The authors would like to thank R&#233;mi Ronzano for his wise advice in manuscript editing. This work was funded by ICM, INSERM, ARSEP foundation grant to NSF, and Bouvet-Labruy&#232;re price.

The care and use of rats in this experiment conforms to institutional policies and guidelines (UPMC, INSERM, and European Community Council Directive 86/609/EEC). The following protocol is established for a standard litter of 12 pups.
1. Preparation of the flasks (~5 min)
NOTE: Perform the following steps the day before dissection in a laminar flow hood under sterile conditions.
<ol>
	<li>Coat the 150 cm2 flasks (T150) with filter cap (1 flask for 2 pups) using 5 mL of polyethylenimine (PEI, 100 mg/L, see protocol in Supplementary File 1).</li>
	<li>Store the flasks at 4 &#176;C overnight.</li>
	<li>Rinse coated flasks 3 times with sterile distilled water on the day of dissection.</li>
</ol>
2. Preparation of media (~10 min)
NOTE: Perform the steps in a laminar flow hood under sterile conditions.
<ol>
	<li>Prepare 500 mL of culture medium, consisting of Dulbecco&#39;s modified Eagle medium (DMEM) supplemented with 10% of fetal calf serum (FCS) and penicillin-streptomycin (100 IU/mL).</li>
	<li>Prepare 20.6 mL of the enzyme digestion medium in a 50 mL tube, consisting of 20 mL of DMEM, 200 &#181;L of DNase (50 &#181;g/mL), 200 &#181;L of papain (30 U/mL) and 200 &#181;L of L-cysteine (0.24 mg/mL).</li>
	<li>Filter-sterilize the media using a 0.22 &#181;m filter.</li>
	<li>Keep the media in the laminar flow hood at room temperature (RT) until dissection.</li>
</ol>
3. Preparation for dissection (~10 min)
NOTE: Perform the steps in a laminar flow hood under sterile conditions.
<ol>
	<li>Prepare 100 mL of phosphate-buffered saline without calcium and magnesium (PBS; 1x). Filter-sterilize using a 0.22 &#181;m filter.</li>
	<li>Prepare 50 mL of ice-cold 1x PBS solution supplemented with 750 &#181;L of 45% glucose. Filter-sterilize using a 0.22 &#181;m filter.</li>
	<li>Fill a 100 mm Petri dish with 1x PBS for cleaning instruments and three 60 mm Petri dishes with ice-cold PBS-glucose for tissue harvesting. Put the petri dishes on ice until dissection.</li>
</ol>
4. Dissection
NOTE: Dissection is performed from male and female Wistar rat pups at postnatal day (P) 2.
<ol>
	<li>In order to provide a sterile environment, make sure to clean the bench with 100% ethanol. Sterilize all surgical tools with 100% ethanol.</li>
	<li>Gently spray the neck of the pup with 70% ethanol.</li>
	<li>Use large surgical scissors to decapitate the animal and place the head in a 100 mm Petri dish containing ice-cold PBS-glucose.</li>
	<li>Use curved forceps to maintain the head of the animal at eye level. Use small surgical scissors to make a small incision at the base of the skull and cut the skull following the brain midline.</li>
	<li>Use forceps to gently peel off the two parts of the skull from the midline.</li>
	<li>Use a small surgical spoon to remove the brain from the head cavity. Put the brain in a 60 mm Petri dish containing ice-cold PBS-glucose on ice.</li>
	<li>Viewing under a steromicroscope, use fine forceps to remove the cerebellum, the brainstem and olfactory bulbs from cerebral hemispheres.</li>
	<li>Use fine forceps to separate the two cerebral hemispheres. Use fine forceps to peel off the meninges. Put the cerebral cortices in a 60 mm-petri dish on ice. 
	NOTE: Ice-cold PBS is critical for correct meninges removal.</li>
</ol>
5. Tissue dissociation
NOTE: Perform the steps in a laminar flow hood under sterile conditions.
<ol>
	<li>Use a sharp scalpel to finely chop the cerebral cortices. Transfer the minced tissue into a 50 mL tube containing enzyme digestion medium.</li>
	<li>Incubate for 30 min in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Use a p1000 micropipette to gently remove the enzyme digestion medium while making sure that the cortical tissue remains at the bottom of the 50 mL tube.</li>
	<li>Use a p1000 micropipette to add 1 mL of DMEM-10% FCS and gently triturate the tissue.</li>
	<li>Use a 70 &#181;m filter and a piston of a 1 mL syringe to filter the cortical tissue into a 50 mL tube. 
	NOTE: One can rinse residual tissue on the inner tube wall several times with DMEM-10% FCS.</li>
	<li>Fill the 50 mL tube with DMEM-10%FCS. Centrifuge at 423 x g for 5 min at RT. Carefully remove supernatant and resuspend cell pellet with 2 mL of DMEM-10%FCS.</li>
	<li>Gently triturate cell pellet with a p1000 micropipette and then with a p200 micropipette. Dilute the cell suspension with the appropriate volume of DMEM-10%FCS. 
	NOTE: Two brains = one T150 = 5 mL of DMEM-10%FCS.</li>
	<li>Plate 5 mL of the cell suspension on a T150 at a density of 1 x 105 cells/cm2. Add 20 mL of warm DMEM-10%FCS to each T150. Incubate in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Renew half of the culture medium after 6 days in vitro (DIV) with warm DMEM-10%FCS.</li>
</ol>
6. Shaking preparation
<ol>
	<li>Perform shaking preparation on the day before shaking in a laminar flow hood under sterile conditions.</li>
