This work was supported by a National Alliance for Research on Schizophrenia and Depression (NARSAD) Young Investigator Award and National Institutes of Health grant R01NS073635 to AV.

1. Preparation of Reagents and Solutions
<ol>
	<li>Coating of 35 mm culture dish: Collagen Type 1 solution is supplied as an aqueous solution in 20 mM acetic acid (~100 mg protein/vial). Dilute an appropriate volume of collagen solution to a working concentration of 0.01% using sterile tissue culture grade water. Coat dishes with 1 ml of collagen solution for 3-4 hr at room temperature (RT) or 37 &#176;C, or overnight at 2-8 &#176;C. Remove excess solution from the coated dish and allow it to dry overnight. Rinse the dish with tissue culture grade water or PBS before adding media. Coated dishes can be stored at 4 &#176;C for one month.</li>
	<li>Prepare complete Dulbecco&#39;s Modified Eagle Medium (DMEM). Supplement the DMEM (500 ml) with 10% FBS and antibiotic-antimycotic solution (1x concentration; 1 ml/100 ml). Complete DMEM can be stored at 4 &#176;C for two months.</li>
	<li>Prepare an aliquot (50 ml) of DMEM with DNase I (0.001 mg/ml), (referred to as DMEM-DNase I).</li>
	<li>Prepare another aliquot (10 ml) of DMEM with collagenase and dispase (1 mg/ml) (referred to as DMEM-collagenase/dispase).</li>
	<li>Prepare Endothelial Cell Culture Medium (ECCM, 500 ml), supplemented with EGF (5 &#956;g), ECGS (100 mg) and 5 &#956;l of antibiotic-antimycotic solution. ECCM can be stored at 4 &#176;C for two months.</li>
	<li>Prewarm all media before use.</li>
	<li>Prepare Purification buffer: PBS, pH 7.2 with 0.5% BSA and 2 mM EDTA. Keep buffer cold (2-8 &#176;C).</li>
</ol>
2. Removal of Embryos and Dissection of Telencephalon
All experiments using laboratory animals are approved by the animal care and use committees of McLean Hospital and conform to NIH guidelines for the care and use of laboratory animals.
<ol>
	<li>Use timed pregnant CD1 mice (embryonic day 15). The day of vaginal plug discovery is considered embryonic day 0 (E0). CD1 dams generally produce large litters, so 10-12 embryos are expected from a pregnant dam.</li>
	<li>For hysterotomy, anesthetize pregnant mice with an intraperitoneal injection of Ketamine (100 mg/kg)/Xylazine (5 mg/kg). For mice approximately 20-30 g, deliver 0.3 ml of a 10 ml/kg Ketamine/Xylazine anesthetic solution and ensure that pain and distress is minimal during intraperitoneal injections of the anesthetic. Use hand restraint for the injections.</li>
	<li>Check deep anesthesia by toe pinch. Remove embryos from deeply anesthetized mice. Decapitate each embryo immediately upon removal from the mother. Place the embryonic heads in sterile Petri dishes in ice cold PBS.</li>
	<li>Follow hysterectomy by immediate euthanasia with anesthetic overdose (130 mg/kg pentobarbital, i.p.), a method for euthanasia, which is consistent with the AVMA Guidelines for the Euthanasia of Animals: 2013 Edition.</li>
	<li>Under a stereo microscope, remove the brain from the head with fine microtip scissors and fine forceps. Note: A high quality dissection is essential to successfully remove the pial membrane from the embryonic brain. This is achieved by practice. Fine forceps and microtip scissors are also key tools for getting a good dissection.</li>
	<li>Use the forceps to get a firm grip on the brain and the microtip scissors to peel away the pial membrane. Remove the mesencephalon and metencephalon and isolate the telencephalon. Transfer pial-free telencephalon from all embryos to a 35 mm culture dish with 2 ml PBS in ice.</li>
</ol>
3. Cell Isolation
<ol>
	<li>Mince the telencephalon into 1-2 mm fragments with a scalpel blade and collect tissue in a 15 ml Falcon tube containing 2 ml of complete DMEM.</li>
	<li>Dissociate tissue gently but thoroughly with a 1 ml pipette until clumps disappear and a milky suspension is achieved.</li>
	<li>Centrifuge dissociated cells at 800-1,000 x g for 5 min at RT.</li>
