This work was supported by funding from the Overstreet Foundation.

1. Basic Set Up Before Proceeding to Dissection:
<ol>
<li>Appropriate volume of complete NSC medium is prepared by mixing NeuroCult NSC Basal Medium and NeuroCult NSC Proliferation Supplements at a 9:1 ratio, respectively.</li>
<li>The medium is warmed up in a 37&deg;C water bath.</li>
<li>Cold HEPES-buffered minimum essential medium (HEM) with high concentration of antibiotics (10%) is prepared for dissection and washing purpose. Alternatively, NSC basal medium with antibiotics supplementation may also be used for this purpose.</li>
<li>25-30 mL of cold HEM containing antibiotics is dispensed into sterile 50 mL tubes for collection of the embryos.</li>
<li>Several 10cm plastic Petri dishes are needed to hold the embryos and brains during dissection and also to hold dissected tissue.</li>
<li>The surgical tools, needed to remove the embryos (large scissors, small pointed scissors, large forceps, small curved forceps) or for embryonic brain dissection (small forceps, curved fine forceps, 45&deg; angled fine forceps, and small scissors) are sterilized using glass bead sterilizer at 250&deg;C or other available autoclave methods.</li>
<li>Dissection microscope is wiped with 70% alcohol and set up inside a laminar flow or PC2 hood.</li>
</ol>
2. Harvesting E14 Mouse Brain and Micro-dissection:
<ol>
<li>A time mated pregnant mouse is anesthetized on day 14th of gestation according to one's institutional approved animal protocol.</li>
<li>Cervical dislocation is performed to make sure the animal does not suffer pain and distress.</li>
<li>The anesthetized mouse is laid on its back on an absorbent tissue paper, and the abdomen is rinsed with 70% ethanol to sterilize the area.</li>
<li>The skin over the abdomen is grasped using a large forceps, and then the skin and the underlying fascia is cut with large scissors to expose the abdominal cavity and the uterine horns.</li>
<li>The uteri are removed with small forceps and scissors and are transferred into a 50&#8208;ml conical tube-containing cold HEM.</li>
<li>The uterine tissues are transferred to the hood and then rinsed once or twice with enough volume of fresh sterile cold HEM to remove possible contaminants like blood and hair.</li>
<li>The uterine tissues are then transferred to a 10cm Petri dish containing cold HEM.</li>
<li>The uterine horns are opened using small curved forceps and scissors and the embryos are transferred to a new 10cm dish, which contains cold HEM.</li>
<li>The heads of the embryos are separated at the cervical spinal cord level and transferred to another Petri dish containing cold HEM.</li>
<li>The Petri dish is transferred under a dissecting microscope to remove the brain from the skull.</li>
<li>The heads are held with a fine curved forceps from the caudal side so as the dorsal side of the heads are facing upwards. Using micro-scissors, first a horizontal cut is made above the eyes and then continued in the midline from the forehead towards the back of the head. Make sure to cut through the skin and the skull and not to damage the underlying brain.</li>
<li>The brain is removed from the skull by pushing the edges of the cut section in a backward motion using the curved forceps. This procedure is continued until all brains are removed from the skulls.</li>
<li>The brain is held steady using the curved forceps so that the dorsal side is facing upwards and then using microscissors a cut is performed through the cortex of each hemisphere extending from the olfactory bulbs to the back of the hemisphere to expose the ganglionic eminences.</li>
<li>Using the curved forceps in one hand and the 45&deg; angled forceps in the other, the cut flaps of cortices are spread and the ganglionic eminences are dissected out.</li>
<li>The dissected tissue is placed in a sterile 10cm Petri dish, and this procedure is repeated until all the brains have been micro-dissected.</li>
<li>Tissue pieces are collected using 1 mL of NSC medium in a 1 mL pipette tip and transferred to a 15 mL centrifuge tube.</li>
<li>Tissue is then dissociated thoroughly, but gently by pressing the pipette tip to the bottom of the tube and pipetting the suspension up and down. This way the clumps are broken up into single cells. Pipetting is performed 3-4 times so that a milky like suspension is achieved. Then, the suspension is allowed to settle for 1-2 minutes so as the non-dissociated clumps precipitates.</li>
