The support and advice of Markus Pajtler and Robert Bohrer were invaluable for the visualization of this protocol.

The authors state that experiments on animals were performed in accordance with the European Communities Council Directive (86/609/EEC), following the Guidelines of the NIH regarding the care and use of animals for experimental procedures and the regulations set forth by the Institutional Animal Care and Use Committee (IACUC) at the University of Duisburg-Essen (Germany).

Part 1: Setting Up (not Shown on Video)
PREPARING MATERIALS AND SOLUTIONS (prior to taking the eggs out of the incubator)
<ul>
<li>Eggs have to be incubated in a humidified incubator for 11 days at 37&deg;C (100&deg;F).</li>
<li>70% ethanol spray, clean plates, precise clean forceps, 4&deg;C (40&deg;F) cold sterile DMEM on ice and 60 mL sterile syringes</li>
<li>50 mL Sterile corning tubes have to be half-filled with 4&deg;C cold DMEM to mix the macerated embryos at a ratio of 1:1 (macerated mass: DMEM). As soon as the eggs are taken out of the incubator dissection of the chick embryos has to be started.</li>
<li>Sterilize dissection tools in the autoclave or on the day of dissection, immerse the tools in 70% ethanol for 20 minutes.</li>
</ul>
Part 2: Dissection of the Chick Embryos (demonstrated on Video)
<ol>
<li>Wet the incubated eggs with a 70% ethanol spray for at least 30 seconds and dry them carefully with clean soft paper towels while not shaking the eggs excessively. 
Note: We recommend not dissecting more than 60 chick embryos simultaneously.</li>
<li>Open the eggs carefully by dashing against a sharp edge and take out the embryo with caution not destroying the yolk sack or the chick embryo itself.</li>
<li>Search for the beginning of the umbilical cord quickly and open the clear wrapping without destroying the yolk sack or any little vessels. Then dissect the umbilical cord with precise clean forceps.</li>
<li>Take the embryo out of the yolk sack. 
Note: Embryos should be decapitated quickly (not shown in the video).</li>
<li>Collect the embryos in minimal essential medium at 4&deg;C.</li>
</ol>
Part 3: Maceration of the Chick Embryos
<ol>
<li>Take the plunger out of a 60 mL sterile syringe.</li>
<li>Transfer approximately 10 embryos into one 60 mL syringe.</li>
<li>Put the plunger carefully back into the syringe in order not to risk losing macerated material.</li>
<li>Macerate by pushing down the plunger.</li>
<li>Collect the macerated mass in the prepared corning tubes half-filled with DMEM at a ratio of 1:1 (macerated mass: DMEM). Using 10 embryos a volume of approximately 25 mL is produced.</li>
<li>Place the mixture on a shaker for 45 min at 4&deg;C.</li>
</ol>
Part 4: Centrifugation of the Chick Embryo - DMEM Suspension
<ol>
<li>Transfer the chick embryo - DMEM suspension into the centrifugation tubes.</li>
<li>Add sterile hyaluronidase at a concentration of 1 mg per 25 mg of embryo.</li>
<li>Tare the centrifugation tubes very precisely. 
Note: This step should be performed with caution as centrifugation is run at very high g-force and damage of material or centrifuge could occur if using imbalanced tubes. With a high accuracy weighing machine accordance regarding the three positions after decimal point for all tubes should be received by adjusting the missing amount with DMEM.</li>
<li>Reduce the temperature of the centrifuge to 4&deg;C. 
Note: Also the centrifugation rotor should be stored in a cooling chamber or fridge over night.</li>
<li>Centrifuge 6 hours at least for 180.000 x g x h. Note: For superior results regarding the separation of the single phases use 266.000 x g x h. If possible, use the vacuum adjustment.</li>
</ol>
Part 5: Filtration of the Chick Embryo Extract
After the centrifugation, three phases can be noticed: The upper dingy liquid phase with fatty fragments, the clear liquid phase in the middle and the pellet at the bottom of the centrifugation tube. Note: Shaking or brisk moving of the centrifuged mixture has to be strictly avoided, as this would destroy the result of the centrifugation step by losing the clear central liquid phase.
Note: All following steps have to be performed under sterile conditions using a laminar air flow bench:
<ol>
<li>Pipette the clear liquid phase into a filter system with pores of 0.45 &mu;m. Then switch on the connected vacuum pump. 
Note: Do not touch the pellet at the bottom. This would lead to a contamination of the extract and a blockage of the filter system.</li>
<li>Transfer the pre-extract into a filter system with pores of 0.22 &mu;m and switch on the connected vacuum pump again. </li>
<li>Aliquot the attained chick embryo extract in sterile 15 mL corning tubes.</li>
<li>Quickly store the aliquots at -80&deg;C (-62&deg;F). Note: The CEE last for up to two years if stored at -80&deg;C.</li>
</ol>

