulation and Analysis of NF-&#954;B-dependent Adult Neurogenesis

The hippocampus plays a pivotal role in the formation and consolidation of episodic memories, and in spatial orientation. Historically, the adult hippocampus has been viewed as a very static anatomical region of the mammalian brain. However, recent findings have demonstrated that the dentate gyrus of the hippocampus is an area of tremendous plasticity in adults, involving not only modifications of existing neuronal circuits, but also adult neurogenesis. This plasticity is regulated by complex transcriptional networks, in which the transcription factor NF-&#954;B plays a prominent role. To study and manipulate adult neurogenesis, a transgenic mouse model for forebrain-specific neuronal inhibition of NF-&#954;B activity can be used.
In this study, methods are described for the analysis of NF-&#954;B-dependent neurogenesis, including its structural aspects, neuronal apoptosis and progenitor proliferation, and cognitive significance, which was specifically assessed via a dentate gyrus (DG)-dependent behavioral test, the spatial pattern separation-Barnes maze (SPS-BM). The SPS-BM protocol could be simply adapted for use with other transgenic animal models designed to assess the influence of particular genes on adult hippocampal neurogenesis. Furthermore, SPS-BM could be used in other experimental settings aimed at investigating and manipulating DG-dependent learning, for example, using pharmacological agents.

Methods for the Modulation and Analysis of NF-&amp;#954;B-dependent Adult Neurogenesis

Methods for the manipulation and analysis of NF-&#954;B-dependent adult hippocampal neurogenesis are described. A detailed protocol is presented for a dentate gyrus-dependent behavioral test (termed the spatial pattern separation-Barnes maze) for the investigation of cognitive outcome in mice. This technique should also help enable investigations in other experimental settings.

Des procédés pour la modulation et de l&#39;analyse de NF-kB-dépendante neurogenèse adulte

The hippocampus plays a pivotal role in the formation and consolidation of episodic memories, and in spatial orientation. Historically, the adult ...

Stab Wound Injury of the Zebrafish Adult Telencephalon: A Method to Investigate Vertebrate Brain Neurogenesis and Regeneration

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular mechanisms involved in zebrafish adult central nervous system (CNS) regeneration and repair, we developed a zebrafish model of adult telencephalic injury.
In this approach, we manually generate an injury by pushing an insulin syringe needle into the zebrafish adult telencephalon. At different post injury days, fish are sacrificed, their brains are dissected out and stained by immunohistochemistry and/or in situ hybridization (ISH) with appropriate markers to observe cell proliferation, gliogenesis, and neurogenesis. The contralateral unlesioned hemisphere serves as an internal control. This method combined for example with RNA deep sequencing can help to screen for new genes with a role in zebrafish adult telencephalon neurogenesis, regeneration, and repair.

To shed light on the cellular and molecular mechanisms of zebrafish adult neurogenesis and regeneration, we developed a protocol for invasive surgery causing mechanical injuries in the zebrafish adult telencephalon and subsequent monitoring of changes in the stabbed hemisphere by immunohistochemistry or in situ hybridization.

Stab blessures plaies du poisson zèbre adulte Télencéphale: Une méthode pour étudier le cerveau des vertébrés neurogenèse et régénération

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular ...

Flow Cytometry Protocols for Surface and Intracellular Antigen Analyses of Neural Cell Types

Flow cytometry has been extensively used to define cell populations in immunology, hematology and oncology. Here, we provide a detailed description of protocols for flow cytometric analysis of the cluster of differentiation (CD) surface antigens and intracellular antigens in neural cell types. Our step-by-step description of the methodological procedures include: the harvesting of neural in vitro cultures, an optional carboxyfluorescein succinimidyl ester (CFSE)-labeling step, followed by surface antigen staining with conjugated CD antibodies (e.g., CD24, CD54), and subsequent intracellar antigen detection via primary/secondary antibodies or fluorescently labeled Fab fragments (Zenon labeling). The video demonstrates the most critical steps. Moreover, principles of experimental planning, the inclusion of critical controls, and fundamentals of flow cytometric analysis (identification of target population and exclusion of debris; gating strategy; compensation for spectral overlap) are briefly explained in order to enable neurobiologists with limited prior knowledge or specific training in flow cytometry to assess its utility and to better exploit this powerful methodology.

