Name: spinal cord neurons isolation and culture from neonatal mice
Uploaded: 2017-07-11T15:00:00
Description: Watch this Scientific Journal Video about Spinal Cord Neurons Isolation and Culture from Neonatal Mice at JoVE.com

The authors have no acknowledgements.

The care and treatment of animals in this procedure were conducted in accordance with the guidelines of the Institutional Animal Care and Use Committee at the University of Colorado.
1. Preparing Solutions
<ol>
	<li>Prepare and store all solutions at appropriate temperatures, as shown in Table 1.</li>
</ol>
2. Coating Wells and Slides
NOTE: Neurons do not adhere well to plastic or glass surfaces.
<ol>
	<li>One day prior t...

<ol>
	<li>Qayumi, A. 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=Animal+model+for+investigation+of+spinal+cord+injury+caused+by+aortic+cross-clamping.">Animal model for investigation of spinal cord injury caused by aortic cross-clamping.</a> J Invest Surg. 10 (1-2), 47-52 (1997).</li><li>Fang, B., 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=Ischemic+preconditioning+protects+against+spinal+cord+ischemia-reperfusion+injury+in+rabbits+by+attenuating+blood+spinal+cord+barrier+disruption.">Ischemic preconditioning protects against spinal cord ischemia-reperfusion injury in rabbits by attenuating blood spinal cord barrier disruption.</a> Int J Mol Sci. 14 (5), 10343-10354 (2013).</li><li>Taira, Y., Marsala, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+proximal+arterial+perfusion+pressure+on+function,+spinal+cord+blood+flow,+and+histopathologic+changes+after+increasing+intervals+of+aortic+occlusion+in+the+rat.">Effect of proximal arterial perfusion pressure on function, spinal cord blood flow, and histopathologic changes after increasing intervals of aortic occlusion in the rat.</a> Stroke. 27 (10), 1850-1858 (1996).</li><li>Stoppini, L., Buchs, P. -. 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R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+culture+of+adult+neurons+and+neurospheres.">Isolation and culture of adult neurons and neurospheres.</a> Nat Protoc. 2 (6), 1490-1498 (2007).</li><li>Banker, G. A., Cowan, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+hippocampal+neurons+in+dispersed+cell+culture.">Rat hippocampal neurons in dispersed cell culture.</a> Brain Res. 126 (3), 397-425 (1977).</li><li>Graber, D. J., Harris, B. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+and+culture+of+spinal+motor+neurons+from+rat+embryos.">Purification and culture of spinal motor neurons from rat embryos.</a> Cold Spring Harb Protoc. 2013 (4), 319-326 (2013).</li><li>Anderson, K. N., Potter, A. C., Piccenna, L. G., Quah, A. K., Davies, K. E., Cheema, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+culture+of+motor+neurons+from+the+newborn+mouse+spinal+cord.">Isolation and culture of motor neurons from the newborn mouse spinal cord.</a> Brain Res Prot. 12 (3), 132-136 (2004).</li><li>Gingras, M., Gagnon, V., Minotti, S., Durham, H. D., Berthod, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+protocols+for+isolation+of+primary+motor+neurons,+astrocytes+and+microglia+from+embryonic+mouse+spinal+cord.">Optimized protocols for isolation of primary motor neurons, astrocytes and microglia from embryonic mouse spinal cord.</a> J Neurosci Methods. 163 (1), 111-118 (2007).</li><li>Brewer, G. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+survival+of+hippocampal+neurons+in+B27-supplemented+Neurobasal,+a+new+serum-free+medium+combination.">Optimized survival of hippocampal neurons in B27-supplemented Neurobasal, a new serum-free medium combination.</a> J Neurosci Res. 35 (5), 567-576 (1993).</li><li>Fang, B., 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=Ischemic+preconditioning+protects+against+spinal+cord+ischemia-reperfusion+injury+in+rabbits+by+attenuating+blood+spinal+cord+barrier+disruption.">Ischemic preconditioning protects against spinal cord ischemia-reperfusion injury in rabbits by attenuating blood spinal cord barrier disruption.</a> Int J Mol Sci. 14 (5), 10343-10354 (2013).</li><li>Su, M., Zhong, W., Ren, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dose-dependent+protection+of+reseveratrol+against+spinal+cord+ischemic-reperfusion+injury+in+rats.">Dose-dependent protection of reseveratrol against spinal cord ischemic-reperfusion injury in rats.</a> Trop J Pharm Res. 15 (6), 1225-1233 (2016).</li><li>Haapanen, H., 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=Remote+ischemic+preconditioning+protects+the+spinal+cord+against+ischemic+insult:+An+experimental+study+in+a+porcine+model.">Remote ischemic preconditioning protects the spinal cord against ischemic insult: An experimental study in a porcine model.</a> J Thorac Cardiovasc Surg. 151 (3), 777-785 (2016).</li><li>Conrad, M. F., Ye, J. Y., Chung, T. K., Davison, J. K., Cambria, R. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+complications+after+thoracic+aortic+surgery:+long-term+survival+and+functional+status+varies+with+deficit+severity.">Spinal cord complications after thoracic aortic surgery: long-term survival and functional status varies with deficit severity.</a> J Vasc Surg. 48 (1), 47-53 (2008).</li><li>Wong, D. R., 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=Delayed+spinal+cord+deficits+after+thoracoabdominal+aortic+aneurysm+repair.">Delayed spinal cord deficits after thoracoabdominal aortic aneurysm repair.</a> Ann Thorac Surg. 83 (4), 1345-1355 (2007).</li><li>Freeman, K. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-2+agonist+attenuates+ischemic+injury+in+spinal+cord+neurons.">Alpha-2 agonist attenuates ischemic injury in spinal cord neurons.</a> J Surg Res. 195 (1), 21-28 (2015).</li><li>Freeman, K. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+protection+via+alpha-2+agonist-mediated+increase+in+glial+cell-line-derived+neurotrophic+factor.">Spinal cord protection via alpha-2 agonist-mediated increase in glial cell-line-derived neurotrophic factor.</a> J Thorac Cardiovasc Surg. 149 (2), 578-586 (2015).</li></ol>