	<li>Renew half of culture medium by adding fresh warm culture medium into the flask and incubate at 37 &#176;C under 5% CO2.</li>
</ol>
7. Shaking
<ol>
	<li>Coat three 100 mm Petri dishes with PEI. Store them at 4 &#176;C overnight.</li>
	<li>Cover the flasks cap with paraffin film and put the flasks into a plastic bag. Shake flasks containing glial cells overnight at 250 rpm at 37 &#176;C. 
	NOTE: First shaking is performed at 8 DIV and one can perform up to three different shakings (see Figure 1 for timing).</li>
</ol>
8. OL lineage cells harvesting and culture
NOTE: These steps should be performed in a laminar flow hood under sterile conditions.
<ol>
	<li>On the day after shaking, prepare Bottenstein-Sato (BS) medium according to Table 1.</li>
	<li>Rinse coated Petri dishes 3 times with sterile distilled water.</li>
	<li>Harvest flasks&#39; supernatant containing mainly OL lineage cells but also some microglial cells and plate it on non-coated 100 mm Petri dishes. 
	NOTE: This step allows removal of microglial cells through differential fast adhesion on the dish surface.</li>
	<li>Incubate the Petri dishes for 15 min in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Fill each T150 flask with 25 mL of warm freshly prepared culture medium and incubate in a humidified incubator at 37 &#176;C under 5% CO2 until the second shaking.</li>
	<li>Transfer the supernatant from the Petri dishes into new non-coated 100 mm Petri dishes to allow adhesion of residual microglial cells.</li>
	<li>Incubate the Petri dishes for 15 min in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Remove the supernatant, which contains non-adherent OL lineage cells, and transfer it into 50 mL tubes (supernatant from 2 Petri dishes for a 50 mL tube). Discard Petri dishes plated with microglia.</li>
	<li>Centrifuge the supernatant for 5 min at 423 x g. Carefully remove supernatant and resuspend cell pellet with 1 mL of BS medium. Pool all pellets in a common 50 mL tube and adjust volume to 10 mL with BS medium.</li>
	<li>Determine cell density counting cells under a microscope. 
	NOTE: A cell density between 3 x 105/mL and 5 x 105/mL should be obtained.</li>
	<li>Add 20 mL of BS if cell density is higher than or equal to 4 x 105/mL to obtain a final volume of 30 mL, or add only 10 mL of BS if cell density is less than 4 x 105/mL to obtain a final volume of 20 mL.</li>
	<li>Plate two or three pre-coated 100 mm Petri dishes with 10 mL of cell suspension. Incubate in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Clear the debris from the Petri dishes by refreshing all of the BS medium 2 h later. 
	NOTE: Examine the culture under the microscope before and after clearing to verify cell density and efficiency of debris removal.</li>
	<li>Incubate for 2 days in BS medium in a humidified incubator at 37 &#176;C under 5% CO2. 
	NOTE: Examine the culture under the microscope. The confluence should be 70% to 80%.</li>
</ol>
9. OCM production
NOTE: Perform these steps in a laminar flow hood under sterile conditions.
<ol>
	<li>Prepare NB-B27low medium according to Table 2.</li>
	<li>Renew culture medium with 10 mL of warm NB-B27low medium. Incubate for 2 days in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Harvest the OCM, i.e., supernatant containing OL secreted factors. Filter-sterilize OCM using a 0.22 &#181;m filter. 
	NOTE: Store OCM at 4 &#176;C for a maximum of 2 months.</li>
</ol>
10. OCM addition
NOTE: Steps should be performed in a laminar flow hood under sterile conditions. OCM can be added to purified hippocampal neuron cultures prepared according to the following protocol14, and obtained by adding, 24 h after isolation, the anti-mitotic agents uridine and 5- fluorodeoxyuridine (5 &#181;M) for 36 h.
<ol>
	<li>At 3 DIV, remove all neuron culture medium containing anti-mitotic agents and add 500 &#181;L of fresh warm OCM.</li>
	<li>Renew half of medium every 3 days with freshly made warm NB-B27. 
	NOTE: Such cultures can be maintained up to 21 DIV.</li>
</ol>
11. Addition of OL to purified hippocampal neuron culture
NOTE: Perform the following steps in a laminar flow hood under sterile conditions. OLs can be added to purified hippocampal cultures obtained the same way as described above.
<ol>
	<li>Prepare co-culture medium according to Table 3.</li>
	<li>Retrieve the OL culture at 70% to 80% confluence. Rinse with 2 mL of warm 1x PBS.</li>
	<li>To detach the cells, add 2 mL of 0.25% trypsin to a 100 mm Petri dish.</li>
	<li>Incubate for 5 min in a humidified incubator at 37 &#176;C under 5% CO2.</li>
	<li>Add 2 mL of DMEM-10% FCS to block the enzymatic reaction. Harvest the supernatant containing OL lineage cells.</li>
	<li>Centrifuge at 423 x g for 5 min at RT. Carefully remove supernatant and resuspend the cell pellet in warm co-culture medium to obtain a concentration of 1.25 x 105 cells/mL.</li>
	<li>Add OL to purified hippocampal neurons culture by removing 200 &#181;L of neuron culture medium and adding 200 &#181;L of cell suspension per well (2.5 x 104 cells/well) of a 24-well plate.</li>
	<li>Refresh half of co-culture medium every 2-3 days. 
	NOTE: Co-cultures can be maintained up to 24 DIV.</li>
</ol>

