This work was supported by Merit Review grant (NEUD-004-07F) from the Veterans Administration (to S.P).

1. Expansion of Human NPCs (Figure 1)
<ol>
	<li>Revive the frozen stock of human NPCs from fetal brain (Lonza, Walkersville, MD, USA) and culture them in suspension in T-75 flasks as neurospheres (Figure 1A) in neurobasal medium containing proliferation supplements, EGF (10 ng/ml) and FGF (10 ng/ml).</li>
	<li>After 3 days in culture, transfer the neurospheres to a 15 ml tube and centrifuge at 500 rpm for 5 min.</li>
	<li>Discard the supernatant leaving behind ~100 &#956;l medium above the cell pellet and transfer into an Eppendorf tube. A 100 &#956;l cell pellet is enough to split into 2 T-75 flasks. If less, reduce the number of flasks as neuroprogenitor cells fail to proliferate if split thin.</li>
	<li>Triturate the pellet with a 200 &#956;l tip 50x while keeping the 200 &#956;l tip against the bottom of the tube. Divide the cell suspension equally into two parts and add them to 2 T-75 flasks (1-2 split), one for continued expansion and another for differentiation.</li>
	<li>Continue the culture of the neuroprogenitor cells for expansion (first flask) by changing the medium every 4-5 days until the neurospheres reach their original size of 300-500 &#956;m. Change medium by centrifugation (500 rpm; 5 min), discard the old medium and add new medium.</li>
</ol>
2. Differentiation of Human NPCs into a Neuron-rich Culture (Figure 2)
<ol>
	<li>For differentiation of neuroprogenitor cells into a neuron rich culture, place a single coverslip into each well of a 24-well plate and coat with 100 &#956;g/ml of poly-L-lysine by adding 500 &#956;l into each well. Incubate the dishes for 30 min at RT.</li>
	<li>Aspirate the poly-L-lysine solution and rinse the plate with sterile water.</li>
	<li>Next, coat the wells of the plate with 500 &#956;l of 5 &#956;g/ml mouse laminin and incubate for 30 min. Following incubation, wash the wells with PBS.</li>
	<li>4 days after splitting the cells (step 1.4), transfer the small neurospheres in the flask labeled &#39;For differentiation&#39; into the coated dishes at a density of ~500 neurospheres per well of a 24-well plate.</li>
	<li>After 6 hr, when the neurospheres attach to the dish, remove the proliferation medium and add differentiation medium consisting of neurobasal medium, B27 supplement, NGF (20 ng/ml), BDNF (10 ng/ml), DBC (100 mM), and retinoic acid (2 &#956;M).</li>
</ol>
3. Immunofluorescence Staining of Differentiated NPCs (Figure 3)
<ol>
	<li>Following culture of neuroprogenitor cells in neuronal differentiation medium for two weeks, a neuron-rich culture is obtained. Rinse the neurons once in PBS and then fix them in 4% paraformaldehyde for 30 min. Once fixed, rinse the cells three times with PBS.</li>
	<li>Incubate the cells with permeabilization buffer (5% BSA and 0.2% Triton X-100 in PBS) at RT for 60 min.</li>
	<li>Incubate the dishes O/N at 4 &#176;C in a shaker with the following combination of polyclonal and monoclonal antibodies in 3% BSA in PBS: NeuN (1:250) and synapsin (1:250); acetyl cholinesterase (1:500) and synaptophysin (1:250); BDNF (1:500) and GAP43 (1:250); STAT3 (1:500) and GFAP (1:1,000).</li>
	<li>Wash the coverslips three times with PBS and then incubate them with anti-rabbit-Cy3 and anti-mouse-FITC secondary antibodies at RT in dark for 90 min. Following incubation, wash the coverslips three times with PBS.</li>
	<li>Place 10 &#956;l of mounting medium onto a glass slide, take out the coverslip from the culture dish with forceps, and place it upside down on the mounting medium. Gently, wipe away any excess mounting medium and seal the edges with nail polish.</li>
	<li>Examine the immunostained neurons in a fluorescence microscope.</li>
</ol>
4. Laser Capture Microdissection of Neurons (Figure 4)
<ol>
	<li>Differentiate NPCs into a neuron-rich culture on PEN membrane slides coated with poly-L-lysine and mouse laminin following the procedures described for Figure 2.</li>
	<li>Perform all subsequent steps under RNAse-free conditions.</li>
	<li>Stain the cultures using HistoGene Stain (Arcturus) to visualize the cells.</li>
	<li>Find the areas of pure neuronal populations devoid of astrocytes using the road map image of the entire slide with the Veritas LCM system. Mark the neurons using the drawing tools.</li>
	<li>Perform laser capture of these areas using computer-controlled precision and automation in a two-step process. First, IR (Infrared) is fired at multiple spots with a laser power setting of 70 mW and a pulse of 2,500 &#956;sec to get the membrane attach to the cap. Next, the marked area is excised using an UV cutting tool at a low level setting of 10 mV.</li>
	<li>Combination of these processes selectively captures the marked areas from the PEN membrane onto CapSure LCM macro caps. When the cap is lifted, the membrane with the neurons adheres to the cap.</li>
	<li>Isolate total RNA from LCM samples using a PicoPure RNA isolation kit (Arcturus) and treat with DNase.</li>
	<li>Amplify the isolated RNA using RiboAMP RNA amplification kit following instructions from the kit.</li>
	<li>Perform Real time RT-PCR analysis using TaqMan probes to detect human neurofilament heavy chain (hNFHc).</li>
</ol>
Abbreviations:
AD, Alzheimer's disease; BDNF, brain-derived neurotrophic factor; CREB, cyclic AMP response element binding protein; DBC, Dibutyryl cyclic AMP; EGF, epidermal growth factor; FGF, fibroblast growth factor; GFAP, glial fibrillary acidic protein; LCM, laser capture microdissection; NGF, Nerve growth factor; NPC, neuroprogenitor cell; PEN, polyethylene naphthalate.