This technique allows for the reliable culture of spinal cord neurons. Once proficiency in the technique is achieved, it takes approximately 3.5 h to complete. We have been able to carry out the isolation of neurons from 2 separate litters (16 mice total) in approximately 4 h. The key step in feasibility is being able to proficiently extract the spinal cords from the mice. The yield allows for plating several wells and for the ability to test the neurons under various conditions. We have been able to treat the neurons af...

Understanding spinal cord pathology requires the use of various models, both on the macroscopic and microscopic levels. Large and small animal models1,2,3 are used for in vivo investigations of spinal cord disease and injury. While studying these issues in vivo has its merits, analysis of the spinal cord is limited to whole spinal cord homogenate or to tissue sections4. This creates some ambiguity when trying to isolate specific responses and targets in the spinal cord among its resident neurons and surrounding glia. The increasing availability of genetically manipulated mice allows for more detailed investigations of the biology at cellular and molecular levels. Thus, a neonatal mouse model is used here, allowing for the study of the unique properties and biology of spinal cord neurons in vitro.
The isolation and maintenance of neurons in vitro is not particularly straightforward. There is a relative abundance of techniques for neuron isolation from the cortical tissue of adult rodents that seem to result in a substantial number of isolated neurons (i.e.&#160;millions)5,6,7. In contrast, the yield of neurons from spinal cord tissue is lower8,9,10, in part due to the smaller mass of tissue. Furthermore, in mice, there is a relative paucity of techniques for the isolation of neonatal spinal cord neurons, and existing methods are limited by lower neuron yields (i.e.&#160;hundreds)9 or laborious and resource-heavy techniques requiring the isolation of embryonic mice10.
In this protocol, we use a technique that allows for the cost- and resource-effective isolation of a substantial number of neurons from the spinal cords of neonatal mice. As is common in previously published techniques, we use papain as an enzymatic protease, allowing for the release of neurons from the spinal cord tissue5,6 . In addition, we use a density gradient for refined cell separation, which has previously been shown to be effective6,10. While the medium in which the cells are incubated can vary, in our experience and as previously published11, supplementation with fresh B27 culture medium supplement has proven to be critical for neuron longevity. The neurons are typically viable for up to 10 days, allowing for treatment to be carried out.