<ol>
	<li>Bronner-Fraser, M., Fraser, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+lineage+analysis+reveals+multipotency+of+some+avian+neural+crest+cells.">Cell lineage analysis reveals multipotency of some avian neural crest cells.</a> Nature. 335, 161-164 (1988).</li><li>Stemple, D. L., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+a+stem+cell+for+neurons+and+glia+from+the+mammalian+neural+crest.">Isolation of a stem cell for neurons and glia from the mammalian neural crest.</a> Cell. 71, 973-985 (1992).</li><li>Rao, M. S., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immortalization+and+controlled+in+vitro+differentiation+of+murine+multipotent+neural+crest+stem+cells.">Immortalization and controlled in vitro differentiation of murine multipotent neural crest stem cells.</a> J Neurobiol. 32, 722-746 (1997).</li><li>Paratore, C., Goerich, D. E., Suter, U., Wegner, M., Sommer, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Survival+and+glial+fate+acquisition+of+neural+crest+cells+are+regulated+by+an+interplay+between+the+transcription+factor+Sox10+and+extrinsic+combinatorial+signaling.">Survival and glial fate acquisition of neural crest cells are regulated by an interplay between the transcription factor Sox10 and extrinsic combinatorial signaling.</a> Cell. 128, 3949-3961 (2001).</li><li>Kim, J., Lo, L., Dormand, E., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SOX10+maintains+multipotency+and+inhibits+neuronal+differentiation+of+neural+crest+stem+cells.">SOX10 maintains multipotency and inhibits neuronal differentiation of neural crest stem cells.</a> Neuron. 38, 17-31 (2003).</li><li>Anderson, D. J., Groves, A., Lo, L., Ma, Q., Rao, M., Shah, N. M., Sommer, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+lineage+determination+and+the+control+of+neuronal+identity+in+the+neural+crest.">Cell lineage determination and the control of neuronal identity in the neural crest.</a> Review Cold Spring Harb Symp Quant Biol. 62, 493-504 (1997).</li><li>Dorsky, R. I., Moon, R. T., Raible, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+signals+and+cell+fate+specification+in+premigratory+neural+crest.">Environmental signals and cell fate specification in premigratory neural crest.</a> Review Bioessays. 22, 708-716 (2000).</li><li>Sieber-Blum, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+controlling+lineage+specification+in+the+neural+crest.">Factors controlling lineage specification in the neural crest.</a> Int Rev Cytol. 197, 1-33 (2000).</li><li>Dupin, E., Real, C., Ledouarin, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+neural+crest+stem+cells:+control+of+neural+crest+cell+fate+and+plasticity+by+endothelin-3.">The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3.</a> Int Rev Cytol. 73, 533-545 (2001).</li><li>Maurer, J., Fuchs, S., J&#228;ger, R., Kurz, B., Sommer, L., Schorle, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+and+controlled+differentiation+of+neural+crest+stem+cell+lines+using+conditional+transgenesis.">Establishment and controlled differentiation of neural crest stem cell lines using conditional transgenesis.</a> Differentiation. 75, 890-891 (2007).</li><li>Wu, Y. Y., Mujtaba, T., Rao, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+stem+and+precursor+cells+from+fetal+tissue.">Isolation of stem and precursor cells from fetal tissue.</a> Methods Mol Biol. 198, 29-40 (2002).</li></ol>

No conflicts of interest declared.

