Name: olfactory neurons obtained through nasal biopsy combined with laser-capture microdissection: a potential approach to study treatment response in mental disorders
Uploaded: 2014-12-04T13:00:00
Description: Watch this Scientific Journal Video about Olfactory Neurons Obtained through Nasal Biopsy Combined with Laser-Capture Microdissection: A Potential Approach to Study Treatment Response in Mental Disord

This work was supported by USPHS grants MH-091460 (E.N.), MH-084018 (A.S.), MH-094268 Silvo O. Conte center (A.S.), MH-069853 (A.S.), MH-085226 (A.S.), MH-088753 (A.S.), MH-092443 (A.S.), and MH-096208 (K.I.), grants from DANA (E.N.), Stanley (A.S.), RUSK (A.S.), S-R foundations (A.S.), NARSAD (A.S. and K.I.), and Maryland Stem Cell Research Fund (A.S. and K.I.).
We sincerely appreciate the efforts and contributions of Pearl Kim, Maria Papapavlou, Nao Gamo, Youjin Chung, Yukiko Lema and Mark Christie towards coordination of the biopsy process.

NOTE: All research volunteers in this study were administered informed consent documents approved by the Institutional Review Board of Howard University and Johns Hopkins University. Only participants who consented by signing the informed consent documents were enrolled into the study. The study base for this analysis consisted of: 20 subjects (12 BD and 10 controls; 30% males) and mean age (s.d.) of 38.2 (14.1) years. 
NOTE: Spray all surfaces with RNase Zap to remove RNase contamination from glass and plastic surf...