<table border="0" cellpadding="0" cellspacing="0" width="1357">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:331px;">Hibernate A Medium - 500 mL</td>
			<td style="width:116px;">Thermo-Fisher</td>
			<td style="width:107px;">A1247501</td>
			<td style="width:805px;">https://www.thermofisher.com/order/catalog/product/A1247501</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hibernate A Minus Calcium - 500 mL</td>
			<td style="width:116px;">Brainbits</td>
			<td>HA-Ca</td>
			<td>http://www.brainbitsllc.com/hibernate-a-minus-calcium/</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glutamax 100X - 100 mL</td>
			<td style="width:116px;">Thermo-Fisher</td>
			<td>35050061</td>
			<td>https://www.thermofisher.com/order/catalog/product/35050079</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">B27 Supplement 50X - 10 mL</td>
			<td style="width:116px;">Thermo-Fisher</td>
			<td>17504044</td>
			<td>https://www.thermofisher.com/order/catalog/product/17504044</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Papain, Lyophilized - 100 mg</td>
			<td style="width:116px;">Worthington</td>
			<td>LS003119</td>
			<td>http://www.worthington-biochem.com/pap/cat.html</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Neurobasal A Medium - 500 mL</td>
			<td style="width:116px;">Thermo-Fisher</td>
			<td>10888022</td>
			<td>https://www.thermofisher.com/order/catalog/product/10888022</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Penicillin-Streptomycin (10,000 U/mL)</td>
			<td style="width:116px;">Thermo-Fisher</td>
			<td>15140122</td>
			<td>https://www.thermofisher.com/order/catalog/product/15140122</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Poly-D-lysine hydrobromide - 5 mg</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>P6407-5MG</td>
			<td>http://www.sigmaaldrich.com/catalog/product/sigma/p6407?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mouse Laminin - 1 mg</td>
			<td style="width:116px;">Thermo-Fisher</td>
			<td>23017015</td>
			<td>https://www.thermofisher.com/order/catalog/product/23017015</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Trypan Blue - 20 mL</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>T8154-20ML</td>
			<td>http://www.sigmaaldrich.com/catalog/product/sigma/t8154?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">OptiPrep Density Gradient Medium - 250 mL</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>D1556-250ML</td>
			<td>http://www.sigmaaldrich.com/catalog/product/sigma/d1556?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dichlorodimethylsilane (DMDCS, Sigma Silicoat)</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>440272-100ML</td>
			<td>http://www.sigmaaldrich.com/catalog/product/aldrich/440272?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Chloroform</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>288306-1L</td>
			<td>http://www.sigmaaldrich.com/catalog/product/sial/288306?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:331px;">Glass Pippette - 9&#34;</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td style="width:107px;">13-678-20C</td>
			<td>http://www.sigmaaldrich.com/catalog/product/sigma/cls7095d9?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pipette bulb - 5 mL</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>Z186678-3EA</td>
			<td>http://www.sigmaaldrich.com/catalog/product/aldrich/z186678?lang=en&#38;region=US&#38;cm_sp=Insite-_-prodRecCold_xviews-_-prodRecCold10-1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BRAND&#174;&#160;Petri dish, glass - 60x15 mm</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>BR455717-10EA</td>
			<td>http://www.sigmaaldrich.com/catalog/product/aldrich/br455717?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sterile 24 Well Cell Culture Plate</td>
			<td style="width:116px;">Sigma-Aldrich</td>
			<td>M8812-100EA</td>
			<td>http://www.sigmaaldrich.com/catalog/product/sigma/m8812?lang=en&#38;region=US</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Hausser Hemacytometer (glass counting chamber)</td>
			<td style="width:116px;">Fischer Scientific</td>
			<td>02-671-6</td>
			<td>https://www.fishersci.com/shop/products/hausser-bright-line-phase-hemacytometer-hemacytometer/026716</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Glass Slides - 12 mm sterile cover glass - uncoated</td>
			<td>Neuvitro</td>
			<td>GG-12-1.5-Pre</td>
			<td>http://www.neuvitro.com/german-coverslip-12mm-diameter.htm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NeuN Rabbit Monoclonal Antibody - 100 &#181;L</td>
			<td style="width:116px;">Abcam</td>
			<td>ab177487</td>
			<td>After fixing in paraformaldehyde and blocking with 5% BSA, cells on a 12 mm coverslip were incubated in the antibody diluded to 1:200 for 18 hours in 4 &#176;C</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MAP-2 Mouse Monoclonal Antibody - 50 &#181;L</td>
			<td style="width:116px;">Abcam</td>
			<td>ab11267</td>
			<td>After fixing in paraformaldehyde and blocking with 5% BSA, cells on a 12 mm coverslip were incubated in the antibody diluded to 1:500 for 18 hours in 4 &#176;C</td>
		</tr>
	</tbody>
</table>