<li>Almost the entire cell suspension is transferred to the other tube and then another 1 mL of NSC medium is added to the remaining clumps and dissociated to single cell as described.</li>
<li>The content of the tubes are pooled and centrifuged for 5 minutes at room temperature, at 700rpm (110g).</li>
<li>The supernatant is vacuumed off down to the actual pellet, and the cells are resuspended in 1 mL of complete NSC medium.</li>
<li>The medium is gently pipetted up and down to have a homogeneous single cell suspension.</li>
<li>10 &mu;L of the cell suspension is mixed with 90 &mu;L of trypan blue to perform a cell count.</li>
<li>Finally, the cells are plated at the density of 2x105 cells/ mL in complete NSC medium supplemented with 20ng/ mL epidermal growth factor (EGF). 5 mL medium is used for T25, 20 mL for T75 and 40 mL for T175 flasks.</li>
<li>Neurospheres are formed in 5-7 days when incubated at 37&deg; C in a humidified incubator with 5% CO2. In 6-7 days, the spheres should measure between 150-200 microns and will be ready to subculture (passage).</li>
</ol>
3. Passaging and Expansion of Embryonic NSCs:
<ol>
<li>When the neurospheres are ready for subculture (150-200 &mu;m in diameter), the medium with suspended spheres is removed from the flasks, placed in an appropriate size sterile tissue culture tube, and centrifuged at 700 rpm (110 g) for 5 min at room temperature.</li>
<li>The supernatant is discarded and the spheres are resuspended in 1 mL of %0.05 trypsin-EDTA.</li>
<li>The cell suspension is then incubated in a 37&deg;C water bath for 2-3 min, then an equal volume of soybean trypsin inhibitor is used to stop the trypsin activity.</li>
<li>The cell suspension is gently pipetted up and down to ensure that the trypsin has been completely inactivated.</li>
<li>The cell suspension is centrifuged at 700 rpm (110g) for 5 min. Then, the supernatant is removed and the cells are resuspended in 1 mL of complete NSC medium.</li>
<li>10 &mu;L of the cell suspension is mixed with 90 &mu;L of trypan blue to perform a cell count.</li>
<li>The cells are plated at a concentration of 5x104 cells/ mL in complete NSC medium supplemented with 20ng/ mL EGF in an appropriate size tissue culture flask. 5 mL medium is used for T25, 20 mL for T75 and 40 mL for T175 flasks.</li>
<li>Secondary neurospheres are formed in 5-7 days when incubated at 37&deg; C in a humidified incubator with 5% CO2.</li>
</ol>
4. Representative Results:
In primary embryonic NSC culture, the majority of the cells will become hypertrophic and attach to the tissue culture dishes upon plating. While the majority of cells will either die or differentiate, after 2-3 days, proliferative cells make small clusters of cells that will detach from the substrate (Figure 1). Formation of large spheroidal aggregates in the first 48-hour of culture should not be mistaken for primary spheres. Aggregate formation mainly depends on the amounts of debris and non-dissociated tissue clumps in the culture. True neurospheres are phase bright and become more spherical as size increases (Figure 2). Small microspikes appears on the outer surface of viable and healthy spheres (Figure 3). After 5-7 days, the spheres must be round but not compacted; and should measure between 150 and 200 &mu;m in diameter. If neurospheres are allowed to grow too large (after 9-10 days in culture), they might form aggregates or become dark in color because of cell death at the center of the spheres (see video). Large neurospheres might eventually begin to differentiate in situ (attaching to the substrate and migrating toward the periphery). It is also difficult to dissociate large neurospheres and subculture them.
<img src="/files/ftp_upload/2457/2457fig1.jpg" alt="Figure 1" /> 
Figure 1. Primary E14 NSC culture 3 days after plating. Arrows show the proliferating clusters of NSCs. Original magnification; 20x
<img src="/files/ftp_upload/2457/2457fig2.jpg" alt="Figure 2" /> 
Figure 2. Primary E14 NSC culture 7 days after plating. Original magnification; 10x
<img src="/files/ftp_upload/2457/2457fig3.jpg" alt="Figure 3" /> 
Figure 3. Passage one E14 neurospheres 5 days after plating. Note the micro-spikes (arrows) at the periphery of the spheres. Original Magnification; 20x