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	<li>Goodwin, F. K., Jamison, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manic-depressive illness. , (1990).</li><li>Einat, H., Manji, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+plasticity+cascades:+genes-to-behavior+pathways+in+animal+models+of+bipolar+disorder.">Cellular plasticity cascades: genes-to-behavior pathways in animal models of bipolar disorder.</a> Biol Psychiatry. 59 (12), 1160-1171 (2006).</li><li>Severino, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharmacogenomics+of+bipolar+disorder.">Pharmacogenomics of bipolar disorder.</a> Pharmacogenomics. 14 (6), 655-674 (2013).</li><li>Beech, R. D., 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=Gene-expression+differences+in+peripheral+blood+between+lithium+responders+and+non-responders+in+the+Lithium+Treatment-Moderate+dose+Use+Study+(LiTMUS).">Gene-expression differences in peripheral blood between lithium responders and non-responders in the Lithium Treatment-Moderate dose Use Study (LiTMUS).</a> Pharmacogenomics J. 14 (2), 182-191 (2013).</li><li>Horiuchi, 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=Olfactory+cells+via+nasal+biopsy+reflect+the+developing+brain+in+gene+expression+profiles:+utility+and+limitation+of+the+surrogate+tissues+in+research+for+brain+disorders.">Olfactory cells via nasal biopsy reflect the developing brain in gene expression profiles: utility and limitation of the surrogate tissues in research for brain disorders.</a> Neurosci Res. 77 (4), 247-250 (2013).</li><li>Dryer, L., Graziadei, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Projections+of+the+olfactory+bulb+in+an+elasmobranch+fish,+Sphyrna+tiburo:+segregation+of+inputs+in+the+telencephalon.">Projections of the olfactory bulb in an elasmobranch fish, Sphyrna tiburo: segregation of inputs in the telencephalon.</a> Anat Embryol (Berl. 190 (6), 563-572 (1994).</li><li>Hahn, C. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+and+in+vitro+neurogenesis+in+human+olfactory+epithelium.">In vivo and in vitro neurogenesis in human olfactory epithelium.</a> J Comp Neurol. 483 (2), 154-163 (2005).</li><li>Cascella, N. G., Takaki, M., Lin, S., Sawa, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurodevelopmental+involvement+in+schizophrenia:+the+olfactory+epithelium+as+an+alternative+model+for+research.">Neurodevelopmental involvement in schizophrenia: the olfactory epithelium as an alternative model for research.</a> J Neurochem. 102 (3), 587-594 (2007).</li><li>Sawa, A., Cascella, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+olfactory+system+for+clinical+and+basic+psychiatry:+a+promising+entry+point+to+the+mystery+of+brain+mechanism+and+biomarker+identification+in+schizophrenia.">Peripheral olfactory system for clinical and basic psychiatry: a promising entry point to the mystery of brain mechanism and biomarker identification in schizophrenia.</a> Am J Psychiatry. 166 (2), 137-139 (2009).</li><li>Mor, 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=MicroRNA-382+expression+is+elevated+in+the+olfactory+neuroepithelium+of+schizophrenia+patients.">MicroRNA-382 expression is elevated in the olfactory neuroepithelium of schizophrenia patients.</a> Neurobiol Dis. 55, 1-10 (2013).</li><li>Kano, 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=Genome-wide+profiling+of+multiple+histone+methylations+in+olfactory+cells:+further+implications+for+cellular+susceptibility+to+oxidative+stress+in+schizophrenia.">Genome-wide profiling of multiple histone methylations in olfactory cells: further implications for cellular susceptibility to oxidative stress in schizophrenia.</a> Mol Psychiatry. 18 (7), 740-742 (2013).</li><li>Toritsuka, 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=Deficits+in+microRNA-mediated+Cxcr4/Cxcl12+signaling+in+neurodevelopmental+deficits+in+a+22q11+deletion+syndrome+mouse+model.">Deficits in microRNA-mediated Cxcr4/Cxcl12 signaling in neurodevelopmental deficits in a 22q11 deletion syndrome mouse model.</a> Proc Natl Acad Sci U S A. 110 (43), 17552-17557 (2013).</li><li>Evgrafov, O. 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=Olfactory+neuroepithelium-derived+neural+progenitor+cells+as+a+model+system+for+investigating+the+molecular+mechanisms+of+neuropsychiatric+disorders.">Olfactory neuroepithelium-derived neural progenitor cells as a model system for investigating the molecular mechanisms of neuropsychiatric disorders.</a> Psychiatr Genet. 21 (5), 217-228 (2011).</li><li>Fan, 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=Focal+adhesion+dynamics+are+altered+in+schizophrenia.">Focal adhesion dynamics are altered in schizophrenia.</a> Biol Psychiatry. 74 (6), 418-426 (2013).</li><li>Ishizuka, 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=Negative+symptoms+of+schizophrenia+correlate+with+impairment+on+the+University+of+Pennsylvania+smell+identification+test.">Negative symptoms of schizophrenia correlate with impairment on the University of Pennsylvania smell identification test.</a> Neurosci Res. 66, 106-110 (2010).</li><li>Sattler, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+nasal+olfactory+epithelium+as+a+dynamic+marker+for+CNS+therapy+development.">Human nasal olfactory epithelium as a dynamic marker for CNS therapy development.</a> Exp Neurol. 232 (2), 203-211 (2011).</li><li>Rimbault, M., Robin, S., Vaysse, A., Galibert, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNA+profiles+of+rat+olfactory+epithelia:+individual+and+age+related+variations.">RNA profiles of rat olfactory epithelia: individual and age related variations.</a> BMC Genomics. 10, 572 (2009).</li><li>Tajinda, 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=Neuronal+biomarkers+from+patients+with+mental+illnesses:+a+novel+method+through+nasal+biopsy+combined+with+laser-captured+microdissection.">Neuronal biomarkers from patients with mental illnesses: a novel method through nasal biopsy combined with laser-captured microdissection.</a> Mol Psychiatry. 15 (3), 231-232 (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 (5342), 1481-1483 (1997).</li><li>Fink, 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=Real-time+quantitative+RT-PCR+after+laser-assisted+cell+picking.">Real-time quantitative RT-PCR after laser-assisted cell picking.</a> Nat Med. 4 (11), 1329-1333 (1998).</li><li>Emmert-Buck, M. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+capture+microdissection.">Laser capture microdissection.</a> Science. 274 (5289), 998-1001 (1996).</li><li>Nurnberger, J. I., 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=Diagnostic+interview+for+genetic+studies.+Rationale,+unique+features,+and+training.">Diagnostic interview for genetic studies. Rationale, unique features, and training.</a> NIMH Genetics Initiative. Arch Gen Psychiatry. 51 (11), 849-859 (1994).</li><li>Montgomery, S. A., Asberg, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+depression+scale+designed+to+be+sensitive+to+change.">A new depression scale designed to be sensitive to change.</a> Br J Psychiatry. 134, 382-389 (1979).</li><li>Young, R. C., Biggs, J. T., Ziegler, V. E., Meyer, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rating+scale+for+mania:+reliability,+validity+and+sensitivity.">A rating scale for mania: reliability, validity and sensitivity.</a> Br J Psychiatry. 133, 429-435 (1978).</li></ol>