This protocol is based on modifications of procedures that have been described in the past10,11. In addition to former publications we here show the individual different steps of the process more expanded. This supports the experimenter with important details assuring correct proceedings and reliable outcomes. Further, as the dissection process is an essential part of CEE extraction we describe the procedure of taking the embryos out of the yolk sack in every detail. There are several important points to note as discussed below.
The dissection of the chick embryos should be started as soon as possible after the incubation has ended. Embryos being dead prior to dissection should not be used for any steps of this protocol as enzymatic activation and protein degradation might influence the result adversely. 
Before getting started some hand-on training should be performed as all steps of the dissection process have to be carried out fast and accurately. It is important for the success of the whole procedure, to avoid contamination with egg yolk which was accompanied by a noteworthy amount of negatively interfering proteins. After the embryos were taken out of the yolk sacks they should be decapitated quickly (not shown in the video).
Temperature as well as celerity of the rotor are very important, too. In order to avoid enzymatic activation and a reduction of quality and quantity of the factors needed for the NCSCM the temperature of the centrifuge and the rotor should be reduced to 4&deg;C. After the centrifugation step the clear central liquid phase is the important pre-extract containing the essential growth factors for the NCSCM. To achieve a considerable separation of the different fractions and an enrichment of the factors needed we recommend a celerity not lower than 180.000 x g x h.
As the difference in density between the clear liquid phase and the dingy liquid phase at the top of the centrifugation tube does not prevent a remixing of the two parts any shaking has to be avoided. The components of the dingy liquid phase cannot be filtrated through a 0.45 &mu;m filter system, as the fatty parts of it would very soon lead to a clogging of the filter system. Also the pellet at the bottom of the centrifuge should not be touched at all, as parts of it would lead to clogging of the filter system.
In a final step the potential of the CEE for cultivation of NCSCs has to be validated. This multipotent transient population of stem cells loses its viability rapidly in media without having added adequate produced CEE. Therefore a transgenic mouse line (JoMa1), which expresses early NCSC markers in a transgene-activity dependent manner and is used to study NCSC biology is cultivated in every newly obtained charge of CEE10. The successful cultivation of NCSCs represents an appropriate validation of the CEE.

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
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<tr>
<td>11 days incubated chicken eggs</td>
<td>&nbsp;</td>
<td>S&ouml;rries-Trockels Vermehrungszucht GmbH &amp; Co.KG</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Alcoholic disinfection spray</td>
<td>&nbsp;</td>
<td>Sch&uuml;lke &amp; Mayr GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>DMEMGlutamax</td>
<td>&nbsp;</td>
<td>GIBCO Invitrogen</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Syringe sterile (60 ml)</td>
<td>&nbsp;</td>
<td>BD Biosciences</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Tubes sterile (50; 15 ml)</td>
<td>&nbsp;</td>
<td>Greiner Bio-One GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Pipet tips sterile</td>
<td>&nbsp;</td>
<td>Starlab GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Hyaluronidase typeIV-S</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Milipore stericups sterile (0.45; 0.22 &mu;l)</td>
<td>&nbsp;</td>
<td>Fisher Scientific AG</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Pipettes sterile (25; 10; 5 ml)</td>
<td>&nbsp;</td>
<td>Greiner Bio-One GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Centrifuge L5-50</td>
<td>&nbsp;</td>
<td>Rotor type Ti-45</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

production of chick embryo extract for the cultivation of murine neural crest stem cells

