This work was supported by the Faculty Development Fund and Summer Research Program grant at Saint Mary&#8217;s College of California. The authors would also like to thank Dr. Pamela Lein at University of California at Davis and Dr. Anthony Iavarone at UC Berkeley Mass spectrometry facility for their advice during the development of these protocols. The authors would also like to thank Haley Nelson in the Office of College Communications at Saint Mary&#8217;s College of California for her help with video production and editing.

All procedures performed in studies involving animals were approved by the Institutional Animal Care and Use Committee (IACUC) at Saint Mary&#8217;s College of California. The animal care and use guidelines at Saint Mary&#8217;s College were developed based on the guidelines provided by Office of Laboratory Animal Welfare at the National Institute for Health (https://olaw.nih.gov/sites/default/files/PHSPolicyLabAnimals.pdf and https://olaw.nih.gov/sites/default/files/Guide-for-the-Care-and-Use-of-Laboratory-Animals.pdf)....

<ol>
	<li>Rees, R. P., Bunge, M. B., Bunge, 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=Morphological+Changes+in+the+neuritic+growth+cone+and+target+neuron+during+synaptic+junction+development+in+culture.">Morphological Changes in the neuritic growth cone and target neuron during synaptic junction development in culture.</a> Journal of Cell Biology. 9, (1976).</li><li>Chandrasekaran, V., Lein, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+Dendritogenesis+in+Sympathetic+Neurons.">Regulation of Dendritogenesis in Sympathetic Neurons.</a> Autonomic Nervous System. , (2018).</li><li>Higgins, D., Burack, M., Lein, P., Banker, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+neuronal+polarity.">Mechanisms of neuronal polarity.</a> Current Opinion in Neurobiology. 7 (5), 599-604 (1997).</li><li>Lein, P., Guo, X., Hedges, A. M., Rueger, D., Johnson, M., Higgins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+Extracellular+Matrix+And+Osteogenic+Protein-1+on+the+morphological+differentiation+of+rat+sympathetic+neurons.">The effects of Extracellular Matrix And Osteogenic Protein-1 on the morphological differentiation of rat sympathetic neurons.</a> International Journal of Developmental Neuroscience. 14 (3), 203-215 (1996).</li><li>Kobayashi, M., Fujii, M., Kurihara, K., Matsuoka, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+morphogenetic+protein-2+and+retinoic+acid+induce+neurotrophin-3+responsiveness+in+developing+rat+sympathetic+neurons.">Bone morphogenetic protein-2 and retinoic acid induce neurotrophin-3 responsiveness in developing rat sympathetic neurons.</a> Molecular Brain Research. 53 (1-2), 206-217 (1998).</li><li>Burnham, P., Louis, J. C., Magal, E., Varon, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+ciliary+neurotrophic+factor+on+the+survival+and+response+to+nerve+growth+factor+of+cultured+rat+sympathetic+neurons.">Effects of ciliary neurotrophic factor on the survival and response to nerve growth factor of cultured rat sympathetic neurons.</a> Developmental Biology. 161 (1), 96-106 (1994).</li><li>Hou, X. E., Li, J. Y., Dahlstr&#246;m, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clathrin+light+chain+and+synaptotagmin+I+in+rat+sympathetic+neurons.">Clathrin light chain and synaptotagmin I in rat sympathetic neurons.</a> Journal of the Autonomic Nervous System. 62 (1-2), 13-26 (1997).</li><li>Harris, G. 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=Nerve+Guidance+by+a+Decellularized+Fibroblast+Extracellular+Matrix.">Nerve Guidance by a Decellularized Fibroblast Extracellular Matrix.</a> Matrix Biology. , 176-189 (2017).</li><li>Wingerd, K. L., 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=&#945;4+integrins+and+vascular+cell+adhesion+molecule-1+play+a+role+in+sympathetic+innervation+of+the+heart.">&#945;4 integrins and vascular cell adhesion molecule-1 play a role in sympathetic innervation of the heart.</a> Journal of Neuroscience. 22 (24), 10772-10780 (2002).</li><li>Higgins, D., Lein, P., Osterhout, D. J., Johnson, M., Banker, G., Goslin, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+culture+of+autonomic+neurons.">Tissue culture of autonomic neurons.</a> Culturing Nerve Cells. , 177-205 (1991).</li><li>Lein, P., Johnson, M., Guo, X., Rueger, D., Higgins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteogenic+protein-1+induces+dendritic+growth+in+rat+sympathetic+neurons.">Osteogenic protein-1 induces dendritic growth in rat sympathetic neurons.</a> Neuron. 15 (3), 597-605 (1995).</li><li>Bruckenstein, D. A., Higgins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+differentiation+of+embryonic+rat+sympathetic+neurons+in+tissue+culture.">Morphological differentiation of embryonic rat sympathetic neurons in tissue culture.</a> Developmental Biology. 128 (2), 337-348 (1988).</li><li>Voyvodic, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+regulation+of+dendrites+in+the+rat+superior+cervical+ganglion.">Development and regulation of dendrites in the rat superior cervical ganglion.</a> The Journal of Neuroscience. 7 (3), 904-912 (1987).</li><li>Garred, M. M., Wang, M. M., Guo, X., Harrington, C. A., Lein, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptional+Responses+of+Cultured+Rat+Sympathetic+Neurons+during+BMP-7-Induced+Dendritic+Growth.">Transcriptional Responses of Cultured Rat Sympathetic Neurons during BMP-7-Induced Dendritic Growth.</a> PLoS ONE. 6 (7), 21754 (2011).</li><li>Pravoverov, 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=MicroRNAs+are+Necessary+for+BMP-7-induced+Dendritic+Growth+in+Cultured+Rat+Sympathetic+Neurons.">MicroRNAs are Necessary for BMP-7-induced Dendritic Growth in Cultured Rat Sympathetic Neurons.</a> Cellular and Molecular Neurobiology. 39 (7), 917-934 (2019).</li><li>Natera-Naranjo, O., Aschrafi, A., Gioio, A. E., Kaplan, B. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+quantitative+analyses+of+microRNAs+located+in+the+distal+axons+of+sympathetic+neurons.">Identification and quantitative analyses of microRNAs located in the distal axons of sympathetic neurons.</a> RNA (New York, N.Y.). 16 (8), 1516-1529 (2010).</li><li>Aschrafi, 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=Angiotensin+II+mediates+the+axonal+trafficking+of+tyrosine+hydroxylase+and+dopamine+&#946;-hydroxylase+mRNAs+and+enhances+norepinephrine+synthesis+in+primary+sympathetic+neurons.">Angiotensin II mediates the axonal trafficking of tyrosine hydroxylase and dopamine &#946;-hydroxylase mRNAs and enhances norepinephrine synthesis in primary sympathetic neurons.