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None of the authors have competing interests or conflicting interests.

Here, we provide a detailed protocol to obtain highly enriched oligodendroglial lineage cell cultures from mixed glial cultures, adapted from a previously published method16, and the subsequent production of OL-conditioned medium. This shaking technique is not expensive, can be repeated three times and is optimal to obtain high quantity of purified OLs, as cells cultured in Bottenstein-Sato (BS) medium containing PDGF&#945; proliferate. Glial cells are prepared using cerebral cortices of Wistar rats at P2, a time point at which a vast majority of the oligodendroglial lineage cells are pre-oligodendrocytes expressing NG2 and O415. Of note, OL lineage maturation is similar at P2 in mouse and rat, and this protocol can also be used to isolate mouse pre-oligodendrocytes17.
After shaking the mixed glial cell cultures, detached cells consist mainly of oligodendroglial lineage cells, but also some microglial cells and few astrocytes. Microglial cells are removed through differential adhesion on uncoated Petri dishes. Of note, removal efficiency can be improved by performing an additional adhesion step. However, about 5% of microglial cells are still found in enriched oligodendroglial cell cultures, as well as 5% to 9% of astrocytes. It is possible to decrease contamination from astrocytes to less than 5% by performing an additional immuno-panning step using O4 antibody-coated Petri dishes; for a detailed protocol see supplemental information in Freeman et al.14. The removal of debris 2 h after plating oligodendroglial cells is a critical step, which relies on the strength of the flow applied with the pipet. At this step, it is important to examine the culture under the microscope before and after clearing to verify the efficiency as the presence of too much debris may impair cell viability and growth. Of note, it is also important to use freshly made BS medium, otherwise it could alter oligodendrocytes survival. In addition, purified cells survive only up to 6 days after plating. Indeed, it is known that other glial cells and neurons promote OPC survival and proliferation or differentiation through secreted factors or direct contacts2,18.
Other methods allow OLs isolation immediately after brain dissociation, using immunolabelling with O4 antibody followed by fluorescent-activated cell sorting by flow cytometry (FACS) or magnetic-activated cell sorting (MACS). In addition, GFP-positive OPCs or GFP-positive oligodendrocytes can be purified by fluorescent-activated cell sorting from PDGF&#945;R:GFP or PLP:GFP mice, respectively19,20. These sorting methods are more relevant for studying physiological state of oligodendrocytes compared to cultures treated with growth factors which could alter their phenotype. Notably, fluorescent-activated cell sorting has been used for gene-profiling approaches in the normal physiological state and demyelinating conditions21. As cell survival could be altered by cell sorting, it is better to perform functional assays immediately after sorting.
We have shown that OL cultures can be detached and added to purified hippocampal neuron cultures at 14 DIV. Such OL-neuron co-culture allows the study of early steps of myelination which starts during the first week of co-culture (Dubessy, unpublished results). Other models of OL-hippocampal neuron myelinating co-culture have been achieved by adding oligodendrocytes immediately after sorting22,23. Furthermore, we produced OCM to further dissect OL-neuron interactions and address the role of OL-secreted factors on neuron cultures. By using this technique, we demonstrated that hippocampal GABAergic neuron subtypes (i.e., parvalbumin+ and/or somatostatin+) can form clusters of nodal proteins along their axon which are induced by OCM prior to myelination14,24. Mass spectrometry analysis of OCM has unraveled several secreted proteins and led to identify oligodendroglial Contactin-1 that in synergy with extracellular matrix proteins mediates early steps of nodal clustering24. Primary cultures are useful models that allow the assessment of oligodendroglial lineage cell differentiation and interactions with neurons. However, other approaches have also been developed to evaluate OL functions and myelination, demyelination and remyelination from ex vivo cerebellar organotypic slice cultures25,26, and in vivo studies, notably with zebrafish and tadpole models27 which are needed in final steps of pre-clinical studies.

Oligodendrocytes (OLs) are glial cells of the central nervous system (CNS) that generate myelin wrapping around axons. OLs originate from oligodendrocyte precursor cells (OPCs) which proliferate within the ventricular zones of the embryonic CNS and then migrate and differentiate into fully mature OLs (i.e., myelin-forming cells)1. OPCs are abundant during early development, but also persist in the adult brain where they represent the major proliferative cell population2. A single OL ensheathes multiple axons in non-excitable sections (i.e., internodes), and the edge of each myelin loop attaches to the axon forming the paranodal domain which is crucial for the insulating properties of myelin1,3. In between the paranodes are small unmyelinated gaps called the nodes of Ranvier. These nodes are rich in voltage-gated sodium channels (Nav), allowing the regeneration and rapid propagation of action potentials through saltatory conduction4. This tight interaction also enables axonal energy support through neuronal uptake of lactate from OLs5,6.
The maturation of oligodendroglial lineage cells and the myelination process are tightly regulated by their interactions with neurons7. Indeed, OLs and OPCs, also named NG2 cells, express an array of receptors for neurotransmitters, and can receive input from excitatory and inhibitory neurons, allowing them to sense neuronal activity that can trigger their proliferation and/or differentiation into myelinating cells2. In turn, OPCs/OLs secrete microvesicles and proteins into the extracellular space which alone or synergistically mediate neuromodulative and neuroprotective functions8,9,10,11,12. However, the molecular mechanisms controlling the multiple modes of interactions between oligodendroglial lineage cells and neurons are yet to be fully deciphered.
Moreover, in several CNS pathological conditions, OLs are primarily affected, thus disturbing their interaction with neurons. For instance, in Multiple Sclerosis (MS), neurological dysfunction is caused by focal demyelination in the CNS, secondary to OLs loss that can lead to axonal damage and related disability accumulation. Remyelination can take place, albeit insufficiently in most cases13. Progress in the last decade, due to the development of immunotherapies, have reduce the relapse rate but promoting remyelination remains to date an unmet need. As such, a better understanding of OLs role, functions and influences is of particular interest to the development of new therapies for a wide spectrum of CNS conditions.
Here, we describe the methods of OLs purification and culture. This enables precise examination of intrinsic mechanisms regulating their development and biology. In addition, such highly enriched OLs cultures allow the production of oligodendrocyte-conditioned medium (OCM), which can be added to purified neuron cultures to gain insight into the impact of OLs-secreted factors on neuronal physiology and connectivity. Furthermore, we describe how to implement an in vitro co-culture system where purified oligodendrocytes and neurons are combined together, allowing to address the mechanisms regulating (re)myelination.