	<li>Carefully remove the supernatant and resuspend pellet in DMEM-DNase I. Gently dissociate the cells again using 1 ml pipette and centrifuge at 800-1,000 x g for 5 min at RT.</li>
	<li>Resuspend the pellet in warm complete DMEM. Filter cells through a sterile 70 &#956;m Nylon mesh. Collect filtered cells and keep in ice.</li>
	<li>Collect the cell-portions retained on the mesh and digest further with DMEM-collagenase/dispase (2 ml) for 1-2 min at RT. Wash cells 3x in DMEM-DNase I through centrifugation at 800-1,000 x g for 5 min at RT. Pool these cells with the filtered cells collected in step 3.5. Wash total cells once with complete DMEM. Proceed to determine cell number and magnetic labeling steps. Note: It is important to obtain a single-cell suspension before magnetic labeling.</li>
</ol>
4. Magnetic Labeling
<ol>
	<li>This protocol shows the magnetic labeling of 107 cells. For cell numbers lower than 107, use the same reagent volume and for cell numbers greater than 107, scale up all reagent volumes and total volumes accordingly (e.g. for 2 x 107 total cells, use twice the volume of all indicated reagents). Keep all the reagents and cells in ice.</li>
	<li>Determine cell number with a hemocytometer.</li>
	<li>Centrifuge cell suspension at 300 x g for 10 min at RT. Aspirate supernatant completely.</li>
	<li>Add 90 &#956;l/107 cells of purification buffer to the cell pellet followed by 10 &#956;l of CD31 MicroBeads. The Microbeads provided by manufacturer are conjugated to monoclonal anti-mouse CD31 antibody.</li>
	<li>Mix well and incubate for 15 min in the refrigerator. Note: Higher temperatures and/or longer incubation time during magnetic labeling may result in nonspecific binding.</li>
	<li>Wash cells by adding 1-2 ml/107 cells of purification buffer and centrifuge at 300 x g for 10 min. Remove supernatant and resuspend cells in 500 &#956;l of purification buffer. Proceed to magnetic separation or purification step.</li>
</ol>
5. Purification
<ol>
	<li>Place MS column in the magnetic field of MACS Separator.</li>
	<li>Rinse column with 500 &#956;l of purification buffer.</li>
	<li>Apply cell suspension onto the column. Load appropriate number of cells to MS column as higher cell number may clog the column. Caution: Each MS column can accommodate a maximum number of 2 x 107 cells, for a higher cell number, use more columns.</li>
	<li>Collect and discard flow-through containing unlabeled cells.</li>
	<li>Wash column with 500 &#956;l of purification buffer three times. During wash steps, make sure that the column reservoir is empty before adding subsequent purification buffer aliquots.</li>
	<li>Remove column from the MACS separator and place it on a 15 ml Falcon tube.</li>
	<li>A plunger is supplied along with the MS column. Pipette 1 ml of purification buffer onto the MS column and immediately flush out the magnetically labeled cells by firmly pushing the plunger into the column.</li>
	<li>Plate cells on a 35 mm culture dish precoated with collagen Type 1 and grow cells in ECCM in an incubator set to 37 &#176;C with 95% O2 and 5% CO2.</li>
	<li>Change the medium every four days. Use PVECs for experiments or subculture after 10-12 days when the dish is confluent.</li>
</ol>
6. Subculture of PV ECS
<ol>
	<li>Remove the ECCM and rinse the monolayer of PVECS with 1-2 ml of sterile PBS.</li>
	<li>Gently add 1.5 ml of 0.25% Trypsin-EDTA solution to cover the cell monolayer.</li>
	<li>Return the dish to the incubator. Within 5-7 min, cells will detach from the surface of the dish.</li>
	<li>After the cells have detached, immediately add an equal volume of trypsin inhibitor and triturate several times.</li>
	<li>Transfer the cells to a sterile 15 ml Falcon tube. Centrifuge the tube at 500 x g for 5 min.</li>
	<li>Remove the supernatant and resuspend the pellet in 1 ml of prewarmed ECCM.</li>
	<li>Seed the cells for expanding the culture, imaging or other assays.</li>
</ol>