</a> Journal of Neurochemistry. 150 (6), 666-677 (2019).</li><li>Ghogha, A., Bruun, D. a., Lein, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inducing+dendritic+growth+in+cultured+sympathetic+neurons.">Inducing dendritic growth in cultured sympathetic neurons.</a> Journal of Visualized Experiments. (61), 4-8 (2012).</li><li>Caceres, A., Banker, G., Steward, O., Binder, L., Payne, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MAP2+is+localized+to+the+dendrites+of+hippocampal+neurons+which+develop+in+culture.">MAP2 is localized to the dendrites of hippocampal neurons which develop in culture.</a> Brain Research. 315 (2), 314-318 (1984).</li><li>Guo, X., Rueger, D., Higgins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteogenic+protein-1+and+related+bone+morphogenetic+proteins+regulate+dendritic+growth+and+the+expression+of+microtubule-associated+protein-2+in+rat+sympathetic+neurons.">Osteogenic protein-1 and related bone morphogenetic proteins regulate dendritic growth and the expression of microtubule-associated protein-2 in rat sympathetic neurons.</a> Neuroscience Letters. 245 (3), 131-134 (1998).</li><li>Mi, 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=PANTHER+version+11:+Expanded+annotation+data+from+Gene+Ontology+and+Reactome+pathways,+and+data+analysis+tool+enhancements.">PANTHER version 11: Expanded annotation data from Gene Ontology and Reactome pathways, and data analysis tool enhancements.</a> Nucleic Acids Research. 45, 183-189 (2017).</li><li>Chandrasekaran, V., 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=Retinoic+acid+regulates+the+morphological+development+of+sympathetic+neurons.">Retinoic acid regulates the morphological development of sympathetic neurons.</a> Journal of Neurobiology. 42 (4), (2000).</li><li>Courter, L. 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=BMP7-induced+dendritic+growth+in+sympathetic+neurons+requires+p75+NTR+signaling.">BMP7-induced dendritic growth in sympathetic neurons requires p75 NTR signaling.</a> Developmental Neurobiology. 76 (9), 1003-1013 (2016).</li><li>Lein, P. J., Fryer, A. D., Higgins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+Culture:+Autonomic+and+Enteric+Neurons.">Cell Culture: Autonomic and Enteric Neurons.</a> Encyclopedia of Neuroscience. , 625-632 (2009).</li><li>Neto, E., 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=Compartmentalized+Microfluidic+Platforms:+The+Unrivaled+Breakthrough+of+In+vitro+Tools+for+Neurobiological+Research.">Compartmentalized Microfluidic Platforms: The Unrivaled Breakthrough of In vitro Tools for Neurobiological Research.</a> Journal of Neuroscience. 36 (46), 11573-11584 (2016).</li><li>Sleigh, J. N., Weir, G. A., Schiavo, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple,+step-by-step+dissection+protocol+for+the+rapid+isolation+of+mouse+dorsal+root+ganglia.">A simple, step-by-step dissection protocol for the rapid isolation of mouse dorsal root ganglia.</a> BMC Research Notes. 9 (1), 82 (2016).</li><li>Conrad, R., Jablonka, S., Sczepan, T., Sendtner, M., Wiese, S., Klausmeyer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lectin-based+isolation+and+culture+of+mouse+embryonic+motoneurons.">Lectin-based isolation and culture of mouse embryonic motoneurons.</a> Journal of Visualized Experiments. (55), e3200 (2011).</li><li>Takeuchi, 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=Microfabricated+device+for+co-culture+of+sympathetic+neuron+and+iPS-derived+cardiomyocytes.">Microfabricated device for co-culture of sympathetic neuron and iPS-derived cardiomyocytes.</a> Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS. 2013, 3817-3820 (2013).</li><li>Takeuchi, 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=Development+of+semi-separated+co-culture+system+of+sympathetic+neuron+and+cardiomyocyte.">Development of semi-separated co-culture system of sympathetic neuron and cardiomyocyte.</a> Proceedings of the 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society: Engineering the Future of Biomedicine, EMBC 2009. , 1832-1835 (2009).</li><li>Chandrasekaran, V., Lea, C., Sosa, J. C., Higgins, D., Lein, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactive+oxygen+species+are+involved+in+BMP-induced+dendritic+growth+in+cultured+rat+sympathetic+neurons.">Reactive oxygen species are involved in BMP-induced dendritic growth in cultured rat sympathetic neurons.</a> Molecular and Cellular Neuroscience. 67, (2015).</li><li>Kim, W. 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=Statins+decrease+dendritic+arborization+in+rat+sympathetic+neurons+by+blocking+RhoA+activation.">Statins decrease dendritic arborization in rat sympathetic neurons by blocking RhoA activation.</a> Journal of Neurochemistry. 108 (4), 1057-1071 (2009).</li><li>Dalby, 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=Advanced+transfection+with+Lipofectamine+2000+reagent:+Primary+neurons,+siRNA,+and+high-throughput+applications.">Advanced transfection with Lipofectamine 2000 reagent: Primary neurons, siRNA, and high-throughput applications.</a> Methods. 33 (2), 95-103 (2004).</li><li>Szpara, M. L., 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=Analysis+of+gene+expression+during+neurite+outgrowth+and+regeneration.">Analysis of gene expression during neurite outgrowth and regeneration.</a> BMC Neuroscience. 8 (1), 100 (2007).</li><li>Pop, C., Mogosan, C., Loghin, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+rapigest+efficacy+for+the+digestion+of+proteins+from+cell+cultures+and+heart+tissue.">Evaluation of rapigest efficacy for the digestion of proteins from cell cultures and heart tissue.</a> Clujul Medical. 87 (4), 5 (2014).</li><li>Vit, O., Petrak, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integral+membrane+proteins+in+proteomics.+How+to+break+open+the+black+box.">Integral membrane proteins in proteomics. How to break open the black box.</a> Journal of Proteomics. 153, 8-20 (2017).</li></ol>

This paper describes the protocols for culturing sympathetic neurons from superior cervical ganglia of embryonic rat pups. The advantages of using this model system are that it is possible to obtain a homogeneous population of neurons providing a similar response to growth factors, and since the growth factor requirements for these neurons has been well -characterized, it is possible to grow these neurons in vitro in defined media, under serum-free conditions10. Although the protocol describes the...