spinal cord neurons isolation and culture from neonatal mice

We present a protocol for the isolation and culture of spinal cord neurons. The neurons are obtained from neonatal C57BL/6 mice and are isolated on postnatal day 1-3. A mouse litter, usually 4-10 pups born from one breeding pair, is gathered for one experiment, and spinal cords are collected individually from each mouse after euthanasia with isoflurane. The spinal column is dissected out and then the spinal cord is released from the column. The spinal cords are then minced to increase the surface area of delivery for an enzymatic protease that allows for the neurons and other cells to be released from the tissue. Trituration is then used to release the cells into solution. This solution is subsequently fractionated in a density gradient to separate the various cells in solution, allowing for neurons to be isolated. Approximately 1-2.5 x 106 neurons can be isolated from one litter group. The neurons are then seeded onto wells coated with adhesive factors that allow for proper growth and maturation. The neurons take approximately 7 days to reach maturity in the growth and culture medium and can be used thereafter for treatment and analysis.

Using this technique, a single litter (4-10 pups) allows for the isolation of 1-2.5 106 neurons suitable for seeding onto culture plates. Typically, 4-8 wells are seeded at the concentration mentioned above (i.e.&#160;300,000 cells/mL). Figure 3 demonstrates the appearance of neurons at this concentration after a week in culture at low- (a) and high- (b) magnification light microscopy. However, we have als...

Watch this Scientific Journal Video about Spinal Cord Neurons Isolation and Culture from Neonatal Mice at JoVE.com

Spinal Cord Neurons Isolation and Culture from Neonatal Mice

This study presents a technique for the isolation of neurons from WT neonatal mice. It requires the careful dissection of the spinal cord from the neonatal mouse, followed by the separation of neurons from the spinal cord tissue through mechanical and enzymatic cleavage.

We present a protocol for the isolation and culture of spinal cord neurons. The neurons are obtained from neonatal C57BL/6 mice and are isolated on ...