<ol>
	<li>Reynolds, B. A., Weiss, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+neurons+and+astrocytes+from+isolated+cells+of+the+adult+mammalian+central+nervous+system.">Generation of neurons and astrocytes from isolated cells of the adult mammalian central nervous system.</a> Science. 255, 1707-1710 (1992).</li><li>Morshead, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+stem+cells+in+the+adult+mammalian+forebrain:+a+relatively+quiescent+subpopulation+of+subependymal+cells.">Neural stem cells in the adult mammalian forebrain: a relatively quiescent subpopulation of subependymal cells.</a> Neuron. 13, 1071-1082 (1994).</li><li>Craig, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+growth+factor+expansion+of+endogenous+subependymal+neural+precursor+cell+populations+in+the+adult+mouse+brain.">In vivo growth factor expansion of endogenous subependymal neural precursor cell populations in the adult mouse brain.</a> J Neurosci. 16, 2649-2658 (1996).</li><li>Golmohammadi, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+the+frequency+and+distribution+of+stem+and+progenitor+cells+in+the+adult+mouse+brain.">Comparative analysis of the frequency and distribution of stem and progenitor cells in the adult mouse brain.</a> Stem Cells. 26, 979-987 (2008).</li><li>Azari, H., Rahman, M., Sharififar, S., BA, R. e. y. n. o. l. 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=Isolation+and+Expansion+of+the+Adult+Mouse+Neural+Stem+Cells+Using+the+Neurosphere+Assay.">Isolation and Expansion of the Adult Mouse Neural Stem Cells Using the Neurosphere Assay.</a> J Vis Exp. , (2010).</li><li>Reynolds, B. A., Rietze, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+stem+cells+and+neurospheres--re-evaluating+the+relationship.">Neural stem cells and neurospheres--re-evaluating the relationship.</a> Nat Methods. 2, 333-336 (2005).</li><li>Louis, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enumeration+of+neural+stem+and+progenitor+cells+in+the+neural+colony-forming+cell+assay.">Enumeration of neural stem and progenitor cells in the neural colony-forming cell assay.</a> Stem Cells. 26, 988-996 (2008).</li></ol>

No conflicts of interest declared.

The neurosphere assay is the method of choice for the isolation and expansion of neural stem cells 1-5 because of its simplicity and reproducibility. This assay is an invaluable tool for large-scale generation of undifferentiated CNS precursor cells, which could be used for both in vitro and in vivo studies. It should be emphasized that neurospheres could be generated from both the bona fide neural stem cells and more restricted progenitors. Therefore, calculating the neurosphere forming freq...

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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<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>
		<tbody>
		
