We thank K. Gill for the laboratory management and technical support, J. Hawkins and the staff of National Institutes of Health (NIH) Building 50 animal facility for the assistance with mouse care, and R. Reed and F. Baldrey for administrative assistance. Thanks also to S. Motegi and M. Udey for sharing their ear skin dissection protocol, N. Burns for editorial help, and members of the Laboratory of Stem Cell and Neuro-Vascular Biology for technical help and thoughtful discussion. T. Yamazaki was supported by the Japan Society for the Promotion of Science (JSPS) NIH-KAITOKU. This work was supported by the Intramural Research Program of the National Heart, Lung, and Blood Institute (HL005702-11 to Y.M.)

All experiments in this section were performed under approval from the National Heart, Lung, and Blood Institute (NHLBI) Animal Care and Use Committee.
1. Adult Mouse Ear Skin Collection
<ol>
	<li>Euthanize adult mice by carbon dioxide (CO2) exposure in a closed chamber and then confirm the euthanasia by cervical dislocation. 
	NOTE: The experiment follows the National Institutes of Health (NIH) guideline for the euthanasia method.</li>
	<li>Dissect the ear from the base and ...

<ol>
	<li>Mukouyama, Y. S., Shin, D., Britsch, S., Taniguchi, M., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensory+nerves+determine+the+pattern+of+arterial+differentiation+and+blood+vessel+branching+in+the+skin.">Sensory nerves determine the pattern of arterial differentiation and blood vessel branching in the skin.</a> Cell. 109, 693-705 (2002).</li><li>Mukouyama, Y. S., James, J., Nam, J., Uchida, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-mount+confocal+microscopy+for+vascular+branching+morphogenesis.">Whole-mount confocal microscopy for vascular branching morphogenesis.</a> Methods Mol Biol. 843, 69-78 (2012).</li><li>Li, W., Mukouyama, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole-mount+immunohistochemical+analysis+for+embryonic+limb+skin+vasculature:+a+model+system+to+study+vascular+branching+morphogenesis+in+embryo.">Whole-mount immunohistochemical analysis for embryonic limb skin vasculature: a model system to study vascular branching morphogenesis in embryo.</a> J Vis Exp. , (2011).</li><li>Yamazaki, T., 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=Tissue+Myeloid+Progenitors+Differentiate+into+Pericytes+through+TGF-beta+Signaling+in+Developing+Skin+Vasculature.">Tissue Myeloid Progenitors Differentiate into Pericytes through TGF-beta Signaling in Developing Skin Vasculature.</a> Cell Rep. 18, 2991-3004 (2017).</li><li>Mukouyama, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vessel-dependent+recruitment+of+sympathetic+axons:+looking+for+innervation+in+all+the+right+places.">Vessel-dependent recruitment of sympathetic axons: looking for innervation in all the right places.</a> J Clin Invest. 124, 2855-2857 (2014).</li><li>Li, W., 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=Peripheral+nerve-derived+CXCL12+and+VEGF-A+regulate+the+patterning+of+arterial+vessel+branching+in+developing+limb+skin.">Peripheral nerve-derived CXCL12 and VEGF-A regulate the patterning of arterial vessel branching in developing limb skin.</a> Dev Cell. 24, 359-371 (2013).</li><li>Chang, H., Wang, Y., Wu, H., Nathans, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flat+mount+imaging+of+mouse+skin+and+its+application+to+the+analysis+of+hair+follicle+patterning+and+sensory+axon+morphology.">Flat mount imaging of mouse skin and its application to the analysis of hair follicle patterning and sensory axon morphology.</a> J Vis Exp. , e51749 (2014).</li><li>Salz, L., Driskell, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Horizontal+Whole+Mount:+A+Novel+Processing+and+Imaging+Protocol+for+Thick,+Three-dimensional+Tissue+Cross-sections+of+Skin.">Horizontal Whole Mount: A Novel Processing and Imaging Protocol for Thick, Three-dimensional Tissue Cross-sections of Skin.</a> J Vis Exp. , (2017).</li><li>Liakath-Ali, 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=Novel+skin+phenotypes+revealed+by+a+genome-wide+mouse+reverse+genetic+screen.">Novel skin phenotypes revealed by a genome-wide mouse reverse genetic screen.</a> Nat Commun. 5, 3540 (2014).</li><li>Gunawan, 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=The+methyltransferase+Ezh2+controls+cell+adhesion+and+migration+through+direct+methylation+of+the+extranuclear+regulatory+protein+talin.">The methyltransferase Ezh2 controls cell adhesion and migration through direct methylation of the extranuclear regulatory protein talin.</a> Nat Immunol. 16, 505-516 (2015).</li><li>Avci, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+skin+disease+for+drug+discovery.">Animal models of skin disease for drug discovery.</a> Expert Opin Drug Dis. 8, 331-355 (2013).</li><li>Jin, H., He, R., Oyoshi, M., Geha, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+atopic+dermatitis.">Animal models of atopic dermatitis.</a> J Invest Dermatol. 129, 31-40 (2009).</li><li>Wagner, E. F., Schonthaler, H. B., Guinea-Viniegra, J., Tschachler, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Psoriasis:+what+we+have+learned+from+mouse+models.">Psoriasis: what we have learned from mouse models.</a> Nat Rev Rheumatol. 6, 704-714 (2010).</li><li>Nunan, R., Harding, K. G., Martin, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+challenges+of+chronic+wounds:+searching+for+an+optimal+animal+model+to+recapitulate+their+complexity.">Clinical challenges of chronic wounds: searching for an optimal animal model to recapitulate their complexity.</a> Dis Model Mech. 7, 1205-1213 (2014).</li><li>O'Brien, P. D., Sakowski, S. A., Feldman, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+of+diabetic+neuropathy.">Mouse models of diabetic neuropathy.</a> ILAR J. 54, 259-272 (2014).</li><li>Yamazaki, T., 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=Whole-Mount+Adult+Ear+Skin+Imaging+Reveals+Defective+Neuro-Vascular++Branching+Morphogenesis+in+Obese+and+Type+2+Diabetic+Mouse+Models.">Whole-Mount Adult Ear Skin Imaging Reveals Defective Neuro-Vascular Branching Morphogenesis in Obese and Type 2 Diabetic Mouse Models.</a> Sci Rep. 8, (2018).</li></ol>