The overall goal of this procedure is to be able to repeatedly and consistently isolate spinal cord neurons that can be used in a variety of experiments. This method can allow us to gain better insight into the biology of spinal cord neurons and hopefully understand their response to a variety of stressors. The main advantage of this technique is, that it allows for the isolation of a significant number of neurons, allowing those neurons to be used in a wide variety of experiments.Visual demonstration of this method is critical as the trituration step where neurons are mechanically isolated from the tissue, requires some time to master, in order to ensure healthy neuron isolation, without killing them. To begin this procedure, separate the head from the body of the euthanized mouse pups, using scissors. Next, stabilize the tail and arms on the procedure table with the dorsal side facing up.Then, cut the skin off using the curved iris scissors. After that, cut the spinal cord from the lumbar region, just above the hips and then cut both sides of the thorax to separate it from the body. Wash the samples sequentially in three 10 centimeter petri dishes, containing five milliliters of sterilized PBS for 10 seconds each, to remove excess tissue.Subsequently, insert a 22 gauge needle and syringe filled with five milliliters of sterilized PBS into the caudal end of the spinal column and flush cranially, allowing the cord to exit into a fourth petri dish. Transfer the spinal cord in a 15 milliliter tube with five milliliters of HABG on ice. Avoid crushing the spinal cord and repeat the procedures for the rest of the pups.Ideally, this process should take no more than 30 minutes for one group of pups, to ensure neuron isolation. To prepare the density gradient, prepare each of the four layers in four 15 milliliter tubes. Then, add one milliliter of each layer into a new 15 milliliter tube.Start with layer one at the bottom, and add sequentially, until reaching layer four at the top. Avoid disturbing the layers while adding and any vigorous movements, that may cause mixing. Next, add the digestion media to the minced tissue.Place the sample in a shaker in the water bath at 30 degrees celsius. Afterward, remove the tissue from the water bath and allow it to settle for a few minutes. To perform trituration, aspirate the excess digestion medium.Suspend the tissue in two milliliters of HABG, using a narrow-bore pipette, triturate 10 times in 45 seconds and avoid introducing air, as it would significantly decrease the viable yield. Trituration is one of the most critical steps of the procedure, the tissue should be carefully drawn into and emptied from the fire polished pipette, avoiding excess vigor which can lead to neuronal death or being too gentle, which would result in a low yield. Following that, aspirate the top two milliliters of the supernatant and transfer it into a new 15 milliliter tube labeled, collection.Repeat the collection procedures two more times, to yield six milliliters of supernatant. Next, slowly transfer the collection tube contents into the gradient tube prepared previously. Avoiding the disruption of the gradient.To purify the neurons, centrifuge the gradient tube for 15 minutes at 800 times G, at 22 degrees celsius. Collect the desired layers and transfer them in a new 15 milliliter tube. For the highest purity neuron isolation, collect layer three.For more yield with less purity, collect layers two to three. Next, dilute the density gradient by adding five milliliters of HABG to the newly collected layers. Centrifuge it, at 200 times G for two minutes at 22 degrees celsius.After two minutes, discard the supernatant and re-suspend the cells in five milliliters of HABG, by flicking the palate. Subsequently, centrifuge the sample at 200 times G for two minutes at 22 degrees celsius again. Then, discard the supernatant and re-suspend the cells in three milliliters of neurobasal medium, by flicking the palate.After that, determine the cell density using a cell counter and then, dilute the suspension to 300, 000 cells per one milliliter of neurobasal medium. Shake gently to distribute the cells and solution and add one milliliter of the sample to each well in the coded 24 well plates. Shown here, is the time course of the neurons in culture, after seeding onto the wells.The cells will typically start adhering to the surface within the first couple of hours. Axons will begin to sprout within the first 24 to 48 hours, connections between various neurons and culture, typically reach maturity at seven days, at which point, experiments are typically carried out on the neurons. In this figure, nuclear staining is shown in blue, with cytoplasmic staining in green and here, the neuron cyctoskeletal protein microtubular associated protein two is stained, showing the outlines and axonal projections of the neurons after a week in culture.The merge images are combined, showing the relative abundance of the neurons. Once mastered, this technique can be done in three to four hours, if it is perform properly. After its development, this technique paves the way for researchers, studying the spinal cord physiology and pathology, to explore the behavior of spinal cord neurons under normal conditions and in response to for pharmacological agents or stressors such as, oxygen and glucose deprivation, just mimicking our surgical procedures.While taking on this procedure, it is important to avoid delaying or prolonging any of the steps to prevent isolation of unhealthy neurons. After watching this video, you should have a good understanding of how to isolate healthy and viable neurons from the spinal cords of neonatal mice that can be cultured in serum free media.

spinal-cord-neurons-isolation-and-culture-from-neonatal-mice

Research

JoVE Journal

Neuroscience

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 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 ...