<ol>
	<li>Shen, Q., S, 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=Endothelial+cells+stimulate+self-renewal+and+expand+neurogenesis+of+neural+stem+cells.">Endothelial cells stimulate self-renewal and expand neurogenesis of neural stem cells.</a> Science. 304, 1338-1340 (2004).</li><li>Milner, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+three-dimensional+system+to+study+interactions+between+endothelial+cells+and+neural+cells+of+the+developing+central+nervous+system.">A novel three-dimensional system to study interactions between endothelial cells and neural cells of the developing central nervous system.</a> BMC Neurosci. 8, 3 (2007).</li><li>Rauch, M. F., Michaud, M., Xu, H., Madri, J. A., Lavik, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Co-culture+of+primary+neural+progenitor+and+endothelial+cells+in+a+macroporous+gel+promotes+stable+vascular+networks+in+vivo.">Co-culture of primary neural progenitor and endothelial cells in a macroporous gel promotes stable vascular networks in vivo.</a> 19, 1469-1485 (2008).</li><li>Vasudevan, A., Long, J. E., Crandall, J. E., Rubenstein, J. L., Bhide, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compartment-specific+transcription+factors+orchestrate+angiogenesis+gradients+in+the+embryonic+brain.">Compartment-specific transcription factors orchestrate angiogenesis gradients in the embryonic brain.</a> Nat. Neurosci. 11, 429-439 (2008).</li><li>Vasudevan, A., Bhide, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Angiogenesis+in+the+embryonic+CNS:+a+new+twist+on+an+old+tale.">Angiogenesis in the embryonic CNS: a new twist on an old tale.</a> Cell Adh. Migr. 2, 167-169 (2008).</li><li>Won, C. K., 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=Autonomous+vascular+networks+synchronize+GABA+neuron+migration+in+the+embryonic+forebrain.">Autonomous vascular networks synchronize GABA neuron migration in the embryonic forebrain.</a> Nat. Commun. 4, 2149-2162 (2013).</li><li>Dong, Q. 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=A+general+strategy+for+isolation+of+endothelial+cells+from+murine+tissues.+Characterization+of+two+endothelial+cell+lines+from+the+murine+lung+and+subcutaneous+sponge+implants.">A general strategy for isolation of endothelial cells from murine tissues. Characterization of two endothelial cell lines from the murine lung and subcutaneous sponge implants.</a> Arterioscler. Thromb. Vasc. Biol. 17, 1599-1604 (1997).</li><li>Erblich, B., Zhu, L., Etgen, A. M., Dobrenis, K., Pollard, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Absence+of+colony+stimulation+factor-1+receptor+results+in+loss+of+microglia,+disrupted+brain+development+and+olfactory+deficits.">Absence of colony stimulation factor-1 receptor results in loss of microglia, disrupted brain development and olfactory deficits.</a> PLoS One. 6, (2011).</li><li>Wichterle, H., Garcia-Verdugo, J. M., Herrera, D. G., Alvarez-Buylla, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Young+neurons+from+medial+ganglionic+eminence+disperse+in+adult+and+embryonic+brain.">Young neurons from medial ganglionic eminence disperse in adult and embryonic brain.</a> 2, 461-466 (1999).</li><li>Snapyan, 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=Vasculature+guides+migrating+neuronal+precursors+in+the+adult+mammalian+forebrain+via+brain-derived+neurotrophic+factor+signaling.">Vasculature guides migrating neuronal precursors in the adult mammalian forebrain via brain-derived neurotrophic factor signaling.</a> J. Neurosci. 29, 4172-4188 (2009).</li><li>Whitman, M. C., Fan, W., Rela, L., Rodriguez-Gil, D. J., Greer, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+vessels+form+a+migratory+scaffold+in+the+rostral+migratory+stream.">Blood vessels form a migratory scaffold in the rostral migratory stream.</a> J. Comp. Neurol. 516, 94-104 (2009).</li></ol>