The neural crest arises from the neuro-ectoderm during embryogenesis and persists only temporarily. Early experiments already proofed pluripotent progenitor cells to be an integral part of the neural crest1. Phenotypically, neural crest stem cells (NCSC) are defined by simultaneously expressing p75 (low-affine nerve growth factor receptor, LNGFR) and SOX10 during their migration from the neural crest2,3,4,5. These progenitor cells can differentiate into smooth muscle cells, chromaffin cells, neurons and glial cells, as well as melanocytes, cartilage and bone6,7,8,9. To cultivate NCSC in vitro, a special neural crest stem cell medium (NCSCM) is required10. The most complex part of the NCSCM is the preparation of chick embryo extract (CEE) representing an essential source of growth factors for the NCSC as well as for other types of neural explants. Other NCSCM ingredients beside CEE are commercially available. Producing CCE using laboratory standard equipment it is of high importance to know about the challenging details as the isolation, maceration, centrifugation, and filtration processes. In this protocol we describe accurate techniques to produce a maximized amount of pure and high quality CEE.

Watch this Scientific Journal Video about Production of Chick Embryo Extract for the Cultivation of Murine Neural Crest Stem Cells at JoVE.com

Production of Chick Embryo Extract for the Cultivation of Murine Neural Crest Stem Cells

To cultivate neural crest stem cells (NCSC) in vitro, a special medium (NCSCM) is required. Essential part of NCSCM is chick embryo extract (CEE). We here describe accurate techniques to produce a maximized amount of pure and high quality CEE, including details as the isolation, maceration, centrifugation, and filtration processes.

The neural crest arises from the neuro-ectoderm during embryogenesis and persists only temporarily. Early experiments already proofed pluripotent ...

production-chick-embryo-extract-for-cultivation-murine-neural-crest

Nanyang Technological University

Research

JoVE Journal

Neuroscience

12.7K Views.  University Children's Hospital Essen. To cultivate neural crest stem cells (NCSC) in vitro, a special medium (NCSCM) is required. Essential part of NCSCM is chick embryo extract (CEE). We here describe accurate techniques to produce a maximized amount of pure and high quality CEE, including details as the isolation, maceration, centrifugation, and filtration processes.

Video: Production of Chick Embryo Extract for the Cultivation of Murine Neural Crest Stem Cells

Isolation and Culture of Neural Crest Stem Cells from Human Hair Follicles

Hair follicles undergo lifelong growth and hair cycle is a well-controlled process involving stem cell proliferation and quiescence. Hair bulge is a well-characterized niche for adult stem cells1. This segment of the outer root sheath contains a number of different types of stem cells, including epithelial stem cells2, melanocyte stem cells3 and neural crest like stem cells4-7. Hair follicles represent an accessible and rich source for different types of human stem cells. We and others have isolated neural crest stem cells (NCSCs) from human fetal and adult hair follicles4,5. These human stem cells are label-retaining cells and are capable of self-renewal through asymmetric cell division in vitro. They express immature neural crest cell markers but not differentiation markers. Our expression profiling study showed that they share a similar gene expression pattern with murine skin immature neural crest cells. They exhibit clonal multipotency that can give rise to myogenic, melanocytic, and neuronal cell lineages after in vitro clonal single cell culture. Differentiated cells not only acquire lineage-specific markers but also demonstrate appropriate functions in ex vivo conditions. In addition, these NCSCs show differentiation potential toward mesenchymal lineages. Differentiated neuronal cells can persist in mouse brain and retain neuronal differentiation markers. It has been shown that hair follicle derived NCSCs can help nerve regrowth, and they improve motor function in mice transplanted with these stem cells following transecting spinal cord injury8. Furthermore, peripheral nerves have been repaired with stem cell grafts9, and implantation of skin-derived precursor cells adjacent to crushed sciatic nerves has resulted in remyelination10. Therefore, the hair follicle/skin derived NCSCs have already shown promising results for regenerative therapy in preclinical models.
Somatic cell reprogramming to induced pluripotent stem (iPS) cells has shown enormous potential for regenerative medicine. However, there are still many issues with iPS cells, particularly the long term effect of oncogene/virus integration and potential tumorigenicity of pluripotent stem cells have not been adequately addressed. There are still many hurdles to be overcome before iPS cells can be used for regenerative medicine. Whereas the adult stem cells are known to be safe and they have been used clinically for many years, such as bone marrow transplant. Many patients have already benefited from the treatment. Autologous adult stem cells are still preferred cells for transplantation. Therefore, the readily accessible and expandable adult stem cells in human skin/hair follicles are a valuable source for regenerative medicine.