This protocol describes the whole-mount immunonohistochemical imaging of adult ear skin for the analysis of neuro-vascular structures and immune cell distribution. We believe this method has numerous experimental advantages for researchers to study branching morphogenesis and the patterning of peripheral nerves and blood vessels, as well as three-dimensional distribution of skin components including immune cells and hair follicles. The results of the imaging can be quantified using imaging softwares for further quantitat...

Skin is comprised of three layers: the epidermis, dermis and hypodermis. It has been used as a model system to study stem cell maintenance, differentiation, and morphogenesis in development as well as the regeneration, tumorigenesis, and inflammation in adult. Skin is richly vascularized and innervated such that the development of the peripheral nervous system and vascular system is well-coordinated.
We have previously demonstrated a whole-mount embryonic skin imaging technique with multiple labeling to study intact peripheral nerves and blood vessels including their cellular components1,2,3,4: sensory axons, sympathetic axons, Schwann cells in nerves, endothelial cells, pericytes, and vascular smooth muscle cells (VSMCs) in blood vessels. During the angiogenesis, a primary capillary network undergoes intensive vascular remodeling and develops into a hierarchical vascular branching network. In the developing dermis/hypodermis, arteries branch alongside peripheral sensory nerves and veins then form adjacent to the arteries. After the hierarchical vascular network is thoroughly covered with VSMCs, sympathetic nerves extend along and innervate large-diameter blood vessels1,5,6. Despite the significance in the close association between the developing nervous and vascular systems, a major question has been to address what happens to the neuro-vascular networks in various pathological situations in adults. A three-dimensional high-resolution imaging is necessary to appreciate the pathogenesis, along with anatomically recognizable branching morphogenesis and patterning.
Neuronal and vascular morphogenesis in adult mouse skin is commonly analyzed by tissue section staining. Other studies have used whole-mount imaging of the skin to visualize the peripheral nerves and blood vessels, in addition to the hair follicles, sebaceous glands, and arrector pili muscles7,8,9. However, the thickness of adult skin has made it difficult to analyze the skin over its entire depth.
In the present study, we developed a novel high-resolution whole-mount imaging of adult ear skin to overcome these challenges. Ear skin is readily accessible for dissection and subsequent whole-mount imaging of the skin over its entire depth. Thus, it is a straightforward and highly reproducible method that can be applied to compare three-dimensional architecture of peripheral nervous and vascular systems in the skin, with comprehensive quantification measurements. We demonstrated that the alignment of peripheral sensory and sympathetic nerves with large-diameter blood vessels is preserved in the adult skin. The goal of this protocol is to visualize branching morphogenesis, and the patterning of peripheral nerves and blood vessels, as well as the immune cell distribution at a cellular level in adult mouse models in various conditions such as inflammation and regeneration.