No conflicts of interest declared.

PVEC&#39;s are more physiologically relevant than adult brain endothelial cells and ECs from other tissue sources for studies focusing on neurovascular interactions and also have therapeutic potential. For PVEC preparation, it is critical beginning with dissection to work fast to achieve a good viability since dead cells may bind nonspecifically to CD31 MicroBeads. In addition, if single-cell suspension is not achieved prior to the magnetic labeling step, this will result in troubleshooting since cell clumps will clog th...

Angiogenesis, neurogenesis and neuronal migration are critical events in central nervous system (CNS) development, repair and regeneration. Several elegant studies have shown that endothelial cells stimulate neuronal proliferation and vice versa through release of soluble factors and by direct contact. We found it curious that in majority of these studies1-3, while neuronal progenitors/neural stem cells are isolated from the embryonic brain, they are cocultured with endothelial cells from the adult brain, other adult tissue sources, or with endothelial cell lines. This might in part be due to the technical difficulties associated with isolating and culturing pure populations of endothelial cells from the embryonic brain. However, angiogenesis, neurogenesis, and neuronal migration are concurrent events occurring in orders of magnitude more robust in the embryonic brain than in the normal adult brain. The periventricular vascular network of the embryonic forebrain (telencephalon) originates from a vessel located within the basal ganglia primordium and develops in the form of an orderly gradient from ventral to dorsal telencephalon by embryonic day 11 (E11)4,5. This plexus of vessels of the periventricular vascular network are distinct from pial vessels based on origins, anatomical location, growth patterns, and developmental regulation4,5. The direction of propagation of the periventricular angiogenesis gradient matches the telencephalic transverse neurogenetic gradient. Within the telencephalon, the periventricular angiogenesis gradient and the gradient of GABA neurons migrating tangentially overlaps spatially as well6. With respect to timing, the angiogenesis gradient is in advance of the neurogenetic gradient and GABA neuron gradient by about a day. Thus, periventricular endothelial cells are spatially and temporally well positioned to provide critical cues to support telencephalic neurogenesis and neuronal migration4,6. Therefore, use of embryonic periventricular endothelial cells in coculture experiments with neuronal progenitors and/or neurons would provide a more favorable model for studying neurovascular interactions and developing novel avenues for treatment of neurodegenerative disease or ischemic/traumatic brain injury.
We emphasize the importance of removing the pial membrane, not only to limit epithelial cell contamination but also to separate pial endothelial cells which are molecularly and functionally distinct from endothelial cells of the periventricular vascular network4,6 (termed PVECs to distinguish from pial ECs). Here, we describe the method that we routinely use in our laboratory to obtain a rich and pure yield of PVECs. These endothelial cells are prepared from embryonic forebrains isolated from a single timed-pregnant mouse. They can be expanded, subcultured, and frozen down successfully for future use.

<table border="0" cellpadding="0" cellspacing="0" width="768">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">DNase I</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:147px;">D-4527</td>
			<td style="width:167px;"> </td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Collagen, Type 1 solution from rat tail </td>
			<td>Sigma</td>
			<td>C3867</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DPBS</td>
			<td>Quality Biologicals</td>
			<td style="width:147px;">114057-131</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EDTA</td>
			<td>Fisher Scientific</td>
			<td>M4055</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BSA</td>
			<td style="width:183px;">Sigma</td>
			<td>A2058</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MS column</td>
			<td>Miltenyi Biotech</td>
			<td>130-042-201</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CD31 microbeads</td>
			<td>Miltenyi Biotech</td>
			<td>130-097-418</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MACS separator</td>
			<td>Miltenyi Biotech</td>
			<td>130-042-102</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MACS multi stand</td>
			<td>Miltenyi Biotech</td>
			<td>130-042-303</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cell strainer 70 &#181;m</td>
			<td style="width:183px;">BD Bioscience</td>
			<td>352350</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Antibiotic and antimycotic solution</td>
			<td>Sigma</td>
			<td>A5955</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FBS</td>
			<td>Sigma</td>
			<td>F4135</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Collagenase/Dispase</td>
			<td>Roche</td>
			<td>10269638001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">DMEM </td>
			<td style="width:183px;">Lonza</td>
			<td>12-604F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">35 mm culture dish</td>
			<td style="width:183px;">BD Bioscience</td>
			<td>353001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">15 ml falcon tube </td>
			<td style="width:183px;">BD Bioscience</td>
			<td>352097</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">50 ml falcon tube</td>
			<td style="width:183px;">BD Bioscience</td>
			<td>352098</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">ECCM kit</td>
			<td style="width:183px;">BD Bioscience</td>
			<td style="width:147px;">355054</td>
			<td>Kit Includes Endothelial cell growth supplement, EGF and Soybean Trypsin Inhibitor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Endothelial Cell Growth Supplement (ECGS)</td>
			<td style="width:183px;">BD Bioscience</td>
			<td style="width:147px;">354006</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">RBECGM</td>
			<td style="width:183px;">Cell applications </td>
			<td style="width:147px;">R819-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMEM F12 </td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:147px;">10565-018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">glutamax</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:147px;">305050-061</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">tissue culture grade water</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:147px;">15230162</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">0.25% Trypsin</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:147px;">15050</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Soyabean trypsin inhibitor</td>
			<td style="width:183px;">BD Bioscience</td>
			<td style="width:147px;">5425</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Matrigel</td>
			<td style="width:183px;">BD Bioscience</td>
			<td style="width:147px;">354234</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Qtracker 655 Cell Labeling Kit</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:147px;">Q25021</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:271px;">CellLight Plasma Membrane-RFP, BacMam 2.0</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:147px;">C10608</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Biotinylated Isolectin B4 antibody</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:147px;">L2140</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Anti-Von Willebrand factor</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:147px;">F3520</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Anti-CD31/PECAM-1</td>
			<td style="width:183px;">BD Pharmingen</td>
			<td style="width:147px;">550274</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:271px;">Vectashield Hardset Mounting media with DAPI</td>
			<td style="width:183px;">Vector Laboratories</td>
			<td style="width:147px;">H-1500</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:271px;">Ketamine</td>
			<td style="width:183px;">Butler Schein Animal Health Supply</td>
			<td style="width:147px;">44028</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Xylazine</td>
			<td style="width:183px;">Lloyd Laboratories</td>
			<td style="width:147px;">1009</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Stereomicroscope</td>
			<td style="width:183px;">Motic</td>
			<td style="width:147px;">SMZ-168</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">hemocytometer</td>
			<td style="width:183px;">Fisher Scientific</td>
			<td style="width:147px;">267110</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">inverted microscope</td>
			<td style="width:183px;">Olympus CK-40</td>
			<td style="width:147px;">CK-40</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Flouroscent microscope</td>
			<td style="width:183px;">Olympus FSX-100</td>
			<td style="width:147px;">FSX-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Fine forceps</td>
			<td style="width:183px;">Roboz surgical instrument</td>
			<td>7 inox</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">Fine microtip scissors</td>
			<td style="width:183px;">Roboz surgical instrument</td>
			<td>RS5611</td>
			<td></td>
		</tr>
	</tbody>
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isolation and culture of endothelial cells from the embryonic forebrain