This article presents a robust protocol for isolation and culture of neural crest stem cells from human hair follicles.

Hair follicles undergo lifelong growth and hair cycle is a well-controlled process involving stem cell proliferation and quiescence. Hair bulge is a ...

The Neuroblast Assay: An Assay for the Generation and Enrichment of Neuronal Progenitor Cells from Differentiating Neural Stem Cell Progeny Using Flow Cytometry

Neural stem cells (NSCs) can be isolated and expanded in large-scale, using the neurosphere assay and differentiated into the three major cell types of the central nervous system (CNS); namely, astrocytes, oligodendrocytes and neurons. These characteristics make neural stem and progenitor cells an invaluable renewable source of cells for in vitro studies such as drug screening, neurotoxicology and electrophysiology and also for cell replacement therapy in many neurological diseases. In practice, however, heterogeneity of NSC progeny, low production of neurons and oligodendrocytes, and predominance of astrocytes following differentiation limit their clinical applications. Here, we describe a novel methodology for the generation and subsequent purification of immature neurons from murine NSC progeny using fluorescence activated cell sorting (FACS) technology. Using this methodology, a highly enriched neuronal progenitor cell population can be achieved without any noticeable astrocyte and bona fide NSC contamination. The procedure includes differentiation of NSC progeny isolated and expanded from E14 mouse ganglionic eminences using the neurosphere assay, followed by isolation and enrichment of immature neuronal cells based on their physical (size and internal complexity) and fluorescent properties using flow cytometry technology. Overall, it takes 5-7 days to generate neurospheres and 6-8 days to differentiate NSC progeny and isolate highly purified immature neuronal cells.

This video protocol demonstrates a novel method for the generation and subsequent purification of neuronal progenitor cells from a renewable source of neural stem cells (NSCs) based on their physical (size and internal granularity) and fluorescent properties using flow cytometry technology.

Neural stem cells (NSCs) can be isolated and expanded in large-scale, using the neurosphere assay and differentiated into the three major cell types of ...

Isolation and Culture of Neural Crest Cells from Embryonic Murine Neural Tube

The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to mesenchymal transition (EMT) and migrates throughout the embryo, giving rise to diverse cell types 1-3. NC also has the unique ability to influence the differentiation and maturation of target organs4-6. When explanted in vitro, NC progenitors undergo self-renewal, migrate and differentiate into a variety of tissue types including neurons, glia, smooth muscle cells, cartilage and bone. 
NC multipotency was first described from explants of the avian neural tube7-9. In vitro isolation of NC cells facilitates the study of NC dynamics including proliferation, migration, and multipotency. Further work in the avian and rat systems demonstrated that explanted NC cells retain their NC potential when transplanted back into the embryo10-13. Because these inherent cellular properties are preserved in explanted NC progenitors, the neural tube explant assay provides an attractive option for studying the NC in vitro. 
To attain a better understanding of the mammalian NC, many methods have been employed to isolate NC populations. NC-derived progenitors can be cultured from post-migratory locations in both the embryo and adult to study the dynamics of post-migratory NC progenitors11,14-20, however isolation of NC progenitors as they emigrate from the neural tube provides optimal preservation of NC cell potential and migratory properties13,21,22. Some protocols employ fluorescence activated cell sorting (FACS) to isolate a NC population enriched for particular progenitors11,13,14,17. However, when starting with early stage embryos, cell numbers adequate for analyses are difficult to obtain with FACS, complicating the isolation of early NC populations from individual embryos. Here, we describe an approach that does not rely on FACS and results in an approximately 96% pure NC population based on a Wnt1-Cre activated lineage reporter23. 
The method presented here is adapted from protocols optimized for the culture of rat NC11,13. The advantages of this protocol compared to previous methods are that 1) the cells are not grown on a feeder layer, 2) FACS is not required to obtain a relatively pure NC population, 3) premigratory NC cells are isolated and 4) results are easily quantified. Furthermore, this protocol can be used for isolation of NC from any mutant mouse model, facilitating the study of NC characteristics with different genetic manipulations. The limitation of this approach is that the NC is removed from the context of the embryo, which is known to influence the survival, migration and differentiation of the NC2,24-28.