We provide a detailed description of a protocol for flow cytometric analysis of surface antigens and/or intracellular antigens in neural cell types. Critical aspects of experimental planning, step-by-step methodological procedures, and fundamental principles of flow cytometry are explained in order to enable neurobiologists to exploit this powerful technology.

Cytométrie en flux pour les protocoles surface et intracellulaire Antigen analyses des types cellulaires de neurones

Flow cytometry has been extensively used to define cell populations in immunology, hematology and oncology. Here, we provide a detailed description of ...

Immunohistochemistry and Multiple Labeling with Antibodies from the Same Host Species to Study Adult Hippocampal Neurogenesis

Adult neurogenesis is a highly regulated, multi-stage process in which new neurons are generated from an activated neural stem cell via increasingly committed intermediate progenitor subtypes. Each of these subtypes expresses a set of specific molecular markers that, together with specific morphological criteria, can be used for their identification. Typically, immunofluorescent techniques are applied involving subtype-specific antibodies in combination with exo- or endogenous proliferation markers. We herein describe immunolabeling methods for the detection and quantification of all stages of adult hippocampal neurogenesis. These comprise the application of thymidine analogs, transcardial perfusion, tissue processing, heat-induced epitope retrieval, ABC immunohistochemistry, multiple indirect immunofluorescence, confocal microscopy and cell quantification. Furthermore we present&#160;a sequential multiple immunofluorescence protocol which circumvents problems usually arising from the need of using primary antibodies raised in the same host species. It allows an accurate identification of all hippocampal progenitor subtypes together with a proliferation marker within a single section. These techniques are a powerful tool to study the regulation of different progenitor subtypes in parallel, their involvement in brain pathologies and their role in specific brain functions.

This video article illustrates a comprehensive protocol to detect and quantify all stages of adult hippocampal neurogenesis within the same tissue section. We elaborated a method to overcome the limitations of indirect multiple immunofluorescence that arise when suitable antibodies from different host species are unavailable.

Immunohistochimie et d&#39;étiquetage multiple avec des anticorps de l&#39;espèce hôte mêmes pour l&#39;étude des adultes hippocampe neurogenèse

Adult neurogenesis is a highly regulated, multi-stage process in which new neurons are generated from an activated neural stem cell via increasingly ...

Derivation of Adult Human Fibroblasts and their Direct Conversion into Expandable Neural Progenitor Cells

Generation of&#160;induced pluripotent stem cell (iPSCs) from adult skin fibroblasts and subsequent differentiation into somatic cells provides fascinating prospects for the derivation of autologous transplants that circumvent histocompatibility barriers. However, progression through a pluripotent state and subsequent complete differentiation into desired lineages remains a roadblock for the clinical translation of iPSC technology because of the associated neoplastic potential and genomic instability. Recently, we and others showed that somatic cells cannot only be converted into iPSCs but also into different types of multipotent somatic stem cells by using defined factors, thereby circumventing progression through the pluripotent state. In particular, the direct conversion of human fibroblasts into induced neural progenitor cells (iNPCs) heralds the possibility of a novel autologous cell source for various applications such as cell replacement, disease modeling and drug screening. Here, we describe the isolation of adult human primary fibroblasts by skin biopsy and their efficient direct conversion into iNPCs by timely restricted expression of Oct4, Sox2, Klf4, as well as c-Myc. Sox2-positive neuroepithelial colonies appear after 17 days of induction and iNPC lines can be established efficiently by monoclonal isolation and expansion. Precise adjustment of viral multiplicity of infection and supplementation of leukemia inhibitory factor during the induction phase represent critical factors to achieve conversion efficiencies of up to 0.2%. Thus far, patient-specific iNPC lines could be expanded for more than 12 passages and uniformly display morphological and molecular features of neural stem/progenitor cells, such as the expression of Nestin and Sox2. The iNPC lines can be differentiated into neurons and astrocytes as judged by staining against TUJ1 and GFAP, respectively. In conclusion, we report a robust protocol for the derivation and direct conversion of human fibroblasts into stably expandable neural progenitor cells that might provide a cellular source for biomedical applications such as autologous neural cell replacement and disease modeling.