Sympathetic neurons derived from embryonic superior cervical ganglia (SCG) have been widely used as a primary neuronal culture system for studying many aspects of neuronal development including growth factor dependence, neuron-target interactions, neurotransmitter signaling, axonal growth, dendrite development and plasticity, synaptogenesis and signaling mechanisms underlying nerve-target/neuron-glia interactions1,2,3,4,5,6,7,8,9. Despite their small size (around 10000 neurons/ganglia), there are three main reasons for the development and extensive use of this culture system are i) being the first ganglia in the sympathetic chain, they are larger, and therefore easier to isolate, than the rest of the sympathetic ganglia10; ii) unlike central neurons, the neurons in the SCG are fairly homogeneous with all the neurons being derived from the neural crest, having a similar size, dependence on nerve growth factor and being nor-adrenergic. This makes them a valuable model for morphological and genomic studies10,11 and iii) these neurons can be maintained in a defined serum-free medium containing nerve growth factor for over a month10,12. Perinatal SCG neurons have been extensively used for studying the mechanisms underlying the initiation and maintenance of dendrites2. This is mainly because, although SCG neurons have an extensive dendritic arbor in vivo, they do not extend dendrites in vitro in the absence of serum but can be induced to grow dendrites in the presence of certain growth factors such as bone morphogenetic proteins2,12,13.
This paper describes the protocol for isolating and culturing embryonic rat SCG neurons. Over the past 50 years, primary neuronal cultures from the SCG have been mainly used for morphological studies with a limited number of studies examining the large-scale genomic or proteomic changes. This is mainly due to small tissue size resulting in the isolation of low amounts of DNA or protein, which makes it difficult to perform genomic and proteomic analyses on these neurons. However, in recent years, increased detection sensitivity has enabled development of methods to examine the genome, miRNome and proteome in the SCG neurons during dendritic growth development14,15,16,17. This paper will also describe the method for morphological analysis of these neurons using immunocytochemistry and a protocol to obtain neuronal protein extracts for mass spectrometric analysis.

<table>
	<tbody>
		<tr>
			<td>2D nanoACQUITY</td>
			<td>Waters Corporation</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium bicarbonate</td>
			<td>Sigma-Aldrich</td>
			<td>9830</td>
			<td></td>
		</tr>
		<tr>
			<td>BMP-7</td>
			<td>R&#38;D Systems</td>
			<td>354-BP</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Alumin</td>
			<td>Sigma-Aldrich</td>
			<td>5470</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell scraper</td>
			<td>Corning</td>
			<td>CLS-3010</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase</td>
			<td>Worthington Biochemical</td>
			<td>4176</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning Costar or Nunc Flat bottomed Cell culture plates</td>
			<td>Fisher Scientific</td>
			<td>07-200, 140675, 142475</td>
			<td></td>
		</tr>
		<tr>
			<td>Cytosine- &#946;- D-arabinofuranoside</td>
			<td>Sigma-Aldrich</td>
			<td>C1768</td>
			<td></td>
		</tr>
		<tr>
			<td>D-phosphate buffered saline (Calcium and magnesium free)</td>
			<td>ATCC</td>
			<td>30-2200</td>
			<td></td>
		</tr>
		<tr>
			<td>Dispase II</td>
			<td>Roche</td>
			<td>4942078001</td>
			<td></td>
		</tr>
		<tr>
			<td>Distilled Water</td>
			<td>Thermo Fisher Scientific</td>
			<td>15230</td>
			<td></td>
		</tr>
		<tr>
			<td>Dithiothreitol</td>
			<td>Sigma-Aldrich</td>
			<td>D0632</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM - Low glucose + Glutamine, + sodium pyruvate</td>
			<td>Thermo Fisher Scientific</td>
			<td>11885</td>
			<td></td>
		</tr>
		<tr>
			<td>Fatty Acid Free BSA</td>
			<td>Calbiochem</td>
			<td>126609</td>
			<td>20 mg/mL stock in low glucose DMEM</td>
		</tr>
		<tr>
			<td>Fine forceps Dumont no.4 and no.5</td>
			<td>Ted Pella Inc</td>
			<td>5621, 5622</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps and Scissors for Dissection</td>
			<td>Ted Pella Inc</td>
			<td>1328, 1329, 5002</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass coverlips - 12mm</td>
			<td>Neuvitro Corporation</td>
			<td>GG-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat-Anti Mouse IgG Alexa 488 conjugated</td>
			<td>Thermo Fisher Scientific</td>
			<td>A32723</td>
			<td></td>
		</tr>
		<tr>
			<td>Ham&#39;s F-12 Nutrient Mix</td>
			<td>Thermo Fisher Scientific</td>
			<td>11765</td>
			<td></td>
		</tr>
		<tr>
			<td>Hank&#39;s balanced salt soltion (Calcium and Magnesium free)</td>
			<td>Thermo Fisher Scientific</td>
			<td>14185</td>
			<td></td>
		</tr>
		<tr>
			<td>Insulin-Selenium-Transferrin (100X)</td>
			<td>Thermo Fisher Scientific</td>
			<td>41400-045</td>
			<td></td>
		</tr>
		<tr>
			<td>Iodoacetamide</td>
			<td>Sigma-Aldrich</td>
			<td>A3221</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>Thermo Fisher Scientific</td>
			<td>25030</td>
			<td></td>
		</tr>
		<tr>
			<td>Leibovitz L-15 medium</td>
			<td>Thermo Fisher Scientific</td>
			<td>11415064</td>
			<td></td>
		</tr>
		<tr>
			<td>Mounting media for glass coverslips</td>
			<td>Thermo Fisher Scientific</td>
			<td>P36931, P36934</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse-anti- MAP2 antibody (SMI-52)</td>
			<td>BioLegend</td>
			<td>SMI 52</td>
			<td></td>
		</tr>
		<tr>
			<td>Nerve growth factor</td>
			<td>Envigo Bioproducts (formerly Harlan Bioproducts)</td>
			<td>BT5017</td>
			<td>Stock 125 &#956;g/mL in 0.2% Prionex in DMEM</td>
		</tr>
		<tr>
			<td>Paraformaldehye</td>
			<td>Spectrum Chemicals</td>
			<td>P1010</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin (100X)</td>
			<td>Thermo Fisher Scientific</td>
			<td>15140</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly-D-Lysine</td>
			<td>Sigma-Aldrich</td>
			<td>P0899</td>
			<td></td>
		</tr>
		<tr>
			<td>Prionex</td>
			<td>Millipore</td>
			<td>529600</td>
			<td>10% solution, 100 mL</td>
		</tr>
		<tr>
			<td>RapiGest SF</td>
			<td>Waters Corporation</td>
			<td>186001861</td>
			<td>5 X 1 mg</td>
		</tr>
		<tr>
			<td>Synapt G2 High Definition Mass Spectrometry</td>
			<td>Waters Corporation</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Trifluoro acetic acid - Sequencing grade</td>
			<td>Thermo Fisher Scientific</td>
			<td>28904</td>
			<td>10 X 1 mL</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>X100</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin</td>
			<td>Promega or NEB</td>
			<td>V511A, P8101S</td>
			<td>100 &#956;g or 5 X 20 mg</td>
		</tr>
		<tr>
			<td>Waters Total recovery vials</td>
			<td>Waters Corporation</td>
			<td>186000385c</td>
			<td></td>
		</tr>
	</tbody>
</table>