Chicken Embryo Spinal Cord Slice Culture Protocol

Slice cultures can facilitate the manipulation of embryo development both pharmacologically and through gene manipulations. In this reduced system, potential lethal side effects due to systemic drug applications can be overcome. However, culture conditions must ensure that normal development proceeds within the reduced environment of the slice. We have focused on the development of the spinal cord, particularly that of spinal motor neurons. We systematically varied culture conditions of chicken embryo slices from the point at which most spinal motor neurons had been born. We assayed the number and type of motor neurons that survived during the culture period and the position of those motor neurons compared to that in vivo. We found that serum type and neurotrophic factors were required during the culture period and were able to keep motor neurons alive for at least 24 hr and allow those motor neurons to migrate to appropriate positions in the spinal cord. We present these culture conditions and the methodology of preparing the embryo slice cultures using eviscerated chicken embryos embedded in agarose and sliced using a vibratome.

Slice cultures facilitate the manipulation of embryo development by gene and pharmacological perturbations. However, culture conditions must ensure that normal development can proceed within the reduced environment of the slice. We illustrate a protocol that facilitates normal spinal cord development to proceed for at least 24 hr.

Slice cultures can facilitate the manipulation of  embryo development both pharmacologically and through gene manipulations. In  this reduced system, ...

Isolation and Culture of Dissociated Sensory Neurons From Chick Embryos

Neurons are multifaceted cells that carry information essential for a variety of functions including sensation, motor movement, learning, and memory. Studying neurons in vivo can be challenging due to their complexity, their varied and dynamic environments, and technical limitations. For these reasons, studying neurons in vitro can prove beneficial to unravel the complex mysteries of neurons. The well-defined nature of cell culture models provides detailed control over environmental conditions and variables. Here we describe how to isolate, dissociate, and culture primary neurons from chick embryos. This technique is rapid, inexpensive, and generates robustly growing sensory neurons. The procedure consistently produces cultures that are highly enriched for neurons and has very few non-neuronal cells (less than 5%). Primary neurons do not adhere well to untreated glass or tissue culture plastic, therefore detailed procedures to create two distinct, well-defined laminin-containing substrata for neuronal plating are described. Cultured neurons are highly amenable to multiple cellular and molecular techniques, including co-immunoprecipitation, live cell imagining, RNAi, and immunocytochemistry. Procedures for double immunocytochemistry on these cultured neurons have been optimized and described here.

Cell culture models provide detailed control over environmental conditions and thus provide a powerful platform to elucidate numerous aspects of neuronal cell biology. We describe a rapid, inexpensive, and reliable method to isolate, dissociate, and culture sensory neurons from chick embryos. Details of substrata preparation and immunocytochemistry are also provided.

Neurons are multifaceted cells that carry information essential for a variety of functions including sensation, motor movement, learning, and memory. ...

Zebrafish In Situ Spinal Cord Preparation for Electrophysiological Recordings from Spinal Sensory and Motor Neurons

Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing organisms, combined with the embryonic optical clarity, served as initial compelling attributes of this model. Over the past two decades, the success of this model has been further propelled by its amenability to large-scale mutagenesis screens and by the ease of transgenesis. More recently, gene-editing approaches have extended the power of the model.
For neurodevelopmental studies, the zebrafish embryo and larva provide a model to which multiple methods can be applied. Here, we focus on methods that allow the study of an essential property of neurons, electrical excitability. Our preparation for the electrophysiological study of zebrafish spinal neurons involves the use of veterinarian suture glue to secure the preparation to a recording chamber. Alternative methods for recording from zebrafish embryos and larvae involve the attachment of the preparation to the chamber using a fine tungsten pin1,2,3,4,5. A tungsten pin is most often used to mount the preparation in a lateral orientation, although it has been used to mount larvae dorsal-side up4. The suture glue has been used to mount embryos and larvae in both orientations. Using the glue, a minimal dissection can be performed, allowing access to spinal neurons without the use of an enzymatic treatment, thereby avoiding any resultant damage. However, for larvae, it is necessary to apply a brief enzyme treatment to remove the muscle tissue surrounding the spinal cord. The methods described here have been used to study the intrinsic electrical properties of motor neurons, interneurons, and sensory neurons at several developmental stages6,7,8,9.