<table><tbody><tr><td>5-fluorodeoxyuridine</td><td>Sigma</td><td>F0503</td><td></td></tr><tr><td>B27 supplement</td><td>ThermoFisher</td><td>17504044</td><td></td></tr><tr><td>D-(+)-Glucose solution</td><td>Sigma</td><td>G8769</td><td></td></tr><tr><td>DNase (Deoxyribonuclease I)</td><td>Worthington</td><td>LS002139</td><td></td></tr><tr><td>Dulbecco&#039;s Modified Eagle Medium</td><td>ThermoFisher</td><td>31966021</td><td></td></tr><tr><td>Ethanol 100%</td><td>Sigma</td><td>32221-M</td><td></td></tr><tr><td>Ethanol 70%</td><td>VWR Chemicals</td><td>83801.360</td><td></td></tr><tr><td>Fetal Calf Serum</td><td>ThermoFisher</td><td>10082147</td><td></td></tr><tr><td>L-cysteine</td><td>Sigma</td><td>C7352</td><td></td></tr><tr><td>Neurobasal</td><td>ThermoFisher</td><td>21103049</td><td></td></tr><tr><td>Papain</td><td>Worthington</td><td>LS003126</td><td></td></tr><tr><td>Penicillin-Streptomycin</td><td>ThermoFisher</td><td>15140122</td><td></td></tr><tr><td>Phosphate Buffered Saline without calcium and magnesium</td><td>ThermoFisher</td><td>A1285601</td><td></td></tr><tr><td>Polyethylenimine(PEI)</td><td>Sigma</td><td>P3143</td><td></td></tr><tr><td>Tetraborate decahydrate</td><td>Sigma</td><td>B9876</td><td></td></tr><tr><td>Trypsin</td><td>Sigma</td><td>Sigma</td><td></td></tr><tr><td>Uridine</td><td>Sigma</td><td>U3750</td><td></td></tr><tr><td>&lt;strong&gt;Bottenstein-Sato (BS) media&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>apo-Transferrin human</td><td>Sigma</td><td>T1147</td><td></td></tr><tr><td>BSA (Bovine Serum Albumin)</td><td>Sigma</td><td>A4161</td><td></td></tr><tr><td>Dulbecco&#039;s Modified Eagle Medium</td><td>ThermoFisher</td><td>31966021</td><td></td></tr><tr><td>Insulin</td><td>Sigma</td><td>I5500</td><td></td></tr><tr><td>PDGF</td><td>Peprotech</td><td>AF-100-13A</td><td></td></tr><tr><td>Penicillin-Streptomycin</td><td>ThermoFisher</td><td>15140122</td><td></td></tr><tr><td>Progesterone</td><td>Sigma</td><td>P8783</td><td></td></tr><tr><td>Putrescine dihydrochloride</td><td>Sigma</td><td>P5780</td><td></td></tr><tr><td>Sodium selenite</td><td>Sigma</td><td>S5261</td><td></td></tr><tr><td>T3 (3,3&#039;,5-Triiodo-L-thyronine sodium salt)</td><td>Sigma</td><td>T6397</td><td></td></tr><tr><td>T4 (L-Thyroxine)</td><td>Sigma</td><td>T1775</td><td></td></tr><tr><td>&lt;strong&gt;Co-culture media&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>apo-Transferrin human</td><td>Sigma</td><td>T1147</td><td></td></tr><tr><td>B27 supplement</td><td>ThermoFisher</td><td>17504044</td><td></td></tr><tr><td>Biotin</td><td>Sigma</td><td>B4639</td><td></td></tr><tr><td>BSA (Bovine Serum Albumin)</td><td>Sigma</td><td>A4161</td><td></td></tr><tr><td>Ceruloplasmin</td><td>Sigma</td><td>239799</td><td></td></tr><tr><td>Dulbecco&#039;s Modified Eagle Medium</td><td>ThermoFisher</td><td>31966021</td><td></td></tr><tr><td>Hydrocortisone</td><td>Sigma</td><td>H4001</td><td></td></tr><tr><td>Insulin</td><td>Sigma</td><td>I5500</td><td></td></tr><tr><td>N-Acetyl-L-cysteine</td><td>Sigma</td><td>A8199</td><td></td></tr><tr><td>Neurobasal</td><td>ThermoFisher</td><td>21103049</td><td></td></tr><tr><td>Penicillin-Streptomycin</td><td>ThermoFisher</td><td>15140122</td><td></td></tr><tr><td>Progesterone</td><td>Sigma</td><td>P8783</td><td></td></tr><tr><td>Putrescin</td><td>Sigma</td><td>P5780</td><td></td></tr><tr><td>Recombinant Human CNTF</td><td>Sigma</td><td>450-13</td><td></td></tr><tr><td>Sodium selenite</td><td>Sigma</td><td>S5261</td><td></td></tr><tr><td>T3 (3,3&#039;,5-Triiodo-L-thyronine sodium salt)</td><td>Sigma</td><td>T6397</td><td></td></tr><tr><td>Vitamin B12</td><td>Sigma</td><td>V6629</td><td></td></tr><tr><td>&lt;strong&gt;Tools&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>0.22 &amp;micro;m filter</td><td>Sartorius</td><td>514-7010</td><td></td></tr><tr><td>1 mL syringe</td><td>Terumo</td><td>1611127</td><td></td></tr><tr><td>100 mm Petri dish</td><td>Dutscher</td><td>193100</td><td></td></tr><tr><td>15 mL tube</td><td>Corning Life Science</td><td>734-1867</td><td></td></tr><tr><td>50 mL tube</td><td>Corning Life Science</td><td>734-1869</td><td></td></tr><tr><td>60 mm Petri dish</td><td>Dutscher</td><td>067003</td><td></td></tr><tr><td>70 &amp;micro;m filter</td><td>Miltenyi Biotec</td><td>130-095-823</td><td></td></tr><tr><td>Binocular microscope</td><td>Olympus</td><td>SZX7</td><td></td></tr><tr><td>Curved forceps</td><td>Fine Science Tools</td><td>11152-10</td><td></td></tr><tr><td>Fine forceps</td><td>Fine Science Tools</td><td>91150-20</td><td></td></tr><tr><td>Large surgical scissors</td><td>Fine Science Tools</td><td>14008-14</td><td></td></tr><tr><td>Scalpel</td><td>Swann-morton</td><td>233-5528</td><td></td></tr><tr><td>Shaker</td><td>Infors HT</td><td></td><td></td></tr><tr><td>Small surgical scissors</td><td>Fine Science Tools</td><td>91460-11</td><td></td></tr><tr><td>Small surgical spoon</td><td>Bar Naor Ltd</td><td>BN2706</td><td></td></tr><tr><td>T150 cm&lt;sup&gt;2&lt;/sup&gt; flask with filter cap</td><td>Dutscher</td><td>190151</td><td></td></tr><tr><td>&lt;strong&gt;Animal&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>P2 Wistar rat</td><td>Janvier</td><td>RjHAn:WI</td><td></td></tr></tbody></table>

generation of oligodendrocytes and oligodendrocyte-conditioned medium for co-culture experiments

In the central nervous system, oligodendrocytes are well-known for their role in axon myelination, that accelerates the propagation of action potentials through saltatory conduction. Moreover, an increasing number of reports suggest that oligodendrocytes interact with neurons beyond myelination, notably through the secretion of soluble factors. Here, we present a detailed protocol allowing purification of oligodendroglial lineage cells from glial cell cultures also containing astrocytes and microglial cells. The method relies on overnight shaking at 37 &#176;C, which allows selective detachment of the overlying oligodendroglial cells and microglial cells, and the elimination of microglia by differential adhesion. We then describe the culture of oligodendrocytes and production of oligodendrocyte-conditioned medium (OCM). We also provide the kinetics of OCM treatment or oligodendrocytes addition to purified hippocampal neurons in co-culture experiments, studying oligodendrocyte-neuron interactions.