<table>
	<tbody>
		<tr>
			<td>10 x Phosphate Buffered Saline</td>
			<td>KD Medical</td>
			<td>RGE-3210</td>
			<td>PBS, without Ca2+/Mg2+</td>
		</tr>
		<tr>
			<td>Hank&#8217;s Balanced Salt Solution</td>
			<td>Gibco</td>
			<td>14025-092</td>
			<td>HBSS, with Ca2+/Mg2+</td>
		</tr>
		<tr>
			<td>16% Paraformaldehyde</td>
			<td>Electron Microscopy Sciences</td>
			<td>15710</td>
			<td>PFA, fixative, diluted in PBS</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma</td>
			<td>X100</td>
			<td>Detergent</td>
		</tr>
		<tr>
			<td>Normal goat serum</td>
			<td>Gibco</td>
			<td>16210064</td>
			<td>Component of blocking/washing buffer</td>
		</tr>
		<tr>
			<td>Normal donkey serum</td>
			<td>Jackson Immuno research</td>
			<td>017-000-121</td>
			<td>Component of blocking/washing buffer</td>
		</tr>
		<tr>
			<td>Curved fine tweezers</td>
			<td>Dumont</td>
			<td>RS-5047</td>
			<td></td>
		</tr>
		<tr>
			<td>Curved tweezers</td>
			<td>Integra Miltex Vantage</td>
			<td>V918-782, V918-784</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter Unit 0.45 mm</td>
			<td>Thermo Scientific</td>
			<td>157-0045</td>
			<td>For filtration</td>
		</tr>
		<tr>
			<td>1 mL syringe</td>
			<td>Coviden</td>
			<td>8881501400</td>
			<td>For filtration</td>
		</tr>
		<tr>
			<td>Syringe filter Unit 0.22 mm</td>
			<td>Millex-GV</td>
			<td>SLGVR04NL</td>
			<td>For filtration</td>
		</tr>
		<tr>
			<td>ProLong Gold</td>
			<td>Thermo Scientific</td>
			<td>P36934</td>
			<td>Anti-fade mounting medium</td>
		</tr>
		<tr>
			<td>Nail Polish</td>
			<td>Electron Microscopy Sciences</td>
			<td>72180</td>
			<td>For sealing</td>
		</tr>
		<tr>
			<td>Dissecting microscope</td>
			<td>Leica</td>
			<td>MZ95</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal microscope</td>
			<td>Leica</td>
			<td>TCS SP5</td>
			<td></td>
		</tr>
		<tr>
			<td>Photoshop CC 2017</td>
			<td>Adobe</td>
			<td></td>
			<td>Graphics editor software</td>
		</tr>
		<tr>
			<td>Illustrator CC 2017</td>
			<td>Adobe</td>
			<td></td>
			<td>Graphics editor software</td>
		</tr>
		<tr>
			<td>Image J</td>
			<td>NIH</td>
			<td></td>
			<td>Image processing software</td>
		</tr>
		<tr>
			<td>Anti-PECAM-1 (CD31) antibody</td>
			<td>Millipore</td>
			<td>MAB1398Z</td>
			<td>Hamster IgG, vascular endothelial cell marker, 1:300</td>
		</tr>
		<tr>
			<td>Anti-PECAM-1 (CD31) antibody</td>
			<td>BD Pharmingen</td>
			<td>553369</td>
			<td>Rat IgG2a kappa, vascular endothelial cell marker, 1:300</td>
		</tr>
		<tr>
			<td>Anti-aSMA antibody conjugated with cy-3</td>
			<td>Sigma</td>
			<td>C6198</td>
			<td>Mouse IgG2a, vascular smooth muscle cell marker, 1:500</td>
		</tr>
		<tr>
			<td>Anti-EphB1 antibody</td>