Isolation of embryonic neural crest from the neural tube facilitates the use of in vitro methods for studying migration, self-renewal, and multipotency of neural crest.

The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to ...

Electroporation of the Hindbrain to Trace Axonal Trajectories and Synaptic Targets in the Chick Embryo

Electroporation of the chick embryonic neural tube has many advantages such as being quick and efficient for the expression of foreign genes into neuronal cells. In this manuscript we provide a method that demonstrates uniquely how to electroporate DNA into the avian hindbrain at E2.75 in order to specifically label a subset of neuronal progenitors, and how to follow their axonal projections and synaptic targets at much advanced stages of development, up to E14.5. We have utilized novel genetic tools including specific enhancer elements, Cre/Lox - based plasmids and the PiggyBac-mediated DNA transposition system to drive GFP expression in a subtype of hindbrain cells (the dorsal most subgroup of interneurons, dA1). Axonal trajectories and targets of dA1 axons are followed at early and late embryonic stages at various brainstem regions. This strategy contributes advanced techniques for targeting cells of interest in the embryonic hindbrain and for tracing circuit formation at multiple stages of development.

How neuronal networks are established in the embryonic brain is a fundamental question in developmental neurobiology. Here we combined an electroporation technique with novel genetic tools, such as Cre/Lox&#x2013;plasmids and PiggyBac-mediated DNA transposition system in the avian hindbrain to label dorsal interneurons and track their axonal projections and synaptic targets at various developmental stages.

Electroporation of  the chick embryonic neural tube has many advantages such as being quick and efficient  for the expression of foreign genes into ...

Growing Neural Stem Cells from Conventional and Nonconventional Regions of the Adult Rodent Brain

Recent work demonstrates that central nervous system (CNS) regeneration and tumorigenesis involves populations of stem cells (SCs) resident within the adult brain. However, the mechanisms these normally quiescent cells employ to ensure proper functioning of neural networks, as well as their role in recovery from injury and mitigation of neurodegenerative processes are little understood. These cells reside in regions referred to as &#34;niches&#34; that provide a sustaining environment involving modulatory signals from both the vascular and immune systems. The isolation, maintenance, and differentiation of CNS SCs under defined culture conditions which exclude unknown factors, makes them accessible to treatment by pharmacological or genetic means, thus providing insight into their in vivo behavior. Here we offer detailed information on the methods for generating cultures of CNS SCs from distinct regions of the adult brain and approaches to assess their differentiation potential into neurons, astrocytes, and oligodendrocytes in vitro. This technique yields a homogeneous cell population as a monolayer culture that can be visualized to study individual SCs and their progeny. Furthermore, it can be applied across different animal model systems and clinical samples, being used previously to predict regenerative responses in the damaged adult nervous system.

Neural stem cells harvested from the adult brain are increasing utilized in applications ranging from the basic research of nervous system development to exploring potential clinical applications in regenerative medicine. This makes rigorous control in the isolation and culturing conditions used to grow these cells critical to sound experimental outcomes.

Recent work demonstrates that central nervous system (CNS) regeneration and tumorigenesis involves populations of stem cells (SCs) resident within the ...