culturing rat sympathetic neurons from embryonic superior cervical ganglia for morphological and proteomic analysis

Sympathetic neurons from the embryonic rat superior cervical ganglia (SCG) have been used as an in vitro model system for peripheral neurons to study axonal growth, axonal trafficking, synaptogenesis, dendritic growth, dendritic plasticity and nerve-target interactions in co-culture systems. This protocol describes the isolation and dissociation of neurons from the superior cervical ganglia of E21 rat embryos, followed by the preparation and maintenance of pure neuronal cultures in serum-free medium. Since neurons do not adhere to uncoated plastic, neurons will be cultured on either 12 mm glass coverslips or 6-well plates coated with poly-D-lysine. Following treatment with an antimitotic agent (Ara-C, cytosine &#946;-D-arabinofuranoside), this protocol generates healthy neuronal cultures with less than 5% non-neuronal cells, which can be maintained for over a month in vitro. Although embryonic rat SCG neurons are multipolar with 5-8 dendrites in vivo; under serum-free conditions, these neurons extend only a single axon in culture and continue to be unipolar for the duration of the culture. However, these neurons can be induced to extend dendrites in the presence of basement membrane extract, bone morphogenetic proteins (BMPs), or 10% fetal calf serum. These homogenous neuronal cultures can be used for immunocytochemical staining and for biochemical studies. This paper also describes optimized protocol for immunocytochemical staining for microtubule associated protein-2 (MAP-2) in these neurons and for the preparation of neuronal extracts for mass spectrometry.

Isolating and maintaining neuronal cultures of embryonic SCG neurons 
Dissociated cells from the rat embryonic SCG were plated in a poly-D-lysine coated plate or coverslip and maintained in serum free culture media containing b-nerve growth factor. The dissociated cells containing a mixture of neurons and glial cells look circular upon plating (Figure 1A). Within 24 hours of plating, the neurons extend small axonal processes with glial cells flattening and appearing pha...

Watch this Scientific Journal Video about Culturing Rat Sympathetic Neurons from Embryonic Superior Cervical Ganglia for Morphological and Proteomic Analysis at JoVE.com

Culturing Rat Sympathetic Neurons from Embryonic Superior Cervical Ganglia for Morphological and Proteomic Analysis

This paper describes the isolation and culturing of embryonic rat sympathetic neurons from the superior cervical ganglia. It also provides detailed protocols for immunocytochemical staining and for preparing neuronal extracts for mass spectrometric analysis.

Sympathetic neurons from the embryonic rat superior cervical ganglia (SCG) have been used as an in vitro model system for peripheral neurons to study ...