			<td>Santa Cruz</td>
			<td>sc-9319</td>
			<td>Goat polyclonal, venous endothelial cell marker, 1:100</td>
		</tr>
		<tr>
			<td>Anti-neuron-specific Class III b-tubulin (Tuj1)</td>
			<td>Abcam</td>
			<td>AB18207</td>
			<td>Tuj1, Rabbit polyclonal IgG, pan-axonal marker, 1:500</td>
		</tr>
		<tr>
			<td>Anti-Tuj1 antibody</td>
			<td>Covance</td>
			<td>MMS-435P</td>
			<td>Mouse IgG2a, pan-axonal marker, 1:500</td>
		</tr>
		<tr>
			<td>Anti-MBP antibody</td>
			<td>Abcam</td>
			<td>AB40390</td>
			<td>Rabbit polyclonal IgG, myelination marker, 1:200</td>
		</tr>
		<tr>
			<td>Anti-Tyrosine Hydroxylase antibody</td>
			<td>Chemicon</td>
			<td>AB152</td>
			<td>Rabbit polyclonal, sympathetic neuron marker, 1:500</td>
		</tr>
		<tr>
			<td>Anti-Peripherin antibody</td>
			<td>Chemicon</td>
			<td>AB1530</td>
			<td>Rabbit polyclonal, peripheral neuron marker, 1:1000</td>
		</tr>
		<tr>
			<td>Anti-CD11b antibody</td>
			<td>Bio-Rad</td>
			<td>MCA74G</td>
			<td>Rat IgG2b, inflammatory cell marker (macrophages), 1:50</td>
		</tr>
		<tr>
			<td>Anti-CD45 antibody</td>
			<td>Thermo Fisher Scientific</td>
			<td>14-0451-85</td>
			<td>Rat IgG2b kappa, pan-hematopoietic cell marker, 1:500</td>
		</tr>
		<tr>
			<td>Anti-CD3 antibody</td>
			<td>Bio-Rad</td>
			<td>MCA1477T</td>
			<td>Rat IgG1, immune cell marker, 1:100</td>
		</tr>
		<tr>
			<td>Anti-CD45R (B220) antibody</td>
			<td>Thermo Fisher Scientific</td>
			<td>14-0452</td>
			<td>Rat IgG2a kappa, inflammatory cell marker, 1:200</td>
		</tr>
		<tr>
			<td>Anti-GFP antibody</td>
			<td>Thermo Fisher Scientific</td>
			<td>A11122</td>
			<td>Rabbit polyclonal, 1:300</td>
		</tr>
		<tr>
			<td>Anti-GFP antibody</td>
			<td>Abcam</td>
			<td>Ab13970</td>
			<td>Chicken polyclonal, 1:500</td>
		</tr>
		<tr>
			<td>Anti-b-gal antibody</td>
			<td>Cappel</td>
			<td>55976</td>
			<td>Rabbit polyclonal, 1:5000</td>
		</tr>
		<tr>
			<td>Anti-RFP antibody</td>
			<td>Abcam</td>
			<td>Ab62341</td>
			<td>Rabbit polyclonal, 1:300</td>
		</tr>
		<tr>
			<td>Goat anti-rabbit IgG (H+L) Alexa 488</td>
			<td>Thermo Fisher Scientific</td>
			<td>A11034</td>
			<td>Rabbit polyclonal secondary antibody, 1:250</td>
		</tr>
		<tr>
			<td>Goat anti-hamster IgG (H+L) Alexa 647</td>
			<td>Jackson Immuno research</td>
			<td>127-605-160</td>
			<td>Hamster polyclonal secondary antibody, 1:250</td>
		</tr>
		<tr>
			<td>Goat anti-rat IgG (H+L) Alexa 594</td>
			<td>Jackson Immuno research</td>
			<td>112-585-167</td>
			<td>Rat polyclonal secondary antibody, 1:250</td>
		</tr>
		<tr>
			<td>Goat anti-mouse IgG2a Alexa 633</td>
			<td>Thermo Fisher Scientific</td>
			<td>A21136</td>
			<td>Mouse IgG2a secondary antibody, 1:250</td>
		</tr>
	</tbody>
</table>