<ol>
	<li>Doetsch, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+glial+identity+of+neural+stem+cells.">The glial identity of neural stem cells.</a> Nat Neurosci. 6, 1127-1134 (2003).</li><li>Galli, R., Gritti, A., Bonfanti, L., Vescovi, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+stem+cells:+an+overview.">Neural stem cells: an overview.</a> Circ. Res. 92, 598-608 (2003).</li><li>Kim, S. U., de Vellis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell-based+cell+therapy+in+neurological+diseases:+a+review.">Stem cell-based cell therapy in neurological diseases: a review.</a> J. Neurosci. Res. 87, 2183-2200 (2009).</li><li>Breier, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+progenitor+cells+as+models+for+high-throughput+screens+of+developmental+neurotoxicity:+state+of+the+science.">Neural progenitor cells as models for high-throughput screens of developmental neurotoxicity: state of the science.</a> Neurotoxicol. Teratol. 32, 4-15 (2010).</li><li>Christie, V. 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=Retinoid+supplementation+of+differentiating+human+neural+progenitors+and+embryonic+stem+cells+leads+to+enhanced+neurogenesis+in+vitro.">Retinoid supplementation of differentiating human neural progenitors and embryonic stem cells leads to enhanced neurogenesis in vitro.</a> J Neurosci Methods. 193, 239-245 (2010).</li><li>Bonner, R. F., 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=Laser+capture+microdissection:+molecular+analysis+of+tissue.">Laser capture microdissection: molecular analysis of tissue.</a> Science. 278, 1481-1483 (1997).</li><li>Vincent, V. A., DeVoss, J. J., Ryan, H. S., Murphy, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+neuronal+gene+expression+with+laser+capture+microdissection.">Analysis of neuronal gene expression with laser capture microdissection.</a> J. Neurosci. Res. 69, 578-586 (2002).</li><li>Robles, Y., 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=Hippocampal+gene+expression+profiling+in+spatial+discrimination+learning.">Hippocampal gene expression profiling in spatial discrimination learning.</a> Neurobiol. Learn Mem. 80, 80-95 (2003).</li><li>Su, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+ethanol+versus+formalin+fixation+on+preservation+of+histology+and+RNA+in+laser+capture+microdissected+brain+tissues.">Comparison of ethanol versus formalin fixation on preservation of histology and RNA in laser capture microdissected brain tissues.</a> Brain Pathol. 14, 175-182 (2004).</li><li>Shimamura, M., Garcia, J. M., Prough, D. S., Hellmich, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+capture+microdissection+and+analysis+of+amplified+antisense+RNA+from+distinct+cell+populations+of+the+young+and+aged+rat+brain:+effect+of+traumatic+brain+injury+on+hippocampal+gene+expression.">Laser capture microdissection and analysis of amplified antisense RNA from distinct cell populations of the young and aged rat brain: effect of traumatic brain injury on hippocampal gene expression.</a> Brain Res. Mol. Brain Res. 122, 47-61 (2004).</li><li>Pugazhenthi, S., Wang, M., Pham, S., Sze, C. I., Eckman, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Downregulation+of+CREB+expression+in+Alzheimer's+brain+and+in+Abeta-treated+rat+hippocampal+neurons.">Downregulation of CREB expression in Alzheimer's brain and in Abeta-treated rat hippocampal neurons.</a> Mol. Neurodegener. 6, 60 (2011).</li><li>Dworkin, S., Mantamadiotis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+CREB+signalling+in+neurogenesis.">Targeting CREB signalling in neurogenesis.</a> Expert Opin. Ther. Targets. 14, 869-879 (2010).</li><li>Trujillo, C. 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=Novel+perspectives+of+neural+stem+cell+differentiation:+from+neurotransmitters+to+therapeutics.">Novel perspectives of neural stem cell differentiation: from neurotransmitters to therapeutics.</a> Cytometry A. 75, 38-53 (2009).</li><li>Pugazhenthi, S., 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=Varicella-zoster+virus+infection+of+differentiated+human+neural+stem+cells.">Varicella-zoster virus infection of differentiated human neural stem cells.</a> J. Virol. 85, 6678-6686 (2011).</li><li>Kamme, F., 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=Single-cell+microarray+analysis+in+hippocampus+CA1:+demonstration+and+validation+of+cellular+heterogeneity.">Single-cell microarray analysis in hippocampus CA1: demonstration and validation of cellular heterogeneity.</a> J. Neurosci. 23, 3607-3615 (2003).</li></ol>