<tr>
<td>NeuroCult NSC Basal Medium</td>
<td>Medium</td>
<td>Stem Cell Technologies</td>
<td>05700</td>
<td>&nbsp;</td>
<tr>
<td>NeuroCult NSC Proliferation Supplements</td>
<td>Medium supplement</td>
<td>Stem Cell Technologies</td>
<td>05701</td>
<td>&nbsp;</td>
<tr>
<td>%0.05 trypsin-EDTA</td>
<td>Reagent</td>
<td>Gibco</td>
<td>25300-062</td>
<td>&nbsp;</td>
<tr>
<td>Soybean trypsin inhibitor </td>
<td>Reagent</td>
<td>Sigma</td>
<td>T6522</td>
<td>&nbsp;</td>
<tr>
<td>Pen/Strep </td>
<td>Reagent</td>
<td>Gibco</td>
<td>15140-122</td>
<td>&nbsp;</td>
<tr>
<td>*MEM</td>
<td>Reagent</td>
<td>Gibco</td>
<td>41500-018</td>
<td>HEM component</td>
</tr>
<tr>
<td>*HEPES</td>
<td>Reagent</td>
<td>Sigma</td>
<td>H4034</td>
<td>HEM component</td>
</tr>
<tr>
<td>*Distilled water</td>
<td>Reagent </td>
<td>Gibco</td>
<td>15230-147</td>
<td>&nbsp;</td>
<tr>
<td>Cell strainer </td>
<td>Sieve</td>
<td>BD Falcon</td>
<td>352340</td>
<td>&nbsp;</td>
<tr>
<td>T25 flask</td>
<td>Culture ware</td>
<td>Nalge Nunc international</td>
<td>136196</td>
<td>&nbsp;</td>
<tr>
<td>T80 flask</td>
<td>Culture ware</td>
<td>Nalge Nunc international</td>
<td>178905</td>
<td>&nbsp;</td>
<tr>
<td>15 ml tubes</td>
<td>Culture ware</td>
<td>BD Falcon</td>
<td>352096</td>
<td>&nbsp;</td>
<tr>
<td>50 ml tubes</td>
<td>Culture ware</td>
<td>BD Falcon</td>
<td>352070</td>
<td>&nbsp;</td>
<tr>
<td>Fine curved forceps</td>
<td>Surgical tools</td>
<td>Fine Science Tools</td>
<td>11251&#x2010;35</td>
<td>&nbsp;</td>
<tr>
<td>Small fine forceps</td>
<td>Surgical tools</td>
<td>Fine Science Tools</td>
<td>11272&#x2010;30</td>
<td>&nbsp;</td>
<tr>
<td>Small forceps</td>
<td>Surgical tools</td>
<td>Fine Science Tools</td>
<td>11050&#x2010;10</td>
<td>&nbsp;</td>
<tr>
<td>Fine scissors</td>
<td>Surgical tools</td>
<td>World Percision Instruments, Inc.</td>
<td>500216</td>
<td>&nbsp;</td>
<tr>
<td>EGF</td>
<td>Growth factor</td>
<td>R&amp;D</td>
<td>2028-EG</td>
<td>&nbsp;</td>
<tr>
<td>b-FGF</td>
<td>Growth factor</td>
<td>R&amp;D</td>
<td>3139-FB</td>
<td>&nbsp;</td>
<tr>
<td>Heparin</td>
<td>Growth factor</td>
<td>Sigma</td>
<td>H4784</td>
<td>Reconstituted in PBS</td>
</tr>		</tbody>
		</table>
		</div>
			<div>
			*To make HEM, mix 1&#215;10L packet of MEM and160ml of 1M HEPES and bring the volume to 8.75 L using distilled water. Set the final PH to 7.4 and store it at 4&deg;C.		</div>

establishing embryonic mouse neural stem cell culture using the neurosphere assay

In mammalians, stem cells acts as a source of undifferentiated cells to maintain cell genesis and renewal in different tissues and organs during the life span of the animal. They can potentially replace cells that are lost in the aging process or in the process of injury and disease. The existence of neural stem cells (NSCs) was first described by Reynolds and Weiss (1992) in the adult mammalian central nervous system (CNS) using a novel serum&#8208;free culture system, the neurosphere assay (NSA). Using this assay, it is also feasible to isolate and expand NSCs from different regions of the embryonic CNS. These in vitro expanded NSCs are multipotent and can give rise to the three major cell types of the CNS. While the NSA seems relatively simple to perform, attention to the procedures demonstrated here is required in order to achieve reliable and consistent results. This video practically demonstrates NSA to generate and expand NSCs from embryonic day 14-mouse brain tissue and provides technical details so one can achieve reproducible neurosphere cultures. The procedure includes harvesting E14 mouse embryos, brain microdissection to harvest the ganglionic eminences, dissociation of the harvested tissue in NSC medium to gain a single cell suspension, and finally plating cells in NSA culture. After 5-7 days in culture, the resulting primary neurospheres are passaged to further expand the number of the NSCs for future experiments.