In this protocol, OL lineage cells are purified from glial cultures by shaking off astrocytes and microglia. Purity and phenotypic examination of OL cultures can be assessed by immunostaining with glial markers15. Analysis of the expression of different markers indicated that OL cultures were mostly pre-OLs with 90% &#177; 4% of O4+ cells, 85% &#177; 7% NG2+ cells, and 4.7% &#177; 2.1% of PLP+ cells, while 7.2% &#177; 2.5% of cells were GFAP+ astrocytes (mean &#177; S.D., n = 3; Figure 2). In addition, 4.6% &#177; 0.7% of cells were CD11b+ microglial cells (mean &#177; S.D., not shown).
OCM produced from such cultures can be added at 3 DIV to purified hippocampal neuron cultures. This treatment promotes the clustering of nodal proteins, consisting of Nav channels associated with Neurofascin 186 and Ankyrin G along the axon of hippocampal GABAergic neurons before myelination, at 17 DIV (Figure 3A,B). Of note, electrophysiological recordings revealed that these clusters are associated with an increased conduction of action potentials14. In addition, expression of phosphorylated intermediate filament protein H stained by Smi31 is increased in OCM-treated hippocampal neurons (Figure 3A). Oligodendroglial secreted factors are therefore implicated in neuronal maturation and physiology.
Myelination of hippocampal neurons can be studied through addition of OL at 14 DIV. From 20 DIV to 24 DIV, immunostaining of myelin markers, such as myelin basic protein (MBP) allows visualization of myelin segments (Figure 4).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/60912/60912fig1.jpg" /> 
Figure 1: Protocol timeline of OL lineage cells isolation and OCM production. After dissecting out cerebral cortices from P2 Wistar rats (step 4), perform tissue dissociation to culture glial cells (step 5). At 8, 12 and 15 DIV (i.e., days before shaking), renew half medium with warm DMEM-10% FCS (step 6). The next day, shake glial cultures overnight at 250 rpm at 37 &#176;C (step 7.2). Harvest supernatant containing OL lineage cells and few microglia cells and plate it for 15 min in a humidified incubator at 37 &#176;C under 5% CO2 (steps 8.3 to 8.7). Centrifuge the supernatant for 5 min at 423 x g, resuspend cell pellet with BS and incubate for 2 days in a humidified incubator at 37 &#176;C under 5% CO2 (steps 8.8 to 8.12). To produce OCM, incubate for 2 days in NB-B27low (step 9). To isolate OLs for co-culture experiments, detach cell using trypsin (step 11.3). <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/60912/60912fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/60912/60912fig2.jpg" /> 
Figure 2: OL lineage cells phenotype in cultures. Images were acquired using a confocal microscope. Maximum intensity projections are presented. (A) OL cultures contain mostly pre-OLs (i.e., expressing only NG2 (red), or both O4 (green) and NG2 (red); cells expressing both markers are indicated with yellow stars), but also some immature OLs (i.e., only expressing O4 and not NG2; white stars). (B) Few mature OLs (i.e., PLP+; green) and few astrocytes (GFAP+ cells; red) are found in OL lineage cell cultures. Scale bars = 25 &#181;m. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/60912/60912fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/60912/60912fig3a.jpg" /> 
Figure 3: Representative applications. (A,B) Hippocampal neurons treated with OCM at 3 DIV and fixed at 17 DIV express phosphorylated intermediate filament protein H (Smi31; green; panel A). GABAergic neurons, identified by glutamate decarboxylase isoform of 67 kDa (GAD67) expression (white), display accumulation of Ankyrin G and Nav sodium channels (red; panels A and B, respectively) at the axon initial segment and form Ankyrin G and Nav clusters along their axon (panels A and B, respectively). Scale bars = 25 &#181;m. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/60912/60912fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/60912/60912fig4.jpg" /> 
Figure 4: Representative applications. OL lineage cells added to hippocampal neuron culture at 14 DIV myelinate some hippocampal axons, here fixed at 23 DIV (MBP as a myelin marker; green). Nodes of Ranvier (Nav; red) are observed in between myelin segments. Scale bar = 25 &#181;m. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/60912/60912fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Bottenstein-Sato (BS) media</td>
			<td>Final concentration</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagle Medium</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>100 IU/mL</td>
		</tr>
		<tr>
			<td>apo-Transferrin human</td>
			<td>100 &#181;g/mL</td>
		</tr>
		<tr>
			<td>BSA (Bovine Serum Albumin)</td>
			<td>100 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Insulin</td>
			<td>5 &#181;g/mL</td>
		</tr>
		<tr>
			<td>PDGF</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>Progesterone</td>
			<td>62 ng/mL</td>
		</tr>
		<tr>
			<td>Putrescine dihydrochloride</td>
			<td>16 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Sodium selenite</td>
			<td>40 ng/mL</td>
		</tr>
		<tr>
			<td>T3 (3,3&#39;,5-Triiodo-L-thyronine sodium salt)</td>
			<td>30 ng/mL</td>
		</tr>
		<tr>
			<td>T4 (L-Thyroxine)</td>
			<td>40 ng/mL</td>
		</tr>
	</tbody>
</table>
Table 1: Preparation of Bottenstein-Sato (BS) media.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>NB-B27 low media</td>
			<td>Final concentration</td>
		</tr>
		<tr>
			<td>Neurobasal</td>
			<td></td>
		</tr>
		<tr>
			<td>B27 supplement</td>
			<td>0.5x</td>
		</tr>
		<tr>
			<td>L-glutamine</td>
			<td>0.5 mM</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>100 IU/mL</td>
		</tr>
		<tr>
			<td>NB-B27 media</td>
			<td>Final concentration</td>
		</tr>
		<tr>
			<td>Neurobasal</td>
			<td></td>
		</tr>
		<tr>
			<td>B27 supplement</td>
			<td>1x</td>
		</tr>
		<tr>
			<td>L-glutamine</td>
			<td>0.5 mM</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>100 IU/mL</td>
		</tr>
	</tbody>
</table>
Table 2: Preparation of NB-B27low and NB-B27 media.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Co-culture media</td>
			<td>Final concentration</td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagle Medium</td>
			<td>1 vol</td>
		</tr>
		<tr>
			<td>Neurobasal</td>
			<td>1 vol</td>
		</tr>
		<tr>
			<td>B27 supplement</td>
			<td>1x</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>100 IU/mL</td>
		</tr>
		<tr>
			<td>apo-Transferrin human</td>
			<td>50 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Biotin</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>BSA (Bovine Serum Albumin)</td>
			<td>50 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Ceruloplasmin</td>
			<td>100 ng/mL</td>
		</tr>
		<tr>
			<td>Hydrocortisone</td>
			<td>0.05 &#181;M</td>
		</tr>
		<tr>
			<td>Insulin</td>
			<td>5 &#181;g/mL</td>
		</tr>
		<tr>
			<td>N-Acetyl-L-cysteine</td>
			<td>5 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Progesterone</td>
			<td>6.2 ng/mL</td>
		</tr>
		<tr>
			<td>Putrescin</td>
			<td>16 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Recombinant Human CNTF</td>
			<td>0.1 ng/mL</td>
		</tr>
		<tr>
			<td>Sodium selenite</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>T3 (3,3&#39;,5-Triiodo-L-thyronine sodium salt)</td>
			<td>40 ng/mL</td>
		</tr>
		<tr>
			<td>Vitamin B12</td>
			<td>27.2 ng/mL</td>
		</tr>
	</tbody>
</table>
Table 3: Preparation of co-culture media.
Supplementary File 1. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/60912/Supplementary_File1.docx" target="_blank">Please click here to view this file (Right click to download).</a>