No conflicts of interest to declare.

We describe in this study a neuron-rich cell culture model by differentiation of self-renewing human neuroprogenitor cells and a method to isolate a pure population of neurons by laser capture microdissection. We have used a combination of NGF, BDNF, DBC and retinoic acid for neuronal differentiation of NPCs. DBC is used to activate CREB, a transcription factor that enhances neurogenesis 12. Retinoic acid induces cell cycle exit and reduces the glial population 13. The method described in this study...

Life-long neurogenesis is known to occur in the subventricular zone of the lateral ventricles and in the subgranular layer of the dentate gyrus of the adult mammalian brain 1. Neuroprogenitor cells (NPCs) that originate from these regions are multipotent cells that can differentiate into neurons, astrocytes and oligodendrocytes 2. NPCs have generated interest because of their potential to be transplanted in patients with various neurodegenerative disorders including Parkinson&#8217;s disease, amyotrophic lateral sclerosis, stroke and Alzheimer&#8217;s disease (AD) 3. Studies with NPCs have generally focused on this transplantation angle but the potential of NPC-derived neurons as a cell culture model to determine the mechanism of neurodegeneration has not been fully exploited. Previous studies have generally used post-mitotic neurons isolated from rodent brain tissues which need to be isolated for each experiment as they are not self-renewing. Although human neuroblastoma cell lines including SH-SY5Y and SK-N-MC cells can be expanded, they do not have the characteristics of primary neurons. Human NPCs, on the other hand, offer both advantages because they can be expanded for multiple passages and can be differentiated to generate a cell population with the characteristics of primary neurons 4,5. In the current study, we describe a new differentiation protocol to obtain a consistent neuron-rich population from commercially available NPCs isolated from human fetal brain. Because these cultures do contain a small percent of glial cells, we need additional methods to isolate a pure population of neurons for molecular characterization. Laser capture microdissection (LCM) is a novel technique by which a homogenous population of cells from a tissue section can be selectively captured for gene expression analysis 6. The brain is a heterogeneous tissue consisting of neurons, glia and other cell types. LCM has been used to determine neuron-specific gene expression analyses 7-10. We have previously performed LCM of hippocampal neurons from AD (Tg2576) mouse brain sections to show decreased expression of cyclic AMP response element binding protein (CREB) and BDNF specifically in hippocampal neurons 11. In the present study, we describe procedures for the expansion of human NPCs, neuronal differentiation, immunofluorescent staining for neuronal markers and LCM for the isolation of neurons cultured on PEN membrane slides.