A new platform for obtaining enriched olfactory neuronal layers by combining nasal biopsy and LCM is presented and has been validated in this study. This technique can have widespread implications. It can be applied towards biomarker studies, including those for treatment response, and drug discovery efforts for other neuropsychiatric conditions, making a broader impact in the field.
To obtain high quality neurons amenable to downstream applications, a few critical and troubleshooting steps mu...

Bipolar disorder (BD) is a severe neuropsychiatric disorder, characterized by pathological changes in mood, drive and cognition1. Lithium used for treatment of BD has been shown to alter steady state mRNA levels of a large number of genes in animal studies2, but it remains unknown if any of these molecules is associated with clinical response in humans2. Understanding the mechanism of lithium response would require investigating lithium-induced molecular changes in neuronal tissues. Unfortunately, it is not practical to obtain brain biopsies of BD patients pre- and post-lithium therapy to identify molecular signatures of lithium response. Post-mortem brain tissues have been used to study biomarkers in BD, however, they cannot be used to assess molecular markers associated with dynamic changes in emotions, cognition and drive; and the validity of retrospectively ascertained lithium treatment response can be problematic4. Lymphocytes and other blood cells could be useful, but molecular changes in blood cells may not reflect neuronal alterations3-5. Cerebrospinal fluid may be insufficient to obtain information on intracellular molecules that may reflect disease-associated and medication-reversible intrinsic changes.
The olfactory epithelium (OE) is a unique part of the central nervous system (CNS), embryologically-related to limbic structures6; and it is easily accessible through nasal biopsies. It consists of glial-like supporting (i.e., sustentacular) cells, basal proliferating cells, and olfactory receptor neurons at different stages of development7-9. Therefore, OE provides a unique opportunity to accessibly study dynamic changes in the CNS of patients with neuropsychiatric diseases7. Studies are demonstrating the utility of the OE as a surrogate tissue for investigating disease associated events that reflect those occurring in brain neurons8,9. For example, studies have utilized OE to investigate molecular profiles associated with psychiatric conditions10-14. Olfactory system also serves to identify clinical endophenoytpes such as smell deficits that are associated with negative symptoms of schizophrenia15. Additionally, neurodevelopmental processes continue in the OE throughout life, providing a useful avenue to model the underlying pathophysiology of psychiatric conditions8,9.
However, a drawback to the use of this tissue is the substantial contamination of olfactory biopsies with non-neuronal cells16. For instance, total RNA used for gene expression studies in previous OE studies contained RNA extracted from the entire nasal biopsied tissue including RNA from non-neuronal cells17. Therefore, previous approaches have been limited by the quality of cells. To overcome this issue, a novel approach to obtain enriched neuronal cell populations by combining nasal biopsies with laser-capture microdissection (LCM) has been developed18.
LCM is a technique that allows for the selective isolation of cells using UV laser cutting combined with infra-red laser19-21. Combining LCM with OE approach minimizes substantial contamination of OE by non-neuronal cells, thereby enhancing enrichment of neuronal cells18. Moreover, the neuronal layer can be distinguished from the submucosa layer under a microscope, thereby eliminating the need for staining. Neuronal cell types can further be distinguished from other cell populations using primary antibodies which are expressed by the cell type of interest7. Therefore, this procedure establishes an easier method for the enrichment of almost purely neuronal cell population that can be used for gene expression studies, immunohistochemistry and other morphologic investigations.
This study aims to establish an experimental platform to investigate molecular changes in olfactory neurons associated with disease states and treatment response. To address this, a small set of non-smoking patients who met the DSM-IV diagnostic criteria for BD based on the Diagnostic Interview for Genetic Studies (DIG)22 was recruited to undergo two nasal biopsies: one biopsy pre-treatment with lithium and the second biopsy, after 6 weeks of daily oral lithium therapy. Furthermore, eligible BD patients must be: symptomatic for depression, based on scoring &#8805;10 out of 60 in the clinician administered Montgomery-Asberg Rating Scale (MADRS)23; symptomatic for hypomania or mania, based on a score &#8805;10 out of 56 on the clinician administered Young-Mania Rating Scale (YMRS)24; or &#8805;10 on both MADRS and YMRS. Rater-Inter-Rater coefficient of agreement between clinicians for both scales is &#62;0.96. After biopsies, neurons were enriched from OE by LCM. Following additional quality control measures, to ensure extraction of high quality RNA from the tissue and neuronal enrichment, Real Time RT PCR was conducted to investigate pre- and post-treatment expression levels of genes of interest. The ensuing sections contain a description of the validation of this approach, highlighting the optimization of the protocol and the strategies that were applied for trouble-shooting the protocol.