Watch this Scientific Journal Video about Establishing Embryonic Mouse Neural Stem Cell Culture Using the Neurosphere Assay at JoVE.com

Establishing Embryonic Mouse Neural Stem Cell Culture Using the Neurosphere Assay

This video protocol demonstrates the application of the neurosphere assay for the isolation and expansion of neural stem cells from the ganglionic eminences of embryonic day 14-mouse brain.

In mammalians, stem cells acts as a source of undifferentiated cells to maintain cell genesis and renewal in different tissues and organs during the life ...

establishing-embryonic-mouse-neural-stem-cell-culture-using

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Neuroscience

24.5K Views.  Shiraz University of Medical Sciences, Shiraz, Iran. This video protocol demonstrates the application of the neurosphere assay for the isolation and expansion of neural stem cells from the ganglionic eminences of embryonic day 14-mouse brain.

Video: Establishing Embryonic Mouse Neural Stem Cell Culture Using the Neurosphere Assay

Dissection and Culture of Commissural Neurons from Embryonic Spinal Cord

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies of these neurons are located in the dorsal spinal cord and their axons follow stereotyped trajectories during embryonic development. Commissural axons initially project ventrally towards the floorplate. After crossing the midline, these axons turn anteriorly and project towards the brain. Each of these steps is regulated by the action of several guidance cues. Cultures highly enriched in commissural neurons are ideally suited for many experiments addressing the mechanisms of axon pathfinding, including turning assays, immunochemistry and biochemistry. Here, we describe a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. First, the spinal cord is isolated and dorsal strips are dissected out. The dorsal tissue is then dissociated into a cell suspension by trypsinization and mechanical disruption. Neurons are plated onto poly-L-lysine-coated glass coverslips or tissue-culture dishes. After 30 hours in vitro, most neurons have extended an axon. The purity of the culture (Yam et al. 2009), typically over 90%, can be assessed by immunolabeling with the commissural neuron markers DCC, LH2 and TAG1 (Helms and Johnson, 1998). This neuronal preparation is a useful tool for in vitro studies of the cellular and molecular mechanisms of commissural axon growth and guidance during spinal cord development.

This video demonstrates a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. Dissociated commissural neurons are useful to study the cellular and molecular mechanisms of axon growth and guidance.

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies ...

Isolation and Expansion of the Adult Mouse Neural Stem Cells Using the Neurosphere Assay

Isolation and expansion of the putative neural stem cells (NSCs) from the adult murine brain was first described by Reynolds and Weiss in 1992 employing a chemically defined serum-free culture system known as the neurosphere assay (NSA). In this assay, the majority of differentiated cell types die within a few days of culture but a small population of growth factor responsive precursor cells undergo active proliferation in the presence of epidermal growth factor (EGF) and/ basic fibroblastic growth factor (bFGF). These cells form colonies of undifferentiated cells called neurospheres, which in turn can be subcultured to expand the pool of neural stem cells. Moreover, the cells can be induced to differentiate, generating the three major cell types of the CNS i.e. neurons, astrocytes, and oligodendrocytes. This assay provides an invaluable tool to supply a consistent, renewable source of undifferentiated CNS precursors, which could be used for in vitro studies and also for therapeutic purposes.
This video demonstrates the NSA method to generate and expand NSCs from the adult mouse periventricular region, and provides technical insights to ensure one can achieve reproducible neurosphere cultures. The procedure includes harvesting the brain from the adult mouse, micro-dissection of the periventricular region, tissue preparation and culture in the NSA. The harvested tissue is first chemically digested using trypsin-EDTA and then mechanically dissociated in NSC medium to achieve a single cell suspension and finally plated in the NSA. After 7-10 days in culture, the resulting primary neurospheres are ready for subculture to reach the amount of cells required for future experiments.