whole-mount confocal microscopy for adult ear skin: a model system to study neuro-vascular branching morphogenesis and immune cell distribution

Here, we present a protocol of a whole-mount adult ear skin imaging technique to study comprehensive three-dimensional neuro-vascular branching morphogenesis and patterning, as well as immune cell distribution at a cellular level. The analysis of peripheral nerve and blood vessel anatomical structures in adult tissues provides some insights into the understanding of functional neuro-vascular wiring and neuro-vascular degeneration in pathological conditions such as wound healing. As a highly informative model system, we have focused our studies on adult ear skin, which is readily accessible for dissection. Our simple and reproducible protocol provides an accurate depiction of the cellular components in the entire skin, such as peripheral nerves (sensory axons, sympathetic axons, and Schwann cells), blood vessels (endothelial cells and vascular smooth muscle cells), and inflammatory cells. We believe this protocol will pave the way to investigate morphological abnormalities in peripheral nerves and blood vessels as well as the inflammation in the adult ear skin under different pathological conditions.

Adult mouse posterior ear skin (Figure 1A) and anterior ear skin (Figure 1B) were immunostained with antibodies to &#945;SMA (red), Tuj1 (green), and PECAM-1 (blue). Posterior skin was immunostained to study neuro-immune distribution using antibodies to CD11b (red) and MBP (green), together with Tuj1 (blue) (Figure 2A). Distribution of CD11b+ inflammatory cells, including macrophages was d...

Watch this Scientific Journal Video about Whole-mount Confocal Microscopy for Adult Ear Skin: A Model System to Study Neuro-vascular Branching Morphogenesis and Immune Cell Distribution at JoVE.com

Whole-mount Confocal Microscopy for Adult Ear Skin: A Model System to Study Neuro-vascular Branching Morphogenesis and Immune Cell Distribution

Here, we describe a high resolution whole-mount imaging method in the entire adult mouse ear skin, which enables us to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels, as well as immune cell distribution.

Here, we present a protocol of a whole-mount adult ear skin imaging technique to study comprehensive three-dimensional neuro-vascular branching ...