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	<tbody>
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			<td height="21" style="height:21px;width:283px;">Reagent</td>
			<td style="width:143px;">Manufacturuer&#160;</td>
			<td style="width:175px;">Manufacturer Catalog #</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tissue Preparation</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Tissue-Tek Cryomold Molds</td>
			<td>Sakura Finetek</td>
			<td>4557</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tissue-Tek O.C.T Compound</td>
			<td>Sakura Finetek</td>
			<td>4583</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Cryosectioning</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Membrane Slide 1.0 PEN (D)</td>
			<td>Carl Zeiss Microscopy</td>
			<td>415190-9041-000</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Rnase Zap</td>
			<td>Ambion</td>
			<td>AM9780</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DEPC Treated Water</td>
			<td>Quality Biological</td>
			<td>351-068-131</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Microdissection</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Microscope: PALM Series MicroLaser System</td>
			<td>Carl Zeiss Microscopy</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Model: Axiovert 200M</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Software: Robo v3.2</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">No.5 Dumont Microdissction Forceps</td>
			<td>Roboz</td>
			<td>RS-49085</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">RNA Extraction</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">RNAqueous Micro Kit</td>
			<td>Ambion</td>
			<td>AM1931</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">cDNA Synthesis</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SuperScript III First Strand Synthesis Kit</td>
			<td>Invitrogen&#160;</td>
			<td>18080-051</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">OMP qPCR</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SYBR GreenER qPCR SuperMix</td>
			<td>Invitrogen&#160;</td>
			<td>11760-500</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Taqman qPCR</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">TaqMan Expression Assay Probes</td>
			<td>Applied Biosystems</td>
			<td>Various</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TaqMan Gene Expression Master Mix</td>
			<td>Applied Biosystems</td>
			<td>4369016</td>
		</tr>
	</tbody>
</table>

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.

The protocol and troubleshooting strategy in the study of molecular signatures were successfully optimized. RNA quality and neuronal enrichment criteria for samples to be used in further downstream Real Time-PCR analysis were standardized. RIN and RNA concentration were examined as confounding factors to detected expression levels. Based on the analysis of several samples with RINs ranging from 1 - 10, it was determined that a minimum RIN of ~3.0 and above is sufficient for downstream analysis in this study. As a result,...

Watch this Scientific Journal Video about Olfactory Neurons Obtained through Nasal Biopsy Combined with Laser-Capture Microdissection: A Potential Approach to Study Treatment Response in Mental Disord

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

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 ...

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Neuroscience

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 ...

Targeting Olfactory Bulb Neurons Using Combined In Vivo Electroporation and Gal4-Based Enhancer Trap Zebrafish Lines