Embryonic brain endothelial cells can serve as an important tool in the study of angiogenesis and neurovascular development and interactions. The two vascular networks of the embryonic forebrain, pial and periventricular, are spatially distinctive and have different origins and growth patterns. Endothelial cells from the pial and periventricular vascular networks have unique gene expression profiles and functions. Here we present a step-by-step protocol for isolation, culture, and verification of pure populations of endothelial cells from the periventricular vascular network (PVECs) of the embryonic forebrain (telencephalon). In this approach, telencephalon devoid of pial membrane obtained from embryonic day 15 mice is minced, digested with collagenase/dispase, and dispersed mechanically into a single cell suspension. PVECs are purified from cell suspension using positive selection with anti-CD-31/PECAM-1 antibody conjugated to MicroBeads using a strong magnetic separation method. Purified cells are cultured on collagen 1&#160;coated culture dishes in endothelial cell culture medium until they become confluent and further subcultured. PVECs obtained with this protocol exhibit cobblestone and spindle shaped phenotypes, as visualized by phase-contrast light microscopy and fluorescence microscopy. Purity of PVEC cultures was established with endothelial cell markers. In our hands, this method reliably and consistently yields pure populations of PVECs. This protocol will benefit studies aimed at gaining mechanistic insights into forebrain angiogenesis, understanding PVEC interactions, and cross-talks with neuronal cell types and holds tremendous potential for therapeutic angiogenesis.

The phenotypic characterization of PVECs from day 1-12 is shown by phase-contrast light microscopy (Figure 2). The cells attached to the dish on day 1 show morphology characteristic of cell division (Figure 2A). Between 5-8 days, PVECs transition from cobble stone to spindle shaped morphology typical for endothelial cells and more akin to its in vivo state (Figures 2B and 2C). By day 12 the PVEC culture achieves full confluence (Figure 2...

Watch this Scientific Journal Video about Isolation and Culture of Endothelial Cells from the Embryonic Forebrain at JoVE.com

Isolation and Culture of Endothelial Cells from the Embryonic Forebrain

This video demonstrates an easy and reliable strategy for preparation of pure cultures of endothelial cells from the embryonic forebrain within 10-12 days and will be useful for research focused on many aspects of cerebral angiogenesis.