Feeder-free Derivation of Neural Crest Progenitor Cells from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) have great potential for studying human embryonic development, for modeling human diseases in the dish and as a source of transplantable cells for regenerative applications after disease or accidents. Neural crest (NC) cells are the precursors for a large variety of adult somatic cells, such as cells from the peripheral nervous system and glia, melanocytes and mesenchymal cells. They are a valuable source of cells to study aspects of human embryonic development, including cell fate specification and migration. Further differentiation of NC progenitor cells into terminally differentiated cell types offers the possibility to model human diseases in vitro, investigate disease mechanisms and generate cells for regenerative medicine. This article presents the adaptation of a currently available in vitro differentiation protocol for the derivation of NC cells from hPSCs. This new protocol requires 18 days of differentiation, is feeder-free, easily scalable and highly reproducible among human embryonic stem cell (hESC) lines as well as human induced pluripotent stem cell (hiPSC) lines. Both old and new protocols yield NC cells of equal identity.

Neural crest (NC) cells derived from human pluripotent stem cells (hPSC) have great potential for modeling human development and disease and for cell replacement therapies. Here, a feeder-free adaptation of the currently widely used in vitro differentiation protocol for the derivation of NC cells from hPSCs is presented.

Human pluripotent stem cells (hPSCs) have great potential for studying human embryonic development, for modeling human diseases in the dish and as a ...

Enumeration of Neural Stem Cells Using Clonal Assays

Neural stem cells (NSCs) have the ability to self-renew and generate the three major neural lineages &#8212; astrocytes, neurons and oligodendrocytes. NSCs and neural progenitors (NPs) are commonly cultured in vitro as neurospheres. This protocol describes in detail how to determine the NSC frequency in a given cell population under clonal conditions. The protocol begins with the seeding of the cells at a density that allows for the generation of clonal neurospheres. The neurospheres are then transferred to chambered coverslips and differentiated under clonal conditions in conditioned medium, which maximizes the differentiation potential of the neurospheres. Finally, the NSC frequency is calculated based on neurosphere formation and multipotency capabilities. Utilities of this protocol include the evaluation of candidate NSC markers, purification of NSCs, and the ability to distinguish NSCs from NPs. This method takes 13 days to perform, which is much shorter than current methods to enumerate NSC frequency.

Neural stem cells (NSCs) refer to cells&#160;which can self-renew and differentiate into the three neural lineages. Here, we describe a protocol to determine NSC frequency in a given cell population using neurosphere formation and differentiation under clonal conditions.

Neural stem cells (NSCs) have the ability to self-renew and generate the three major neural lineages &#8212; astrocytes, neurons and oligodendrocytes. ...

Development of a Refined Protocol for Trans-scleral Subretinal Transplantation of Human Retinal Pigment Epithelial Cells into Rat Eyes

Degenerative retinal diseases such as age-related macular degeneration (AMD) are the leading cause of irreversible vision loss worldwide. AMD is characterized by the degeneration of retinal pigment epithelial (RPE) cells, which are a monolayer of cells functionally supporting and anatomically wrapping around the neural retina. Current pharmacological treatments for the non-neovascular AMD (dry AMD) only slow down the disease progression but cannot restore vision, necessitating studies aimed at identifying novel therapeutic strategies. Replacing the degenerative RPE cells with healthy cells holds promise to treat dry AMD in the future. Extensive preclinical studies of stem cell replacement therapies for AMD involve the transplantation of stem cell-derived RPE cells into the subretinal space of animal models, in which the subretinal injection technique is applied. The approach most frequently used in these preclinical animal studies is through the trans-scleral route, which is made difficult by the lack of direct visualization of the needle end and can often result in retinal damage. An alternative approach through the vitreous allows for direct observation of the needle end position, but it carries a high risk of surgical traumas as more eye tissues are disturbed. We have developed a less risky and reproducible modified trans-scleral injection method that uses defined needle angles and depths to successfully and consistently deliver RPE cells into the rat subretinal space and avoid excessive retinal damage. Cells delivered in this manner have been previously demonstrated to be efficacious in the Royal College of Surgeons (RCS) rat for at least 2 months. This technique can be used not only for cell transplantation but also for delivery of small molecules or gene therapies.