In vivo electroporation is a powerful method for delivering DNA expression plasmids, RNAi reagents, and morpholino anti-sense oligonucleotides to specific regions of developing embryos, including those of C. elegans, chick, Xenopus, zebrafish, and mouse 1. In zebrafish, in vivo electroporation has been shown to have excellent spatial and temporal resolution for the delivery of these reagents 2-7. The temporal resolution of this method is important because it allows for incorporation of these reagents at specific stages in development. Furthermore, because expression from electroporated vectors occurs within 6 hours 7, this method is more timely than transgenic approaches. While the spatial resolution can be extremely precise when targeting a single cell 2, 6, it is often preferable to incorporate reagents into a specific cell population within a tissue or structure. When targeting multiple cells, in vivo electroporation is efficient for delivery to a specific region of the embryo; however, particularly within the developing nervous system, it is difficult to target specific cell types solely through spatially discrete electroporation. Alternatively, enhancer trap transgenic lines offer excellent cell type-specific expression of transgenes 8. Here we describe an approach that combines transgenic Gal4-based enhancer trap lines 8 with spatially discrete in vivo electroporation 7, 9 to specifically target developing neurons of the zebrafish olfactory bulb. The Et(zic4:Gal4TA4,UAS:mCherry)hzm5 (formerly GA80_9) enhancer trap line previously described 8, displays targeted transgenic expression of mCherry mediated by a zebrafish optimized Gal4 (KalTA4) transcriptional activator in multiple regions of the developing brain including hindbrain, cerebellum, forebrain, and the olfactory bulb. To target GFP expression specifically to the olfactory bulb, a plasmid with the coding sequence of GFP under control of multiple Gal4 binding sites (UAS) was electroporated into the anterior end of the forebrain at 24-28 hours post-fertilization (hpf). Although this method incorporates plasmid DNA into multiple regions of the forebrain, GFP expression is only induced in cells transgenically expressing the KalTA4 transcription factor. Thus, by using the GA080_9 transgenic line, this approach led to GFP expression exclusively in the developing olfactory bulb. GFP expressing cells targeted through this approach showed typical axonal projections, as previously described for mitral cells of the olfactory bulb 10. This method could also be used for targeted delivery of other reagents including short-hairpin RNA interference expression plasmids, which would provide a method for spatially and temporally discrete loss-of-function analysis.

Targeting Olfactory Bulb Neurons Using Combined In Vivo Electroporation and Gal4-Based Enhancer Trap Zebrafish Lines

The temporal and spatial resolution of genetic manipulations determines the spectrum of biological phenomena that they can perturb. Here we use temporally and spatially discrete in vivo electroporation, combined with transgenic lines of zebrafish, to induce expression of a GFP transgene specifically in neurons of the developing olfactory bulb.

In vivo electroporation is a powerful method for delivering DNA expression plasmids, RNAi reagents, and morpholino anti-sense oligonucleotides to specific ...

Non-Laser Capture Microscopy Approach for the Microdissection of Discrete Mouse Brain Regions for Total RNA Isolation and Downstream Next-Generation Sequencing and Gene Expression Profiling

As technological platforms, approaches such as next-generation sequencing, microarray, and qRT-PCR have great promise for expanding our understanding of the breadth of molecular regulation. Newer approaches such as high-resolution RNA sequencing (RNA-Seq)1 provides new and expansive information about tissue- or state-specific expression such as relative transcript levels, alternative splicing, and micro RNAs2-4. Prospects for employing the RNA-Seq method in comparative whole transcriptome profiling5 within discrete tissues or between phenotypically distinct groups of individuals affords new avenues for elucidating molecular mechanisms involved in both normal and abnormal physiological states. Recently, whole transcriptome profiling has been performed on human brain tissue, identifying gene expression differences associated with disease progression6. However, the use of next-generation sequencing has yet to be more widely integrated into mammalian studies.
Gene expression studies in mouse models have reported distinct profiles within various brain nuclei using laser capture microscopy (LCM) for sample excision7,8. While LCM affords sample collection with single-cell and discrete brain region precision, the relatively low total RNA yields from the LCM approach can be prohibitive to RNA-Seq and other profiling approaches in mouse brain tissues and may require sub-optimal sample amplification steps. Here, a protocol is presented for microdissection and total RNA extraction from discrete mouse brain regions. Set-diameter tissue corers are used to isolate 13 tissues from 750-&mu;m serial coronal sections of an individual mouse brain. Tissue micropunch samples are immediately frozen and archived. Total RNA is obtained from the samples using magnetic bead-enabled total RNA isolation technology. Resulting RNA samples have adequate yield and quality for use in downstream expression profiling. This microdissection strategy provides a viable option to existing sample collection strategies for obtaining total RNA from discrete brain regions, opening possibilities for new gene expression discoveries.

Non-Laser Capture Microscopy Approach for the Microdissection of Discrete Mouse Brain Regions for Total RNA Isolation and Downstream Next-Generation Sequencing and Gene Expression Profiling  |

RNA expression profiling of discrete mouse brain regions requires a precise and repeatable tissue collection strategy. A protocol that uses both coronal brain sectioning and tissue corer-assisted microdissection is described here. The yield and quality of total RNA obtained from the resulting samples confirms the utility of the outlined method.