<table border="1">
		<tbody>
		 <tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		 </tr>
		 <tr>
			<td>Neuroprogenitor cells (NPCs) </td>
			<td>Lonza</td>
			<td>PT-2599</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Neurocult NS-A human basal medium</td>
			<td>Stem cell technology</td>
			<td>5750</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Neurocult NS-A Proliferation supplement</td>
			<td>Stem cell technology</td>
			<td>5753</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Neurocult NS-A Differentiation supplement</td>
			<td>Stem cell technology</td>
			<td>5754</td>
			<td></td>
		 </tr>
		 <tr>
			<td>B-27 Supplement (50x) </td>
			<td>Invitrogen</td>
			<td>17504-044</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Human epidermal growth factor</td>
			<td>Stem cell technology</td>
			<td>2633</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Fibroblast growth factor </td>
			<td>Sigma</td>
			<td>F0291</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Brain Derived Neurotrophic Factor </td>
			<td>Cell signaling </td>
			<td>3897S</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Nerve Growth Factor </td>
			<td>Invitrogen</td>
			<td>13257-019</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Dibutyryl cyclic AMP</td>
			<td>Sigma</td>
			<td>D-0627</td>
			<td></td>
		 </tr>
		 <tr>
			<td>poly-L-lysine </td>
			<td>Sigma</td>
			<td>P-5899</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Mouse laminin </td>
			<td>Sigma</td>
			<td>L-2020</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Retinoic acid</td>
			<td>Sigma</td>
			<td>R-2625</td>
			<td></td>
		 </tr>
		 <tr>
			<td>STAT3 antibody</td>
			<td>Cell signaling</td>
			<td>9132</td>
			<td></td>
		 </tr>
		 <tr>
			<td>GFAP antibody</td>
			<td>Cell signaling</td>
			<td>3670</td>
			<td></td>
		 </tr>
		 <tr>
			<td>GAP43 antibody</td>
			<td>Transduction laboratories</td>
			<td>612262</td>
			<td></td>
		 </tr>
		 <tr>
			<td>BDNF antibody</td>
			<td>Millipore</td>
			<td>AB1534SP</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Acetyl cholinesterase antibody </td>
			<td>Santz cruz</td>
			<td>Sc-11409</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Synaptophysin antibody</td>
			<td>Abcam</td>
			<td>ab18008-50</td>
			<td></td>
		 </tr>
		 <tr>
			<td>NeuN antibody</td>
			<td>Chemicon</td>
			<td>MAB377</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Synapsin antibody</td>
			<td>Novus</td>
			<td>NB300-104</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Anti mouse FITC</td>
			<td>Jackson Immuno </td>
			<td>115-095-146</td>
			<td></td>
		 </tr>
		 <tr>
			<td></td>
			<td>Research Laboratories</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Anti Rabbit Cy3</td>
			<td>Jackson Immuno </td>
			<td>711-165-152</td>
			<td></td>
		 </tr>
		 <tr>
			<td></td>
			<td>Research Laboratories</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>BSA</td>
			<td>Sigma</td>
			<td>A1653</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Triton-X 100</td>
			<td>Acros</td>
			<td>21568-2500</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Paraformaldehye </td>
			<td>Fisher</td>
			<td>4042</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Coverslip (Big circle cover slip)</td>
			<td>Fisherbrand</td>
			<td>12-545-102</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Mounting medium (Prolong Gold)</td>
			<td>Invitrogen</td>
			<td>P36930</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Pen membrane</td>
			<td>Applied biosystems</td>
			<td>LCM0521</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Histogene LCM frozen section staining kit</td>
			<td>Applied biosystems</td>
			<td>KIT0401</td>
			<td></td>
		 </tr>
		 <tr>
			<td>RiboAmp RNA Amplification kit</td>
			<td>Applied biosystems</td>
			<td>KIT0201</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Picopure RNA Isolation kit</td>
			<td>Applied biosystems</td>
			<td>KIT0202</td>
			<td></td>
		 </tr>
		 <tr>
			<td>CapsureMacro LCM caps</td>
			<td>Applied biosystems</td>
			<td>LCM0211</td>
			<td></td>
		 </tr>
		</tbody>
 </table>

laser capture microdissection of neurons from differentiated human neuroprogenitor cells in culture