Embryonic brain endothelial cells can serve as an important tool in the study of angiogenesis and neurovascular development and interactions. The two ...

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15.3K Views.  Harvard Medical School. This video demonstrates an easy and reliable strategy for preparation of pure cultures of endothelial cells from the embryonic forebrain within 10-12 days and will be useful for research focused on many aspects of cerebral angiogenesis.

Video: Isolation and Culture of Endothelial Cells from the Embryonic Forebrain

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 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 ...

Lectin-based Isolation and Culture of Mouse Embryonic Motoneurons

Spinal motoneurons develop towards postmitotic stages through early embryonic nervous system development and subsequently grow out dendrites and axons. Neuroepithelial cells of the neural tube that express Nkx6.1 are the unique precursor cells for spinal motoneurons1. Though postmitotic motoneurons move towards their final position and organize themselves into columns along the spinal tract2,3. More than 90% of all these differentiated and positioned motoneurons express the transcription factors Islet 1/2. They innervate the muscles of the limbs as well as those of the body and the inner organs. Among others, motoneurons typically express the high affinity receptors for brain derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3), the tropomyosin-related kinase B and C (TrkB, TrkC). They do not express the tropomyosin-related kinase A (TrkA)4. Beside the two high affinity receptors, motoneurons do express the low affinity neurotrophin receptor p75NTR. The p75NTR can bind all neurotrophins with similar but lower affinity to all neurotrophins than the high affinity receptors would bind the mature neurotrophins. Within the embryonic spinal cord, the p75NTR is exclusively expressed by the spinal motoneurons5. This has been used to develop motoneuron isolation techniques to purify the cells from the vast majority of surrounding cells6. Isolating motoneurons with the help of specific antibodies (panning) against the extracellular domains of p75NTR has turned out to be an expensive method as the amount of antibody used for a single experiment is high due to the size of the plate used for panning. A much more economical alternative is the use of lectin. Lectin has been shown to specifically bind to p75NTR as well7. The following method describes an alternative technique using wheat germ agglutinin for a preplating procedure instead of the p75NTR antibody. The lectin is an extremely inexpensive alternative to the p75NTR antibody and the purification grades using lectin are comparable to that of the p75NTR antibody. Motoneurons from the embryonic spinal cord can be isolated by this method, survive and grow out neurites.

An alternative way of isolating mouse embryonic motoneurons from the spinal cord is described. The method takes into account the fact that lectin can bind to the low affinity nerve growth factor receptor p75NTR. This lectin-based preplating allows a purification similar to that with a specific antibody against the p75NTR.

Spinal motoneurons develop towards postmitotic stages through early embryonic nervous system development and subsequently grow out dendrites and axons. ...

Isolation and Culture of Hippocampal Neurons from Prenatal Mice

Primary cultures of rat and murine hippocampal neurons are widely used to reveal cellular mechanisms in neurobiology. By isolating and growing individual neurons, researchers are able to analyze properties related to cellular trafficking, cellular structure and individual protein localization using a variety of biochemical techniques. Results from such experiments are critical for testing theories addressing the neural basis of memory and learning. However, unambiguous results from these forms of experiments are predicated on the ability to grow neuronal cultures with minimum contamination by other brain cell types. In this protocol, we use specific media designed for neuron growth and careful dissection of embryonic hippocampal tissue to optimize growth of healthy neurons while minimizing contaminating cell types (i.e. astrocytes). Embryonic mouse hippocampal tissue can be more difficult to isolate than similar rodent tissue due to the size of the sample for dissection. We show detailed dissection techniques of hippocampus from embryonic day 19 (E19) mouse pups. Once hippocampal tissue is isolated, gentle dissociation of neuronal cells is achieved with a dilute concentration of trypsin and mechanical disruption designed to separate cells from connective tissue while providing minimum damage to individual cells. A detailed description of how to prepare pipettes to be used in the disruption is included. Optimal plating densities are provided for immuno-fluorescence protocols to maximize successful cell culture. The protocol provides a fast (approximately 2 hr) and efficient technique for the culture of neuronal cells from mouse hippocampal tissue.

We provide a protocol for the culture of highly purified hippocampal neurons from prenatal mouse brains without the use of a feeder glial cell layer.

Primary cultures of rat and murine hippocampal neurons are widely used to reveal cellular mechanisms in neurobiology. By isolating and growing individual ...