In this video, we will be demonstrating the culturing of embryonic rats'superior cervical ganglia for morphological and proteomic analysis. Before beginning the dissection, prepare control and dissection media. Control medium contains F-12 and low glucose DMEM supplemented with an insulin-selenium-transferrin mixture, glutamine, nerve growth factor, and BSA.Dissection medium contains L-15 supplemented with pen-strep and BSA. Refer to the manuscript for detailed protocols for media preparation. Preparation of plates for culturing neurons.Dilute a one milligram per milliliter stock of poly-D-lysine to 100 micrograms per milliliter with sterile distilled water. For proteomic or genomic analysis, one to two days before the dissection, coat six-well plates with approximately two milliliters of sterile 100 grams per milliliter of poly-D-lysine. This is necessary to ensure cell adhesion to the well.Wrap the plates with cling film and store the plates overnight at four degrees Celsius. On the day of the dissection, before the start of the dissection, remove the poly-D-lysine solution from the wells and rinse the wells five times with sterile distilled water, followed by once with low-glucose DMEM. During the enzymatic digestion of the ganglia, approximately an hour before plating the cells, aspirate the DMEM from the plates and replace it with 0.3 milliliters of control medium.Store the plates at 35 degrees Celsius under 5%CO2 in a humidified chamber. In the hood, set up the following items for dissection. Four 50 milliliter sterile conical tubes with about 20 milliliters of dissection media in each tube.Four sterile 35 millimeter dishes with 1.5 milliliters of dissection media. One sterile 50 milliliter conical tube with 20 milliliters of dissection media for centrifugation. One 15 milliliter sterile conical tube for centrifuging the ganglia, one sterile 10 milliliter tube for collecting the dissociated cells.Use a dry beads sterilizer to sterilize a pair of fine forceps for at least one minute. All procedures performed in studies involving animals were approved by the Institutional Animal Care and Use Committee at Saint Mary's College of California. The animal care and use guidelines at Saint Mary's College of California were developed based on guidelines provided by the Office of Laboratory Animal Welfare at the National Institutes for Health.Removal of E21 embryos from the pregnant rat. Note that the removal of the uterine horn can be performed outside of the hood if the surrounding area is thoroughly sterilized. Euthanize a pregnant rat with CO2 inhalation.Shear the fur from the abdominal region and wipe the skin in the area with 70%alcohol to sterilize it. Using a fresh set of sterile scissors and forceps, cut through the skin and then the muscle to expose the uterine horns containing the embryos. Remove the uterine horn with the embryos, using a new set of scissors and forceps, taking care not to damage the intestines in the process.Transfer the uterine horn with the embryos into 150 millimeter sterile Petri dish and transfer them into the hood. Using a new set of forceps and scissors, remove the embryos from the uterine horn and separate the embryos from the amniotic membranes and the placenta. To euthanize the embryos, cut the spinal cord of the embryos along the midline under the right arm.This will reduce the bleeding from the carotid artery during removal of the SCG. Transfer these embryos into the prepared 50 milliliter conical tubes containing dissection media. Make sure the embryos are submerged in the media.Each tube can hold up to three embryos. Isolation of the superior cervical ganglion from the embryo. Transfer one pup from the dissection media onto a sterile 150 millimeter Petri dish half-filled with solid substrate with its dorsal surface on the substrate.Using three sterile 23 gauge needles, pin the pub to the dish with one needle under each arm and a third needle through the mouth to carefully hyperextend the neck. Cut through the skin in the neck region using sterile fine forceps to expose the salivary glands underneath. Remove these glands using fine forceps.Locate the sternocleidomastoid and omohyoid muscles near the clavicle and trachea respectively. First, cut the transverse sternocleidomastoid muscles. And then carefully cut the thin omohyoid muscle using fine forceps.Once these muscles are removed, the bifurcation in the carotid artery on the anterior end, will be visible on either side of the trachea with the SCG located under this fork in the carotid artery. Using closed forceps, gently lift the carotid artery to visualize the SCG. Using one forceps on either side of the SCG, pull out the carotid and transfer it to the prepared sterile 35 millimeter dishes.This tissue will most likely contain the SCG with the carotid artery, the vagus nerve with the nodose ganglia, as well as other segments of muscle or fat in the area. Repeat the dissection process on the other side. Remove SCGs from all embryos before continuing with the remaining dissection steps outlined.Distribute the isolated tissues between two of the 35 millimeter dishes to facilitate processing of the tissue samples. Post-processing of the SCG. To separate the SCG from the dissected tissue, first use fine forceps to remove any extraneous tissue, such as muscle or fat, taking care to avoid the area near the carotid bifurcation.Once these tissues have been removed, two ganglia are visible. The nodose ganglion is smaller and circular while the SCG is almond shaped. Gently pull on the vagus nerve to separate the vagus nerve and the nodose ganglia from the carotid and then separate the SCG from the carotid artery.Use fine forceps to remove the capsule that surrounds SCG. Transfer the SCG to a new 35 millimeter culture dish. Repeat this process with all of the dissected tissue samples.Coat a sterilized, cotton-plugged glass pipette with dissection media to prevent the tissue from adhering to the pipette walls. Use the pipette to replace the dissection media with sterile two milliliters of collagenase type II, dispase type II in calcium and magnesium-free HBSS and incubate for 50 minutes at 37 degrees Celsius to help break down the tissues. Note that the incubation times may need to be optimized with different batches of collagenase/dispase and usually ranges from 40 minutes to an hour.Following the incubation, transfer the SCGs and collagenase/dispase to a sterile 15 milliliter conical tube. Use the dissection media to rinse the plates and transfer the solution to the tube. Add enough dissection media to bring the volume to approximately 10 milliliters.Centrifuge at 200 x g, 1, 000 to 1, 200 rpm for five minutes at room temperature to pellet the sample. Aspirate the supernatant, taking care to not dislodge the pellet. Resuspend the pellet with 10 milliliters of dissection media, repeat the centrifugation and discard the supernatant.Replace with one to two milliliters of culture medium. Using a narrow-bore, bent-tip sterile Pasteur pipette, pre-coat it with culture medium, mechanically dissociate the clumps by gently triturating five to six times. Let the larger clumps settle for about one minute and transfer the supernatant cell suspension to a new 10 milliliter tube.Repeat this process three more times with increasing force of trituration each time to ensure almost complete dissociation of the SCGs. Transfer the supernatant after each round of trituration to the 10 milliliter tube with the supernatant from the first trituration. Add enough culture media to bring the volume to eight to 10 milliliters.Gently mix a cell suspension and quantify the cell density with a hemocytometer. Distribute the cell suspension into the wells at the appropriate cell density for the experiments. Mix the cell suspension continually during the plating process to ensure even distribution of cells into the wells.For morphological analysis, plate the cells around 8, 000 cells per well in a 24-well plate. And for genomic and proteomic protocols, plate the cells as high as 30, 000 cells per well. Transfer the plates to a glass desiccator with sterile water at the bottom to create a humidified chamber.Inject enough CO2, around 120 milliliters, to obtain a 5%CO2 environment in the desiccator, prior to sealing. Maintain the plates at 35.5 degrees Celsius. This is referred to as day zero in the protocol.These plates can also be maintained in a regular 5%CO2 incubator. The method described above minimizes temperature and pH changes and also helps prevent cross-contamination. Maintenance of the cultured SCG neurons and treatments.These pictures show the dissociated superior cervical ganglia cells on day zero, day one, and day five. The day zero image shows the cells upon plating. The cells plated on day zero contain a mixture of both neuronal and non-neuronal cells.On day one, 24 hours after plating, carefully remove half of the culture media and replace with two micromolar Ara-C, cytosine D-arabinofuranoside, an anti-mitotic agent. Leave the treatment on the cells for 48 hours. Usually this length of treatment is sufficient to eliminate non-neuronal cells in the culture.On day three, gently aspirate half the medium and replace with control medium. On day four, the cells are ready for experimental treatments. Feed cultures every other day with the appropriate medium.Gently replacing half of the medium in the well with fresh medium. The picture on day five shows extensive axonal growth with no dendritic growth observed. To induce dendritic growth, neurons can be grown on Matrigel or treated with 10%serum or 50 nanograms per milliliter of bone morphogenetic protein-7.Figure two shows changes in neuronal morphology of E21 rat SCG neurons following treatment with BMP-7. Representative phase contrast micrographs at 10 X magnification show the circular neuronal cell body with axons in control neurons in panel A, and neurons with multiple short dendrite-like processes when treated with BMP-7 shown by the arrows in panel B.Cultured SCG neurons following appropriate treatments can be used for morphological analysis using immunocytochemical staining for genomic analysis and for biochemical studies, such as for proteomic analyses. Refer to the manuscript for detailed protocols for immunostaining and sample preparation for proteomic analysis.Figure three shows immunostaining from MAP-2 protein in cultured embryonic rats sympathetic neurons. Panels A through D show cultured SCG neurons treated with control media and panels E through H show neurons treated with BMP-7 at 50 nanograms per milliliter for five days. Representative micrographs showing immunocytochemical staining of the neurons with microtubule associated protein-2 in C and G, a nuclear stain in D and H with phase contrast micrographs in B and F, and emerge of the three channels in A and D.Immunocytochemical staining from microtubule associated protein-2 is present in the cell body and proximal axons of control neurons in panel C.And staining from MAP-2 protein in the cell body, and dendrites in BMP-7 treated neurons is in panel G.Here's a sample run of superior cervical ganglia treated with control media, which detected 1, 100 proteins.Gene ontology using the Panther database found that most of the proteins were cytoplasmic. However, there were membrane-bound proteins and proteins at cellular junctions in the sample. This analysis also revealed that proteins that are involved in a wide array of neuronal signaling pathways were detected in the sample.In conclusion, after watching this video, you should be able to isolate and culture rat embryonic superior cervical ganglion neurons for morphological and proteomic analysis. This work was funded by the faculty development fund and summer research program at Saint Mary's College of California.