Neuroprogenitor cells (NPCs) isolated from the human fetal brain were expanded under proliferative conditions in the presence of epidermal growth factor (EGF) and fibroblast growth factor (FGF) to provide an abundant supply of cells. NPCs were differentiated in the presence of a new combination of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), dibutyryl cAMP (DBC) and retinoic acid on dishes coated with poly-L-lysine and mouse laminin to obtain neuron-rich cultures. NPCs were also differentiated in the absence of neurotrophins, DBC and retinoic acid and in the presence of ciliary neurotrophic factor (CNTF) to yield astrocyte-rich cultures. Differentiated NPCs were characterized by immunofluorescence staining for a panel of neuronal markers including NeuN, synapsin, acetylcholinesterase, synaptophysin and GAP43. Glial fibrillary acidic protein (GFAP) and STAT3, astrocyte markers, were detected in 10-15% of differentiated NPCs. To facilitate cell-type specific molecular characterization, laser capture microdissection was performed to isolate neurons cultured on polyethylene naphthalate (PEN) membrane slides. The methods described in this study provide valuable tools to advance our understanding of the molecular mechanism of neurodegeneration.

Expansion of NPCs (Figure 1)
When neurospheres are broken down to a single cell suspension by trituration, the pipette tip needs to touch the bottom of the tube so that there is some resistance when the suspension is pipetted up and down. The number of times of trituration will vary between individuals and needs to be decided by trial and error by examining the resulting cell suspension under a microscope. It is critical to provide sufficient density of cell suspension because th...

Watch this Scientific Journal Video about Laser Capture Microdissection of Neurons from Differentiated Human Neuroprogenitor Cells in Culture at JoVE.com

Laser Capture Microdissection of Neurons from Differentiated Human Neuroprogenitor Cells in Culture

Human neuroprogenitor cells (NPCs) were expanded under proliferating conditions. NPCs were differentiated into neuron-rich cultures in the presence of a combination of neurotrophins. Neuronal markers were detected by immunofluorescence staining. To isolate a pure population of neurons, NPCs were differentiated on PEN membrane slides and laser capture microdissection was performed.

Neuroprogenitor cells (NPCs) isolated from the human fetal brain were expanded under proliferative conditions in the presence of epidermal growth factor ...

laser-capture-microdissection-neurons-from-differentiated-human

Research

JoVE Journal

Neuroscience

12.1K Görüntüleme.  Denver VA Medical Center.  İnsan neuroprogenitor hücreleri (NPC) çoğalan koşullar altında genişletilmiştir. NPC nörotrofinlerin bir kombinasyonunun mevcudiyetinde nöron zengin kültürler içine ayırt edildi. Nöronal belirteçler immunofloresan boyama ile tespit edilmiştir. Nöron saf bir popülasyonu izole etmek için, NPC PEN membran slaytlar üzerinde farklılaştırılmış ve lazer yakalama mikrodiseksiyon uygulandı.

Video: Laser Capture Microdissection of Neurons from Differentiated Human Neuroprogenitor Cells in Culture

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 ...

Laser Capture Microdissection of Drosophila Peripheral Neurons

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the molecular mechanisms underlying class-specific dendrite morphogenesis1,2. To facilitate molecular analyses of class-specific da neuron development, it is vital to obtain these cells in a pure population. Although a range of different cell, and tissue-specific RNA isolation techniques exist for Drosophila cells, including magnetic bead based cell purification3,4, Fluorescent Activated Cell Sorting (FACS)5-8, and RNA binding protein based strategies9, none of these methods can be readily utilized for isolating single or multiple class-specific Drosophila da neurons with a high degree of spatial precision. Laser Capture Microdissection (LCM) has emerged as an extremely powerful tool that can be used to isolate specific cell types from tissue sections with a high degree of spatial resolution and accuracy. RNA obtained from isolated cells can then be used for analyses including qRT-PCR and microarray expression profiling within a given cell type10-16. To date, LCM has not been widely applied in the analysis of Drosophila tissues and cells17,18, including da neurons at the third instar larval stage of development. 
Here we present our optimized protocol for isolation of Drosophila da neurons using the infrared (IR) class of LCM. This method allows for the capture of single, class-specific or multiple da neurons with high specificity and spatial resolution. Age-matched third instar larvae expressing a UAS-mCD8::GFP19 transgene under the control of either the class IV da neuron specific ppk-GAL420 driver or the pan-da neuron specific 21-7-GAL421 driver were used for these experiments. RNA obtained from the isolated da neurons is of very high quality and can be directly used for downstream applications, including qRT-PCR or microarray analyses. Furthermore, this LCM protocol can be readily adapted to capture other Drosophila cell types a various stages of development dependent upon the cell type specific, GAL4-driven expression pattern of GFP.