Watch this Scientific Journal Video about Generation of Oligodendrocytes and Oligodendrocyte-Conditioned Medium for Co-Culture Experiments at JoVE.com

Generation of Oligodendrocytes and Oligodendrocyte-Conditioned Medium for Co-Culture Experiments

Herein, we display an efficient method for the purification of oligodendrocytes and production of oligodendrocyte-conditioned medium that can be used for co-culture experiments.

In the central nervous system, oligodendrocytes are well-known for their role in axon myelination, that accelerates the propagation of action potentials ...

generation-oligodendrocytes-oligodendrocyte-conditioned-medium-for-co

Nanyang Technological University

Research

JoVE Journal

Neuroscience

10.4K Views.  Institut du Cerveau et de la Moelle épinière, ICM. We beschrijven een efficiënte methode van oligodendroglial lijncellen zuivering en cultuur. Dit maakt het mogelijk om de moleculaire mechanismen aan te pakken die oligodendrocyten differentiatie en hun interacties met neuronen tijdens het myelineproces controleren. Deze schudtechniek is niet duur en is optimaal om een grote hoeveelheid oligodendrocyten te verkrijgen.Dergelijke culturen maken de productie van oligodendrocyten-geconditioneerde medium en co-culturen van oligodendrocyten ...

Video: Generation of Oligodendrocytes and Oligodendrocyte-Conditioned Medium for Co-Culture Experiments

Production and Use of Lentivirus to Selectively Transduce Primary Oligodendrocyte Precursor Cells for In Vitro Myelination Assays

Myelination is a complex process that involves both neurons and the myelin forming glial cells, oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS). We use an in vitro myelination assay, an established model for studying CNS myelination in vitro. To do this, oligodendrocyte precursor cells (OPCs) are added to the purified primary rodent dorsal root ganglion (DRG) neurons to form myelinating co-cultures. In order to specifically interrogate the roles that particular proteins expressed by oligodendrocytes exert upon myelination we have developed protocols that selectively transduce OPCs using the lentivirus overexpressing wild type, constitutively active or dominant negative proteins before being seeded onto the DRG neurons. This allows us to specifically interrogate the roles of these oligodendroglial proteins in regulating myelination. The protocols can also be applied in the study of other cell types, thus providing an approach that allows selective manipulation of proteins expressed by a desired cell type, such as oligodendrocytes for the targeted study of signaling and compensation mechanisms. In conclusion, combining the in vitro myelination assay with lentiviral infected OPCs provides a strategic tool for the analysis of molecular mechanisms involved in myelination.

Production and Use of Lentivirus to Selectively Transduce Primary Oligodendrocyte Precursor Cells for In Vitro Myelination Assays

Here we present protocols that offer a flexible and strategic foundation for virally manipulating oligodendrocyte precursor cells to overexpress proteins of interest in order to specifically interrogate their role in oligodendrocytes via the in vitro model of central nervous system myelination.

Myelination is a complex process that involves both neurons and the myelin forming glial cells, oligodendrocytes in the central nervous system (CNS) and ...

Developmental Biology

Preparation of Rat Oligodendrocyte Progenitor Cultures and Quantification of Oligodendrogenesis Using Dual-infrared Fluorescence Scanning

Efficient oligodendrogenesis is the therapeutic goal of a number of areas of research including spinal cord injury, neonatal hypoxia, and demyelinating diseases such as multiple sclerosis and transverse myelitis. Myelination is required to not only facilitate rapid impulse propagation within the central nervous system, but also to provide trophic support to underlying axons. Oligodendrocyte progenitor cells (OPCs) can be studied in vitro to help identify factors that may promote or inhibit oligodendrocyte differentiation. To date, many of the methods available to evaluate this process have either required large numbers of cells, thus limiting the number of conditions that can be investigated at any one time, or labor-intensive methods of quantification. Herein, we describe a protocol for the isolation of large numbers of highly pure OPCs together with a fast and reliable method to determine oligodendrogenesis from multiple conditions simultaneously. OPCs are isolated from P5-P7 neonatal rat cortices and grown in vitro for three days prior to differentiation. Four days after differentiation, oligodendrogenesis is evaluated using a dual-infrared fluorescence-scanning assay to determine expression of the myelin protein.

Oligodendrocytes are the myelinating cells of the central nervous system. This protocol describes a method for the isolation and culture of their precursors, oligodendrocyte progenitor cells, from rat cortices, as well as a fast and reliable quantitative method to evaluate oligodendrogenesis in vitro in response to experimental factors.