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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 ...

Physiological, Morphological and Neurochemical Characterization of Neurons Modulated by Movement

The role of individual neurons and their function in neuronal circuits is fundamental to understanding the neuronal mechanisms of sensory and motor functions. Most investigations of sensorimotor mechanisms rely on either examination of neurons while an animal is static1,2 or record extracellular neuronal activity during a movement.3,4 While these studies have provided the fundamental background for sensorimotor function, they either do not evaluate functional information which occurs during a movement or are limited in their ability to fully characterize the anatomy, physiology and neurochemical phenotype of the neuron. A technique is shown here which allows extensive characterization of individual neurons during an in vivo movement. This technique can be used not only to study primary afferent neurons but also to characterize motoneurons and sensorimotor interneurons. Initially the response of a single neuron is recorded using electrophysiological methods during various movements of the mandible followed by determination of the receptive field for the neuron. A neuronal tracer is then intracellularly injected into the neuron and the brain is processed so that the neuron can be visualized with light, electron or confocal microscopy (Fig. 1). The detailed morphology of the characterized neuron is then reconstructed so that neuronal morphology can be correlated with the physiological response of the neuron (Figs. 2,3). In this communication important key details and tips for successful implementation of this technique are provided. Valuable additional information can be determined for the neuron under study by combining this method with other techniques. Retrograde neuronal labeling can be used to determine neurons with which the labeled neuron synapses; thus allowing detailed determination of neuronal circuitry. Immunocytochemistry can be combined with this method to examine neurotransmitters within the labeled neuron and to determine the chemical phenotypes of neurons with which the labeled neuron synapses. The labeled neuron can also be processed for electron microscopy to determine the ultrastructural features and microcircuitry of the labeled neuron. Overall this technique is a powerful method to thoroughly characterize neurons during in vivo movement thus allowing substantial insight into the role of the neuron in sensorimotor function.

A technique is described to quantify the in vivo physiological response of mammalian neurons during movement and correlate the physiology of the neuron with neuronal morphology, neurochemical phenotype and synaptic microcircuitry.

The role of individual neurons and their function in neuronal circuits is fundamental to understanding the neuronal mechanisms of sensory and motor ...

Chromatin Immunoprecipitation from Dorsal Root Ganglia Tissue following Axonal Injury

Axons in the central nervous system (CNS) do not regenerate while those in the peripheral nervous system (PNS) do regenerate 
to a limited extent after injury (Teng et al., 2006). It is recognized that transcriptional programs essential for neurite and axonal outgrowth are 
reactivated upon injury in the PNS (Makwana et al., 2005). However the tools available to analyze neuronal gene regulation in vivo are limited and 
often challenging.
The dorsal root ganglia (DRG) offer an excellent injury model system because both the CNS and PNS are innervated by a 
bifurcated axon originating from the same soma. The ganglia represent a discrete collection of cell bodies where all transcriptional events occur, 
and thus provide a clearly defined region of transcriptional activity that can be easily and reproducibly removed from the animal. Injury of nerve 
fibers in the PNS (e.g. sciatic nerve), where axonal regeneration does occur, should reveal a set of transcriptional programs that are distinct from 
those responding to a similar injury in the CNS, where regeneration does not take place (e.g. spinal cord). Sites for transcription factor binding, 
histone and DNA modification resulting from injury to either PNS or CNS can be characterized using chromatin immunoprecipitation (ChIP). 
Here, we describe a ChIP protocol using fixed mouse DRG tissue following axonal injury. This powerful combination provides a means for characterizing the pro-regeneration chromatin environment necessary for promoting axonal regeneration.

We present a method for chromatin immunoprecipitation from dorsal root ganglia tissue following axonal injury. The approach can be used to identify specific transcription factor binding sites and epigenetic modification of histone and DNA important for the regeneration of injured axons in both the peripheral and central nervous system.

Axons in the central nervous system (CNS) do not regenerate while those in the peripheral nervous system (PNS) do regenerate 
to a limited extent after ...