This video protocol demonstrates the neurosphere assay method to generate and expand neural stem cells from the adult mouse periventricular region, and provides technical insights to ensure one can achieve reproducible neurosphere cultures.

Isolation and expansion of the putative neural stem cells (NSCs) from the adult murine brain was first described by Reynolds and Weiss in 1992 employing a ...

Localizing Protein in 3D Neural Stem Cell Culture: a Hybrid Visualization Methodology

The importance of 3-dimensional (3D) topography in influencing neural stem and progenitor cell (NPC) phenotype is widely acknowledged yet challenging to study. When dissociated from embryonic or post-natal brain, single NPCs will proliferate in suspension to form neurospheres. Daughter cells within these cultures spontaneously adopt distinct developmental lineages (neurons, oligodendrocytes, and astrocytes) over the course of expansion despite being exposed to the same extracellular milieu. This progression recapitulates many of the stages observed over the course of neurogenesis and gliogenesis in post-natal brain and is often used to study basic NPC biology within a controlled environment. Assessing the full impact of 3D topography and cellular positioning within these cultures on NPC fate is, however, difficult. To localize target proteins and identify NPC lineages by immunocytochemistry, free-floating neurospheres must be plated on a substrate or serially sectioned. This processing is required to ensure equivalent cell permeabilization and antibody access throughout the sphere. As a result, 2D epifluorescent images of cryosections or confocal reconstructions of 3D Z-stacks can only provide spatial information about cell position within discrete physical or digital 3D slices and do not visualize cellular position in the intact sphere. Here, to reiterate the topography of the neurosphere culture and permit spatial analysis of protein expression throughout the entire culture, we present a protocol for isolation, expansion, and serial sectioning of post-natal hippocampal neurospheres suitable for epifluorescent or confocal immunodetection of target proteins. Connexin29 (Cx29) is analyzed as an example. Next, using a hybrid of graphic editing and 3D modelling softwares rigorously applied to maintain biological detail, we describe how to re-assemble the 3D structural positioning of these images and digitally map labelled cells within the complete neurosphere. This methodology enables visualization and analysis of the cellular position of target proteins and cells throughout the entire 3D culture topography and will facilitate a more detailed analysis of the spatial relationships between cells over the course of neurogenesis and gliogenesis in vitro.
Both Imbeault and Valenzuela contributed equally and should be considered joint first authors.

Here, we describe how to produce, expand, and immunolabel postnatal hippocampal neural progenitor cells (NPCs) in three-dimensional (3D) culture. Next, using hybrid visualization technologies, we demonstrate how digital images of immunolabelled cryosections can be used to reconstruct and map the spatial position of immunopositive cells throughout the entire 3D neurosphere.

The importance of 3-dimensional (3D) topography in influencing neural stem and progenitor cell (NPC) phenotype is widely acknowledged yet challenging to ...

Neural-Colony Forming Cell Assay: An Assay To Discriminate Bona Fide Neural Stem Cells from Neural Progenitor Cells

The neurosphere assay (NSA) is one of the most frequently used methods to isolate, expand and also calculate the frequency of neural stem cells (NSCs). Furthermore, this serum-free culture system has also been employed to expand stem cells and determine their frequency from a variety of tumors and normal tissues. It has been shown recently that a one-to-one relationship does not exist between neurosphere formation and NSCs. This suggests that the NSA as currently applied, overestimates the frequency of NSCs in a mixed population of neural precursor cells isolated from both the embryonic and adult mammalian brain. This video practically demonstrates a novel collagen based semi- solid assay, the neural-colony forming cell assay (N-CFCA), which has the ability to discriminate stem from progenitor cells based on their long-term proliferative potential, and thus provides a method to enumerate NSC frequency. In the N-CFCA, colonies &ge;2 mm in diameter are derived from cells that meet all the functional criteria of a NSC, while colonies &lt; 2mm are derived from progenitors. The N-CFCA procedure can be used for cells prepared from different sources including primary and cultured adult or embryonic mouse CNS cells. Here we use cells prepared from passage one neurospheres generated from embryonic day 14 mice brain to perform N-CFCA. The cultures are replenished with proliferation medium every seven days for three weeks to allow the plated cells to exhibit their full proliferative potential and then the frequency of neural progenitor and bona fide neural stem cells is calculated respectively by counting the number of colonies that are &lt; 2mm and the ones that are &ge;2mm in reference to the number of cells that were initially plated.