The overall goal of this procedure is to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels, as well as immune cell distribution. This method can help answer key questions in the fields of neurobiology, vascular biology, and immunology by illuminating morphological abnormalities in peripheral nerves and blood vessels, as well as inflammation. The main strength of this technique is that we can visualize the cellular components of peripheral nerves, blood vessels, and immune cells in the skin over its entire depth and can compare three-dimensional architecture on nervous and vascular systems.This method can provide insight into neuro-vasculature structures and immune cell distribution in juvenile to adult mice under normal and pathology conditions. After euthanizing adult mice according to the text protocol, dissect the ear from the base, and place it in a 35-by-10-millimeter Petri dish containing two milliliters of HBSS. Then, use scissors to briefly trim the hairs.Carefully peel the posterior and anterior skin away from the intervening cartilage. Transfer each section of skin separately to a 24-well plate containing one milliliter of ice-cold, fresh 4%PFA in PBS per well. Then, flatten the skin in the PFA.Next, fix the posterior and anterior skin with cartilage at four degrees Celsius for one hour. Then, use one milliliter of PBS to wash the skin three times for five minutes with gentle mixing at room temperature. Transfer the skin with cartilage to the bottom of a 35-by-10-millimeter Petri dish.Use fine curved forceps to peel off the cartilage from the anterior skin. Then, cut off the base region, which is folded and has adipose and connective tissues. Using the same forceps, carefully remove the hairs, adipose tissue, and connective tissue from the inside of the posterior skin.Use PBS to keep the skin wet. To carry out whole-mount immunohistochemical staining, transfer the posterior and anterior skin to a 24-well plate containing one milliliter of 10%heat-inactivated serum blocking buffer per well. Incubate the skin with gentle mixing at room temperature for 30 minutes.Dilute the primary antibodies in the blocking buffer as described in the text protocol, and add 150 microliters of primary antibodies in blocking buffer to the well. Then, transfer the posterior and anterior skin to new wells containing primary antibodies. Incubate the skin with gentle mixing at four degrees Celsius overnight.The following day, after transferring the skin to new wells or aspirating the primary antibodies, add one milliliter of 2%serum in PBS with 0.2%Triton X-100. Wash the samples with gentle mixing at room temperature for 15 minutes. Repeat the wash two more times.In the meantime, prepare secondary antibodies in 10%blocking buffer and filter the antibody solutions through a 0.22-micrometer PVDF membrane syringe filter connected to a one-milliliter syringe. Centrifuge the solution at 13, 000 times gravity for 10 minutes to remove aggregated particles of the secondary antibodies from the blocking buffer, adding 150 microliters of secondary antibodies in blocking buffer to the new well. Transfer the skin to the well containing secondary antibodies.Wrap the 24-well plate in aluminum foil to protect it from light, and incubate the skin with gentle mixing at room temperature for one hour. Add one milliliter of 2%serum washing buffer. Then, transfer the posterior and anterior skin to the wells containing washing buffer.Wrap the plate, and wash the samples with gentle mixing at room temperature for 15 minutes. Repeat the wash two more times. Place the skin on the bottom of a 35-by-10-millimeter Petri dish.Then, under a stereo microscope with low illumination to minimize photo bleaching, use fine curved forceps to carefully remove the hairs, adipose tissue, connective tissue, dust, and fibers from the inside of the skin. Use PBS to keep the skin wet. With forceps, transfer the posterior and anterior skin, with the inside facing up, on an adhesive microscope slide.Use forceps to flatten the skin. Mount the skin in a liquid anti-fade mounting medium to avoid photo-bleaching and preserve fluorescent signals. Make sure that no air bubbles are on or around the skin.Store the stained skin sample slides in the dark overnight at room temperature to allow the mounting medium to get firm. Then, use nail polish to seal the coverslip to the slide, and store it at four degrees Celsius for long-term storage. To carry out confocal microscopy, set up appropriate lasers for fluorophores.A confocal microscope with three laser sources is used in this experiment. Image the samples under a 10X objective, and use the sequential scan tool, which simultaneously excites triple-stained samples, to avoid and reduce any overlap. In this experiment, adult mouse posterior ear skin and anterior ear skin were immunostained with antibodies to alpha-SMA, Tuj1, and PECAM-1.The posterior skin was immunostained to study neuroimmune distribution using antibodies to CD11b and MBP, together with Tuj1. Finally, as shown here, distribution of CD11b-positive inflammatory cells, including macrophages, was detected at a single-cell resolution. While attempting this procedure, it's important to remember to handle your skin with care and to gently and slowly remove the hairs, adipose tissue, and connective tissue from the inside of the ear skin before mounting.This technique will pave the way for researchers to study branching morphogenesis and patterning of peripheral nerves and blood vessels, as well as three-dimensional distribution of skin components, including immune cells in juvenile to adult mouse models. Thanks for watching. Good luck with your experiments.

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Research

JoVE Journal

Developmental Biology

12.8K visualizações.  National Institutes of Health. The overall goal of this procedure is to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels, as well as immune cell distribution. This method can help answer key questions in the fields of neurobiology, vascular biology, and immunology by illuminating morphological abnormalities in peripheral nerves and blood vessels, as well as inflammation. The main strength of this technique is that we can visualize the cellular components of peripheral nerves, blood ve...