Cerebrovascular Casting of the Adult Mouse for 3D Imaging and Morphological Analysis

Vascular imaging is crucial in the clinical diagnosis and management of cerebrovascular diseases, such as brain arteriovenous malformations (BAVMs). Animal models are necessary for studying the etiopathology and potential therapies of cerebrovascular diseases. Imaging the vasculature in large animals is relatively easy. However, developing vessel imaging methods of murine brain disease models is desirable due to the cost and availability of genetically-modified mouse lines. Imaging the murine cerebral vascular tree is a challenge. In humans and larger animals, the gold standard for assessing the angioarchitecture at the macrovascular (conductance) level is x-ray catheter contrast-based angiography, a method not suited for small rodents.
In this article, we present a method of cerebrovascular casting that produces a durable skeleton of the entire vascular bed, including arteries, veins, and capillaries that may be analyzed using many different modalities. Complete casting of the microvessels of the mouse cerebrovasculature can be difficult; however, these challenges are addressed in this step-by-step protocol. Through intracardial perfusion of the vascular casting material, all vessels of the body are casted. The brain can then be removed and clarified using the organic solvent methyl salicylate. Three dimensional imaging of the brain blood vessels can be visualized simply and inexpensively with any conventional brightfield microscope or dissecting microscope. The casted cerebrovasculature can also be imaged and quantified using micro-computed tomography (micro-CT)1. In addition, after being imaged, the casted brain can be embedded in paraffin for histological analysis.
The benefit of this vascular casting method as compared to other techniques is its broad adaptation to various analytic tools, including brightfield microscopic analysis, CT scanning due to the radiopaque characteristic of the material, as well as histological and immunohistochemical analysis. This efficient use of tissue can save animal usage and reduce costs. We have recently demonstrated application of this method to visualize the irregular blood vessels in a mouse model of adult BAVM at a microscopic level2, and provide additional images of the malformed vessels imaged by micro-CT scan. Although this method has drawbacks and may not be ideal for all types of analyses, it is a simple, practical technique that can be easily learned and widely applied to vascular casting of blood vessels throughout the body.

In this article, we present a simple, practical technique for cerebrovascular casting that is easy to perform and can be utilized to image the vascular tree of the adult mouse brain.

Vascular imaging is crucial in the clinical diagnosis and management of cerebrovascular diseases, such as brain arteriovenous malformations (BAVMs). ...

Inducing Dendritic Growth in Cultured Sympathetic Neurons

The shape of the dendritic arbor determines the total synaptic input a neuron can receive 1-3, and influences the types and distribution of these inputs 4-6. Altered patterns of dendritic growth and plasticity are associated with impaired neurobehavioral function in experimental models 7, and are thought to contribute to clinical symptoms observed in both neurodevelopmental disorders 8-10 and neurodegenerative diseases 11-13. Such observations underscore the functional importance of precisely regulating dendritic morphology, and suggest that identifying mechanisms that control dendritic growth will not only advance understanding of how neuronal connectivity is regulated during normal development, but may also provide insight on novel therapeutic strategies for diverse neurological diseases.
Mechanistic studies of dendritic growth would be greatly facilitated by the availability of a model system that allows neurons to be experimentally switched from a state in which they do not extend dendrites to one in which they elaborate a dendritic arbor comparable to that of their in vivo counterparts. Primary cultures of sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rodents provide such a model. When cultured in defined medium in the absence of serum and ganglionic glial cells, sympathetic neurons extend a single process which is axonal, and this unipolar state persists for weeks to months in culture 14,15. However, the addition of either bone morphogenetic protein-7 (BMP-7) 16,17 or Matrigel 18 to the culture medium triggers these neurons to extend multiple processes that meet the morphologic, biochemical and functional criteria for dendrites. Sympathetic neurons dissociated from the SCG of perinatal rodents and grown under defined conditions are a homogenous population of neurons 19 that respond uniformly to the dendrite-promoting activity of Matrigel, BMP-7 and other BMPs of the decapentaplegic (dpp) and 60A subfamilies 17,18,20,21. Importantly, Matrigel- and BMP-induced dendrite formation occurs in the absence of changes in cell survival or axonal growth 17,18.
Here, we describe how to set up dissociated cultures of sympathetic neurons derived from the SCG of perinatal rats so that they are responsive to the selective dendrite-promoting activity of Matrigel or BMPs.

We describe a protocol for using bone morphogenetic protein-7 (BMP-7) or Matrigel to selectively induce dendritic growth in primary sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rats.

The shape of the dendritic arbor determines the total synaptic input a neuron can receive 1-3, and influences the types and distribution of these inputs ...

Production and Isolation of Axons from Sensory Neurons for Biochemical Analysis Using Porous Filters

Neuronal axons use specific mechanisms to mediate extension, maintain integrity, and induce degeneration. An appropriate balance of these events is required to shape functional neuronal circuits. The protocol described here explains how to use cell culture inserts bearing a porous membrane (filter) to obtain large amounts of pure axonal preparations suitable for examination by conventional biochemical or immunocytochemical techniques. The functionality of these filter inserts will be demonstrated with models of developmental pruning and Wallerian degeneration, using explants of embryonic dorsal root ganglion. Axonal integrity and function is compromised in a wide variety of neurodegenerative pathologies. Indeed, it is now clear that axonal dysfunction appears much earlier in the course of the disease than neuronal soma loss in several neurodegenerative diseases, indicating that axonal-specific processes are primarily targeted in these disorders. By obtaining pure axonal samples for analysis by molecular and biochemical techniques, this technique has the potential to shed new light into mechanisms regulating the physiology and pathophysiology of axons. This in turn will have an impact in our understanding of the processes that drive degenerative diseases of the nervous system.

This article describes a neuronal culture system that can be used to obtain large quantities of pure axonal samples for biochemical and immunocytochemical analyses. This technique will allow an improved understanding of normal axonal physiology and signaling pathways leading to neurodegeneration.

Neuronal axons use specific mechanisms to mediate extension, maintain integrity, and induce degeneration. An appropriate balance of these events is ...

A Method of Nodose Ganglia Injection in Sprague-Dawley Rat

Afferent signaling via the vagus nerve transmits important general visceral information to the central nervous system from many diverse receptors located in the organs of the abdomen and thorax. The vagus nerve communicates information from stimuli such as heart rate, blood pressure, bronchopulmonary irritation, and gastrointestinal distension to the nucleus of solitary tract of the medulla. The cell bodies of the vagus nerve are located in the nodose and petrosal ganglia, of which the majority are located in the former. The nodose ganglia contain a wealth of receptors for amino acids, monoamines, neuropeptides, and other neurochemicals that can modify afferent vagus nerve activity. Modifying vagal afferents through systemic peripheral drug treatments targeted at the receptors on nodose ganglia has the potential of treating diseases such as sleep apnea, gastroesophageal reflux disease, or chronic cough. The protocol here describes a method of injection neurochemicals directly into the nodose ganglion. Injecting neurochemicals directly into the nodose ganglia allows study of effects solely on cell bodies that modulate afferent nerve activity, and prevents the complication of involving the central nervous system as seen in systemic neurochemical treatment. Using readily available and inexpensive equipment, intranodose ganglia injections are easily done in anesthetized Sprague-Dawley rats.