Isolation and Culture of Rat Embryonic Neural Cells: A Quick Protocol

We are describing a quick method to dissociate and culture hippocampal or cortical neurons from E15-17 rat embryos. The procedure can be applied successfully to the isolation of mouse and human primary neurons and neural progenitors. Dissociated neurons are maintained in serum-free medium up to several weeks. These cultures can be used for nucleofection, immunocytochemistry, nucleic acids preparation, as well as electrophysiology. Older neuronal cultures can also be transfected with a good efficiency rate by lentiviral transduction and, less efficiently, with calcium phosphate or lipid-based methods such as lipofectamine.

We describe a rapid methodology to isolate and culture hippocampal and cortical neurons from rodent embryos. This protocol allows us to perform experiments in which nearly pure neuronal cultures are required.

We are describing a quick method to dissociate and culture hippocampal or cortical neurons from E15-17 rat embryos. The procedure can be applied ...

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 ...

Isolation of Primary Murine Brain Microvascular Endothelial Cells

The blood-brain-barrier is ultrastructurally assembled by a monolayer of brain microvascular endothelial cells (BMEC) interconnected by a junctional complex of tight and adherens junctions. Together with other cell-types such as astrocytes or pericytes, they form the neurovascular unit (NVU), which specifically regulates the interchange of fluids, molecules and cells between the peripheral blood and the CNS. Through this complex and dynamic system BMECs are involved in various processes maintaining the homeostasis of the CNS. A dysfunction of the BBB is observed as an essential step in the pathogenesis of many severe CNS diseases. However, specific and targeted therapies are very limited, as the underlying mechanisms are still far from being understood. 
Animal and in vitro models have been extensively used to gain in-depth understanding of complex physiological and pathophysiological processes. By reduction and simplification it is possible to focus the investigation on the subject of interest and to exclude a variety of confounding factors. However, comparability and transferability are also reduced in model systems, which have to be taken into account for evaluation. The most common animal models are based on mice, among other reasons, mainly due to the constantly increasing possibilities of methodology. In vitro studies of isolated murine BMECs might enable an in-depth analysis of their properties and of the blood-brain-barrier under physiological and pathophysiological conditions. Further insights into the complex mechanisms at the BBB potentially provide the basis for new therapeutic strategies.
This protocol describes a method to isolate primary murine microvascular endothelial cells by a sequence of physical and chemical purification steps. Special considerations for purity and cultivation of MBMECs as well as quality control, potential applications and limitations are discussed.

Brain microvascular endothelial cells (BMEC) are interconnected by specific junctional proteins forming a highly regulated barrier separating blood and the central nervous system (CNS), the so-called blood-brain-barrier (BBB). The isolation of primary murine brain microvascular endothelial cells, as discussed in this protocol, enables detailed in vitro studies of the BBB.

The blood-brain-barrier is ultrastructurally assembled by a monolayer of brain microvascular endothelial cells (BMEC) interconnected by a junctional ...

Isolation, Culture and Long-Term Maintenance of Primary Mesencephalic Dopaminergic Neurons From Embryonic Rodent Brains

Degeneration of mesencephalic dopaminergic (mesDA) neurons is the pathological hallmark of Parkinson&#8217;s diseae. Study of the biological processes involved in physiological functions and vulnerability and death of these neurons is imparative to understanding the underlying causes and unraveling the cure for this common neurodegenerative disorder. Primary cultures of mesDA neurons provide a tool for investigation of the molecular, biochemical and electrophysiological properties, in order to understand the development, long-term survival and degeneration of these neurons during the course of disease. Here we present a detailed method for the isolation, culturing and maintenance of midbrain dopaminergic neurons from E12.5 mouse (or E14.5 rat) embryos. Optimized cell culture conditions in this protocol result in presence of axonal and dendritic projections, synaptic connections and other neuronal morphological properties, which make the cultures suitable for study of the physiological, cell biological and molecular characteristics of this neuronal population.

The causes of degeneration of midbrain dopaminergic neurons during Parkinson&#8217;s disease are not fully understood. Cellular culture systems provide an essential tool for study of the neurophysiological properties of these neurons. Here we present an optimized protocol, which can be utilized for in vitro modeling of neurodegeneration.

Degeneration of mesencephalic dopaminergic (mesDA) neurons is the pathological hallmark of Parkinson&#8217;s diseae. Study of the biological processes ...

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 ...

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.