Subretinal injection has been widely applied in preclinical studies of stem cell replacement therapy for age-related macular degeneration. In this visualized article, we describe a less risky, reproducible and precisely modified subretinal injection technique via the trans-scleral approach to deliver cells into rat eyes.

Degenerative retinal diseases such as age-related macular degeneration (AMD) are the leading cause of irreversible vision loss worldwide. AMD is ...

Isolation and Culture of Embryonic Mouse Neural Stem Cells

Neural stem cells (NSCs) are multipotent and can give rise to the three major cell types of the central nervous system (CNS). In vitro culture and expansion of NSCs provide a suitable source of cells for neuroscientists to study the function of neurons and glial cells along with their interactions. There are several reported techniques for the isolation of neural stem cells from adult or embryo mammalian brains. During the microsurgical operation to isolate NSCs from different regions of the embryonic CNS, it is very important to reduce the damage to the brain cells to obtain the highest ratio of live and expandable stem cells. A possible technique for stress reduction during isolation of these cells from the mouse embryo brain is the reduction of surgical time. Here, we demonstrate a developed technique for rapid isolation of these cells from the E13 mouse embryo ganglionic eminence. Surgical procedures include harvesting E13 mouse embryos from the uterus, cutting the frontal fontanelle of the embryo with a bent needle tip, extracting the brain from the skull, microdissection of the isolated brain to harvest the ganglionic eminence, dissociation of the harvested tissue in NSC medium to gain a single cell suspension, and finally plating cells in suspension culture to generate neurospheres.

Here, we introduce a novel microsurgical technique for the isolation of neural stem cells from the E13 mouse embryo ganglionic eminence.

Neural stem cells (NSCs) are multipotent and can give rise to the three major cell types of the central nervous system (CNS). In vitro culture and ...

Identifying Cell Surface Markers of Primary Neural Stem and Progenitor Cells by Metabolic Labeling of Sialoglycan

Neural stem and progenitor cells (NSPCs) are the cellular basis for the complex structures and functions of the brain. They are located in specialized niches in vivo and can be isolated and expanded in vitro, serving as an important resource for cell transplantation to repair brain damage. However, NSPCs are heterogeneous and not clearly defined at the molecular level or purified due to a lack of specific cell surface markers. The protocol presented, which has been previously reported, combines a neural-endothelial co-culture system with a metabolic glycan labeling method to identify the surface sialoglycoproteome of primary NSPCs. The NSPC-endothelial co-culture system allows self-renewal and expansion of primary NSPCs in vitro, generating a sufficient number of NSPCs. Sialoglycans in cultured NSPCs are labeled using an unnatural sialic acid metabolic reporter with bioorthogonal functional groups. By comparing the sialoglycoproteome from self-renewing NSPCs expanded in an endothelial co-culture with differentiating neural culture, we identify a list of membrane proteins that are enriched in NSPCs. In detail, the protocol involves: 1) set-up of an NSPC-endothelial co-culture and NSPC differentiating culture; 2) labeling with azidosugar per-O-acetylated N-azidoacetylmannosamine (Ac4ManNAz); and 3) biotin conjugation to modified sialoglycan for imaging after fixation of neural culture or protein extraction from neural culture for mass spectrometry analysis. Then, the NSPC-enriched surface marker candidates are selected by comparative analysis of mass spectrometry data from both the expanded NSPC and differentiated neural cultures. This protocol is highly sensitive for identifying membrane proteins of low abundance in the starting materials, and it can be applied to marker discovery in other systems with appropriate modifications

Presented here is a protocol that combines an in vitro neural-endothelial co-culture system and metabolic incorporation of sialoglycan with bioorthogonal functional groups to expand primary neural stem and progenitor cells and label their surface sialoglycoproteins for imaging or mass-spectrometry analysis of cell surface markers.

Neural stem and progenitor cells (NSPCs) are the cellular basis for the complex structures and functions of the brain. They are located in specialized ...