Generation of induced pluripotent stem cells provides fascinating prospects for the derivation of autologous transplants. However, progression through a pluripotent state and laborious re-differentiation still hinders clinical translation. Here we describe the derivation of adult human fibroblasts and their direct conversion into induced neural progenitor cells and the subsequent differentiation into neural lineages.

Dérivation des adultes fibroblastes humains et de leur conversion directe dans les cellules progénitrices neurales extensible

Generation of&#160;induced pluripotent stem cell (iPSCs) from adult skin fibroblasts and subsequent differentiation into somatic cells provides ...

Preparation of Acute Brain Slices Using an Optimized N-Methyl-D-glucamine Protective Recovery Method

This protocol is a practical guide to the N-methyl-D-glucamine (NMDG) protective recovery method of brain slice preparation. Numerous recent studies have validated the utility of this method for enhancing neuronal preservation and overall brain slice viability. The implementation of this technique by early adopters has facilitated detailed investigations into brain function using diverse experimental applications and spanning a wide range of animal ages, brain regions, and cell types. Steps are outlined for carrying out the protective recovery brain slice technique using an optimized NMDG artificial cerebrospinal fluid (aCSF) media formulation and enhanced procedure to reliably obtain healthy brain slices for patch clamp electrophysiology. With this updated approach, a substantial improvement is observed in the speed and reliability of gigaohm seal formation during targeted patch clamp recording experiments while maintaining excellent neuronal preservation, thereby facilitating challenging experimental applications. Representative results are provided from multi-neuron patch clamp recording experiments to assay synaptic connectivity in neocortical brain slices prepared from young adult transgenic mice and mature adult human neurosurgical specimens. Furthermore, the optimized NMDG protective recovery method of brain slicing is compatible with both juvenile and adult animals, thus resolving a limitation of the original methodology. In summary, a single media formulation and brain slicing procedure can be implemented across various species and ages to achieve excellent viability and tissue preservation.

Preparation of Acute Brain Slices Using an Optimized N-Methyl-D-glucamine Protective Recovery Method

This protocol demonstrates the implementation of an optimized N-methyl-D-glucamine (NMDG) protective recovery method of brain slice preparation. A single media formulation is used to reliably obtain healthy brain slices from animals of any age and for diverse experimental applications.

Préparation de tranches de cerveau aiguë en utilisant un optimisé N-méthyl-D-glucamine méthode de recouvrement protecteur

This protocol is a practical guide to the N-methyl-D-glucamine (NMDG) protective recovery method of brain slice preparation. Numerous recent studies have ...

Assessing Primary Neurogenesis in Xenopus Embryos Using Immunostaining

Primary neurogenesis is a dynamic and complex process during embryonic development that sets up the initial layout of the central nervous system. During this process, a portion of neural stem cells undergo differentiation and give rise to the first populations of differentiated primary neurons within the nascent central nervous system. Several vertebrate model organisms have been used to explore the mechanisms of neural cell fate specification, patterning, and differentiation. Among these is the African clawed frog, Xenopus, which provides a powerful system for investigating the molecular and cellular mechanisms responsible for primary neurogenesis due to its rapid and accessible development and ease of embryological and molecular manipulations. Here, we present a convenient and rapid method to observe the different populations of neuronal cells within Xenopus central nervous system. Using antibody staining and immunofluorescence on sections of Xenopus embryos, we are able to observe the locations of neural stem cells and differentiated primary neurons during primary neurogenesis.

Assessing Primary Neurogenesis in Xenopus Embryos Using Immunostaining

This article presents a convenient and rapid method for visualizing different neuronal cell populations in the central nervous system of Xenopus embryos using immunofluorescent staining on sections.

Évaluation de la neurogenèse primaire en<em&gt; Xenopus</em&gt; Embryons Utilisation de immunocoloration

Primary neurogenesis is a dynamic and complex process during embryonic development that sets up the initial layout of the central nervous system. During ...