Laser Capture Microdissection of Drosophila Peripheral Neurons

In this video-article we present a method for isolating single or multiple Drosophila da neurons from third instar larvae using the infrared capture (IR) class of Laser Capture Microdissection (LCM). RNA obtained from the isolated neurons can be readily used for downstream applications including qRT-PCR or microarray analyses.

The dendritic arborization (da) neurons of the Drosophila peripheral nervous system (PNS) provide an excellent model system in which to investigate the ...

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Laser Capture Microdissection of Enriched Populations of Neurons or Single Neurons for Gene Expression Analysis After Traumatic Brain Injury

Long-term cognitive disability after TBI is associated with injury-induced neurodegeneration in the hippocampus-a region in the medial temporal lobe that is critical for learning, memory and executive function.1,2 Hence our studies focus on gene expression analysis of specific neuronal populations in distinct subregions of the hippocampus. The technique of laser capture microdissection (LCM), introduced in 1996 by Emmert-Buck, et al.,3 has allowed for significant advances in gene expression analysis of single cells and enriched populations of cells from heterogeneous tissues such as the mammalian brain that contains thousands of functional cell types.4 We use LCM and a well established rat model of traumatic brain injury (TBI) to investigate the molecular mechanisms that underlie the pathogenesis of TBI. Following fluid-percussion TBI, brains are removed at pre-determined times post-injury, immediately frozen on dry ice, and prepared for sectioning in a cryostat. The rat brains can be embedded in OCT and sectioned immediately, or stored several months at -80 &deg;C before sectioning for laser capture microdissection. Additionally, we use LCM to study the effects of TBI on circadian rhythms. For this, we capture neurons from the suprachiasmatic nuclei that contain the master clock of the mammalian brain. Here, we demonstrate the use of LCM to obtain single identified neurons (injured and degenerating, Fluoro-Jade-positive, or uninjured, Fluoro-Jade-negative) and enriched populations of hippocampal neurons for subsequent gene expression analysis by real time PCR and/or whole-genome microarrays. These LCM-enabled studies have revealed that the selective vulnerability of anatomically distinct regions of the rat hippocampus are reflected in the different gene expression profiles of different populations of neurons obtained by LCM from these distinct regions. The results from our single-cell studies, where we compare the transcriptional profiles of dying and adjacent surviving hippocampal neurons, suggest the existence of a cell survival rheostat that regulates cell death and survival after TBI.

We describe how to use laser capture microdissection (LCM) to obtain enriched populations of hippocampal neurons or single neurons from frozen sections of the injured rat brain for subsequent gene expression analysis using quantitative real time PCR and/or whole-genome microarrays.

Long-term cognitive disability after TBI is associated with injury-induced neurodegeneration in the hippocampus-a region in the medial temporal lobe that ...

The Specification of Telencephalic Glutamatergic Neurons from Human Pluripotent Stem Cells

Here, a stepwise procedure for efficiently generating telencephalic glutamatergic neurons from human pluripotent stem cells (PSCs) has been described. The differentiation process is initiated by breaking the human PSCs into clumps which round up to form aggregates when the cells are placed in a suspension culture. The aggregates are then grown in hESC medium from days 1-4 to allow for spontaneous differentiation. During this time, the cells have the capacity to become any of the three germ layers. From days 5-8, the cells are placed in a neural induction medium to push them into the neural lineage. Around day 8, the cells are allowed to attach onto 6 well plates and differentiate during which time the neuroepithelial cells form. These neuroepithelial cells can be isolated at day 17. The cells can then be kept as neurospheres until they are ready to be plated onto coverslips. Using a basic medium without any caudalizing factors, neuroepithelial cells are specified into telencephalic precursors, which can then be further differentiated into dorsal telencephalic progenitors and glutamatergic neurons efficiently. Overall, our system provides a tool to generate human glutamatergic neurons for researchers to study the development of these neurons and the diseases which affect them.

This procedure yields telencephalic neurons by going through checkpoints which are similar to those observed during human development. The cells are allowed to spontaneously differentiate, are exposed to factors which push them towards the neural lineage, are isolated, and are plated onto coverslips to allow for terminal differentiation and maturation.