Efficient oligodendrogenesis is the therapeutic goal of a number of areas of research including spinal cord injury, neonatal hypoxia, and demyelinating ...

Derivation of Enriched Oligodendrocyte Cultures and Oligodendrocyte/Neuron Myelinating Co-cultures from Post-natal Murine Tissues

Identifying the molecular mechanisms underlying OL development is not only critical to furthering our knowledge of OL biology, but also has implications for understanding the pathogenesis of demyelinating diseases such as Multiple Sclerosis (MS). Cellular development is commonly studied with primary cell culture models. Primary cell culture facilitates the evaluation of a given cell type by providing a controlled environment, free of the extraneous variables that are present in vivo. While OL cultures derived from rats have provided a vast amount of insight into OL biology, similar efforts at establishing OL cultures from mice has been met with major obstacles. Developing methods to culture murine primary OLs is imperative in order to take advantage of the available transgenic mouse lines. 
Multiple methods for extraction of OPCs from rodent tissue have been described, ranging from neurosphere derivation, differential adhesion purification and immunopurification 1-3. While many methods offer success, most require extensive culture times and/or costly equipment/reagents. To circumvent this, purifying OPCs from murine tissue with an adaptation of the method originally described by McCarthy &amp; 
de Vellis 2 is preferred. This method involves physically separating OPCs from a mixed glial culture derived from neonatal rodent cortices. The result is a purified OPC population that can be differentiated into an OL-enriched culture. This approach is appealing due to its relatively short culture time and the unnecessary requirement for growth factors or immunopanning antibodies. 
While exploring the mechanisms of OL development in a purified culture is informative, it does not provide the most physiologically relevant environment for assessing myelin sheath formation. Co-culturing OLs with neurons would lend insight into the molecular underpinnings regulating OL-mediated myelination of axons. For many OL/neuron co-culture studies, dorsal root ganglion neurons (DRGNs) have proven to be the neuron type of choice. They are ideal for co-culture with OLs due to their ease of extraction, minimal amount of contaminating cells, and formation of dense neurite beds. While studies using rat/mouse myelinating xenocultures have been published 4-6, a method for the derivation of such OL/DRGN myelinating co-cultures from post-natal murine tissue has not been described. Here we present detailed methods on how to effectively produce such cultures, along with examples of expected results. These methods are useful for addressing questions relevant to OL development/myelinating function, and are useful tools in the field of neuroscience.

This article describes methods to derive enriched populations of murine oligodendrocyte precursor cells (OPCs) in primary culture, which differentiate to produce mature oligodendrocytes (OLs). In addition, this report describes techniques to produce murine myelinating co-cultures by seeding mouse OPCs onto a neurite bed of mouse dorsal root ganglion neurons (DRGNs).

Identifying the molecular mechanisms underlying OL development is not only critical to furthering our knowledge of OL biology, but also has implications ...

Progenitor-derived Oligodendrocyte Culture System from Human Fetal Brain

Differentiation of human neural progenitors into neuronal and glial cell types offers a model to study and compare molecular regulation of neural cell lineage development. In vitro expansion of neural progenitors from fetal CNS tissue has been well characterized. Despite the identification and isolation of glial progenitors from adult human sub-cortical white matter and development of various culture conditions to direct differentiation of fetal neural progenitors into myelin producing oligodendrocytes, acquiring sufficient human oligodendrocytes for in vitro experimentation remains difficult. Differentiation of galactocerebroside+ (GalC) and O4+ oligodendrocyte precursor or progenitor cells (OPC) from neural precursor cells has been reported using second trimester fetal brain. However, these cells do not proliferate in the absence of support cells including astrocytes and neurons, and are lost quickly over time in culture. The need remains for a culture system to produce cells of the oligodendrocyte lineage suitable for in vitro experimentation.
Culture of primary human oligodendrocytes could, for example, be a useful model to study the pathogenesis of neurotropic infectious agents like the human polyomavirus, JCV, that in vivo infects those cells. These cultured cells could also provide models of other demyelinating diseases of the central nervous system (CNS). Primary, human fetal brain-derived, multipotential neural progenitor cells proliferate in vitro while maintaining the capacity to differentiate into neurons (progenitor-derived neurons, PDN) and astrocytes (progenitor-derived astrocytes, PDA) This study shows that neural progenitors can be induced to differentiate through many of the stages of oligodendrocytic lineage development (progenitor-derived oligodendrocytes, PDO). We culture neural progenitor cells in DMEM-F12 serum-free media supplemented with basic fibroblast growth factor (bFGF), platelet derived growth factor (PDGF-AA), Sonic hedgehog (Shh), neurotrophic factor 3 (NT-3), N-2 and triiodothyronine (T3). The cultured cells are passaged at 2.5e6 cells per 75cm flasks approximately every seven days. Using these conditions, the majority of the cells in culture maintain a morphology characterized by few processes and express markers of pre-oligodendrocyte cells, such as A2B5 and O-4. When we remove the four growth factors (GF) (bFGF, PDGF-AA, Shh, NT-3) and add conditioned media from PDN, the cells start to acquire more processes and express markers specific of oligodendrocyte differentiation, such as GalC and myelin basic protein (MBP). We performed phenotypic characterization using multicolor flow cytometry to identify unique markers of oligodendrocyte.

Primary, human fetal brain-derived, multipotential progenitor cells proliferate in vitro while maintaining the capacity to differentiate into neurons and astrocytes. This work shows that neural progenitors can be induced to differentiate through stages of the oligodendrocytic lineage by conditioning with select growth factors.

Differentiation of human neural progenitors into neuronal and glial cell types offers a model to study and compare molecular regulation of neural cell ...