This video protocol demonstrates how to discriminate and enumerate bona fide neural stem cells in a mixed population of neural precursor cells using the neural colony-forming cell assay.

The neurosphere assay (NSA) is one of the most frequently used methods to isolate, expand and also calculate the frequency of neural stem cells (NSCs). ...

Surgical Transplantation of Mouse Neural Stem Cells into the Spinal Cords of Mice Infected with Neurotropic Mouse Hepatitis Virus

Mice infected with the neurotropic JHM strain of mouse hepatitis virus (MHV) develop pathological and clinical outcomes similar to patients with the demyelinating disease Multiple Sclerosis (MS). We have shown that transplantation of NSCs into the spinal cords of sick mice results in a significant improvement in both remyelination and in clinical outcome. Cell replacement therapies for the treatment of chronic neurologic diseases are now a reality and in vivo models are vital in understanding the interactions between the engrafted cells and host tissue microenvironment. This presentation provides an adapted method for transplanting cells into the spinal cord of JHMV-infected mice. In brief, we provide a procedure for i) preparation of NSCs prior to transplant, ii) pre-operative care of mice, iii) exposure of the spinal cord via laminectomy, iv) stereotactic injection of NSCs, and iv) post-operative care.

The transplantation of mouse neural stem cells (NSCs) into the spinal cords of mice with established demyelination is detailed. The preparation of NSCs, the laminectomy of thoracic vertebra 9 (T9), and transplantation of NSCs is outlined along with the pre- and post-operative care of the mice.

Mice infected with the neurotropic JHM strain of mouse hepatitis virus (MHV) develop pathological and clinical outcomes similar to patients with the ...

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 ...

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. ...

Isolation and Culture of Adult Neural Stem Cells from the Mouse Subcallosal Zone

Adult neural stem cells (aNSCs) can be used for the regeneration of damaged brain tissue. NSCs have the potential for differentiation and proliferation into three types of cells: neurons, astrocytes, and oligodendrocytes. Identifying aNSC-derived regions and characterizing the aNSC properties are critical for the potential use of aNSCs and for the elucidation of their role in neural regeneration. The subcallosal zone (SCZ), located between white matter and the hippocampus, has recently been reported to contain aNSCs and continuously give rise to neuroblasts. A low percentage of aNSCs from the SCZ is differentiated into neurons; most cells are differentiated into glial cells, such as oligodendrocytes and astrocytes. These cells are suggested to have a therapeutic potential for traumatic cortical injury. This protocol describes in detail the process to generate SCZ-aNSCs from an adult mouse brain. A brain matrix with intervals of 1 mm is used to obtain the SCZ-containing coronal slices and to precisely dissect the SCZ from the whole brain. The SCZ sections are initially subjected to a neurosphere culture. A well-developed culture system allows for the verification of their characteristics and can increase research on NSCs. A neurosphere culture system provides a useful tool for determining proliferation and collecting the genuine NSCs. A monolayer culture is also an in vitro system to assay proliferation and differentiation. Significantly, this culture system provides a more homogenous environment for NSCs than the neurosphere culture system. Thus, using a discrete brain region, these culture systems will be helpful for expanding our knowledge about aNSCs and their applications for therapeutic uses.

Establishing culture systems for the expansion of adult neural stem cells (aNSCs) allows for the examination and application of aNSCs for therapy. The subcallosal zone (SCZ) has recently been recognized as a novel neuroblast-forming region in adult mice. Here, methods for the isolation, expansion, and differentiation of SCZ-aNSCs are described.

Adult neural stem cells (aNSCs) can be used for the regeneration of damaged brain tissue. NSCs have the potential for differentiation and proliferation ...

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.