Here, a stepwise procedure for efficiently generating telencephalic glutamatergic neurons from human pluripotent stem cells (PSCs) has been described. The ...

Production of RNA for Transcriptomic Analysis from Mouse Spinal Cord Motor Neuron Cell Bodies by Laser Capture Microdissection

Preparation of high-quality RNA from cells of interest is critical to precise and meaningful analysis of transcriptional differences among cell types or between the same cell type in health and disease or following pharmacologic treatments.&#160;In the spinal cord, such preparation from motor neurons, the target of interest in many neurologic and neurodegenerative diseases, is complicated by the fact that motor neurons represent &#60;10% of the total cell population.&#160;Laser capture microdissection (LMD) has been developed to address this problem.&#160;Here, we describe a protocol to quickly recover, freeze, and section mouse spinal cord to avoid RNA damage by endogenous and exogenous RNases, followed by staining with Azure B in 70% ethanol to identify the motor neurons while keeping endogenous RNase inhibited.&#160;LMD is then used to capture the stained neurons directly into guanidine thiocyanate lysis buffer, maintaining RNA integrity.&#160;Standard techniques are used to recover the total RNA and measure its integrity.&#160;This material can then be used for downstream analysis of the transcripts by RNA-seq and qRT-PCR.

High-quality total RNA has been prepared from cell bodies of mouse spinal cord motor neurons by laser capture microdissection after staining spinal cord sections with Azure B in 70% ethanol.&#160;Sufficient RNA (~40-60 ng) is recovered from 3,000-4,000 motor neurons to allow downstream RNA analysis by RNA-seq and qRT-PCR.

Preparation of high-quality RNA from cells of interest is critical to precise and meaningful analysis of transcriptional differences among cell types or ...

Olfactory Neurons Obtained through Nasal Biopsy Combined with Laser-Capture Microdissection: A Potential Approach to Study Treatment Response in Mental Disorders

Bipolar disorder (BD) is a severe neuropsychiatric disorder with poorly understood pathophysiology and typically treated with the mood stabilizer, lithium carbonate. Animal studies as well as human genetic studies indicate that lithium affects molecular targets that are involved in neuronal growth, survival and maturation, and notably molecules involved in Wnt signaling. Given the ethical challenge to obtaining brain biopsies for investigating dynamic molecular changes associated with lithium-response in the central nervous system (CNS), one may consider the use of neurons obtained from olfactory tissues to achieve this goal.The olfactory epithelium contains olfactory receptor neurons at different stages of development and glial-like supporting cells. This provides a unique opportunity to study dynamic changes in the CNS of patients with neuropsychiatric diseases, using olfactory tissue safely obtained from nasal biopsies. To overcome the drawback posed by substantial contamination of biopsied olfactory tissue with non-neuronal cells, a novel approach to obtain enriched neuronal cell populations was developed by combining nasal biopsies with laser-capture microdissection. In this study, a system for investigating treatment-associated dynamic molecular changes in neuronal tissue was developed and validated, using a small pilot sample of BD patients recruited for the study of the molecular mechanisms of lithium treatment response.

In this study, a novel platform to investigate intraneuronal molecular signatures of treatment response in bipolar disorder (BD) was developed and validated. Olfactory epithelium from BD patients was obtained through nasal biopsies. Then laser-capture microdissection was combined with Real Time RT PCR to investigate the molecular signature of lithium response in BD.

Bipolar disorder (BD) is a severe neuropsychiatric disorder with poorly understood pathophysiology and typically treated with the mood stabilizer, lithium ...

Laser Capture Microdissection - A Demonstration of the Isolation of Individual Dopamine Neurons and the Entire Ventral Tegmental Area