Generation of Human Neurons and Oligodendrocytes from Pluripotent Stem Cells for Modeling Neuron-Oligodendrocyte Interactions

In Alzheimer&#8217;s disease (AD) and other neurodegenerative disorders, oligodendroglial failure is a common early pathological feature, but how it contributes to disease development and progression, particularly in the gray matter of the brain, remains largely unknown. The dysfunction of oligodendrocyte lineage cells is hallmarked by deficiencies in myelination and impaired self-renewal of oligodendrocyte precursor cells (OPCs). These two defects are caused at least in part by the disruption of interactions between neuron and oligodendrocytes along the buildup of pathology. OPCs give rise to myelinating oligodendrocytes during CNS development. In the mature brain cortex, OPCs are the major proliferative cells (comprising ~5% of total brain cells) and control new myelin formation in a neural activity-dependent manner. Such neuron-to-oligodendrocyte communications are significantly understudied, especially in the context of neurodegenerative conditions such as AD, due to the lack of appropriate tools. In recent years, our group and others have made significant progress to improve currently available protocols to generate functional neurons and oligodendrocytes individually from human pluripotent stem cells. In this manuscript, we describe our optimized procedures, including the establishment of a co-culture system to model the neuron-oligodendrocyte connections. Our illustrative results suggest an unexpected contribution from OPCs/oligodendrocytes to the brain amyloidosis and synapse integrity and highlight the utility of this methodology for AD research. This reductionist approach is a powerful tool to dissect the specific hetero-cellular interactions out of the inherent complexity inside the brain. The protocols we describe here are expected to facilitate future studies on oligodendroglial defects in the pathogenesis of neurodegeneration.

The neuron-glial interactions in neurodegeneration are not well understood due to inadequate tools and methods. Here, we describe optimized protocols to obtain induced neurons, oligodendrocyte precursor cells, and oligodendrocytes from human pluripotent stem cells and provide examples of the values of these methods in understanding cell-type-specific contributions in Alzheimer&#8217;s disease.

In Alzheimer&#8217;s disease (AD) and other neurodegenerative disorders, oligodendroglial failure is a common early pathological feature, but how it ...

A Co-culture Method to Model Neuron-Oligodendrocyte Interactions

Source: Assetta, B.,et al. <a href="https://app-jove-com.remotexs.ntu.edu.sg/v/61778">Generation of Human Neurons and Oligodendrocytes from Pluripotent Stem Cells for Modeling Neuron-Oligodendrocyte Interactions.</a> J. Vis. Exp. (2020).
This video demonstrates the establishment of a co-culture of human induced neurons (iNs) and induced oligodendrocyte precursor cells (iOPCs). iNs are mixed with iOPCs in a co-culture and then incubated to support the maturation of both iNs into neurons and iOPCs into oligodendrocytes. Neurons form synaptic connections with other neurons and oligodendrocytes, while oligodendrocytes develop myelin sheaths around the neurons&#39; axons.

1. Human neuron induction from human pluripotent stem cells

	Lentivirus preparation (~5 days)
	
		Plate ~1 million Human embryonic kidney 293T (HEK293T) ...

JoVE Encyclopedia of Experiments

Neuronal Culture Techniques

Co-culture and Interaction Studies

Obtaining a Mixed Oligodendrocyte and Astrocyte Culture From Adult Mouse Neural Stem Cells

Source: Baldassarro, V. A. <a href="https://app-jove-com.remotexs.ntu.edu.sg/v/61988">High-Content Screening Differentiation and Maturation Analysis of Fetal and Adult Neural Stem Cell-Derived Oligodendrocyte Precursor Cell Cultures.</a> J. Vis. Exp. (2021)
This video demonstrates a detailed protocol for isolating the lateral ventricle walls from the adult mouse brain and performing enzymatic tissue dissociation to obtain single cells. These cells are then subjected to specific culture conditions that selectively enhance the proliferation of neural stem cells and promote their differentiation into co-cultures of oligodendrocytes and astrocytes.

All procedures involving sample collection have been performed in accordance with the institute&#39;s IRB guidelines.
1. Solutions and reagents

	Prepare ...

Primary Neuronal Culture

Isolating and Culturing Oligodendrocyte Precursor Cells from Mouse Pup Brain Cortex

Source: Sinyuk, M., et al. <a href="https://app-jove-com.remotexs.ntu.edu.sg/v/61345">Dissection and Isolation of Murine Glia from Multiple Central Nervous System Regions.</a> J. Vis. Exp. (2020)
This video demonstrates a technique for isolating and culturing oligodendrocyte precursor cells (OPCs) from the mouse pup brain cortex.

All procedures involving sample collection have been performed in accordance with the institute&#39;s IRB guidelines.
1. Tissue dissociation
NOTE: All the ...

Differentiating Human Embryonic Stem Cells into Oligodendrocytes

Source: Assetta, B., et al. <a href="https://app-jove-com.remotexs.ntu.edu.sg/v/61778">Generation of Human Neurons and Oligodendrocytes from Pluripotent Stem Cells for Modeling Neuron-Oligodendrocyte Interactions.</a> J. Vis. Exp (2020).
This video demonstrates the process of generating oligodendrocyte precursor cells (OPCs) from human embryonic stem cells, followed by the maturation of OPCs to oligodendrocytes. This process of generating oligodendrocytes opens numerous avenues to improve research and treatment of neurodegenerative diseases, including Alzheimer&#39;s.

1. Human oligodendrocyte precursor cell (OPC) induction from pluripotent stem cells and oligodendrocyte maturation

	Neural Progenitor Cell (NPC) ...

Advanced Neuronal Models

An In Vitro Transduction-Induced Myelination Assay for Oligodendrocyte Precursor Cells

Source: Peckham, H. M., et al. <a href="https://app-jove-com.remotexs.ntu.edu.sg/v/52179">Production and Use of Lentivirus to Selectively Transduce Primary Oligodendrocyte Precursor Cells for In Vitro Myelination Assays.</a> J. Vis. Exp. (2015).
The video demonstrates a protocol for differentiating oligodendrocyte precursor cells (OPCs) into oligodendrocytes and inducing myelination in a co-culture with dorsal root ganglion (DRG) neurons. The OPCs are transduced with lentiviral vectors encoding a signaling protein that regulates myelination. The transduced OPCs are co-cultured with DRG neurons to assess the differentiation into oligodendrocytes and the signaling protein-induced myelination.

1. Cloning of 2K7 Lentivector

	Before cloning the gene of interest into the 2K7 lentiviral vector, subclone the gene into the pENTR vector (3637 bp, ...

Generation of Oligodendrocytes and Oligodendrocyte-Conditioned Medium for Co-Culture Experiments

Samenvatting

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