As technological platforms, approaches such as next-generation sequencing, microarray, and qRT-PCR have great promise for expanding our understanding of ...

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 ...

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.

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 ...

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 ...

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 ...

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.

The ability to isolate specific brain regions of interest can be impeded in tissue disassociation techniques that do not preserve their spatial ...

Tracking Drosophila Larval Behavior in Response to Optogenetic Stimulation of Olfactory Neurons

The ability of insects to navigate toward odor sources is based on the activities of their first-order olfactory receptor neurons (ORNs). While a considerable amount of information has been generated regarding ORN responses to odorants, the role of specific ORNs in driving behavioral responses remains poorly understood. Complications in behavior analyses arise due to different volatilities of odorants that activate individual ORNs, multiple ORNs activated by single odorants, and the difficulty in replicating naturally observed temporal variations in olfactory stimuli using conventional odor-delivery methods in the laboratory. Here, we describe a protocol that analyzes Drosophila larval behavior in response to simultaneous optogenetic stimulation of its ORNs. The optogenetic technology used here allows for specificity of ORN activation and precise control of temporal patterns of ORN activation. Corresponding larval movement is tracked, digitally recorded, and analyzed using custom written software. By replacing odor stimuli with light stimuli, this method allows for a more precise control of individual ORN activation in order to study its impact on larval behavior. Our method could be further extended to study the impact of second-order projection neurons (PNs) as well as local neurons (LNs) on larval behavior. This method will thus enable a comprehensive dissection of olfactory circuit function and complement studies on how olfactory neuron activities translate in to behavior responses.

Tracking Drosophila Larval Behavior in Response to Optogenetic Stimulation of Olfactory Neurons

This protocol analyzes navigational behavior of Drosophila larva in response to simultaneous optogenetic stimulation of its olfactory neurons. Light of 630 nm wavelength is used to activate individual olfactory neurons expressing a red-shifted channel rhodopsin. Larval movement is simultaneously tracked, digitally recorded, and analyzed using custom-written software.

The ability of insects to navigate toward odor sources is based on the activities of their first-order olfactory receptor neurons (ORNs). While a ...

Optimization of Laser-Capture Microdissection for the Isolation of Enteric Ganglia from Fresh-Frozen Human Tissue

The purpose of this method is to obtain high-integrity RNA samples from enteric ganglia collected from unfixed, freshly-resected human intestinal tissue using laser capture microdissection (LCM). We have identified five steps in the workflow that are crucial for obtaining RNA isolates from enteric ganglia with sufficiently high quality and quantity for RNA-seq. First, when preparing intestinal tissue, each sample must have all excess liquid removed by blotting prior to flattening the serosa as much as possible across the bottom of large base molds. Samples are then quickly frozen atop a slurry of dry ice and 2-methylbutane. Second, when sectioning the tissue, it is important to position cryomolds so that intestinal sections parallel the full plane of the myenteric plexus, thereby yielding the greatest surface area of enteric ganglia per slide. Third, during LCM, polyethylene napthalate (PEN)-membrane slides offer the greatest speed and flexibility in outlining the non-uniform shapes of enteric ganglia when collecting enteric ganglia. Fourth, for distinct visualization of enteric ganglia within sections, ethanol-compatible dyes, like Cresyl Violet, offer excellent preservation of RNA integrity relative to aqueous dyes. Finally, for the extraction of RNA from captured ganglia, we observed differences between commercial RNA extraction kits that yielded superior RNA quantity and quality, while eliminating DNA contamination. Optimization of these factors in the current protocol greatly accelerates the workflow and yields enteric ganglia samples with exceptional RNA quality and quantity.

The goal of this protocol is to obtain high-integrity RNA samples from enteric ganglia isolated from unfixed, freshly-resected human intestinal tissue using laser capture microdissection (LCM). This protocol involves preparing flash-frozen samples of human intestinal tissue, cryosectioning, ethanolic staining and dehydration, LCM, and RNA extraction.

The purpose of this method is to obtain high-integrity RNA samples from enteric ganglia collected from unfixed, freshly-resected human intestinal tissue ...