Laser capture microdissection (LCM) is used to isolate a concentrated population of individual cells or precise anatomical regions of tissue from tissue sections on a microscope slide. When combined with immunohistochemistry, LCM can be used to isolate individual cells types based on a specific protein marker. Here, the LCM technique is described for collecting a specific population of dopamine neurons directly labeled with&#160;tyrosine hydroxylase immunohistochemistry and for isolation of the dopamine neuron containing region of the ventral tegmental area using indirect tyrosine hydroxylase immunohistochemistry on a section adjacent to those used for LCM. An infrared (IR) capture laser is used to both dissect individual neurons as well as the ventral tegmental area off glass slides and onto an LCM cap for analysis. Complete dehydration of the tissue with 100% ethanol and xylene is critical. The combination of the IR capture laser and the ultraviolet (UV) cutting laser is used to isolate individual dopamine neurons or the ventral tegmental area when using PEN membrane slides. A PEN membrane slide has significant advantages over a glass slide as it offers better consistency in capturing and collecting cells, is faster collecting large pieces of tissue, is less reliant on dehydration and results in complete removal of the tissue from the slide. Although removal of large areas of tissue from a glass slide is feasible, it is considerably more time consuming and frequently leaves some residual tissue behind. Data shown here demonstrate that RNA of sufficient quantity and quality can be obtained using these procedures for quantitative PCR measurements. Although RNA and DNA are the most commonly isolated molecules from tissue and cells collected with LCM, isolation and measurement of microRNA, protein and epigenetic changes in DNA can also benefit from the enhanced anatomical and cellular resolution obtained using LCM.

The isolation of individual dopamine neurons or the ventral tegmental area with direct or indirect immunohistochemistry is demonstrated using laser capture microdissection. Parameters for isolation of tissue from a glass slide using an infrared laser and from membrane slides using the combination of an infrared and ultraviolet laser are discussed.

Laser capture microdissection (LCM) is used to isolate a concentrated population of individual cells or precise anatomical regions of tissue from tissue ...

Dorsal Root Ganglia Neurons and Differentiated Adipose-derived Stem Cells: An In Vitro Co-culture Model to Study Peripheral Nerve Regeneration

Dorsal root ganglia (DRG) neurons, located in the intervertebral foramina of the spinal column, can be used to create an in vitro system facilitating the study of nerve regeneration and myelination. The glial cells of the peripheral nervous system, Schwann cells (SC), are key facilitators of these processes; it is therefore crucial that the interactions of these cellular components are studied together. Direct contact between DRG neurons and glial cells provides additional stimuli sensed by specific membrane receptors, further improving the neuronal response. SC release growth factors and proteins in the culture medium, which enhance neuron survival and stimulate neurite sprouting and extension. However, SC require long proliferation time to be used for tissue engineering applications and the sacrifice of an healthy nerve for their sourcing. Adipose-derived stem cells (ASC) differentiated into SC phenotype are a valid alternative to SC for the set-up of a co-culture model with DRG neurons to study nerve regeneration. The present work presents a detailed and reproducible step-by-step protocol to harvest both DRG neurons and ASC from adult rats; to differentiate ASC towards a SC phenotype; and combines the two cell types in a direct co-culture system to investigate the interplay between neurons and SC in the peripheral nervous system. This tool has great potential in the optimization of tissue-engineered constructs for peripheral nerve repair.

Dorsal Root Ganglia Neurons and Differentiated Adipose-derived Stem Cells: An In Vitro Co-culture Model to Study Peripheral Nerve Regeneration

Dorsal root ganglia (DRG) are structures containing the sensory neurons of the peripheral nervous system. When dissociated, they can be co-cultured with SC-like adipose-derived stem cells (ASC), providing a valuable model to study in vitro nerve regeneration and myelination, mimicking the in vivo environment at the injury site.

Dorsal root ganglia (DRG) neurons, located in the intervertebral foramina of the spinal column, can be used to create an in vitro system facilitating the ...

Stereotactic Atlas-Guided Laser Capture Microdissection of Brain Regions Affected by Traumatic Injury

The ability to isolate specific brain regions of interest can be impeded in tissue disassociation techniques that do not preserve their spatial distribution. Such techniques also potentially skew gene expression analysis because the process itself can alter expression patterns in individual cells. Here we describe a laser capture microdissection (LCM) method to selectively collect specific brain regions affected by traumatic brain injury (TBI) by using a modified Nissl (cresyl violet) staining protocol and the guidance of a rat brain atlas. LCM provides access to brain regions in their native positions and the ability to use anatomical landmarks for identification of each specific region. To this end, LCM has been used previously to examine brain region specific gene expression in TBI. This protocol allows examination of TBI-induced alterations in gene and microRNA expression in distinct brain areas within the same animal. The principles of this protocol can be amended and applied to a wide range of studies examining genomic expression in other disease and/or animal models.

We describe the use of laser capture microdissection to obtain samples of distinct cell populations from different brain regions for gene and microRNA analysis. This technique allows the study of differential effects of traumatic brain injury in specific regions of the rat brain.