Afferent vagal signaling transmits important information to central nervous system from receptors located in organs of the abdomen and thorax. The nodose ganglia of vagus nerves contain many types of receptors that modulate vagal activity. This protocol describes a method of local injections of neurochemicals into the nodose ganglia.

Afferent signaling via the vagus nerve transmits important general visceral information to the central nervous system from many diverse receptors located ...

Functional and Morphological Assessment of Diaphragm Innervation by Phrenic Motor Neurons

This protocol specifically focuses on tools for assessing phrenic motor neuron (PhMN) innervation of the diaphragm at both the electrophysiological and morphological levels. Compound muscle action potential (CMAP) recording following phrenic nerve stimulation can be used to quantitatively assess functional diaphragm innervation by PhMNs of the cervical spinal cord in vivo in anesthetized rats and mice. Because CMAPs represent simultaneous recording of all myofibers of the whole hemi-diaphragm, it is useful to also examine the phenotypes of individual motor axons and myofibers at the diaphragm NMJ in order to track disease- and therapy-relevant morphological changes such as partial and complete denervation, regenerative sprouting and reinnervation. This can be accomplished via whole-mount immunohistochemistry (IHC) of the diaphragm, followed by detailed morphological assessment of individual NMJs throughout the muscle. Combining CMAPs and NMJ analysis provides a powerful approach for quantitatively studying diaphragmatic innervation in rodent models of CNS and PNS disease.

Compound muscle action potential recording quantitatively assesses functional diaphragm innervation by phrenic motor neurons. Whole-mount diaphragm immunohistochemistry assesses morphological innervation at individual neuromuscular junctions. The goal of this protocol is to demonstrate how these two powerful methodologies can be used in various rodent models of spinal cord disease.

This protocol specifically focuses on tools for assessing phrenic motor neuron (PhMN) innervation of the diaphragm at both the electrophysiological and ...

Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons

Susceptibility to neuron cell death associated to neurodegeneration and ischemia are exceedingly increased in the aged brain but mechanisms responsible are badly known. Excitotoxicity, a process believed to contribute to neuron damage induced by both insults, is mediated by activation of glutamate receptors that promotes Ca2+ influx and mitochondrial Ca2+ overload. A substantial change in intracellular Ca2+ homeostasis or remodeling of intracellular Ca2+ homeostasis may favor neuron damage in old neurons. For investigating Ca2+ remodeling in aging we have used live cell imaging in long-term cultures of rat hippocampal neurons that resemble in some aspects aged neurons in vivo. For this end, hippocampal cells are, in first place, freshly dispersed from new born rat hippocampi and plated on poli-D-lysine coated, glass coverslips. Then cultures are kept in controlled media for several days or several weeks for investigating young and old neurons, respectively. Second, cultured neurons are loaded with fura2 and subjected to measurements of cytosolic Ca2+ concentration using digital fluorescence ratio imaging. Third, cultured neurons are transfected with plasmids expressing a tandem of low-affinity aequorin and GFP targeted to mitochondria. After 24 hr, aequorin inside cells is reconstituted with coelenterazine and neurons are subjected to bioluminescence imaging for monitoring of mitochondrial Ca2+ concentration. This three-step procedure allows the monitoring of cytosolic and mitochondrial Ca2+ responses to relevant stimuli as for example the glutamate receptor agonist NMDA and compare whether these and other responses are influenced by aging. This procedure may yield new insights as to how aging influence cytosolic and mitochondrial Ca2+ responses to selected stimuli as well as the testing of selected drugs aimed at preventing neuron cell death in age-related diseases.

Fluorescence and Bioluminescence Imaging of Subcellular Ca2+ in Aged Hippocampal Neurons

Intracellular Ca2+ remodeling in aging may contribute to excitotoxicity and neuron damage, processes mediated by Ca2+ overload. We aimed at investigating Ca2+ remodeling in the aging brain using fluorescence and bioluminescence imaging of cytosolic and mitochondrial Ca2+ in long-term cultures of rat hippocampal neurons, a model of neuronal aging.

Susceptibility to neuron cell death associated to neurodegeneration and ischemia are exceedingly increased in the aged brain but mechanisms responsible ...

Fluorescence Activated Cell Sorting (FACS) and Gene Expression Analysis of Fos-expressing Neurons from Fresh and Frozen Rat Brain Tissue

The study of neuroplasticity and molecular alterations in learned behaviors is switching from the study of whole brain regions to the study of specific sets of sparsely distributed activated neurons called neuronal ensembles that mediate learned associations. Fluorescence Activated Cell Sorting (FACS) has recently been optimized for adult rat brain tissue and allowed isolation of activated neurons using antibodies against the neuronal marker NeuN and Fos protein, a marker of strongly activated neurons. Until now, Fos-expressing neurons and other cell types were isolated from fresh tissue, which entailed long processing days and allowed very limited numbers of brain samples to be assessed after lengthy and complex behavioral procedures. Here we found that yields of Fos-expressing neurons and Fos mRNA from dorsal striatum were similar between freshly dissected tissue and tissue frozen at -80 &#186;C for 3 - 21 days. In addition, we confirmed the phenotype of the NeuN-positive and NeuN-negative sorted cells by assessing gene expression of neuronal (NeuN), astrocytic (GFAP), oligodendrocytic (Oligo2) and microgial (Iba1) markers, which indicates that frozen tissue can also be used for FACS isolation of glial cell types. Overall, it is possible to collect, dissect and freeze brain tissue for multiple FACS sessions. This maximizes the amount of data obtained from valuable animal subjects that have often undergone long and complex behavioral procedures.

Fluorescence Activated Cell Sorting FACS and Gene Expression Analysis of Fos-expressing Neurons from Fresh and Frozen Rat Brain Tissue

Here we present a Fluorescence Activated Cell Sorting (FACS) protocol to study molecular alterations in Fos-expressing neuronal ensembles from both fresh and frozen brain tissue. The use of frozen tissue allows FACS isolation of many brain areas over multiple sessions to maximize the use of valuable animal subjects.

The study of neuroplasticity and molecular alterations in learned behaviors is switching from the study of whole brain regions to the study of specific ...