Zebrafish In Situ Spinal Cord Preparation for Electrophysiological Recordings from Spinal Sensory and Motor Neurons

This manuscript describes methods for electrophysiological recordings from spinal neurons of zebrafish embryos and larvae. The preparation maintains neurons in situ and often involves minimum dissection. These methods allow for the electrophysiological study of a variety of spinal neurons, from the initial electrical excitability acquisition through the early larval stages.

Zebrafish, first introduced as a developmental model, have gained popularity in many other fields. The ease of rearing large numbers of rapidly developing ...

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in adult mammalian animals remains elusive. In this study, we describe an experimental procedure for measuring calcium dynamics through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy. This method enables recordings and quantifications of neural activity in bilateral mouse brain regions one at a time in the same experiment for a prolonged period in vivo. Key aspects of this method, which can be completed within an hour, include minimally invasive surgery procedures for creating dual optical windows, and the use of 2P imaging. Although we only demonstrate the technique in the S1 area, the method can be applied to other regions of the living brain facilitating the elucidation of structural and functional complexities of brain neural networks.

Imaging Neural Activity in the Primary Somatosensory Cortex Using Thy1-GCaMP6s Transgenic Mice

We describe an experimental procedure for measuring neuronal activity through dual optical windows above bilateral primary somatosensory corticies (S1) in Thy1-GCaMP6s transgenic mice using 2-photon (2P) microscopy in vivo.

The mammalian brain exhibits marked symmetry across the sagittal plane. However, detailed description of neural dynamics in symmetric brain regions in ...

Preparation of Rhythmically-active In Vitro Neonatal Rodent Brainstem-spinal Cord and Thin Slice

Mammalian inspiratory rhythm is generated from a neuronal network in a region of the medulla called the preB&#246;tzinger complex (pBC), which produces a signal driving the rhythmic contraction of inspiratory muscles. Rhythmic neural activity generated in the pBC and carried to other neuronal pools to drive the musculature of breathing may be studied using various approaches, including en bloc nerve recordings and transverse slice recordings. However, previously published methods have not extensively described the brainstem-spinal cord dissection process in a transparent and reproducible manner for future studies. Here, we present a comprehensive overview of a method used to reproducibly cut rhythmically-active brainstem slices containing the necessary and sufficient neuronal circuitry for generating and transmitting inspiratory drive. This work builds upon previous brainstem-spinal cord electrophysiology protocols to enhance the likelihood of reliably obtaining viable and rhythmically-active slices for recording neuronal output from the pBC, hypoglossal premotor neurons (XII pMN), and hypoglossal motor neurons (XII MN). The work presented expands upon previous published methods by providing detailed, step-by-step illustrations of the dissection, from whole rat pup, to in vitro slice containing the XII rootlets.

This protocol both visually communicates the brainstem-spinal cord preparation and clarifies the preparation of brainstem transverse slices in a comprehensive step-by-step manner. It was designed to increase reproducibility and enhance the likelihood of obtaining viable, long lasting, rhythmically-active slices for recording neural output from the respiratory regions of the brainstem.

Mammalian inspiratory rhythm is generated from a neuronal network in a region of the medulla called the preB&#246;tzinger complex (pBC), which produces a ...

Isolation and Culture of Oculomotor, Trochlear, and Spinal Motor Neurons from Prenatal Islmn:GFP Transgenic Mice

Oculomotor neurons (CN3s) and trochlear neurons (CN4s) exhibit remarkable resistance to degenerative motor neuron diseases such as amyotrophic lateral sclerosis (ALS) when compared to spinal motor neurons (SMNs). The ability to isolate and culture primary mouse CN3s, CN4s, and SMNs would provide an approach to study mechanisms underlying this selective vulnerability. To date, most protocols use heterogeneous cell cultures, which can confound the interpretation of experimental outcomes. To minimize the problems associated with mixed-cell populations, pure cultures are indispensable. Here, the first protocol describes in detail how to efficiently purify and cultivate CN3s/CN4s alongside SMNs counterparts from the same embryos using embryonic day 11.5 (E11.5) IslMN:GFP transgenic mouse embryos. The protocol provides details on the tissue dissection and dissociation, FACS-based cell isolation, and in vitro cultivation of cells from CN3/CN4 and SMN nuclei. This protocol adds a novel in vitro CN3/CN4 culture system to existing protocols and simultaneously provides a pure species- and age-matched SMN culture for comparison. Analyses focusing on the morphological, cellular, molecular, and electrophysiological characteristics of motor neurons are feasible in this culture system. This protocol will enable research into the mechanisms that define motor neuron development, selective vulnerability, and disease.

Isolation and Culture of Oculomotor, Trochlear, and Spinal Motor Neurons from Prenatal Islmn:GFP Transgenic Mice

This work presents a protocol to yield homogeneous cell cultures of primary oculomotor, trochlear, and spinal motor neurons. These cultures can be used for comparative analyses of the morphological, cellular, molecular, and electrophysiological characteristics of ocular and spinal motor neurons.

Oculomotor neurons (CN3s) and trochlear neurons (CN4s) exhibit remarkable resistance to degenerative motor neuron diseases such as amyotrophic lateral ...

Induction of Complete Transection-Type Spinal Cord Injury in Mice

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, such as cell transplantation methods, are being researched to overcome the debilitating disabilities arising from SCI. Most pre-clinical animal trials are conducted in rodent models of SCI. While rat models of SCI have been widely used, mouse models have received less attention, even though mouse models can have significant advantages over rat models. The small size of mice equates to lower animal maintenance costs than for rats, and the availability of numerous transgenic mouse models is advantageous for many types of studies. Inducing repeatable and precise injury in the animals is the primary challenge for SCI research, which in small rodents requires high-precision surgery. The transection-type injury model has been a commonly used injury model over the last decade for transplantation-based therapeutic research, however a standardized method for inducing a complete transection-type injury in mice does not exist. We have developed a surgical protocol for inducing a complete transection type injury in C57BL/6 mice at thoracic vertebral level 10 (T10). The procedure uses a small tip drill instead of rongeurs to precisely remove the lamina, after which a thin blade with rounded cutting edge is used to induce the spinal cord transection. This method leads to reproducible transection-type injury in small rodents with minimal collateral muscle and bone damage and therefore minimizes confounding factors, specifically where behavioral functional outcomes are analyzed.

This protocol describes how to create a precise laminectomy for induction of stable transection-type spinal cord injury in the mouse model, with minimal collateral damage for spinal cord injury research.

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, ...

Electromagnetic Controlled Closed-Head Model of Mild Traumatic Brain Injury in Mice

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and understanding the mechanisms of how a TBI alters brain function. The availability of multiple animal models of TBI is necessary to model the different aspects and severities of TBI seen in people. This manuscript describes the use of a midline closed head injury (CHI) to develop a mouse model of mild TBI. The model is considered mild because it does not produce structural brain lesions based on neuroimaging or gross neuronal loss. However, a single impact creates enough pathology that cognitive impairment is measurable at least 1 month after injury. A step-by-step protocol to induce a CHI in mice using a stereotaxically guided electromagnetic impactor is defined in the paper. The benefits of the mild midline CHI model include the reproducibility of the injury-induced changes with low mortality. The model has been temporally characterized up to 1 year after the injury for neuroimaging, neurochemical, neuropathological, and behavioral changes. The model is complementary to open skull models of controlled cortical impact using the same impactor device. Thus, labs can model both mild diffuse TBI and focal moderate-to-severe TBI with the same impactor.

The protocol describes mild traumatic brain injury in a mouse model. In particular, a step-by-step protocol to induce a mild midline closed head injury and the characterization of the animal model is fully explained.

Highly reproducible animal models of traumatic brain injury (TBI), with well-defined pathologies, are needed for testing therapeutic interventions and ...